[PATCH v9 0/4] MAX9286 GMSL Support (+RDACM20)

[PATCH v9 0/4] MAX9286 GMSL Support (+RDACM20)

[Kieran Bingham]

This series provides a pair of drivers for the GMSL cameras on the R-Car ADAS
platforms.

These drivers originate from Cogent Embedded, and have been refactored to split
the MAX9286 away from the RDACM20 drivers which were once very tightly coupled.

The MAX9286 is capable of capturing up to 4 streams simultaneously, and while
the V4L2-Multiplexed streams series is not available, this works purely on the
assumption that the receiver will correctly map each of the 4 VCs to separate
video nodes, as the RCar-VIN does.

This driver along with a camera driver for the RDACM20 and the
associated platform support for the Renesas R-Car Salvator-X, and the Eagle-V3M
can be found at:

  git://git.kernel.org/pub/scm/linux/kernel/git/kbingham/rcar.git gmsl/v9

This latest v9 brings in a few minor comments from v8, and has been
successfully tested to capture from all 4 inputs simultaneously.

We're very much hoping that we can aim to get the max9286 into the next
merge-window. Please let us know if there are any issues blocking this.

Jacopo Mondi (2):
  dt-bindings: media: i2c: Add bindings for IMI RDACM2x
  media: i2c: Add RDACM20 driver

Kieran Bingham (1):
  media: i2c: Add MAX9286 driver

Laurent Pinchart (1):
  dt-bindings: media: i2c: Add bindings for Maxim Integrated MAX9286

 .../bindings/media/i2c/imi,rdacm2x-gmsl.yaml  |  159 ++
 .../bindings/media/i2c/maxim,max9286.yaml     |  287 ++++
 .../devicetree/bindings/vendor-prefixes.yaml  |    2 +
 MAINTAINERS                                   |   22 +
 drivers/media/i2c/Kconfig                     |   26 +
 drivers/media/i2c/Makefile                    |    3 +
 drivers/media/i2c/max9271.c                   |  341 +++++
 drivers/media/i2c/max9271.h                   |  224 +++
 drivers/media/i2c/max9286.c                   | 1332 +++++++++++++++++
 drivers/media/i2c/rdacm20.c                   |  667 +++++++++
 10 files changed, 3063 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/media/i2c/imi,rdacm2x-gmsl.yaml
 create mode 100644 Documentation/devicetree/bindings/media/i2c/maxim,max9286.yaml
 create mode 100644 drivers/media/i2c/max9271.c
 create mode 100644 drivers/media/i2c/max9271.h
 create mode 100644 drivers/media/i2c/max9286.c
 create mode 100644 drivers/media/i2c/rdacm20.c

-- 
2.25.1

[PATCH v9 1/4] dt-bindings: media: i2c: Add bindings for Maxim Integrated MAX9286

[Kieran Bingham]

From: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>

The MAX9286 deserializes video data received on up to 4 Gigabit
Multimedia Serial Links (GMSL) and outputs them on a CSI-2 port using up
to 4 data lanes.

Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Signed-off-by: Jacopo Mondi <jacopo+renesas@jmondi.org>
Signed-off-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
Reviewed-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Reviewed-by: Rob Herring <robh@kernel.org>

---

v7:
 - Collect Rob's RB tag
 - Remove redundant maxItems from remote-endpoints
 - Fix SPDX licence tag

 .../bindings/media/i2c/maxim,max9286.yaml     | 287 ++++++++++++++++++
 1 file changed, 287 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/media/i2c/maxim,max9286.yaml

diff --git a/Documentation/devicetree/bindings/media/i2c/maxim,max9286.yaml b/Documentation/devicetree/bindings/media/i2c/maxim,max9286.yaml
new file mode 100644
index 000000000000..f9d3e5712c59
--- /dev/null
+++ b/Documentation/devicetree/bindings/media/i2c/maxim,max9286.yaml
@@ -0,0 +1,287 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+# Copyright (C) 2019 Renesas Electronics Corp.
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/media/i2c/maxim,max9286.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Maxim Integrated Quad GMSL Deserializer
+
+maintainers:
+  - Jacopo Mondi <jacopo+renesas@jmondi.org>
+  - Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
+  - Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
+  - Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
+
+description: |
+  The MAX9286 deserializer receives video data on up to 4 Gigabit Multimedia
+  Serial Links (GMSL) and outputs them on a CSI-2 D-PHY port using up to 4 data
+  lanes.
+
+  In addition to video data, the GMSL links carry a bidirectional control
+  channel that encapsulates I2C messages. The MAX9286 forwards all I2C traffic
+  not addressed to itself to the other side of the links, where a GMSL
+  serializer will output it on a local I2C bus. In the other direction all I2C
+  traffic received over GMSL by the MAX9286 is output on the local I2C bus.
+
+properties:
+  '#address-cells':
+    const: 1
+
+  '#size-cells':
+    const: 0
+
+  compatible:
+    const: maxim,max9286
+
+  reg:
+    description: I2C device address
+    maxItems: 1
+
+  poc-supply:
+    description: Regulator providing Power over Coax to the cameras
+    maxItems: 1
+
+  enable-gpios:
+    description: GPIO connected to the \#PWDN pin with inverted polarity
+    maxItems: 1
+
+  ports:
+    type: object
+    description: |
+      The connections to the MAX9286 GMSL and its endpoint nodes are modelled
+      using the OF graph bindings in accordance with the video interface
+      bindings defined in
+      Documentation/devicetree/bindings/media/video-interfaces.txt.
+
+      The following table lists the port number corresponding to each device
+      port.
+
+        Port            Description
+        ----------------------------------------
+        Port 0          GMSL Input 0
+        Port 1          GMSL Input 1
+        Port 2          GMSL Input 2
+        Port 3          GMSL Input 3
+        Port 4          CSI-2 Output
+
+    properties:
+      '#address-cells':
+        const: 1
+
+      '#size-cells':
+        const: 0
+
+      port@[0-3]:
+        type: object
+        properties:
+          reg:
+            enum: [ 0, 1, 2, 3 ]
+
+          endpoint:
+            type: object
+
+            properties:
+              remote-endpoint:
+                description: |
+                 phandle to the remote GMSL source endpoint subnode in the
+                 remote node port.
+
+            required:
+              - remote-endpoint
+
+        required:
+          - reg
+          - endpoint
+
+        additionalProperties: false
+
+      port@4:
+        type: object
+        properties:
+          reg:
+            const: 4
+
+          endpoint:
+            type: object
+
+            properties:
+              remote-endpoint:
+                description: phandle to the remote CSI-2 sink endpoint.
+
+              data-lanes:
+                description: array of physical CSI-2 data lane indexes.
+
+            required:
+              - remote-endpoint
+              - data-lanes
+
+        required:
+          - reg
+          - endpoint
+
+        additionalProperties: false
+
+    required:
+      - port@4
+
+  i2c-mux:
+    type: object
+    description: |
+      Each GMSL link is modelled as a child bus of an i2c bus
+      multiplexer/switch, in accordance with bindings described in
+      Documentation/devicetree/bindings/i2c/i2c-mux.txt. The serializer
+      device on the remote end of the GMSL link shall be modelled as a child
+      node of the corresponding I2C bus.
+
+    properties:
+      '#address-cells':
+        const: 1
+
+      '#size-cells':
+        const: 0
+
+  additionalProperties: false
+
+required:
+  - compatible
+  - reg
+  - ports
+  - i2c-mux
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/gpio/gpio.h>
+
+    i2c@e66d8000 {
+      #address-cells = <1>;
+      #size-cells = <0>;
+
+      reg = <0 0xe66d8000 0 0x40>;
+
+      gmsl-deserializer@2c {
+        compatible = "maxim,max9286";
+        reg = <0x2c>;
+        poc-supply = <&camera_poc_12v>;
+        enable-gpios = <&gpio 13 GPIO_ACTIVE_HIGH>;
+
+        ports {
+          #address-cells = <1>;
+          #size-cells = <0>;
+
+          port@0 {
+            reg = <0>;
+
+            max9286_in0: endpoint {
+              remote-endpoint = <&rdacm20_out0>;
+            };
+          };
+
+          port@1 {
+            reg = <1>;
+
+            max9286_in1: endpoint {
+              remote-endpoint = <&rdacm20_out1>;
+            };
+          };
+
+          port@2 {
+            reg = <2>;
+
+            max9286_in2: endpoint {
+              remote-endpoint = <&rdacm20_out2>;
+            };
+          };
+
+          port@3 {
+            reg = <3>;
+
+            max9286_in3: endpoint {
+              remote-endpoint = <&rdacm20_out3>;
+            };
+          };
+
+          port@4 {
+            reg = <4>;
+
+            max9286_out: endpoint {
+              data-lanes = <1 2 3 4>;
+              remote-endpoint = <&csi40_in>;
+            };
+          };
+        };
+
+        i2c-mux {
+          #address-cells = <1>;
+          #size-cells = <0>;
+
+          i2c@0 {
+            #address-cells = <1>;
+            #size-cells = <0>;
+
+            reg = <0>;
+
+            camera@51 {
+              reg = <0x51>;
+
+              port {
+                rdacm20_out0: endpoint {
+                  remote-endpoint = <&max9286_in0>;
+                };
+              };
+
+            };
+          };
+
+          i2c@1 {
+            #address-cells = <1>;
+            #size-cells = <0>;
+            reg = <1>;
+
+            camera@52 {
+              reg = <0x52>;
+
+              port {
+                rdacm20_out1: endpoint {
+                  remote-endpoint = <&max9286_in1>;
+                };
+              };
+            };
+          };
+
+          i2c@2 {
+            #address-cells = <1>;
+            #size-cells = <0>;
+            reg = <2>;
+
+            camera@53 {
+              reg = <0x53>;
+
+              port {
+                rdacm20_out2: endpoint {
+                  remote-endpoint = <&max9286_in2>;
+                };
+              };
+            };
+          };
+
+          i2c@3 {
+            #address-cells = <1>;
+            #size-cells = <0>;
+            reg = <3>;
+
+            camera@54 {
+              reg = <0x54>;
+
+              port {
+                rdacm20_out3: endpoint {
+                  remote-endpoint = <&max9286_in3>;
+                };
+              };
+            };
+          };
+        };
+      };
+    };
-- 
2.25.1

Re: [PATCH v9 1/4] dt-bindings: media: i2c: Add bindings for Maxim Integrated MAX9286

[Rob Herring]

On Tue, 12 May 2020 16:51:02 +0100, Kieran Bingham wrote:
> From: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
> 
> The MAX9286 deserializes video data received on up to 4 Gigabit
> Multimedia Serial Links (GMSL) and outputs them on a CSI-2 port using up
> to 4 data lanes.
> 
> Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
> Signed-off-by: Jacopo Mondi <jacopo+renesas@jmondi.org>
> Signed-off-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
> Reviewed-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
> Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
> Reviewed-by: Rob Herring <robh@kernel.org>
> 
> ---
> 
> v7:
>  - Collect Rob's RB tag
>  - Remove redundant maxItems from remote-endpoints
>  - Fix SPDX licence tag
> 
>  .../bindings/media/i2c/maxim,max9286.yaml     | 287 ++++++++++++++++++
>  1 file changed, 287 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/media/i2c/maxim,max9286.yaml
> 


My bot found errors running 'make dt_binding_check' on your patch:

/builds/robherring/linux-dt-review/Documentation/devicetree/bindings/media/i2c/maxim,max9286.yaml: properties: {'enum': ['$ref', 'additionalItems', 'additionalProperties', 'allOf', 'anyOf', 'const', 'contains', 'default', 'dependencies', 'deprecated', 'description', 'else', 'enum', 'if', 'items', 'maxItems', 'maximum', 'minItems', 'minimum', 'multipleOf', 'not', 'oneOf', 'pattern', 'patternProperties', 'properties', 'propertyNames', 'required', 'then', 'unevaluatedProperties']} is not allowed for 'additionalProperties'
Documentation/devicetree/bindings/Makefile:12: recipe for target 'Documentation/devicetree/bindings/media/i2c/maxim,max9286.example.dts' failed
make[1]: *** [Documentation/devicetree/bindings/media/i2c/maxim,max9286.example.dts] Error 1
make[1]: *** Waiting for unfinished jobs....
Makefile:1300: recipe for target 'dt_binding_check' failed
make: *** [dt_binding_check] Error 2

See https://patchwork.ozlabs.org/patch/1288573

If you already ran 'make dt_binding_check' and didn't see the above
error(s), then make sure dt-schema is up to date:

pip3 install git+https://github.com/devicetree-org/dt-schema.git@master --upgrade

Please check and re-submit.

(no subject)

[Jacopo Mondi]

Subject: [PATCH] fixup! dt-bindings: media: i2c: Add bindings for Maxima Integrated MAX9286

Temporary fixup to ease review. To be squashed into v10 if accepted.

Signed-off-by: Jacopo Mondi <jacopo+renesas@jmondi.org>
---

While fixing Rob's reported bug on v9 I realized thanks to a
dt_binding_check warning that the i2c-mux child nodes where under-specified.

This fixup epxands the i2c-mux child nodes description and updates the
example to match our currently-out-of-tree DTS files for GMSL platforms.

dt_binding_check still reports a warning:

Documentation/devicetree/bindings/media/i2c/maxim,max9286.example.dt.yaml: camera@51: reg: [[81, 97]] is too short
Documentation/devicetree/bindings/media/i2c/maxim,max9286.example.dt.yaml: camera@52: reg: [[82, 98]] is too short
Documentation/devicetree/bindings/media/i2c/maxim,max9286.example.dt.yaml: camera@53: reg: [[83, 99]] is too short
Documentation/devicetree/bindings/media/i2c/maxim,max9286.example.dt.yaml: camera@54: reg: [[84, 100]] is too short

Which I was not able to silence.
---
 .../bindings/media/i2c/maxim,max9286.yaml     | 86 +++++++++++++++++--
 1 file changed, 77 insertions(+), 9 deletions(-)

diff --git a/Documentation/devicetree/bindings/media/i2c/maxim,max9286.yaml b/Documentation/devicetree/bindings/media/i2c/maxim,max9286.yaml
index f9d3e5712c59..d9bd19caed2f 100644
--- a/Documentation/devicetree/bindings/media/i2c/maxim,max9286.yaml
+++ b/Documentation/devicetree/bindings/media/i2c/maxim,max9286.yaml
@@ -130,9 +130,7 @@ properties:
     description: |
       Each GMSL link is modelled as a child bus of an i2c bus
       multiplexer/switch, in accordance with bindings described in
-      Documentation/devicetree/bindings/i2c/i2c-mux.txt. The serializer
-      device on the remote end of the GMSL link shall be modelled as a child
-      node of the corresponding I2C bus.
+      Documentation/devicetree/bindings/i2c/i2c-mux.txt.

     properties:
       '#address-cells':
@@ -141,7 +139,74 @@ properties:
       '#size-cells':
         const: 0

-  additionalProperties: false
+    patternProperties:
+      "^i2c@[0-3]$":
+        type: object
+        description: |
+          Child node of the i2c bus multiplexer which represents a GMSL link.
+          Each serializer device on the GMSL link remote end is represented with
+          an i2c-mux child node. The MAX9286 chip supports up to 4 GMSL
+          channels.
+
+        properties:
+          '#address-cells':
+            const: 1
+
+          '#size-cells':
+            const: 0
+
+          reg:
+            description: The index of the GMSL channel.
+            maxItems: 1
+
+        patternProperties:
+          "^camera@[0-9]+":
+            type: object
+            description: |
+              The remote camera device, composed by a GMSL serializer and a
+              connected video source.
+
+            properties:
+              compatible:
+                description: The remote device compatible string.
+
+              reg:
+                description: |
+                  The I2C addresses to be assigned to the remote devices through
+                  address reprogramming. The number of entries depends on the
+                  requirements of the currently connected remote device.
+
+              port:
+                type: object
+
+                properties:
+                  endpoint:
+                    type: object
+
+                    properties:
+                      remote-endpoint:
+                        description: phandle to the MAX9286 sink endpoint.
+
+                    required:
+                      - remote-endpoint
+
+                    additionalProperties: false
+
+                required:
+                  - endpoint
+
+                additionalProperties: false
+
+            required:
+              - compatible
+              - reg
+              - port
+
+            additionalProperties: false
+
+        additionalProperties: false
+
+    additionalProperties: false

 required:
   - compatible
@@ -220,11 +285,11 @@ examples:
           i2c@0 {
             #address-cells = <1>;
             #size-cells = <0>;
-
             reg = <0>;

             camera@51 {
-              reg = <0x51>;
+              compatible = "imi,rdacm20";
+              reg = <0x51 0x61>;

               port {
                 rdacm20_out0: endpoint {
@@ -241,7 +306,8 @@ examples:
             reg = <1>;

             camera@52 {
-              reg = <0x52>;
+              compatible = "imi,rdacm20";
+              reg = <0x52 0x62>;

               port {
                 rdacm20_out1: endpoint {
@@ -257,7 +323,8 @@ examples:
             reg = <2>;

             camera@53 {
-              reg = <0x53>;
+              compatible = "imi,rdacm20";
+              reg = <0x53 0x63>;

               port {
                 rdacm20_out2: endpoint {
@@ -273,7 +340,8 @@ examples:
             reg = <3>;

             camera@54 {
-              reg = <0x54>;
+              compatible = "imi,rdacm20";
+              reg = <0x54 0x64>;

               port {
                 rdacm20_out3: endpoint {
--
2.26.2

Re: [PATCH] fixup! dt-bindings: media: i2c: Add bindings for Maxima Integrated MAX9286

[Kieran Bingham]

Hi Jacopo,

On 13/05/2020 13:54, Jacopo Mondi wrote:
> Subject: [PATCH] fixup! dt-bindings: media: i2c: Add bindings for Maxima Integrated MAX9286
> 
> Temporary fixup to ease review. To be squashed into v10 if accepted.
> 
> Signed-off-by: Jacopo Mondi <jacopo+renesas@jmondi.org>
> ---
> 
> While fixing Rob's reported bug on v9 I realized thanks to a
> dt_binding_check warning that the i2c-mux child nodes where under-specified.
> 
> This fixup epxands the i2c-mux child nodes description and updates the
> example to match our currently-out-of-tree DTS files for GMSL platforms.
> 
> dt_binding_check still reports a warning:
> 
> Documentation/devicetree/bindings/media/i2c/maxim,max9286.example.dt.yaml: camera@51: reg: [[81, 97]] is too short
> Documentation/devicetree/bindings/media/i2c/maxim,max9286.example.dt.yaml: camera@52: reg: [[82, 98]] is too short
> Documentation/devicetree/bindings/media/i2c/maxim,max9286.example.dt.yaml: camera@53: reg: [[83, 99]] is too short
> Documentation/devicetree/bindings/media/i2c/maxim,max9286.example.dt.yaml: camera@54: reg: [[84, 100]] is too short

Is too short? That seems odd. We accept 1, 2, or 3 values in the reg
(for the serializer, camera, mcu addresses) but those values are
specific to the camera device, and are managed by that driver and
shouldn't be validated here.


> 
> Which I was not able to silence.
> ---
>  .../bindings/media/i2c/maxim,max9286.yaml     | 86 +++++++++++++++++--
>  1 file changed, 77 insertions(+), 9 deletions(-)
> 
> diff --git a/Documentation/devicetree/bindings/media/i2c/maxim,max9286.yaml b/Documentation/devicetree/bindings/media/i2c/maxim,max9286.yaml
> index f9d3e5712c59..d9bd19caed2f 100644
> --- a/Documentation/devicetree/bindings/media/i2c/maxim,max9286.yaml
> +++ b/Documentation/devicetree/bindings/media/i2c/maxim,max9286.yaml
> @@ -130,9 +130,7 @@ properties:
>      description: |
>        Each GMSL link is modelled as a child bus of an i2c bus
>        multiplexer/switch, in accordance with bindings described in
> -      Documentation/devicetree/bindings/i2c/i2c-mux.txt. The serializer
> -      device on the remote end of the GMSL link shall be modelled as a child
> -      node of the corresponding I2C bus.
> +      Documentation/devicetree/bindings/i2c/i2c-mux.txt.
> 
>      properties:
>        '#address-cells':
> @@ -141,7 +139,74 @@ properties:
>        '#size-cells':
>          const: 0
> 
> -  additionalProperties: false
> +    patternProperties:
> +      "^i2c@[0-3]$":
> +        type: object
> +        description: |
> +          Child node of the i2c bus multiplexer which represents a GMSL link.
> +          Each serializer device on the GMSL link remote end is represented with
> +          an i2c-mux child node. The MAX9286 chip supports up to 4 GMSL
> +          channels.
> +
> +        properties:
> +          '#address-cells':
> +            const: 1
> +
> +          '#size-cells':
> +            const: 0
> +
> +          reg:
> +            description: The index of the GMSL channel.
> +            maxItems: 1
> +
> +        patternProperties:
> +          "^camera@[0-9]+":

This value after @ represents a non 0x prefixed hex value, where your
regex will only match numerical values.

	"^camera@[a-f0-9]+":



is likely therefore required.

I see other uses of this patternProperties also terminate the regex with
a $ (end of line) but that confuses me, as the node is often presented
with the opening brace after the name and identifier:

 (i.e.)
   camera@52 {

But perhaps the validator extracts the node name and reg and matches on
that directly in which case it would be

	"^camera@[a-f0-9]+$":



> +            type: object
> +            description: |
> +              The remote camera device, composed by a GMSL serializer and a
> +              connected video source.
> +
> +            properties:
> +              compatible:
> +                description: The remote device compatible string.
> +
> +              reg:
> +                description: |
> +                  The I2C addresses to be assigned to the remote devices through
> +                  address reprogramming. The number of entries depends on the
> +                  requirements of the currently connected remote device.
> +
> +              port:
> +                type: object
> +
> +                properties:
> +                  endpoint:
> +                    type: object
> +
> +                    properties:
> +                      remote-endpoint:
> +                        description: phandle to the MAX9286 sink endpoint.
> +
> +                    required:
> +                      - remote-endpoint
> +
> +                    additionalProperties: false
> +
> +                required:
> +                  - endpoint
> +
> +                additionalProperties: false
> +
> +            required:
> +              - compatible
> +              - reg
> +              - port
> +
> +            additionalProperties: false
> +
> +        additionalProperties: false
> +
> +    additionalProperties: false
> 


Wow, is it required to specify additionalProperties: false quite so many
times?


>  required:
>    - compatible
> @@ -220,11 +285,11 @@ examples:
>            i2c@0 {
>              #address-cells = <1>;
>              #size-cells = <0>;
> -
>              reg = <0>;
> 
>              camera@51 {
> -              reg = <0x51>;
> +              compatible = "imi,rdacm20";
> +              reg = <0x51 0x61>;
> 
>                port {
>                  rdacm20_out0: endpoint {
> @@ -241,7 +306,8 @@ examples:
>              reg = <1>;
> 
>              camera@52 {
> -              reg = <0x52>;
> +              compatible = "imi,rdacm20";
> +              reg = <0x52 0x62>;
> 
>                port {
>                  rdacm20_out1: endpoint {
> @@ -257,7 +323,8 @@ examples:
>              reg = <2>;
> 
>              camera@53 {
> -              reg = <0x53>;
> +              compatible = "imi,rdacm20";
> +              reg = <0x53 0x63>;
> 
>                port {
>                  rdacm20_out2: endpoint {
> @@ -273,7 +340,8 @@ examples:
>              reg = <3>;
> 
>              camera@54 {
> -              reg = <0x54>;
> +              compatible = "imi,rdacm20";
> +              reg = <0x54 0x64>;
> 
>                port {
>                  rdacm20_out3: endpoint {
> --
> 2.26.2
> 

Re: [PATCH] fixup! dt-bindings: media: i2c: Add bindings for Maxima Integrated MAX9286

[Jacopo Mondi]

Hi Kieran,

On Thu, May 14, 2020 at 10:43:10AM +0100, Kieran Bingham wrote:
> Hi Jacopo,
>
> On 13/05/2020 13:54, Jacopo Mondi wrote:
> > Subject: [PATCH] fixup! dt-bindings: media: i2c: Add bindings for Maxima Integrated MAX9286
> >
> > Temporary fixup to ease review. To be squashed into v10 if accepted.
> >
> > Signed-off-by: Jacopo Mondi <jacopo+renesas@jmondi.org>
> > ---
> >
> > While fixing Rob's reported bug on v9 I realized thanks to a
> > dt_binding_check warning that the i2c-mux child nodes where under-specified.
> >
> > This fixup epxands the i2c-mux child nodes description and updates the
> > example to match our currently-out-of-tree DTS files for GMSL platforms.
> >
> > dt_binding_check still reports a warning:
> >
> > Documentation/devicetree/bindings/media/i2c/maxim,max9286.example.dt.yaml: camera@51: reg: [[81, 97]] is too short
> > Documentation/devicetree/bindings/media/i2c/maxim,max9286.example.dt.yaml: camera@52: reg: [[82, 98]] is too short
> > Documentation/devicetree/bindings/media/i2c/maxim,max9286.example.dt.yaml: camera@53: reg: [[83, 99]] is too short
> > Documentation/devicetree/bindings/media/i2c/maxim,max9286.example.dt.yaml: camera@54: reg: [[84, 100]] is too short
>
> Is too short? That seems odd. We accept 1, 2, or 3 values in the reg
> (for the serializer, camera, mcu addresses) but those values are
> specific to the camera device, and are managed by that driver and
> shouldn't be validated here.

I think it's expected them to be validated against this schema, not
sure what's the warning about though.

>
>
> >
> > Which I was not able to silence.
> > ---
> >  .../bindings/media/i2c/maxim,max9286.yaml     | 86 +++++++++++++++++--
> >  1 file changed, 77 insertions(+), 9 deletions(-)
> >
> > diff --git a/Documentation/devicetree/bindings/media/i2c/maxim,max9286.yaml b/Documentation/devicetree/bindings/media/i2c/maxim,max9286.yaml
> > index f9d3e5712c59..d9bd19caed2f 100644
> > --- a/Documentation/devicetree/bindings/media/i2c/maxim,max9286.yaml
> > +++ b/Documentation/devicetree/bindings/media/i2c/maxim,max9286.yaml
> > @@ -130,9 +130,7 @@ properties:
> >      description: |
> >        Each GMSL link is modelled as a child bus of an i2c bus
> >        multiplexer/switch, in accordance with bindings described in
> > -      Documentation/devicetree/bindings/i2c/i2c-mux.txt. The serializer
> > -      device on the remote end of the GMSL link shall be modelled as a child
> > -      node of the corresponding I2C bus.
> > +      Documentation/devicetree/bindings/i2c/i2c-mux.txt.
> >
> >      properties:
> >        '#address-cells':
> > @@ -141,7 +139,74 @@ properties:
> >        '#size-cells':
> >          const: 0
> >
> > -  additionalProperties: false
> > +    patternProperties:
> > +      "^i2c@[0-3]$":
> > +        type: object
> > +        description: |
> > +          Child node of the i2c bus multiplexer which represents a GMSL link.
> > +          Each serializer device on the GMSL link remote end is represented with
> > +          an i2c-mux child node. The MAX9286 chip supports up to 4 GMSL
> > +          channels.
> > +
> > +        properties:
> > +          '#address-cells':
> > +            const: 1
> > +
> > +          '#size-cells':
> > +            const: 0
> > +
> > +          reg:
> > +            description: The index of the GMSL channel.
> > +            maxItems: 1
> > +
> > +        patternProperties:
> > +          "^camera@[0-9]+":
>
> This value after @ represents a non 0x prefixed hex value, where your
> regex will only match numerical values.
>
> 	"^camera@[a-f0-9]+":
>
>
>
> is likely therefore required.
>

Uh, correct

> I see other uses of this patternProperties also terminate the regex with
> a $ (end of line) but that confuses me, as the node is often presented
> with the opening brace after the name and identifier:
>
>  (i.e.)
>    camera@52 {
>
> But perhaps the validator extracts the node name and reg and matches on
> that directly in which case it would be
>
> 	"^camera@[a-f0-9]+$":

I've initially used '$' as well then removed it for the same reason.
MAybe the patter is only matched against the node name, leaving out the
rest of the line.

>
>
>
> > +            type: object
> > +            description: |
> > +              The remote camera device, composed by a GMSL serializer and a
> > +              connected video source.
> > +
> > +            properties:
> > +              compatible:
> > +                description: The remote device compatible string.
> > +
> > +              reg:
> > +                description: |
> > +                  The I2C addresses to be assigned to the remote devices through
> > +                  address reprogramming. The number of entries depends on the
> > +                  requirements of the currently connected remote device.
> > +
> > +              port:
> > +                type: object
> > +
> > +                properties:
> > +                  endpoint:
> > +                    type: object
> > +
> > +                    properties:
> > +                      remote-endpoint:
> > +                        description: phandle to the MAX9286 sink endpoint.
> > +
> > +                    required:
> > +                      - remote-endpoint
> > +
> > +                    additionalProperties: false
> > +
> > +                required:
> > +                  - endpoint
> > +
> > +                additionalProperties: false
> > +
> > +            required:
> > +              - compatible
> > +              - reg
> > +              - port
> > +
> > +            additionalProperties: false
> > +
> > +        additionalProperties: false
> > +
> > +    additionalProperties: false
> >
>
>
> Wow, is it required to specify additionalProperties: false quite so many
> times?

I -think- so, it's one per section, and unless it's by default it
makes sense to have it there ?

>
>
> >  required:
> >    - compatible
> > @@ -220,11 +285,11 @@ examples:
> >            i2c@0 {
> >              #address-cells = <1>;
> >              #size-cells = <0>;
> > -
> >              reg = <0>;
> >
> >              camera@51 {
> > -              reg = <0x51>;
> > +              compatible = "imi,rdacm20";
> > +              reg = <0x51 0x61>;
> >
> >                port {
> >                  rdacm20_out0: endpoint {
> > @@ -241,7 +306,8 @@ examples:
> >              reg = <1>;
> >
> >              camera@52 {
> > -              reg = <0x52>;
> > +              compatible = "imi,rdacm20";
> > +              reg = <0x52 0x62>;
> >
> >                port {
> >                  rdacm20_out1: endpoint {
> > @@ -257,7 +323,8 @@ examples:
> >              reg = <2>;
> >
> >              camera@53 {
> > -              reg = <0x53>;
> > +              compatible = "imi,rdacm20";
> > +              reg = <0x53 0x63>;
> >
> >                port {
> >                  rdacm20_out2: endpoint {
> > @@ -273,7 +340,8 @@ examples:
> >              reg = <3>;
> >
> >              camera@54 {
> > -              reg = <0x54>;
> > +              compatible = "imi,rdacm20";
> > +              reg = <0x54 0x64>;
> >
> >                port {
> >                  rdacm20_out3: endpoint {
> > --
> > 2.26.2
> >
>

Re: [PATCH v9 1/4] dt-bindings: media: i2c: Add bindings for Maxim Integrated MAX9286

[Rob Herring]

On Tue, May 12, 2020 at 04:51:02PM +0100, Kieran Bingham wrote:
> From: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
> 
> The MAX9286 deserializes video data received on up to 4 Gigabit
> Multimedia Serial Links (GMSL) and outputs them on a CSI-2 port using up
> to 4 data lanes.
> 
> Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
> Signed-off-by: Jacopo Mondi <jacopo+renesas@jmondi.org>
> Signed-off-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
> Reviewed-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
> Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
> Reviewed-by: Rob Herring <robh@kernel.org>
> 
> ---
> 
> v7:
>  - Collect Rob's RB tag
>  - Remove redundant maxItems from remote-endpoints
>  - Fix SPDX licence tag
> 
>  .../bindings/media/i2c/maxim,max9286.yaml     | 287 ++++++++++++++++++
>  1 file changed, 287 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/media/i2c/maxim,max9286.yaml
> 
> diff --git a/Documentation/devicetree/bindings/media/i2c/maxim,max9286.yaml b/Documentation/devicetree/bindings/media/i2c/maxim,max9286.yaml
> new file mode 100644
> index 000000000000..f9d3e5712c59
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/media/i2c/maxim,max9286.yaml
> @@ -0,0 +1,287 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +# Copyright (C) 2019 Renesas Electronics Corp.
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/media/i2c/maxim,max9286.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Maxim Integrated Quad GMSL Deserializer
> +
> +maintainers:
> +  - Jacopo Mondi <jacopo+renesas@jmondi.org>
> +  - Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
> +  - Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
> +  - Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
> +
> +description: |
> +  The MAX9286 deserializer receives video data on up to 4 Gigabit Multimedia
> +  Serial Links (GMSL) and outputs them on a CSI-2 D-PHY port using up to 4 data
> +  lanes.
> +
> +  In addition to video data, the GMSL links carry a bidirectional control
> +  channel that encapsulates I2C messages. The MAX9286 forwards all I2C traffic
> +  not addressed to itself to the other side of the links, where a GMSL
> +  serializer will output it on a local I2C bus. In the other direction all I2C
> +  traffic received over GMSL by the MAX9286 is output on the local I2C bus.
> +
> +properties:
> +  '#address-cells':
> +    const: 1
> +
> +  '#size-cells':
> +    const: 0
> +
> +  compatible:
> +    const: maxim,max9286
> +
> +  reg:
> +    description: I2C device address
> +    maxItems: 1
> +
> +  poc-supply:
> +    description: Regulator providing Power over Coax to the cameras
> +    maxItems: 1
> +
> +  enable-gpios:
> +    description: GPIO connected to the \#PWDN pin with inverted polarity
> +    maxItems: 1
> +
> +  ports:
> +    type: object
> +    description: |
> +      The connections to the MAX9286 GMSL and its endpoint nodes are modelled
> +      using the OF graph bindings in accordance with the video interface
> +      bindings defined in
> +      Documentation/devicetree/bindings/media/video-interfaces.txt.
> +
> +      The following table lists the port number corresponding to each device
> +      port.
> +
> +        Port            Description
> +        ----------------------------------------
> +        Port 0          GMSL Input 0
> +        Port 1          GMSL Input 1
> +        Port 2          GMSL Input 2
> +        Port 3          GMSL Input 3
> +        Port 4          CSI-2 Output
> +
> +    properties:
> +      '#address-cells':
> +        const: 1
> +
> +      '#size-cells':
> +        const: 0
> +
> +      port@[0-3]:
> +        type: object
> +        properties:
> +          reg:
> +            enum: [ 0, 1, 2, 3 ]
> +
> +          endpoint:
> +            type: object
> +
> +            properties:
> +              remote-endpoint:
> +                description: |
> +                 phandle to the remote GMSL source endpoint subnode in the
> +                 remote node port.
> +
> +            required:
> +              - remote-endpoint
> +
> +        required:
> +          - reg
> +          - endpoint
> +
> +        additionalProperties: false
> +
> +      port@4:
> +        type: object
> +        properties:
> +          reg:
> +            const: 4
> +
> +          endpoint:
> +            type: object
> +
> +            properties:
> +              remote-endpoint:
> +                description: phandle to the remote CSI-2 sink endpoint.
> +
> +              data-lanes:
> +                description: array of physical CSI-2 data lane indexes.
> +
> +            required:
> +              - remote-endpoint
> +              - data-lanes
> +
> +        required:
> +          - reg
> +          - endpoint
> +
> +        additionalProperties: false
> +
> +    required:
> +      - port@4
> +
> +  i2c-mux:
> +    type: object
> +    description: |
> +      Each GMSL link is modelled as a child bus of an i2c bus
> +      multiplexer/switch, in accordance with bindings described in
> +      Documentation/devicetree/bindings/i2c/i2c-mux.txt. The serializer
> +      device on the remote end of the GMSL link shall be modelled as a child
> +      node of the corresponding I2C bus.
> +
> +    properties:
> +      '#address-cells':
> +        const: 1
> +
> +      '#size-cells':
> +        const: 0
> +
> +  additionalProperties: false

Wrong indentation. Should be 2 more or this is a DT property.

> +
> +required:
> +  - compatible
> +  - reg
> +  - ports
> +  - i2c-mux
> +
> +additionalProperties: false
> +
> +examples:
> +  - |
> +    #include <dt-bindings/gpio/gpio.h>
> +
> +    i2c@e66d8000 {
> +      #address-cells = <1>;
> +      #size-cells = <0>;
> +
> +      reg = <0 0xe66d8000 0 0x40>;
> +
> +      gmsl-deserializer@2c {
> +        compatible = "maxim,max9286";
> +        reg = <0x2c>;
> +        poc-supply = <&camera_poc_12v>;
> +        enable-gpios = <&gpio 13 GPIO_ACTIVE_HIGH>;
> +
> +        ports {
> +          #address-cells = <1>;
> +          #size-cells = <0>;
> +
> +          port@0 {
> +            reg = <0>;
> +
> +            max9286_in0: endpoint {
> +              remote-endpoint = <&rdacm20_out0>;
> +            };
> +          };
> +
> +          port@1 {
> +            reg = <1>;
> +
> +            max9286_in1: endpoint {
> +              remote-endpoint = <&rdacm20_out1>;
> +            };
> +          };
> +
> +          port@2 {
> +            reg = <2>;
> +
> +            max9286_in2: endpoint {
> +              remote-endpoint = <&rdacm20_out2>;
> +            };
> +          };
> +
> +          port@3 {
> +            reg = <3>;
> +
> +            max9286_in3: endpoint {
> +              remote-endpoint = <&rdacm20_out3>;
> +            };
> +          };
> +
> +          port@4 {
> +            reg = <4>;
> +
> +            max9286_out: endpoint {
> +              data-lanes = <1 2 3 4>;
> +              remote-endpoint = <&csi40_in>;
> +            };
> +          };
> +        };
> +
> +        i2c-mux {
> +          #address-cells = <1>;
> +          #size-cells = <0>;
> +
> +          i2c@0 {
> +            #address-cells = <1>;
> +            #size-cells = <0>;
> +
> +            reg = <0>;
> +
> +            camera@51 {
> +              reg = <0x51>;
> +
> +              port {
> +                rdacm20_out0: endpoint {
> +                  remote-endpoint = <&max9286_in0>;
> +                };
> +              };
> +
> +            };
> +          };
> +
> +          i2c@1 {
> +            #address-cells = <1>;
> +            #size-cells = <0>;
> +            reg = <1>;
> +
> +            camera@52 {
> +              reg = <0x52>;
> +
> +              port {
> +                rdacm20_out1: endpoint {
> +                  remote-endpoint = <&max9286_in1>;
> +                };
> +              };
> +            };
> +          };
> +
> +          i2c@2 {
> +            #address-cells = <1>;
> +            #size-cells = <0>;
> +            reg = <2>;
> +
> +            camera@53 {
> +              reg = <0x53>;
> +
> +              port {
> +                rdacm20_out2: endpoint {
> +                  remote-endpoint = <&max9286_in2>;
> +                };
> +              };
> +            };
> +          };
> +
> +          i2c@3 {
> +            #address-cells = <1>;
> +            #size-cells = <0>;
> +            reg = <3>;
> +
> +            camera@54 {
> +              reg = <0x54>;
> +
> +              port {
> +                rdacm20_out3: endpoint {
> +                  remote-endpoint = <&max9286_in3>;
> +                };
> +              };
> +            };
> +          };
> +        };
> +      };
> +    };
> -- 
> 2.25.1
> 

Re: [PATCH v9 1/4] dt-bindings: media: i2c: Add bindings for Maxim Integrated MAX9286

[Jacopo Mondi]

Hi Rob,

On Tue, May 12, 2020 at 05:36:10PM -0500, Rob Herring wrote:
> On Tue, May 12, 2020 at 04:51:02PM +0100, Kieran Bingham wrote:
> > From: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
> >
> > The MAX9286 deserializes video data received on up to 4 Gigabit
> > Multimedia Serial Links (GMSL) and outputs them on a CSI-2 port using up
> > to 4 data lanes.
> >
> > Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
> > Signed-off-by: Jacopo Mondi <jacopo+renesas@jmondi.org>
> > Signed-off-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
> > Reviewed-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
> > Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
> > Reviewed-by: Rob Herring <robh@kernel.org>
> >
> > ---
> >
> > v7:
> >  - Collect Rob's RB tag
> >  - Remove redundant maxItems from remote-endpoints
> >  - Fix SPDX licence tag
> >
> >  .../bindings/media/i2c/maxim,max9286.yaml     | 287 ++++++++++++++++++
> >  1 file changed, 287 insertions(+)
> >  create mode 100644 Documentation/devicetree/bindings/media/i2c/maxim,max9286.yaml
> >
> > diff --git a/Documentation/devicetree/bindings/media/i2c/maxim,max9286.yaml b/Documentation/devicetree/bindings/media/i2c/maxim,max9286.yaml
> > new file mode 100644
> > index 000000000000..f9d3e5712c59
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/media/i2c/maxim,max9286.yaml
> > @@ -0,0 +1,287 @@
> > +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> > +# Copyright (C) 2019 Renesas Electronics Corp.
> > +%YAML 1.2
> > +---
> > +$id: http://devicetree.org/schemas/media/i2c/maxim,max9286.yaml#
> > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > +
> > +title: Maxim Integrated Quad GMSL Deserializer
> > +
> > +maintainers:
> > +  - Jacopo Mondi <jacopo+renesas@jmondi.org>
> > +  - Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
> > +  - Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
> > +  - Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
> > +
> > +description: |
> > +  The MAX9286 deserializer receives video data on up to 4 Gigabit Multimedia
> > +  Serial Links (GMSL) and outputs them on a CSI-2 D-PHY port using up to 4 data
> > +  lanes.
> > +
> > +  In addition to video data, the GMSL links carry a bidirectional control
> > +  channel that encapsulates I2C messages. The MAX9286 forwards all I2C traffic
> > +  not addressed to itself to the other side of the links, where a GMSL
> > +  serializer will output it on a local I2C bus. In the other direction all I2C
> > +  traffic received over GMSL by the MAX9286 is output on the local I2C bus.
> > +
> > +properties:
> > +  '#address-cells':
> > +    const: 1
> > +
> > +  '#size-cells':
> > +    const: 0
> > +
> > +  compatible:
> > +    const: maxim,max9286
> > +
> > +  reg:
> > +    description: I2C device address
> > +    maxItems: 1
> > +
> > +  poc-supply:
> > +    description: Regulator providing Power over Coax to the cameras
> > +    maxItems: 1
> > +
> > +  enable-gpios:
> > +    description: GPIO connected to the \#PWDN pin with inverted polarity
> > +    maxItems: 1
> > +
> > +  ports:
> > +    type: object
> > +    description: |
> > +      The connections to the MAX9286 GMSL and its endpoint nodes are modelled
> > +      using the OF graph bindings in accordance with the video interface
> > +      bindings defined in
> > +      Documentation/devicetree/bindings/media/video-interfaces.txt.
> > +
> > +      The following table lists the port number corresponding to each device
> > +      port.
> > +
> > +        Port            Description
> > +        ----------------------------------------
> > +        Port 0          GMSL Input 0
> > +        Port 1          GMSL Input 1
> > +        Port 2          GMSL Input 2
> > +        Port 3          GMSL Input 3
> > +        Port 4          CSI-2 Output
> > +
> > +    properties:
> > +      '#address-cells':
> > +        const: 1
> > +
> > +      '#size-cells':
> > +        const: 0
> > +
> > +      port@[0-3]:
> > +        type: object
> > +        properties:
> > +          reg:
> > +            enum: [ 0, 1, 2, 3 ]
> > +
> > +          endpoint:
> > +            type: object
> > +
> > +            properties:
> > +              remote-endpoint:
> > +                description: |
> > +                 phandle to the remote GMSL source endpoint subnode in the
> > +                 remote node port.
> > +
> > +            required:
> > +              - remote-endpoint
> > +
> > +        required:
> > +          - reg
> > +          - endpoint
> > +
> > +        additionalProperties: false
> > +
> > +      port@4:
> > +        type: object
> > +        properties:
> > +          reg:
> > +            const: 4
> > +
> > +          endpoint:
> > +            type: object
> > +
> > +            properties:
> > +              remote-endpoint:
> > +                description: phandle to the remote CSI-2 sink endpoint.
> > +
> > +              data-lanes:
> > +                description: array of physical CSI-2 data lane indexes.
> > +
> > +            required:
> > +              - remote-endpoint
> > +              - data-lanes
> > +
> > +        required:
> > +          - reg
> > +          - endpoint
> > +
> > +        additionalProperties: false
> > +
> > +    required:
> > +      - port@4
> > +
> > +  i2c-mux:
> > +    type: object
> > +    description: |
> > +      Each GMSL link is modelled as a child bus of an i2c bus
> > +      multiplexer/switch, in accordance with bindings described in
> > +      Documentation/devicetree/bindings/i2c/i2c-mux.txt. The serializer
> > +      device on the remote end of the GMSL link shall be modelled as a child
> > +      node of the corresponding I2C bus.
> > +
> > +    properties:
> > +      '#address-cells':
> > +        const: 1
> > +
> > +      '#size-cells':
> > +        const: 0
> > +
> > +  additionalProperties: false
>
> Wrong indentation. Should be 2 more or this is a DT property.
>

Thanks, updating the dt tools helped spotting the error locally as
well.

This fixes the error reported in the previous email, now I get a
Documentation/devicetree/bindings/media/i2c/maxim,max9286.example.dt.yaml:
gmsl-deserializer@2c: i2c-mux: 'i2c@0', 'i2c@1', 'i2c@2', 'i2c@3' do not match any of the regexes: 'pinctrl-[0-9]+'

which makes me think the i2c-mux child nodes are under-specified in
this bindings.

I have expanded them and will reply with a fixup to be applied on top
of this patch to ease review and eventually include in v10.

Thanks
  j

> > +
> > +required:
> > +  - compatible
> > +  - reg
> > +  - ports
> > +  - i2c-mux
> > +
> > +additionalProperties: false
> > +
> > +examples:
> > +  - |
> > +    #include <dt-bindings/gpio/gpio.h>
> > +
> > +    i2c@e66d8000 {
> > +      #address-cells = <1>;
> > +      #size-cells = <0>;
> > +
> > +      reg = <0 0xe66d8000 0 0x40>;
> > +
> > +      gmsl-deserializer@2c {
> > +        compatible = "maxim,max9286";
> > +        reg = <0x2c>;
> > +        poc-supply = <&camera_poc_12v>;
> > +        enable-gpios = <&gpio 13 GPIO_ACTIVE_HIGH>;
> > +
> > +        ports {
> > +          #address-cells = <1>;
> > +          #size-cells = <0>;
> > +
> > +          port@0 {
> > +            reg = <0>;
> > +
> > +            max9286_in0: endpoint {
> > +              remote-endpoint = <&rdacm20_out0>;
> > +            };
> > +          };
> > +
> > +          port@1 {
> > +            reg = <1>;
> > +
> > +            max9286_in1: endpoint {
> > +              remote-endpoint = <&rdacm20_out1>;
> > +            };
> > +          };
> > +
> > +          port@2 {
> > +            reg = <2>;
> > +
> > +            max9286_in2: endpoint {
> > +              remote-endpoint = <&rdacm20_out2>;
> > +            };
> > +          };
> > +
> > +          port@3 {
> > +            reg = <3>;
> > +
> > +            max9286_in3: endpoint {
> > +              remote-endpoint = <&rdacm20_out3>;
> > +            };
> > +          };
> > +
> > +          port@4 {
> > +            reg = <4>;
> > +
> > +            max9286_out: endpoint {
> > +              data-lanes = <1 2 3 4>;
> > +              remote-endpoint = <&csi40_in>;
> > +            };
> > +          };
> > +        };
> > +
> > +        i2c-mux {
> > +          #address-cells = <1>;
> > +          #size-cells = <0>;
> > +
> > +          i2c@0 {
> > +            #address-cells = <1>;
> > +            #size-cells = <0>;
> > +
> > +            reg = <0>;
> > +
> > +            camera@51 {
> > +              reg = <0x51>;
> > +
> > +              port {
> > +                rdacm20_out0: endpoint {
> > +                  remote-endpoint = <&max9286_in0>;
> > +                };
> > +              };
> > +
> > +            };
> > +          };
> > +
> > +          i2c@1 {
> > +            #address-cells = <1>;
> > +            #size-cells = <0>;
> > +            reg = <1>;
> > +
> > +            camera@52 {
> > +              reg = <0x52>;
> > +
> > +              port {
> > +                rdacm20_out1: endpoint {
> > +                  remote-endpoint = <&max9286_in1>;
> > +                };
> > +              };
> > +            };
> > +          };
> > +
> > +          i2c@2 {
> > +            #address-cells = <1>;
> > +            #size-cells = <0>;
> > +            reg = <2>;
> > +
> > +            camera@53 {
> > +              reg = <0x53>;
> > +
> > +              port {
> > +                rdacm20_out2: endpoint {
> > +                  remote-endpoint = <&max9286_in2>;
> > +                };
> > +              };
> > +            };
> > +          };
> > +
> > +          i2c@3 {
> > +            #address-cells = <1>;
> > +            #size-cells = <0>;
> > +            reg = <3>;
> > +
> > +            camera@54 {
> > +              reg = <0x54>;
> > +
> > +              port {
> > +                rdacm20_out3: endpoint {
> > +                  remote-endpoint = <&max9286_in3>;
> > +                };
> > +              };
> > +            };
> > +          };
> > +        };
> > +      };
> > +    };
> > --
> > 2.25.1
> >

[PATCH v9 2/4] media: i2c: Add MAX9286 driver

[Kieran Bingham]

The MAX9286 is a 4-channel GMSL deserializer with coax or STP input and
CSI-2 output. The device supports multicamera streaming applications,
and features the ability to synchronise the attached cameras.

CSI-2 output can be configured with 1 to 4 lanes, and a control channel
is supported over I2C, which implements an I2C mux to facilitate
communications with connected cameras across the reverse control
channel.

Signed-off-by: Jacopo Mondi <jacopo+renesas@jmondi.org>
Signed-off-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>

--
v2:
 - Fix MAINTAINERS entry

This posting is released with the following modifications to work
without Sakari's VC developments:
 - max9286_g_mbus_config() re-instated
 - max9286_get_frame_desc() is not bus/csi aware
 - max9286_{get,set}_routing() removed

v3:
 - Initialise notifier with v4l2_async_notifier_init
 - Update for new mbus csi2 format V4L2_MBUS_CSI2_DPHY

v4: - Re-introduce required code to function with the VC series.

 - Implement max9286_get_routing, max9286_set_routing
 - Remove max9286_g_mbus_config

v5: (internal release)
 - Fix printk formatting for hex value
 - max9286->sd.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE (add |)
 - MEDIA_ENT_F_PROC_VIDEO_PIXEL_FORMATTER -> MEDIA_ENT_F_VID_IF_BRIDGE
 - Remove 'device is bound' workaround

v6:
 - v4l2_subdev_krouting instead of v4l2_subdev_routing separated
   to allow integration without the VC/V4L2-Mux series.
 - convert sd_to_max9286 to inline function
 - rename max9286_device to max9286_priv
 - Cleanup the v4l2_async_notifier
 - Extend MODULE_AUTHOR
 - Replace of_graph_get_endpoint_by_regs with fwnode_graph_get_endpoint_by_id
 - Pass default bus type when parsing fwnode endpoint (Manivannan Sadhasivam)
 - Use new YAML file reference in MAINTAINERS
 - Parse new i2c-mux node in max9286_get_i2c_by_id
   (This could/should be refactored to parse these separately first)
 - Spelling and calculation fixes in the FSYNC_LOCKED check comments
 - Identify each enabled i2c-mux channel in a single pass
 - max9286: Improve mux-state readbility [v2]
 - Fix frame sync lock durations
 - Add comment to describe /why/ we must open the mux in s_stream
 - use -EXDEV as return code for failed link synchronisation.
 - Fix reference counting of the dt nodeS
 - Convert to probe_new for I2C
 - Remove redundant max9286_i2c_mux_state
 - Provide optional enable-gpio (max9286-pwdn)

v7:
 [Kieran]
 - Ensure powerdown lines are optional
 - Add a 4ms power-up delay
 - Add max9286_check_config_link() to core
 - Add GPIO chip controller for GPIO0OUT and GPIO1OUT
 - Fix GPIO registration
 - max9286: Split out async registration
   (fixes regulator -EPROBE_DEFERs failures)
 - Collect all V4L2 registrations
 - balance v4l2_async refcnting
 - Rename max9286_v4l2_async_ => max9286_v4l2_notifier_

 [Jacopo]
 - Remove redundanct MAXIM_I2C_SPEED macros
 - Move notifiers operations
 - Add delay after reverse channel reconfiguration
 - Move link setup to completion
 - Fix up max9286_check_config_link() implementation
 - Remove redundant dual configuration of reverse channel

v8:

[Kieran]
 - Update the bound_sources mask on unbind
 - Convert probe kzalloc usage to devm_ variant
 - Fix up cleanup path from GPIO PowerDown registration
 - cleanup GPIO device registration fail path
 - Convert to use devm_regulator_get()
 - Fit max9286_parse_dt print on one line
 - Move multi-device workarounds out of upstream driver
 - Remove I2C mod-table
 - Lock format changes
 - Describe pad index usage
 - Remove poc_enabled workaround
 - Rename the max9286_gpio to be more explicit on it's actions.
 - Move max9286_init_format call
 - Rework probe sequence and simplify error paths.
 - Simplify i2c comments
 - Implement Pixelrate control
 - Disable overlap window

[Jacopo]
 - Adapt Kconfig to latest upstream changes
 - Put of node on error
 - Calculate pixel rate
 - Simplify overlap window disablement

v9:

[Kieran]
 - Kconfig: Depend on OF
 - Re-sort addition to Makefile
---
 MAINTAINERS                 |   10 +
 drivers/media/i2c/Kconfig   |   13 +
 drivers/media/i2c/Makefile  |    1 +
 drivers/media/i2c/max9286.c | 1332 +++++++++++++++++++++++++++++++++++
 4 files changed, 1356 insertions(+)
 create mode 100644 drivers/media/i2c/max9286.c

diff --git a/MAINTAINERS b/MAINTAINERS
index a7bb6e22d5da..99e3bf7760fd 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -10274,6 +10274,16 @@ F:	Documentation/hwmon/max6697.rst
 F:	drivers/hwmon/max6697.c
 F:	include/linux/platform_data/max6697.h
 
+MAX9286 QUAD GMSL DESERIALIZER DRIVER
+M:	Jacopo Mondi <jacopo+renesas@jmondi.org>
+M:	Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
+M:	Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
+M:	Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
+L:	linux-media@vger.kernel.org
+S:	Maintained
+F:	Documentation/devicetree/bindings/media/i2c/maxim,max9286.yaml
+F:	drivers/media/i2c/max9286.c
+
 MAX9860 MONO AUDIO VOICE CODEC DRIVER
 M:	Peter Rosin <peda@axentia.se>
 L:	alsa-devel@alsa-project.org (moderated for non-subscribers)
diff --git a/drivers/media/i2c/Kconfig b/drivers/media/i2c/Kconfig
index 3abc80373ec0..2e390f41f6da 100644
--- a/drivers/media/i2c/Kconfig
+++ b/drivers/media/i2c/Kconfig
@@ -464,6 +464,19 @@ config VIDEO_VPX3220
 	  To compile this driver as a module, choose M here: the
 	  module will be called vpx3220.
 
+config VIDEO_MAX9286
+	tristate "Maxim MAX9286 GMSL deserializer support"
+	depends on I2C && I2C_MUX
+	depends on OF
+	select V4L2_FWNODE
+	select VIDEO_V4L2_SUBDEV_API
+	select MEDIA_CONTROLLER
+	help
+	  This driver supports the Maxim MAX9286 GMSL deserializer.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called max9286.
+
 comment "Video and audio decoders"
 
 config VIDEO_SAA717X
diff --git a/drivers/media/i2c/Makefile b/drivers/media/i2c/Makefile
index 77bf7d0b691f..f0b001ee4b05 100644
--- a/drivers/media/i2c/Makefile
+++ b/drivers/media/i2c/Makefile
@@ -117,6 +117,7 @@ obj-$(CONFIG_VIDEO_IMX274)	+= imx274.o
 obj-$(CONFIG_VIDEO_IMX290)	+= imx290.o
 obj-$(CONFIG_VIDEO_IMX319)	+= imx319.o
 obj-$(CONFIG_VIDEO_IMX355)	+= imx355.o
+obj-$(CONFIG_VIDEO_MAX9286)	+= max9286.o
 obj-$(CONFIG_VIDEO_ST_MIPID02) += st-mipid02.o
 
 obj-$(CONFIG_SDR_MAX2175) += max2175.o
diff --git a/drivers/media/i2c/max9286.c b/drivers/media/i2c/max9286.c
new file mode 100644
index 000000000000..481d65f2b51d
--- /dev/null
+++ b/drivers/media/i2c/max9286.c
@@ -0,0 +1,1332 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Maxim MAX9286 GMSL Deserializer Driver
+ *
+ * Copyright (C) 2017-2019 Jacopo Mondi
+ * Copyright (C) 2017-2019 Kieran Bingham
+ * Copyright (C) 2017-2019 Laurent Pinchart
+ * Copyright (C) 2017-2019 Niklas Söderlund
+ * Copyright (C) 2016 Renesas Electronics Corporation
+ * Copyright (C) 2015 Cogent Embedded, Inc.
+ */
+
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/fwnode.h>
+#include <linux/gpio/consumer.h>
+#include <linux/gpio/driver.h>
+#include <linux/i2c.h>
+#include <linux/i2c-mux.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/of_graph.h>
+#include <linux/regulator/consumer.h>
+#include <linux/slab.h>
+
+#include <media/v4l2-async.h>
+#include <media/v4l2-ctrls.h>
+#include <media/v4l2-device.h>
+#include <media/v4l2-fwnode.h>
+#include <media/v4l2-subdev.h>
+
+/* Register 0x00 */
+#define MAX9286_MSTLINKSEL_AUTO		(7 << 5)
+#define MAX9286_MSTLINKSEL(n)		((n) << 5)
+#define MAX9286_EN_VS_GEN		BIT(4)
+#define MAX9286_LINKEN(n)		(1 << (n))
+/* Register 0x01 */
+#define MAX9286_FSYNCMODE_ECU		(3 << 6)
+#define MAX9286_FSYNCMODE_EXT		(2 << 6)
+#define MAX9286_FSYNCMODE_INT_OUT	(1 << 6)
+#define MAX9286_FSYNCMODE_INT_HIZ	(0 << 6)
+#define MAX9286_GPIEN			BIT(5)
+#define MAX9286_ENLMO_RSTFSYNC		BIT(2)
+#define MAX9286_FSYNCMETH_AUTO		(2 << 0)
+#define MAX9286_FSYNCMETH_SEMI_AUTO	(1 << 0)
+#define MAX9286_FSYNCMETH_MANUAL	(0 << 0)
+#define MAX9286_REG_FSYNC_PERIOD_L	0x06
+#define MAX9286_REG_FSYNC_PERIOD_M	0x07
+#define MAX9286_REG_FSYNC_PERIOD_H	0x08
+/* Register 0x0a */
+#define MAX9286_FWDCCEN(n)		(1 << ((n) + 4))
+#define MAX9286_REVCCEN(n)		(1 << (n))
+/* Register 0x0c */
+#define MAX9286_HVEN			BIT(7)
+#define MAX9286_EDC_6BIT_HAMMING	(2 << 5)
+#define MAX9286_EDC_6BIT_CRC		(1 << 5)
+#define MAX9286_EDC_1BIT_PARITY		(0 << 5)
+#define MAX9286_DESEL			BIT(4)
+#define MAX9286_INVVS			BIT(3)
+#define MAX9286_INVHS			BIT(2)
+#define MAX9286_HVSRC_D0		(2 << 0)
+#define MAX9286_HVSRC_D14		(1 << 0)
+#define MAX9286_HVSRC_D18		(0 << 0)
+/* Register 0x0f */
+#define MAX9286_0X0F_RESERVED		BIT(3)
+/* Register 0x12 */
+#define MAX9286_CSILANECNT(n)		(((n) - 1) << 6)
+#define MAX9286_CSIDBL			BIT(5)
+#define MAX9286_DBL			BIT(4)
+#define MAX9286_DATATYPE_USER_8BIT	(11 << 0)
+#define MAX9286_DATATYPE_USER_YUV_12BIT	(10 << 0)
+#define MAX9286_DATATYPE_USER_24BIT	(9 << 0)
+#define MAX9286_DATATYPE_RAW14		(8 << 0)
+#define MAX9286_DATATYPE_RAW11		(7 << 0)
+#define MAX9286_DATATYPE_RAW10		(6 << 0)
+#define MAX9286_DATATYPE_RAW8		(5 << 0)
+#define MAX9286_DATATYPE_YUV422_10BIT	(4 << 0)
+#define MAX9286_DATATYPE_YUV422_8BIT	(3 << 0)
+#define MAX9286_DATATYPE_RGB555		(2 << 0)
+#define MAX9286_DATATYPE_RGB565		(1 << 0)
+#define MAX9286_DATATYPE_RGB888		(0 << 0)
+/* Register 0x15 */
+#define MAX9286_VC(n)			((n) << 5)
+#define MAX9286_VCTYPE			BIT(4)
+#define MAX9286_CSIOUTEN		BIT(3)
+#define MAX9286_0X15_RESV		(3 << 0)
+/* Register 0x1b */
+#define MAX9286_SWITCHIN(n)		(1 << ((n) + 4))
+#define MAX9286_ENEQ(n)			(1 << (n))
+/* Register 0x27 */
+#define MAX9286_LOCKED			BIT(7)
+/* Register 0x31 */
+#define MAX9286_FSYNC_LOCKED		BIT(6)
+/* Register 0x34 */
+#define MAX9286_I2CLOCACK		BIT(7)
+#define MAX9286_I2CSLVSH_1046NS_469NS	(3 << 5)
+#define MAX9286_I2CSLVSH_938NS_352NS	(2 << 5)
+#define MAX9286_I2CSLVSH_469NS_234NS	(1 << 5)
+#define MAX9286_I2CSLVSH_352NS_117NS	(0 << 5)
+#define MAX9286_I2CMSTBT_837KBPS	(7 << 2)
+#define MAX9286_I2CMSTBT_533KBPS	(6 << 2)
+#define MAX9286_I2CMSTBT_339KBPS	(5 << 2)
+#define MAX9286_I2CMSTBT_173KBPS	(4 << 2)
+#define MAX9286_I2CMSTBT_105KBPS	(3 << 2)
+#define MAX9286_I2CMSTBT_84KBPS		(2 << 2)
+#define MAX9286_I2CMSTBT_28KBPS		(1 << 2)
+#define MAX9286_I2CMSTBT_8KBPS		(0 << 2)
+#define MAX9286_I2CSLVTO_NONE		(3 << 0)
+#define MAX9286_I2CSLVTO_1024US		(2 << 0)
+#define MAX9286_I2CSLVTO_256US		(1 << 0)
+#define MAX9286_I2CSLVTO_64US		(0 << 0)
+/* Register 0x3b */
+#define MAX9286_REV_TRF(n)		((n) << 4)
+#define MAX9286_REV_AMP(n)		((((n) - 30) / 10) << 1) /* in mV */
+#define MAX9286_REV_AMP_X		BIT(0)
+/* Register 0x3f */
+#define MAX9286_EN_REV_CFG		BIT(6)
+#define MAX9286_REV_FLEN(n)		((n) - 20)
+/* Register 0x49 */
+#define MAX9286_VIDEO_DETECT_MASK	0x0f
+/* Register 0x69 */
+#define MAX9286_LFLTBMONMASKED		BIT(7)
+#define MAX9286_LOCKMONMASKED		BIT(6)
+#define MAX9286_AUTOCOMBACKEN		BIT(5)
+#define MAX9286_AUTOMASKEN		BIT(4)
+#define MAX9286_MASKLINK(n)		((n) << 0)
+
+/*
+ * The sink and source pads are created to match the OF graph port numbers so
+ * that their indexes can be used interchangeably.
+ */
+#define MAX9286_NUM_GMSL		4
+#define MAX9286_N_SINKS			4
+#define MAX9286_N_PADS			5
+#define MAX9286_SRC_PAD			4
+
+struct max9286_source {
+	struct v4l2_async_subdev asd;
+	struct v4l2_subdev *sd;
+	struct fwnode_handle *fwnode;
+};
+
+#define asd_to_max9286_source(_asd) \
+	container_of(_asd, struct max9286_source, asd)
+
+struct max9286_priv {
+	struct i2c_client *client;
+	struct gpio_desc *gpiod_pwdn;
+	struct v4l2_subdev sd;
+	struct media_pad pads[MAX9286_N_PADS];
+	struct regulator *regulator;
+
+	struct gpio_chip gpio;
+	u8 gpio_state;
+
+	struct i2c_mux_core *mux;
+	unsigned int mux_channel;
+	bool mux_open;
+
+	struct v4l2_ctrl_handler ctrls;
+	struct v4l2_ctrl *pixelrate;
+
+	struct v4l2_mbus_framefmt fmt[MAX9286_N_SINKS];
+
+	/* Protects controls and fmt structures */
+	struct mutex mutex;
+
+	unsigned int nsources;
+	unsigned int source_mask;
+	unsigned int route_mask;
+	unsigned int bound_sources;
+	unsigned int csi2_data_lanes;
+	struct max9286_source sources[MAX9286_NUM_GMSL];
+	struct v4l2_async_notifier notifier;
+};
+
+static struct max9286_source *next_source(struct max9286_priv *priv,
+					  struct max9286_source *source)
+{
+	if (!source)
+		source = &priv->sources[0];
+	else
+		source++;
+
+	for (; source < &priv->sources[MAX9286_NUM_GMSL]; source++) {
+		if (source->fwnode)
+			return source;
+	}
+
+	return NULL;
+}
+
+#define for_each_source(priv, source) \
+	for ((source) = NULL; ((source) = next_source((priv), (source))); )
+
+#define to_index(priv, source) ((source) - &(priv)->sources[0])
+
+static inline struct max9286_priv *sd_to_max9286(struct v4l2_subdev *sd)
+{
+	return container_of(sd, struct max9286_priv, sd);
+}
+
+/* -----------------------------------------------------------------------------
+ * I2C IO
+ */
+
+static int max9286_read(struct max9286_priv *priv, u8 reg)
+{
+	int ret;
+
+	ret = i2c_smbus_read_byte_data(priv->client, reg);
+	if (ret < 0)
+		dev_err(&priv->client->dev,
+			"%s: register 0x%02x read failed (%d)\n",
+			__func__, reg, ret);
+
+	return ret;
+}
+
+static int max9286_write(struct max9286_priv *priv, u8 reg, u8 val)
+{
+	int ret;
+
+	ret = i2c_smbus_write_byte_data(priv->client, reg, val);
+	if (ret < 0)
+		dev_err(&priv->client->dev,
+			"%s: register 0x%02x write failed (%d)\n",
+			__func__, reg, ret);
+
+	return ret;
+}
+
+/* -----------------------------------------------------------------------------
+ * I2C Multiplexer
+ */
+
+static void max9286_i2c_mux_configure(struct max9286_priv *priv, u8 conf)
+{
+	max9286_write(priv, 0x0a, conf);
+
+	/*
+	 * We must sleep after any change to the forward or reverse channel
+	 * configuration.
+	 */
+	usleep_range(3000, 5000);
+}
+
+static void max9286_i2c_mux_open(struct max9286_priv *priv)
+{
+	/* Open all channels on the MAX9286 */
+	max9286_i2c_mux_configure(priv, 0xff);
+
+	priv->mux_open = true;
+}
+
+static void max9286_i2c_mux_close(struct max9286_priv *priv)
+{
+	/*
+	 * Ensure that both the forward and reverse channel are disabled on the
+	 * mux, and that the channel ID is invalidated to ensure we reconfigure
+	 * on the next max9286_i2c_mux_select() call.
+	 */
+	max9286_i2c_mux_configure(priv, 0x00);
+
+	priv->mux_open = false;
+	priv->mux_channel = -1;
+}
+
+static int max9286_i2c_mux_select(struct i2c_mux_core *muxc, u32 chan)
+{
+	struct max9286_priv *priv = i2c_mux_priv(muxc);
+
+	/* Channel select is disabled when configured in the opened state. */
+	if (priv->mux_open)
+		return 0;
+
+	if (priv->mux_channel == chan)
+		return 0;
+
+	priv->mux_channel = chan;
+
+	max9286_i2c_mux_configure(priv,
+				  MAX9286_FWDCCEN(chan) |
+				  MAX9286_REVCCEN(chan));
+
+	return 0;
+}
+
+static int max9286_i2c_mux_init(struct max9286_priv *priv)
+{
+	struct max9286_source *source;
+	int ret;
+
+	if (!i2c_check_functionality(priv->client->adapter,
+				     I2C_FUNC_SMBUS_WRITE_BYTE_DATA))
+		return -ENODEV;
+
+	priv->mux = i2c_mux_alloc(priv->client->adapter, &priv->client->dev,
+				  priv->nsources, 0, I2C_MUX_LOCKED,
+				  max9286_i2c_mux_select, NULL);
+	if (!priv->mux)
+		return -ENOMEM;
+
+	priv->mux->priv = priv;
+
+	for_each_source(priv, source) {
+		unsigned int index = to_index(priv, source);
+
+		ret = i2c_mux_add_adapter(priv->mux, 0, index, 0);
+		if (ret < 0)
+			goto error;
+	}
+
+	return 0;
+
+error:
+	i2c_mux_del_adapters(priv->mux);
+	return ret;
+}
+
+static void max9286_configure_i2c(struct max9286_priv *priv, bool localack)
+{
+	u8 config = MAX9286_I2CSLVSH_469NS_234NS | MAX9286_I2CSLVTO_1024US |
+		    MAX9286_I2CMSTBT_105KBPS;
+
+	if (localack)
+		config |= MAX9286_I2CLOCACK;
+
+	max9286_write(priv, 0x34, config);
+	usleep_range(3000, 5000);
+}
+
+/*
+ * max9286_check_video_links() - Make sure video links are detected and locked
+ *
+ * Performs safety checks on video link status. Make sure they are detected
+ * and all enabled links are locked.
+ *
+ * Returns 0 for success, -EIO for errors.
+ */
+static int max9286_check_video_links(struct max9286_priv *priv)
+{
+	unsigned int i;
+	int ret;
+
+	/*
+	 * Make sure valid video links are detected.
+	 * The delay is not characterized in de-serializer manual, wait up
+	 * to 5 ms.
+	 */
+	for (i = 0; i < 10; i++) {
+		ret = max9286_read(priv, 0x49);
+		if (ret < 0)
+			return -EIO;
+
+		if ((ret & MAX9286_VIDEO_DETECT_MASK) == priv->source_mask)
+			break;
+
+		usleep_range(350, 500);
+	}
+
+	if (i == 10) {
+		dev_err(&priv->client->dev,
+			"Unable to detect video links: 0x%02x\n", ret);
+		return -EIO;
+	}
+
+	/* Make sure all enabled links are locked (4ms max). */
+	for (i = 0; i < 10; i++) {
+		ret = max9286_read(priv, 0x27);
+		if (ret < 0)
+			return -EIO;
+
+		if (ret & MAX9286_LOCKED)
+			break;
+
+		usleep_range(350, 450);
+	}
+
+	if (i == 10) {
+		dev_err(&priv->client->dev, "Not all enabled links locked\n");
+		return -EIO;
+	}
+
+	return 0;
+}
+
+/*
+ * max9286_check_config_link() - Detect and wait for configuration links
+ *
+ * Determine if the configuration channel is up and settled for a link.
+ *
+ * Returns 0 for success, -EIO for errors.
+ */
+static int max9286_check_config_link(struct max9286_priv *priv,
+				     unsigned int source_mask)
+{
+	unsigned int conflink_mask = (source_mask & 0x0f) << 4;
+	unsigned int i;
+	int ret;
+
+	/*
+	 * Make sure requested configuration links are detected.
+	 * The delay is not characterized in the chip manual: wait up
+	 * to 5 milliseconds.
+	 */
+	for (i = 0; i < 10; i++) {
+		ret = max9286_read(priv, 0x49) & 0xf0;
+		if (ret < 0)
+			return -EIO;
+
+		if (ret == conflink_mask)
+			break;
+
+		usleep_range(350, 500);
+	}
+
+	if (ret != conflink_mask) {
+		dev_err(&priv->client->dev,
+			"Unable to detect configuration links: 0x%02x expected 0x%02x\n",
+			ret, conflink_mask);
+		return -EIO;
+	}
+
+	dev_info(&priv->client->dev,
+		 "Successfully detected configuration links after %u loops: 0x%02x\n",
+		 i, conflink_mask);
+
+	return 0;
+}
+
+/* -----------------------------------------------------------------------------
+ * V4L2 Subdev
+ */
+
+static int max9286_set_pixelrate(struct max9286_priv *priv)
+{
+	struct max9286_source *source = NULL;
+	u64 pixelrate = 0;
+
+	for_each_source(priv, source) {
+		struct v4l2_ctrl *ctrl;
+		u64 source_rate = 0;
+
+		/* Pixel rate is mandatory to be reported by sources. */
+		ctrl = v4l2_ctrl_find(source->sd->ctrl_handler,
+				      V4L2_CID_PIXEL_RATE);
+		if (!ctrl) {
+			pixelrate = 0;
+			break;
+		}
+
+		/* All source must report the same pixel rate. */
+		source_rate = v4l2_ctrl_g_ctrl_int64(ctrl);
+		if (!pixelrate) {
+			pixelrate = source_rate;
+		} else if (pixelrate != source_rate) {
+			dev_err(&priv->client->dev,
+				"Unable to calculate pixel rate\n");
+			return -EINVAL;
+		}
+	}
+
+	if (!pixelrate) {
+		dev_err(&priv->client->dev,
+			"No pixel rate control available in sources\n");
+		return -EINVAL;
+	}
+
+	/*
+	 * The CSI-2 transmitter pixel rate is the single source rate multiplied
+	 * by the number of available sources.
+	 */
+	return v4l2_ctrl_s_ctrl_int64(priv->pixelrate,
+				      pixelrate * priv->nsources);
+}
+
+static int max9286_notify_bound(struct v4l2_async_notifier *notifier,
+				struct v4l2_subdev *subdev,
+				struct v4l2_async_subdev *asd)
+{
+	struct max9286_priv *priv = sd_to_max9286(notifier->sd);
+	struct max9286_source *source = asd_to_max9286_source(asd);
+	unsigned int index = to_index(priv, source);
+	unsigned int src_pad;
+	int ret;
+
+	ret = media_entity_get_fwnode_pad(&subdev->entity,
+					  source->fwnode,
+					  MEDIA_PAD_FL_SOURCE);
+	if (ret < 0) {
+		dev_err(&priv->client->dev,
+			"Failed to find pad for %s\n", subdev->name);
+		return ret;
+	}
+
+	priv->bound_sources |= BIT(index);
+	source->sd = subdev;
+	src_pad = ret;
+
+	ret = media_create_pad_link(&source->sd->entity, src_pad,
+				    &priv->sd.entity, index,
+				    MEDIA_LNK_FL_ENABLED |
+				    MEDIA_LNK_FL_IMMUTABLE);
+	if (ret) {
+		dev_err(&priv->client->dev,
+			"Unable to link %s:%u -> %s:%u\n",
+			source->sd->name, src_pad, priv->sd.name, index);
+		return ret;
+	}
+
+	dev_dbg(&priv->client->dev, "Bound %s pad: %u on index %u\n",
+		subdev->name, src_pad, index);
+
+	/*
+	 * We can only register v4l2_async_notifiers, which do not provide a
+	 * means to register a complete callback. bound_sources allows us to
+	 * identify when all remote serializers have completed their probe.
+	 */
+	if (priv->bound_sources != priv->source_mask)
+		return 0;
+
+	/*
+	 * All enabled sources have probed and enabled their reverse control
+	 * channels:
+	 *
+	 * - Verify all configuration links are properly detected
+	 * - Disable auto-ack as communication on the control channel are now
+	 *   stable.
+	 */
+	max9286_check_config_link(priv, priv->source_mask);
+
+	/*
+	 * Re-configure I2C with local acknowledge disabled after cameras have
+	 * probed.
+	 */
+	max9286_configure_i2c(priv, false);
+
+	return max9286_set_pixelrate(priv);
+}
+
+static void max9286_notify_unbind(struct v4l2_async_notifier *notifier,
+				  struct v4l2_subdev *subdev,
+				  struct v4l2_async_subdev *asd)
+{
+	struct max9286_priv *priv = sd_to_max9286(notifier->sd);
+	struct max9286_source *source = asd_to_max9286_source(asd);
+	unsigned int index = to_index(priv, source);
+
+	source->sd = NULL;
+	priv->bound_sources &= ~BIT(index);
+}
+
+static const struct v4l2_async_notifier_operations max9286_notify_ops = {
+	.bound = max9286_notify_bound,
+	.unbind = max9286_notify_unbind,
+};
+
+static int max9286_v4l2_notifier_register(struct max9286_priv *priv)
+{
+	struct device *dev = &priv->client->dev;
+	struct max9286_source *source = NULL;
+	int ret;
+
+	if (!priv->nsources)
+		return 0;
+
+	v4l2_async_notifier_init(&priv->notifier);
+
+	for_each_source(priv, source) {
+		unsigned int i = to_index(priv, source);
+
+		source->asd.match_type = V4L2_ASYNC_MATCH_FWNODE;
+		source->asd.match.fwnode = source->fwnode;
+
+		ret = v4l2_async_notifier_add_subdev(&priv->notifier,
+						     &source->asd);
+		if (ret) {
+			dev_err(dev, "Failed to add subdev for source %d", i);
+			v4l2_async_notifier_cleanup(&priv->notifier);
+			return ret;
+		}
+
+		/*
+		 * Balance the reference counting handled through
+		 * v4l2_async_notifier_cleanup()
+		 */
+		fwnode_handle_get(source->fwnode);
+	}
+
+	priv->notifier.ops = &max9286_notify_ops;
+
+	ret = v4l2_async_subdev_notifier_register(&priv->sd, &priv->notifier);
+	if (ret) {
+		dev_err(dev, "Failed to register subdev_notifier");
+		v4l2_async_notifier_cleanup(&priv->notifier);
+		return ret;
+	}
+
+	return 0;
+}
+
+static void max9286_v4l2_notifier_unregister(struct max9286_priv *priv)
+{
+	if (!priv->nsources)
+		return;
+
+	v4l2_async_notifier_unregister(&priv->notifier);
+	v4l2_async_notifier_cleanup(&priv->notifier);
+}
+
+static int max9286_s_stream(struct v4l2_subdev *sd, int enable)
+{
+	struct max9286_priv *priv = sd_to_max9286(sd);
+	struct max9286_source *source;
+	unsigned int i;
+	bool sync = false;
+	int ret;
+
+	if (enable) {
+		/*
+		 * The frame sync between cameras is transmitted across the
+		 * reverse channel as GPIO. We must open all channels while
+		 * streaming to allow this synchronisation signal to be shared.
+		 */
+		max9286_i2c_mux_open(priv);
+
+		/* Start all cameras. */
+		for_each_source(priv, source) {
+			ret = v4l2_subdev_call(source->sd, video, s_stream, 1);
+			if (ret)
+				return ret;
+		}
+
+		ret = max9286_check_video_links(priv);
+		if (ret)
+			return ret;
+
+		/*
+		 * Wait until frame synchronization is locked.
+		 *
+		 * Manual says frame sync locking should take ~6 VTS.
+		 * From practical experience at least 8 are required. Give
+		 * 12 complete frames time (~400ms at 30 fps) to achieve frame
+		 * locking before returning error.
+		 */
+		for (i = 0; i < 40; i++) {
+			if (max9286_read(priv, 0x31) & MAX9286_FSYNC_LOCKED) {
+				sync = true;
+				break;
+			}
+			usleep_range(9000, 11000);
+		}
+
+		if (!sync) {
+			dev_err(&priv->client->dev,
+				"Failed to get frame synchronization\n");
+			return -EXDEV; /* Invalid cross-device link */
+		}
+
+		/*
+		 * Enable CSI output, VC set according to link number.
+		 * Bit 7 must be set (chip manual says it's 0 and reserved).
+		 */
+		max9286_write(priv, 0x15, 0x80 | MAX9286_VCTYPE |
+			      MAX9286_CSIOUTEN | MAX9286_0X15_RESV);
+	} else {
+		max9286_write(priv, 0x15, MAX9286_VCTYPE | MAX9286_0X15_RESV);
+
+		/* Stop all cameras. */
+		for_each_source(priv, source)
+			v4l2_subdev_call(source->sd, video, s_stream, 0);
+
+		max9286_i2c_mux_close(priv);
+	}
+
+	return 0;
+}
+
+static int max9286_enum_mbus_code(struct v4l2_subdev *sd,
+				  struct v4l2_subdev_pad_config *cfg,
+				  struct v4l2_subdev_mbus_code_enum *code)
+{
+	if (code->pad || code->index > 0)
+		return -EINVAL;
+
+	code->code = MEDIA_BUS_FMT_UYVY8_2X8;
+
+	return 0;
+}
+
+static struct v4l2_mbus_framefmt *
+max9286_get_pad_format(struct max9286_priv *priv,
+		       struct v4l2_subdev_pad_config *cfg,
+		       unsigned int pad, u32 which)
+{
+	switch (which) {
+	case V4L2_SUBDEV_FORMAT_TRY:
+		return v4l2_subdev_get_try_format(&priv->sd, cfg, pad);
+	case V4L2_SUBDEV_FORMAT_ACTIVE:
+		return &priv->fmt[pad];
+	default:
+		return NULL;
+	}
+}
+
+static int max9286_set_fmt(struct v4l2_subdev *sd,
+			   struct v4l2_subdev_pad_config *cfg,
+			   struct v4l2_subdev_format *format)
+{
+	struct max9286_priv *priv = sd_to_max9286(sd);
+	struct v4l2_mbus_framefmt *cfg_fmt;
+
+	if (format->pad >= MAX9286_SRC_PAD)
+		return -EINVAL;
+
+	/* Refuse non YUV422 formats as we hardcode DT to 8 bit YUV422 */
+	switch (format->format.code) {
+	case MEDIA_BUS_FMT_UYVY8_2X8:
+	case MEDIA_BUS_FMT_VYUY8_2X8:
+	case MEDIA_BUS_FMT_YUYV8_2X8:
+	case MEDIA_BUS_FMT_YVYU8_2X8:
+		break;
+	default:
+		format->format.code = MEDIA_BUS_FMT_YUYV8_2X8;
+		break;
+	}
+
+	cfg_fmt = max9286_get_pad_format(priv, cfg, format->pad, format->which);
+	if (!cfg_fmt)
+		return -EINVAL;
+
+	mutex_lock(&priv->mutex);
+	*cfg_fmt = format->format;
+	mutex_unlock(&priv->mutex);
+
+	return 0;
+}
+
+static int max9286_get_fmt(struct v4l2_subdev *sd,
+			   struct v4l2_subdev_pad_config *cfg,
+			   struct v4l2_subdev_format *format)
+{
+	struct max9286_priv *priv = sd_to_max9286(sd);
+	struct v4l2_mbus_framefmt *cfg_fmt;
+
+	if (format->pad >= MAX9286_SRC_PAD)
+		return -EINVAL;
+
+	cfg_fmt = max9286_get_pad_format(priv, cfg, format->pad, format->which);
+	if (!cfg_fmt)
+		return -EINVAL;
+
+	mutex_lock(&priv->mutex);
+	format->format = *cfg_fmt;
+	mutex_unlock(&priv->mutex);
+
+	return 0;
+}
+
+static const struct v4l2_subdev_video_ops max9286_video_ops = {
+	.s_stream	= max9286_s_stream,
+};
+
+static const struct v4l2_subdev_pad_ops max9286_pad_ops = {
+	.enum_mbus_code = max9286_enum_mbus_code,
+	.get_fmt	= max9286_get_fmt,
+	.set_fmt	= max9286_set_fmt,
+};
+
+static const struct v4l2_subdev_ops max9286_subdev_ops = {
+	.video		= &max9286_video_ops,
+	.pad		= &max9286_pad_ops,
+};
+
+static void max9286_init_format(struct v4l2_mbus_framefmt *fmt)
+{
+	fmt->width		= 1280;
+	fmt->height		= 800;
+	fmt->code		= MEDIA_BUS_FMT_UYVY8_2X8;
+	fmt->colorspace		= V4L2_COLORSPACE_SRGB;
+	fmt->field		= V4L2_FIELD_NONE;
+	fmt->ycbcr_enc		= V4L2_YCBCR_ENC_DEFAULT;
+	fmt->quantization	= V4L2_QUANTIZATION_DEFAULT;
+	fmt->xfer_func		= V4L2_XFER_FUNC_DEFAULT;
+}
+
+static int max9286_open(struct v4l2_subdev *subdev, struct v4l2_subdev_fh *fh)
+{
+	struct v4l2_mbus_framefmt *format;
+	unsigned int i;
+
+	for (i = 0; i < MAX9286_N_SINKS; i++) {
+		format = v4l2_subdev_get_try_format(subdev, fh->pad, i);
+		max9286_init_format(format);
+	}
+
+	return 0;
+}
+
+static const struct v4l2_subdev_internal_ops max9286_subdev_internal_ops = {
+	.open = max9286_open,
+};
+
+static int max9286_s_ctrl(struct v4l2_ctrl *ctrl)
+{
+	switch (ctrl->id) {
+	case V4L2_CID_PIXEL_RATE:
+		return 0;
+	default:
+		return -EINVAL;
+	}
+}
+
+static const struct v4l2_ctrl_ops max9286_ctrl_ops = {
+	.s_ctrl	= max9286_s_ctrl,
+};
+
+static int max9286_v4l2_register(struct max9286_priv *priv)
+{
+	struct device *dev = &priv->client->dev;
+	struct fwnode_handle *ep;
+	int ret;
+	int i;
+
+	/* Register v4l2 async notifiers for connected Camera subdevices */
+	ret = max9286_v4l2_notifier_register(priv);
+	if (ret) {
+		dev_err(dev, "Unable to register V4L2 async notifiers\n");
+		return ret;
+	}
+
+	/* Configure V4L2 for the MAX9286 itself */
+
+	for (i = 0; i < MAX9286_N_SINKS; i++)
+		max9286_init_format(&priv->fmt[i]);
+
+	v4l2_i2c_subdev_init(&priv->sd, priv->client, &max9286_subdev_ops);
+	priv->sd.internal_ops = &max9286_subdev_internal_ops;
+	priv->sd.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;
+
+	v4l2_ctrl_handler_init(&priv->ctrls, 1);
+	priv->pixelrate = v4l2_ctrl_new_std(&priv->ctrls,
+					    &max9286_ctrl_ops,
+					    V4L2_CID_PIXEL_RATE,
+					    1, INT_MAX, 1, 50000000);
+
+	priv->sd.ctrl_handler = &priv->ctrls;
+	ret = priv->ctrls.error;
+	if (ret)
+		goto err_async;
+
+	priv->sd.entity.function = MEDIA_ENT_F_VID_IF_BRIDGE;
+
+	priv->pads[MAX9286_SRC_PAD].flags = MEDIA_PAD_FL_SOURCE;
+	for (i = 0; i < MAX9286_SRC_PAD; i++)
+		priv->pads[i].flags = MEDIA_PAD_FL_SINK;
+	ret = media_entity_pads_init(&priv->sd.entity, MAX9286_N_PADS,
+				     priv->pads);
+	if (ret)
+		goto err_async;
+
+	ep = fwnode_graph_get_endpoint_by_id(dev_fwnode(dev), MAX9286_SRC_PAD,
+					     0, 0);
+	if (!ep) {
+		dev_err(dev, "Unable to retrieve endpoint on \"port@4\"\n");
+		ret = -ENOENT;
+		goto err_async;
+	}
+	priv->sd.fwnode = ep;
+
+	ret = v4l2_async_register_subdev(&priv->sd);
+	if (ret < 0) {
+		dev_err(dev, "Unable to register subdevice\n");
+		goto err_put_node;
+	}
+
+	return 0;
+
+err_put_node:
+	fwnode_handle_put(ep);
+err_async:
+	max9286_v4l2_notifier_unregister(priv);
+
+	return ret;
+}
+
+static void max9286_v4l2_unregister(struct max9286_priv *priv)
+{
+	fwnode_handle_put(priv->sd.fwnode);
+	v4l2_async_unregister_subdev(&priv->sd);
+	max9286_v4l2_notifier_unregister(priv);
+}
+
+/* -----------------------------------------------------------------------------
+ * Probe/Remove
+ */
+
+static int max9286_setup(struct max9286_priv *priv)
+{
+	/*
+	 * Link ordering values for all enabled links combinations. Orders must
+	 * be assigned sequentially from 0 to the number of enabled links
+	 * without leaving any hole for disabled links. We thus assign orders to
+	 * enabled links first, and use the remaining order values for disabled
+	 * links are all links must have a different order value;
+	 */
+	static const u8 link_order[] = {
+		(3 << 6) | (2 << 4) | (1 << 2) | (0 << 0), /* xxxx */
+		(3 << 6) | (2 << 4) | (1 << 2) | (0 << 0), /* xxx0 */
+		(3 << 6) | (2 << 4) | (0 << 2) | (1 << 0), /* xx0x */
+		(3 << 6) | (2 << 4) | (1 << 2) | (0 << 0), /* xx10 */
+		(3 << 6) | (0 << 4) | (2 << 2) | (1 << 0), /* x0xx */
+		(3 << 6) | (1 << 4) | (2 << 2) | (0 << 0), /* x1x0 */
+		(3 << 6) | (1 << 4) | (0 << 2) | (2 << 0), /* x10x */
+		(3 << 6) | (1 << 4) | (1 << 2) | (0 << 0), /* x210 */
+		(0 << 6) | (3 << 4) | (2 << 2) | (1 << 0), /* 0xxx */
+		(1 << 6) | (3 << 4) | (2 << 2) | (0 << 0), /* 1xx0 */
+		(1 << 6) | (3 << 4) | (0 << 2) | (2 << 0), /* 1x0x */
+		(2 << 6) | (3 << 4) | (1 << 2) | (0 << 0), /* 2x10 */
+		(1 << 6) | (0 << 4) | (3 << 2) | (2 << 0), /* 10xx */
+		(2 << 6) | (1 << 4) | (3 << 2) | (0 << 0), /* 21x0 */
+		(2 << 6) | (1 << 4) | (0 << 2) | (3 << 0), /* 210x */
+		(3 << 6) | (2 << 4) | (1 << 2) | (0 << 0), /* 3210 */
+	};
+
+	/*
+	 * Set the I2C bus speed.
+	 *
+	 * Enable I2C Local Acknowledge during the probe sequences of the camera
+	 * only. This should be disabled after the mux is initialised.
+	 */
+	max9286_configure_i2c(priv, true);
+
+	/*
+	 * Reverse channel setup.
+	 *
+	 * - Enable custom reverse channel configuration (through register 0x3f)
+	 *   and set the first pulse length to 35 clock cycles.
+	 * - Increase the reverse channel amplitude to 170mV to accommodate the
+	 *   high threshold enabled by the serializer driver.
+	 */
+	max9286_write(priv, 0x3f, MAX9286_EN_REV_CFG | MAX9286_REV_FLEN(35));
+	max9286_write(priv, 0x3b, MAX9286_REV_TRF(1) | MAX9286_REV_AMP(70) |
+		      MAX9286_REV_AMP_X);
+	usleep_range(2000, 2500);
+
+	/*
+	 * Enable GMSL links, mask unused ones and autodetect link
+	 * used as CSI clock source.
+	 */
+	max9286_write(priv, 0x00, MAX9286_MSTLINKSEL_AUTO | priv->route_mask);
+	max9286_write(priv, 0x0b, link_order[priv->route_mask]);
+	max9286_write(priv, 0x69, (0xf & ~priv->route_mask));
+
+	/*
+	 * Video format setup:
+	 * Disable CSI output, VC is set according to Link number.
+	 */
+	max9286_write(priv, 0x15, MAX9286_VCTYPE | MAX9286_0X15_RESV);
+
+	/* Enable CSI-2 Lane D0-D3 only, DBL mode, YUV422 8-bit. */
+	max9286_write(priv, 0x12, MAX9286_CSIDBL | MAX9286_DBL |
+		      MAX9286_CSILANECNT(priv->csi2_data_lanes) |
+		      MAX9286_DATATYPE_YUV422_8BIT);
+
+	/* Automatic: FRAMESYNC taken from the slowest Link. */
+	max9286_write(priv, 0x01, MAX9286_FSYNCMODE_INT_HIZ |
+		      MAX9286_FSYNCMETH_AUTO);
+
+	/* Enable HS/VS encoding, use D14/15 for HS/VS, invert VS. */
+	max9286_write(priv, 0x0c, MAX9286_HVEN | MAX9286_INVVS |
+		      MAX9286_HVSRC_D14);
+
+	/*
+	 * The overlap window seems to provide additional validation by tracking
+	 * the delay between vsync and frame sync, generating an error if the
+	 * delay is bigger than the programmed window, though it's not yet clear
+	 * what value should be set.
+	 *
+	 * As it's an optional value and can be disabled, we do so by setting
+	 * a 0 overlap value.
+	 */
+	max9286_write(priv, 0x63, 0);
+	max9286_write(priv, 0x64, 0);
+
+	/*
+	 * Wait for 2ms to allow the link to resynchronize after the
+	 * configuration change.
+	 */
+	usleep_range(2000, 5000);
+
+	return 0;
+}
+
+static void max9286_gpio_set(struct gpio_chip *chip,
+			     unsigned int offset, int value)
+{
+	struct max9286_priv *priv = gpiochip_get_data(chip);
+
+	if (value)
+		priv->gpio_state |= BIT(offset);
+	else
+		priv->gpio_state &= ~BIT(offset);
+
+	max9286_write(priv, 0x0f, MAX9286_0X0F_RESERVED | priv->gpio_state);
+}
+
+static int max9286_gpio_get(struct gpio_chip *chip, unsigned int offset)
+{
+	struct max9286_priv *priv = gpiochip_get_data(chip);
+
+	return priv->gpio_state & BIT(offset);
+}
+
+static int max9286_register_gpio(struct max9286_priv *priv)
+{
+	struct device *dev = &priv->client->dev;
+	struct gpio_chip *gpio = &priv->gpio;
+	int ret;
+
+	static const char * const names[] = {
+		"GPIO0OUT",
+		"GPIO1OUT",
+	};
+
+	/* Configure the GPIO */
+	gpio->label = dev_name(dev);
+	gpio->parent = dev;
+	gpio->owner = THIS_MODULE;
+	gpio->of_node = dev->of_node;
+	gpio->ngpio = 2;
+	gpio->base = -1;
+	gpio->set = max9286_gpio_set;
+	gpio->get = max9286_gpio_get;
+	gpio->can_sleep = true;
+	gpio->names = names;
+
+	/* GPIO values default to high */
+	priv->gpio_state = BIT(0) | BIT(1);
+
+	ret = devm_gpiochip_add_data(dev, gpio, priv);
+	if (ret)
+		dev_err(dev, "Unable to create gpio_chip\n");
+
+	return ret;
+}
+
+static int max9286_init(struct device *dev)
+{
+	struct max9286_priv *priv;
+	struct i2c_client *client;
+	int ret;
+
+	client = to_i2c_client(dev);
+	priv = i2c_get_clientdata(client);
+
+	/* Enable the bus power. */
+	ret = regulator_enable(priv->regulator);
+	if (ret < 0) {
+		dev_err(&client->dev, "Unable to turn PoC on\n");
+		return ret;
+	}
+
+	ret = max9286_setup(priv);
+	if (ret) {
+		dev_err(dev, "Unable to setup max9286\n");
+		goto err_regulator;
+	}
+
+	/*
+	 * Register all V4L2 interactions for the MAX9286 and notifiers for
+	 * any subdevices connected.
+	 */
+	ret = max9286_v4l2_register(priv);
+	if (ret) {
+		dev_err(dev, "Failed to register with V4L2\n");
+		goto err_regulator;
+	}
+
+	ret = max9286_i2c_mux_init(priv);
+	if (ret) {
+		dev_err(dev, "Unable to initialize I2C multiplexer\n");
+		goto err_v4l2_register;
+	}
+
+	/* Leave the mux channels disabled until they are selected. */
+	max9286_i2c_mux_close(priv);
+
+	return 0;
+
+err_v4l2_register:
+	max9286_v4l2_unregister(priv);
+err_regulator:
+	regulator_disable(priv->regulator);
+
+	return ret;
+}
+
+static void max9286_cleanup_dt(struct max9286_priv *priv)
+{
+	struct max9286_source *source;
+
+	for_each_source(priv, source) {
+		fwnode_handle_put(source->fwnode);
+		source->fwnode = NULL;
+	}
+}
+
+static int max9286_parse_dt(struct max9286_priv *priv)
+{
+	struct device *dev = &priv->client->dev;
+	struct device_node *i2c_mux;
+	struct device_node *node = NULL;
+	unsigned int i2c_mux_mask = 0;
+
+	of_node_get(dev->of_node);
+	i2c_mux = of_find_node_by_name(dev->of_node, "i2c-mux");
+	if (!i2c_mux) {
+		dev_err(dev, "Failed to find i2c-mux node\n");
+		of_node_put(dev->of_node);
+		return -EINVAL;
+	}
+
+	/* Identify which i2c-mux channels are enabled */
+	for_each_child_of_node(i2c_mux, node) {
+		u32 id = 0;
+
+		of_property_read_u32(node, "reg", &id);
+		if (id >= MAX9286_NUM_GMSL)
+			continue;
+
+		if (!of_device_is_available(node)) {
+			dev_dbg(dev, "Skipping disabled I2C bus port %u\n", id);
+			continue;
+		}
+
+		i2c_mux_mask |= BIT(id);
+	}
+	of_node_put(node);
+	of_node_put(i2c_mux);
+
+	/* Parse the endpoints */
+	for_each_endpoint_of_node(dev->of_node, node) {
+		struct max9286_source *source;
+		struct of_endpoint ep;
+
+		of_graph_parse_endpoint(node, &ep);
+		dev_dbg(dev, "Endpoint %pOF on port %d",
+			ep.local_node, ep.port);
+
+		if (ep.port > MAX9286_NUM_GMSL) {
+			dev_err(dev, "Invalid endpoint %s on port %d",
+				of_node_full_name(ep.local_node), ep.port);
+			continue;
+		}
+
+		/* For the source endpoint just parse the bus configuration. */
+		if (ep.port == MAX9286_SRC_PAD) {
+			struct v4l2_fwnode_endpoint vep = {
+				.bus_type = V4L2_MBUS_CSI2_DPHY
+			};
+			int ret;
+
+			ret = v4l2_fwnode_endpoint_parse(
+					of_fwnode_handle(node), &vep);
+			if (ret) {
+				of_node_put(node);
+				of_node_put(dev->of_node);
+				return ret;
+			}
+
+			if (vep.bus_type != V4L2_MBUS_CSI2_DPHY) {
+				dev_err(dev,
+					"Media bus %u type not supported\n",
+					vep.bus_type);
+				v4l2_fwnode_endpoint_free(&vep);
+				of_node_put(node);
+				of_node_put(dev->of_node);
+				return -EINVAL;
+			}
+
+			priv->csi2_data_lanes =
+				vep.bus.mipi_csi2.num_data_lanes;
+			v4l2_fwnode_endpoint_free(&vep);
+
+			continue;
+		}
+
+		/* Skip if the corresponding GMSL link is unavailable. */
+		if (!(i2c_mux_mask & BIT(ep.port)))
+			continue;
+
+		if (priv->sources[ep.port].fwnode) {
+			dev_err(dev,
+				"Multiple port endpoints are not supported: %d",
+				ep.port);
+
+			continue;
+		}
+
+		source = &priv->sources[ep.port];
+		source->fwnode = fwnode_graph_get_remote_endpoint(
+						of_fwnode_handle(node));
+		if (!source->fwnode) {
+			dev_err(dev,
+				"Endpoint %pOF has no remote endpoint connection\n",
+				ep.local_node);
+
+			continue;
+		}
+
+		priv->source_mask |= BIT(ep.port);
+		priv->nsources++;
+	}
+	of_node_put(node);
+	of_node_put(dev->of_node);
+
+	priv->route_mask = priv->source_mask;
+
+	return 0;
+}
+
+static int max9286_probe(struct i2c_client *client)
+{
+	struct max9286_priv *priv;
+	int ret;
+
+	priv = devm_kzalloc(&client->dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	mutex_init(&priv->mutex);
+
+	priv->client = client;
+	i2c_set_clientdata(client, priv);
+
+	priv->gpiod_pwdn = devm_gpiod_get_optional(&client->dev, "enable",
+						   GPIOD_OUT_HIGH);
+	if (IS_ERR(priv->gpiod_pwdn))
+		return PTR_ERR(priv->gpiod_pwdn);
+
+	gpiod_set_consumer_name(priv->gpiod_pwdn, "max9286-pwdn");
+	gpiod_set_value_cansleep(priv->gpiod_pwdn, 1);
+
+	/* Wait at least 4ms before the I2C lines latch to the address */
+	if (priv->gpiod_pwdn)
+		usleep_range(4000, 5000);
+
+	/*
+	 * The MAX9286 starts by default with all ports enabled, we disable all
+	 * ports early to ensure that all channels are disabled if we error out
+	 * and keep the bus consistent.
+	 */
+	max9286_i2c_mux_close(priv);
+
+	/*
+	 * The MAX9286 initialises with auto-acknowledge enabled by default.
+	 * This can be invasive to other transactions on the same bus, so
+	 * disable it early. It will be enabled only as and when needed.
+	 */
+	max9286_configure_i2c(priv, false);
+
+	ret = max9286_register_gpio(priv);
+	if (ret)
+		goto err_powerdown;
+
+	priv->regulator = devm_regulator_get(&client->dev, "poc");
+	if (IS_ERR(priv->regulator)) {
+		if (PTR_ERR(priv->regulator) != -EPROBE_DEFER)
+			dev_err(&client->dev,
+				"Unable to get PoC regulator (%ld)\n",
+				PTR_ERR(priv->regulator));
+		ret = PTR_ERR(priv->regulator);
+		goto err_powerdown;
+	}
+
+	ret = max9286_parse_dt(priv);
+	if (ret)
+		goto err_powerdown;
+
+	ret = max9286_init(&client->dev);
+	if (ret < 0)
+		goto err_cleanup_dt;
+
+	return 0;
+
+err_cleanup_dt:
+	max9286_cleanup_dt(priv);
+err_powerdown:
+	gpiod_set_value_cansleep(priv->gpiod_pwdn, 0);
+
+	return ret;
+}
+
+static int max9286_remove(struct i2c_client *client)
+{
+	struct max9286_priv *priv = i2c_get_clientdata(client);
+
+	i2c_mux_del_adapters(priv->mux);
+
+	max9286_v4l2_unregister(priv);
+
+	regulator_disable(priv->regulator);
+
+	gpiod_set_value_cansleep(priv->gpiod_pwdn, 0);
+
+	max9286_cleanup_dt(priv);
+
+	return 0;
+}
+
+static const struct of_device_id max9286_dt_ids[] = {
+	{ .compatible = "maxim,max9286" },
+	{},
+};
+MODULE_DEVICE_TABLE(of, max9286_dt_ids);
+
+static struct i2c_driver max9286_i2c_driver = {
+	.driver	= {
+		.name		= "max9286",
+		.of_match_table	= of_match_ptr(max9286_dt_ids),
+	},
+	.probe_new	= max9286_probe,
+	.remove		= max9286_remove,
+};
+
+module_i2c_driver(max9286_i2c_driver);
+
+MODULE_DESCRIPTION("Maxim MAX9286 GMSL Deserializer Driver");
+MODULE_AUTHOR("Jacopo Mondi, Kieran Bingham, Laurent Pinchart, Niklas Söderlund, Vladimir Barinov");
+MODULE_LICENSE("GPL");
-- 
2.25.1

Re: [PATCH v9 2/4] media: i2c: Add MAX9286 driver

[Manivannan Sadhasivam]

Hi Kieran,

On Tue, May 12, 2020 at 04:51:03PM +0100, Kieran Bingham wrote:
> The MAX9286 is a 4-channel GMSL deserializer with coax or STP input and
> CSI-2 output. The device supports multicamera streaming applications,
> and features the ability to synchronise the attached cameras.
> 
> CSI-2 output can be configured with 1 to 4 lanes, and a control channel
> is supported over I2C, which implements an I2C mux to facilitate
> communications with connected cameras across the reverse control
> channel.
> 
> Signed-off-by: Jacopo Mondi <jacopo+renesas@jmondi.org>
> Signed-off-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
> Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
> Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
> 
> --
> v2:
>  - Fix MAINTAINERS entry
> 
> This posting is released with the following modifications to work
> without Sakari's VC developments:
>  - max9286_g_mbus_config() re-instated
>  - max9286_get_frame_desc() is not bus/csi aware
>  - max9286_{get,set}_routing() removed
> 
> v3:
>  - Initialise notifier with v4l2_async_notifier_init
>  - Update for new mbus csi2 format V4L2_MBUS_CSI2_DPHY
> 
> v4: - Re-introduce required code to function with the VC series.
> 
>  - Implement max9286_get_routing, max9286_set_routing
>  - Remove max9286_g_mbus_config
> 
> v5: (internal release)
>  - Fix printk formatting for hex value
>  - max9286->sd.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE (add |)
>  - MEDIA_ENT_F_PROC_VIDEO_PIXEL_FORMATTER -> MEDIA_ENT_F_VID_IF_BRIDGE
>  - Remove 'device is bound' workaround
> 
> v6:
>  - v4l2_subdev_krouting instead of v4l2_subdev_routing separated
>    to allow integration without the VC/V4L2-Mux series.
>  - convert sd_to_max9286 to inline function
>  - rename max9286_device to max9286_priv
>  - Cleanup the v4l2_async_notifier
>  - Extend MODULE_AUTHOR
>  - Replace of_graph_get_endpoint_by_regs with fwnode_graph_get_endpoint_by_id
>  - Pass default bus type when parsing fwnode endpoint (Manivannan Sadhasivam)
>  - Use new YAML file reference in MAINTAINERS
>  - Parse new i2c-mux node in max9286_get_i2c_by_id
>    (This could/should be refactored to parse these separately first)
>  - Spelling and calculation fixes in the FSYNC_LOCKED check comments
>  - Identify each enabled i2c-mux channel in a single pass
>  - max9286: Improve mux-state readbility [v2]
>  - Fix frame sync lock durations
>  - Add comment to describe /why/ we must open the mux in s_stream
>  - use -EXDEV as return code for failed link synchronisation.
>  - Fix reference counting of the dt nodeS
>  - Convert to probe_new for I2C
>  - Remove redundant max9286_i2c_mux_state
>  - Provide optional enable-gpio (max9286-pwdn)
> 
> v7:
>  [Kieran]
>  - Ensure powerdown lines are optional
>  - Add a 4ms power-up delay
>  - Add max9286_check_config_link() to core
>  - Add GPIO chip controller for GPIO0OUT and GPIO1OUT
>  - Fix GPIO registration
>  - max9286: Split out async registration
>    (fixes regulator -EPROBE_DEFERs failures)
>  - Collect all V4L2 registrations
>  - balance v4l2_async refcnting
>  - Rename max9286_v4l2_async_ => max9286_v4l2_notifier_
> 
>  [Jacopo]
>  - Remove redundanct MAXIM_I2C_SPEED macros
>  - Move notifiers operations
>  - Add delay after reverse channel reconfiguration
>  - Move link setup to completion
>  - Fix up max9286_check_config_link() implementation
>  - Remove redundant dual configuration of reverse channel
> 
> v8:
> 
> [Kieran]
>  - Update the bound_sources mask on unbind
>  - Convert probe kzalloc usage to devm_ variant
>  - Fix up cleanup path from GPIO PowerDown registration
>  - cleanup GPIO device registration fail path
>  - Convert to use devm_regulator_get()
>  - Fit max9286_parse_dt print on one line
>  - Move multi-device workarounds out of upstream driver
>  - Remove I2C mod-table
>  - Lock format changes
>  - Describe pad index usage
>  - Remove poc_enabled workaround
>  - Rename the max9286_gpio to be more explicit on it's actions.
>  - Move max9286_init_format call
>  - Rework probe sequence and simplify error paths.
>  - Simplify i2c comments
>  - Implement Pixelrate control
>  - Disable overlap window
> 
> [Jacopo]
>  - Adapt Kconfig to latest upstream changes
>  - Put of node on error
>  - Calculate pixel rate
>  - Simplify overlap window disablement
> 
> v9:
> 
> [Kieran]
>  - Kconfig: Depend on OF
>  - Re-sort addition to Makefile
> ---
>  MAINTAINERS                 |   10 +
>  drivers/media/i2c/Kconfig   |   13 +
>  drivers/media/i2c/Makefile  |    1 +
>  drivers/media/i2c/max9286.c | 1332 +++++++++++++++++++++++++++++++++++
>  4 files changed, 1356 insertions(+)
>  create mode 100644 drivers/media/i2c/max9286.c
> 
> diff --git a/MAINTAINERS b/MAINTAINERS
> index a7bb6e22d5da..99e3bf7760fd 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -10274,6 +10274,16 @@ F:	Documentation/hwmon/max6697.rst
>  F:	drivers/hwmon/max6697.c
>  F:	include/linux/platform_data/max6697.h
>  
> +MAX9286 QUAD GMSL DESERIALIZER DRIVER
> +M:	Jacopo Mondi <jacopo+renesas@jmondi.org>
> +M:	Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
> +M:	Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
> +M:	Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
> +L:	linux-media@vger.kernel.org
> +S:	Maintained
> +F:	Documentation/devicetree/bindings/media/i2c/maxim,max9286.yaml
> +F:	drivers/media/i2c/max9286.c
> +
>  MAX9860 MONO AUDIO VOICE CODEC DRIVER
>  M:	Peter Rosin <peda@axentia.se>
>  L:	alsa-devel@alsa-project.org (moderated for non-subscribers)
> diff --git a/drivers/media/i2c/Kconfig b/drivers/media/i2c/Kconfig
> index 3abc80373ec0..2e390f41f6da 100644
> --- a/drivers/media/i2c/Kconfig
> +++ b/drivers/media/i2c/Kconfig
> @@ -464,6 +464,19 @@ config VIDEO_VPX3220
>  	  To compile this driver as a module, choose M here: the
>  	  module will be called vpx3220.
>  
> +config VIDEO_MAX9286
> +	tristate "Maxim MAX9286 GMSL deserializer support"
> +	depends on I2C && I2C_MUX
> +	depends on OF
> +	select V4L2_FWNODE
> +	select VIDEO_V4L2_SUBDEV_API
> +	select MEDIA_CONTROLLER
> +	help
> +	  This driver supports the Maxim MAX9286 GMSL deserializer.
> +
> +	  To compile this driver as a module, choose M here: the
> +	  module will be called max9286.
> +
>  comment "Video and audio decoders"
>  
>  config VIDEO_SAA717X
> diff --git a/drivers/media/i2c/Makefile b/drivers/media/i2c/Makefile
> index 77bf7d0b691f..f0b001ee4b05 100644
> --- a/drivers/media/i2c/Makefile
> +++ b/drivers/media/i2c/Makefile
> @@ -117,6 +117,7 @@ obj-$(CONFIG_VIDEO_IMX274)	+= imx274.o
>  obj-$(CONFIG_VIDEO_IMX290)	+= imx290.o
>  obj-$(CONFIG_VIDEO_IMX319)	+= imx319.o
>  obj-$(CONFIG_VIDEO_IMX355)	+= imx355.o
> +obj-$(CONFIG_VIDEO_MAX9286)	+= max9286.o
>  obj-$(CONFIG_VIDEO_ST_MIPID02) += st-mipid02.o
>  
>  obj-$(CONFIG_SDR_MAX2175) += max2175.o
> diff --git a/drivers/media/i2c/max9286.c b/drivers/media/i2c/max9286.c
> new file mode 100644
> index 000000000000..481d65f2b51d
> --- /dev/null
> +++ b/drivers/media/i2c/max9286.c
> @@ -0,0 +1,1332 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/*
> + * Maxim MAX9286 GMSL Deserializer Driver
> + *
> + * Copyright (C) 2017-2019 Jacopo Mondi
> + * Copyright (C) 2017-2019 Kieran Bingham
> + * Copyright (C) 2017-2019 Laurent Pinchart
> + * Copyright (C) 2017-2019 Niklas Söderlund
> + * Copyright (C) 2016 Renesas Electronics Corporation
> + * Copyright (C) 2015 Cogent Embedded, Inc.
> + */
> +
> +#include <linux/delay.h>
> +#include <linux/device.h>
> +#include <linux/fwnode.h>
> +#include <linux/gpio/consumer.h>
> +#include <linux/gpio/driver.h>
> +#include <linux/i2c.h>
> +#include <linux/i2c-mux.h>
> +#include <linux/module.h>
> +#include <linux/mutex.h>
> +#include <linux/of_graph.h>
> +#include <linux/regulator/consumer.h>
> +#include <linux/slab.h>
> +
> +#include <media/v4l2-async.h>
> +#include <media/v4l2-ctrls.h>
> +#include <media/v4l2-device.h>
> +#include <media/v4l2-fwnode.h>
> +#include <media/v4l2-subdev.h>
> +
> +/* Register 0x00 */
> +#define MAX9286_MSTLINKSEL_AUTO		(7 << 5)
> +#define MAX9286_MSTLINKSEL(n)		((n) << 5)
> +#define MAX9286_EN_VS_GEN		BIT(4)
> +#define MAX9286_LINKEN(n)		(1 << (n))
> +/* Register 0x01 */
> +#define MAX9286_FSYNCMODE_ECU		(3 << 6)
> +#define MAX9286_FSYNCMODE_EXT		(2 << 6)
> +#define MAX9286_FSYNCMODE_INT_OUT	(1 << 6)
> +#define MAX9286_FSYNCMODE_INT_HIZ	(0 << 6)
> +#define MAX9286_GPIEN			BIT(5)
> +#define MAX9286_ENLMO_RSTFSYNC		BIT(2)
> +#define MAX9286_FSYNCMETH_AUTO		(2 << 0)
> +#define MAX9286_FSYNCMETH_SEMI_AUTO	(1 << 0)
> +#define MAX9286_FSYNCMETH_MANUAL	(0 << 0)
> +#define MAX9286_REG_FSYNC_PERIOD_L	0x06
> +#define MAX9286_REG_FSYNC_PERIOD_M	0x07
> +#define MAX9286_REG_FSYNC_PERIOD_H	0x08
> +/* Register 0x0a */
> +#define MAX9286_FWDCCEN(n)		(1 << ((n) + 4))
> +#define MAX9286_REVCCEN(n)		(1 << (n))
> +/* Register 0x0c */
> +#define MAX9286_HVEN			BIT(7)
> +#define MAX9286_EDC_6BIT_HAMMING	(2 << 5)
> +#define MAX9286_EDC_6BIT_CRC		(1 << 5)
> +#define MAX9286_EDC_1BIT_PARITY		(0 << 5)
> +#define MAX9286_DESEL			BIT(4)
> +#define MAX9286_INVVS			BIT(3)
> +#define MAX9286_INVHS			BIT(2)
> +#define MAX9286_HVSRC_D0		(2 << 0)
> +#define MAX9286_HVSRC_D14		(1 << 0)
> +#define MAX9286_HVSRC_D18		(0 << 0)
> +/* Register 0x0f */
> +#define MAX9286_0X0F_RESERVED		BIT(3)
> +/* Register 0x12 */
> +#define MAX9286_CSILANECNT(n)		(((n) - 1) << 6)
> +#define MAX9286_CSIDBL			BIT(5)
> +#define MAX9286_DBL			BIT(4)
> +#define MAX9286_DATATYPE_USER_8BIT	(11 << 0)
> +#define MAX9286_DATATYPE_USER_YUV_12BIT	(10 << 0)
> +#define MAX9286_DATATYPE_USER_24BIT	(9 << 0)
> +#define MAX9286_DATATYPE_RAW14		(8 << 0)
> +#define MAX9286_DATATYPE_RAW11		(7 << 0)
> +#define MAX9286_DATATYPE_RAW10		(6 << 0)
> +#define MAX9286_DATATYPE_RAW8		(5 << 0)
> +#define MAX9286_DATATYPE_YUV422_10BIT	(4 << 0)
> +#define MAX9286_DATATYPE_YUV422_8BIT	(3 << 0)
> +#define MAX9286_DATATYPE_RGB555		(2 << 0)
> +#define MAX9286_DATATYPE_RGB565		(1 << 0)
> +#define MAX9286_DATATYPE_RGB888		(0 << 0)
> +/* Register 0x15 */
> +#define MAX9286_VC(n)			((n) << 5)
> +#define MAX9286_VCTYPE			BIT(4)
> +#define MAX9286_CSIOUTEN		BIT(3)
> +#define MAX9286_0X15_RESV		(3 << 0)
> +/* Register 0x1b */
> +#define MAX9286_SWITCHIN(n)		(1 << ((n) + 4))
> +#define MAX9286_ENEQ(n)			(1 << (n))
> +/* Register 0x27 */
> +#define MAX9286_LOCKED			BIT(7)
> +/* Register 0x31 */
> +#define MAX9286_FSYNC_LOCKED		BIT(6)
> +/* Register 0x34 */
> +#define MAX9286_I2CLOCACK		BIT(7)
> +#define MAX9286_I2CSLVSH_1046NS_469NS	(3 << 5)
> +#define MAX9286_I2CSLVSH_938NS_352NS	(2 << 5)
> +#define MAX9286_I2CSLVSH_469NS_234NS	(1 << 5)
> +#define MAX9286_I2CSLVSH_352NS_117NS	(0 << 5)
> +#define MAX9286_I2CMSTBT_837KBPS	(7 << 2)
> +#define MAX9286_I2CMSTBT_533KBPS	(6 << 2)
> +#define MAX9286_I2CMSTBT_339KBPS	(5 << 2)
> +#define MAX9286_I2CMSTBT_173KBPS	(4 << 2)
> +#define MAX9286_I2CMSTBT_105KBPS	(3 << 2)
> +#define MAX9286_I2CMSTBT_84KBPS		(2 << 2)
> +#define MAX9286_I2CMSTBT_28KBPS		(1 << 2)
> +#define MAX9286_I2CMSTBT_8KBPS		(0 << 2)
> +#define MAX9286_I2CSLVTO_NONE		(3 << 0)
> +#define MAX9286_I2CSLVTO_1024US		(2 << 0)
> +#define MAX9286_I2CSLVTO_256US		(1 << 0)
> +#define MAX9286_I2CSLVTO_64US		(0 << 0)
> +/* Register 0x3b */
> +#define MAX9286_REV_TRF(n)		((n) << 4)
> +#define MAX9286_REV_AMP(n)		((((n) - 30) / 10) << 1) /* in mV */
> +#define MAX9286_REV_AMP_X		BIT(0)
> +/* Register 0x3f */
> +#define MAX9286_EN_REV_CFG		BIT(6)
> +#define MAX9286_REV_FLEN(n)		((n) - 20)
> +/* Register 0x49 */
> +#define MAX9286_VIDEO_DETECT_MASK	0x0f
> +/* Register 0x69 */
> +#define MAX9286_LFLTBMONMASKED		BIT(7)
> +#define MAX9286_LOCKMONMASKED		BIT(6)
> +#define MAX9286_AUTOCOMBACKEN		BIT(5)
> +#define MAX9286_AUTOMASKEN		BIT(4)
> +#define MAX9286_MASKLINK(n)		((n) << 0)
> +
> +/*
> + * The sink and source pads are created to match the OF graph port numbers so
> + * that their indexes can be used interchangeably.
> + */
> +#define MAX9286_NUM_GMSL		4
> +#define MAX9286_N_SINKS			4
> +#define MAX9286_N_PADS			5
> +#define MAX9286_SRC_PAD			4
> +
> +struct max9286_source {
> +	struct v4l2_async_subdev asd;
> +	struct v4l2_subdev *sd;
> +	struct fwnode_handle *fwnode;
> +};
> +
> +#define asd_to_max9286_source(_asd) \
> +	container_of(_asd, struct max9286_source, asd)
> +
> +struct max9286_priv {
> +	struct i2c_client *client;
> +	struct gpio_desc *gpiod_pwdn;
> +	struct v4l2_subdev sd;
> +	struct media_pad pads[MAX9286_N_PADS];
> +	struct regulator *regulator;
> +
> +	struct gpio_chip gpio;
> +	u8 gpio_state;
> +
> +	struct i2c_mux_core *mux;
> +	unsigned int mux_channel;
> +	bool mux_open;
> +
> +	struct v4l2_ctrl_handler ctrls;
> +	struct v4l2_ctrl *pixelrate;
> +
> +	struct v4l2_mbus_framefmt fmt[MAX9286_N_SINKS];
> +
> +	/* Protects controls and fmt structures */
> +	struct mutex mutex;
> +
> +	unsigned int nsources;
> +	unsigned int source_mask;
> +	unsigned int route_mask;
> +	unsigned int bound_sources;
> +	unsigned int csi2_data_lanes;
> +	struct max9286_source sources[MAX9286_NUM_GMSL];
> +	struct v4l2_async_notifier notifier;
> +};
> +
> +static struct max9286_source *next_source(struct max9286_priv *priv,
> +					  struct max9286_source *source)
> +{
> +	if (!source)
> +		source = &priv->sources[0];
> +	else
> +		source++;
> +
> +	for (; source < &priv->sources[MAX9286_NUM_GMSL]; source++) {
> +		if (source->fwnode)
> +			return source;
> +	}
> +
> +	return NULL;
> +}
> +
> +#define for_each_source(priv, source) \
> +	for ((source) = NULL; ((source) = next_source((priv), (source))); )
> +
> +#define to_index(priv, source) ((source) - &(priv)->sources[0])
> +
> +static inline struct max9286_priv *sd_to_max9286(struct v4l2_subdev *sd)
> +{
> +	return container_of(sd, struct max9286_priv, sd);
> +}
> +
> +/* -----------------------------------------------------------------------------
> + * I2C IO
> + */
> +
> +static int max9286_read(struct max9286_priv *priv, u8 reg)
> +{
> +	int ret;
> +
> +	ret = i2c_smbus_read_byte_data(priv->client, reg);
> +	if (ret < 0)
> +		dev_err(&priv->client->dev,
> +			"%s: register 0x%02x read failed (%d)\n",
> +			__func__, reg, ret);
> +
> +	return ret;
> +}
> +
> +static int max9286_write(struct max9286_priv *priv, u8 reg, u8 val)
> +{
> +	int ret;
> +
> +	ret = i2c_smbus_write_byte_data(priv->client, reg, val);
> +	if (ret < 0)
> +		dev_err(&priv->client->dev,
> +			"%s: register 0x%02x write failed (%d)\n",
> +			__func__, reg, ret);
> +
> +	return ret;
> +}
> +
> +/* -----------------------------------------------------------------------------
> + * I2C Multiplexer
> + */
> +
> +static void max9286_i2c_mux_configure(struct max9286_priv *priv, u8 conf)
> +{
> +	max9286_write(priv, 0x0a, conf);
> +
> +	/*
> +	 * We must sleep after any change to the forward or reverse channel
> +	 * configuration.
> +	 */
> +	usleep_range(3000, 5000);
> +}
> +
> +static void max9286_i2c_mux_open(struct max9286_priv *priv)
> +{
> +	/* Open all channels on the MAX9286 */
> +	max9286_i2c_mux_configure(priv, 0xff);
> +
> +	priv->mux_open = true;
> +}
> +
> +static void max9286_i2c_mux_close(struct max9286_priv *priv)
> +{
> +	/*
> +	 * Ensure that both the forward and reverse channel are disabled on the
> +	 * mux, and that the channel ID is invalidated to ensure we reconfigure
> +	 * on the next max9286_i2c_mux_select() call.
> +	 */
> +	max9286_i2c_mux_configure(priv, 0x00);
> +
> +	priv->mux_open = false;
> +	priv->mux_channel = -1;
> +}
> +
> +static int max9286_i2c_mux_select(struct i2c_mux_core *muxc, u32 chan)
> +{
> +	struct max9286_priv *priv = i2c_mux_priv(muxc);
> +
> +	/* Channel select is disabled when configured in the opened state. */
> +	if (priv->mux_open)
> +		return 0;
> +
> +	if (priv->mux_channel == chan)
> +		return 0;
> +
> +	priv->mux_channel = chan;
> +
> +	max9286_i2c_mux_configure(priv,
> +				  MAX9286_FWDCCEN(chan) |
> +				  MAX9286_REVCCEN(chan));
> +
> +	return 0;
> +}
> +
> +static int max9286_i2c_mux_init(struct max9286_priv *priv)
> +{
> +	struct max9286_source *source;
> +	int ret;
> +
> +	if (!i2c_check_functionality(priv->client->adapter,
> +				     I2C_FUNC_SMBUS_WRITE_BYTE_DATA))
> +		return -ENODEV;
> +
> +	priv->mux = i2c_mux_alloc(priv->client->adapter, &priv->client->dev,
> +				  priv->nsources, 0, I2C_MUX_LOCKED,
> +				  max9286_i2c_mux_select, NULL);
> +	if (!priv->mux)
> +		return -ENOMEM;
> +
> +	priv->mux->priv = priv;
> +
> +	for_each_source(priv, source) {
> +		unsigned int index = to_index(priv, source);
> +
> +		ret = i2c_mux_add_adapter(priv->mux, 0, index, 0);
> +		if (ret < 0)
> +			goto error;
> +	}
> +
> +	return 0;
> +
> +error:
> +	i2c_mux_del_adapters(priv->mux);
> +	return ret;
> +}
> +
> +static void max9286_configure_i2c(struct max9286_priv *priv, bool localack)
> +{
> +	u8 config = MAX9286_I2CSLVSH_469NS_234NS | MAX9286_I2CSLVTO_1024US |
> +		    MAX9286_I2CMSTBT_105KBPS;
> +
> +	if (localack)
> +		config |= MAX9286_I2CLOCACK;
> +
> +	max9286_write(priv, 0x34, config);
> +	usleep_range(3000, 5000);
> +}
> +
> +/*
> + * max9286_check_video_links() - Make sure video links are detected and locked
> + *
> + * Performs safety checks on video link status. Make sure they are detected
> + * and all enabled links are locked.
> + *
> + * Returns 0 for success, -EIO for errors.
> + */
> +static int max9286_check_video_links(struct max9286_priv *priv)
> +{
> +	unsigned int i;
> +	int ret;
> +
> +	/*
> +	 * Make sure valid video links are detected.
> +	 * The delay is not characterized in de-serializer manual, wait up
> +	 * to 5 ms.
> +	 */
> +	for (i = 0; i < 10; i++) {
> +		ret = max9286_read(priv, 0x49);
> +		if (ret < 0)
> +			return -EIO;
> +
> +		if ((ret & MAX9286_VIDEO_DETECT_MASK) == priv->source_mask)
> +			break;
> +
> +		usleep_range(350, 500);
> +	}
> +
> +	if (i == 10) {
> +		dev_err(&priv->client->dev,
> +			"Unable to detect video links: 0x%02x\n", ret);
> +		return -EIO;
> +	}
> +
> +	/* Make sure all enabled links are locked (4ms max). */
> +	for (i = 0; i < 10; i++) {
> +		ret = max9286_read(priv, 0x27);
> +		if (ret < 0)
> +			return -EIO;
> +
> +		if (ret & MAX9286_LOCKED)
> +			break;
> +
> +		usleep_range(350, 450);
> +	}
> +
> +	if (i == 10) {
> +		dev_err(&priv->client->dev, "Not all enabled links locked\n");
> +		return -EIO;
> +	}
> +
> +	return 0;
> +}
> +
> +/*
> + * max9286_check_config_link() - Detect and wait for configuration links
> + *
> + * Determine if the configuration channel is up and settled for a link.
> + *
> + * Returns 0 for success, -EIO for errors.
> + */
> +static int max9286_check_config_link(struct max9286_priv *priv,
> +				     unsigned int source_mask)
> +{
> +	unsigned int conflink_mask = (source_mask & 0x0f) << 4;
> +	unsigned int i;
> +	int ret;
> +
> +	/*
> +	 * Make sure requested configuration links are detected.
> +	 * The delay is not characterized in the chip manual: wait up
> +	 * to 5 milliseconds.
> +	 */
> +	for (i = 0; i < 10; i++) {
> +		ret = max9286_read(priv, 0x49) & 0xf0;
> +		if (ret < 0)
> +			return -EIO;
> +
> +		if (ret == conflink_mask)
> +			break;
> +
> +		usleep_range(350, 500);
> +	}
> +
> +	if (ret != conflink_mask) {
> +		dev_err(&priv->client->dev,
> +			"Unable to detect configuration links: 0x%02x expected 0x%02x\n",
> +			ret, conflink_mask);
> +		return -EIO;
> +	}
> +
> +	dev_info(&priv->client->dev,
> +		 "Successfully detected configuration links after %u loops: 0x%02x\n",
> +		 i, conflink_mask);
> +
> +	return 0;
> +}
> +
> +/* -----------------------------------------------------------------------------
> + * V4L2 Subdev
> + */
> +
> +static int max9286_set_pixelrate(struct max9286_priv *priv)
> +{
> +	struct max9286_source *source = NULL;
> +	u64 pixelrate = 0;
> +
> +	for_each_source(priv, source) {
> +		struct v4l2_ctrl *ctrl;
> +		u64 source_rate = 0;
> +
> +		/* Pixel rate is mandatory to be reported by sources. */
> +		ctrl = v4l2_ctrl_find(source->sd->ctrl_handler,
> +				      V4L2_CID_PIXEL_RATE);
> +		if (!ctrl) {
> +			pixelrate = 0;
> +			break;
> +		}
> +
> +		/* All source must report the same pixel rate. */
> +		source_rate = v4l2_ctrl_g_ctrl_int64(ctrl);
> +		if (!pixelrate) {
> +			pixelrate = source_rate;
> +		} else if (pixelrate != source_rate) {
> +			dev_err(&priv->client->dev,
> +				"Unable to calculate pixel rate\n");
> +			return -EINVAL;
> +		}
> +	}
> +
> +	if (!pixelrate) {
> +		dev_err(&priv->client->dev,
> +			"No pixel rate control available in sources\n");
> +		return -EINVAL;
> +	}
> +
> +	/*
> +	 * The CSI-2 transmitter pixel rate is the single source rate multiplied
> +	 * by the number of available sources.
> +	 */
> +	return v4l2_ctrl_s_ctrl_int64(priv->pixelrate,
> +				      pixelrate * priv->nsources);
> +}
> +
> +static int max9286_notify_bound(struct v4l2_async_notifier *notifier,
> +				struct v4l2_subdev *subdev,
> +				struct v4l2_async_subdev *asd)
> +{
> +	struct max9286_priv *priv = sd_to_max9286(notifier->sd);
> +	struct max9286_source *source = asd_to_max9286_source(asd);
> +	unsigned int index = to_index(priv, source);
> +	unsigned int src_pad;
> +	int ret;
> +
> +	ret = media_entity_get_fwnode_pad(&subdev->entity,
> +					  source->fwnode,
> +					  MEDIA_PAD_FL_SOURCE);
> +	if (ret < 0) {
> +		dev_err(&priv->client->dev,
> +			"Failed to find pad for %s\n", subdev->name);
> +		return ret;
> +	}
> +
> +	priv->bound_sources |= BIT(index);
> +	source->sd = subdev;
> +	src_pad = ret;
> +
> +	ret = media_create_pad_link(&source->sd->entity, src_pad,
> +				    &priv->sd.entity, index,
> +				    MEDIA_LNK_FL_ENABLED |
> +				    MEDIA_LNK_FL_IMMUTABLE);
> +	if (ret) {
> +		dev_err(&priv->client->dev,
> +			"Unable to link %s:%u -> %s:%u\n",
> +			source->sd->name, src_pad, priv->sd.name, index);
> +		return ret;
> +	}
> +
> +	dev_dbg(&priv->client->dev, "Bound %s pad: %u on index %u\n",
> +		subdev->name, src_pad, index);
> +
> +	/*
> +	 * We can only register v4l2_async_notifiers, which do not provide a
> +	 * means to register a complete callback. bound_sources allows us to
> +	 * identify when all remote serializers have completed their probe.
> +	 */
> +	if (priv->bound_sources != priv->source_mask)
> +		return 0;
> +
> +	/*
> +	 * All enabled sources have probed and enabled their reverse control
> +	 * channels:
> +	 *
> +	 * - Verify all configuration links are properly detected
> +	 * - Disable auto-ack as communication on the control channel are now
> +	 *   stable.
> +	 */
> +	max9286_check_config_link(priv, priv->source_mask);
> +
> +	/*
> +	 * Re-configure I2C with local acknowledge disabled after cameras have
> +	 * probed.
> +	 */
> +	max9286_configure_i2c(priv, false);
> +
> +	return max9286_set_pixelrate(priv);
> +}
> +
> +static void max9286_notify_unbind(struct v4l2_async_notifier *notifier,
> +				  struct v4l2_subdev *subdev,
> +				  struct v4l2_async_subdev *asd)
> +{
> +	struct max9286_priv *priv = sd_to_max9286(notifier->sd);
> +	struct max9286_source *source = asd_to_max9286_source(asd);
> +	unsigned int index = to_index(priv, source);
> +
> +	source->sd = NULL;
> +	priv->bound_sources &= ~BIT(index);
> +}
> +
> +static const struct v4l2_async_notifier_operations max9286_notify_ops = {
> +	.bound = max9286_notify_bound,
> +	.unbind = max9286_notify_unbind,
> +};
> +
> +static int max9286_v4l2_notifier_register(struct max9286_priv *priv)
> +{
> +	struct device *dev = &priv->client->dev;
> +	struct max9286_source *source = NULL;
> +	int ret;
> +
> +	if (!priv->nsources)
> +		return 0;
> +
> +	v4l2_async_notifier_init(&priv->notifier);
> +
> +	for_each_source(priv, source) {
> +		unsigned int i = to_index(priv, source);
> +
> +		source->asd.match_type = V4L2_ASYNC_MATCH_FWNODE;
> +		source->asd.match.fwnode = source->fwnode;
> +
> +		ret = v4l2_async_notifier_add_subdev(&priv->notifier,
> +						     &source->asd);
> +		if (ret) {
> +			dev_err(dev, "Failed to add subdev for source %d", i);
> +			v4l2_async_notifier_cleanup(&priv->notifier);
> +			return ret;
> +		}
> +
> +		/*
> +		 * Balance the reference counting handled through
> +		 * v4l2_async_notifier_cleanup()
> +		 */
> +		fwnode_handle_get(source->fwnode);
> +	}
> +
> +	priv->notifier.ops = &max9286_notify_ops;
> +
> +	ret = v4l2_async_subdev_notifier_register(&priv->sd, &priv->notifier);
> +	if (ret) {
> +		dev_err(dev, "Failed to register subdev_notifier");
> +		v4l2_async_notifier_cleanup(&priv->notifier);
> +		return ret;
> +	}
> +
> +	return 0;
> +}
> +
> +static void max9286_v4l2_notifier_unregister(struct max9286_priv *priv)
> +{
> +	if (!priv->nsources)
> +		return;
> +
> +	v4l2_async_notifier_unregister(&priv->notifier);
> +	v4l2_async_notifier_cleanup(&priv->notifier);
> +}
> +
> +static int max9286_s_stream(struct v4l2_subdev *sd, int enable)
> +{
> +	struct max9286_priv *priv = sd_to_max9286(sd);
> +	struct max9286_source *source;
> +	unsigned int i;
> +	bool sync = false;
> +	int ret;
> +
> +	if (enable) {
> +		/*
> +		 * The frame sync between cameras is transmitted across the
> +		 * reverse channel as GPIO. We must open all channels while
> +		 * streaming to allow this synchronisation signal to be shared.
> +		 */
> +		max9286_i2c_mux_open(priv);
> +
> +		/* Start all cameras. */
> +		for_each_source(priv, source) {
> +			ret = v4l2_subdev_call(source->sd, video, s_stream, 1);
> +			if (ret)
> +				return ret;
> +		}
> +
> +		ret = max9286_check_video_links(priv);
> +		if (ret)
> +			return ret;
> +
> +		/*
> +		 * Wait until frame synchronization is locked.
> +		 *
> +		 * Manual says frame sync locking should take ~6 VTS.
> +		 * From practical experience at least 8 are required. Give
> +		 * 12 complete frames time (~400ms at 30 fps) to achieve frame
> +		 * locking before returning error.
> +		 */
> +		for (i = 0; i < 40; i++) {
> +			if (max9286_read(priv, 0x31) & MAX9286_FSYNC_LOCKED) {
> +				sync = true;
> +				break;
> +			}
> +			usleep_range(9000, 11000);
> +		}
> +
> +		if (!sync) {
> +			dev_err(&priv->client->dev,
> +				"Failed to get frame synchronization\n");
> +			return -EXDEV; /* Invalid cross-device link */
> +		}
> +
> +		/*
> +		 * Enable CSI output, VC set according to link number.
> +		 * Bit 7 must be set (chip manual says it's 0 and reserved).
> +		 */
> +		max9286_write(priv, 0x15, 0x80 | MAX9286_VCTYPE |
> +			      MAX9286_CSIOUTEN | MAX9286_0X15_RESV);
> +	} else {
> +		max9286_write(priv, 0x15, MAX9286_VCTYPE | MAX9286_0X15_RESV);
> +
> +		/* Stop all cameras. */
> +		for_each_source(priv, source)
> +			v4l2_subdev_call(source->sd, video, s_stream, 0);
> +
> +		max9286_i2c_mux_close(priv);
> +	}
> +
> +	return 0;
> +}
> +
> +static int max9286_enum_mbus_code(struct v4l2_subdev *sd,
> +				  struct v4l2_subdev_pad_config *cfg,
> +				  struct v4l2_subdev_mbus_code_enum *code)
> +{
> +	if (code->pad || code->index > 0)
> +		return -EINVAL;
> +
> +	code->code = MEDIA_BUS_FMT_UYVY8_2X8;
> +
> +	return 0;
> +}
> +
> +static struct v4l2_mbus_framefmt *
> +max9286_get_pad_format(struct max9286_priv *priv,
> +		       struct v4l2_subdev_pad_config *cfg,
> +		       unsigned int pad, u32 which)
> +{
> +	switch (which) {
> +	case V4L2_SUBDEV_FORMAT_TRY:
> +		return v4l2_subdev_get_try_format(&priv->sd, cfg, pad);
> +	case V4L2_SUBDEV_FORMAT_ACTIVE:
> +		return &priv->fmt[pad];
> +	default:
> +		return NULL;
> +	}
> +}
> +
> +static int max9286_set_fmt(struct v4l2_subdev *sd,
> +			   struct v4l2_subdev_pad_config *cfg,
> +			   struct v4l2_subdev_format *format)
> +{
> +	struct max9286_priv *priv = sd_to_max9286(sd);
> +	struct v4l2_mbus_framefmt *cfg_fmt;
> +
> +	if (format->pad >= MAX9286_SRC_PAD)
> +		return -EINVAL;
> +
> +	/* Refuse non YUV422 formats as we hardcode DT to 8 bit YUV422 */
> +	switch (format->format.code) {
> +	case MEDIA_BUS_FMT_UYVY8_2X8:
> +	case MEDIA_BUS_FMT_VYUY8_2X8:
> +	case MEDIA_BUS_FMT_YUYV8_2X8:
> +	case MEDIA_BUS_FMT_YVYU8_2X8:
> +		break;
> +	default:
> +		format->format.code = MEDIA_BUS_FMT_YUYV8_2X8;

Is there any reason for not setting default format to MEDIA_BUS_FMT_UYVY8_2X8?

Thanks,
Mani

> +		break;
> +	}
> +
> +	cfg_fmt = max9286_get_pad_format(priv, cfg, format->pad, format->which);
> +	if (!cfg_fmt)
> +		return -EINVAL;
> +
> +	mutex_lock(&priv->mutex);
> +	*cfg_fmt = format->format;
> +	mutex_unlock(&priv->mutex);
> +
> +	return 0;
> +}
> +
> +static int max9286_get_fmt(struct v4l2_subdev *sd,
> +			   struct v4l2_subdev_pad_config *cfg,
> +			   struct v4l2_subdev_format *format)
> +{
> +	struct max9286_priv *priv = sd_to_max9286(sd);
> +	struct v4l2_mbus_framefmt *cfg_fmt;
> +
> +	if (format->pad >= MAX9286_SRC_PAD)
> +		return -EINVAL;
> +
> +	cfg_fmt = max9286_get_pad_format(priv, cfg, format->pad, format->which);
> +	if (!cfg_fmt)
> +		return -EINVAL;
> +
> +	mutex_lock(&priv->mutex);
> +	format->format = *cfg_fmt;
> +	mutex_unlock(&priv->mutex);
> +
> +	return 0;
> +}
> +
> +static const struct v4l2_subdev_video_ops max9286_video_ops = {
> +	.s_stream	= max9286_s_stream,
> +};
> +
> +static const struct v4l2_subdev_pad_ops max9286_pad_ops = {
> +	.enum_mbus_code = max9286_enum_mbus_code,
> +	.get_fmt	= max9286_get_fmt,
> +	.set_fmt	= max9286_set_fmt,
> +};
> +
> +static const struct v4l2_subdev_ops max9286_subdev_ops = {
> +	.video		= &max9286_video_ops,
> +	.pad		= &max9286_pad_ops,
> +};
> +
> +static void max9286_init_format(struct v4l2_mbus_framefmt *fmt)
> +{
> +	fmt->width		= 1280;
> +	fmt->height		= 800;
> +	fmt->code		= MEDIA_BUS_FMT_UYVY8_2X8;
> +	fmt->colorspace		= V4L2_COLORSPACE_SRGB;
> +	fmt->field		= V4L2_FIELD_NONE;
> +	fmt->ycbcr_enc		= V4L2_YCBCR_ENC_DEFAULT;
> +	fmt->quantization	= V4L2_QUANTIZATION_DEFAULT;
> +	fmt->xfer_func		= V4L2_XFER_FUNC_DEFAULT;
> +}
> +
> +static int max9286_open(struct v4l2_subdev *subdev, struct v4l2_subdev_fh *fh)
> +{
> +	struct v4l2_mbus_framefmt *format;
> +	unsigned int i;
> +
> +	for (i = 0; i < MAX9286_N_SINKS; i++) {
> +		format = v4l2_subdev_get_try_format(subdev, fh->pad, i);
> +		max9286_init_format(format);
> +	}
> +
> +	return 0;
> +}
> +
> +static const struct v4l2_subdev_internal_ops max9286_subdev_internal_ops = {
> +	.open = max9286_open,
> +};
> +
> +static int max9286_s_ctrl(struct v4l2_ctrl *ctrl)
> +{
> +	switch (ctrl->id) {
> +	case V4L2_CID_PIXEL_RATE:
> +		return 0;
> +	default:
> +		return -EINVAL;
> +	}
> +}
> +
> +static const struct v4l2_ctrl_ops max9286_ctrl_ops = {
> +	.s_ctrl	= max9286_s_ctrl,
> +};
> +
> +static int max9286_v4l2_register(struct max9286_priv *priv)
> +{
> +	struct device *dev = &priv->client->dev;
> +	struct fwnode_handle *ep;
> +	int ret;
> +	int i;
> +
> +	/* Register v4l2 async notifiers for connected Camera subdevices */
> +	ret = max9286_v4l2_notifier_register(priv);
> +	if (ret) {
> +		dev_err(dev, "Unable to register V4L2 async notifiers\n");
> +		return ret;
> +	}
> +
> +	/* Configure V4L2 for the MAX9286 itself */
> +
> +	for (i = 0; i < MAX9286_N_SINKS; i++)
> +		max9286_init_format(&priv->fmt[i]);
> +
> +	v4l2_i2c_subdev_init(&priv->sd, priv->client, &max9286_subdev_ops);
> +	priv->sd.internal_ops = &max9286_subdev_internal_ops;
> +	priv->sd.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;
> +
> +	v4l2_ctrl_handler_init(&priv->ctrls, 1);
> +	priv->pixelrate = v4l2_ctrl_new_std(&priv->ctrls,
> +					    &max9286_ctrl_ops,
> +					    V4L2_CID_PIXEL_RATE,
> +					    1, INT_MAX, 1, 50000000);
> +
> +	priv->sd.ctrl_handler = &priv->ctrls;
> +	ret = priv->ctrls.error;
> +	if (ret)
> +		goto err_async;
> +
> +	priv->sd.entity.function = MEDIA_ENT_F_VID_IF_BRIDGE;
> +
> +	priv->pads[MAX9286_SRC_PAD].flags = MEDIA_PAD_FL_SOURCE;
> +	for (i = 0; i < MAX9286_SRC_PAD; i++)
> +		priv->pads[i].flags = MEDIA_PAD_FL_SINK;
> +	ret = media_entity_pads_init(&priv->sd.entity, MAX9286_N_PADS,
> +				     priv->pads);
> +	if (ret)
> +		goto err_async;
> +
> +	ep = fwnode_graph_get_endpoint_by_id(dev_fwnode(dev), MAX9286_SRC_PAD,
> +					     0, 0);
> +	if (!ep) {
> +		dev_err(dev, "Unable to retrieve endpoint on \"port@4\"\n");
> +		ret = -ENOENT;
> +		goto err_async;
> +	}
> +	priv->sd.fwnode = ep;
> +
> +	ret = v4l2_async_register_subdev(&priv->sd);
> +	if (ret < 0) {
> +		dev_err(dev, "Unable to register subdevice\n");
> +		goto err_put_node;
> +	}
> +
> +	return 0;
> +
> +err_put_node:
> +	fwnode_handle_put(ep);
> +err_async:
> +	max9286_v4l2_notifier_unregister(priv);
> +
> +	return ret;
> +}
> +
> +static void max9286_v4l2_unregister(struct max9286_priv *priv)
> +{
> +	fwnode_handle_put(priv->sd.fwnode);
> +	v4l2_async_unregister_subdev(&priv->sd);
> +	max9286_v4l2_notifier_unregister(priv);
> +}
> +
> +/* -----------------------------------------------------------------------------
> + * Probe/Remove
> + */
> +
> +static int max9286_setup(struct max9286_priv *priv)
> +{
> +	/*
> +	 * Link ordering values for all enabled links combinations. Orders must
> +	 * be assigned sequentially from 0 to the number of enabled links
> +	 * without leaving any hole for disabled links. We thus assign orders to
> +	 * enabled links first, and use the remaining order values for disabled
> +	 * links are all links must have a different order value;
> +	 */
> +	static const u8 link_order[] = {
> +		(3 << 6) | (2 << 4) | (1 << 2) | (0 << 0), /* xxxx */
> +		(3 << 6) | (2 << 4) | (1 << 2) | (0 << 0), /* xxx0 */
> +		(3 << 6) | (2 << 4) | (0 << 2) | (1 << 0), /* xx0x */
> +		(3 << 6) | (2 << 4) | (1 << 2) | (0 << 0), /* xx10 */
> +		(3 << 6) | (0 << 4) | (2 << 2) | (1 << 0), /* x0xx */
> +		(3 << 6) | (1 << 4) | (2 << 2) | (0 << 0), /* x1x0 */
> +		(3 << 6) | (1 << 4) | (0 << 2) | (2 << 0), /* x10x */
> +		(3 << 6) | (1 << 4) | (1 << 2) | (0 << 0), /* x210 */
> +		(0 << 6) | (3 << 4) | (2 << 2) | (1 << 0), /* 0xxx */
> +		(1 << 6) | (3 << 4) | (2 << 2) | (0 << 0), /* 1xx0 */
> +		(1 << 6) | (3 << 4) | (0 << 2) | (2 << 0), /* 1x0x */
> +		(2 << 6) | (3 << 4) | (1 << 2) | (0 << 0), /* 2x10 */
> +		(1 << 6) | (0 << 4) | (3 << 2) | (2 << 0), /* 10xx */
> +		(2 << 6) | (1 << 4) | (3 << 2) | (0 << 0), /* 21x0 */
> +		(2 << 6) | (1 << 4) | (0 << 2) | (3 << 0), /* 210x */
> +		(3 << 6) | (2 << 4) | (1 << 2) | (0 << 0), /* 3210 */
> +	};
> +
> +	/*
> +	 * Set the I2C bus speed.
> +	 *
> +	 * Enable I2C Local Acknowledge during the probe sequences of the camera
> +	 * only. This should be disabled after the mux is initialised.
> +	 */
> +	max9286_configure_i2c(priv, true);
> +
> +	/*
> +	 * Reverse channel setup.
> +	 *
> +	 * - Enable custom reverse channel configuration (through register 0x3f)
> +	 *   and set the first pulse length to 35 clock cycles.
> +	 * - Increase the reverse channel amplitude to 170mV to accommodate the
> +	 *   high threshold enabled by the serializer driver.
> +	 */
> +	max9286_write(priv, 0x3f, MAX9286_EN_REV_CFG | MAX9286_REV_FLEN(35));
> +	max9286_write(priv, 0x3b, MAX9286_REV_TRF(1) | MAX9286_REV_AMP(70) |
> +		      MAX9286_REV_AMP_X);
> +	usleep_range(2000, 2500);
> +
> +	/*
> +	 * Enable GMSL links, mask unused ones and autodetect link
> +	 * used as CSI clock source.
> +	 */
> +	max9286_write(priv, 0x00, MAX9286_MSTLINKSEL_AUTO | priv->route_mask);
> +	max9286_write(priv, 0x0b, link_order[priv->route_mask]);
> +	max9286_write(priv, 0x69, (0xf & ~priv->route_mask));
> +
> +	/*
> +	 * Video format setup:
> +	 * Disable CSI output, VC is set according to Link number.
> +	 */
> +	max9286_write(priv, 0x15, MAX9286_VCTYPE | MAX9286_0X15_RESV);
> +
> +	/* Enable CSI-2 Lane D0-D3 only, DBL mode, YUV422 8-bit. */
> +	max9286_write(priv, 0x12, MAX9286_CSIDBL | MAX9286_DBL |
> +		      MAX9286_CSILANECNT(priv->csi2_data_lanes) |
> +		      MAX9286_DATATYPE_YUV422_8BIT);
> +
> +	/* Automatic: FRAMESYNC taken from the slowest Link. */
> +	max9286_write(priv, 0x01, MAX9286_FSYNCMODE_INT_HIZ |
> +		      MAX9286_FSYNCMETH_AUTO);
> +
> +	/* Enable HS/VS encoding, use D14/15 for HS/VS, invert VS. */
> +	max9286_write(priv, 0x0c, MAX9286_HVEN | MAX9286_INVVS |
> +		      MAX9286_HVSRC_D14);
> +
> +	/*
> +	 * The overlap window seems to provide additional validation by tracking
> +	 * the delay between vsync and frame sync, generating an error if the
> +	 * delay is bigger than the programmed window, though it's not yet clear
> +	 * what value should be set.
> +	 *
> +	 * As it's an optional value and can be disabled, we do so by setting
> +	 * a 0 overlap value.
> +	 */
> +	max9286_write(priv, 0x63, 0);
> +	max9286_write(priv, 0x64, 0);
> +
> +	/*
> +	 * Wait for 2ms to allow the link to resynchronize after the
> +	 * configuration change.
> +	 */
> +	usleep_range(2000, 5000);
> +
> +	return 0;
> +}
> +
> +static void max9286_gpio_set(struct gpio_chip *chip,
> +			     unsigned int offset, int value)
> +{
> +	struct max9286_priv *priv = gpiochip_get_data(chip);
> +
> +	if (value)
> +		priv->gpio_state |= BIT(offset);
> +	else
> +		priv->gpio_state &= ~BIT(offset);
> +
> +	max9286_write(priv, 0x0f, MAX9286_0X0F_RESERVED | priv->gpio_state);
> +}
> +
> +static int max9286_gpio_get(struct gpio_chip *chip, unsigned int offset)
> +{
> +	struct max9286_priv *priv = gpiochip_get_data(chip);
> +
> +	return priv->gpio_state & BIT(offset);
> +}
> +
> +static int max9286_register_gpio(struct max9286_priv *priv)
> +{
> +	struct device *dev = &priv->client->dev;
> +	struct gpio_chip *gpio = &priv->gpio;
> +	int ret;
> +
> +	static const char * const names[] = {
> +		"GPIO0OUT",
> +		"GPIO1OUT",
> +	};
> +
> +	/* Configure the GPIO */
> +	gpio->label = dev_name(dev);
> +	gpio->parent = dev;
> +	gpio->owner = THIS_MODULE;
> +	gpio->of_node = dev->of_node;
> +	gpio->ngpio = 2;
> +	gpio->base = -1;
> +	gpio->set = max9286_gpio_set;
> +	gpio->get = max9286_gpio_get;
> +	gpio->can_sleep = true;
> +	gpio->names = names;
> +
> +	/* GPIO values default to high */
> +	priv->gpio_state = BIT(0) | BIT(1);
> +
> +	ret = devm_gpiochip_add_data(dev, gpio, priv);
> +	if (ret)
> +		dev_err(dev, "Unable to create gpio_chip\n");
> +
> +	return ret;
> +}
> +
> +static int max9286_init(struct device *dev)
> +{
> +	struct max9286_priv *priv;
> +	struct i2c_client *client;
> +	int ret;
> +
> +	client = to_i2c_client(dev);
> +	priv = i2c_get_clientdata(client);
> +
> +	/* Enable the bus power. */
> +	ret = regulator_enable(priv->regulator);
> +	if (ret < 0) {
> +		dev_err(&client->dev, "Unable to turn PoC on\n");
> +		return ret;
> +	}
> +
> +	ret = max9286_setup(priv);
> +	if (ret) {
> +		dev_err(dev, "Unable to setup max9286\n");
> +		goto err_regulator;
> +	}
> +
> +	/*
> +	 * Register all V4L2 interactions for the MAX9286 and notifiers for
> +	 * any subdevices connected.
> +	 */
> +	ret = max9286_v4l2_register(priv);
> +	if (ret) {
> +		dev_err(dev, "Failed to register with V4L2\n");
> +		goto err_regulator;
> +	}
> +
> +	ret = max9286_i2c_mux_init(priv);
> +	if (ret) {
> +		dev_err(dev, "Unable to initialize I2C multiplexer\n");
> +		goto err_v4l2_register;
> +	}
> +
> +	/* Leave the mux channels disabled until they are selected. */
> +	max9286_i2c_mux_close(priv);
> +
> +	return 0;
> +
> +err_v4l2_register:
> +	max9286_v4l2_unregister(priv);
> +err_regulator:
> +	regulator_disable(priv->regulator);
> +
> +	return ret;
> +}
> +
> +static void max9286_cleanup_dt(struct max9286_priv *priv)
> +{
> +	struct max9286_source *source;
> +
> +	for_each_source(priv, source) {
> +		fwnode_handle_put(source->fwnode);
> +		source->fwnode = NULL;
> +	}
> +}
> +
> +static int max9286_parse_dt(struct max9286_priv *priv)
> +{
> +	struct device *dev = &priv->client->dev;
> +	struct device_node *i2c_mux;
> +	struct device_node *node = NULL;
> +	unsigned int i2c_mux_mask = 0;
> +
> +	of_node_get(dev->of_node);
> +	i2c_mux = of_find_node_by_name(dev->of_node, "i2c-mux");
> +	if (!i2c_mux) {
> +		dev_err(dev, "Failed to find i2c-mux node\n");
> +		of_node_put(dev->of_node);
> +		return -EINVAL;
> +	}
> +
> +	/* Identify which i2c-mux channels are enabled */
> +	for_each_child_of_node(i2c_mux, node) {
> +		u32 id = 0;
> +
> +		of_property_read_u32(node, "reg", &id);
> +		if (id >= MAX9286_NUM_GMSL)
> +			continue;
> +
> +		if (!of_device_is_available(node)) {
> +			dev_dbg(dev, "Skipping disabled I2C bus port %u\n", id);
> +			continue;
> +		}
> +
> +		i2c_mux_mask |= BIT(id);
> +	}
> +	of_node_put(node);
> +	of_node_put(i2c_mux);
> +
> +	/* Parse the endpoints */
> +	for_each_endpoint_of_node(dev->of_node, node) {
> +		struct max9286_source *source;
> +		struct of_endpoint ep;
> +
> +		of_graph_parse_endpoint(node, &ep);
> +		dev_dbg(dev, "Endpoint %pOF on port %d",
> +			ep.local_node, ep.port);
> +
> +		if (ep.port > MAX9286_NUM_GMSL) {
> +			dev_err(dev, "Invalid endpoint %s on port %d",
> +				of_node_full_name(ep.local_node), ep.port);
> +			continue;
> +		}
> +
> +		/* For the source endpoint just parse the bus configuration. */
> +		if (ep.port == MAX9286_SRC_PAD) {
> +			struct v4l2_fwnode_endpoint vep = {
> +				.bus_type = V4L2_MBUS_CSI2_DPHY
> +			};
> +			int ret;
> +
> +			ret = v4l2_fwnode_endpoint_parse(
> +					of_fwnode_handle(node), &vep);
> +			if (ret) {
> +				of_node_put(node);
> +				of_node_put(dev->of_node);
> +				return ret;
> +			}
> +
> +			if (vep.bus_type != V4L2_MBUS_CSI2_DPHY) {
> +				dev_err(dev,
> +					"Media bus %u type not supported\n",
> +					vep.bus_type);
> +				v4l2_fwnode_endpoint_free(&vep);
> +				of_node_put(node);
> +				of_node_put(dev->of_node);
> +				return -EINVAL;
> +			}
> +
> +			priv->csi2_data_lanes =
> +				vep.bus.mipi_csi2.num_data_lanes;
> +			v4l2_fwnode_endpoint_free(&vep);
> +
> +			continue;
> +		}
> +
> +		/* Skip if the corresponding GMSL link is unavailable. */
> +		if (!(i2c_mux_mask & BIT(ep.port)))
> +			continue;
> +
> +		if (priv->sources[ep.port].fwnode) {
> +			dev_err(dev,
> +				"Multiple port endpoints are not supported: %d",
> +				ep.port);
> +
> +			continue;
> +		}
> +
> +		source = &priv->sources[ep.port];
> +		source->fwnode = fwnode_graph_get_remote_endpoint(
> +						of_fwnode_handle(node));
> +		if (!source->fwnode) {
> +			dev_err(dev,
> +				"Endpoint %pOF has no remote endpoint connection\n",
> +				ep.local_node);
> +
> +			continue;
> +		}
> +
> +		priv->source_mask |= BIT(ep.port);
> +		priv->nsources++;
> +	}
> +	of_node_put(node);
> +	of_node_put(dev->of_node);
> +
> +	priv->route_mask = priv->source_mask;
> +
> +	return 0;
> +}
> +
> +static int max9286_probe(struct i2c_client *client)
> +{
> +	struct max9286_priv *priv;
> +	int ret;
> +
> +	priv = devm_kzalloc(&client->dev, sizeof(*priv), GFP_KERNEL);
> +	if (!priv)
> +		return -ENOMEM;
> +
> +	mutex_init(&priv->mutex);
> +
> +	priv->client = client;
> +	i2c_set_clientdata(client, priv);
> +
> +	priv->gpiod_pwdn = devm_gpiod_get_optional(&client->dev, "enable",
> +						   GPIOD_OUT_HIGH);
> +	if (IS_ERR(priv->gpiod_pwdn))
> +		return PTR_ERR(priv->gpiod_pwdn);
> +
> +	gpiod_set_consumer_name(priv->gpiod_pwdn, "max9286-pwdn");
> +	gpiod_set_value_cansleep(priv->gpiod_pwdn, 1);
> +
> +	/* Wait at least 4ms before the I2C lines latch to the address */
> +	if (priv->gpiod_pwdn)
> +		usleep_range(4000, 5000);
> +
> +	/*
> +	 * The MAX9286 starts by default with all ports enabled, we disable all
> +	 * ports early to ensure that all channels are disabled if we error out
> +	 * and keep the bus consistent.
> +	 */
> +	max9286_i2c_mux_close(priv);
> +
> +	/*
> +	 * The MAX9286 initialises with auto-acknowledge enabled by default.
> +	 * This can be invasive to other transactions on the same bus, so
> +	 * disable it early. It will be enabled only as and when needed.
> +	 */
> +	max9286_configure_i2c(priv, false);
> +
> +	ret = max9286_register_gpio(priv);
> +	if (ret)
> +		goto err_powerdown;
> +
> +	priv->regulator = devm_regulator_get(&client->dev, "poc");
> +	if (IS_ERR(priv->regulator)) {
> +		if (PTR_ERR(priv->regulator) != -EPROBE_DEFER)
> +			dev_err(&client->dev,
> +				"Unable to get PoC regulator (%ld)\n",
> +				PTR_ERR(priv->regulator));
> +		ret = PTR_ERR(priv->regulator);
> +		goto err_powerdown;
> +	}
> +
> +	ret = max9286_parse_dt(priv);
> +	if (ret)
> +		goto err_powerdown;
> +
> +	ret = max9286_init(&client->dev);
> +	if (ret < 0)
> +		goto err_cleanup_dt;
> +
> +	return 0;
> +
> +err_cleanup_dt:
> +	max9286_cleanup_dt(priv);
> +err_powerdown:
> +	gpiod_set_value_cansleep(priv->gpiod_pwdn, 0);
> +
> +	return ret;
> +}
> +
> +static int max9286_remove(struct i2c_client *client)
> +{
> +	struct max9286_priv *priv = i2c_get_clientdata(client);
> +
> +	i2c_mux_del_adapters(priv->mux);
> +
> +	max9286_v4l2_unregister(priv);
> +
> +	regulator_disable(priv->regulator);
> +
> +	gpiod_set_value_cansleep(priv->gpiod_pwdn, 0);
> +
> +	max9286_cleanup_dt(priv);
> +
> +	return 0;
> +}
> +
> +static const struct of_device_id max9286_dt_ids[] = {
> +	{ .compatible = "maxim,max9286" },
> +	{},
> +};
> +MODULE_DEVICE_TABLE(of, max9286_dt_ids);
> +
> +static struct i2c_driver max9286_i2c_driver = {
> +	.driver	= {
> +		.name		= "max9286",
> +		.of_match_table	= of_match_ptr(max9286_dt_ids),
> +	},
> +	.probe_new	= max9286_probe,
> +	.remove		= max9286_remove,
> +};
> +
> +module_i2c_driver(max9286_i2c_driver);
> +
> +MODULE_DESCRIPTION("Maxim MAX9286 GMSL Deserializer Driver");
> +MODULE_AUTHOR("Jacopo Mondi, Kieran Bingham, Laurent Pinchart, Niklas Söderlund, Vladimir Barinov");
> +MODULE_LICENSE("GPL");
> -- 
> 2.25.1
> 

Re: [PATCH v9 2/4] media: i2c: Add MAX9286 driver

[Kieran Bingham]

Hi Mani,

On 12/05/2020 18:40, Manivannan Sadhasivam wrote:
> Hi Kieran,
> 
> On Tue, May 12, 2020 at 04:51:03PM +0100, Kieran Bingham wrote:
>> The MAX9286 is a 4-channel GMSL deserializer with coax or STP input and
>> CSI-2 output. The device supports multicamera streaming applications,
>> and features the ability to synchronise the attached cameras.
>>
>> CSI-2 output can be configured with 1 to 4 lanes, and a control channel
>> is supported over I2C, which implements an I2C mux to facilitate
>> communications with connected cameras across the reverse control
>> channel.
>>
>> Signed-off-by: Jacopo Mondi <jacopo+renesas@jmondi.org>
>> Signed-off-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
>> Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
>> Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
>>
>> --
>> v2:
>>  - Fix MAINTAINERS entry
>>
>> This posting is released with the following modifications to work
>> without Sakari's VC developments:
>>  - max9286_g_mbus_config() re-instated
>>  - max9286_get_frame_desc() is not bus/csi aware
>>  - max9286_{get,set}_routing() removed
>>
>> v3:
>>  - Initialise notifier with v4l2_async_notifier_init
>>  - Update for new mbus csi2 format V4L2_MBUS_CSI2_DPHY
>>
>> v4: - Re-introduce required code to function with the VC series.
>>
>>  - Implement max9286_get_routing, max9286_set_routing
>>  - Remove max9286_g_mbus_config
>>
>> v5: (internal release)
>>  - Fix printk formatting for hex value
>>  - max9286->sd.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE (add |)
>>  - MEDIA_ENT_F_PROC_VIDEO_PIXEL_FORMATTER -> MEDIA_ENT_F_VID_IF_BRIDGE
>>  - Remove 'device is bound' workaround
>>
>> v6:
>>  - v4l2_subdev_krouting instead of v4l2_subdev_routing separated
>>    to allow integration without the VC/V4L2-Mux series.
>>  - convert sd_to_max9286 to inline function
>>  - rename max9286_device to max9286_priv
>>  - Cleanup the v4l2_async_notifier
>>  - Extend MODULE_AUTHOR
>>  - Replace of_graph_get_endpoint_by_regs with fwnode_graph_get_endpoint_by_id
>>  - Pass default bus type when parsing fwnode endpoint (Manivannan Sadhasivam)
>>  - Use new YAML file reference in MAINTAINERS
>>  - Parse new i2c-mux node in max9286_get_i2c_by_id
>>    (This could/should be refactored to parse these separately first)
>>  - Spelling and calculation fixes in the FSYNC_LOCKED check comments
>>  - Identify each enabled i2c-mux channel in a single pass
>>  - max9286: Improve mux-state readbility [v2]
>>  - Fix frame sync lock durations
>>  - Add comment to describe /why/ we must open the mux in s_stream
>>  - use -EXDEV as return code for failed link synchronisation.
>>  - Fix reference counting of the dt nodeS
>>  - Convert to probe_new for I2C
>>  - Remove redundant max9286_i2c_mux_state
>>  - Provide optional enable-gpio (max9286-pwdn)
>>
>> v7:
>>  [Kieran]
>>  - Ensure powerdown lines are optional
>>  - Add a 4ms power-up delay
>>  - Add max9286_check_config_link() to core
>>  - Add GPIO chip controller for GPIO0OUT and GPIO1OUT
>>  - Fix GPIO registration
>>  - max9286: Split out async registration
>>    (fixes regulator -EPROBE_DEFERs failures)
>>  - Collect all V4L2 registrations
>>  - balance v4l2_async refcnting
>>  - Rename max9286_v4l2_async_ => max9286_v4l2_notifier_
>>
>>  [Jacopo]
>>  - Remove redundanct MAXIM_I2C_SPEED macros
>>  - Move notifiers operations
>>  - Add delay after reverse channel reconfiguration
>>  - Move link setup to completion
>>  - Fix up max9286_check_config_link() implementation
>>  - Remove redundant dual configuration of reverse channel
>>
>> v8:
>>
>> [Kieran]
>>  - Update the bound_sources mask on unbind
>>  - Convert probe kzalloc usage to devm_ variant
>>  - Fix up cleanup path from GPIO PowerDown registration
>>  - cleanup GPIO device registration fail path
>>  - Convert to use devm_regulator_get()
>>  - Fit max9286_parse_dt print on one line
>>  - Move multi-device workarounds out of upstream driver
>>  - Remove I2C mod-table
>>  - Lock format changes
>>  - Describe pad index usage
>>  - Remove poc_enabled workaround
>>  - Rename the max9286_gpio to be more explicit on it's actions.
>>  - Move max9286_init_format call
>>  - Rework probe sequence and simplify error paths.
>>  - Simplify i2c comments
>>  - Implement Pixelrate control
>>  - Disable overlap window
>>
>> [Jacopo]
>>  - Adapt Kconfig to latest upstream changes
>>  - Put of node on error
>>  - Calculate pixel rate
>>  - Simplify overlap window disablement
>>
>> v9:
>>
>> [Kieran]
>>  - Kconfig: Depend on OF
>>  - Re-sort addition to Makefile
>> ---
>>  MAINTAINERS                 |   10 +
>>  drivers/media/i2c/Kconfig   |   13 +
>>  drivers/media/i2c/Makefile  |    1 +
>>  drivers/media/i2c/max9286.c | 1332 +++++++++++++++++++++++++++++++++++
>>  4 files changed, 1356 insertions(+)
>>  create mode 100644 drivers/media/i2c/max9286.c
>>
>> diff --git a/MAINTAINERS b/MAINTAINERS
>> index a7bb6e22d5da..99e3bf7760fd 100644
>> --- a/MAINTAINERS
>> +++ b/MAINTAINERS
>> @@ -10274,6 +10274,16 @@ F:	Documentation/hwmon/max6697.rst
>>  F:	drivers/hwmon/max6697.c
>>  F:	include/linux/platform_data/max6697.h
>>  
>> +MAX9286 QUAD GMSL DESERIALIZER DRIVER
>> +M:	Jacopo Mondi <jacopo+renesas@jmondi.org>
>> +M:	Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
>> +M:	Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
>> +M:	Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
>> +L:	linux-media@vger.kernel.org
>> +S:	Maintained
>> +F:	Documentation/devicetree/bindings/media/i2c/maxim,max9286.yaml
>> +F:	drivers/media/i2c/max9286.c
>> +
>>  MAX9860 MONO AUDIO VOICE CODEC DRIVER
>>  M:	Peter Rosin <peda@axentia.se>
>>  L:	alsa-devel@alsa-project.org (moderated for non-subscribers)
>> diff --git a/drivers/media/i2c/Kconfig b/drivers/media/i2c/Kconfig
>> index 3abc80373ec0..2e390f41f6da 100644
>> --- a/drivers/media/i2c/Kconfig
>> +++ b/drivers/media/i2c/Kconfig
>> @@ -464,6 +464,19 @@ config VIDEO_VPX3220
>>  	  To compile this driver as a module, choose M here: the
>>  	  module will be called vpx3220.
>>  
>> +config VIDEO_MAX9286
>> +	tristate "Maxim MAX9286 GMSL deserializer support"
>> +	depends on I2C && I2C_MUX
>> +	depends on OF
>> +	select V4L2_FWNODE
>> +	select VIDEO_V4L2_SUBDEV_API
>> +	select MEDIA_CONTROLLER
>> +	help
>> +	  This driver supports the Maxim MAX9286 GMSL deserializer.
>> +
>> +	  To compile this driver as a module, choose M here: the
>> +	  module will be called max9286.
>> +
>>  comment "Video and audio decoders"
>>  
>>  config VIDEO_SAA717X
>> diff --git a/drivers/media/i2c/Makefile b/drivers/media/i2c/Makefile
>> index 77bf7d0b691f..f0b001ee4b05 100644
>> --- a/drivers/media/i2c/Makefile
>> +++ b/drivers/media/i2c/Makefile
>> @@ -117,6 +117,7 @@ obj-$(CONFIG_VIDEO_IMX274)	+= imx274.o
>>  obj-$(CONFIG_VIDEO_IMX290)	+= imx290.o
>>  obj-$(CONFIG_VIDEO_IMX319)	+= imx319.o
>>  obj-$(CONFIG_VIDEO_IMX355)	+= imx355.o
>> +obj-$(CONFIG_VIDEO_MAX9286)	+= max9286.o
>>  obj-$(CONFIG_VIDEO_ST_MIPID02) += st-mipid02.o
>>  
>>  obj-$(CONFIG_SDR_MAX2175) += max2175.o
>> diff --git a/drivers/media/i2c/max9286.c b/drivers/media/i2c/max9286.c
>> new file mode 100644
>> index 000000000000..481d65f2b51d
>> --- /dev/null
>> +++ b/drivers/media/i2c/max9286.c
>> @@ -0,0 +1,1332 @@
>> +// SPDX-License-Identifier: GPL-2.0+
>> +/*
>> + * Maxim MAX9286 GMSL Deserializer Driver
>> + *
>> + * Copyright (C) 2017-2019 Jacopo Mondi
>> + * Copyright (C) 2017-2019 Kieran Bingham
>> + * Copyright (C) 2017-2019 Laurent Pinchart
>> + * Copyright (C) 2017-2019 Niklas Söderlund
>> + * Copyright (C) 2016 Renesas Electronics Corporation
>> + * Copyright (C) 2015 Cogent Embedded, Inc.
>> + */
>> +
>> +#include <linux/delay.h>
>> +#include <linux/device.h>
>> +#include <linux/fwnode.h>
>> +#include <linux/gpio/consumer.h>
>> +#include <linux/gpio/driver.h>
>> +#include <linux/i2c.h>
>> +#include <linux/i2c-mux.h>
>> +#include <linux/module.h>
>> +#include <linux/mutex.h>
>> +#include <linux/of_graph.h>
>> +#include <linux/regulator/consumer.h>
>> +#include <linux/slab.h>
>> +
>> +#include <media/v4l2-async.h>
>> +#include <media/v4l2-ctrls.h>
>> +#include <media/v4l2-device.h>
>> +#include <media/v4l2-fwnode.h>
>> +#include <media/v4l2-subdev.h>
>> +
>> +/* Register 0x00 */
>> +#define MAX9286_MSTLINKSEL_AUTO		(7 << 5)
>> +#define MAX9286_MSTLINKSEL(n)		((n) << 5)
>> +#define MAX9286_EN_VS_GEN		BIT(4)
>> +#define MAX9286_LINKEN(n)		(1 << (n))
>> +/* Register 0x01 */
>> +#define MAX9286_FSYNCMODE_ECU		(3 << 6)
>> +#define MAX9286_FSYNCMODE_EXT		(2 << 6)
>> +#define MAX9286_FSYNCMODE_INT_OUT	(1 << 6)
>> +#define MAX9286_FSYNCMODE_INT_HIZ	(0 << 6)
>> +#define MAX9286_GPIEN			BIT(5)
>> +#define MAX9286_ENLMO_RSTFSYNC		BIT(2)
>> +#define MAX9286_FSYNCMETH_AUTO		(2 << 0)
>> +#define MAX9286_FSYNCMETH_SEMI_AUTO	(1 << 0)
>> +#define MAX9286_FSYNCMETH_MANUAL	(0 << 0)
>> +#define MAX9286_REG_FSYNC_PERIOD_L	0x06
>> +#define MAX9286_REG_FSYNC_PERIOD_M	0x07
>> +#define MAX9286_REG_FSYNC_PERIOD_H	0x08
>> +/* Register 0x0a */
>> +#define MAX9286_FWDCCEN(n)		(1 << ((n) + 4))
>> +#define MAX9286_REVCCEN(n)		(1 << (n))
>> +/* Register 0x0c */
>> +#define MAX9286_HVEN			BIT(7)
>> +#define MAX9286_EDC_6BIT_HAMMING	(2 << 5)
>> +#define MAX9286_EDC_6BIT_CRC		(1 << 5)
>> +#define MAX9286_EDC_1BIT_PARITY		(0 << 5)
>> +#define MAX9286_DESEL			BIT(4)
>> +#define MAX9286_INVVS			BIT(3)
>> +#define MAX9286_INVHS			BIT(2)
>> +#define MAX9286_HVSRC_D0		(2 << 0)
>> +#define MAX9286_HVSRC_D14		(1 << 0)
>> +#define MAX9286_HVSRC_D18		(0 << 0)
>> +/* Register 0x0f */
>> +#define MAX9286_0X0F_RESERVED		BIT(3)
>> +/* Register 0x12 */
>> +#define MAX9286_CSILANECNT(n)		(((n) - 1) << 6)
>> +#define MAX9286_CSIDBL			BIT(5)
>> +#define MAX9286_DBL			BIT(4)
>> +#define MAX9286_DATATYPE_USER_8BIT	(11 << 0)
>> +#define MAX9286_DATATYPE_USER_YUV_12BIT	(10 << 0)
>> +#define MAX9286_DATATYPE_USER_24BIT	(9 << 0)
>> +#define MAX9286_DATATYPE_RAW14		(8 << 0)
>> +#define MAX9286_DATATYPE_RAW11		(7 << 0)
>> +#define MAX9286_DATATYPE_RAW10		(6 << 0)
>> +#define MAX9286_DATATYPE_RAW8		(5 << 0)
>> +#define MAX9286_DATATYPE_YUV422_10BIT	(4 << 0)
>> +#define MAX9286_DATATYPE_YUV422_8BIT	(3 << 0)
>> +#define MAX9286_DATATYPE_RGB555		(2 << 0)
>> +#define MAX9286_DATATYPE_RGB565		(1 << 0)
>> +#define MAX9286_DATATYPE_RGB888		(0 << 0)
>> +/* Register 0x15 */
>> +#define MAX9286_VC(n)			((n) << 5)
>> +#define MAX9286_VCTYPE			BIT(4)
>> +#define MAX9286_CSIOUTEN		BIT(3)
>> +#define MAX9286_0X15_RESV		(3 << 0)
>> +/* Register 0x1b */
>> +#define MAX9286_SWITCHIN(n)		(1 << ((n) + 4))
>> +#define MAX9286_ENEQ(n)			(1 << (n))
>> +/* Register 0x27 */
>> +#define MAX9286_LOCKED			BIT(7)
>> +/* Register 0x31 */
>> +#define MAX9286_FSYNC_LOCKED		BIT(6)
>> +/* Register 0x34 */
>> +#define MAX9286_I2CLOCACK		BIT(7)
>> +#define MAX9286_I2CSLVSH_1046NS_469NS	(3 << 5)
>> +#define MAX9286_I2CSLVSH_938NS_352NS	(2 << 5)
>> +#define MAX9286_I2CSLVSH_469NS_234NS	(1 << 5)
>> +#define MAX9286_I2CSLVSH_352NS_117NS	(0 << 5)
>> +#define MAX9286_I2CMSTBT_837KBPS	(7 << 2)
>> +#define MAX9286_I2CMSTBT_533KBPS	(6 << 2)
>> +#define MAX9286_I2CMSTBT_339KBPS	(5 << 2)
>> +#define MAX9286_I2CMSTBT_173KBPS	(4 << 2)
>> +#define MAX9286_I2CMSTBT_105KBPS	(3 << 2)
>> +#define MAX9286_I2CMSTBT_84KBPS		(2 << 2)
>> +#define MAX9286_I2CMSTBT_28KBPS		(1 << 2)
>> +#define MAX9286_I2CMSTBT_8KBPS		(0 << 2)
>> +#define MAX9286_I2CSLVTO_NONE		(3 << 0)
>> +#define MAX9286_I2CSLVTO_1024US		(2 << 0)
>> +#define MAX9286_I2CSLVTO_256US		(1 << 0)
>> +#define MAX9286_I2CSLVTO_64US		(0 << 0)
>> +/* Register 0x3b */
>> +#define MAX9286_REV_TRF(n)		((n) << 4)
>> +#define MAX9286_REV_AMP(n)		((((n) - 30) / 10) << 1) /* in mV */
>> +#define MAX9286_REV_AMP_X		BIT(0)
>> +/* Register 0x3f */
>> +#define MAX9286_EN_REV_CFG		BIT(6)
>> +#define MAX9286_REV_FLEN(n)		((n) - 20)
>> +/* Register 0x49 */
>> +#define MAX9286_VIDEO_DETECT_MASK	0x0f
>> +/* Register 0x69 */
>> +#define MAX9286_LFLTBMONMASKED		BIT(7)
>> +#define MAX9286_LOCKMONMASKED		BIT(6)
>> +#define MAX9286_AUTOCOMBACKEN		BIT(5)
>> +#define MAX9286_AUTOMASKEN		BIT(4)
>> +#define MAX9286_MASKLINK(n)		((n) << 0)
>> +
>> +/*
>> + * The sink and source pads are created to match the OF graph port numbers so
>> + * that their indexes can be used interchangeably.
>> + */
>> +#define MAX9286_NUM_GMSL		4
>> +#define MAX9286_N_SINKS			4
>> +#define MAX9286_N_PADS			5
>> +#define MAX9286_SRC_PAD			4
>> +
>> +struct max9286_source {
>> +	struct v4l2_async_subdev asd;
>> +	struct v4l2_subdev *sd;
>> +	struct fwnode_handle *fwnode;
>> +};
>> +
>> +#define asd_to_max9286_source(_asd) \
>> +	container_of(_asd, struct max9286_source, asd)
>> +
>> +struct max9286_priv {
>> +	struct i2c_client *client;
>> +	struct gpio_desc *gpiod_pwdn;
>> +	struct v4l2_subdev sd;
>> +	struct media_pad pads[MAX9286_N_PADS];
>> +	struct regulator *regulator;
>> +
>> +	struct gpio_chip gpio;
>> +	u8 gpio_state;
>> +
>> +	struct i2c_mux_core *mux;
>> +	unsigned int mux_channel;
>> +	bool mux_open;
>> +
>> +	struct v4l2_ctrl_handler ctrls;
>> +	struct v4l2_ctrl *pixelrate;
>> +
>> +	struct v4l2_mbus_framefmt fmt[MAX9286_N_SINKS];
>> +
>> +	/* Protects controls and fmt structures */
>> +	struct mutex mutex;
>> +
>> +	unsigned int nsources;
>> +	unsigned int source_mask;
>> +	unsigned int route_mask;
>> +	unsigned int bound_sources;
>> +	unsigned int csi2_data_lanes;
>> +	struct max9286_source sources[MAX9286_NUM_GMSL];
>> +	struct v4l2_async_notifier notifier;
>> +};
>> +
>> +static struct max9286_source *next_source(struct max9286_priv *priv,
>> +					  struct max9286_source *source)
>> +{
>> +	if (!source)
>> +		source = &priv->sources[0];
>> +	else
>> +		source++;
>> +
>> +	for (; source < &priv->sources[MAX9286_NUM_GMSL]; source++) {
>> +		if (source->fwnode)
>> +			return source;
>> +	}
>> +
>> +	return NULL;
>> +}
>> +
>> +#define for_each_source(priv, source) \
>> +	for ((source) = NULL; ((source) = next_source((priv), (source))); )
>> +
>> +#define to_index(priv, source) ((source) - &(priv)->sources[0])
>> +
>> +static inline struct max9286_priv *sd_to_max9286(struct v4l2_subdev *sd)
>> +{
>> +	return container_of(sd, struct max9286_priv, sd);
>> +}
>> +
>> +/* -----------------------------------------------------------------------------
>> + * I2C IO
>> + */
>> +
>> +static int max9286_read(struct max9286_priv *priv, u8 reg)
>> +{
>> +	int ret;
>> +
>> +	ret = i2c_smbus_read_byte_data(priv->client, reg);
>> +	if (ret < 0)
>> +		dev_err(&priv->client->dev,
>> +			"%s: register 0x%02x read failed (%d)\n",
>> +			__func__, reg, ret);
>> +
>> +	return ret;
>> +}
>> +
>> +static int max9286_write(struct max9286_priv *priv, u8 reg, u8 val)
>> +{
>> +	int ret;
>> +
>> +	ret = i2c_smbus_write_byte_data(priv->client, reg, val);
>> +	if (ret < 0)
>> +		dev_err(&priv->client->dev,
>> +			"%s: register 0x%02x write failed (%d)\n",
>> +			__func__, reg, ret);
>> +
>> +	return ret;
>> +}
>> +
>> +/* -----------------------------------------------------------------------------
>> + * I2C Multiplexer
>> + */
>> +
>> +static void max9286_i2c_mux_configure(struct max9286_priv *priv, u8 conf)
>> +{
>> +	max9286_write(priv, 0x0a, conf);
>> +
>> +	/*
>> +	 * We must sleep after any change to the forward or reverse channel
>> +	 * configuration.
>> +	 */
>> +	usleep_range(3000, 5000);
>> +}
>> +
>> +static void max9286_i2c_mux_open(struct max9286_priv *priv)
>> +{
>> +	/* Open all channels on the MAX9286 */
>> +	max9286_i2c_mux_configure(priv, 0xff);
>> +
>> +	priv->mux_open = true;
>> +}
>> +
>> +static void max9286_i2c_mux_close(struct max9286_priv *priv)
>> +{
>> +	/*
>> +	 * Ensure that both the forward and reverse channel are disabled on the
>> +	 * mux, and that the channel ID is invalidated to ensure we reconfigure
>> +	 * on the next max9286_i2c_mux_select() call.
>> +	 */
>> +	max9286_i2c_mux_configure(priv, 0x00);
>> +
>> +	priv->mux_open = false;
>> +	priv->mux_channel = -1;
>> +}
>> +
>> +static int max9286_i2c_mux_select(struct i2c_mux_core *muxc, u32 chan)
>> +{
>> +	struct max9286_priv *priv = i2c_mux_priv(muxc);
>> +
>> +	/* Channel select is disabled when configured in the opened state. */
>> +	if (priv->mux_open)
>> +		return 0;
>> +
>> +	if (priv->mux_channel == chan)
>> +		return 0;
>> +
>> +	priv->mux_channel = chan;
>> +
>> +	max9286_i2c_mux_configure(priv,
>> +				  MAX9286_FWDCCEN(chan) |
>> +				  MAX9286_REVCCEN(chan));
>> +
>> +	return 0;
>> +}
>> +
>> +static int max9286_i2c_mux_init(struct max9286_priv *priv)
>> +{
>> +	struct max9286_source *source;
>> +	int ret;
>> +
>> +	if (!i2c_check_functionality(priv->client->adapter,
>> +				     I2C_FUNC_SMBUS_WRITE_BYTE_DATA))
>> +		return -ENODEV;
>> +
>> +	priv->mux = i2c_mux_alloc(priv->client->adapter, &priv->client->dev,
>> +				  priv->nsources, 0, I2C_MUX_LOCKED,
>> +				  max9286_i2c_mux_select, NULL);
>> +	if (!priv->mux)
>> +		return -ENOMEM;
>> +
>> +	priv->mux->priv = priv;
>> +
>> +	for_each_source(priv, source) {
>> +		unsigned int index = to_index(priv, source);
>> +
>> +		ret = i2c_mux_add_adapter(priv->mux, 0, index, 0);
>> +		if (ret < 0)
>> +			goto error;
>> +	}
>> +
>> +	return 0;
>> +
>> +error:
>> +	i2c_mux_del_adapters(priv->mux);
>> +	return ret;
>> +}
>> +
>> +static void max9286_configure_i2c(struct max9286_priv *priv, bool localack)
>> +{
>> +	u8 config = MAX9286_I2CSLVSH_469NS_234NS | MAX9286_I2CSLVTO_1024US |
>> +		    MAX9286_I2CMSTBT_105KBPS;
>> +
>> +	if (localack)
>> +		config |= MAX9286_I2CLOCACK;
>> +
>> +	max9286_write(priv, 0x34, config);
>> +	usleep_range(3000, 5000);
>> +}
>> +
>> +/*
>> + * max9286_check_video_links() - Make sure video links are detected and locked
>> + *
>> + * Performs safety checks on video link status. Make sure they are detected
>> + * and all enabled links are locked.
>> + *
>> + * Returns 0 for success, -EIO for errors.
>> + */
>> +static int max9286_check_video_links(struct max9286_priv *priv)
>> +{
>> +	unsigned int i;
>> +	int ret;
>> +
>> +	/*
>> +	 * Make sure valid video links are detected.
>> +	 * The delay is not characterized in de-serializer manual, wait up
>> +	 * to 5 ms.
>> +	 */
>> +	for (i = 0; i < 10; i++) {
>> +		ret = max9286_read(priv, 0x49);
>> +		if (ret < 0)
>> +			return -EIO;
>> +
>> +		if ((ret & MAX9286_VIDEO_DETECT_MASK) == priv->source_mask)
>> +			break;
>> +
>> +		usleep_range(350, 500);
>> +	}
>> +
>> +	if (i == 10) {
>> +		dev_err(&priv->client->dev,
>> +			"Unable to detect video links: 0x%02x\n", ret);
>> +		return -EIO;
>> +	}
>> +
>> +	/* Make sure all enabled links are locked (4ms max). */
>> +	for (i = 0; i < 10; i++) {
>> +		ret = max9286_read(priv, 0x27);
>> +		if (ret < 0)
>> +			return -EIO;
>> +
>> +		if (ret & MAX9286_LOCKED)
>> +			break;
>> +
>> +		usleep_range(350, 450);
>> +	}
>> +
>> +	if (i == 10) {
>> +		dev_err(&priv->client->dev, "Not all enabled links locked\n");
>> +		return -EIO;
>> +	}
>> +
>> +	return 0;
>> +}
>> +
>> +/*
>> + * max9286_check_config_link() - Detect and wait for configuration links
>> + *
>> + * Determine if the configuration channel is up and settled for a link.
>> + *
>> + * Returns 0 for success, -EIO for errors.
>> + */
>> +static int max9286_check_config_link(struct max9286_priv *priv,
>> +				     unsigned int source_mask)
>> +{
>> +	unsigned int conflink_mask = (source_mask & 0x0f) << 4;
>> +	unsigned int i;
>> +	int ret;
>> +
>> +	/*
>> +	 * Make sure requested configuration links are detected.
>> +	 * The delay is not characterized in the chip manual: wait up
>> +	 * to 5 milliseconds.
>> +	 */
>> +	for (i = 0; i < 10; i++) {
>> +		ret = max9286_read(priv, 0x49) & 0xf0;
>> +		if (ret < 0)
>> +			return -EIO;
>> +
>> +		if (ret == conflink_mask)
>> +			break;
>> +
>> +		usleep_range(350, 500);
>> +	}
>> +
>> +	if (ret != conflink_mask) {
>> +		dev_err(&priv->client->dev,
>> +			"Unable to detect configuration links: 0x%02x expected 0x%02x\n",
>> +			ret, conflink_mask);
>> +		return -EIO;
>> +	}
>> +
>> +	dev_info(&priv->client->dev,
>> +		 "Successfully detected configuration links after %u loops: 0x%02x\n",
>> +		 i, conflink_mask);
>> +
>> +	return 0;
>> +}
>> +
>> +/* -----------------------------------------------------------------------------
>> + * V4L2 Subdev
>> + */
>> +
>> +static int max9286_set_pixelrate(struct max9286_priv *priv)
>> +{
>> +	struct max9286_source *source = NULL;
>> +	u64 pixelrate = 0;
>> +
>> +	for_each_source(priv, source) {
>> +		struct v4l2_ctrl *ctrl;
>> +		u64 source_rate = 0;
>> +
>> +		/* Pixel rate is mandatory to be reported by sources. */
>> +		ctrl = v4l2_ctrl_find(source->sd->ctrl_handler,
>> +				      V4L2_CID_PIXEL_RATE);
>> +		if (!ctrl) {
>> +			pixelrate = 0;
>> +			break;
>> +		}
>> +
>> +		/* All source must report the same pixel rate. */
>> +		source_rate = v4l2_ctrl_g_ctrl_int64(ctrl);
>> +		if (!pixelrate) {
>> +			pixelrate = source_rate;
>> +		} else if (pixelrate != source_rate) {
>> +			dev_err(&priv->client->dev,
>> +				"Unable to calculate pixel rate\n");
>> +			return -EINVAL;
>> +		}
>> +	}
>> +
>> +	if (!pixelrate) {
>> +		dev_err(&priv->client->dev,
>> +			"No pixel rate control available in sources\n");
>> +		return -EINVAL;
>> +	}
>> +
>> +	/*
>> +	 * The CSI-2 transmitter pixel rate is the single source rate multiplied
>> +	 * by the number of available sources.
>> +	 */
>> +	return v4l2_ctrl_s_ctrl_int64(priv->pixelrate,
>> +				      pixelrate * priv->nsources);
>> +}
>> +
>> +static int max9286_notify_bound(struct v4l2_async_notifier *notifier,
>> +				struct v4l2_subdev *subdev,
>> +				struct v4l2_async_subdev *asd)
>> +{
>> +	struct max9286_priv *priv = sd_to_max9286(notifier->sd);
>> +	struct max9286_source *source = asd_to_max9286_source(asd);
>> +	unsigned int index = to_index(priv, source);
>> +	unsigned int src_pad;
>> +	int ret;
>> +
>> +	ret = media_entity_get_fwnode_pad(&subdev->entity,
>> +					  source->fwnode,
>> +					  MEDIA_PAD_FL_SOURCE);
>> +	if (ret < 0) {
>> +		dev_err(&priv->client->dev,
>> +			"Failed to find pad for %s\n", subdev->name);
>> +		return ret;
>> +	}
>> +
>> +	priv->bound_sources |= BIT(index);
>> +	source->sd = subdev;
>> +	src_pad = ret;
>> +
>> +	ret = media_create_pad_link(&source->sd->entity, src_pad,
>> +				    &priv->sd.entity, index,
>> +				    MEDIA_LNK_FL_ENABLED |
>> +				    MEDIA_LNK_FL_IMMUTABLE);
>> +	if (ret) {
>> +		dev_err(&priv->client->dev,
>> +			"Unable to link %s:%u -> %s:%u\n",
>> +			source->sd->name, src_pad, priv->sd.name, index);
>> +		return ret;
>> +	}
>> +
>> +	dev_dbg(&priv->client->dev, "Bound %s pad: %u on index %u\n",
>> +		subdev->name, src_pad, index);
>> +
>> +	/*
>> +	 * We can only register v4l2_async_notifiers, which do not provide a
>> +	 * means to register a complete callback. bound_sources allows us to
>> +	 * identify when all remote serializers have completed their probe.
>> +	 */
>> +	if (priv->bound_sources != priv->source_mask)
>> +		return 0;
>> +
>> +	/*
>> +	 * All enabled sources have probed and enabled their reverse control
>> +	 * channels:
>> +	 *
>> +	 * - Verify all configuration links are properly detected
>> +	 * - Disable auto-ack as communication on the control channel are now
>> +	 *   stable.
>> +	 */
>> +	max9286_check_config_link(priv, priv->source_mask);
>> +
>> +	/*
>> +	 * Re-configure I2C with local acknowledge disabled after cameras have
>> +	 * probed.
>> +	 */
>> +	max9286_configure_i2c(priv, false);
>> +
>> +	return max9286_set_pixelrate(priv);
>> +}
>> +
>> +static void max9286_notify_unbind(struct v4l2_async_notifier *notifier,
>> +				  struct v4l2_subdev *subdev,
>> +				  struct v4l2_async_subdev *asd)
>> +{
>> +	struct max9286_priv *priv = sd_to_max9286(notifier->sd);
>> +	struct max9286_source *source = asd_to_max9286_source(asd);
>> +	unsigned int index = to_index(priv, source);
>> +
>> +	source->sd = NULL;
>> +	priv->bound_sources &= ~BIT(index);
>> +}
>> +
>> +static const struct v4l2_async_notifier_operations max9286_notify_ops = {
>> +	.bound = max9286_notify_bound,
>> +	.unbind = max9286_notify_unbind,
>> +};
>> +
>> +static int max9286_v4l2_notifier_register(struct max9286_priv *priv)
>> +{
>> +	struct device *dev = &priv->client->dev;
>> +	struct max9286_source *source = NULL;
>> +	int ret;
>> +
>> +	if (!priv->nsources)
>> +		return 0;
>> +
>> +	v4l2_async_notifier_init(&priv->notifier);
>> +
>> +	for_each_source(priv, source) {
>> +		unsigned int i = to_index(priv, source);
>> +
>> +		source->asd.match_type = V4L2_ASYNC_MATCH_FWNODE;
>> +		source->asd.match.fwnode = source->fwnode;
>> +
>> +		ret = v4l2_async_notifier_add_subdev(&priv->notifier,
>> +						     &source->asd);
>> +		if (ret) {
>> +			dev_err(dev, "Failed to add subdev for source %d", i);
>> +			v4l2_async_notifier_cleanup(&priv->notifier);
>> +			return ret;
>> +		}
>> +
>> +		/*
>> +		 * Balance the reference counting handled through
>> +		 * v4l2_async_notifier_cleanup()
>> +		 */
>> +		fwnode_handle_get(source->fwnode);
>> +	}
>> +
>> +	priv->notifier.ops = &max9286_notify_ops;
>> +
>> +	ret = v4l2_async_subdev_notifier_register(&priv->sd, &priv->notifier);
>> +	if (ret) {
>> +		dev_err(dev, "Failed to register subdev_notifier");
>> +		v4l2_async_notifier_cleanup(&priv->notifier);
>> +		return ret;
>> +	}
>> +
>> +	return 0;
>> +}
>> +
>> +static void max9286_v4l2_notifier_unregister(struct max9286_priv *priv)
>> +{
>> +	if (!priv->nsources)
>> +		return;
>> +
>> +	v4l2_async_notifier_unregister(&priv->notifier);
>> +	v4l2_async_notifier_cleanup(&priv->notifier);
>> +}
>> +
>> +static int max9286_s_stream(struct v4l2_subdev *sd, int enable)
>> +{
>> +	struct max9286_priv *priv = sd_to_max9286(sd);
>> +	struct max9286_source *source;
>> +	unsigned int i;
>> +	bool sync = false;
>> +	int ret;
>> +
>> +	if (enable) {
>> +		/*
>> +		 * The frame sync between cameras is transmitted across the
>> +		 * reverse channel as GPIO. We must open all channels while
>> +		 * streaming to allow this synchronisation signal to be shared.
>> +		 */
>> +		max9286_i2c_mux_open(priv);
>> +
>> +		/* Start all cameras. */
>> +		for_each_source(priv, source) {
>> +			ret = v4l2_subdev_call(source->sd, video, s_stream, 1);
>> +			if (ret)
>> +				return ret;
>> +		}
>> +
>> +		ret = max9286_check_video_links(priv);
>> +		if (ret)
>> +			return ret;
>> +
>> +		/*
>> +		 * Wait until frame synchronization is locked.
>> +		 *
>> +		 * Manual says frame sync locking should take ~6 VTS.
>> +		 * From practical experience at least 8 are required. Give
>> +		 * 12 complete frames time (~400ms at 30 fps) to achieve frame
>> +		 * locking before returning error.
>> +		 */
>> +		for (i = 0; i < 40; i++) {
>> +			if (max9286_read(priv, 0x31) & MAX9286_FSYNC_LOCKED) {
>> +				sync = true;
>> +				break;
>> +			}
>> +			usleep_range(9000, 11000);
>> +		}
>> +
>> +		if (!sync) {
>> +			dev_err(&priv->client->dev,
>> +				"Failed to get frame synchronization\n");
>> +			return -EXDEV; /* Invalid cross-device link */
>> +		}
>> +
>> +		/*
>> +		 * Enable CSI output, VC set according to link number.
>> +		 * Bit 7 must be set (chip manual says it's 0 and reserved).
>> +		 */
>> +		max9286_write(priv, 0x15, 0x80 | MAX9286_VCTYPE |
>> +			      MAX9286_CSIOUTEN | MAX9286_0X15_RESV);
>> +	} else {
>> +		max9286_write(priv, 0x15, MAX9286_VCTYPE | MAX9286_0X15_RESV);
>> +
>> +		/* Stop all cameras. */
>> +		for_each_source(priv, source)
>> +			v4l2_subdev_call(source->sd, video, s_stream, 0);
>> +
>> +		max9286_i2c_mux_close(priv);
>> +	}
>> +
>> +	return 0;
>> +}
>> +
>> +static int max9286_enum_mbus_code(struct v4l2_subdev *sd,
>> +				  struct v4l2_subdev_pad_config *cfg,
>> +				  struct v4l2_subdev_mbus_code_enum *code)
>> +{
>> +	if (code->pad || code->index > 0)
>> +		return -EINVAL;
>> +
>> +	code->code = MEDIA_BUS_FMT_UYVY8_2X8;
>> +
>> +	return 0;
>> +}
>> +
>> +static struct v4l2_mbus_framefmt *
>> +max9286_get_pad_format(struct max9286_priv *priv,
>> +		       struct v4l2_subdev_pad_config *cfg,
>> +		       unsigned int pad, u32 which)
>> +{
>> +	switch (which) {
>> +	case V4L2_SUBDEV_FORMAT_TRY:
>> +		return v4l2_subdev_get_try_format(&priv->sd, cfg, pad);
>> +	case V4L2_SUBDEV_FORMAT_ACTIVE:
>> +		return &priv->fmt[pad];
>> +	default:
>> +		return NULL;
>> +	}
>> +}
>> +
>> +static int max9286_set_fmt(struct v4l2_subdev *sd,
>> +			   struct v4l2_subdev_pad_config *cfg,
>> +			   struct v4l2_subdev_format *format)
>> +{
>> +	struct max9286_priv *priv = sd_to_max9286(sd);
>> +	struct v4l2_mbus_framefmt *cfg_fmt;
>> +
>> +	if (format->pad >= MAX9286_SRC_PAD)
>> +		return -EINVAL;
>> +
>> +	/* Refuse non YUV422 formats as we hardcode DT to 8 bit YUV422 */
>> +	switch (format->format.code) {
>> +	case MEDIA_BUS_FMT_UYVY8_2X8:
>> +	case MEDIA_BUS_FMT_VYUY8_2X8:
>> +	case MEDIA_BUS_FMT_YUYV8_2X8:
>> +	case MEDIA_BUS_FMT_YVYU8_2X8:
>> +		break;
>> +	default:
>> +		format->format.code = MEDIA_BUS_FMT_YUYV8_2X8;
> 
> Is there any reason for not setting default format to MEDIA_BUS_FMT_UYVY8_2X8?
> 


No good reason no, and I see that in max9286_enum_mbus_code(), we
currently code to MEDIA_BUS_FMT_YUYV8_2X8, and that's the value that we
init to, so that would be a better default indeed.

I'll update this for v10.


> Thanks,
> Mani
> 
>> +		break;
>> +	}
>> +
>> +	cfg_fmt = max9286_get_pad_format(priv, cfg, format->pad, format->which);
>> +	if (!cfg_fmt)
>> +		return -EINVAL;
>> +
>> +	mutex_lock(&priv->mutex);
>> +	*cfg_fmt = format->format;
>> +	mutex_unlock(&priv->mutex);
>> +
>> +	return 0;
>> +}
>> +
>> +static int max9286_get_fmt(struct v4l2_subdev *sd,
>> +			   struct v4l2_subdev_pad_config *cfg,
>> +			   struct v4l2_subdev_format *format)
>> +{
>> +	struct max9286_priv *priv = sd_to_max9286(sd);
>> +	struct v4l2_mbus_framefmt *cfg_fmt;
>> +
>> +	if (format->pad >= MAX9286_SRC_PAD)
>> +		return -EINVAL;
>> +
>> +	cfg_fmt = max9286_get_pad_format(priv, cfg, format->pad, format->which);
>> +	if (!cfg_fmt)
>> +		return -EINVAL;
>> +
>> +	mutex_lock(&priv->mutex);
>> +	format->format = *cfg_fmt;
>> +	mutex_unlock(&priv->mutex);
>> +
>> +	return 0;
>> +}
>> +
>> +static const struct v4l2_subdev_video_ops max9286_video_ops = {
>> +	.s_stream	= max9286_s_stream,
>> +};
>> +
>> +static const struct v4l2_subdev_pad_ops max9286_pad_ops = {
>> +	.enum_mbus_code = max9286_enum_mbus_code,
>> +	.get_fmt	= max9286_get_fmt,
>> +	.set_fmt	= max9286_set_fmt,
>> +};
>> +
>> +static const struct v4l2_subdev_ops max9286_subdev_ops = {
>> +	.video		= &max9286_video_ops,
>> +	.pad		= &max9286_pad_ops,
>> +};
>> +
>> +static void max9286_init_format(struct v4l2_mbus_framefmt *fmt)
>> +{
>> +	fmt->width		= 1280;
>> +	fmt->height		= 800;
>> +	fmt->code		= MEDIA_BUS_FMT_UYVY8_2X8;
>> +	fmt->colorspace		= V4L2_COLORSPACE_SRGB;
>> +	fmt->field		= V4L2_FIELD_NONE;
>> +	fmt->ycbcr_enc		= V4L2_YCBCR_ENC_DEFAULT;
>> +	fmt->quantization	= V4L2_QUANTIZATION_DEFAULT;
>> +	fmt->xfer_func		= V4L2_XFER_FUNC_DEFAULT;
>> +}
>> +
>> +static int max9286_open(struct v4l2_subdev *subdev, struct v4l2_subdev_fh *fh)
>> +{
>> +	struct v4l2_mbus_framefmt *format;
>> +	unsigned int i;
>> +
>> +	for (i = 0; i < MAX9286_N_SINKS; i++) {
>> +		format = v4l2_subdev_get_try_format(subdev, fh->pad, i);
>> +		max9286_init_format(format);
>> +	}
>> +
>> +	return 0;
>> +}
>> +
>> +static const struct v4l2_subdev_internal_ops max9286_subdev_internal_ops = {
>> +	.open = max9286_open,
>> +};
>> +
>> +static int max9286_s_ctrl(struct v4l2_ctrl *ctrl)
>> +{
>> +	switch (ctrl->id) {
>> +	case V4L2_CID_PIXEL_RATE:
>> +		return 0;
>> +	default:
>> +		return -EINVAL;
>> +	}
>> +}
>> +
>> +static const struct v4l2_ctrl_ops max9286_ctrl_ops = {
>> +	.s_ctrl	= max9286_s_ctrl,
>> +};
>> +
>> +static int max9286_v4l2_register(struct max9286_priv *priv)
>> +{
>> +	struct device *dev = &priv->client->dev;
>> +	struct fwnode_handle *ep;
>> +	int ret;
>> +	int i;
>> +
>> +	/* Register v4l2 async notifiers for connected Camera subdevices */
>> +	ret = max9286_v4l2_notifier_register(priv);
>> +	if (ret) {
>> +		dev_err(dev, "Unable to register V4L2 async notifiers\n");
>> +		return ret;
>> +	}
>> +
>> +	/* Configure V4L2 for the MAX9286 itself */
>> +
>> +	for (i = 0; i < MAX9286_N_SINKS; i++)
>> +		max9286_init_format(&priv->fmt[i]);
>> +
>> +	v4l2_i2c_subdev_init(&priv->sd, priv->client, &max9286_subdev_ops);
>> +	priv->sd.internal_ops = &max9286_subdev_internal_ops;
>> +	priv->sd.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;
>> +
>> +	v4l2_ctrl_handler_init(&priv->ctrls, 1);
>> +	priv->pixelrate = v4l2_ctrl_new_std(&priv->ctrls,
>> +					    &max9286_ctrl_ops,
>> +					    V4L2_CID_PIXEL_RATE,
>> +					    1, INT_MAX, 1, 50000000);
>> +
>> +	priv->sd.ctrl_handler = &priv->ctrls;
>> +	ret = priv->ctrls.error;
>> +	if (ret)
>> +		goto err_async;
>> +
>> +	priv->sd.entity.function = MEDIA_ENT_F_VID_IF_BRIDGE;
>> +
>> +	priv->pads[MAX9286_SRC_PAD].flags = MEDIA_PAD_FL_SOURCE;
>> +	for (i = 0; i < MAX9286_SRC_PAD; i++)
>> +		priv->pads[i].flags = MEDIA_PAD_FL_SINK;
>> +	ret = media_entity_pads_init(&priv->sd.entity, MAX9286_N_PADS,
>> +				     priv->pads);
>> +	if (ret)
>> +		goto err_async;
>> +
>> +	ep = fwnode_graph_get_endpoint_by_id(dev_fwnode(dev), MAX9286_SRC_PAD,
>> +					     0, 0);
>> +	if (!ep) {
>> +		dev_err(dev, "Unable to retrieve endpoint on \"port@4\"\n");
>> +		ret = -ENOENT;
>> +		goto err_async;
>> +	}
>> +	priv->sd.fwnode = ep;
>> +
>> +	ret = v4l2_async_register_subdev(&priv->sd);
>> +	if (ret < 0) {
>> +		dev_err(dev, "Unable to register subdevice\n");
>> +		goto err_put_node;
>> +	}
>> +
>> +	return 0;
>> +
>> +err_put_node:
>> +	fwnode_handle_put(ep);
>> +err_async:
>> +	max9286_v4l2_notifier_unregister(priv);
>> +
>> +	return ret;
>> +}
>> +
>> +static void max9286_v4l2_unregister(struct max9286_priv *priv)
>> +{
>> +	fwnode_handle_put(priv->sd.fwnode);
>> +	v4l2_async_unregister_subdev(&priv->sd);
>> +	max9286_v4l2_notifier_unregister(priv);
>> +}
>> +
>> +/* -----------------------------------------------------------------------------
>> + * Probe/Remove
>> + */
>> +
>> +static int max9286_setup(struct max9286_priv *priv)
>> +{
>> +	/*
>> +	 * Link ordering values for all enabled links combinations. Orders must
>> +	 * be assigned sequentially from 0 to the number of enabled links
>> +	 * without leaving any hole for disabled links. We thus assign orders to
>> +	 * enabled links first, and use the remaining order values for disabled
>> +	 * links are all links must have a different order value;
>> +	 */
>> +	static const u8 link_order[] = {
>> +		(3 << 6) | (2 << 4) | (1 << 2) | (0 << 0), /* xxxx */
>> +		(3 << 6) | (2 << 4) | (1 << 2) | (0 << 0), /* xxx0 */
>> +		(3 << 6) | (2 << 4) | (0 << 2) | (1 << 0), /* xx0x */
>> +		(3 << 6) | (2 << 4) | (1 << 2) | (0 << 0), /* xx10 */
>> +		(3 << 6) | (0 << 4) | (2 << 2) | (1 << 0), /* x0xx */
>> +		(3 << 6) | (1 << 4) | (2 << 2) | (0 << 0), /* x1x0 */
>> +		(3 << 6) | (1 << 4) | (0 << 2) | (2 << 0), /* x10x */
>> +		(3 << 6) | (1 << 4) | (1 << 2) | (0 << 0), /* x210 */
>> +		(0 << 6) | (3 << 4) | (2 << 2) | (1 << 0), /* 0xxx */
>> +		(1 << 6) | (3 << 4) | (2 << 2) | (0 << 0), /* 1xx0 */
>> +		(1 << 6) | (3 << 4) | (0 << 2) | (2 << 0), /* 1x0x */
>> +		(2 << 6) | (3 << 4) | (1 << 2) | (0 << 0), /* 2x10 */
>> +		(1 << 6) | (0 << 4) | (3 << 2) | (2 << 0), /* 10xx */
>> +		(2 << 6) | (1 << 4) | (3 << 2) | (0 << 0), /* 21x0 */
>> +		(2 << 6) | (1 << 4) | (0 << 2) | (3 << 0), /* 210x */
>> +		(3 << 6) | (2 << 4) | (1 << 2) | (0 << 0), /* 3210 */
>> +	};
>> +
>> +	/*
>> +	 * Set the I2C bus speed.
>> +	 *
>> +	 * Enable I2C Local Acknowledge during the probe sequences of the camera
>> +	 * only. This should be disabled after the mux is initialised.
>> +	 */
>> +	max9286_configure_i2c(priv, true);
>> +
>> +	/*
>> +	 * Reverse channel setup.
>> +	 *
>> +	 * - Enable custom reverse channel configuration (through register 0x3f)
>> +	 *   and set the first pulse length to 35 clock cycles.
>> +	 * - Increase the reverse channel amplitude to 170mV to accommodate the
>> +	 *   high threshold enabled by the serializer driver.
>> +	 */
>> +	max9286_write(priv, 0x3f, MAX9286_EN_REV_CFG | MAX9286_REV_FLEN(35));
>> +	max9286_write(priv, 0x3b, MAX9286_REV_TRF(1) | MAX9286_REV_AMP(70) |
>> +		      MAX9286_REV_AMP_X);
>> +	usleep_range(2000, 2500);
>> +
>> +	/*
>> +	 * Enable GMSL links, mask unused ones and autodetect link
>> +	 * used as CSI clock source.
>> +	 */
>> +	max9286_write(priv, 0x00, MAX9286_MSTLINKSEL_AUTO | priv->route_mask);
>> +	max9286_write(priv, 0x0b, link_order[priv->route_mask]);
>> +	max9286_write(priv, 0x69, (0xf & ~priv->route_mask));
>> +
>> +	/*
>> +	 * Video format setup:
>> +	 * Disable CSI output, VC is set according to Link number.
>> +	 */
>> +	max9286_write(priv, 0x15, MAX9286_VCTYPE | MAX9286_0X15_RESV);
>> +
>> +	/* Enable CSI-2 Lane D0-D3 only, DBL mode, YUV422 8-bit. */
>> +	max9286_write(priv, 0x12, MAX9286_CSIDBL | MAX9286_DBL |
>> +		      MAX9286_CSILANECNT(priv->csi2_data_lanes) |
>> +		      MAX9286_DATATYPE_YUV422_8BIT);
>> +
>> +	/* Automatic: FRAMESYNC taken from the slowest Link. */
>> +	max9286_write(priv, 0x01, MAX9286_FSYNCMODE_INT_HIZ |
>> +		      MAX9286_FSYNCMETH_AUTO);
>> +
>> +	/* Enable HS/VS encoding, use D14/15 for HS/VS, invert VS. */
>> +	max9286_write(priv, 0x0c, MAX9286_HVEN | MAX9286_INVVS |
>> +		      MAX9286_HVSRC_D14);
>> +
>> +	/*
>> +	 * The overlap window seems to provide additional validation by tracking
>> +	 * the delay between vsync and frame sync, generating an error if the
>> +	 * delay is bigger than the programmed window, though it's not yet clear
>> +	 * what value should be set.
>> +	 *
>> +	 * As it's an optional value and can be disabled, we do so by setting
>> +	 * a 0 overlap value.
>> +	 */
>> +	max9286_write(priv, 0x63, 0);
>> +	max9286_write(priv, 0x64, 0);
>> +
>> +	/*
>> +	 * Wait for 2ms to allow the link to resynchronize after the
>> +	 * configuration change.
>> +	 */
>> +	usleep_range(2000, 5000);
>> +
>> +	return 0;
>> +}
>> +
>> +static void max9286_gpio_set(struct gpio_chip *chip,
>> +			     unsigned int offset, int value)
>> +{
>> +	struct max9286_priv *priv = gpiochip_get_data(chip);
>> +
>> +	if (value)
>> +		priv->gpio_state |= BIT(offset);
>> +	else
>> +		priv->gpio_state &= ~BIT(offset);
>> +
>> +	max9286_write(priv, 0x0f, MAX9286_0X0F_RESERVED | priv->gpio_state);
>> +}
>> +
>> +static int max9286_gpio_get(struct gpio_chip *chip, unsigned int offset)
>> +{
>> +	struct max9286_priv *priv = gpiochip_get_data(chip);
>> +
>> +	return priv->gpio_state & BIT(offset);
>> +}
>> +
>> +static int max9286_register_gpio(struct max9286_priv *priv)
>> +{
>> +	struct device *dev = &priv->client->dev;
>> +	struct gpio_chip *gpio = &priv->gpio;
>> +	int ret;
>> +
>> +	static const char * const names[] = {
>> +		"GPIO0OUT",
>> +		"GPIO1OUT",
>> +	};
>> +
>> +	/* Configure the GPIO */
>> +	gpio->label = dev_name(dev);
>> +	gpio->parent = dev;
>> +	gpio->owner = THIS_MODULE;
>> +	gpio->of_node = dev->of_node;
>> +	gpio->ngpio = 2;
>> +	gpio->base = -1;
>> +	gpio->set = max9286_gpio_set;
>> +	gpio->get = max9286_gpio_get;
>> +	gpio->can_sleep = true;
>> +	gpio->names = names;
>> +
>> +	/* GPIO values default to high */
>> +	priv->gpio_state = BIT(0) | BIT(1);
>> +
>> +	ret = devm_gpiochip_add_data(dev, gpio, priv);
>> +	if (ret)
>> +		dev_err(dev, "Unable to create gpio_chip\n");
>> +
>> +	return ret;
>> +}
>> +
>> +static int max9286_init(struct device *dev)
>> +{
>> +	struct max9286_priv *priv;
>> +	struct i2c_client *client;
>> +	int ret;
>> +
>> +	client = to_i2c_client(dev);
>> +	priv = i2c_get_clientdata(client);
>> +
>> +	/* Enable the bus power. */
>> +	ret = regulator_enable(priv->regulator);
>> +	if (ret < 0) {
>> +		dev_err(&client->dev, "Unable to turn PoC on\n");
>> +		return ret;
>> +	}
>> +
>> +	ret = max9286_setup(priv);
>> +	if (ret) {
>> +		dev_err(dev, "Unable to setup max9286\n");
>> +		goto err_regulator;
>> +	}
>> +
>> +	/*
>> +	 * Register all V4L2 interactions for the MAX9286 and notifiers for
>> +	 * any subdevices connected.
>> +	 */
>> +	ret = max9286_v4l2_register(priv);
>> +	if (ret) {
>> +		dev_err(dev, "Failed to register with V4L2\n");
>> +		goto err_regulator;
>> +	}
>> +
>> +	ret = max9286_i2c_mux_init(priv);
>> +	if (ret) {
>> +		dev_err(dev, "Unable to initialize I2C multiplexer\n");
>> +		goto err_v4l2_register;
>> +	}
>> +
>> +	/* Leave the mux channels disabled until they are selected. */
>> +	max9286_i2c_mux_close(priv);
>> +
>> +	return 0;
>> +
>> +err_v4l2_register:
>> +	max9286_v4l2_unregister(priv);
>> +err_regulator:
>> +	regulator_disable(priv->regulator);
>> +
>> +	return ret;
>> +}
>> +
>> +static void max9286_cleanup_dt(struct max9286_priv *priv)
>> +{
>> +	struct max9286_source *source;
>> +
>> +	for_each_source(priv, source) {
>> +		fwnode_handle_put(source->fwnode);
>> +		source->fwnode = NULL;
>> +	}
>> +}
>> +
>> +static int max9286_parse_dt(struct max9286_priv *priv)
>> +{
>> +	struct device *dev = &priv->client->dev;
>> +	struct device_node *i2c_mux;
>> +	struct device_node *node = NULL;
>> +	unsigned int i2c_mux_mask = 0;
>> +
>> +	of_node_get(dev->of_node);
>> +	i2c_mux = of_find_node_by_name(dev->of_node, "i2c-mux");
>> +	if (!i2c_mux) {
>> +		dev_err(dev, "Failed to find i2c-mux node\n");
>> +		of_node_put(dev->of_node);
>> +		return -EINVAL;
>> +	}
>> +
>> +	/* Identify which i2c-mux channels are enabled */
>> +	for_each_child_of_node(i2c_mux, node) {
>> +		u32 id = 0;
>> +
>> +		of_property_read_u32(node, "reg", &id);
>> +		if (id >= MAX9286_NUM_GMSL)
>> +			continue;
>> +
>> +		if (!of_device_is_available(node)) {
>> +			dev_dbg(dev, "Skipping disabled I2C bus port %u\n", id);
>> +			continue;
>> +		}
>> +
>> +		i2c_mux_mask |= BIT(id);
>> +	}
>> +	of_node_put(node);
>> +	of_node_put(i2c_mux);
>> +
>> +	/* Parse the endpoints */
>> +	for_each_endpoint_of_node(dev->of_node, node) {
>> +		struct max9286_source *source;
>> +		struct of_endpoint ep;
>> +
>> +		of_graph_parse_endpoint(node, &ep);
>> +		dev_dbg(dev, "Endpoint %pOF on port %d",
>> +			ep.local_node, ep.port);
>> +
>> +		if (ep.port > MAX9286_NUM_GMSL) {
>> +			dev_err(dev, "Invalid endpoint %s on port %d",
>> +				of_node_full_name(ep.local_node), ep.port);
>> +			continue;
>> +		}
>> +
>> +		/* For the source endpoint just parse the bus configuration. */
>> +		if (ep.port == MAX9286_SRC_PAD) {
>> +			struct v4l2_fwnode_endpoint vep = {
>> +				.bus_type = V4L2_MBUS_CSI2_DPHY
>> +			};
>> +			int ret;
>> +
>> +			ret = v4l2_fwnode_endpoint_parse(
>> +					of_fwnode_handle(node), &vep);
>> +			if (ret) {
>> +				of_node_put(node);
>> +				of_node_put(dev->of_node);
>> +				return ret;
>> +			}
>> +
>> +			if (vep.bus_type != V4L2_MBUS_CSI2_DPHY) {
>> +				dev_err(dev,
>> +					"Media bus %u type not supported\n",
>> +					vep.bus_type);
>> +				v4l2_fwnode_endpoint_free(&vep);
>> +				of_node_put(node);
>> +				of_node_put(dev->of_node);
>> +				return -EINVAL;
>> +			}
>> +
>> +			priv->csi2_data_lanes =
>> +				vep.bus.mipi_csi2.num_data_lanes;
>> +			v4l2_fwnode_endpoint_free(&vep);
>> +
>> +			continue;
>> +		}
>> +
>> +		/* Skip if the corresponding GMSL link is unavailable. */
>> +		if (!(i2c_mux_mask & BIT(ep.port)))
>> +			continue;
>> +
>> +		if (priv->sources[ep.port].fwnode) {
>> +			dev_err(dev,
>> +				"Multiple port endpoints are not supported: %d",
>> +				ep.port);
>> +
>> +			continue;
>> +		}
>> +
>> +		source = &priv->sources[ep.port];
>> +		source->fwnode = fwnode_graph_get_remote_endpoint(
>> +						of_fwnode_handle(node));
>> +		if (!source->fwnode) {
>> +			dev_err(dev,
>> +				"Endpoint %pOF has no remote endpoint connection\n",
>> +				ep.local_node);
>> +
>> +			continue;
>> +		}
>> +
>> +		priv->source_mask |= BIT(ep.port);
>> +		priv->nsources++;
>> +	}
>> +	of_node_put(node);
>> +	of_node_put(dev->of_node);
>> +
>> +	priv->route_mask = priv->source_mask;
>> +
>> +	return 0;
>> +}
>> +
>> +static int max9286_probe(struct i2c_client *client)
>> +{
>> +	struct max9286_priv *priv;
>> +	int ret;
>> +
>> +	priv = devm_kzalloc(&client->dev, sizeof(*priv), GFP_KERNEL);
>> +	if (!priv)
>> +		return -ENOMEM;
>> +
>> +	mutex_init(&priv->mutex);
>> +
>> +	priv->client = client;
>> +	i2c_set_clientdata(client, priv);
>> +
>> +	priv->gpiod_pwdn = devm_gpiod_get_optional(&client->dev, "enable",
>> +						   GPIOD_OUT_HIGH);
>> +	if (IS_ERR(priv->gpiod_pwdn))
>> +		return PTR_ERR(priv->gpiod_pwdn);
>> +
>> +	gpiod_set_consumer_name(priv->gpiod_pwdn, "max9286-pwdn");
>> +	gpiod_set_value_cansleep(priv->gpiod_pwdn, 1);
>> +
>> +	/* Wait at least 4ms before the I2C lines latch to the address */
>> +	if (priv->gpiod_pwdn)
>> +		usleep_range(4000, 5000);
>> +
>> +	/*
>> +	 * The MAX9286 starts by default with all ports enabled, we disable all
>> +	 * ports early to ensure that all channels are disabled if we error out
>> +	 * and keep the bus consistent.
>> +	 */
>> +	max9286_i2c_mux_close(priv);
>> +
>> +	/*
>> +	 * The MAX9286 initialises with auto-acknowledge enabled by default.
>> +	 * This can be invasive to other transactions on the same bus, so
>> +	 * disable it early. It will be enabled only as and when needed.
>> +	 */
>> +	max9286_configure_i2c(priv, false);
>> +
>> +	ret = max9286_register_gpio(priv);
>> +	if (ret)
>> +		goto err_powerdown;
>> +
>> +	priv->regulator = devm_regulator_get(&client->dev, "poc");
>> +	if (IS_ERR(priv->regulator)) {
>> +		if (PTR_ERR(priv->regulator) != -EPROBE_DEFER)
>> +			dev_err(&client->dev,
>> +				"Unable to get PoC regulator (%ld)\n",
>> +				PTR_ERR(priv->regulator));
>> +		ret = PTR_ERR(priv->regulator);
>> +		goto err_powerdown;
>> +	}
>> +
>> +	ret = max9286_parse_dt(priv);
>> +	if (ret)
>> +		goto err_powerdown;
>> +
>> +	ret = max9286_init(&client->dev);
>> +	if (ret < 0)
>> +		goto err_cleanup_dt;
>> +
>> +	return 0;
>> +
>> +err_cleanup_dt:
>> +	max9286_cleanup_dt(priv);
>> +err_powerdown:
>> +	gpiod_set_value_cansleep(priv->gpiod_pwdn, 0);
>> +
>> +	return ret;
>> +}
>> +
>> +static int max9286_remove(struct i2c_client *client)
>> +{
>> +	struct max9286_priv *priv = i2c_get_clientdata(client);
>> +
>> +	i2c_mux_del_adapters(priv->mux);
>> +
>> +	max9286_v4l2_unregister(priv);
>> +
>> +	regulator_disable(priv->regulator);
>> +
>> +	gpiod_set_value_cansleep(priv->gpiod_pwdn, 0);
>> +
>> +	max9286_cleanup_dt(priv);
>> +
>> +	return 0;
>> +}
>> +
>> +static const struct of_device_id max9286_dt_ids[] = {
>> +	{ .compatible = "maxim,max9286" },
>> +	{},
>> +};
>> +MODULE_DEVICE_TABLE(of, max9286_dt_ids);
>> +
>> +static struct i2c_driver max9286_i2c_driver = {
>> +	.driver	= {
>> +		.name		= "max9286",
>> +		.of_match_table	= of_match_ptr(max9286_dt_ids),
>> +	},
>> +	.probe_new	= max9286_probe,
>> +	.remove		= max9286_remove,
>> +};
>> +
>> +module_i2c_driver(max9286_i2c_driver);
>> +
>> +MODULE_DESCRIPTION("Maxim MAX9286 GMSL Deserializer Driver");
>> +MODULE_AUTHOR("Jacopo Mondi, Kieran Bingham, Laurent Pinchart, Niklas Söderlund, Vladimir Barinov");
>> +MODULE_LICENSE("GPL");
>> -- 
>> 2.25.1
>>

Re: [PATCH v9 2/4] media: i2c: Add MAX9286 driver

[Manivannan Sadhasivam]

On Thu, May 14, 2020 at 10:53:00AM +0100, Kieran Bingham wrote:
> Hi Mani,
> 
> On 12/05/2020 18:40, Manivannan Sadhasivam wrote:
> > Hi Kieran,
> > 
> > On Tue, May 12, 2020 at 04:51:03PM +0100, Kieran Bingham wrote:
> >> The MAX9286 is a 4-channel GMSL deserializer with coax or STP input and
> >> CSI-2 output. The device supports multicamera streaming applications,
> >> and features the ability to synchronise the attached cameras.
> >>
> >> CSI-2 output can be configured with 1 to 4 lanes, and a control channel
> >> is supported over I2C, which implements an I2C mux to facilitate
> >> communications with connected cameras across the reverse control
> >> channel.
> >>
> >> Signed-off-by: Jacopo Mondi <jacopo+renesas@jmondi.org>
> >> Signed-off-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
> >> Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
> >> Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
> >>
> >> --
> >> v2:
> >>  - Fix MAINTAINERS entry
> >>
> >> This posting is released with the following modifications to work
> >> without Sakari's VC developments:
> >>  - max9286_g_mbus_config() re-instated
> >>  - max9286_get_frame_desc() is not bus/csi aware
> >>  - max9286_{get,set}_routing() removed
> >>
> >> v3:
> >>  - Initialise notifier with v4l2_async_notifier_init
> >>  - Update for new mbus csi2 format V4L2_MBUS_CSI2_DPHY
> >>
> >> v4: - Re-introduce required code to function with the VC series.
> >>
> >>  - Implement max9286_get_routing, max9286_set_routing
> >>  - Remove max9286_g_mbus_config
> >>
> >> v5: (internal release)
> >>  - Fix printk formatting for hex value
> >>  - max9286->sd.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE (add |)
> >>  - MEDIA_ENT_F_PROC_VIDEO_PIXEL_FORMATTER -> MEDIA_ENT_F_VID_IF_BRIDGE
> >>  - Remove 'device is bound' workaround
> >>
> >> v6:
> >>  - v4l2_subdev_krouting instead of v4l2_subdev_routing separated
> >>    to allow integration without the VC/V4L2-Mux series.
> >>  - convert sd_to_max9286 to inline function
> >>  - rename max9286_device to max9286_priv
> >>  - Cleanup the v4l2_async_notifier
> >>  - Extend MODULE_AUTHOR
> >>  - Replace of_graph_get_endpoint_by_regs with fwnode_graph_get_endpoint_by_id
> >>  - Pass default bus type when parsing fwnode endpoint (Manivannan Sadhasivam)
> >>  - Use new YAML file reference in MAINTAINERS
> >>  - Parse new i2c-mux node in max9286_get_i2c_by_id
> >>    (This could/should be refactored to parse these separately first)
> >>  - Spelling and calculation fixes in the FSYNC_LOCKED check comments
> >>  - Identify each enabled i2c-mux channel in a single pass
> >>  - max9286: Improve mux-state readbility [v2]
> >>  - Fix frame sync lock durations
> >>  - Add comment to describe /why/ we must open the mux in s_stream
> >>  - use -EXDEV as return code for failed link synchronisation.
> >>  - Fix reference counting of the dt nodeS
> >>  - Convert to probe_new for I2C
> >>  - Remove redundant max9286_i2c_mux_state
> >>  - Provide optional enable-gpio (max9286-pwdn)
> >>
> >> v7:
> >>  [Kieran]
> >>  - Ensure powerdown lines are optional
> >>  - Add a 4ms power-up delay
> >>  - Add max9286_check_config_link() to core
> >>  - Add GPIO chip controller for GPIO0OUT and GPIO1OUT
> >>  - Fix GPIO registration
> >>  - max9286: Split out async registration
> >>    (fixes regulator -EPROBE_DEFERs failures)
> >>  - Collect all V4L2 registrations
> >>  - balance v4l2_async refcnting
> >>  - Rename max9286_v4l2_async_ => max9286_v4l2_notifier_
> >>
> >>  [Jacopo]
> >>  - Remove redundanct MAXIM_I2C_SPEED macros
> >>  - Move notifiers operations
> >>  - Add delay after reverse channel reconfiguration
> >>  - Move link setup to completion
> >>  - Fix up max9286_check_config_link() implementation
> >>  - Remove redundant dual configuration of reverse channel
> >>
> >> v8:
> >>
> >> [Kieran]
> >>  - Update the bound_sources mask on unbind
> >>  - Convert probe kzalloc usage to devm_ variant
> >>  - Fix up cleanup path from GPIO PowerDown registration
> >>  - cleanup GPIO device registration fail path
> >>  - Convert to use devm_regulator_get()
> >>  - Fit max9286_parse_dt print on one line
> >>  - Move multi-device workarounds out of upstream driver
> >>  - Remove I2C mod-table
> >>  - Lock format changes
> >>  - Describe pad index usage
> >>  - Remove poc_enabled workaround
> >>  - Rename the max9286_gpio to be more explicit on it's actions.
> >>  - Move max9286_init_format call
> >>  - Rework probe sequence and simplify error paths.
> >>  - Simplify i2c comments
> >>  - Implement Pixelrate control
> >>  - Disable overlap window
> >>
> >> [Jacopo]
> >>  - Adapt Kconfig to latest upstream changes
> >>  - Put of node on error
> >>  - Calculate pixel rate
> >>  - Simplify overlap window disablement
> >>
> >> v9:
> >>
> >> [Kieran]
> >>  - Kconfig: Depend on OF
> >>  - Re-sort addition to Makefile
> >> ---
> >>  MAINTAINERS                 |   10 +
> >>  drivers/media/i2c/Kconfig   |   13 +
> >>  drivers/media/i2c/Makefile  |    1 +
> >>  drivers/media/i2c/max9286.c | 1332 +++++++++++++++++++++++++++++++++++
> >>  4 files changed, 1356 insertions(+)
> >>  create mode 100644 drivers/media/i2c/max9286.c
> >>
> >> diff --git a/MAINTAINERS b/MAINTAINERS
> >> index a7bb6e22d5da..99e3bf7760fd 100644
> >> --- a/MAINTAINERS
> >> +++ b/MAINTAINERS
> >> @@ -10274,6 +10274,16 @@ F:	Documentation/hwmon/max6697.rst
> >>  F:	drivers/hwmon/max6697.c
> >>  F:	include/linux/platform_data/max6697.h
> >>  
> >> +MAX9286 QUAD GMSL DESERIALIZER DRIVER
> >> +M:	Jacopo Mondi <jacopo+renesas@jmondi.org>
> >> +M:	Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
> >> +M:	Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
> >> +M:	Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
> >> +L:	linux-media@vger.kernel.org
> >> +S:	Maintained
> >> +F:	Documentation/devicetree/bindings/media/i2c/maxim,max9286.yaml
> >> +F:	drivers/media/i2c/max9286.c
> >> +
> >>  MAX9860 MONO AUDIO VOICE CODEC DRIVER
> >>  M:	Peter Rosin <peda@axentia.se>
> >>  L:	alsa-devel@alsa-project.org (moderated for non-subscribers)
> >> diff --git a/drivers/media/i2c/Kconfig b/drivers/media/i2c/Kconfig
> >> index 3abc80373ec0..2e390f41f6da 100644
> >> --- a/drivers/media/i2c/Kconfig
> >> +++ b/drivers/media/i2c/Kconfig
> >> @@ -464,6 +464,19 @@ config VIDEO_VPX3220
> >>  	  To compile this driver as a module, choose M here: the
> >>  	  module will be called vpx3220.
> >>  
> >> +config VIDEO_MAX9286
> >> +	tristate "Maxim MAX9286 GMSL deserializer support"
> >> +	depends on I2C && I2C_MUX
> >> +	depends on OF
> >> +	select V4L2_FWNODE
> >> +	select VIDEO_V4L2_SUBDEV_API
> >> +	select MEDIA_CONTROLLER
> >> +	help
> >> +	  This driver supports the Maxim MAX9286 GMSL deserializer.
> >> +
> >> +	  To compile this driver as a module, choose M here: the
> >> +	  module will be called max9286.
> >> +
> >>  comment "Video and audio decoders"
> >>  
> >>  config VIDEO_SAA717X
> >> diff --git a/drivers/media/i2c/Makefile b/drivers/media/i2c/Makefile
> >> index 77bf7d0b691f..f0b001ee4b05 100644
> >> --- a/drivers/media/i2c/Makefile
> >> +++ b/drivers/media/i2c/Makefile
> >> @@ -117,6 +117,7 @@ obj-$(CONFIG_VIDEO_IMX274)	+= imx274.o
> >>  obj-$(CONFIG_VIDEO_IMX290)	+= imx290.o
> >>  obj-$(CONFIG_VIDEO_IMX319)	+= imx319.o
> >>  obj-$(CONFIG_VIDEO_IMX355)	+= imx355.o
> >> +obj-$(CONFIG_VIDEO_MAX9286)	+= max9286.o
> >>  obj-$(CONFIG_VIDEO_ST_MIPID02) += st-mipid02.o
> >>  
> >>  obj-$(CONFIG_SDR_MAX2175) += max2175.o
> >> diff --git a/drivers/media/i2c/max9286.c b/drivers/media/i2c/max9286.c
> >> new file mode 100644
> >> index 000000000000..481d65f2b51d
> >> --- /dev/null
> >> +++ b/drivers/media/i2c/max9286.c
> >> @@ -0,0 +1,1332 @@
> >> +// SPDX-License-Identifier: GPL-2.0+
> >> +/*
> >> + * Maxim MAX9286 GMSL Deserializer Driver
> >> + *
> >> + * Copyright (C) 2017-2019 Jacopo Mondi
> >> + * Copyright (C) 2017-2019 Kieran Bingham
> >> + * Copyright (C) 2017-2019 Laurent Pinchart
> >> + * Copyright (C) 2017-2019 Niklas Söderlund
> >> + * Copyright (C) 2016 Renesas Electronics Corporation
> >> + * Copyright (C) 2015 Cogent Embedded, Inc.
> >> + */
> >> +
> >> +#include <linux/delay.h>
> >> +#include <linux/device.h>
> >> +#include <linux/fwnode.h>
> >> +#include <linux/gpio/consumer.h>
> >> +#include <linux/gpio/driver.h>
> >> +#include <linux/i2c.h>
> >> +#include <linux/i2c-mux.h>
> >> +#include <linux/module.h>
> >> +#include <linux/mutex.h>
> >> +#include <linux/of_graph.h>
> >> +#include <linux/regulator/consumer.h>
> >> +#include <linux/slab.h>
> >> +
> >> +#include <media/v4l2-async.h>
> >> +#include <media/v4l2-ctrls.h>
> >> +#include <media/v4l2-device.h>
> >> +#include <media/v4l2-fwnode.h>
> >> +#include <media/v4l2-subdev.h>
> >> +
> >> +/* Register 0x00 */
> >> +#define MAX9286_MSTLINKSEL_AUTO		(7 << 5)
> >> +#define MAX9286_MSTLINKSEL(n)		((n) << 5)
> >> +#define MAX9286_EN_VS_GEN		BIT(4)
> >> +#define MAX9286_LINKEN(n)		(1 << (n))
> >> +/* Register 0x01 */
> >> +#define MAX9286_FSYNCMODE_ECU		(3 << 6)
> >> +#define MAX9286_FSYNCMODE_EXT		(2 << 6)
> >> +#define MAX9286_FSYNCMODE_INT_OUT	(1 << 6)
> >> +#define MAX9286_FSYNCMODE_INT_HIZ	(0 << 6)
> >> +#define MAX9286_GPIEN			BIT(5)
> >> +#define MAX9286_ENLMO_RSTFSYNC		BIT(2)
> >> +#define MAX9286_FSYNCMETH_AUTO		(2 << 0)
> >> +#define MAX9286_FSYNCMETH_SEMI_AUTO	(1 << 0)
> >> +#define MAX9286_FSYNCMETH_MANUAL	(0 << 0)
> >> +#define MAX9286_REG_FSYNC_PERIOD_L	0x06
> >> +#define MAX9286_REG_FSYNC_PERIOD_M	0x07
> >> +#define MAX9286_REG_FSYNC_PERIOD_H	0x08
> >> +/* Register 0x0a */
> >> +#define MAX9286_FWDCCEN(n)		(1 << ((n) + 4))
> >> +#define MAX9286_REVCCEN(n)		(1 << (n))
> >> +/* Register 0x0c */
> >> +#define MAX9286_HVEN			BIT(7)
> >> +#define MAX9286_EDC_6BIT_HAMMING	(2 << 5)
> >> +#define MAX9286_EDC_6BIT_CRC		(1 << 5)
> >> +#define MAX9286_EDC_1BIT_PARITY		(0 << 5)
> >> +#define MAX9286_DESEL			BIT(4)
> >> +#define MAX9286_INVVS			BIT(3)
> >> +#define MAX9286_INVHS			BIT(2)
> >> +#define MAX9286_HVSRC_D0		(2 << 0)
> >> +#define MAX9286_HVSRC_D14		(1 << 0)
> >> +#define MAX9286_HVSRC_D18		(0 << 0)
> >> +/* Register 0x0f */
> >> +#define MAX9286_0X0F_RESERVED		BIT(3)
> >> +/* Register 0x12 */
> >> +#define MAX9286_CSILANECNT(n)		(((n) - 1) << 6)
> >> +#define MAX9286_CSIDBL			BIT(5)
> >> +#define MAX9286_DBL			BIT(4)
> >> +#define MAX9286_DATATYPE_USER_8BIT	(11 << 0)
> >> +#define MAX9286_DATATYPE_USER_YUV_12BIT	(10 << 0)
> >> +#define MAX9286_DATATYPE_USER_24BIT	(9 << 0)
> >> +#define MAX9286_DATATYPE_RAW14		(8 << 0)
> >> +#define MAX9286_DATATYPE_RAW11		(7 << 0)
> >> +#define MAX9286_DATATYPE_RAW10		(6 << 0)
> >> +#define MAX9286_DATATYPE_RAW8		(5 << 0)
> >> +#define MAX9286_DATATYPE_YUV422_10BIT	(4 << 0)
> >> +#define MAX9286_DATATYPE_YUV422_8BIT	(3 << 0)
> >> +#define MAX9286_DATATYPE_RGB555		(2 << 0)
> >> +#define MAX9286_DATATYPE_RGB565		(1 << 0)
> >> +#define MAX9286_DATATYPE_RGB888		(0 << 0)
> >> +/* Register 0x15 */
> >> +#define MAX9286_VC(n)			((n) << 5)
> >> +#define MAX9286_VCTYPE			BIT(4)
> >> +#define MAX9286_CSIOUTEN		BIT(3)
> >> +#define MAX9286_0X15_RESV		(3 << 0)
> >> +/* Register 0x1b */
> >> +#define MAX9286_SWITCHIN(n)		(1 << ((n) + 4))
> >> +#define MAX9286_ENEQ(n)			(1 << (n))
> >> +/* Register 0x27 */
> >> +#define MAX9286_LOCKED			BIT(7)
> >> +/* Register 0x31 */
> >> +#define MAX9286_FSYNC_LOCKED		BIT(6)
> >> +/* Register 0x34 */
> >> +#define MAX9286_I2CLOCACK		BIT(7)
> >> +#define MAX9286_I2CSLVSH_1046NS_469NS	(3 << 5)
> >> +#define MAX9286_I2CSLVSH_938NS_352NS	(2 << 5)
> >> +#define MAX9286_I2CSLVSH_469NS_234NS	(1 << 5)
> >> +#define MAX9286_I2CSLVSH_352NS_117NS	(0 << 5)
> >> +#define MAX9286_I2CMSTBT_837KBPS	(7 << 2)
> >> +#define MAX9286_I2CMSTBT_533KBPS	(6 << 2)
> >> +#define MAX9286_I2CMSTBT_339KBPS	(5 << 2)
> >> +#define MAX9286_I2CMSTBT_173KBPS	(4 << 2)
> >> +#define MAX9286_I2CMSTBT_105KBPS	(3 << 2)
> >> +#define MAX9286_I2CMSTBT_84KBPS		(2 << 2)
> >> +#define MAX9286_I2CMSTBT_28KBPS		(1 << 2)
> >> +#define MAX9286_I2CMSTBT_8KBPS		(0 << 2)
> >> +#define MAX9286_I2CSLVTO_NONE		(3 << 0)
> >> +#define MAX9286_I2CSLVTO_1024US		(2 << 0)
> >> +#define MAX9286_I2CSLVTO_256US		(1 << 0)
> >> +#define MAX9286_I2CSLVTO_64US		(0 << 0)
> >> +/* Register 0x3b */
> >> +#define MAX9286_REV_TRF(n)		((n) << 4)
> >> +#define MAX9286_REV_AMP(n)		((((n) - 30) / 10) << 1) /* in mV */
> >> +#define MAX9286_REV_AMP_X		BIT(0)
> >> +/* Register 0x3f */
> >> +#define MAX9286_EN_REV_CFG		BIT(6)
> >> +#define MAX9286_REV_FLEN(n)		((n) - 20)
> >> +/* Register 0x49 */
> >> +#define MAX9286_VIDEO_DETECT_MASK	0x0f
> >> +/* Register 0x69 */
> >> +#define MAX9286_LFLTBMONMASKED		BIT(7)
> >> +#define MAX9286_LOCKMONMASKED		BIT(6)
> >> +#define MAX9286_AUTOCOMBACKEN		BIT(5)
> >> +#define MAX9286_AUTOMASKEN		BIT(4)
> >> +#define MAX9286_MASKLINK(n)		((n) << 0)
> >> +
> >> +/*
> >> + * The sink and source pads are created to match the OF graph port numbers so
> >> + * that their indexes can be used interchangeably.
> >> + */
> >> +#define MAX9286_NUM_GMSL		4
> >> +#define MAX9286_N_SINKS			4
> >> +#define MAX9286_N_PADS			5
> >> +#define MAX9286_SRC_PAD			4
> >> +
> >> +struct max9286_source {
> >> +	struct v4l2_async_subdev asd;
> >> +	struct v4l2_subdev *sd;
> >> +	struct fwnode_handle *fwnode;
> >> +};
> >> +
> >> +#define asd_to_max9286_source(_asd) \
> >> +	container_of(_asd, struct max9286_source, asd)
> >> +
> >> +struct max9286_priv {
> >> +	struct i2c_client *client;
> >> +	struct gpio_desc *gpiod_pwdn;
> >> +	struct v4l2_subdev sd;
> >> +	struct media_pad pads[MAX9286_N_PADS];
> >> +	struct regulator *regulator;
> >> +
> >> +	struct gpio_chip gpio;
> >> +	u8 gpio_state;
> >> +
> >> +	struct i2c_mux_core *mux;
> >> +	unsigned int mux_channel;
> >> +	bool mux_open;
> >> +
> >> +	struct v4l2_ctrl_handler ctrls;
> >> +	struct v4l2_ctrl *pixelrate;
> >> +
> >> +	struct v4l2_mbus_framefmt fmt[MAX9286_N_SINKS];
> >> +
> >> +	/* Protects controls and fmt structures */
> >> +	struct mutex mutex;
> >> +
> >> +	unsigned int nsources;
> >> +	unsigned int source_mask;
> >> +	unsigned int route_mask;
> >> +	unsigned int bound_sources;
> >> +	unsigned int csi2_data_lanes;
> >> +	struct max9286_source sources[MAX9286_NUM_GMSL];
> >> +	struct v4l2_async_notifier notifier;
> >> +};
> >> +
[...]
> >> +static int max9286_enum_mbus_code(struct v4l2_subdev *sd,
> >> +				  struct v4l2_subdev_pad_config *cfg,
> >> +				  struct v4l2_subdev_mbus_code_enum *code)
> >> +{
> >> +	if (code->pad || code->index > 0)
> >> +		return -EINVAL;
> >> +
> >> +	code->code = MEDIA_BUS_FMT_UYVY8_2X8;
> >> +
> >> +	return 0;
> >> +}
> >> +
> >> +static struct v4l2_mbus_framefmt *
> >> +max9286_get_pad_format(struct max9286_priv *priv,
> >> +		       struct v4l2_subdev_pad_config *cfg,
> >> +		       unsigned int pad, u32 which)
> >> +{
> >> +	switch (which) {
> >> +	case V4L2_SUBDEV_FORMAT_TRY:
> >> +		return v4l2_subdev_get_try_format(&priv->sd, cfg, pad);
> >> +	case V4L2_SUBDEV_FORMAT_ACTIVE:
> >> +		return &priv->fmt[pad];
> >> +	default:
> >> +		return NULL;
> >> +	}
> >> +}
> >> +
> >> +static int max9286_set_fmt(struct v4l2_subdev *sd,
> >> +			   struct v4l2_subdev_pad_config *cfg,
> >> +			   struct v4l2_subdev_format *format)
> >> +{
> >> +	struct max9286_priv *priv = sd_to_max9286(sd);
> >> +	struct v4l2_mbus_framefmt *cfg_fmt;
> >> +
> >> +	if (format->pad >= MAX9286_SRC_PAD)
> >> +		return -EINVAL;
> >> +
> >> +	/* Refuse non YUV422 formats as we hardcode DT to 8 bit YUV422 */
> >> +	switch (format->format.code) {
> >> +	case MEDIA_BUS_FMT_UYVY8_2X8:
> >> +	case MEDIA_BUS_FMT_VYUY8_2X8:
> >> +	case MEDIA_BUS_FMT_YUYV8_2X8:
> >> +	case MEDIA_BUS_FMT_YVYU8_2X8:
> >> +		break;
> >> +	default:
> >> +		format->format.code = MEDIA_BUS_FMT_YUYV8_2X8;
> > 
> > Is there any reason for not setting default format to MEDIA_BUS_FMT_UYVY8_2X8?
> > 
> 
> 
> No good reason no, and I see that in max9286_enum_mbus_code(), we
> currently code to MEDIA_BUS_FMT_YUYV8_2X8, and that's the value that we
> init to, so that would be a better default indeed.
> 

max9286_enum_mbus_code() returns MEDIA_BUS_FMT_UYVY8_2X8, no?

Thanks,
Mani

> I'll update this for v10.
> 
> 
> > Thanks,
> > Mani
> > 
> >> +		break;
> >> +	}
> >> +
> >> +	cfg_fmt = max9286_get_pad_format(priv, cfg, format->pad, format->which);
> >> +	if (!cfg_fmt)
> >> +		return -EINVAL;
> >> +
> >> +	mutex_lock(&priv->mutex);
> >> +	*cfg_fmt = format->format;
> >> +	mutex_unlock(&priv->mutex);
> >> +
> >> +	return 0;
> >> +}
> >> +
> >> +static int max9286_get_fmt(struct v4l2_subdev *sd,
> >> +			   struct v4l2_subdev_pad_config *cfg,
> >> +			   struct v4l2_subdev_format *format)
> >> +{
> >> +	struct max9286_priv *priv = sd_to_max9286(sd);
> >> +	struct v4l2_mbus_framefmt *cfg_fmt;
> >> +
> >> +	if (format->pad >= MAX9286_SRC_PAD)
> >> +		return -EINVAL;
> >> +
> >> +	cfg_fmt = max9286_get_pad_format(priv, cfg, format->pad, format->which);
> >> +	if (!cfg_fmt)
> >> +		return -EINVAL;
> >> +
> >> +	mutex_lock(&priv->mutex);
> >> +	format->format = *cfg_fmt;
> >> +	mutex_unlock(&priv->mutex);
> >> +
> >> +	return 0;
> >> +}
> >> +
> >> +static const struct v4l2_subdev_video_ops max9286_video_ops = {
> >> +	.s_stream	= max9286_s_stream,
> >> +};
> >> +
> >> +static const struct v4l2_subdev_pad_ops max9286_pad_ops = {
> >> +	.enum_mbus_code = max9286_enum_mbus_code,
> >> +	.get_fmt	= max9286_get_fmt,
> >> +	.set_fmt	= max9286_set_fmt,
> >> +};
> >> +
> >> +static const struct v4l2_subdev_ops max9286_subdev_ops = {
> >> +	.video		= &max9286_video_ops,
> >> +	.pad		= &max9286_pad_ops,
> >> +};
> >> +
> >> +static void max9286_init_format(struct v4l2_mbus_framefmt *fmt)
> >> +{
> >> +	fmt->width		= 1280;
> >> +	fmt->height		= 800;
> >> +	fmt->code		= MEDIA_BUS_FMT_UYVY8_2X8;
> >> +	fmt->colorspace		= V4L2_COLORSPACE_SRGB;
> >> +	fmt->field		= V4L2_FIELD_NONE;
> >> +	fmt->ycbcr_enc		= V4L2_YCBCR_ENC_DEFAULT;
> >> +	fmt->quantization	= V4L2_QUANTIZATION_DEFAULT;
> >> +	fmt->xfer_func		= V4L2_XFER_FUNC_DEFAULT;
> >> +}
> >> +
> >> +static int max9286_open(struct v4l2_subdev *subdev, struct v4l2_subdev_fh *fh)
> >> +{
> >> +	struct v4l2_mbus_framefmt *format;
> >> +	unsigned int i;
> >> +
> >> +	for (i = 0; i < MAX9286_N_SINKS; i++) {
> >> +		format = v4l2_subdev_get_try_format(subdev, fh->pad, i);
> >> +		max9286_init_format(format);
> >> +	}
> >> +
> >> +	return 0;
> >> +}
> >> +
> >> +static const struct v4l2_subdev_internal_ops max9286_subdev_internal_ops = {
> >> +	.open = max9286_open,
> >> +};
> >> +
> >> +static int max9286_s_ctrl(struct v4l2_ctrl *ctrl)
> >> +{
> >> +	switch (ctrl->id) {
> >> +	case V4L2_CID_PIXEL_RATE:
> >> +		return 0;
> >> +	default:
> >> +		return -EINVAL;
> >> +	}
> >> +}
> >> +
> >> +static const struct v4l2_ctrl_ops max9286_ctrl_ops = {
> >> +	.s_ctrl	= max9286_s_ctrl,
> >> +};
> >> +
> >> +static int max9286_v4l2_register(struct max9286_priv *priv)
> >> +{
> >> +	struct device *dev = &priv->client->dev;
> >> +	struct fwnode_handle *ep;
> >> +	int ret;
> >> +	int i;
> >> +
> >> +	/* Register v4l2 async notifiers for connected Camera subdevices */
> >> +	ret = max9286_v4l2_notifier_register(priv);
> >> +	if (ret) {
> >> +		dev_err(dev, "Unable to register V4L2 async notifiers\n");
> >> +		return ret;
> >> +	}
> >> +
> >> +	/* Configure V4L2 for the MAX9286 itself */
> >> +
> >> +	for (i = 0; i < MAX9286_N_SINKS; i++)
> >> +		max9286_init_format(&priv->fmt[i]);
> >> +
> >> +	v4l2_i2c_subdev_init(&priv->sd, priv->client, &max9286_subdev_ops);
> >> +	priv->sd.internal_ops = &max9286_subdev_internal_ops;
> >> +	priv->sd.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;
> >> +
> >> +	v4l2_ctrl_handler_init(&priv->ctrls, 1);
> >> +	priv->pixelrate = v4l2_ctrl_new_std(&priv->ctrls,
> >> +					    &max9286_ctrl_ops,
> >> +					    V4L2_CID_PIXEL_RATE,
> >> +					    1, INT_MAX, 1, 50000000);
> >> +
> >> +	priv->sd.ctrl_handler = &priv->ctrls;
> >> +	ret = priv->ctrls.error;
> >> +	if (ret)
> >> +		goto err_async;
> >> +
> >> +	priv->sd.entity.function = MEDIA_ENT_F_VID_IF_BRIDGE;
> >> +
> >> +	priv->pads[MAX9286_SRC_PAD].flags = MEDIA_PAD_FL_SOURCE;
> >> +	for (i = 0; i < MAX9286_SRC_PAD; i++)
> >> +		priv->pads[i].flags = MEDIA_PAD_FL_SINK;
> >> +	ret = media_entity_pads_init(&priv->sd.entity, MAX9286_N_PADS,
> >> +				     priv->pads);
> >> +	if (ret)
> >> +		goto err_async;
> >> +
> >> +	ep = fwnode_graph_get_endpoint_by_id(dev_fwnode(dev), MAX9286_SRC_PAD,
> >> +					     0, 0);
> >> +	if (!ep) {
> >> +		dev_err(dev, "Unable to retrieve endpoint on \"port@4\"\n");
> >> +		ret = -ENOENT;
> >> +		goto err_async;
> >> +	}
> >> +	priv->sd.fwnode = ep;
> >> +
> >> +	ret = v4l2_async_register_subdev(&priv->sd);
> >> +	if (ret < 0) {
> >> +		dev_err(dev, "Unable to register subdevice\n");
> >> +		goto err_put_node;
> >> +	}
> >> +
> >> +	return 0;
> >> +
> >> +err_put_node:
> >> +	fwnode_handle_put(ep);
> >> +err_async:
> >> +	max9286_v4l2_notifier_unregister(priv);
> >> +
> >> +	return ret;
> >> +}
> >> +
> >> +static void max9286_v4l2_unregister(struct max9286_priv *priv)
> >> +{
> >> +	fwnode_handle_put(priv->sd.fwnode);
> >> +	v4l2_async_unregister_subdev(&priv->sd);
> >> +	max9286_v4l2_notifier_unregister(priv);
> >> +}
> >> +
> >> +/* -----------------------------------------------------------------------------
> >> + * Probe/Remove
> >> + */
> >> +
> >> +static int max9286_setup(struct max9286_priv *priv)
> >> +{
> >> +	/*
> >> +	 * Link ordering values for all enabled links combinations. Orders must
> >> +	 * be assigned sequentially from 0 to the number of enabled links
> >> +	 * without leaving any hole for disabled links. We thus assign orders to
> >> +	 * enabled links first, and use the remaining order values for disabled
> >> +	 * links are all links must have a different order value;
> >> +	 */
> >> +	static const u8 link_order[] = {
> >> +		(3 << 6) | (2 << 4) | (1 << 2) | (0 << 0), /* xxxx */
> >> +		(3 << 6) | (2 << 4) | (1 << 2) | (0 << 0), /* xxx0 */
> >> +		(3 << 6) | (2 << 4) | (0 << 2) | (1 << 0), /* xx0x */
> >> +		(3 << 6) | (2 << 4) | (1 << 2) | (0 << 0), /* xx10 */
> >> +		(3 << 6) | (0 << 4) | (2 << 2) | (1 << 0), /* x0xx */
> >> +		(3 << 6) | (1 << 4) | (2 << 2) | (0 << 0), /* x1x0 */
> >> +		(3 << 6) | (1 << 4) | (0 << 2) | (2 << 0), /* x10x */
> >> +		(3 << 6) | (1 << 4) | (1 << 2) | (0 << 0), /* x210 */
> >> +		(0 << 6) | (3 << 4) | (2 << 2) | (1 << 0), /* 0xxx */
> >> +		(1 << 6) | (3 << 4) | (2 << 2) | (0 << 0), /* 1xx0 */
> >> +		(1 << 6) | (3 << 4) | (0 << 2) | (2 << 0), /* 1x0x */
> >> +		(2 << 6) | (3 << 4) | (1 << 2) | (0 << 0), /* 2x10 */
> >> +		(1 << 6) | (0 << 4) | (3 << 2) | (2 << 0), /* 10xx */
> >> +		(2 << 6) | (1 << 4) | (3 << 2) | (0 << 0), /* 21x0 */
> >> +		(2 << 6) | (1 << 4) | (0 << 2) | (3 << 0), /* 210x */
> >> +		(3 << 6) | (2 << 4) | (1 << 2) | (0 << 0), /* 3210 */
> >> +	};
> >> +
> >> +	/*
> >> +	 * Set the I2C bus speed.
> >> +	 *
> >> +	 * Enable I2C Local Acknowledge during the probe sequences of the camera
> >> +	 * only. This should be disabled after the mux is initialised.
> >> +	 */
> >> +	max9286_configure_i2c(priv, true);
> >> +
> >> +	/*
> >> +	 * Reverse channel setup.
> >> +	 *
> >> +	 * - Enable custom reverse channel configuration (through register 0x3f)
> >> +	 *   and set the first pulse length to 35 clock cycles.
> >> +	 * - Increase the reverse channel amplitude to 170mV to accommodate the
> >> +	 *   high threshold enabled by the serializer driver.
> >> +	 */
> >> +	max9286_write(priv, 0x3f, MAX9286_EN_REV_CFG | MAX9286_REV_FLEN(35));
> >> +	max9286_write(priv, 0x3b, MAX9286_REV_TRF(1) | MAX9286_REV_AMP(70) |
> >> +		      MAX9286_REV_AMP_X);
> >> +	usleep_range(2000, 2500);
> >> +
> >> +	/*
> >> +	 * Enable GMSL links, mask unused ones and autodetect link
> >> +	 * used as CSI clock source.
> >> +	 */
> >> +	max9286_write(priv, 0x00, MAX9286_MSTLINKSEL_AUTO | priv->route_mask);
> >> +	max9286_write(priv, 0x0b, link_order[priv->route_mask]);
> >> +	max9286_write(priv, 0x69, (0xf & ~priv->route_mask));
> >> +
> >> +	/*
> >> +	 * Video format setup:
> >> +	 * Disable CSI output, VC is set according to Link number.
> >> +	 */
> >> +	max9286_write(priv, 0x15, MAX9286_VCTYPE | MAX9286_0X15_RESV);
> >> +
> >> +	/* Enable CSI-2 Lane D0-D3 only, DBL mode, YUV422 8-bit. */
> >> +	max9286_write(priv, 0x12, MAX9286_CSIDBL | MAX9286_DBL |
> >> +		      MAX9286_CSILANECNT(priv->csi2_data_lanes) |
> >> +		      MAX9286_DATATYPE_YUV422_8BIT);
> >> +
> >> +	/* Automatic: FRAMESYNC taken from the slowest Link. */
> >> +	max9286_write(priv, 0x01, MAX9286_FSYNCMODE_INT_HIZ |
> >> +		      MAX9286_FSYNCMETH_AUTO);
> >> +
> >> +	/* Enable HS/VS encoding, use D14/15 for HS/VS, invert VS. */
> >> +	max9286_write(priv, 0x0c, MAX9286_HVEN | MAX9286_INVVS |
> >> +		      MAX9286_HVSRC_D14);
> >> +
> >> +	/*
> >> +	 * The overlap window seems to provide additional validation by tracking
> >> +	 * the delay between vsync and frame sync, generating an error if the
> >> +	 * delay is bigger than the programmed window, though it's not yet clear
> >> +	 * what value should be set.
> >> +	 *
> >> +	 * As it's an optional value and can be disabled, we do so by setting
> >> +	 * a 0 overlap value.
> >> +	 */
> >> +	max9286_write(priv, 0x63, 0);
> >> +	max9286_write(priv, 0x64, 0);
> >> +
> >> +	/*
> >> +	 * Wait for 2ms to allow the link to resynchronize after the
> >> +	 * configuration change.
> >> +	 */
> >> +	usleep_range(2000, 5000);
> >> +
> >> +	return 0;
> >> +}
> >> +
> >> +static void max9286_gpio_set(struct gpio_chip *chip,
> >> +			     unsigned int offset, int value)
> >> +{
> >> +	struct max9286_priv *priv = gpiochip_get_data(chip);
> >> +
> >> +	if (value)
> >> +		priv->gpio_state |= BIT(offset);
> >> +	else
> >> +		priv->gpio_state &= ~BIT(offset);
> >> +
> >> +	max9286_write(priv, 0x0f, MAX9286_0X0F_RESERVED | priv->gpio_state);
> >> +}
> >> +
> >> +static int max9286_gpio_get(struct gpio_chip *chip, unsigned int offset)
> >> +{
> >> +	struct max9286_priv *priv = gpiochip_get_data(chip);
> >> +
> >> +	return priv->gpio_state & BIT(offset);
> >> +}
> >> +
> >> +static int max9286_register_gpio(struct max9286_priv *priv)
> >> +{
> >> +	struct device *dev = &priv->client->dev;
> >> +	struct gpio_chip *gpio = &priv->gpio;
> >> +	int ret;
> >> +
> >> +	static const char * const names[] = {
> >> +		"GPIO0OUT",
> >> +		"GPIO1OUT",
> >> +	};
> >> +
> >> +	/* Configure the GPIO */
> >> +	gpio->label = dev_name(dev);
> >> +	gpio->parent = dev;
> >> +	gpio->owner = THIS_MODULE;
> >> +	gpio->of_node = dev->of_node;
> >> +	gpio->ngpio = 2;
> >> +	gpio->base = -1;
> >> +	gpio->set = max9286_gpio_set;
> >> +	gpio->get = max9286_gpio_get;
> >> +	gpio->can_sleep = true;
> >> +	gpio->names = names;
> >> +
> >> +	/* GPIO values default to high */
> >> +	priv->gpio_state = BIT(0) | BIT(1);
> >> +
> >> +	ret = devm_gpiochip_add_data(dev, gpio, priv);
> >> +	if (ret)
> >> +		dev_err(dev, "Unable to create gpio_chip\n");
> >> +
> >> +	return ret;
> >> +}
> >> +
> >> +static int max9286_init(struct device *dev)
> >> +{
> >> +	struct max9286_priv *priv;
> >> +	struct i2c_client *client;
> >> +	int ret;
> >> +
> >> +	client = to_i2c_client(dev);
> >> +	priv = i2c_get_clientdata(client);
> >> +
> >> +	/* Enable the bus power. */
> >> +	ret = regulator_enable(priv->regulator);
> >> +	if (ret < 0) {
> >> +		dev_err(&client->dev, "Unable to turn PoC on\n");
> >> +		return ret;
> >> +	}
> >> +
> >> +	ret = max9286_setup(priv);
> >> +	if (ret) {
> >> +		dev_err(dev, "Unable to setup max9286\n");
> >> +		goto err_regulator;
> >> +	}
> >> +
> >> +	/*
> >> +	 * Register all V4L2 interactions for the MAX9286 and notifiers for
> >> +	 * any subdevices connected.
> >> +	 */
> >> +	ret = max9286_v4l2_register(priv);
> >> +	if (ret) {
> >> +		dev_err(dev, "Failed to register with V4L2\n");
> >> +		goto err_regulator;
> >> +	}
> >> +
> >> +	ret = max9286_i2c_mux_init(priv);
> >> +	if (ret) {
> >> +		dev_err(dev, "Unable to initialize I2C multiplexer\n");
> >> +		goto err_v4l2_register;
> >> +	}
> >> +
> >> +	/* Leave the mux channels disabled until they are selected. */
> >> +	max9286_i2c_mux_close(priv);
> >> +
> >> +	return 0;
> >> +
> >> +err_v4l2_register:
> >> +	max9286_v4l2_unregister(priv);
> >> +err_regulator:
> >> +	regulator_disable(priv->regulator);
> >> +
> >> +	return ret;
> >> +}
> >> +
> >> +static void max9286_cleanup_dt(struct max9286_priv *priv)
> >> +{
> >> +	struct max9286_source *source;
> >> +
> >> +	for_each_source(priv, source) {
> >> +		fwnode_handle_put(source->fwnode);
> >> +		source->fwnode = NULL;
> >> +	}
> >> +}
> >> +
> >> +static int max9286_parse_dt(struct max9286_priv *priv)
> >> +{
> >> +	struct device *dev = &priv->client->dev;
> >> +	struct device_node *i2c_mux;
> >> +	struct device_node *node = NULL;
> >> +	unsigned int i2c_mux_mask = 0;
> >> +
> >> +	of_node_get(dev->of_node);
> >> +	i2c_mux = of_find_node_by_name(dev->of_node, "i2c-mux");
> >> +	if (!i2c_mux) {
> >> +		dev_err(dev, "Failed to find i2c-mux node\n");
> >> +		of_node_put(dev->of_node);
> >> +		return -EINVAL;
> >> +	}
> >> +
> >> +	/* Identify which i2c-mux channels are enabled */
> >> +	for_each_child_of_node(i2c_mux, node) {
> >> +		u32 id = 0;
> >> +
> >> +		of_property_read_u32(node, "reg", &id);
> >> +		if (id >= MAX9286_NUM_GMSL)
> >> +			continue;
> >> +
> >> +		if (!of_device_is_available(node)) {
> >> +			dev_dbg(dev, "Skipping disabled I2C bus port %u\n", id);
> >> +			continue;
> >> +		}
> >> +
> >> +		i2c_mux_mask |= BIT(id);
> >> +	}
> >> +	of_node_put(node);
> >> +	of_node_put(i2c_mux);
> >> +
> >> +	/* Parse the endpoints */
> >> +	for_each_endpoint_of_node(dev->of_node, node) {
> >> +		struct max9286_source *source;
> >> +		struct of_endpoint ep;
> >> +
> >> +		of_graph_parse_endpoint(node, &ep);
> >> +		dev_dbg(dev, "Endpoint %pOF on port %d",
> >> +			ep.local_node, ep.port);
> >> +
> >> +		if (ep.port > MAX9286_NUM_GMSL) {
> >> +			dev_err(dev, "Invalid endpoint %s on port %d",
> >> +				of_node_full_name(ep.local_node), ep.port);
> >> +			continue;
> >> +		}
> >> +
> >> +		/* For the source endpoint just parse the bus configuration. */
> >> +		if (ep.port == MAX9286_SRC_PAD) {
> >> +			struct v4l2_fwnode_endpoint vep = {
> >> +				.bus_type = V4L2_MBUS_CSI2_DPHY
> >> +			};
> >> +			int ret;
> >> +
> >> +			ret = v4l2_fwnode_endpoint_parse(
> >> +					of_fwnode_handle(node), &vep);
> >> +			if (ret) {
> >> +				of_node_put(node);
> >> +				of_node_put(dev->of_node);
> >> +				return ret;
> >> +			}
> >> +
> >> +			if (vep.bus_type != V4L2_MBUS_CSI2_DPHY) {
> >> +				dev_err(dev,
> >> +					"Media bus %u type not supported\n",
> >> +					vep.bus_type);
> >> +				v4l2_fwnode_endpoint_free(&vep);
> >> +				of_node_put(node);
> >> +				of_node_put(dev->of_node);
> >> +				return -EINVAL;
> >> +			}
> >> +
> >> +			priv->csi2_data_lanes =
> >> +				vep.bus.mipi_csi2.num_data_lanes;
> >> +			v4l2_fwnode_endpoint_free(&vep);
> >> +
> >> +			continue;
> >> +		}
> >> +
> >> +		/* Skip if the corresponding GMSL link is unavailable. */
> >> +		if (!(i2c_mux_mask & BIT(ep.port)))
> >> +			continue;
> >> +
> >> +		if (priv->sources[ep.port].fwnode) {
> >> +			dev_err(dev,
> >> +				"Multiple port endpoints are not supported: %d",
> >> +				ep.port);
> >> +
> >> +			continue;
> >> +		}
> >> +
> >> +		source = &priv->sources[ep.port];
> >> +		source->fwnode = fwnode_graph_get_remote_endpoint(
> >> +						of_fwnode_handle(node));
> >> +		if (!source->fwnode) {
> >> +			dev_err(dev,
> >> +				"Endpoint %pOF has no remote endpoint connection\n",
> >> +				ep.local_node);
> >> +
> >> +			continue;
> >> +		}
> >> +
> >> +		priv->source_mask |= BIT(ep.port);
> >> +		priv->nsources++;
> >> +	}
> >> +	of_node_put(node);
> >> +	of_node_put(dev->of_node);
> >> +
> >> +	priv->route_mask = priv->source_mask;
> >> +
> >> +	return 0;
> >> +}
> >> +
> >> +static int max9286_probe(struct i2c_client *client)
> >> +{
> >> +	struct max9286_priv *priv;
> >> +	int ret;
> >> +
> >> +	priv = devm_kzalloc(&client->dev, sizeof(*priv), GFP_KERNEL);
> >> +	if (!priv)
> >> +		return -ENOMEM;
> >> +
> >> +	mutex_init(&priv->mutex);
> >> +
> >> +	priv->client = client;
> >> +	i2c_set_clientdata(client, priv);
> >> +
> >> +	priv->gpiod_pwdn = devm_gpiod_get_optional(&client->dev, "enable",
> >> +						   GPIOD_OUT_HIGH);
> >> +	if (IS_ERR(priv->gpiod_pwdn))
> >> +		return PTR_ERR(priv->gpiod_pwdn);
> >> +
> >> +	gpiod_set_consumer_name(priv->gpiod_pwdn, "max9286-pwdn");
> >> +	gpiod_set_value_cansleep(priv->gpiod_pwdn, 1);
> >> +
> >> +	/* Wait at least 4ms before the I2C lines latch to the address */
> >> +	if (priv->gpiod_pwdn)
> >> +		usleep_range(4000, 5000);
> >> +
> >> +	/*
> >> +	 * The MAX9286 starts by default with all ports enabled, we disable all
> >> +	 * ports early to ensure that all channels are disabled if we error out
> >> +	 * and keep the bus consistent.
> >> +	 */
> >> +	max9286_i2c_mux_close(priv);
> >> +
> >> +	/*
> >> +	 * The MAX9286 initialises with auto-acknowledge enabled by default.
> >> +	 * This can be invasive to other transactions on the same bus, so
> >> +	 * disable it early. It will be enabled only as and when needed.
> >> +	 */
> >> +	max9286_configure_i2c(priv, false);
> >> +
> >> +	ret = max9286_register_gpio(priv);
> >> +	if (ret)
> >> +		goto err_powerdown;
> >> +
> >> +	priv->regulator = devm_regulator_get(&client->dev, "poc");
> >> +	if (IS_ERR(priv->regulator)) {
> >> +		if (PTR_ERR(priv->regulator) != -EPROBE_DEFER)
> >> +			dev_err(&client->dev,
> >> +				"Unable to get PoC regulator (%ld)\n",
> >> +				PTR_ERR(priv->regulator));
> >> +		ret = PTR_ERR(priv->regulator);
> >> +		goto err_powerdown;
> >> +	}
> >> +
> >> +	ret = max9286_parse_dt(priv);
> >> +	if (ret)
> >> +		goto err_powerdown;
> >> +
> >> +	ret = max9286_init(&client->dev);
> >> +	if (ret < 0)
> >> +		goto err_cleanup_dt;
> >> +
> >> +	return 0;
> >> +
> >> +err_cleanup_dt:
> >> +	max9286_cleanup_dt(priv);
> >> +err_powerdown:
> >> +	gpiod_set_value_cansleep(priv->gpiod_pwdn, 0);
> >> +
> >> +	return ret;
> >> +}
> >> +
> >> +static int max9286_remove(struct i2c_client *client)
> >> +{
> >> +	struct max9286_priv *priv = i2c_get_clientdata(client);
> >> +
> >> +	i2c_mux_del_adapters(priv->mux);
> >> +
> >> +	max9286_v4l2_unregister(priv);
> >> +
> >> +	regulator_disable(priv->regulator);
> >> +
> >> +	gpiod_set_value_cansleep(priv->gpiod_pwdn, 0);
> >> +
> >> +	max9286_cleanup_dt(priv);
> >> +
> >> +	return 0;
> >> +}
> >> +
> >> +static const struct of_device_id max9286_dt_ids[] = {
> >> +	{ .compatible = "maxim,max9286" },
> >> +	{},
> >> +};
> >> +MODULE_DEVICE_TABLE(of, max9286_dt_ids);
> >> +
> >> +static struct i2c_driver max9286_i2c_driver = {
> >> +	.driver	= {
> >> +		.name		= "max9286",
> >> +		.of_match_table	= of_match_ptr(max9286_dt_ids),
> >> +	},
> >> +	.probe_new	= max9286_probe,
> >> +	.remove		= max9286_remove,
> >> +};
> >> +
> >> +module_i2c_driver(max9286_i2c_driver);
> >> +
> >> +MODULE_DESCRIPTION("Maxim MAX9286 GMSL Deserializer Driver");
> >> +MODULE_AUTHOR("Jacopo Mondi, Kieran Bingham, Laurent Pinchart, Niklas Söderlund, Vladimir Barinov");
> >> +MODULE_LICENSE("GPL");
> >> -- 
> >> 2.25.1
> >>
> 

Re: [PATCH v9 2/4] media: i2c: Add MAX9286 driver

[Kieran Bingham]

Hi Mani,

On 14/05/2020 10:59, Manivannan Sadhasivam wrote:
> On Thu, May 14, 2020 at 10:53:00AM +0100, Kieran Bingham wrote:
>> Hi Mani,
>>>> +static int max9286_set_fmt(struct v4l2_subdev *sd,
>>>> +			   struct v4l2_subdev_pad_config *cfg,
>>>> +			   struct v4l2_subdev_format *format)
>>>> +{
>>>> +	struct max9286_priv *priv = sd_to_max9286(sd);
>>>> +	struct v4l2_mbus_framefmt *cfg_fmt;
>>>> +
>>>> +	if (format->pad >= MAX9286_SRC_PAD)
>>>> +		return -EINVAL;
>>>> +
>>>> +	/* Refuse non YUV422 formats as we hardcode DT to 8 bit YUV422 */
>>>> +	switch (format->format.code) {
>>>> +	case MEDIA_BUS_FMT_UYVY8_2X8:
>>>> +	case MEDIA_BUS_FMT_VYUY8_2X8:
>>>> +	case MEDIA_BUS_FMT_YUYV8_2X8:
>>>> +	case MEDIA_BUS_FMT_YVYU8_2X8:
>>>> +		break;
>>>> +	default:
>>>> +		format->format.code = MEDIA_BUS_FMT_YUYV8_2X8;
>>>
>>> Is there any reason for not setting default format to MEDIA_BUS_FMT_UYVY8_2X8?
>>>
>>
>>
>> No good reason no, and I see that in max9286_enum_mbus_code(), we
>> currently code to MEDIA_BUS_FMT_YUYV8_2X8, and that's the value that we
>> init to, so that would be a better default indeed.
>>
> 
> max9286_enum_mbus_code() returns MEDIA_BUS_FMT_UYVY8_2X8, no?

Argh, sorry - yet anther typo or copy/paste error.

Indeed, I have changed this locally to ...
   <double checks> MEDIA_BUS_FMT_UYVY8_2X8 </double checks>
as suggested. ;-)


> 
> Thanks,
> Mani

Re: [PATCH v9 2/4] media: i2c: Add MAX9286 driver

[Manivannan Sadhasivam]

On Tue, May 12, 2020 at 04:51:03PM +0100, Kieran Bingham wrote:
> The MAX9286 is a 4-channel GMSL deserializer with coax or STP input and
> CSI-2 output. The device supports multicamera streaming applications,
> and features the ability to synchronise the attached cameras.
> 
> CSI-2 output can be configured with 1 to 4 lanes, and a control channel
> is supported over I2C, which implements an I2C mux to facilitate
> communications with connected cameras across the reverse control
> channel.
> 
> Signed-off-by: Jacopo Mondi <jacopo+renesas@jmondi.org>
> Signed-off-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
> Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
> Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
> 
> --
> v2:
>  - Fix MAINTAINERS entry
> 
> This posting is released with the following modifications to work
> without Sakari's VC developments:
>  - max9286_g_mbus_config() re-instated
>  - max9286_get_frame_desc() is not bus/csi aware
>  - max9286_{get,set}_routing() removed
> 
> v3:
>  - Initialise notifier with v4l2_async_notifier_init
>  - Update for new mbus csi2 format V4L2_MBUS_CSI2_DPHY
> 
> v4: - Re-introduce required code to function with the VC series.
> 
>  - Implement max9286_get_routing, max9286_set_routing
>  - Remove max9286_g_mbus_config
> 
> v5: (internal release)
>  - Fix printk formatting for hex value
>  - max9286->sd.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE (add |)
>  - MEDIA_ENT_F_PROC_VIDEO_PIXEL_FORMATTER -> MEDIA_ENT_F_VID_IF_BRIDGE
>  - Remove 'device is bound' workaround
> 
> v6:
>  - v4l2_subdev_krouting instead of v4l2_subdev_routing separated
>    to allow integration without the VC/V4L2-Mux series.
>  - convert sd_to_max9286 to inline function
>  - rename max9286_device to max9286_priv
>  - Cleanup the v4l2_async_notifier
>  - Extend MODULE_AUTHOR
>  - Replace of_graph_get_endpoint_by_regs with fwnode_graph_get_endpoint_by_id
>  - Pass default bus type when parsing fwnode endpoint (Manivannan Sadhasivam)
>  - Use new YAML file reference in MAINTAINERS
>  - Parse new i2c-mux node in max9286_get_i2c_by_id
>    (This could/should be refactored to parse these separately first)
>  - Spelling and calculation fixes in the FSYNC_LOCKED check comments
>  - Identify each enabled i2c-mux channel in a single pass
>  - max9286: Improve mux-state readbility [v2]
>  - Fix frame sync lock durations
>  - Add comment to describe /why/ we must open the mux in s_stream
>  - use -EXDEV as return code for failed link synchronisation.
>  - Fix reference counting of the dt nodeS
>  - Convert to probe_new for I2C
>  - Remove redundant max9286_i2c_mux_state
>  - Provide optional enable-gpio (max9286-pwdn)
> 
> v7:
>  [Kieran]
>  - Ensure powerdown lines are optional
>  - Add a 4ms power-up delay
>  - Add max9286_check_config_link() to core
>  - Add GPIO chip controller for GPIO0OUT and GPIO1OUT
>  - Fix GPIO registration
>  - max9286: Split out async registration
>    (fixes regulator -EPROBE_DEFERs failures)
>  - Collect all V4L2 registrations
>  - balance v4l2_async refcnting
>  - Rename max9286_v4l2_async_ => max9286_v4l2_notifier_
> 
>  [Jacopo]
>  - Remove redundanct MAXIM_I2C_SPEED macros
>  - Move notifiers operations
>  - Add delay after reverse channel reconfiguration
>  - Move link setup to completion
>  - Fix up max9286_check_config_link() implementation
>  - Remove redundant dual configuration of reverse channel
> 
> v8:
> 
> [Kieran]
>  - Update the bound_sources mask on unbind
>  - Convert probe kzalloc usage to devm_ variant
>  - Fix up cleanup path from GPIO PowerDown registration
>  - cleanup GPIO device registration fail path
>  - Convert to use devm_regulator_get()
>  - Fit max9286_parse_dt print on one line
>  - Move multi-device workarounds out of upstream driver
>  - Remove I2C mod-table
>  - Lock format changes
>  - Describe pad index usage
>  - Remove poc_enabled workaround
>  - Rename the max9286_gpio to be more explicit on it's actions.
>  - Move max9286_init_format call
>  - Rework probe sequence and simplify error paths.
>  - Simplify i2c comments
>  - Implement Pixelrate control
>  - Disable overlap window
> 
> [Jacopo]
>  - Adapt Kconfig to latest upstream changes
>  - Put of node on error
>  - Calculate pixel rate
>  - Simplify overlap window disablement
> 
> v9:
> 
> [Kieran]
>  - Kconfig: Depend on OF
>  - Re-sort addition to Makefile
> ---
>  MAINTAINERS                 |   10 +
>  drivers/media/i2c/Kconfig   |   13 +
>  drivers/media/i2c/Makefile  |    1 +
>  drivers/media/i2c/max9286.c | 1332 +++++++++++++++++++++++++++++++++++
>  4 files changed, 1356 insertions(+)
>  create mode 100644 drivers/media/i2c/max9286.c
> 
> diff --git a/MAINTAINERS b/MAINTAINERS
> index a7bb6e22d5da..99e3bf7760fd 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -10274,6 +10274,16 @@ F:	Documentation/hwmon/max6697.rst
>  F:	drivers/hwmon/max6697.c
>  F:	include/linux/platform_data/max6697.h
>  
> +MAX9286 QUAD GMSL DESERIALIZER DRIVER
> +M:	Jacopo Mondi <jacopo+renesas@jmondi.org>
> +M:	Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
> +M:	Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
> +M:	Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
> +L:	linux-media@vger.kernel.org
> +S:	Maintained
> +F:	Documentation/devicetree/bindings/media/i2c/maxim,max9286.yaml
> +F:	drivers/media/i2c/max9286.c
> +
>  MAX9860 MONO AUDIO VOICE CODEC DRIVER
>  M:	Peter Rosin <peda@axentia.se>
>  L:	alsa-devel@alsa-project.org (moderated for non-subscribers)
> diff --git a/drivers/media/i2c/Kconfig b/drivers/media/i2c/Kconfig
> index 3abc80373ec0..2e390f41f6da 100644
> --- a/drivers/media/i2c/Kconfig
> +++ b/drivers/media/i2c/Kconfig
> @@ -464,6 +464,19 @@ config VIDEO_VPX3220
>  	  To compile this driver as a module, choose M here: the
>  	  module will be called vpx3220.
>  
> +config VIDEO_MAX9286
> +	tristate "Maxim MAX9286 GMSL deserializer support"
> +	depends on I2C && I2C_MUX
> +	depends on OF
> +	select V4L2_FWNODE
> +	select VIDEO_V4L2_SUBDEV_API
> +	select MEDIA_CONTROLLER
> +	help
> +	  This driver supports the Maxim MAX9286 GMSL deserializer.
> +
> +	  To compile this driver as a module, choose M here: the
> +	  module will be called max9286.
> +
>  comment "Video and audio decoders"
>  
>  config VIDEO_SAA717X
> diff --git a/drivers/media/i2c/Makefile b/drivers/media/i2c/Makefile
> index 77bf7d0b691f..f0b001ee4b05 100644
> --- a/drivers/media/i2c/Makefile
> +++ b/drivers/media/i2c/Makefile
> @@ -117,6 +117,7 @@ obj-$(CONFIG_VIDEO_IMX274)	+= imx274.o
>  obj-$(CONFIG_VIDEO_IMX290)	+= imx290.o
>  obj-$(CONFIG_VIDEO_IMX319)	+= imx319.o
>  obj-$(CONFIG_VIDEO_IMX355)	+= imx355.o
> +obj-$(CONFIG_VIDEO_MAX9286)	+= max9286.o
>  obj-$(CONFIG_VIDEO_ST_MIPID02) += st-mipid02.o
>  
>  obj-$(CONFIG_SDR_MAX2175) += max2175.o
> diff --git a/drivers/media/i2c/max9286.c b/drivers/media/i2c/max9286.c
> new file mode 100644
> index 000000000000..481d65f2b51d
> --- /dev/null
> +++ b/drivers/media/i2c/max9286.c
> @@ -0,0 +1,1332 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/*
> + * Maxim MAX9286 GMSL Deserializer Driver
> + *
> + * Copyright (C) 2017-2019 Jacopo Mondi
> + * Copyright (C) 2017-2019 Kieran Bingham
> + * Copyright (C) 2017-2019 Laurent Pinchart
> + * Copyright (C) 2017-2019 Niklas Söderlund
> + * Copyright (C) 2016 Renesas Electronics Corporation
> + * Copyright (C) 2015 Cogent Embedded, Inc.
> + */
> +
> +#include <linux/delay.h>
> +#include <linux/device.h>
> +#include <linux/fwnode.h>
> +#include <linux/gpio/consumer.h>
> +#include <linux/gpio/driver.h>
> +#include <linux/i2c.h>
> +#include <linux/i2c-mux.h>
> +#include <linux/module.h>
> +#include <linux/mutex.h>
> +#include <linux/of_graph.h>
> +#include <linux/regulator/consumer.h>
> +#include <linux/slab.h>
> +
> +#include <media/v4l2-async.h>
> +#include <media/v4l2-ctrls.h>
> +#include <media/v4l2-device.h>
> +#include <media/v4l2-fwnode.h>
> +#include <media/v4l2-subdev.h>
> +
> +/* Register 0x00 */
> +#define MAX9286_MSTLINKSEL_AUTO		(7 << 5)
> +#define MAX9286_MSTLINKSEL(n)		((n) << 5)
> +#define MAX9286_EN_VS_GEN		BIT(4)
> +#define MAX9286_LINKEN(n)		(1 << (n))
> +/* Register 0x01 */
> +#define MAX9286_FSYNCMODE_ECU		(3 << 6)
> +#define MAX9286_FSYNCMODE_EXT		(2 << 6)
> +#define MAX9286_FSYNCMODE_INT_OUT	(1 << 6)
> +#define MAX9286_FSYNCMODE_INT_HIZ	(0 << 6)
> +#define MAX9286_GPIEN			BIT(5)
> +#define MAX9286_ENLMO_RSTFSYNC		BIT(2)
> +#define MAX9286_FSYNCMETH_AUTO		(2 << 0)
> +#define MAX9286_FSYNCMETH_SEMI_AUTO	(1 << 0)
> +#define MAX9286_FSYNCMETH_MANUAL	(0 << 0)
> +#define MAX9286_REG_FSYNC_PERIOD_L	0x06
> +#define MAX9286_REG_FSYNC_PERIOD_M	0x07
> +#define MAX9286_REG_FSYNC_PERIOD_H	0x08
> +/* Register 0x0a */
> +#define MAX9286_FWDCCEN(n)		(1 << ((n) + 4))
> +#define MAX9286_REVCCEN(n)		(1 << (n))
> +/* Register 0x0c */
> +#define MAX9286_HVEN			BIT(7)
> +#define MAX9286_EDC_6BIT_HAMMING	(2 << 5)
> +#define MAX9286_EDC_6BIT_CRC		(1 << 5)
> +#define MAX9286_EDC_1BIT_PARITY		(0 << 5)
> +#define MAX9286_DESEL			BIT(4)
> +#define MAX9286_INVVS			BIT(3)
> +#define MAX9286_INVHS			BIT(2)
> +#define MAX9286_HVSRC_D0		(2 << 0)
> +#define MAX9286_HVSRC_D14		(1 << 0)
> +#define MAX9286_HVSRC_D18		(0 << 0)
> +/* Register 0x0f */
> +#define MAX9286_0X0F_RESERVED		BIT(3)
> +/* Register 0x12 */
> +#define MAX9286_CSILANECNT(n)		(((n) - 1) << 6)
> +#define MAX9286_CSIDBL			BIT(5)
> +#define MAX9286_DBL			BIT(4)
> +#define MAX9286_DATATYPE_USER_8BIT	(11 << 0)
> +#define MAX9286_DATATYPE_USER_YUV_12BIT	(10 << 0)
> +#define MAX9286_DATATYPE_USER_24BIT	(9 << 0)
> +#define MAX9286_DATATYPE_RAW14		(8 << 0)
> +#define MAX9286_DATATYPE_RAW11		(7 << 0)
> +#define MAX9286_DATATYPE_RAW10		(6 << 0)
> +#define MAX9286_DATATYPE_RAW8		(5 << 0)
> +#define MAX9286_DATATYPE_YUV422_10BIT	(4 << 0)
> +#define MAX9286_DATATYPE_YUV422_8BIT	(3 << 0)
> +#define MAX9286_DATATYPE_RGB555		(2 << 0)
> +#define MAX9286_DATATYPE_RGB565		(1 << 0)
> +#define MAX9286_DATATYPE_RGB888		(0 << 0)
> +/* Register 0x15 */
> +#define MAX9286_VC(n)			((n) << 5)
> +#define MAX9286_VCTYPE			BIT(4)
> +#define MAX9286_CSIOUTEN		BIT(3)
> +#define MAX9286_0X15_RESV		(3 << 0)
> +/* Register 0x1b */
> +#define MAX9286_SWITCHIN(n)		(1 << ((n) + 4))
> +#define MAX9286_ENEQ(n)			(1 << (n))
> +/* Register 0x27 */
> +#define MAX9286_LOCKED			BIT(7)
> +/* Register 0x31 */
> +#define MAX9286_FSYNC_LOCKED		BIT(6)
> +/* Register 0x34 */
> +#define MAX9286_I2CLOCACK		BIT(7)
> +#define MAX9286_I2CSLVSH_1046NS_469NS	(3 << 5)
> +#define MAX9286_I2CSLVSH_938NS_352NS	(2 << 5)
> +#define MAX9286_I2CSLVSH_469NS_234NS	(1 << 5)
> +#define MAX9286_I2CSLVSH_352NS_117NS	(0 << 5)
> +#define MAX9286_I2CMSTBT_837KBPS	(7 << 2)
> +#define MAX9286_I2CMSTBT_533KBPS	(6 << 2)
> +#define MAX9286_I2CMSTBT_339KBPS	(5 << 2)
> +#define MAX9286_I2CMSTBT_173KBPS	(4 << 2)
> +#define MAX9286_I2CMSTBT_105KBPS	(3 << 2)
> +#define MAX9286_I2CMSTBT_84KBPS		(2 << 2)
> +#define MAX9286_I2CMSTBT_28KBPS		(1 << 2)
> +#define MAX9286_I2CMSTBT_8KBPS		(0 << 2)
> +#define MAX9286_I2CSLVTO_NONE		(3 << 0)
> +#define MAX9286_I2CSLVTO_1024US		(2 << 0)
> +#define MAX9286_I2CSLVTO_256US		(1 << 0)
> +#define MAX9286_I2CSLVTO_64US		(0 << 0)
> +/* Register 0x3b */
> +#define MAX9286_REV_TRF(n)		((n) << 4)
> +#define MAX9286_REV_AMP(n)		((((n) - 30) / 10) << 1) /* in mV */
> +#define MAX9286_REV_AMP_X		BIT(0)
> +/* Register 0x3f */
> +#define MAX9286_EN_REV_CFG		BIT(6)
> +#define MAX9286_REV_FLEN(n)		((n) - 20)
> +/* Register 0x49 */
> +#define MAX9286_VIDEO_DETECT_MASK	0x0f
> +/* Register 0x69 */
> +#define MAX9286_LFLTBMONMASKED		BIT(7)
> +#define MAX9286_LOCKMONMASKED		BIT(6)
> +#define MAX9286_AUTOCOMBACKEN		BIT(5)
> +#define MAX9286_AUTOMASKEN		BIT(4)
> +#define MAX9286_MASKLINK(n)		((n) << 0)
> +
> +/*
> + * The sink and source pads are created to match the OF graph port numbers so
> + * that their indexes can be used interchangeably.
> + */
> +#define MAX9286_NUM_GMSL		4
> +#define MAX9286_N_SINKS			4
> +#define MAX9286_N_PADS			5
> +#define MAX9286_SRC_PAD			4
> +
> +struct max9286_source {
> +	struct v4l2_async_subdev asd;
> +	struct v4l2_subdev *sd;
> +	struct fwnode_handle *fwnode;
> +};
> +
> +#define asd_to_max9286_source(_asd) \
> +	container_of(_asd, struct max9286_source, asd)
> +
> +struct max9286_priv {
> +	struct i2c_client *client;
> +	struct gpio_desc *gpiod_pwdn;
> +	struct v4l2_subdev sd;
> +	struct media_pad pads[MAX9286_N_PADS];
> +	struct regulator *regulator;
> +
> +	struct gpio_chip gpio;
> +	u8 gpio_state;
> +
> +	struct i2c_mux_core *mux;
> +	unsigned int mux_channel;
> +	bool mux_open;
> +
> +	struct v4l2_ctrl_handler ctrls;
> +	struct v4l2_ctrl *pixelrate;
> +
> +	struct v4l2_mbus_framefmt fmt[MAX9286_N_SINKS];
> +
> +	/* Protects controls and fmt structures */
> +	struct mutex mutex;
> +
> +	unsigned int nsources;
> +	unsigned int source_mask;
> +	unsigned int route_mask;
> +	unsigned int bound_sources;
> +	unsigned int csi2_data_lanes;
> +	struct max9286_source sources[MAX9286_NUM_GMSL];
> +	struct v4l2_async_notifier notifier;
> +};
> +

[...]

> +static int max9286_register_gpio(struct max9286_priv *priv)
> +{
> +	struct device *dev = &priv->client->dev;
> +	struct gpio_chip *gpio = &priv->gpio;
> +	int ret;
> +
> +	static const char * const names[] = {
> +		"GPIO0OUT",
> +		"GPIO1OUT",
> +	};
> +
> +	/* Configure the GPIO */
> +	gpio->label = dev_name(dev);

So if you have more than one MAX9286 in a system, all gpiochips will appear
with the same name. I'd recommend to append the index to distinguish properly.

> +	gpio->parent = dev;
> +	gpio->owner = THIS_MODULE;
> +	gpio->of_node = dev->of_node;
> +	gpio->ngpio = 2;
> +	gpio->base = -1;
> +	gpio->set = max9286_gpio_set;
> +	gpio->get = max9286_gpio_get;
> +	gpio->can_sleep = true;
> +	gpio->names = names;
> +
> +	/* GPIO values default to high */
> +	priv->gpio_state = BIT(0) | BIT(1);
> +
> +	ret = devm_gpiochip_add_data(dev, gpio, priv);
> +	if (ret)
> +		dev_err(dev, "Unable to create gpio_chip\n");
> +
> +	return ret;
> +}
> +

[...]

> +static int max9286_parse_dt(struct max9286_priv *priv)
> +{
> +	struct device *dev = &priv->client->dev;
> +	struct device_node *i2c_mux;
> +	struct device_node *node = NULL;
> +	unsigned int i2c_mux_mask = 0;
> +
> +	of_node_get(dev->of_node);

Why this is needed?

> +	i2c_mux = of_find_node_by_name(dev->of_node, "i2c-mux");
> +	if (!i2c_mux) {
> +		dev_err(dev, "Failed to find i2c-mux node\n");
> +		of_node_put(dev->of_node);
> +		return -EINVAL;
> +	}
> +
> +	/* Identify which i2c-mux channels are enabled */
> +	for_each_child_of_node(i2c_mux, node) {
> +		u32 id = 0;
> +
> +		of_property_read_u32(node, "reg", &id);
> +		if (id >= MAX9286_NUM_GMSL)
> +			continue;
> +
> +		if (!of_device_is_available(node)) {
> +			dev_dbg(dev, "Skipping disabled I2C bus port %u\n", id);
> +			continue;
> +		}
> +
> +		i2c_mux_mask |= BIT(id);
> +	}
> +	of_node_put(node);
> +	of_node_put(i2c_mux);
> +
> +	/* Parse the endpoints */
> +	for_each_endpoint_of_node(dev->of_node, node) {
> +		struct max9286_source *source;
> +		struct of_endpoint ep;
> +
> +		of_graph_parse_endpoint(node, &ep);
> +		dev_dbg(dev, "Endpoint %pOF on port %d",
> +			ep.local_node, ep.port);
> +
> +		if (ep.port > MAX9286_NUM_GMSL) {
> +			dev_err(dev, "Invalid endpoint %s on port %d",
> +				of_node_full_name(ep.local_node), ep.port);
> +			continue;
> +		}
> +
> +		/* For the source endpoint just parse the bus configuration. */
> +		if (ep.port == MAX9286_SRC_PAD) {
> +			struct v4l2_fwnode_endpoint vep = {
> +				.bus_type = V4L2_MBUS_CSI2_DPHY
> +			};
> +			int ret;
> +
> +			ret = v4l2_fwnode_endpoint_parse(
> +					of_fwnode_handle(node), &vep);
> +			if (ret) {
> +				of_node_put(node);
> +				of_node_put(dev->of_node);
> +				return ret;
> +			}
> +
> +			if (vep.bus_type != V4L2_MBUS_CSI2_DPHY) {
> +				dev_err(dev,
> +					"Media bus %u type not supported\n",
> +					vep.bus_type);
> +				v4l2_fwnode_endpoint_free(&vep);
> +				of_node_put(node);
> +				of_node_put(dev->of_node);
> +				return -EINVAL;
> +			}
> +
> +			priv->csi2_data_lanes =
> +				vep.bus.mipi_csi2.num_data_lanes;
> +			v4l2_fwnode_endpoint_free(&vep);
> +
> +			continue;
> +		}
> +
> +		/* Skip if the corresponding GMSL link is unavailable. */
> +		if (!(i2c_mux_mask & BIT(ep.port)))
> +			continue;
> +
> +		if (priv->sources[ep.port].fwnode) {
> +			dev_err(dev,
> +				"Multiple port endpoints are not supported: %d",
> +				ep.port);
> +
> +			continue;
> +		}
> +
> +		source = &priv->sources[ep.port];
> +		source->fwnode = fwnode_graph_get_remote_endpoint(
> +						of_fwnode_handle(node));
> +		if (!source->fwnode) {
> +			dev_err(dev,
> +				"Endpoint %pOF has no remote endpoint connection\n",
> +				ep.local_node);
> +
> +			continue;
> +		}
> +
> +		priv->source_mask |= BIT(ep.port);
> +		priv->nsources++;
> +	}
> +	of_node_put(node);
> +	of_node_put(dev->of_node);
> +
> +	priv->route_mask = priv->source_mask;
> +
> +	return 0;
> +}
> +

[...]

> +static int max9286_remove(struct i2c_client *client)
> +{
> +	struct max9286_priv *priv = i2c_get_clientdata(client);
> +
> +	i2c_mux_del_adapters(priv->mux);
> +
> +	max9286_v4l2_unregister(priv);
> +
> +	regulator_disable(priv->regulator);
> +
> +	gpiod_set_value_cansleep(priv->gpiod_pwdn, 0);

Usual power down sequence is to pull the power down gpio low and then turn off
the regulators. This helps in clearing up the internal state machine properly.

Thanks,
Mani

> +
> +	max9286_cleanup_dt(priv);
> +
> +	return 0;
> +}
> +
> +static const struct of_device_id max9286_dt_ids[] = {
> +	{ .compatible = "maxim,max9286" },
> +	{},
> +};
> +MODULE_DEVICE_TABLE(of, max9286_dt_ids);
> +
> +static struct i2c_driver max9286_i2c_driver = {
> +	.driver	= {
> +		.name		= "max9286",
> +		.of_match_table	= of_match_ptr(max9286_dt_ids),
> +	},
> +	.probe_new	= max9286_probe,
> +	.remove		= max9286_remove,
> +};
> +
> +module_i2c_driver(max9286_i2c_driver);
> +
> +MODULE_DESCRIPTION("Maxim MAX9286 GMSL Deserializer Driver");
> +MODULE_AUTHOR("Jacopo Mondi, Kieran Bingham, Laurent Pinchart, Niklas Söderlund, Vladimir Barinov");
> +MODULE_LICENSE("GPL");
> -- 
> 2.25.1
> 

Re: [PATCH v9 2/4] media: i2c: Add MAX9286 driver

[Kieran Bingham]

Hi Mani,

On 12/05/2020 19:17, Manivannan Sadhasivam wrote:
> On Tue, May 12, 2020 at 04:51:03PM +0100, Kieran Bingham wrote:
>> The MAX9286 is a 4-channel GMSL deserializer with coax or STP input and
>> CSI-2 output. The device supports multicamera streaming applications,
>> and features the ability to synchronise the attached cameras.
>>
>> CSI-2 output can be configured with 1 to 4 lanes, and a control channel
>> is supported over I2C, which implements an I2C mux to facilitate
>> communications with connected cameras across the reverse control
>> channel.
>>
>> Signed-off-by: Jacopo Mondi <jacopo+renesas@jmondi.org>
>> Signed-off-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
>> Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
>> Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
>>
>> --
>> v2:
>>  - Fix MAINTAINERS entry
>>
>> This posting is released with the following modifications to work
>> without Sakari's VC developments:
>>  - max9286_g_mbus_config() re-instated
>>  - max9286_get_frame_desc() is not bus/csi aware
>>  - max9286_{get,set}_routing() removed
>>
>> v3:
>>  - Initialise notifier with v4l2_async_notifier_init
>>  - Update for new mbus csi2 format V4L2_MBUS_CSI2_DPHY
>>
>> v4: - Re-introduce required code to function with the VC series.
>>
>>  - Implement max9286_get_routing, max9286_set_routing
>>  - Remove max9286_g_mbus_config
>>
>> v5: (internal release)
>>  - Fix printk formatting for hex value
>>  - max9286->sd.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE (add |)
>>  - MEDIA_ENT_F_PROC_VIDEO_PIXEL_FORMATTER -> MEDIA_ENT_F_VID_IF_BRIDGE
>>  - Remove 'device is bound' workaround
>>
>> v6:
>>  - v4l2_subdev_krouting instead of v4l2_subdev_routing separated
>>    to allow integration without the VC/V4L2-Mux series.
>>  - convert sd_to_max9286 to inline function
>>  - rename max9286_device to max9286_priv
>>  - Cleanup the v4l2_async_notifier
>>  - Extend MODULE_AUTHOR
>>  - Replace of_graph_get_endpoint_by_regs with fwnode_graph_get_endpoint_by_id
>>  - Pass default bus type when parsing fwnode endpoint (Manivannan Sadhasivam)
>>  - Use new YAML file reference in MAINTAINERS
>>  - Parse new i2c-mux node in max9286_get_i2c_by_id
>>    (This could/should be refactored to parse these separately first)
>>  - Spelling and calculation fixes in the FSYNC_LOCKED check comments
>>  - Identify each enabled i2c-mux channel in a single pass
>>  - max9286: Improve mux-state readbility [v2]
>>  - Fix frame sync lock durations
>>  - Add comment to describe /why/ we must open the mux in s_stream
>>  - use -EXDEV as return code for failed link synchronisation.
>>  - Fix reference counting of the dt nodeS
>>  - Convert to probe_new for I2C
>>  - Remove redundant max9286_i2c_mux_state
>>  - Provide optional enable-gpio (max9286-pwdn)
>>
>> v7:
>>  [Kieran]
>>  - Ensure powerdown lines are optional
>>  - Add a 4ms power-up delay
>>  - Add max9286_check_config_link() to core
>>  - Add GPIO chip controller for GPIO0OUT and GPIO1OUT
>>  - Fix GPIO registration
>>  - max9286: Split out async registration
>>    (fixes regulator -EPROBE_DEFERs failures)
>>  - Collect all V4L2 registrations
>>  - balance v4l2_async refcnting
>>  - Rename max9286_v4l2_async_ => max9286_v4l2_notifier_
>>
>>  [Jacopo]
>>  - Remove redundanct MAXIM_I2C_SPEED macros
>>  - Move notifiers operations
>>  - Add delay after reverse channel reconfiguration
>>  - Move link setup to completion
>>  - Fix up max9286_check_config_link() implementation
>>  - Remove redundant dual configuration of reverse channel
>>
>> v8:
>>
>> [Kieran]
>>  - Update the bound_sources mask on unbind
>>  - Convert probe kzalloc usage to devm_ variant
>>  - Fix up cleanup path from GPIO PowerDown registration
>>  - cleanup GPIO device registration fail path
>>  - Convert to use devm_regulator_get()
>>  - Fit max9286_parse_dt print on one line
>>  - Move multi-device workarounds out of upstream driver
>>  - Remove I2C mod-table
>>  - Lock format changes
>>  - Describe pad index usage
>>  - Remove poc_enabled workaround
>>  - Rename the max9286_gpio to be more explicit on it's actions.
>>  - Move max9286_init_format call
>>  - Rework probe sequence and simplify error paths.
>>  - Simplify i2c comments
>>  - Implement Pixelrate control
>>  - Disable overlap window
>>
>> [Jacopo]
>>  - Adapt Kconfig to latest upstream changes
>>  - Put of node on error
>>  - Calculate pixel rate
>>  - Simplify overlap window disablement
>>
>> v9:
>>
>> [Kieran]
>>  - Kconfig: Depend on OF
>>  - Re-sort addition to Makefile
>> ---
>>  MAINTAINERS                 |   10 +
>>  drivers/media/i2c/Kconfig   |   13 +
>>  drivers/media/i2c/Makefile  |    1 +
>>  drivers/media/i2c/max9286.c | 1332 +++++++++++++++++++++++++++++++++++
>>  4 files changed, 1356 insertions(+)
>>  create mode 100644 drivers/media/i2c/max9286.c
>>
>> diff --git a/MAINTAINERS b/MAINTAINERS
>> index a7bb6e22d5da..99e3bf7760fd 100644
>> --- a/MAINTAINERS
>> +++ b/MAINTAINERS
>> @@ -10274,6 +10274,16 @@ F:	Documentation/hwmon/max6697.rst
>>  F:	drivers/hwmon/max6697.c
>>  F:	include/linux/platform_data/max6697.h
>>  
>> +MAX9286 QUAD GMSL DESERIALIZER DRIVER
>> +M:	Jacopo Mondi <jacopo+renesas@jmondi.org>
>> +M:	Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
>> +M:	Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
>> +M:	Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
>> +L:	linux-media@vger.kernel.org
>> +S:	Maintained
>> +F:	Documentation/devicetree/bindings/media/i2c/maxim,max9286.yaml
>> +F:	drivers/media/i2c/max9286.c
>> +
>>  MAX9860 MONO AUDIO VOICE CODEC DRIVER
>>  M:	Peter Rosin <peda@axentia.se>
>>  L:	alsa-devel@alsa-project.org (moderated for non-subscribers)
>> diff --git a/drivers/media/i2c/Kconfig b/drivers/media/i2c/Kconfig
>> index 3abc80373ec0..2e390f41f6da 100644
>> --- a/drivers/media/i2c/Kconfig
>> +++ b/drivers/media/i2c/Kconfig
>> @@ -464,6 +464,19 @@ config VIDEO_VPX3220
>>  	  To compile this driver as a module, choose M here: the
>>  	  module will be called vpx3220.
>>  
>> +config VIDEO_MAX9286
>> +	tristate "Maxim MAX9286 GMSL deserializer support"
>> +	depends on I2C && I2C_MUX
>> +	depends on OF
>> +	select V4L2_FWNODE
>> +	select VIDEO_V4L2_SUBDEV_API
>> +	select MEDIA_CONTROLLER
>> +	help
>> +	  This driver supports the Maxim MAX9286 GMSL deserializer.
>> +
>> +	  To compile this driver as a module, choose M here: the
>> +	  module will be called max9286.
>> +
>>  comment "Video and audio decoders"
>>  
>>  config VIDEO_SAA717X
>> diff --git a/drivers/media/i2c/Makefile b/drivers/media/i2c/Makefile
>> index 77bf7d0b691f..f0b001ee4b05 100644
>> --- a/drivers/media/i2c/Makefile
>> +++ b/drivers/media/i2c/Makefile
>> @@ -117,6 +117,7 @@ obj-$(CONFIG_VIDEO_IMX274)	+= imx274.o
>>  obj-$(CONFIG_VIDEO_IMX290)	+= imx290.o
>>  obj-$(CONFIG_VIDEO_IMX319)	+= imx319.o
>>  obj-$(CONFIG_VIDEO_IMX355)	+= imx355.o
>> +obj-$(CONFIG_VIDEO_MAX9286)	+= max9286.o
>>  obj-$(CONFIG_VIDEO_ST_MIPID02) += st-mipid02.o
>>  
>>  obj-$(CONFIG_SDR_MAX2175) += max2175.o
>> diff --git a/drivers/media/i2c/max9286.c b/drivers/media/i2c/max9286.c
>> new file mode 100644
>> index 000000000000..481d65f2b51d
>> --- /dev/null
>> +++ b/drivers/media/i2c/max9286.c
>> @@ -0,0 +1,1332 @@
>> +// SPDX-License-Identifier: GPL-2.0+
>> +/*
>> + * Maxim MAX9286 GMSL Deserializer Driver
>> + *
>> + * Copyright (C) 2017-2019 Jacopo Mondi
>> + * Copyright (C) 2017-2019 Kieran Bingham
>> + * Copyright (C) 2017-2019 Laurent Pinchart
>> + * Copyright (C) 2017-2019 Niklas Söderlund
>> + * Copyright (C) 2016 Renesas Electronics Corporation
>> + * Copyright (C) 2015 Cogent Embedded, Inc.
>> + */
>> +
>> +#include <linux/delay.h>
>> +#include <linux/device.h>
>> +#include <linux/fwnode.h>
>> +#include <linux/gpio/consumer.h>
>> +#include <linux/gpio/driver.h>
>> +#include <linux/i2c.h>
>> +#include <linux/i2c-mux.h>
>> +#include <linux/module.h>
>> +#include <linux/mutex.h>
>> +#include <linux/of_graph.h>
>> +#include <linux/regulator/consumer.h>
>> +#include <linux/slab.h>
>> +
>> +#include <media/v4l2-async.h>
>> +#include <media/v4l2-ctrls.h>
>> +#include <media/v4l2-device.h>
>> +#include <media/v4l2-fwnode.h>
>> +#include <media/v4l2-subdev.h>
>> +
>> +/* Register 0x00 */
>> +#define MAX9286_MSTLINKSEL_AUTO		(7 << 5)
>> +#define MAX9286_MSTLINKSEL(n)		((n) << 5)
>> +#define MAX9286_EN_VS_GEN		BIT(4)
>> +#define MAX9286_LINKEN(n)		(1 << (n))
>> +/* Register 0x01 */
>> +#define MAX9286_FSYNCMODE_ECU		(3 << 6)
>> +#define MAX9286_FSYNCMODE_EXT		(2 << 6)
>> +#define MAX9286_FSYNCMODE_INT_OUT	(1 << 6)
>> +#define MAX9286_FSYNCMODE_INT_HIZ	(0 << 6)
>> +#define MAX9286_GPIEN			BIT(5)
>> +#define MAX9286_ENLMO_RSTFSYNC		BIT(2)
>> +#define MAX9286_FSYNCMETH_AUTO		(2 << 0)
>> +#define MAX9286_FSYNCMETH_SEMI_AUTO	(1 << 0)
>> +#define MAX9286_FSYNCMETH_MANUAL	(0 << 0)
>> +#define MAX9286_REG_FSYNC_PERIOD_L	0x06
>> +#define MAX9286_REG_FSYNC_PERIOD_M	0x07
>> +#define MAX9286_REG_FSYNC_PERIOD_H	0x08
>> +/* Register 0x0a */
>> +#define MAX9286_FWDCCEN(n)		(1 << ((n) + 4))
>> +#define MAX9286_REVCCEN(n)		(1 << (n))
>> +/* Register 0x0c */
>> +#define MAX9286_HVEN			BIT(7)
>> +#define MAX9286_EDC_6BIT_HAMMING	(2 << 5)
>> +#define MAX9286_EDC_6BIT_CRC		(1 << 5)
>> +#define MAX9286_EDC_1BIT_PARITY		(0 << 5)
>> +#define MAX9286_DESEL			BIT(4)
>> +#define MAX9286_INVVS			BIT(3)
>> +#define MAX9286_INVHS			BIT(2)
>> +#define MAX9286_HVSRC_D0		(2 << 0)
>> +#define MAX9286_HVSRC_D14		(1 << 0)
>> +#define MAX9286_HVSRC_D18		(0 << 0)
>> +/* Register 0x0f */
>> +#define MAX9286_0X0F_RESERVED		BIT(3)
>> +/* Register 0x12 */
>> +#define MAX9286_CSILANECNT(n)		(((n) - 1) << 6)
>> +#define MAX9286_CSIDBL			BIT(5)
>> +#define MAX9286_DBL			BIT(4)
>> +#define MAX9286_DATATYPE_USER_8BIT	(11 << 0)
>> +#define MAX9286_DATATYPE_USER_YUV_12BIT	(10 << 0)
>> +#define MAX9286_DATATYPE_USER_24BIT	(9 << 0)
>> +#define MAX9286_DATATYPE_RAW14		(8 << 0)
>> +#define MAX9286_DATATYPE_RAW11		(7 << 0)
>> +#define MAX9286_DATATYPE_RAW10		(6 << 0)
>> +#define MAX9286_DATATYPE_RAW8		(5 << 0)
>> +#define MAX9286_DATATYPE_YUV422_10BIT	(4 << 0)
>> +#define MAX9286_DATATYPE_YUV422_8BIT	(3 << 0)
>> +#define MAX9286_DATATYPE_RGB555		(2 << 0)
>> +#define MAX9286_DATATYPE_RGB565		(1 << 0)
>> +#define MAX9286_DATATYPE_RGB888		(0 << 0)
>> +/* Register 0x15 */
>> +#define MAX9286_VC(n)			((n) << 5)
>> +#define MAX9286_VCTYPE			BIT(4)
>> +#define MAX9286_CSIOUTEN		BIT(3)
>> +#define MAX9286_0X15_RESV		(3 << 0)
>> +/* Register 0x1b */
>> +#define MAX9286_SWITCHIN(n)		(1 << ((n) + 4))
>> +#define MAX9286_ENEQ(n)			(1 << (n))
>> +/* Register 0x27 */
>> +#define MAX9286_LOCKED			BIT(7)
>> +/* Register 0x31 */
>> +#define MAX9286_FSYNC_LOCKED		BIT(6)
>> +/* Register 0x34 */
>> +#define MAX9286_I2CLOCACK		BIT(7)
>> +#define MAX9286_I2CSLVSH_1046NS_469NS	(3 << 5)
>> +#define MAX9286_I2CSLVSH_938NS_352NS	(2 << 5)
>> +#define MAX9286_I2CSLVSH_469NS_234NS	(1 << 5)
>> +#define MAX9286_I2CSLVSH_352NS_117NS	(0 << 5)
>> +#define MAX9286_I2CMSTBT_837KBPS	(7 << 2)
>> +#define MAX9286_I2CMSTBT_533KBPS	(6 << 2)
>> +#define MAX9286_I2CMSTBT_339KBPS	(5 << 2)
>> +#define MAX9286_I2CMSTBT_173KBPS	(4 << 2)
>> +#define MAX9286_I2CMSTBT_105KBPS	(3 << 2)
>> +#define MAX9286_I2CMSTBT_84KBPS		(2 << 2)
>> +#define MAX9286_I2CMSTBT_28KBPS		(1 << 2)
>> +#define MAX9286_I2CMSTBT_8KBPS		(0 << 2)
>> +#define MAX9286_I2CSLVTO_NONE		(3 << 0)
>> +#define MAX9286_I2CSLVTO_1024US		(2 << 0)
>> +#define MAX9286_I2CSLVTO_256US		(1 << 0)
>> +#define MAX9286_I2CSLVTO_64US		(0 << 0)
>> +/* Register 0x3b */
>> +#define MAX9286_REV_TRF(n)		((n) << 4)
>> +#define MAX9286_REV_AMP(n)		((((n) - 30) / 10) << 1) /* in mV */
>> +#define MAX9286_REV_AMP_X		BIT(0)
>> +/* Register 0x3f */
>> +#define MAX9286_EN_REV_CFG		BIT(6)
>> +#define MAX9286_REV_FLEN(n)		((n) - 20)
>> +/* Register 0x49 */
>> +#define MAX9286_VIDEO_DETECT_MASK	0x0f
>> +/* Register 0x69 */
>> +#define MAX9286_LFLTBMONMASKED		BIT(7)
>> +#define MAX9286_LOCKMONMASKED		BIT(6)
>> +#define MAX9286_AUTOCOMBACKEN		BIT(5)
>> +#define MAX9286_AUTOMASKEN		BIT(4)
>> +#define MAX9286_MASKLINK(n)		((n) << 0)
>> +
>> +/*
>> + * The sink and source pads are created to match the OF graph port numbers so
>> + * that their indexes can be used interchangeably.
>> + */
>> +#define MAX9286_NUM_GMSL		4
>> +#define MAX9286_N_SINKS			4
>> +#define MAX9286_N_PADS			5
>> +#define MAX9286_SRC_PAD			4
>> +
>> +struct max9286_source {
>> +	struct v4l2_async_subdev asd;
>> +	struct v4l2_subdev *sd;
>> +	struct fwnode_handle *fwnode;
>> +};
>> +
>> +#define asd_to_max9286_source(_asd) \
>> +	container_of(_asd, struct max9286_source, asd)
>> +
>> +struct max9286_priv {
>> +	struct i2c_client *client;
>> +	struct gpio_desc *gpiod_pwdn;
>> +	struct v4l2_subdev sd;
>> +	struct media_pad pads[MAX9286_N_PADS];
>> +	struct regulator *regulator;
>> +
>> +	struct gpio_chip gpio;
>> +	u8 gpio_state;
>> +
>> +	struct i2c_mux_core *mux;
>> +	unsigned int mux_channel;
>> +	bool mux_open;
>> +
>> +	struct v4l2_ctrl_handler ctrls;
>> +	struct v4l2_ctrl *pixelrate;
>> +
>> +	struct v4l2_mbus_framefmt fmt[MAX9286_N_SINKS];
>> +
>> +	/* Protects controls and fmt structures */
>> +	struct mutex mutex;
>> +
>> +	unsigned int nsources;
>> +	unsigned int source_mask;
>> +	unsigned int route_mask;
>> +	unsigned int bound_sources;
>> +	unsigned int csi2_data_lanes;
>> +	struct max9286_source sources[MAX9286_NUM_GMSL];
>> +	struct v4l2_async_notifier notifier;
>> +};
>> +
> 
> [...]
> 
>> +static int max9286_register_gpio(struct max9286_priv *priv)
>> +{
>> +	struct device *dev = &priv->client->dev;
>> +	struct gpio_chip *gpio = &priv->gpio;
>> +	int ret;
>> +
>> +	static const char * const names[] = {
>> +		"GPIO0OUT",
>> +		"GPIO1OUT",
>> +	};
>> +
>> +	/* Configure the GPIO */
>> +	gpio->label = dev_name(dev);
> 
> So if you have more than one MAX9286 in a system, all gpiochips will appear
> with the same name. I'd recommend to append the index to distinguish properly.

Ah yes, that's a good point, and I think I've even seen that.

I'll fix it now.

> 
>> +	gpio->parent = dev;
>> +	gpio->owner = THIS_MODULE;
>> +	gpio->of_node = dev->of_node;
>> +	gpio->ngpio = 2;
>> +	gpio->base = -1;
>> +	gpio->set = max9286_gpio_set;
>> +	gpio->get = max9286_gpio_get;
>> +	gpio->can_sleep = true;
>> +	gpio->names = names;
>> +
>> +	/* GPIO values default to high */
>> +	priv->gpio_state = BIT(0) | BIT(1);
>> +
>> +	ret = devm_gpiochip_add_data(dev, gpio, priv);
>> +	if (ret)
>> +		dev_err(dev, "Unable to create gpio_chip\n");
>> +
>> +	return ret;
>> +}
>> +
> 
> [...]
> 
>> +static int max9286_parse_dt(struct max9286_priv *priv)
>> +{
>> +	struct device *dev = &priv->client->dev;
>> +	struct device_node *i2c_mux;
>> +	struct device_node *node = NULL;
>> +	unsigned int i2c_mux_mask = 0;
>> +
>> +	of_node_get(dev->of_node);
> 
> Why this is needed?

Hrm .. I recall adding it to solve dt reference balancing.

I wish I'd added a comment at the time ... as I can't recall the details
now.

>> +	i2c_mux = of_find_node_by_name(dev->of_node, "i2c-mux");
>> +	if (!i2c_mux) {
>> +		dev_err(dev, "Failed to find i2c-mux node\n");
>> +		of_node_put(dev->of_node);
>> +		return -EINVAL;
>> +	}
>> +
>> +	/* Identify which i2c-mux channels are enabled */
>> +	for_each_child_of_node(i2c_mux, node) {
>> +		u32 id = 0;
>> +
>> +		of_property_read_u32(node, "reg", &id);
>> +		if (id >= MAX9286_NUM_GMSL)
>> +			continue;
>> +
>> +		if (!of_device_is_available(node)) {
>> +			dev_dbg(dev, "Skipping disabled I2C bus port %u\n", id);
>> +			continue;
>> +		}
>> +
>> +		i2c_mux_mask |= BIT(id);
>> +	}
>> +	of_node_put(node);
>> +	of_node_put(i2c_mux);
>> +
>> +	/* Parse the endpoints */
>> +	for_each_endpoint_of_node(dev->of_node, node) {
>> +		struct max9286_source *source;
>> +		struct of_endpoint ep;
>> +
>> +		of_graph_parse_endpoint(node, &ep);
>> +		dev_dbg(dev, "Endpoint %pOF on port %d",
>> +			ep.local_node, ep.port);
>> +
>> +		if (ep.port > MAX9286_NUM_GMSL) {
>> +			dev_err(dev, "Invalid endpoint %s on port %d",
>> +				of_node_full_name(ep.local_node), ep.port);
>> +			continue;
>> +		}
>> +
>> +		/* For the source endpoint just parse the bus configuration. */
>> +		if (ep.port == MAX9286_SRC_PAD) {
>> +			struct v4l2_fwnode_endpoint vep = {
>> +				.bus_type = V4L2_MBUS_CSI2_DPHY
>> +			};
>> +			int ret;
>> +
>> +			ret = v4l2_fwnode_endpoint_parse(
>> +					of_fwnode_handle(node), &vep);
>> +			if (ret) {
>> +				of_node_put(node);
>> +				of_node_put(dev->of_node);
>> +				return ret;
>> +			}
>> +
>> +			if (vep.bus_type != V4L2_MBUS_CSI2_DPHY) {
>> +				dev_err(dev,
>> +					"Media bus %u type not supported\n",
>> +					vep.bus_type);
>> +				v4l2_fwnode_endpoint_free(&vep);
>> +				of_node_put(node);
>> +				of_node_put(dev->of_node);
>> +				return -EINVAL;
>> +			}
>> +
>> +			priv->csi2_data_lanes =
>> +				vep.bus.mipi_csi2.num_data_lanes;
>> +			v4l2_fwnode_endpoint_free(&vep);
>> +
>> +			continue;
>> +		}
>> +
>> +		/* Skip if the corresponding GMSL link is unavailable. */
>> +		if (!(i2c_mux_mask & BIT(ep.port)))
>> +			continue;
>> +
>> +		if (priv->sources[ep.port].fwnode) {
>> +			dev_err(dev,
>> +				"Multiple port endpoints are not supported: %d",
>> +				ep.port);
>> +
>> +			continue;
>> +		}
>> +
>> +		source = &priv->sources[ep.port];
>> +		source->fwnode = fwnode_graph_get_remote_endpoint(
>> +						of_fwnode_handle(node));
>> +		if (!source->fwnode) {
>> +			dev_err(dev,
>> +				"Endpoint %pOF has no remote endpoint connection\n",
>> +				ep.local_node);
>> +
>> +			continue;
>> +		}
>> +
>> +		priv->source_mask |= BIT(ep.port);
>> +		priv->nsources++;
>> +	}
>> +	of_node_put(node);
>> +	of_node_put(dev->of_node);
>> +
>> +	priv->route_mask = priv->source_mask;
>> +
>> +	return 0;
>> +}
>> +
> 
> [...]
> 
>> +static int max9286_remove(struct i2c_client *client)
>> +{
>> +	struct max9286_priv *priv = i2c_get_clientdata(client);
>> +
>> +	i2c_mux_del_adapters(priv->mux);
>> +
>> +	max9286_v4l2_unregister(priv);
>> +
>> +	regulator_disable(priv->regulator);
>> +
>> +	gpiod_set_value_cansleep(priv->gpiod_pwdn, 0);
> 
> Usual power down sequence is to pull the power down gpio low and then turn off
> the regulators. This helps in clearing up the internal state machine properly.

Do you mean usual, among drivers using regulators? or usual for the max9286?

I have a platform which controls the regulators for the cameras
(priv->regulator) through one of the GPIOs provided by the MAX9286.

If we powerdown the max9286 first, then we will not be able to change
the GPIO value on the gpio controlled regulator.

(Currently it doesn't expose as a gpio regulator, but just a gpio-hog -
but thats a different matter)

--
Kieran


> 
> Thanks,
> Mani
> 
>> +
>> +	max9286_cleanup_dt(priv);
>> +
>> +	return 0;
>> +}
>> +
>> +static const struct of_device_id max9286_dt_ids[] = {
>> +	{ .compatible = "maxim,max9286" },
>> +	{},
>> +};
>> +MODULE_DEVICE_TABLE(of, max9286_dt_ids);
>> +
>> +static struct i2c_driver max9286_i2c_driver = {
>> +	.driver	= {
>> +		.name		= "max9286",
>> +		.of_match_table	= of_match_ptr(max9286_dt_ids),
>> +	},
>> +	.probe_new	= max9286_probe,
>> +	.remove		= max9286_remove,
>> +};
>> +
>> +module_i2c_driver(max9286_i2c_driver);
>> +
>> +MODULE_DESCRIPTION("Maxim MAX9286 GMSL Deserializer Driver");
>> +MODULE_AUTHOR("Jacopo Mondi, Kieran Bingham, Laurent Pinchart, Niklas Söderlund, Vladimir Barinov");
>> +MODULE_LICENSE("GPL");
>> -- 
>> 2.25.1
>>

Re: [PATCH v9 2/4] media: i2c: Add MAX9286 driver

[Manivannan Sadhasivam]

Hi Kieran,

On Thu, May 14, 2020 at 11:02:53AM +0100, Kieran Bingham wrote:
> Hi Mani,
> 
> On 12/05/2020 19:17, Manivannan Sadhasivam wrote:
> > On Tue, May 12, 2020 at 04:51:03PM +0100, Kieran Bingham wrote:
> >> The MAX9286 is a 4-channel GMSL deserializer with coax or STP input and
> >> CSI-2 output. The device supports multicamera streaming applications,
> >> and features the ability to synchronise the attached cameras.
> >>
> >> CSI-2 output can be configured with 1 to 4 lanes, and a control channel
> >> is supported over I2C, which implements an I2C mux to facilitate
> >> communications with connected cameras across the reverse control
> >> channel.
> >>
> >> Signed-off-by: Jacopo Mondi <jacopo+renesas@jmondi.org>
> >> Signed-off-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
> >> Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
> >> Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
> >>
> >> --
> >> v2:
> >>  - Fix MAINTAINERS entry
> >>
> >> This posting is released with the following modifications to work
> >> without Sakari's VC developments:
> >>  - max9286_g_mbus_config() re-instated
> >>  - max9286_get_frame_desc() is not bus/csi aware
> >>  - max9286_{get,set}_routing() removed
> >>
> >> v3:
> >>  - Initialise notifier with v4l2_async_notifier_init
> >>  - Update for new mbus csi2 format V4L2_MBUS_CSI2_DPHY
> >>
> >> v4: - Re-introduce required code to function with the VC series.
> >>
> >>  - Implement max9286_get_routing, max9286_set_routing
> >>  - Remove max9286_g_mbus_config
> >>
> >> v5: (internal release)
> >>  - Fix printk formatting for hex value
> >>  - max9286->sd.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE (add |)
> >>  - MEDIA_ENT_F_PROC_VIDEO_PIXEL_FORMATTER -> MEDIA_ENT_F_VID_IF_BRIDGE
> >>  - Remove 'device is bound' workaround
> >>
> >> v6:
> >>  - v4l2_subdev_krouting instead of v4l2_subdev_routing separated
> >>    to allow integration without the VC/V4L2-Mux series.
> >>  - convert sd_to_max9286 to inline function
> >>  - rename max9286_device to max9286_priv
> >>  - Cleanup the v4l2_async_notifier
> >>  - Extend MODULE_AUTHOR
> >>  - Replace of_graph_get_endpoint_by_regs with fwnode_graph_get_endpoint_by_id
> >>  - Pass default bus type when parsing fwnode endpoint (Manivannan Sadhasivam)
> >>  - Use new YAML file reference in MAINTAINERS
> >>  - Parse new i2c-mux node in max9286_get_i2c_by_id
> >>    (This could/should be refactored to parse these separately first)
> >>  - Spelling and calculation fixes in the FSYNC_LOCKED check comments
> >>  - Identify each enabled i2c-mux channel in a single pass
> >>  - max9286: Improve mux-state readbility [v2]
> >>  - Fix frame sync lock durations
> >>  - Add comment to describe /why/ we must open the mux in s_stream
> >>  - use -EXDEV as return code for failed link synchronisation.
> >>  - Fix reference counting of the dt nodeS
> >>  - Convert to probe_new for I2C
> >>  - Remove redundant max9286_i2c_mux_state
> >>  - Provide optional enable-gpio (max9286-pwdn)
> >>
> >> v7:
> >>  [Kieran]
> >>  - Ensure powerdown lines are optional
> >>  - Add a 4ms power-up delay
> >>  - Add max9286_check_config_link() to core
> >>  - Add GPIO chip controller for GPIO0OUT and GPIO1OUT
> >>  - Fix GPIO registration
> >>  - max9286: Split out async registration
> >>    (fixes regulator -EPROBE_DEFERs failures)
> >>  - Collect all V4L2 registrations
> >>  - balance v4l2_async refcnting
> >>  - Rename max9286_v4l2_async_ => max9286_v4l2_notifier_
> >>
> >>  [Jacopo]
> >>  - Remove redundanct MAXIM_I2C_SPEED macros
> >>  - Move notifiers operations
> >>  - Add delay after reverse channel reconfiguration
> >>  - Move link setup to completion
> >>  - Fix up max9286_check_config_link() implementation
> >>  - Remove redundant dual configuration of reverse channel
> >>
> >> v8:
> >>
> >> [Kieran]
> >>  - Update the bound_sources mask on unbind
> >>  - Convert probe kzalloc usage to devm_ variant
> >>  - Fix up cleanup path from GPIO PowerDown registration
> >>  - cleanup GPIO device registration fail path
> >>  - Convert to use devm_regulator_get()
> >>  - Fit max9286_parse_dt print on one line
> >>  - Move multi-device workarounds out of upstream driver
> >>  - Remove I2C mod-table
> >>  - Lock format changes
> >>  - Describe pad index usage
> >>  - Remove poc_enabled workaround
> >>  - Rename the max9286_gpio to be more explicit on it's actions.
> >>  - Move max9286_init_format call
> >>  - Rework probe sequence and simplify error paths.
> >>  - Simplify i2c comments
> >>  - Implement Pixelrate control
> >>  - Disable overlap window
> >>
> >> [Jacopo]
> >>  - Adapt Kconfig to latest upstream changes
> >>  - Put of node on error
> >>  - Calculate pixel rate
> >>  - Simplify overlap window disablement
> >>
> >> v9:
> >>
> >> [Kieran]
> >>  - Kconfig: Depend on OF
> >>  - Re-sort addition to Makefile
> >> ---
> >>  MAINTAINERS                 |   10 +
> >>  drivers/media/i2c/Kconfig   |   13 +
> >>  drivers/media/i2c/Makefile  |    1 +
> >>  drivers/media/i2c/max9286.c | 1332 +++++++++++++++++++++++++++++++++++
> >>  4 files changed, 1356 insertions(+)
> >>  create mode 100644 drivers/media/i2c/max9286.c
> >>
> >> diff --git a/MAINTAINERS b/MAINTAINERS
> >> index a7bb6e22d5da..99e3bf7760fd 100644
> >> --- a/MAINTAINERS
> >> +++ b/MAINTAINERS
> >> @@ -10274,6 +10274,16 @@ F:	Documentation/hwmon/max6697.rst
> >>  F:	drivers/hwmon/max6697.c
> >>  F:	include/linux/platform_data/max6697.h
> >>  
> >> +MAX9286 QUAD GMSL DESERIALIZER DRIVER
> >> +M:	Jacopo Mondi <jacopo+renesas@jmondi.org>
> >> +M:	Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
> >> +M:	Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
> >> +M:	Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
> >> +L:	linux-media@vger.kernel.org
> >> +S:	Maintained
> >> +F:	Documentation/devicetree/bindings/media/i2c/maxim,max9286.yaml
> >> +F:	drivers/media/i2c/max9286.c
> >> +
> >>  MAX9860 MONO AUDIO VOICE CODEC DRIVER
> >>  M:	Peter Rosin <peda@axentia.se>
> >>  L:	alsa-devel@alsa-project.org (moderated for non-subscribers)
> >> diff --git a/drivers/media/i2c/Kconfig b/drivers/media/i2c/Kconfig
> >> index 3abc80373ec0..2e390f41f6da 100644
> >> --- a/drivers/media/i2c/Kconfig
> >> +++ b/drivers/media/i2c/Kconfig
> >> @@ -464,6 +464,19 @@ config VIDEO_VPX3220
> >>  	  To compile this driver as a module, choose M here: the
> >>  	  module will be called vpx3220.
> >>  
> >> +config VIDEO_MAX9286
> >> +	tristate "Maxim MAX9286 GMSL deserializer support"
> >> +	depends on I2C && I2C_MUX
> >> +	depends on OF
> >> +	select V4L2_FWNODE
> >> +	select VIDEO_V4L2_SUBDEV_API
> >> +	select MEDIA_CONTROLLER
> >> +	help
> >> +	  This driver supports the Maxim MAX9286 GMSL deserializer.
> >> +
> >> +	  To compile this driver as a module, choose M here: the
> >> +	  module will be called max9286.
> >> +
> >>  comment "Video and audio decoders"
> >>  
> >>  config VIDEO_SAA717X
> >> diff --git a/drivers/media/i2c/Makefile b/drivers/media/i2c/Makefile
> >> index 77bf7d0b691f..f0b001ee4b05 100644
> >> --- a/drivers/media/i2c/Makefile
> >> +++ b/drivers/media/i2c/Makefile
> >> @@ -117,6 +117,7 @@ obj-$(CONFIG_VIDEO_IMX274)	+= imx274.o
> >>  obj-$(CONFIG_VIDEO_IMX290)	+= imx290.o
> >>  obj-$(CONFIG_VIDEO_IMX319)	+= imx319.o
> >>  obj-$(CONFIG_VIDEO_IMX355)	+= imx355.o
> >> +obj-$(CONFIG_VIDEO_MAX9286)	+= max9286.o
> >>  obj-$(CONFIG_VIDEO_ST_MIPID02) += st-mipid02.o
> >>  
> >>  obj-$(CONFIG_SDR_MAX2175) += max2175.o
> >> diff --git a/drivers/media/i2c/max9286.c b/drivers/media/i2c/max9286.c
> >> new file mode 100644
> >> index 000000000000..481d65f2b51d
> >> --- /dev/null
> >> +++ b/drivers/media/i2c/max9286.c
> >> @@ -0,0 +1,1332 @@
> >> +// SPDX-License-Identifier: GPL-2.0+
> >> +/*
> >> + * Maxim MAX9286 GMSL Deserializer Driver
> >> + *
> >> + * Copyright (C) 2017-2019 Jacopo Mondi
> >> + * Copyright (C) 2017-2019 Kieran Bingham
> >> + * Copyright (C) 2017-2019 Laurent Pinchart
> >> + * Copyright (C) 2017-2019 Niklas Söderlund
> >> + * Copyright (C) 2016 Renesas Electronics Corporation
> >> + * Copyright (C) 2015 Cogent Embedded, Inc.
> >> + */
> >> +
> >> +#include <linux/delay.h>
> >> +#include <linux/device.h>
> >> +#include <linux/fwnode.h>
> >> +#include <linux/gpio/consumer.h>
> >> +#include <linux/gpio/driver.h>
> >> +#include <linux/i2c.h>
> >> +#include <linux/i2c-mux.h>
> >> +#include <linux/module.h>
> >> +#include <linux/mutex.h>
> >> +#include <linux/of_graph.h>
> >> +#include <linux/regulator/consumer.h>
> >> +#include <linux/slab.h>
> >> +
> >> +#include <media/v4l2-async.h>
> >> +#include <media/v4l2-ctrls.h>
> >> +#include <media/v4l2-device.h>
> >> +#include <media/v4l2-fwnode.h>
> >> +#include <media/v4l2-subdev.h>
> >> +
> >> +/* Register 0x00 */
> >> +#define MAX9286_MSTLINKSEL_AUTO		(7 << 5)
> >> +#define MAX9286_MSTLINKSEL(n)		((n) << 5)
> >> +#define MAX9286_EN_VS_GEN		BIT(4)
> >> +#define MAX9286_LINKEN(n)		(1 << (n))
> >> +/* Register 0x01 */
> >> +#define MAX9286_FSYNCMODE_ECU		(3 << 6)
> >> +#define MAX9286_FSYNCMODE_EXT		(2 << 6)
> >> +#define MAX9286_FSYNCMODE_INT_OUT	(1 << 6)
> >> +#define MAX9286_FSYNCMODE_INT_HIZ	(0 << 6)
> >> +#define MAX9286_GPIEN			BIT(5)
> >> +#define MAX9286_ENLMO_RSTFSYNC		BIT(2)
> >> +#define MAX9286_FSYNCMETH_AUTO		(2 << 0)
> >> +#define MAX9286_FSYNCMETH_SEMI_AUTO	(1 << 0)
> >> +#define MAX9286_FSYNCMETH_MANUAL	(0 << 0)
> >> +#define MAX9286_REG_FSYNC_PERIOD_L	0x06
> >> +#define MAX9286_REG_FSYNC_PERIOD_M	0x07
> >> +#define MAX9286_REG_FSYNC_PERIOD_H	0x08
> >> +/* Register 0x0a */
> >> +#define MAX9286_FWDCCEN(n)		(1 << ((n) + 4))
> >> +#define MAX9286_REVCCEN(n)		(1 << (n))
> >> +/* Register 0x0c */
> >> +#define MAX9286_HVEN			BIT(7)
> >> +#define MAX9286_EDC_6BIT_HAMMING	(2 << 5)
> >> +#define MAX9286_EDC_6BIT_CRC		(1 << 5)
> >> +#define MAX9286_EDC_1BIT_PARITY		(0 << 5)
> >> +#define MAX9286_DESEL			BIT(4)
> >> +#define MAX9286_INVVS			BIT(3)
> >> +#define MAX9286_INVHS			BIT(2)
> >> +#define MAX9286_HVSRC_D0		(2 << 0)
> >> +#define MAX9286_HVSRC_D14		(1 << 0)
> >> +#define MAX9286_HVSRC_D18		(0 << 0)
> >> +/* Register 0x0f */
> >> +#define MAX9286_0X0F_RESERVED		BIT(3)
> >> +/* Register 0x12 */
> >> +#define MAX9286_CSILANECNT(n)		(((n) - 1) << 6)
> >> +#define MAX9286_CSIDBL			BIT(5)
> >> +#define MAX9286_DBL			BIT(4)
> >> +#define MAX9286_DATATYPE_USER_8BIT	(11 << 0)
> >> +#define MAX9286_DATATYPE_USER_YUV_12BIT	(10 << 0)
> >> +#define MAX9286_DATATYPE_USER_24BIT	(9 << 0)
> >> +#define MAX9286_DATATYPE_RAW14		(8 << 0)
> >> +#define MAX9286_DATATYPE_RAW11		(7 << 0)
> >> +#define MAX9286_DATATYPE_RAW10		(6 << 0)
> >> +#define MAX9286_DATATYPE_RAW8		(5 << 0)
> >> +#define MAX9286_DATATYPE_YUV422_10BIT	(4 << 0)
> >> +#define MAX9286_DATATYPE_YUV422_8BIT	(3 << 0)
> >> +#define MAX9286_DATATYPE_RGB555		(2 << 0)
> >> +#define MAX9286_DATATYPE_RGB565		(1 << 0)
> >> +#define MAX9286_DATATYPE_RGB888		(0 << 0)
> >> +/* Register 0x15 */
> >> +#define MAX9286_VC(n)			((n) << 5)
> >> +#define MAX9286_VCTYPE			BIT(4)
> >> +#define MAX9286_CSIOUTEN		BIT(3)
> >> +#define MAX9286_0X15_RESV		(3 << 0)
> >> +/* Register 0x1b */
> >> +#define MAX9286_SWITCHIN(n)		(1 << ((n) + 4))
> >> +#define MAX9286_ENEQ(n)			(1 << (n))
> >> +/* Register 0x27 */
> >> +#define MAX9286_LOCKED			BIT(7)
> >> +/* Register 0x31 */
> >> +#define MAX9286_FSYNC_LOCKED		BIT(6)
> >> +/* Register 0x34 */
> >> +#define MAX9286_I2CLOCACK		BIT(7)
> >> +#define MAX9286_I2CSLVSH_1046NS_469NS	(3 << 5)
> >> +#define MAX9286_I2CSLVSH_938NS_352NS	(2 << 5)
> >> +#define MAX9286_I2CSLVSH_469NS_234NS	(1 << 5)
> >> +#define MAX9286_I2CSLVSH_352NS_117NS	(0 << 5)
> >> +#define MAX9286_I2CMSTBT_837KBPS	(7 << 2)
> >> +#define MAX9286_I2CMSTBT_533KBPS	(6 << 2)
> >> +#define MAX9286_I2CMSTBT_339KBPS	(5 << 2)
> >> +#define MAX9286_I2CMSTBT_173KBPS	(4 << 2)
> >> +#define MAX9286_I2CMSTBT_105KBPS	(3 << 2)
> >> +#define MAX9286_I2CMSTBT_84KBPS		(2 << 2)
> >> +#define MAX9286_I2CMSTBT_28KBPS		(1 << 2)
> >> +#define MAX9286_I2CMSTBT_8KBPS		(0 << 2)
> >> +#define MAX9286_I2CSLVTO_NONE		(3 << 0)
> >> +#define MAX9286_I2CSLVTO_1024US		(2 << 0)
> >> +#define MAX9286_I2CSLVTO_256US		(1 << 0)
> >> +#define MAX9286_I2CSLVTO_64US		(0 << 0)
> >> +/* Register 0x3b */
> >> +#define MAX9286_REV_TRF(n)		((n) << 4)
> >> +#define MAX9286_REV_AMP(n)		((((n) - 30) / 10) << 1) /* in mV */
> >> +#define MAX9286_REV_AMP_X		BIT(0)
> >> +/* Register 0x3f */
> >> +#define MAX9286_EN_REV_CFG		BIT(6)
> >> +#define MAX9286_REV_FLEN(n)		((n) - 20)
> >> +/* Register 0x49 */
> >> +#define MAX9286_VIDEO_DETECT_MASK	0x0f
> >> +/* Register 0x69 */
> >> +#define MAX9286_LFLTBMONMASKED		BIT(7)
> >> +#define MAX9286_LOCKMONMASKED		BIT(6)
> >> +#define MAX9286_AUTOCOMBACKEN		BIT(5)
> >> +#define MAX9286_AUTOMASKEN		BIT(4)
> >> +#define MAX9286_MASKLINK(n)		((n) << 0)
> >> +
> >> +/*
> >> + * The sink and source pads are created to match the OF graph port numbers so
> >> + * that their indexes can be used interchangeably.
> >> + */
> >> +#define MAX9286_NUM_GMSL		4
> >> +#define MAX9286_N_SINKS			4
> >> +#define MAX9286_N_PADS			5
> >> +#define MAX9286_SRC_PAD			4
> >> +
> >> +struct max9286_source {
> >> +	struct v4l2_async_subdev asd;
> >> +	struct v4l2_subdev *sd;
> >> +	struct fwnode_handle *fwnode;
> >> +};
> >> +
> >> +#define asd_to_max9286_source(_asd) \
> >> +	container_of(_asd, struct max9286_source, asd)
> >> +
> >> +struct max9286_priv {
> >> +	struct i2c_client *client;
> >> +	struct gpio_desc *gpiod_pwdn;
> >> +	struct v4l2_subdev sd;
> >> +	struct media_pad pads[MAX9286_N_PADS];
> >> +	struct regulator *regulator;
> >> +
> >> +	struct gpio_chip gpio;
> >> +	u8 gpio_state;
> >> +
> >> +	struct i2c_mux_core *mux;
> >> +	unsigned int mux_channel;
> >> +	bool mux_open;
> >> +
> >> +	struct v4l2_ctrl_handler ctrls;
> >> +	struct v4l2_ctrl *pixelrate;
> >> +
> >> +	struct v4l2_mbus_framefmt fmt[MAX9286_N_SINKS];
> >> +
> >> +	/* Protects controls and fmt structures */
> >> +	struct mutex mutex;
> >> +
> >> +	unsigned int nsources;
> >> +	unsigned int source_mask;
> >> +	unsigned int route_mask;
> >> +	unsigned int bound_sources;
> >> +	unsigned int csi2_data_lanes;
> >> +	struct max9286_source sources[MAX9286_NUM_GMSL];
> >> +	struct v4l2_async_notifier notifier;
> >> +};
> >> +
> > 
> > [...]
> > 
> >> +static int max9286_register_gpio(struct max9286_priv *priv)
> >> +{
> >> +	struct device *dev = &priv->client->dev;
> >> +	struct gpio_chip *gpio = &priv->gpio;
> >> +	int ret;
> >> +
> >> +	static const char * const names[] = {
> >> +		"GPIO0OUT",
> >> +		"GPIO1OUT",
> >> +	};
> >> +
> >> +	/* Configure the GPIO */
> >> +	gpio->label = dev_name(dev);
> > 
> > So if you have more than one MAX9286 in a system, all gpiochips will appear
> > with the same name. I'd recommend to append the index to distinguish properly.
> 
> Ah yes, that's a good point, and I think I've even seen that.
> 
> I'll fix it now.
> 
> > 
> >> +	gpio->parent = dev;
> >> +	gpio->owner = THIS_MODULE;
> >> +	gpio->of_node = dev->of_node;
> >> +	gpio->ngpio = 2;
> >> +	gpio->base = -1;
> >> +	gpio->set = max9286_gpio_set;
> >> +	gpio->get = max9286_gpio_get;
> >> +	gpio->can_sleep = true;
> >> +	gpio->names = names;
> >> +
> >> +	/* GPIO values default to high */
> >> +	priv->gpio_state = BIT(0) | BIT(1);
> >> +
> >> +	ret = devm_gpiochip_add_data(dev, gpio, priv);
> >> +	if (ret)
> >> +		dev_err(dev, "Unable to create gpio_chip\n");
> >> +
> >> +	return ret;
> >> +}
> >> +
> > 
> > [...]
> > 
> >> +static int max9286_parse_dt(struct max9286_priv *priv)
> >> +{
> >> +	struct device *dev = &priv->client->dev;
> >> +	struct device_node *i2c_mux;
> >> +	struct device_node *node = NULL;
> >> +	unsigned int i2c_mux_mask = 0;
> >> +
> >> +	of_node_get(dev->of_node);
> > 
> > Why this is needed?
> 
> Hrm .. I recall adding it to solve dt reference balancing.
> 
> I wish I'd added a comment at the time ... as I can't recall the details
> now.
>

I understand that it is for the refcount balancing but I certainly don't see
a need for it.
 
> >> +	i2c_mux = of_find_node_by_name(dev->of_node, "i2c-mux");
> >> +	if (!i2c_mux) {
> >> +		dev_err(dev, "Failed to find i2c-mux node\n");
> >> +		of_node_put(dev->of_node);
> >> +		return -EINVAL;
> >> +	}
> >> +
[...]
> > 
> > [...]
> > 
> >> +static int max9286_remove(struct i2c_client *client)
> >> +{
> >> +	struct max9286_priv *priv = i2c_get_clientdata(client);
> >> +
> >> +	i2c_mux_del_adapters(priv->mux);
> >> +
> >> +	max9286_v4l2_unregister(priv);
> >> +
> >> +	regulator_disable(priv->regulator);
> >> +
> >> +	gpiod_set_value_cansleep(priv->gpiod_pwdn, 0);
> > 
> > Usual power down sequence is to pull the power down gpio low and then turn off
> > the regulators. This helps in clearing up the internal state machine properly.
> 
> Do you mean usual, among drivers using regulators? or usual for the max9286?
> 

Usual for devices exposing shutdown gpios and powered by an external regulator.

> I have a platform which controls the regulators for the cameras
> (priv->regulator) through one of the GPIOs provided by the MAX9286.
> 
> If we powerdown the max9286 first, then we will not be able to change
> the GPIO value on the gpio controlled regulator.
> 

Hmm, I didn't think of this usecase. Let's keep it as it is.

Thanks,
Mani

> (Currently it doesn't expose as a gpio regulator, but just a gpio-hog -
> but thats a different matter)
> 
> --
> Kieran
> 
> 
> > 
> > Thanks,
> > Mani
> > 
> >> +
> >> +	max9286_cleanup_dt(priv);
> >> +
> >> +	return 0;
> >> +}
> >> +
> >> +static const struct of_device_id max9286_dt_ids[] = {
> >> +	{ .compatible = "maxim,max9286" },
> >> +	{},
> >> +};
> >> +MODULE_DEVICE_TABLE(of, max9286_dt_ids);
> >> +
> >> +static struct i2c_driver max9286_i2c_driver = {
> >> +	.driver	= {
> >> +		.name		= "max9286",
> >> +		.of_match_table	= of_match_ptr(max9286_dt_ids),
> >> +	},
> >> +	.probe_new	= max9286_probe,
> >> +	.remove		= max9286_remove,
> >> +};
> >> +
> >> +module_i2c_driver(max9286_i2c_driver);
> >> +
> >> +MODULE_DESCRIPTION("Maxim MAX9286 GMSL Deserializer Driver");
> >> +MODULE_AUTHOR("Jacopo Mondi, Kieran Bingham, Laurent Pinchart, Niklas Söderlund, Vladimir Barinov");
> >> +MODULE_LICENSE("GPL");
> >> -- 
> >> 2.25.1
> >>
> 

Re: [PATCH v9 2/4] media: i2c: Add MAX9286 driver

[Kieran Bingham]

Hi Mani,

On 14/05/2020 11:13, Manivannan Sadhasivam wrote:
> Hi Kieran,
> 
> On Thu, May 14, 2020 at 11:02:53AM +0100, Kieran Bingham wrote:
>> Hi Mani,
>>
>> On 12/05/2020 19:17, Manivannan Sadhasivam wrote:
>>> On Tue, May 12, 2020 at 04:51:03PM +0100, Kieran Bingham wrote:
>>>> The MAX9286 is a 4-channel GMSL deserializer with coax or STP input and
>>>> CSI-2 output. The device supports multicamera streaming applications,
>>>> and features the ability to synchronise the attached cameras.
>>>>
>>>> CSI-2 output can be configured with 1 to 4 lanes, and a control channel
>>>> is supported over I2C, which implements an I2C mux to facilitate
>>>> communications with connected cameras across the reverse control
>>>> channel.
>>>>
>>>> Signed-off-by: Jacopo Mondi <jacopo+renesas@jmondi.org>
>>>> Signed-off-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
>>>> Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
>>>> Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
>>>>
>>>> --
>>>> v2:
>>>>  - Fix MAINTAINERS entry
>>>>
>>>> This posting is released with the following modifications to work
>>>> without Sakari's VC developments:
>>>>  - max9286_g_mbus_config() re-instated
>>>>  - max9286_get_frame_desc() is not bus/csi aware
>>>>  - max9286_{get,set}_routing() removed
>>>>
>>>> v3:
>>>>  - Initialise notifier with v4l2_async_notifier_init
>>>>  - Update for new mbus csi2 format V4L2_MBUS_CSI2_DPHY
>>>>
>>>> v4: - Re-introduce required code to function with the VC series.
>>>>
>>>>  - Implement max9286_get_routing, max9286_set_routing
>>>>  - Remove max9286_g_mbus_config
>>>>
>>>> v5: (internal release)
>>>>  - Fix printk formatting for hex value
>>>>  - max9286->sd.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE (add |)
>>>>  - MEDIA_ENT_F_PROC_VIDEO_PIXEL_FORMATTER -> MEDIA_ENT_F_VID_IF_BRIDGE
>>>>  - Remove 'device is bound' workaround
>>>>
>>>> v6:
>>>>  - v4l2_subdev_krouting instead of v4l2_subdev_routing separated
>>>>    to allow integration without the VC/V4L2-Mux series.
>>>>  - convert sd_to_max9286 to inline function
>>>>  - rename max9286_device to max9286_priv
>>>>  - Cleanup the v4l2_async_notifier
>>>>  - Extend MODULE_AUTHOR
>>>>  - Replace of_graph_get_endpoint_by_regs with fwnode_graph_get_endpoint_by_id
>>>>  - Pass default bus type when parsing fwnode endpoint (Manivannan Sadhasivam)
>>>>  - Use new YAML file reference in MAINTAINERS
>>>>  - Parse new i2c-mux node in max9286_get_i2c_by_id
>>>>    (This could/should be refactored to parse these separately first)
>>>>  - Spelling and calculation fixes in the FSYNC_LOCKED check comments
>>>>  - Identify each enabled i2c-mux channel in a single pass
>>>>  - max9286: Improve mux-state readbility [v2]
>>>>  - Fix frame sync lock durations
>>>>  - Add comment to describe /why/ we must open the mux in s_stream
>>>>  - use -EXDEV as return code for failed link synchronisation.
>>>>  - Fix reference counting of the dt nodeS
>>>>  - Convert to probe_new for I2C
>>>>  - Remove redundant max9286_i2c_mux_state
>>>>  - Provide optional enable-gpio (max9286-pwdn)
>>>>
>>>> v7:
>>>>  [Kieran]
>>>>  - Ensure powerdown lines are optional
>>>>  - Add a 4ms power-up delay
>>>>  - Add max9286_check_config_link() to core
>>>>  - Add GPIO chip controller for GPIO0OUT and GPIO1OUT
>>>>  - Fix GPIO registration
>>>>  - max9286: Split out async registration
>>>>    (fixes regulator -EPROBE_DEFERs failures)
>>>>  - Collect all V4L2 registrations
>>>>  - balance v4l2_async refcnting
>>>>  - Rename max9286_v4l2_async_ => max9286_v4l2_notifier_
>>>>
>>>>  [Jacopo]
>>>>  - Remove redundanct MAXIM_I2C_SPEED macros
>>>>  - Move notifiers operations
>>>>  - Add delay after reverse channel reconfiguration
>>>>  - Move link setup to completion
>>>>  - Fix up max9286_check_config_link() implementation
>>>>  - Remove redundant dual configuration of reverse channel
>>>>
>>>> v8:
>>>>
>>>> [Kieran]
>>>>  - Update the bound_sources mask on unbind
>>>>  - Convert probe kzalloc usage to devm_ variant
>>>>  - Fix up cleanup path from GPIO PowerDown registration
>>>>  - cleanup GPIO device registration fail path
>>>>  - Convert to use devm_regulator_get()
>>>>  - Fit max9286_parse_dt print on one line
>>>>  - Move multi-device workarounds out of upstream driver
>>>>  - Remove I2C mod-table
>>>>  - Lock format changes
>>>>  - Describe pad index usage
>>>>  - Remove poc_enabled workaround
>>>>  - Rename the max9286_gpio to be more explicit on it's actions.
>>>>  - Move max9286_init_format call
>>>>  - Rework probe sequence and simplify error paths.
>>>>  - Simplify i2c comments
>>>>  - Implement Pixelrate control
>>>>  - Disable overlap window
>>>>
>>>> [Jacopo]
>>>>  - Adapt Kconfig to latest upstream changes
>>>>  - Put of node on error
>>>>  - Calculate pixel rate
>>>>  - Simplify overlap window disablement
>>>>
>>>> v9:
>>>>
>>>> [Kieran]
>>>>  - Kconfig: Depend on OF
>>>>  - Re-sort addition to Makefile
>>>> ---
>>>>  MAINTAINERS                 |   10 +
>>>>  drivers/media/i2c/Kconfig   |   13 +
>>>>  drivers/media/i2c/Makefile  |    1 +
>>>>  drivers/media/i2c/max9286.c | 1332 +++++++++++++++++++++++++++++++++++
>>>>  4 files changed, 1356 insertions(+)
>>>>  create mode 100644 drivers/media/i2c/max9286.c
>>>>
>>>> diff --git a/MAINTAINERS b/MAINTAINERS
>>>> index a7bb6e22d5da..99e3bf7760fd 100644
>>>> --- a/MAINTAINERS
>>>> +++ b/MAINTAINERS
>>>> @@ -10274,6 +10274,16 @@ F:	Documentation/hwmon/max6697.rst
>>>>  F:	drivers/hwmon/max6697.c
>>>>  F:	include/linux/platform_data/max6697.h
>>>>  
>>>> +MAX9286 QUAD GMSL DESERIALIZER DRIVER
>>>> +M:	Jacopo Mondi <jacopo+renesas@jmondi.org>
>>>> +M:	Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
>>>> +M:	Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
>>>> +M:	Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
>>>> +L:	linux-media@vger.kernel.org
>>>> +S:	Maintained
>>>> +F:	Documentation/devicetree/bindings/media/i2c/maxim,max9286.yaml
>>>> +F:	drivers/media/i2c/max9286.c
>>>> +
>>>>  MAX9860 MONO AUDIO VOICE CODEC DRIVER
>>>>  M:	Peter Rosin <peda@axentia.se>
>>>>  L:	alsa-devel@alsa-project.org (moderated for non-subscribers)
>>>> diff --git a/drivers/media/i2c/Kconfig b/drivers/media/i2c/Kconfig
>>>> index 3abc80373ec0..2e390f41f6da 100644
>>>> --- a/drivers/media/i2c/Kconfig
>>>> +++ b/drivers/media/i2c/Kconfig
>>>> @@ -464,6 +464,19 @@ config VIDEO_VPX3220
>>>>  	  To compile this driver as a module, choose M here: the
>>>>  	  module will be called vpx3220.
>>>>  
>>>> +config VIDEO_MAX9286
>>>> +	tristate "Maxim MAX9286 GMSL deserializer support"
>>>> +	depends on I2C && I2C_MUX
>>>> +	depends on OF
>>>> +	select V4L2_FWNODE
>>>> +	select VIDEO_V4L2_SUBDEV_API
>>>> +	select MEDIA_CONTROLLER
>>>> +	help
>>>> +	  This driver supports the Maxim MAX9286 GMSL deserializer.
>>>> +
>>>> +	  To compile this driver as a module, choose M here: the
>>>> +	  module will be called max9286.
>>>> +
>>>>  comment "Video and audio decoders"
>>>>  
>>>>  config VIDEO_SAA717X
>>>> diff --git a/drivers/media/i2c/Makefile b/drivers/media/i2c/Makefile
>>>> index 77bf7d0b691f..f0b001ee4b05 100644
>>>> --- a/drivers/media/i2c/Makefile
>>>> +++ b/drivers/media/i2c/Makefile
>>>> @@ -117,6 +117,7 @@ obj-$(CONFIG_VIDEO_IMX274)	+= imx274.o
>>>>  obj-$(CONFIG_VIDEO_IMX290)	+= imx290.o
>>>>  obj-$(CONFIG_VIDEO_IMX319)	+= imx319.o
>>>>  obj-$(CONFIG_VIDEO_IMX355)	+= imx355.o
>>>> +obj-$(CONFIG_VIDEO_MAX9286)	+= max9286.o
>>>>  obj-$(CONFIG_VIDEO_ST_MIPID02) += st-mipid02.o
>>>>  
>>>>  obj-$(CONFIG_SDR_MAX2175) += max2175.o
>>>> diff --git a/drivers/media/i2c/max9286.c b/drivers/media/i2c/max9286.c
>>>> new file mode 100644
>>>> index 000000000000..481d65f2b51d
>>>> --- /dev/null
>>>> +++ b/drivers/media/i2c/max9286.c
>>>> @@ -0,0 +1,1332 @@
>>>> +// SPDX-License-Identifier: GPL-2.0+
>>>> +/*
>>>> + * Maxim MAX9286 GMSL Deserializer Driver
>>>> + *
>>>> + * Copyright (C) 2017-2019 Jacopo Mondi
>>>> + * Copyright (C) 2017-2019 Kieran Bingham
>>>> + * Copyright (C) 2017-2019 Laurent Pinchart
>>>> + * Copyright (C) 2017-2019 Niklas Söderlund
>>>> + * Copyright (C) 2016 Renesas Electronics Corporation
>>>> + * Copyright (C) 2015 Cogent Embedded, Inc.
>>>> + */
>>>> +
>>>> +#include <linux/delay.h>
>>>> +#include <linux/device.h>
>>>> +#include <linux/fwnode.h>
>>>> +#include <linux/gpio/consumer.h>
>>>> +#include <linux/gpio/driver.h>
>>>> +#include <linux/i2c.h>
>>>> +#include <linux/i2c-mux.h>
>>>> +#include <linux/module.h>
>>>> +#include <linux/mutex.h>
>>>> +#include <linux/of_graph.h>
>>>> +#include <linux/regulator/consumer.h>
>>>> +#include <linux/slab.h>
>>>> +
>>>> +#include <media/v4l2-async.h>
>>>> +#include <media/v4l2-ctrls.h>
>>>> +#include <media/v4l2-device.h>
>>>> +#include <media/v4l2-fwnode.h>
>>>> +#include <media/v4l2-subdev.h>
>>>> +
>>>> +/* Register 0x00 */
>>>> +#define MAX9286_MSTLINKSEL_AUTO		(7 << 5)
>>>> +#define MAX9286_MSTLINKSEL(n)		((n) << 5)
>>>> +#define MAX9286_EN_VS_GEN		BIT(4)
>>>> +#define MAX9286_LINKEN(n)		(1 << (n))
>>>> +/* Register 0x01 */
>>>> +#define MAX9286_FSYNCMODE_ECU		(3 << 6)
>>>> +#define MAX9286_FSYNCMODE_EXT		(2 << 6)
>>>> +#define MAX9286_FSYNCMODE_INT_OUT	(1 << 6)
>>>> +#define MAX9286_FSYNCMODE_INT_HIZ	(0 << 6)
>>>> +#define MAX9286_GPIEN			BIT(5)
>>>> +#define MAX9286_ENLMO_RSTFSYNC		BIT(2)
>>>> +#define MAX9286_FSYNCMETH_AUTO		(2 << 0)
>>>> +#define MAX9286_FSYNCMETH_SEMI_AUTO	(1 << 0)
>>>> +#define MAX9286_FSYNCMETH_MANUAL	(0 << 0)
>>>> +#define MAX9286_REG_FSYNC_PERIOD_L	0x06
>>>> +#define MAX9286_REG_FSYNC_PERIOD_M	0x07
>>>> +#define MAX9286_REG_FSYNC_PERIOD_H	0x08
>>>> +/* Register 0x0a */
>>>> +#define MAX9286_FWDCCEN(n)		(1 << ((n) + 4))
>>>> +#define MAX9286_REVCCEN(n)		(1 << (n))
>>>> +/* Register 0x0c */
>>>> +#define MAX9286_HVEN			BIT(7)
>>>> +#define MAX9286_EDC_6BIT_HAMMING	(2 << 5)
>>>> +#define MAX9286_EDC_6BIT_CRC		(1 << 5)
>>>> +#define MAX9286_EDC_1BIT_PARITY		(0 << 5)
>>>> +#define MAX9286_DESEL			BIT(4)
>>>> +#define MAX9286_INVVS			BIT(3)
>>>> +#define MAX9286_INVHS			BIT(2)
>>>> +#define MAX9286_HVSRC_D0		(2 << 0)
>>>> +#define MAX9286_HVSRC_D14		(1 << 0)
>>>> +#define MAX9286_HVSRC_D18		(0 << 0)
>>>> +/* Register 0x0f */
>>>> +#define MAX9286_0X0F_RESERVED		BIT(3)
>>>> +/* Register 0x12 */
>>>> +#define MAX9286_CSILANECNT(n)		(((n) - 1) << 6)
>>>> +#define MAX9286_CSIDBL			BIT(5)
>>>> +#define MAX9286_DBL			BIT(4)
>>>> +#define MAX9286_DATATYPE_USER_8BIT	(11 << 0)
>>>> +#define MAX9286_DATATYPE_USER_YUV_12BIT	(10 << 0)
>>>> +#define MAX9286_DATATYPE_USER_24BIT	(9 << 0)
>>>> +#define MAX9286_DATATYPE_RAW14		(8 << 0)
>>>> +#define MAX9286_DATATYPE_RAW11		(7 << 0)
>>>> +#define MAX9286_DATATYPE_RAW10		(6 << 0)
>>>> +#define MAX9286_DATATYPE_RAW8		(5 << 0)
>>>> +#define MAX9286_DATATYPE_YUV422_10BIT	(4 << 0)
>>>> +#define MAX9286_DATATYPE_YUV422_8BIT	(3 << 0)
>>>> +#define MAX9286_DATATYPE_RGB555		(2 << 0)
>>>> +#define MAX9286_DATATYPE_RGB565		(1 << 0)
>>>> +#define MAX9286_DATATYPE_RGB888		(0 << 0)
>>>> +/* Register 0x15 */
>>>> +#define MAX9286_VC(n)			((n) << 5)
>>>> +#define MAX9286_VCTYPE			BIT(4)
>>>> +#define MAX9286_CSIOUTEN		BIT(3)
>>>> +#define MAX9286_0X15_RESV		(3 << 0)
>>>> +/* Register 0x1b */
>>>> +#define MAX9286_SWITCHIN(n)		(1 << ((n) + 4))
>>>> +#define MAX9286_ENEQ(n)			(1 << (n))
>>>> +/* Register 0x27 */
>>>> +#define MAX9286_LOCKED			BIT(7)
>>>> +/* Register 0x31 */
>>>> +#define MAX9286_FSYNC_LOCKED		BIT(6)
>>>> +/* Register 0x34 */
>>>> +#define MAX9286_I2CLOCACK		BIT(7)
>>>> +#define MAX9286_I2CSLVSH_1046NS_469NS	(3 << 5)
>>>> +#define MAX9286_I2CSLVSH_938NS_352NS	(2 << 5)
>>>> +#define MAX9286_I2CSLVSH_469NS_234NS	(1 << 5)
>>>> +#define MAX9286_I2CSLVSH_352NS_117NS	(0 << 5)
>>>> +#define MAX9286_I2CMSTBT_837KBPS	(7 << 2)
>>>> +#define MAX9286_I2CMSTBT_533KBPS	(6 << 2)
>>>> +#define MAX9286_I2CMSTBT_339KBPS	(5 << 2)
>>>> +#define MAX9286_I2CMSTBT_173KBPS	(4 << 2)
>>>> +#define MAX9286_I2CMSTBT_105KBPS	(3 << 2)
>>>> +#define MAX9286_I2CMSTBT_84KBPS		(2 << 2)
>>>> +#define MAX9286_I2CMSTBT_28KBPS		(1 << 2)
>>>> +#define MAX9286_I2CMSTBT_8KBPS		(0 << 2)
>>>> +#define MAX9286_I2CSLVTO_NONE		(3 << 0)
>>>> +#define MAX9286_I2CSLVTO_1024US		(2 << 0)
>>>> +#define MAX9286_I2CSLVTO_256US		(1 << 0)
>>>> +#define MAX9286_I2CSLVTO_64US		(0 << 0)
>>>> +/* Register 0x3b */
>>>> +#define MAX9286_REV_TRF(n)		((n) << 4)
>>>> +#define MAX9286_REV_AMP(n)		((((n) - 30) / 10) << 1) /* in mV */
>>>> +#define MAX9286_REV_AMP_X		BIT(0)
>>>> +/* Register 0x3f */
>>>> +#define MAX9286_EN_REV_CFG		BIT(6)
>>>> +#define MAX9286_REV_FLEN(n)		((n) - 20)
>>>> +/* Register 0x49 */
>>>> +#define MAX9286_VIDEO_DETECT_MASK	0x0f
>>>> +/* Register 0x69 */
>>>> +#define MAX9286_LFLTBMONMASKED		BIT(7)
>>>> +#define MAX9286_LOCKMONMASKED		BIT(6)
>>>> +#define MAX9286_AUTOCOMBACKEN		BIT(5)
>>>> +#define MAX9286_AUTOMASKEN		BIT(4)
>>>> +#define MAX9286_MASKLINK(n)		((n) << 0)
>>>> +
>>>> +/*
>>>> + * The sink and source pads are created to match the OF graph port numbers so
>>>> + * that their indexes can be used interchangeably.
>>>> + */
>>>> +#define MAX9286_NUM_GMSL		4
>>>> +#define MAX9286_N_SINKS			4
>>>> +#define MAX9286_N_PADS			5
>>>> +#define MAX9286_SRC_PAD			4
>>>> +
>>>> +struct max9286_source {
>>>> +	struct v4l2_async_subdev asd;
>>>> +	struct v4l2_subdev *sd;
>>>> +	struct fwnode_handle *fwnode;
>>>> +};
>>>> +
>>>> +#define asd_to_max9286_source(_asd) \
>>>> +	container_of(_asd, struct max9286_source, asd)
>>>> +
>>>> +struct max9286_priv {
>>>> +	struct i2c_client *client;
>>>> +	struct gpio_desc *gpiod_pwdn;
>>>> +	struct v4l2_subdev sd;
>>>> +	struct media_pad pads[MAX9286_N_PADS];
>>>> +	struct regulator *regulator;
>>>> +
>>>> +	struct gpio_chip gpio;
>>>> +	u8 gpio_state;
>>>> +
>>>> +	struct i2c_mux_core *mux;
>>>> +	unsigned int mux_channel;
>>>> +	bool mux_open;
>>>> +
>>>> +	struct v4l2_ctrl_handler ctrls;
>>>> +	struct v4l2_ctrl *pixelrate;
>>>> +
>>>> +	struct v4l2_mbus_framefmt fmt[MAX9286_N_SINKS];
>>>> +
>>>> +	/* Protects controls and fmt structures */
>>>> +	struct mutex mutex;
>>>> +
>>>> +	unsigned int nsources;
>>>> +	unsigned int source_mask;
>>>> +	unsigned int route_mask;
>>>> +	unsigned int bound_sources;
>>>> +	unsigned int csi2_data_lanes;
>>>> +	struct max9286_source sources[MAX9286_NUM_GMSL];
>>>> +	struct v4l2_async_notifier notifier;
>>>> +};
>>>> +
>>>
>>> [...]
>>>
>>>> +static int max9286_register_gpio(struct max9286_priv *priv)
>>>> +{
>>>> +	struct device *dev = &priv->client->dev;
>>>> +	struct gpio_chip *gpio = &priv->gpio;
>>>> +	int ret;
>>>> +
>>>> +	static const char * const names[] = {
>>>> +		"GPIO0OUT",
>>>> +		"GPIO1OUT",
>>>> +	};
>>>> +
>>>> +	/* Configure the GPIO */
>>>> +	gpio->label = dev_name(dev);
>>>
>>> So if you have more than one MAX9286 in a system, all gpiochips will appear
>>> with the same name. I'd recommend to append the index to distinguish properly.
>>
>> Ah yes, that's a good point, and I think I've even seen that.
>>
>> I'll fix it now.

Oh, in fact actually this doesn't.

gpiodetect prints:

gpiochip10 [4-004c] (2 lines)
gpiochip11 [4-006c] (2 lines)

and mostly references them as gpiochip10 and gpiochip11.

However,

> [    2.318533] gpio gpiochip11: Detected name collision for GPIO name 'GPIO0OUT'
> [    2.325739] gpio gpiochip11: Detected name collision for GPIO name 'GPIO1OUT'

That seems to be more of a problem for the gpio library, so I think I'll
just drop the const names. I don't think they add much value.


>>>> +	gpio->parent = dev;
>>>> +	gpio->owner = THIS_MODULE;
>>>> +	gpio->of_node = dev->of_node;
>>>> +	gpio->ngpio = 2;
>>>> +	gpio->base = -1;
>>>> +	gpio->set = max9286_gpio_set;
>>>> +	gpio->get = max9286_gpio_get;
>>>> +	gpio->can_sleep = true;
>>>> +	gpio->names = names;
>>>> +
>>>> +	/* GPIO values default to high */
>>>> +	priv->gpio_state = BIT(0) | BIT(1);
>>>> +
>>>> +	ret = devm_gpiochip_add_data(dev, gpio, priv);
>>>> +	if (ret)
>>>> +		dev_err(dev, "Unable to create gpio_chip\n");
>>>> +
>>>> +	return ret;
>>>> +}
>>>> +
>>>
>>> [...]
>>>
>>>> +static int max9286_parse_dt(struct max9286_priv *priv)
>>>> +{
>>>> +	struct device *dev = &priv->client->dev;
>>>> +	struct device_node *i2c_mux;
>>>> +	struct device_node *node = NULL;
>>>> +	unsigned int i2c_mux_mask = 0;
>>>> +
>>>> +	of_node_get(dev->of_node);
>>>
>>> Why this is needed?
>>
>> Hrm .. I recall adding it to solve dt reference balancing.
>>
>> I wish I'd added a comment at the time ... as I can't recall the details
>> now.
>>
> 
> I understand that it is for the refcount balancing but I certainly don't see
> a need for it.
>  
>>>> +	i2c_mux = of_find_node_by_name(dev->of_node, "i2c-mux");
>>>> +	if (!i2c_mux) {
>>>> +		dev_err(dev, "Failed to find i2c-mux node\n");
>>>> +		of_node_put(dev->of_node);
>>>> +		return -EINVAL;
>>>> +	}
>>>> +
> [...]
>>>
>>> [...]
>>>
>>>> +static int max9286_remove(struct i2c_client *client)
>>>> +{
>>>> +	struct max9286_priv *priv = i2c_get_clientdata(client);
>>>> +
>>>> +	i2c_mux_del_adapters(priv->mux);
>>>> +
>>>> +	max9286_v4l2_unregister(priv);
>>>> +
>>>> +	regulator_disable(priv->regulator);
>>>> +
>>>> +	gpiod_set_value_cansleep(priv->gpiod_pwdn, 0);
>>>
>>> Usual power down sequence is to pull the power down gpio low and then turn off
>>> the regulators. This helps in clearing up the internal state machine properly.
>>
>> Do you mean usual, among drivers using regulators? or usual for the max9286?
>>
> 
> Usual for devices exposing shutdown gpios and powered by an external regulator.
> 
>> I have a platform which controls the regulators for the cameras
>> (priv->regulator) through one of the GPIOs provided by the MAX9286.
>>
>> If we powerdown the max9286 first, then we will not be able to change
>> the GPIO value on the gpio controlled regulator.
>>
> 
> Hmm, I didn't think of this usecase. Let's keep it as it is.
> 
> Thanks,
> Mani
> 
>> (Currently it doesn't expose as a gpio regulator, but just a gpio-hog -
>> but thats a different matter)
>>
>> --
>> Kieran
>>
>>
>>>
>>> Thanks,
>>> Mani
>>>
>>>> +
>>>> +	max9286_cleanup_dt(priv);
>>>> +
>>>> +	return 0;
>>>> +}
>>>> +
>>>> +static const struct of_device_id max9286_dt_ids[] = {
>>>> +	{ .compatible = "maxim,max9286" },
>>>> +	{},
>>>> +};
>>>> +MODULE_DEVICE_TABLE(of, max9286_dt_ids);
>>>> +
>>>> +static struct i2c_driver max9286_i2c_driver = {
>>>> +	.driver	= {
>>>> +		.name		= "max9286",
>>>> +		.of_match_table	= of_match_ptr(max9286_dt_ids),
>>>> +	},
>>>> +	.probe_new	= max9286_probe,
>>>> +	.remove		= max9286_remove,
>>>> +};
>>>> +
>>>> +module_i2c_driver(max9286_i2c_driver);
>>>> +
>>>> +MODULE_DESCRIPTION("Maxim MAX9286 GMSL Deserializer Driver");
>>>> +MODULE_AUTHOR("Jacopo Mondi, Kieran Bingham, Laurent Pinchart, Niklas Söderlund, Vladimir Barinov");
>>>> +MODULE_LICENSE("GPL");
>>>> -- 
>>>> 2.25.1
>>>>
>>

Re: [PATCH v9 2/4] media: i2c: Add MAX9286 driver

[Geert Uytterhoeven]

Hi Kieran,

On Thu, May 14, 2020 at 1:47 PM Kieran Bingham
<kieran.bingham+renesas@ideasonboard.com> wrote:
> On 14/05/2020 11:13, Manivannan Sadhasivam wrote:
> > On Thu, May 14, 2020 at 11:02:53AM +0100, Kieran Bingham wrote:
> >> On 12/05/2020 19:17, Manivannan Sadhasivam wrote:
> >>> On Tue, May 12, 2020 at 04:51:03PM +0100, Kieran Bingham wrote:
> >>>> The MAX9286 is a 4-channel GMSL deserializer with coax or STP input and
> >>>> CSI-2 output. The device supports multicamera streaming applications,
> >>>> and features the ability to synchronise the attached cameras.
> >>>>
> >>>> CSI-2 output can be configured with 1 to 4 lanes, and a control channel
> >>>> is supported over I2C, which implements an I2C mux to facilitate
> >>>> communications with connected cameras across the reverse control
> >>>> channel.
> >>>>
> >>>> Signed-off-by: Jacopo Mondi <jacopo+renesas@jmondi.org>
> >>>> Signed-off-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
> >>>> Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
> >>>> Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>

> >>>> --- /dev/null
> >>>> +++ b/drivers/media/i2c/max9286.c

> >>>> +static int max9286_register_gpio(struct max9286_priv *priv)
> >>>> +{
> >>>> +  struct device *dev = &priv->client->dev;
> >>>> +  struct gpio_chip *gpio = &priv->gpio;
> >>>> +  int ret;
> >>>> +
> >>>> +  static const char * const names[] = {
> >>>> +          "GPIO0OUT",
> >>>> +          "GPIO1OUT",
> >>>> +  };
> >>>> +
> >>>> +  /* Configure the GPIO */
> >>>> +  gpio->label = dev_name(dev);
> >>>
> >>> So if you have more than one MAX9286 in a system, all gpiochips will appear
> >>> with the same name. I'd recommend to append the index to distinguish properly.
> >>
> >> Ah yes, that's a good point, and I think I've even seen that.
> >>
> >> I'll fix it now.
>
> Oh, in fact actually this doesn't.
>
> gpiodetect prints:
>
> gpiochip10 [4-004c] (2 lines)
> gpiochip11 [4-006c] (2 lines)
>
> and mostly references them as gpiochip10 and gpiochip11.

Indeed, dev_name() should be different for each instance.

> However,
>
> > [    2.318533] gpio gpiochip11: Detected name collision for GPIO name 'GPIO0OUT'
> > [    2.325739] gpio gpiochip11: Detected name collision for GPIO name 'GPIO1OUT'
>
> That seems to be more of a problem for the gpio library, so I think I'll
> just drop the const names. I don't think they add much value.

These are the line names.  If they're not unique, a warning is printed,
but they are still registered.
So probably you want to use kasprintf("%s.%s", dev_name(dev), names[i]) to
generate names.

See "[PATCH] gpiolib: Document that GPIO line names are not globally unique"
(https://lore.kernel.org/linux-gpio/20200511101828.30046-1-geert+renesas@glider.be/)
to clear up the details.

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds

Re: [PATCH v9 2/4] media: i2c: Add MAX9286 driver

[Manivannan Sadhasivam]

On Thu, May 14, 2020 at 01:59:35PM +0200, Geert Uytterhoeven wrote:
> Hi Kieran,
> 
> On Thu, May 14, 2020 at 1:47 PM Kieran Bingham
> <kieran.bingham+renesas@ideasonboard.com> wrote:
> > On 14/05/2020 11:13, Manivannan Sadhasivam wrote:
> > > On Thu, May 14, 2020 at 11:02:53AM +0100, Kieran Bingham wrote:
> > >> On 12/05/2020 19:17, Manivannan Sadhasivam wrote:
> > >>> On Tue, May 12, 2020 at 04:51:03PM +0100, Kieran Bingham wrote:
> > >>>> The MAX9286 is a 4-channel GMSL deserializer with coax or STP input and
> > >>>> CSI-2 output. The device supports multicamera streaming applications,
> > >>>> and features the ability to synchronise the attached cameras.
> > >>>>
> > >>>> CSI-2 output can be configured with 1 to 4 lanes, and a control channel
> > >>>> is supported over I2C, which implements an I2C mux to facilitate
> > >>>> communications with connected cameras across the reverse control
> > >>>> channel.
> > >>>>
> > >>>> Signed-off-by: Jacopo Mondi <jacopo+renesas@jmondi.org>
> > >>>> Signed-off-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
> > >>>> Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
> > >>>> Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
> 
> > >>>> --- /dev/null
> > >>>> +++ b/drivers/media/i2c/max9286.c
> 
> > >>>> +static int max9286_register_gpio(struct max9286_priv *priv)
> > >>>> +{
> > >>>> +  struct device *dev = &priv->client->dev;
> > >>>> +  struct gpio_chip *gpio = &priv->gpio;
> > >>>> +  int ret;
> > >>>> +
> > >>>> +  static const char * const names[] = {
> > >>>> +          "GPIO0OUT",
> > >>>> +          "GPIO1OUT",
> > >>>> +  };
> > >>>> +
> > >>>> +  /* Configure the GPIO */
> > >>>> +  gpio->label = dev_name(dev);
> > >>>
> > >>> So if you have more than one MAX9286 in a system, all gpiochips will appear
> > >>> with the same name. I'd recommend to append the index to distinguish properly.
> > >>
> > >> Ah yes, that's a good point, and I think I've even seen that.
> > >>
> > >> I'll fix it now.
> >
> > Oh, in fact actually this doesn't.
> >
> > gpiodetect prints:
> >
> > gpiochip10 [4-004c] (2 lines)
> > gpiochip11 [4-006c] (2 lines)
> >
> > and mostly references them as gpiochip10 and gpiochip11.
> 
> Indeed, dev_name() should be different for each instance.
> 

Ah, my bad! Somehow I got confused that this delivers static name... Sorry for
the noise, Kieran.

> > However,
> >
> > > [    2.318533] gpio gpiochip11: Detected name collision for GPIO name 'GPIO0OUT'
> > > [    2.325739] gpio gpiochip11: Detected name collision for GPIO name 'GPIO1OUT'
> >
> > That seems to be more of a problem for the gpio library, so I think I'll
> > just drop the const names. I don't think they add much value.
> 

Well, I should've pointed this instead of above...

(lack of coffee)

> These are the line names.  If they're not unique, a warning is printed,
> but they are still registered.
> So probably you want to use kasprintf("%s.%s", dev_name(dev), names[i]) to
> generate names.
> 

Ack.

I think you should CC Linus W for next iteration to get review for gpiolib
implementation.

Thanks,
Mani

> See "[PATCH] gpiolib: Document that GPIO line names are not globally unique"
> (https://lore.kernel.org/linux-gpio/20200511101828.30046-1-geert+renesas@glider.be/)
> to clear up the details.
> 
> Gr{oetje,eeting}s,
> 
>                         Geert
> 
> -- 
> Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org
> 
> In personal conversations with technical people, I call myself a hacker. But
> when I'm talking to journalists I just say "programmer" or something like that.
>                                 -- Linus Torvalds

Re: [PATCH v9 2/4] media: i2c: Add MAX9286 driver

[Kieran Bingham]

On 14/05/2020 13:48, Manivannan Sadhasivam wrote:
> On Thu, May 14, 2020 at 01:59:35PM +0200, Geert Uytterhoeven wrote:
>> Hi Kieran,
>>
>> On Thu, May 14, 2020 at 1:47 PM Kieran Bingham
>> <kieran.bingham+renesas@ideasonboard.com> wrote:
>>> On 14/05/2020 11:13, Manivannan Sadhasivam wrote:
>>>> On Thu, May 14, 2020 at 11:02:53AM +0100, Kieran Bingham wrote:
>>>>> On 12/05/2020 19:17, Manivannan Sadhasivam wrote:
>>>>>> On Tue, May 12, 2020 at 04:51:03PM +0100, Kieran Bingham wrote:
>>>>>>> The MAX9286 is a 4-channel GMSL deserializer with coax or STP input and
>>>>>>> CSI-2 output. The device supports multicamera streaming applications,
>>>>>>> and features the ability to synchronise the attached cameras.
>>>>>>>
>>>>>>> CSI-2 output can be configured with 1 to 4 lanes, and a control channel
>>>>>>> is supported over I2C, which implements an I2C mux to facilitate
>>>>>>> communications with connected cameras across the reverse control
>>>>>>> channel.
>>>>>>>
>>>>>>> Signed-off-by: Jacopo Mondi <jacopo+renesas@jmondi.org>
>>>>>>> Signed-off-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
>>>>>>> Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
>>>>>>> Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
>>
>>>>>>> --- /dev/null
>>>>>>> +++ b/drivers/media/i2c/max9286.c
>>
>>>>>>> +static int max9286_register_gpio(struct max9286_priv *priv)
>>>>>>> +{
>>>>>>> +  struct device *dev = &priv->client->dev;
>>>>>>> +  struct gpio_chip *gpio = &priv->gpio;
>>>>>>> +  int ret;
>>>>>>> +
>>>>>>> +  static const char * const names[] = {
>>>>>>> +          "GPIO0OUT",
>>>>>>> +          "GPIO1OUT",
>>>>>>> +  };
>>>>>>> +
>>>>>>> +  /* Configure the GPIO */
>>>>>>> +  gpio->label = dev_name(dev);
>>>>>>
>>>>>> So if you have more than one MAX9286 in a system, all gpiochips will appear
>>>>>> with the same name. I'd recommend to append the index to distinguish properly.
>>>>>
>>>>> Ah yes, that's a good point, and I think I've even seen that.
>>>>>
>>>>> I'll fix it now.
>>>
>>> Oh, in fact actually this doesn't.
>>>
>>> gpiodetect prints:
>>>
>>> gpiochip10 [4-004c] (2 lines)
>>> gpiochip11 [4-006c] (2 lines)
>>>
>>> and mostly references them as gpiochip10 and gpiochip11.
>>
>> Indeed, dev_name() should be different for each instance.
>>
> 
> Ah, my bad! Somehow I got confused that this delivers static name... Sorry for
> the noise, Kieran.
> 
>>> However,
>>>
>>>> [    2.318533] gpio gpiochip11: Detected name collision for GPIO name 'GPIO0OUT'
>>>> [    2.325739] gpio gpiochip11: Detected name collision for GPIO name 'GPIO1OUT'
>>>
>>> That seems to be more of a problem for the gpio library, so I think I'll
>>> just drop the const names. I don't think they add much value.
>>
> 
> Well, I should've pointed this instead of above...
> 
> (lack of coffee)
> 
>> These are the line names.  If they're not unique, a warning is printed,
>> but they are still registered.
>> So probably you want to use kasprintf("%s.%s", dev_name(dev), names[i]) to
>> generate names.
>>
> 
> Ack.
> 
> I think you should CC Linus W for next iteration to get review for gpiolib
> implementation.

Good idea. I think I'll drop the names though for now.

--
Kieran


> 
> Thanks,
> Mani
> 
>> See "[PATCH] gpiolib: Document that GPIO line names are not globally unique"
>> (https://lore.kernel.org/linux-gpio/20200511101828.30046-1-geert+renesas@glider.be/)
>> to clear up the details.
>>
>> Gr{oetje,eeting}s,
>>
>>                         Geert
>>
>> -- 
>> Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org
>>
>> In personal conversations with technical people, I call myself a hacker. But
>> when I'm talking to journalists I just say "programmer" or something like that.
>>                                 -- Linus Torvalds

Re: [PATCH v9 2/4] media: i2c: Add MAX9286 driver

[Kieran Bingham]

On 14/05/2020 11:13, Manivannan Sadhasivam wrote:
> Hi Kieran,
> 
> On Thu, May 14, 2020 at 11:02:53AM +0100, Kieran Bingham wrote:
>> Hi Mani,
>>
>> On 12/05/2020 19:17, Manivannan Sadhasivam wrote:
>>> On Tue, May 12, 2020 at 04:51:03PM +0100, Kieran Bingham wrote:
>>>> The MAX9286 is a 4-channel GMSL deserializer with coax or STP input and
>>>> CSI-2 output. The device supports multicamera streaming applications,
>>>> and features the ability to synchronise the attached cameras.
>>>>
>>>> CSI-2 output can be configured with 1 to 4 lanes, and a control channel
>>>> is supported over I2C, which implements an I2C mux to facilitate
>>>> communications with connected cameras across the reverse control
>>>> channel.
>>>>
>>>> Signed-off-by: Jacopo Mondi <jacopo+renesas@jmondi.org>
>>>> Signed-off-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
>>>> Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
>>>> Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
>>>>
>>>> --
>>>> v2:
>>>>  - Fix MAINTAINERS entry
>>>>
>>>> This posting is released with the following modifications to work
>>>> without Sakari's VC developments:
>>>>  - max9286_g_mbus_config() re-instated
>>>>  - max9286_get_frame_desc() is not bus/csi aware
>>>>  - max9286_{get,set}_routing() removed
>>>>
>>>> v3:
>>>>  - Initialise notifier with v4l2_async_notifier_init
>>>>  - Update for new mbus csi2 format V4L2_MBUS_CSI2_DPHY
>>>>
>>>> v4: - Re-introduce required code to function with the VC series.
>>>>
>>>>  - Implement max9286_get_routing, max9286_set_routing
>>>>  - Remove max9286_g_mbus_config
>>>>
>>>> v5: (internal release)
>>>>  - Fix printk formatting for hex value
>>>>  - max9286->sd.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE (add |)
>>>>  - MEDIA_ENT_F_PROC_VIDEO_PIXEL_FORMATTER -> MEDIA_ENT_F_VID_IF_BRIDGE
>>>>  - Remove 'device is bound' workaround
>>>>
>>>> v6:
>>>>  - v4l2_subdev_krouting instead of v4l2_subdev_routing separated
>>>>    to allow integration without the VC/V4L2-Mux series.
>>>>  - convert sd_to_max9286 to inline function
>>>>  - rename max9286_device to max9286_priv
>>>>  - Cleanup the v4l2_async_notifier
>>>>  - Extend MODULE_AUTHOR
>>>>  - Replace of_graph_get_endpoint_by_regs with fwnode_graph_get_endpoint_by_id
>>>>  - Pass default bus type when parsing fwnode endpoint (Manivannan Sadhasivam)
>>>>  - Use new YAML file reference in MAINTAINERS
>>>>  - Parse new i2c-mux node in max9286_get_i2c_by_id
>>>>    (This could/should be refactored to parse these separately first)
>>>>  - Spelling and calculation fixes in the FSYNC_LOCKED check comments
>>>>  - Identify each enabled i2c-mux channel in a single pass
>>>>  - max9286: Improve mux-state readbility [v2]
>>>>  - Fix frame sync lock durations
>>>>  - Add comment to describe /why/ we must open the mux in s_stream
>>>>  - use -EXDEV as return code for failed link synchronisation.
>>>>  - Fix reference counting of the dt nodeS
>>>>  - Convert to probe_new for I2C
>>>>  - Remove redundant max9286_i2c_mux_state
>>>>  - Provide optional enable-gpio (max9286-pwdn)
>>>>
>>>> v7:
>>>>  [Kieran]
>>>>  - Ensure powerdown lines are optional
>>>>  - Add a 4ms power-up delay
>>>>  - Add max9286_check_config_link() to core
>>>>  - Add GPIO chip controller for GPIO0OUT and GPIO1OUT
>>>>  - Fix GPIO registration
>>>>  - max9286: Split out async registration
>>>>    (fixes regulator -EPROBE_DEFERs failures)
>>>>  - Collect all V4L2 registrations
>>>>  - balance v4l2_async refcnting
>>>>  - Rename max9286_v4l2_async_ => max9286_v4l2_notifier_
>>>>
>>>>  [Jacopo]
>>>>  - Remove redundanct MAXIM_I2C_SPEED macros
>>>>  - Move notifiers operations
>>>>  - Add delay after reverse channel reconfiguration
>>>>  - Move link setup to completion
>>>>  - Fix up max9286_check_config_link() implementation
>>>>  - Remove redundant dual configuration of reverse channel
>>>>
>>>> v8:
>>>>
>>>> [Kieran]
>>>>  - Update the bound_sources mask on unbind
>>>>  - Convert probe kzalloc usage to devm_ variant
>>>>  - Fix up cleanup path from GPIO PowerDown registration
>>>>  - cleanup GPIO device registration fail path
>>>>  - Convert to use devm_regulator_get()
>>>>  - Fit max9286_parse_dt print on one line
>>>>  - Move multi-device workarounds out of upstream driver
>>>>  - Remove I2C mod-table
>>>>  - Lock format changes
>>>>  - Describe pad index usage
>>>>  - Remove poc_enabled workaround
>>>>  - Rename the max9286_gpio to be more explicit on it's actions.
>>>>  - Move max9286_init_format call
>>>>  - Rework probe sequence and simplify error paths.
>>>>  - Simplify i2c comments
>>>>  - Implement Pixelrate control
>>>>  - Disable overlap window
>>>>
>>>> [Jacopo]
>>>>  - Adapt Kconfig to latest upstream changes
>>>>  - Put of node on error
>>>>  - Calculate pixel rate
>>>>  - Simplify overlap window disablement
>>>>
>>>> v9:
>>>>
>>>> [Kieran]
>>>>  - Kconfig: Depend on OF
>>>>  - Re-sort addition to Makefile
>>>> ---
>>>>  MAINTAINERS                 |   10 +
>>>>  drivers/media/i2c/Kconfig   |   13 +
>>>>  drivers/media/i2c/Makefile  |    1 +
>>>>  drivers/media/i2c/max9286.c | 1332 +++++++++++++++++++++++++++++++++++
>>>>  4 files changed, 1356 insertions(+)
>>>>  create mode 100644 drivers/media/i2c/max9286.c
>>>>
>>>> diff --git a/MAINTAINERS b/MAINTAINERS
>>>> index a7bb6e22d5da..99e3bf7760fd 100644
>>>> --- a/MAINTAINERS
>>>> +++ b/MAINTAINERS
>>>> @@ -10274,6 +10274,16 @@ F:	Documentation/hwmon/max6697.rst
>>>>  F:	drivers/hwmon/max6697.c
>>>>  F:	include/linux/platform_data/max6697.h
>>>>  
>>>> +MAX9286 QUAD GMSL DESERIALIZER DRIVER
>>>> +M:	Jacopo Mondi <jacopo+renesas@jmondi.org>
>>>> +M:	Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
>>>> +M:	Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
>>>> +M:	Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
>>>> +L:	linux-media@vger.kernel.org
>>>> +S:	Maintained
>>>> +F:	Documentation/devicetree/bindings/media/i2c/maxim,max9286.yaml
>>>> +F:	drivers/media/i2c/max9286.c
>>>> +
>>>>  MAX9860 MONO AUDIO VOICE CODEC DRIVER
>>>>  M:	Peter Rosin <peda@axentia.se>
>>>>  L:	alsa-devel@alsa-project.org (moderated for non-subscribers)
>>>> diff --git a/drivers/media/i2c/Kconfig b/drivers/media/i2c/Kconfig
>>>> index 3abc80373ec0..2e390f41f6da 100644
>>>> --- a/drivers/media/i2c/Kconfig
>>>> +++ b/drivers/media/i2c/Kconfig
>>>> @@ -464,6 +464,19 @@ config VIDEO_VPX3220
>>>>  	  To compile this driver as a module, choose M here: the
>>>>  	  module will be called vpx3220.
>>>>  
>>>> +config VIDEO_MAX9286
>>>> +	tristate "Maxim MAX9286 GMSL deserializer support"
>>>> +	depends on I2C && I2C_MUX
>>>> +	depends on OF
>>>> +	select V4L2_FWNODE
>>>> +	select VIDEO_V4L2_SUBDEV_API
>>>> +	select MEDIA_CONTROLLER
>>>> +	help
>>>> +	  This driver supports the Maxim MAX9286 GMSL deserializer.
>>>> +
>>>> +	  To compile this driver as a module, choose M here: the
>>>> +	  module will be called max9286.
>>>> +
>>>>  comment "Video and audio decoders"
>>>>  
>>>>  config VIDEO_SAA717X
>>>> diff --git a/drivers/media/i2c/Makefile b/drivers/media/i2c/Makefile
>>>> index 77bf7d0b691f..f0b001ee4b05 100644
>>>> --- a/drivers/media/i2c/Makefile
>>>> +++ b/drivers/media/i2c/Makefile
>>>> @@ -117,6 +117,7 @@ obj-$(CONFIG_VIDEO_IMX274)	+= imx274.o
>>>>  obj-$(CONFIG_VIDEO_IMX290)	+= imx290.o
>>>>  obj-$(CONFIG_VIDEO_IMX319)	+= imx319.o
>>>>  obj-$(CONFIG_VIDEO_IMX355)	+= imx355.o
>>>> +obj-$(CONFIG_VIDEO_MAX9286)	+= max9286.o
>>>>  obj-$(CONFIG_VIDEO_ST_MIPID02) += st-mipid02.o
>>>>  
>>>>  obj-$(CONFIG_SDR_MAX2175) += max2175.o
>>>> diff --git a/drivers/media/i2c/max9286.c b/drivers/media/i2c/max9286.c
>>>> new file mode 100644
>>>> index 000000000000..481d65f2b51d
>>>> --- /dev/null
>>>> +++ b/drivers/media/i2c/max9286.c
>>>> @@ -0,0 +1,1332 @@
>>>> +// SPDX-License-Identifier: GPL-2.0+
>>>> +/*
>>>> + * Maxim MAX9286 GMSL Deserializer Driver
>>>> + *
>>>> + * Copyright (C) 2017-2019 Jacopo Mondi
>>>> + * Copyright (C) 2017-2019 Kieran Bingham
>>>> + * Copyright (C) 2017-2019 Laurent Pinchart
>>>> + * Copyright (C) 2017-2019 Niklas Söderlund
>>>> + * Copyright (C) 2016 Renesas Electronics Corporation
>>>> + * Copyright (C) 2015 Cogent Embedded, Inc.
>>>> + */
>>>> +
>>>> +#include <linux/delay.h>
>>>> +#include <linux/device.h>
>>>> +#include <linux/fwnode.h>
>>>> +#include <linux/gpio/consumer.h>
>>>> +#include <linux/gpio/driver.h>
>>>> +#include <linux/i2c.h>
>>>> +#include <linux/i2c-mux.h>
>>>> +#include <linux/module.h>
>>>> +#include <linux/mutex.h>
>>>> +#include <linux/of_graph.h>
>>>> +#include <linux/regulator/consumer.h>
>>>> +#include <linux/slab.h>
>>>> +
>>>> +#include <media/v4l2-async.h>
>>>> +#include <media/v4l2-ctrls.h>
>>>> +#include <media/v4l2-device.h>
>>>> +#include <media/v4l2-fwnode.h>
>>>> +#include <media/v4l2-subdev.h>
>>>> +
>>>> +/* Register 0x00 */
>>>> +#define MAX9286_MSTLINKSEL_AUTO		(7 << 5)
>>>> +#define MAX9286_MSTLINKSEL(n)		((n) << 5)
>>>> +#define MAX9286_EN_VS_GEN		BIT(4)
>>>> +#define MAX9286_LINKEN(n)		(1 << (n))
>>>> +/* Register 0x01 */
>>>> +#define MAX9286_FSYNCMODE_ECU		(3 << 6)
>>>> +#define MAX9286_FSYNCMODE_EXT		(2 << 6)
>>>> +#define MAX9286_FSYNCMODE_INT_OUT	(1 << 6)
>>>> +#define MAX9286_FSYNCMODE_INT_HIZ	(0 << 6)
>>>> +#define MAX9286_GPIEN			BIT(5)
>>>> +#define MAX9286_ENLMO_RSTFSYNC		BIT(2)
>>>> +#define MAX9286_FSYNCMETH_AUTO		(2 << 0)
>>>> +#define MAX9286_FSYNCMETH_SEMI_AUTO	(1 << 0)
>>>> +#define MAX9286_FSYNCMETH_MANUAL	(0 << 0)
>>>> +#define MAX9286_REG_FSYNC_PERIOD_L	0x06
>>>> +#define MAX9286_REG_FSYNC_PERIOD_M	0x07
>>>> +#define MAX9286_REG_FSYNC_PERIOD_H	0x08
>>>> +/* Register 0x0a */
>>>> +#define MAX9286_FWDCCEN(n)		(1 << ((n) + 4))
>>>> +#define MAX9286_REVCCEN(n)		(1 << (n))
>>>> +/* Register 0x0c */
>>>> +#define MAX9286_HVEN			BIT(7)
>>>> +#define MAX9286_EDC_6BIT_HAMMING	(2 << 5)
>>>> +#define MAX9286_EDC_6BIT_CRC		(1 << 5)
>>>> +#define MAX9286_EDC_1BIT_PARITY		(0 << 5)
>>>> +#define MAX9286_DESEL			BIT(4)
>>>> +#define MAX9286_INVVS			BIT(3)
>>>> +#define MAX9286_INVHS			BIT(2)
>>>> +#define MAX9286_HVSRC_D0		(2 << 0)
>>>> +#define MAX9286_HVSRC_D14		(1 << 0)
>>>> +#define MAX9286_HVSRC_D18		(0 << 0)
>>>> +/* Register 0x0f */
>>>> +#define MAX9286_0X0F_RESERVED		BIT(3)
>>>> +/* Register 0x12 */
>>>> +#define MAX9286_CSILANECNT(n)		(((n) - 1) << 6)
>>>> +#define MAX9286_CSIDBL			BIT(5)
>>>> +#define MAX9286_DBL			BIT(4)
>>>> +#define MAX9286_DATATYPE_USER_8BIT	(11 << 0)
>>>> +#define MAX9286_DATATYPE_USER_YUV_12BIT	(10 << 0)
>>>> +#define MAX9286_DATATYPE_USER_24BIT	(9 << 0)
>>>> +#define MAX9286_DATATYPE_RAW14		(8 << 0)
>>>> +#define MAX9286_DATATYPE_RAW11		(7 << 0)
>>>> +#define MAX9286_DATATYPE_RAW10		(6 << 0)
>>>> +#define MAX9286_DATATYPE_RAW8		(5 << 0)
>>>> +#define MAX9286_DATATYPE_YUV422_10BIT	(4 << 0)
>>>> +#define MAX9286_DATATYPE_YUV422_8BIT	(3 << 0)
>>>> +#define MAX9286_DATATYPE_RGB555		(2 << 0)
>>>> +#define MAX9286_DATATYPE_RGB565		(1 << 0)
>>>> +#define MAX9286_DATATYPE_RGB888		(0 << 0)
>>>> +/* Register 0x15 */
>>>> +#define MAX9286_VC(n)			((n) << 5)
>>>> +#define MAX9286_VCTYPE			BIT(4)
>>>> +#define MAX9286_CSIOUTEN		BIT(3)
>>>> +#define MAX9286_0X15_RESV		(3 << 0)
>>>> +/* Register 0x1b */
>>>> +#define MAX9286_SWITCHIN(n)		(1 << ((n) + 4))
>>>> +#define MAX9286_ENEQ(n)			(1 << (n))
>>>> +/* Register 0x27 */
>>>> +#define MAX9286_LOCKED			BIT(7)
>>>> +/* Register 0x31 */
>>>> +#define MAX9286_FSYNC_LOCKED		BIT(6)
>>>> +/* Register 0x34 */
>>>> +#define MAX9286_I2CLOCACK		BIT(7)
>>>> +#define MAX9286_I2CSLVSH_1046NS_469NS	(3 << 5)
>>>> +#define MAX9286_I2CSLVSH_938NS_352NS	(2 << 5)
>>>> +#define MAX9286_I2CSLVSH_469NS_234NS	(1 << 5)
>>>> +#define MAX9286_I2CSLVSH_352NS_117NS	(0 << 5)
>>>> +#define MAX9286_I2CMSTBT_837KBPS	(7 << 2)
>>>> +#define MAX9286_I2CMSTBT_533KBPS	(6 << 2)
>>>> +#define MAX9286_I2CMSTBT_339KBPS	(5 << 2)
>>>> +#define MAX9286_I2CMSTBT_173KBPS	(4 << 2)
>>>> +#define MAX9286_I2CMSTBT_105KBPS	(3 << 2)
>>>> +#define MAX9286_I2CMSTBT_84KBPS		(2 << 2)
>>>> +#define MAX9286_I2CMSTBT_28KBPS		(1 << 2)
>>>> +#define MAX9286_I2CMSTBT_8KBPS		(0 << 2)
>>>> +#define MAX9286_I2CSLVTO_NONE		(3 << 0)
>>>> +#define MAX9286_I2CSLVTO_1024US		(2 << 0)
>>>> +#define MAX9286_I2CSLVTO_256US		(1 << 0)
>>>> +#define MAX9286_I2CSLVTO_64US		(0 << 0)
>>>> +/* Register 0x3b */
>>>> +#define MAX9286_REV_TRF(n)		((n) << 4)
>>>> +#define MAX9286_REV_AMP(n)		((((n) - 30) / 10) << 1) /* in mV */
>>>> +#define MAX9286_REV_AMP_X		BIT(0)
>>>> +/* Register 0x3f */
>>>> +#define MAX9286_EN_REV_CFG		BIT(6)
>>>> +#define MAX9286_REV_FLEN(n)		((n) - 20)
>>>> +/* Register 0x49 */
>>>> +#define MAX9286_VIDEO_DETECT_MASK	0x0f
>>>> +/* Register 0x69 */
>>>> +#define MAX9286_LFLTBMONMASKED		BIT(7)
>>>> +#define MAX9286_LOCKMONMASKED		BIT(6)
>>>> +#define MAX9286_AUTOCOMBACKEN		BIT(5)
>>>> +#define MAX9286_AUTOMASKEN		BIT(4)
>>>> +#define MAX9286_MASKLINK(n)		((n) << 0)
>>>> +
>>>> +/*
>>>> + * The sink and source pads are created to match the OF graph port numbers so
>>>> + * that their indexes can be used interchangeably.
>>>> + */
>>>> +#define MAX9286_NUM_GMSL		4
>>>> +#define MAX9286_N_SINKS			4
>>>> +#define MAX9286_N_PADS			5
>>>> +#define MAX9286_SRC_PAD			4
>>>> +
>>>> +struct max9286_source {
>>>> +	struct v4l2_async_subdev asd;
>>>> +	struct v4l2_subdev *sd;
>>>> +	struct fwnode_handle *fwnode;
>>>> +};
>>>> +
>>>> +#define asd_to_max9286_source(_asd) \
>>>> +	container_of(_asd, struct max9286_source, asd)
>>>> +
>>>> +struct max9286_priv {
>>>> +	struct i2c_client *client;
>>>> +	struct gpio_desc *gpiod_pwdn;
>>>> +	struct v4l2_subdev sd;
>>>> +	struct media_pad pads[MAX9286_N_PADS];
>>>> +	struct regulator *regulator;
>>>> +
>>>> +	struct gpio_chip gpio;
>>>> +	u8 gpio_state;
>>>> +
>>>> +	struct i2c_mux_core *mux;
>>>> +	unsigned int mux_channel;
>>>> +	bool mux_open;
>>>> +
>>>> +	struct v4l2_ctrl_handler ctrls;
>>>> +	struct v4l2_ctrl *pixelrate;
>>>> +
>>>> +	struct v4l2_mbus_framefmt fmt[MAX9286_N_SINKS];
>>>> +
>>>> +	/* Protects controls and fmt structures */
>>>> +	struct mutex mutex;
>>>> +
>>>> +	unsigned int nsources;
>>>> +	unsigned int source_mask;
>>>> +	unsigned int route_mask;
>>>> +	unsigned int bound_sources;
>>>> +	unsigned int csi2_data_lanes;
>>>> +	struct max9286_source sources[MAX9286_NUM_GMSL];
>>>> +	struct v4l2_async_notifier notifier;
>>>> +};
>>>> +
>>>
>>> [...]
>>>
>>>> +static int max9286_register_gpio(struct max9286_priv *priv)
>>>> +{
>>>> +	struct device *dev = &priv->client->dev;
>>>> +	struct gpio_chip *gpio = &priv->gpio;
>>>> +	int ret;
>>>> +
>>>> +	static const char * const names[] = {
>>>> +		"GPIO0OUT",
>>>> +		"GPIO1OUT",
>>>> +	};
>>>> +
>>>> +	/* Configure the GPIO */
>>>> +	gpio->label = dev_name(dev);
>>>
>>> So if you have more than one MAX9286 in a system, all gpiochips will appear
>>> with the same name. I'd recommend to append the index to distinguish properly.
>>
>> Ah yes, that's a good point, and I think I've even seen that.
>>
>> I'll fix it now.
>>
>>>
>>>> +	gpio->parent = dev;
>>>> +	gpio->owner = THIS_MODULE;
>>>> +	gpio->of_node = dev->of_node;
>>>> +	gpio->ngpio = 2;
>>>> +	gpio->base = -1;
>>>> +	gpio->set = max9286_gpio_set;
>>>> +	gpio->get = max9286_gpio_get;
>>>> +	gpio->can_sleep = true;
>>>> +	gpio->names = names;
>>>> +
>>>> +	/* GPIO values default to high */
>>>> +	priv->gpio_state = BIT(0) | BIT(1);
>>>> +
>>>> +	ret = devm_gpiochip_add_data(dev, gpio, priv);
>>>> +	if (ret)
>>>> +		dev_err(dev, "Unable to create gpio_chip\n");
>>>> +
>>>> +	return ret;
>>>> +}
>>>> +
>>>
>>> [...]
>>>
>>>> +static int max9286_parse_dt(struct max9286_priv *priv)
>>>> +{
>>>> +	struct device *dev = &priv->client->dev;
>>>> +	struct device_node *i2c_mux;
>>>> +	struct device_node *node = NULL;
>>>> +	unsigned int i2c_mux_mask = 0;
>>>> +
>>>> +	of_node_get(dev->of_node);
>>>
>>> Why this is needed?
>>
>> Hrm .. I recall adding it to solve dt reference balancing.
>>
>> I wish I'd added a comment at the time ... as I can't recall the details
>> now.
>>
> 
> I understand that it is for the refcount balancing but I certainly don't see
> a need for it.

I'll go through and try to validate this again now.

>  
>>>> +	i2c_mux = of_find_node_by_name(dev->of_node, "i2c-mux");
>>>> +	if (!i2c_mux) {
>>>> +		dev_err(dev, "Failed to find i2c-mux node\n");
>>>> +		of_node_put(dev->of_node);
>>>> +		return -EINVAL;
>>>> +	}
>>>> +
> [...]
>>>
>>> [...]
>>>
>>>> +static int max9286_remove(struct i2c_client *client)
>>>> +{
>>>> +	struct max9286_priv *priv = i2c_get_clientdata(client);
>>>> +
>>>> +	i2c_mux_del_adapters(priv->mux);
>>>> +
>>>> +	max9286_v4l2_unregister(priv);
>>>> +
>>>> +	regulator_disable(priv->regulator);
>>>> +
>>>> +	gpiod_set_value_cansleep(priv->gpiod_pwdn, 0);
>>>
>>> Usual power down sequence is to pull the power down gpio low and then turn off
>>> the regulators. This helps in clearing up the internal state machine properly.
>>
>> Do you mean usual, among drivers using regulators? or usual for the max9286?
>>
> 
> Usual for devices exposing shutdown gpios and powered by an external regulator.
> 
>> I have a platform which controls the regulators for the cameras
>> (priv->regulator) through one of the GPIOs provided by the MAX9286.
>>
>> If we powerdown the max9286 first, then we will not be able to change
>> the GPIO value on the gpio controlled regulator.
>>
> 
> Hmm, I didn't think of this usecase. Let's keep it as it is.

Aha indeed it's not clear (especially as the variable is just
'regulator'). The regulator being controlled here does not power the
max9286, but the cameras attached to the max9286 which can be powered up
/ down separately to the max9286.

--
Kieran

> 
> Thanks,
> Mani
> 
>> (Currently it doesn't expose as a gpio regulator, but just a gpio-hog -
>> but thats a different matter)
>>
>> --
>> Kieran
>>
>>
>>>
>>> Thanks,
>>> Mani
>>>
>>>> +
>>>> +	max9286_cleanup_dt(priv);
>>>> +
>>>> +	return 0;
>>>> +}
>>>> +
>>>> +static const struct of_device_id max9286_dt_ids[] = {
>>>> +	{ .compatible = "maxim,max9286" },
>>>> +	{},
>>>> +};
>>>> +MODULE_DEVICE_TABLE(of, max9286_dt_ids);
>>>> +
>>>> +static struct i2c_driver max9286_i2c_driver = {
>>>> +	.driver	= {
>>>> +		.name		= "max9286",
>>>> +		.of_match_table	= of_match_ptr(max9286_dt_ids),
>>>> +	},
>>>> +	.probe_new	= max9286_probe,
>>>> +	.remove		= max9286_remove,
>>>> +};
>>>> +
>>>> +module_i2c_driver(max9286_i2c_driver);
>>>> +
>>>> +MODULE_DESCRIPTION("Maxim MAX9286 GMSL Deserializer Driver");
>>>> +MODULE_AUTHOR("Jacopo Mondi, Kieran Bingham, Laurent Pinchart, Niklas Söderlund, Vladimir Barinov");
>>>> +MODULE_LICENSE("GPL");
>>>> -- 
>>>> 2.25.1
>>>>
>>

Re: [PATCH v9 2/4] media: i2c: Add MAX9286 driver

[Kieran Bingham]

Hi Mani,

On 14/05/2020 12:47, Kieran Bingham wrote:
> On 14/05/2020 11:13, Manivannan Sadhasivam wrote:
>> Hi Kieran,
<snip>

>>>>> +static int max9286_parse_dt(struct max9286_priv *priv)
>>>>> +{
>>>>> +	struct device *dev = &priv->client->dev;
>>>>> +	struct device_node *i2c_mux;
>>>>> +	struct device_node *node = NULL;
>>>>> +	unsigned int i2c_mux_mask = 0;
>>>>> +
>>>>> +	of_node_get(dev->of_node);
>>>>
>>>> Why this is needed?
>>>
>>> Hrm .. I recall adding it to solve dt reference balancing.
>>>
>>> I wish I'd added a comment at the time ... as I can't recall the details
>>> now.
>>>
>>
>> I understand that it is for the refcount balancing but I certainly don't see
>> a need for it.
> 
> I'll go through and try to validate this again now.

Aha, that's why:

 *	of_find_node_by_name - Find a node by its "name" property
 *	@from:	The node to start searching from or NULL; the node
 *		you pass will not be searched, only the next one
 *		will. Typically, you pass what the previous call
 *		returned. of_node_put() will be called on @from.
 *	@name:	The name string to match against

I'll add a comment to state that it is to balance the of_node_put during
of_find_node_by_name().

--
Kieran


>>>>> +	i2c_mux = of_find_node_by_name(dev->of_node, "i2c-mux");
>>>>> +	if (!i2c_mux) {
>>>>> +		dev_err(dev, "Failed to find i2c-mux node\n");
>>>>> +		of_node_put(dev->of_node);
>>>>> +		return -EINVAL;
>>>>> +	}
>>>>> +
>> [...]
>>>>
-- 
Regards
--
Kieran

Re: [PATCH v9 2/4] media: i2c: Add MAX9286 driver

[Manivannan Sadhasivam]

On Thu, May 14, 2020 at 01:27:01PM +0100, Kieran Bingham wrote:
> Hi Mani,
> 
> On 14/05/2020 12:47, Kieran Bingham wrote:
> > On 14/05/2020 11:13, Manivannan Sadhasivam wrote:
> >> Hi Kieran,
> <snip>
> 
> >>>>> +static int max9286_parse_dt(struct max9286_priv *priv)
> >>>>> +{
> >>>>> +	struct device *dev = &priv->client->dev;
> >>>>> +	struct device_node *i2c_mux;
> >>>>> +	struct device_node *node = NULL;
> >>>>> +	unsigned int i2c_mux_mask = 0;
> >>>>> +
> >>>>> +	of_node_get(dev->of_node);
> >>>>
> >>>> Why this is needed?
> >>>
> >>> Hrm .. I recall adding it to solve dt reference balancing.
> >>>
> >>> I wish I'd added a comment at the time ... as I can't recall the details
> >>> now.
> >>>
> >>
> >> I understand that it is for the refcount balancing but I certainly don't see
> >> a need for it.
> > 
> > I'll go through and try to validate this again now.
> 
> Aha, that's why:
> 
>  *	of_find_node_by_name - Find a node by its "name" property
>  *	@from:	The node to start searching from or NULL; the node
>  *		you pass will not be searched, only the next one
>  *		will. Typically, you pass what the previous call
>  *		returned. of_node_put() will be called on @from.
>  *	@name:	The name string to match against
> 
> I'll add a comment to state that it is to balance the of_node_put during
> of_find_node_by_name().
> 

Ah, right. I mostly use of_find_node_by_name() with NULL, so didn't realize
this.

And yeah, a comment would be helpful.

Thanks,
Mani

> --
> Kieran
> 
> 
> >>>>> +	i2c_mux = of_find_node_by_name(dev->of_node, "i2c-mux");
> >>>>> +	if (!i2c_mux) {
> >>>>> +		dev_err(dev, "Failed to find i2c-mux node\n");
> >>>>> +		of_node_put(dev->of_node);
> >>>>> +		return -EINVAL;
> >>>>> +	}
> >>>>> +
> >> [...]
> >>>>
> -- 
> Regards
> --
> Kieran

Re: [PATCH v9 2/4] media: i2c: Add MAX9286 driver

[Sakari Ailus]

Hi Kieran,

Thanks for the update.

On Tue, May 12, 2020 at 04:51:03PM +0100, Kieran Bingham wrote:

...

> +static int max9286_enum_mbus_code(struct v4l2_subdev *sd,
> +				  struct v4l2_subdev_pad_config *cfg,
> +				  struct v4l2_subdev_mbus_code_enum *code)
> +{
> +	if (code->pad || code->index > 0)
> +		return -EINVAL;
> +
> +	code->code = MEDIA_BUS_FMT_UYVY8_2X8;

Why UYVY8_2X8 and not UYVY8_1X16? In general, the single sample / pixel
variant of the format is generally used on the serial busses. This choice
was made when serial busses were introduced.

> +
> +	return 0;
> +}
> +
> +static struct v4l2_mbus_framefmt *
> +max9286_get_pad_format(struct max9286_priv *priv,
> +		       struct v4l2_subdev_pad_config *cfg,
> +		       unsigned int pad, u32 which)
> +{
> +	switch (which) {
> +	case V4L2_SUBDEV_FORMAT_TRY:
> +		return v4l2_subdev_get_try_format(&priv->sd, cfg, pad);
> +	case V4L2_SUBDEV_FORMAT_ACTIVE:
> +		return &priv->fmt[pad];
> +	default:
> +		return NULL;
> +	}
> +}
> +
> +static int max9286_set_fmt(struct v4l2_subdev *sd,
> +			   struct v4l2_subdev_pad_config *cfg,
> +			   struct v4l2_subdev_format *format)
> +{
> +	struct max9286_priv *priv = sd_to_max9286(sd);
> +	struct v4l2_mbus_framefmt *cfg_fmt;
> +
> +	if (format->pad >= MAX9286_SRC_PAD)
> +		return -EINVAL;

You can remove these checks; it's been already done by the caller.

...

> +static int max9286_parse_dt(struct max9286_priv *priv)
> +{
> +	struct device *dev = &priv->client->dev;
> +	struct device_node *i2c_mux;
> +	struct device_node *node = NULL;
> +	unsigned int i2c_mux_mask = 0;
> +
> +	of_node_get(dev->of_node);
> +	i2c_mux = of_find_node_by_name(dev->of_node, "i2c-mux");
> +	if (!i2c_mux) {
> +		dev_err(dev, "Failed to find i2c-mux node\n");
> +		of_node_put(dev->of_node);
> +		return -EINVAL;
> +	}
> +
> +	/* Identify which i2c-mux channels are enabled */
> +	for_each_child_of_node(i2c_mux, node) {
> +		u32 id = 0;
> +
> +		of_property_read_u32(node, "reg", &id);
> +		if (id >= MAX9286_NUM_GMSL)
> +			continue;
> +
> +		if (!of_device_is_available(node)) {
> +			dev_dbg(dev, "Skipping disabled I2C bus port %u\n", id);
> +			continue;
> +		}
> +
> +		i2c_mux_mask |= BIT(id);
> +	}
> +	of_node_put(node);
> +	of_node_put(i2c_mux);
> +
> +	/* Parse the endpoints */
> +	for_each_endpoint_of_node(dev->of_node, node) {
> +		struct max9286_source *source;
> +		struct of_endpoint ep;
> +
> +		of_graph_parse_endpoint(node, &ep);
> +		dev_dbg(dev, "Endpoint %pOF on port %d",
> +			ep.local_node, ep.port);
> +
> +		if (ep.port > MAX9286_NUM_GMSL) {
> +			dev_err(dev, "Invalid endpoint %s on port %d",
> +				of_node_full_name(ep.local_node), ep.port);
> +			continue;
> +		}
> +
> +		/* For the source endpoint just parse the bus configuration. */
> +		if (ep.port == MAX9286_SRC_PAD) {
> +			struct v4l2_fwnode_endpoint vep = {
> +				.bus_type = V4L2_MBUS_CSI2_DPHY
> +			};
> +			int ret;
> +
> +			ret = v4l2_fwnode_endpoint_parse(
> +					of_fwnode_handle(node), &vep);
> +			if (ret) {
> +				of_node_put(node);
> +				of_node_put(dev->of_node);
> +				return ret;
> +			}
> +
> +			if (vep.bus_type != V4L2_MBUS_CSI2_DPHY) {

This won't happen, the bus type will stay if you set it to a non-zero
value.

> +				dev_err(dev,
> +					"Media bus %u type not supported\n",
> +					vep.bus_type);
> +				v4l2_fwnode_endpoint_free(&vep);
> +				of_node_put(node);
> +				of_node_put(dev->of_node);
> +				return -EINVAL;
> +			}
> +
> +			priv->csi2_data_lanes =
> +				vep.bus.mipi_csi2.num_data_lanes;
> +			v4l2_fwnode_endpoint_free(&vep);

No need to call this unless you use v4l2_fwnode_endpoint_alloc_parse().

And as you don't, you also won't know which frequencies are known to be
safe to use. That said, perhaps where this device is used having a random
frequency on that bus could not be an issue. Perhaps.

> +
> +			continue;
> +		}
> +
> +		/* Skip if the corresponding GMSL link is unavailable. */
> +		if (!(i2c_mux_mask & BIT(ep.port)))
> +			continue;
> +
> +		if (priv->sources[ep.port].fwnode) {
> +			dev_err(dev,
> +				"Multiple port endpoints are not supported: %d",
> +				ep.port);
> +
> +			continue;
> +		}
> +
> +		source = &priv->sources[ep.port];
> +		source->fwnode = fwnode_graph_get_remote_endpoint(
> +						of_fwnode_handle(node));
> +		if (!source->fwnode) {
> +			dev_err(dev,
> +				"Endpoint %pOF has no remote endpoint connection\n",
> +				ep.local_node);
> +
> +			continue;
> +		}
> +
> +		priv->source_mask |= BIT(ep.port);
> +		priv->nsources++;
> +	}
> +	of_node_put(node);
> +	of_node_put(dev->of_node);
> +
> +	priv->route_mask = priv->source_mask;
> +
> +	return 0;
> +}

-- 
Kind regards,

Sakari Ailus

Re: [PATCH v9 2/4] media: i2c: Add MAX9286 driver

[Kieran Bingham]

Hi Sakari,

There are only fairly minor comments here, fix ups will be included in a
v10.

Is there anything major blocking integration?

Regards

Kieran



On 16/05/2020 22:51, Sakari Ailus wrote:
> Hi Kieran,
> 
> Thanks for the update.
> 
> On Tue, May 12, 2020 at 04:51:03PM +0100, Kieran Bingham wrote:
> 
> ...
> 
>> +static int max9286_enum_mbus_code(struct v4l2_subdev *sd,
>> +				  struct v4l2_subdev_pad_config *cfg,
>> +				  struct v4l2_subdev_mbus_code_enum *code)
>> +{
>> +	if (code->pad || code->index > 0)
>> +		return -EINVAL;
>> +
>> +	code->code = MEDIA_BUS_FMT_UYVY8_2X8;
> 
> Why UYVY8_2X8 and not UYVY8_1X16? In general, the single sample / pixel
> variant of the format is generally used on the serial busses. This choice
> was made when serial busses were introduced.

Ok - I presume this doesn't really have much effect anyway, they just
have to match for the transmitter/receiver?

But it makes sense to me, so I'll update to the 1x16 variant.

>> +
>> +	return 0;
>> +}
>> +
>> +static struct v4l2_mbus_framefmt *
>> +max9286_get_pad_format(struct max9286_priv *priv,
>> +		       struct v4l2_subdev_pad_config *cfg,
>> +		       unsigned int pad, u32 which)
>> +{
>> +	switch (which) {
>> +	case V4L2_SUBDEV_FORMAT_TRY:
>> +		return v4l2_subdev_get_try_format(&priv->sd, cfg, pad);
>> +	case V4L2_SUBDEV_FORMAT_ACTIVE:
>> +		return &priv->fmt[pad];
>> +	default:
>> +		return NULL;
>> +	}
>> +}
>> +
>> +static int max9286_set_fmt(struct v4l2_subdev *sd,
>> +			   struct v4l2_subdev_pad_config *cfg,
>> +			   struct v4l2_subdev_format *format)
>> +{
>> +	struct max9286_priv *priv = sd_to_max9286(sd);
>> +	struct v4l2_mbus_framefmt *cfg_fmt;
>> +
>> +	if (format->pad >= MAX9286_SRC_PAD)
>> +		return -EINVAL;
> 
> You can remove these checks; it's been already done by the caller.
> 

Ok.


> ...
> 
>> +static int max9286_parse_dt(struct max9286_priv *priv)
>> +{
>> +	struct device *dev = &priv->client->dev;
>> +	struct device_node *i2c_mux;
>> +	struct device_node *node = NULL;
>> +	unsigned int i2c_mux_mask = 0;
>> +
>> +	of_node_get(dev->of_node);
>> +	i2c_mux = of_find_node_by_name(dev->of_node, "i2c-mux");
>> +	if (!i2c_mux) {
>> +		dev_err(dev, "Failed to find i2c-mux node\n");
>> +		of_node_put(dev->of_node);
>> +		return -EINVAL;
>> +	}
>> +
>> +	/* Identify which i2c-mux channels are enabled */
>> +	for_each_child_of_node(i2c_mux, node) {
>> +		u32 id = 0;
>> +
>> +		of_property_read_u32(node, "reg", &id);
>> +		if (id >= MAX9286_NUM_GMSL)
>> +			continue;
>> +
>> +		if (!of_device_is_available(node)) {
>> +			dev_dbg(dev, "Skipping disabled I2C bus port %u\n", id);
>> +			continue;
>> +		}
>> +
>> +		i2c_mux_mask |= BIT(id);
>> +	}
>> +	of_node_put(node);
>> +	of_node_put(i2c_mux);
>> +
>> +	/* Parse the endpoints */
>> +	for_each_endpoint_of_node(dev->of_node, node) {
>> +		struct max9286_source *source;
>> +		struct of_endpoint ep;
>> +
>> +		of_graph_parse_endpoint(node, &ep);
>> +		dev_dbg(dev, "Endpoint %pOF on port %d",
>> +			ep.local_node, ep.port);
>> +
>> +		if (ep.port > MAX9286_NUM_GMSL) {
>> +			dev_err(dev, "Invalid endpoint %s on port %d",
>> +				of_node_full_name(ep.local_node), ep.port);
>> +			continue;
>> +		}
>> +
>> +		/* For the source endpoint just parse the bus configuration. */
>> +		if (ep.port == MAX9286_SRC_PAD) {
>> +			struct v4l2_fwnode_endpoint vep = {
>> +				.bus_type = V4L2_MBUS_CSI2_DPHY
>> +			};
>> +			int ret;
>> +
>> +			ret = v4l2_fwnode_endpoint_parse(
>> +					of_fwnode_handle(node), &vep);
>> +			if (ret) {
>> +				of_node_put(node);
>> +				of_node_put(dev->of_node);
>> +				return ret;
>> +			}
>> +
>> +			if (vep.bus_type != V4L2_MBUS_CSI2_DPHY) {
> 
> This won't happen, the bus type will stay if you set it to a non-zero
> value.


Ok - I'll remove this check.


> 
>> +				dev_err(dev,
>> +					"Media bus %u type not supported\n",
>> +					vep.bus_type);
>> +				v4l2_fwnode_endpoint_free(&vep);
>> +				of_node_put(node);
>> +				of_node_put(dev->of_node);
>> +				return -EINVAL;
>> +			}
>> +
>> +			priv->csi2_data_lanes =
>> +				vep.bus.mipi_csi2.num_data_lanes;
>> +			v4l2_fwnode_endpoint_free(&vep);
> 
> No need to call this unless you use v4l2_fwnode_endpoint_alloc_parse().
> 
> And as you don't, you also won't know which frequencies are known to be
> safe to use. That said, perhaps where this device is used having a random
> frequency on that bus could not be an issue. Perhaps.

Does this generate a range? or a list of static supported frequencies?

We configure the pixel clock based upon the number of cameras connected,
and their pixel rates etc ...

Are you saying that the frequency of this clock should be validated to
be a specific range? or are you talking about a different frequency?


For now I'll remove the v4l2_fwnode_endpoint_alloc_parse().



>> +
>> +			continue;
>> +		}
>> +
>> +		/* Skip if the corresponding GMSL link is unavailable. */
>> +		if (!(i2c_mux_mask & BIT(ep.port)))
>> +			continue;
>> +
>> +		if (priv->sources[ep.port].fwnode) {
>> +			dev_err(dev,
>> +				"Multiple port endpoints are not supported: %d",
>> +				ep.port);
>> +
>> +			continue;
>> +		}
>> +
>> +		source = &priv->sources[ep.port];
>> +		source->fwnode = fwnode_graph_get_remote_endpoint(
>> +						of_fwnode_handle(node));
>> +		if (!source->fwnode) {
>> +			dev_err(dev,
>> +				"Endpoint %pOF has no remote endpoint connection\n",
>> +				ep.local_node);
>> +
>> +			continue;
>> +		}
>> +
>> +		priv->source_mask |= BIT(ep.port);
>> +		priv->nsources++;
>> +	}
>> +	of_node_put(node);
>> +	of_node_put(dev->of_node);
>> +
>> +	priv->route_mask = priv->source_mask;
>> +
>> +	return 0;
>> +}
> 

Re: [PATCH v9 2/4] media: i2c: Add MAX9286 driver

[Jacopo Mondi]

Hi Kieran, Sakari

On Mon, May 18, 2020 at 12:45:18PM +0100, Kieran Bingham wrote:
> Hi Sakari,
>
> There are only fairly minor comments here, fix ups will be included in a
> v10.
>
> Is there anything major blocking integration?
>
> Regards
>
> Kieran
>
>
>
> On 16/05/2020 22:51, Sakari Ailus wrote:
> > Hi Kieran,
> >
> > Thanks for the update.
> >
> > On Tue, May 12, 2020 at 04:51:03PM +0100, Kieran Bingham wrote:
> >
> > ...
> >
> >> +static int max9286_enum_mbus_code(struct v4l2_subdev *sd,
> >> +				  struct v4l2_subdev_pad_config *cfg,
> >> +				  struct v4l2_subdev_mbus_code_enum *code)
> >> +{
> >> +	if (code->pad || code->index > 0)
> >> +		return -EINVAL;
> >> +
> >> +	code->code = MEDIA_BUS_FMT_UYVY8_2X8;
> >
> > Why UYVY8_2X8 and not UYVY8_1X16? In general, the single sample / pixel
> > variant of the format is generally used on the serial busses. This choice
> > was made when serial busses were introduced.
>
> Ok - I presume this doesn't really have much effect anyway, they just
> have to match for the transmitter/receiver?
>
> But it makes sense to me, so I'll update to the 1x16 variant.
>
> >> +
> >> +	return 0;
> >> +}
> >> +
> >> +static struct v4l2_mbus_framefmt *
> >> +max9286_get_pad_format(struct max9286_priv *priv,
> >> +		       struct v4l2_subdev_pad_config *cfg,
> >> +		       unsigned int pad, u32 which)
> >> +{
> >> +	switch (which) {
> >> +	case V4L2_SUBDEV_FORMAT_TRY:
> >> +		return v4l2_subdev_get_try_format(&priv->sd, cfg, pad);
> >> +	case V4L2_SUBDEV_FORMAT_ACTIVE:
> >> +		return &priv->fmt[pad];
> >> +	default:
> >> +		return NULL;
> >> +	}
> >> +}
> >> +
> >> +static int max9286_set_fmt(struct v4l2_subdev *sd,
> >> +			   struct v4l2_subdev_pad_config *cfg,
> >> +			   struct v4l2_subdev_format *format)
> >> +{
> >> +	struct max9286_priv *priv = sd_to_max9286(sd);
> >> +	struct v4l2_mbus_framefmt *cfg_fmt;
> >> +
> >> +	if (format->pad >= MAX9286_SRC_PAD)
> >> +		return -EINVAL;
> >
> > You can remove these checks; it's been already done by the caller.
> >
>
> Ok.
>

I think this shold be kept. The core validates that the pad number is
valid, but we're here checking that set_fmt has been called on a sink
pad [0-3], returning -EINVAL if set_fmt (and get_ftm as well) are
called on the source one.

My question now is how does link validation work, if get_fmt() is not
allowed on the source pad :/ ? Anyway, I would keep this check for
set_fmt (maybe make it an == to address Sakari's comment).

Thanks
  j

>
> > ...
> >
> >> +static int max9286_parse_dt(struct max9286_priv *priv)
> >> +{
> >> +	struct device *dev = &priv->client->dev;
> >> +	struct device_node *i2c_mux;
> >> +	struct device_node *node = NULL;
> >> +	unsigned int i2c_mux_mask = 0;
> >> +
> >> +	of_node_get(dev->of_node);
> >> +	i2c_mux = of_find_node_by_name(dev->of_node, "i2c-mux");
> >> +	if (!i2c_mux) {
> >> +		dev_err(dev, "Failed to find i2c-mux node\n");
> >> +		of_node_put(dev->of_node);
> >> +		return -EINVAL;
> >> +	}
> >> +
> >> +	/* Identify which i2c-mux channels are enabled */
> >> +	for_each_child_of_node(i2c_mux, node) {
> >> +		u32 id = 0;
> >> +
> >> +		of_property_read_u32(node, "reg", &id);
> >> +		if (id >= MAX9286_NUM_GMSL)
> >> +			continue;
> >> +
> >> +		if (!of_device_is_available(node)) {
> >> +			dev_dbg(dev, "Skipping disabled I2C bus port %u\n", id);
> >> +			continue;
> >> +		}
> >> +
> >> +		i2c_mux_mask |= BIT(id);
> >> +	}
> >> +	of_node_put(node);
> >> +	of_node_put(i2c_mux);
> >> +
> >> +	/* Parse the endpoints */
> >> +	for_each_endpoint_of_node(dev->of_node, node) {
> >> +		struct max9286_source *source;
> >> +		struct of_endpoint ep;
> >> +
> >> +		of_graph_parse_endpoint(node, &ep);
> >> +		dev_dbg(dev, "Endpoint %pOF on port %d",
> >> +			ep.local_node, ep.port);
> >> +
> >> +		if (ep.port > MAX9286_NUM_GMSL) {
> >> +			dev_err(dev, "Invalid endpoint %s on port %d",
> >> +				of_node_full_name(ep.local_node), ep.port);
> >> +			continue;
> >> +		}
> >> +
> >> +		/* For the source endpoint just parse the bus configuration. */
> >> +		if (ep.port == MAX9286_SRC_PAD) {
> >> +			struct v4l2_fwnode_endpoint vep = {
> >> +				.bus_type = V4L2_MBUS_CSI2_DPHY
> >> +			};
> >> +			int ret;
> >> +
> >> +			ret = v4l2_fwnode_endpoint_parse(
> >> +					of_fwnode_handle(node), &vep);
> >> +			if (ret) {
> >> +				of_node_put(node);
> >> +				of_node_put(dev->of_node);
> >> +				return ret;
> >> +			}
> >> +
> >> +			if (vep.bus_type != V4L2_MBUS_CSI2_DPHY) {
> >
> > This won't happen, the bus type will stay if you set it to a non-zero
> > value.
>
>
> Ok - I'll remove this check.
>
>
> >
> >> +				dev_err(dev,
> >> +					"Media bus %u type not supported\n",
> >> +					vep.bus_type);
> >> +				v4l2_fwnode_endpoint_free(&vep);
> >> +				of_node_put(node);
> >> +				of_node_put(dev->of_node);
> >> +				return -EINVAL;
> >> +			}
> >> +
> >> +			priv->csi2_data_lanes =
> >> +				vep.bus.mipi_csi2.num_data_lanes;
> >> +			v4l2_fwnode_endpoint_free(&vep);
> >
> > No need to call this unless you use v4l2_fwnode_endpoint_alloc_parse().
> >
> > And as you don't, you also won't know which frequencies are known to be
> > safe to use. That said, perhaps where this device is used having a random
> > frequency on that bus could not be an issue. Perhaps.
>
> Does this generate a range? or a list of static supported frequencies?
>
> We configure the pixel clock based upon the number of cameras connected,
> and their pixel rates etc ...
>
> Are you saying that the frequency of this clock should be validated to
> be a specific range? or are you talking about a different frequency?
>
>
> For now I'll remove the v4l2_fwnode_endpoint_alloc_parse().
>
>
>
> >> +
> >> +			continue;
> >> +		}
> >> +
> >> +		/* Skip if the corresponding GMSL link is unavailable. */
> >> +		if (!(i2c_mux_mask & BIT(ep.port)))
> >> +			continue;
> >> +
> >> +		if (priv->sources[ep.port].fwnode) {
> >> +			dev_err(dev,
> >> +				"Multiple port endpoints are not supported: %d",
> >> +				ep.port);
> >> +
> >> +			continue;
> >> +		}
> >> +
> >> +		source = &priv->sources[ep.port];
> >> +		source->fwnode = fwnode_graph_get_remote_endpoint(
> >> +						of_fwnode_handle(node));
> >> +		if (!source->fwnode) {
> >> +			dev_err(dev,
> >> +				"Endpoint %pOF has no remote endpoint connection\n",
> >> +				ep.local_node);
> >> +
> >> +			continue;
> >> +		}
> >> +
> >> +		priv->source_mask |= BIT(ep.port);
> >> +		priv->nsources++;
> >> +	}
> >> +	of_node_put(node);
> >> +	of_node_put(dev->of_node);
> >> +
> >> +	priv->route_mask = priv->source_mask;
> >> +
> >> +	return 0;
> >> +}
> >
>

Re: [PATCH v9 2/4] media: i2c: Add MAX9286 driver

[Kieran Bingham]

Hi Jacopo, Sakari,

On 18/05/2020 13:38, Jacopo Mondi wrote:
> Hi Kieran, Sakari
> 
> On Mon, May 18, 2020 at 12:45:18PM +0100, Kieran Bingham wrote:
>> Hi Sakari,
>>
>> There are only fairly minor comments here, fix ups will be included in a
>> v10.
>>
>> Is there anything major blocking integration?
>>
>> Regards
>>
>> Kieran
>>
>>
>>
>> On 16/05/2020 22:51, Sakari Ailus wrote:
>>> Hi Kieran,
>>>
>>> Thanks for the update.
>>>
>>> On Tue, May 12, 2020 at 04:51:03PM +0100, Kieran Bingham wrote:
>>>
>>> ...
>>>
>>>> +static int max9286_enum_mbus_code(struct v4l2_subdev *sd,
>>>> +				  struct v4l2_subdev_pad_config *cfg,
>>>> +				  struct v4l2_subdev_mbus_code_enum *code)
>>>> +{
>>>> +	if (code->pad || code->index > 0)
>>>> +		return -EINVAL;
>>>> +
>>>> +	code->code = MEDIA_BUS_FMT_UYVY8_2X8;
>>>
>>> Why UYVY8_2X8 and not UYVY8_1X16? In general, the single sample / pixel
>>> variant of the format is generally used on the serial busses. This choice
>>> was made when serial busses were introduced.
>>
>> Ok - I presume this doesn't really have much effect anyway, they just
>> have to match for the transmitter/receiver?
>>
>> But it makes sense to me, so I'll update to the 1x16 variant.
>>
>>>> +
>>>> +	return 0;
>>>> +}
>>>> +
>>>> +static struct v4l2_mbus_framefmt *
>>>> +max9286_get_pad_format(struct max9286_priv *priv,
>>>> +		       struct v4l2_subdev_pad_config *cfg,
>>>> +		       unsigned int pad, u32 which)
>>>> +{
>>>> +	switch (which) {
>>>> +	case V4L2_SUBDEV_FORMAT_TRY:
>>>> +		return v4l2_subdev_get_try_format(&priv->sd, cfg, pad);
>>>> +	case V4L2_SUBDEV_FORMAT_ACTIVE:
>>>> +		return &priv->fmt[pad];
>>>> +	default:
>>>> +		return NULL;
>>>> +	}
>>>> +}
>>>> +
>>>> +static int max9286_set_fmt(struct v4l2_subdev *sd,
>>>> +			   struct v4l2_subdev_pad_config *cfg,
>>>> +			   struct v4l2_subdev_format *format)
>>>> +{
>>>> +	struct max9286_priv *priv = sd_to_max9286(sd);
>>>> +	struct v4l2_mbus_framefmt *cfg_fmt;
>>>> +
>>>> +	if (format->pad >= MAX9286_SRC_PAD)
>>>> +		return -EINVAL;
>>>
>>> You can remove these checks; it's been already done by the caller.
>>>
>>
>> Ok.
>>
> 
> I think this shold be kept. The core validates that the pad number is
> valid, but we're here checking that set_fmt has been called on a sink
> pad [0-3], returning -EINVAL if set_fmt (and get_ftm as well) are
> called on the source one.
> 

Indeed, this is actually preventing get/set format on the intermediate
(multiplexed) stream. But it is "breaking" link validation (or
preventing it from happening maybe?), which is defaulting 'open' ...
that might be a problem we need to look at, but as we don't have a real
multiplexed stream support implementation then that's perhaps more
difficult to give a 'correct' answer.


> My question now is how does link validation work, if get_fmt() is not
> allowed on the source pad :/ ? Anyway, I would keep this check for
> set_fmt (maybe make it an == to address Sakari's comment).


Ok - so as long as we return -EINVAL for the MAX9286_SRC_PAD, then
v4l2_subdev_link_validate() will fail on
v4l2_subdev_link_validate_get_format() for that pad, which causes a return 0

(v4l2_subdev_link_validate defaulting to success if it can't get both pads)

We could convert this to:

/*
 * \todo: Prevent validation of the source pad, as it represents a
 * multiplexed stream, and we do not have multiplexed stream support in
 * V4L2 yet.
 */
if (format->pad == MAX9286_SRC_PAD)


Or we could call this a blocker. Which will make me sad, as I really
want to be able to have a baseline for development for this driver, but
I've been calling out for "What blockers prevent this driver from being
merged" since February so if this is it - so be it...


Sakari - is this a blocking issue for you? Or can we consider this a
topic that we (already know) needs visiting as part of V4L2 Multiplexed
stream support.

We already know of course that this driver is taking liberties due to
the lack of multiplexed stream support, and requires the receiver to
assume that each camera is on a different (consecutive?) VC.


Or perhaps - to enforce validation, we could have the get_fmt call pass
on the bus format of the first camera link ?

Thoughts anyone?



> 
> Thanks
>   j
> 
>>
>>> ...
>>>
>>>> +static int max9286_parse_dt(struct max9286_priv *priv)
>>>> +{
>>>> +	struct device *dev = &priv->client->dev;
>>>> +	struct device_node *i2c_mux;
>>>> +	struct device_node *node = NULL;
>>>> +	unsigned int i2c_mux_mask = 0;
>>>> +
>>>> +	of_node_get(dev->of_node);
>>>> +	i2c_mux = of_find_node_by_name(dev->of_node, "i2c-mux");
>>>> +	if (!i2c_mux) {
>>>> +		dev_err(dev, "Failed to find i2c-mux node\n");
>>>> +		of_node_put(dev->of_node);
>>>> +		return -EINVAL;
>>>> +	}
>>>> +
>>>> +	/* Identify which i2c-mux channels are enabled */
>>>> +	for_each_child_of_node(i2c_mux, node) {
>>>> +		u32 id = 0;
>>>> +
>>>> +		of_property_read_u32(node, "reg", &id);
>>>> +		if (id >= MAX9286_NUM_GMSL)
>>>> +			continue;
>>>> +
>>>> +		if (!of_device_is_available(node)) {
>>>> +			dev_dbg(dev, "Skipping disabled I2C bus port %u\n", id);
>>>> +			continue;
>>>> +		}
>>>> +
>>>> +		i2c_mux_mask |= BIT(id);
>>>> +	}
>>>> +	of_node_put(node);
>>>> +	of_node_put(i2c_mux);
>>>> +
>>>> +	/* Parse the endpoints */
>>>> +	for_each_endpoint_of_node(dev->of_node, node) {
>>>> +		struct max9286_source *source;
>>>> +		struct of_endpoint ep;
>>>> +
>>>> +		of_graph_parse_endpoint(node, &ep);
>>>> +		dev_dbg(dev, "Endpoint %pOF on port %d",
>>>> +			ep.local_node, ep.port);
>>>> +
>>>> +		if (ep.port > MAX9286_NUM_GMSL) {
>>>> +			dev_err(dev, "Invalid endpoint %s on port %d",
>>>> +				of_node_full_name(ep.local_node), ep.port);
>>>> +			continue;
>>>> +		}
>>>> +
>>>> +		/* For the source endpoint just parse the bus configuration. */
>>>> +		if (ep.port == MAX9286_SRC_PAD) {
>>>> +			struct v4l2_fwnode_endpoint vep = {
>>>> +				.bus_type = V4L2_MBUS_CSI2_DPHY
>>>> +			};
>>>> +			int ret;
>>>> +
>>>> +			ret = v4l2_fwnode_endpoint_parse(
>>>> +					of_fwnode_handle(node), &vep);
>>>> +			if (ret) {
>>>> +				of_node_put(node);
>>>> +				of_node_put(dev->of_node);
>>>> +				return ret;
>>>> +			}
>>>> +
>>>> +			if (vep.bus_type != V4L2_MBUS_CSI2_DPHY) {
>>>
>>> This won't happen, the bus type will stay if you set it to a non-zero
>>> value.
>>
>>
>> Ok - I'll remove this check.
>>
>>
>>>
>>>> +				dev_err(dev,
>>>> +					"Media bus %u type not supported\n",
>>>> +					vep.bus_type);
>>>> +				v4l2_fwnode_endpoint_free(&vep);
>>>> +				of_node_put(node);
>>>> +				of_node_put(dev->of_node);
>>>> +				return -EINVAL;
>>>> +			}
>>>> +
>>>> +			priv->csi2_data_lanes =
>>>> +				vep.bus.mipi_csi2.num_data_lanes;
>>>> +			v4l2_fwnode_endpoint_free(&vep);
>>>
>>> No need to call this unless you use v4l2_fwnode_endpoint_alloc_parse().
>>>
>>> And as you don't, you also won't know which frequencies are known to be
>>> safe to use. That said, perhaps where this device is used having a random
>>> frequency on that bus could not be an issue. Perhaps.
>>
>> Does this generate a range? or a list of static supported frequencies?
>>
>> We configure the pixel clock based upon the number of cameras connected,
>> and their pixel rates etc ...
>>
>> Are you saying that the frequency of this clock should be validated to
>> be a specific range? or are you talking about a different frequency?
>>
>>
>> For now I'll remove the v4l2_fwnode_endpoint_alloc_parse().
>>
>>
>>
>>>> +
>>>> +			continue;
>>>> +		}
>>>> +
>>>> +		/* Skip if the corresponding GMSL link is unavailable. */
>>>> +		if (!(i2c_mux_mask & BIT(ep.port)))
>>>> +			continue;
>>>> +
>>>> +		if (priv->sources[ep.port].fwnode) {
>>>> +			dev_err(dev,
>>>> +				"Multiple port endpoints are not supported: %d",
>>>> +				ep.port);
>>>> +
>>>> +			continue;
>>>> +		}
>>>> +
>>>> +		source = &priv->sources[ep.port];
>>>> +		source->fwnode = fwnode_graph_get_remote_endpoint(
>>>> +						of_fwnode_handle(node));
>>>> +		if (!source->fwnode) {
>>>> +			dev_err(dev,
>>>> +				"Endpoint %pOF has no remote endpoint connection\n",
>>>> +				ep.local_node);
>>>> +
>>>> +			continue;
>>>> +		}
>>>> +
>>>> +		priv->source_mask |= BIT(ep.port);
>>>> +		priv->nsources++;
>>>> +	}
>>>> +	of_node_put(node);
>>>> +	of_node_put(dev->of_node);
>>>> +
>>>> +	priv->route_mask = priv->source_mask;
>>>> +
>>>> +	return 0;
>>>> +}
>>>
>>

[PATCH] fixes! [max9286]: Validate link formats

[Kieran Bingham]

Disallow setting a format on the source link, but enable link validation
by returning the format of the first bound source when getting the
format of the source pad.

Signed-off-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
---
 drivers/media/i2c/max9286.c | 17 +++++++++++++----
 1 file changed, 13 insertions(+), 4 deletions(-)

diff --git a/drivers/media/i2c/max9286.c b/drivers/media/i2c/max9286.c
index ef824d2b26b8..6c01595936d7 100644
--- a/drivers/media/i2c/max9286.c
+++ b/drivers/media/i2c/max9286.c
@@ -711,7 +711,10 @@ static int max9286_set_fmt(struct v4l2_subdev *sd,
 	struct max9286_priv *priv = sd_to_max9286(sd);
 	struct v4l2_mbus_framefmt *cfg_fmt;
 
-	if (format->pad >= MAX9286_SRC_PAD)
+	/* \todo: Multiplexed streams support
+	 * Prevent setting the format on the shared multiplexed bus.
+	 */
+	if (format->pad == MAX9286_SRC_PAD)
 		return -EINVAL;
 
 	/* Refuse non YUV422 formats as we hardcode DT to 8 bit YUV422 */
@@ -743,11 +746,17 @@ static int max9286_get_fmt(struct v4l2_subdev *sd,
 {
 	struct max9286_priv *priv = sd_to_max9286(sd);
 	struct v4l2_mbus_framefmt *cfg_fmt;
+	unsigned int pad = format->pad;
 
-	if (format->pad >= MAX9286_SRC_PAD)
-		return -EINVAL;
+	/* \todo: Multiplexed Stream Support
+	 * Support link validation by returning the format of the first bound
+	 * link. All links must have the same format, as we do not support
+	 * mixing, and matching of cameras connected to the max9286.
+	 */
+	if (format->pad == MAX9286_SRC_PAD)
+		pad = ffs(priv->bound_sources);
 
-	cfg_fmt = max9286_get_pad_format(priv, cfg, format->pad, format->which);
+	cfg_fmt = max9286_get_pad_format(priv, cfg, pad, format->which);
 	if (!cfg_fmt)
 		return -EINVAL;
 
-- 
2.25.1

Re: [PATCH] fixes! [max9286]: Validate link formats

[Kieran Bingham]

Hi Kieran

On 18/05/2020 17:11, Kieran Bingham wrote:
> Disallow setting a format on the source link, but enable link validation
> by returning the format of the first bound source when getting the
> format of the source pad.
> 
> Signed-off-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
> ---
>  drivers/media/i2c/max9286.c | 17 +++++++++++++----
>  1 file changed, 13 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/media/i2c/max9286.c b/drivers/media/i2c/max9286.c
> index ef824d2b26b8..6c01595936d7 100644
> --- a/drivers/media/i2c/max9286.c
> +++ b/drivers/media/i2c/max9286.c
> @@ -711,7 +711,10 @@ static int max9286_set_fmt(struct v4l2_subdev *sd,
>  	struct max9286_priv *priv = sd_to_max9286(sd);
>  	struct v4l2_mbus_framefmt *cfg_fmt;
>  
> -	if (format->pad >= MAX9286_SRC_PAD)
> +	/* \todo: Multiplexed streams support
> +	 * Prevent setting the format on the shared multiplexed bus.
> +	 */
> +	if (format->pad == MAX9286_SRC_PAD)
>  		return -EINVAL;
>  
>  	/* Refuse non YUV422 formats as we hardcode DT to 8 bit YUV422 */
> @@ -743,11 +746,17 @@ static int max9286_get_fmt(struct v4l2_subdev *sd,
>  {
>  	struct max9286_priv *priv = sd_to_max9286(sd);
>  	struct v4l2_mbus_framefmt *cfg_fmt;
> +	unsigned int pad = format->pad;
>  
> -	if (format->pad >= MAX9286_SRC_PAD)
> -		return -EINVAL;
> +	/* \todo: Multiplexed Stream Support
> +	 * Support link validation by returning the format of the first bound
> +	 * link. All links must have the same format, as we do not support
> +	 * mixing, and matching of cameras connected to the max9286.
> +	 */
> +	if (format->pad == MAX9286_SRC_PAD)
> +		pad = ffs(priv->bound_sources);

of course this would have to be (ffs(priv->bound_sources) - 1) as the
first pad index is 0 ;-)

>  
> -	cfg_fmt = max9286_get_pad_format(priv, cfg, format->pad, format->which);
> +	cfg_fmt = max9286_get_pad_format(priv, cfg, pad, format->which);
>  	if (!cfg_fmt)
>  		return -EINVAL;
>  
> 

Re: [PATCH] fixes! [max9286]: Validate link formats

[Sakari Ailus]

On Mon, May 18, 2020 at 07:44:41PM +0100, Kieran Bingham wrote:
> Hi Kieran
> 
> On 18/05/2020 17:11, Kieran Bingham wrote:
> > Disallow setting a format on the source link, but enable link validation
> > by returning the format of the first bound source when getting the
> > format of the source pad.
> > 
> > Signed-off-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
> > ---
> >  drivers/media/i2c/max9286.c | 17 +++++++++++++----
> >  1 file changed, 13 insertions(+), 4 deletions(-)
> > 
> > diff --git a/drivers/media/i2c/max9286.c b/drivers/media/i2c/max9286.c
> > index ef824d2b26b8..6c01595936d7 100644
> > --- a/drivers/media/i2c/max9286.c
> > +++ b/drivers/media/i2c/max9286.c
> > @@ -711,7 +711,10 @@ static int max9286_set_fmt(struct v4l2_subdev *sd,
> >  	struct max9286_priv *priv = sd_to_max9286(sd);
> >  	struct v4l2_mbus_framefmt *cfg_fmt;
> >  
> > -	if (format->pad >= MAX9286_SRC_PAD)
> > +	/* \todo: Multiplexed streams support
> > +	 * Prevent setting the format on the shared multiplexed bus.
> > +	 */
> > +	if (format->pad == MAX9286_SRC_PAD)
> >  		return -EINVAL;
> >  
> >  	/* Refuse non YUV422 formats as we hardcode DT to 8 bit YUV422 */
> > @@ -743,11 +746,17 @@ static int max9286_get_fmt(struct v4l2_subdev *sd,
> >  {
> >  	struct max9286_priv *priv = sd_to_max9286(sd);
> >  	struct v4l2_mbus_framefmt *cfg_fmt;
> > +	unsigned int pad = format->pad;
> >  
> > -	if (format->pad >= MAX9286_SRC_PAD)
> > -		return -EINVAL;
> > +	/* \todo: Multiplexed Stream Support
> > +	 * Support link validation by returning the format of the first bound
> > +	 * link. All links must have the same format, as we do not support
> > +	 * mixing, and matching of cameras connected to the max9286.
> > +	 */
> > +	if (format->pad == MAX9286_SRC_PAD)
> > +		pad = ffs(priv->bound_sources);
> 
> of course this would have to be (ffs(priv->bound_sources) - 1) as the
> first pad index is 0 ;-)

You could be clever and use __ffs() instead. :-)

> 
> >  
> > -	cfg_fmt = max9286_get_pad_format(priv, cfg, format->pad, format->which);
> > +	cfg_fmt = max9286_get_pad_format(priv, cfg, pad, format->which);
> >  	if (!cfg_fmt)
> >  		return -EINVAL;
> >  
> > 
> 

-- 
Sakari Ailus

Re: [PATCH] fixes! [max9286]: Validate link formats

[Jacopo Mondi]

Hi Kieran,

On Mon, May 18, 2020 at 05:11:59PM +0100, Kieran Bingham wrote:
> Disallow setting a format on the source link, but enable link validation
> by returning the format of the first bound source when getting the
> format of the source pad.
>
> Signed-off-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
> ---
>  drivers/media/i2c/max9286.c | 17 +++++++++++++----
>  1 file changed, 13 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/media/i2c/max9286.c b/drivers/media/i2c/max9286.c
> index ef824d2b26b8..6c01595936d7 100644
> --- a/drivers/media/i2c/max9286.c
> +++ b/drivers/media/i2c/max9286.c
> @@ -711,7 +711,10 @@ static int max9286_set_fmt(struct v4l2_subdev *sd,
>  	struct max9286_priv *priv = sd_to_max9286(sd);
>  	struct v4l2_mbus_framefmt *cfg_fmt;
>
> -	if (format->pad >= MAX9286_SRC_PAD)
> +	/* \todo: Multiplexed streams support

I know where \todo comes from, but it's usually TODO.
Also
        /*
         * TODO:

if the comment is multiline

> +	 * Prevent setting the format on the shared multiplexed bus.
> +	 */
> +	if (format->pad == MAX9286_SRC_PAD)
>  		return -EINVAL;
>
>  	/* Refuse non YUV422 formats as we hardcode DT to 8 bit YUV422 */
> @@ -743,11 +746,17 @@ static int max9286_get_fmt(struct v4l2_subdev *sd,
>  {
>  	struct max9286_priv *priv = sd_to_max9286(sd);
>  	struct v4l2_mbus_framefmt *cfg_fmt;
> +	unsigned int pad = format->pad;
>
> -	if (format->pad >= MAX9286_SRC_PAD)
> -		return -EINVAL;
> +	/* \todo: Multiplexed Stream Support
> +	 * Support link validation by returning the format of the first bound
> +	 * link. All links must have the same format, as we do not support
> +	 * mixing, and matching of cameras connected to the max9286.
> +	 */
> +	if (format->pad == MAX9286_SRC_PAD)

You can use pad

> +		pad = ffs(priv->bound_sources);
>
> -	cfg_fmt = max9286_get_pad_format(priv, cfg, format->pad, format->which);
> +	cfg_fmt = max9286_get_pad_format(priv, cfg, pad, format->which);

Or you could add one entry to struct max9286_priv.fmt for the source
pad format, set the format there when is set on one sink, and just
drop the check on the pad index in get_fmt. Up to you.

Please squash in v10

Thanks
  j

>  	if (!cfg_fmt)
>  		return -EINVAL;
>
> --
> 2.25.1
>

Re: [PATCH] fixes! [max9286]: Validate link formats

[Kieran Bingham]

Hi Jacopo,

On 19/05/2020 08:56, Jacopo Mondi wrote:
> Hi Kieran,
> 
> On Mon, May 18, 2020 at 05:11:59PM +0100, Kieran Bingham wrote:
>> Disallow setting a format on the source link, but enable link validation
>> by returning the format of the first bound source when getting the
>> format of the source pad.
>>
>> Signed-off-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
>> ---
>>  drivers/media/i2c/max9286.c | 17 +++++++++++++----
>>  1 file changed, 13 insertions(+), 4 deletions(-)
>>
>> diff --git a/drivers/media/i2c/max9286.c b/drivers/media/i2c/max9286.c
>> index ef824d2b26b8..6c01595936d7 100644
>> --- a/drivers/media/i2c/max9286.c
>> +++ b/drivers/media/i2c/max9286.c
>> @@ -711,7 +711,10 @@ static int max9286_set_fmt(struct v4l2_subdev *sd,
>>  	struct max9286_priv *priv = sd_to_max9286(sd);
>>  	struct v4l2_mbus_framefmt *cfg_fmt;
>>
>> -	if (format->pad >= MAX9286_SRC_PAD)
>> +	/* \todo: Multiplexed streams support
> 
> I know where \todo comes from, but it's usually TODO.
> Also

to much time playing in doxygen ;-)

>         /*
>          * TODO:
> 
> if the comment is multiline
> 
>> +	 * Prevent setting the format on the shared multiplexed bus.
>> +	 */
>> +	if (format->pad == MAX9286_SRC_PAD)
>>  		return -EINVAL;
>>
>>  	/* Refuse non YUV422 formats as we hardcode DT to 8 bit YUV422 */
>> @@ -743,11 +746,17 @@ static int max9286_get_fmt(struct v4l2_subdev *sd,
>>  {
>>  	struct max9286_priv *priv = sd_to_max9286(sd);
>>  	struct v4l2_mbus_framefmt *cfg_fmt;
>> +	unsigned int pad = format->pad;
>>
>> -	if (format->pad >= MAX9286_SRC_PAD)
>> -		return -EINVAL;
>> +	/* \todo: Multiplexed Stream Support
>> +	 * Support link validation by returning the format of the first bound
>> +	 * link. All links must have the same format, as we do not support
>> +	 * mixing, and matching of cameras connected to the max9286.
>> +	 */
>> +	if (format->pad == MAX9286_SRC_PAD)
> 
> You can use pad

Sure ;-)
> 
>> +		pad = ffs(priv->bound_sources);
>>
>> -	cfg_fmt = max9286_get_pad_format(priv, cfg, format->pad, format->which);
>> +	cfg_fmt = max9286_get_pad_format(priv, cfg, pad, format->which);
> 
> Or you could add one entry to struct max9286_priv.fmt for the source
> pad format, set the format there when is set on one sink, and just
> drop the check on the pad index in get_fmt. Up to you.
> 

I'd prefer to  reference the actual first source, rather than
duplicating as that's the link that we're validating against.

> Please squash in v10

Thanks, v10 soon!.

Just need to determine the best route for the remaining dt cleanups.

--
Kieran

> Thanks
>   j
> 
>>  	if (!cfg_fmt)
>>  		return -EINVAL;
>>
>> --
>> 2.25.1
>>

Re: [PATCH v9 2/4] media: i2c: Add MAX9286 driver

[Sakari Ailus]

Hi Kieran,

On Mon, May 18, 2020 at 12:45:18PM +0100, Kieran Bingham wrote:
> Hi Sakari,
> 
> There are only fairly minor comments here, fix ups will be included in a
> v10.
> 
> Is there anything major blocking integration?

Not that I can see. But please see my comments below.

> 
> Regards
> 
> Kieran
> 
> 
> 
> On 16/05/2020 22:51, Sakari Ailus wrote:
> > Hi Kieran,
> > 
> > Thanks for the update.
> > 
> > On Tue, May 12, 2020 at 04:51:03PM +0100, Kieran Bingham wrote:
> > 
> > ...
> > 
> >> +static int max9286_enum_mbus_code(struct v4l2_subdev *sd,
> >> +				  struct v4l2_subdev_pad_config *cfg,
> >> +				  struct v4l2_subdev_mbus_code_enum *code)
> >> +{
> >> +	if (code->pad || code->index > 0)
> >> +		return -EINVAL;
> >> +
> >> +	code->code = MEDIA_BUS_FMT_UYVY8_2X8;
> > 
> > Why UYVY8_2X8 and not UYVY8_1X16? In general, the single sample / pixel
> > variant of the format is generally used on the serial busses. This choice
> > was made when serial busses were introduced.
> 
> Ok - I presume this doesn't really have much effect anyway, they just
> have to match for the transmitter/receiver?

In this case, yes. But it's harder to change later, so let's indeed do that
now.

> 
> But it makes sense to me, so I'll update to the 1x16 variant.

...

> 
> > And as you don't, you also won't know which frequencies are known to be
> > safe to use. That said, perhaps where this device is used having a random
> > frequency on that bus could not be an issue. Perhaps.
> 
> Does this generate a range? or a list of static supported frequencies?
> 
> We configure the pixel clock based upon the number of cameras connected,
> and their pixel rates etc ...
> 
> Are you saying that the frequency of this clock should be validated to
> be a specific range? or are you talking about a different frequency?

It depends on the system. In general, only frequencies known to be safe
should be used. If this one has enough shielding to guarantee there won't
be problems in using a random frequency in the entire range, is there a
guarantee that will be the case for all systems with this chip?

-- 
Kind regards,

Sakari Ailus

Re: [PATCH v9 2/4] media: i2c: Add MAX9286 driver

[Kieran Bingham]

Hi Sakari,

On 19/05/2020 09:10, Sakari Ailus wrote:
> Hi Kieran,
> 
> On Mon, May 18, 2020 at 12:45:18PM +0100, Kieran Bingham wrote:
>> Hi Sakari,
>>
>> There are only fairly minor comments here, fix ups will be included in a
>> v10.
>>
>> Is there anything major blocking integration?
> 
> Not that I can see. But please see my comments below.

Thanks,

We might have some more work tidying up the DT validation anyway which
has come too late, and perhaps is going to bump this to v5.9 now anyway.

I can still try but ... ;-S

At least hopefully now we /can/ see a path to integration though.

I probably don't care if it's 5.8 or 5.9 as long as it's not 8.5 ;-)

>>
>> Regards
>>
>> Kieran
>>
>>
>>
>> On 16/05/2020 22:51, Sakari Ailus wrote:
>>> Hi Kieran,
>>>
>>> Thanks for the update.
>>>
>>> On Tue, May 12, 2020 at 04:51:03PM +0100, Kieran Bingham wrote:
>>>
>>> ...
>>>
>>>> +static int max9286_enum_mbus_code(struct v4l2_subdev *sd,
>>>> +				  struct v4l2_subdev_pad_config *cfg,
>>>> +				  struct v4l2_subdev_mbus_code_enum *code)
>>>> +{
>>>> +	if (code->pad || code->index > 0)
>>>> +		return -EINVAL;
>>>> +
>>>> +	code->code = MEDIA_BUS_FMT_UYVY8_2X8;
>>>
>>> Why UYVY8_2X8 and not UYVY8_1X16? In general, the single sample / pixel
>>> variant of the format is generally used on the serial busses. This choice
>>> was made when serial busses were introduced.
>>
>> Ok - I presume this doesn't really have much effect anyway, they just
>> have to match for the transmitter/receiver?
> 
> In this case, yes. But it's harder to change later, so let's indeed do that
> now.

Yes indeed, I have to change my test scripts for the new configuration
(or we should update the scripts to get the configuration from the
device ;D)


>> But it makes sense to me, so I'll update to the 1x16 variant.
> 
> ...

done anyway ;-)

I see the ADV748x is using the 2x8 variants though ... (all the more
reason for our scripts to /get/ the correct version when propagating
formats).

Perhaps I should/could add the 1x16 formats to the ADV748x too. (later)


>>> And as you don't, you also won't know which frequencies are known to be
>>> safe to use. That said, perhaps where this device is used having a random
>>> frequency on that bus could not be an issue. Perhaps.
>>
>> Does this generate a range? or a list of static supported frequencies?
>>
>> We configure the pixel clock based upon the number of cameras connected,
>> and their pixel rates etc ...
>>
>> Are you saying that the frequency of this clock should be validated to
>> be a specific range? or are you talking about a different frequency?
> 
> It depends on the system. In general, only frequencies known to be safe
> should be used. If this one has enough shielding to guarantee there won't
> be problems in using a random frequency in the entire range, is there a
> guarantee that will be the case for all systems with this chip?

I have no idea here... Maybe Niklas knows more having dealt more with
the RCar-VIN/CSI parts.

It seems like this is something we can add later if necessary, by
extending the descriptions in the DT?

--
Kieran

Re: [PATCH v9 2/4] media: i2c: Add MAX9286 driver

[Sakari Ailus]

Hi Kieran,

On Tue, May 19, 2020 at 09:55:24AM +0100, Kieran Bingham wrote:
> Hi Sakari,
> 
> On 19/05/2020 09:10, Sakari Ailus wrote:
> > Hi Kieran,
> > 
> > On Mon, May 18, 2020 at 12:45:18PM +0100, Kieran Bingham wrote:
> >> Hi Sakari,
> >>
> >> There are only fairly minor comments here, fix ups will be included in a
> >> v10.
> >>
> >> Is there anything major blocking integration?
> > 
> > Not that I can see. But please see my comments below.
> 
> Thanks,
> 
> We might have some more work tidying up the DT validation anyway which
> has come too late, and perhaps is going to bump this to v5.9 now anyway.
> 
> I can still try but ... ;-S
> 
> At least hopefully now we /can/ see a path to integration though.
> 
> I probably don't care if it's 5.8 or 5.9 as long as it's not 8.5 ;-)
> 
> >>
> >> Regards
> >>
> >> Kieran
> >>
> >>
> >>
> >> On 16/05/2020 22:51, Sakari Ailus wrote:
> >>> Hi Kieran,
> >>>
> >>> Thanks for the update.
> >>>
> >>> On Tue, May 12, 2020 at 04:51:03PM +0100, Kieran Bingham wrote:
> >>>
> >>> ...
> >>>
> >>>> +static int max9286_enum_mbus_code(struct v4l2_subdev *sd,
> >>>> +				  struct v4l2_subdev_pad_config *cfg,
> >>>> +				  struct v4l2_subdev_mbus_code_enum *code)
> >>>> +{
> >>>> +	if (code->pad || code->index > 0)
> >>>> +		return -EINVAL;
> >>>> +
> >>>> +	code->code = MEDIA_BUS_FMT_UYVY8_2X8;
> >>>
> >>> Why UYVY8_2X8 and not UYVY8_1X16? In general, the single sample / pixel
> >>> variant of the format is generally used on the serial busses. This choice
> >>> was made when serial busses were introduced.
> >>
> >> Ok - I presume this doesn't really have much effect anyway, they just
> >> have to match for the transmitter/receiver?
> > 
> > In this case, yes. But it's harder to change later, so let's indeed do that
> > now.
> 
> Yes indeed, I have to change my test scripts for the new configuration
> (or we should update the scripts to get the configuration from the
> device ;D)
> 
> 
> >> But it makes sense to me, so I'll update to the 1x16 variant.
> > 
> > ...
> 
> done anyway ;-)
> 
> I see the ADV748x is using the 2x8 variants though ... (all the more
> reason for our scripts to /get/ the correct version when propagating
> formats).
> 
> Perhaps I should/could add the 1x16 formats to the ADV748x too. (later)

It's a driver bug, yes.

> 
> 
> >>> And as you don't, you also won't know which frequencies are known to be
> >>> safe to use. That said, perhaps where this device is used having a random
> >>> frequency on that bus could not be an issue. Perhaps.
> >>
> >> Does this generate a range? or a list of static supported frequencies?
> >>
> >> We configure the pixel clock based upon the number of cameras connected,
> >> and their pixel rates etc ...
> >>
> >> Are you saying that the frequency of this clock should be validated to
> >> be a specific range? or are you talking about a different frequency?
> > 
> > It depends on the system. In general, only frequencies known to be safe
> > should be used. If this one has enough shielding to guarantee there won't
> > be problems in using a random frequency in the entire range, is there a
> > guarantee that will be the case for all systems with this chip?
> 
> I have no idea here... Maybe Niklas knows more having dealt more with
> the RCar-VIN/CSI parts.
> 
> It seems like this is something we can add later if necessary, by
> extending the descriptions in the DT?

Works for me.

Niklas, any idea?

-- 
Regards,

Sakari Ailus

Re: [PATCH v9 2/4] media: i2c: Add MAX9286 driver

[Laurent Pinchart]

Hi Sakari,

On Mon, May 18, 2020 at 12:45:18PM +0100, Kieran Bingham wrote:
> Hi Sakari,
> 
> There are only fairly minor comments here, fix ups will be included in a
> v10.
> 
> Is there anything major blocking integration?
> 
> On 16/05/2020 22:51, Sakari Ailus wrote:
> > On Tue, May 12, 2020 at 04:51:03PM +0100, Kieran Bingham wrote:
> > 
> > ...
> > 
> >> +static int max9286_enum_mbus_code(struct v4l2_subdev *sd,
> >> +				  struct v4l2_subdev_pad_config *cfg,
> >> +				  struct v4l2_subdev_mbus_code_enum *code)
> >> +{
> >> +	if (code->pad || code->index > 0)
> >> +		return -EINVAL;
> >> +
> >> +	code->code = MEDIA_BUS_FMT_UYVY8_2X8;
> > 
> > Why UYVY8_2X8 and not UYVY8_1X16? In general, the single sample / pixel
> > variant of the format is generally used on the serial busses. This choice
> > was made when serial busses were introduced.

This is a bit of a tricky one. On the camera size, for the RDACM20, the
O10635 sensor outputs UYVY8_2X8. This if fed to the MAX9271 serializer,
which doesn't care about the data type. The MAX9271 has a 16-bit input
bus, with 10 bits reserved for data, 2 bits dynamically configurable
to carry H/V sync or extra data, and 4 bits dynamically configurable to
carry GPIOs or extra data. The 16-bit words are then serialized (it's a
bit more complicated, when using the H/V sync signals they are
transmitted in a different way, and the MAX9271 also supports a DDR mode
that makes the "serial link word" carry up to 30 bits). Effectively, the
two samples of UYVY8_2X8 are serialized in a 16-bit word each.

Sakari, with this information in mind, what would you recommend ?

> Ok - I presume this doesn't really have much effect anyway, they just
> have to match for the transmitter/receiver?
> 
> But it makes sense to me, so I'll update to the 1x16 variant.
> 
> >> +
> >> +	return 0;
> >> +}
> >> +
> >> +static struct v4l2_mbus_framefmt *
> >> +max9286_get_pad_format(struct max9286_priv *priv,
> >> +		       struct v4l2_subdev_pad_config *cfg,
> >> +		       unsigned int pad, u32 which)
> >> +{
> >> +	switch (which) {
> >> +	case V4L2_SUBDEV_FORMAT_TRY:
> >> +		return v4l2_subdev_get_try_format(&priv->sd, cfg, pad);
> >> +	case V4L2_SUBDEV_FORMAT_ACTIVE:
> >> +		return &priv->fmt[pad];
> >> +	default:
> >> +		return NULL;
> >> +	}
> >> +}
> >> +
> >> +static int max9286_set_fmt(struct v4l2_subdev *sd,
> >> +			   struct v4l2_subdev_pad_config *cfg,
> >> +			   struct v4l2_subdev_format *format)
> >> +{
> >> +	struct max9286_priv *priv = sd_to_max9286(sd);
> >> +	struct v4l2_mbus_framefmt *cfg_fmt;
> >> +
> >> +	if (format->pad >= MAX9286_SRC_PAD)
> >> +		return -EINVAL;
> > 
> > You can remove these checks; it's been already done by the caller.
> > 
> 
> Ok.
> 
> 
> > ...
> > 
> >> +static int max9286_parse_dt(struct max9286_priv *priv)
> >> +{
> >> +	struct device *dev = &priv->client->dev;
> >> +	struct device_node *i2c_mux;
> >> +	struct device_node *node = NULL;
> >> +	unsigned int i2c_mux_mask = 0;
> >> +
> >> +	of_node_get(dev->of_node);
> >> +	i2c_mux = of_find_node_by_name(dev->of_node, "i2c-mux");
> >> +	if (!i2c_mux) {
> >> +		dev_err(dev, "Failed to find i2c-mux node\n");
> >> +		of_node_put(dev->of_node);
> >> +		return -EINVAL;
> >> +	}
> >> +
> >> +	/* Identify which i2c-mux channels are enabled */
> >> +	for_each_child_of_node(i2c_mux, node) {
> >> +		u32 id = 0;
> >> +
> >> +		of_property_read_u32(node, "reg", &id);
> >> +		if (id >= MAX9286_NUM_GMSL)
> >> +			continue;
> >> +
> >> +		if (!of_device_is_available(node)) {
> >> +			dev_dbg(dev, "Skipping disabled I2C bus port %u\n", id);
> >> +			continue;
> >> +		}
> >> +
> >> +		i2c_mux_mask |= BIT(id);
> >> +	}
> >> +	of_node_put(node);
> >> +	of_node_put(i2c_mux);
> >> +
> >> +	/* Parse the endpoints */
> >> +	for_each_endpoint_of_node(dev->of_node, node) {
> >> +		struct max9286_source *source;
> >> +		struct of_endpoint ep;
> >> +
> >> +		of_graph_parse_endpoint(node, &ep);
> >> +		dev_dbg(dev, "Endpoint %pOF on port %d",
> >> +			ep.local_node, ep.port);
> >> +
> >> +		if (ep.port > MAX9286_NUM_GMSL) {
> >> +			dev_err(dev, "Invalid endpoint %s on port %d",
> >> +				of_node_full_name(ep.local_node), ep.port);
> >> +			continue;
> >> +		}
> >> +
> >> +		/* For the source endpoint just parse the bus configuration. */
> >> +		if (ep.port == MAX9286_SRC_PAD) {
> >> +			struct v4l2_fwnode_endpoint vep = {
> >> +				.bus_type = V4L2_MBUS_CSI2_DPHY
> >> +			};
> >> +			int ret;
> >> +
> >> +			ret = v4l2_fwnode_endpoint_parse(
> >> +					of_fwnode_handle(node), &vep);
> >> +			if (ret) {
> >> +				of_node_put(node);
> >> +				of_node_put(dev->of_node);
> >> +				return ret;
> >> +			}
> >> +
> >> +			if (vep.bus_type != V4L2_MBUS_CSI2_DPHY) {
> > 
> > This won't happen, the bus type will stay if you set it to a non-zero
> > value.
> 
> 
> Ok - I'll remove this check.
> 
> 
> > 
> >> +				dev_err(dev,
> >> +					"Media bus %u type not supported\n",
> >> +					vep.bus_type);
> >> +				v4l2_fwnode_endpoint_free(&vep);
> >> +				of_node_put(node);
> >> +				of_node_put(dev->of_node);
> >> +				return -EINVAL;
> >> +			}
> >> +
> >> +			priv->csi2_data_lanes =
> >> +				vep.bus.mipi_csi2.num_data_lanes;
> >> +			v4l2_fwnode_endpoint_free(&vep);
> > 
> > No need to call this unless you use v4l2_fwnode_endpoint_alloc_parse().
> > 
> > And as you don't, you also won't know which frequencies are known to be
> > safe to use. That said, perhaps where this device is used having a random
> > frequency on that bus could not be an issue. Perhaps.
> 
> Does this generate a range? or a list of static supported frequencies?
> 
> We configure the pixel clock based upon the number of cameras connected,
> and their pixel rates etc ...
> 
> Are you saying that the frequency of this clock should be validated to
> be a specific range? or are you talking about a different frequency?
> 
> 
> For now I'll remove the v4l2_fwnode_endpoint_alloc_parse().
> 
> 
> 
> >> +
> >> +			continue;
> >> +		}
> >> +
> >> +		/* Skip if the corresponding GMSL link is unavailable. */
> >> +		if (!(i2c_mux_mask & BIT(ep.port)))
> >> +			continue;
> >> +
> >> +		if (priv->sources[ep.port].fwnode) {
> >> +			dev_err(dev,
> >> +				"Multiple port endpoints are not supported: %d",
> >> +				ep.port);
> >> +
> >> +			continue;
> >> +		}
> >> +
> >> +		source = &priv->sources[ep.port];
> >> +		source->fwnode = fwnode_graph_get_remote_endpoint(
> >> +						of_fwnode_handle(node));
> >> +		if (!source->fwnode) {
> >> +			dev_err(dev,
> >> +				"Endpoint %pOF has no remote endpoint connection\n",
> >> +				ep.local_node);
> >> +
> >> +			continue;
> >> +		}
> >> +
> >> +		priv->source_mask |= BIT(ep.port);
> >> +		priv->nsources++;
> >> +	}
> >> +	of_node_put(node);
> >> +	of_node_put(dev->of_node);
> >> +
> >> +	priv->route_mask = priv->source_mask;
> >> +
> >> +	return 0;
> >> +}
> > 
> 

-- 
Regards,

Laurent Pinchart

Re: [PATCH v9 2/4] media: i2c: Add MAX9286 driver

[Sakari Ailus]

Hi Laurent,

On Wed, May 20, 2020 at 03:50:20AM +0300, Laurent Pinchart wrote:
> Hi Sakari,
> 
> On Mon, May 18, 2020 at 12:45:18PM +0100, Kieran Bingham wrote:
> > Hi Sakari,
> > 
> > There are only fairly minor comments here, fix ups will be included in a
> > v10.
> > 
> > Is there anything major blocking integration?
> > 
> > On 16/05/2020 22:51, Sakari Ailus wrote:
> > > On Tue, May 12, 2020 at 04:51:03PM +0100, Kieran Bingham wrote:
> > > 
> > > ...
> > > 
> > >> +static int max9286_enum_mbus_code(struct v4l2_subdev *sd,
> > >> +				  struct v4l2_subdev_pad_config *cfg,
> > >> +				  struct v4l2_subdev_mbus_code_enum *code)
> > >> +{
> > >> +	if (code->pad || code->index > 0)
> > >> +		return -EINVAL;
> > >> +
> > >> +	code->code = MEDIA_BUS_FMT_UYVY8_2X8;
> > > 
> > > Why UYVY8_2X8 and not UYVY8_1X16? In general, the single sample / pixel
> > > variant of the format is generally used on the serial busses. This choice
> > > was made when serial busses were introduced.
> 
> This is a bit of a tricky one. On the camera size, for the RDACM20, the
> O10635 sensor outputs UYVY8_2X8. This if fed to the MAX9271 serializer,
> which doesn't care about the data type. The MAX9271 has a 16-bit input
> bus, with 10 bits reserved for data, 2 bits dynamically configurable
> to carry H/V sync or extra data, and 4 bits dynamically configurable to
> carry GPIOs or extra data. The 16-bit words are then serialized (it's a
> bit more complicated, when using the H/V sync signals they are
> transmitted in a different way, and the MAX9271 also supports a DDR mode
> that makes the "serial link word" carry up to 30 bits). Effectively, the
> two samples of UYVY8_2X8 are serialized in a 16-bit word each.
> 
> Sakari, with this information in mind, what would you recommend ?

As this pad describes a serial bus --- doesn't it? --- it should use the
same formats as other serial busses such as CSI-2. I.e. the 1X16 variant.

-- 
Regards,

Sakari Ailus

[PATCH v9 3/4] dt-bindings: media: i2c: Add bindings for IMI RDACM2x

[Kieran Bingham]

From: Jacopo Mondi <jacopo+renesas@jmondi.org>

The IMI RDACM20 and IMI RDACM21 are Gigabit Multimedia Serial Link (GMSL) camera
capable of transmitting video and I2C control messages on a coax cable
physical link for automotive applications.

Document their device tree bindings.

Signed-off-by: Jacopo Mondi <jacopo+renesas@jmondi.org>
Signed-off-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Rob Herring <robh@kernel.org>

---
v2:
 - Provide imi vendor prefix
 - Fix minor spelling

v3:
 - update binding descriptions

v4:
 - No change

v5:
 - Specify optional third reg address for the MCU

v7:
 [Jacopo]
 - Rename to imi,rdacm2x-gmsl.yaml
 - Exand bindings to describe RDACM21

v9:
  [Jacopo]
  - Rework 'compatible' property as suggested by Rob
  - Re-order vendor prefixes ('g' comes before 'i' ... )
  - Add Rob's tag

 .../bindings/media/i2c/imi,rdacm2x-gmsl.yaml  | 159 ++++++++++++++++++
 .../devicetree/bindings/vendor-prefixes.yaml  |   2 +
 2 files changed, 161 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/media/i2c/imi,rdacm2x-gmsl.yaml

diff --git a/Documentation/devicetree/bindings/media/i2c/imi,rdacm2x-gmsl.yaml b/Documentation/devicetree/bindings/media/i2c/imi,rdacm2x-gmsl.yaml
new file mode 100644
index 000000000000..fe524490e6a2
--- /dev/null
+++ b/Documentation/devicetree/bindings/media/i2c/imi,rdacm2x-gmsl.yaml
@@ -0,0 +1,159 @@
+# SPDX-License-Identifier: GPL-2.0 OR BSD-2-Clause
+# Copyright (C) 2019 Renesas Electronics Corp.
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/media/i2c/imi,rdacm2x-gmsl.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title:  IMI D&D RDACM20 and RDACM21 Automotive Camera Platforms
+
+maintainers:
+  - Jacopo Mondi <jacopo+renesas@jmondi.org>
+  - Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
+  - Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
+  - Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
+
+description: -|
+  The IMI D&D RDACM20 and RDACM21 are GMSL-compatible camera designed for
+  automotive applications.
+
+  The RDACM20 camera module encloses a Maxim Integrated MAX9271 GMSL serializer,
+  coupled with an OV10635 image sensor and an embedded MCU. Both the MCU and
+  the image sensor are connected to the serializer local I2C bus and are
+  accessible by the host SoC by direct addressing.
+
+  The RDACM21 camera module encloses the same serializer, coupled with an
+  OV10640 image sensor and an OV490 ISP. Only the OV490 ISP is interfaced to
+  the serializer local I2C bus while the image sensor is not accessible from
+  the host SoC.
+
+  They both connect to a remote GMSL endpoint through a coaxial cable.
+
+                                                   IMI RDACM20
+  +---------------+                        +--------------------------------+
+  |      GMSL     |   <- Video Stream      |       <- Video--------\        |
+  |               |< === GMSL Link ====== >|MAX9271<- I2C bus-> <-->OV10635 |
+  | de-serializer |   <- I2C messages ->   |                   \<-->MCU     |
+  +---------------+                        +--------------------------------+
+
+                                                   IMI RDACM21
+  +---------------+                        +--------------------------------+
+  |      GMSL     |   <- Video Stream      |       <- Video--------\        |
+  |               |< === GMSL Link ====== >|MAX9271<- I2C bus-> <-->OV490   |
+  |               |   <- I2C messages ->   |                          |     |
+  | de-serializer |                        |          OV10640 <-------|     |
+  +---------------+                        +--------------------------------+
+
+  Both camera modules serialize video data generated by the embedded camera
+  sensor on the GMSL serial channel to a remote GMSL de-serializer. They also
+  receive and transmit I2C messages encapsulated and transmitted on the GMSL
+  bidirectional control channel.
+
+  All I2C traffic received on the GMSL link not directed to the serializer is
+  propagated on the local I2C bus to the remote device there connected. All the
+  I2C traffic generated on the local I2C bus not directed to the serializer is
+  propagated to the remote de-serializer encapsulated in the GMSL control
+  channel.
+
+  The RDACM20 and RDACM21 DT node should be a direct child of the GMSL
+  deserializer's I2C bus corresponding to the GMSL link that the camera is
+  attached to.
+
+properties:
+  '#address-cells':
+    const: 1
+
+  '#size-cells':
+    const: 0
+
+  compatible:
+    enum:
+      - imi,rdacm20
+      - imi,rdacm21
+
+  reg:
+    description: -|
+      I2C device addresses, the first to be assigned to the serializer, the
+      following ones to be assigned to the remote devices.
+
+      For RDACM20 the second entry of the property is assigned to the
+      OV10635 image sensor and the optional third one to the embedded MCU.
+
+      For RDACM21 the second entry is assigned to the OV490 ISP and the optional
+      third one ignored.
+
+    minItems: 2
+    maxItems: 3
+
+  port:
+    type: object
+    additionalProperties: false
+    description: -|
+      Connection to the remote GMSL endpoint are modelled using the OF graph
+      bindings in accordance with the video interface bindings defined in
+      Documentation/devicetree/bindings/media/video-interfaces.txt.
+
+      The device node contains a single "port" child node with a single
+      "endpoint" sub-device.
+
+    properties:
+      endpoint:
+        type: object
+        additionalProperties: false
+
+        properties:
+          remote-endpoint:
+            description: -|
+              phandle to the remote GMSL endpoint sub-node in the remote node
+              port.
+            maxItems: 1
+
+        required:
+          - remote-endpoint
+
+    required:
+      - endpoint
+
+required:
+  - compatible
+  - reg
+  - port
+
+examples:
+  - |
+    i2c@e66d8000 {
+      #address-cells = <1>;
+      #size-cells = <0>;
+
+      reg = <0 0xe66d8000 0 0x40>;
+
+      camera@31 {
+        compatible = "imi,rdacm20";
+        reg = <0x31>, <0x41>, <0x51>;
+
+        port {
+          rdacm20_out0: endpoint {
+            remote-endpoint = <&max9286_in0>;
+          };
+        };
+      };
+    };
+
+  - |
+    i2c@e66d8000 {
+      #address-cells = <1>;
+      #size-cells = <0>;
+
+      reg = <0 0xe66d8000 0 0x40>;
+
+      camera@31 {
+        compatible = "imi,rdacm21";
+        reg = <0x31>, <0x41>;
+
+        port {
+          rdacm21_out0: endpoint {
+            remote-endpoint = <&max9286_in0>;
+          };
+        };
+      };
+    };
diff --git a/Documentation/devicetree/bindings/vendor-prefixes.yaml b/Documentation/devicetree/bindings/vendor-prefixes.yaml
index d3891386d671..f0f09a4c23ad 100644
--- a/Documentation/devicetree/bindings/vendor-prefixes.yaml
+++ b/Documentation/devicetree/bindings/vendor-prefixes.yaml
@@ -455,6 +455,8 @@ patternProperties:
     description: ILI Technology Corporation (ILITEK)
   "^img,.*":
     description: Imagination Technologies Ltd.
+  "^imi,.*":
+    description: Integrated Micro-Electronics Inc.
   "^incircuit,.*":
     description: In-Circuit GmbH
   "^inet-tek,.*":
-- 
2.25.1

[PATCH v9 4/4] media: i2c: Add RDACM20 driver

[Kieran Bingham]

From: Jacopo Mondi <jacopo+renesas@jmondi.org>

The RDACM20 is a GMSL camera supporting 1280x800 resolution images
developed by IMI based on an Omnivision 10635 sensor and a Maxim MAX9271
GMSL serializer.

The GMSL link carries power, control (I2C) and video data over a
single coax cable.

Signed-off-by: Jacopo Mondi <jacopo+renesas@jmondi.org>
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Signed-off-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
Reviewed-by: Rob Herring <robh@kernel.org>

---
v2:
 - Fix MAINTAINERS entry

v3:
 - Use new V4L2_MBUS_CSI2_DPHY bus type
 - Remove 'always zero' error print
 - Fix module description

v5:
 - use sleep rather than busy loops for 10 ms delays
 - Return ov10635_set_regs directly
 - Use devm_kzalloc instead of kzalloc in probe()
 - Or in the flags: dev->sd.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE
 - Ensure v4l2_ctrl_handler_free() is called
 - rdacm20_probe converted to use .probe_new and drop i2c device id
   tables
 - Remove rdacm20_g_mbus_config

v7:
 - Use new i2c_new_dummy_device API

v8:
 - Almost a new version, main changes are:
   - Split max9271 out
   - Rework bindings to yaml format and include forthcoming RDACM21
   - Remove unecessary header file
   - Add pixel rate calculation
   - Drop unused fields and dead code
   - Rebase on media-master v5.7-rc1
   - A detailed list of changes provided as fixup patches is avilable at
     git://jmondi.org/linux #gmsl/jmondi/media-master/max9286-v8+old-rdacm20+split

     which includes the following list of patches:
    	 squash!: rdacm20: Report pixel rate
	 squash!: rdacm20: Force sensor ID re-read
	 squash!: rdamc20: Check register programming result
	 squash!: rdacm20: Update to use the new max9271 APIs
	 squash!: rdacm20: Start with serial link disabled
	 squash!: rdacm20: Hard reset the sensor
	 squash!: rdacm20: Cache i2c addresses
	 squash!: rdacm20: Adjust to use new max9271 API
	 squash!: rdacm20: Drop unused format definition
	 squash!: rdacm20: Refresh file header
	 squash!: max9271: Add two functions to control addresses
	 squash!: max9271: Do not rewrite i2c address
	 squash!: max9271: Improve gpio handling
	 squash!: max9271: Rework core functions
	 squash!: max9271 refresh
	 squash!: rdacm20: Update maintainers file
	 squash!: rdacm20: Remove unsued/duplicated defines
	 squash!: rdacm20: Remove header file
	 squash!: rdacm20: Move content of  header into C file
	 squash!: rdacm20: Reorganize register table
	 squash!: rdacm20: Fix subdevice flag creation
	 squash!: rdacm20: Drop i2c id table
	 squash!: rdacm20: Release control handler
	 squash!: rdacm20: Better handle i2c dummy error
	 squash!: rdacm20: Use devm_kzalloc
	 squash!: rdacm20: Use probe_new()
	 squash!: rdacm20: Drop deprecated g_mbus_config
	 media: i2c: rdacm20: Break max9271 out from rdacm20
	 squash!: rdacm20: Rebase on latest media/maste
	 media: i2c: Add RDACM20 driver
	 dt-bindings: media: i2c: Add bindings for IMI RDACM2x

v9:
- Drop OV10635_FORMAT and use MEDIA_BUS_FMT_UYVY8_2X8 as suggested by
  Hans

 MAINTAINERS                 |  12 +
 drivers/media/i2c/Kconfig   |  13 +
 drivers/media/i2c/Makefile  |   2 +
 drivers/media/i2c/max9271.c | 341 ++++++++++++++++++
 drivers/media/i2c/max9271.h | 224 ++++++++++++
 drivers/media/i2c/rdacm20.c | 667 ++++++++++++++++++++++++++++++++++++
 6 files changed, 1259 insertions(+)
 create mode 100644 drivers/media/i2c/max9271.c
 create mode 100644 drivers/media/i2c/max9271.h
 create mode 100644 drivers/media/i2c/rdacm20.c

diff --git a/MAINTAINERS b/MAINTAINERS
index 99e3bf7760fd..713b56652181 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -14206,6 +14206,18 @@ S:	Supported
 T:	git git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu.git dev
 F:	tools/testing/selftests/rcutorture
 
+RDACM20 Camera Sensor
+M:	Jacopo Mondi <jacopo+renesas@jmondi.org>
+M:	Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
+M:	Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
+M:	Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
+L:	linux-media@vger.kernel.org
+S:	Maintained
+F:	Documentation/devicetree/bindings/media/i2c/imi,rdacm2x-gmsl.yaml
+F:	drivers/media/i2c/rdacm20.c
+F:	drivers/media/i2c/max9271.c
+F:	drivers/media/i2c/max9271.h
+
 RDC R-321X SoC
 M:	Florian Fainelli <florian@openwrt.org>
 S:	Maintained
diff --git a/drivers/media/i2c/Kconfig b/drivers/media/i2c/Kconfig
index 2e390f41f6da..6e3300760c7f 100644
--- a/drivers/media/i2c/Kconfig
+++ b/drivers/media/i2c/Kconfig
@@ -1157,6 +1157,19 @@ config VIDEO_NOON010PC30
 
 source "drivers/media/i2c/m5mols/Kconfig"
 
+config VIDEO_RDACM20
+	tristate "IMI RDACM20 camera support"
+	depends on I2C
+	select V4L2_FWNODE
+	select VIDEO_V4L2_SUBDEV_API
+	select MEDIA_CONTROLLER
+	help
+	  This driver supports the IMI RDACM20 GMSL camera, used in
+	  ADAS systems.
+
+	  This camera should be used in conjunction with a GMSL
+	  deserialiser such as the MAX9286.
+
 config VIDEO_RJ54N1
 	tristate "Sharp RJ54N1CB0C sensor support"
 	depends on I2C && VIDEO_V4L2
diff --git a/drivers/media/i2c/Makefile b/drivers/media/i2c/Makefile
index f0b001ee4b05..64e6df50f68c 100644
--- a/drivers/media/i2c/Makefile
+++ b/drivers/media/i2c/Makefile
@@ -118,6 +118,8 @@ obj-$(CONFIG_VIDEO_IMX290)	+= imx290.o
 obj-$(CONFIG_VIDEO_IMX319)	+= imx319.o
 obj-$(CONFIG_VIDEO_IMX355)	+= imx355.o
 obj-$(CONFIG_VIDEO_MAX9286)	+= max9286.o
+rdacm20-camera_module-objs	:= rdacm20.o max9271.o
+obj-$(CONFIG_VIDEO_RDACM20)	+= rdacm20-camera_module.o
 obj-$(CONFIG_VIDEO_ST_MIPID02) += st-mipid02.o
 
 obj-$(CONFIG_SDR_MAX2175) += max2175.o
diff --git a/drivers/media/i2c/max9271.c b/drivers/media/i2c/max9271.c
new file mode 100644
index 000000000000..0f6f7a092a46
--- /dev/null
+++ b/drivers/media/i2c/max9271.c
@@ -0,0 +1,341 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2017-2020 Jacopo Mondi
+ * Copyright (C) 2017-2020 Kieran Bingham
+ * Copyright (C) 2017-2020 Laurent Pinchart
+ * Copyright (C) 2017-2020 Niklas Söderlund
+ * Copyright (C) 2016 Renesas Electronics Corporation
+ * Copyright (C) 2015 Cogent Embedded, Inc.
+ *
+ * This file exports functions to control the Maxim MAX9271 GMSL serializer
+ * chip. This is not a self-contained driver, as MAX9271 is usually embedded in
+ * camera modules with at least one image sensor and optional additional
+ * components, such as uController units or ISPs/DSPs.
+ *
+ * Drivers for the camera modules (i.e. rdacm20/21) are expected to use
+ * functions exported from this library driver to maximize code re-use.
+ */
+
+#include <linux/delay.h>
+#include <linux/i2c.h>
+
+#include "max9271.h"
+
+static int max9271_read(struct max9271_device *dev, u8 reg)
+{
+	int ret;
+
+	dev_dbg(&dev->client->dev, "%s(0x%02x)\n", __func__, reg);
+
+	ret = i2c_smbus_read_byte_data(dev->client, reg);
+	if (ret < 0)
+		dev_dbg(&dev->client->dev,
+			"%s: register 0x%02x read failed (%d)\n",
+			__func__, reg, ret);
+
+	return ret;
+}
+
+static int max9271_write(struct max9271_device *dev, u8 reg, u8 val)
+{
+	int ret;
+
+	dev_dbg(&dev->client->dev, "%s(0x%02x, 0x%02x)\n", __func__, reg, val);
+
+	ret = i2c_smbus_write_byte_data(dev->client, reg, val);
+	if (ret < 0)
+		dev_err(&dev->client->dev,
+			"%s: register 0x%02x write failed (%d)\n",
+			__func__, reg, ret);
+
+	return ret;
+}
+
+/*
+ * max9271_pclk_detect() - Detect valid pixel clock from image sensor
+ *
+ * Wait up to 10ms for a valid pixel clock.
+ *
+ * Returns 0 for success, < 0 for pixel clock not properly detected
+ */
+static int max9271_pclk_detect(struct max9271_device *dev)
+{
+	unsigned int i;
+	int ret;
+
+	for (i = 0; i < 100; i++) {
+		ret = max9271_read(dev, 0x15);
+		if (ret < 0)
+			return ret;
+
+		if (ret & MAX9271_PCLKDET)
+			return 0;
+
+		usleep_range(50, 100);
+	}
+
+	dev_err(&dev->client->dev, "Unable to detect valid pixel clock\n");
+
+	return -EIO;
+}
+
+int max9271_set_serial_link(struct max9271_device *dev, bool enable)
+{
+	int ret;
+	u8 val = MAX9271_REVCCEN | MAX9271_FWDCCEN;
+
+	if (enable) {
+		ret = max9271_pclk_detect(dev);
+		if (ret)
+			return ret;
+
+		val |= MAX9271_SEREN;
+	} else {
+		val |= MAX9271_CLINKEN;
+	}
+
+	/*
+	 * The serializer temporarily disables the reverse control channel for
+	 * 350µs after starting/stopping the forward serial link, but the
+	 * deserializer synchronization time isn't clearly documented.
+	 *
+	 * According to the serializer datasheet we should wait 3ms, while
+	 * according to the deserializer datasheet we should wait 5ms.
+	 *
+	 * Short delays here appear to show bit-errors in the writes following.
+	 * Therefore a conservative delay seems best here.
+	 */
+	max9271_write(dev, 0x04, val);
+	usleep_range(5000, 8000);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(max9271_set_serial_link);
+
+int max9271_configure_i2c(struct max9271_device *dev, u8 i2c_config)
+{
+	int ret;
+
+	ret = max9271_write(dev, 0x0d, i2c_config);
+	if (ret)
+		return ret;
+
+	/* The delay required after an I2C bus configuration change is not
+	 * characterized in the serializer manual. Sleep up to 5msec to
+	 * stay safe.
+	 */
+	usleep_range(3500, 5000);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(max9271_configure_i2c);
+
+int max9271_set_high_threshold(struct max9271_device *dev, bool enable)
+{
+	int ret;
+
+	ret = max9271_read(dev, 0x08);
+	if (ret < 0)
+		return ret;
+
+	/*
+	 * Enable or disable reverse channel high threshold to increase
+	 * immunity to power supply noise.
+	 */
+	max9271_write(dev, 0x08, enable ? ret | BIT(0) : ret & ~BIT(0));
+	usleep_range(2000, 2500);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(max9271_set_high_threshold);
+
+int max9271_configure_gmsl_link(struct max9271_device *dev)
+{
+	/*
+	 * Configure the GMSL link:
+	 *
+	 * - Double input mode, high data rate, 24-bit mode
+	 * - Latch input data on PCLKIN rising edge
+	 * - Enable HS/VS encoding
+	 * - 1-bit parity error detection
+	 *
+	 * TODO: Make the GMSL link configuration parametric.
+	 */
+	max9271_write(dev, 0x07, MAX9271_DBL | MAX9271_HVEN |
+		      MAX9271_EDC_1BIT_PARITY);
+	usleep_range(5000, 8000);
+
+	/*
+	 * Adjust spread spectrum to +4% and auto-detect pixel clock
+	 * and serial link rate.
+	 */
+	max9271_write(dev, 0x02, MAX9271_SPREAD_SPECT_4 | MAX9271_R02_RES |
+		      MAX9271_PCLK_AUTODETECT | MAX9271_SERIAL_AUTODETECT);
+	usleep_range(5000, 8000);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(max9271_configure_gmsl_link);
+
+int max9271_set_gpios(struct max9271_device *dev, u8 gpio_mask)
+{
+	int ret;
+
+	ret = max9271_read(dev, 0x0f);
+	if (ret < 0)
+		return 0;
+
+	ret |= gpio_mask;
+	ret = max9271_write(dev, 0x0f, ret);
+	if (ret < 0) {
+		dev_err(&dev->client->dev, "Failed to set gpio (%d)\n", ret);
+		return ret;
+	}
+
+	usleep_range(3500, 5000);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(max9271_set_gpios);
+
+int max9271_clear_gpios(struct max9271_device *dev, u8 gpio_mask)
+{
+	int ret;
+
+	ret = max9271_read(dev, 0x0f);
+	if (ret < 0)
+		return 0;
+
+	ret &= ~gpio_mask;
+	ret = max9271_write(dev, 0x0f, ret);
+	if (ret < 0) {
+		dev_err(&dev->client->dev, "Failed to clear gpio (%d)\n", ret);
+		return ret;
+	}
+
+	usleep_range(3500, 5000);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(max9271_clear_gpios);
+
+int max9271_enable_gpios(struct max9271_device *dev, u8 gpio_mask)
+{
+	int ret;
+
+	ret = max9271_read(dev, 0x0f);
+	if (ret < 0)
+		return 0;
+
+	/* BIT(0) reserved: GPO is always enabled. */
+	ret |= gpio_mask | BIT(0);
+	ret = max9271_write(dev, 0x0e, ret);
+	if (ret < 0) {
+		dev_err(&dev->client->dev, "Failed to enable gpio (%d)\n", ret);
+		return ret;
+	}
+
+	usleep_range(3500, 5000);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(max9271_enable_gpios);
+
+int max9271_disable_gpios(struct max9271_device *dev, u8 gpio_mask)
+{
+	int ret;
+
+	ret = max9271_read(dev, 0x0f);
+	if (ret < 0)
+		return 0;
+
+	/* BIT(0) reserved: GPO cannot be disabled */
+	ret &= (~gpio_mask | BIT(0));
+	ret = max9271_write(dev, 0x0e, ret);
+	if (ret < 0) {
+		dev_err(&dev->client->dev, "Failed to disable gpio (%d)\n", ret);
+		return ret;
+	}
+
+	usleep_range(3500, 5000);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(max9271_disable_gpios);
+
+int max9271_verify_id(struct max9271_device *dev)
+{
+	int ret;
+
+	ret = max9271_read(dev, 0x1e);
+	if (ret < 0) {
+		dev_err(&dev->client->dev, "MAX9271 ID read failed (%d)\n",
+			ret);
+		return ret;
+	}
+
+	if (ret != MAX9271_ID) {
+		dev_err(&dev->client->dev, "MAX9271 ID mismatch (0x%02x)\n",
+			ret);
+		return -ENXIO;
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(max9271_verify_id);
+
+int max9271_set_address(struct max9271_device *dev, u8 addr)
+{
+	int ret;
+
+	ret = max9271_write(dev, 0x00, addr << 1);
+	if (ret < 0) {
+		dev_err(&dev->client->dev,
+			"MAX9271 I2C address change failed (%d)\n", ret);
+		return ret;
+	}
+	usleep_range(3500, 5000);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(max9271_set_address);
+
+int max9271_set_deserializer_address(struct max9271_device *dev, u8 addr)
+{
+	int ret;
+
+	ret = max9271_write(dev, 0x01, addr << 1);
+	if (ret < 0) {
+		dev_err(&dev->client->dev,
+			"MAX9271 deserializer address set failed (%d)\n", ret);
+		return ret;
+	}
+	usleep_range(3500, 5000);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(max9271_set_deserializer_address);
+
+int max9271_set_translation(struct max9271_device *dev, u8 source, u8 dest)
+{
+	int ret;
+
+	ret = max9271_write(dev, 0x09, source << 1);
+	if (ret < 0) {
+		dev_err(&dev->client->dev,
+			"MAX9271 I2C translation setup failed (%d)\n", ret);
+		return ret;
+	}
+	usleep_range(3500, 5000);
+
+	ret = max9271_write(dev, 0x0a, dest << 1);
+	if (ret < 0) {
+		dev_err(&dev->client->dev,
+			"MAX9271 I2C translation setup failed (%d)\n", ret);
+		return ret;
+	}
+	usleep_range(3500, 5000);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(max9271_set_translation);
diff --git a/drivers/media/i2c/max9271.h b/drivers/media/i2c/max9271.h
new file mode 100644
index 000000000000..d78fb21441e9
--- /dev/null
+++ b/drivers/media/i2c/max9271.h
@@ -0,0 +1,224 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * Copyright (C) 2017-2020 Jacopo Mondi
+ * Copyright (C) 2017-2020 Kieran Bingham
+ * Copyright (C) 2017-2020 Laurent Pinchart
+ * Copyright (C) 2017-2020 Niklas Söderlund
+ * Copyright (C) 2016 Renesas Electronics Corporation
+ * Copyright (C) 2015 Cogent Embedded, Inc.
+ */
+
+#include <linux/i2c.h>
+
+#define MAX9271_DEFAULT_ADDR	0x40
+
+/* Register 0x02 */
+#define MAX9271_SPREAD_SPECT_0		(0 << 5)
+#define MAX9271_SPREAD_SPECT_05		(1 << 5)
+#define MAX9271_SPREAD_SPECT_15		(2 << 5)
+#define MAX9271_SPREAD_SPECT_1		(5 << 5)
+#define MAX9271_SPREAD_SPECT_2		(3 << 5)
+#define MAX9271_SPREAD_SPECT_3		(6 << 5)
+#define MAX9271_SPREAD_SPECT_4		(7 << 5)
+#define MAX9271_R02_RES			BIT(4)
+#define MAX9271_PCLK_AUTODETECT		(3 << 2)
+#define MAX9271_SERIAL_AUTODETECT	(0x03)
+/* Register 0x04 */
+#define MAX9271_SEREN			BIT(7)
+#define MAX9271_CLINKEN			BIT(6)
+#define MAX9271_PRBSEN			BIT(5)
+#define MAX9271_SLEEP			BIT(4)
+#define MAX9271_INTTYPE_I2C		(0 << 2)
+#define MAX9271_INTTYPE_UART		(1 << 2)
+#define MAX9271_INTTYPE_NONE		(2 << 2)
+#define MAX9271_REVCCEN			BIT(1)
+#define MAX9271_FWDCCEN			BIT(0)
+/* Register 0x07 */
+#define MAX9271_DBL			BIT(7)
+#define MAX9271_DRS			BIT(6)
+#define MAX9271_BWS			BIT(5)
+#define MAX9271_ES			BIT(4)
+#define MAX9271_HVEN			BIT(2)
+#define MAX9271_EDC_1BIT_PARITY		(0 << 0)
+#define MAX9271_EDC_6BIT_CRC		(1 << 0)
+#define MAX9271_EDC_6BIT_HAMMING	(2 << 0)
+/* Register 0x08 */
+#define MAX9271_INVVS			BIT(7)
+#define MAX9271_INVHS			BIT(6)
+#define MAX9271_REV_LOGAIN		BIT(3)
+#define MAX9271_REV_HIVTH		BIT(0)
+/* Register 0x09 */
+#define MAX9271_ID			0x09
+/* Register 0x0d */
+#define MAX9271_I2CLOCACK		BIT(7)
+#define MAX9271_I2CSLVSH_1046NS_469NS	(3 << 5)
+#define MAX9271_I2CSLVSH_938NS_352NS	(2 << 5)
+#define MAX9271_I2CSLVSH_469NS_234NS	(1 << 5)
+#define MAX9271_I2CSLVSH_352NS_117NS	(0 << 5)
+#define MAX9271_I2CMSTBT_837KBPS	(7 << 2)
+#define MAX9271_I2CMSTBT_533KBPS	(6 << 2)
+#define MAX9271_I2CMSTBT_339KBPS	(5 << 2)
+#define MAX9271_I2CMSTBT_173KBPS	(4 << 2)
+#define MAX9271_I2CMSTBT_105KBPS	(3 << 2)
+#define MAX9271_I2CMSTBT_84KBPS		(2 << 2)
+#define MAX9271_I2CMSTBT_28KBPS		(1 << 2)
+#define MAX9271_I2CMSTBT_8KBPS		(0 << 2)
+#define MAX9271_I2CSLVTO_NONE		(3 << 0)
+#define MAX9271_I2CSLVTO_1024US		(2 << 0)
+#define MAX9271_I2CSLVTO_256US		(1 << 0)
+#define MAX9271_I2CSLVTO_64US		(0 << 0)
+/* Register 0x0f */
+#define MAX9271_GPIO5OUT		BIT(5)
+#define MAX9271_GPIO4OUT		BIT(4)
+#define MAX9271_GPIO3OUT		BIT(3)
+#define MAX9271_GPIO2OUT		BIT(2)
+#define MAX9271_GPIO1OUT		BIT(1)
+#define MAX9271_GPO			BIT(0)
+/* Register 0x15 */
+#define MAX9271_PCLKDET			BIT(0)
+
+/**
+ * struct max9271_device - max9271 device
+ * @client: The i2c client for the max9271 instance
+ */
+struct max9271_device {
+	struct i2c_client *client;
+};
+
+/**
+ * max9271_set_serial_link() - Enable/disable serial link
+ * @dev: The max9271 device
+ * @enable: Serial link enable/disable flag
+ *
+ * Return 0 on success or a negative error code on failure
+ */
+int max9271_set_serial_link(struct max9271_device *dev, bool enable);
+
+/**
+ * max9271_configure_i2c() - Configure I2C bus parameters
+ * @dev: The max9271 device
+ * @i2c_config: The I2C bus configuration bit mask
+ *
+ * Configure MAX9271 I2C interface. The bus configuration provided in the
+ * @i2c_config parameter shall be assembled using bit values defined by the
+ * MAX9271_I2C* macros.
+ *
+ * Return 0 on success or a negative error code on failure
+ */
+int max9271_configure_i2c(struct max9271_device *dev, u8 i2c_config);
+
+/**
+ * max9271_set_high_threshold() - Enable or disable reverse channel high
+ *				  threshold
+ * @dev: The max9271 device
+ * @enable: High threshold enable/disable flag
+ *
+ * Return 0 on success or a negative error code on failure
+ */
+int max9271_set_high_threshold(struct max9271_device *dev, bool enable);
+
+/**
+ * max9271_configure_gmsl_link() - Configure the GMSL link
+ * @dev: The max9271 device
+ *
+ * FIXME: the GMSL link configuration is currently hardcoded and performed
+ * by programming registers 0x04, 0x07 and 0x02.
+ *
+ * Return 0 on success or a negative error code on failure
+ */
+int max9271_configure_gmsl_link(struct max9271_device *dev);
+
+/**
+ * max9271_set_gpios() - Set gpio lines to physical high value
+ * @dev: The max9271 device
+ * @gpio_mask: The mask of gpio lines to set to high value
+ *
+ * The @gpio_mask parameter shall be assembled using the MAX9271_GP[IO|O]*
+ * bit values.
+ *
+ * Return 0 on success or a negative error code on failure
+ */
+int max9271_set_gpios(struct max9271_device *dev, u8 gpio_mask);
+
+/**
+ * max9271_clear_gpios() - Set gpio lines to physical low value
+ * @dev: The max9271 device
+ * @gpio_mask: The mask of gpio lines to set to low value
+ *
+ * The @gpio_mask parameter shall be assembled using the MAX9271_GP[IO|O]*
+ * bit values.
+ *
+ * Return 0 on success or a negative error code on failure
+ */
+int max9271_clear_gpios(struct max9271_device *dev, u8 gpio_mask);
+
+/**
+ * max9271_enable_gpios() - Enable gpio lines
+ * @dev: The max9271 device
+ * @gpio_mask: The mask of gpio lines to enable
+ *
+ * The @gpio_mask parameter shall be assembled using the MAX9271_GPIO*
+ * bit values. GPO line is always enabled by default.
+ *
+ * Return 0 on success or a negative error code on failure
+ */
+int max9271_enable_gpios(struct max9271_device *dev, u8 gpio_mask);
+
+/**
+ * max9271_disable_gpios() - Disable gpio lines
+ * @dev: The max9271 device
+ * @gpio_mask: The mask of gpio lines to disable
+ *
+ * The @gpio_mask parameter shall be assembled using the MAX9271_GPIO*
+ * bit values. GPO line is always enabled by default and cannot be disabled.
+ *
+ * Return 0 on success or a negative error code on failure
+ */
+int max9271_disable_gpios(struct max9271_device *dev, u8 gpio_mask);
+
+/**
+ * max9271_verify_id() - Read and verify MAX9271 id
+ * @dev: The max9271 device
+ *
+ * Return 0 on success or a negative error code on failure
+ */
+int max9271_verify_id(struct max9271_device *dev);
+
+/**
+ * max9271_set_address() - Program a new I2C address
+ * @dev: The max9271 device
+ * @addr: The new I2C address in 7-bit format
+ *
+ * This function only takes care of programming the new I2C address @addr to
+ * in the MAX9271 chip registers, it is responsiblity of the caller to set
+ * the i2c address client to the @addr value to be able to communicate with
+ * the MAX9271 chip using the I2C framework APIs after this function returns.
+ *
+ * Return 0 on success or a negative error code on failure
+ */
+int max9271_set_address(struct max9271_device *dev, u8 addr);
+
+/**
+ * max9271_set_deserializer_address() - Program the remote deserializer address
+ * @dev: The max9271 device
+ * @addr: The deserializer I2C address in 7-bit format
+ *
+ * Return 0 on success or a negative error code on failure
+ */
+int max9271_set_deserializer_address(struct max9271_device *dev, u8 addr);
+
+/**
+ * max9271_set_translation() - Program I2C address translation
+ * @dev: The max9271 device
+ * @source: The I2C source address
+ * @dest: The I2C destination address
+ *
+ * Program address translation from @source to @dest. This is required to
+ * communicate with local devices that do not support address reprogramming.
+ *
+ * TODO: The device supports translation of two address, this function currently
+ * supports a single one.
+ *
+ * Return 0 on success or a negative error code on failure
+ */
+int max9271_set_translation(struct max9271_device *dev, u8 source, u8 dest);
diff --git a/drivers/media/i2c/rdacm20.c b/drivers/media/i2c/rdacm20.c
new file mode 100644
index 000000000000..cda3e6372ea9
--- /dev/null
+++ b/drivers/media/i2c/rdacm20.c
@@ -0,0 +1,667 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * IMI RDACM20 GMSL Camera Driver
+ *
+ * Copyright (C) 2017-2020 Jacopo Mondi
+ * Copyright (C) 2017-2020 Kieran Bingham
+ * Copyright (C) 2017-2019 Laurent Pinchart
+ * Copyright (C) 2017-2019 Niklas Söderlund
+ * Copyright (C) 2016 Renesas Electronics Corporation
+ * Copyright (C) 2015 Cogent Embedded, Inc.
+ */
+
+/*
+ * The camera is made of an Omnivision OV10635 sensor connected to a Maxim
+ * MAX9271 GMSL serializer.
+ */
+
+#include <linux/delay.h>
+#include <linux/fwnode.h>
+#include <linux/init.h>
+#include <linux/i2c.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/videodev2.h>
+
+#include <media/v4l2-async.h>
+#include <media/v4l2-ctrls.h>
+#include <media/v4l2-subdev.h>
+
+#include "max9271.h"
+
+#define OV10635_I2C_ADDRESS		0x30
+
+#define OV10635_SOFTWARE_RESET		0x0103
+#define OV10635_PID			0x300a
+#define OV10635_VER			0x300b
+#define OV10635_SC_CMMN_SCCB_ID		0x300c
+#define OV10635_SC_CMMN_SCCB_ID_SELECT	BIT(0)
+#define OV10635_VERSION			0xa635
+
+#define OV10635_WIDTH			1280
+#define OV10635_HEIGHT			800
+
+/* VTS = PCLK / FPS / HTS / 2 (= 88MHz / 1572 / 30 / 2) */
+#define OV10635_HTS			1572
+/* FPS = 29,9998 */
+#define OV10635_VTS			933
+
+/*
+ * As the drivers supports a single MEDIA_BUS_FMT_UYVY8_2X8 format we
+ * can harcode the pixel rate.
+ *
+ * PCLK is fed through the system clock, programmed @88MHz.
+ * MEDIA_BUS_FMT_UYVY8_2X8 format = 2 samples per pixel.
+ *
+ * Pixelrate = PCLK / 2
+ * FPS = (OV10635_VTS * OV10635_HTS) / PixelRate
+ *     = 29,9998
+ */
+#define OV10635_PIXEL_RATE		(44000000)
+
+static const struct ov10635_reg {
+	u16	reg;
+	u8	val;
+} ov10635_regs_wizard[] = {
+	{ 0x301b, 0xff }, { 0x301c, 0xff }, { 0x301a, 0xff }, { 0x3011, 0x42 },
+	{ 0x6900, 0x0c }, { 0x6901, 0x19 }, { 0x3503, 0x10 }, { 0x3025, 0x03 },
+	{ 0x3003, 0x16 }, { 0x3004, 0x30 }, { 0x3005, 0x40 }, { 0x3006, 0x91 },
+	{ 0x3600, 0x74 }, { 0x3601, 0x2b }, { 0x3612, 0x00 }, { 0x3611, 0x67 },
+	{ 0x3633, 0xca }, { 0x3602, 0xaf }, { 0x3603, 0x04 }, { 0x3630, 0x28 },
+	{ 0x3631, 0x16 }, { 0x3714, 0x10 }, { 0x371d, 0x01 }, { 0x4300, 0x3a },
+	{ 0x3007, 0x01 }, { 0x3024, 0x03 }, { 0x3020, 0x0a }, { 0x3702, 0x0d },
+	{ 0x3703, 0x20 }, { 0x3704, 0x15 }, { 0x3709, 0xa8 }, { 0x370c, 0xc7 },
+	{ 0x370d, 0x80 }, { 0x3712, 0x00 }, { 0x3713, 0x20 }, { 0x3715, 0x04 },
+	{ 0x381d, 0x40 }, { 0x381c, 0x00 }, { 0x3822, 0x50 }, { 0x3824, 0x10 },
+	{ 0x3815, 0x8c }, { 0x3804, 0x05 }, { 0x3805, 0x1f }, { 0x3800, 0x00 },
+	{ 0x3801, 0x00 }, { 0x3806, 0x03 }, { 0x3807, 0x28 }, { 0x3802, 0x00 },
+	{ 0x3803, 0x07 }, { 0x3808, 0x05 }, { 0x3809, 0x00 }, { 0x380a, 0x03 },
+	{ 0x380b, 0x20 }, { 0x380c, OV10635_HTS >> 8 },
+	{ 0x380d, OV10635_HTS & 0xff }, { 0x380e, OV10635_VTS >> 8 },
+	{ 0x380f, OV10635_VTS & 0xff },	{ 0x3813, 0x02 }, { 0x3811, 0x08 },
+	{ 0x381f, 0x0c }, { 0x3819, 0x04 }, { 0x3804, 0x01 }, { 0x3805, 0x00 },
+	{ 0x3828, 0x03 }, { 0x3829, 0x10 }, { 0x382a, 0x10 }, { 0x3621, 0x63 },
+	{ 0x5005, 0x08 }, { 0x56d5, 0x00 }, { 0x56d6, 0x80 }, { 0x56d7, 0x00 },
+	{ 0x56d8, 0x00 }, { 0x56d9, 0x00 }, { 0x56da, 0x80 }, { 0x56db, 0x00 },
+	{ 0x56dc, 0x00 }, { 0x56e8, 0x00 }, { 0x56e9, 0x7f }, { 0x56ea, 0x00 },
+	{ 0x56eb, 0x7f }, { 0x5100, 0x00 }, { 0x5101, 0x80 }, { 0x5102, 0x00 },
+	{ 0x5103, 0x80 }, { 0x5104, 0x00 }, { 0x5105, 0x80 }, { 0x5106, 0x00 },
+	{ 0x5107, 0x80 }, { 0x5108, 0x00 }, { 0x5109, 0x00 }, { 0x510a, 0x00 },
+	{ 0x510b, 0x00 }, { 0x510c, 0x00 }, { 0x510d, 0x00 }, { 0x510e, 0x00 },
+	{ 0x510f, 0x00 }, { 0x5110, 0x00 }, { 0x5111, 0x80 }, { 0x5112, 0x00 },
+	{ 0x5113, 0x80 }, { 0x5114, 0x00 }, { 0x5115, 0x80 }, { 0x5116, 0x00 },
+	{ 0x5117, 0x80 }, { 0x5118, 0x00 }, { 0x5119, 0x00 }, { 0x511a, 0x00 },
+	{ 0x511b, 0x00 }, { 0x511c, 0x00 }, { 0x511d, 0x00 }, { 0x511e, 0x00 },
+	{ 0x511f, 0x00 }, { 0x56d0, 0x00 }, { 0x5006, 0x04 }, { 0x5608, 0x05 },
+	{ 0x52d7, 0x06 }, { 0x528d, 0x08 }, { 0x5293, 0x12 }, { 0x52d3, 0x12 },
+	{ 0x5288, 0x06 }, { 0x5289, 0x20 }, { 0x52c8, 0x06 }, { 0x52c9, 0x20 },
+	{ 0x52cd, 0x04 }, { 0x5381, 0x00 }, { 0x5382, 0xff }, { 0x5589, 0x76 },
+	{ 0x558a, 0x47 }, { 0x558b, 0xef }, { 0x558c, 0xc9 }, { 0x558d, 0x49 },
+	{ 0x558e, 0x30 }, { 0x558f, 0x67 }, { 0x5590, 0x3f }, { 0x5591, 0xf0 },
+	{ 0x5592, 0x10 }, { 0x55a2, 0x6d }, { 0x55a3, 0x55 }, { 0x55a4, 0xc3 },
+	{ 0x55a5, 0xb5 }, { 0x55a6, 0x43 }, { 0x55a7, 0x38 }, { 0x55a8, 0x5f },
+	{ 0x55a9, 0x4b }, { 0x55aa, 0xf0 }, { 0x55ab, 0x10 }, { 0x5581, 0x52 },
+	{ 0x5300, 0x01 }, { 0x5301, 0x00 }, { 0x5302, 0x00 }, { 0x5303, 0x0e },
+	{ 0x5304, 0x00 }, { 0x5305, 0x0e }, { 0x5306, 0x00 }, { 0x5307, 0x36 },
+	{ 0x5308, 0x00 }, { 0x5309, 0xd9 }, { 0x530a, 0x00 }, { 0x530b, 0x0f },
+	{ 0x530c, 0x00 }, { 0x530d, 0x2c }, { 0x530e, 0x00 }, { 0x530f, 0x59 },
+	{ 0x5310, 0x00 }, { 0x5311, 0x7b }, { 0x5312, 0x00 }, { 0x5313, 0x22 },
+	{ 0x5314, 0x00 }, { 0x5315, 0xd5 }, { 0x5316, 0x00 }, { 0x5317, 0x13 },
+	{ 0x5318, 0x00 }, { 0x5319, 0x18 }, { 0x531a, 0x00 }, { 0x531b, 0x26 },
+	{ 0x531c, 0x00 }, { 0x531d, 0xdc }, { 0x531e, 0x00 }, { 0x531f, 0x02 },
+	{ 0x5320, 0x00 }, { 0x5321, 0x24 }, { 0x5322, 0x00 }, { 0x5323, 0x56 },
+	{ 0x5324, 0x00 }, { 0x5325, 0x85 }, { 0x5326, 0x00 }, { 0x5327, 0x20 },
+	{ 0x5609, 0x01 }, { 0x560a, 0x40 }, { 0x560b, 0x01 }, { 0x560c, 0x40 },
+	{ 0x560d, 0x00 }, { 0x560e, 0xfa }, { 0x560f, 0x00 }, { 0x5610, 0xfa },
+	{ 0x5611, 0x02 }, { 0x5612, 0x80 }, { 0x5613, 0x02 }, { 0x5614, 0x80 },
+	{ 0x5615, 0x01 }, { 0x5616, 0x2c }, { 0x5617, 0x01 }, { 0x5618, 0x2c },
+	{ 0x563b, 0x01 }, { 0x563c, 0x01 }, { 0x563d, 0x01 }, { 0x563e, 0x01 },
+	{ 0x563f, 0x03 }, { 0x5640, 0x03 }, { 0x5641, 0x03 }, { 0x5642, 0x05 },
+	{ 0x5643, 0x09 }, { 0x5644, 0x05 }, { 0x5645, 0x05 }, { 0x5646, 0x05 },
+	{ 0x5647, 0x05 }, { 0x5651, 0x00 }, { 0x5652, 0x80 }, { 0x521a, 0x01 },
+	{ 0x521b, 0x03 }, { 0x521c, 0x06 }, { 0x521d, 0x0a }, { 0x521e, 0x0e },
+	{ 0x521f, 0x12 }, { 0x5220, 0x16 }, { 0x5223, 0x02 }, { 0x5225, 0x04 },
+	{ 0x5227, 0x08 }, { 0x5229, 0x0c }, { 0x522b, 0x12 }, { 0x522d, 0x18 },
+	{ 0x522f, 0x1e }, { 0x5241, 0x04 }, { 0x5242, 0x01 }, { 0x5243, 0x03 },
+	{ 0x5244, 0x06 }, { 0x5245, 0x0a }, { 0x5246, 0x0e }, { 0x5247, 0x12 },
+	{ 0x5248, 0x16 }, { 0x524a, 0x03 }, { 0x524c, 0x04 }, { 0x524e, 0x08 },
+	{ 0x5250, 0x0c }, { 0x5252, 0x12 }, { 0x5254, 0x18 }, { 0x5256, 0x1e },
+	/* fifo_line_length = 2*hts */
+	{ 0x4606, (2 * OV10635_HTS) >> 8 }, { 0x4607, (2 * OV10635_HTS) & 0xff },
+	/* fifo_hsync_start = 2*(hts - xres) */
+	{ 0x460a, (2 * (OV10635_HTS - OV10635_WIDTH)) >> 8 },
+	{ 0x460b, (2 * (OV10635_HTS - OV10635_WIDTH)) & 0xff },
+	{ 0x460c, 0x00 }, { 0x4620, 0x0e },
+	/* BT601: 0x08 is also acceptable as HS/VS mode */
+	{ 0x4700, 0x04 }, { 0x4701, 0x00 }, { 0x4702, 0x01 }, { 0x4004, 0x04 },
+	{ 0x4005, 0x18 }, { 0x4001, 0x06 }, { 0x4050, 0x22 }, { 0x4051, 0x24 },
+	{ 0x4052, 0x02 }, { 0x4057, 0x9c }, { 0x405a, 0x00 }, { 0x4202, 0x02 },
+	{ 0x3023, 0x10 }, { 0x0100, 0x01 }, { 0x0100, 0x01 }, { 0x6f10, 0x07 },
+	{ 0x6f11, 0x82 }, { 0x6f12, 0x04 }, { 0x6f13, 0x00 }, { 0xd000, 0x19 },
+	{ 0xd001, 0xa0 }, { 0xd002, 0x00 }, { 0xd003, 0x01 }, { 0xd004, 0xa9 },
+	{ 0xd005, 0xad }, { 0xd006, 0x10 }, { 0xd007, 0x40 }, { 0xd008, 0x44 },
+	{ 0xd009, 0x00 }, { 0xd00a, 0x68 }, { 0xd00b, 0x00 }, { 0xd00c, 0x15 },
+	{ 0xd00d, 0x00 }, { 0xd00e, 0x00 }, { 0xd00f, 0x00 }, { 0xd040, 0x9c },
+	{ 0xd041, 0x21 }, { 0xd042, 0xff }, { 0xd043, 0xf8 }, { 0xd044, 0xd4 },
+	{ 0xd045, 0x01 }, { 0xd046, 0x48 }, { 0xd047, 0x00 }, { 0xd048, 0xd4 },
+	{ 0xd049, 0x01 }, { 0xd04a, 0x50 }, { 0xd04b, 0x04 }, { 0xd04c, 0x18 },
+	{ 0xd04d, 0x60 }, { 0xd04e, 0x00 }, { 0xd04f, 0x01 }, { 0xd050, 0xa8 },
+	{ 0xd051, 0x63 }, { 0xd052, 0x02 }, { 0xd053, 0xa4 }, { 0xd054, 0x85 },
+	{ 0xd055, 0x43 }, { 0xd056, 0x00 }, { 0xd057, 0x00 }, { 0xd058, 0x18 },
+	{ 0xd059, 0x60 }, { 0xd05a, 0x00 }, { 0xd05b, 0x01 }, { 0xd05c, 0xa8 },
+	{ 0xd05d, 0x63 }, { 0xd05e, 0x03 }, { 0xd05f, 0xf0 }, { 0xd060, 0x98 },
+	{ 0xd061, 0xa3 }, { 0xd062, 0x00 }, { 0xd063, 0x00 }, { 0xd064, 0x8c },
+	{ 0xd065, 0x6a }, { 0xd066, 0x00 }, { 0xd067, 0x6e }, { 0xd068, 0xe5 },
+	{ 0xd069, 0x85 }, { 0xd06a, 0x18 }, { 0xd06b, 0x00 }, { 0xd06c, 0x10 },
+	{ 0xd06d, 0x00 }, { 0xd06e, 0x00 }, { 0xd06f, 0x10 }, { 0xd070, 0x9c },
+	{ 0xd071, 0x80 }, { 0xd072, 0x00 }, { 0xd073, 0x03 }, { 0xd074, 0x18 },
+	{ 0xd075, 0x60 }, { 0xd076, 0x00 }, { 0xd077, 0x01 }, { 0xd078, 0xa8 },
+	{ 0xd079, 0x63 }, { 0xd07a, 0x07 }, { 0xd07b, 0x80 }, { 0xd07c, 0x07 },
+	{ 0xd07d, 0xff }, { 0xd07e, 0xf9 }, { 0xd07f, 0x03 }, { 0xd080, 0x8c },
+	{ 0xd081, 0x63 }, { 0xd082, 0x00 }, { 0xd083, 0x00 }, { 0xd084, 0xa5 },
+	{ 0xd085, 0x6b }, { 0xd086, 0x00 }, { 0xd087, 0xff }, { 0xd088, 0x18 },
+	{ 0xd089, 0x80 }, { 0xd08a, 0x00 }, { 0xd08b, 0x01 }, { 0xd08c, 0xa8 },
+	{ 0xd08d, 0x84 }, { 0xd08e, 0x01 }, { 0xd08f, 0x04 }, { 0xd090, 0xe1 },
+	{ 0xd091, 0x6b }, { 0xd092, 0x58 }, { 0xd093, 0x00 }, { 0xd094, 0x94 },
+	{ 0xd095, 0x6a }, { 0xd096, 0x00 }, { 0xd097, 0x70 }, { 0xd098, 0xe1 },
+	{ 0xd099, 0x6b }, { 0xd09a, 0x20 }, { 0xd09b, 0x00 }, { 0xd09c, 0x95 },
+	{ 0xd09d, 0x6b }, { 0xd09e, 0x00 }, { 0xd09f, 0x00 }, { 0xd0a0, 0xe4 },
+	{ 0xd0a1, 0x8b }, { 0xd0a2, 0x18 }, { 0xd0a3, 0x00 }, { 0xd0a4, 0x0c },
+	{ 0xd0a5, 0x00 }, { 0xd0a6, 0x00 }, { 0xd0a7, 0x23 }, { 0xd0a8, 0x15 },
+	{ 0xd0a9, 0x00 }, { 0xd0aa, 0x00 }, { 0xd0ab, 0x00 }, { 0xd0ac, 0x18 },
+	{ 0xd0ad, 0x60 }, { 0xd0ae, 0x80 }, { 0xd0af, 0x06 }, { 0xd0b0, 0xa8 },
+	{ 0xd0b1, 0x83 }, { 0xd0b2, 0x40 }, { 0xd0b3, 0x08 }, { 0xd0b4, 0xa8 },
+	{ 0xd0b5, 0xe3 }, { 0xd0b6, 0x38 }, { 0xd0b7, 0x2a }, { 0xd0b8, 0xa8 },
+	{ 0xd0b9, 0xc3 }, { 0xd0ba, 0x40 }, { 0xd0bb, 0x09 }, { 0xd0bc, 0xa8 },
+	{ 0xd0bd, 0xa3 }, { 0xd0be, 0x38 }, { 0xd0bf, 0x29 }, { 0xd0c0, 0x8c },
+	{ 0xd0c1, 0x65 }, { 0xd0c2, 0x00 }, { 0xd0c3, 0x00 }, { 0xd0c4, 0xd8 },
+	{ 0xd0c5, 0x04 }, { 0xd0c6, 0x18 }, { 0xd0c7, 0x00 }, { 0xd0c8, 0x8c },
+	{ 0xd0c9, 0x67 }, { 0xd0ca, 0x00 }, { 0xd0cb, 0x00 }, { 0xd0cc, 0xd8 },
+	{ 0xd0cd, 0x06 }, { 0xd0ce, 0x18 }, { 0xd0cf, 0x00 }, { 0xd0d0, 0x18 },
+	{ 0xd0d1, 0x60 }, { 0xd0d2, 0x80 }, { 0xd0d3, 0x06 }, { 0xd0d4, 0xa8 },
+	{ 0xd0d5, 0xe3 }, { 0xd0d6, 0x67 }, { 0xd0d7, 0x02 }, { 0xd0d8, 0xa9 },
+	{ 0xd0d9, 0x03 }, { 0xd0da, 0x67 }, { 0xd0db, 0x03 }, { 0xd0dc, 0xa8 },
+	{ 0xd0dd, 0xc3 }, { 0xd0de, 0x3d }, { 0xd0df, 0x05 }, { 0xd0e0, 0x8c },
+	{ 0xd0e1, 0x66 }, { 0xd0e2, 0x00 }, { 0xd0e3, 0x00 }, { 0xd0e4, 0xb8 },
+	{ 0xd0e5, 0x63 }, { 0xd0e6, 0x00 }, { 0xd0e7, 0x18 }, { 0xd0e8, 0xb8 },
+	{ 0xd0e9, 0x63 }, { 0xd0ea, 0x00 }, { 0xd0eb, 0x98 }, { 0xd0ec, 0xbc },
+	{ 0xd0ed, 0x03 }, { 0xd0ee, 0x00 }, { 0xd0ef, 0x00 }, { 0xd0f0, 0x10 },
+	{ 0xd0f1, 0x00 }, { 0xd0f2, 0x00 }, { 0xd0f3, 0x16 }, { 0xd0f4, 0xb8 },
+	{ 0xd0f5, 0x83 }, { 0xd0f6, 0x00 }, { 0xd0f7, 0x19 }, { 0xd0f8, 0x8c },
+	{ 0xd0f9, 0x67 }, { 0xd0fa, 0x00 }, { 0xd0fb, 0x00 }, { 0xd0fc, 0xb8 },
+	{ 0xd0fd, 0xa4 }, { 0xd0fe, 0x00 }, { 0xd0ff, 0x98 }, { 0xd100, 0xb8 },
+	{ 0xd101, 0x83 }, { 0xd102, 0x00 }, { 0xd103, 0x08 }, { 0xd104, 0x8c },
+	{ 0xd105, 0x68 }, { 0xd106, 0x00 }, { 0xd107, 0x00 }, { 0xd108, 0xe0 },
+	{ 0xd109, 0x63 }, { 0xd10a, 0x20 }, { 0xd10b, 0x04 }, { 0xd10c, 0xe0 },
+	{ 0xd10d, 0x65 }, { 0xd10e, 0x18 }, { 0xd10f, 0x00 }, { 0xd110, 0xa4 },
+	{ 0xd111, 0x83 }, { 0xd112, 0xff }, { 0xd113, 0xff }, { 0xd114, 0xb8 },
+	{ 0xd115, 0x64 }, { 0xd116, 0x00 }, { 0xd117, 0x48 }, { 0xd118, 0xd8 },
+	{ 0xd119, 0x07 }, { 0xd11a, 0x18 }, { 0xd11b, 0x00 }, { 0xd11c, 0xd8 },
+	{ 0xd11d, 0x08 }, { 0xd11e, 0x20 }, { 0xd11f, 0x00 }, { 0xd120, 0x9c },
+	{ 0xd121, 0x60 }, { 0xd122, 0x00 }, { 0xd123, 0x00 }, { 0xd124, 0xd8 },
+	{ 0xd125, 0x06 }, { 0xd126, 0x18 }, { 0xd127, 0x00 }, { 0xd128, 0x00 },
+	{ 0xd129, 0x00 }, { 0xd12a, 0x00 }, { 0xd12b, 0x08 }, { 0xd12c, 0x15 },
+	{ 0xd12d, 0x00 }, { 0xd12e, 0x00 }, { 0xd12f, 0x00 }, { 0xd130, 0x8c },
+	{ 0xd131, 0x6a }, { 0xd132, 0x00 }, { 0xd133, 0x76 }, { 0xd134, 0xbc },
+	{ 0xd135, 0x23 }, { 0xd136, 0x00 }, { 0xd137, 0x00 }, { 0xd138, 0x13 },
+	{ 0xd139, 0xff }, { 0xd13a, 0xff }, { 0xd13b, 0xe6 }, { 0xd13c, 0x18 },
+	{ 0xd13d, 0x60 }, { 0xd13e, 0x80 }, { 0xd13f, 0x06 }, { 0xd140, 0x03 },
+	{ 0xd141, 0xff }, { 0xd142, 0xff }, { 0xd143, 0xdd }, { 0xd144, 0xa8 },
+	{ 0xd145, 0x83 }, { 0xd146, 0x40 }, { 0xd147, 0x08 }, { 0xd148, 0x85 },
+	{ 0xd149, 0x21 }, { 0xd14a, 0x00 }, { 0xd14b, 0x00 }, { 0xd14c, 0x85 },
+	{ 0xd14d, 0x41 }, { 0xd14e, 0x00 }, { 0xd14f, 0x04 }, { 0xd150, 0x44 },
+	{ 0xd151, 0x00 }, { 0xd152, 0x48 }, { 0xd153, 0x00 }, { 0xd154, 0x9c },
+	{ 0xd155, 0x21 }, { 0xd156, 0x00 }, { 0xd157, 0x08 }, { 0x6f0e, 0x03 },
+	{ 0x6f0f, 0x00 }, { 0x460e, 0x08 }, { 0x460f, 0x01 }, { 0x4610, 0x00 },
+	{ 0x4611, 0x01 }, { 0x4612, 0x00 }, { 0x4613, 0x01 },
+	/* 8 bits */
+	{ 0x4605, 0x08 },
+	/* Swap data bits order [9:0] -> [0:9] */
+	{ 0x4709, 0x10 }, { 0x4608, 0x00 }, { 0x4609, 0x08 }, { 0x6804, 0x00 },
+	{ 0x6805, 0x06 }, { 0x6806, 0x00 }, { 0x5120, 0x00 }, { 0x3510, 0x00 },
+	{ 0x3504, 0x00 }, { 0x6800, 0x00 }, { 0x6f0d, 0x01 },
+	/* PCLK falling edge */
+	{ 0x4708, 0x01 }, { 0x5000, 0xff }, { 0x5001, 0xbf }, { 0x5002, 0x7e },
+	{ 0x503d, 0x00 }, { 0xc450, 0x01 }, { 0xc452, 0x04 }, { 0xc453, 0x00 },
+	{ 0xc454, 0x00 }, { 0xc455, 0x01 }, { 0xc456, 0x01 }, { 0xc457, 0x00 },
+	{ 0xc458, 0x00 }, { 0xc459, 0x00 }, { 0xc45b, 0x00 }, { 0xc45c, 0x01 },
+	{ 0xc45d, 0x00 }, { 0xc45e, 0x00 }, { 0xc45f, 0x00 }, { 0xc460, 0x00 },
+	{ 0xc461, 0x01 }, { 0xc462, 0x01 }, { 0xc464, 0x03 }, { 0xc465, 0x00 },
+	{ 0xc466, 0x8a }, { 0xc467, 0x00 }, { 0xc468, 0x86 }, { 0xc469, 0x00 },
+	{ 0xc46a, 0x40 }, { 0xc46b, 0x50 }, { 0xc46c, 0x30 }, { 0xc46d, 0x28 },
+	{ 0xc46e, 0x60 }, { 0xc46f, 0x40 }, { 0xc47c, 0x01 }, { 0xc47d, 0x38 },
+	{ 0xc47e, 0x00 }, { 0xc47f, 0x00 }, { 0xc480, 0x00 }, { 0xc481, 0xff },
+	{ 0xc482, 0x00 }, { 0xc483, 0x40 }, { 0xc484, 0x00 }, { 0xc485, 0x18 },
+	{ 0xc486, 0x00 }, { 0xc487, 0x18 },
+	{ 0xc488, (OV10635_VTS - 8) * 16 >> 8},
+	{ 0xc489, (OV10635_VTS - 8) * 16 & 0xff},
+	{ 0xc48a, (OV10635_VTS - 8) * 16 >> 8},
+	{ 0xc48b, (OV10635_VTS - 8) * 16 & 0xff}, { 0xc48c, 0x00 },
+	{ 0xc48d, 0x04 }, { 0xc48e, 0x00 }, { 0xc48f, 0x04 }, { 0xc490, 0x03 },
+	{ 0xc492, 0x20 }, { 0xc493, 0x08 }, { 0xc498, 0x02 }, { 0xc499, 0x00 },
+	{ 0xc49a, 0x02 }, { 0xc49b, 0x00 }, { 0xc49c, 0x02 }, { 0xc49d, 0x00 },
+	{ 0xc49e, 0x02 }, { 0xc49f, 0x60 }, { 0xc4a0, 0x03 }, { 0xc4a1, 0x00 },
+	{ 0xc4a2, 0x04 }, { 0xc4a3, 0x00 }, { 0xc4a4, 0x00 }, { 0xc4a5, 0x10 },
+	{ 0xc4a6, 0x00 }, { 0xc4a7, 0x40 }, { 0xc4a8, 0x00 }, { 0xc4a9, 0x80 },
+	{ 0xc4aa, 0x0d }, { 0xc4ab, 0x00 }, { 0xc4ac, 0x0f }, { 0xc4ad, 0xc0 },
+	{ 0xc4b4, 0x01 }, { 0xc4b5, 0x01 }, { 0xc4b6, 0x00 }, { 0xc4b7, 0x01 },
+	{ 0xc4b8, 0x00 }, { 0xc4b9, 0x01 }, { 0xc4ba, 0x01 }, { 0xc4bb, 0x00 },
+	{ 0xc4bc, 0x01 }, { 0xc4bd, 0x60 }, { 0xc4be, 0x02 }, { 0xc4bf, 0x33 },
+	{ 0xc4c8, 0x03 }, { 0xc4c9, 0xd0 }, { 0xc4ca, 0x0e }, { 0xc4cb, 0x00 },
+	{ 0xc4cc, 0x0e }, { 0xc4cd, 0x51 }, { 0xc4ce, 0x0e }, { 0xc4cf, 0x51 },
+	{ 0xc4d0, 0x04 }, { 0xc4d1, 0x80 }, { 0xc4e0, 0x04 }, { 0xc4e1, 0x02 },
+	{ 0xc4e2, 0x01 }, { 0xc4e4, 0x10 }, { 0xc4e5, 0x20 }, { 0xc4e6, 0x30 },
+	{ 0xc4e7, 0x40 }, { 0xc4e8, 0x50 }, { 0xc4e9, 0x60 }, { 0xc4ea, 0x70 },
+	{ 0xc4eb, 0x80 }, { 0xc4ec, 0x90 }, { 0xc4ed, 0xa0 }, { 0xc4ee, 0xb0 },
+	{ 0xc4ef, 0xc0 }, { 0xc4f0, 0xd0 }, { 0xc4f1, 0xe0 }, { 0xc4f2, 0xf0 },
+	{ 0xc4f3, 0x80 }, { 0xc4f4, 0x00 }, { 0xc4f5, 0x20 }, { 0xc4f6, 0x02 },
+	{ 0xc4f7, 0x00 }, { 0xc4f8, 0x00 }, { 0xc4f9, 0x00 }, { 0xc4fa, 0x00 },
+	{ 0xc4fb, 0x01 }, { 0xc4fc, 0x01 }, { 0xc4fd, 0x00 }, { 0xc4fe, 0x04 },
+	{ 0xc4ff, 0x02 }, { 0xc500, 0x48 }, { 0xc501, 0x74 }, { 0xc502, 0x58 },
+	{ 0xc503, 0x80 }, { 0xc504, 0x05 }, { 0xc505, 0x80 }, { 0xc506, 0x03 },
+	{ 0xc507, 0x80 }, { 0xc508, 0x01 }, { 0xc509, 0xc0 }, { 0xc50a, 0x01 },
+	{ 0xc50b, 0xa0 }, { 0xc50c, 0x01 }, { 0xc50d, 0x2c }, { 0xc50e, 0x01 },
+	{ 0xc50f, 0x0a }, { 0xc510, 0x00 }, { 0xc511, 0x00 }, { 0xc512, 0xe5 },
+	{ 0xc513, 0x14 }, { 0xc514, 0x04 }, { 0xc515, 0x00 }, { 0xc518, OV10635_VTS >> 8},
+	{ 0xc519, OV10635_VTS & 0xff}, { 0xc51a, OV10635_HTS >> 8},
+	{ 0xc51b, OV10635_HTS & 0xff}, { 0xc2e0, 0x00 }, { 0xc2e1, 0x51 },
+	{ 0xc2e2, 0x00 }, { 0xc2e3, 0xd6 }, { 0xc2e4, 0x01 }, { 0xc2e5, 0x5e },
+	{ 0xc2e9, 0x01 }, { 0xc2ea, 0x7a }, { 0xc2eb, 0x90 }, { 0xc2ed, 0x00 },
+	{ 0xc2ee, 0x7a }, { 0xc2ef, 0x64 }, { 0xc308, 0x00 }, { 0xc309, 0x00 },
+	{ 0xc30a, 0x00 }, { 0xc30c, 0x00 }, { 0xc30d, 0x01 }, { 0xc30e, 0x00 },
+	{ 0xc30f, 0x00 }, { 0xc310, 0x01 }, { 0xc311, 0x60 }, { 0xc312, 0xff },
+	{ 0xc313, 0x08 }, { 0xc314, 0x01 }, { 0xc315, 0x00 }, { 0xc316, 0xff },
+	{ 0xc317, 0x0b }, { 0xc318, 0x00 }, { 0xc319, 0x0c }, { 0xc31a, 0x00 },
+	{ 0xc31b, 0xe0 }, { 0xc31c, 0x00 }, { 0xc31d, 0x14 }, { 0xc31e, 0x00 },
+	{ 0xc31f, 0xc5 }, { 0xc320, 0xff }, { 0xc321, 0x4b }, { 0xc322, 0xff },
+	{ 0xc323, 0xf0 }, { 0xc324, 0xff }, { 0xc325, 0xe8 }, { 0xc326, 0x00 },
+	{ 0xc327, 0x46 }, { 0xc328, 0xff }, { 0xc329, 0xd2 }, { 0xc32a, 0xff },
+	{ 0xc32b, 0xe4 }, { 0xc32c, 0xff }, { 0xc32d, 0xbb }, { 0xc32e, 0x00 },
+	{ 0xc32f, 0x61 }, { 0xc330, 0xff }, { 0xc331, 0xf9 }, { 0xc332, 0x00 },
+	{ 0xc333, 0xd9 }, { 0xc334, 0x00 }, { 0xc335, 0x2e }, { 0xc336, 0x00 },
+	{ 0xc337, 0xb1 }, { 0xc338, 0xff }, { 0xc339, 0x64 }, { 0xc33a, 0xff },
+	{ 0xc33b, 0xeb }, { 0xc33c, 0xff }, { 0xc33d, 0xe8 }, { 0xc33e, 0x00 },
+	{ 0xc33f, 0x48 }, { 0xc340, 0xff }, { 0xc341, 0xd0 }, { 0xc342, 0xff },
+	{ 0xc343, 0xed }, { 0xc344, 0xff }, { 0xc345, 0xad }, { 0xc346, 0x00 },
+	{ 0xc347, 0x66 }, { 0xc348, 0x01 }, { 0xc349, 0x00 }, { 0x6700, 0x04 },
+	{ 0x6701, 0x7b }, { 0x6702, 0xfd }, { 0x6703, 0xf9 }, { 0x6704, 0x3d },
+	{ 0x6705, 0x71 }, { 0x6706, 0x78 }, { 0x6708, 0x05 }, { 0x6f06, 0x6f },
+	{ 0x6f07, 0x00 }, { 0x6f0a, 0x6f }, { 0x6f0b, 0x00 }, { 0x6f00, 0x03 },
+	{ 0xc34c, 0x01 }, { 0xc34d, 0x00 }, { 0xc34e, 0x46 }, { 0xc34f, 0x55 },
+	{ 0xc350, 0x00 }, { 0xc351, 0x40 }, { 0xc352, 0x00 }, { 0xc353, 0xff },
+	{ 0xc354, 0x04 }, { 0xc355, 0x08 }, { 0xc356, 0x01 }, { 0xc357, 0xef },
+	{ 0xc358, 0x30 }, { 0xc359, 0x01 }, { 0xc35a, 0x64 }, { 0xc35b, 0x46 },
+	{ 0xc35c, 0x00 }, { 0x3042, 0xf0 }, { 0x3042, 0xf0 }, { 0x3042, 0xf0 },
+	{ 0x3042, 0xf0 }, { 0x3042, 0xf0 }, { 0x3042, 0xf0 }, { 0x3042, 0xf0 },
+	{ 0x3042, 0xf0 }, { 0x3042, 0xf0 }, { 0x3042, 0xf0 }, { 0x3042, 0xf0 },
+	{ 0x3042, 0xf0 }, { 0x3042, 0xf0 }, { 0x3042, 0xf0 }, { 0x3042, 0xf0 },
+	{ 0x3042, 0xf0 }, { 0x3042, 0xf0 }, { 0x3042, 0xf0 }, { 0x3042, 0xf0 },
+	{ 0x3042, 0xf0 }, { 0x3042, 0xf0 }, { 0x3042, 0xf0 }, { 0x3042, 0xf0 },
+	{ 0x3042, 0xf0 }, { 0x3042, 0xf0 }, { 0x3042, 0xf0 }, { 0xc261, 0x01 },
+	{ 0x301b, 0xf0 }, { 0x301c, 0xf0 }, { 0x301a, 0xf0 }, { 0x6f00, 0xc3 },
+	{ 0xc46a, 0x30 }, { 0xc46d, 0x20 }, { 0xc464, 0x84 }, { 0xc465, 0x00 },
+	{ 0x6f00, 0x03 }, { 0x6f00, 0x43 }, { 0x381c, 0x00 }, { 0x381d, 0x40 },
+	{ 0xc454, 0x01 }, { 0x6f00, 0xc3 }, { 0xc454, 0x00 }, { 0xc4b1, 0x02 },
+	{ 0xc4b2, 0x01 }, { 0xc4b3, 0x03 }, { 0x6f00, 0x03 }, { 0x6f00, 0x43 },
+	/* enable FSIN (FRAMESYNC input) functionality */
+	{ 0x3832, (0x0d + 2 * 0x20 + 0x15 + 38) >> 8 },
+	{ 0x3833, (0x0d + 2 * 0x20 + 0x15 + 38) & 0xff },
+	{ 0x3834, OV10635_VTS >> 8 }, { 0x3835, OV10635_VTS & 0xff },
+	{ 0x302e, 0x01 },
+};
+
+struct rdacm20_device {
+	struct device			*dev;
+	struct max9271_device		*serializer;
+	struct i2c_client		*sensor;
+	struct v4l2_subdev		sd;
+	struct media_pad		pad;
+	struct v4l2_ctrl_handler	ctrls;
+	u32				addrs[2];
+};
+
+static inline struct rdacm20_device *sd_to_rdacm20(struct v4l2_subdev *sd)
+{
+	return container_of(sd, struct rdacm20_device, sd);
+}
+
+static inline struct rdacm20_device *i2c_to_rdacm20(struct i2c_client *client)
+{
+	return sd_to_rdacm20(i2c_get_clientdata(client));
+}
+
+static int ov10635_read16(struct rdacm20_device *dev, u16 reg)
+{
+	u8 buf[2] = { reg >> 8, reg & 0xff };
+	int ret;
+
+	ret = i2c_master_send(dev->sensor, buf, 2);
+	if (ret != 2) {
+		dev_dbg(dev->dev, "%s: register 0x%04x write failed (%d)\n",
+			__func__, reg, ret);
+		return ret;
+	}
+
+	ret = i2c_master_recv(dev->sensor, buf, 2);
+	if (ret < 0) {
+		dev_dbg(dev->dev, "%s: register 0x%04x read failed (%d)\n",
+			__func__, reg, ret);
+		return ret;
+	}
+
+	return (buf[0] << 8) | buf[1];
+}
+
+static int __ov10635_write(struct rdacm20_device *dev, u16 reg, u8 val)
+{
+	u8 buf[3] = { reg >> 8, reg & 0xff, val };
+	int ret;
+
+	dev_dbg(dev->dev, "%s(0x%04x, 0x%02x)\n", __func__, reg, val);
+
+	ret = i2c_master_send(dev->sensor, buf, 3);
+	return ret < 0 ? ret : 0;
+}
+
+static int ov10635_write(struct rdacm20_device *dev, u16 reg, u8 val)
+{
+	int ret;
+
+	ret = __ov10635_write(dev, reg, val);
+	if (ret < 0)
+		dev_err(dev->dev, "%s: register 0x%04x write failed (%d)\n",
+			__func__, reg, ret);
+
+	return ret;
+}
+
+static int ov10635_set_regs(struct rdacm20_device *dev,
+			    const struct ov10635_reg *regs,
+			    unsigned int nr_regs)
+{
+	unsigned int i;
+	int ret;
+
+	for (i = 0; i < nr_regs; i++) {
+		ret = __ov10635_write(dev, regs[i].reg, regs[i].val);
+		if (ret) {
+			dev_err(dev->dev,
+				"%s: register %u (0x%04x) write failed (%d)\n",
+				__func__, i, regs[i].reg, ret);
+			return ret;
+		}
+	}
+
+	return 0;
+}
+
+static int rdacm20_s_stream(struct v4l2_subdev *sd, int enable)
+{
+	struct rdacm20_device *dev = sd_to_rdacm20(sd);
+
+	return max9271_set_serial_link(dev->serializer, enable);
+}
+
+static int rdacm20_enum_mbus_code(struct v4l2_subdev *sd,
+				  struct v4l2_subdev_pad_config *cfg,
+				  struct v4l2_subdev_mbus_code_enum *code)
+{
+	if (code->pad || code->index > 0)
+		return -EINVAL;
+
+	code->code = MEDIA_BUS_FMT_UYVY8_2X8;
+
+	return 0;
+}
+
+static int rdacm20_get_fmt(struct v4l2_subdev *sd,
+			   struct v4l2_subdev_pad_config *cfg,
+			   struct v4l2_subdev_format *format)
+{
+	struct v4l2_mbus_framefmt *mf = &format->format;
+
+	if (format->pad)
+		return -EINVAL;
+
+	mf->width		= OV10635_WIDTH;
+	mf->height		= OV10635_HEIGHT;
+	mf->code		= MEDIA_BUS_FMT_UYVY8_2X8;
+	mf->colorspace		= V4L2_COLORSPACE_RAW;
+	mf->field		= V4L2_FIELD_NONE;
+	mf->ycbcr_enc		= V4L2_YCBCR_ENC_601;
+	mf->quantization	= V4L2_QUANTIZATION_FULL_RANGE;
+	mf->xfer_func		= V4L2_XFER_FUNC_NONE;
+
+	return 0;
+}
+
+static struct v4l2_subdev_video_ops rdacm20_video_ops = {
+	.s_stream	= rdacm20_s_stream,
+};
+
+static const struct v4l2_subdev_pad_ops rdacm20_subdev_pad_ops = {
+	.enum_mbus_code = rdacm20_enum_mbus_code,
+	.get_fmt	= rdacm20_get_fmt,
+	.set_fmt	= rdacm20_get_fmt,
+};
+
+static struct v4l2_subdev_ops rdacm20_subdev_ops = {
+	.video		= &rdacm20_video_ops,
+	.pad		= &rdacm20_subdev_pad_ops,
+};
+
+static int rdacm20_initialize(struct rdacm20_device *dev)
+{
+	unsigned int retry = 3;
+	int ret;
+
+	/* Verify communication with the MAX9271: ping to wakeup. */
+	dev->serializer->client->addr = MAX9271_DEFAULT_ADDR;
+	i2c_smbus_read_byte(dev->serializer->client);
+
+	/* Serial link disabled during config as it needs a valid pixel clock. */
+	ret = max9271_set_serial_link(dev->serializer, false);
+	if (ret)
+		return ret;
+
+	/*
+	 *  Ensure that we have a good link configuration before attempting to
+	 *  identify the device.
+	 */
+	max9271_configure_i2c(dev->serializer, MAX9271_I2CSLVSH_469NS_234NS |
+					       MAX9271_I2CSLVTO_1024US |
+					       MAX9271_I2CMSTBT_105KBPS);
+
+	max9271_configure_gmsl_link(dev->serializer);
+
+	ret = max9271_verify_id(dev->serializer);
+	if (ret < 0)
+		return ret;
+
+	ret = max9271_set_address(dev->serializer, dev->addrs[0]);
+	if (ret < 0)
+		return ret;
+	dev->serializer->client->addr = dev->addrs[0];
+
+	/*
+	 * Reset the sensor by cycling the OV10635 reset signal connected to the
+	 * MAX9271 GPIO1 and verify communication with the OV10635.
+	 */
+	max9271_clear_gpios(dev->serializer, MAX9271_GPIO1OUT);
+	mdelay(10);
+	max9271_set_gpios(dev->serializer, MAX9271_GPIO1OUT);
+	mdelay(10);
+
+again:
+	ret = ov10635_read16(dev, OV10635_PID);
+	if (ret < 0) {
+		if (retry--)
+			goto again;
+
+		dev_err(dev->dev, "OV10635 ID read failed (%d)\n",
+			ret);
+		return -ENXIO;
+	}
+
+	if (ret != OV10635_VERSION) {
+		if (retry--)
+			goto again;
+
+		dev_err(dev->dev, "OV10635 ID mismatch (0x%04x)\n",
+			ret);
+		return -ENXIO;
+	}
+
+	/* Change the sensor I2C address. */
+	ret = ov10635_write(dev, OV10635_SC_CMMN_SCCB_ID,
+			    (dev->addrs[1] << 1) |
+			    OV10635_SC_CMMN_SCCB_ID_SELECT);
+	if (ret < 0) {
+		dev_err(dev->dev,
+			"OV10635 I2C address change failed (%d)\n", ret);
+		return ret;
+	}
+	dev->sensor->addr = dev->addrs[1];
+	usleep_range(3500, 5000);
+
+	/* Program the 0V10635 initial configuration. */
+	ret = ov10635_set_regs(dev, ov10635_regs_wizard,
+			       ARRAY_SIZE(ov10635_regs_wizard));
+	if (ret)
+		return ret;
+
+	dev_info(dev->dev, "Identified MAX9271 + OV10635 device\n");
+
+	return 0;
+}
+
+static int rdacm20_probe(struct i2c_client *client)
+{
+	struct rdacm20_device *dev;
+	struct fwnode_handle *ep;
+	int ret;
+
+	dev = devm_kzalloc(&client->dev, sizeof(*dev), GFP_KERNEL);
+	if (!dev)
+		return -ENOMEM;
+	dev->dev = &client->dev;
+
+	dev->serializer = devm_kzalloc(&client->dev, sizeof(*dev->serializer),
+				       GFP_KERNEL);
+	if (!dev->serializer)
+		return -ENOMEM;
+
+	dev->serializer->client = client;
+
+	ret = of_property_read_u32_array(client->dev.of_node, "reg",
+					 dev->addrs, 2);
+	if (ret < 0) {
+		dev_err(dev->dev, "Invalid DT reg property: %d\n", ret);
+		return -EINVAL;
+	}
+
+	/* Create the dummy I2C client for the sensor. */
+	dev->sensor = i2c_new_dummy_device(client->adapter,
+					   OV10635_I2C_ADDRESS);
+	if (IS_ERR(dev->sensor)) {
+		ret = PTR_ERR(dev->sensor);
+		goto error;
+	}
+
+	/* Initialize the hardware. */
+	ret = rdacm20_initialize(dev);
+	if (ret < 0)
+		goto error;
+
+	/* Initialize and register the subdevice. */
+	v4l2_i2c_subdev_init(&dev->sd, client, &rdacm20_subdev_ops);
+	dev->sd.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;
+
+	v4l2_ctrl_handler_init(&dev->ctrls, 1);
+	v4l2_ctrl_new_std(&dev->ctrls, NULL, V4L2_CID_PIXEL_RATE,
+			  OV10635_PIXEL_RATE, OV10635_PIXEL_RATE, 1,
+			  OV10635_PIXEL_RATE);
+	dev->sd.ctrl_handler = &dev->ctrls;
+
+	ret = dev->ctrls.error;
+	if (ret)
+		goto error_free_ctrls;
+
+	dev->pad.flags = MEDIA_PAD_FL_SOURCE;
+	dev->sd.entity.flags |= MEDIA_ENT_F_CAM_SENSOR;
+	ret = media_entity_pads_init(&dev->sd.entity, 1, &dev->pad);
+	if (ret < 0)
+		goto error_free_ctrls;
+
+	ep = fwnode_graph_get_next_endpoint(dev_fwnode(&client->dev), NULL);
+	if (!ep) {
+		dev_err(&client->dev,
+			"Unable to get endpoint in node %pOF\n",
+			client->dev.of_node);
+		ret = -ENOENT;
+		goto error_free_ctrls;
+	}
+	dev->sd.fwnode = ep;
+
+	ret = v4l2_async_register_subdev(&dev->sd);
+	if (ret)
+		goto error_put_node;
+
+	return 0;
+
+error_put_node:
+	fwnode_handle_put(ep);
+error_free_ctrls:
+	v4l2_ctrl_handler_free(&dev->ctrls);
+error:
+	media_entity_cleanup(&dev->sd.entity);
+	if (dev->sensor)
+		i2c_unregister_device(dev->sensor);
+
+	dev_err(&client->dev, "probe failed\n");
+
+	return ret;
+}
+
+static int rdacm20_remove(struct i2c_client *client)
+{
+	struct rdacm20_device *dev = i2c_to_rdacm20(client);
+
+	fwnode_handle_put(dev->sd.fwnode);
+	v4l2_async_unregister_subdev(&dev->sd);
+	v4l2_ctrl_handler_free(&dev->ctrls);
+	media_entity_cleanup(&dev->sd.entity);
+	i2c_unregister_device(dev->sensor);
+
+	return 0;
+}
+
+static void rdacm20_shutdown(struct i2c_client *client)
+{
+	struct rdacm20_device *dev = i2c_to_rdacm20(client);
+
+	/* make sure stream off during shutdown (reset/reboot) */
+	rdacm20_s_stream(&dev->sd, 0);
+}
+
+static const struct of_device_id rdacm20_of_ids[] = {
+	{ .compatible = "imi,rdacm20", },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, rdacm20_of_ids);
+
+static struct i2c_driver rdacm20_i2c_driver = {
+	.driver	= {
+		.name	= "rdacm20",
+		.of_match_table = rdacm20_of_ids,
+	},
+	.probe_new	= rdacm20_probe,
+	.remove		= rdacm20_remove,
+	.shutdown	= rdacm20_shutdown,
+};
+
+module_i2c_driver(rdacm20_i2c_driver);
+
+MODULE_DESCRIPTION("GMSL Camera driver for RDACM20");
+MODULE_AUTHOR("Vladimir Barinov");
+MODULE_LICENSE("GPL");
-- 
2.25.1

Re: [PATCH v9 4/4] media: i2c: Add RDACM20 driver

[Sakari Ailus]

Hi Kieran,

On Tue, May 12, 2020 at 04:51:05PM +0100, Kieran Bingham wrote:
> From: Jacopo Mondi <jacopo+renesas@jmondi.org>
> 
> The RDACM20 is a GMSL camera supporting 1280x800 resolution images
> developed by IMI based on an Omnivision 10635 sensor and a Maxim MAX9271
> GMSL serializer.
> 
> The GMSL link carries power, control (I2C) and video data over a
> single coax cable.
> 
> Signed-off-by: Jacopo Mondi <jacopo+renesas@jmondi.org>
> Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
> Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
> Signed-off-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
> Reviewed-by: Rob Herring <robh@kernel.org>
> 
> ---
> v2:
>  - Fix MAINTAINERS entry
> 
> v3:
>  - Use new V4L2_MBUS_CSI2_DPHY bus type
>  - Remove 'always zero' error print
>  - Fix module description
> 
> v5:
>  - use sleep rather than busy loops for 10 ms delays
>  - Return ov10635_set_regs directly
>  - Use devm_kzalloc instead of kzalloc in probe()
>  - Or in the flags: dev->sd.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE
>  - Ensure v4l2_ctrl_handler_free() is called
>  - rdacm20_probe converted to use .probe_new and drop i2c device id
>    tables
>  - Remove rdacm20_g_mbus_config
> 
> v7:
>  - Use new i2c_new_dummy_device API
> 
> v8:
>  - Almost a new version, main changes are:
>    - Split max9271 out
>    - Rework bindings to yaml format and include forthcoming RDACM21
>    - Remove unecessary header file
>    - Add pixel rate calculation
>    - Drop unused fields and dead code
>    - Rebase on media-master v5.7-rc1
>    - A detailed list of changes provided as fixup patches is avilable at
>      git://jmondi.org/linux #gmsl/jmondi/media-master/max9286-v8+old-rdacm20+split
> 
>      which includes the following list of patches:
>     	 squash!: rdacm20: Report pixel rate
> 	 squash!: rdacm20: Force sensor ID re-read
> 	 squash!: rdamc20: Check register programming result
> 	 squash!: rdacm20: Update to use the new max9271 APIs
> 	 squash!: rdacm20: Start with serial link disabled
> 	 squash!: rdacm20: Hard reset the sensor
> 	 squash!: rdacm20: Cache i2c addresses
> 	 squash!: rdacm20: Adjust to use new max9271 API
> 	 squash!: rdacm20: Drop unused format definition
> 	 squash!: rdacm20: Refresh file header
> 	 squash!: max9271: Add two functions to control addresses
> 	 squash!: max9271: Do not rewrite i2c address
> 	 squash!: max9271: Improve gpio handling
> 	 squash!: max9271: Rework core functions
> 	 squash!: max9271 refresh
> 	 squash!: rdacm20: Update maintainers file
> 	 squash!: rdacm20: Remove unsued/duplicated defines
> 	 squash!: rdacm20: Remove header file
> 	 squash!: rdacm20: Move content of  header into C file
> 	 squash!: rdacm20: Reorganize register table
> 	 squash!: rdacm20: Fix subdevice flag creation
> 	 squash!: rdacm20: Drop i2c id table
> 	 squash!: rdacm20: Release control handler
> 	 squash!: rdacm20: Better handle i2c dummy error
> 	 squash!: rdacm20: Use devm_kzalloc
> 	 squash!: rdacm20: Use probe_new()
> 	 squash!: rdacm20: Drop deprecated g_mbus_config
> 	 media: i2c: rdacm20: Break max9271 out from rdacm20
> 	 squash!: rdacm20: Rebase on latest media/maste
> 	 media: i2c: Add RDACM20 driver
> 	 dt-bindings: media: i2c: Add bindings for IMI RDACM2x
> 
> v9:
> - Drop OV10635_FORMAT and use MEDIA_BUS_FMT_UYVY8_2X8 as suggested by
>   Hans
> 
>  MAINTAINERS                 |  12 +
>  drivers/media/i2c/Kconfig   |  13 +
>  drivers/media/i2c/Makefile  |   2 +
>  drivers/media/i2c/max9271.c | 341 ++++++++++++++++++
>  drivers/media/i2c/max9271.h | 224 ++++++++++++
>  drivers/media/i2c/rdacm20.c | 667 ++++++++++++++++++++++++++++++++++++
>  6 files changed, 1259 insertions(+)
>  create mode 100644 drivers/media/i2c/max9271.c
>  create mode 100644 drivers/media/i2c/max9271.h
>  create mode 100644 drivers/media/i2c/rdacm20.c
> 
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 99e3bf7760fd..713b56652181 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -14206,6 +14206,18 @@ S:	Supported
>  T:	git git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu.git dev
>  F:	tools/testing/selftests/rcutorture
>  
> +RDACM20 Camera Sensor
> +M:	Jacopo Mondi <jacopo+renesas@jmondi.org>
> +M:	Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
> +M:	Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
> +M:	Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
> +L:	linux-media@vger.kernel.org
> +S:	Maintained
> +F:	Documentation/devicetree/bindings/media/i2c/imi,rdacm2x-gmsl.yaml
> +F:	drivers/media/i2c/rdacm20.c
> +F:	drivers/media/i2c/max9271.c
> +F:	drivers/media/i2c/max9271.h
> +
>  RDC R-321X SoC
>  M:	Florian Fainelli <florian@openwrt.org>
>  S:	Maintained
> diff --git a/drivers/media/i2c/Kconfig b/drivers/media/i2c/Kconfig
> index 2e390f41f6da..6e3300760c7f 100644
> --- a/drivers/media/i2c/Kconfig
> +++ b/drivers/media/i2c/Kconfig
> @@ -1157,6 +1157,19 @@ config VIDEO_NOON010PC30
>  
>  source "drivers/media/i2c/m5mols/Kconfig"
>  
> +config VIDEO_RDACM20
> +	tristate "IMI RDACM20 camera support"
> +	depends on I2C
> +	select V4L2_FWNODE
> +	select VIDEO_V4L2_SUBDEV_API
> +	select MEDIA_CONTROLLER
> +	help
> +	  This driver supports the IMI RDACM20 GMSL camera, used in
> +	  ADAS systems.
> +
> +	  This camera should be used in conjunction with a GMSL
> +	  deserialiser such as the MAX9286.
> +
>  config VIDEO_RJ54N1
>  	tristate "Sharp RJ54N1CB0C sensor support"
>  	depends on I2C && VIDEO_V4L2
> diff --git a/drivers/media/i2c/Makefile b/drivers/media/i2c/Makefile
> index f0b001ee4b05..64e6df50f68c 100644
> --- a/drivers/media/i2c/Makefile
> +++ b/drivers/media/i2c/Makefile
> @@ -118,6 +118,8 @@ obj-$(CONFIG_VIDEO_IMX290)	+= imx290.o
>  obj-$(CONFIG_VIDEO_IMX319)	+= imx319.o
>  obj-$(CONFIG_VIDEO_IMX355)	+= imx355.o
>  obj-$(CONFIG_VIDEO_MAX9286)	+= max9286.o
> +rdacm20-camera_module-objs	:= rdacm20.o max9271.o
> +obj-$(CONFIG_VIDEO_RDACM20)	+= rdacm20-camera_module.o
>  obj-$(CONFIG_VIDEO_ST_MIPID02) += st-mipid02.o
>  
>  obj-$(CONFIG_SDR_MAX2175) += max2175.o
> diff --git a/drivers/media/i2c/max9271.c b/drivers/media/i2c/max9271.c
> new file mode 100644
> index 000000000000..0f6f7a092a46
> --- /dev/null
> +++ b/drivers/media/i2c/max9271.c
> @@ -0,0 +1,341 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/*
> + * Copyright (C) 2017-2020 Jacopo Mondi
> + * Copyright (C) 2017-2020 Kieran Bingham
> + * Copyright (C) 2017-2020 Laurent Pinchart
> + * Copyright (C) 2017-2020 Niklas Söderlund
> + * Copyright (C) 2016 Renesas Electronics Corporation
> + * Copyright (C) 2015 Cogent Embedded, Inc.
> + *
> + * This file exports functions to control the Maxim MAX9271 GMSL serializer
> + * chip. This is not a self-contained driver, as MAX9271 is usually embedded in
> + * camera modules with at least one image sensor and optional additional
> + * components, such as uController units or ISPs/DSPs.
> + *
> + * Drivers for the camera modules (i.e. rdacm20/21) are expected to use
> + * functions exported from this library driver to maximize code re-use.
> + */
> +
> +#include <linux/delay.h>
> +#include <linux/i2c.h>
> +
> +#include "max9271.h"
> +
> +static int max9271_read(struct max9271_device *dev, u8 reg)
> +{
> +	int ret;
> +
> +	dev_dbg(&dev->client->dev, "%s(0x%02x)\n", __func__, reg);
> +
> +	ret = i2c_smbus_read_byte_data(dev->client, reg);
> +	if (ret < 0)
> +		dev_dbg(&dev->client->dev,
> +			"%s: register 0x%02x read failed (%d)\n",
> +			__func__, reg, ret);
> +
> +	return ret;
> +}
> +
> +static int max9271_write(struct max9271_device *dev, u8 reg, u8 val)
> +{
> +	int ret;
> +
> +	dev_dbg(&dev->client->dev, "%s(0x%02x, 0x%02x)\n", __func__, reg, val);
> +
> +	ret = i2c_smbus_write_byte_data(dev->client, reg, val);
> +	if (ret < 0)
> +		dev_err(&dev->client->dev,
> +			"%s: register 0x%02x write failed (%d)\n",
> +			__func__, reg, ret);
> +
> +	return ret;
> +}
> +
> +/*
> + * max9271_pclk_detect() - Detect valid pixel clock from image sensor
> + *
> + * Wait up to 10ms for a valid pixel clock.
> + *
> + * Returns 0 for success, < 0 for pixel clock not properly detected
> + */
> +static int max9271_pclk_detect(struct max9271_device *dev)
> +{
> +	unsigned int i;
> +	int ret;
> +
> +	for (i = 0; i < 100; i++) {
> +		ret = max9271_read(dev, 0x15);
> +		if (ret < 0)
> +			return ret;
> +
> +		if (ret & MAX9271_PCLKDET)
> +			return 0;
> +
> +		usleep_range(50, 100);
> +	}
> +
> +	dev_err(&dev->client->dev, "Unable to detect valid pixel clock\n");
> +
> +	return -EIO;
> +}
> +
> +int max9271_set_serial_link(struct max9271_device *dev, bool enable)
> +{
> +	int ret;
> +	u8 val = MAX9271_REVCCEN | MAX9271_FWDCCEN;
> +
> +	if (enable) {
> +		ret = max9271_pclk_detect(dev);
> +		if (ret)
> +			return ret;
> +
> +		val |= MAX9271_SEREN;
> +	} else {
> +		val |= MAX9271_CLINKEN;
> +	}
> +
> +	/*
> +	 * The serializer temporarily disables the reverse control channel for
> +	 * 350µs after starting/stopping the forward serial link, but the
> +	 * deserializer synchronization time isn't clearly documented.
> +	 *
> +	 * According to the serializer datasheet we should wait 3ms, while
> +	 * according to the deserializer datasheet we should wait 5ms.
> +	 *
> +	 * Short delays here appear to show bit-errors in the writes following.
> +	 * Therefore a conservative delay seems best here.
> +	 */
> +	max9271_write(dev, 0x04, val);
> +	usleep_range(5000, 8000);
> +
> +	return 0;
> +}
> +EXPORT_SYMBOL_GPL(max9271_set_serial_link);
> +
> +int max9271_configure_i2c(struct max9271_device *dev, u8 i2c_config)
> +{
> +	int ret;
> +
> +	ret = max9271_write(dev, 0x0d, i2c_config);
> +	if (ret)
> +		return ret;
> +
> +	/* The delay required after an I2C bus configuration change is not
> +	 * characterized in the serializer manual. Sleep up to 5msec to
> +	 * stay safe.
> +	 */
> +	usleep_range(3500, 5000);
> +
> +	return 0;
> +}
> +EXPORT_SYMBOL_GPL(max9271_configure_i2c);
> +
> +int max9271_set_high_threshold(struct max9271_device *dev, bool enable)
> +{
> +	int ret;
> +
> +	ret = max9271_read(dev, 0x08);
> +	if (ret < 0)
> +		return ret;
> +
> +	/*
> +	 * Enable or disable reverse channel high threshold to increase
> +	 * immunity to power supply noise.
> +	 */
> +	max9271_write(dev, 0x08, enable ? ret | BIT(0) : ret & ~BIT(0));
> +	usleep_range(2000, 2500);
> +
> +	return 0;
> +}
> +EXPORT_SYMBOL_GPL(max9271_set_high_threshold);
> +
> +int max9271_configure_gmsl_link(struct max9271_device *dev)
> +{
> +	/*
> +	 * Configure the GMSL link:
> +	 *
> +	 * - Double input mode, high data rate, 24-bit mode
> +	 * - Latch input data on PCLKIN rising edge
> +	 * - Enable HS/VS encoding
> +	 * - 1-bit parity error detection
> +	 *
> +	 * TODO: Make the GMSL link configuration parametric.
> +	 */
> +	max9271_write(dev, 0x07, MAX9271_DBL | MAX9271_HVEN |
> +		      MAX9271_EDC_1BIT_PARITY);
> +	usleep_range(5000, 8000);
> +
> +	/*
> +	 * Adjust spread spectrum to +4% and auto-detect pixel clock
> +	 * and serial link rate.
> +	 */
> +	max9271_write(dev, 0x02, MAX9271_SPREAD_SPECT_4 | MAX9271_R02_RES |
> +		      MAX9271_PCLK_AUTODETECT | MAX9271_SERIAL_AUTODETECT);
> +	usleep_range(5000, 8000);
> +
> +	return 0;
> +}
> +EXPORT_SYMBOL_GPL(max9271_configure_gmsl_link);
> +
> +int max9271_set_gpios(struct max9271_device *dev, u8 gpio_mask)
> +{
> +	int ret;
> +
> +	ret = max9271_read(dev, 0x0f);
> +	if (ret < 0)
> +		return 0;
> +
> +	ret |= gpio_mask;
> +	ret = max9271_write(dev, 0x0f, ret);
> +	if (ret < 0) {
> +		dev_err(&dev->client->dev, "Failed to set gpio (%d)\n", ret);
> +		return ret;
> +	}
> +
> +	usleep_range(3500, 5000);
> +
> +	return 0;
> +}
> +EXPORT_SYMBOL_GPL(max9271_set_gpios);
> +
> +int max9271_clear_gpios(struct max9271_device *dev, u8 gpio_mask)
> +{
> +	int ret;
> +
> +	ret = max9271_read(dev, 0x0f);
> +	if (ret < 0)
> +		return 0;
> +
> +	ret &= ~gpio_mask;
> +	ret = max9271_write(dev, 0x0f, ret);
> +	if (ret < 0) {
> +		dev_err(&dev->client->dev, "Failed to clear gpio (%d)\n", ret);
> +		return ret;
> +	}
> +
> +	usleep_range(3500, 5000);
> +
> +	return 0;
> +}
> +EXPORT_SYMBOL_GPL(max9271_clear_gpios);
> +
> +int max9271_enable_gpios(struct max9271_device *dev, u8 gpio_mask)
> +{
> +	int ret;
> +
> +	ret = max9271_read(dev, 0x0f);
> +	if (ret < 0)
> +		return 0;
> +
> +	/* BIT(0) reserved: GPO is always enabled. */
> +	ret |= gpio_mask | BIT(0);
> +	ret = max9271_write(dev, 0x0e, ret);
> +	if (ret < 0) {
> +		dev_err(&dev->client->dev, "Failed to enable gpio (%d)\n", ret);
> +		return ret;
> +	}
> +
> +	usleep_range(3500, 5000);
> +
> +	return 0;
> +}
> +EXPORT_SYMBOL_GPL(max9271_enable_gpios);
> +
> +int max9271_disable_gpios(struct max9271_device *dev, u8 gpio_mask)
> +{
> +	int ret;
> +
> +	ret = max9271_read(dev, 0x0f);
> +	if (ret < 0)
> +		return 0;
> +
> +	/* BIT(0) reserved: GPO cannot be disabled */
> +	ret &= (~gpio_mask | BIT(0));
> +	ret = max9271_write(dev, 0x0e, ret);
> +	if (ret < 0) {
> +		dev_err(&dev->client->dev, "Failed to disable gpio (%d)\n", ret);
> +		return ret;
> +	}
> +
> +	usleep_range(3500, 5000);
> +
> +	return 0;
> +}
> +EXPORT_SYMBOL_GPL(max9271_disable_gpios);
> +
> +int max9271_verify_id(struct max9271_device *dev)
> +{
> +	int ret;
> +
> +	ret = max9271_read(dev, 0x1e);
> +	if (ret < 0) {
> +		dev_err(&dev->client->dev, "MAX9271 ID read failed (%d)\n",
> +			ret);
> +		return ret;
> +	}
> +
> +	if (ret != MAX9271_ID) {
> +		dev_err(&dev->client->dev, "MAX9271 ID mismatch (0x%02x)\n",
> +			ret);
> +		return -ENXIO;
> +	}
> +
> +	return 0;
> +}
> +EXPORT_SYMBOL_GPL(max9271_verify_id);
> +
> +int max9271_set_address(struct max9271_device *dev, u8 addr)
> +{
> +	int ret;
> +
> +	ret = max9271_write(dev, 0x00, addr << 1);
> +	if (ret < 0) {
> +		dev_err(&dev->client->dev,
> +			"MAX9271 I2C address change failed (%d)\n", ret);
> +		return ret;
> +	}
> +	usleep_range(3500, 5000);
> +
> +	return 0;
> +}
> +EXPORT_SYMBOL_GPL(max9271_set_address);
> +
> +int max9271_set_deserializer_address(struct max9271_device *dev, u8 addr)
> +{
> +	int ret;
> +
> +	ret = max9271_write(dev, 0x01, addr << 1);
> +	if (ret < 0) {
> +		dev_err(&dev->client->dev,
> +			"MAX9271 deserializer address set failed (%d)\n", ret);
> +		return ret;
> +	}
> +	usleep_range(3500, 5000);
> +
> +	return 0;
> +}
> +EXPORT_SYMBOL_GPL(max9271_set_deserializer_address);
> +
> +int max9271_set_translation(struct max9271_device *dev, u8 source, u8 dest)
> +{
> +	int ret;
> +
> +	ret = max9271_write(dev, 0x09, source << 1);
> +	if (ret < 0) {
> +		dev_err(&dev->client->dev,
> +			"MAX9271 I2C translation setup failed (%d)\n", ret);
> +		return ret;
> +	}
> +	usleep_range(3500, 5000);
> +
> +	ret = max9271_write(dev, 0x0a, dest << 1);
> +	if (ret < 0) {
> +		dev_err(&dev->client->dev,
> +			"MAX9271 I2C translation setup failed (%d)\n", ret);
> +		return ret;
> +	}
> +	usleep_range(3500, 5000);
> +
> +	return 0;
> +}
> +EXPORT_SYMBOL_GPL(max9271_set_translation);
> diff --git a/drivers/media/i2c/max9271.h b/drivers/media/i2c/max9271.h
> new file mode 100644
> index 000000000000..d78fb21441e9
> --- /dev/null
> +++ b/drivers/media/i2c/max9271.h
> @@ -0,0 +1,224 @@
> +/* SPDX-License-Identifier: GPL-2.0+ */
> +/*
> + * Copyright (C) 2017-2020 Jacopo Mondi
> + * Copyright (C) 2017-2020 Kieran Bingham
> + * Copyright (C) 2017-2020 Laurent Pinchart
> + * Copyright (C) 2017-2020 Niklas Söderlund
> + * Copyright (C) 2016 Renesas Electronics Corporation
> + * Copyright (C) 2015 Cogent Embedded, Inc.
> + */
> +
> +#include <linux/i2c.h>
> +
> +#define MAX9271_DEFAULT_ADDR	0x40
> +
> +/* Register 0x02 */
> +#define MAX9271_SPREAD_SPECT_0		(0 << 5)
> +#define MAX9271_SPREAD_SPECT_05		(1 << 5)
> +#define MAX9271_SPREAD_SPECT_15		(2 << 5)
> +#define MAX9271_SPREAD_SPECT_1		(5 << 5)
> +#define MAX9271_SPREAD_SPECT_2		(3 << 5)
> +#define MAX9271_SPREAD_SPECT_3		(6 << 5)
> +#define MAX9271_SPREAD_SPECT_4		(7 << 5)
> +#define MAX9271_R02_RES			BIT(4)
> +#define MAX9271_PCLK_AUTODETECT		(3 << 2)
> +#define MAX9271_SERIAL_AUTODETECT	(0x03)
> +/* Register 0x04 */
> +#define MAX9271_SEREN			BIT(7)
> +#define MAX9271_CLINKEN			BIT(6)
> +#define MAX9271_PRBSEN			BIT(5)
> +#define MAX9271_SLEEP			BIT(4)
> +#define MAX9271_INTTYPE_I2C		(0 << 2)
> +#define MAX9271_INTTYPE_UART		(1 << 2)
> +#define MAX9271_INTTYPE_NONE		(2 << 2)
> +#define MAX9271_REVCCEN			BIT(1)
> +#define MAX9271_FWDCCEN			BIT(0)
> +/* Register 0x07 */
> +#define MAX9271_DBL			BIT(7)
> +#define MAX9271_DRS			BIT(6)
> +#define MAX9271_BWS			BIT(5)
> +#define MAX9271_ES			BIT(4)
> +#define MAX9271_HVEN			BIT(2)
> +#define MAX9271_EDC_1BIT_PARITY		(0 << 0)
> +#define MAX9271_EDC_6BIT_CRC		(1 << 0)
> +#define MAX9271_EDC_6BIT_HAMMING	(2 << 0)
> +/* Register 0x08 */
> +#define MAX9271_INVVS			BIT(7)
> +#define MAX9271_INVHS			BIT(6)
> +#define MAX9271_REV_LOGAIN		BIT(3)
> +#define MAX9271_REV_HIVTH		BIT(0)
> +/* Register 0x09 */
> +#define MAX9271_ID			0x09
> +/* Register 0x0d */
> +#define MAX9271_I2CLOCACK		BIT(7)
> +#define MAX9271_I2CSLVSH_1046NS_469NS	(3 << 5)
> +#define MAX9271_I2CSLVSH_938NS_352NS	(2 << 5)
> +#define MAX9271_I2CSLVSH_469NS_234NS	(1 << 5)
> +#define MAX9271_I2CSLVSH_352NS_117NS	(0 << 5)
> +#define MAX9271_I2CMSTBT_837KBPS	(7 << 2)
> +#define MAX9271_I2CMSTBT_533KBPS	(6 << 2)
> +#define MAX9271_I2CMSTBT_339KBPS	(5 << 2)
> +#define MAX9271_I2CMSTBT_173KBPS	(4 << 2)
> +#define MAX9271_I2CMSTBT_105KBPS	(3 << 2)
> +#define MAX9271_I2CMSTBT_84KBPS		(2 << 2)
> +#define MAX9271_I2CMSTBT_28KBPS		(1 << 2)
> +#define MAX9271_I2CMSTBT_8KBPS		(0 << 2)
> +#define MAX9271_I2CSLVTO_NONE		(3 << 0)
> +#define MAX9271_I2CSLVTO_1024US		(2 << 0)
> +#define MAX9271_I2CSLVTO_256US		(1 << 0)
> +#define MAX9271_I2CSLVTO_64US		(0 << 0)
> +/* Register 0x0f */
> +#define MAX9271_GPIO5OUT		BIT(5)
> +#define MAX9271_GPIO4OUT		BIT(4)
> +#define MAX9271_GPIO3OUT		BIT(3)
> +#define MAX9271_GPIO2OUT		BIT(2)
> +#define MAX9271_GPIO1OUT		BIT(1)
> +#define MAX9271_GPO			BIT(0)
> +/* Register 0x15 */
> +#define MAX9271_PCLKDET			BIT(0)
> +
> +/**
> + * struct max9271_device - max9271 device
> + * @client: The i2c client for the max9271 instance
> + */
> +struct max9271_device {
> +	struct i2c_client *client;
> +};
> +
> +/**
> + * max9271_set_serial_link() - Enable/disable serial link
> + * @dev: The max9271 device
> + * @enable: Serial link enable/disable flag
> + *
> + * Return 0 on success or a negative error code on failure
> + */
> +int max9271_set_serial_link(struct max9271_device *dev, bool enable);
> +
> +/**
> + * max9271_configure_i2c() - Configure I2C bus parameters
> + * @dev: The max9271 device
> + * @i2c_config: The I2C bus configuration bit mask
> + *
> + * Configure MAX9271 I2C interface. The bus configuration provided in the
> + * @i2c_config parameter shall be assembled using bit values defined by the
> + * MAX9271_I2C* macros.
> + *
> + * Return 0 on success or a negative error code on failure
> + */
> +int max9271_configure_i2c(struct max9271_device *dev, u8 i2c_config);
> +
> +/**
> + * max9271_set_high_threshold() - Enable or disable reverse channel high
> + *				  threshold
> + * @dev: The max9271 device
> + * @enable: High threshold enable/disable flag
> + *
> + * Return 0 on success or a negative error code on failure
> + */
> +int max9271_set_high_threshold(struct max9271_device *dev, bool enable);
> +
> +/**
> + * max9271_configure_gmsl_link() - Configure the GMSL link
> + * @dev: The max9271 device
> + *
> + * FIXME: the GMSL link configuration is currently hardcoded and performed
> + * by programming registers 0x04, 0x07 and 0x02.
> + *
> + * Return 0 on success or a negative error code on failure
> + */
> +int max9271_configure_gmsl_link(struct max9271_device *dev);
> +
> +/**
> + * max9271_set_gpios() - Set gpio lines to physical high value
> + * @dev: The max9271 device
> + * @gpio_mask: The mask of gpio lines to set to high value
> + *
> + * The @gpio_mask parameter shall be assembled using the MAX9271_GP[IO|O]*
> + * bit values.
> + *
> + * Return 0 on success or a negative error code on failure
> + */
> +int max9271_set_gpios(struct max9271_device *dev, u8 gpio_mask);
> +
> +/**
> + * max9271_clear_gpios() - Set gpio lines to physical low value
> + * @dev: The max9271 device
> + * @gpio_mask: The mask of gpio lines to set to low value
> + *
> + * The @gpio_mask parameter shall be assembled using the MAX9271_GP[IO|O]*
> + * bit values.
> + *
> + * Return 0 on success or a negative error code on failure
> + */
> +int max9271_clear_gpios(struct max9271_device *dev, u8 gpio_mask);
> +
> +/**
> + * max9271_enable_gpios() - Enable gpio lines
> + * @dev: The max9271 device
> + * @gpio_mask: The mask of gpio lines to enable
> + *
> + * The @gpio_mask parameter shall be assembled using the MAX9271_GPIO*
> + * bit values. GPO line is always enabled by default.
> + *
> + * Return 0 on success or a negative error code on failure
> + */
> +int max9271_enable_gpios(struct max9271_device *dev, u8 gpio_mask);
> +
> +/**
> + * max9271_disable_gpios() - Disable gpio lines
> + * @dev: The max9271 device
> + * @gpio_mask: The mask of gpio lines to disable
> + *
> + * The @gpio_mask parameter shall be assembled using the MAX9271_GPIO*
> + * bit values. GPO line is always enabled by default and cannot be disabled.
> + *
> + * Return 0 on success or a negative error code on failure
> + */
> +int max9271_disable_gpios(struct max9271_device *dev, u8 gpio_mask);
> +
> +/**
> + * max9271_verify_id() - Read and verify MAX9271 id
> + * @dev: The max9271 device
> + *
> + * Return 0 on success or a negative error code on failure
> + */
> +int max9271_verify_id(struct max9271_device *dev);
> +
> +/**
> + * max9271_set_address() - Program a new I2C address
> + * @dev: The max9271 device
> + * @addr: The new I2C address in 7-bit format
> + *
> + * This function only takes care of programming the new I2C address @addr to
> + * in the MAX9271 chip registers, it is responsiblity of the caller to set
> + * the i2c address client to the @addr value to be able to communicate with
> + * the MAX9271 chip using the I2C framework APIs after this function returns.
> + *
> + * Return 0 on success or a negative error code on failure
> + */
> +int max9271_set_address(struct max9271_device *dev, u8 addr);
> +
> +/**
> + * max9271_set_deserializer_address() - Program the remote deserializer address
> + * @dev: The max9271 device
> + * @addr: The deserializer I2C address in 7-bit format
> + *
> + * Return 0 on success or a negative error code on failure
> + */
> +int max9271_set_deserializer_address(struct max9271_device *dev, u8 addr);
> +
> +/**
> + * max9271_set_translation() - Program I2C address translation
> + * @dev: The max9271 device
> + * @source: The I2C source address
> + * @dest: The I2C destination address
> + *
> + * Program address translation from @source to @dest. This is required to
> + * communicate with local devices that do not support address reprogramming.
> + *
> + * TODO: The device supports translation of two address, this function currently
> + * supports a single one.
> + *
> + * Return 0 on success or a negative error code on failure
> + */
> +int max9271_set_translation(struct max9271_device *dev, u8 source, u8 dest);
> diff --git a/drivers/media/i2c/rdacm20.c b/drivers/media/i2c/rdacm20.c
> new file mode 100644
> index 000000000000..cda3e6372ea9
> --- /dev/null
> +++ b/drivers/media/i2c/rdacm20.c
> @@ -0,0 +1,667 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/*
> + * IMI RDACM20 GMSL Camera Driver
> + *
> + * Copyright (C) 2017-2020 Jacopo Mondi
> + * Copyright (C) 2017-2020 Kieran Bingham
> + * Copyright (C) 2017-2019 Laurent Pinchart
> + * Copyright (C) 2017-2019 Niklas Söderlund
> + * Copyright (C) 2016 Renesas Electronics Corporation
> + * Copyright (C) 2015 Cogent Embedded, Inc.
> + */
> +
> +/*
> + * The camera is made of an Omnivision OV10635 sensor connected to a Maxim
> + * MAX9271 GMSL serializer.
> + */
> +
> +#include <linux/delay.h>
> +#include <linux/fwnode.h>
> +#include <linux/init.h>
> +#include <linux/i2c.h>
> +#include <linux/module.h>
> +#include <linux/slab.h>
> +#include <linux/videodev2.h>
> +
> +#include <media/v4l2-async.h>
> +#include <media/v4l2-ctrls.h>
> +#include <media/v4l2-subdev.h>
> +
> +#include "max9271.h"
> +
> +#define OV10635_I2C_ADDRESS		0x30
> +
> +#define OV10635_SOFTWARE_RESET		0x0103
> +#define OV10635_PID			0x300a
> +#define OV10635_VER			0x300b
> +#define OV10635_SC_CMMN_SCCB_ID		0x300c
> +#define OV10635_SC_CMMN_SCCB_ID_SELECT	BIT(0)
> +#define OV10635_VERSION			0xa635
> +
> +#define OV10635_WIDTH			1280
> +#define OV10635_HEIGHT			800
> +
> +/* VTS = PCLK / FPS / HTS / 2 (= 88MHz / 1572 / 30 / 2) */
> +#define OV10635_HTS			1572
> +/* FPS = 29,9998 */
> +#define OV10635_VTS			933
> +
> +/*
> + * As the drivers supports a single MEDIA_BUS_FMT_UYVY8_2X8 format we
> + * can harcode the pixel rate.

Is this somehow the property of RDACM20? Or could you use other
configurations here? (I'm not suggesting you should do now.)

> + *
> + * PCLK is fed through the system clock, programmed @88MHz.
> + * MEDIA_BUS_FMT_UYVY8_2X8 format = 2 samples per pixel.
> + *
> + * Pixelrate = PCLK / 2
> + * FPS = (OV10635_VTS * OV10635_HTS) / PixelRate
> + *     = 29,9998
> + */
> +#define OV10635_PIXEL_RATE		(44000000)
> +
> +static const struct ov10635_reg {
> +	u16	reg;
> +	u8	val;
> +} ov10635_regs_wizard[] = {
> +	{ 0x301b, 0xff }, { 0x301c, 0xff }, { 0x301a, 0xff }, { 0x3011, 0x42 },
> +	{ 0x6900, 0x0c }, { 0x6901, 0x19 }, { 0x3503, 0x10 }, { 0x3025, 0x03 },
> +	{ 0x3003, 0x16 }, { 0x3004, 0x30 }, { 0x3005, 0x40 }, { 0x3006, 0x91 },
> +	{ 0x3600, 0x74 }, { 0x3601, 0x2b }, { 0x3612, 0x00 }, { 0x3611, 0x67 },
> +	{ 0x3633, 0xca }, { 0x3602, 0xaf }, { 0x3603, 0x04 }, { 0x3630, 0x28 },
> +	{ 0x3631, 0x16 }, { 0x3714, 0x10 }, { 0x371d, 0x01 }, { 0x4300, 0x3a },
> +	{ 0x3007, 0x01 }, { 0x3024, 0x03 }, { 0x3020, 0x0a }, { 0x3702, 0x0d },
> +	{ 0x3703, 0x20 }, { 0x3704, 0x15 }, { 0x3709, 0xa8 }, { 0x370c, 0xc7 },
> +	{ 0x370d, 0x80 }, { 0x3712, 0x00 }, { 0x3713, 0x20 }, { 0x3715, 0x04 },
> +	{ 0x381d, 0x40 }, { 0x381c, 0x00 }, { 0x3822, 0x50 }, { 0x3824, 0x10 },
> +	{ 0x3815, 0x8c }, { 0x3804, 0x05 }, { 0x3805, 0x1f }, { 0x3800, 0x00 },
> +	{ 0x3801, 0x00 }, { 0x3806, 0x03 }, { 0x3807, 0x28 }, { 0x3802, 0x00 },
> +	{ 0x3803, 0x07 }, { 0x3808, 0x05 }, { 0x3809, 0x00 }, { 0x380a, 0x03 },
> +	{ 0x380b, 0x20 }, { 0x380c, OV10635_HTS >> 8 },
> +	{ 0x380d, OV10635_HTS & 0xff }, { 0x380e, OV10635_VTS >> 8 },
> +	{ 0x380f, OV10635_VTS & 0xff },	{ 0x3813, 0x02 }, { 0x3811, 0x08 },
> +	{ 0x381f, 0x0c }, { 0x3819, 0x04 }, { 0x3804, 0x01 }, { 0x3805, 0x00 },
> +	{ 0x3828, 0x03 }, { 0x3829, 0x10 }, { 0x382a, 0x10 }, { 0x3621, 0x63 },
> +	{ 0x5005, 0x08 }, { 0x56d5, 0x00 }, { 0x56d6, 0x80 }, { 0x56d7, 0x00 },
> +	{ 0x56d8, 0x00 }, { 0x56d9, 0x00 }, { 0x56da, 0x80 }, { 0x56db, 0x00 },
> +	{ 0x56dc, 0x00 }, { 0x56e8, 0x00 }, { 0x56e9, 0x7f }, { 0x56ea, 0x00 },
> +	{ 0x56eb, 0x7f }, { 0x5100, 0x00 }, { 0x5101, 0x80 }, { 0x5102, 0x00 },
> +	{ 0x5103, 0x80 }, { 0x5104, 0x00 }, { 0x5105, 0x80 }, { 0x5106, 0x00 },
> +	{ 0x5107, 0x80 }, { 0x5108, 0x00 }, { 0x5109, 0x00 }, { 0x510a, 0x00 },
> +	{ 0x510b, 0x00 }, { 0x510c, 0x00 }, { 0x510d, 0x00 }, { 0x510e, 0x00 },
> +	{ 0x510f, 0x00 }, { 0x5110, 0x00 }, { 0x5111, 0x80 }, { 0x5112, 0x00 },
> +	{ 0x5113, 0x80 }, { 0x5114, 0x00 }, { 0x5115, 0x80 }, { 0x5116, 0x00 },
> +	{ 0x5117, 0x80 }, { 0x5118, 0x00 }, { 0x5119, 0x00 }, { 0x511a, 0x00 },
> +	{ 0x511b, 0x00 }, { 0x511c, 0x00 }, { 0x511d, 0x00 }, { 0x511e, 0x00 },
> +	{ 0x511f, 0x00 }, { 0x56d0, 0x00 }, { 0x5006, 0x04 }, { 0x5608, 0x05 },
> +	{ 0x52d7, 0x06 }, { 0x528d, 0x08 }, { 0x5293, 0x12 }, { 0x52d3, 0x12 },
> +	{ 0x5288, 0x06 }, { 0x5289, 0x20 }, { 0x52c8, 0x06 }, { 0x52c9, 0x20 },
> +	{ 0x52cd, 0x04 }, { 0x5381, 0x00 }, { 0x5382, 0xff }, { 0x5589, 0x76 },
> +	{ 0x558a, 0x47 }, { 0x558b, 0xef }, { 0x558c, 0xc9 }, { 0x558d, 0x49 },
> +	{ 0x558e, 0x30 }, { 0x558f, 0x67 }, { 0x5590, 0x3f }, { 0x5591, 0xf0 },
> +	{ 0x5592, 0x10 }, { 0x55a2, 0x6d }, { 0x55a3, 0x55 }, { 0x55a4, 0xc3 },
> +	{ 0x55a5, 0xb5 }, { 0x55a6, 0x43 }, { 0x55a7, 0x38 }, { 0x55a8, 0x5f },
> +	{ 0x55a9, 0x4b }, { 0x55aa, 0xf0 }, { 0x55ab, 0x10 }, { 0x5581, 0x52 },
> +	{ 0x5300, 0x01 }, { 0x5301, 0x00 }, { 0x5302, 0x00 }, { 0x5303, 0x0e },
> +	{ 0x5304, 0x00 }, { 0x5305, 0x0e }, { 0x5306, 0x00 }, { 0x5307, 0x36 },
> +	{ 0x5308, 0x00 }, { 0x5309, 0xd9 }, { 0x530a, 0x00 }, { 0x530b, 0x0f },
> +	{ 0x530c, 0x00 }, { 0x530d, 0x2c }, { 0x530e, 0x00 }, { 0x530f, 0x59 },
> +	{ 0x5310, 0x00 }, { 0x5311, 0x7b }, { 0x5312, 0x00 }, { 0x5313, 0x22 },
> +	{ 0x5314, 0x00 }, { 0x5315, 0xd5 }, { 0x5316, 0x00 }, { 0x5317, 0x13 },
> +	{ 0x5318, 0x00 }, { 0x5319, 0x18 }, { 0x531a, 0x00 }, { 0x531b, 0x26 },
> +	{ 0x531c, 0x00 }, { 0x531d, 0xdc }, { 0x531e, 0x00 }, { 0x531f, 0x02 },
> +	{ 0x5320, 0x00 }, { 0x5321, 0x24 }, { 0x5322, 0x00 }, { 0x5323, 0x56 },
> +	{ 0x5324, 0x00 }, { 0x5325, 0x85 }, { 0x5326, 0x00 }, { 0x5327, 0x20 },
> +	{ 0x5609, 0x01 }, { 0x560a, 0x40 }, { 0x560b, 0x01 }, { 0x560c, 0x40 },
> +	{ 0x560d, 0x00 }, { 0x560e, 0xfa }, { 0x560f, 0x00 }, { 0x5610, 0xfa },
> +	{ 0x5611, 0x02 }, { 0x5612, 0x80 }, { 0x5613, 0x02 }, { 0x5614, 0x80 },
> +	{ 0x5615, 0x01 }, { 0x5616, 0x2c }, { 0x5617, 0x01 }, { 0x5618, 0x2c },
> +	{ 0x563b, 0x01 }, { 0x563c, 0x01 }, { 0x563d, 0x01 }, { 0x563e, 0x01 },
> +	{ 0x563f, 0x03 }, { 0x5640, 0x03 }, { 0x5641, 0x03 }, { 0x5642, 0x05 },
> +	{ 0x5643, 0x09 }, { 0x5644, 0x05 }, { 0x5645, 0x05 }, { 0x5646, 0x05 },
> +	{ 0x5647, 0x05 }, { 0x5651, 0x00 }, { 0x5652, 0x80 }, { 0x521a, 0x01 },
> +	{ 0x521b, 0x03 }, { 0x521c, 0x06 }, { 0x521d, 0x0a }, { 0x521e, 0x0e },
> +	{ 0x521f, 0x12 }, { 0x5220, 0x16 }, { 0x5223, 0x02 }, { 0x5225, 0x04 },
> +	{ 0x5227, 0x08 }, { 0x5229, 0x0c }, { 0x522b, 0x12 }, { 0x522d, 0x18 },
> +	{ 0x522f, 0x1e }, { 0x5241, 0x04 }, { 0x5242, 0x01 }, { 0x5243, 0x03 },
> +	{ 0x5244, 0x06 }, { 0x5245, 0x0a }, { 0x5246, 0x0e }, { 0x5247, 0x12 },
> +	{ 0x5248, 0x16 }, { 0x524a, 0x03 }, { 0x524c, 0x04 }, { 0x524e, 0x08 },
> +	{ 0x5250, 0x0c }, { 0x5252, 0x12 }, { 0x5254, 0x18 }, { 0x5256, 0x1e },
> +	/* fifo_line_length = 2*hts */
> +	{ 0x4606, (2 * OV10635_HTS) >> 8 }, { 0x4607, (2 * OV10635_HTS) & 0xff },
> +	/* fifo_hsync_start = 2*(hts - xres) */
> +	{ 0x460a, (2 * (OV10635_HTS - OV10635_WIDTH)) >> 8 },
> +	{ 0x460b, (2 * (OV10635_HTS - OV10635_WIDTH)) & 0xff },
> +	{ 0x460c, 0x00 }, { 0x4620, 0x0e },
> +	/* BT601: 0x08 is also acceptable as HS/VS mode */
> +	{ 0x4700, 0x04 }, { 0x4701, 0x00 }, { 0x4702, 0x01 }, { 0x4004, 0x04 },
> +	{ 0x4005, 0x18 }, { 0x4001, 0x06 }, { 0x4050, 0x22 }, { 0x4051, 0x24 },
> +	{ 0x4052, 0x02 }, { 0x4057, 0x9c }, { 0x405a, 0x00 }, { 0x4202, 0x02 },
> +	{ 0x3023, 0x10 }, { 0x0100, 0x01 }, { 0x0100, 0x01 }, { 0x6f10, 0x07 },
> +	{ 0x6f11, 0x82 }, { 0x6f12, 0x04 }, { 0x6f13, 0x00 }, { 0xd000, 0x19 },
> +	{ 0xd001, 0xa0 }, { 0xd002, 0x00 }, { 0xd003, 0x01 }, { 0xd004, 0xa9 },
> +	{ 0xd005, 0xad }, { 0xd006, 0x10 }, { 0xd007, 0x40 }, { 0xd008, 0x44 },
> +	{ 0xd009, 0x00 }, { 0xd00a, 0x68 }, { 0xd00b, 0x00 }, { 0xd00c, 0x15 },
> +	{ 0xd00d, 0x00 }, { 0xd00e, 0x00 }, { 0xd00f, 0x00 }, { 0xd040, 0x9c },
> +	{ 0xd041, 0x21 }, { 0xd042, 0xff }, { 0xd043, 0xf8 }, { 0xd044, 0xd4 },
> +	{ 0xd045, 0x01 }, { 0xd046, 0x48 }, { 0xd047, 0x00 }, { 0xd048, 0xd4 },
> +	{ 0xd049, 0x01 }, { 0xd04a, 0x50 }, { 0xd04b, 0x04 }, { 0xd04c, 0x18 },
> +	{ 0xd04d, 0x60 }, { 0xd04e, 0x00 }, { 0xd04f, 0x01 }, { 0xd050, 0xa8 },
> +	{ 0xd051, 0x63 }, { 0xd052, 0x02 }, { 0xd053, 0xa4 }, { 0xd054, 0x85 },
> +	{ 0xd055, 0x43 }, { 0xd056, 0x00 }, { 0xd057, 0x00 }, { 0xd058, 0x18 },
> +	{ 0xd059, 0x60 }, { 0xd05a, 0x00 }, { 0xd05b, 0x01 }, { 0xd05c, 0xa8 },
> +	{ 0xd05d, 0x63 }, { 0xd05e, 0x03 }, { 0xd05f, 0xf0 }, { 0xd060, 0x98 },
> +	{ 0xd061, 0xa3 }, { 0xd062, 0x00 }, { 0xd063, 0x00 }, { 0xd064, 0x8c },
> +	{ 0xd065, 0x6a }, { 0xd066, 0x00 }, { 0xd067, 0x6e }, { 0xd068, 0xe5 },
> +	{ 0xd069, 0x85 }, { 0xd06a, 0x18 }, { 0xd06b, 0x00 }, { 0xd06c, 0x10 },
> +	{ 0xd06d, 0x00 }, { 0xd06e, 0x00 }, { 0xd06f, 0x10 }, { 0xd070, 0x9c },
> +	{ 0xd071, 0x80 }, { 0xd072, 0x00 }, { 0xd073, 0x03 }, { 0xd074, 0x18 },
> +	{ 0xd075, 0x60 }, { 0xd076, 0x00 }, { 0xd077, 0x01 }, { 0xd078, 0xa8 },
> +	{ 0xd079, 0x63 }, { 0xd07a, 0x07 }, { 0xd07b, 0x80 }, { 0xd07c, 0x07 },
> +	{ 0xd07d, 0xff }, { 0xd07e, 0xf9 }, { 0xd07f, 0x03 }, { 0xd080, 0x8c },
> +	{ 0xd081, 0x63 }, { 0xd082, 0x00 }, { 0xd083, 0x00 }, { 0xd084, 0xa5 },
> +	{ 0xd085, 0x6b }, { 0xd086, 0x00 }, { 0xd087, 0xff }, { 0xd088, 0x18 },
> +	{ 0xd089, 0x80 }, { 0xd08a, 0x00 }, { 0xd08b, 0x01 }, { 0xd08c, 0xa8 },
> +	{ 0xd08d, 0x84 }, { 0xd08e, 0x01 }, { 0xd08f, 0x04 }, { 0xd090, 0xe1 },
> +	{ 0xd091, 0x6b }, { 0xd092, 0x58 }, { 0xd093, 0x00 }, { 0xd094, 0x94 },
> +	{ 0xd095, 0x6a }, { 0xd096, 0x00 }, { 0xd097, 0x70 }, { 0xd098, 0xe1 },
> +	{ 0xd099, 0x6b }, { 0xd09a, 0x20 }, { 0xd09b, 0x00 }, { 0xd09c, 0x95 },
> +	{ 0xd09d, 0x6b }, { 0xd09e, 0x00 }, { 0xd09f, 0x00 }, { 0xd0a0, 0xe4 },
> +	{ 0xd0a1, 0x8b }, { 0xd0a2, 0x18 }, { 0xd0a3, 0x00 }, { 0xd0a4, 0x0c },
> +	{ 0xd0a5, 0x00 }, { 0xd0a6, 0x00 }, { 0xd0a7, 0x23 }, { 0xd0a8, 0x15 },
> +	{ 0xd0a9, 0x00 }, { 0xd0aa, 0x00 }, { 0xd0ab, 0x00 }, { 0xd0ac, 0x18 },
> +	{ 0xd0ad, 0x60 }, { 0xd0ae, 0x80 }, { 0xd0af, 0x06 }, { 0xd0b0, 0xa8 },
> +	{ 0xd0b1, 0x83 }, { 0xd0b2, 0x40 }, { 0xd0b3, 0x08 }, { 0xd0b4, 0xa8 },
> +	{ 0xd0b5, 0xe3 }, { 0xd0b6, 0x38 }, { 0xd0b7, 0x2a }, { 0xd0b8, 0xa8 },
> +	{ 0xd0b9, 0xc3 }, { 0xd0ba, 0x40 }, { 0xd0bb, 0x09 }, { 0xd0bc, 0xa8 },
> +	{ 0xd0bd, 0xa3 }, { 0xd0be, 0x38 }, { 0xd0bf, 0x29 }, { 0xd0c0, 0x8c },
> +	{ 0xd0c1, 0x65 }, { 0xd0c2, 0x00 }, { 0xd0c3, 0x00 }, { 0xd0c4, 0xd8 },
> +	{ 0xd0c5, 0x04 }, { 0xd0c6, 0x18 }, { 0xd0c7, 0x00 }, { 0xd0c8, 0x8c },
> +	{ 0xd0c9, 0x67 }, { 0xd0ca, 0x00 }, { 0xd0cb, 0x00 }, { 0xd0cc, 0xd8 },
> +	{ 0xd0cd, 0x06 }, { 0xd0ce, 0x18 }, { 0xd0cf, 0x00 }, { 0xd0d0, 0x18 },
> +	{ 0xd0d1, 0x60 }, { 0xd0d2, 0x80 }, { 0xd0d3, 0x06 }, { 0xd0d4, 0xa8 },
> +	{ 0xd0d5, 0xe3 }, { 0xd0d6, 0x67 }, { 0xd0d7, 0x02 }, { 0xd0d8, 0xa9 },
> +	{ 0xd0d9, 0x03 }, { 0xd0da, 0x67 }, { 0xd0db, 0x03 }, { 0xd0dc, 0xa8 },
> +	{ 0xd0dd, 0xc3 }, { 0xd0de, 0x3d }, { 0xd0df, 0x05 }, { 0xd0e0, 0x8c },
> +	{ 0xd0e1, 0x66 }, { 0xd0e2, 0x00 }, { 0xd0e3, 0x00 }, { 0xd0e4, 0xb8 },
> +	{ 0xd0e5, 0x63 }, { 0xd0e6, 0x00 }, { 0xd0e7, 0x18 }, { 0xd0e8, 0xb8 },
> +	{ 0xd0e9, 0x63 }, { 0xd0ea, 0x00 }, { 0xd0eb, 0x98 }, { 0xd0ec, 0xbc },
> +	{ 0xd0ed, 0x03 }, { 0xd0ee, 0x00 }, { 0xd0ef, 0x00 }, { 0xd0f0, 0x10 },
> +	{ 0xd0f1, 0x00 }, { 0xd0f2, 0x00 }, { 0xd0f3, 0x16 }, { 0xd0f4, 0xb8 },
> +	{ 0xd0f5, 0x83 }, { 0xd0f6, 0x00 }, { 0xd0f7, 0x19 }, { 0xd0f8, 0x8c },
> +	{ 0xd0f9, 0x67 }, { 0xd0fa, 0x00 }, { 0xd0fb, 0x00 }, { 0xd0fc, 0xb8 },
> +	{ 0xd0fd, 0xa4 }, { 0xd0fe, 0x00 }, { 0xd0ff, 0x98 }, { 0xd100, 0xb8 },
> +	{ 0xd101, 0x83 }, { 0xd102, 0x00 }, { 0xd103, 0x08 }, { 0xd104, 0x8c },
> +	{ 0xd105, 0x68 }, { 0xd106, 0x00 }, { 0xd107, 0x00 }, { 0xd108, 0xe0 },
> +	{ 0xd109, 0x63 }, { 0xd10a, 0x20 }, { 0xd10b, 0x04 }, { 0xd10c, 0xe0 },
> +	{ 0xd10d, 0x65 }, { 0xd10e, 0x18 }, { 0xd10f, 0x00 }, { 0xd110, 0xa4 },
> +	{ 0xd111, 0x83 }, { 0xd112, 0xff }, { 0xd113, 0xff }, { 0xd114, 0xb8 },
> +	{ 0xd115, 0x64 }, { 0xd116, 0x00 }, { 0xd117, 0x48 }, { 0xd118, 0xd8 },
> +	{ 0xd119, 0x07 }, { 0xd11a, 0x18 }, { 0xd11b, 0x00 }, { 0xd11c, 0xd8 },
> +	{ 0xd11d, 0x08 }, { 0xd11e, 0x20 }, { 0xd11f, 0x00 }, { 0xd120, 0x9c },
> +	{ 0xd121, 0x60 }, { 0xd122, 0x00 }, { 0xd123, 0x00 }, { 0xd124, 0xd8 },
> +	{ 0xd125, 0x06 }, { 0xd126, 0x18 }, { 0xd127, 0x00 }, { 0xd128, 0x00 },
> +	{ 0xd129, 0x00 }, { 0xd12a, 0x00 }, { 0xd12b, 0x08 }, { 0xd12c, 0x15 },
> +	{ 0xd12d, 0x00 }, { 0xd12e, 0x00 }, { 0xd12f, 0x00 }, { 0xd130, 0x8c },
> +	{ 0xd131, 0x6a }, { 0xd132, 0x00 }, { 0xd133, 0x76 }, { 0xd134, 0xbc },
> +	{ 0xd135, 0x23 }, { 0xd136, 0x00 }, { 0xd137, 0x00 }, { 0xd138, 0x13 },
> +	{ 0xd139, 0xff }, { 0xd13a, 0xff }, { 0xd13b, 0xe6 }, { 0xd13c, 0x18 },
> +	{ 0xd13d, 0x60 }, { 0xd13e, 0x80 }, { 0xd13f, 0x06 }, { 0xd140, 0x03 },
> +	{ 0xd141, 0xff }, { 0xd142, 0xff }, { 0xd143, 0xdd }, { 0xd144, 0xa8 },
> +	{ 0xd145, 0x83 }, { 0xd146, 0x40 }, { 0xd147, 0x08 }, { 0xd148, 0x85 },
> +	{ 0xd149, 0x21 }, { 0xd14a, 0x00 }, { 0xd14b, 0x00 }, { 0xd14c, 0x85 },
> +	{ 0xd14d, 0x41 }, { 0xd14e, 0x00 }, { 0xd14f, 0x04 }, { 0xd150, 0x44 },
> +	{ 0xd151, 0x00 }, { 0xd152, 0x48 }, { 0xd153, 0x00 }, { 0xd154, 0x9c },
> +	{ 0xd155, 0x21 }, { 0xd156, 0x00 }, { 0xd157, 0x08 }, { 0x6f0e, 0x03 },
> +	{ 0x6f0f, 0x00 }, { 0x460e, 0x08 }, { 0x460f, 0x01 }, { 0x4610, 0x00 },
> +	{ 0x4611, 0x01 }, { 0x4612, 0x00 }, { 0x4613, 0x01 },
> +	/* 8 bits */
> +	{ 0x4605, 0x08 },
> +	/* Swap data bits order [9:0] -> [0:9] */
> +	{ 0x4709, 0x10 }, { 0x4608, 0x00 }, { 0x4609, 0x08 }, { 0x6804, 0x00 },
> +	{ 0x6805, 0x06 }, { 0x6806, 0x00 }, { 0x5120, 0x00 }, { 0x3510, 0x00 },
> +	{ 0x3504, 0x00 }, { 0x6800, 0x00 }, { 0x6f0d, 0x01 },
> +	/* PCLK falling edge */
> +	{ 0x4708, 0x01 }, { 0x5000, 0xff }, { 0x5001, 0xbf }, { 0x5002, 0x7e },
> +	{ 0x503d, 0x00 }, { 0xc450, 0x01 }, { 0xc452, 0x04 }, { 0xc453, 0x00 },
> +	{ 0xc454, 0x00 }, { 0xc455, 0x01 }, { 0xc456, 0x01 }, { 0xc457, 0x00 },
> +	{ 0xc458, 0x00 }, { 0xc459, 0x00 }, { 0xc45b, 0x00 }, { 0xc45c, 0x01 },
> +	{ 0xc45d, 0x00 }, { 0xc45e, 0x00 }, { 0xc45f, 0x00 }, { 0xc460, 0x00 },
> +	{ 0xc461, 0x01 }, { 0xc462, 0x01 }, { 0xc464, 0x03 }, { 0xc465, 0x00 },
> +	{ 0xc466, 0x8a }, { 0xc467, 0x00 }, { 0xc468, 0x86 }, { 0xc469, 0x00 },
> +	{ 0xc46a, 0x40 }, { 0xc46b, 0x50 }, { 0xc46c, 0x30 }, { 0xc46d, 0x28 },
> +	{ 0xc46e, 0x60 }, { 0xc46f, 0x40 }, { 0xc47c, 0x01 }, { 0xc47d, 0x38 },
> +	{ 0xc47e, 0x00 }, { 0xc47f, 0x00 }, { 0xc480, 0x00 }, { 0xc481, 0xff },
> +	{ 0xc482, 0x00 }, { 0xc483, 0x40 }, { 0xc484, 0x00 }, { 0xc485, 0x18 },
> +	{ 0xc486, 0x00 }, { 0xc487, 0x18 },
> +	{ 0xc488, (OV10635_VTS - 8) * 16 >> 8},
> +	{ 0xc489, (OV10635_VTS - 8) * 16 & 0xff},
> +	{ 0xc48a, (OV10635_VTS - 8) * 16 >> 8},
> +	{ 0xc48b, (OV10635_VTS - 8) * 16 & 0xff}, { 0xc48c, 0x00 },
> +	{ 0xc48d, 0x04 }, { 0xc48e, 0x00 }, { 0xc48f, 0x04 }, { 0xc490, 0x03 },
> +	{ 0xc492, 0x20 }, { 0xc493, 0x08 }, { 0xc498, 0x02 }, { 0xc499, 0x00 },
> +	{ 0xc49a, 0x02 }, { 0xc49b, 0x00 }, { 0xc49c, 0x02 }, { 0xc49d, 0x00 },
> +	{ 0xc49e, 0x02 }, { 0xc49f, 0x60 }, { 0xc4a0, 0x03 }, { 0xc4a1, 0x00 },
> +	{ 0xc4a2, 0x04 }, { 0xc4a3, 0x00 }, { 0xc4a4, 0x00 }, { 0xc4a5, 0x10 },
> +	{ 0xc4a6, 0x00 }, { 0xc4a7, 0x40 }, { 0xc4a8, 0x00 }, { 0xc4a9, 0x80 },
> +	{ 0xc4aa, 0x0d }, { 0xc4ab, 0x00 }, { 0xc4ac, 0x0f }, { 0xc4ad, 0xc0 },
> +	{ 0xc4b4, 0x01 }, { 0xc4b5, 0x01 }, { 0xc4b6, 0x00 }, { 0xc4b7, 0x01 },
> +	{ 0xc4b8, 0x00 }, { 0xc4b9, 0x01 }, { 0xc4ba, 0x01 }, { 0xc4bb, 0x00 },
> +	{ 0xc4bc, 0x01 }, { 0xc4bd, 0x60 }, { 0xc4be, 0x02 }, { 0xc4bf, 0x33 },
> +	{ 0xc4c8, 0x03 }, { 0xc4c9, 0xd0 }, { 0xc4ca, 0x0e }, { 0xc4cb, 0x00 },
> +	{ 0xc4cc, 0x0e }, { 0xc4cd, 0x51 }, { 0xc4ce, 0x0e }, { 0xc4cf, 0x51 },
> +	{ 0xc4d0, 0x04 }, { 0xc4d1, 0x80 }, { 0xc4e0, 0x04 }, { 0xc4e1, 0x02 },
> +	{ 0xc4e2, 0x01 }, { 0xc4e4, 0x10 }, { 0xc4e5, 0x20 }, { 0xc4e6, 0x30 },
> +	{ 0xc4e7, 0x40 }, { 0xc4e8, 0x50 }, { 0xc4e9, 0x60 }, { 0xc4ea, 0x70 },
> +	{ 0xc4eb, 0x80 }, { 0xc4ec, 0x90 }, { 0xc4ed, 0xa0 }, { 0xc4ee, 0xb0 },
> +	{ 0xc4ef, 0xc0 }, { 0xc4f0, 0xd0 }, { 0xc4f1, 0xe0 }, { 0xc4f2, 0xf0 },
> +	{ 0xc4f3, 0x80 }, { 0xc4f4, 0x00 }, { 0xc4f5, 0x20 }, { 0xc4f6, 0x02 },
> +	{ 0xc4f7, 0x00 }, { 0xc4f8, 0x00 }, { 0xc4f9, 0x00 }, { 0xc4fa, 0x00 },
> +	{ 0xc4fb, 0x01 }, { 0xc4fc, 0x01 }, { 0xc4fd, 0x00 }, { 0xc4fe, 0x04 },
> +	{ 0xc4ff, 0x02 }, { 0xc500, 0x48 }, { 0xc501, 0x74 }, { 0xc502, 0x58 },
> +	{ 0xc503, 0x80 }, { 0xc504, 0x05 }, { 0xc505, 0x80 }, { 0xc506, 0x03 },
> +	{ 0xc507, 0x80 }, { 0xc508, 0x01 }, { 0xc509, 0xc0 }, { 0xc50a, 0x01 },
> +	{ 0xc50b, 0xa0 }, { 0xc50c, 0x01 }, { 0xc50d, 0x2c }, { 0xc50e, 0x01 },
> +	{ 0xc50f, 0x0a }, { 0xc510, 0x00 }, { 0xc511, 0x00 }, { 0xc512, 0xe5 },
> +	{ 0xc513, 0x14 }, { 0xc514, 0x04 }, { 0xc515, 0x00 }, { 0xc518, OV10635_VTS >> 8},
> +	{ 0xc519, OV10635_VTS & 0xff}, { 0xc51a, OV10635_HTS >> 8},
> +	{ 0xc51b, OV10635_HTS & 0xff}, { 0xc2e0, 0x00 }, { 0xc2e1, 0x51 },
> +	{ 0xc2e2, 0x00 }, { 0xc2e3, 0xd6 }, { 0xc2e4, 0x01 }, { 0xc2e5, 0x5e },
> +	{ 0xc2e9, 0x01 }, { 0xc2ea, 0x7a }, { 0xc2eb, 0x90 }, { 0xc2ed, 0x00 },
> +	{ 0xc2ee, 0x7a }, { 0xc2ef, 0x64 }, { 0xc308, 0x00 }, { 0xc309, 0x00 },
> +	{ 0xc30a, 0x00 }, { 0xc30c, 0x00 }, { 0xc30d, 0x01 }, { 0xc30e, 0x00 },
> +	{ 0xc30f, 0x00 }, { 0xc310, 0x01 }, { 0xc311, 0x60 }, { 0xc312, 0xff },
> +	{ 0xc313, 0x08 }, { 0xc314, 0x01 }, { 0xc315, 0x00 }, { 0xc316, 0xff },
> +	{ 0xc317, 0x0b }, { 0xc318, 0x00 }, { 0xc319, 0x0c }, { 0xc31a, 0x00 },
> +	{ 0xc31b, 0xe0 }, { 0xc31c, 0x00 }, { 0xc31d, 0x14 }, { 0xc31e, 0x00 },
> +	{ 0xc31f, 0xc5 }, { 0xc320, 0xff }, { 0xc321, 0x4b }, { 0xc322, 0xff },
> +	{ 0xc323, 0xf0 }, { 0xc324, 0xff }, { 0xc325, 0xe8 }, { 0xc326, 0x00 },
> +	{ 0xc327, 0x46 }, { 0xc328, 0xff }, { 0xc329, 0xd2 }, { 0xc32a, 0xff },
> +	{ 0xc32b, 0xe4 }, { 0xc32c, 0xff }, { 0xc32d, 0xbb }, { 0xc32e, 0x00 },
> +	{ 0xc32f, 0x61 }, { 0xc330, 0xff }, { 0xc331, 0xf9 }, { 0xc332, 0x00 },
> +	{ 0xc333, 0xd9 }, { 0xc334, 0x00 }, { 0xc335, 0x2e }, { 0xc336, 0x00 },
> +	{ 0xc337, 0xb1 }, { 0xc338, 0xff }, { 0xc339, 0x64 }, { 0xc33a, 0xff },
> +	{ 0xc33b, 0xeb }, { 0xc33c, 0xff }, { 0xc33d, 0xe8 }, { 0xc33e, 0x00 },
> +	{ 0xc33f, 0x48 }, { 0xc340, 0xff }, { 0xc341, 0xd0 }, { 0xc342, 0xff },
> +	{ 0xc343, 0xed }, { 0xc344, 0xff }, { 0xc345, 0xad }, { 0xc346, 0x00 },
> +	{ 0xc347, 0x66 }, { 0xc348, 0x01 }, { 0xc349, 0x00 }, { 0x6700, 0x04 },
> +	{ 0x6701, 0x7b }, { 0x6702, 0xfd }, { 0x6703, 0xf9 }, { 0x6704, 0x3d },
> +	{ 0x6705, 0x71 }, { 0x6706, 0x78 }, { 0x6708, 0x05 }, { 0x6f06, 0x6f },
> +	{ 0x6f07, 0x00 }, { 0x6f0a, 0x6f }, { 0x6f0b, 0x00 }, { 0x6f00, 0x03 },
> +	{ 0xc34c, 0x01 }, { 0xc34d, 0x00 }, { 0xc34e, 0x46 }, { 0xc34f, 0x55 },
> +	{ 0xc350, 0x00 }, { 0xc351, 0x40 }, { 0xc352, 0x00 }, { 0xc353, 0xff },
> +	{ 0xc354, 0x04 }, { 0xc355, 0x08 }, { 0xc356, 0x01 }, { 0xc357, 0xef },
> +	{ 0xc358, 0x30 }, { 0xc359, 0x01 }, { 0xc35a, 0x64 }, { 0xc35b, 0x46 },
> +	{ 0xc35c, 0x00 }, { 0x3042, 0xf0 }, { 0x3042, 0xf0 }, { 0x3042, 0xf0 },
> +	{ 0x3042, 0xf0 }, { 0x3042, 0xf0 }, { 0x3042, 0xf0 }, { 0x3042, 0xf0 },
> +	{ 0x3042, 0xf0 }, { 0x3042, 0xf0 }, { 0x3042, 0xf0 }, { 0x3042, 0xf0 },
> +	{ 0x3042, 0xf0 }, { 0x3042, 0xf0 }, { 0x3042, 0xf0 }, { 0x3042, 0xf0 },
> +	{ 0x3042, 0xf0 }, { 0x3042, 0xf0 }, { 0x3042, 0xf0 }, { 0x3042, 0xf0 },
> +	{ 0x3042, 0xf0 }, { 0x3042, 0xf0 }, { 0x3042, 0xf0 }, { 0x3042, 0xf0 },
> +	{ 0x3042, 0xf0 }, { 0x3042, 0xf0 }, { 0x3042, 0xf0 }, { 0xc261, 0x01 },
> +	{ 0x301b, 0xf0 }, { 0x301c, 0xf0 }, { 0x301a, 0xf0 }, { 0x6f00, 0xc3 },
> +	{ 0xc46a, 0x30 }, { 0xc46d, 0x20 }, { 0xc464, 0x84 }, { 0xc465, 0x00 },
> +	{ 0x6f00, 0x03 }, { 0x6f00, 0x43 }, { 0x381c, 0x00 }, { 0x381d, 0x40 },
> +	{ 0xc454, 0x01 }, { 0x6f00, 0xc3 }, { 0xc454, 0x00 }, { 0xc4b1, 0x02 },
> +	{ 0xc4b2, 0x01 }, { 0xc4b3, 0x03 }, { 0x6f00, 0x03 }, { 0x6f00, 0x43 },
> +	/* enable FSIN (FRAMESYNC input) functionality */
> +	{ 0x3832, (0x0d + 2 * 0x20 + 0x15 + 38) >> 8 },
> +	{ 0x3833, (0x0d + 2 * 0x20 + 0x15 + 38) & 0xff },
> +	{ 0x3834, OV10635_VTS >> 8 }, { 0x3835, OV10635_VTS & 0xff },
> +	{ 0x302e, 0x01 },

Ergh.

> +};
> +
> +struct rdacm20_device {
> +	struct device			*dev;
> +	struct max9271_device		*serializer;
> +	struct i2c_client		*sensor;
> +	struct v4l2_subdev		sd;
> +	struct media_pad		pad;
> +	struct v4l2_ctrl_handler	ctrls;
> +	u32				addrs[2];
> +};
> +
> +static inline struct rdacm20_device *sd_to_rdacm20(struct v4l2_subdev *sd)
> +{
> +	return container_of(sd, struct rdacm20_device, sd);
> +}
> +
> +static inline struct rdacm20_device *i2c_to_rdacm20(struct i2c_client *client)
> +{
> +	return sd_to_rdacm20(i2c_get_clientdata(client));
> +}
> +
> +static int ov10635_read16(struct rdacm20_device *dev, u16 reg)
> +{
> +	u8 buf[2] = { reg >> 8, reg & 0xff };
> +	int ret;
> +
> +	ret = i2c_master_send(dev->sensor, buf, 2);
> +	if (ret != 2) {
> +		dev_dbg(dev->dev, "%s: register 0x%04x write failed (%d)\n",
> +			__func__, reg, ret);
> +		return ret;
> +	}
> +
> +	ret = i2c_master_recv(dev->sensor, buf, 2);
> +	if (ret < 0) {
> +		dev_dbg(dev->dev, "%s: register 0x%04x read failed (%d)\n",
> +			__func__, reg, ret);
> +		return ret;
> +	}
> +
> +	return (buf[0] << 8) | buf[1];
> +}
> +
> +static int __ov10635_write(struct rdacm20_device *dev, u16 reg, u8 val)
> +{
> +	u8 buf[3] = { reg >> 8, reg & 0xff, val };
> +	int ret;
> +
> +	dev_dbg(dev->dev, "%s(0x%04x, 0x%02x)\n", __func__, reg, val);
> +
> +	ret = i2c_master_send(dev->sensor, buf, 3);
> +	return ret < 0 ? ret : 0;
> +}
> +
> +static int ov10635_write(struct rdacm20_device *dev, u16 reg, u8 val)
> +{
> +	int ret;
> +
> +	ret = __ov10635_write(dev, reg, val);
> +	if (ret < 0)
> +		dev_err(dev->dev, "%s: register 0x%04x write failed (%d)\n",
> +			__func__, reg, ret);
> +
> +	return ret;
> +}
> +
> +static int ov10635_set_regs(struct rdacm20_device *dev,
> +			    const struct ov10635_reg *regs,
> +			    unsigned int nr_regs)
> +{
> +	unsigned int i;
> +	int ret;
> +
> +	for (i = 0; i < nr_regs; i++) {
> +		ret = __ov10635_write(dev, regs[i].reg, regs[i].val);
> +		if (ret) {
> +			dev_err(dev->dev,
> +				"%s: register %u (0x%04x) write failed (%d)\n",
> +				__func__, i, regs[i].reg, ret);
> +			return ret;
> +		}
> +	}
> +
> +	return 0;
> +}
> +
> +static int rdacm20_s_stream(struct v4l2_subdev *sd, int enable)
> +{
> +	struct rdacm20_device *dev = sd_to_rdacm20(sd);
> +
> +	return max9271_set_serial_link(dev->serializer, enable);
> +}
> +
> +static int rdacm20_enum_mbus_code(struct v4l2_subdev *sd,
> +				  struct v4l2_subdev_pad_config *cfg,
> +				  struct v4l2_subdev_mbus_code_enum *code)
> +{
> +	if (code->pad || code->index > 0)
> +		return -EINVAL;
> +
> +	code->code = MEDIA_BUS_FMT_UYVY8_2X8;
> +
> +	return 0;
> +}
> +
> +static int rdacm20_get_fmt(struct v4l2_subdev *sd,
> +			   struct v4l2_subdev_pad_config *cfg,
> +			   struct v4l2_subdev_format *format)
> +{
> +	struct v4l2_mbus_framefmt *mf = &format->format;
> +
> +	if (format->pad)
> +		return -EINVAL;
> +
> +	mf->width		= OV10635_WIDTH;
> +	mf->height		= OV10635_HEIGHT;
> +	mf->code		= MEDIA_BUS_FMT_UYVY8_2X8;
> +	mf->colorspace		= V4L2_COLORSPACE_RAW;
> +	mf->field		= V4L2_FIELD_NONE;
> +	mf->ycbcr_enc		= V4L2_YCBCR_ENC_601;
> +	mf->quantization	= V4L2_QUANTIZATION_FULL_RANGE;
> +	mf->xfer_func		= V4L2_XFER_FUNC_NONE;
> +
> +	return 0;
> +}
> +
> +static struct v4l2_subdev_video_ops rdacm20_video_ops = {
> +	.s_stream	= rdacm20_s_stream,
> +};
> +
> +static const struct v4l2_subdev_pad_ops rdacm20_subdev_pad_ops = {
> +	.enum_mbus_code = rdacm20_enum_mbus_code,
> +	.get_fmt	= rdacm20_get_fmt,
> +	.set_fmt	= rdacm20_get_fmt,
> +};
> +
> +static struct v4l2_subdev_ops rdacm20_subdev_ops = {
> +	.video		= &rdacm20_video_ops,
> +	.pad		= &rdacm20_subdev_pad_ops,
> +};
> +
> +static int rdacm20_initialize(struct rdacm20_device *dev)
> +{
> +	unsigned int retry = 3;
> +	int ret;
> +
> +	/* Verify communication with the MAX9271: ping to wakeup. */
> +	dev->serializer->client->addr = MAX9271_DEFAULT_ADDR;
> +	i2c_smbus_read_byte(dev->serializer->client);
> +
> +	/* Serial link disabled during config as it needs a valid pixel clock. */
> +	ret = max9271_set_serial_link(dev->serializer, false);
> +	if (ret)
> +		return ret;
> +
> +	/*
> +	 *  Ensure that we have a good link configuration before attempting to
> +	 *  identify the device.
> +	 */
> +	max9271_configure_i2c(dev->serializer, MAX9271_I2CSLVSH_469NS_234NS |
> +					       MAX9271_I2CSLVTO_1024US |
> +					       MAX9271_I2CMSTBT_105KBPS);
> +
> +	max9271_configure_gmsl_link(dev->serializer);
> +
> +	ret = max9271_verify_id(dev->serializer);
> +	if (ret < 0)
> +		return ret;
> +
> +	ret = max9271_set_address(dev->serializer, dev->addrs[0]);
> +	if (ret < 0)
> +		return ret;
> +	dev->serializer->client->addr = dev->addrs[0];
> +
> +	/*
> +	 * Reset the sensor by cycling the OV10635 reset signal connected to the
> +	 * MAX9271 GPIO1 and verify communication with the OV10635.
> +	 */
> +	max9271_clear_gpios(dev->serializer, MAX9271_GPIO1OUT);
> +	mdelay(10);

Why mdelay(), a busy loop and not msleep()??? Same below.

> +	max9271_set_gpios(dev->serializer, MAX9271_GPIO1OUT);
> +	mdelay(10);
> +
> +again:
> +	ret = ov10635_read16(dev, OV10635_PID);
> +	if (ret < 0) {
> +		if (retry--)
> +			goto again;
> +
> +		dev_err(dev->dev, "OV10635 ID read failed (%d)\n",
> +			ret);
> +		return -ENXIO;
> +	}
> +
> +	if (ret != OV10635_VERSION) {
> +		if (retry--)
> +			goto again;
> +
> +		dev_err(dev->dev, "OV10635 ID mismatch (0x%04x)\n",
> +			ret);
> +		return -ENXIO;
> +	}
> +
> +	/* Change the sensor I2C address. */
> +	ret = ov10635_write(dev, OV10635_SC_CMMN_SCCB_ID,
> +			    (dev->addrs[1] << 1) |
> +			    OV10635_SC_CMMN_SCCB_ID_SELECT);
> +	if (ret < 0) {
> +		dev_err(dev->dev,
> +			"OV10635 I2C address change failed (%d)\n", ret);
> +		return ret;
> +	}
> +	dev->sensor->addr = dev->addrs[1];
> +	usleep_range(3500, 5000);
> +
> +	/* Program the 0V10635 initial configuration. */
> +	ret = ov10635_set_regs(dev, ov10635_regs_wizard,
> +			       ARRAY_SIZE(ov10635_regs_wizard));
> +	if (ret)
> +		return ret;
> +
> +	dev_info(dev->dev, "Identified MAX9271 + OV10635 device\n");
> +
> +	return 0;
> +}
> +
> +static int rdacm20_probe(struct i2c_client *client)
> +{
> +	struct rdacm20_device *dev;
> +	struct fwnode_handle *ep;
> +	int ret;
> +
> +	dev = devm_kzalloc(&client->dev, sizeof(*dev), GFP_KERNEL);
> +	if (!dev)
> +		return -ENOMEM;
> +	dev->dev = &client->dev;
> +
> +	dev->serializer = devm_kzalloc(&client->dev, sizeof(*dev->serializer),
> +				       GFP_KERNEL);
> +	if (!dev->serializer)
> +		return -ENOMEM;
> +
> +	dev->serializer->client = client;
> +
> +	ret = of_property_read_u32_array(client->dev.of_node, "reg",
> +					 dev->addrs, 2);
> +	if (ret < 0) {
> +		dev_err(dev->dev, "Invalid DT reg property: %d\n", ret);
> +		return -EINVAL;
> +	}
> +
> +	/* Create the dummy I2C client for the sensor. */
> +	dev->sensor = i2c_new_dummy_device(client->adapter,
> +					   OV10635_I2C_ADDRESS);
> +	if (IS_ERR(dev->sensor)) {
> +		ret = PTR_ERR(dev->sensor);
> +		goto error;
> +	}
> +
> +	/* Initialize the hardware. */
> +	ret = rdacm20_initialize(dev);
> +	if (ret < 0)
> +		goto error;
> +
> +	/* Initialize and register the subdevice. */
> +	v4l2_i2c_subdev_init(&dev->sd, client, &rdacm20_subdev_ops);
> +	dev->sd.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;
> +
> +	v4l2_ctrl_handler_init(&dev->ctrls, 1);
> +	v4l2_ctrl_new_std(&dev->ctrls, NULL, V4L2_CID_PIXEL_RATE,
> +			  OV10635_PIXEL_RATE, OV10635_PIXEL_RATE, 1,
> +			  OV10635_PIXEL_RATE);
> +	dev->sd.ctrl_handler = &dev->ctrls;
> +
> +	ret = dev->ctrls.error;
> +	if (ret)
> +		goto error_free_ctrls;
> +
> +	dev->pad.flags = MEDIA_PAD_FL_SOURCE;
> +	dev->sd.entity.flags |= MEDIA_ENT_F_CAM_SENSOR;
> +	ret = media_entity_pads_init(&dev->sd.entity, 1, &dev->pad);
> +	if (ret < 0)
> +		goto error_free_ctrls;
> +
> +	ep = fwnode_graph_get_next_endpoint(dev_fwnode(&client->dev), NULL);
> +	if (!ep) {
> +		dev_err(&client->dev,
> +			"Unable to get endpoint in node %pOF\n",
> +			client->dev.of_node);
> +		ret = -ENOENT;
> +		goto error_free_ctrls;
> +	}
> +	dev->sd.fwnode = ep;
> +
> +	ret = v4l2_async_register_subdev(&dev->sd);
> +	if (ret)
> +		goto error_put_node;
> +
> +	return 0;
> +
> +error_put_node:
> +	fwnode_handle_put(ep);
> +error_free_ctrls:
> +	v4l2_ctrl_handler_free(&dev->ctrls);
> +error:
> +	media_entity_cleanup(&dev->sd.entity);
> +	if (dev->sensor)
> +		i2c_unregister_device(dev->sensor);
> +
> +	dev_err(&client->dev, "probe failed\n");
> +
> +	return ret;
> +}
> +
> +static int rdacm20_remove(struct i2c_client *client)
> +{
> +	struct rdacm20_device *dev = i2c_to_rdacm20(client);
> +
> +	fwnode_handle_put(dev->sd.fwnode);
> +	v4l2_async_unregister_subdev(&dev->sd);
> +	v4l2_ctrl_handler_free(&dev->ctrls);
> +	media_entity_cleanup(&dev->sd.entity);
> +	i2c_unregister_device(dev->sensor);
> +
> +	return 0;
> +}
> +
> +static void rdacm20_shutdown(struct i2c_client *client)
> +{
> +	struct rdacm20_device *dev = i2c_to_rdacm20(client);
> +
> +	/* make sure stream off during shutdown (reset/reboot) */
> +	rdacm20_s_stream(&dev->sd, 0);
> +}
> +
> +static const struct of_device_id rdacm20_of_ids[] = {
> +	{ .compatible = "imi,rdacm20", },
> +	{ }
> +};
> +MODULE_DEVICE_TABLE(of, rdacm20_of_ids);
> +
> +static struct i2c_driver rdacm20_i2c_driver = {
> +	.driver	= {
> +		.name	= "rdacm20",
> +		.of_match_table = rdacm20_of_ids,
> +	},
> +	.probe_new	= rdacm20_probe,
> +	.remove		= rdacm20_remove,
> +	.shutdown	= rdacm20_shutdown,
> +};
> +
> +module_i2c_driver(rdacm20_i2c_driver);
> +
> +MODULE_DESCRIPTION("GMSL Camera driver for RDACM20");
> +MODULE_AUTHOR("Vladimir Barinov");
> +MODULE_LICENSE("GPL");

-- 
Regards,

Sakari Ailus

Re: [PATCH v9 4/4] media: i2c: Add RDACM20 driver

[Jacopo Mondi]

Hi Sakari

On Sun, May 17, 2020 at 01:36:57AM +0300, Sakari Ailus wrote:
> Hi Kieran,
>

[snip]

> > +
> > +/*
> > + * As the drivers supports a single MEDIA_BUS_FMT_UYVY8_2X8 format we
> > + * can harcode the pixel rate.
>
> Is this somehow the property of RDACM20? Or could you use other
> configurations here? (I'm not suggesting you should do now.)
>

As per the device datasheet RAW10 and YUYV10 is also supported.
The driver currently supports YUYV8_2X8 only.

> > + *
> > + * PCLK is fed through the system clock, programmed @88MHz.
> > + * MEDIA_BUS_FMT_UYVY8_2X8 format = 2 samples per pixel.
> > + *
> > + * Pixelrate = PCLK / 2
> > + * FPS = (OV10635_VTS * OV10635_HTS) / PixelRate
> > + *     = 29,9998
> > + */
> > +#define OV10635_PIXEL_RATE		(44000000)
> > +
> > +static const struct ov10635_reg {
> > +	u16	reg;
> > +	u8	val;
> > +} ov10635_regs_wizard[] = {
> > +	{ 0x301b, 0xff }, { 0x301c, 0xff }, { 0x301a, 0xff }, { 0x3011, 0x42 },
> > +	{ 0x6900, 0x0c }, { 0x6901, 0x19 }, { 0x3503, 0x10 }, { 0x3025, 0x03 },
> > +	{ 0x3003, 0x16 }, { 0x3004, 0x30 }, { 0x3005, 0x40 }, { 0x3006, 0x91 },
> > +	{ 0x3600, 0x74 }, { 0x3601, 0x2b }, { 0x3612, 0x00 }, { 0x3611, 0x67 },
> > +	{ 0x3633, 0xca }, { 0x3602, 0xaf }, { 0x3603, 0x04 }, { 0x3630, 0x28 },
> > +	{ 0x3631, 0x16 }, { 0x3714, 0x10 }, { 0x371d, 0x01 }, { 0x4300, 0x3a },
> > +	{ 0x3007, 0x01 }, { 0x3024, 0x03 }, { 0x3020, 0x0a }, { 0x3702, 0x0d },
> > +	{ 0x3703, 0x20 }, { 0x3704, 0x15 }, { 0x3709, 0xa8 }, { 0x370c, 0xc7 },
> > +	{ 0x370d, 0x80 }, { 0x3712, 0x00 }, { 0x3713, 0x20 }, { 0x3715, 0x04 },
> > +	{ 0x381d, 0x40 }, { 0x381c, 0x00 }, { 0x3822, 0x50 }, { 0x3824, 0x10 },
> > +	{ 0x3815, 0x8c }, { 0x3804, 0x05 }, { 0x3805, 0x1f }, { 0x3800, 0x00 },
> > +	{ 0x3801, 0x00 }, { 0x3806, 0x03 }, { 0x3807, 0x28 }, { 0x3802, 0x00 },
> > +	{ 0x3803, 0x07 }, { 0x3808, 0x05 }, { 0x3809, 0x00 }, { 0x380a, 0x03 },
> > +	{ 0x380b, 0x20 }, { 0x380c, OV10635_HTS >> 8 },
> > +	{ 0x380d, OV10635_HTS & 0xff }, { 0x380e, OV10635_VTS >> 8 },
> > +	{ 0x380f, OV10635_VTS & 0xff },	{ 0x3813, 0x02 }, { 0x3811, 0x08 },
> > +	{ 0x381f, 0x0c }, { 0x3819, 0x04 }, { 0x3804, 0x01 }, { 0x3805, 0x00 },
> > +	{ 0x3828, 0x03 }, { 0x3829, 0x10 }, { 0x382a, 0x10 }, { 0x3621, 0x63 },
> > +	{ 0x5005, 0x08 }, { 0x56d5, 0x00 }, { 0x56d6, 0x80 }, { 0x56d7, 0x00 },
> > +	{ 0x56d8, 0x00 }, { 0x56d9, 0x00 }, { 0x56da, 0x80 }, { 0x56db, 0x00 },
> > +	{ 0x56dc, 0x00 }, { 0x56e8, 0x00 }, { 0x56e9, 0x7f }, { 0x56ea, 0x00 },
> > +	{ 0x56eb, 0x7f }, { 0x5100, 0x00 }, { 0x5101, 0x80 }, { 0x5102, 0x00 },
> > +	{ 0x5103, 0x80 }, { 0x5104, 0x00 }, { 0x5105, 0x80 }, { 0x5106, 0x00 },
> > +	{ 0x5107, 0x80 }, { 0x5108, 0x00 }, { 0x5109, 0x00 }, { 0x510a, 0x00 },
> > +	{ 0x510b, 0x00 }, { 0x510c, 0x00 }, { 0x510d, 0x00 }, { 0x510e, 0x00 },
> > +	{ 0x510f, 0x00 }, { 0x5110, 0x00 }, { 0x5111, 0x80 }, { 0x5112, 0x00 },
> > +	{ 0x5113, 0x80 }, { 0x5114, 0x00 }, { 0x5115, 0x80 }, { 0x5116, 0x00 },
> > +	{ 0x5117, 0x80 }, { 0x5118, 0x00 }, { 0x5119, 0x00 }, { 0x511a, 0x00 },
> > +	{ 0x511b, 0x00 }, { 0x511c, 0x00 }, { 0x511d, 0x00 }, { 0x511e, 0x00 },
> > +	{ 0x511f, 0x00 }, { 0x56d0, 0x00 }, { 0x5006, 0x04 }, { 0x5608, 0x05 },
> > +	{ 0x52d7, 0x06 }, { 0x528d, 0x08 }, { 0x5293, 0x12 }, { 0x52d3, 0x12 },
> > +	{ 0x5288, 0x06 }, { 0x5289, 0x20 }, { 0x52c8, 0x06 }, { 0x52c9, 0x20 },
> > +	{ 0x52cd, 0x04 }, { 0x5381, 0x00 }, { 0x5382, 0xff }, { 0x5589, 0x76 },
> > +	{ 0x558a, 0x47 }, { 0x558b, 0xef }, { 0x558c, 0xc9 }, { 0x558d, 0x49 },
> > +	{ 0x558e, 0x30 }, { 0x558f, 0x67 }, { 0x5590, 0x3f }, { 0x5591, 0xf0 },
> > +	{ 0x5592, 0x10 }, { 0x55a2, 0x6d }, { 0x55a3, 0x55 }, { 0x55a4, 0xc3 },
> > +	{ 0x55a5, 0xb5 }, { 0x55a6, 0x43 }, { 0x55a7, 0x38 }, { 0x55a8, 0x5f },
> > +	{ 0x55a9, 0x4b }, { 0x55aa, 0xf0 }, { 0x55ab, 0x10 }, { 0x5581, 0x52 },
> > +	{ 0x5300, 0x01 }, { 0x5301, 0x00 }, { 0x5302, 0x00 }, { 0x5303, 0x0e },
> > +	{ 0x5304, 0x00 }, { 0x5305, 0x0e }, { 0x5306, 0x00 }, { 0x5307, 0x36 },
> > +	{ 0x5308, 0x00 }, { 0x5309, 0xd9 }, { 0x530a, 0x00 }, { 0x530b, 0x0f },
> > +	{ 0x530c, 0x00 }, { 0x530d, 0x2c }, { 0x530e, 0x00 }, { 0x530f, 0x59 },
> > +	{ 0x5310, 0x00 }, { 0x5311, 0x7b }, { 0x5312, 0x00 }, { 0x5313, 0x22 },
> > +	{ 0x5314, 0x00 }, { 0x5315, 0xd5 }, { 0x5316, 0x00 }, { 0x5317, 0x13 },
> > +	{ 0x5318, 0x00 }, { 0x5319, 0x18 }, { 0x531a, 0x00 }, { 0x531b, 0x26 },
> > +	{ 0x531c, 0x00 }, { 0x531d, 0xdc }, { 0x531e, 0x00 }, { 0x531f, 0x02 },
> > +	{ 0x5320, 0x00 }, { 0x5321, 0x24 }, { 0x5322, 0x00 }, { 0x5323, 0x56 },
> > +	{ 0x5324, 0x00 }, { 0x5325, 0x85 }, { 0x5326, 0x00 }, { 0x5327, 0x20 },
> > +	{ 0x5609, 0x01 }, { 0x560a, 0x40 }, { 0x560b, 0x01 }, { 0x560c, 0x40 },
> > +	{ 0x560d, 0x00 }, { 0x560e, 0xfa }, { 0x560f, 0x00 }, { 0x5610, 0xfa },
> > +	{ 0x5611, 0x02 }, { 0x5612, 0x80 }, { 0x5613, 0x02 }, { 0x5614, 0x80 },
> > +	{ 0x5615, 0x01 }, { 0x5616, 0x2c }, { 0x5617, 0x01 }, { 0x5618, 0x2c },
> > +	{ 0x563b, 0x01 }, { 0x563c, 0x01 }, { 0x563d, 0x01 }, { 0x563e, 0x01 },
> > +	{ 0x563f, 0x03 }, { 0x5640, 0x03 }, { 0x5641, 0x03 }, { 0x5642, 0x05 },
> > +	{ 0x5643, 0x09 }, { 0x5644, 0x05 }, { 0x5645, 0x05 }, { 0x5646, 0x05 },
> > +	{ 0x5647, 0x05 }, { 0x5651, 0x00 }, { 0x5652, 0x80 }, { 0x521a, 0x01 },
> > +	{ 0x521b, 0x03 }, { 0x521c, 0x06 }, { 0x521d, 0x0a }, { 0x521e, 0x0e },
> > +	{ 0x521f, 0x12 }, { 0x5220, 0x16 }, { 0x5223, 0x02 }, { 0x5225, 0x04 },
> > +	{ 0x5227, 0x08 }, { 0x5229, 0x0c }, { 0x522b, 0x12 }, { 0x522d, 0x18 },
> > +	{ 0x522f, 0x1e }, { 0x5241, 0x04 }, { 0x5242, 0x01 }, { 0x5243, 0x03 },
> > +	{ 0x5244, 0x06 }, { 0x5245, 0x0a }, { 0x5246, 0x0e }, { 0x5247, 0x12 },
> > +	{ 0x5248, 0x16 }, { 0x524a, 0x03 }, { 0x524c, 0x04 }, { 0x524e, 0x08 },
> > +	{ 0x5250, 0x0c }, { 0x5252, 0x12 }, { 0x5254, 0x18 }, { 0x5256, 0x1e },
> > +	/* fifo_line_length = 2*hts */
> > +	{ 0x4606, (2 * OV10635_HTS) >> 8 }, { 0x4607, (2 * OV10635_HTS) & 0xff },
> > +	/* fifo_hsync_start = 2*(hts - xres) */
> > +	{ 0x460a, (2 * (OV10635_HTS - OV10635_WIDTH)) >> 8 },
> > +	{ 0x460b, (2 * (OV10635_HTS - OV10635_WIDTH)) & 0xff },
> > +	{ 0x460c, 0x00 }, { 0x4620, 0x0e },
> > +	/* BT601: 0x08 is also acceptable as HS/VS mode */
> > +	{ 0x4700, 0x04 }, { 0x4701, 0x00 }, { 0x4702, 0x01 }, { 0x4004, 0x04 },
> > +	{ 0x4005, 0x18 }, { 0x4001, 0x06 }, { 0x4050, 0x22 }, { 0x4051, 0x24 },
> > +	{ 0x4052, 0x02 }, { 0x4057, 0x9c }, { 0x405a, 0x00 }, { 0x4202, 0x02 },
> > +	{ 0x3023, 0x10 }, { 0x0100, 0x01 }, { 0x0100, 0x01 }, { 0x6f10, 0x07 },
> > +	{ 0x6f11, 0x82 }, { 0x6f12, 0x04 }, { 0x6f13, 0x00 }, { 0xd000, 0x19 },
> > +	{ 0xd001, 0xa0 }, { 0xd002, 0x00 }, { 0xd003, 0x01 }, { 0xd004, 0xa9 },
> > +	{ 0xd005, 0xad }, { 0xd006, 0x10 }, { 0xd007, 0x40 }, { 0xd008, 0x44 },
> > +	{ 0xd009, 0x00 }, { 0xd00a, 0x68 }, { 0xd00b, 0x00 }, { 0xd00c, 0x15 },
> > +	{ 0xd00d, 0x00 }, { 0xd00e, 0x00 }, { 0xd00f, 0x00 }, { 0xd040, 0x9c },
> > +	{ 0xd041, 0x21 }, { 0xd042, 0xff }, { 0xd043, 0xf8 }, { 0xd044, 0xd4 },
> > +	{ 0xd045, 0x01 }, { 0xd046, 0x48 }, { 0xd047, 0x00 }, { 0xd048, 0xd4 },
> > +	{ 0xd049, 0x01 }, { 0xd04a, 0x50 }, { 0xd04b, 0x04 }, { 0xd04c, 0x18 },
> > +	{ 0xd04d, 0x60 }, { 0xd04e, 0x00 }, { 0xd04f, 0x01 }, { 0xd050, 0xa8 },
> > +	{ 0xd051, 0x63 }, { 0xd052, 0x02 }, { 0xd053, 0xa4 }, { 0xd054, 0x85 },
> > +	{ 0xd055, 0x43 }, { 0xd056, 0x00 }, { 0xd057, 0x00 }, { 0xd058, 0x18 },
> > +	{ 0xd059, 0x60 }, { 0xd05a, 0x00 }, { 0xd05b, 0x01 }, { 0xd05c, 0xa8 },
> > +	{ 0xd05d, 0x63 }, { 0xd05e, 0x03 }, { 0xd05f, 0xf0 }, { 0xd060, 0x98 },
> > +	{ 0xd061, 0xa3 }, { 0xd062, 0x00 }, { 0xd063, 0x00 }, { 0xd064, 0x8c },
> > +	{ 0xd065, 0x6a }, { 0xd066, 0x00 }, { 0xd067, 0x6e }, { 0xd068, 0xe5 },
> > +	{ 0xd069, 0x85 }, { 0xd06a, 0x18 }, { 0xd06b, 0x00 }, { 0xd06c, 0x10 },
> > +	{ 0xd06d, 0x00 }, { 0xd06e, 0x00 }, { 0xd06f, 0x10 }, { 0xd070, 0x9c },
> > +	{ 0xd071, 0x80 }, { 0xd072, 0x00 }, { 0xd073, 0x03 }, { 0xd074, 0x18 },
> > +	{ 0xd075, 0x60 }, { 0xd076, 0x00 }, { 0xd077, 0x01 }, { 0xd078, 0xa8 },
> > +	{ 0xd079, 0x63 }, { 0xd07a, 0x07 }, { 0xd07b, 0x80 }, { 0xd07c, 0x07 },
> > +	{ 0xd07d, 0xff }, { 0xd07e, 0xf9 }, { 0xd07f, 0x03 }, { 0xd080, 0x8c },
> > +	{ 0xd081, 0x63 }, { 0xd082, 0x00 }, { 0xd083, 0x00 }, { 0xd084, 0xa5 },
> > +	{ 0xd085, 0x6b }, { 0xd086, 0x00 }, { 0xd087, 0xff }, { 0xd088, 0x18 },
> > +	{ 0xd089, 0x80 }, { 0xd08a, 0x00 }, { 0xd08b, 0x01 }, { 0xd08c, 0xa8 },
> > +	{ 0xd08d, 0x84 }, { 0xd08e, 0x01 }, { 0xd08f, 0x04 }, { 0xd090, 0xe1 },
> > +	{ 0xd091, 0x6b }, { 0xd092, 0x58 }, { 0xd093, 0x00 }, { 0xd094, 0x94 },
> > +	{ 0xd095, 0x6a }, { 0xd096, 0x00 }, { 0xd097, 0x70 }, { 0xd098, 0xe1 },
> > +	{ 0xd099, 0x6b }, { 0xd09a, 0x20 }, { 0xd09b, 0x00 }, { 0xd09c, 0x95 },
> > +	{ 0xd09d, 0x6b }, { 0xd09e, 0x00 }, { 0xd09f, 0x00 }, { 0xd0a0, 0xe4 },
> > +	{ 0xd0a1, 0x8b }, { 0xd0a2, 0x18 }, { 0xd0a3, 0x00 }, { 0xd0a4, 0x0c },
> > +	{ 0xd0a5, 0x00 }, { 0xd0a6, 0x00 }, { 0xd0a7, 0x23 }, { 0xd0a8, 0x15 },
> > +	{ 0xd0a9, 0x00 }, { 0xd0aa, 0x00 }, { 0xd0ab, 0x00 }, { 0xd0ac, 0x18 },
> > +	{ 0xd0ad, 0x60 }, { 0xd0ae, 0x80 }, { 0xd0af, 0x06 }, { 0xd0b0, 0xa8 },
> > +	{ 0xd0b1, 0x83 }, { 0xd0b2, 0x40 }, { 0xd0b3, 0x08 }, { 0xd0b4, 0xa8 },
> > +	{ 0xd0b5, 0xe3 }, { 0xd0b6, 0x38 }, { 0xd0b7, 0x2a }, { 0xd0b8, 0xa8 },
> > +	{ 0xd0b9, 0xc3 }, { 0xd0ba, 0x40 }, { 0xd0bb, 0x09 }, { 0xd0bc, 0xa8 },
> > +	{ 0xd0bd, 0xa3 }, { 0xd0be, 0x38 }, { 0xd0bf, 0x29 }, { 0xd0c0, 0x8c },
> > +	{ 0xd0c1, 0x65 }, { 0xd0c2, 0x00 }, { 0xd0c3, 0x00 }, { 0xd0c4, 0xd8 },
> > +	{ 0xd0c5, 0x04 }, { 0xd0c6, 0x18 }, { 0xd0c7, 0x00 }, { 0xd0c8, 0x8c },
> > +	{ 0xd0c9, 0x67 }, { 0xd0ca, 0x00 }, { 0xd0cb, 0x00 }, { 0xd0cc, 0xd8 },
> > +	{ 0xd0cd, 0x06 }, { 0xd0ce, 0x18 }, { 0xd0cf, 0x00 }, { 0xd0d0, 0x18 },
> > +	{ 0xd0d1, 0x60 }, { 0xd0d2, 0x80 }, { 0xd0d3, 0x06 }, { 0xd0d4, 0xa8 },
> > +	{ 0xd0d5, 0xe3 }, { 0xd0d6, 0x67 }, { 0xd0d7, 0x02 }, { 0xd0d8, 0xa9 },
> > +	{ 0xd0d9, 0x03 }, { 0xd0da, 0x67 }, { 0xd0db, 0x03 }, { 0xd0dc, 0xa8 },
> > +	{ 0xd0dd, 0xc3 }, { 0xd0de, 0x3d }, { 0xd0df, 0x05 }, { 0xd0e0, 0x8c },
> > +	{ 0xd0e1, 0x66 }, { 0xd0e2, 0x00 }, { 0xd0e3, 0x00 }, { 0xd0e4, 0xb8 },
> > +	{ 0xd0e5, 0x63 }, { 0xd0e6, 0x00 }, { 0xd0e7, 0x18 }, { 0xd0e8, 0xb8 },
> > +	{ 0xd0e9, 0x63 }, { 0xd0ea, 0x00 }, { 0xd0eb, 0x98 }, { 0xd0ec, 0xbc },
> > +	{ 0xd0ed, 0x03 }, { 0xd0ee, 0x00 }, { 0xd0ef, 0x00 }, { 0xd0f0, 0x10 },
> > +	{ 0xd0f1, 0x00 }, { 0xd0f2, 0x00 }, { 0xd0f3, 0x16 }, { 0xd0f4, 0xb8 },
> > +	{ 0xd0f5, 0x83 }, { 0xd0f6, 0x00 }, { 0xd0f7, 0x19 }, { 0xd0f8, 0x8c },
> > +	{ 0xd0f9, 0x67 }, { 0xd0fa, 0x00 }, { 0xd0fb, 0x00 }, { 0xd0fc, 0xb8 },
> > +	{ 0xd0fd, 0xa4 }, { 0xd0fe, 0x00 }, { 0xd0ff, 0x98 }, { 0xd100, 0xb8 },
> > +	{ 0xd101, 0x83 }, { 0xd102, 0x00 }, { 0xd103, 0x08 }, { 0xd104, 0x8c },
> > +	{ 0xd105, 0x68 }, { 0xd106, 0x00 }, { 0xd107, 0x00 }, { 0xd108, 0xe0 },
> > +	{ 0xd109, 0x63 }, { 0xd10a, 0x20 }, { 0xd10b, 0x04 }, { 0xd10c, 0xe0 },
> > +	{ 0xd10d, 0x65 }, { 0xd10e, 0x18 }, { 0xd10f, 0x00 }, { 0xd110, 0xa4 },
> > +	{ 0xd111, 0x83 }, { 0xd112, 0xff }, { 0xd113, 0xff }, { 0xd114, 0xb8 },
> > +	{ 0xd115, 0x64 }, { 0xd116, 0x00 }, { 0xd117, 0x48 }, { 0xd118, 0xd8 },
> > +	{ 0xd119, 0x07 }, { 0xd11a, 0x18 }, { 0xd11b, 0x00 }, { 0xd11c, 0xd8 },
> > +	{ 0xd11d, 0x08 }, { 0xd11e, 0x20 }, { 0xd11f, 0x00 }, { 0xd120, 0x9c },
> > +	{ 0xd121, 0x60 }, { 0xd122, 0x00 }, { 0xd123, 0x00 }, { 0xd124, 0xd8 },
> > +	{ 0xd125, 0x06 }, { 0xd126, 0x18 }, { 0xd127, 0x00 }, { 0xd128, 0x00 },
> > +	{ 0xd129, 0x00 }, { 0xd12a, 0x00 }, { 0xd12b, 0x08 }, { 0xd12c, 0x15 },
> > +	{ 0xd12d, 0x00 }, { 0xd12e, 0x00 }, { 0xd12f, 0x00 }, { 0xd130, 0x8c },
> > +	{ 0xd131, 0x6a }, { 0xd132, 0x00 }, { 0xd133, 0x76 }, { 0xd134, 0xbc },
> > +	{ 0xd135, 0x23 }, { 0xd136, 0x00 }, { 0xd137, 0x00 }, { 0xd138, 0x13 },
> > +	{ 0xd139, 0xff }, { 0xd13a, 0xff }, { 0xd13b, 0xe6 }, { 0xd13c, 0x18 },
> > +	{ 0xd13d, 0x60 }, { 0xd13e, 0x80 }, { 0xd13f, 0x06 }, { 0xd140, 0x03 },
> > +	{ 0xd141, 0xff }, { 0xd142, 0xff }, { 0xd143, 0xdd }, { 0xd144, 0xa8 },
> > +	{ 0xd145, 0x83 }, { 0xd146, 0x40 }, { 0xd147, 0x08 }, { 0xd148, 0x85 },
> > +	{ 0xd149, 0x21 }, { 0xd14a, 0x00 }, { 0xd14b, 0x00 }, { 0xd14c, 0x85 },
> > +	{ 0xd14d, 0x41 }, { 0xd14e, 0x00 }, { 0xd14f, 0x04 }, { 0xd150, 0x44 },
> > +	{ 0xd151, 0x00 }, { 0xd152, 0x48 }, { 0xd153, 0x00 }, { 0xd154, 0x9c },
> > +	{ 0xd155, 0x21 }, { 0xd156, 0x00 }, { 0xd157, 0x08 }, { 0x6f0e, 0x03 },
> > +	{ 0x6f0f, 0x00 }, { 0x460e, 0x08 }, { 0x460f, 0x01 }, { 0x4610, 0x00 },
> > +	{ 0x4611, 0x01 }, { 0x4612, 0x00 }, { 0x4613, 0x01 },
> > +	/* 8 bits */
> > +	{ 0x4605, 0x08 },
> > +	/* Swap data bits order [9:0] -> [0:9] */
> > +	{ 0x4709, 0x10 }, { 0x4608, 0x00 }, { 0x4609, 0x08 }, { 0x6804, 0x00 },
> > +	{ 0x6805, 0x06 }, { 0x6806, 0x00 }, { 0x5120, 0x00 }, { 0x3510, 0x00 },
> > +	{ 0x3504, 0x00 }, { 0x6800, 0x00 }, { 0x6f0d, 0x01 },
> > +	/* PCLK falling edge */
> > +	{ 0x4708, 0x01 }, { 0x5000, 0xff }, { 0x5001, 0xbf }, { 0x5002, 0x7e },
> > +	{ 0x503d, 0x00 }, { 0xc450, 0x01 }, { 0xc452, 0x04 }, { 0xc453, 0x00 },
> > +	{ 0xc454, 0x00 }, { 0xc455, 0x01 }, { 0xc456, 0x01 }, { 0xc457, 0x00 },
> > +	{ 0xc458, 0x00 }, { 0xc459, 0x00 }, { 0xc45b, 0x00 }, { 0xc45c, 0x01 },
> > +	{ 0xc45d, 0x00 }, { 0xc45e, 0x00 }, { 0xc45f, 0x00 }, { 0xc460, 0x00 },
> > +	{ 0xc461, 0x01 }, { 0xc462, 0x01 }, { 0xc464, 0x03 }, { 0xc465, 0x00 },
> > +	{ 0xc466, 0x8a }, { 0xc467, 0x00 }, { 0xc468, 0x86 }, { 0xc469, 0x00 },
> > +	{ 0xc46a, 0x40 }, { 0xc46b, 0x50 }, { 0xc46c, 0x30 }, { 0xc46d, 0x28 },
> > +	{ 0xc46e, 0x60 }, { 0xc46f, 0x40 }, { 0xc47c, 0x01 }, { 0xc47d, 0x38 },
> > +	{ 0xc47e, 0x00 }, { 0xc47f, 0x00 }, { 0xc480, 0x00 }, { 0xc481, 0xff },
> > +	{ 0xc482, 0x00 }, { 0xc483, 0x40 }, { 0xc484, 0x00 }, { 0xc485, 0x18 },
> > +	{ 0xc486, 0x00 }, { 0xc487, 0x18 },
> > +	{ 0xc488, (OV10635_VTS - 8) * 16 >> 8},
> > +	{ 0xc489, (OV10635_VTS - 8) * 16 & 0xff},
> > +	{ 0xc48a, (OV10635_VTS - 8) * 16 >> 8},
> > +	{ 0xc48b, (OV10635_VTS - 8) * 16 & 0xff}, { 0xc48c, 0x00 },
> > +	{ 0xc48d, 0x04 }, { 0xc48e, 0x00 }, { 0xc48f, 0x04 }, { 0xc490, 0x03 },
> > +	{ 0xc492, 0x20 }, { 0xc493, 0x08 }, { 0xc498, 0x02 }, { 0xc499, 0x00 },
> > +	{ 0xc49a, 0x02 }, { 0xc49b, 0x00 }, { 0xc49c, 0x02 }, { 0xc49d, 0x00 },
> > +	{ 0xc49e, 0x02 }, { 0xc49f, 0x60 }, { 0xc4a0, 0x03 }, { 0xc4a1, 0x00 },
> > +	{ 0xc4a2, 0x04 }, { 0xc4a3, 0x00 }, { 0xc4a4, 0x00 }, { 0xc4a5, 0x10 },
> > +	{ 0xc4a6, 0x00 }, { 0xc4a7, 0x40 }, { 0xc4a8, 0x00 }, { 0xc4a9, 0x80 },
> > +	{ 0xc4aa, 0x0d }, { 0xc4ab, 0x00 }, { 0xc4ac, 0x0f }, { 0xc4ad, 0xc0 },
> > +	{ 0xc4b4, 0x01 }, { 0xc4b5, 0x01 }, { 0xc4b6, 0x00 }, { 0xc4b7, 0x01 },
> > +	{ 0xc4b8, 0x00 }, { 0xc4b9, 0x01 }, { 0xc4ba, 0x01 }, { 0xc4bb, 0x00 },
> > +	{ 0xc4bc, 0x01 }, { 0xc4bd, 0x60 }, { 0xc4be, 0x02 }, { 0xc4bf, 0x33 },
> > +	{ 0xc4c8, 0x03 }, { 0xc4c9, 0xd0 }, { 0xc4ca, 0x0e }, { 0xc4cb, 0x00 },
> > +	{ 0xc4cc, 0x0e }, { 0xc4cd, 0x51 }, { 0xc4ce, 0x0e }, { 0xc4cf, 0x51 },
> > +	{ 0xc4d0, 0x04 }, { 0xc4d1, 0x80 }, { 0xc4e0, 0x04 }, { 0xc4e1, 0x02 },
> > +	{ 0xc4e2, 0x01 }, { 0xc4e4, 0x10 }, { 0xc4e5, 0x20 }, { 0xc4e6, 0x30 },
> > +	{ 0xc4e7, 0x40 }, { 0xc4e8, 0x50 }, { 0xc4e9, 0x60 }, { 0xc4ea, 0x70 },
> > +	{ 0xc4eb, 0x80 }, { 0xc4ec, 0x90 }, { 0xc4ed, 0xa0 }, { 0xc4ee, 0xb0 },
> > +	{ 0xc4ef, 0xc0 }, { 0xc4f0, 0xd0 }, { 0xc4f1, 0xe0 }, { 0xc4f2, 0xf0 },
> > +	{ 0xc4f3, 0x80 }, { 0xc4f4, 0x00 }, { 0xc4f5, 0x20 }, { 0xc4f6, 0x02 },
> > +	{ 0xc4f7, 0x00 }, { 0xc4f8, 0x00 }, { 0xc4f9, 0x00 }, { 0xc4fa, 0x00 },
> > +	{ 0xc4fb, 0x01 }, { 0xc4fc, 0x01 }, { 0xc4fd, 0x00 }, { 0xc4fe, 0x04 },
> > +	{ 0xc4ff, 0x02 }, { 0xc500, 0x48 }, { 0xc501, 0x74 }, { 0xc502, 0x58 },
> > +	{ 0xc503, 0x80 }, { 0xc504, 0x05 }, { 0xc505, 0x80 }, { 0xc506, 0x03 },
> > +	{ 0xc507, 0x80 }, { 0xc508, 0x01 }, { 0xc509, 0xc0 }, { 0xc50a, 0x01 },
> > +	{ 0xc50b, 0xa0 }, { 0xc50c, 0x01 }, { 0xc50d, 0x2c }, { 0xc50e, 0x01 },
> > +	{ 0xc50f, 0x0a }, { 0xc510, 0x00 }, { 0xc511, 0x00 }, { 0xc512, 0xe5 },
> > +	{ 0xc513, 0x14 }, { 0xc514, 0x04 }, { 0xc515, 0x00 }, { 0xc518, OV10635_VTS >> 8},
> > +	{ 0xc519, OV10635_VTS & 0xff}, { 0xc51a, OV10635_HTS >> 8},
> > +	{ 0xc51b, OV10635_HTS & 0xff}, { 0xc2e0, 0x00 }, { 0xc2e1, 0x51 },
> > +	{ 0xc2e2, 0x00 }, { 0xc2e3, 0xd6 }, { 0xc2e4, 0x01 }, { 0xc2e5, 0x5e },
> > +	{ 0xc2e9, 0x01 }, { 0xc2ea, 0x7a }, { 0xc2eb, 0x90 }, { 0xc2ed, 0x00 },
> > +	{ 0xc2ee, 0x7a }, { 0xc2ef, 0x64 }, { 0xc308, 0x00 }, { 0xc309, 0x00 },
> > +	{ 0xc30a, 0x00 }, { 0xc30c, 0x00 }, { 0xc30d, 0x01 }, { 0xc30e, 0x00 },
> > +	{ 0xc30f, 0x00 }, { 0xc310, 0x01 }, { 0xc311, 0x60 }, { 0xc312, 0xff },
> > +	{ 0xc313, 0x08 }, { 0xc314, 0x01 }, { 0xc315, 0x00 }, { 0xc316, 0xff },
> > +	{ 0xc317, 0x0b }, { 0xc318, 0x00 }, { 0xc319, 0x0c }, { 0xc31a, 0x00 },
> > +	{ 0xc31b, 0xe0 }, { 0xc31c, 0x00 }, { 0xc31d, 0x14 }, { 0xc31e, 0x00 },
> > +	{ 0xc31f, 0xc5 }, { 0xc320, 0xff }, { 0xc321, 0x4b }, { 0xc322, 0xff },
> > +	{ 0xc323, 0xf0 }, { 0xc324, 0xff }, { 0xc325, 0xe8 }, { 0xc326, 0x00 },
> > +	{ 0xc327, 0x46 }, { 0xc328, 0xff }, { 0xc329, 0xd2 }, { 0xc32a, 0xff },
> > +	{ 0xc32b, 0xe4 }, { 0xc32c, 0xff }, { 0xc32d, 0xbb }, { 0xc32e, 0x00 },
> > +	{ 0xc32f, 0x61 }, { 0xc330, 0xff }, { 0xc331, 0xf9 }, { 0xc332, 0x00 },
> > +	{ 0xc333, 0xd9 }, { 0xc334, 0x00 }, { 0xc335, 0x2e }, { 0xc336, 0x00 },
> > +	{ 0xc337, 0xb1 }, { 0xc338, 0xff }, { 0xc339, 0x64 }, { 0xc33a, 0xff },
> > +	{ 0xc33b, 0xeb }, { 0xc33c, 0xff }, { 0xc33d, 0xe8 }, { 0xc33e, 0x00 },
> > +	{ 0xc33f, 0x48 }, { 0xc340, 0xff }, { 0xc341, 0xd0 }, { 0xc342, 0xff },
> > +	{ 0xc343, 0xed }, { 0xc344, 0xff }, { 0xc345, 0xad }, { 0xc346, 0x00 },
> > +	{ 0xc347, 0x66 }, { 0xc348, 0x01 }, { 0xc349, 0x00 }, { 0x6700, 0x04 },
> > +	{ 0x6701, 0x7b }, { 0x6702, 0xfd }, { 0x6703, 0xf9 }, { 0x6704, 0x3d },
> > +	{ 0x6705, 0x71 }, { 0x6706, 0x78 }, { 0x6708, 0x05 }, { 0x6f06, 0x6f },
> > +	{ 0x6f07, 0x00 }, { 0x6f0a, 0x6f }, { 0x6f0b, 0x00 }, { 0x6f00, 0x03 },
> > +	{ 0xc34c, 0x01 }, { 0xc34d, 0x00 }, { 0xc34e, 0x46 }, { 0xc34f, 0x55 },
> > +	{ 0xc350, 0x00 }, { 0xc351, 0x40 }, { 0xc352, 0x00 }, { 0xc353, 0xff },
> > +	{ 0xc354, 0x04 }, { 0xc355, 0x08 }, { 0xc356, 0x01 }, { 0xc357, 0xef },
> > +	{ 0xc358, 0x30 }, { 0xc359, 0x01 }, { 0xc35a, 0x64 }, { 0xc35b, 0x46 },
> > +	{ 0xc35c, 0x00 }, { 0x3042, 0xf0 }, { 0x3042, 0xf0 }, { 0x3042, 0xf0 },
> > +	{ 0x3042, 0xf0 }, { 0x3042, 0xf0 }, { 0x3042, 0xf0 }, { 0x3042, 0xf0 },
> > +	{ 0x3042, 0xf0 }, { 0x3042, 0xf0 }, { 0x3042, 0xf0 }, { 0x3042, 0xf0 },
> > +	{ 0x3042, 0xf0 }, { 0x3042, 0xf0 }, { 0x3042, 0xf0 }, { 0x3042, 0xf0 },
> > +	{ 0x3042, 0xf0 }, { 0x3042, 0xf0 }, { 0x3042, 0xf0 }, { 0x3042, 0xf0 },
> > +	{ 0x3042, 0xf0 }, { 0x3042, 0xf0 }, { 0x3042, 0xf0 }, { 0x3042, 0xf0 },
> > +	{ 0x3042, 0xf0 }, { 0x3042, 0xf0 }, { 0x3042, 0xf0 }, { 0xc261, 0x01 },
> > +	{ 0x301b, 0xf0 }, { 0x301c, 0xf0 }, { 0x301a, 0xf0 }, { 0x6f00, 0xc3 },
> > +	{ 0xc46a, 0x30 }, { 0xc46d, 0x20 }, { 0xc464, 0x84 }, { 0xc465, 0x00 },
> > +	{ 0x6f00, 0x03 }, { 0x6f00, 0x43 }, { 0x381c, 0x00 }, { 0x381d, 0x40 },
> > +	{ 0xc454, 0x01 }, { 0x6f00, 0xc3 }, { 0xc454, 0x00 }, { 0xc4b1, 0x02 },
> > +	{ 0xc4b2, 0x01 }, { 0xc4b3, 0x03 }, { 0x6f00, 0x03 }, { 0x6f00, 0x43 },
> > +	/* enable FSIN (FRAMESYNC input) functionality */
> > +	{ 0x3832, (0x0d + 2 * 0x20 + 0x15 + 38) >> 8 },
> > +	{ 0x3833, (0x0d + 2 * 0x20 + 0x15 + 38) & 0xff },
> > +	{ 0x3834, OV10635_VTS >> 8 }, { 0x3835, OV10635_VTS & 0xff },
> > +	{ 0x302e, 0x01 },
>
> Ergh.
>

I know :(

> > +};
> > +
> > +struct rdacm20_device {
> > +	struct device			*dev;
> > +	struct max9271_device		*serializer;
> > +	struct i2c_client		*sensor;
> > +	struct v4l2_subdev		sd;
> > +	struct media_pad		pad;
> > +	struct v4l2_ctrl_handler	ctrls;
> > +	u32				addrs[2];
> > +};
> > +
> > +static inline struct rdacm20_device *sd_to_rdacm20(struct v4l2_subdev *sd)
> > +{
> > +	return container_of(sd, struct rdacm20_device, sd);
> > +}
> > +
> > +static inline struct rdacm20_device *i2c_to_rdacm20(struct i2c_client *client)
> > +{
> > +	return sd_to_rdacm20(i2c_get_clientdata(client));
> > +}
> > +
> > +static int ov10635_read16(struct rdacm20_device *dev, u16 reg)
> > +{
> > +	u8 buf[2] = { reg >> 8, reg & 0xff };
> > +	int ret;
> > +
> > +	ret = i2c_master_send(dev->sensor, buf, 2);
> > +	if (ret != 2) {
> > +		dev_dbg(dev->dev, "%s: register 0x%04x write failed (%d)\n",
> > +			__func__, reg, ret);
> > +		return ret;
> > +	}
> > +
> > +	ret = i2c_master_recv(dev->sensor, buf, 2);
> > +	if (ret < 0) {
> > +		dev_dbg(dev->dev, "%s: register 0x%04x read failed (%d)\n",
> > +			__func__, reg, ret);
> > +		return ret;
> > +	}
> > +
> > +	return (buf[0] << 8) | buf[1];
> > +}
> > +
> > +static int __ov10635_write(struct rdacm20_device *dev, u16 reg, u8 val)
> > +{
> > +	u8 buf[3] = { reg >> 8, reg & 0xff, val };
> > +	int ret;
> > +
> > +	dev_dbg(dev->dev, "%s(0x%04x, 0x%02x)\n", __func__, reg, val);
> > +
> > +	ret = i2c_master_send(dev->sensor, buf, 3);
> > +	return ret < 0 ? ret : 0;
> > +}
> > +
> > +static int ov10635_write(struct rdacm20_device *dev, u16 reg, u8 val)
> > +{
> > +	int ret;
> > +
> > +	ret = __ov10635_write(dev, reg, val);
> > +	if (ret < 0)
> > +		dev_err(dev->dev, "%s: register 0x%04x write failed (%d)\n",
> > +			__func__, reg, ret);
> > +
> > +	return ret;
> > +}
> > +
> > +static int ov10635_set_regs(struct rdacm20_device *dev,
> > +			    const struct ov10635_reg *regs,
> > +			    unsigned int nr_regs)
> > +{
> > +	unsigned int i;
> > +	int ret;
> > +
> > +	for (i = 0; i < nr_regs; i++) {
> > +		ret = __ov10635_write(dev, regs[i].reg, regs[i].val);
> > +		if (ret) {
> > +			dev_err(dev->dev,
> > +				"%s: register %u (0x%04x) write failed (%d)\n",
> > +				__func__, i, regs[i].reg, ret);
> > +			return ret;
> > +		}
> > +	}
> > +
> > +	return 0;
> > +}
> > +
> > +static int rdacm20_s_stream(struct v4l2_subdev *sd, int enable)
> > +{
> > +	struct rdacm20_device *dev = sd_to_rdacm20(sd);
> > +
> > +	return max9271_set_serial_link(dev->serializer, enable);
> > +}
> > +
> > +static int rdacm20_enum_mbus_code(struct v4l2_subdev *sd,
> > +				  struct v4l2_subdev_pad_config *cfg,
> > +				  struct v4l2_subdev_mbus_code_enum *code)
> > +{
> > +	if (code->pad || code->index > 0)
> > +		return -EINVAL;
> > +
> > +	code->code = MEDIA_BUS_FMT_UYVY8_2X8;
> > +
> > +	return 0;
> > +}
> > +
> > +static int rdacm20_get_fmt(struct v4l2_subdev *sd,
> > +			   struct v4l2_subdev_pad_config *cfg,
> > +			   struct v4l2_subdev_format *format)
> > +{
> > +	struct v4l2_mbus_framefmt *mf = &format->format;
> > +
> > +	if (format->pad)
> > +		return -EINVAL;
> > +
> > +	mf->width		= OV10635_WIDTH;
> > +	mf->height		= OV10635_HEIGHT;
> > +	mf->code		= MEDIA_BUS_FMT_UYVY8_2X8;
> > +	mf->colorspace		= V4L2_COLORSPACE_RAW;
> > +	mf->field		= V4L2_FIELD_NONE;
> > +	mf->ycbcr_enc		= V4L2_YCBCR_ENC_601;
> > +	mf->quantization	= V4L2_QUANTIZATION_FULL_RANGE;
> > +	mf->xfer_func		= V4L2_XFER_FUNC_NONE;
> > +
> > +	return 0;
> > +}
> > +
> > +static struct v4l2_subdev_video_ops rdacm20_video_ops = {
> > +	.s_stream	= rdacm20_s_stream,
> > +};
> > +
> > +static const struct v4l2_subdev_pad_ops rdacm20_subdev_pad_ops = {
> > +	.enum_mbus_code = rdacm20_enum_mbus_code,
> > +	.get_fmt	= rdacm20_get_fmt,
> > +	.set_fmt	= rdacm20_get_fmt,
> > +};
> > +
> > +static struct v4l2_subdev_ops rdacm20_subdev_ops = {
> > +	.video		= &rdacm20_video_ops,
> > +	.pad		= &rdacm20_subdev_pad_ops,
> > +};
> > +
> > +static int rdacm20_initialize(struct rdacm20_device *dev)
> > +{
> > +	unsigned int retry = 3;
> > +	int ret;
> > +
> > +	/* Verify communication with the MAX9271: ping to wakeup. */
> > +	dev->serializer->client->addr = MAX9271_DEFAULT_ADDR;
> > +	i2c_smbus_read_byte(dev->serializer->client);
> > +
> > +	/* Serial link disabled during config as it needs a valid pixel clock. */
> > +	ret = max9271_set_serial_link(dev->serializer, false);
> > +	if (ret)
> > +		return ret;
> > +
> > +	/*
> > +	 *  Ensure that we have a good link configuration before attempting to
> > +	 *  identify the device.
> > +	 */
> > +	max9271_configure_i2c(dev->serializer, MAX9271_I2CSLVSH_469NS_234NS |
> > +					       MAX9271_I2CSLVTO_1024US |
> > +					       MAX9271_I2CMSTBT_105KBPS);
> > +
> > +	max9271_configure_gmsl_link(dev->serializer);
> > +
> > +	ret = max9271_verify_id(dev->serializer);
> > +	if (ret < 0)
> > +		return ret;
> > +
> > +	ret = max9271_set_address(dev->serializer, dev->addrs[0]);
> > +	if (ret < 0)
> > +		return ret;
> > +	dev->serializer->client->addr = dev->addrs[0];
> > +
> > +	/*
> > +	 * Reset the sensor by cycling the OV10635 reset signal connected to the
> > +	 * MAX9271 GPIO1 and verify communication with the OV10635.
> > +	 */
> > +	max9271_clear_gpios(dev->serializer, MAX9271_GPIO1OUT);
> > +	mdelay(10);
>
> Why mdelay(), a busy loop and not msleep()??? Same below.
>

As I don't recall a reason that could very well be a leftover from the
BSP driver. I'll fix it.

Thanks
  j

> > +	max9271_set_gpios(dev->serializer, MAX9271_GPIO1OUT);
> > +	mdelay(10);
> > +
> > +again:
> > +	ret = ov10635_read16(dev, OV10635_PID);
> > +	if (ret < 0) {
> > +		if (retry--)
> > +			goto again;
> > +
> > +		dev_err(dev->dev, "OV10635 ID read failed (%d)\n",
> > +			ret);
> > +		return -ENXIO;
> > +	}
> > +
> > +	if (ret != OV10635_VERSION) {
> > +		if (retry--)
> > +			goto again;
> > +
> > +		dev_err(dev->dev, "OV10635 ID mismatch (0x%04x)\n",
> > +			ret);
> > +		return -ENXIO;
> > +	}
> > +
> > +	/* Change the sensor I2C address. */
> > +	ret = ov10635_write(dev, OV10635_SC_CMMN_SCCB_ID,
> > +			    (dev->addrs[1] << 1) |
> > +			    OV10635_SC_CMMN_SCCB_ID_SELECT);
> > +	if (ret < 0) {
> > +		dev_err(dev->dev,
> > +			"OV10635 I2C address change failed (%d)\n", ret);
> > +		return ret;
> > +	}
> > +	dev->sensor->addr = dev->addrs[1];
> > +	usleep_range(3500, 5000);
> > +
> > +	/* Program the 0V10635 initial configuration. */
> > +	ret = ov10635_set_regs(dev, ov10635_regs_wizard,
> > +			       ARRAY_SIZE(ov10635_regs_wizard));
> > +	if (ret)
> > +		return ret;
> > +
> > +	dev_info(dev->dev, "Identified MAX9271 + OV10635 device\n");
> > +
> > +	return 0;
> > +}
> > +
> > +static int rdacm20_probe(struct i2c_client *client)
> > +{
> > +	struct rdacm20_device *dev;
> > +	struct fwnode_handle *ep;
> > +	int ret;
> > +
> > +	dev = devm_kzalloc(&client->dev, sizeof(*dev), GFP_KERNEL);
> > +	if (!dev)
> > +		return -ENOMEM;
> > +	dev->dev = &client->dev;
> > +
> > +	dev->serializer = devm_kzalloc(&client->dev, sizeof(*dev->serializer),
> > +				       GFP_KERNEL);
> > +	if (!dev->serializer)
> > +		return -ENOMEM;
> > +
> > +	dev->serializer->client = client;
> > +
> > +	ret = of_property_read_u32_array(client->dev.of_node, "reg",
> > +					 dev->addrs, 2);
> > +	if (ret < 0) {
> > +		dev_err(dev->dev, "Invalid DT reg property: %d\n", ret);
> > +		return -EINVAL;
> > +	}
> > +
> > +	/* Create the dummy I2C client for the sensor. */
> > +	dev->sensor = i2c_new_dummy_device(client->adapter,
> > +					   OV10635_I2C_ADDRESS);
> > +	if (IS_ERR(dev->sensor)) {
> > +		ret = PTR_ERR(dev->sensor);
> > +		goto error;
> > +	}
> > +
> > +	/* Initialize the hardware. */
> > +	ret = rdacm20_initialize(dev);
> > +	if (ret < 0)
> > +		goto error;
> > +
> > +	/* Initialize and register the subdevice. */
> > +	v4l2_i2c_subdev_init(&dev->sd, client, &rdacm20_subdev_ops);
> > +	dev->sd.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;
> > +
> > +	v4l2_ctrl_handler_init(&dev->ctrls, 1);
> > +	v4l2_ctrl_new_std(&dev->ctrls, NULL, V4L2_CID_PIXEL_RATE,
> > +			  OV10635_PIXEL_RATE, OV10635_PIXEL_RATE, 1,
> > +			  OV10635_PIXEL_RATE);
> > +	dev->sd.ctrl_handler = &dev->ctrls;
> > +
> > +	ret = dev->ctrls.error;
> > +	if (ret)
> > +		goto error_free_ctrls;
> > +
> > +	dev->pad.flags = MEDIA_PAD_FL_SOURCE;
> > +	dev->sd.entity.flags |= MEDIA_ENT_F_CAM_SENSOR;
> > +	ret = media_entity_pads_init(&dev->sd.entity, 1, &dev->pad);
> > +	if (ret < 0)
> > +		goto error_free_ctrls;
> > +
> > +	ep = fwnode_graph_get_next_endpoint(dev_fwnode(&client->dev), NULL);
> > +	if (!ep) {
> > +		dev_err(&client->dev,
> > +			"Unable to get endpoint in node %pOF\n",
> > +			client->dev.of_node);
> > +		ret = -ENOENT;
> > +		goto error_free_ctrls;
> > +	}
> > +	dev->sd.fwnode = ep;
> > +
> > +	ret = v4l2_async_register_subdev(&dev->sd);
> > +	if (ret)
> > +		goto error_put_node;
> > +
> > +	return 0;
> > +
> > +error_put_node:
> > +	fwnode_handle_put(ep);
> > +error_free_ctrls:
> > +	v4l2_ctrl_handler_free(&dev->ctrls);
> > +error:
> > +	media_entity_cleanup(&dev->sd.entity);
> > +	if (dev->sensor)
> > +		i2c_unregister_device(dev->sensor);
> > +
> > +	dev_err(&client->dev, "probe failed\n");
> > +
> > +	return ret;
> > +}
> > +
> > +static int rdacm20_remove(struct i2c_client *client)
> > +{
> > +	struct rdacm20_device *dev = i2c_to_rdacm20(client);
> > +
> > +	fwnode_handle_put(dev->sd.fwnode);
> > +	v4l2_async_unregister_subdev(&dev->sd);
> > +	v4l2_ctrl_handler_free(&dev->ctrls);
> > +	media_entity_cleanup(&dev->sd.entity);
> > +	i2c_unregister_device(dev->sensor);
> > +
> > +	return 0;
> > +}
> > +
> > +static void rdacm20_shutdown(struct i2c_client *client)
> > +{
> > +	struct rdacm20_device *dev = i2c_to_rdacm20(client);
> > +
> > +	/* make sure stream off during shutdown (reset/reboot) */
> > +	rdacm20_s_stream(&dev->sd, 0);
> > +}
> > +
> > +static const struct of_device_id rdacm20_of_ids[] = {
> > +	{ .compatible = "imi,rdacm20", },
> > +	{ }
> > +};
> > +MODULE_DEVICE_TABLE(of, rdacm20_of_ids);
> > +
> > +static struct i2c_driver rdacm20_i2c_driver = {
> > +	.driver	= {
> > +		.name	= "rdacm20",
> > +		.of_match_table = rdacm20_of_ids,
> > +	},
> > +	.probe_new	= rdacm20_probe,
> > +	.remove		= rdacm20_remove,
> > +	.shutdown	= rdacm20_shutdown,
> > +};
> > +
> > +module_i2c_driver(rdacm20_i2c_driver);
> > +
> > +MODULE_DESCRIPTION("GMSL Camera driver for RDACM20");
> > +MODULE_AUTHOR("Vladimir Barinov");
> > +MODULE_LICENSE("GPL");
>
> --
> Regards,
>
> Sakari Ailus