[PATCH v3 0/4] MAX9286 GMSL Support

[PATCH v3 0/4] MAX9286 GMSL Support

[Kieran Bingham]

This series provides a pair of drivers for 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.

This posting is the culmination of ~100 changesets spread across Jacopo,
Niklas, Laurent and myself - thus they contain all of our SoB tags.

Although this device is capable of handling up to 4 streams, this is not
possible until the VC work comes through from Sakari and as such - this
driver is only functional on a *single* stream.

This driver along with 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/v3

---
v2:
 - Add Jacopo's dt-binding patches
 - Fix MAINTAINERS entries
 - Add imi vendor prefix to Jacopo's patches
 - Remove VC support

v3:
  MAX9286:
    - Initialise notifier with v4l2_async_notifier_init
    - Update for new mbus csi2 format V4L2_MBUS_CSI2_DPHY
  RDACM20:
    - Use new V4L2_MBUS_CSI2_DPHY bus type
    - Remove 'always zero' error print
    - Fix module description
  Bindings:
    - Fixes from Laurent's review comments on V2


Jacopo Mondi (1):
  dt-bindings: media: i2c: Add bindings for IMI RDACM20

Kieran Bingham (2):
  media: i2c: Add MAX9286 driver
  media: i2c: Add RDACM20 driver

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

 .../bindings/media/i2c/imi,rdacm20.txt        |   65 +
 .../bindings/media/i2c/maxim,max9286.txt      |  182 +++
 .../devicetree/bindings/vendor-prefixes.txt   |    1 +
 MAINTAINERS                                   |   20 +
 drivers/media/i2c/Kconfig                     |   22 +
 drivers/media/i2c/Makefile                    |    2 +
 drivers/media/i2c/max9286.c                   | 1136 +++++++++++++++++
 drivers/media/i2c/rdacm20-ov10635.h           |  953 ++++++++++++++
 drivers/media/i2c/rdacm20.c                   |  635 +++++++++
 9 files changed, 3016 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/media/i2c/imi,rdacm20.txt
 create mode 100644 Documentation/devicetree/bindings/media/i2c/maxim,max9286.txt
 create mode 100644 drivers/media/i2c/max9286.c
 create mode 100644 drivers/media/i2c/rdacm20-ov10635.h
 create mode 100644 drivers/media/i2c/rdacm20.c

-- 
2.17.1

[PATCH v3 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>

---
v3:
 - Update binding descriptions
---
 .../bindings/media/i2c/maxim,max9286.txt      | 182 ++++++++++++++++++
 1 file changed, 182 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/media/i2c/maxim,max9286.txt

diff --git a/Documentation/devicetree/bindings/media/i2c/maxim,max9286.txt b/Documentation/devicetree/bindings/media/i2c/maxim,max9286.txt
new file mode 100644
index 000000000000..a73e3c0dc31b
--- /dev/null
+++ b/Documentation/devicetree/bindings/media/i2c/maxim,max9286.txt
@@ -0,0 +1,182 @@
+Maxim Integrated Quad GMSL Deserializer
+---------------------------------------
+
+The MAX9286 deserializer receives video data on up to 4 Gigabit Multimedia
+Serial Links (GMSL) and outputs them on a CSI-2 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.
+
+Required Properties:
+
+- compatible: Shall be "maxim,max9286"
+- reg: I2C device address
+
+Optional Properties:
+
+- poc-supply: Regulator providing Power over Coax to the cameras
+- pwdn-gpios: GPIO connected to the #PWDN pin
+
+Required endpoint nodes:
+-----------------------
+
+The connections to the MAX9286 GMSL and its endpoint nodes are modeled 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
+
+Optional Endpoint Properties for GSML Input Ports (Port [0-3]):
+
+- remote-endpoint: phandle to the remote GMSL source endpoint subnode in the
+  remote node port.
+
+Required Endpoint Properties for CSI-2 Output Port (Port 4):
+
+- data-lanes: array of physical CSI-2 data lane indexes.
+- clock-lanes: index of CSI-2 clock lane.
+
+Required i2c-mux nodes:
+----------------------
+
+Each GMSL link is modeled 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.
+
+Required i2c child bus properties:
+- all properties described as required i2c child bus nodes properties in
+  Documentation/devicetree/bindings/i2c/i2c-mux.txt.
+
+Example:
+-------
+
+	gmsl-deserializer@2c {
+		compatible = "maxim,max9286";
+		reg = <0x2c>;
+		poc-supply = <&camera_poc_12v>;
+		pwdn-gpios = <&gpio 13 GPIO_ACTIVE_LOW>;
+
+		#address-cells = <1>;
+		#size-cells = <0>;
+
+		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 {
+					clock-lanes = <0>;
+					data-lanes = <1 2 3 4>;
+					remote-endpoint = <&csi40_in>;
+				};
+			};
+		};
+
+		i2c@0 {
+			#address-cells = <1>;
+			#size-cells = <0>;
+			reg = <0>;
+
+			camera@51 {
+				compatible = "imi,rdacm20";
+				reg = <0x51 0x61>;
+
+				port {
+					rdacm20_out0: endpoint {
+						remote-endpoint = <&max9286_in0>;
+					};
+				};
+
+			};
+		};
+
+		i2c@1 {
+			#address-cells = <1>;
+			#size-cells = <0>;
+			reg = <1>;
+
+			camera@52 {
+				compatible = "imi,rdacm20";
+				reg = <0x52 0x62>;
+				port {
+					rdacm20_out1: endpoint {
+						remote-endpoint = <&max9286_in1>;
+					};
+				};
+			};
+		};
+
+		i2c@2 {
+			#address-cells = <1>;
+			#size-cells = <0>;
+			reg = <2>;
+
+			camera@53 {
+				compatible = "imi,rdacm20";
+				reg = <0x53 0x63>;
+				port {
+					rdacm20_out2: endpoint {
+						remote-endpoint = <&max9286_in2>;
+					};
+				};
+			};
+		};
+
+		i2c@3 {
+			#address-cells = <1>;
+			#size-cells = <0>;
+			reg = <3>;
+
+			camera@54 {
+				compatible = "imi,rdacm20";
+				reg = <0x54 0x64>;
+				port {
+					rdacm20_out3: endpoint {
+						remote-endpoint = <&max9286_in3>;
+					};
+				};
+			};
+		};
+	};
-- 
2.17.1

[PATCH v3 2/4] dt-bindings: media: i2c: Add bindings for IMI RDACM20

[Kieran Bingham]

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

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

Document its device tree binding interface.

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>

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

v3:
 - update binding descriptions
---
 .../bindings/media/i2c/imi,rdacm20.txt        | 65 +++++++++++++++++++
 .../devicetree/bindings/vendor-prefixes.txt   |  1 +
 2 files changed, 66 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/media/i2c/imi,rdacm20.txt

diff --git a/Documentation/devicetree/bindings/media/i2c/imi,rdacm20.txt b/Documentation/devicetree/bindings/media/i2c/imi,rdacm20.txt
new file mode 100644
index 000000000000..23915da4c3bf
--- /dev/null
+++ b/Documentation/devicetree/bindings/media/i2c/imi,rdacm20.txt
@@ -0,0 +1,65 @@
+IMI D&D RDACM20 Automotive Camera Platform
+------------------------------------------
+
+The IMI D&D RDACM20 is a GMSL-compatible camera designed for automotive
+applications. It encloses a Maxim Integrated MAX9271 GMSL serializer, an
+Omnivision OV10635 camera sensor and an embedded MCU, and connects 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     |
+ ---------------                               --------------------------------
+
+The RDACM20 transmits video data generated by the embedded camera sensor on the
+GMSL serial channel to a remote GMSL de-serializer, as well as it receives and
+transmits I2C messages encapsulated in 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 embedded camera sensor and MCU. All
+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 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.
+
+Required Properties:
+
+- compatible: Shall be "imi,rdacm20".
+- reg: Pair of I2C device addresses, the first to be assigned to the serializer
+  the second to be assigned to the camera sensor.
+
+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.
+
+Required endpoint properties:
+
+- remote-endpoint: phandle to the remote GMSL endpoint sub-node in the remote
+  node port.
+
+Example:
+-------
+
+	i2c@0 {
+		#address-cells = <1>;
+		#size-cells = <0>;
+		reg = <0>;
+
+		camera@51 {
+			compatible = "imi,rdacm20";
+			reg = <0x51 0x61>;
+
+			port {
+				rdacm20_out0: endpoint {
+					remote-endpoint = <&max9286_in0>;
+				};
+			};
+
+		};
+	};
diff --git a/Documentation/devicetree/bindings/vendor-prefixes.txt b/Documentation/devicetree/bindings/vendor-prefixes.txt
index 2c3fc512e746..34b0ed876850 100644
--- a/Documentation/devicetree/bindings/vendor-prefixes.txt
+++ b/Documentation/devicetree/bindings/vendor-prefixes.txt
@@ -171,6 +171,7 @@ idt	Integrated Device Technologies, Inc.
 ifi	Ingenieurburo Fur Ic-Technologie (I/F/I)
 ilitek	ILI Technology Corporation (ILITEK)
 img	Imagination Technologies Ltd.
+imi	Integrated Micro-Electronics Inc.
 infineon Infineon Technologies
 inforce	Inforce Computing
 ingenic	Ingenic Semiconductor
-- 
2.17.1

[PATCH v3 3/4] media: i2c: Add MAX9286 driver

[Kieran Bingham]

From: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>

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
---
 MAINTAINERS                 |   10 +
 drivers/media/i2c/Kconfig   |   11 +
 drivers/media/i2c/Makefile  |    1 +
 drivers/media/i2c/max9286.c | 1136 +++++++++++++++++++++++++++++++++++
 4 files changed, 1158 insertions(+)
 create mode 100644 drivers/media/i2c/max9286.c

diff --git a/MAINTAINERS b/MAINTAINERS
index 23021e0df5d7..745f0fd1fff1 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -8864,6 +8864,16 @@ F:	Documentation/devicetree/bindings/hwmon/max6697.txt
 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/max9286.txt
+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 704af210e270..eadc00bdd3bf 100644
--- a/drivers/media/i2c/Kconfig
+++ b/drivers/media/i2c/Kconfig
@@ -472,6 +472,17 @@ 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 VIDEO_V4L2_SUBDEV_API && MEDIA_CONTROLLER
+	select V4L2_FWNODE
+	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 260d4d9ec2a1..4de7fe62b179 100644
--- a/drivers/media/i2c/Makefile
+++ b/drivers/media/i2c/Makefile
@@ -110,5 +110,6 @@ obj-$(CONFIG_VIDEO_IMX258)	+= imx258.o
 obj-$(CONFIG_VIDEO_IMX274)	+= imx274.o
 obj-$(CONFIG_VIDEO_IMX319)	+= imx319.o
 obj-$(CONFIG_VIDEO_IMX355)	+= imx355.o
+obj-$(CONFIG_VIDEO_MAX9286)	+= max9286.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..7ac694cd47f8
--- /dev/null
+++ b/drivers/media/i2c/max9286.c
@@ -0,0 +1,1136 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Maxim MAX9286 GMSL Deserializer Driver
+ *
+ * Copyright (C) 2017-2018 Jacopo Mondi
+ * Copyright (C) 2017-2018 Kieran Bingham
+ * Copyright (C) 2017-2018 Laurent Pinchart
+ * Copyright (C) 2017-2018 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/i2c.h>
+#include <linux/i2c-mux.h>
+#include <linux/module.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 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)
+
+#define MAX9286_NUM_GMSL		4
+#define MAX9286_N_SINKS			4
+#define MAX9286_N_PADS			5
+#define MAX9286_SRC_PAD			4
+
+#define MAXIM_I2C_I2C_SPEED_400KHZ	MAX9286_I2CMSTBT_339KBPS
+#define MAXIM_I2C_I2C_SPEED_100KHZ	MAX9286_I2CMSTBT_105KBPS
+#define MAXIM_I2C_SPEED			MAXIM_I2C_I2C_SPEED_100KHZ
+
+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_device {
+	struct i2c_client *client;
+	struct v4l2_subdev sd;
+	struct media_pad pads[MAX9286_N_PADS];
+	struct regulator *regulator;
+	bool poc_enabled;
+	int streaming;
+
+	struct i2c_mux_core *mux;
+	unsigned int mux_channel;
+
+	struct v4l2_ctrl_handler ctrls;
+
+	struct v4l2_mbus_framefmt fmt[MAX9286_N_SINKS];
+
+	unsigned int nsources;
+	unsigned int source_mask;
+	unsigned int route_mask;
+	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_device *max9286,
+					  struct max9286_source *source)
+{
+	if (!source)
+		source = &max9286->sources[0];
+	else
+		source++;
+
+	for (; source < &max9286->sources[MAX9286_NUM_GMSL]; source++) {
+		if (source->fwnode)
+			return source;
+	}
+
+	return NULL;
+}
+
+#define for_each_source(max9286, source) \
+	for (source = NULL; (source = next_source(max9286, source)); )
+
+#define to_index(max9286, source) (source - &max9286->sources[0])
+
+#define sd_to_max9286(_sd) container_of(_sd, struct max9286_device, sd)
+
+/* -----------------------------------------------------------------------------
+ * I2C IO
+ */
+
+static int max9286_read(struct max9286_device *dev, u8 reg)
+{
+	int ret;
+
+	ret = i2c_smbus_read_byte_data(dev->client, reg);
+	if (ret < 0)
+		dev_err(&dev->client->dev,
+			"%s: register 0x%02x read failed (%d)\n",
+			__func__, reg, ret);
+
+	return ret;
+}
+
+static int max9286_write(struct max9286_device *dev, u8 reg, u8 val)
+{
+	int ret;
+
+	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;
+}
+
+/* -----------------------------------------------------------------------------
+ * I2C Multiplexer
+ */
+
+static int max9286_i2c_mux_close(struct max9286_device *dev)
+{
+
+	/* FIXME: See note in max9286_i2c_mux_select() */
+	if (dev->streaming)
+		return 0;
+	/*
+	 * 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 select call.
+	 */
+	dev->mux_channel = -1;
+	max9286_write(dev, 0x0a, 0x00);
+	usleep_range(3000, 5000);
+
+	return 0;
+}
+
+static int max9286_i2c_mux_select(struct i2c_mux_core *muxc, u32 chan)
+{
+	struct max9286_device *dev = i2c_mux_priv(muxc);
+
+	/*
+	 * FIXME: This state keeping is a hack and do the job. It should
+	 * be should be reworked. One option to consider is that once all
+	 * cameras are programmed the mux selection logic should be disabled
+	 * and all all reverse and forward channels enable all the time.
+	 *
+	 * In any case this logic with a int that have two states should be
+	 * reworked!
+	 */
+	if (dev->streaming == 1) {
+		max9286_write(dev, 0x0a, 0xff);
+		dev->streaming = 2;
+		return 0;
+	} else if (dev->streaming == 2) {
+		return 0;
+	}
+
+	if (dev->mux_channel == chan)
+		return 0;
+
+	dev->mux_channel = chan;
+
+	max9286_write(dev, 0x0a, MAX9286_FWDCCEN(chan) | MAX9286_REVCCEN(chan));
+
+	/*
+	 * We must sleep after any change to the forward or reverse channel
+	 * configuration.
+	 */
+	usleep_range(3000, 5000);
+
+	return 0;
+}
+
+static int max9286_i2c_mux_init(struct max9286_device *dev)
+{
+	struct max9286_source *source;
+	int ret;
+
+	if (!i2c_check_functionality(dev->client->adapter,
+				     I2C_FUNC_SMBUS_WRITE_BYTE_DATA))
+		return -ENODEV;
+
+	dev->mux = i2c_mux_alloc(dev->client->adapter, &dev->client->dev,
+				 dev->nsources, 0, I2C_MUX_LOCKED,
+				 max9286_i2c_mux_select, NULL);
+	if (!dev->mux)
+		return -ENOMEM;
+
+	dev->mux->priv = dev;
+
+	for_each_source(dev, source) {
+		unsigned int index = to_index(dev, source);
+
+		ret = i2c_mux_add_adapter(dev->mux, 0, index, 0);
+		if (ret < 0)
+			goto error;
+	}
+
+	return 0;
+
+error:
+	i2c_mux_del_adapters(dev->mux);
+	return ret;
+}
+
+static void max9286_configure_i2c(struct max9286_device *dev, bool localack)
+{
+	u8 config = MAX9286_I2CSLVSH_469NS_234NS | MAX9286_I2CSLVTO_1024US |
+		    MAXIM_I2C_SPEED;
+
+	if (localack)
+		config |= MAX9286_I2CLOCACK;
+
+	max9286_write(dev, 0x34, config);
+	usleep_range(3000, 5000);
+}
+
+/* -----------------------------------------------------------------------------
+ * V4L2 Subdev
+ */
+
+static int max9286_notify_bound(struct v4l2_async_notifier *notifier,
+				struct v4l2_subdev *subdev,
+				struct v4l2_async_subdev *asd)
+{
+	struct max9286_device *dev = sd_to_max9286(notifier->sd);
+	struct max9286_source *source = asd_to_max9286_source(asd);
+	unsigned int index = to_index(dev, 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(&dev->client->dev,
+			"Failed to find pad for %s\n", subdev->name);
+		return ret;
+	}
+
+	source->sd = subdev;
+	src_pad = ret;
+
+	ret = media_create_pad_link(&source->sd->entity, src_pad,
+				    &dev->sd.entity, index,
+				    MEDIA_LNK_FL_ENABLED |
+				    MEDIA_LNK_FL_IMMUTABLE);
+	if (ret) {
+		dev_err(&dev->client->dev,
+			"Unable to link %s:%u -> %s:%u\n",
+			source->sd->name, src_pad, dev->sd.name, index);
+		return ret;
+	}
+
+	dev_dbg(&dev->client->dev, "Bound %s pad: %u on index %u\n",
+		subdev->name, src_pad, index);
+
+	return 0;
+}
+
+static void max9286_notify_unbind(struct v4l2_async_notifier *notifier,
+				  struct v4l2_subdev *subdev,
+				  struct v4l2_async_subdev *asd)
+{
+	struct max9286_source *source = asd_to_max9286_source(asd);
+
+	source->sd = NULL;
+}
+
+static const struct v4l2_async_notifier_operations max9286_notify_ops = {
+	.bound = max9286_notify_bound,
+	.unbind = max9286_notify_unbind,
+};
+
+/*
+ * 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_device *dev)
+{
+	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(dev, 0x49);
+		if (ret < 0)
+			return -EIO;
+
+		if ((ret & MAX9286_VIDEO_DETECT_MASK) == dev->source_mask)
+			break;
+
+		usleep_range(350, 500);
+	}
+
+	if (i == 10) {
+		dev_err(&dev->client->dev,
+			"Unable to detect video links: 0x%2x\n", ret);
+		return -EIO;
+	}
+
+	/* Make sure all enabled links are locked (4ms max). */
+	for (i = 0; i < 10; i++) {
+		ret = max9286_read(dev, 0x27);
+		if (ret < 0)
+			return -EIO;
+
+		if (ret & MAX9286_LOCKED)
+			break;
+
+		usleep_range(350, 450);
+	}
+
+	if (i == 10) {
+		dev_err(&dev->client->dev, "Not all enabled links locked\n");
+		return -EIO;
+	}
+
+	return 0;
+}
+
+static int max9286_g_mbus_config(struct v4l2_subdev *sd,
+				 struct v4l2_mbus_config *cfg)
+{
+	cfg->flags = V4L2_MBUS_CSI2_1_LANE | V4L2_MBUS_CSI2_CHANNEL_0 |
+		     V4L2_MBUS_CSI2_CONTINUOUS_CLOCK;
+	cfg->type = V4L2_MBUS_CSI2_DPHY;
+
+	return 0;
+}
+
+static int max9286_s_stream(struct v4l2_subdev *sd, int enable)
+{
+	struct max9286_device *dev = sd_to_max9286(sd);
+	struct max9286_source *source;
+	unsigned int i;
+	bool sync = false;
+	int ret;
+
+	if (enable) {
+		/* FIXME: See note in max9286_i2c_mux_select() */
+		dev->streaming = 1;
+
+		/* Start all cameras. */
+		for_each_source(dev, source) {
+			ret = v4l2_subdev_call(source->sd, video, s_stream, 1);
+			if (ret)
+				return ret;
+		}
+
+		ret = max9286_check_video_links(dev);
+		if (ret)
+			return ret;
+
+		/*
+		 * Wait until frame synchronization is locked.
+		 *
+		 * Manual says frame sync locking should take ~6 VTS.
+		 * From pratical experience at least 8 are required. Give
+		 * 12 complete frames time (~33ms at 30 fps) to achieve frame
+		 * locking before returning error.
+		 */
+		for (i = 0; i < 36; i++) {
+			if (max9286_read(dev, 0x31) & MAX9286_FSYNC_LOCKED) {
+				sync = true;
+				break;
+			}
+			usleep_range(9000, 11000);
+		}
+
+		if (!sync) {
+			dev_err(&dev->client->dev,
+				"Failed to get frame synchronization\n");
+			return -EINVAL;
+		}
+
+		/*
+		 * Enable CSI output, VC set according to link number.
+		 * Bit 7 must be set (chip manual says it's 0 and reserved).
+		 */
+		max9286_write(dev, 0x15, 0x80 | MAX9286_VCTYPE |
+			      MAX9286_CSIOUTEN | MAX9286_0X15_RESV);
+	} else {
+		max9286_write(dev, 0x15, MAX9286_VCTYPE | MAX9286_0X15_RESV);
+
+		/* Stop all cameras. */
+		for_each_source(dev, source)
+			v4l2_subdev_call(source->sd, video, s_stream, 0);
+
+		/* FIXME: See note in max9286_i2c_mux_select() */
+		dev->streaming = 0;
+	}
+
+	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_device *dev,
+		       struct v4l2_subdev_pad_config *cfg,
+		       unsigned int pad, u32 which)
+{
+	switch (which) {
+	case V4L2_SUBDEV_FORMAT_TRY:
+		return v4l2_subdev_get_try_format(&dev->sd, cfg, pad);
+	case V4L2_SUBDEV_FORMAT_ACTIVE:
+		return &dev->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_device *dev = 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(dev, cfg, format->pad, format->which);
+	if (!cfg_fmt)
+		return -EINVAL;
+
+	*cfg_fmt = format->format;
+
+	return 0;
+}
+
+static int max9286_get_fmt(struct v4l2_subdev *sd,
+			   struct v4l2_subdev_pad_config *cfg,
+			   struct v4l2_subdev_format *format)
+{
+	struct max9286_device *dev = sd_to_max9286(sd);
+	struct v4l2_mbus_framefmt *cfg_fmt;
+
+	if (format->pad >= MAX9286_SRC_PAD)
+		return -EINVAL;
+
+	cfg_fmt = max9286_get_pad_format(dev, cfg, format->pad, format->which);
+	if (!cfg_fmt)
+		return -EINVAL;
+
+	format->format = *cfg_fmt;
+
+	return 0;
+}
+
+static int max9286_get_frame_desc(struct v4l2_subdev *sd, unsigned int pad,
+			   struct v4l2_mbus_frame_desc *fd)
+{
+	struct max9286_device *dev = sd_to_max9286(sd);
+	struct max9286_source *source;
+	unsigned int i = 0;
+
+	memset(fd, 0, sizeof(*fd));
+
+	for_each_source(dev, source) {
+		fd->entry[i].flags = V4L2_MBUS_FRAME_DESC_FL_LEN_MAX;
+		fd->entry[i].pixelcode = MEDIA_BUS_FMT_UYVY8_2X8;
+		i++;
+	}
+
+	fd->num_entries = dev->nsources;
+
+	return 0;
+}
+
+
+static const struct v4l2_subdev_video_ops max9286_video_ops = {
+	.g_mbus_config	= max9286_g_mbus_config,
+	.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,
+	.get_frame_desc = max9286_get_frame_desc,
+};
+
+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,
+};
+
+/* -----------------------------------------------------------------------------
+ * Probe/Remove
+ */
+
+static int max9286_setup(struct max9286_device *dev)
+{
+	/*
+	 * 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(dev, 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(dev, 0x3f, MAX9286_EN_REV_CFG | MAX9286_REV_FLEN(35));
+	max9286_write(dev, 0x3b, MAX9286_REV_TRF(1) | MAX9286_REV_AMP(70) |
+		      MAX9286_REV_AMP_X);
+
+	/*
+	 * Enable GMSL links, mask unused ones and autodetect link
+	 * used as CSI clock source.
+	 */
+	max9286_write(dev, 0x00, MAX9286_MSTLINKSEL_AUTO | dev->route_mask);
+	max9286_write(dev, 0x0b, link_order[dev->route_mask]);
+	max9286_write(dev, 0x69, (0xf & ~dev->route_mask));
+
+	/*
+	 * Video format setup:
+	 * Disable CSI output, VC is set accordingly to Link number.
+	 */
+	max9286_write(dev, 0x15, MAX9286_VCTYPE | MAX9286_0X15_RESV);
+
+	/* Enable CSI-2 Lane D0-D3 only, DBL mode, YUV422 8-bit. */
+	max9286_write(dev, 0x12, MAX9286_CSIDBL	| MAX9286_DBL |
+		      MAX9286_CSILANECNT(dev->csi2_data_lanes) |
+		      MAX9286_DATATYPE_YUV422_8BIT);
+
+	/* Automatic: FRAMESYNC taken from the slowest Link. */
+	max9286_write(dev, 0x01, MAX9286_FSYNCMODE_INT_HIZ |
+		      MAX9286_FSYNCMETH_AUTO);
+
+	/* Enable HS/VS encoding, use D14/15 for HS/VS, invert VS. */
+	max9286_write(dev, 0x0c, MAX9286_HVEN | MAX9286_INVVS |
+		      MAX9286_HVSRC_D14);
+
+	/*
+	 * Wait for 2ms to allow the link to resynchronize after the
+	 * configuration change.
+	 */
+	usleep_range(2000, 5000);
+
+	return 0;
+}
+
+static const struct of_device_id max9286_dt_ids[] = {
+	{ .compatible = "maxim,max9286" },
+	{},
+};
+MODULE_DEVICE_TABLE(of, max9286_dt_ids);
+
+static int max9286_init(struct device *dev, void *data)
+{
+	struct max9286_device *max9286;
+	struct i2c_client *client;
+	struct device_node *ep;
+	unsigned int i;
+	int ret;
+
+	/* Skip non-max9286 devices. */
+	if (!dev->of_node || !of_match_node(max9286_dt_ids, dev->of_node))
+		return 0;
+
+	client = to_i2c_client(dev);
+	max9286 = i2c_get_clientdata(client);
+
+	/* Enable the bus power. */
+	ret = regulator_enable(max9286->regulator);
+	if (ret < 0) {
+		dev_err(&client->dev, "Unable to turn PoC on\n");
+		return ret;
+	}
+
+	max9286->poc_enabled = true;
+
+	ret = max9286_setup(max9286);
+	if (ret) {
+		dev_err(dev, "Unable to setup max9286\n");
+		goto err_regulator;
+	}
+
+	v4l2_i2c_subdev_init(&max9286->sd, client, &max9286_subdev_ops);
+	max9286->sd.internal_ops = &max9286_subdev_internal_ops;
+	max9286->sd.flags = V4L2_SUBDEV_FL_HAS_DEVNODE;
+
+	v4l2_ctrl_handler_init(&max9286->ctrls, 1);
+	/*
+	 * FIXME: Compute the real pixel rate. The 50 MP/s value comes from the
+	 * hardcoded frequency in the BSP CSI-2 receiver driver.
+	 */
+	v4l2_ctrl_new_std(&max9286->ctrls, NULL, V4L2_CID_PIXEL_RATE,
+			  50000000, 50000000, 1, 50000000);
+	max9286->sd.ctrl_handler = &max9286->ctrls;
+	ret = max9286->ctrls.error;
+	if (ret)
+		goto err_regulator;
+
+	max9286->sd.entity.function = MEDIA_ENT_F_PROC_VIDEO_PIXEL_FORMATTER;
+
+	max9286->pads[MAX9286_SRC_PAD].flags = MEDIA_PAD_FL_SOURCE;
+	for (i = 0; i < MAX9286_SRC_PAD; i++)
+		max9286->pads[i].flags = MEDIA_PAD_FL_SINK;
+	ret = media_entity_pads_init(&max9286->sd.entity, MAX9286_N_PADS,
+				     max9286->pads);
+	if (ret)
+		goto err_regulator;
+
+	ep = of_graph_get_endpoint_by_regs(dev->of_node, MAX9286_SRC_PAD, -1);
+	if (!ep) {
+		dev_err(dev, "Unable to retrieve endpoint on \"port@4\"\n");
+		ret = -ENOENT;
+		goto err_regulator;
+	}
+	max9286->sd.fwnode = of_fwnode_handle(ep);
+
+	ret = v4l2_async_register_subdev(&max9286->sd);
+	if (ret < 0) {
+		dev_err(dev, "Unable to register subdevice\n");
+		goto err_put_node;
+	}
+
+	ret = max9286_i2c_mux_init(max9286);
+	if (ret) {
+		dev_err(dev, "Unable to initialize I2C multiplexer\n");
+		goto err_subdev_unregister;
+	}
+
+	/*
+	 * Re-configure I2C with local acknowledge disabled after cameras
+	 * have probed.
+	 */
+	max9286_configure_i2c(max9286, false);
+
+	/* Leave the mux channels disabled until they are selected. */
+	max9286_i2c_mux_close(max9286);
+
+	return 0;
+
+err_subdev_unregister:
+	v4l2_async_unregister_subdev(&max9286->sd);
+	max9286_i2c_mux_close(max9286);
+err_put_node:
+	of_node_put(ep);
+err_regulator:
+	regulator_disable(max9286->regulator);
+	max9286->poc_enabled = false;
+
+	return ret;
+}
+
+static int max9286_is_bound(struct device *dev, void *data)
+{
+	struct device *this = data;
+	int ret;
+
+	if (dev == this)
+		return 0;
+
+	/* Skip non-max9286 devices. */
+	if (!dev->of_node || !of_match_node(max9286_dt_ids, dev->of_node))
+		return 0;
+
+	ret = device_is_bound(dev);
+	if (!ret)
+		return -EPROBE_DEFER;
+
+	return 0;
+}
+
+static struct device_node *max9286_get_i2c_by_id(struct device_node *parent,
+						 u32 id)
+{
+	struct device_node *child;
+
+	for_each_child_of_node(parent, child) {
+		u32 i2c_id = 0;
+
+		if (of_node_cmp(child->name, "i2c") != 0)
+			continue;
+		of_property_read_u32(child, "reg", &i2c_id);
+		if (id == i2c_id)
+			return child;
+	}
+
+	return NULL;
+}
+
+static int max9286_check_i2c_bus_by_id(struct device *dev, int id)
+{
+	struct device_node *i2c_np;
+
+	i2c_np = max9286_get_i2c_by_id(dev->of_node, id);
+	if (!i2c_np) {
+		dev_err(dev, "Failed to find corresponding i2c@%u\n", id);
+		return -ENODEV;
+	}
+
+	if (!of_device_is_available(i2c_np)) {
+		dev_dbg(dev, "Skipping port %u with disabled I2C bus\n", id);
+		of_node_put(i2c_np);
+		return -ENODEV;
+	}
+
+	of_node_put(i2c_np);
+
+	return 0;
+}
+
+static void max9286_cleanup_dt(struct max9286_device *max9286)
+{
+	struct max9286_source *source;
+
+	/*
+	 * Not strictly part of the DT, but the notifier is registered during
+	 * max9286_parse_dt(), and the notifier holds references to the fwnodes
+	 * thus the cleanup is here to mirror the registration.
+	 */
+	v4l2_async_notifier_unregister(&max9286->notifier);
+
+	for_each_source(max9286, source) {
+		fwnode_handle_put(source->fwnode);
+		source->fwnode = NULL;
+	}
+}
+
+static int max9286_parse_dt(struct max9286_device *max9286)
+{
+	struct device *dev = &max9286->client->dev;
+	struct device_node *ep_np = NULL;
+	int ret;
+
+	v4l2_async_notifier_init(&max9286->notifier);
+
+	for_each_endpoint_of_node(dev->of_node, ep_np) {
+		struct max9286_source *source;
+		struct of_endpoint ep;
+
+		of_graph_parse_endpoint(ep_np, &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;
+			int ret;
+
+			ret = v4l2_fwnode_endpoint_alloc_parse(
+					of_fwnode_handle(ep_np), &vep);
+			if (ret)
+				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);
+				return -EINVAL;
+			}
+
+			max9286->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 (max9286_check_i2c_bus_by_id(dev, ep.port))
+			continue;
+
+		if (max9286->sources[ep.port].fwnode) {
+			dev_err(dev,
+				"Multiple port endpoints are not supported: %d",
+				ep.port);
+
+			continue;
+		}
+
+		source = &max9286->sources[ep.port];
+		source->fwnode = fwnode_graph_get_remote_endpoint(
+						of_fwnode_handle(ep_np));
+		if (!source->fwnode) {
+			dev_err(dev,
+				"Endpoint %pOF has no remote endpoint connection\n",
+				ep.local_node);
+
+			continue;
+		}
+
+		source->asd.match_type = V4L2_ASYNC_MATCH_FWNODE;
+		source->asd.match.fwnode = source->fwnode;
+
+		ret = v4l2_async_notifier_add_subdev(&max9286->notifier,
+						     &source->asd);
+		if (ret) /* TODO: Cleanup notifier! */
+			return ret;
+
+		max9286->source_mask |= BIT(ep.port);
+		max9286->nsources++;
+	}
+
+	/* Do not register the subdev notifier if there are no devices. */
+	if (!max9286->nsources)
+		return 0;
+
+	max9286->route_mask = max9286->source_mask;
+	max9286->notifier.ops = &max9286_notify_ops;
+
+	return v4l2_async_subdev_notifier_register(&max9286->sd,
+						   &max9286->notifier);
+}
+
+static int max9286_probe(struct i2c_client *client,
+			 const struct i2c_device_id *did)
+{
+	struct max9286_device *dev;
+	unsigned int i;
+	int ret;
+
+	dev = kzalloc(sizeof(*dev), GFP_KERNEL);
+	if (!dev)
+		return -ENOMEM;
+
+	dev->client = client;
+	i2c_set_clientdata(client, dev);
+
+	for (i = 0; i < MAX9286_N_SINKS; i++)
+		max9286_init_format(&dev->fmt[i]);
+
+	ret = max9286_parse_dt(dev);
+	if (ret)
+		return ret;
+
+	dev->regulator = regulator_get(&client->dev, "poc");
+	if (IS_ERR(dev->regulator)) {
+		if (PTR_ERR(dev->regulator) != -EPROBE_DEFER)
+			dev_err(&client->dev,
+				"Unable to get PoC regulator (%ld)\n",
+				PTR_ERR(dev->regulator));
+		ret = PTR_ERR(dev->regulator);
+		goto err_free;
+	}
+
+	/*
+	 * We can have multiple MAX9286 instances on the same physical I2C
+	 * bus, and I2C children behind ports of separate MAX9286 instances
+	 * having the same I2C address. As the MAX9286 starts by default with
+	 * all ports enabled, we need to disable all ports on all MAX9286
+	 * instances before proceeding to further initialize the devices and
+	 * instantiate children.
+	 *
+	 * Start by just disabling all channels on the current device. Then,
+	 * if all other MAX9286 on the parent bus have been probed, proceed
+	 * to initialize them all, including the current one.
+	 */
+	max9286_i2c_mux_close(dev);
+
+	/*
+	 * The MAX9286 initialises with auto-acknowledge enabled by default.
+	 * This means that if multiple MAX9286 devices are connected to an I2C
+	 * bus, another MAX9286 could ack I2C transfers meant for a device on
+	 * the other side of the GMSL links for this MAX9286 (such as a
+	 * MAX9271). To prevent that disable auto-acknowledge early on; it
+	 * will be enabled later as needed.
+	 */
+	max9286_configure_i2c(dev, false);
+
+	ret = device_for_each_child(client->dev.parent, &client->dev,
+				    max9286_is_bound);
+	if (ret)
+		return 0;
+
+	dev_dbg(&client->dev,
+		"All max9286 probed: start initialization sequence\n");
+	ret = device_for_each_child(client->dev.parent, NULL,
+				    max9286_init);
+	if (ret < 0)
+		goto err_regulator;
+
+	/* Leave the mux channels disabled until they are selected. */
+	max9286_i2c_mux_close(dev);
+
+	return 0;
+
+err_regulator:
+	regulator_put(dev->regulator);
+	max9286_i2c_mux_close(dev);
+	max9286_configure_i2c(dev, false);
+err_free:
+	max9286_cleanup_dt(dev);
+	kfree(dev);
+
+	return ret;
+}
+
+static int max9286_remove(struct i2c_client *client)
+{
+	struct max9286_device *dev = i2c_get_clientdata(client);
+
+	i2c_mux_del_adapters(dev->mux);
+
+	fwnode_handle_put(dev->sd.fwnode);
+	v4l2_async_unregister_subdev(&dev->sd);
+
+	if (dev->poc_enabled)
+		regulator_disable(dev->regulator);
+	regulator_put(dev->regulator);
+
+	max9286_cleanup_dt(dev);
+	kfree(dev);
+
+	return 0;
+}
+
+static const struct i2c_device_id max9286_id[] = {
+	{ "max9286", 0 },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, max9286_id);
+
+static struct i2c_driver max9286_i2c_driver = {
+	.driver	= {
+		.name		= "max9286",
+		.of_match_table	= of_match_ptr(max9286_dt_ids),
+	},
+	.probe		= max9286_probe,
+	.remove		= max9286_remove,
+	.id_table	= max9286_id,
+};
+
+module_i2c_driver(max9286_i2c_driver);
+
+MODULE_DESCRIPTION("Maxim MAX9286 GMSL Deserializer Driver");
+MODULE_AUTHOR("Vladimir Barinov");
+MODULE_LICENSE("GPL");
-- 
2.17.1

[PATCH v3 4/4] media: i2c: Add RDACM20 driver

[Kieran Bingham]

From: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>

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>

---
v2:
 - Fix MAINTAINERS entry

v3:
 - Use new V4L2_MBUS_CSI2_DPHY bus type
 - Remove 'always zero' error print
 - Fix module description
---
 MAINTAINERS                         |  10 +
 drivers/media/i2c/Kconfig           |  11 +
 drivers/media/i2c/Makefile          |   1 +
 drivers/media/i2c/rdacm20-ov10635.h | 953 ++++++++++++++++++++++++++++
 drivers/media/i2c/rdacm20.c         | 635 ++++++++++++++++++
 5 files changed, 1610 insertions(+)
 create mode 100644 drivers/media/i2c/rdacm20-ov10635.h
 create mode 100644 drivers/media/i2c/rdacm20.c

diff --git a/MAINTAINERS b/MAINTAINERS
index 745f0fd1fff1..26ef20087a43 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -12230,6 +12230,16 @@ S:	Supported
 T:	git git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu.git
 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/rdacm20.txt
+F:	drivers/media/i2c/rdacm20*
+
 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 eadc00bdd3bf..5eded5e337ec 100644
--- a/drivers/media/i2c/Kconfig
+++ b/drivers/media/i2c/Kconfig
@@ -989,6 +989,17 @@ config VIDEO_S5C73M3
 	  This is a V4L2 sensor driver for Samsung S5C73M3
 	  8 Mpixel camera.
 
+config VIDEO_RDACM20
+	tristate "IMI RDACM20 camera support"
+	depends on I2C && VIDEO_V4L2_SUBDEV_API && MEDIA_CONTROLLER
+	select V4L2_FWNODE
+	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.
+
 comment "Flash devices"
 
 config VIDEO_ADP1653
diff --git a/drivers/media/i2c/Makefile b/drivers/media/i2c/Makefile
index 4de7fe62b179..121d28283d45 100644
--- a/drivers/media/i2c/Makefile
+++ b/drivers/media/i2c/Makefile
@@ -111,5 +111,6 @@ obj-$(CONFIG_VIDEO_IMX274)	+= imx274.o
 obj-$(CONFIG_VIDEO_IMX319)	+= imx319.o
 obj-$(CONFIG_VIDEO_IMX355)	+= imx355.o
 obj-$(CONFIG_VIDEO_MAX9286)	+= max9286.o
+obj-$(CONFIG_VIDEO_RDACM20)	+= rdacm20.o
 
 obj-$(CONFIG_SDR_MAX2175) += max2175.o
diff --git a/drivers/media/i2c/rdacm20-ov10635.h b/drivers/media/i2c/rdacm20-ov10635.h
new file mode 100644
index 000000000000..3c53a3262ee2
--- /dev/null
+++ b/drivers/media/i2c/rdacm20-ov10635.h
@@ -0,0 +1,953 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * IMI RDACM20 camera OV10635 sensor register initialization values
+ *
+ * Copyright (C) 2017-2018 Jacopo Mondi
+ * Copyright (C) 2017-2018 Kieran Bingham
+ * Copyright (C) 2017-2018 Laurent Pinchart
+ * Copyright (C) 2017-2018 Niklas Söderlund
+ * Copyright (C) 2016 Renesas Electronics Corporation
+ * Copyright (C) 2015 Cogent Embedded, Inc.
+ *
+ */
+
+/*
+ * Generated by the OmniVision ov10635 sensor camera wizard for
+ * 1280x800@30/UYVY/BT601/8bit.
+ */
+
+#ifndef __RDACM20_OV10635_H__
+#define __RDACM20_OV10635_H__
+
+#define OV10635_SENSOR_WIDTH		1312
+#define OV10635_SENSOR_HEIGHT		814
+
+#define OV10635_MAX_WIDTH		1280
+#define OV10635_MAX_HEIGHT		800
+
+/* VTS = PCLK / FPS / HTS / 2 (= 88MHz / 1572 / 30 / 2) */
+#define OV10635_HTS			1572
+/* FPS = 29,9998 */
+#define OV10635_VTS			933
+
+struct ov10635_reg {
+	u16	reg;
+	u8	val;
+};
+
+static const struct ov10635_reg 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_MAX_WIDTH)) >> 8 },
+	{ 0x460b, (2 * (OV10635_HTS - OV10635_MAX_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 },
+};
+
+#endif /* __RDACM20_OV10635_H__ */
diff --git a/drivers/media/i2c/rdacm20.c b/drivers/media/i2c/rdacm20.c
new file mode 100644
index 000000000000..d96b2eb5ab1b
--- /dev/null
+++ b/drivers/media/i2c/rdacm20.c
@@ -0,0 +1,635 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * IMI RDACM20 GMSL Camera Driver
+ *
+ * Copyright (C) 2017-2018 Jacopo Mondi
+ * Copyright (C) 2017-2018 Kieran Bingham
+ * Copyright (C) 2017-2018 Laurent Pinchart
+ * Copyright (C) 2017-2018 Niklas Söderlund
+ * Copyright (C) 2016 Renesas Electronics Corporation
+ * Copyright (C) 2015 Cogent Embedded, Inc.
+ */
+
+/*
+ * The camera is mode 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 "rdacm20-ov10635.h"
+
+#define RDACM20_SENSOR_HARD_RESET
+
+#define MAX9271_I2C_ADDRESS		0x40
+
+/* 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_SETGPO			BIT(0)
+/* Register 0x15 */
+#define MAX9271_PCLKDET			BIT(0)
+
+#define MAXIM_I2C_I2C_SPEED_400KHZ	MAX9271_I2CMSTBT_339KBPS
+#define MAXIM_I2C_I2C_SPEED_100KHZ	MAX9271_I2CMSTBT_105KBPS
+#define MAXIM_I2C_SPEED			MAXIM_I2C_I2C_SPEED_100KHZ
+
+#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
+#define OV10635_FORMAT			MEDIA_BUS_FMT_UYVY8_2X8
+/* #define OV10635_FORMAT			MEDIA_BUS_FMT_UYVY10_2X10 */
+
+struct rdacm20_device {
+	struct i2c_client		*client;
+	struct i2c_client		*sensor;
+	struct v4l2_subdev		sd;
+	struct media_pad		pad;
+	struct v4l2_ctrl_handler	ctrls;
+};
+
+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 max9271_read(struct rdacm20_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 rdacm20_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;
+}
+
+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)
+		ret = i2c_master_recv(dev->sensor, buf, 2);
+
+	if (ret < 0) {
+		dev_dbg(&dev->client->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->client->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->client->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->client->dev,
+				"%s: register %u (0x%04x) write failed (%d)\n",
+				__func__, i, regs[i].reg, ret);
+			return ret;
+		}
+	}
+
+	return 0;
+}
+
+/*
+ * rdacm20_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 rdacm20_pclk_detect(struct rdacm20_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;
+}
+
+static int rdacm20_s_stream(struct v4l2_subdev *sd, int enable)
+{
+	struct rdacm20_device *dev = sd_to_rdacm20(sd);
+	int ret;
+
+	if (enable) {
+		ret = rdacm20_pclk_detect(dev);
+		if (ret)
+			return ret;
+
+		/* Enable the serial link. */
+		max9271_write(dev, 0x04, MAX9271_SEREN | MAX9271_REVCCEN |
+			      MAX9271_FWDCCEN);
+	} else {
+		/* Disable the serial link. */
+		max9271_write(dev, 0x04, MAX9271_CLINKEN | MAX9271_REVCCEN |
+			      MAX9271_FWDCCEN);
+	}
+
+	return 0;
+}
+
+static int rdacm20_g_mbus_config(struct v4l2_subdev *sd,
+				 struct v4l2_mbus_config *cfg)
+{
+	cfg->flags = V4L2_MBUS_CSI2_1_LANE | V4L2_MBUS_CSI2_CHANNEL_0 |
+		     V4L2_MBUS_CSI2_CONTINUOUS_CLOCK;
+	cfg->type = V4L2_MBUS_CSI2_DPHY;
+
+	return 0;
+}
+
+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 = OV10635_FORMAT;
+
+	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		= OV10635_FORMAT;
+	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,
+	.g_mbus_config	= rdacm20_g_mbus_config,
+};
+
+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 max9271_configure_i2c(struct rdacm20_device *dev)
+{
+	/*
+	 * Configure the I2C bus:
+	 *
+	 * - Enable high thresholds on the reverse channel
+	 * - Disable artificial ACK and set I2C speed
+	 */
+	max9271_write(dev, 0x08, MAX9271_REV_HIVTH);
+	usleep_range(5000, 8000);
+
+	max9271_write(dev, 0x0d, MAX9271_I2CSLVSH_469NS_234NS |
+		      MAX9271_I2CSLVTO_1024US | MAXIM_I2C_SPEED);
+	usleep_range(5000, 8000);
+
+	return 0;
+}
+
+static int max9271_configure_gmsl_link(struct rdacm20_device *dev)
+{
+	/*
+	 * Disable the serial link and enable the configuration link to allow
+	 * the control channel to operate in a low-speed mode in the absence of
+	 * the serial link clock.
+	 */
+	max9271_write(dev, 0x04, MAX9271_CLINKEN | MAX9271_REVCCEN |
+		      MAX9271_FWDCCEN);
+
+	/*
+	 * 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.
+	 */
+	usleep_range(5000, 8000);
+
+	/*
+	 * 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
+	 */
+	max9271_write(dev, 0x07, MAX9271_DBL | MAX9271_HVEN |
+		      MAX9271_EDC_1BIT_PARITY);
+	usleep_range(5000, 8000);
+
+	return 0;
+}
+
+static int max9271_verify_id(struct rdacm20_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;
+}
+
+static int max9271_configure_address(struct rdacm20_device *dev, u8 addr)
+{
+	int ret;
+
+	/* Change the MAX9271 I2C address. */
+	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;
+	}
+	dev->client->addr = addr;
+	usleep_range(3500, 5000);
+
+	return 0;
+}
+
+static int rdacm20_initialize(struct rdacm20_device *dev)
+{
+	u32 addrs[2];
+	int ret;
+
+	ret = of_property_read_u32_array(dev->client->dev.of_node, "reg",
+					 addrs, ARRAY_SIZE(addrs));
+	if (ret < 0) {
+		dev_err(&dev->client->dev, "Invalid DT reg property\n");
+		return -EINVAL;
+	}
+
+	/*
+	 * FIXME: The MAX9271 boots at a default address that we will change to
+	 * the address specified in DT. Set the client address back to the
+	 * default for initial communication.
+	 */
+	dev->client->addr = MAX9271_I2C_ADDRESS;
+
+	/* Verify communication with the MAX9271. */
+	i2c_smbus_read_byte(dev->client);	/* ping to wake-up */
+
+	/*
+	 *  Ensure that we have a good link configuration before attempting to
+	 *  identify the device.
+	 */
+	max9271_configure_i2c(dev);
+	max9271_configure_gmsl_link(dev);
+
+	ret = max9271_verify_id(dev);
+	if (ret < 0)
+		return ret;
+
+	ret = max9271_configure_address(dev, addrs[0]);
+	if (ret < 0)
+		return ret;
+
+	/* Reset and verify communication with the OV10635. */
+#ifdef RDACM20_SENSOR_HARD_RESET
+	/* Cycle the OV10635 reset signal connected to the MAX9271 GPIO1. */
+	max9271_write(dev, 0x0f, 0xff & ~(MAX9271_GPIO1OUT | MAX9271_SETGPO));
+	mdelay(10);
+	max9271_write(dev, 0x0f, 0xff & ~MAX9271_SETGPO);
+	mdelay(10);
+#else
+	/* Perform a software reset. */
+	ret = ov10635_write(dev, OV10635_SOFTWARE_RESET, 1);
+	if (ret < 0) {
+		dev_err(&dev->client->dev, "OV10635 reset failed (%d)\n", ret);
+		return -ENXIO;
+	}
+
+	udelay(100);
+#endif
+
+	ret = ov10635_read16(dev, OV10635_PID);
+	if (ret < 0) {
+		dev_err(&dev->client->dev, "OV10635 ID read failed (%d)\n",
+			ret);
+		return -ENXIO;
+	}
+
+	if (ret != OV10635_VERSION) {
+		dev_err(&dev->client->dev, "OV10635 ID mismatch (0x%04x)\n",
+			ret);
+		return -ENXIO;
+	}
+
+	dev_info(&dev->client->dev, "Identified MAX9271 + OV10635 device\n");
+
+	/* Change the sensor I2C address. */
+	ret = ov10635_write(dev, OV10635_SC_CMMN_SCCB_ID,
+			    (addrs[1] << 1) | OV10635_SC_CMMN_SCCB_ID_SELECT);
+	if (ret < 0) {
+		dev_err(&dev->client->dev,
+			"OV10635 I2C address change failed (%d)\n", ret);
+		return ret;
+	}
+	dev->sensor->addr = 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;
+
+	return 0;
+}
+
+static int rdacm20_probe(struct i2c_client *client,
+			 const struct i2c_device_id *did)
+{
+	struct rdacm20_device *dev;
+	struct fwnode_handle *ep;
+	int ret;
+
+	dev = kzalloc(sizeof(*dev), GFP_KERNEL);
+	if (!dev)
+		return -ENOMEM;
+
+	dev->client = client;
+
+	/* Create the dummy I2C client for the sensor. */
+	dev->sensor = i2c_new_dummy(client->adapter, OV10635_I2C_ADDRESS);
+	if (!dev->sensor) {
+		ret = -ENXIO;
+		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);
+	/*
+	 * FIXME: Compute the real pixel rate. The 50 MP/s value comes from the
+	 * hardcoded frequency in the BSP CSI-2 receiver driver.
+	 */
+	v4l2_ctrl_new_std(&dev->ctrls, NULL, V4L2_CID_PIXEL_RATE, 50000000,
+			  50000000, 1, 50000000);
+	dev->sd.ctrl_handler = &dev->ctrls;
+
+	ret = dev->ctrls.error;
+	if (ret)
+		goto error;
+
+	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;
+
+	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;
+	}
+	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:
+	media_entity_cleanup(&dev->sd.entity);
+	if (dev->sensor)
+		i2c_unregister_device(dev->sensor);
+	kfree(dev);
+
+	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);
+	media_entity_cleanup(&dev->sd.entity);
+	i2c_unregister_device(dev->sensor);
+	kfree(dev);
+
+	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 i2c_device_id rdacm20_id[] = {
+	{ "rdacm20", 0 },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, rdacm20_id);
+
+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		= rdacm20_probe,
+	.remove		= rdacm20_remove,
+	.shutdown	= rdacm20_shutdown,
+	.id_table	= rdacm20_id,
+};
+
+module_i2c_driver(rdacm20_i2c_driver);
+
+MODULE_DESCRIPTION("GMSL Camera driver for RDACM20");
+MODULE_AUTHOR("Vladimir Barinov");
+MODULE_LICENSE("GPL");
-- 
2.17.1

Re: [PATCH v3 1/4] dt-bindings: media: i2c: Add bindings for Maxim Integrated MAX9286

[Sakari Ailus]

Hi Kieran,

Could you cc the devicetree list for the next version, please?

On Tue, Oct 09, 2018 at 09:57:23PM +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>
> 
> ---
> v3:
>  - Update binding descriptions
> ---
>  .../bindings/media/i2c/maxim,max9286.txt      | 182 ++++++++++++++++++
>  1 file changed, 182 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/media/i2c/maxim,max9286.txt
> 
> diff --git a/Documentation/devicetree/bindings/media/i2c/maxim,max9286.txt b/Documentation/devicetree/bindings/media/i2c/maxim,max9286.txt
> new file mode 100644
> index 000000000000..a73e3c0dc31b
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/media/i2c/maxim,max9286.txt
> @@ -0,0 +1,182 @@
> +Maxim Integrated Quad GMSL Deserializer
> +---------------------------------------
> +
> +The MAX9286 deserializer receives video data on up to 4 Gigabit Multimedia
> +Serial Links (GMSL) and outputs them on a CSI-2 port using up to 4 data lanes.

CSI-2 D-PHY I presume?

> +
> +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.
> +
> +Required Properties:
> +
> +- compatible: Shall be "maxim,max9286"
> +- reg: I2C device address
> +
> +Optional Properties:
> +
> +- poc-supply: Regulator providing Power over Coax to the cameras
> +- pwdn-gpios: GPIO connected to the #PWDN pin

If this is basically a hardware reset pin, then you could call it e.g.
enable-gpios or reset-gpios. There was recently a similar discussion
related to ad5820 DT bindings.

> +
> +Required endpoint nodes:
> +-----------------------
> +
> +The connections to the MAX9286 GMSL and its endpoint nodes are modeled 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
> +
> +Optional Endpoint Properties for GSML Input Ports (Port [0-3]):

Isn't port 4 included?

> +
> +- remote-endpoint: phandle to the remote GMSL source endpoint subnode in the
> +  remote node port.
> +
> +Required Endpoint Properties for CSI-2 Output Port (Port 4):
> +
> +- data-lanes: array of physical CSI-2 data lane indexes.
> +- clock-lanes: index of CSI-2 clock lane.

Is any number of lanes supported? How about lane remapping? If you do not
have lane remapping, the clock-lanes property is redundant.

> +
> +Required i2c-mux nodes:
> +----------------------
> +
> +Each GMSL link is modeled 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.
> +
> +Required i2c child bus properties:
> +- all properties described as required i2c child bus nodes properties in
> +  Documentation/devicetree/bindings/i2c/i2c-mux.txt.
> +
> +Example:
> +-------
> +
> +	gmsl-deserializer@2c {
> +		compatible = "maxim,max9286";
> +		reg = <0x2c>;
> +		poc-supply = <&camera_poc_12v>;
> +		pwdn-gpios = <&gpio 13 GPIO_ACTIVE_LOW>;
> +
> +		#address-cells = <1>;
> +		#size-cells = <0>;
> +
> +		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 {
> +					clock-lanes = <0>;
> +					data-lanes = <1 2 3 4>;
> +					remote-endpoint = <&csi40_in>;
> +				};
> +			};
> +		};
> +
> +		i2c@0 {
> +			#address-cells = <1>;
> +			#size-cells = <0>;
> +			reg = <0>;
> +
> +			camera@51 {
> +				compatible = "imi,rdacm20";
> +				reg = <0x51 0x61>;

What's the second value for in the reg property? There's more of the same
below.

> +
> +				port {
> +					rdacm20_out0: endpoint {
> +						remote-endpoint = <&max9286_in0>;
> +					};
> +				};
> +
> +			};
> +		};
> +
> +		i2c@1 {
> +			#address-cells = <1>;
> +			#size-cells = <0>;
> +			reg = <1>;
> +
> +			camera@52 {
> +				compatible = "imi,rdacm20";
> +				reg = <0x52 0x62>;
> +				port {
> +					rdacm20_out1: endpoint {
> +						remote-endpoint = <&max9286_in1>;
> +					};
> +				};
> +			};
> +		};
> +
> +		i2c@2 {
> +			#address-cells = <1>;
> +			#size-cells = <0>;
> +			reg = <2>;
> +
> +			camera@53 {
> +				compatible = "imi,rdacm20";
> +				reg = <0x53 0x63>;
> +				port {
> +					rdacm20_out2: endpoint {
> +						remote-endpoint = <&max9286_in2>;
> +					};
> +				};
> +			};
> +		};
> +
> +		i2c@3 {
> +			#address-cells = <1>;
> +			#size-cells = <0>;
> +			reg = <3>;
> +
> +			camera@54 {
> +				compatible = "imi,rdacm20";
> +				reg = <0x54 0x64>;
> +				port {
> +					rdacm20_out3: endpoint {
> +						remote-endpoint = <&max9286_in3>;
> +					};
> +				};
> +			};
> +		};
> +	};

-- 
Regards,

Sakari Ailus
e-mail: sakari.ailus@iki.fi

Re: [PATCH v3 1/4] dt-bindings: media: i2c: Add bindings for Maxim Integrated MAX9286

[Kieran Bingham]

Hi Sakari,

Thank you for the review,

On 15/10/18 17:45, Sakari Ailus wrote:
> Hi Kieran,
> 
> Could you cc the devicetree list for the next version, please?

Argh - looks like I've missed the DT list on all three postings.

No wonder the responses have been quiet :-)

I'll do a v4 post after I've gone through some of your comments, and
make sure I remember the DT guys this time :)


> On Tue, Oct 09, 2018 at 09:57:23PM +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>
>>
>> ---
>> v3:
>>  - Update binding descriptions
>> ---
>>  .../bindings/media/i2c/maxim,max9286.txt      | 182 ++++++++++++++++++
>>  1 file changed, 182 insertions(+)
>>  create mode 100644 Documentation/devicetree/bindings/media/i2c/maxim,max9286.txt
>>
>> diff --git a/Documentation/devicetree/bindings/media/i2c/maxim,max9286.txt b/Documentation/devicetree/bindings/media/i2c/maxim,max9286.txt
>> new file mode 100644
>> index 000000000000..a73e3c0dc31b
>> --- /dev/null
>> +++ b/Documentation/devicetree/bindings/media/i2c/maxim,max9286.txt
>> @@ -0,0 +1,182 @@
>> +Maxim Integrated Quad GMSL Deserializer
>> +---------------------------------------
>> +
>> +The MAX9286 deserializer receives video data on up to 4 Gigabit Multimedia
>> +Serial Links (GMSL) and outputs them on a CSI-2 port using up to 4 data lanes.
> 
> CSI-2 D-PHY I presume?

Yes, that's how I've adapted the driver based on the latest bus changes.

Niklas - Could you confirm that everything in VIN/CSI2 is configured to
use D-PHY and not C-PHY at all ?


>> +
>> +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.
>> +
>> +Required Properties:
>> +
>> +- compatible: Shall be "maxim,max9286"
>> +- reg: I2C device address
>> +
>> +Optional Properties:
>> +
>> +- poc-supply: Regulator providing Power over Coax to the cameras
>> +- pwdn-gpios: GPIO connected to the #PWDN pin
> 
> If this is basically a hardware reset pin, then you could call it e.g.
> enable-gpios or reset-gpios. There was recently a similar discussion
> related to ad5820 DT bindings.

Ah yes ... now which polarity ;-)


>> +
>> +Required endpoint nodes:
>> +-----------------------
>> +
>> +The connections to the MAX9286 GMSL and its endpoint nodes are modeled 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
>> +
>> +Optional Endpoint Properties for GSML Input Ports (Port [0-3]):
> 
> Isn't port 4 included?

Hrm ... yes well I guess these are mandatory for port 4. I'll look at
the wording here.

> 
>> +
>> +- remote-endpoint: phandle to the remote GMSL source endpoint subnode in the
>> +  remote node port.
>> +
>> +Required Endpoint Properties for CSI-2 Output Port (Port 4):
>> +
>> +- data-lanes: array of physical CSI-2 data lane indexes.
>> +- clock-lanes: index of CSI-2 clock lane.
> 
> Is any number of lanes supported? How about lane remapping? If you do not
> have lane remapping, the clock-lanes property is redundant.


Uhm ... Niklas?


> 
>> +
>> +Required i2c-mux nodes:
>> +----------------------
>> +
>> +Each GMSL link is modeled 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.
>> +
>> +Required i2c child bus properties:
>> +- all properties described as required i2c child bus nodes properties in
>> +  Documentation/devicetree/bindings/i2c/i2c-mux.txt.
>> +
>> +Example:
>> +-------
>> +
>> +	gmsl-deserializer@2c {
>> +		compatible = "maxim,max9286";
>> +		reg = <0x2c>;
>> +		poc-supply = <&camera_poc_12v>;
>> +		pwdn-gpios = <&gpio 13 GPIO_ACTIVE_LOW>;
>> +
>> +		#address-cells = <1>;
>> +		#size-cells = <0>;
>> +
>> +		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 {
>> +					clock-lanes = <0>;
>> +					data-lanes = <1 2 3 4>;
>> +					remote-endpoint = <&csi40_in>;
>> +				};
>> +			};
>> +		};
>> +
>> +		i2c@0 {
>> +			#address-cells = <1>;
>> +			#size-cells = <0>;
>> +			reg = <0>;
>> +
>> +			camera@51 {
>> +				compatible = "imi,rdacm20";
>> +				reg = <0x51 0x61>;
> 
> What's the second value for in the reg property? There's more of the same
> below.
> 

These are specific to the RDACM20:

>From the RDACM20 documentation:

- reg: Pair of I2C device addresses, the first to be assigned to the
serializer, the second to be assigned to the camera sensor.

Each RDACM20 camera boots up with the same I2C addresses. The driver
remaps them to the new values specified here.

But they are not relevant to the max9286 except for the example of
adding in the rdacm20.


>> +
>> +				port {
>> +					rdacm20_out0: endpoint {
>> +						remote-endpoint = <&max9286_in0>;
>> +					};
>> +				};
>> +
>> +			};
>> +		};
>> +
>> +		i2c@1 {
>> +			#address-cells = <1>;
>> +			#size-cells = <0>;
>> +			reg = <1>;
>> +
>> +			camera@52 {
>> +				compatible = "imi,rdacm20";
>> +				reg = <0x52 0x62>;
>> +				port {
>> +					rdacm20_out1: endpoint {
>> +						remote-endpoint = <&max9286_in1>;
>> +					};
>> +				};
>> +			};
>> +		};
>> +
>> +		i2c@2 {
>> +			#address-cells = <1>;
>> +			#size-cells = <0>;
>> +			reg = <2>;
>> +
>> +			camera@53 {
>> +				compatible = "imi,rdacm20";
>> +				reg = <0x53 0x63>;
>> +				port {
>> +					rdacm20_out2: endpoint {
>> +						remote-endpoint = <&max9286_in2>;
>> +					};
>> +				};
>> +			};
>> +		};
>> +
>> +		i2c@3 {
>> +			#address-cells = <1>;
>> +			#size-cells = <0>;
>> +			reg = <3>;
>> +
>> +			camera@54 {
>> +				compatible = "imi,rdacm20";
>> +				reg = <0x54 0x64>;
>> +				port {
>> +					rdacm20_out3: endpoint {
>> +						remote-endpoint = <&max9286_in3>;
>> +					};
>> +				};
>> +			};
>> +		};
>> +	};
> 

Re: [PATCH v3 1/4] dt-bindings: media: i2c: Add bindings for Maxim Integrated MAX9286

[Niklas Söderlund]

Hi Kieran,

On 2018-10-15 18:37:40 +0100, Kieran Bingham wrote:

> >> diff --git 
> >> a/Documentation/devicetree/bindings/media/i2c/maxim,max9286.txt 
> >> b/Documentation/devicetree/bindings/media/i2c/maxim,max9286.txt
> >> new file mode 100644
> >> index 000000000000..a73e3c0dc31b
> >> --- /dev/null
> >> +++ b/Documentation/devicetree/bindings/media/i2c/maxim,max9286.txt
> >> @@ -0,0 +1,182 @@
> >> +Maxim Integrated Quad GMSL Deserializer
> >> +---------------------------------------
> >> +
> >> +The MAX9286 deserializer receives video data on up to 4 Gigabit Multimedia
> >> +Serial Links (GMSL) and outputs them on a CSI-2 port using up to 4 data lanes.
> > 
> > CSI-2 D-PHY I presume?
> 
> Yes, that's how I've adapted the driver based on the latest bus changes.
> 
> Niklas - Could you confirm that everything in VIN/CSI2 is configured to
> use D-PHY and not C-PHY at all ?

Yes it's only D-PHY.

> >> +
> >> +- remote-endpoint: phandle to the remote GMSL source endpoint subnode in the
> >> +  remote node port.
> >> +
> >> +Required Endpoint Properties for CSI-2 Output Port (Port 4):
> >> +
> >> +- data-lanes: array of physical CSI-2 data lane indexes.
> >> +- clock-lanes: index of CSI-2 clock lane.
> > 
> > Is any number of lanes supported? How about lane remapping? If you do not
> > have lane remapping, the clock-lanes property is redundant.
> 
> 
> Uhm ... Niklas?

The MAX9286 documentation contains information on lane remapping and 
support for any number (1-4) of enabled data-lanes. I have not tested if 
this works in practice but the registers are there and documented :-)

-- 
Regards,
Niklas Söderlund

Re: [PATCH v3 1/4] dt-bindings: media: i2c: Add bindings for Maxim Integrated MAX9286

[Niklas Söderlund]

Hi Kieran,

On 2018-10-15 18:37:40 +0100, Kieran Bingham wrote:

> >> diff --git 
> >> a/Documentation/devicetree/bindings/media/i2c/maxim,max9286.txt 
> >> b/Documentation/devicetree/bindings/media/i2c/maxim,max9286.txt
> >> new file mode 100644
> >> index 000000000000..a73e3c0dc31b
> >> --- /dev/null
> >> +++ b/Documentation/devicetree/bindings/media/i2c/maxim,max9286.txt
> >> @@ -0,0 +1,182 @@
> >> +Maxim Integrated Quad GMSL Deserializer
> >> +---------------------------------------
> >> +
> >> +The MAX9286 deserializer receives video data on up to 4 Gigabit Multimedia
> >> +Serial Links (GMSL) and outputs them on a CSI-2 port using up to 4 data lanes.
> > 
> > CSI-2 D-PHY I presume?
> 
> Yes, that's how I've adapted the driver based on the latest bus changes.
> 
> Niklas - Could you confirm that everything in VIN/CSI2 is configured to
> use D-PHY and not C-PHY at all ?

Yes it's only D-PHY.

> >> +
> >> +- remote-endpoint: phandle to the remote GMSL source endpoint subnode in the
> >> +  remote node port.
> >> +
> >> +Required Endpoint Properties for CSI-2 Output Port (Port 4):
> >> +
> >> +- data-lanes: array of physical CSI-2 data lane indexes.
> >> +- clock-lanes: index of CSI-2 clock lane.
> > 
> > Is any number of lanes supported? How about lane remapping? If you do not
> > have lane remapping, the clock-lanes property is redundant.
> 
> 
> Uhm ... Niklas?

The MAX9286 documentation contains information on lane remapping and 
support for any number (1-4) of enabled data-lanes. I have not tested if 
this works in practice but the registers are there and documented :-)

-- 
Regards,
Niklas S�derlund

Re: [PATCH v3 1/4] dt-bindings: media: i2c: Add bindings for Maxim Integrated MAX9286

[jacopo mondi]

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Hi Kieran,

On Mon, Oct 15, 2018 at 06:37:40PM +0100, Kieran Bingham wrote:
> Hi Sakari,
>
> Thank you for the review,
>
> On 15/10/18 17:45, Sakari Ailus wrote:
> > Hi Kieran,
> >
> > Could you cc the devicetree list for the next version, please?
>
> Argh - looks like I've missed the DT list on all three postings.
>
> No wonder the responses have been quiet :-)
>
> I'll do a v4 post after I've gone through some of your comments, and
> make sure I remember the DT guys this time :)
>
>
> > On Tue, Oct 09, 2018 at 09:57:23PM +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>
> >>
> >> ---
> >> v3:
> >>  - Update binding descriptions
> >> ---
> >>  .../bindings/media/i2c/maxim,max9286.txt      | 182 ++++++++++++++++++
> >>  1 file changed, 182 insertions(+)
> >>  create mode 100644 Documentation/devicetree/bindings/media/i2c/maxim,max9286.txt
> >>
> >> diff --git a/Documentation/devicetree/bindings/media/i2c/maxim,max9286.txt b/Documentation/devicetree/bindings/media/i2c/maxim,max9286.txt
> >> new file mode 100644
> >> index 000000000000..a73e3c0dc31b
> >> --- /dev/null
> >> +++ b/Documentation/devicetree/bindings/media/i2c/maxim,max9286.txt
> >> @@ -0,0 +1,182 @@
> >> +Maxim Integrated Quad GMSL Deserializer
> >> +---------------------------------------
> >> +
> >> +The MAX9286 deserializer receives video data on up to 4 Gigabit Multimedia
> >> +Serial Links (GMSL) and outputs them on a CSI-2 port using up to 4 data lanes.
> >
> > CSI-2 D-PHY I presume?
>
> Yes, that's how I've adapted the driver based on the latest bus changes.
>
> Niklas - Could you confirm that everything in VIN/CSI2 is configured to
> use D-PHY and not C-PHY at all ?
>
>
> >> +
> >> +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.
> >> +
> >> +Required Properties:
> >> +
> >> +- compatible: Shall be "maxim,max9286"
> >> +- reg: I2C device address
> >> +
> >> +Optional Properties:
> >> +
> >> +- poc-supply: Regulator providing Power over Coax to the cameras
> >> +- pwdn-gpios: GPIO connected to the #PWDN pin
> >
> > If this is basically a hardware reset pin, then you could call it e.g.
> > enable-gpios or reset-gpios. There was recently a similar discussion
> > related to ad5820 DT bindings.

Techinically is a powerdown control, it shuts the current to the chip,
not reset it.

>
> Ah yes ... now which polarity ;-)

The signal is active low (when is at physical level 0, the chip is
off).

According to the gpio bindings documentation

"The gpio-specifier's polarity flag should represent the physical level at the
GPIO controller that achieves (or represents, for inputs) a logically asserted
value at the device."

Sakari's argument, which I understand and has been debated before, is
to use generic names (ie. don't use the pin name as specified by the HW
manual, but name it after its function. It doesn't matter if your pin
is called "#RST", just call it "reset-gpios' and state the pin name in the
documentation if you like to.)

I count much more 'enable-gpios' compared to 'powerdown-gpios', so
that seems the obvious choice, as generic names have not yet been
documented anywhere as far as I know, but the most common ones should
be used.

Using generic names is good because in the power up/down routines,
you don't have to care about the signals polarities, but only
about their logical levels. At power-up if you have an "enable-gpio"
just set it to logical 1, the gpio framework translates it to the
appropriate physical level. Easier to write and to review.

To comply with GPIO bindings we would have to

        enable-gpios: <&gpio 13 GPIO_ACTIVE_LOW>;

And at power up we would have to use the logical value, and for an
enable signal, setting it to "1" at power up would be the natural choice.
However to have our line set to physical 1 and have the chip powered
we would have to:

        gpiod_set_value(&enable, 0);

Which makes any reason to use generic names vanish.

All of this to say that, even if less popular, I would call it
"powerdown-gpios", which is anyway quite generic, and describe it as:

powerdown-gpios: Power down GPIO signal, pin name "PWDN". Active low.

So that at power_up:
        gpiod_set_value(&pwdn, 0);

And at power down:
        gpiod_set_value(&pwdn, 1);

>
>
> >> +
> >> +Required endpoint nodes:
> >> +-----------------------
> >> +
> >> +The connections to the MAX9286 GMSL and its endpoint nodes are modeled 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
> >> +
> >> +Optional Endpoint Properties for GSML Input Ports (Port [0-3]):

I guess Sakari means s/3/4 here:                                 ^

Or didn't I get his questions and then neither your answer :) ?

Thanks
  j

> >
> > Isn't port 4 included?
>
> Hrm ... yes well I guess these are mandatory for port 4. I'll look at
> the wording here.
>
> >
> >> +
> >> +- remote-endpoint: phandle to the remote GMSL source endpoint subnode in the
> >> +  remote node port.
> >> +
> >> +Required Endpoint Properties for CSI-2 Output Port (Port 4):
> >> +
> >> +- data-lanes: array of physical CSI-2 data lane indexes.
> >> +- clock-lanes: index of CSI-2 clock lane.
> >
> > Is any number of lanes supported? How about lane remapping? If you do not
> > have lane remapping, the clock-lanes property is redundant.
>
>
> Uhm ... Niklas?
>
>
> >
> >> +
> >> +Required i2c-mux nodes:
> >> +----------------------
> >> +
> >> +Each GMSL link is modeled 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.
> >> +
> >> +Required i2c child bus properties:
> >> +- all properties described as required i2c child bus nodes properties in
> >> +  Documentation/devicetree/bindings/i2c/i2c-mux.txt.
> >> +
> >> +Example:
> >> +-------
> >> +
> >> +	gmsl-deserializer@2c {
> >> +		compatible = "maxim,max9286";
> >> +		reg = <0x2c>;
> >> +		poc-supply = <&camera_poc_12v>;
> >> +		pwdn-gpios = <&gpio 13 GPIO_ACTIVE_LOW>;
> >> +
> >> +		#address-cells = <1>;
> >> +		#size-cells = <0>;
> >> +
> >> +		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 {
> >> +					clock-lanes = <0>;
> >> +					data-lanes = <1 2 3 4>;
> >> +					remote-endpoint = <&csi40_in>;
> >> +				};
> >> +			};
> >> +		};
> >> +
> >> +		i2c@0 {
> >> +			#address-cells = <1>;
> >> +			#size-cells = <0>;
> >> +			reg = <0>;
> >> +
> >> +			camera@51 {
> >> +				compatible = "imi,rdacm20";
> >> +				reg = <0x51 0x61>;
> >
> > What's the second value for in the reg property? There's more of the same
> > below.
> >
>
> These are specific to the RDACM20:
>
> From the RDACM20 documentation:
>
> - reg: Pair of I2C device addresses, the first to be assigned to the
> serializer, the second to be assigned to the camera sensor.
>
> Each RDACM20 camera boots up with the same I2C addresses. The driver
> remaps them to the new values specified here.
>
> But they are not relevant to the max9286 except for the example of
> adding in the rdacm20.
>
>
> >> +
> >> +				port {
> >> +					rdacm20_out0: endpoint {
> >> +						remote-endpoint = <&max9286_in0>;
> >> +					};
> >> +				};
> >> +
> >> +			};
> >> +		};
> >> +
> >> +		i2c@1 {
> >> +			#address-cells = <1>;
> >> +			#size-cells = <0>;
> >> +			reg = <1>;
> >> +
> >> +			camera@52 {
> >> +				compatible = "imi,rdacm20";
> >> +				reg = <0x52 0x62>;
> >> +				port {
> >> +					rdacm20_out1: endpoint {
> >> +						remote-endpoint = <&max9286_in1>;
> >> +					};
> >> +				};
> >> +			};
> >> +		};
> >> +
> >> +		i2c@2 {
> >> +			#address-cells = <1>;
> >> +			#size-cells = <0>;
> >> +			reg = <2>;
> >> +
> >> +			camera@53 {
> >> +				compatible = "imi,rdacm20";
> >> +				reg = <0x53 0x63>;
> >> +				port {
> >> +					rdacm20_out2: endpoint {
> >> +						remote-endpoint = <&max9286_in2>;
> >> +					};
> >> +				};
> >> +			};
> >> +		};
> >> +
> >> +		i2c@3 {
> >> +			#address-cells = <1>;
> >> +			#size-cells = <0>;
> >> +			reg = <3>;
> >> +
> >> +			camera@54 {
> >> +				compatible = "imi,rdacm20";
> >> +				reg = <0x54 0x64>;
> >> +				port {
> >> +					rdacm20_out3: endpoint {
> >> +						remote-endpoint = <&max9286_in3>;
> >> +					};
> >> +				};
> >> +			};
> >> +		};
> >> +	};
> >

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Re: [PATCH v3 1/4] dt-bindings: media: i2c: Add bindings for Maxim Integrated MAX9286

[Laurent Pinchart]

Hello,

On Monday, 15 October 2018 22:01:21 EEST Niklas Söderlund wrote:
> On 2018-10-15 18:37:40 +0100, Kieran Bingham wrote:
> >>> diff --git
> >>> a/Documentation/devicetree/bindings/media/i2c/maxim,max9286.txt
> >>> b/Documentation/devicetree/bindings/media/i2c/maxim,max9286.txt
> >>> new file mode 100644
> >>> index 000000000000..a73e3c0dc31b
> >>> --- /dev/null
> >>> +++ b/Documentation/devicetree/bindings/media/i2c/maxim,max9286.txt
> >>> @@ -0,0 +1,182 @@
> >>> +Maxim Integrated Quad GMSL Deserializer
> >>> +---------------------------------------
> >>> +
> >>> +The MAX9286 deserializer receives video data on up to 4 Gigabit
> >>> Multimedia
> >>> +Serial Links (GMSL) and outputs them on a CSI-2 port using up to 4
> >>> data lanes.
> >>
> >> CSI-2 D-PHY I presume?
> > 
> > Yes, that's how I've adapted the driver based on the latest bus changes.
> > 
> > Niklas - Could you confirm that everything in VIN/CSI2 is configured to
> > use D-PHY and not C-PHY at all ?
> 
> Yes it's only D-PHY.
> 
> >>> +
> >>> +- remote-endpoint: phandle to the remote GMSL source endpoint subnode
> >>> in the
> >>> +  remote node port.
> >>> +
> >>> +Required Endpoint Properties for CSI-2 Output Port (Port 4):
> >>> +
> >>> +- data-lanes: array of physical CSI-2 data lane indexes.
> >>> +- clock-lanes: index of CSI-2 clock lane.
> >> 
> >> Is any number of lanes supported? How about lane remapping? If you do
> >> not have lane remapping, the clock-lanes property is redundant.
> > 
> > Uhm ... Niklas?
> 
> The MAX9286 documentation contains information on lane remapping and
> support for any number (1-4) of enabled data-lanes. I have not tested if
> this works in practice but the registers are there and documented :-)

That's my understanding too. Clock lane remapping doesn't seem to be supported 
though. We could thus omit the clock-lanes property.

-- 
Regards,

Laurent Pinchart

Re: [PATCH v3 1/4] dt-bindings: media: i2c: Add bindings for Maxim Integrated MAX9286

[Kieran Bingham]

On 16/10/2018 01:37, Laurent Pinchart wrote:
> Hello,
> 
> On Monday, 15 October 2018 22:01:21 EEST Niklas Söderlund wrote:
>> On 2018-10-15 18:37:40 +0100, Kieran Bingham wrote:
>>>>> diff --git
>>>>> a/Documentation/devicetree/bindings/media/i2c/maxim,max9286.txt
>>>>> b/Documentation/devicetree/bindings/media/i2c/maxim,max9286.txt
>>>>> new file mode 100644
>>>>> index 000000000000..a73e3c0dc31b
>>>>> --- /dev/null
>>>>> +++ b/Documentation/devicetree/bindings/media/i2c/maxim,max9286.txt
>>>>> @@ -0,0 +1,182 @@
>>>>> +Maxim Integrated Quad GMSL Deserializer
>>>>> +---------------------------------------
>>>>> +
>>>>> +The MAX9286 deserializer receives video data on up to 4 Gigabit
>>>>> Multimedia
>>>>> +Serial Links (GMSL) and outputs them on a CSI-2 port using up to 4
>>>>> data lanes.
>>>>
>>>> CSI-2 D-PHY I presume?

Updated.

>>>
>>> Yes, that's how I've adapted the driver based on the latest bus changes.
>>>
>>> Niklas - Could you confirm that everything in VIN/CSI2 is configured to
>>> use D-PHY and not C-PHY at all ?
>>
>> Yes it's only D-PHY.
>>
>>>>> +
>>>>> +- remote-endpoint: phandle to the remote GMSL source endpoint subnode
>>>>> in the
>>>>> +  remote node port.
>>>>> +
>>>>> +Required Endpoint Properties for CSI-2 Output Port (Port 4):
>>>>> +
>>>>> +- data-lanes: array of physical CSI-2 data lane indexes.
>>>>> +- clock-lanes: index of CSI-2 clock lane.
>>>>
>>>> Is any number of lanes supported? How about lane remapping? If you do
>>>> not have lane remapping, the clock-lanes property is redundant.
>>>
>>> Uhm ... Niklas?
>>
>> The MAX9286 documentation contains information on lane remapping and
>> support for any number (1-4) of enabled data-lanes. I have not tested if
>> this works in practice but the registers are there and documented :-)
> 
> That's my understanding too. Clock lane remapping doesn't seem to be supported 
> though. We could thus omit the clock-lanes property.

Ok - no point describing something that can't be changed.

Dropped.

--
Regards

Kieran

Re: [PATCH v3 1/4] dt-bindings: media: i2c: Add bindings for Maxim Integrated MAX9286

[Kieran Bingham]

Hi Jacopo,

On 15/10/2018 20:37, jacopo mondi wrote:
> Hi Kieran,
> 
> On Mon, Oct 15, 2018 at 06:37:40PM +0100, Kieran Bingham wrote:
>> Hi Sakari,
>>
>> Thank you for the review,
>>
>> On 15/10/18 17:45, Sakari Ailus wrote:
>>> Hi Kieran,
>>>
>>> Could you cc the devicetree list for the next version, please?
>>
>> Argh - looks like I've missed the DT list on all three postings.
>>
>> No wonder the responses have been quiet :-)
>>
>> I'll do a v4 post after I've gone through some of your comments, and
>> make sure I remember the DT guys this time :)
>>
>>
>>> On Tue, Oct 09, 2018 at 09:57:23PM +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>
>>>>
>>>> ---
>>>> v3:
>>>>  - Update binding descriptions
>>>> ---
>>>>  .../bindings/media/i2c/maxim,max9286.txt      | 182 ++++++++++++++++++
>>>>  1 file changed, 182 insertions(+)
>>>>  create mode 100644 Documentation/devicetree/bindings/media/i2c/maxim,max9286.txt
>>>>
>>>> diff --git a/Documentation/devicetree/bindings/media/i2c/maxim,max9286.txt b/Documentation/devicetree/bindings/media/i2c/maxim,max9286.txt
>>>> new file mode 100644
>>>> index 000000000000..a73e3c0dc31b
>>>> --- /dev/null
>>>> +++ b/Documentation/devicetree/bindings/media/i2c/maxim,max9286.txt
>>>> @@ -0,0 +1,182 @@
>>>> +Maxim Integrated Quad GMSL Deserializer
>>>> +---------------------------------------
>>>> +
>>>> +The MAX9286 deserializer receives video data on up to 4 Gigabit Multimedia
>>>> +Serial Links (GMSL) and outputs them on a CSI-2 port using up to 4 data lanes.
>>>
>>> CSI-2 D-PHY I presume?
>>
>> Yes, that's how I've adapted the driver based on the latest bus changes.
>>
>> Niklas - Could you confirm that everything in VIN/CSI2 is configured to
>> use D-PHY and not C-PHY at all ?
>>
>>
>>>> +
>>>> +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.
>>>> +
>>>> +Required Properties:
>>>> +
>>>> +- compatible: Shall be "maxim,max9286"
>>>> +- reg: I2C device address
>>>> +
>>>> +Optional Properties:
>>>> +
>>>> +- poc-supply: Regulator providing Power over Coax to the cameras
>>>> +- pwdn-gpios: GPIO connected to the #PWDN pin
>>>
>>> If this is basically a hardware reset pin, then you could call it e.g.
>>> enable-gpios or reset-gpios. There was recently a similar discussion
>>> related to ad5820 DT bindings.
> 
> Techinically is a powerdown control, it shuts the current to the chip,
> not reset it.
> 
>>
>> Ah yes ... now which polarity ;-)
> 
> The signal is active low (when is at physical level 0, the chip is
> off).

Great - so this is the same as having an enable-gpio which is
GPIO_ACTIVE_HIGH right ?


> According to the gpio bindings documentation
> 
> "The gpio-specifier's polarity flag should represent the physical level at the
> GPIO controller that achieves (or represents, for inputs) a logically asserted
> value at the device."
> 
> Sakari's argument, which I understand and has been debated before, is
> to use generic names (ie. don't use the pin name as specified by the HW
> manual, but name it after its function. It doesn't matter if your pin
> is called "#RST", just call it "reset-gpios' and state the pin name in the
> documentation if you like to.)
> 
> I count much more 'enable-gpios' compared to 'powerdown-gpios', so
> that seems the obvious choice, as generic names have not yet been
> documented anywhere as far as I know, but the most common ones should
> be used.
> 
> Using generic names is good because in the power up/down routines,
> you don't have to care about the signals polarities, but only
> about their logical levels. At power-up if you have an "enable-gpio"
> just set it to logical 1, the gpio framework translates it to the
> appropriate physical level. Easier to write and to review.
> 
> To comply with GPIO bindings we would have to
> 
>         enable-gpios: <&gpio 13 GPIO_ACTIVE_LOW>;

I think I misunderstand your point here.

Why do we have to set the polarity as ACTIVE_LOW to comply with the
bindings?

A logically asserted 'enable' value of the device is GPIO_ACTIVE_HIGH on
this pin?

If 'powerdown' is inverted to 'enable' then so is the signal polarity?


> And at power up we would have to use the logical value, and for an
> enable signal, setting it to "1" at power up would be the natural choice.
> However to have our line set to physical 1 and have the chip powered
> we would have to:
> 
>         gpiod_set_value(&enable, 0);
> 
> Which makes any reason to use generic names vanish.

So then we should be able to use:


enable-gpios: <&gpio 13 GPIO_ACTIVE_HIGH>;

At power up:
         gpiod_set_value(&enable, 1);

At power down:
         gpiod_set_value(&enable, 0);


Interestingly though - we don't yet touch this in the driver at all!

So I assume the device is conveniently at the right level for us already?

But if we want any runtime-pm we would need to add in this support.


> All of this to say that, even if less popular, I would call it
> "powerdown-gpios", which is anyway quite generic, and describe it as:
> 
> powerdown-gpios: Power down GPIO signal, pin name "PWDN". Active low.
> 
> So that at power_up:
>         gpiod_set_value(&pwdn, 0);
> 
> And at power down:
>         gpiod_set_value(&pwdn, 1);
> 
>>
>>
>>>> +
>>>> +Required endpoint nodes:
>>>> +-----------------------
>>>> +
>>>> +The connections to the MAX9286 GMSL and its endpoint nodes are modeled 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
>>>> +
>>>> +Optional Endpoint Properties for GSML Input Ports (Port [0-3]):
> 
> I guess Sakari means s/3/4 here:                                 ^
> 

That would be incorrect, because Port 4 is an output port, not an input
port.

> Or didn't I get his questions and then neither your answer :) ?
> 
> Thanks
>   j
> 
>>>
>>> Isn't port 4 included?
>>
>> Hrm ... yes well I guess these are mandatory for port 4. I'll look at
>> the wording here.

Port 4 does also need a remote-endpoint, but it is to a CSI2 sink
endpoint node. Not a GMSL source endpoint node - hence it's not
appropriate to just 's/3/4/' above.



>>>> +
>>>> +- remote-endpoint: phandle to the remote GMSL source endpoint subnode in the
>>>> +  remote node port.
>>>> +
>>>> +Required Endpoint Properties for CSI-2 Output Port (Port 4):
>>>> +
>>>> +- data-lanes: array of physical CSI-2 data lane indexes.
>>>> +- clock-lanes: index of CSI-2 clock lane.
>>>
>>> Is any number of lanes supported? How about lane remapping? If you do not
>>> have lane remapping, the clock-lanes property is redundant.
>>
>>
>> Uhm ... Niklas?
>>
>>
>>>
>>>> +
>>>> +Required i2c-mux nodes:
>>>> +----------------------
>>>> +
>>>> +Each GMSL link is modeled 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.
>>>> +
>>>> +Required i2c child bus properties:
>>>> +- all properties described as required i2c child bus nodes properties in
>>>> +  Documentation/devicetree/bindings/i2c/i2c-mux.txt.
>>>> +
>>>> +Example:
>>>> +-------
>>>> +
>>>> +	gmsl-deserializer@2c {
>>>> +		compatible = "maxim,max9286";
>>>> +		reg = <0x2c>;
>>>> +		poc-supply = <&camera_poc_12v>;
>>>> +		pwdn-gpios = <&gpio 13 GPIO_ACTIVE_LOW>;
>>>> +
>>>> +		#address-cells = <1>;
>>>> +		#size-cells = <0>;
>>>> +
>>>> +		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 {
>>>> +					clock-lanes = <0>;
>>>> +					data-lanes = <1 2 3 4>;
>>>> +					remote-endpoint = <&csi40_in>;
>>>> +				};
>>>> +			};
>>>> +		};
>>>> +
>>>> +		i2c@0 {
>>>> +			#address-cells = <1>;
>>>> +			#size-cells = <0>;
>>>> +			reg = <0>;
>>>> +
>>>> +			camera@51 {
>>>> +				compatible = "imi,rdacm20";
>>>> +				reg = <0x51 0x61>;
>>>
>>> What's the second value for in the reg property? There's more of the same
>>> below.
>>>
>>
>> These are specific to the RDACM20:
>>
>> From the RDACM20 documentation:
>>
>> - reg: Pair of I2C device addresses, the first to be assigned to the
>> serializer, the second to be assigned to the camera sensor.
>>
>> Each RDACM20 camera boots up with the same I2C addresses. The driver
>> remaps them to the new values specified here.
>>
>> But they are not relevant to the max9286 except for the example of
>> adding in the rdacm20.

I wonder if perhaps we should specify a reg-names field here to make
this clear? Especially as we could/should also add a third register
"mcu" on this at some point.


>>>> +
>>>> +				port {
>>>> +					rdacm20_out0: endpoint {
>>>> +						remote-endpoint = <&max9286_in0>;
>>>> +					};
>>>> +				};
>>>> +
>>>> +			};
>>>> +		};
>>>> +
>>>> +		i2c@1 {
>>>> +			#address-cells = <1>;
>>>> +			#size-cells = <0>;
>>>> +			reg = <1>;
>>>> +
>>>> +			camera@52 {
>>>> +				compatible = "imi,rdacm20";
>>>> +				reg = <0x52 0x62>;
>>>> +				port {
>>>> +					rdacm20_out1: endpoint {
>>>> +						remote-endpoint = <&max9286_in1>;
>>>> +					};
>>>> +				};
>>>> +			};
>>>> +		};
>>>> +
>>>> +		i2c@2 {
>>>> +			#address-cells = <1>;
>>>> +			#size-cells = <0>;
>>>> +			reg = <2>;
>>>> +
>>>> +			camera@53 {
>>>> +				compatible = "imi,rdacm20";
>>>> +				reg = <0x53 0x63>;
>>>> +				port {
>>>> +					rdacm20_out2: endpoint {
>>>> +						remote-endpoint = <&max9286_in2>;
>>>> +					};
>>>> +				};
>>>> +			};
>>>> +		};
>>>> +
>>>> +		i2c@3 {
>>>> +			#address-cells = <1>;
>>>> +			#size-cells = <0>;
>>>> +			reg = <3>;
>>>> +
>>>> +			camera@54 {
>>>> +				compatible = "imi,rdacm20";
>>>> +				reg = <0x54 0x64>;
>>>> +				port {
>>>> +					rdacm20_out3: endpoint {
>>>> +						remote-endpoint = <&max9286_in3>;
>>>> +					};
>>>> +				};
>>>> +			};
>>>> +		};
>>>> +	};
>>>

Re: [PATCH v3 1/4] dt-bindings: media: i2c: Add bindings for Maxim Integrated MAX9286

[jacopo mondi]

[-- Attachment #1: Type: text/plain, Size: 13158 bytes --]

Hi Kieran,

On Fri, Nov 02, 2018 at 01:29:54PM +0000, Kieran Bingham wrote:
> Hi Jacopo,
>
> On 15/10/2018 20:37, jacopo mondi wrote:
> > Hi Kieran,
> >
> > On Mon, Oct 15, 2018 at 06:37:40PM +0100, Kieran Bingham wrote:
> >> Hi Sakari,
> >>
> >> Thank you for the review,
> >>
> >> On 15/10/18 17:45, Sakari Ailus wrote:
> >>> Hi Kieran,
> >>>
> >>> Could you cc the devicetree list for the next version, please?
> >>
> >> Argh - looks like I've missed the DT list on all three postings.
> >>
> >> No wonder the responses have been quiet :-)
> >>
> >> I'll do a v4 post after I've gone through some of your comments, and
> >> make sure I remember the DT guys this time :)
> >>
> >>
> >>> On Tue, Oct 09, 2018 at 09:57:23PM +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>
> >>>>
> >>>> ---
> >>>> v3:
> >>>>  - Update binding descriptions
> >>>> ---
> >>>>  .../bindings/media/i2c/maxim,max9286.txt      | 182 ++++++++++++++++++
> >>>>  1 file changed, 182 insertions(+)
> >>>>  create mode 100644 Documentation/devicetree/bindings/media/i2c/maxim,max9286.txt
> >>>>
> >>>> diff --git a/Documentation/devicetree/bindings/media/i2c/maxim,max9286.txt b/Documentation/devicetree/bindings/media/i2c/maxim,max9286.txt
> >>>> new file mode 100644
> >>>> index 000000000000..a73e3c0dc31b
> >>>> --- /dev/null
> >>>> +++ b/Documentation/devicetree/bindings/media/i2c/maxim,max9286.txt
> >>>> @@ -0,0 +1,182 @@
> >>>> +Maxim Integrated Quad GMSL Deserializer
> >>>> +---------------------------------------
> >>>> +
> >>>> +The MAX9286 deserializer receives video data on up to 4 Gigabit Multimedia
> >>>> +Serial Links (GMSL) and outputs them on a CSI-2 port using up to 4 data lanes.
> >>>
> >>> CSI-2 D-PHY I presume?
> >>
> >> Yes, that's how I've adapted the driver based on the latest bus changes.
> >>
> >> Niklas - Could you confirm that everything in VIN/CSI2 is configured to
> >> use D-PHY and not C-PHY at all ?
> >>
> >>
> >>>> +
> >>>> +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.
> >>>> +
> >>>> +Required Properties:
> >>>> +
> >>>> +- compatible: Shall be "maxim,max9286"
> >>>> +- reg: I2C device address
> >>>> +
> >>>> +Optional Properties:
> >>>> +
> >>>> +- poc-supply: Regulator providing Power over Coax to the cameras
> >>>> +- pwdn-gpios: GPIO connected to the #PWDN pin
> >>>
> >>> If this is basically a hardware reset pin, then you could call it e.g.
> >>> enable-gpios or reset-gpios. There was recently a similar discussion
> >>> related to ad5820 DT bindings.
> >
> > Techinically is a powerdown control, it shuts the current to the chip,
> > not reset it.
> >
> >>
> >> Ah yes ... now which polarity ;-)
> >
> > The signal is active low (when is at physical level 0, the chip is
> > off).
>
> Great - so this is the same as having an enable-gpio which is
> GPIO_ACTIVE_HIGH right ?
>
>
> > According to the gpio bindings documentation
> >
> > "The gpio-specifier's polarity flag should represent the physical level at the
> > GPIO controller that achieves (or represents, for inputs) a logically asserted
> > value at the device."
> >
> > Sakari's argument, which I understand and has been debated before, is
> > to use generic names (ie. don't use the pin name as specified by the HW
> > manual, but name it after its function. It doesn't matter if your pin
> > is called "#RST", just call it "reset-gpios' and state the pin name in the
> > documentation if you like to.)
> >
> > I count much more 'enable-gpios' compared to 'powerdown-gpios', so
> > that seems the obvious choice, as generic names have not yet been
> > documented anywhere as far as I know, but the most common ones should
> > be used.
> >
> > Using generic names is good because in the power up/down routines,
> > you don't have to care about the signals polarities, but only
> > about their logical levels. At power-up if you have an "enable-gpio"
> > just set it to logical 1, the gpio framework translates it to the
> > appropriate physical level. Easier to write and to review.
> >
> > To comply with GPIO bindings we would have to
> >
> >         enable-gpios: <&gpio 13 GPIO_ACTIVE_LOW>;
>
> I think I misunderstand your point here.
>
> Why do we have to set the polarity as ACTIVE_LOW to comply with the
> bindings?
>

As I read this

> > "The gpio-specifier's polarity flag should represent the physical level at the
> > GPIO controller that achieves (or represents, for inputs) a logically asserted
> > value at the device."
> A logically asserted 'enable' value of the device is GPIO_ACTIVE_HIGH on
> this pin?
>
> If 'powerdown' is inverted to 'enable' then so is the signal polarity?

Ok then, I see. An 'enable' is logically asserted when the pin is
physically HIGH. A 'powerdown' is logically asserted when the pin is
physically LOW. My previous reasoning was taking into account the
actual pin function (eg. the #PWDN pin is logicall asserted when is
physically LOW). But yeah, if we call it enable, it should be
described as physically active HIGH.

>
>
> > And at power up we would have to use the logical value, and for an
> > enable signal, setting it to "1" at power up would be the natural choice.
> > However to have our line set to physical 1 and have the chip powered
> > we would have to:
> >
> >         gpiod_set_value(&enable, 0);
> >
> > Which makes any reason to use generic names vanish.
>
> So then we should be able to use:
>
>
> enable-gpios: <&gpio 13 GPIO_ACTIVE_HIGH>;
>
> At power up:
>          gpiod_set_value(&enable, 1);
>
> At power down:
>          gpiod_set_value(&enable, 0);

Yes, seems good to me :) I've been overthinking this possibly.

Thanks
  j

>
>
> Interestingly though - we don't yet touch this in the driver at all!
>
> So I assume the device is conveniently at the right level for us already?
>
> But if we want any runtime-pm we would need to add in this support.
>
>
> > All of this to say that, even if less popular, I would call it
> > "powerdown-gpios", which is anyway quite generic, and describe it as:
> >
> > powerdown-gpios: Power down GPIO signal, pin name "PWDN". Active low.
> >
> > So that at power_up:
> >         gpiod_set_value(&pwdn, 0);
> >
> > And at power down:
> >         gpiod_set_value(&pwdn, 1);
> >
> >>
> >>
> >>>> +
> >>>> +Required endpoint nodes:
> >>>> +-----------------------
> >>>> +
> >>>> +The connections to the MAX9286 GMSL and its endpoint nodes are modeled 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
> >>>> +
> >>>> +Optional Endpoint Properties for GSML Input Ports (Port [0-3]):
> >
> > I guess Sakari means s/3/4 here:                                 ^
> >
>
> That would be incorrect, because Port 4 is an output port, not an input
> port.
>
> > Or didn't I get his questions and then neither your answer :) ?
> >
> > Thanks
> >   j
> >
> >>>
> >>> Isn't port 4 included?
> >>
> >> Hrm ... yes well I guess these are mandatory for port 4. I'll look at
> >> the wording here.
>
> Port 4 does also need a remote-endpoint, but it is to a CSI2 sink
> endpoint node. Not a GMSL source endpoint node - hence it's not
> appropriate to just 's/3/4/' above.
>
>
>
> >>>> +
> >>>> +- remote-endpoint: phandle to the remote GMSL source endpoint subnode in the
> >>>> +  remote node port.
> >>>> +
> >>>> +Required Endpoint Properties for CSI-2 Output Port (Port 4):
> >>>> +
> >>>> +- data-lanes: array of physical CSI-2 data lane indexes.
> >>>> +- clock-lanes: index of CSI-2 clock lane.
> >>>
> >>> Is any number of lanes supported? How about lane remapping? If you do not
> >>> have lane remapping, the clock-lanes property is redundant.
> >>
> >>
> >> Uhm ... Niklas?
> >>
> >>
> >>>
> >>>> +
> >>>> +Required i2c-mux nodes:
> >>>> +----------------------
> >>>> +
> >>>> +Each GMSL link is modeled 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.
> >>>> +
> >>>> +Required i2c child bus properties:
> >>>> +- all properties described as required i2c child bus nodes properties in
> >>>> +  Documentation/devicetree/bindings/i2c/i2c-mux.txt.
> >>>> +
> >>>> +Example:
> >>>> +-------
> >>>> +
> >>>> +	gmsl-deserializer@2c {
> >>>> +		compatible = "maxim,max9286";
> >>>> +		reg = <0x2c>;
> >>>> +		poc-supply = <&camera_poc_12v>;
> >>>> +		pwdn-gpios = <&gpio 13 GPIO_ACTIVE_LOW>;
> >>>> +
> >>>> +		#address-cells = <1>;
> >>>> +		#size-cells = <0>;
> >>>> +
> >>>> +		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 {
> >>>> +					clock-lanes = <0>;
> >>>> +					data-lanes = <1 2 3 4>;
> >>>> +					remote-endpoint = <&csi40_in>;
> >>>> +				};
> >>>> +			};
> >>>> +		};
> >>>> +
> >>>> +		i2c@0 {
> >>>> +			#address-cells = <1>;
> >>>> +			#size-cells = <0>;
> >>>> +			reg = <0>;
> >>>> +
> >>>> +			camera@51 {
> >>>> +				compatible = "imi,rdacm20";
> >>>> +				reg = <0x51 0x61>;
> >>>
> >>> What's the second value for in the reg property? There's more of the same
> >>> below.
> >>>
> >>
> >> These are specific to the RDACM20:
> >>
> >> From the RDACM20 documentation:
> >>
> >> - reg: Pair of I2C device addresses, the first to be assigned to the
> >> serializer, the second to be assigned to the camera sensor.
> >>
> >> Each RDACM20 camera boots up with the same I2C addresses. The driver
> >> remaps them to the new values specified here.
> >>
> >> But they are not relevant to the max9286 except for the example of
> >> adding in the rdacm20.
>
> I wonder if perhaps we should specify a reg-names field here to make
> this clear? Especially as we could/should also add a third register
> "mcu" on this at some point.
>
>
> >>>> +
> >>>> +				port {
> >>>> +					rdacm20_out0: endpoint {
> >>>> +						remote-endpoint = <&max9286_in0>;
> >>>> +					};
> >>>> +				};
> >>>> +
> >>>> +			};
> >>>> +		};
> >>>> +
> >>>> +		i2c@1 {
> >>>> +			#address-cells = <1>;
> >>>> +			#size-cells = <0>;
> >>>> +			reg = <1>;
> >>>> +
> >>>> +			camera@52 {
> >>>> +				compatible = "imi,rdacm20";
> >>>> +				reg = <0x52 0x62>;
> >>>> +				port {
> >>>> +					rdacm20_out1: endpoint {
> >>>> +						remote-endpoint = <&max9286_in1>;
> >>>> +					};
> >>>> +				};
> >>>> +			};
> >>>> +		};
> >>>> +
> >>>> +		i2c@2 {
> >>>> +			#address-cells = <1>;
> >>>> +			#size-cells = <0>;
> >>>> +			reg = <2>;
> >>>> +
> >>>> +			camera@53 {
> >>>> +				compatible = "imi,rdacm20";
> >>>> +				reg = <0x53 0x63>;
> >>>> +				port {
> >>>> +					rdacm20_out2: endpoint {
> >>>> +						remote-endpoint = <&max9286_in2>;
> >>>> +					};
> >>>> +				};
> >>>> +			};
> >>>> +		};
> >>>> +
> >>>> +		i2c@3 {
> >>>> +			#address-cells = <1>;
> >>>> +			#size-cells = <0>;
> >>>> +			reg = <3>;
> >>>> +
> >>>> +			camera@54 {
> >>>> +				compatible = "imi,rdacm20";
> >>>> +				reg = <0x54 0x64>;
> >>>> +				port {
> >>>> +					rdacm20_out3: endpoint {
> >>>> +						remote-endpoint = <&max9286_in3>;
> >>>> +					};
> >>>> +				};
> >>>> +			};
> >>>> +		};
> >>>> +	};
> >>>
>

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Re: [PATCH v3 1/4] dt-bindings: media: i2c: Add bindings for Maxim Integrated MAX9286

[Sakari Ailus]

Hi Kieran,

On Fri, Nov 02, 2018 at 01:29:54PM +0000, Kieran Bingham wrote:
...
> >>>> +Required endpoint nodes:
> >>>> +-----------------------
> >>>> +
> >>>> +The connections to the MAX9286 GMSL and its endpoint nodes are modeled 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
> >>>> +
> >>>> +Optional Endpoint Properties for GSML Input Ports (Port [0-3]):
> > 
> > I guess Sakari means s/3/4 here:                                 ^
> > 
> 
> That would be incorrect, because Port 4 is an output port, not an input
> port.
> 
> > Or didn't I get his questions and then neither your answer :) ?
> > 
> > Thanks
> >   j
> > 
> >>>
> >>> Isn't port 4 included?
> >>
> >> Hrm ... yes well I guess these are mandatory for port 4. I'll look at
> >> the wording here.
> 
> Port 4 does also need a remote-endpoint, but it is to a CSI2 sink
> endpoint node. Not a GMSL source endpoint node - hence it's not
> appropriate to just 's/3/4/' above.

Ah, right. And now I recall Rob's position has been that remote-endpoint
property doesn't really need documenting in per-device bindings as it's
part of the graph bindings anyway; just refer to the graph bindings ---
just like you refer to video-interfaces.txt.

-- 
Sakari Ailus
e-mail: sakari.ailus@iki.fi