[PATCH v3 0/4] Add support for Toshiba TC358746

[PATCH v3 0/4] Add support for Toshiba TC358746

[Marco Felsch]

Hi,

this small series adds the support for the Toshiba TC358746 MIPI-CSI to
Parallel converter chip. The different versions of this serie can be
found here [1]. Thanks a lot for the review feedback from Laurent and
Sakari, which was very helpful.

[1] https://lore.kernel.org/all/20220916134535.128131-1-m.felsch@pengutronix.de/
    https://lore.kernel.org/all/20220818143307.967150-5-m.felsch@pengutronix.de/

Marco Felsch (4):
  phy: dphy: refactor get_default_config
  phy: dphy: add support to calculate the timing based on hs_clk_rate
  media: dt-bindings: add bindings for Toshiba TC358746
  media: tc358746: add Toshiba TC358746 Parallel to CSI-2 bridge driver

 .../bindings/media/i2c/toshiba,tc358746.yaml  |  183 ++
 drivers/media/i2c/Kconfig                     |   17 +
 drivers/media/i2c/Makefile                    |    1 +
 drivers/media/i2c/tc358746.c                  | 1692 +++++++++++++++++
 drivers/phy/phy-core-mipi-dphy.c              |   31 +-
 include/linux/phy/phy-mipi-dphy.h             |    3 +
 6 files changed, 1923 insertions(+), 4 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/media/i2c/toshiba,tc358746.yaml
 create mode 100644 drivers/media/i2c/tc358746.c

-- 
2.30.2

[PATCH v3 0/4] Add support for Toshiba TC358746

[Marco Felsch]

Hi,

this small series adds the support for the Toshiba TC358746 MIPI-CSI to
Parallel converter chip. The different versions of this serie can be
found here [1]. Thanks a lot for the review feedback from Laurent and
Sakari, which was very helpful.

[1] https://lore.kernel.org/all/20220916134535.128131-1-m.felsch@pengutronix.de/
    https://lore.kernel.org/all/20220818143307.967150-5-m.felsch@pengutronix.de/

Marco Felsch (4):
  phy: dphy: refactor get_default_config
  phy: dphy: add support to calculate the timing based on hs_clk_rate
  media: dt-bindings: add bindings for Toshiba TC358746
  media: tc358746: add Toshiba TC358746 Parallel to CSI-2 bridge driver

 .../bindings/media/i2c/toshiba,tc358746.yaml  |  183 ++
 drivers/media/i2c/Kconfig                     |   17 +
 drivers/media/i2c/Makefile                    |    1 +
 drivers/media/i2c/tc358746.c                  | 1692 +++++++++++++++++
 drivers/phy/phy-core-mipi-dphy.c              |   31 +-
 include/linux/phy/phy-mipi-dphy.h             |    3 +
 6 files changed, 1923 insertions(+), 4 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/media/i2c/toshiba,tc358746.yaml
 create mode 100644 drivers/media/i2c/tc358746.c

-- 
2.30.2


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[PATCH v3 1/4] phy: dphy: refactor get_default_config

[Marco Felsch]

Factor out the calculation into phy_mipi_dphy_calc_config(). This is
needed for the follow up patch which adds the support to calculate the
timings based on a given hs clock. No functional changes are done.

Signed-off-by: Marco Felsch <m.felsch@pengutronix.de>
Acked-by: Vinod Koul <vkoul@kernel.org>
---
Changelog:

v2:
- added Vinod Koul a-b
---
 drivers/phy/phy-core-mipi-dphy.c | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/drivers/phy/phy-core-mipi-dphy.c b/drivers/phy/phy-core-mipi-dphy.c
index 929e86d6558e..ba365bc77407 100644
--- a/drivers/phy/phy-core-mipi-dphy.c
+++ b/drivers/phy/phy-core-mipi-dphy.c
@@ -17,7 +17,7 @@
  * from the valid ranges specified in Section 6.9, Table 14, Page 41
  * of the D-PHY specification (v1.2).
  */
-int phy_mipi_dphy_get_default_config(unsigned long pixel_clock,
+static int phy_mipi_dphy_calc_config(unsigned long pixel_clock,
 				     unsigned int bpp,
 				     unsigned int lanes,
 				     struct phy_configure_opts_mipi_dphy *cfg)
@@ -75,6 +75,15 @@ int phy_mipi_dphy_get_default_config(unsigned long pixel_clock,
 
 	return 0;
 }
+
+int phy_mipi_dphy_get_default_config(unsigned long pixel_clock,
+				     unsigned int bpp,
+				     unsigned int lanes,
+				     struct phy_configure_opts_mipi_dphy *cfg)
+{
+	return phy_mipi_dphy_calc_config(pixel_clock, bpp, lanes, cfg);
+
+}
 EXPORT_SYMBOL(phy_mipi_dphy_get_default_config);
 
 /*
-- 
2.30.2

[PATCH v3 1/4] phy: dphy: refactor get_default_config

[Marco Felsch]

Factor out the calculation into phy_mipi_dphy_calc_config(). This is
needed for the follow up patch which adds the support to calculate the
timings based on a given hs clock. No functional changes are done.

Signed-off-by: Marco Felsch <m.felsch@pengutronix.de>
Acked-by: Vinod Koul <vkoul@kernel.org>
---
Changelog:

v2:
- added Vinod Koul a-b
---
 drivers/phy/phy-core-mipi-dphy.c | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/drivers/phy/phy-core-mipi-dphy.c b/drivers/phy/phy-core-mipi-dphy.c
index 929e86d6558e..ba365bc77407 100644
--- a/drivers/phy/phy-core-mipi-dphy.c
+++ b/drivers/phy/phy-core-mipi-dphy.c
@@ -17,7 +17,7 @@
  * from the valid ranges specified in Section 6.9, Table 14, Page 41
  * of the D-PHY specification (v1.2).
  */
-int phy_mipi_dphy_get_default_config(unsigned long pixel_clock,
+static int phy_mipi_dphy_calc_config(unsigned long pixel_clock,
 				     unsigned int bpp,
 				     unsigned int lanes,
 				     struct phy_configure_opts_mipi_dphy *cfg)
@@ -75,6 +75,15 @@ int phy_mipi_dphy_get_default_config(unsigned long pixel_clock,
 
 	return 0;
 }
+
+int phy_mipi_dphy_get_default_config(unsigned long pixel_clock,
+				     unsigned int bpp,
+				     unsigned int lanes,
+				     struct phy_configure_opts_mipi_dphy *cfg)
+{
+	return phy_mipi_dphy_calc_config(pixel_clock, bpp, lanes, cfg);
+
+}
 EXPORT_SYMBOL(phy_mipi_dphy_get_default_config);
 
 /*
-- 
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[PATCH v3 2/4] phy: dphy: add support to calculate the timing based on hs_clk_rate

[Marco Felsch]

For MIPI-CSI sender use-case it is common to specify the allowed
link-frequencies which should be used for the MIPI link and is
half the hs-clock rate.

This commit adds a helper to calculate the D-PHY timing based on the
hs-clock rate so we don't need to calculate the timings within the
driver.

Signed-off-by: Marco Felsch <m.felsch@pengutronix.de>
Acked-by: Vinod Koul <vkoul@kernel.org>
---
Changelog:

v2:
- added Vinod Koul a-b
---
 drivers/phy/phy-core-mipi-dphy.c  | 22 ++++++++++++++++++----
 include/linux/phy/phy-mipi-dphy.h |  3 +++
 2 files changed, 21 insertions(+), 4 deletions(-)

diff --git a/drivers/phy/phy-core-mipi-dphy.c b/drivers/phy/phy-core-mipi-dphy.c
index ba365bc77407..f4956a417a47 100644
--- a/drivers/phy/phy-core-mipi-dphy.c
+++ b/drivers/phy/phy-core-mipi-dphy.c
@@ -20,16 +20,18 @@
 static int phy_mipi_dphy_calc_config(unsigned long pixel_clock,
 				     unsigned int bpp,
 				     unsigned int lanes,
+				     unsigned long long hs_clk_rate,
 				     struct phy_configure_opts_mipi_dphy *cfg)
 {
-	unsigned long long hs_clk_rate;
 	unsigned long long ui;
 
 	if (!cfg)
 		return -EINVAL;
 
-	hs_clk_rate = pixel_clock * bpp;
-	do_div(hs_clk_rate, lanes);
+	if (!hs_clk_rate) {
+		hs_clk_rate = pixel_clock * bpp;
+		do_div(hs_clk_rate, lanes);
+	}
 
 	ui = ALIGN(PSEC_PER_SEC, hs_clk_rate);
 	do_div(ui, hs_clk_rate);
@@ -81,11 +83,23 @@ int phy_mipi_dphy_get_default_config(unsigned long pixel_clock,
 				     unsigned int lanes,
 				     struct phy_configure_opts_mipi_dphy *cfg)
 {
-	return phy_mipi_dphy_calc_config(pixel_clock, bpp, lanes, cfg);
+	return phy_mipi_dphy_calc_config(pixel_clock, bpp, lanes, 0, cfg);
 
 }
 EXPORT_SYMBOL(phy_mipi_dphy_get_default_config);
 
+int phy_mipi_dphy_get_default_config_for_hsclk(unsigned long long hs_clk_rate,
+					       unsigned int lanes,
+					       struct phy_configure_opts_mipi_dphy *cfg)
+{
+	if (!hs_clk_rate)
+		return -EINVAL;
+
+	return phy_mipi_dphy_calc_config(0, 0, lanes, hs_clk_rate, cfg);
+
+}
+EXPORT_SYMBOL(phy_mipi_dphy_get_default_config_for_hsclk);
+
 /*
  * Validate D-PHY configuration according to MIPI D-PHY specification
  * (v1.2, Section Section 6.9 "Global Operation Timing Parameters").
diff --git a/include/linux/phy/phy-mipi-dphy.h b/include/linux/phy/phy-mipi-dphy.h
index a877ffee845d..1ac128d78dfe 100644
--- a/include/linux/phy/phy-mipi-dphy.h
+++ b/include/linux/phy/phy-mipi-dphy.h
@@ -279,6 +279,9 @@ int phy_mipi_dphy_get_default_config(unsigned long pixel_clock,
 				     unsigned int bpp,
 				     unsigned int lanes,
 				     struct phy_configure_opts_mipi_dphy *cfg);
+int phy_mipi_dphy_get_default_config_for_hsclk(unsigned long long hs_clk_rate,
+					       unsigned int lanes,
+					       struct phy_configure_opts_mipi_dphy *cfg);
 int phy_mipi_dphy_config_validate(struct phy_configure_opts_mipi_dphy *cfg);
 
 #endif /* __PHY_MIPI_DPHY_H_ */
-- 
2.30.2

[PATCH v3 2/4] phy: dphy: add support to calculate the timing based on hs_clk_rate

[Marco Felsch]

For MIPI-CSI sender use-case it is common to specify the allowed
link-frequencies which should be used for the MIPI link and is
half the hs-clock rate.

This commit adds a helper to calculate the D-PHY timing based on the
hs-clock rate so we don't need to calculate the timings within the
driver.

Signed-off-by: Marco Felsch <m.felsch@pengutronix.de>
Acked-by: Vinod Koul <vkoul@kernel.org>
---
Changelog:

v2:
- added Vinod Koul a-b
---
 drivers/phy/phy-core-mipi-dphy.c  | 22 ++++++++++++++++++----
 include/linux/phy/phy-mipi-dphy.h |  3 +++
 2 files changed, 21 insertions(+), 4 deletions(-)

diff --git a/drivers/phy/phy-core-mipi-dphy.c b/drivers/phy/phy-core-mipi-dphy.c
index ba365bc77407..f4956a417a47 100644
--- a/drivers/phy/phy-core-mipi-dphy.c
+++ b/drivers/phy/phy-core-mipi-dphy.c
@@ -20,16 +20,18 @@
 static int phy_mipi_dphy_calc_config(unsigned long pixel_clock,
 				     unsigned int bpp,
 				     unsigned int lanes,
+				     unsigned long long hs_clk_rate,
 				     struct phy_configure_opts_mipi_dphy *cfg)
 {
-	unsigned long long hs_clk_rate;
 	unsigned long long ui;
 
 	if (!cfg)
 		return -EINVAL;
 
-	hs_clk_rate = pixel_clock * bpp;
-	do_div(hs_clk_rate, lanes);
+	if (!hs_clk_rate) {
+		hs_clk_rate = pixel_clock * bpp;
+		do_div(hs_clk_rate, lanes);
+	}
 
 	ui = ALIGN(PSEC_PER_SEC, hs_clk_rate);
 	do_div(ui, hs_clk_rate);
@@ -81,11 +83,23 @@ int phy_mipi_dphy_get_default_config(unsigned long pixel_clock,
 				     unsigned int lanes,
 				     struct phy_configure_opts_mipi_dphy *cfg)
 {
-	return phy_mipi_dphy_calc_config(pixel_clock, bpp, lanes, cfg);
+	return phy_mipi_dphy_calc_config(pixel_clock, bpp, lanes, 0, cfg);
 
 }
 EXPORT_SYMBOL(phy_mipi_dphy_get_default_config);
 
+int phy_mipi_dphy_get_default_config_for_hsclk(unsigned long long hs_clk_rate,
+					       unsigned int lanes,
+					       struct phy_configure_opts_mipi_dphy *cfg)
+{
+	if (!hs_clk_rate)
+		return -EINVAL;
+
+	return phy_mipi_dphy_calc_config(0, 0, lanes, hs_clk_rate, cfg);
+
+}
+EXPORT_SYMBOL(phy_mipi_dphy_get_default_config_for_hsclk);
+
 /*
  * Validate D-PHY configuration according to MIPI D-PHY specification
  * (v1.2, Section Section 6.9 "Global Operation Timing Parameters").
diff --git a/include/linux/phy/phy-mipi-dphy.h b/include/linux/phy/phy-mipi-dphy.h
index a877ffee845d..1ac128d78dfe 100644
--- a/include/linux/phy/phy-mipi-dphy.h
+++ b/include/linux/phy/phy-mipi-dphy.h
@@ -279,6 +279,9 @@ int phy_mipi_dphy_get_default_config(unsigned long pixel_clock,
 				     unsigned int bpp,
 				     unsigned int lanes,
 				     struct phy_configure_opts_mipi_dphy *cfg);
+int phy_mipi_dphy_get_default_config_for_hsclk(unsigned long long hs_clk_rate,
+					       unsigned int lanes,
+					       struct phy_configure_opts_mipi_dphy *cfg);
 int phy_mipi_dphy_config_validate(struct phy_configure_opts_mipi_dphy *cfg);
 
 #endif /* __PHY_MIPI_DPHY_H_ */
-- 
2.30.2


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[PATCH v3 3/4] media: dt-bindings: add bindings for Toshiba TC358746

[Marco Felsch]

Add the bindings for the Toshiba TC358746 Parallel <-> MIPI-CSI bridge
driver.

Signed-off-by: Marco Felsch <m.felsch@pengutronix.de>
Reviewed-by: Rob Herring <robh@kernel.org>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
---
Changelog

v3:
- put the mclk comment into the description of #clock-cells
- make bus-type required
- allow all sync values
- allow all possible parallel bus-types
- added Laurent's r-b

v2:
- addded Robs r-b
- s/than/then/
- added hsync/vsync/bus-type, make hsync/vsync required
- fix example indent
---
 .../bindings/media/i2c/toshiba,tc358746.yaml  | 178 ++++++++++++++++++
 1 file changed, 178 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/media/i2c/toshiba,tc358746.yaml

diff --git a/Documentation/devicetree/bindings/media/i2c/toshiba,tc358746.yaml b/Documentation/devicetree/bindings/media/i2c/toshiba,tc358746.yaml
new file mode 100644
index 000000000000..b8ba85a2416c
--- /dev/null
+++ b/Documentation/devicetree/bindings/media/i2c/toshiba,tc358746.yaml
@@ -0,0 +1,178 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/media/i2c/toshiba,tc358746.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Toshiba TC358746 Parallel to MIPI CSI2 Bridge
+
+maintainers:
+  - Marco Felsch <kernel@pengutronix.de>
+
+description: |-
+  The Toshiba TC358746 converts a parallel video stream into a MIPI CSI-2
+  stream. The direction can be either parallel-in -> csi-out or csi-in ->
+  parallel-out The chip is programmable trough I2C and SPI but the SPI
+  interface is only supported in parallel-in -> csi-out mode.
+
+  Note that the current device tree bindings only support the
+  parallel-in -> csi-out path.
+
+properties:
+  compatible:
+    const: toshiba,tc358746
+
+  reg:
+    maxItems: 1
+
+  clocks:
+    description:
+      The phandle to the reference clock source. This corresponds to the
+      hardware pin REFCLK.
+    maxItems: 1
+
+  clock-names:
+    const: refclk
+
+  "#clock-cells":
+    description: |
+      The bridge can act as clock provider for the sensor. To enable this
+      support #clock-cells must be specified. Attention if this feature is used
+      then the mclk rate must be at least: (2 * link-frequency) / 8
+                                           `------------------´   ^
+                                           internal PLL rate   smallest possible
+                                                                   mclk-div
+    const: 0
+
+  clock-output-names:
+    description:
+      The clock name of the MCLK output, the default name is tc358746-mclk.
+    maxItems: 1
+
+  vddc-supply:
+    description: Digital core voltage supply, 1.2 volts
+
+  vddio-supply:
+    description: Digital I/O voltage supply, 1.8 volts
+
+  vddmipi-supply:
+    description: MIPI CSI phy voltage supply, 1.2 volts
+
+  reset-gpios:
+    description:
+      The phandle and specifier for the GPIO that controls the chip reset.
+      This corresponds to the hardware pin RESX which is physically active low.
+    maxItems: 1
+
+  ports:
+    $ref: /schemas/graph.yaml#/properties/ports
+    properties:
+      port@0:
+        $ref: /schemas/graph.yaml#/$defs/port-base
+        description: Input port
+
+        properties:
+          endpoint:
+            $ref: /schemas/media/video-interfaces.yaml#
+            unevaluatedProperties: false
+
+            properties:
+              hsync-active: true
+              vsync-active: true
+              bus-type:
+                enum: [ 5, 6 ]
+
+            required:
+              - hsync-active
+              - vsync-active
+              - bus-type
+
+      port@1:
+        $ref: /schemas/graph.yaml#/$defs/port-base
+        description: Output port
+
+        properties:
+          endpoint:
+            $ref: /schemas/media/video-interfaces.yaml#
+            unevaluatedProperties: false
+
+            properties:
+              data-lanes:
+                minItems: 1
+                maxItems: 4
+
+              clock-noncontinuous: true
+              link-frequencies: true
+
+            required:
+              - data-lanes
+              - link-frequencies
+
+    required:
+      - port@0
+      - port@1
+
+required:
+  - compatible
+  - reg
+  - clocks
+  - clock-names
+  - vddc-supply
+  - vddio-supply
+  - vddmipi-supply
+  - ports
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/gpio/gpio.h>
+
+    i2c {
+      #address-cells = <1>;
+      #size-cells = <0>;
+
+      csi-bridge@e {
+        compatible = "toshiba,tc358746";
+        reg = <0xe>;
+
+        clocks = <&refclk>;
+        clock-names = "refclk";
+
+        reset-gpios = <&gpio 2 GPIO_ACTIVE_LOW>;
+
+        vddc-supply = <&v1_2d>;
+        vddio-supply = <&v1_8d>;
+        vddmipi-supply = <&v1_2d>;
+
+        /* sensor mclk provider */
+        #clock-cells = <0>;
+
+        ports {
+          #address-cells = <1>;
+          #size-cells = <0>;
+
+          /* Input */
+          port@0 {
+            reg = <0>;
+            tc358746_in: endpoint {
+              remote-endpoint = <&sensor_out>;
+              hsync-active = <0>;
+              vsync-active = <0>;
+              bus-type = <5>;
+            };
+          };
+
+          /* Output */
+          port@1 {
+            reg = <1>;
+            tc358746_out: endpoint {
+              remote-endpoint = <&mipi_csi2_in>;
+              data-lanes = <1 2>;
+              clock-noncontinuous;
+              link-frequencies = /bits/ 64 <216000000>;
+            };
+          };
+        };
+      };
+    };
-- 
2.30.2

[PATCH v3 3/4] media: dt-bindings: add bindings for Toshiba TC358746

[Marco Felsch]

Add the bindings for the Toshiba TC358746 Parallel <-> MIPI-CSI bridge
driver.

Signed-off-by: Marco Felsch <m.felsch@pengutronix.de>
Reviewed-by: Rob Herring <robh@kernel.org>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
---
Changelog

v3:
- put the mclk comment into the description of #clock-cells
- make bus-type required
- allow all sync values
- allow all possible parallel bus-types
- added Laurent's r-b

v2:
- addded Robs r-b
- s/than/then/
- added hsync/vsync/bus-type, make hsync/vsync required
- fix example indent
---
 .../bindings/media/i2c/toshiba,tc358746.yaml  | 178 ++++++++++++++++++
 1 file changed, 178 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/media/i2c/toshiba,tc358746.yaml

diff --git a/Documentation/devicetree/bindings/media/i2c/toshiba,tc358746.yaml b/Documentation/devicetree/bindings/media/i2c/toshiba,tc358746.yaml
new file mode 100644
index 000000000000..b8ba85a2416c
--- /dev/null
+++ b/Documentation/devicetree/bindings/media/i2c/toshiba,tc358746.yaml
@@ -0,0 +1,178 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/media/i2c/toshiba,tc358746.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Toshiba TC358746 Parallel to MIPI CSI2 Bridge
+
+maintainers:
+  - Marco Felsch <kernel@pengutronix.de>
+
+description: |-
+  The Toshiba TC358746 converts a parallel video stream into a MIPI CSI-2
+  stream. The direction can be either parallel-in -> csi-out or csi-in ->
+  parallel-out The chip is programmable trough I2C and SPI but the SPI
+  interface is only supported in parallel-in -> csi-out mode.
+
+  Note that the current device tree bindings only support the
+  parallel-in -> csi-out path.
+
+properties:
+  compatible:
+    const: toshiba,tc358746
+
+  reg:
+    maxItems: 1
+
+  clocks:
+    description:
+      The phandle to the reference clock source. This corresponds to the
+      hardware pin REFCLK.
+    maxItems: 1
+
+  clock-names:
+    const: refclk
+
+  "#clock-cells":
+    description: |
+      The bridge can act as clock provider for the sensor. To enable this
+      support #clock-cells must be specified. Attention if this feature is used
+      then the mclk rate must be at least: (2 * link-frequency) / 8
+                                           `------------------´   ^
+                                           internal PLL rate   smallest possible
+                                                                   mclk-div
+    const: 0
+
+  clock-output-names:
+    description:
+      The clock name of the MCLK output, the default name is tc358746-mclk.
+    maxItems: 1
+
+  vddc-supply:
+    description: Digital core voltage supply, 1.2 volts
+
+  vddio-supply:
+    description: Digital I/O voltage supply, 1.8 volts
+
+  vddmipi-supply:
+    description: MIPI CSI phy voltage supply, 1.2 volts
+
+  reset-gpios:
+    description:
+      The phandle and specifier for the GPIO that controls the chip reset.
+      This corresponds to the hardware pin RESX which is physically active low.
+    maxItems: 1
+
+  ports:
+    $ref: /schemas/graph.yaml#/properties/ports
+    properties:
+      port@0:
+        $ref: /schemas/graph.yaml#/$defs/port-base
+        description: Input port
+
+        properties:
+          endpoint:
+            $ref: /schemas/media/video-interfaces.yaml#
+            unevaluatedProperties: false
+
+            properties:
+              hsync-active: true
+              vsync-active: true
+              bus-type:
+                enum: [ 5, 6 ]
+
+            required:
+              - hsync-active
+              - vsync-active
+              - bus-type
+
+      port@1:
+        $ref: /schemas/graph.yaml#/$defs/port-base
+        description: Output port
+
+        properties:
+          endpoint:
+            $ref: /schemas/media/video-interfaces.yaml#
+            unevaluatedProperties: false
+
+            properties:
+              data-lanes:
+                minItems: 1
+                maxItems: 4
+
+              clock-noncontinuous: true
+              link-frequencies: true
+
+            required:
+              - data-lanes
+              - link-frequencies
+
+    required:
+      - port@0
+      - port@1
+
+required:
+  - compatible
+  - reg
+  - clocks
+  - clock-names
+  - vddc-supply
+  - vddio-supply
+  - vddmipi-supply
+  - ports
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/gpio/gpio.h>
+
+    i2c {
+      #address-cells = <1>;
+      #size-cells = <0>;
+
+      csi-bridge@e {
+        compatible = "toshiba,tc358746";
+        reg = <0xe>;
+
+        clocks = <&refclk>;
+        clock-names = "refclk";
+
+        reset-gpios = <&gpio 2 GPIO_ACTIVE_LOW>;
+
+        vddc-supply = <&v1_2d>;
+        vddio-supply = <&v1_8d>;
+        vddmipi-supply = <&v1_2d>;
+
+        /* sensor mclk provider */
+        #clock-cells = <0>;
+
+        ports {
+          #address-cells = <1>;
+          #size-cells = <0>;
+
+          /* Input */
+          port@0 {
+            reg = <0>;
+            tc358746_in: endpoint {
+              remote-endpoint = <&sensor_out>;
+              hsync-active = <0>;
+              vsync-active = <0>;
+              bus-type = <5>;
+            };
+          };
+
+          /* Output */
+          port@1 {
+            reg = <1>;
+            tc358746_out: endpoint {
+              remote-endpoint = <&mipi_csi2_in>;
+              data-lanes = <1 2>;
+              clock-noncontinuous;
+              link-frequencies = /bits/ 64 <216000000>;
+            };
+          };
+        };
+      };
+    };
-- 
2.30.2


-- 
linux-phy mailing list
linux-phy@lists.infradead.org
https://lists.infradead.org/mailman/listinfo/linux-phy

[PATCH v3 4/4] media: tc358746: add Toshiba TC358746 Parallel to CSI-2 bridge driver

[Marco Felsch]

Adding support for the TC358746 parallel <-> MIPI CSI bridge. This chip
supports two operating modes:
  1st) parallel-in -> mipi-csi out
  2nd) mipi-csi in -> parallel out

This patch only adds the support for the 1st mode.

Signed-off-by: Marco Felsch <m.felsch@pengutronix.de>
---
Changelog:

v3:
- added missing static
- drop s/MHZ/HZ_PER_MHZ/
- kconfig: add "depends on PM"
- Add tc358746_valid_reg() for regmap.
- tc358746_set_fmt: fix format negotiation for pad == SOURCE
- tc358746_write/read: add error messages
- replace udelay with fsleep()
- tc358746_apply_misc_config: const mbusfmt
- tc358746_s_stream: fix comment about LP-00/11 state change
- tc358746_link_validate: s/sensor/source/
- tc358746_link_validate: s/pclk_rate/link_freq/
- tc358746_link_validate: fix v4l2_subdev_unlock_state()
- tc358746_link_validate: adapt fifo-sz comment
- tc358746_g/s_register: use pm_runtime_get_if_in_use
- tc358746_setup_mclk_provider: move to clk related location
- tc358746_init_hw: fix error case
- tc358746_init_controls: add comment
- tc358746_notify_bound: add MEDIA_LNK_FL_IMMUTABLE
- tc358746_async_register: fix error path
- tc358746_async_register: put sd.fwnode on error and remove
- tc358746_probe: increase autosuspend to 1s

v2:
- use the correct CID_LINK_FREQ control to query the sensor_pclk_rate
- remove now not needed tc358746_link_setup() and
  struct v4l2_ctrl sensor_pclk_ctrl
- call v4l2_subdev_link_validate_default() during link validation
- remove MEDIA_BUS_FMT_GBR888_1X24/YUV444 format support
- use subdev active_state API
- replace own .get_fmt with v4l2_subdev_get_fmt
- remove unnecessary pad checks
- restructure tc358746_get_format_by_code() if-case
- move apply_dphy_config|apply_misc_config from resume intos s_stream
- use goto in s_stream enable case
- fix error handling in suspend/resume
- split probe() into more sub-functions
---
 drivers/media/i2c/Kconfig    |   17 +
 drivers/media/i2c/Makefile   |    1 +
 drivers/media/i2c/tc358746.c | 1692 ++++++++++++++++++++++++++++++++++
 3 files changed, 1710 insertions(+)
 create mode 100644 drivers/media/i2c/tc358746.c

diff --git a/drivers/media/i2c/Kconfig b/drivers/media/i2c/Kconfig
index 7806d4b81716..f85cdb94c524 100644
--- a/drivers/media/i2c/Kconfig
+++ b/drivers/media/i2c/Kconfig
@@ -1272,6 +1272,23 @@ config VIDEO_TC358743_CEC
 	  When selected the tc358743 will support the optional
 	  HDMI CEC feature.
 
+config VIDEO_TC358746
+	tristate "Toshiba TC358746 parallel-CSI2 bridge"
+	depends on VIDEO_DEV && PM && I2C
+	select VIDEO_V4L2_SUBDEV_API
+	select MEDIA_CONTROLLER
+	select V4L2_FWNODE
+	select GENERIC_PHY_MIPI_DPHY
+	select REGMAP_I2C
+	select COMMON_CLK
+	help
+	  Support for the Toshiba TC358746 parallel to MIPI CSI-2 bridge.
+	  The bridge can work in both directions but currently only the
+	  parallel-in / csi-out path is supported.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called tc358746.
+
 config VIDEO_TVP514X
 	tristate "Texas Instruments TVP514x video decoder"
 	depends on VIDEO_DEV && I2C
diff --git a/drivers/media/i2c/Makefile b/drivers/media/i2c/Makefile
index 0a2933103dd9..d1096c2ab480 100644
--- a/drivers/media/i2c/Makefile
+++ b/drivers/media/i2c/Makefile
@@ -118,6 +118,7 @@ obj-$(CONFIG_VIDEO_SONY_BTF_MPX) += sony-btf-mpx.o
 obj-$(CONFIG_VIDEO_SR030PC30) += sr030pc30.o
 obj-$(CONFIG_VIDEO_ST_MIPID02) += st-mipid02.o
 obj-$(CONFIG_VIDEO_TC358743) += tc358743.o
+obj-$(CONFIG_VIDEO_TC358746) += tc358746.o
 obj-$(CONFIG_VIDEO_TDA1997X) += tda1997x.o
 obj-$(CONFIG_VIDEO_TDA7432) += tda7432.o
 obj-$(CONFIG_VIDEO_TDA9840) += tda9840.o
diff --git a/drivers/media/i2c/tc358746.c b/drivers/media/i2c/tc358746.c
new file mode 100644
index 000000000000..0dcd5e0e0855
--- /dev/null
+++ b/drivers/media/i2c/tc358746.c
@@ -0,0 +1,1692 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * TC358746 - Parallel <-> CSI-2 Bridge
+ *
+ * Copyright 2022 Marco Felsch <kernel@pengutronix.de>
+ *
+ * Notes:
+ *  - Currently only 'Parallel-in -> CSI-out' mode is supported!
+ */
+
+#include <linux/bitfield.h>
+#include <linux/clk.h>
+#include <linux/clk-provider.h>
+#include <linux/delay.h>
+#include <linux/i2c.h>
+#include <linux/interrupt.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/phy/phy-mipi-dphy.h>
+#include <linux/property.h>
+#include <linux/pm_runtime.h>
+#include <linux/regmap.h>
+#include <linux/units.h>
+#include <media/v4l2-ctrls.h>
+#include <media/v4l2-device.h>
+#include <media/v4l2-fwnode.h>
+#include <media/v4l2-mc.h>
+
+/* 16-bit registers */
+#define CHIPID_REG			0x0000
+#define		CHIPID			GENMASK(15, 8)
+
+#define SYSCTL_REG			0x0002
+#define		SRESET			BIT(0)
+
+#define CONFCTL_REG			0x0004
+#define		PDATAF_MASK		GENMASK(9, 8)
+#define		PDATAF_MODE0		0
+#define		PDATAF_MODE1		1
+#define		PDATAF_MODE2		2
+#define		PDATAF(val)		FIELD_PREP(PDATAF_MASK, (val))
+#define		PPEN			BIT(6)
+#define		DATALANE_MASK		GENMASK(1, 0)
+
+#define FIFOCTL_REG			0x0006
+#define DATAFMT_REG			0x0008
+#define		PDFMT(val)		FIELD_PREP(GENMASK(7, 4), (val))
+
+#define MCLKCTL_REG			0x000c
+#define		MCLK_HIGH_MASK		GENMASK(15, 8)
+#define		MCLK_LOW_MASK		GENMASK(7, 0)
+#define		MCLK_HIGH(val)		FIELD_PREP(MCLK_HIGH_MASK, (val))
+#define		MCLK_LOW(val)		FIELD_PREP(MCLK_LOW_MASK, (val))
+
+#define PLLCTL0_REG			0x0016
+#define		PLL_PRD_MASK		GENMASK(15, 12)
+#define		PLL_PRD(val)		FIELD_PREP(PLL_PRD_MASK, (val))
+#define		PLL_FBD_MASK		GENMASK(8, 0)
+#define		PLL_FBD(val)		FIELD_PREP(PLL_FBD_MASK, (val))
+
+#define PLLCTL1_REG			0x0018
+#define		PLL_FRS_MASK		GENMASK(11, 10)
+#define		PLL_FRS(val)		FIELD_PREP(PLL_FRS_MASK, (val))
+#define		CKEN			BIT(4)
+#define		RESETB			BIT(1)
+#define		PLL_EN			BIT(0)
+
+#define CLKCTL_REG			0x0020
+#define		MCLKDIV_MASK		GENMASK(3, 2)
+#define		MCLKDIV(val)		FIELD_PREP(MCLKDIV_MASK, (val))
+#define		MCLKDIV_8		0
+#define		MCLKDIV_4		1
+#define		MCLKDIV_2		2
+
+#define WORDCNT_REG			0x0022
+#define PP_MISC_REG			0x0032
+#define		FRMSTOP			BIT(15)
+#define		RSTPTR			BIT(14)
+
+/* 32-bit registers */
+#define CLW_DPHYCONTTX_REG		0x0100
+#define CLW_CNTRL_REG			0x0140
+#define D0W_CNTRL_REG			0x0144
+#define		LANEDISABLE		BIT(0)
+
+#define STARTCNTRL_REG			0x0204
+#define		START			BIT(0)
+
+#define LINEINITCNT_REG			0x0210
+#define LPTXTIMECNT_REG			0x0214
+#define TCLK_HEADERCNT_REG		0x0218
+#define		TCLK_ZEROCNT(val)	FIELD_PREP(GENMASK(15, 8), (val))
+#define		TCLK_PREPARECNT(val)	FIELD_PREP(GENMASK(6, 0), (val))
+
+#define TCLK_TRAILCNT_REG		0x021C
+#define THS_HEADERCNT_REG		0x0220
+#define		THS_ZEROCNT(val)	FIELD_PREP(GENMASK(14, 8), (val))
+#define		THS_PREPARECNT(val)	FIELD_PREP(GENMASK(6, 0), (val))
+
+#define TWAKEUP_REG			0x0224
+#define TCLK_POSTCNT_REG		0x0228
+#define THS_TRAILCNT_REG		0x022C
+#define HSTXVREGEN_REG			0x0234
+#define TXOPTIONCNTRL_REG		0x0238
+#define CSI_CONTROL_REG			0x040C
+#define		CSI_MODE		BIT(15)
+#define		TXHSMD			BIT(7)
+#define		NOL(val)		FIELD_PREP(GENMASK(2, 1), (val))
+
+#define CSI_CONFW_REG			0x0500
+#define		MODE(val)		FIELD_PREP(GENMASK(31, 29), (val))
+#define		MODE_SET		0x5
+#define		ADDRESS(val)		FIELD_PREP(GENMASK(28, 24), (val))
+#define		CSI_CONTROL_ADDRESS	0x3
+#define		DATA(val)		FIELD_PREP(GENMASK(15, 0), (val))
+
+#define CSI_START_REG			0x0518
+#define		STRT			BIT(0)
+
+static const struct v4l2_mbus_framefmt tc358746_def_fmt = {
+	.width		= 640,
+	.height		= 480,
+	.code		= MEDIA_BUS_FMT_UYVY8_2X8,
+	.field		= V4L2_FIELD_NONE,
+	.colorspace	= V4L2_COLORSPACE_DEFAULT,
+	.ycbcr_enc	= V4L2_YCBCR_ENC_DEFAULT,
+	.quantization	= V4L2_QUANTIZATION_DEFAULT,
+	.xfer_func	= V4L2_XFER_FUNC_DEFAULT,
+};
+
+static const char * const tc358746_supplies[] = {
+	"vddc", "vddio", "vddmipi"
+};
+
+enum {
+	TC358746_SINK,
+	TC358746_SOURCE,
+	TC358746_NR_PADS
+};
+
+struct tc358746 {
+	struct v4l2_subdev		sd;
+	struct media_pad		pads[TC358746_NR_PADS];
+	struct v4l2_async_notifier	notifier;
+	struct v4l2_fwnode_endpoint	csi_vep;
+
+	struct v4l2_ctrl_handler	ctrl_hdl;
+
+	struct regmap			*regmap;
+	struct clk			*refclk;
+	struct gpio_desc		*reset_gpio;
+	struct regulator_bulk_data	supplies[ARRAY_SIZE(tc358746_supplies)];
+
+	struct clk_hw			mclk_hw;
+	unsigned long			mclk_rate;
+	u8				mclk_prediv;
+	u16				mclk_postdiv;
+
+	unsigned long			pll_rate;
+	u8				pll_post_div;
+	u16				pll_pre_div;
+	u16				pll_mul;
+
+#define TC358746_VB_MAX_SIZE		(511 * 32)
+#define TC358746_VB_DEFAULT_SIZE	  (1 * 32)
+	unsigned int			vb_size; /* Video buffer size in bits */
+
+	struct phy_configure_opts_mipi_dphy dphy_cfg;
+};
+
+static inline struct tc358746 *to_tc358746(struct v4l2_subdev *sd)
+{
+	return container_of(sd, struct tc358746, sd);
+}
+
+static inline struct tc358746 *clk_hw_to_tc358746(struct clk_hw *hw)
+{
+	return container_of(hw, struct tc358746, mclk_hw);
+}
+
+struct tc358746_format {
+	u32		code;
+	bool		csi_format;
+	unsigned char	bus_width;
+	unsigned char	bpp;
+	/* Register values */
+	u8		pdformat; /* Peripheral Data Format */
+	u8		pdataf;   /* Parallel Data Format Option */
+};
+
+enum {
+	PDFORMAT_RAW8 = 0,
+	PDFORMAT_RAW10,
+	PDFORMAT_RAW12,
+	PDFORMAT_RGB888,
+	PDFORMAT_RGB666,
+	PDFORMAT_RGB565,
+	PDFORMAT_YUV422_8BIT,
+	/* RESERVED = 7 */
+	PDFORMAT_RAW14 = 8,
+	PDFORMAT_YUV422_10BIT,
+	PDFORMAT_YUV444,
+};
+
+/* Check tc358746_src_mbus_code() if you add new formats */
+static const struct tc358746_format tc358746_formats[] = {
+	{
+		.code = MEDIA_BUS_FMT_UYVY8_2X8,
+		.bus_width = 8,
+		.bpp = 16,
+		.pdformat = PDFORMAT_YUV422_8BIT,
+		.pdataf = PDATAF_MODE0,
+	}, {
+		.code = MEDIA_BUS_FMT_UYVY8_1X16,
+		.csi_format = true,
+		.bus_width = 16,
+		.bpp = 16,
+		.pdformat = PDFORMAT_YUV422_8BIT,
+		.pdataf = PDATAF_MODE1,
+	}, {
+		.code = MEDIA_BUS_FMT_YUYV8_1X16,
+		.csi_format = true,
+		.bus_width = 16,
+		.bpp = 16,
+		.pdformat = PDFORMAT_YUV422_8BIT,
+		.pdataf = PDATAF_MODE2,
+	}, {
+		.code = MEDIA_BUS_FMT_UYVY10_2X10,
+		.bus_width = 10,
+		.bpp = 20,
+		.pdformat = PDFORMAT_YUV422_10BIT,
+		.pdataf = PDATAF_MODE0, /* don't care */
+	}
+};
+
+/* Get n-th format for pad */
+static const struct tc358746_format *
+tc358746_get_format_by_idx(unsigned int pad, unsigned int index)
+{
+	unsigned int idx = 0;
+	unsigned int i;
+
+	for (i = 0; i < ARRAY_SIZE(tc358746_formats); i++) {
+		const struct tc358746_format *fmt = &tc358746_formats[i];
+
+		if ((pad == TC358746_SOURCE && fmt->csi_format) ||
+		    (pad == TC358746_SINK)) {
+			if (idx == index)
+				return fmt;
+			idx++;
+		}
+	}
+
+	return ERR_PTR(-EINVAL);
+}
+
+static const struct tc358746_format *
+tc358746_get_format_by_code(unsigned int pad, u32 code)
+{
+	unsigned int i;
+
+	for (i = 0; i < ARRAY_SIZE(tc358746_formats); i++) {
+		const struct tc358746_format *fmt = &tc358746_formats[i];
+
+		if (pad == TC358746_SINK && fmt->code == code)
+			return fmt;
+
+		if (pad == TC358746_SOURCE && !fmt->csi_format)
+			continue;
+
+		if (fmt->code == code)
+			return fmt;
+	}
+
+	return ERR_PTR(-EINVAL);
+}
+
+static u32 tc358746_src_mbus_code(u32 code)
+{
+	switch (code) {
+	case MEDIA_BUS_FMT_UYVY8_2X8:
+		return MEDIA_BUS_FMT_UYVY8_1X16;
+	case MEDIA_BUS_FMT_UYVY10_2X10:
+		return MEDIA_BUS_FMT_UYVY10_1X20;
+	default:
+		return code;
+	}
+}
+
+static bool tc358746_valid_reg(struct device *dev, unsigned int reg)
+{
+	switch (reg) {
+	case CHIPID_REG ... CSI_START_REG:
+		return true;
+	default:
+		return false;
+	}
+}
+
+static const struct regmap_config tc358746_regmap_config = {
+	.name = "tc358746",
+	.reg_bits = 16,
+	.val_bits = 16,
+	.max_register = CSI_START_REG,
+	.writeable_reg = tc358746_valid_reg,
+	.readable_reg = tc358746_valid_reg,
+	.reg_format_endian = REGMAP_ENDIAN_BIG,
+	.val_format_endian = REGMAP_ENDIAN_BIG,
+};
+
+static int tc358746_write(struct tc358746 *tc358746, u32 reg, u32 val)
+{
+	size_t count;
+	int err;
+
+	/* 32-bit registers starting from CLW_DPHYCONTTX */
+	count = reg < CLW_DPHYCONTTX_REG ? 1 : 2;
+
+	err = regmap_bulk_write(tc358746->regmap, reg, &val, count);
+	if (err)
+		dev_dbg(tc358746->sd.dev,
+			"Failed to write reg:0x%04x val:0x%04x\n", reg, val);
+
+	return err;
+}
+
+static int tc358746_read(struct tc358746 *tc358746, u32 reg, u32 *val)
+{
+	size_t count;
+	int err;
+
+	/* 32-bit registers starting from CLW_DPHYCONTTX */
+	count = reg < CLW_DPHYCONTTX_REG ? 1 : 2;
+	*val = 0;
+
+	err = regmap_bulk_read(tc358746->regmap, reg, val, count);
+	if (err)
+		dev_dbg(tc358746->sd.dev, "Failed to read reg:0x%04x\n", reg);
+
+	return err;
+}
+
+static int
+tc358746_update_bits(struct tc358746 *tc358746, u32 reg, u32 mask, u32 val)
+{
+	u32 tmp, orig;
+	int err;
+
+	err = tc358746_read(tc358746, reg, &orig);
+	if (err)
+		return err;
+
+	tmp = orig & ~mask;
+	tmp |= val & mask;
+
+	return tc358746_write(tc358746, reg, tmp);
+}
+
+static int tc358746_set_bits(struct tc358746 *tc358746, u32 reg, u32 bits)
+{
+	return tc358746_update_bits(tc358746, reg, bits, bits);
+}
+
+static int tc358746_clear_bits(struct tc358746 *tc358746, u32 reg, u32 bits)
+{
+	return tc358746_update_bits(tc358746, reg, bits, 0);
+}
+
+static int tc358746_sw_reset(struct tc358746 *tc358746)
+{
+	int err;
+
+	err = tc358746_set_bits(tc358746, SYSCTL_REG, SRESET);
+	if (err)
+		return err;
+
+	fsleep(10);
+
+	return tc358746_clear_bits(tc358746, SYSCTL_REG, SRESET);
+}
+
+static int
+tc358746_apply_pll_config(struct tc358746 *tc358746)
+{
+	u8 post = tc358746->pll_post_div;
+	u16 pre = tc358746->pll_pre_div;
+	u16 mul = tc358746->pll_mul;
+	u32 val, mask;
+	int err;
+
+	err = tc358746_read(tc358746, PLLCTL1_REG, &val);
+	if (err)
+		return err;
+
+	/* Don't touch the PLL if running */
+	if (FIELD_GET(PLL_EN, val) == 1)
+		return 0;
+
+	/* Pre-div and Multiplicator have a internal +1 logic */
+	val = PLL_PRD(pre - 1) | PLL_FBD(mul - 1);
+	mask = PLL_PRD_MASK | PLL_FBD_MASK;
+	err = tc358746_update_bits(tc358746, PLLCTL0_REG, mask, val);
+	if (err)
+		return err;
+
+	val = PLL_FRS(ilog2(post)) | RESETB | PLL_EN;
+	mask = PLL_FRS_MASK | RESETB | PLL_EN;
+	tc358746_update_bits(tc358746, PLLCTL1_REG, mask, val);
+	if (err)
+		return err;
+
+	fsleep(1000);
+
+	return tc358746_set_bits(tc358746, PLLCTL1_REG, CKEN);
+}
+
+static int tc358746_apply_misc_config(struct tc358746 *tc358746)
+{
+	const struct v4l2_mbus_framefmt *mbusfmt;
+	struct v4l2_subdev *sd = &tc358746->sd;
+	struct v4l2_subdev_state *sink_state;
+	const struct tc358746_format *fmt;
+	struct device *dev = sd->dev;
+	u32 val;
+	int err;
+
+	sink_state = v4l2_subdev_lock_and_get_active_state(sd);
+	mbusfmt = v4l2_subdev_get_pad_format(sd, sink_state, TC358746_SINK);
+	v4l2_subdev_unlock_state(sink_state);
+
+	fmt = tc358746_get_format_by_code(TC358746_SINK, mbusfmt->code);
+
+	/* Self defined CSI user data type id's are not supported yet */
+	val = PDFMT(fmt->pdformat);
+	dev_dbg(dev, "DATAFMT: 0x%x\n", val);
+	err = tc358746_write(tc358746, DATAFMT_REG, val);
+	if (err)
+		return err;
+
+	val = PDATAF(fmt->pdataf);
+	dev_dbg(dev, "CONFCTL[PDATAF]: 0x%x\n", fmt->pdataf);
+	err = tc358746_update_bits(tc358746, CONFCTL_REG, PDATAF_MASK, val);
+	if (err)
+		return err;
+
+	val = tc358746->vb_size / 32;
+	dev_dbg(dev, "FIFOCTL: %u (0x%x)\n", val, val);
+	err = tc358746_write(tc358746, FIFOCTL_REG, val);
+	if (err)
+		return err;
+
+	/* Total number of bytes for each line/width */
+	val = mbusfmt->width * fmt->bpp / 8;
+	dev_dbg(dev, "WORDCNT: %u (0x%x)\n", val, val);
+	return tc358746_write(tc358746, WORDCNT_REG, val);
+}
+
+/* Use MHz as base so the div needs no u64 */
+static u32 tc358746_cfg_to_cnt(unsigned int cfg_val,
+			       unsigned int clk_mhz,
+			       unsigned int time_base)
+{
+	return DIV_ROUND_UP(cfg_val * clk_mhz, time_base);
+}
+
+static u32 tc358746_ps_to_cnt(unsigned int cfg_val,
+			      unsigned int clk_mhz)
+{
+	return tc358746_cfg_to_cnt(cfg_val, clk_mhz, USEC_PER_SEC);
+}
+
+static u32 tc358746_us_to_cnt(unsigned int cfg_val,
+			      unsigned int clk_mhz)
+{
+	return tc358746_cfg_to_cnt(cfg_val, clk_mhz, 1);
+}
+
+static int tc358746_apply_dphy_config(struct tc358746 *tc358746)
+{
+	struct phy_configure_opts_mipi_dphy *cfg = &tc358746->dphy_cfg;
+	bool non_cont_clk = !!(tc358746->csi_vep.bus.mipi_csi2.flags &
+			       V4L2_MBUS_CSI2_NONCONTINUOUS_CLOCK);
+	struct device *dev = tc358746->sd.dev;
+	unsigned long hs_byte_clk, hf_clk;
+	u32 val, val2, lptxcnt;
+	int err;
+
+	/* The hs_byte_clk is also called SYSCLK in the excel sheet */
+	hs_byte_clk = cfg->hs_clk_rate / 8;
+	hs_byte_clk /= HZ_PER_MHZ;
+	hf_clk = hs_byte_clk / 2;
+
+	val = tc358746_us_to_cnt(cfg->init, hf_clk) - 1;
+	dev_dbg(dev, "LINEINITCNT: %u (0x%x)\n", val, val);
+	err = tc358746_write(tc358746, LINEINITCNT_REG, val);
+	if (err)
+		return err;
+
+	val = tc358746_ps_to_cnt(cfg->lpx, hs_byte_clk) - 1;
+	lptxcnt = val;
+	dev_dbg(dev, "LPTXTIMECNT: %u (0x%x)\n", val, val);
+	err = tc358746_write(tc358746, LPTXTIMECNT_REG, val);
+	if (err)
+		return err;
+
+	val = tc358746_ps_to_cnt(cfg->clk_prepare, hs_byte_clk) - 1;
+	val2 = tc358746_ps_to_cnt(cfg->clk_zero, hs_byte_clk) - 1;
+	dev_dbg(dev, "TCLK_PREPARECNT: %u (0x%x)\n", val, val);
+	dev_dbg(dev, "TCLK_ZEROCNT: %u (0x%x)\n", val2, val2);
+	dev_dbg(dev, "TCLK_HEADERCNT: 0x%x\n",
+		(u32)(TCLK_PREPARECNT(val) | TCLK_ZEROCNT(val2)));
+	err = tc358746_write(tc358746, TCLK_HEADERCNT_REG,
+			     TCLK_PREPARECNT(val) | TCLK_ZEROCNT(val2));
+	if (err)
+		return err;
+
+	val = tc358746_ps_to_cnt(cfg->clk_trail, hs_byte_clk);
+	dev_dbg(dev, "TCLK_TRAILCNT: %u (0x%x)\n", val, val);
+	err = tc358746_write(tc358746, TCLK_TRAILCNT_REG, val);
+	if (err)
+		return err;
+
+	val = tc358746_ps_to_cnt(cfg->hs_prepare, hs_byte_clk) - 1;
+	val2 = tc358746_ps_to_cnt(cfg->hs_zero, hs_byte_clk) - 1;
+	dev_dbg(dev, "THS_PREPARECNT: %u (0x%x)\n", val, val);
+	dev_dbg(dev, "THS_ZEROCNT: %u (0x%x)\n", val2, val2);
+	dev_dbg(dev, "THS_HEADERCNT: 0x%x\n",
+		(u32)(THS_PREPARECNT(val) | THS_ZEROCNT(val2)));
+	err = tc358746_write(tc358746, THS_HEADERCNT_REG,
+			     THS_PREPARECNT(val) | THS_ZEROCNT(val2));
+	if (err)
+		return err;
+
+	/* TWAKEUP > 1ms in lptxcnt steps */
+	val = tc358746_us_to_cnt(cfg->wakeup, hs_byte_clk);
+	val = val / (lptxcnt + 1) - 1;
+	dev_dbg(dev, "TWAKEUP: %u (0x%x)\n", val, val);
+	err = tc358746_write(tc358746, TWAKEUP_REG, val);
+	if (err)
+		return err;
+
+	val = tc358746_ps_to_cnt(cfg->clk_post, hs_byte_clk);
+	dev_dbg(dev, "TCLK_POSTCNT: %u (0x%x)\n", val, val);
+	err = tc358746_write(tc358746, TCLK_POSTCNT_REG, val);
+	if (err)
+		return err;
+
+	val = tc358746_ps_to_cnt(cfg->hs_trail, hs_byte_clk);
+	dev_dbg(dev, "THS_TRAILCNT: %u (0x%x)\n", val, val);
+	err = tc358746_write(tc358746, THS_TRAILCNT_REG, val);
+	if (err)
+		return err;
+
+	dev_dbg(dev, "CONTCLKMODE: %u", non_cont_clk ? 0 : 1);
+	return  tc358746_write(tc358746, TXOPTIONCNTRL_REG, non_cont_clk ? 0 : 1);
+}
+
+#define MAX_DATA_LANES 4
+
+static int tc358746_enable_csi_lanes(struct tc358746 *tc358746, int enable)
+{
+	unsigned int lanes = tc358746->dphy_cfg.lanes;
+	unsigned int lane;
+	u32 reg, val;
+	int err;
+
+	err = tc358746_update_bits(tc358746, CONFCTL_REG, DATALANE_MASK,
+				   lanes - 1);
+	if (err)
+		return err;
+
+	/* Clock lane */
+	val = enable ? 0 : LANEDISABLE;
+	dev_dbg(tc358746->sd.dev, "CLW_CNTRL: 0x%x\n", val);
+	err = tc358746_write(tc358746, CLW_CNTRL_REG, val);
+	if (err)
+		return err;
+
+	for (lane = 0; lane < MAX_DATA_LANES; lane++) {
+		/* Data lanes */
+		reg = D0W_CNTRL_REG + lane * 0x4;
+		val = (enable && lane < lanes) ? 0 : LANEDISABLE;
+
+		dev_dbg(tc358746->sd.dev, "D%uW_CNTRL: 0x%x\n", lane, val);
+		err = tc358746_write(tc358746, reg, val);
+		if (err)
+			return err;
+	}
+
+	val = 0;
+	if (enable) {
+		/* Clock lane */
+		val |= BIT(0);
+
+		/* Data lanes */
+		for (lane = 1; lane <= lanes; lane++)
+			val |= BIT(lane);
+	}
+
+	dev_dbg(tc358746->sd.dev, "HSTXVREGEN: 0x%x\n", val);
+	return tc358746_write(tc358746, HSTXVREGEN_REG, val);
+}
+
+static int tc358746_enable_csi_module(struct tc358746 *tc358746, int enable)
+{
+	unsigned int lanes = tc358746->dphy_cfg.lanes;
+	int err;
+
+	/*
+	 * START and STRT are only reseted/disabled by sw reset. This is
+	 * required to put the lane state back into LP-11 state. The sw reset
+	 * don't reset register values.
+	 */
+	if (!enable)
+		return tc358746_sw_reset(tc358746);
+
+	err = tc358746_write(tc358746, STARTCNTRL_REG, START);
+	if (err)
+		return err;
+
+	err = tc358746_write(tc358746, CSI_START_REG, STRT);
+	if (err)
+		return err;
+
+	/* CSI_CONTROL_REG is only indirect accessible */
+	return tc358746_write(tc358746, CSI_CONFW_REG,
+			      MODE(MODE_SET) |
+			      ADDRESS(CSI_CONTROL_ADDRESS) |
+			      DATA(CSI_MODE | TXHSMD | NOL(lanes - 1)));
+}
+
+static int tc358746_enable_parallel_port(struct tc358746 *tc358746, int enable)
+{
+	int err;
+
+	if (enable) {
+		err = tc358746_write(tc358746, PP_MISC_REG, 0);
+		if (err)
+			return err;
+
+		return tc358746_set_bits(tc358746, CONFCTL_REG, PPEN);
+	}
+
+	err = tc358746_set_bits(tc358746, PP_MISC_REG, FRMSTOP);
+	if (err)
+		return err;
+
+	err = tc358746_clear_bits(tc358746, CONFCTL_REG, PPEN);
+	if (err)
+		return err;
+
+	return tc358746_set_bits(tc358746, PP_MISC_REG, RSTPTR);
+}
+
+static inline struct v4l2_subdev *tc358746_get_remote_sd(struct media_pad *pad)
+{
+	pad = media_pad_remote_pad_first(pad);
+	if (!pad)
+		return NULL;
+
+	return media_entity_to_v4l2_subdev(pad->entity);
+}
+
+static int tc358746_s_stream(struct v4l2_subdev *sd, int enable)
+{
+	struct tc358746 *tc358746 = to_tc358746(sd);
+	struct v4l2_subdev *src;
+	int err;
+
+	dev_dbg(sd->dev, "%sable\n", enable ? "en" : "dis");
+
+	src = tc358746_get_remote_sd(&tc358746->pads[TC358746_SINK]);
+	if (!src)
+		return -EPIPE;
+
+	if (enable) {
+		err = pm_runtime_resume_and_get(sd->dev);
+		if (err)
+			return err;
+
+		err = tc358746_apply_dphy_config(tc358746);
+		if (err)
+			goto err_out;
+
+		err = tc358746_apply_misc_config(tc358746);
+		if (err)
+			goto err_out;
+
+		err = tc358746_enable_csi_lanes(tc358746, 1);
+		if (err)
+			goto err_out;
+
+		err = tc358746_enable_csi_module(tc358746, 1);
+		if (err)
+			goto err_out;
+
+		err = tc358746_enable_parallel_port(tc358746, 1);
+		if (err)
+			goto err_out;
+
+		err = v4l2_subdev_call(src, video, s_stream, 1);
+		if (err)
+			goto err_out;
+
+		return err;
+
+err_out:
+		pm_runtime_mark_last_busy(sd->dev);
+		pm_runtime_put_sync_autosuspend(sd->dev);
+
+		return err;
+	}
+
+	 /*
+	  * The lanes must be disabled first (before the csi module) so the
+	  * LP-11 state is entered correctly.
+	  */
+	err = tc358746_enable_csi_lanes(tc358746, 0);
+	if (err)
+		return err;
+
+	err = tc358746_enable_csi_module(tc358746, 0);
+	if (err)
+		return err;
+
+	err = tc358746_enable_parallel_port(tc358746, 0);
+	if (err)
+		return err;
+
+	pm_runtime_mark_last_busy(sd->dev);
+	pm_runtime_put_sync_autosuspend(sd->dev);
+
+	return v4l2_subdev_call(src, video, s_stream, 0);
+}
+
+static int tc358746_init_cfg(struct v4l2_subdev *sd,
+			     struct v4l2_subdev_state *state)
+{
+	struct v4l2_mbus_framefmt *fmt;
+
+	fmt = v4l2_subdev_get_pad_format(sd, state, TC358746_SINK);
+	*fmt = tc358746_def_fmt;
+
+	fmt = v4l2_subdev_get_pad_format(sd, state, TC358746_SOURCE);
+	*fmt = tc358746_def_fmt;
+	fmt->code = tc358746_src_mbus_code(tc358746_def_fmt.code);
+
+	return 0;
+}
+
+static int tc358746_enum_mbus_code(struct v4l2_subdev *sd,
+				   struct v4l2_subdev_state *sd_state,
+				   struct v4l2_subdev_mbus_code_enum *code)
+{
+	const struct tc358746_format *fmt;
+
+	fmt = tc358746_get_format_by_idx(code->pad, code->index);
+	if (IS_ERR(fmt))
+		return PTR_ERR(fmt);
+
+	code->code = fmt->code;
+
+	return 0;
+}
+
+static int tc358746_set_fmt(struct v4l2_subdev *sd,
+			    struct v4l2_subdev_state *sd_state,
+			    struct v4l2_subdev_format *format)
+{
+	struct v4l2_mbus_framefmt *src_fmt, *sink_fmt;
+	const struct tc358746_format *fmt;
+
+	/* Source follows the sink */
+	if (format->pad == TC358746_SOURCE)
+		return v4l2_subdev_get_fmt(sd, sd_state, format);
+
+	sink_fmt = v4l2_subdev_get_pad_format(sd, sd_state, TC358746_SINK);
+
+	fmt = tc358746_get_format_by_code(format->pad, format->format.code);
+	if (IS_ERR(fmt))
+		fmt = tc358746_get_format_by_code(format->pad, tc358746_def_fmt.code);
+
+	format->format.code = fmt->code;
+	format->format.field = V4L2_FIELD_NONE;
+
+	dev_dbg(sd->dev, "Update format: %ux%u code:0x%x -> %ux%u code:0x%x",
+		sink_fmt->width, sink_fmt->height, sink_fmt->code,
+		format->format.width, format->format.height, format->format.code);
+
+	*sink_fmt = format->format;
+
+	src_fmt = v4l2_subdev_get_pad_format(sd, sd_state, TC358746_SOURCE);
+	*src_fmt = *sink_fmt;
+	src_fmt->code = tc358746_src_mbus_code(sink_fmt->code);
+
+	return 0;
+}
+
+static unsigned long tc358746_find_pll_settings(struct tc358746 *tc358746,
+						unsigned long refclk,
+						unsigned long fout)
+
+{
+	struct device *dev = tc358746->sd.dev;
+	unsigned long best_freq = 0;
+	u32 min_delta = 0xffffffff;
+	u16 prediv_max = 17;
+	u16 prediv_min = 1;
+	u16 m_best, mul;
+	u16 p_best, p;
+	u8 postdiv;
+
+	if (fout > 1000 * HZ_PER_MHZ) {
+		dev_err(dev, "HS-Clock above 1 Ghz are not supported\n");
+		return 0;
+	}
+
+	if (fout >= 500 * HZ_PER_MHZ)
+		postdiv = 1;
+	else if (fout >= 250 * HZ_PER_MHZ)
+		postdiv = 2;
+	else if (fout >= 125 * HZ_PER_MHZ)
+		postdiv = 4;
+	else
+		postdiv = 8;
+
+	for (p = prediv_min; p <= prediv_max; p++) {
+		unsigned long delta, fin;
+		u64 tmp;
+
+		fin = DIV_ROUND_CLOSEST(refclk, p);
+		if (fin < 4 * HZ_PER_MHZ || fin > 40 * HZ_PER_MHZ)
+			continue;
+
+		tmp = fout * p * postdiv;
+		do_div(tmp, fin);
+		mul = tmp;
+		if (mul > 511)
+			continue;
+
+		tmp = mul * fin;
+		do_div(tmp, p * postdiv);
+
+		delta = abs(fout - tmp);
+		if (delta < min_delta) {
+			p_best = p;
+			m_best = mul;
+			min_delta = delta;
+			best_freq = tmp;
+		};
+
+		if (delta == 0)
+			break;
+	};
+
+	if (!best_freq) {
+		dev_err(dev, "Failed find PLL frequency\n");
+		return 0;
+	}
+
+	tc358746->pll_post_div = postdiv;
+	tc358746->pll_pre_div = p_best;
+	tc358746->pll_mul = m_best;
+
+	if (best_freq != fout)
+		dev_warn(dev, "Request PLL freq:%lu, found PLL freq:%lu\n",
+			 fout, best_freq);
+
+	dev_dbg(dev, "Found PLL settings: freq:%lu prediv:%u multi:%u postdiv:%u\n",
+		best_freq, p_best, m_best, postdiv);
+
+	return best_freq;
+}
+
+#define TC358746_PRECISION 10
+
+static int
+tc358746_link_validate(struct v4l2_subdev *sd, struct media_link *link,
+		       struct v4l2_subdev_format *source_fmt,
+		       struct v4l2_subdev_format *sink_fmt)
+{
+	struct tc358746 *tc358746 = to_tc358746(sd);
+	unsigned long csi_bitrate, source_bitrate;
+	struct v4l2_subdev_state *sink_state;
+	struct v4l2_mbus_framefmt *mbusfmt;
+	const struct tc358746_format *fmt;
+	unsigned int fifo_sz, tmp, n;
+	struct v4l2_subdev *source;
+	s64 source_link_freq;
+	int err;
+
+	err = v4l2_subdev_link_validate_default(sd, link, source_fmt, sink_fmt);
+	if (err)
+		return err;
+
+	sink_state = v4l2_subdev_lock_and_get_active_state(sd);
+	mbusfmt = v4l2_subdev_get_pad_format(sd, sink_state, TC358746_SINK);
+
+	/* Check the FIFO settings */
+	fmt = tc358746_get_format_by_code(TC358746_SINK, mbusfmt->code);
+
+	source = media_entity_to_v4l2_subdev(link->source->entity);
+	source_link_freq = v4l2_get_link_freq(source->ctrl_handler, 0, 0);
+	if (source_link_freq <= 0) {
+		dev_err(tc358746->sd.dev,
+			"Failed to query or invalid source link frequency\n");
+		v4l2_subdev_unlock_state(sink_state);
+		/* Return -EINVAL in case of source_link_freq is 0 */
+		return source_link_freq ? : -EINVAL;
+	}
+	source_bitrate = source_link_freq * fmt->bus_width;
+
+	csi_bitrate = tc358746->dphy_cfg.lanes * tc358746->pll_rate;
+
+	dev_dbg(tc358746->sd.dev,
+		"Fifo settings params: source-bitrate:%lu csi-bitrate:%lu",
+		source_bitrate, csi_bitrate);
+
+	/* Avoid possible FIFO overflows */
+	if (csi_bitrate < source_bitrate) {
+		v4l2_subdev_unlock_state(sink_state);
+		return -EINVAL;
+	}
+
+	/* Best case */
+	if (csi_bitrate == source_bitrate) {
+		fifo_sz = TC358746_VB_DEFAULT_SIZE;
+		tc358746->vb_size = TC358746_VB_DEFAULT_SIZE;
+		goto out;
+	}
+
+	/*
+	 * Avoid possible FIFO underflow in case of
+	 * csi_bitrate > source_bitrate. For such case the chip has a internal
+	 * fifo which can be used to delay the line output.
+	 *
+	 * Fifo size calculation (excluding precision):
+	 *
+	 * fifo-sz, image-width - in bits
+	 * sbr                  - source_bitrate in bits/s
+	 * csir                 - csi_bitrate in bits/s
+	 *
+	 *                1               1      1
+	 * image-width * --- + fifo-sz * --- >= ---- * image-width
+	 *               sbr             sbr    csir
+	 *
+	 * fifo-sz >= abs(sbr/csir * image-width - image-width); with n = csir/sbr
+	 *
+	 * fifo-sz >= abs(image-width / n - image-width)
+	 *         >= image-width - image-width / n
+	 */
+
+	source_bitrate /= TC358746_PRECISION;
+	n = csi_bitrate / source_bitrate;
+	tmp = (mbusfmt->width * TC358746_PRECISION) / n;
+	fifo_sz = mbusfmt->width - tmp;
+	fifo_sz *= fmt->bpp;
+	tc358746->vb_size = round_up(fifo_sz, 32);
+
+out:
+	dev_dbg(tc358746->sd.dev,
+		"Found FIFO size[bits]:%u -> aligned to size[bits]:%u\n",
+		fifo_sz, tc358746->vb_size);
+
+	v4l2_subdev_unlock_state(sink_state);
+
+	return tc358746->vb_size > TC358746_VB_MAX_SIZE ? -EINVAL : 0;
+}
+
+static int tc358746_get_mbus_config(struct v4l2_subdev *sd, unsigned int pad,
+				    struct v4l2_mbus_config *config)
+{
+	struct tc358746 *tc358746 = to_tc358746(sd);
+
+	if (pad != TC358746_SOURCE)
+		return -EINVAL;
+
+	config->type = V4L2_MBUS_CSI2_DPHY;
+	config->bus.mipi_csi2 = tc358746->csi_vep.bus.mipi_csi2;
+
+	return 0;
+}
+
+static int __maybe_unused
+tc358746_g_register(struct v4l2_subdev *sd, struct v4l2_dbg_register *reg)
+{
+	struct tc358746 *tc358746 = to_tc358746(sd);
+
+	/* 32-bit registers starting from CLW_DPHYCONTTX */
+	reg->size = reg->reg < CLW_DPHYCONTTX_REG ? 2 : 4;
+
+	if (!pm_runtime_get_if_in_use(sd->dev))
+		return 0;
+
+	tc358746_read(tc358746, reg->reg, (u32 *)&reg->val);
+
+	pm_runtime_mark_last_busy(sd->dev);
+	pm_runtime_put_sync_autosuspend(sd->dev);
+
+	return 0;
+}
+
+static int __maybe_unused
+tc358746_s_register(struct v4l2_subdev *sd, const struct v4l2_dbg_register *reg)
+{
+	struct tc358746 *tc358746 = to_tc358746(sd);
+
+	if (!pm_runtime_get_if_in_use(sd->dev))
+		return 0;
+
+	tc358746_write(tc358746, (u32)reg->reg, (u32)reg->val);
+
+	pm_runtime_mark_last_busy(sd->dev);
+	pm_runtime_put_sync_autosuspend(sd->dev);
+
+	return 0;
+}
+
+static const struct v4l2_subdev_core_ops tc358746_core_ops = {
+#ifdef CONFIG_VIDEO_ADV_DEBUG
+	.g_register = tc358746_g_register,
+	.s_register = tc358746_s_register,
+#endif
+};
+
+static const struct v4l2_subdev_video_ops tc358746_video_ops = {
+	.s_stream = tc358746_s_stream,
+};
+
+static const struct v4l2_subdev_pad_ops tc358746_pad_ops = {
+	.init_cfg = tc358746_init_cfg,
+	.enum_mbus_code = tc358746_enum_mbus_code,
+	.set_fmt = tc358746_set_fmt,
+	.get_fmt = v4l2_subdev_get_fmt,
+	.link_validate = tc358746_link_validate,
+	.get_mbus_config = tc358746_get_mbus_config,
+};
+
+static const struct v4l2_subdev_ops tc358746_ops = {
+	.core = &tc358746_core_ops,
+	.video = &tc358746_video_ops,
+	.pad = &tc358746_pad_ops,
+};
+
+static const struct media_entity_operations tc358746_entity_ops = {
+	.get_fwnode_pad = v4l2_subdev_get_fwnode_pad_1_to_1,
+	.link_validate = v4l2_subdev_link_validate,
+};
+
+static int tc358746_mclk_enable(struct clk_hw *hw)
+{
+	struct tc358746 *tc358746 = clk_hw_to_tc358746(hw);
+	unsigned int div;
+	u32 val;
+	int err;
+
+	div = tc358746->mclk_postdiv / 2;
+	val = MCLK_HIGH(div - 1) | MCLK_LOW(div - 1);
+	dev_dbg(tc358746->sd.dev, "MCLKCTL: %u (0x%x)\n", val, val);
+	err = tc358746_write(tc358746, MCLKCTL_REG, val);
+	if (err)
+		return err;
+
+	if (tc358746->mclk_prediv == 8)
+		val = MCLKDIV(MCLKDIV_8);
+	else if (tc358746->mclk_prediv == 4)
+		val = MCLKDIV(MCLKDIV_4);
+	else
+		val = MCLKDIV(MCLKDIV_2);
+
+	dev_dbg(tc358746->sd.dev, "CLKCTL[MCLKDIV]: %u (0x%x)\n", val, val);
+	return tc358746_update_bits(tc358746, CLKCTL_REG, MCLKDIV_MASK, val);
+}
+
+static void tc358746_mclk_disable(struct clk_hw *hw)
+{
+	struct tc358746 *tc358746 = clk_hw_to_tc358746(hw);
+
+	tc358746_write(tc358746, MCLKCTL_REG, 0);
+}
+
+static long
+tc358746_find_mclk_settings(struct tc358746 *tc358746, unsigned long mclk_rate)
+{
+	unsigned long pll_rate = tc358746->pll_rate;
+	const unsigned char prediv[] = { 2, 4, 8 };
+	unsigned int mclk_prediv, mclk_postdiv;
+	struct device *dev = tc358746->sd.dev;
+	unsigned int postdiv, mclkdiv;
+	unsigned long best_mclk_rate;
+	unsigned int i;
+
+	/*
+	 *                          MCLK-Div
+	 *           -------------------´`---------------------
+	 *          ´                                          `
+	 *         +-------------+     +------------------------+
+	 *         | MCLK-PreDiv |     |       MCLK-PostDiv     |
+	 * PLL --> |   (2/4/8)   | --> | (mclk_low + mclk_high) | --> MCLK
+	 *         +-------------+     +------------------------+
+	 *
+	 * The register value of mclk_low/high is mclk_low/high+1, i.e.:
+	 *   mclk_low/high = 1   --> 2 MCLK-Ref Counts
+	 *   mclk_low/high = 255 --> 256 MCLK-Ref Counts == max.
+	 * If mclk_low and mclk_high are 0 then MCLK is disabled.
+	 *
+	 * Keep it simple and support 50/50 duty cycles only for now,
+	 * so the calc will be:
+	 *
+	 *   MCLK = PLL / (MCLK-PreDiv * 2 * MCLK-PostDiv)
+	 */
+
+	if (mclk_rate == tc358746->mclk_rate)
+		return mclk_rate;
+
+	/* Highest possible rate */
+	mclkdiv = pll_rate / mclk_rate;
+	if (mclkdiv <= 8) {
+		mclk_prediv = 2;
+		mclk_postdiv = 4;
+		best_mclk_rate = pll_rate / (2 * 4);
+		goto out;
+	}
+
+	/* First check the prediv */
+	for (i = 0; i < ARRAY_SIZE(prediv); i++) {
+		postdiv = mclkdiv / prediv[i];
+
+		if (postdiv % 2)
+			continue;
+
+		if (postdiv >= 4 && postdiv <= 512) {
+			mclk_prediv = prediv[i];
+			mclk_postdiv = postdiv;
+			best_mclk_rate = pll_rate / (prediv[i] * postdiv);
+			goto out;
+		}
+	}
+
+	/* No suitable prediv found, so try to adjust the postdiv */
+	for (postdiv = 4; postdiv <= 512; postdiv += 2) {
+		unsigned int pre;
+
+		pre = mclkdiv / postdiv;
+		if (pre == 2 || pre == 4 || pre == 8) {
+			mclk_prediv = pre;
+			mclk_postdiv = postdiv;
+			best_mclk_rate = pll_rate / (pre * postdiv);
+			goto out;
+		}
+	}
+
+	/* The MCLK <-> PLL gap is to high -> use largest possible div */
+	mclk_prediv = 8;
+	mclk_postdiv = 512;
+	best_mclk_rate = pll_rate / (8 * 512);
+
+out:
+	tc358746->mclk_prediv = mclk_prediv;
+	tc358746->mclk_postdiv = mclk_postdiv;
+	tc358746->mclk_rate = best_mclk_rate;
+
+	if (best_mclk_rate != mclk_rate)
+		dev_warn(dev, "Request MCLK freq:%lu, found MCLK freq:%lu\n",
+			 mclk_rate, best_mclk_rate);
+
+	dev_dbg(dev, "Found MCLK settings: freq:%lu prediv:%u postdiv:%u\n",
+		best_mclk_rate, mclk_prediv, mclk_postdiv);
+
+	return best_mclk_rate;
+}
+
+static unsigned long
+tc358746_recalc_rate(struct clk_hw *hw, unsigned long parent_rate)
+{
+	struct tc358746 *tc358746 = clk_hw_to_tc358746(hw);
+	unsigned int prediv, postdiv;
+	u32 val;
+	int err;
+
+	err = tc358746_read(tc358746, MCLKCTL_REG, &val);
+	if (err)
+		return 0;
+
+	postdiv = FIELD_GET(MCLK_LOW_MASK, val) + 1;
+	postdiv += FIELD_GET(MCLK_HIGH_MASK, val) + 1;
+
+	err = tc358746_read(tc358746, CLKCTL_REG, &val);
+	if (err)
+		return 0;
+
+	prediv = FIELD_GET(MCLKDIV_MASK, val);
+	if (prediv == MCLKDIV_8)
+		prediv = 8;
+	else if (prediv == MCLKDIV_4)
+		prediv = 4;
+	else
+		prediv = 2;
+
+	return tc358746->pll_rate / (prediv * postdiv);
+}
+
+static long tc358746_mclk_round_rate(struct clk_hw *hw, unsigned long rate,
+				     unsigned long *parent_rate)
+{
+	struct tc358746 *tc358746 = clk_hw_to_tc358746(hw);
+
+	*parent_rate = tc358746->pll_rate;
+
+	return tc358746_find_mclk_settings(tc358746, rate);
+}
+
+static int tc358746_mclk_set_rate(struct clk_hw *hw, unsigned long rate,
+				  unsigned long parent_rate)
+{
+	struct tc358746 *tc358746 = clk_hw_to_tc358746(hw);
+
+	tc358746_find_mclk_settings(tc358746, rate);
+
+	return tc358746_mclk_enable(hw);
+}
+
+static const struct clk_ops tc358746_mclk_ops = {
+	.enable = tc358746_mclk_enable,
+	.disable = tc358746_mclk_disable,
+	.recalc_rate = tc358746_recalc_rate,
+	.round_rate = tc358746_mclk_round_rate,
+	.set_rate = tc358746_mclk_set_rate,
+};
+
+static int tc358746_setup_mclk_provider(struct tc358746 *tc358746)
+{
+	struct clk_init_data mclk_initdata = { };
+	struct device *dev = tc358746->sd.dev;
+	const char *mclk_name;
+	int err;
+
+	/* MCLK clk provider support is optional */
+	if (!device_property_present(dev, "#clock-cells"))
+		return 0;
+
+	/* Init to highest possibel MCLK */
+	tc358746->mclk_postdiv = 512;
+	tc358746->mclk_prediv = 8;
+
+	mclk_name = "tc358746-mclk";
+	device_property_read_string(dev, "clock-output-names", &mclk_name);
+
+	mclk_initdata.name = mclk_name;
+	mclk_initdata.ops = &tc358746_mclk_ops;
+	tc358746->mclk_hw.init = &mclk_initdata;
+
+	err = devm_clk_hw_register(dev, &tc358746->mclk_hw);
+	if (err) {
+		dev_err(dev, "Failed to register mclk provider\n");
+		return err;
+	}
+
+	err = devm_of_clk_add_hw_provider(dev, of_clk_hw_simple_get,
+					  &tc358746->mclk_hw);
+	if (err)
+		dev_err(dev, "Failed to add mclk provider\n");
+
+	return err;
+}
+
+static int
+tc358746_init_subdev(struct tc358746 *tc358746, struct i2c_client *client)
+{
+	struct v4l2_subdev *sd = &tc358746->sd;
+	int err;
+
+	v4l2_i2c_subdev_init(sd, client, &tc358746_ops);
+	sd->flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;
+	sd->entity.function = MEDIA_ENT_F_VID_IF_BRIDGE;
+	sd->entity.ops = &tc358746_entity_ops;
+
+	tc358746->pads[TC358746_SINK].flags = MEDIA_PAD_FL_SINK;
+	tc358746->pads[TC358746_SOURCE].flags = MEDIA_PAD_FL_SOURCE;
+	err = media_entity_pads_init(&sd->entity, TC358746_NR_PADS,
+				     tc358746->pads);
+	if (err)
+		return err;
+
+	err = v4l2_subdev_init_finalize(sd);
+	if (err)
+		media_entity_cleanup(&sd->entity);
+
+	return err;
+}
+
+static int
+tc358746_init_output_port(struct tc358746 *tc358746, unsigned long refclk)
+{
+	struct device *dev = tc358746->sd.dev;
+	struct v4l2_fwnode_endpoint *vep;
+	unsigned long csi_link_rate;
+	struct fwnode_handle *ep;
+	unsigned char csi_lanes;
+	int err;
+
+	ep = fwnode_graph_get_endpoint_by_id(dev_fwnode(dev), TC358746_SOURCE,
+					     0, 0);
+	if (!ep) {
+		dev_err(dev, "Missing endpoint node\n");
+		return -EINVAL;
+	}
+
+	/* Currently we only support 'parallel in' -> 'csi out' */
+	vep = &tc358746->csi_vep;
+	vep->bus_type = V4L2_MBUS_CSI2_DPHY;
+	err = v4l2_fwnode_endpoint_alloc_parse(ep, vep);
+	fwnode_handle_put(ep);
+	if (err) {
+		dev_err(dev, "Failed to parse source endpoint\n");
+		return err;
+	}
+
+	csi_lanes = vep->bus.mipi_csi2.num_data_lanes;
+	if (csi_lanes == 0 || csi_lanes > 4 ||
+	    vep->nr_of_link_frequencies == 0) {
+		dev_err(dev, "error: Invalid CSI-2 settings\n");
+		err = -EINVAL;
+		goto err;
+	}
+
+	/* TODO: Add support to handle multiple link frequencies */
+	csi_link_rate = (unsigned long)vep->link_frequencies[0];
+	tc358746->pll_rate = tc358746_find_pll_settings(tc358746, refclk,
+							csi_link_rate * 2);
+	if (!tc358746->pll_rate) {
+		err = -EINVAL;
+		goto err;
+	}
+
+	err = phy_mipi_dphy_get_default_config_for_hsclk(tc358746->pll_rate,
+						csi_lanes, &tc358746->dphy_cfg);
+	if (err)
+		goto err;
+
+	tc358746->vb_size = TC358746_VB_DEFAULT_SIZE;
+
+	return 0;
+
+err:
+	v4l2_fwnode_endpoint_free(vep);
+
+	return err;
+}
+
+static int tc358746_init_hw(struct tc358746 *tc358746)
+{
+	struct device *dev = tc358746->sd.dev;
+	unsigned int chipid;
+	u32 val;
+	int err;
+
+	err = pm_runtime_resume_and_get(dev);
+	if (err < 0) {
+		dev_err(dev, "Failed to resume the device\n");
+		return err;
+	}
+
+	 /* Ensure that CSI interface is put into LP-11 state */
+	err = tc358746_sw_reset(tc358746);
+	if (err) {
+		pm_runtime_put_sync(dev);
+		dev_err(dev, "Failed to reset the device\n");
+		return err;
+	}
+
+	err = tc358746_read(tc358746, CHIPID_REG, &val);
+	pm_runtime_mark_last_busy(dev);
+	pm_runtime_put_sync_autosuspend(dev);
+	if (err)
+		return -ENODEV;
+
+	chipid = FIELD_GET(CHIPID, val);
+	if (chipid != 0x44) {
+		dev_err(dev, "Invalid chipid 0x%02x\n", chipid);
+		return -ENODEV;
+	}
+
+	return 0;
+}
+
+static int tc358746_init_controls(struct tc358746 *tc358746)
+{
+	u64 *link_frequencies = tc358746->csi_vep.link_frequencies;
+	struct v4l2_ctrl *ctrl;
+	int err;
+
+	err = v4l2_ctrl_handler_init(&tc358746->ctrl_hdl, 1);
+	if (err)
+		return err;
+
+	/*
+	 * The driver currently supports only one link-frequency, regardless of
+	 * the input from the firmware, see: tc358746_init_output_port(). So
+	 * report only the first frequency from the array of possible given
+	 * frequencies.
+	 */
+	ctrl = v4l2_ctrl_new_int_menu(&tc358746->ctrl_hdl, NULL,
+				      V4L2_CID_LINK_FREQ, 0, 0,
+				      link_frequencies);
+	if (ctrl)
+		ctrl->flags |= V4L2_CTRL_FLAG_READ_ONLY;
+
+	err = tc358746->ctrl_hdl.error;
+	if (err) {
+		v4l2_ctrl_handler_free(&tc358746->ctrl_hdl);
+		return err;
+	}
+
+	tc358746->sd.ctrl_handler = &tc358746->ctrl_hdl;
+
+	return 0;
+}
+
+static int tc358746_notify_bound(struct v4l2_async_notifier *notifier,
+				 struct v4l2_subdev *sd,
+				 struct v4l2_async_subdev *asd)
+{
+	struct tc358746 *tc358746 =
+		container_of(notifier, struct tc358746, notifier);
+	u32 flags = MEDIA_LNK_FL_ENABLED | MEDIA_LNK_FL_IMMUTABLE;
+	struct media_pad *sink = &tc358746->pads[TC358746_SINK];
+
+	return v4l2_create_fwnode_links_to_pad(sd, sink, flags);
+}
+
+static const struct v4l2_async_notifier_operations tc358746_notify_ops = {
+	.bound = tc358746_notify_bound,
+};
+
+static int tc358746_async_register(struct tc358746 *tc358746)
+{
+	struct v4l2_fwnode_endpoint vep = {
+		.bus_type = V4L2_MBUS_PARALLEL,
+	};
+	struct v4l2_async_subdev *asd;
+	struct fwnode_handle *ep;
+	int err;
+
+	ep = fwnode_graph_get_endpoint_by_id(dev_fwnode(tc358746->sd.dev),
+					     TC358746_SINK, 0, 0);
+	if (!ep)
+		return -ENOTCONN;
+
+	err = v4l2_fwnode_endpoint_parse(ep, &vep);
+	if (err) {
+		fwnode_handle_put(ep);
+		return err;
+	}
+
+	v4l2_async_nf_init(&tc358746->notifier);
+	asd = v4l2_async_nf_add_fwnode_remote(&tc358746->notifier, ep,
+					      struct v4l2_async_subdev);
+	fwnode_handle_put(ep);
+
+	if (IS_ERR(asd)) {
+		err = PTR_ERR(asd);
+		goto err_cleanup;
+	}
+
+	tc358746->notifier.ops = &tc358746_notify_ops;
+
+	err = v4l2_async_subdev_nf_register(&tc358746->sd, &tc358746->notifier);
+	if (err)
+		goto err_cleanup;
+
+	tc358746->sd.fwnode = fwnode_graph_get_endpoint_by_id(
+		dev_fwnode(tc358746->sd.dev), TC358746_SOURCE, 0, 0);
+
+	err = v4l2_async_register_subdev(&tc358746->sd);
+	if (err)
+		goto err_unregister;
+
+	return 0;
+
+err_unregister:
+	fwnode_handle_put(tc358746->sd.fwnode);
+	v4l2_async_nf_unregister(&tc358746->notifier);
+err_cleanup:
+	v4l2_async_nf_cleanup(&tc358746->notifier);
+
+	return err;
+}
+
+static int tc358746_probe(struct i2c_client *client)
+{
+	struct device *dev = &client->dev;
+	struct tc358746 *tc358746;
+	unsigned long refclk;
+	unsigned int i;
+	int err;
+
+	tc358746 = devm_kzalloc(&client->dev, sizeof(*tc358746), GFP_KERNEL);
+	if (!tc358746)
+		return -ENOMEM;
+
+	tc358746->regmap = devm_regmap_init_i2c(client, &tc358746_regmap_config);
+	if (IS_ERR(tc358746->regmap))
+		return dev_err_probe(dev, PTR_ERR(tc358746->regmap),
+				     "Failed to init regmap\n");
+
+	tc358746->refclk = devm_clk_get(dev, "refclk");
+	if (IS_ERR(tc358746->refclk))
+		return dev_err_probe(dev, PTR_ERR(tc358746->refclk),
+				     "Failed to get refclk\n");
+
+	err = clk_prepare_enable(tc358746->refclk);
+	if (err)
+		return dev_err_probe(dev, err,
+				     "Failed to enable refclk\n");
+
+	refclk = clk_get_rate(tc358746->refclk);
+	clk_disable_unprepare(tc358746->refclk);
+
+	if (refclk < 6 * HZ_PER_MHZ || refclk > 40 * HZ_PER_MHZ)
+		return dev_err_probe(dev, -EINVAL, "Invalid refclk range\n");
+
+	for (i = 0; i < ARRAY_SIZE(tc358746_supplies); i++)
+		tc358746->supplies[i].supply = tc358746_supplies[i];
+
+	err = devm_regulator_bulk_get(dev, ARRAY_SIZE(tc358746_supplies),
+				      tc358746->supplies);
+	if (err)
+		return dev_err_probe(dev, err, "Failed to get supplies\n");
+
+	tc358746->reset_gpio = devm_gpiod_get_optional(dev, "reset",
+						       GPIOD_OUT_HIGH);
+	if (IS_ERR(tc358746->reset_gpio))
+		return dev_err_probe(dev, PTR_ERR(tc358746->reset_gpio),
+				     "Failed to get reset-gpios\n");
+
+	err = tc358746_init_subdev(tc358746, client);
+	if (err)
+		return dev_err_probe(dev, err, "Failed to init subdev\n");
+
+	err = tc358746_init_output_port(tc358746, refclk);
+	if (err)
+		goto err_subdev;
+
+	/*
+	 * Keep this order since we need the output port link-frequencies
+	 * information.
+	 */
+	err = tc358746_init_controls(tc358746);
+	if (err)
+		goto err_fwnode;
+
+	dev_set_drvdata(dev, tc358746);
+
+	/* Set to 1sec to give the stream reconfiguration enough time */
+	pm_runtime_set_autosuspend_delay(dev, 1000);
+	pm_runtime_use_autosuspend(dev);
+	pm_runtime_enable(dev);
+
+	err = tc358746_init_hw(tc358746);
+	if (err)
+		goto err_pm;
+
+	err = tc358746_setup_mclk_provider(tc358746);
+	if (err)
+		goto err_pm;
+
+	err = tc358746_async_register(tc358746);
+	if (err < 0)
+		goto err_pm;
+
+	dev_dbg(dev, "%s found @ 0x%x (%s)\n", client->name,
+		client->addr, client->adapter->name);
+
+	return 0;
+
+err_pm:
+	pm_runtime_disable(dev);
+	pm_runtime_set_suspended(dev);
+	pm_runtime_dont_use_autosuspend(dev);
+	v4l2_ctrl_handler_free(&tc358746->ctrl_hdl);
+err_fwnode:
+	v4l2_fwnode_endpoint_free(&tc358746->csi_vep);
+err_subdev:
+	v4l2_subdev_cleanup(&tc358746->sd);
+	media_entity_cleanup(&tc358746->sd.entity);
+
+	return err;
+}
+
+static int tc358746_remove(struct i2c_client *client)
+{
+	struct v4l2_subdev *sd = i2c_get_clientdata(client);
+	struct tc358746 *tc358746 = to_tc358746(sd);
+
+	v4l2_subdev_cleanup(sd);
+	v4l2_ctrl_handler_free(&tc358746->ctrl_hdl);
+	v4l2_fwnode_endpoint_free(&tc358746->csi_vep);
+	v4l2_async_nf_unregister(&tc358746->notifier);
+	v4l2_async_nf_cleanup(&tc358746->notifier);
+	fwnode_handle_put(sd->fwnode);
+	v4l2_async_unregister_subdev(sd);
+	media_entity_cleanup(&sd->entity);
+
+	pm_runtime_disable(sd->dev);
+	pm_runtime_set_suspended(sd->dev);
+	pm_runtime_dont_use_autosuspend(sd->dev);
+
+	return 0;
+}
+
+static int tc358746_suspend(struct device *dev)
+{
+	struct tc358746 *tc358746 = dev_get_drvdata(dev);
+	int err;
+
+	clk_disable_unprepare(tc358746->refclk);
+
+	err = regulator_bulk_disable(ARRAY_SIZE(tc358746_supplies),
+				     tc358746->supplies);
+	if (err)
+		clk_prepare_enable(tc358746->refclk);
+
+	return err;
+}
+
+static int tc358746_resume(struct device *dev)
+{
+	struct tc358746 *tc358746 = dev_get_drvdata(dev);
+	int err;
+
+	gpiod_set_value(tc358746->reset_gpio, 1);
+
+	err = regulator_bulk_enable(ARRAY_SIZE(tc358746_supplies),
+				    tc358746->supplies);
+	if (err)
+		return err;
+
+	/* min. 200ns */
+	usleep_range(10, 20);
+
+	gpiod_set_value(tc358746->reset_gpio, 0);
+
+	err = clk_prepare_enable(tc358746->refclk);
+	if (err)
+		goto err;
+
+	/* min. 700us ... 1ms */
+	usleep_range(1000, 1500);
+
+	/*
+	 * Enable the PLL here since it can be called by the clk-framework or by
+	 * the .s_stream() callback. So this is the common place for both.
+	 */
+	err = tc358746_apply_pll_config(tc358746);
+	if (err)
+		goto err_clk;
+
+	return 0;
+
+err_clk:
+	clk_disable_unprepare(tc358746->refclk);
+err:
+	regulator_bulk_disable(ARRAY_SIZE(tc358746_supplies),
+			       tc358746->supplies);
+	return err;
+}
+
+DEFINE_RUNTIME_DEV_PM_OPS(tc358746_pm_ops, tc358746_suspend,
+			  tc358746_resume, NULL);
+
+static const struct of_device_id __maybe_unused tc358746_of_match[] = {
+	{ .compatible = "toshiba,tc358746" },
+	{ },
+};
+MODULE_DEVICE_TABLE(of, tc358746_of_match);
+
+static struct i2c_driver tc358746_driver = {
+	.driver = {
+		.name = "tc358746",
+		.pm = pm_ptr(&tc358746_pm_ops),
+		.of_match_table = tc358746_of_match,
+	},
+	.probe_new = tc358746_probe,
+	.remove = tc358746_remove,
+};
+
+module_i2c_driver(tc358746_driver);
+
+MODULE_DESCRIPTION("Toshiba TC358746 Parallel to CSI-2 bridge driver");
+MODULE_AUTHOR("Marco Felsch <kernel@pengutronix.de>");
+MODULE_LICENSE("GPL");
-- 
2.30.2

[PATCH v3 4/4] media: tc358746: add Toshiba TC358746 Parallel to CSI-2 bridge driver

[Marco Felsch]

Adding support for the TC358746 parallel <-> MIPI CSI bridge. This chip
supports two operating modes:
  1st) parallel-in -> mipi-csi out
  2nd) mipi-csi in -> parallel out

This patch only adds the support for the 1st mode.

Signed-off-by: Marco Felsch <m.felsch@pengutronix.de>
---
Changelog:

v3:
- added missing static
- drop s/MHZ/HZ_PER_MHZ/
- kconfig: add "depends on PM"
- Add tc358746_valid_reg() for regmap.
- tc358746_set_fmt: fix format negotiation for pad == SOURCE
- tc358746_write/read: add error messages
- replace udelay with fsleep()
- tc358746_apply_misc_config: const mbusfmt
- tc358746_s_stream: fix comment about LP-00/11 state change
- tc358746_link_validate: s/sensor/source/
- tc358746_link_validate: s/pclk_rate/link_freq/
- tc358746_link_validate: fix v4l2_subdev_unlock_state()
- tc358746_link_validate: adapt fifo-sz comment
- tc358746_g/s_register: use pm_runtime_get_if_in_use
- tc358746_setup_mclk_provider: move to clk related location
- tc358746_init_hw: fix error case
- tc358746_init_controls: add comment
- tc358746_notify_bound: add MEDIA_LNK_FL_IMMUTABLE
- tc358746_async_register: fix error path
- tc358746_async_register: put sd.fwnode on error and remove
- tc358746_probe: increase autosuspend to 1s

v2:
- use the correct CID_LINK_FREQ control to query the sensor_pclk_rate
- remove now not needed tc358746_link_setup() and
  struct v4l2_ctrl sensor_pclk_ctrl
- call v4l2_subdev_link_validate_default() during link validation
- remove MEDIA_BUS_FMT_GBR888_1X24/YUV444 format support
- use subdev active_state API
- replace own .get_fmt with v4l2_subdev_get_fmt
- remove unnecessary pad checks
- restructure tc358746_get_format_by_code() if-case
- move apply_dphy_config|apply_misc_config from resume intos s_stream
- use goto in s_stream enable case
- fix error handling in suspend/resume
- split probe() into more sub-functions
---
 drivers/media/i2c/Kconfig    |   17 +
 drivers/media/i2c/Makefile   |    1 +
 drivers/media/i2c/tc358746.c | 1692 ++++++++++++++++++++++++++++++++++
 3 files changed, 1710 insertions(+)
 create mode 100644 drivers/media/i2c/tc358746.c

diff --git a/drivers/media/i2c/Kconfig b/drivers/media/i2c/Kconfig
index 7806d4b81716..f85cdb94c524 100644
--- a/drivers/media/i2c/Kconfig
+++ b/drivers/media/i2c/Kconfig
@@ -1272,6 +1272,23 @@ config VIDEO_TC358743_CEC
 	  When selected the tc358743 will support the optional
 	  HDMI CEC feature.
 
+config VIDEO_TC358746
+	tristate "Toshiba TC358746 parallel-CSI2 bridge"
+	depends on VIDEO_DEV && PM && I2C
+	select VIDEO_V4L2_SUBDEV_API
+	select MEDIA_CONTROLLER
+	select V4L2_FWNODE
+	select GENERIC_PHY_MIPI_DPHY
+	select REGMAP_I2C
+	select COMMON_CLK
+	help
+	  Support for the Toshiba TC358746 parallel to MIPI CSI-2 bridge.
+	  The bridge can work in both directions but currently only the
+	  parallel-in / csi-out path is supported.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called tc358746.
+
 config VIDEO_TVP514X
 	tristate "Texas Instruments TVP514x video decoder"
 	depends on VIDEO_DEV && I2C
diff --git a/drivers/media/i2c/Makefile b/drivers/media/i2c/Makefile
index 0a2933103dd9..d1096c2ab480 100644
--- a/drivers/media/i2c/Makefile
+++ b/drivers/media/i2c/Makefile
@@ -118,6 +118,7 @@ obj-$(CONFIG_VIDEO_SONY_BTF_MPX) += sony-btf-mpx.o
 obj-$(CONFIG_VIDEO_SR030PC30) += sr030pc30.o
 obj-$(CONFIG_VIDEO_ST_MIPID02) += st-mipid02.o
 obj-$(CONFIG_VIDEO_TC358743) += tc358743.o
+obj-$(CONFIG_VIDEO_TC358746) += tc358746.o
 obj-$(CONFIG_VIDEO_TDA1997X) += tda1997x.o
 obj-$(CONFIG_VIDEO_TDA7432) += tda7432.o
 obj-$(CONFIG_VIDEO_TDA9840) += tda9840.o
diff --git a/drivers/media/i2c/tc358746.c b/drivers/media/i2c/tc358746.c
new file mode 100644
index 000000000000..0dcd5e0e0855
--- /dev/null
+++ b/drivers/media/i2c/tc358746.c
@@ -0,0 +1,1692 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * TC358746 - Parallel <-> CSI-2 Bridge
+ *
+ * Copyright 2022 Marco Felsch <kernel@pengutronix.de>
+ *
+ * Notes:
+ *  - Currently only 'Parallel-in -> CSI-out' mode is supported!
+ */
+
+#include <linux/bitfield.h>
+#include <linux/clk.h>
+#include <linux/clk-provider.h>
+#include <linux/delay.h>
+#include <linux/i2c.h>
+#include <linux/interrupt.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/phy/phy-mipi-dphy.h>
+#include <linux/property.h>
+#include <linux/pm_runtime.h>
+#include <linux/regmap.h>
+#include <linux/units.h>
+#include <media/v4l2-ctrls.h>
+#include <media/v4l2-device.h>
+#include <media/v4l2-fwnode.h>
+#include <media/v4l2-mc.h>
+
+/* 16-bit registers */
+#define CHIPID_REG			0x0000
+#define		CHIPID			GENMASK(15, 8)
+
+#define SYSCTL_REG			0x0002
+#define		SRESET			BIT(0)
+
+#define CONFCTL_REG			0x0004
+#define		PDATAF_MASK		GENMASK(9, 8)
+#define		PDATAF_MODE0		0
+#define		PDATAF_MODE1		1
+#define		PDATAF_MODE2		2
+#define		PDATAF(val)		FIELD_PREP(PDATAF_MASK, (val))
+#define		PPEN			BIT(6)
+#define		DATALANE_MASK		GENMASK(1, 0)
+
+#define FIFOCTL_REG			0x0006
+#define DATAFMT_REG			0x0008
+#define		PDFMT(val)		FIELD_PREP(GENMASK(7, 4), (val))
+
+#define MCLKCTL_REG			0x000c
+#define		MCLK_HIGH_MASK		GENMASK(15, 8)
+#define		MCLK_LOW_MASK		GENMASK(7, 0)
+#define		MCLK_HIGH(val)		FIELD_PREP(MCLK_HIGH_MASK, (val))
+#define		MCLK_LOW(val)		FIELD_PREP(MCLK_LOW_MASK, (val))
+
+#define PLLCTL0_REG			0x0016
+#define		PLL_PRD_MASK		GENMASK(15, 12)
+#define		PLL_PRD(val)		FIELD_PREP(PLL_PRD_MASK, (val))
+#define		PLL_FBD_MASK		GENMASK(8, 0)
+#define		PLL_FBD(val)		FIELD_PREP(PLL_FBD_MASK, (val))
+
+#define PLLCTL1_REG			0x0018
+#define		PLL_FRS_MASK		GENMASK(11, 10)
+#define		PLL_FRS(val)		FIELD_PREP(PLL_FRS_MASK, (val))
+#define		CKEN			BIT(4)
+#define		RESETB			BIT(1)
+#define		PLL_EN			BIT(0)
+
+#define CLKCTL_REG			0x0020
+#define		MCLKDIV_MASK		GENMASK(3, 2)
+#define		MCLKDIV(val)		FIELD_PREP(MCLKDIV_MASK, (val))
+#define		MCLKDIV_8		0
+#define		MCLKDIV_4		1
+#define		MCLKDIV_2		2
+
+#define WORDCNT_REG			0x0022
+#define PP_MISC_REG			0x0032
+#define		FRMSTOP			BIT(15)
+#define		RSTPTR			BIT(14)
+
+/* 32-bit registers */
+#define CLW_DPHYCONTTX_REG		0x0100
+#define CLW_CNTRL_REG			0x0140
+#define D0W_CNTRL_REG			0x0144
+#define		LANEDISABLE		BIT(0)
+
+#define STARTCNTRL_REG			0x0204
+#define		START			BIT(0)
+
+#define LINEINITCNT_REG			0x0210
+#define LPTXTIMECNT_REG			0x0214
+#define TCLK_HEADERCNT_REG		0x0218
+#define		TCLK_ZEROCNT(val)	FIELD_PREP(GENMASK(15, 8), (val))
+#define		TCLK_PREPARECNT(val)	FIELD_PREP(GENMASK(6, 0), (val))
+
+#define TCLK_TRAILCNT_REG		0x021C
+#define THS_HEADERCNT_REG		0x0220
+#define		THS_ZEROCNT(val)	FIELD_PREP(GENMASK(14, 8), (val))
+#define		THS_PREPARECNT(val)	FIELD_PREP(GENMASK(6, 0), (val))
+
+#define TWAKEUP_REG			0x0224
+#define TCLK_POSTCNT_REG		0x0228
+#define THS_TRAILCNT_REG		0x022C
+#define HSTXVREGEN_REG			0x0234
+#define TXOPTIONCNTRL_REG		0x0238
+#define CSI_CONTROL_REG			0x040C
+#define		CSI_MODE		BIT(15)
+#define		TXHSMD			BIT(7)
+#define		NOL(val)		FIELD_PREP(GENMASK(2, 1), (val))
+
+#define CSI_CONFW_REG			0x0500
+#define		MODE(val)		FIELD_PREP(GENMASK(31, 29), (val))
+#define		MODE_SET		0x5
+#define		ADDRESS(val)		FIELD_PREP(GENMASK(28, 24), (val))
+#define		CSI_CONTROL_ADDRESS	0x3
+#define		DATA(val)		FIELD_PREP(GENMASK(15, 0), (val))
+
+#define CSI_START_REG			0x0518
+#define		STRT			BIT(0)
+
+static const struct v4l2_mbus_framefmt tc358746_def_fmt = {
+	.width		= 640,
+	.height		= 480,
+	.code		= MEDIA_BUS_FMT_UYVY8_2X8,
+	.field		= V4L2_FIELD_NONE,
+	.colorspace	= V4L2_COLORSPACE_DEFAULT,
+	.ycbcr_enc	= V4L2_YCBCR_ENC_DEFAULT,
+	.quantization	= V4L2_QUANTIZATION_DEFAULT,
+	.xfer_func	= V4L2_XFER_FUNC_DEFAULT,
+};
+
+static const char * const tc358746_supplies[] = {
+	"vddc", "vddio", "vddmipi"
+};
+
+enum {
+	TC358746_SINK,
+	TC358746_SOURCE,
+	TC358746_NR_PADS
+};
+
+struct tc358746 {
+	struct v4l2_subdev		sd;
+	struct media_pad		pads[TC358746_NR_PADS];
+	struct v4l2_async_notifier	notifier;
+	struct v4l2_fwnode_endpoint	csi_vep;
+
+	struct v4l2_ctrl_handler	ctrl_hdl;
+
+	struct regmap			*regmap;
+	struct clk			*refclk;
+	struct gpio_desc		*reset_gpio;
+	struct regulator_bulk_data	supplies[ARRAY_SIZE(tc358746_supplies)];
+
+	struct clk_hw			mclk_hw;
+	unsigned long			mclk_rate;
+	u8				mclk_prediv;
+	u16				mclk_postdiv;
+
+	unsigned long			pll_rate;
+	u8				pll_post_div;
+	u16				pll_pre_div;
+	u16				pll_mul;
+
+#define TC358746_VB_MAX_SIZE		(511 * 32)
+#define TC358746_VB_DEFAULT_SIZE	  (1 * 32)
+	unsigned int			vb_size; /* Video buffer size in bits */
+
+	struct phy_configure_opts_mipi_dphy dphy_cfg;
+};
+
+static inline struct tc358746 *to_tc358746(struct v4l2_subdev *sd)
+{
+	return container_of(sd, struct tc358746, sd);
+}
+
+static inline struct tc358746 *clk_hw_to_tc358746(struct clk_hw *hw)
+{
+	return container_of(hw, struct tc358746, mclk_hw);
+}
+
+struct tc358746_format {
+	u32		code;
+	bool		csi_format;
+	unsigned char	bus_width;
+	unsigned char	bpp;
+	/* Register values */
+	u8		pdformat; /* Peripheral Data Format */
+	u8		pdataf;   /* Parallel Data Format Option */
+};
+
+enum {
+	PDFORMAT_RAW8 = 0,
+	PDFORMAT_RAW10,
+	PDFORMAT_RAW12,
+	PDFORMAT_RGB888,
+	PDFORMAT_RGB666,
+	PDFORMAT_RGB565,
+	PDFORMAT_YUV422_8BIT,
+	/* RESERVED = 7 */
+	PDFORMAT_RAW14 = 8,
+	PDFORMAT_YUV422_10BIT,
+	PDFORMAT_YUV444,
+};
+
+/* Check tc358746_src_mbus_code() if you add new formats */
+static const struct tc358746_format tc358746_formats[] = {
+	{
+		.code = MEDIA_BUS_FMT_UYVY8_2X8,
+		.bus_width = 8,
+		.bpp = 16,
+		.pdformat = PDFORMAT_YUV422_8BIT,
+		.pdataf = PDATAF_MODE0,
+	}, {
+		.code = MEDIA_BUS_FMT_UYVY8_1X16,
+		.csi_format = true,
+		.bus_width = 16,
+		.bpp = 16,
+		.pdformat = PDFORMAT_YUV422_8BIT,
+		.pdataf = PDATAF_MODE1,
+	}, {
+		.code = MEDIA_BUS_FMT_YUYV8_1X16,
+		.csi_format = true,
+		.bus_width = 16,
+		.bpp = 16,
+		.pdformat = PDFORMAT_YUV422_8BIT,
+		.pdataf = PDATAF_MODE2,
+	}, {
+		.code = MEDIA_BUS_FMT_UYVY10_2X10,
+		.bus_width = 10,
+		.bpp = 20,
+		.pdformat = PDFORMAT_YUV422_10BIT,
+		.pdataf = PDATAF_MODE0, /* don't care */
+	}
+};
+
+/* Get n-th format for pad */
+static const struct tc358746_format *
+tc358746_get_format_by_idx(unsigned int pad, unsigned int index)
+{
+	unsigned int idx = 0;
+	unsigned int i;
+
+	for (i = 0; i < ARRAY_SIZE(tc358746_formats); i++) {
+		const struct tc358746_format *fmt = &tc358746_formats[i];
+
+		if ((pad == TC358746_SOURCE && fmt->csi_format) ||
+		    (pad == TC358746_SINK)) {
+			if (idx == index)
+				return fmt;
+			idx++;
+		}
+	}
+
+	return ERR_PTR(-EINVAL);
+}
+
+static const struct tc358746_format *
+tc358746_get_format_by_code(unsigned int pad, u32 code)
+{
+	unsigned int i;
+
+	for (i = 0; i < ARRAY_SIZE(tc358746_formats); i++) {
+		const struct tc358746_format *fmt = &tc358746_formats[i];
+
+		if (pad == TC358746_SINK && fmt->code == code)
+			return fmt;
+
+		if (pad == TC358746_SOURCE && !fmt->csi_format)
+			continue;
+
+		if (fmt->code == code)
+			return fmt;
+	}
+
+	return ERR_PTR(-EINVAL);
+}
+
+static u32 tc358746_src_mbus_code(u32 code)
+{
+	switch (code) {
+	case MEDIA_BUS_FMT_UYVY8_2X8:
+		return MEDIA_BUS_FMT_UYVY8_1X16;
+	case MEDIA_BUS_FMT_UYVY10_2X10:
+		return MEDIA_BUS_FMT_UYVY10_1X20;
+	default:
+		return code;
+	}
+}
+
+static bool tc358746_valid_reg(struct device *dev, unsigned int reg)
+{
+	switch (reg) {
+	case CHIPID_REG ... CSI_START_REG:
+		return true;
+	default:
+		return false;
+	}
+}
+
+static const struct regmap_config tc358746_regmap_config = {
+	.name = "tc358746",
+	.reg_bits = 16,
+	.val_bits = 16,
+	.max_register = CSI_START_REG,
+	.writeable_reg = tc358746_valid_reg,
+	.readable_reg = tc358746_valid_reg,
+	.reg_format_endian = REGMAP_ENDIAN_BIG,
+	.val_format_endian = REGMAP_ENDIAN_BIG,
+};
+
+static int tc358746_write(struct tc358746 *tc358746, u32 reg, u32 val)
+{
+	size_t count;
+	int err;
+
+	/* 32-bit registers starting from CLW_DPHYCONTTX */
+	count = reg < CLW_DPHYCONTTX_REG ? 1 : 2;
+
+	err = regmap_bulk_write(tc358746->regmap, reg, &val, count);
+	if (err)
+		dev_dbg(tc358746->sd.dev,
+			"Failed to write reg:0x%04x val:0x%04x\n", reg, val);
+
+	return err;
+}
+
+static int tc358746_read(struct tc358746 *tc358746, u32 reg, u32 *val)
+{
+	size_t count;
+	int err;
+
+	/* 32-bit registers starting from CLW_DPHYCONTTX */
+	count = reg < CLW_DPHYCONTTX_REG ? 1 : 2;
+	*val = 0;
+
+	err = regmap_bulk_read(tc358746->regmap, reg, val, count);
+	if (err)
+		dev_dbg(tc358746->sd.dev, "Failed to read reg:0x%04x\n", reg);
+
+	return err;
+}
+
+static int
+tc358746_update_bits(struct tc358746 *tc358746, u32 reg, u32 mask, u32 val)
+{
+	u32 tmp, orig;
+	int err;
+
+	err = tc358746_read(tc358746, reg, &orig);
+	if (err)
+		return err;
+
+	tmp = orig & ~mask;
+	tmp |= val & mask;
+
+	return tc358746_write(tc358746, reg, tmp);
+}
+
+static int tc358746_set_bits(struct tc358746 *tc358746, u32 reg, u32 bits)
+{
+	return tc358746_update_bits(tc358746, reg, bits, bits);
+}
+
+static int tc358746_clear_bits(struct tc358746 *tc358746, u32 reg, u32 bits)
+{
+	return tc358746_update_bits(tc358746, reg, bits, 0);
+}
+
+static int tc358746_sw_reset(struct tc358746 *tc358746)
+{
+	int err;
+
+	err = tc358746_set_bits(tc358746, SYSCTL_REG, SRESET);
+	if (err)
+		return err;
+
+	fsleep(10);
+
+	return tc358746_clear_bits(tc358746, SYSCTL_REG, SRESET);
+}
+
+static int
+tc358746_apply_pll_config(struct tc358746 *tc358746)
+{
+	u8 post = tc358746->pll_post_div;
+	u16 pre = tc358746->pll_pre_div;
+	u16 mul = tc358746->pll_mul;
+	u32 val, mask;
+	int err;
+
+	err = tc358746_read(tc358746, PLLCTL1_REG, &val);
+	if (err)
+		return err;
+
+	/* Don't touch the PLL if running */
+	if (FIELD_GET(PLL_EN, val) == 1)
+		return 0;
+
+	/* Pre-div and Multiplicator have a internal +1 logic */
+	val = PLL_PRD(pre - 1) | PLL_FBD(mul - 1);
+	mask = PLL_PRD_MASK | PLL_FBD_MASK;
+	err = tc358746_update_bits(tc358746, PLLCTL0_REG, mask, val);
+	if (err)
+		return err;
+
+	val = PLL_FRS(ilog2(post)) | RESETB | PLL_EN;
+	mask = PLL_FRS_MASK | RESETB | PLL_EN;
+	tc358746_update_bits(tc358746, PLLCTL1_REG, mask, val);
+	if (err)
+		return err;
+
+	fsleep(1000);
+
+	return tc358746_set_bits(tc358746, PLLCTL1_REG, CKEN);
+}
+
+static int tc358746_apply_misc_config(struct tc358746 *tc358746)
+{
+	const struct v4l2_mbus_framefmt *mbusfmt;
+	struct v4l2_subdev *sd = &tc358746->sd;
+	struct v4l2_subdev_state *sink_state;
+	const struct tc358746_format *fmt;
+	struct device *dev = sd->dev;
+	u32 val;
+	int err;
+
+	sink_state = v4l2_subdev_lock_and_get_active_state(sd);
+	mbusfmt = v4l2_subdev_get_pad_format(sd, sink_state, TC358746_SINK);
+	v4l2_subdev_unlock_state(sink_state);
+
+	fmt = tc358746_get_format_by_code(TC358746_SINK, mbusfmt->code);
+
+	/* Self defined CSI user data type id's are not supported yet */
+	val = PDFMT(fmt->pdformat);
+	dev_dbg(dev, "DATAFMT: 0x%x\n", val);
+	err = tc358746_write(tc358746, DATAFMT_REG, val);
+	if (err)
+		return err;
+
+	val = PDATAF(fmt->pdataf);
+	dev_dbg(dev, "CONFCTL[PDATAF]: 0x%x\n", fmt->pdataf);
+	err = tc358746_update_bits(tc358746, CONFCTL_REG, PDATAF_MASK, val);
+	if (err)
+		return err;
+
+	val = tc358746->vb_size / 32;
+	dev_dbg(dev, "FIFOCTL: %u (0x%x)\n", val, val);
+	err = tc358746_write(tc358746, FIFOCTL_REG, val);
+	if (err)
+		return err;
+
+	/* Total number of bytes for each line/width */
+	val = mbusfmt->width * fmt->bpp / 8;
+	dev_dbg(dev, "WORDCNT: %u (0x%x)\n", val, val);
+	return tc358746_write(tc358746, WORDCNT_REG, val);
+}
+
+/* Use MHz as base so the div needs no u64 */
+static u32 tc358746_cfg_to_cnt(unsigned int cfg_val,
+			       unsigned int clk_mhz,
+			       unsigned int time_base)
+{
+	return DIV_ROUND_UP(cfg_val * clk_mhz, time_base);
+}
+
+static u32 tc358746_ps_to_cnt(unsigned int cfg_val,
+			      unsigned int clk_mhz)
+{
+	return tc358746_cfg_to_cnt(cfg_val, clk_mhz, USEC_PER_SEC);
+}
+
+static u32 tc358746_us_to_cnt(unsigned int cfg_val,
+			      unsigned int clk_mhz)
+{
+	return tc358746_cfg_to_cnt(cfg_val, clk_mhz, 1);
+}
+
+static int tc358746_apply_dphy_config(struct tc358746 *tc358746)
+{
+	struct phy_configure_opts_mipi_dphy *cfg = &tc358746->dphy_cfg;
+	bool non_cont_clk = !!(tc358746->csi_vep.bus.mipi_csi2.flags &
+			       V4L2_MBUS_CSI2_NONCONTINUOUS_CLOCK);
+	struct device *dev = tc358746->sd.dev;
+	unsigned long hs_byte_clk, hf_clk;
+	u32 val, val2, lptxcnt;
+	int err;
+
+	/* The hs_byte_clk is also called SYSCLK in the excel sheet */
+	hs_byte_clk = cfg->hs_clk_rate / 8;
+	hs_byte_clk /= HZ_PER_MHZ;
+	hf_clk = hs_byte_clk / 2;
+
+	val = tc358746_us_to_cnt(cfg->init, hf_clk) - 1;
+	dev_dbg(dev, "LINEINITCNT: %u (0x%x)\n", val, val);
+	err = tc358746_write(tc358746, LINEINITCNT_REG, val);
+	if (err)
+		return err;
+
+	val = tc358746_ps_to_cnt(cfg->lpx, hs_byte_clk) - 1;
+	lptxcnt = val;
+	dev_dbg(dev, "LPTXTIMECNT: %u (0x%x)\n", val, val);
+	err = tc358746_write(tc358746, LPTXTIMECNT_REG, val);
+	if (err)
+		return err;
+
+	val = tc358746_ps_to_cnt(cfg->clk_prepare, hs_byte_clk) - 1;
+	val2 = tc358746_ps_to_cnt(cfg->clk_zero, hs_byte_clk) - 1;
+	dev_dbg(dev, "TCLK_PREPARECNT: %u (0x%x)\n", val, val);
+	dev_dbg(dev, "TCLK_ZEROCNT: %u (0x%x)\n", val2, val2);
+	dev_dbg(dev, "TCLK_HEADERCNT: 0x%x\n",
+		(u32)(TCLK_PREPARECNT(val) | TCLK_ZEROCNT(val2)));
+	err = tc358746_write(tc358746, TCLK_HEADERCNT_REG,
+			     TCLK_PREPARECNT(val) | TCLK_ZEROCNT(val2));
+	if (err)
+		return err;
+
+	val = tc358746_ps_to_cnt(cfg->clk_trail, hs_byte_clk);
+	dev_dbg(dev, "TCLK_TRAILCNT: %u (0x%x)\n", val, val);
+	err = tc358746_write(tc358746, TCLK_TRAILCNT_REG, val);
+	if (err)
+		return err;
+
+	val = tc358746_ps_to_cnt(cfg->hs_prepare, hs_byte_clk) - 1;
+	val2 = tc358746_ps_to_cnt(cfg->hs_zero, hs_byte_clk) - 1;
+	dev_dbg(dev, "THS_PREPARECNT: %u (0x%x)\n", val, val);
+	dev_dbg(dev, "THS_ZEROCNT: %u (0x%x)\n", val2, val2);
+	dev_dbg(dev, "THS_HEADERCNT: 0x%x\n",
+		(u32)(THS_PREPARECNT(val) | THS_ZEROCNT(val2)));
+	err = tc358746_write(tc358746, THS_HEADERCNT_REG,
+			     THS_PREPARECNT(val) | THS_ZEROCNT(val2));
+	if (err)
+		return err;
+
+	/* TWAKEUP > 1ms in lptxcnt steps */
+	val = tc358746_us_to_cnt(cfg->wakeup, hs_byte_clk);
+	val = val / (lptxcnt + 1) - 1;
+	dev_dbg(dev, "TWAKEUP: %u (0x%x)\n", val, val);
+	err = tc358746_write(tc358746, TWAKEUP_REG, val);
+	if (err)
+		return err;
+
+	val = tc358746_ps_to_cnt(cfg->clk_post, hs_byte_clk);
+	dev_dbg(dev, "TCLK_POSTCNT: %u (0x%x)\n", val, val);
+	err = tc358746_write(tc358746, TCLK_POSTCNT_REG, val);
+	if (err)
+		return err;
+
+	val = tc358746_ps_to_cnt(cfg->hs_trail, hs_byte_clk);
+	dev_dbg(dev, "THS_TRAILCNT: %u (0x%x)\n", val, val);
+	err = tc358746_write(tc358746, THS_TRAILCNT_REG, val);
+	if (err)
+		return err;
+
+	dev_dbg(dev, "CONTCLKMODE: %u", non_cont_clk ? 0 : 1);
+	return  tc358746_write(tc358746, TXOPTIONCNTRL_REG, non_cont_clk ? 0 : 1);
+}
+
+#define MAX_DATA_LANES 4
+
+static int tc358746_enable_csi_lanes(struct tc358746 *tc358746, int enable)
+{
+	unsigned int lanes = tc358746->dphy_cfg.lanes;
+	unsigned int lane;
+	u32 reg, val;
+	int err;
+
+	err = tc358746_update_bits(tc358746, CONFCTL_REG, DATALANE_MASK,
+				   lanes - 1);
+	if (err)
+		return err;
+
+	/* Clock lane */
+	val = enable ? 0 : LANEDISABLE;
+	dev_dbg(tc358746->sd.dev, "CLW_CNTRL: 0x%x\n", val);
+	err = tc358746_write(tc358746, CLW_CNTRL_REG, val);
+	if (err)
+		return err;
+
+	for (lane = 0; lane < MAX_DATA_LANES; lane++) {
+		/* Data lanes */
+		reg = D0W_CNTRL_REG + lane * 0x4;
+		val = (enable && lane < lanes) ? 0 : LANEDISABLE;
+
+		dev_dbg(tc358746->sd.dev, "D%uW_CNTRL: 0x%x\n", lane, val);
+		err = tc358746_write(tc358746, reg, val);
+		if (err)
+			return err;
+	}
+
+	val = 0;
+	if (enable) {
+		/* Clock lane */
+		val |= BIT(0);
+
+		/* Data lanes */
+		for (lane = 1; lane <= lanes; lane++)
+			val |= BIT(lane);
+	}
+
+	dev_dbg(tc358746->sd.dev, "HSTXVREGEN: 0x%x\n", val);
+	return tc358746_write(tc358746, HSTXVREGEN_REG, val);
+}
+
+static int tc358746_enable_csi_module(struct tc358746 *tc358746, int enable)
+{
+	unsigned int lanes = tc358746->dphy_cfg.lanes;
+	int err;
+
+	/*
+	 * START and STRT are only reseted/disabled by sw reset. This is
+	 * required to put the lane state back into LP-11 state. The sw reset
+	 * don't reset register values.
+	 */
+	if (!enable)
+		return tc358746_sw_reset(tc358746);
+
+	err = tc358746_write(tc358746, STARTCNTRL_REG, START);
+	if (err)
+		return err;
+
+	err = tc358746_write(tc358746, CSI_START_REG, STRT);
+	if (err)
+		return err;
+
+	/* CSI_CONTROL_REG is only indirect accessible */
+	return tc358746_write(tc358746, CSI_CONFW_REG,
+			      MODE(MODE_SET) |
+			      ADDRESS(CSI_CONTROL_ADDRESS) |
+			      DATA(CSI_MODE | TXHSMD | NOL(lanes - 1)));
+}
+
+static int tc358746_enable_parallel_port(struct tc358746 *tc358746, int enable)
+{
+	int err;
+
+	if (enable) {
+		err = tc358746_write(tc358746, PP_MISC_REG, 0);
+		if (err)
+			return err;
+
+		return tc358746_set_bits(tc358746, CONFCTL_REG, PPEN);
+	}
+
+	err = tc358746_set_bits(tc358746, PP_MISC_REG, FRMSTOP);
+	if (err)
+		return err;
+
+	err = tc358746_clear_bits(tc358746, CONFCTL_REG, PPEN);
+	if (err)
+		return err;
+
+	return tc358746_set_bits(tc358746, PP_MISC_REG, RSTPTR);
+}
+
+static inline struct v4l2_subdev *tc358746_get_remote_sd(struct media_pad *pad)
+{
+	pad = media_pad_remote_pad_first(pad);
+	if (!pad)
+		return NULL;
+
+	return media_entity_to_v4l2_subdev(pad->entity);
+}
+
+static int tc358746_s_stream(struct v4l2_subdev *sd, int enable)
+{
+	struct tc358746 *tc358746 = to_tc358746(sd);
+	struct v4l2_subdev *src;
+	int err;
+
+	dev_dbg(sd->dev, "%sable\n", enable ? "en" : "dis");
+
+	src = tc358746_get_remote_sd(&tc358746->pads[TC358746_SINK]);
+	if (!src)
+		return -EPIPE;
+
+	if (enable) {
+		err = pm_runtime_resume_and_get(sd->dev);
+		if (err)
+			return err;
+
+		err = tc358746_apply_dphy_config(tc358746);
+		if (err)
+			goto err_out;
+
+		err = tc358746_apply_misc_config(tc358746);
+		if (err)
+			goto err_out;
+
+		err = tc358746_enable_csi_lanes(tc358746, 1);
+		if (err)
+			goto err_out;
+
+		err = tc358746_enable_csi_module(tc358746, 1);
+		if (err)
+			goto err_out;
+
+		err = tc358746_enable_parallel_port(tc358746, 1);
+		if (err)
+			goto err_out;
+
+		err = v4l2_subdev_call(src, video, s_stream, 1);
+		if (err)
+			goto err_out;
+
+		return err;
+
+err_out:
+		pm_runtime_mark_last_busy(sd->dev);
+		pm_runtime_put_sync_autosuspend(sd->dev);
+
+		return err;
+	}
+
+	 /*
+	  * The lanes must be disabled first (before the csi module) so the
+	  * LP-11 state is entered correctly.
+	  */
+	err = tc358746_enable_csi_lanes(tc358746, 0);
+	if (err)
+		return err;
+
+	err = tc358746_enable_csi_module(tc358746, 0);
+	if (err)
+		return err;
+
+	err = tc358746_enable_parallel_port(tc358746, 0);
+	if (err)
+		return err;
+
+	pm_runtime_mark_last_busy(sd->dev);
+	pm_runtime_put_sync_autosuspend(sd->dev);
+
+	return v4l2_subdev_call(src, video, s_stream, 0);
+}
+
+static int tc358746_init_cfg(struct v4l2_subdev *sd,
+			     struct v4l2_subdev_state *state)
+{
+	struct v4l2_mbus_framefmt *fmt;
+
+	fmt = v4l2_subdev_get_pad_format(sd, state, TC358746_SINK);
+	*fmt = tc358746_def_fmt;
+
+	fmt = v4l2_subdev_get_pad_format(sd, state, TC358746_SOURCE);
+	*fmt = tc358746_def_fmt;
+	fmt->code = tc358746_src_mbus_code(tc358746_def_fmt.code);
+
+	return 0;
+}
+
+static int tc358746_enum_mbus_code(struct v4l2_subdev *sd,
+				   struct v4l2_subdev_state *sd_state,
+				   struct v4l2_subdev_mbus_code_enum *code)
+{
+	const struct tc358746_format *fmt;
+
+	fmt = tc358746_get_format_by_idx(code->pad, code->index);
+	if (IS_ERR(fmt))
+		return PTR_ERR(fmt);
+
+	code->code = fmt->code;
+
+	return 0;
+}
+
+static int tc358746_set_fmt(struct v4l2_subdev *sd,
+			    struct v4l2_subdev_state *sd_state,
+			    struct v4l2_subdev_format *format)
+{
+	struct v4l2_mbus_framefmt *src_fmt, *sink_fmt;
+	const struct tc358746_format *fmt;
+
+	/* Source follows the sink */
+	if (format->pad == TC358746_SOURCE)
+		return v4l2_subdev_get_fmt(sd, sd_state, format);
+
+	sink_fmt = v4l2_subdev_get_pad_format(sd, sd_state, TC358746_SINK);
+
+	fmt = tc358746_get_format_by_code(format->pad, format->format.code);
+	if (IS_ERR(fmt))
+		fmt = tc358746_get_format_by_code(format->pad, tc358746_def_fmt.code);
+
+	format->format.code = fmt->code;
+	format->format.field = V4L2_FIELD_NONE;
+
+	dev_dbg(sd->dev, "Update format: %ux%u code:0x%x -> %ux%u code:0x%x",
+		sink_fmt->width, sink_fmt->height, sink_fmt->code,
+		format->format.width, format->format.height, format->format.code);
+
+	*sink_fmt = format->format;
+
+	src_fmt = v4l2_subdev_get_pad_format(sd, sd_state, TC358746_SOURCE);
+	*src_fmt = *sink_fmt;
+	src_fmt->code = tc358746_src_mbus_code(sink_fmt->code);
+
+	return 0;
+}
+
+static unsigned long tc358746_find_pll_settings(struct tc358746 *tc358746,
+						unsigned long refclk,
+						unsigned long fout)
+
+{
+	struct device *dev = tc358746->sd.dev;
+	unsigned long best_freq = 0;
+	u32 min_delta = 0xffffffff;
+	u16 prediv_max = 17;
+	u16 prediv_min = 1;
+	u16 m_best, mul;
+	u16 p_best, p;
+	u8 postdiv;
+
+	if (fout > 1000 * HZ_PER_MHZ) {
+		dev_err(dev, "HS-Clock above 1 Ghz are not supported\n");
+		return 0;
+	}
+
+	if (fout >= 500 * HZ_PER_MHZ)
+		postdiv = 1;
+	else if (fout >= 250 * HZ_PER_MHZ)
+		postdiv = 2;
+	else if (fout >= 125 * HZ_PER_MHZ)
+		postdiv = 4;
+	else
+		postdiv = 8;
+
+	for (p = prediv_min; p <= prediv_max; p++) {
+		unsigned long delta, fin;
+		u64 tmp;
+
+		fin = DIV_ROUND_CLOSEST(refclk, p);
+		if (fin < 4 * HZ_PER_MHZ || fin > 40 * HZ_PER_MHZ)
+			continue;
+
+		tmp = fout * p * postdiv;
+		do_div(tmp, fin);
+		mul = tmp;
+		if (mul > 511)
+			continue;
+
+		tmp = mul * fin;
+		do_div(tmp, p * postdiv);
+
+		delta = abs(fout - tmp);
+		if (delta < min_delta) {
+			p_best = p;
+			m_best = mul;
+			min_delta = delta;
+			best_freq = tmp;
+		};
+
+		if (delta == 0)
+			break;
+	};
+
+	if (!best_freq) {
+		dev_err(dev, "Failed find PLL frequency\n");
+		return 0;
+	}
+
+	tc358746->pll_post_div = postdiv;
+	tc358746->pll_pre_div = p_best;
+	tc358746->pll_mul = m_best;
+
+	if (best_freq != fout)
+		dev_warn(dev, "Request PLL freq:%lu, found PLL freq:%lu\n",
+			 fout, best_freq);
+
+	dev_dbg(dev, "Found PLL settings: freq:%lu prediv:%u multi:%u postdiv:%u\n",
+		best_freq, p_best, m_best, postdiv);
+
+	return best_freq;
+}
+
+#define TC358746_PRECISION 10
+
+static int
+tc358746_link_validate(struct v4l2_subdev *sd, struct media_link *link,
+		       struct v4l2_subdev_format *source_fmt,
+		       struct v4l2_subdev_format *sink_fmt)
+{
+	struct tc358746 *tc358746 = to_tc358746(sd);
+	unsigned long csi_bitrate, source_bitrate;
+	struct v4l2_subdev_state *sink_state;
+	struct v4l2_mbus_framefmt *mbusfmt;
+	const struct tc358746_format *fmt;
+	unsigned int fifo_sz, tmp, n;
+	struct v4l2_subdev *source;
+	s64 source_link_freq;
+	int err;
+
+	err = v4l2_subdev_link_validate_default(sd, link, source_fmt, sink_fmt);
+	if (err)
+		return err;
+
+	sink_state = v4l2_subdev_lock_and_get_active_state(sd);
+	mbusfmt = v4l2_subdev_get_pad_format(sd, sink_state, TC358746_SINK);
+
+	/* Check the FIFO settings */
+	fmt = tc358746_get_format_by_code(TC358746_SINK, mbusfmt->code);
+
+	source = media_entity_to_v4l2_subdev(link->source->entity);
+	source_link_freq = v4l2_get_link_freq(source->ctrl_handler, 0, 0);
+	if (source_link_freq <= 0) {
+		dev_err(tc358746->sd.dev,
+			"Failed to query or invalid source link frequency\n");
+		v4l2_subdev_unlock_state(sink_state);
+		/* Return -EINVAL in case of source_link_freq is 0 */
+		return source_link_freq ? : -EINVAL;
+	}
+	source_bitrate = source_link_freq * fmt->bus_width;
+
+	csi_bitrate = tc358746->dphy_cfg.lanes * tc358746->pll_rate;
+
+	dev_dbg(tc358746->sd.dev,
+		"Fifo settings params: source-bitrate:%lu csi-bitrate:%lu",
+		source_bitrate, csi_bitrate);
+
+	/* Avoid possible FIFO overflows */
+	if (csi_bitrate < source_bitrate) {
+		v4l2_subdev_unlock_state(sink_state);
+		return -EINVAL;
+	}
+
+	/* Best case */
+	if (csi_bitrate == source_bitrate) {
+		fifo_sz = TC358746_VB_DEFAULT_SIZE;
+		tc358746->vb_size = TC358746_VB_DEFAULT_SIZE;
+		goto out;
+	}
+
+	/*
+	 * Avoid possible FIFO underflow in case of
+	 * csi_bitrate > source_bitrate. For such case the chip has a internal
+	 * fifo which can be used to delay the line output.
+	 *
+	 * Fifo size calculation (excluding precision):
+	 *
+	 * fifo-sz, image-width - in bits
+	 * sbr                  - source_bitrate in bits/s
+	 * csir                 - csi_bitrate in bits/s
+	 *
+	 *                1               1      1
+	 * image-width * --- + fifo-sz * --- >= ---- * image-width
+	 *               sbr             sbr    csir
+	 *
+	 * fifo-sz >= abs(sbr/csir * image-width - image-width); with n = csir/sbr
+	 *
+	 * fifo-sz >= abs(image-width / n - image-width)
+	 *         >= image-width - image-width / n
+	 */
+
+	source_bitrate /= TC358746_PRECISION;
+	n = csi_bitrate / source_bitrate;
+	tmp = (mbusfmt->width * TC358746_PRECISION) / n;
+	fifo_sz = mbusfmt->width - tmp;
+	fifo_sz *= fmt->bpp;
+	tc358746->vb_size = round_up(fifo_sz, 32);
+
+out:
+	dev_dbg(tc358746->sd.dev,
+		"Found FIFO size[bits]:%u -> aligned to size[bits]:%u\n",
+		fifo_sz, tc358746->vb_size);
+
+	v4l2_subdev_unlock_state(sink_state);
+
+	return tc358746->vb_size > TC358746_VB_MAX_SIZE ? -EINVAL : 0;
+}
+
+static int tc358746_get_mbus_config(struct v4l2_subdev *sd, unsigned int pad,
+				    struct v4l2_mbus_config *config)
+{
+	struct tc358746 *tc358746 = to_tc358746(sd);
+
+	if (pad != TC358746_SOURCE)
+		return -EINVAL;
+
+	config->type = V4L2_MBUS_CSI2_DPHY;
+	config->bus.mipi_csi2 = tc358746->csi_vep.bus.mipi_csi2;
+
+	return 0;
+}
+
+static int __maybe_unused
+tc358746_g_register(struct v4l2_subdev *sd, struct v4l2_dbg_register *reg)
+{
+	struct tc358746 *tc358746 = to_tc358746(sd);
+
+	/* 32-bit registers starting from CLW_DPHYCONTTX */
+	reg->size = reg->reg < CLW_DPHYCONTTX_REG ? 2 : 4;
+
+	if (!pm_runtime_get_if_in_use(sd->dev))
+		return 0;
+
+	tc358746_read(tc358746, reg->reg, (u32 *)&reg->val);
+
+	pm_runtime_mark_last_busy(sd->dev);
+	pm_runtime_put_sync_autosuspend(sd->dev);
+
+	return 0;
+}
+
+static int __maybe_unused
+tc358746_s_register(struct v4l2_subdev *sd, const struct v4l2_dbg_register *reg)
+{
+	struct tc358746 *tc358746 = to_tc358746(sd);
+
+	if (!pm_runtime_get_if_in_use(sd->dev))
+		return 0;
+
+	tc358746_write(tc358746, (u32)reg->reg, (u32)reg->val);
+
+	pm_runtime_mark_last_busy(sd->dev);
+	pm_runtime_put_sync_autosuspend(sd->dev);
+
+	return 0;
+}
+
+static const struct v4l2_subdev_core_ops tc358746_core_ops = {
+#ifdef CONFIG_VIDEO_ADV_DEBUG
+	.g_register = tc358746_g_register,
+	.s_register = tc358746_s_register,
+#endif
+};
+
+static const struct v4l2_subdev_video_ops tc358746_video_ops = {
+	.s_stream = tc358746_s_stream,
+};
+
+static const struct v4l2_subdev_pad_ops tc358746_pad_ops = {
+	.init_cfg = tc358746_init_cfg,
+	.enum_mbus_code = tc358746_enum_mbus_code,
+	.set_fmt = tc358746_set_fmt,
+	.get_fmt = v4l2_subdev_get_fmt,
+	.link_validate = tc358746_link_validate,
+	.get_mbus_config = tc358746_get_mbus_config,
+};
+
+static const struct v4l2_subdev_ops tc358746_ops = {
+	.core = &tc358746_core_ops,
+	.video = &tc358746_video_ops,
+	.pad = &tc358746_pad_ops,
+};
+
+static const struct media_entity_operations tc358746_entity_ops = {
+	.get_fwnode_pad = v4l2_subdev_get_fwnode_pad_1_to_1,
+	.link_validate = v4l2_subdev_link_validate,
+};
+
+static int tc358746_mclk_enable(struct clk_hw *hw)
+{
+	struct tc358746 *tc358746 = clk_hw_to_tc358746(hw);
+	unsigned int div;
+	u32 val;
+	int err;
+
+	div = tc358746->mclk_postdiv / 2;
+	val = MCLK_HIGH(div - 1) | MCLK_LOW(div - 1);
+	dev_dbg(tc358746->sd.dev, "MCLKCTL: %u (0x%x)\n", val, val);
+	err = tc358746_write(tc358746, MCLKCTL_REG, val);
+	if (err)
+		return err;
+
+	if (tc358746->mclk_prediv == 8)
+		val = MCLKDIV(MCLKDIV_8);
+	else if (tc358746->mclk_prediv == 4)
+		val = MCLKDIV(MCLKDIV_4);
+	else
+		val = MCLKDIV(MCLKDIV_2);
+
+	dev_dbg(tc358746->sd.dev, "CLKCTL[MCLKDIV]: %u (0x%x)\n", val, val);
+	return tc358746_update_bits(tc358746, CLKCTL_REG, MCLKDIV_MASK, val);
+}
+
+static void tc358746_mclk_disable(struct clk_hw *hw)
+{
+	struct tc358746 *tc358746 = clk_hw_to_tc358746(hw);
+
+	tc358746_write(tc358746, MCLKCTL_REG, 0);
+}
+
+static long
+tc358746_find_mclk_settings(struct tc358746 *tc358746, unsigned long mclk_rate)
+{
+	unsigned long pll_rate = tc358746->pll_rate;
+	const unsigned char prediv[] = { 2, 4, 8 };
+	unsigned int mclk_prediv, mclk_postdiv;
+	struct device *dev = tc358746->sd.dev;
+	unsigned int postdiv, mclkdiv;
+	unsigned long best_mclk_rate;
+	unsigned int i;
+
+	/*
+	 *                          MCLK-Div
+	 *           -------------------´`---------------------
+	 *          ´                                          `
+	 *         +-------------+     +------------------------+
+	 *         | MCLK-PreDiv |     |       MCLK-PostDiv     |
+	 * PLL --> |   (2/4/8)   | --> | (mclk_low + mclk_high) | --> MCLK
+	 *         +-------------+     +------------------------+
+	 *
+	 * The register value of mclk_low/high is mclk_low/high+1, i.e.:
+	 *   mclk_low/high = 1   --> 2 MCLK-Ref Counts
+	 *   mclk_low/high = 255 --> 256 MCLK-Ref Counts == max.
+	 * If mclk_low and mclk_high are 0 then MCLK is disabled.
+	 *
+	 * Keep it simple and support 50/50 duty cycles only for now,
+	 * so the calc will be:
+	 *
+	 *   MCLK = PLL / (MCLK-PreDiv * 2 * MCLK-PostDiv)
+	 */
+
+	if (mclk_rate == tc358746->mclk_rate)
+		return mclk_rate;
+
+	/* Highest possible rate */
+	mclkdiv = pll_rate / mclk_rate;
+	if (mclkdiv <= 8) {
+		mclk_prediv = 2;
+		mclk_postdiv = 4;
+		best_mclk_rate = pll_rate / (2 * 4);
+		goto out;
+	}
+
+	/* First check the prediv */
+	for (i = 0; i < ARRAY_SIZE(prediv); i++) {
+		postdiv = mclkdiv / prediv[i];
+
+		if (postdiv % 2)
+			continue;
+
+		if (postdiv >= 4 && postdiv <= 512) {
+			mclk_prediv = prediv[i];
+			mclk_postdiv = postdiv;
+			best_mclk_rate = pll_rate / (prediv[i] * postdiv);
+			goto out;
+		}
+	}
+
+	/* No suitable prediv found, so try to adjust the postdiv */
+	for (postdiv = 4; postdiv <= 512; postdiv += 2) {
+		unsigned int pre;
+
+		pre = mclkdiv / postdiv;
+		if (pre == 2 || pre == 4 || pre == 8) {
+			mclk_prediv = pre;
+			mclk_postdiv = postdiv;
+			best_mclk_rate = pll_rate / (pre * postdiv);
+			goto out;
+		}
+	}
+
+	/* The MCLK <-> PLL gap is to high -> use largest possible div */
+	mclk_prediv = 8;
+	mclk_postdiv = 512;
+	best_mclk_rate = pll_rate / (8 * 512);
+
+out:
+	tc358746->mclk_prediv = mclk_prediv;
+	tc358746->mclk_postdiv = mclk_postdiv;
+	tc358746->mclk_rate = best_mclk_rate;
+
+	if (best_mclk_rate != mclk_rate)
+		dev_warn(dev, "Request MCLK freq:%lu, found MCLK freq:%lu\n",
+			 mclk_rate, best_mclk_rate);
+
+	dev_dbg(dev, "Found MCLK settings: freq:%lu prediv:%u postdiv:%u\n",
+		best_mclk_rate, mclk_prediv, mclk_postdiv);
+
+	return best_mclk_rate;
+}
+
+static unsigned long
+tc358746_recalc_rate(struct clk_hw *hw, unsigned long parent_rate)
+{
+	struct tc358746 *tc358746 = clk_hw_to_tc358746(hw);
+	unsigned int prediv, postdiv;
+	u32 val;
+	int err;
+
+	err = tc358746_read(tc358746, MCLKCTL_REG, &val);
+	if (err)
+		return 0;
+
+	postdiv = FIELD_GET(MCLK_LOW_MASK, val) + 1;
+	postdiv += FIELD_GET(MCLK_HIGH_MASK, val) + 1;
+
+	err = tc358746_read(tc358746, CLKCTL_REG, &val);
+	if (err)
+		return 0;
+
+	prediv = FIELD_GET(MCLKDIV_MASK, val);
+	if (prediv == MCLKDIV_8)
+		prediv = 8;
+	else if (prediv == MCLKDIV_4)
+		prediv = 4;
+	else
+		prediv = 2;
+
+	return tc358746->pll_rate / (prediv * postdiv);
+}
+
+static long tc358746_mclk_round_rate(struct clk_hw *hw, unsigned long rate,
+				     unsigned long *parent_rate)
+{
+	struct tc358746 *tc358746 = clk_hw_to_tc358746(hw);
+
+	*parent_rate = tc358746->pll_rate;
+
+	return tc358746_find_mclk_settings(tc358746, rate);
+}
+
+static int tc358746_mclk_set_rate(struct clk_hw *hw, unsigned long rate,
+				  unsigned long parent_rate)
+{
+	struct tc358746 *tc358746 = clk_hw_to_tc358746(hw);
+
+	tc358746_find_mclk_settings(tc358746, rate);
+
+	return tc358746_mclk_enable(hw);
+}
+
+static const struct clk_ops tc358746_mclk_ops = {
+	.enable = tc358746_mclk_enable,
+	.disable = tc358746_mclk_disable,
+	.recalc_rate = tc358746_recalc_rate,
+	.round_rate = tc358746_mclk_round_rate,
+	.set_rate = tc358746_mclk_set_rate,
+};
+
+static int tc358746_setup_mclk_provider(struct tc358746 *tc358746)
+{
+	struct clk_init_data mclk_initdata = { };
+	struct device *dev = tc358746->sd.dev;
+	const char *mclk_name;
+	int err;
+
+	/* MCLK clk provider support is optional */
+	if (!device_property_present(dev, "#clock-cells"))
+		return 0;
+
+	/* Init to highest possibel MCLK */
+	tc358746->mclk_postdiv = 512;
+	tc358746->mclk_prediv = 8;
+
+	mclk_name = "tc358746-mclk";
+	device_property_read_string(dev, "clock-output-names", &mclk_name);
+
+	mclk_initdata.name = mclk_name;
+	mclk_initdata.ops = &tc358746_mclk_ops;
+	tc358746->mclk_hw.init = &mclk_initdata;
+
+	err = devm_clk_hw_register(dev, &tc358746->mclk_hw);
+	if (err) {
+		dev_err(dev, "Failed to register mclk provider\n");
+		return err;
+	}
+
+	err = devm_of_clk_add_hw_provider(dev, of_clk_hw_simple_get,
+					  &tc358746->mclk_hw);
+	if (err)
+		dev_err(dev, "Failed to add mclk provider\n");
+
+	return err;
+}
+
+static int
+tc358746_init_subdev(struct tc358746 *tc358746, struct i2c_client *client)
+{
+	struct v4l2_subdev *sd = &tc358746->sd;
+	int err;
+
+	v4l2_i2c_subdev_init(sd, client, &tc358746_ops);
+	sd->flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;
+	sd->entity.function = MEDIA_ENT_F_VID_IF_BRIDGE;
+	sd->entity.ops = &tc358746_entity_ops;
+
+	tc358746->pads[TC358746_SINK].flags = MEDIA_PAD_FL_SINK;
+	tc358746->pads[TC358746_SOURCE].flags = MEDIA_PAD_FL_SOURCE;
+	err = media_entity_pads_init(&sd->entity, TC358746_NR_PADS,
+				     tc358746->pads);
+	if (err)
+		return err;
+
+	err = v4l2_subdev_init_finalize(sd);
+	if (err)
+		media_entity_cleanup(&sd->entity);
+
+	return err;
+}
+
+static int
+tc358746_init_output_port(struct tc358746 *tc358746, unsigned long refclk)
+{
+	struct device *dev = tc358746->sd.dev;
+	struct v4l2_fwnode_endpoint *vep;
+	unsigned long csi_link_rate;
+	struct fwnode_handle *ep;
+	unsigned char csi_lanes;
+	int err;
+
+	ep = fwnode_graph_get_endpoint_by_id(dev_fwnode(dev), TC358746_SOURCE,
+					     0, 0);
+	if (!ep) {
+		dev_err(dev, "Missing endpoint node\n");
+		return -EINVAL;
+	}
+
+	/* Currently we only support 'parallel in' -> 'csi out' */
+	vep = &tc358746->csi_vep;
+	vep->bus_type = V4L2_MBUS_CSI2_DPHY;
+	err = v4l2_fwnode_endpoint_alloc_parse(ep, vep);
+	fwnode_handle_put(ep);
+	if (err) {
+		dev_err(dev, "Failed to parse source endpoint\n");
+		return err;
+	}
+
+	csi_lanes = vep->bus.mipi_csi2.num_data_lanes;
+	if (csi_lanes == 0 || csi_lanes > 4 ||
+	    vep->nr_of_link_frequencies == 0) {
+		dev_err(dev, "error: Invalid CSI-2 settings\n");
+		err = -EINVAL;
+		goto err;
+	}
+
+	/* TODO: Add support to handle multiple link frequencies */
+	csi_link_rate = (unsigned long)vep->link_frequencies[0];
+	tc358746->pll_rate = tc358746_find_pll_settings(tc358746, refclk,
+							csi_link_rate * 2);
+	if (!tc358746->pll_rate) {
+		err = -EINVAL;
+		goto err;
+	}
+
+	err = phy_mipi_dphy_get_default_config_for_hsclk(tc358746->pll_rate,
+						csi_lanes, &tc358746->dphy_cfg);
+	if (err)
+		goto err;
+
+	tc358746->vb_size = TC358746_VB_DEFAULT_SIZE;
+
+	return 0;
+
+err:
+	v4l2_fwnode_endpoint_free(vep);
+
+	return err;
+}
+
+static int tc358746_init_hw(struct tc358746 *tc358746)
+{
+	struct device *dev = tc358746->sd.dev;
+	unsigned int chipid;
+	u32 val;
+	int err;
+
+	err = pm_runtime_resume_and_get(dev);
+	if (err < 0) {
+		dev_err(dev, "Failed to resume the device\n");
+		return err;
+	}
+
+	 /* Ensure that CSI interface is put into LP-11 state */
+	err = tc358746_sw_reset(tc358746);
+	if (err) {
+		pm_runtime_put_sync(dev);
+		dev_err(dev, "Failed to reset the device\n");
+		return err;
+	}
+
+	err = tc358746_read(tc358746, CHIPID_REG, &val);
+	pm_runtime_mark_last_busy(dev);
+	pm_runtime_put_sync_autosuspend(dev);
+	if (err)
+		return -ENODEV;
+
+	chipid = FIELD_GET(CHIPID, val);
+	if (chipid != 0x44) {
+		dev_err(dev, "Invalid chipid 0x%02x\n", chipid);
+		return -ENODEV;
+	}
+
+	return 0;
+}
+
+static int tc358746_init_controls(struct tc358746 *tc358746)
+{
+	u64 *link_frequencies = tc358746->csi_vep.link_frequencies;
+	struct v4l2_ctrl *ctrl;
+	int err;
+
+	err = v4l2_ctrl_handler_init(&tc358746->ctrl_hdl, 1);
+	if (err)
+		return err;
+
+	/*
+	 * The driver currently supports only one link-frequency, regardless of
+	 * the input from the firmware, see: tc358746_init_output_port(). So
+	 * report only the first frequency from the array of possible given
+	 * frequencies.
+	 */
+	ctrl = v4l2_ctrl_new_int_menu(&tc358746->ctrl_hdl, NULL,
+				      V4L2_CID_LINK_FREQ, 0, 0,
+				      link_frequencies);
+	if (ctrl)
+		ctrl->flags |= V4L2_CTRL_FLAG_READ_ONLY;
+
+	err = tc358746->ctrl_hdl.error;
+	if (err) {
+		v4l2_ctrl_handler_free(&tc358746->ctrl_hdl);
+		return err;
+	}
+
+	tc358746->sd.ctrl_handler = &tc358746->ctrl_hdl;
+
+	return 0;
+}
+
+static int tc358746_notify_bound(struct v4l2_async_notifier *notifier,
+				 struct v4l2_subdev *sd,
+				 struct v4l2_async_subdev *asd)
+{
+	struct tc358746 *tc358746 =
+		container_of(notifier, struct tc358746, notifier);
+	u32 flags = MEDIA_LNK_FL_ENABLED | MEDIA_LNK_FL_IMMUTABLE;
+	struct media_pad *sink = &tc358746->pads[TC358746_SINK];
+
+	return v4l2_create_fwnode_links_to_pad(sd, sink, flags);
+}
+
+static const struct v4l2_async_notifier_operations tc358746_notify_ops = {
+	.bound = tc358746_notify_bound,
+};
+
+static int tc358746_async_register(struct tc358746 *tc358746)
+{
+	struct v4l2_fwnode_endpoint vep = {
+		.bus_type = V4L2_MBUS_PARALLEL,
+	};
+	struct v4l2_async_subdev *asd;
+	struct fwnode_handle *ep;
+	int err;
+
+	ep = fwnode_graph_get_endpoint_by_id(dev_fwnode(tc358746->sd.dev),
+					     TC358746_SINK, 0, 0);
+	if (!ep)
+		return -ENOTCONN;
+
+	err = v4l2_fwnode_endpoint_parse(ep, &vep);
+	if (err) {
+		fwnode_handle_put(ep);
+		return err;
+	}
+
+	v4l2_async_nf_init(&tc358746->notifier);
+	asd = v4l2_async_nf_add_fwnode_remote(&tc358746->notifier, ep,
+					      struct v4l2_async_subdev);
+	fwnode_handle_put(ep);
+
+	if (IS_ERR(asd)) {
+		err = PTR_ERR(asd);
+		goto err_cleanup;
+	}
+
+	tc358746->notifier.ops = &tc358746_notify_ops;
+
+	err = v4l2_async_subdev_nf_register(&tc358746->sd, &tc358746->notifier);
+	if (err)
+		goto err_cleanup;
+
+	tc358746->sd.fwnode = fwnode_graph_get_endpoint_by_id(
+		dev_fwnode(tc358746->sd.dev), TC358746_SOURCE, 0, 0);
+
+	err = v4l2_async_register_subdev(&tc358746->sd);
+	if (err)
+		goto err_unregister;
+
+	return 0;
+
+err_unregister:
+	fwnode_handle_put(tc358746->sd.fwnode);
+	v4l2_async_nf_unregister(&tc358746->notifier);
+err_cleanup:
+	v4l2_async_nf_cleanup(&tc358746->notifier);
+
+	return err;
+}
+
+static int tc358746_probe(struct i2c_client *client)
+{
+	struct device *dev = &client->dev;
+	struct tc358746 *tc358746;
+	unsigned long refclk;
+	unsigned int i;
+	int err;
+
+	tc358746 = devm_kzalloc(&client->dev, sizeof(*tc358746), GFP_KERNEL);
+	if (!tc358746)
+		return -ENOMEM;
+
+	tc358746->regmap = devm_regmap_init_i2c(client, &tc358746_regmap_config);
+	if (IS_ERR(tc358746->regmap))
+		return dev_err_probe(dev, PTR_ERR(tc358746->regmap),
+				     "Failed to init regmap\n");
+
+	tc358746->refclk = devm_clk_get(dev, "refclk");
+	if (IS_ERR(tc358746->refclk))
+		return dev_err_probe(dev, PTR_ERR(tc358746->refclk),
+				     "Failed to get refclk\n");
+
+	err = clk_prepare_enable(tc358746->refclk);
+	if (err)
+		return dev_err_probe(dev, err,
+				     "Failed to enable refclk\n");
+
+	refclk = clk_get_rate(tc358746->refclk);
+	clk_disable_unprepare(tc358746->refclk);
+
+	if (refclk < 6 * HZ_PER_MHZ || refclk > 40 * HZ_PER_MHZ)
+		return dev_err_probe(dev, -EINVAL, "Invalid refclk range\n");
+
+	for (i = 0; i < ARRAY_SIZE(tc358746_supplies); i++)
+		tc358746->supplies[i].supply = tc358746_supplies[i];
+
+	err = devm_regulator_bulk_get(dev, ARRAY_SIZE(tc358746_supplies),
+				      tc358746->supplies);
+	if (err)
+		return dev_err_probe(dev, err, "Failed to get supplies\n");
+
+	tc358746->reset_gpio = devm_gpiod_get_optional(dev, "reset",
+						       GPIOD_OUT_HIGH);
+	if (IS_ERR(tc358746->reset_gpio))
+		return dev_err_probe(dev, PTR_ERR(tc358746->reset_gpio),
+				     "Failed to get reset-gpios\n");
+
+	err = tc358746_init_subdev(tc358746, client);
+	if (err)
+		return dev_err_probe(dev, err, "Failed to init subdev\n");
+
+	err = tc358746_init_output_port(tc358746, refclk);
+	if (err)
+		goto err_subdev;
+
+	/*
+	 * Keep this order since we need the output port link-frequencies
+	 * information.
+	 */
+	err = tc358746_init_controls(tc358746);
+	if (err)
+		goto err_fwnode;
+
+	dev_set_drvdata(dev, tc358746);
+
+	/* Set to 1sec to give the stream reconfiguration enough time */
+	pm_runtime_set_autosuspend_delay(dev, 1000);
+	pm_runtime_use_autosuspend(dev);
+	pm_runtime_enable(dev);
+
+	err = tc358746_init_hw(tc358746);
+	if (err)
+		goto err_pm;
+
+	err = tc358746_setup_mclk_provider(tc358746);
+	if (err)
+		goto err_pm;
+
+	err = tc358746_async_register(tc358746);
+	if (err < 0)
+		goto err_pm;
+
+	dev_dbg(dev, "%s found @ 0x%x (%s)\n", client->name,
+		client->addr, client->adapter->name);
+
+	return 0;
+
+err_pm:
+	pm_runtime_disable(dev);
+	pm_runtime_set_suspended(dev);
+	pm_runtime_dont_use_autosuspend(dev);
+	v4l2_ctrl_handler_free(&tc358746->ctrl_hdl);
+err_fwnode:
+	v4l2_fwnode_endpoint_free(&tc358746->csi_vep);
+err_subdev:
+	v4l2_subdev_cleanup(&tc358746->sd);
+	media_entity_cleanup(&tc358746->sd.entity);
+
+	return err;
+}
+
+static int tc358746_remove(struct i2c_client *client)
+{
+	struct v4l2_subdev *sd = i2c_get_clientdata(client);
+	struct tc358746 *tc358746 = to_tc358746(sd);
+
+	v4l2_subdev_cleanup(sd);
+	v4l2_ctrl_handler_free(&tc358746->ctrl_hdl);
+	v4l2_fwnode_endpoint_free(&tc358746->csi_vep);
+	v4l2_async_nf_unregister(&tc358746->notifier);
+	v4l2_async_nf_cleanup(&tc358746->notifier);
+	fwnode_handle_put(sd->fwnode);
+	v4l2_async_unregister_subdev(sd);
+	media_entity_cleanup(&sd->entity);
+
+	pm_runtime_disable(sd->dev);
+	pm_runtime_set_suspended(sd->dev);
+	pm_runtime_dont_use_autosuspend(sd->dev);
+
+	return 0;
+}
+
+static int tc358746_suspend(struct device *dev)
+{
+	struct tc358746 *tc358746 = dev_get_drvdata(dev);
+	int err;
+
+	clk_disable_unprepare(tc358746->refclk);
+
+	err = regulator_bulk_disable(ARRAY_SIZE(tc358746_supplies),
+				     tc358746->supplies);
+	if (err)
+		clk_prepare_enable(tc358746->refclk);
+
+	return err;
+}
+
+static int tc358746_resume(struct device *dev)
+{
+	struct tc358746 *tc358746 = dev_get_drvdata(dev);
+	int err;
+
+	gpiod_set_value(tc358746->reset_gpio, 1);
+
+	err = regulator_bulk_enable(ARRAY_SIZE(tc358746_supplies),
+				    tc358746->supplies);
+	if (err)
+		return err;
+
+	/* min. 200ns */
+	usleep_range(10, 20);
+
+	gpiod_set_value(tc358746->reset_gpio, 0);
+
+	err = clk_prepare_enable(tc358746->refclk);
+	if (err)
+		goto err;
+
+	/* min. 700us ... 1ms */
+	usleep_range(1000, 1500);
+
+	/*
+	 * Enable the PLL here since it can be called by the clk-framework or by
+	 * the .s_stream() callback. So this is the common place for both.
+	 */
+	err = tc358746_apply_pll_config(tc358746);
+	if (err)
+		goto err_clk;
+
+	return 0;
+
+err_clk:
+	clk_disable_unprepare(tc358746->refclk);
+err:
+	regulator_bulk_disable(ARRAY_SIZE(tc358746_supplies),
+			       tc358746->supplies);
+	return err;
+}
+
+DEFINE_RUNTIME_DEV_PM_OPS(tc358746_pm_ops, tc358746_suspend,
+			  tc358746_resume, NULL);
+
+static const struct of_device_id __maybe_unused tc358746_of_match[] = {
+	{ .compatible = "toshiba,tc358746" },
+	{ },
+};
+MODULE_DEVICE_TABLE(of, tc358746_of_match);
+
+static struct i2c_driver tc358746_driver = {
+	.driver = {
+		.name = "tc358746",
+		.pm = pm_ptr(&tc358746_pm_ops),
+		.of_match_table = tc358746_of_match,
+	},
+	.probe_new = tc358746_probe,
+	.remove = tc358746_remove,
+};
+
+module_i2c_driver(tc358746_driver);
+
+MODULE_DESCRIPTION("Toshiba TC358746 Parallel to CSI-2 bridge driver");
+MODULE_AUTHOR("Marco Felsch <kernel@pengutronix.de>");
+MODULE_LICENSE("GPL");
-- 
2.30.2


-- 
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Re: [PATCH v3 4/4] media: tc358746: add Toshiba TC358746 Parallel to CSI-2 bridge driver

[Laurent Pinchart]

Hi Marco,

Thank you for the patch.

On Thu, Sep 22, 2022 at 03:48:43PM +0200, Marco Felsch wrote:
> Adding support for the TC358746 parallel <-> MIPI CSI bridge. This chip
> supports two operating modes:
>   1st) parallel-in -> mipi-csi out
>   2nd) mipi-csi in -> parallel out
> 
> This patch only adds the support for the 1st mode.
> 
> Signed-off-by: Marco Felsch <m.felsch@pengutronix.de>
> ---
> Changelog:
> 
> v3:
> - added missing static
> - drop s/MHZ/HZ_PER_MHZ/
> - kconfig: add "depends on PM"
> - Add tc358746_valid_reg() for regmap.
> - tc358746_set_fmt: fix format negotiation for pad == SOURCE
> - tc358746_write/read: add error messages
> - replace udelay with fsleep()
> - tc358746_apply_misc_config: const mbusfmt
> - tc358746_s_stream: fix comment about LP-00/11 state change
> - tc358746_link_validate: s/sensor/source/
> - tc358746_link_validate: s/pclk_rate/link_freq/
> - tc358746_link_validate: fix v4l2_subdev_unlock_state()
> - tc358746_link_validate: adapt fifo-sz comment
> - tc358746_g/s_register: use pm_runtime_get_if_in_use
> - tc358746_setup_mclk_provider: move to clk related location
> - tc358746_init_hw: fix error case
> - tc358746_init_controls: add comment
> - tc358746_notify_bound: add MEDIA_LNK_FL_IMMUTABLE
> - tc358746_async_register: fix error path
> - tc358746_async_register: put sd.fwnode on error and remove
> - tc358746_probe: increase autosuspend to 1s
> 
> v2:
> - use the correct CID_LINK_FREQ control to query the sensor_pclk_rate
> - remove now not needed tc358746_link_setup() and
>   struct v4l2_ctrl sensor_pclk_ctrl
> - call v4l2_subdev_link_validate_default() during link validation
> - remove MEDIA_BUS_FMT_GBR888_1X24/YUV444 format support
> - use subdev active_state API
> - replace own .get_fmt with v4l2_subdev_get_fmt
> - remove unnecessary pad checks
> - restructure tc358746_get_format_by_code() if-case
> - move apply_dphy_config|apply_misc_config from resume intos s_stream
> - use goto in s_stream enable case
> - fix error handling in suspend/resume
> - split probe() into more sub-functions
> ---
>  drivers/media/i2c/Kconfig    |   17 +
>  drivers/media/i2c/Makefile   |    1 +
>  drivers/media/i2c/tc358746.c | 1692 ++++++++++++++++++++++++++++++++++
>  3 files changed, 1710 insertions(+)
>  create mode 100644 drivers/media/i2c/tc358746.c
> 
> diff --git a/drivers/media/i2c/Kconfig b/drivers/media/i2c/Kconfig
> index 7806d4b81716..f85cdb94c524 100644
> --- a/drivers/media/i2c/Kconfig
> +++ b/drivers/media/i2c/Kconfig
> @@ -1272,6 +1272,23 @@ config VIDEO_TC358743_CEC
>  	  When selected the tc358743 will support the optional
>  	  HDMI CEC feature.
>  
> +config VIDEO_TC358746
> +	tristate "Toshiba TC358746 parallel-CSI2 bridge"
> +	depends on VIDEO_DEV && PM && I2C
> +	select VIDEO_V4L2_SUBDEV_API
> +	select MEDIA_CONTROLLER
> +	select V4L2_FWNODE
> +	select GENERIC_PHY_MIPI_DPHY
> +	select REGMAP_I2C
> +	select COMMON_CLK
> +	help
> +	  Support for the Toshiba TC358746 parallel to MIPI CSI-2 bridge.
> +	  The bridge can work in both directions but currently only the
> +	  parallel-in / csi-out path is supported.
> +
> +	  To compile this driver as a module, choose M here: the
> +	  module will be called tc358746.
> +
>  config VIDEO_TVP514X
>  	tristate "Texas Instruments TVP514x video decoder"
>  	depends on VIDEO_DEV && I2C
> diff --git a/drivers/media/i2c/Makefile b/drivers/media/i2c/Makefile
> index 0a2933103dd9..d1096c2ab480 100644
> --- a/drivers/media/i2c/Makefile
> +++ b/drivers/media/i2c/Makefile
> @@ -118,6 +118,7 @@ obj-$(CONFIG_VIDEO_SONY_BTF_MPX) += sony-btf-mpx.o
>  obj-$(CONFIG_VIDEO_SR030PC30) += sr030pc30.o
>  obj-$(CONFIG_VIDEO_ST_MIPID02) += st-mipid02.o
>  obj-$(CONFIG_VIDEO_TC358743) += tc358743.o
> +obj-$(CONFIG_VIDEO_TC358746) += tc358746.o
>  obj-$(CONFIG_VIDEO_TDA1997X) += tda1997x.o
>  obj-$(CONFIG_VIDEO_TDA7432) += tda7432.o
>  obj-$(CONFIG_VIDEO_TDA9840) += tda9840.o
> diff --git a/drivers/media/i2c/tc358746.c b/drivers/media/i2c/tc358746.c
> new file mode 100644
> index 000000000000..0dcd5e0e0855
> --- /dev/null
> +++ b/drivers/media/i2c/tc358746.c
> @@ -0,0 +1,1692 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * TC358746 - Parallel <-> CSI-2 Bridge
> + *
> + * Copyright 2022 Marco Felsch <kernel@pengutronix.de>
> + *
> + * Notes:
> + *  - Currently only 'Parallel-in -> CSI-out' mode is supported!
> + */
> +
> +#include <linux/bitfield.h>
> +#include <linux/clk.h>
> +#include <linux/clk-provider.h>
> +#include <linux/delay.h>
> +#include <linux/i2c.h>
> +#include <linux/interrupt.h>
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/phy/phy-mipi-dphy.h>
> +#include <linux/property.h>
> +#include <linux/pm_runtime.h>
> +#include <linux/regmap.h>
> +#include <linux/units.h>
> +#include <media/v4l2-ctrls.h>
> +#include <media/v4l2-device.h>
> +#include <media/v4l2-fwnode.h>
> +#include <media/v4l2-mc.h>
> +
> +/* 16-bit registers */
> +#define CHIPID_REG			0x0000
> +#define		CHIPID			GENMASK(15, 8)
> +
> +#define SYSCTL_REG			0x0002
> +#define		SRESET			BIT(0)
> +
> +#define CONFCTL_REG			0x0004
> +#define		PDATAF_MASK		GENMASK(9, 8)
> +#define		PDATAF_MODE0		0
> +#define		PDATAF_MODE1		1
> +#define		PDATAF_MODE2		2
> +#define		PDATAF(val)		FIELD_PREP(PDATAF_MASK, (val))
> +#define		PPEN			BIT(6)
> +#define		DATALANE_MASK		GENMASK(1, 0)
> +
> +#define FIFOCTL_REG			0x0006
> +#define DATAFMT_REG			0x0008
> +#define		PDFMT(val)		FIELD_PREP(GENMASK(7, 4), (val))
> +
> +#define MCLKCTL_REG			0x000c
> +#define		MCLK_HIGH_MASK		GENMASK(15, 8)
> +#define		MCLK_LOW_MASK		GENMASK(7, 0)
> +#define		MCLK_HIGH(val)		FIELD_PREP(MCLK_HIGH_MASK, (val))
> +#define		MCLK_LOW(val)		FIELD_PREP(MCLK_LOW_MASK, (val))
> +
> +#define PLLCTL0_REG			0x0016
> +#define		PLL_PRD_MASK		GENMASK(15, 12)
> +#define		PLL_PRD(val)		FIELD_PREP(PLL_PRD_MASK, (val))
> +#define		PLL_FBD_MASK		GENMASK(8, 0)
> +#define		PLL_FBD(val)		FIELD_PREP(PLL_FBD_MASK, (val))
> +
> +#define PLLCTL1_REG			0x0018
> +#define		PLL_FRS_MASK		GENMASK(11, 10)
> +#define		PLL_FRS(val)		FIELD_PREP(PLL_FRS_MASK, (val))
> +#define		CKEN			BIT(4)
> +#define		RESETB			BIT(1)
> +#define		PLL_EN			BIT(0)
> +
> +#define CLKCTL_REG			0x0020
> +#define		MCLKDIV_MASK		GENMASK(3, 2)
> +#define		MCLKDIV(val)		FIELD_PREP(MCLKDIV_MASK, (val))
> +#define		MCLKDIV_8		0
> +#define		MCLKDIV_4		1
> +#define		MCLKDIV_2		2
> +
> +#define WORDCNT_REG			0x0022
> +#define PP_MISC_REG			0x0032
> +#define		FRMSTOP			BIT(15)
> +#define		RSTPTR			BIT(14)
> +
> +/* 32-bit registers */
> +#define CLW_DPHYCONTTX_REG		0x0100
> +#define CLW_CNTRL_REG			0x0140
> +#define D0W_CNTRL_REG			0x0144
> +#define		LANEDISABLE		BIT(0)
> +
> +#define STARTCNTRL_REG			0x0204
> +#define		START			BIT(0)
> +
> +#define LINEINITCNT_REG			0x0210
> +#define LPTXTIMECNT_REG			0x0214
> +#define TCLK_HEADERCNT_REG		0x0218
> +#define		TCLK_ZEROCNT(val)	FIELD_PREP(GENMASK(15, 8), (val))
> +#define		TCLK_PREPARECNT(val)	FIELD_PREP(GENMASK(6, 0), (val))
> +
> +#define TCLK_TRAILCNT_REG		0x021C
> +#define THS_HEADERCNT_REG		0x0220
> +#define		THS_ZEROCNT(val)	FIELD_PREP(GENMASK(14, 8), (val))
> +#define		THS_PREPARECNT(val)	FIELD_PREP(GENMASK(6, 0), (val))
> +
> +#define TWAKEUP_REG			0x0224
> +#define TCLK_POSTCNT_REG		0x0228
> +#define THS_TRAILCNT_REG		0x022C
> +#define HSTXVREGEN_REG			0x0234
> +#define TXOPTIONCNTRL_REG		0x0238
> +#define CSI_CONTROL_REG			0x040C
> +#define		CSI_MODE		BIT(15)
> +#define		TXHSMD			BIT(7)
> +#define		NOL(val)		FIELD_PREP(GENMASK(2, 1), (val))
> +
> +#define CSI_CONFW_REG			0x0500
> +#define		MODE(val)		FIELD_PREP(GENMASK(31, 29), (val))
> +#define		MODE_SET		0x5
> +#define		ADDRESS(val)		FIELD_PREP(GENMASK(28, 24), (val))
> +#define		CSI_CONTROL_ADDRESS	0x3
> +#define		DATA(val)		FIELD_PREP(GENMASK(15, 0), (val))
> +
> +#define CSI_START_REG			0x0518
> +#define		STRT			BIT(0)
> +
> +static const struct v4l2_mbus_framefmt tc358746_def_fmt = {
> +	.width		= 640,
> +	.height		= 480,
> +	.code		= MEDIA_BUS_FMT_UYVY8_2X8,
> +	.field		= V4L2_FIELD_NONE,
> +	.colorspace	= V4L2_COLORSPACE_DEFAULT,
> +	.ycbcr_enc	= V4L2_YCBCR_ENC_DEFAULT,
> +	.quantization	= V4L2_QUANTIZATION_DEFAULT,
> +	.xfer_func	= V4L2_XFER_FUNC_DEFAULT,
> +};
> +
> +static const char * const tc358746_supplies[] = {
> +	"vddc", "vddio", "vddmipi"
> +};
> +
> +enum {
> +	TC358746_SINK,
> +	TC358746_SOURCE,
> +	TC358746_NR_PADS
> +};
> +
> +struct tc358746 {
> +	struct v4l2_subdev		sd;
> +	struct media_pad		pads[TC358746_NR_PADS];
> +	struct v4l2_async_notifier	notifier;
> +	struct v4l2_fwnode_endpoint	csi_vep;
> +
> +	struct v4l2_ctrl_handler	ctrl_hdl;
> +
> +	struct regmap			*regmap;
> +	struct clk			*refclk;
> +	struct gpio_desc		*reset_gpio;
> +	struct regulator_bulk_data	supplies[ARRAY_SIZE(tc358746_supplies)];
> +
> +	struct clk_hw			mclk_hw;
> +	unsigned long			mclk_rate;
> +	u8				mclk_prediv;
> +	u16				mclk_postdiv;
> +
> +	unsigned long			pll_rate;
> +	u8				pll_post_div;
> +	u16				pll_pre_div;
> +	u16				pll_mul;
> +
> +#define TC358746_VB_MAX_SIZE		(511 * 32)
> +#define TC358746_VB_DEFAULT_SIZE	  (1 * 32)
> +	unsigned int			vb_size; /* Video buffer size in bits */
> +
> +	struct phy_configure_opts_mipi_dphy dphy_cfg;
> +};
> +
> +static inline struct tc358746 *to_tc358746(struct v4l2_subdev *sd)
> +{
> +	return container_of(sd, struct tc358746, sd);
> +}
> +
> +static inline struct tc358746 *clk_hw_to_tc358746(struct clk_hw *hw)
> +{
> +	return container_of(hw, struct tc358746, mclk_hw);
> +}
> +
> +struct tc358746_format {
> +	u32		code;
> +	bool		csi_format;
> +	unsigned char	bus_width;
> +	unsigned char	bpp;
> +	/* Register values */
> +	u8		pdformat; /* Peripheral Data Format */
> +	u8		pdataf;   /* Parallel Data Format Option */
> +};
> +
> +enum {
> +	PDFORMAT_RAW8 = 0,
> +	PDFORMAT_RAW10,
> +	PDFORMAT_RAW12,
> +	PDFORMAT_RGB888,
> +	PDFORMAT_RGB666,
> +	PDFORMAT_RGB565,
> +	PDFORMAT_YUV422_8BIT,
> +	/* RESERVED = 7 */
> +	PDFORMAT_RAW14 = 8,
> +	PDFORMAT_YUV422_10BIT,
> +	PDFORMAT_YUV444,
> +};
> +
> +/* Check tc358746_src_mbus_code() if you add new formats */
> +static const struct tc358746_format tc358746_formats[] = {
> +	{
> +		.code = MEDIA_BUS_FMT_UYVY8_2X8,
> +		.bus_width = 8,
> +		.bpp = 16,
> +		.pdformat = PDFORMAT_YUV422_8BIT,
> +		.pdataf = PDATAF_MODE0,
> +	}, {
> +		.code = MEDIA_BUS_FMT_UYVY8_1X16,
> +		.csi_format = true,
> +		.bus_width = 16,
> +		.bpp = 16,
> +		.pdformat = PDFORMAT_YUV422_8BIT,
> +		.pdataf = PDATAF_MODE1,
> +	}, {
> +		.code = MEDIA_BUS_FMT_YUYV8_1X16,
> +		.csi_format = true,
> +		.bus_width = 16,
> +		.bpp = 16,
> +		.pdformat = PDFORMAT_YUV422_8BIT,
> +		.pdataf = PDATAF_MODE2,
> +	}, {
> +		.code = MEDIA_BUS_FMT_UYVY10_2X10,
> +		.bus_width = 10,
> +		.bpp = 20,
> +		.pdformat = PDFORMAT_YUV422_10BIT,
> +		.pdataf = PDATAF_MODE0, /* don't care */
> +	}
> +};
> +
> +/* Get n-th format for pad */
> +static const struct tc358746_format *
> +tc358746_get_format_by_idx(unsigned int pad, unsigned int index)
> +{
> +	unsigned int idx = 0;
> +	unsigned int i;
> +
> +	for (i = 0; i < ARRAY_SIZE(tc358746_formats); i++) {
> +		const struct tc358746_format *fmt = &tc358746_formats[i];
> +
> +		if ((pad == TC358746_SOURCE && fmt->csi_format) ||
> +		    (pad == TC358746_SINK)) {
> +			if (idx == index)
> +				return fmt;
> +			idx++;
> +		}
> +	}
> +
> +	return ERR_PTR(-EINVAL);
> +}
> +
> +static const struct tc358746_format *
> +tc358746_get_format_by_code(unsigned int pad, u32 code)
> +{
> +	unsigned int i;
> +
> +	for (i = 0; i < ARRAY_SIZE(tc358746_formats); i++) {
> +		const struct tc358746_format *fmt = &tc358746_formats[i];
> +
> +		if (pad == TC358746_SINK && fmt->code == code)
> +			return fmt;
> +
> +		if (pad == TC358746_SOURCE && !fmt->csi_format)
> +			continue;
> +
> +		if (fmt->code == code)
> +			return fmt;
> +	}
> +
> +	return ERR_PTR(-EINVAL);
> +}
> +
> +static u32 tc358746_src_mbus_code(u32 code)
> +{
> +	switch (code) {
> +	case MEDIA_BUS_FMT_UYVY8_2X8:
> +		return MEDIA_BUS_FMT_UYVY8_1X16;
> +	case MEDIA_BUS_FMT_UYVY10_2X10:
> +		return MEDIA_BUS_FMT_UYVY10_1X20;
> +	default:
> +		return code;
> +	}
> +}
> +
> +static bool tc358746_valid_reg(struct device *dev, unsigned int reg)
> +{
> +	switch (reg) {
> +	case CHIPID_REG ... CSI_START_REG:
> +		return true;
> +	default:
> +		return false;
> +	}
> +}
> +
> +static const struct regmap_config tc358746_regmap_config = {
> +	.name = "tc358746",
> +	.reg_bits = 16,
> +	.val_bits = 16,
> +	.max_register = CSI_START_REG,
> +	.writeable_reg = tc358746_valid_reg,
> +	.readable_reg = tc358746_valid_reg,
> +	.reg_format_endian = REGMAP_ENDIAN_BIG,
> +	.val_format_endian = REGMAP_ENDIAN_BIG,
> +};
> +
> +static int tc358746_write(struct tc358746 *tc358746, u32 reg, u32 val)
> +{
> +	size_t count;
> +	int err;
> +
> +	/* 32-bit registers starting from CLW_DPHYCONTTX */
> +	count = reg < CLW_DPHYCONTTX_REG ? 1 : 2;
> +
> +	err = regmap_bulk_write(tc358746->regmap, reg, &val, count);
> +	if (err)
> +		dev_dbg(tc358746->sd.dev,
> +			"Failed to write reg:0x%04x val:0x%04x\n", reg, val);

I'm not sure if the value is relevant here, but I'd add the error, it's
useful to know what kind of I2C issue occurred. Same for read().

By the way, this isn't something you need to do in this driver, but I've
found the following pattern to be useful for error handling:

static int tc358746_write(struct tc358746 *tc358746, u32 reg, u32 val, int *err)
{
	size_t count;
	int ret;

	if (err && *err)
		return *err;

	/* 32-bit registers starting from CLW_DPHYCONTTX */
	count = reg < CLW_DPHYCONTTX_REG ? 1 : 2;

	ret = regmap_bulk_write(tc358746->regmap, reg, &val, count);
	if (ret)
		dev_dbg(tc358746->sd.dev,
			"Failed to write reg 0x%04x: %d\n", reg, ret);
		if (err)
			*err = ret;
		return ret;
	}

	return 0;
}

With this, you could simplify functions such as
tc358746_apply_dphy_config(), by initializing the local err variable to
0, calling 

	tc358746_write(tc358746, ..., ..., &err);

without checking for errors, and just returning err at the end of the
function. With the same pattern enabled in tc358746_update_bits() you
could simplify other functions too.

> +
> +	return err;
> +}
> +
> +static int tc358746_read(struct tc358746 *tc358746, u32 reg, u32 *val)
> +{
> +	size_t count;
> +	int err;
> +
> +	/* 32-bit registers starting from CLW_DPHYCONTTX */
> +	count = reg < CLW_DPHYCONTTX_REG ? 1 : 2;
> +	*val = 0;
> +
> +	err = regmap_bulk_read(tc358746->regmap, reg, val, count);
> +	if (err)
> +		dev_dbg(tc358746->sd.dev, "Failed to read reg:0x%04x\n", reg);
> +
> +	return err;
> +}
> +
> +static int
> +tc358746_update_bits(struct tc358746 *tc358746, u32 reg, u32 mask, u32 val)
> +{
> +	u32 tmp, orig;
> +	int err;
> +
> +	err = tc358746_read(tc358746, reg, &orig);
> +	if (err)
> +		return err;
> +
> +	tmp = orig & ~mask;
> +	tmp |= val & mask;
> +
> +	return tc358746_write(tc358746, reg, tmp);
> +}
> +
> +static int tc358746_set_bits(struct tc358746 *tc358746, u32 reg, u32 bits)
> +{
> +	return tc358746_update_bits(tc358746, reg, bits, bits);
> +}
> +
> +static int tc358746_clear_bits(struct tc358746 *tc358746, u32 reg, u32 bits)
> +{
> +	return tc358746_update_bits(tc358746, reg, bits, 0);
> +}
> +
> +static int tc358746_sw_reset(struct tc358746 *tc358746)
> +{
> +	int err;
> +
> +	err = tc358746_set_bits(tc358746, SYSCTL_REG, SRESET);
> +	if (err)
> +		return err;
> +
> +	fsleep(10);
> +
> +	return tc358746_clear_bits(tc358746, SYSCTL_REG, SRESET);
> +}
> +
> +static int
> +tc358746_apply_pll_config(struct tc358746 *tc358746)
> +{
> +	u8 post = tc358746->pll_post_div;
> +	u16 pre = tc358746->pll_pre_div;
> +	u16 mul = tc358746->pll_mul;
> +	u32 val, mask;
> +	int err;
> +
> +	err = tc358746_read(tc358746, PLLCTL1_REG, &val);
> +	if (err)
> +		return err;
> +
> +	/* Don't touch the PLL if running */
> +	if (FIELD_GET(PLL_EN, val) == 1)
> +		return 0;
> +
> +	/* Pre-div and Multiplicator have a internal +1 logic */
> +	val = PLL_PRD(pre - 1) | PLL_FBD(mul - 1);
> +	mask = PLL_PRD_MASK | PLL_FBD_MASK;
> +	err = tc358746_update_bits(tc358746, PLLCTL0_REG, mask, val);
> +	if (err)
> +		return err;
> +
> +	val = PLL_FRS(ilog2(post)) | RESETB | PLL_EN;
> +	mask = PLL_FRS_MASK | RESETB | PLL_EN;
> +	tc358746_update_bits(tc358746, PLLCTL1_REG, mask, val);
> +	if (err)
> +		return err;
> +
> +	fsleep(1000);
> +
> +	return tc358746_set_bits(tc358746, PLLCTL1_REG, CKEN);
> +}
> +
> +static int tc358746_apply_misc_config(struct tc358746 *tc358746)
> +{
> +	const struct v4l2_mbus_framefmt *mbusfmt;
> +	struct v4l2_subdev *sd = &tc358746->sd;
> +	struct v4l2_subdev_state *sink_state;
> +	const struct tc358746_format *fmt;
> +	struct device *dev = sd->dev;
> +	u32 val;
> +	int err;
> +
> +	sink_state = v4l2_subdev_lock_and_get_active_state(sd);
> +	mbusfmt = v4l2_subdev_get_pad_format(sd, sink_state, TC358746_SINK);
> +	v4l2_subdev_unlock_state(sink_state);
> +
> +	fmt = tc358746_get_format_by_code(TC358746_SINK, mbusfmt->code);
> +
> +	/* Self defined CSI user data type id's are not supported yet */
> +	val = PDFMT(fmt->pdformat);
> +	dev_dbg(dev, "DATAFMT: 0x%x\n", val);
> +	err = tc358746_write(tc358746, DATAFMT_REG, val);
> +	if (err)
> +		return err;
> +
> +	val = PDATAF(fmt->pdataf);
> +	dev_dbg(dev, "CONFCTL[PDATAF]: 0x%x\n", fmt->pdataf);
> +	err = tc358746_update_bits(tc358746, CONFCTL_REG, PDATAF_MASK, val);
> +	if (err)
> +		return err;
> +
> +	val = tc358746->vb_size / 32;
> +	dev_dbg(dev, "FIFOCTL: %u (0x%x)\n", val, val);
> +	err = tc358746_write(tc358746, FIFOCTL_REG, val);
> +	if (err)
> +		return err;
> +
> +	/* Total number of bytes for each line/width */
> +	val = mbusfmt->width * fmt->bpp / 8;
> +	dev_dbg(dev, "WORDCNT: %u (0x%x)\n", val, val);
> +	return tc358746_write(tc358746, WORDCNT_REG, val);
> +}
> +
> +/* Use MHz as base so the div needs no u64 */
> +static u32 tc358746_cfg_to_cnt(unsigned int cfg_val,
> +			       unsigned int clk_mhz,
> +			       unsigned int time_base)
> +{
> +	return DIV_ROUND_UP(cfg_val * clk_mhz, time_base);
> +}
> +
> +static u32 tc358746_ps_to_cnt(unsigned int cfg_val,
> +			      unsigned int clk_mhz)
> +{
> +	return tc358746_cfg_to_cnt(cfg_val, clk_mhz, USEC_PER_SEC);
> +}
> +
> +static u32 tc358746_us_to_cnt(unsigned int cfg_val,
> +			      unsigned int clk_mhz)
> +{
> +	return tc358746_cfg_to_cnt(cfg_val, clk_mhz, 1);
> +}
> +
> +static int tc358746_apply_dphy_config(struct tc358746 *tc358746)
> +{
> +	struct phy_configure_opts_mipi_dphy *cfg = &tc358746->dphy_cfg;
> +	bool non_cont_clk = !!(tc358746->csi_vep.bus.mipi_csi2.flags &
> +			       V4L2_MBUS_CSI2_NONCONTINUOUS_CLOCK);
> +	struct device *dev = tc358746->sd.dev;
> +	unsigned long hs_byte_clk, hf_clk;
> +	u32 val, val2, lptxcnt;
> +	int err;
> +
> +	/* The hs_byte_clk is also called SYSCLK in the excel sheet */
> +	hs_byte_clk = cfg->hs_clk_rate / 8;
> +	hs_byte_clk /= HZ_PER_MHZ;
> +	hf_clk = hs_byte_clk / 2;
> +
> +	val = tc358746_us_to_cnt(cfg->init, hf_clk) - 1;
> +	dev_dbg(dev, "LINEINITCNT: %u (0x%x)\n", val, val);
> +	err = tc358746_write(tc358746, LINEINITCNT_REG, val);
> +	if (err)
> +		return err;
> +
> +	val = tc358746_ps_to_cnt(cfg->lpx, hs_byte_clk) - 1;
> +	lptxcnt = val;
> +	dev_dbg(dev, "LPTXTIMECNT: %u (0x%x)\n", val, val);
> +	err = tc358746_write(tc358746, LPTXTIMECNT_REG, val);
> +	if (err)
> +		return err;
> +
> +	val = tc358746_ps_to_cnt(cfg->clk_prepare, hs_byte_clk) - 1;
> +	val2 = tc358746_ps_to_cnt(cfg->clk_zero, hs_byte_clk) - 1;
> +	dev_dbg(dev, "TCLK_PREPARECNT: %u (0x%x)\n", val, val);
> +	dev_dbg(dev, "TCLK_ZEROCNT: %u (0x%x)\n", val2, val2);
> +	dev_dbg(dev, "TCLK_HEADERCNT: 0x%x\n",
> +		(u32)(TCLK_PREPARECNT(val) | TCLK_ZEROCNT(val2)));
> +	err = tc358746_write(tc358746, TCLK_HEADERCNT_REG,
> +			     TCLK_PREPARECNT(val) | TCLK_ZEROCNT(val2));
> +	if (err)
> +		return err;
> +
> +	val = tc358746_ps_to_cnt(cfg->clk_trail, hs_byte_clk);
> +	dev_dbg(dev, "TCLK_TRAILCNT: %u (0x%x)\n", val, val);
> +	err = tc358746_write(tc358746, TCLK_TRAILCNT_REG, val);
> +	if (err)
> +		return err;
> +
> +	val = tc358746_ps_to_cnt(cfg->hs_prepare, hs_byte_clk) - 1;
> +	val2 = tc358746_ps_to_cnt(cfg->hs_zero, hs_byte_clk) - 1;
> +	dev_dbg(dev, "THS_PREPARECNT: %u (0x%x)\n", val, val);
> +	dev_dbg(dev, "THS_ZEROCNT: %u (0x%x)\n", val2, val2);
> +	dev_dbg(dev, "THS_HEADERCNT: 0x%x\n",
> +		(u32)(THS_PREPARECNT(val) | THS_ZEROCNT(val2)));
> +	err = tc358746_write(tc358746, THS_HEADERCNT_REG,
> +			     THS_PREPARECNT(val) | THS_ZEROCNT(val2));
> +	if (err)
> +		return err;
> +
> +	/* TWAKEUP > 1ms in lptxcnt steps */
> +	val = tc358746_us_to_cnt(cfg->wakeup, hs_byte_clk);
> +	val = val / (lptxcnt + 1) - 1;
> +	dev_dbg(dev, "TWAKEUP: %u (0x%x)\n", val, val);
> +	err = tc358746_write(tc358746, TWAKEUP_REG, val);
> +	if (err)
> +		return err;
> +
> +	val = tc358746_ps_to_cnt(cfg->clk_post, hs_byte_clk);
> +	dev_dbg(dev, "TCLK_POSTCNT: %u (0x%x)\n", val, val);
> +	err = tc358746_write(tc358746, TCLK_POSTCNT_REG, val);
> +	if (err)
> +		return err;
> +
> +	val = tc358746_ps_to_cnt(cfg->hs_trail, hs_byte_clk);
> +	dev_dbg(dev, "THS_TRAILCNT: %u (0x%x)\n", val, val);
> +	err = tc358746_write(tc358746, THS_TRAILCNT_REG, val);
> +	if (err)
> +		return err;
> +
> +	dev_dbg(dev, "CONTCLKMODE: %u", non_cont_clk ? 0 : 1);
> +	return  tc358746_write(tc358746, TXOPTIONCNTRL_REG, non_cont_clk ? 0 : 1);

Extra space after return.

> +}
> +
> +#define MAX_DATA_LANES 4
> +
> +static int tc358746_enable_csi_lanes(struct tc358746 *tc358746, int enable)
> +{
> +	unsigned int lanes = tc358746->dphy_cfg.lanes;
> +	unsigned int lane;
> +	u32 reg, val;
> +	int err;
> +
> +	err = tc358746_update_bits(tc358746, CONFCTL_REG, DATALANE_MASK,
> +				   lanes - 1);
> +	if (err)
> +		return err;
> +
> +	/* Clock lane */
> +	val = enable ? 0 : LANEDISABLE;
> +	dev_dbg(tc358746->sd.dev, "CLW_CNTRL: 0x%x\n", val);
> +	err = tc358746_write(tc358746, CLW_CNTRL_REG, val);
> +	if (err)
> +		return err;
> +
> +	for (lane = 0; lane < MAX_DATA_LANES; lane++) {
> +		/* Data lanes */
> +		reg = D0W_CNTRL_REG + lane * 0x4;
> +		val = (enable && lane < lanes) ? 0 : LANEDISABLE;
> +
> +		dev_dbg(tc358746->sd.dev, "D%uW_CNTRL: 0x%x\n", lane, val);
> +		err = tc358746_write(tc358746, reg, val);
> +		if (err)
> +			return err;
> +	}
> +
> +	val = 0;
> +	if (enable) {
> +		/* Clock lane */
> +		val |= BIT(0);
> +
> +		/* Data lanes */
> +		for (lane = 1; lane <= lanes; lane++)
> +			val |= BIT(lane);
> +	}
> +
> +	dev_dbg(tc358746->sd.dev, "HSTXVREGEN: 0x%x\n", val);
> +	return tc358746_write(tc358746, HSTXVREGEN_REG, val);
> +}
> +
> +static int tc358746_enable_csi_module(struct tc358746 *tc358746, int enable)
> +{
> +	unsigned int lanes = tc358746->dphy_cfg.lanes;
> +	int err;
> +
> +	/*
> +	 * START and STRT are only reseted/disabled by sw reset. This is
> +	 * required to put the lane state back into LP-11 state. The sw reset
> +	 * don't reset register values.
> +	 */
> +	if (!enable)
> +		return tc358746_sw_reset(tc358746);
> +
> +	err = tc358746_write(tc358746, STARTCNTRL_REG, START);
> +	if (err)
> +		return err;
> +
> +	err = tc358746_write(tc358746, CSI_START_REG, STRT);
> +	if (err)
> +		return err;
> +
> +	/* CSI_CONTROL_REG is only indirect accessible */
> +	return tc358746_write(tc358746, CSI_CONFW_REG,
> +			      MODE(MODE_SET) |
> +			      ADDRESS(CSI_CONTROL_ADDRESS) |
> +			      DATA(CSI_MODE | TXHSMD | NOL(lanes - 1)));
> +}
> +
> +static int tc358746_enable_parallel_port(struct tc358746 *tc358746, int enable)
> +{
> +	int err;
> +
> +	if (enable) {
> +		err = tc358746_write(tc358746, PP_MISC_REG, 0);
> +		if (err)
> +			return err;
> +
> +		return tc358746_set_bits(tc358746, CONFCTL_REG, PPEN);
> +	}
> +
> +	err = tc358746_set_bits(tc358746, PP_MISC_REG, FRMSTOP);
> +	if (err)
> +		return err;
> +
> +	err = tc358746_clear_bits(tc358746, CONFCTL_REG, PPEN);
> +	if (err)
> +		return err;
> +
> +	return tc358746_set_bits(tc358746, PP_MISC_REG, RSTPTR);
> +}
> +
> +static inline struct v4l2_subdev *tc358746_get_remote_sd(struct media_pad *pad)
> +{
> +	pad = media_pad_remote_pad_first(pad);
> +	if (!pad)
> +		return NULL;
> +
> +	return media_entity_to_v4l2_subdev(pad->entity);
> +}
> +
> +static int tc358746_s_stream(struct v4l2_subdev *sd, int enable)
> +{
> +	struct tc358746 *tc358746 = to_tc358746(sd);
> +	struct v4l2_subdev *src;
> +	int err;
> +
> +	dev_dbg(sd->dev, "%sable\n", enable ? "en" : "dis");
> +
> +	src = tc358746_get_remote_sd(&tc358746->pads[TC358746_SINK]);
> +	if (!src)
> +		return -EPIPE;
> +
> +	if (enable) {
> +		err = pm_runtime_resume_and_get(sd->dev);
> +		if (err)
> +			return err;
> +
> +		err = tc358746_apply_dphy_config(tc358746);
> +		if (err)
> +			goto err_out;
> +
> +		err = tc358746_apply_misc_config(tc358746);
> +		if (err)
> +			goto err_out;
> +
> +		err = tc358746_enable_csi_lanes(tc358746, 1);
> +		if (err)
> +			goto err_out;
> +
> +		err = tc358746_enable_csi_module(tc358746, 1);
> +		if (err)
> +			goto err_out;
> +
> +		err = tc358746_enable_parallel_port(tc358746, 1);
> +		if (err)
> +			goto err_out;
> +
> +		err = v4l2_subdev_call(src, video, s_stream, 1);
> +		if (err)
> +			goto err_out;
> +
> +		return err;
> +
> +err_out:
> +		pm_runtime_mark_last_busy(sd->dev);
> +		pm_runtime_put_sync_autosuspend(sd->dev);
> +
> +		return err;
> +	}
> +
> +	 /*
> +	  * The lanes must be disabled first (before the csi module) so the
> +	  * LP-11 state is entered correctly.
> +	  */

Wrong indentation.

> +	err = tc358746_enable_csi_lanes(tc358746, 0);
> +	if (err)
> +		return err;
> +
> +	err = tc358746_enable_csi_module(tc358746, 0);
> +	if (err)
> +		return err;
> +
> +	err = tc358746_enable_parallel_port(tc358746, 0);
> +	if (err)
> +		return err;
> +
> +	pm_runtime_mark_last_busy(sd->dev);
> +	pm_runtime_put_sync_autosuspend(sd->dev);
> +
> +	return v4l2_subdev_call(src, video, s_stream, 0);
> +}
> +
> +static int tc358746_init_cfg(struct v4l2_subdev *sd,
> +			     struct v4l2_subdev_state *state)
> +{
> +	struct v4l2_mbus_framefmt *fmt;
> +
> +	fmt = v4l2_subdev_get_pad_format(sd, state, TC358746_SINK);
> +	*fmt = tc358746_def_fmt;
> +
> +	fmt = v4l2_subdev_get_pad_format(sd, state, TC358746_SOURCE);
> +	*fmt = tc358746_def_fmt;
> +	fmt->code = tc358746_src_mbus_code(tc358746_def_fmt.code);
> +
> +	return 0;
> +}
> +
> +static int tc358746_enum_mbus_code(struct v4l2_subdev *sd,
> +				   struct v4l2_subdev_state *sd_state,
> +				   struct v4l2_subdev_mbus_code_enum *code)
> +{
> +	const struct tc358746_format *fmt;
> +
> +	fmt = tc358746_get_format_by_idx(code->pad, code->index);
> +	if (IS_ERR(fmt))
> +		return PTR_ERR(fmt);
> +
> +	code->code = fmt->code;
> +
> +	return 0;
> +}
> +
> +static int tc358746_set_fmt(struct v4l2_subdev *sd,
> +			    struct v4l2_subdev_state *sd_state,
> +			    struct v4l2_subdev_format *format)
> +{
> +	struct v4l2_mbus_framefmt *src_fmt, *sink_fmt;
> +	const struct tc358746_format *fmt;
> +
> +	/* Source follows the sink */
> +	if (format->pad == TC358746_SOURCE)
> +		return v4l2_subdev_get_fmt(sd, sd_state, format);
> +
> +	sink_fmt = v4l2_subdev_get_pad_format(sd, sd_state, TC358746_SINK);
> +
> +	fmt = tc358746_get_format_by_code(format->pad, format->format.code);
> +	if (IS_ERR(fmt))
> +		fmt = tc358746_get_format_by_code(format->pad, tc358746_def_fmt.code);
> +
> +	format->format.code = fmt->code;
> +	format->format.field = V4L2_FIELD_NONE;
> +
> +	dev_dbg(sd->dev, "Update format: %ux%u code:0x%x -> %ux%u code:0x%x",
> +		sink_fmt->width, sink_fmt->height, sink_fmt->code,
> +		format->format.width, format->format.height, format->format.code);
> +
> +	*sink_fmt = format->format;
> +
> +	src_fmt = v4l2_subdev_get_pad_format(sd, sd_state, TC358746_SOURCE);
> +	*src_fmt = *sink_fmt;
> +	src_fmt->code = tc358746_src_mbus_code(sink_fmt->code);
> +
> +	return 0;
> +}
> +
> +static unsigned long tc358746_find_pll_settings(struct tc358746 *tc358746,
> +						unsigned long refclk,
> +						unsigned long fout)
> +
> +{
> +	struct device *dev = tc358746->sd.dev;
> +	unsigned long best_freq = 0;
> +	u32 min_delta = 0xffffffff;
> +	u16 prediv_max = 17;
> +	u16 prediv_min = 1;
> +	u16 m_best, mul;
> +	u16 p_best, p;
> +	u8 postdiv;
> +
> +	if (fout > 1000 * HZ_PER_MHZ) {
> +		dev_err(dev, "HS-Clock above 1 Ghz are not supported\n");
> +		return 0;
> +	}
> +
> +	if (fout >= 500 * HZ_PER_MHZ)
> +		postdiv = 1;
> +	else if (fout >= 250 * HZ_PER_MHZ)
> +		postdiv = 2;
> +	else if (fout >= 125 * HZ_PER_MHZ)
> +		postdiv = 4;
> +	else
> +		postdiv = 8;
> +
> +	for (p = prediv_min; p <= prediv_max; p++) {
> +		unsigned long delta, fin;
> +		u64 tmp;
> +
> +		fin = DIV_ROUND_CLOSEST(refclk, p);
> +		if (fin < 4 * HZ_PER_MHZ || fin > 40 * HZ_PER_MHZ)
> +			continue;
> +
> +		tmp = fout * p * postdiv;
> +		do_div(tmp, fin);
> +		mul = tmp;
> +		if (mul > 511)
> +			continue;
> +
> +		tmp = mul * fin;
> +		do_div(tmp, p * postdiv);
> +
> +		delta = abs(fout - tmp);
> +		if (delta < min_delta) {
> +			p_best = p;
> +			m_best = mul;
> +			min_delta = delta;
> +			best_freq = tmp;
> +		};
> +
> +		if (delta == 0)
> +			break;
> +	};
> +
> +	if (!best_freq) {
> +		dev_err(dev, "Failed find PLL frequency\n");
> +		return 0;
> +	}
> +
> +	tc358746->pll_post_div = postdiv;
> +	tc358746->pll_pre_div = p_best;
> +	tc358746->pll_mul = m_best;
> +
> +	if (best_freq != fout)
> +		dev_warn(dev, "Request PLL freq:%lu, found PLL freq:%lu\n",
> +			 fout, best_freq);
> +
> +	dev_dbg(dev, "Found PLL settings: freq:%lu prediv:%u multi:%u postdiv:%u\n",
> +		best_freq, p_best, m_best, postdiv);
> +
> +	return best_freq;
> +}
> +
> +#define TC358746_PRECISION 10
> +
> +static int
> +tc358746_link_validate(struct v4l2_subdev *sd, struct media_link *link,
> +		       struct v4l2_subdev_format *source_fmt,
> +		       struct v4l2_subdev_format *sink_fmt)
> +{
> +	struct tc358746 *tc358746 = to_tc358746(sd);
> +	unsigned long csi_bitrate, source_bitrate;
> +	struct v4l2_subdev_state *sink_state;
> +	struct v4l2_mbus_framefmt *mbusfmt;
> +	const struct tc358746_format *fmt;
> +	unsigned int fifo_sz, tmp, n;
> +	struct v4l2_subdev *source;
> +	s64 source_link_freq;
> +	int err;
> +
> +	err = v4l2_subdev_link_validate_default(sd, link, source_fmt, sink_fmt);
> +	if (err)
> +		return err;
> +
> +	sink_state = v4l2_subdev_lock_and_get_active_state(sd);
> +	mbusfmt = v4l2_subdev_get_pad_format(sd, sink_state, TC358746_SINK);
> +
> +	/* Check the FIFO settings */
> +	fmt = tc358746_get_format_by_code(TC358746_SINK, mbusfmt->code);
> +
> +	source = media_entity_to_v4l2_subdev(link->source->entity);
> +	source_link_freq = v4l2_get_link_freq(source->ctrl_handler, 0, 0);
> +	if (source_link_freq <= 0) {
> +		dev_err(tc358746->sd.dev,
> +			"Failed to query or invalid source link frequency\n");
> +		v4l2_subdev_unlock_state(sink_state);
> +		/* Return -EINVAL in case of source_link_freq is 0 */
> +		return source_link_freq ? : -EINVAL;
> +	}
> +	source_bitrate = source_link_freq * fmt->bus_width;
> +
> +	csi_bitrate = tc358746->dphy_cfg.lanes * tc358746->pll_rate;
> +
> +	dev_dbg(tc358746->sd.dev,
> +		"Fifo settings params: source-bitrate:%lu csi-bitrate:%lu",
> +		source_bitrate, csi_bitrate);
> +
> +	/* Avoid possible FIFO overflows */
> +	if (csi_bitrate < source_bitrate) {
> +		v4l2_subdev_unlock_state(sink_state);
> +		return -EINVAL;
> +	}
> +
> +	/* Best case */
> +	if (csi_bitrate == source_bitrate) {
> +		fifo_sz = TC358746_VB_DEFAULT_SIZE;
> +		tc358746->vb_size = TC358746_VB_DEFAULT_SIZE;
> +		goto out;
> +	}
> +
> +	/*
> +	 * Avoid possible FIFO underflow in case of
> +	 * csi_bitrate > source_bitrate. For such case the chip has a internal
> +	 * fifo which can be used to delay the line output.
> +	 *
> +	 * Fifo size calculation (excluding precision):
> +	 *
> +	 * fifo-sz, image-width - in bits
> +	 * sbr                  - source_bitrate in bits/s
> +	 * csir                 - csi_bitrate in bits/s
> +	 *
> +	 *                1               1      1
> +	 * image-width * --- + fifo-sz * --- >= ---- * image-width
> +	 *               sbr             sbr    csir

I still think there's something fishy here. The inequality is always
true as csir > sbr. You will get a non-zero fifo size in your
calculation because you artifically add an abs(), but I don't think
that's right.

If I understand things correctly, you need to ensure that once the FIFO
threshold is reached and the CSI-2 side starts sending data, the input
size will keep feeding data fast enough for the FIFO to never underrun.

The FIFO level triggers the CSI-2 transmission. This means that once the
CSI-2 transmission start, fifo-sz bits have been written to the FIFO
already, and image-width - fifo-sz bits still need to be written. To
avoid underruns, you need to ensure that the time required to read all
the data (image-width) on the CSI-2 size will be higher than or equal to
the time required to write the remaining data (image-width - fifo-sz) on
the input side. This translates to

	image-width / csir >= (image-width - fifo-sz) / sbr
	image-width * sbr / csir >= image-width - fifo-sz
	fifo-sz >= image-width - image-width * sbr / csir

The calculation is thus correct, but not for the right reason :-) All
you need to fix here is the comment, not the code.

With these small issues fixed,

Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

> +	 *
> +	 * fifo-sz >= abs(sbr/csir * image-width - image-width); with n = csir/sbr
> +	 *
> +	 * fifo-sz >= abs(image-width / n - image-width)
> +	 *         >= image-width - image-width / n
> +	 */
> +
> +	source_bitrate /= TC358746_PRECISION;
> +	n = csi_bitrate / source_bitrate;
> +	tmp = (mbusfmt->width * TC358746_PRECISION) / n;
> +	fifo_sz = mbusfmt->width - tmp;
> +	fifo_sz *= fmt->bpp;
> +	tc358746->vb_size = round_up(fifo_sz, 32);
> +
> +out:
> +	dev_dbg(tc358746->sd.dev,
> +		"Found FIFO size[bits]:%u -> aligned to size[bits]:%u\n",
> +		fifo_sz, tc358746->vb_size);
> +
> +	v4l2_subdev_unlock_state(sink_state);
> +
> +	return tc358746->vb_size > TC358746_VB_MAX_SIZE ? -EINVAL : 0;
> +}
> +
> +static int tc358746_get_mbus_config(struct v4l2_subdev *sd, unsigned int pad,
> +				    struct v4l2_mbus_config *config)
> +{
> +	struct tc358746 *tc358746 = to_tc358746(sd);
> +
> +	if (pad != TC358746_SOURCE)
> +		return -EINVAL;
> +
> +	config->type = V4L2_MBUS_CSI2_DPHY;
> +	config->bus.mipi_csi2 = tc358746->csi_vep.bus.mipi_csi2;
> +
> +	return 0;
> +}
> +
> +static int __maybe_unused
> +tc358746_g_register(struct v4l2_subdev *sd, struct v4l2_dbg_register *reg)
> +{
> +	struct tc358746 *tc358746 = to_tc358746(sd);
> +
> +	/* 32-bit registers starting from CLW_DPHYCONTTX */
> +	reg->size = reg->reg < CLW_DPHYCONTTX_REG ? 2 : 4;
> +
> +	if (!pm_runtime_get_if_in_use(sd->dev))
> +		return 0;
> +
> +	tc358746_read(tc358746, reg->reg, (u32 *)&reg->val);
> +
> +	pm_runtime_mark_last_busy(sd->dev);
> +	pm_runtime_put_sync_autosuspend(sd->dev);
> +
> +	return 0;
> +}
> +
> +static int __maybe_unused
> +tc358746_s_register(struct v4l2_subdev *sd, const struct v4l2_dbg_register *reg)
> +{
> +	struct tc358746 *tc358746 = to_tc358746(sd);
> +
> +	if (!pm_runtime_get_if_in_use(sd->dev))
> +		return 0;
> +
> +	tc358746_write(tc358746, (u32)reg->reg, (u32)reg->val);
> +
> +	pm_runtime_mark_last_busy(sd->dev);
> +	pm_runtime_put_sync_autosuspend(sd->dev);
> +
> +	return 0;
> +}
> +
> +static const struct v4l2_subdev_core_ops tc358746_core_ops = {
> +#ifdef CONFIG_VIDEO_ADV_DEBUG
> +	.g_register = tc358746_g_register,
> +	.s_register = tc358746_s_register,
> +#endif
> +};
> +
> +static const struct v4l2_subdev_video_ops tc358746_video_ops = {
> +	.s_stream = tc358746_s_stream,
> +};
> +
> +static const struct v4l2_subdev_pad_ops tc358746_pad_ops = {
> +	.init_cfg = tc358746_init_cfg,
> +	.enum_mbus_code = tc358746_enum_mbus_code,
> +	.set_fmt = tc358746_set_fmt,
> +	.get_fmt = v4l2_subdev_get_fmt,
> +	.link_validate = tc358746_link_validate,
> +	.get_mbus_config = tc358746_get_mbus_config,
> +};
> +
> +static const struct v4l2_subdev_ops tc358746_ops = {
> +	.core = &tc358746_core_ops,
> +	.video = &tc358746_video_ops,
> +	.pad = &tc358746_pad_ops,
> +};
> +
> +static const struct media_entity_operations tc358746_entity_ops = {
> +	.get_fwnode_pad = v4l2_subdev_get_fwnode_pad_1_to_1,
> +	.link_validate = v4l2_subdev_link_validate,
> +};
> +
> +static int tc358746_mclk_enable(struct clk_hw *hw)
> +{
> +	struct tc358746 *tc358746 = clk_hw_to_tc358746(hw);
> +	unsigned int div;
> +	u32 val;
> +	int err;
> +
> +	div = tc358746->mclk_postdiv / 2;
> +	val = MCLK_HIGH(div - 1) | MCLK_LOW(div - 1);
> +	dev_dbg(tc358746->sd.dev, "MCLKCTL: %u (0x%x)\n", val, val);
> +	err = tc358746_write(tc358746, MCLKCTL_REG, val);
> +	if (err)
> +		return err;
> +
> +	if (tc358746->mclk_prediv == 8)
> +		val = MCLKDIV(MCLKDIV_8);
> +	else if (tc358746->mclk_prediv == 4)
> +		val = MCLKDIV(MCLKDIV_4);
> +	else
> +		val = MCLKDIV(MCLKDIV_2);
> +
> +	dev_dbg(tc358746->sd.dev, "CLKCTL[MCLKDIV]: %u (0x%x)\n", val, val);
> +	return tc358746_update_bits(tc358746, CLKCTL_REG, MCLKDIV_MASK, val);
> +}
> +
> +static void tc358746_mclk_disable(struct clk_hw *hw)
> +{
> +	struct tc358746 *tc358746 = clk_hw_to_tc358746(hw);
> +
> +	tc358746_write(tc358746, MCLKCTL_REG, 0);
> +}
> +
> +static long
> +tc358746_find_mclk_settings(struct tc358746 *tc358746, unsigned long mclk_rate)
> +{
> +	unsigned long pll_rate = tc358746->pll_rate;
> +	const unsigned char prediv[] = { 2, 4, 8 };
> +	unsigned int mclk_prediv, mclk_postdiv;
> +	struct device *dev = tc358746->sd.dev;
> +	unsigned int postdiv, mclkdiv;
> +	unsigned long best_mclk_rate;
> +	unsigned int i;
> +
> +	/*
> +	 *                          MCLK-Div
> +	 *           -------------------´`---------------------
> +	 *          ´                                          `
> +	 *         +-------------+     +------------------------+
> +	 *         | MCLK-PreDiv |     |       MCLK-PostDiv     |
> +	 * PLL --> |   (2/4/8)   | --> | (mclk_low + mclk_high) | --> MCLK
> +	 *         +-------------+     +------------------------+
> +	 *
> +	 * The register value of mclk_low/high is mclk_low/high+1, i.e.:
> +	 *   mclk_low/high = 1   --> 2 MCLK-Ref Counts
> +	 *   mclk_low/high = 255 --> 256 MCLK-Ref Counts == max.
> +	 * If mclk_low and mclk_high are 0 then MCLK is disabled.
> +	 *
> +	 * Keep it simple and support 50/50 duty cycles only for now,
> +	 * so the calc will be:
> +	 *
> +	 *   MCLK = PLL / (MCLK-PreDiv * 2 * MCLK-PostDiv)
> +	 */
> +
> +	if (mclk_rate == tc358746->mclk_rate)
> +		return mclk_rate;
> +
> +	/* Highest possible rate */
> +	mclkdiv = pll_rate / mclk_rate;
> +	if (mclkdiv <= 8) {
> +		mclk_prediv = 2;
> +		mclk_postdiv = 4;
> +		best_mclk_rate = pll_rate / (2 * 4);
> +		goto out;
> +	}
> +
> +	/* First check the prediv */
> +	for (i = 0; i < ARRAY_SIZE(prediv); i++) {
> +		postdiv = mclkdiv / prediv[i];
> +
> +		if (postdiv % 2)
> +			continue;
> +
> +		if (postdiv >= 4 && postdiv <= 512) {
> +			mclk_prediv = prediv[i];
> +			mclk_postdiv = postdiv;
> +			best_mclk_rate = pll_rate / (prediv[i] * postdiv);
> +			goto out;
> +		}
> +	}
> +
> +	/* No suitable prediv found, so try to adjust the postdiv */
> +	for (postdiv = 4; postdiv <= 512; postdiv += 2) {
> +		unsigned int pre;
> +
> +		pre = mclkdiv / postdiv;
> +		if (pre == 2 || pre == 4 || pre == 8) {
> +			mclk_prediv = pre;
> +			mclk_postdiv = postdiv;
> +			best_mclk_rate = pll_rate / (pre * postdiv);
> +			goto out;
> +		}
> +	}
> +
> +	/* The MCLK <-> PLL gap is to high -> use largest possible div */
> +	mclk_prediv = 8;
> +	mclk_postdiv = 512;
> +	best_mclk_rate = pll_rate / (8 * 512);
> +
> +out:
> +	tc358746->mclk_prediv = mclk_prediv;
> +	tc358746->mclk_postdiv = mclk_postdiv;
> +	tc358746->mclk_rate = best_mclk_rate;
> +
> +	if (best_mclk_rate != mclk_rate)
> +		dev_warn(dev, "Request MCLK freq:%lu, found MCLK freq:%lu\n",
> +			 mclk_rate, best_mclk_rate);
> +
> +	dev_dbg(dev, "Found MCLK settings: freq:%lu prediv:%u postdiv:%u\n",
> +		best_mclk_rate, mclk_prediv, mclk_postdiv);
> +
> +	return best_mclk_rate;
> +}
> +
> +static unsigned long
> +tc358746_recalc_rate(struct clk_hw *hw, unsigned long parent_rate)
> +{
> +	struct tc358746 *tc358746 = clk_hw_to_tc358746(hw);
> +	unsigned int prediv, postdiv;
> +	u32 val;
> +	int err;
> +
> +	err = tc358746_read(tc358746, MCLKCTL_REG, &val);
> +	if (err)
> +		return 0;
> +
> +	postdiv = FIELD_GET(MCLK_LOW_MASK, val) + 1;
> +	postdiv += FIELD_GET(MCLK_HIGH_MASK, val) + 1;
> +
> +	err = tc358746_read(tc358746, CLKCTL_REG, &val);
> +	if (err)
> +		return 0;
> +
> +	prediv = FIELD_GET(MCLKDIV_MASK, val);
> +	if (prediv == MCLKDIV_8)
> +		prediv = 8;
> +	else if (prediv == MCLKDIV_4)
> +		prediv = 4;
> +	else
> +		prediv = 2;
> +
> +	return tc358746->pll_rate / (prediv * postdiv);
> +}
> +
> +static long tc358746_mclk_round_rate(struct clk_hw *hw, unsigned long rate,
> +				     unsigned long *parent_rate)
> +{
> +	struct tc358746 *tc358746 = clk_hw_to_tc358746(hw);
> +
> +	*parent_rate = tc358746->pll_rate;
> +
> +	return tc358746_find_mclk_settings(tc358746, rate);
> +}
> +
> +static int tc358746_mclk_set_rate(struct clk_hw *hw, unsigned long rate,
> +				  unsigned long parent_rate)
> +{
> +	struct tc358746 *tc358746 = clk_hw_to_tc358746(hw);
> +
> +	tc358746_find_mclk_settings(tc358746, rate);
> +
> +	return tc358746_mclk_enable(hw);
> +}
> +
> +static const struct clk_ops tc358746_mclk_ops = {
> +	.enable = tc358746_mclk_enable,
> +	.disable = tc358746_mclk_disable,
> +	.recalc_rate = tc358746_recalc_rate,
> +	.round_rate = tc358746_mclk_round_rate,
> +	.set_rate = tc358746_mclk_set_rate,
> +};
> +
> +static int tc358746_setup_mclk_provider(struct tc358746 *tc358746)
> +{
> +	struct clk_init_data mclk_initdata = { };
> +	struct device *dev = tc358746->sd.dev;
> +	const char *mclk_name;
> +	int err;
> +
> +	/* MCLK clk provider support is optional */
> +	if (!device_property_present(dev, "#clock-cells"))
> +		return 0;
> +
> +	/* Init to highest possibel MCLK */
> +	tc358746->mclk_postdiv = 512;
> +	tc358746->mclk_prediv = 8;
> +
> +	mclk_name = "tc358746-mclk";
> +	device_property_read_string(dev, "clock-output-names", &mclk_name);
> +
> +	mclk_initdata.name = mclk_name;
> +	mclk_initdata.ops = &tc358746_mclk_ops;
> +	tc358746->mclk_hw.init = &mclk_initdata;
> +
> +	err = devm_clk_hw_register(dev, &tc358746->mclk_hw);
> +	if (err) {
> +		dev_err(dev, "Failed to register mclk provider\n");
> +		return err;
> +	}
> +
> +	err = devm_of_clk_add_hw_provider(dev, of_clk_hw_simple_get,
> +					  &tc358746->mclk_hw);
> +	if (err)
> +		dev_err(dev, "Failed to add mclk provider\n");
> +
> +	return err;
> +}
> +
> +static int
> +tc358746_init_subdev(struct tc358746 *tc358746, struct i2c_client *client)
> +{
> +	struct v4l2_subdev *sd = &tc358746->sd;
> +	int err;
> +
> +	v4l2_i2c_subdev_init(sd, client, &tc358746_ops);
> +	sd->flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;
> +	sd->entity.function = MEDIA_ENT_F_VID_IF_BRIDGE;
> +	sd->entity.ops = &tc358746_entity_ops;
> +
> +	tc358746->pads[TC358746_SINK].flags = MEDIA_PAD_FL_SINK;
> +	tc358746->pads[TC358746_SOURCE].flags = MEDIA_PAD_FL_SOURCE;
> +	err = media_entity_pads_init(&sd->entity, TC358746_NR_PADS,
> +				     tc358746->pads);
> +	if (err)
> +		return err;
> +
> +	err = v4l2_subdev_init_finalize(sd);
> +	if (err)
> +		media_entity_cleanup(&sd->entity);
> +
> +	return err;
> +}
> +
> +static int
> +tc358746_init_output_port(struct tc358746 *tc358746, unsigned long refclk)
> +{
> +	struct device *dev = tc358746->sd.dev;
> +	struct v4l2_fwnode_endpoint *vep;
> +	unsigned long csi_link_rate;
> +	struct fwnode_handle *ep;
> +	unsigned char csi_lanes;
> +	int err;
> +
> +	ep = fwnode_graph_get_endpoint_by_id(dev_fwnode(dev), TC358746_SOURCE,
> +					     0, 0);
> +	if (!ep) {
> +		dev_err(dev, "Missing endpoint node\n");
> +		return -EINVAL;
> +	}
> +
> +	/* Currently we only support 'parallel in' -> 'csi out' */
> +	vep = &tc358746->csi_vep;
> +	vep->bus_type = V4L2_MBUS_CSI2_DPHY;
> +	err = v4l2_fwnode_endpoint_alloc_parse(ep, vep);
> +	fwnode_handle_put(ep);
> +	if (err) {
> +		dev_err(dev, "Failed to parse source endpoint\n");
> +		return err;
> +	}
> +
> +	csi_lanes = vep->bus.mipi_csi2.num_data_lanes;
> +	if (csi_lanes == 0 || csi_lanes > 4 ||
> +	    vep->nr_of_link_frequencies == 0) {
> +		dev_err(dev, "error: Invalid CSI-2 settings\n");
> +		err = -EINVAL;
> +		goto err;
> +	}
> +
> +	/* TODO: Add support to handle multiple link frequencies */
> +	csi_link_rate = (unsigned long)vep->link_frequencies[0];
> +	tc358746->pll_rate = tc358746_find_pll_settings(tc358746, refclk,
> +							csi_link_rate * 2);
> +	if (!tc358746->pll_rate) {
> +		err = -EINVAL;
> +		goto err;
> +	}
> +
> +	err = phy_mipi_dphy_get_default_config_for_hsclk(tc358746->pll_rate,
> +						csi_lanes, &tc358746->dphy_cfg);
> +	if (err)
> +		goto err;
> +
> +	tc358746->vb_size = TC358746_VB_DEFAULT_SIZE;
> +
> +	return 0;
> +
> +err:
> +	v4l2_fwnode_endpoint_free(vep);
> +
> +	return err;
> +}
> +
> +static int tc358746_init_hw(struct tc358746 *tc358746)
> +{
> +	struct device *dev = tc358746->sd.dev;
> +	unsigned int chipid;
> +	u32 val;
> +	int err;
> +
> +	err = pm_runtime_resume_and_get(dev);
> +	if (err < 0) {
> +		dev_err(dev, "Failed to resume the device\n");
> +		return err;
> +	}
> +
> +	 /* Ensure that CSI interface is put into LP-11 state */
> +	err = tc358746_sw_reset(tc358746);
> +	if (err) {
> +		pm_runtime_put_sync(dev);
> +		dev_err(dev, "Failed to reset the device\n");
> +		return err;
> +	}
> +
> +	err = tc358746_read(tc358746, CHIPID_REG, &val);
> +	pm_runtime_mark_last_busy(dev);
> +	pm_runtime_put_sync_autosuspend(dev);
> +	if (err)
> +		return -ENODEV;
> +
> +	chipid = FIELD_GET(CHIPID, val);
> +	if (chipid != 0x44) {
> +		dev_err(dev, "Invalid chipid 0x%02x\n", chipid);
> +		return -ENODEV;
> +	}
> +
> +	return 0;
> +}
> +
> +static int tc358746_init_controls(struct tc358746 *tc358746)
> +{
> +	u64 *link_frequencies = tc358746->csi_vep.link_frequencies;
> +	struct v4l2_ctrl *ctrl;
> +	int err;
> +
> +	err = v4l2_ctrl_handler_init(&tc358746->ctrl_hdl, 1);
> +	if (err)
> +		return err;
> +
> +	/*
> +	 * The driver currently supports only one link-frequency, regardless of
> +	 * the input from the firmware, see: tc358746_init_output_port(). So
> +	 * report only the first frequency from the array of possible given
> +	 * frequencies.
> +	 */
> +	ctrl = v4l2_ctrl_new_int_menu(&tc358746->ctrl_hdl, NULL,
> +				      V4L2_CID_LINK_FREQ, 0, 0,
> +				      link_frequencies);
> +	if (ctrl)
> +		ctrl->flags |= V4L2_CTRL_FLAG_READ_ONLY;
> +
> +	err = tc358746->ctrl_hdl.error;
> +	if (err) {
> +		v4l2_ctrl_handler_free(&tc358746->ctrl_hdl);
> +		return err;
> +	}
> +
> +	tc358746->sd.ctrl_handler = &tc358746->ctrl_hdl;
> +
> +	return 0;
> +}
> +
> +static int tc358746_notify_bound(struct v4l2_async_notifier *notifier,
> +				 struct v4l2_subdev *sd,
> +				 struct v4l2_async_subdev *asd)
> +{
> +	struct tc358746 *tc358746 =
> +		container_of(notifier, struct tc358746, notifier);
> +	u32 flags = MEDIA_LNK_FL_ENABLED | MEDIA_LNK_FL_IMMUTABLE;
> +	struct media_pad *sink = &tc358746->pads[TC358746_SINK];
> +
> +	return v4l2_create_fwnode_links_to_pad(sd, sink, flags);
> +}
> +
> +static const struct v4l2_async_notifier_operations tc358746_notify_ops = {
> +	.bound = tc358746_notify_bound,
> +};
> +
> +static int tc358746_async_register(struct tc358746 *tc358746)
> +{
> +	struct v4l2_fwnode_endpoint vep = {
> +		.bus_type = V4L2_MBUS_PARALLEL,
> +	};
> +	struct v4l2_async_subdev *asd;
> +	struct fwnode_handle *ep;
> +	int err;
> +
> +	ep = fwnode_graph_get_endpoint_by_id(dev_fwnode(tc358746->sd.dev),
> +					     TC358746_SINK, 0, 0);
> +	if (!ep)
> +		return -ENOTCONN;
> +
> +	err = v4l2_fwnode_endpoint_parse(ep, &vep);
> +	if (err) {
> +		fwnode_handle_put(ep);
> +		return err;
> +	}
> +
> +	v4l2_async_nf_init(&tc358746->notifier);
> +	asd = v4l2_async_nf_add_fwnode_remote(&tc358746->notifier, ep,
> +					      struct v4l2_async_subdev);
> +	fwnode_handle_put(ep);
> +
> +	if (IS_ERR(asd)) {
> +		err = PTR_ERR(asd);
> +		goto err_cleanup;
> +	}
> +
> +	tc358746->notifier.ops = &tc358746_notify_ops;
> +
> +	err = v4l2_async_subdev_nf_register(&tc358746->sd, &tc358746->notifier);
> +	if (err)
> +		goto err_cleanup;
> +
> +	tc358746->sd.fwnode = fwnode_graph_get_endpoint_by_id(
> +		dev_fwnode(tc358746->sd.dev), TC358746_SOURCE, 0, 0);
> +
> +	err = v4l2_async_register_subdev(&tc358746->sd);
> +	if (err)
> +		goto err_unregister;
> +
> +	return 0;
> +
> +err_unregister:
> +	fwnode_handle_put(tc358746->sd.fwnode);
> +	v4l2_async_nf_unregister(&tc358746->notifier);
> +err_cleanup:
> +	v4l2_async_nf_cleanup(&tc358746->notifier);
> +
> +	return err;
> +}
> +
> +static int tc358746_probe(struct i2c_client *client)
> +{
> +	struct device *dev = &client->dev;
> +	struct tc358746 *tc358746;
> +	unsigned long refclk;
> +	unsigned int i;
> +	int err;
> +
> +	tc358746 = devm_kzalloc(&client->dev, sizeof(*tc358746), GFP_KERNEL);
> +	if (!tc358746)
> +		return -ENOMEM;
> +
> +	tc358746->regmap = devm_regmap_init_i2c(client, &tc358746_regmap_config);
> +	if (IS_ERR(tc358746->regmap))
> +		return dev_err_probe(dev, PTR_ERR(tc358746->regmap),
> +				     "Failed to init regmap\n");
> +
> +	tc358746->refclk = devm_clk_get(dev, "refclk");
> +	if (IS_ERR(tc358746->refclk))
> +		return dev_err_probe(dev, PTR_ERR(tc358746->refclk),
> +				     "Failed to get refclk\n");
> +
> +	err = clk_prepare_enable(tc358746->refclk);
> +	if (err)
> +		return dev_err_probe(dev, err,
> +				     "Failed to enable refclk\n");
> +
> +	refclk = clk_get_rate(tc358746->refclk);
> +	clk_disable_unprepare(tc358746->refclk);
> +
> +	if (refclk < 6 * HZ_PER_MHZ || refclk > 40 * HZ_PER_MHZ)
> +		return dev_err_probe(dev, -EINVAL, "Invalid refclk range\n");
> +
> +	for (i = 0; i < ARRAY_SIZE(tc358746_supplies); i++)
> +		tc358746->supplies[i].supply = tc358746_supplies[i];
> +
> +	err = devm_regulator_bulk_get(dev, ARRAY_SIZE(tc358746_supplies),
> +				      tc358746->supplies);
> +	if (err)
> +		return dev_err_probe(dev, err, "Failed to get supplies\n");
> +
> +	tc358746->reset_gpio = devm_gpiod_get_optional(dev, "reset",
> +						       GPIOD_OUT_HIGH);
> +	if (IS_ERR(tc358746->reset_gpio))
> +		return dev_err_probe(dev, PTR_ERR(tc358746->reset_gpio),
> +				     "Failed to get reset-gpios\n");
> +
> +	err = tc358746_init_subdev(tc358746, client);
> +	if (err)
> +		return dev_err_probe(dev, err, "Failed to init subdev\n");
> +
> +	err = tc358746_init_output_port(tc358746, refclk);
> +	if (err)
> +		goto err_subdev;
> +
> +	/*
> +	 * Keep this order since we need the output port link-frequencies
> +	 * information.
> +	 */
> +	err = tc358746_init_controls(tc358746);
> +	if (err)
> +		goto err_fwnode;
> +
> +	dev_set_drvdata(dev, tc358746);
> +
> +	/* Set to 1sec to give the stream reconfiguration enough time */
> +	pm_runtime_set_autosuspend_delay(dev, 1000);
> +	pm_runtime_use_autosuspend(dev);
> +	pm_runtime_enable(dev);
> +
> +	err = tc358746_init_hw(tc358746);
> +	if (err)
> +		goto err_pm;
> +
> +	err = tc358746_setup_mclk_provider(tc358746);
> +	if (err)
> +		goto err_pm;
> +
> +	err = tc358746_async_register(tc358746);
> +	if (err < 0)
> +		goto err_pm;
> +
> +	dev_dbg(dev, "%s found @ 0x%x (%s)\n", client->name,
> +		client->addr, client->adapter->name);
> +
> +	return 0;
> +
> +err_pm:
> +	pm_runtime_disable(dev);
> +	pm_runtime_set_suspended(dev);
> +	pm_runtime_dont_use_autosuspend(dev);
> +	v4l2_ctrl_handler_free(&tc358746->ctrl_hdl);
> +err_fwnode:
> +	v4l2_fwnode_endpoint_free(&tc358746->csi_vep);
> +err_subdev:
> +	v4l2_subdev_cleanup(&tc358746->sd);
> +	media_entity_cleanup(&tc358746->sd.entity);
> +
> +	return err;
> +}
> +
> +static int tc358746_remove(struct i2c_client *client)
> +{
> +	struct v4l2_subdev *sd = i2c_get_clientdata(client);
> +	struct tc358746 *tc358746 = to_tc358746(sd);
> +
> +	v4l2_subdev_cleanup(sd);
> +	v4l2_ctrl_handler_free(&tc358746->ctrl_hdl);
> +	v4l2_fwnode_endpoint_free(&tc358746->csi_vep);
> +	v4l2_async_nf_unregister(&tc358746->notifier);
> +	v4l2_async_nf_cleanup(&tc358746->notifier);
> +	fwnode_handle_put(sd->fwnode);
> +	v4l2_async_unregister_subdev(sd);
> +	media_entity_cleanup(&sd->entity);
> +
> +	pm_runtime_disable(sd->dev);
> +	pm_runtime_set_suspended(sd->dev);
> +	pm_runtime_dont_use_autosuspend(sd->dev);
> +
> +	return 0;
> +}
> +
> +static int tc358746_suspend(struct device *dev)
> +{
> +	struct tc358746 *tc358746 = dev_get_drvdata(dev);
> +	int err;
> +
> +	clk_disable_unprepare(tc358746->refclk);
> +
> +	err = regulator_bulk_disable(ARRAY_SIZE(tc358746_supplies),
> +				     tc358746->supplies);
> +	if (err)
> +		clk_prepare_enable(tc358746->refclk);
> +
> +	return err;
> +}
> +
> +static int tc358746_resume(struct device *dev)
> +{
> +	struct tc358746 *tc358746 = dev_get_drvdata(dev);
> +	int err;
> +
> +	gpiod_set_value(tc358746->reset_gpio, 1);
> +
> +	err = regulator_bulk_enable(ARRAY_SIZE(tc358746_supplies),
> +				    tc358746->supplies);
> +	if (err)
> +		return err;
> +
> +	/* min. 200ns */
> +	usleep_range(10, 20);
> +
> +	gpiod_set_value(tc358746->reset_gpio, 0);
> +
> +	err = clk_prepare_enable(tc358746->refclk);
> +	if (err)
> +		goto err;
> +
> +	/* min. 700us ... 1ms */
> +	usleep_range(1000, 1500);
> +
> +	/*
> +	 * Enable the PLL here since it can be called by the clk-framework or by
> +	 * the .s_stream() callback. So this is the common place for both.
> +	 */
> +	err = tc358746_apply_pll_config(tc358746);
> +	if (err)
> +		goto err_clk;
> +
> +	return 0;
> +
> +err_clk:
> +	clk_disable_unprepare(tc358746->refclk);
> +err:
> +	regulator_bulk_disable(ARRAY_SIZE(tc358746_supplies),
> +			       tc358746->supplies);
> +	return err;
> +}
> +
> +DEFINE_RUNTIME_DEV_PM_OPS(tc358746_pm_ops, tc358746_suspend,
> +			  tc358746_resume, NULL);
> +
> +static const struct of_device_id __maybe_unused tc358746_of_match[] = {
> +	{ .compatible = "toshiba,tc358746" },
> +	{ },
> +};
> +MODULE_DEVICE_TABLE(of, tc358746_of_match);
> +
> +static struct i2c_driver tc358746_driver = {
> +	.driver = {
> +		.name = "tc358746",
> +		.pm = pm_ptr(&tc358746_pm_ops),
> +		.of_match_table = tc358746_of_match,
> +	},
> +	.probe_new = tc358746_probe,
> +	.remove = tc358746_remove,
> +};
> +
> +module_i2c_driver(tc358746_driver);
> +
> +MODULE_DESCRIPTION("Toshiba TC358746 Parallel to CSI-2 bridge driver");
> +MODULE_AUTHOR("Marco Felsch <kernel@pengutronix.de>");
> +MODULE_LICENSE("GPL");

-- 
Regards,

Laurent Pinchart

Re: [PATCH v3 4/4] media: tc358746: add Toshiba TC358746 Parallel to CSI-2 bridge driver

[Laurent Pinchart]

Hi Marco,

Thank you for the patch.

On Thu, Sep 22, 2022 at 03:48:43PM +0200, Marco Felsch wrote:
> Adding support for the TC358746 parallel <-> MIPI CSI bridge. This chip
> supports two operating modes:
>   1st) parallel-in -> mipi-csi out
>   2nd) mipi-csi in -> parallel out
> 
> This patch only adds the support for the 1st mode.
> 
> Signed-off-by: Marco Felsch <m.felsch@pengutronix.de>
> ---
> Changelog:
> 
> v3:
> - added missing static
> - drop s/MHZ/HZ_PER_MHZ/
> - kconfig: add "depends on PM"
> - Add tc358746_valid_reg() for regmap.
> - tc358746_set_fmt: fix format negotiation for pad == SOURCE
> - tc358746_write/read: add error messages
> - replace udelay with fsleep()
> - tc358746_apply_misc_config: const mbusfmt
> - tc358746_s_stream: fix comment about LP-00/11 state change
> - tc358746_link_validate: s/sensor/source/
> - tc358746_link_validate: s/pclk_rate/link_freq/
> - tc358746_link_validate: fix v4l2_subdev_unlock_state()
> - tc358746_link_validate: adapt fifo-sz comment
> - tc358746_g/s_register: use pm_runtime_get_if_in_use
> - tc358746_setup_mclk_provider: move to clk related location
> - tc358746_init_hw: fix error case
> - tc358746_init_controls: add comment
> - tc358746_notify_bound: add MEDIA_LNK_FL_IMMUTABLE
> - tc358746_async_register: fix error path
> - tc358746_async_register: put sd.fwnode on error and remove
> - tc358746_probe: increase autosuspend to 1s
> 
> v2:
> - use the correct CID_LINK_FREQ control to query the sensor_pclk_rate
> - remove now not needed tc358746_link_setup() and
>   struct v4l2_ctrl sensor_pclk_ctrl
> - call v4l2_subdev_link_validate_default() during link validation
> - remove MEDIA_BUS_FMT_GBR888_1X24/YUV444 format support
> - use subdev active_state API
> - replace own .get_fmt with v4l2_subdev_get_fmt
> - remove unnecessary pad checks
> - restructure tc358746_get_format_by_code() if-case
> - move apply_dphy_config|apply_misc_config from resume intos s_stream
> - use goto in s_stream enable case
> - fix error handling in suspend/resume
> - split probe() into more sub-functions
> ---
>  drivers/media/i2c/Kconfig    |   17 +
>  drivers/media/i2c/Makefile   |    1 +
>  drivers/media/i2c/tc358746.c | 1692 ++++++++++++++++++++++++++++++++++
>  3 files changed, 1710 insertions(+)
>  create mode 100644 drivers/media/i2c/tc358746.c
> 
> diff --git a/drivers/media/i2c/Kconfig b/drivers/media/i2c/Kconfig
> index 7806d4b81716..f85cdb94c524 100644
> --- a/drivers/media/i2c/Kconfig
> +++ b/drivers/media/i2c/Kconfig
> @@ -1272,6 +1272,23 @@ config VIDEO_TC358743_CEC
>  	  When selected the tc358743 will support the optional
>  	  HDMI CEC feature.
>  
> +config VIDEO_TC358746
> +	tristate "Toshiba TC358746 parallel-CSI2 bridge"
> +	depends on VIDEO_DEV && PM && I2C
> +	select VIDEO_V4L2_SUBDEV_API
> +	select MEDIA_CONTROLLER
> +	select V4L2_FWNODE
> +	select GENERIC_PHY_MIPI_DPHY
> +	select REGMAP_I2C
> +	select COMMON_CLK
> +	help
> +	  Support for the Toshiba TC358746 parallel to MIPI CSI-2 bridge.
> +	  The bridge can work in both directions but currently only the
> +	  parallel-in / csi-out path is supported.
> +
> +	  To compile this driver as a module, choose M here: the
> +	  module will be called tc358746.
> +
>  config VIDEO_TVP514X
>  	tristate "Texas Instruments TVP514x video decoder"
>  	depends on VIDEO_DEV && I2C
> diff --git a/drivers/media/i2c/Makefile b/drivers/media/i2c/Makefile
> index 0a2933103dd9..d1096c2ab480 100644
> --- a/drivers/media/i2c/Makefile
> +++ b/drivers/media/i2c/Makefile
> @@ -118,6 +118,7 @@ obj-$(CONFIG_VIDEO_SONY_BTF_MPX) += sony-btf-mpx.o
>  obj-$(CONFIG_VIDEO_SR030PC30) += sr030pc30.o
>  obj-$(CONFIG_VIDEO_ST_MIPID02) += st-mipid02.o
>  obj-$(CONFIG_VIDEO_TC358743) += tc358743.o
> +obj-$(CONFIG_VIDEO_TC358746) += tc358746.o
>  obj-$(CONFIG_VIDEO_TDA1997X) += tda1997x.o
>  obj-$(CONFIG_VIDEO_TDA7432) += tda7432.o
>  obj-$(CONFIG_VIDEO_TDA9840) += tda9840.o
> diff --git a/drivers/media/i2c/tc358746.c b/drivers/media/i2c/tc358746.c
> new file mode 100644
> index 000000000000..0dcd5e0e0855
> --- /dev/null
> +++ b/drivers/media/i2c/tc358746.c
> @@ -0,0 +1,1692 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * TC358746 - Parallel <-> CSI-2 Bridge
> + *
> + * Copyright 2022 Marco Felsch <kernel@pengutronix.de>
> + *
> + * Notes:
> + *  - Currently only 'Parallel-in -> CSI-out' mode is supported!
> + */
> +
> +#include <linux/bitfield.h>
> +#include <linux/clk.h>
> +#include <linux/clk-provider.h>
> +#include <linux/delay.h>
> +#include <linux/i2c.h>
> +#include <linux/interrupt.h>
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/phy/phy-mipi-dphy.h>
> +#include <linux/property.h>
> +#include <linux/pm_runtime.h>
> +#include <linux/regmap.h>
> +#include <linux/units.h>
> +#include <media/v4l2-ctrls.h>
> +#include <media/v4l2-device.h>
> +#include <media/v4l2-fwnode.h>
> +#include <media/v4l2-mc.h>
> +
> +/* 16-bit registers */
> +#define CHIPID_REG			0x0000
> +#define		CHIPID			GENMASK(15, 8)
> +
> +#define SYSCTL_REG			0x0002
> +#define		SRESET			BIT(0)
> +
> +#define CONFCTL_REG			0x0004
> +#define		PDATAF_MASK		GENMASK(9, 8)
> +#define		PDATAF_MODE0		0
> +#define		PDATAF_MODE1		1
> +#define		PDATAF_MODE2		2
> +#define		PDATAF(val)		FIELD_PREP(PDATAF_MASK, (val))
> +#define		PPEN			BIT(6)
> +#define		DATALANE_MASK		GENMASK(1, 0)
> +
> +#define FIFOCTL_REG			0x0006
> +#define DATAFMT_REG			0x0008
> +#define		PDFMT(val)		FIELD_PREP(GENMASK(7, 4), (val))
> +
> +#define MCLKCTL_REG			0x000c
> +#define		MCLK_HIGH_MASK		GENMASK(15, 8)
> +#define		MCLK_LOW_MASK		GENMASK(7, 0)
> +#define		MCLK_HIGH(val)		FIELD_PREP(MCLK_HIGH_MASK, (val))
> +#define		MCLK_LOW(val)		FIELD_PREP(MCLK_LOW_MASK, (val))
> +
> +#define PLLCTL0_REG			0x0016
> +#define		PLL_PRD_MASK		GENMASK(15, 12)
> +#define		PLL_PRD(val)		FIELD_PREP(PLL_PRD_MASK, (val))
> +#define		PLL_FBD_MASK		GENMASK(8, 0)
> +#define		PLL_FBD(val)		FIELD_PREP(PLL_FBD_MASK, (val))
> +
> +#define PLLCTL1_REG			0x0018
> +#define		PLL_FRS_MASK		GENMASK(11, 10)
> +#define		PLL_FRS(val)		FIELD_PREP(PLL_FRS_MASK, (val))
> +#define		CKEN			BIT(4)
> +#define		RESETB			BIT(1)
> +#define		PLL_EN			BIT(0)
> +
> +#define CLKCTL_REG			0x0020
> +#define		MCLKDIV_MASK		GENMASK(3, 2)
> +#define		MCLKDIV(val)		FIELD_PREP(MCLKDIV_MASK, (val))
> +#define		MCLKDIV_8		0
> +#define		MCLKDIV_4		1
> +#define		MCLKDIV_2		2
> +
> +#define WORDCNT_REG			0x0022
> +#define PP_MISC_REG			0x0032
> +#define		FRMSTOP			BIT(15)
> +#define		RSTPTR			BIT(14)
> +
> +/* 32-bit registers */
> +#define CLW_DPHYCONTTX_REG		0x0100
> +#define CLW_CNTRL_REG			0x0140
> +#define D0W_CNTRL_REG			0x0144
> +#define		LANEDISABLE		BIT(0)
> +
> +#define STARTCNTRL_REG			0x0204
> +#define		START			BIT(0)
> +
> +#define LINEINITCNT_REG			0x0210
> +#define LPTXTIMECNT_REG			0x0214
> +#define TCLK_HEADERCNT_REG		0x0218
> +#define		TCLK_ZEROCNT(val)	FIELD_PREP(GENMASK(15, 8), (val))
> +#define		TCLK_PREPARECNT(val)	FIELD_PREP(GENMASK(6, 0), (val))
> +
> +#define TCLK_TRAILCNT_REG		0x021C
> +#define THS_HEADERCNT_REG		0x0220
> +#define		THS_ZEROCNT(val)	FIELD_PREP(GENMASK(14, 8), (val))
> +#define		THS_PREPARECNT(val)	FIELD_PREP(GENMASK(6, 0), (val))
> +
> +#define TWAKEUP_REG			0x0224
> +#define TCLK_POSTCNT_REG		0x0228
> +#define THS_TRAILCNT_REG		0x022C
> +#define HSTXVREGEN_REG			0x0234
> +#define TXOPTIONCNTRL_REG		0x0238
> +#define CSI_CONTROL_REG			0x040C
> +#define		CSI_MODE		BIT(15)
> +#define		TXHSMD			BIT(7)
> +#define		NOL(val)		FIELD_PREP(GENMASK(2, 1), (val))
> +
> +#define CSI_CONFW_REG			0x0500
> +#define		MODE(val)		FIELD_PREP(GENMASK(31, 29), (val))
> +#define		MODE_SET		0x5
> +#define		ADDRESS(val)		FIELD_PREP(GENMASK(28, 24), (val))
> +#define		CSI_CONTROL_ADDRESS	0x3
> +#define		DATA(val)		FIELD_PREP(GENMASK(15, 0), (val))
> +
> +#define CSI_START_REG			0x0518
> +#define		STRT			BIT(0)
> +
> +static const struct v4l2_mbus_framefmt tc358746_def_fmt = {
> +	.width		= 640,
> +	.height		= 480,
> +	.code		= MEDIA_BUS_FMT_UYVY8_2X8,
> +	.field		= V4L2_FIELD_NONE,
> +	.colorspace	= V4L2_COLORSPACE_DEFAULT,
> +	.ycbcr_enc	= V4L2_YCBCR_ENC_DEFAULT,
> +	.quantization	= V4L2_QUANTIZATION_DEFAULT,
> +	.xfer_func	= V4L2_XFER_FUNC_DEFAULT,
> +};
> +
> +static const char * const tc358746_supplies[] = {
> +	"vddc", "vddio", "vddmipi"
> +};
> +
> +enum {
> +	TC358746_SINK,
> +	TC358746_SOURCE,
> +	TC358746_NR_PADS
> +};
> +
> +struct tc358746 {
> +	struct v4l2_subdev		sd;
> +	struct media_pad		pads[TC358746_NR_PADS];
> +	struct v4l2_async_notifier	notifier;
> +	struct v4l2_fwnode_endpoint	csi_vep;
> +
> +	struct v4l2_ctrl_handler	ctrl_hdl;
> +
> +	struct regmap			*regmap;
> +	struct clk			*refclk;
> +	struct gpio_desc		*reset_gpio;
> +	struct regulator_bulk_data	supplies[ARRAY_SIZE(tc358746_supplies)];
> +
> +	struct clk_hw			mclk_hw;
> +	unsigned long			mclk_rate;
> +	u8				mclk_prediv;
> +	u16				mclk_postdiv;
> +
> +	unsigned long			pll_rate;
> +	u8				pll_post_div;
> +	u16				pll_pre_div;
> +	u16				pll_mul;
> +
> +#define TC358746_VB_MAX_SIZE		(511 * 32)
> +#define TC358746_VB_DEFAULT_SIZE	  (1 * 32)
> +	unsigned int			vb_size; /* Video buffer size in bits */
> +
> +	struct phy_configure_opts_mipi_dphy dphy_cfg;
> +};
> +
> +static inline struct tc358746 *to_tc358746(struct v4l2_subdev *sd)
> +{
> +	return container_of(sd, struct tc358746, sd);
> +}
> +
> +static inline struct tc358746 *clk_hw_to_tc358746(struct clk_hw *hw)
> +{
> +	return container_of(hw, struct tc358746, mclk_hw);
> +}
> +
> +struct tc358746_format {
> +	u32		code;
> +	bool		csi_format;
> +	unsigned char	bus_width;
> +	unsigned char	bpp;
> +	/* Register values */
> +	u8		pdformat; /* Peripheral Data Format */
> +	u8		pdataf;   /* Parallel Data Format Option */
> +};
> +
> +enum {
> +	PDFORMAT_RAW8 = 0,
> +	PDFORMAT_RAW10,
> +	PDFORMAT_RAW12,
> +	PDFORMAT_RGB888,
> +	PDFORMAT_RGB666,
> +	PDFORMAT_RGB565,
> +	PDFORMAT_YUV422_8BIT,
> +	/* RESERVED = 7 */
> +	PDFORMAT_RAW14 = 8,
> +	PDFORMAT_YUV422_10BIT,
> +	PDFORMAT_YUV444,
> +};
> +
> +/* Check tc358746_src_mbus_code() if you add new formats */
> +static const struct tc358746_format tc358746_formats[] = {
> +	{
> +		.code = MEDIA_BUS_FMT_UYVY8_2X8,
> +		.bus_width = 8,
> +		.bpp = 16,
> +		.pdformat = PDFORMAT_YUV422_8BIT,
> +		.pdataf = PDATAF_MODE0,
> +	}, {
> +		.code = MEDIA_BUS_FMT_UYVY8_1X16,
> +		.csi_format = true,
> +		.bus_width = 16,
> +		.bpp = 16,
> +		.pdformat = PDFORMAT_YUV422_8BIT,
> +		.pdataf = PDATAF_MODE1,
> +	}, {
> +		.code = MEDIA_BUS_FMT_YUYV8_1X16,
> +		.csi_format = true,
> +		.bus_width = 16,
> +		.bpp = 16,
> +		.pdformat = PDFORMAT_YUV422_8BIT,
> +		.pdataf = PDATAF_MODE2,
> +	}, {
> +		.code = MEDIA_BUS_FMT_UYVY10_2X10,
> +		.bus_width = 10,
> +		.bpp = 20,
> +		.pdformat = PDFORMAT_YUV422_10BIT,
> +		.pdataf = PDATAF_MODE0, /* don't care */
> +	}
> +};
> +
> +/* Get n-th format for pad */
> +static const struct tc358746_format *
> +tc358746_get_format_by_idx(unsigned int pad, unsigned int index)
> +{
> +	unsigned int idx = 0;
> +	unsigned int i;
> +
> +	for (i = 0; i < ARRAY_SIZE(tc358746_formats); i++) {
> +		const struct tc358746_format *fmt = &tc358746_formats[i];
> +
> +		if ((pad == TC358746_SOURCE && fmt->csi_format) ||
> +		    (pad == TC358746_SINK)) {
> +			if (idx == index)
> +				return fmt;
> +			idx++;
> +		}
> +	}
> +
> +	return ERR_PTR(-EINVAL);
> +}
> +
> +static const struct tc358746_format *
> +tc358746_get_format_by_code(unsigned int pad, u32 code)
> +{
> +	unsigned int i;
> +
> +	for (i = 0; i < ARRAY_SIZE(tc358746_formats); i++) {
> +		const struct tc358746_format *fmt = &tc358746_formats[i];
> +
> +		if (pad == TC358746_SINK && fmt->code == code)
> +			return fmt;
> +
> +		if (pad == TC358746_SOURCE && !fmt->csi_format)
> +			continue;
> +
> +		if (fmt->code == code)
> +			return fmt;
> +	}
> +
> +	return ERR_PTR(-EINVAL);
> +}
> +
> +static u32 tc358746_src_mbus_code(u32 code)
> +{
> +	switch (code) {
> +	case MEDIA_BUS_FMT_UYVY8_2X8:
> +		return MEDIA_BUS_FMT_UYVY8_1X16;
> +	case MEDIA_BUS_FMT_UYVY10_2X10:
> +		return MEDIA_BUS_FMT_UYVY10_1X20;
> +	default:
> +		return code;
> +	}
> +}
> +
> +static bool tc358746_valid_reg(struct device *dev, unsigned int reg)
> +{
> +	switch (reg) {
> +	case CHIPID_REG ... CSI_START_REG:
> +		return true;
> +	default:
> +		return false;
> +	}
> +}
> +
> +static const struct regmap_config tc358746_regmap_config = {
> +	.name = "tc358746",
> +	.reg_bits = 16,
> +	.val_bits = 16,
> +	.max_register = CSI_START_REG,
> +	.writeable_reg = tc358746_valid_reg,
> +	.readable_reg = tc358746_valid_reg,
> +	.reg_format_endian = REGMAP_ENDIAN_BIG,
> +	.val_format_endian = REGMAP_ENDIAN_BIG,
> +};
> +
> +static int tc358746_write(struct tc358746 *tc358746, u32 reg, u32 val)
> +{
> +	size_t count;
> +	int err;
> +
> +	/* 32-bit registers starting from CLW_DPHYCONTTX */
> +	count = reg < CLW_DPHYCONTTX_REG ? 1 : 2;
> +
> +	err = regmap_bulk_write(tc358746->regmap, reg, &val, count);
> +	if (err)
> +		dev_dbg(tc358746->sd.dev,
> +			"Failed to write reg:0x%04x val:0x%04x\n", reg, val);

I'm not sure if the value is relevant here, but I'd add the error, it's
useful to know what kind of I2C issue occurred. Same for read().

By the way, this isn't something you need to do in this driver, but I've
found the following pattern to be useful for error handling:

static int tc358746_write(struct tc358746 *tc358746, u32 reg, u32 val, int *err)
{
	size_t count;
	int ret;

	if (err && *err)
		return *err;

	/* 32-bit registers starting from CLW_DPHYCONTTX */
	count = reg < CLW_DPHYCONTTX_REG ? 1 : 2;

	ret = regmap_bulk_write(tc358746->regmap, reg, &val, count);
	if (ret)
		dev_dbg(tc358746->sd.dev,
			"Failed to write reg 0x%04x: %d\n", reg, ret);
		if (err)
			*err = ret;
		return ret;
	}

	return 0;
}

With this, you could simplify functions such as
tc358746_apply_dphy_config(), by initializing the local err variable to
0, calling 

	tc358746_write(tc358746, ..., ..., &err);

without checking for errors, and just returning err at the end of the
function. With the same pattern enabled in tc358746_update_bits() you
could simplify other functions too.

> +
> +	return err;
> +}
> +
> +static int tc358746_read(struct tc358746 *tc358746, u32 reg, u32 *val)
> +{
> +	size_t count;
> +	int err;
> +
> +	/* 32-bit registers starting from CLW_DPHYCONTTX */
> +	count = reg < CLW_DPHYCONTTX_REG ? 1 : 2;
> +	*val = 0;
> +
> +	err = regmap_bulk_read(tc358746->regmap, reg, val, count);
> +	if (err)
> +		dev_dbg(tc358746->sd.dev, "Failed to read reg:0x%04x\n", reg);
> +
> +	return err;
> +}
> +
> +static int
> +tc358746_update_bits(struct tc358746 *tc358746, u32 reg, u32 mask, u32 val)
> +{
> +	u32 tmp, orig;
> +	int err;
> +
> +	err = tc358746_read(tc358746, reg, &orig);
> +	if (err)
> +		return err;
> +
> +	tmp = orig & ~mask;
> +	tmp |= val & mask;
> +
> +	return tc358746_write(tc358746, reg, tmp);
> +}
> +
> +static int tc358746_set_bits(struct tc358746 *tc358746, u32 reg, u32 bits)
> +{
> +	return tc358746_update_bits(tc358746, reg, bits, bits);
> +}
> +
> +static int tc358746_clear_bits(struct tc358746 *tc358746, u32 reg, u32 bits)
> +{
> +	return tc358746_update_bits(tc358746, reg, bits, 0);
> +}
> +
> +static int tc358746_sw_reset(struct tc358746 *tc358746)
> +{
> +	int err;
> +
> +	err = tc358746_set_bits(tc358746, SYSCTL_REG, SRESET);
> +	if (err)
> +		return err;
> +
> +	fsleep(10);
> +
> +	return tc358746_clear_bits(tc358746, SYSCTL_REG, SRESET);
> +}
> +
> +static int
> +tc358746_apply_pll_config(struct tc358746 *tc358746)
> +{
> +	u8 post = tc358746->pll_post_div;
> +	u16 pre = tc358746->pll_pre_div;
> +	u16 mul = tc358746->pll_mul;
> +	u32 val, mask;
> +	int err;
> +
> +	err = tc358746_read(tc358746, PLLCTL1_REG, &val);
> +	if (err)
> +		return err;
> +
> +	/* Don't touch the PLL if running */
> +	if (FIELD_GET(PLL_EN, val) == 1)
> +		return 0;
> +
> +	/* Pre-div and Multiplicator have a internal +1 logic */
> +	val = PLL_PRD(pre - 1) | PLL_FBD(mul - 1);
> +	mask = PLL_PRD_MASK | PLL_FBD_MASK;
> +	err = tc358746_update_bits(tc358746, PLLCTL0_REG, mask, val);
> +	if (err)
> +		return err;
> +
> +	val = PLL_FRS(ilog2(post)) | RESETB | PLL_EN;
> +	mask = PLL_FRS_MASK | RESETB | PLL_EN;
> +	tc358746_update_bits(tc358746, PLLCTL1_REG, mask, val);
> +	if (err)
> +		return err;
> +
> +	fsleep(1000);
> +
> +	return tc358746_set_bits(tc358746, PLLCTL1_REG, CKEN);
> +}
> +
> +static int tc358746_apply_misc_config(struct tc358746 *tc358746)
> +{
> +	const struct v4l2_mbus_framefmt *mbusfmt;
> +	struct v4l2_subdev *sd = &tc358746->sd;
> +	struct v4l2_subdev_state *sink_state;
> +	const struct tc358746_format *fmt;
> +	struct device *dev = sd->dev;
> +	u32 val;
> +	int err;
> +
> +	sink_state = v4l2_subdev_lock_and_get_active_state(sd);
> +	mbusfmt = v4l2_subdev_get_pad_format(sd, sink_state, TC358746_SINK);
> +	v4l2_subdev_unlock_state(sink_state);
> +
> +	fmt = tc358746_get_format_by_code(TC358746_SINK, mbusfmt->code);
> +
> +	/* Self defined CSI user data type id's are not supported yet */
> +	val = PDFMT(fmt->pdformat);
> +	dev_dbg(dev, "DATAFMT: 0x%x\n", val);
> +	err = tc358746_write(tc358746, DATAFMT_REG, val);
> +	if (err)
> +		return err;
> +
> +	val = PDATAF(fmt->pdataf);
> +	dev_dbg(dev, "CONFCTL[PDATAF]: 0x%x\n", fmt->pdataf);
> +	err = tc358746_update_bits(tc358746, CONFCTL_REG, PDATAF_MASK, val);
> +	if (err)
> +		return err;
> +
> +	val = tc358746->vb_size / 32;
> +	dev_dbg(dev, "FIFOCTL: %u (0x%x)\n", val, val);
> +	err = tc358746_write(tc358746, FIFOCTL_REG, val);
> +	if (err)
> +		return err;
> +
> +	/* Total number of bytes for each line/width */
> +	val = mbusfmt->width * fmt->bpp / 8;
> +	dev_dbg(dev, "WORDCNT: %u (0x%x)\n", val, val);
> +	return tc358746_write(tc358746, WORDCNT_REG, val);
> +}
> +
> +/* Use MHz as base so the div needs no u64 */
> +static u32 tc358746_cfg_to_cnt(unsigned int cfg_val,
> +			       unsigned int clk_mhz,
> +			       unsigned int time_base)
> +{
> +	return DIV_ROUND_UP(cfg_val * clk_mhz, time_base);
> +}
> +
> +static u32 tc358746_ps_to_cnt(unsigned int cfg_val,
> +			      unsigned int clk_mhz)
> +{
> +	return tc358746_cfg_to_cnt(cfg_val, clk_mhz, USEC_PER_SEC);
> +}
> +
> +static u32 tc358746_us_to_cnt(unsigned int cfg_val,
> +			      unsigned int clk_mhz)
> +{
> +	return tc358746_cfg_to_cnt(cfg_val, clk_mhz, 1);
> +}
> +
> +static int tc358746_apply_dphy_config(struct tc358746 *tc358746)
> +{
> +	struct phy_configure_opts_mipi_dphy *cfg = &tc358746->dphy_cfg;
> +	bool non_cont_clk = !!(tc358746->csi_vep.bus.mipi_csi2.flags &
> +			       V4L2_MBUS_CSI2_NONCONTINUOUS_CLOCK);
> +	struct device *dev = tc358746->sd.dev;
> +	unsigned long hs_byte_clk, hf_clk;
> +	u32 val, val2, lptxcnt;
> +	int err;
> +
> +	/* The hs_byte_clk is also called SYSCLK in the excel sheet */
> +	hs_byte_clk = cfg->hs_clk_rate / 8;
> +	hs_byte_clk /= HZ_PER_MHZ;
> +	hf_clk = hs_byte_clk / 2;
> +
> +	val = tc358746_us_to_cnt(cfg->init, hf_clk) - 1;
> +	dev_dbg(dev, "LINEINITCNT: %u (0x%x)\n", val, val);
> +	err = tc358746_write(tc358746, LINEINITCNT_REG, val);
> +	if (err)
> +		return err;
> +
> +	val = tc358746_ps_to_cnt(cfg->lpx, hs_byte_clk) - 1;
> +	lptxcnt = val;
> +	dev_dbg(dev, "LPTXTIMECNT: %u (0x%x)\n", val, val);
> +	err = tc358746_write(tc358746, LPTXTIMECNT_REG, val);
> +	if (err)
> +		return err;
> +
> +	val = tc358746_ps_to_cnt(cfg->clk_prepare, hs_byte_clk) - 1;
> +	val2 = tc358746_ps_to_cnt(cfg->clk_zero, hs_byte_clk) - 1;
> +	dev_dbg(dev, "TCLK_PREPARECNT: %u (0x%x)\n", val, val);
> +	dev_dbg(dev, "TCLK_ZEROCNT: %u (0x%x)\n", val2, val2);
> +	dev_dbg(dev, "TCLK_HEADERCNT: 0x%x\n",
> +		(u32)(TCLK_PREPARECNT(val) | TCLK_ZEROCNT(val2)));
> +	err = tc358746_write(tc358746, TCLK_HEADERCNT_REG,
> +			     TCLK_PREPARECNT(val) | TCLK_ZEROCNT(val2));
> +	if (err)
> +		return err;
> +
> +	val = tc358746_ps_to_cnt(cfg->clk_trail, hs_byte_clk);
> +	dev_dbg(dev, "TCLK_TRAILCNT: %u (0x%x)\n", val, val);
> +	err = tc358746_write(tc358746, TCLK_TRAILCNT_REG, val);
> +	if (err)
> +		return err;
> +
> +	val = tc358746_ps_to_cnt(cfg->hs_prepare, hs_byte_clk) - 1;
> +	val2 = tc358746_ps_to_cnt(cfg->hs_zero, hs_byte_clk) - 1;
> +	dev_dbg(dev, "THS_PREPARECNT: %u (0x%x)\n", val, val);
> +	dev_dbg(dev, "THS_ZEROCNT: %u (0x%x)\n", val2, val2);
> +	dev_dbg(dev, "THS_HEADERCNT: 0x%x\n",
> +		(u32)(THS_PREPARECNT(val) | THS_ZEROCNT(val2)));
> +	err = tc358746_write(tc358746, THS_HEADERCNT_REG,
> +			     THS_PREPARECNT(val) | THS_ZEROCNT(val2));
> +	if (err)
> +		return err;
> +
> +	/* TWAKEUP > 1ms in lptxcnt steps */
> +	val = tc358746_us_to_cnt(cfg->wakeup, hs_byte_clk);
> +	val = val / (lptxcnt + 1) - 1;
> +	dev_dbg(dev, "TWAKEUP: %u (0x%x)\n", val, val);
> +	err = tc358746_write(tc358746, TWAKEUP_REG, val);
> +	if (err)
> +		return err;
> +
> +	val = tc358746_ps_to_cnt(cfg->clk_post, hs_byte_clk);
> +	dev_dbg(dev, "TCLK_POSTCNT: %u (0x%x)\n", val, val);
> +	err = tc358746_write(tc358746, TCLK_POSTCNT_REG, val);
> +	if (err)
> +		return err;
> +
> +	val = tc358746_ps_to_cnt(cfg->hs_trail, hs_byte_clk);
> +	dev_dbg(dev, "THS_TRAILCNT: %u (0x%x)\n", val, val);
> +	err = tc358746_write(tc358746, THS_TRAILCNT_REG, val);
> +	if (err)
> +		return err;
> +
> +	dev_dbg(dev, "CONTCLKMODE: %u", non_cont_clk ? 0 : 1);
> +	return  tc358746_write(tc358746, TXOPTIONCNTRL_REG, non_cont_clk ? 0 : 1);

Extra space after return.

> +}
> +
> +#define MAX_DATA_LANES 4
> +
> +static int tc358746_enable_csi_lanes(struct tc358746 *tc358746, int enable)
> +{
> +	unsigned int lanes = tc358746->dphy_cfg.lanes;
> +	unsigned int lane;
> +	u32 reg, val;
> +	int err;
> +
> +	err = tc358746_update_bits(tc358746, CONFCTL_REG, DATALANE_MASK,
> +				   lanes - 1);
> +	if (err)
> +		return err;
> +
> +	/* Clock lane */
> +	val = enable ? 0 : LANEDISABLE;
> +	dev_dbg(tc358746->sd.dev, "CLW_CNTRL: 0x%x\n", val);
> +	err = tc358746_write(tc358746, CLW_CNTRL_REG, val);
> +	if (err)
> +		return err;
> +
> +	for (lane = 0; lane < MAX_DATA_LANES; lane++) {
> +		/* Data lanes */
> +		reg = D0W_CNTRL_REG + lane * 0x4;
> +		val = (enable && lane < lanes) ? 0 : LANEDISABLE;
> +
> +		dev_dbg(tc358746->sd.dev, "D%uW_CNTRL: 0x%x\n", lane, val);
> +		err = tc358746_write(tc358746, reg, val);
> +		if (err)
> +			return err;
> +	}
> +
> +	val = 0;
> +	if (enable) {
> +		/* Clock lane */
> +		val |= BIT(0);
> +
> +		/* Data lanes */
> +		for (lane = 1; lane <= lanes; lane++)
> +			val |= BIT(lane);
> +	}
> +
> +	dev_dbg(tc358746->sd.dev, "HSTXVREGEN: 0x%x\n", val);
> +	return tc358746_write(tc358746, HSTXVREGEN_REG, val);
> +}
> +
> +static int tc358746_enable_csi_module(struct tc358746 *tc358746, int enable)
> +{
> +	unsigned int lanes = tc358746->dphy_cfg.lanes;
> +	int err;
> +
> +	/*
> +	 * START and STRT are only reseted/disabled by sw reset. This is
> +	 * required to put the lane state back into LP-11 state. The sw reset
> +	 * don't reset register values.
> +	 */
> +	if (!enable)
> +		return tc358746_sw_reset(tc358746);
> +
> +	err = tc358746_write(tc358746, STARTCNTRL_REG, START);
> +	if (err)
> +		return err;
> +
> +	err = tc358746_write(tc358746, CSI_START_REG, STRT);
> +	if (err)
> +		return err;
> +
> +	/* CSI_CONTROL_REG is only indirect accessible */
> +	return tc358746_write(tc358746, CSI_CONFW_REG,
> +			      MODE(MODE_SET) |
> +			      ADDRESS(CSI_CONTROL_ADDRESS) |
> +			      DATA(CSI_MODE | TXHSMD | NOL(lanes - 1)));
> +}
> +
> +static int tc358746_enable_parallel_port(struct tc358746 *tc358746, int enable)
> +{
> +	int err;
> +
> +	if (enable) {
> +		err = tc358746_write(tc358746, PP_MISC_REG, 0);
> +		if (err)
> +			return err;
> +
> +		return tc358746_set_bits(tc358746, CONFCTL_REG, PPEN);
> +	}
> +
> +	err = tc358746_set_bits(tc358746, PP_MISC_REG, FRMSTOP);
> +	if (err)
> +		return err;
> +
> +	err = tc358746_clear_bits(tc358746, CONFCTL_REG, PPEN);
> +	if (err)
> +		return err;
> +
> +	return tc358746_set_bits(tc358746, PP_MISC_REG, RSTPTR);
> +}
> +
> +static inline struct v4l2_subdev *tc358746_get_remote_sd(struct media_pad *pad)
> +{
> +	pad = media_pad_remote_pad_first(pad);
> +	if (!pad)
> +		return NULL;
> +
> +	return media_entity_to_v4l2_subdev(pad->entity);
> +}
> +
> +static int tc358746_s_stream(struct v4l2_subdev *sd, int enable)
> +{
> +	struct tc358746 *tc358746 = to_tc358746(sd);
> +	struct v4l2_subdev *src;
> +	int err;
> +
> +	dev_dbg(sd->dev, "%sable\n", enable ? "en" : "dis");
> +
> +	src = tc358746_get_remote_sd(&tc358746->pads[TC358746_SINK]);
> +	if (!src)
> +		return -EPIPE;
> +
> +	if (enable) {
> +		err = pm_runtime_resume_and_get(sd->dev);
> +		if (err)
> +			return err;
> +
> +		err = tc358746_apply_dphy_config(tc358746);
> +		if (err)
> +			goto err_out;
> +
> +		err = tc358746_apply_misc_config(tc358746);
> +		if (err)
> +			goto err_out;
> +
> +		err = tc358746_enable_csi_lanes(tc358746, 1);
> +		if (err)
> +			goto err_out;
> +
> +		err = tc358746_enable_csi_module(tc358746, 1);
> +		if (err)
> +			goto err_out;
> +
> +		err = tc358746_enable_parallel_port(tc358746, 1);
> +		if (err)
> +			goto err_out;
> +
> +		err = v4l2_subdev_call(src, video, s_stream, 1);
> +		if (err)
> +			goto err_out;
> +
> +		return err;
> +
> +err_out:
> +		pm_runtime_mark_last_busy(sd->dev);
> +		pm_runtime_put_sync_autosuspend(sd->dev);
> +
> +		return err;
> +	}
> +
> +	 /*
> +	  * The lanes must be disabled first (before the csi module) so the
> +	  * LP-11 state is entered correctly.
> +	  */

Wrong indentation.

> +	err = tc358746_enable_csi_lanes(tc358746, 0);
> +	if (err)
> +		return err;
> +
> +	err = tc358746_enable_csi_module(tc358746, 0);
> +	if (err)
> +		return err;
> +
> +	err = tc358746_enable_parallel_port(tc358746, 0);
> +	if (err)
> +		return err;
> +
> +	pm_runtime_mark_last_busy(sd->dev);
> +	pm_runtime_put_sync_autosuspend(sd->dev);
> +
> +	return v4l2_subdev_call(src, video, s_stream, 0);
> +}
> +
> +static int tc358746_init_cfg(struct v4l2_subdev *sd,
> +			     struct v4l2_subdev_state *state)
> +{
> +	struct v4l2_mbus_framefmt *fmt;
> +
> +	fmt = v4l2_subdev_get_pad_format(sd, state, TC358746_SINK);
> +	*fmt = tc358746_def_fmt;
> +
> +	fmt = v4l2_subdev_get_pad_format(sd, state, TC358746_SOURCE);
> +	*fmt = tc358746_def_fmt;
> +	fmt->code = tc358746_src_mbus_code(tc358746_def_fmt.code);
> +
> +	return 0;
> +}
> +
> +static int tc358746_enum_mbus_code(struct v4l2_subdev *sd,
> +				   struct v4l2_subdev_state *sd_state,
> +				   struct v4l2_subdev_mbus_code_enum *code)
> +{
> +	const struct tc358746_format *fmt;
> +
> +	fmt = tc358746_get_format_by_idx(code->pad, code->index);
> +	if (IS_ERR(fmt))
> +		return PTR_ERR(fmt);
> +
> +	code->code = fmt->code;
> +
> +	return 0;
> +}
> +
> +static int tc358746_set_fmt(struct v4l2_subdev *sd,
> +			    struct v4l2_subdev_state *sd_state,
> +			    struct v4l2_subdev_format *format)
> +{
> +	struct v4l2_mbus_framefmt *src_fmt, *sink_fmt;
> +	const struct tc358746_format *fmt;
> +
> +	/* Source follows the sink */
> +	if (format->pad == TC358746_SOURCE)
> +		return v4l2_subdev_get_fmt(sd, sd_state, format);
> +
> +	sink_fmt = v4l2_subdev_get_pad_format(sd, sd_state, TC358746_SINK);
> +
> +	fmt = tc358746_get_format_by_code(format->pad, format->format.code);
> +	if (IS_ERR(fmt))
> +		fmt = tc358746_get_format_by_code(format->pad, tc358746_def_fmt.code);
> +
> +	format->format.code = fmt->code;
> +	format->format.field = V4L2_FIELD_NONE;
> +
> +	dev_dbg(sd->dev, "Update format: %ux%u code:0x%x -> %ux%u code:0x%x",
> +		sink_fmt->width, sink_fmt->height, sink_fmt->code,
> +		format->format.width, format->format.height, format->format.code);
> +
> +	*sink_fmt = format->format;
> +
> +	src_fmt = v4l2_subdev_get_pad_format(sd, sd_state, TC358746_SOURCE);
> +	*src_fmt = *sink_fmt;
> +	src_fmt->code = tc358746_src_mbus_code(sink_fmt->code);
> +
> +	return 0;
> +}
> +
> +static unsigned long tc358746_find_pll_settings(struct tc358746 *tc358746,
> +						unsigned long refclk,
> +						unsigned long fout)
> +
> +{
> +	struct device *dev = tc358746->sd.dev;
> +	unsigned long best_freq = 0;
> +	u32 min_delta = 0xffffffff;
> +	u16 prediv_max = 17;
> +	u16 prediv_min = 1;
> +	u16 m_best, mul;
> +	u16 p_best, p;
> +	u8 postdiv;
> +
> +	if (fout > 1000 * HZ_PER_MHZ) {
> +		dev_err(dev, "HS-Clock above 1 Ghz are not supported\n");
> +		return 0;
> +	}
> +
> +	if (fout >= 500 * HZ_PER_MHZ)
> +		postdiv = 1;
> +	else if (fout >= 250 * HZ_PER_MHZ)
> +		postdiv = 2;
> +	else if (fout >= 125 * HZ_PER_MHZ)
> +		postdiv = 4;
> +	else
> +		postdiv = 8;
> +
> +	for (p = prediv_min; p <= prediv_max; p++) {
> +		unsigned long delta, fin;
> +		u64 tmp;
> +
> +		fin = DIV_ROUND_CLOSEST(refclk, p);
> +		if (fin < 4 * HZ_PER_MHZ || fin > 40 * HZ_PER_MHZ)
> +			continue;
> +
> +		tmp = fout * p * postdiv;
> +		do_div(tmp, fin);
> +		mul = tmp;
> +		if (mul > 511)
> +			continue;
> +
> +		tmp = mul * fin;
> +		do_div(tmp, p * postdiv);
> +
> +		delta = abs(fout - tmp);
> +		if (delta < min_delta) {
> +			p_best = p;
> +			m_best = mul;
> +			min_delta = delta;
> +			best_freq = tmp;
> +		};
> +
> +		if (delta == 0)
> +			break;
> +	};
> +
> +	if (!best_freq) {
> +		dev_err(dev, "Failed find PLL frequency\n");
> +		return 0;
> +	}
> +
> +	tc358746->pll_post_div = postdiv;
> +	tc358746->pll_pre_div = p_best;
> +	tc358746->pll_mul = m_best;
> +
> +	if (best_freq != fout)
> +		dev_warn(dev, "Request PLL freq:%lu, found PLL freq:%lu\n",
> +			 fout, best_freq);
> +
> +	dev_dbg(dev, "Found PLL settings: freq:%lu prediv:%u multi:%u postdiv:%u\n",
> +		best_freq, p_best, m_best, postdiv);
> +
> +	return best_freq;
> +}
> +
> +#define TC358746_PRECISION 10
> +
> +static int
> +tc358746_link_validate(struct v4l2_subdev *sd, struct media_link *link,
> +		       struct v4l2_subdev_format *source_fmt,
> +		       struct v4l2_subdev_format *sink_fmt)
> +{
> +	struct tc358746 *tc358746 = to_tc358746(sd);
> +	unsigned long csi_bitrate, source_bitrate;
> +	struct v4l2_subdev_state *sink_state;
> +	struct v4l2_mbus_framefmt *mbusfmt;
> +	const struct tc358746_format *fmt;
> +	unsigned int fifo_sz, tmp, n;
> +	struct v4l2_subdev *source;
> +	s64 source_link_freq;
> +	int err;
> +
> +	err = v4l2_subdev_link_validate_default(sd, link, source_fmt, sink_fmt);
> +	if (err)
> +		return err;
> +
> +	sink_state = v4l2_subdev_lock_and_get_active_state(sd);
> +	mbusfmt = v4l2_subdev_get_pad_format(sd, sink_state, TC358746_SINK);
> +
> +	/* Check the FIFO settings */
> +	fmt = tc358746_get_format_by_code(TC358746_SINK, mbusfmt->code);
> +
> +	source = media_entity_to_v4l2_subdev(link->source->entity);
> +	source_link_freq = v4l2_get_link_freq(source->ctrl_handler, 0, 0);
> +	if (source_link_freq <= 0) {
> +		dev_err(tc358746->sd.dev,
> +			"Failed to query or invalid source link frequency\n");
> +		v4l2_subdev_unlock_state(sink_state);
> +		/* Return -EINVAL in case of source_link_freq is 0 */
> +		return source_link_freq ? : -EINVAL;
> +	}
> +	source_bitrate = source_link_freq * fmt->bus_width;
> +
> +	csi_bitrate = tc358746->dphy_cfg.lanes * tc358746->pll_rate;
> +
> +	dev_dbg(tc358746->sd.dev,
> +		"Fifo settings params: source-bitrate:%lu csi-bitrate:%lu",
> +		source_bitrate, csi_bitrate);
> +
> +	/* Avoid possible FIFO overflows */
> +	if (csi_bitrate < source_bitrate) {
> +		v4l2_subdev_unlock_state(sink_state);
> +		return -EINVAL;
> +	}
> +
> +	/* Best case */
> +	if (csi_bitrate == source_bitrate) {
> +		fifo_sz = TC358746_VB_DEFAULT_SIZE;
> +		tc358746->vb_size = TC358746_VB_DEFAULT_SIZE;
> +		goto out;
> +	}
> +
> +	/*
> +	 * Avoid possible FIFO underflow in case of
> +	 * csi_bitrate > source_bitrate. For such case the chip has a internal
> +	 * fifo which can be used to delay the line output.
> +	 *
> +	 * Fifo size calculation (excluding precision):
> +	 *
> +	 * fifo-sz, image-width - in bits
> +	 * sbr                  - source_bitrate in bits/s
> +	 * csir                 - csi_bitrate in bits/s
> +	 *
> +	 *                1               1      1
> +	 * image-width * --- + fifo-sz * --- >= ---- * image-width
> +	 *               sbr             sbr    csir

I still think there's something fishy here. The inequality is always
true as csir > sbr. You will get a non-zero fifo size in your
calculation because you artifically add an abs(), but I don't think
that's right.

If I understand things correctly, you need to ensure that once the FIFO
threshold is reached and the CSI-2 side starts sending data, the input
size will keep feeding data fast enough for the FIFO to never underrun.

The FIFO level triggers the CSI-2 transmission. This means that once the
CSI-2 transmission start, fifo-sz bits have been written to the FIFO
already, and image-width - fifo-sz bits still need to be written. To
avoid underruns, you need to ensure that the time required to read all
the data (image-width) on the CSI-2 size will be higher than or equal to
the time required to write the remaining data (image-width - fifo-sz) on
the input side. This translates to

	image-width / csir >= (image-width - fifo-sz) / sbr
	image-width * sbr / csir >= image-width - fifo-sz
	fifo-sz >= image-width - image-width * sbr / csir

The calculation is thus correct, but not for the right reason :-) All
you need to fix here is the comment, not the code.

With these small issues fixed,

Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

> +	 *
> +	 * fifo-sz >= abs(sbr/csir * image-width - image-width); with n = csir/sbr
> +	 *
> +	 * fifo-sz >= abs(image-width / n - image-width)
> +	 *         >= image-width - image-width / n
> +	 */
> +
> +	source_bitrate /= TC358746_PRECISION;
> +	n = csi_bitrate / source_bitrate;
> +	tmp = (mbusfmt->width * TC358746_PRECISION) / n;
> +	fifo_sz = mbusfmt->width - tmp;
> +	fifo_sz *= fmt->bpp;
> +	tc358746->vb_size = round_up(fifo_sz, 32);
> +
> +out:
> +	dev_dbg(tc358746->sd.dev,
> +		"Found FIFO size[bits]:%u -> aligned to size[bits]:%u\n",
> +		fifo_sz, tc358746->vb_size);
> +
> +	v4l2_subdev_unlock_state(sink_state);
> +
> +	return tc358746->vb_size > TC358746_VB_MAX_SIZE ? -EINVAL : 0;
> +}
> +
> +static int tc358746_get_mbus_config(struct v4l2_subdev *sd, unsigned int pad,
> +				    struct v4l2_mbus_config *config)
> +{
> +	struct tc358746 *tc358746 = to_tc358746(sd);
> +
> +	if (pad != TC358746_SOURCE)
> +		return -EINVAL;
> +
> +	config->type = V4L2_MBUS_CSI2_DPHY;
> +	config->bus.mipi_csi2 = tc358746->csi_vep.bus.mipi_csi2;
> +
> +	return 0;
> +}
> +
> +static int __maybe_unused
> +tc358746_g_register(struct v4l2_subdev *sd, struct v4l2_dbg_register *reg)
> +{
> +	struct tc358746 *tc358746 = to_tc358746(sd);
> +
> +	/* 32-bit registers starting from CLW_DPHYCONTTX */
> +	reg->size = reg->reg < CLW_DPHYCONTTX_REG ? 2 : 4;
> +
> +	if (!pm_runtime_get_if_in_use(sd->dev))
> +		return 0;
> +
> +	tc358746_read(tc358746, reg->reg, (u32 *)&reg->val);
> +
> +	pm_runtime_mark_last_busy(sd->dev);
> +	pm_runtime_put_sync_autosuspend(sd->dev);
> +
> +	return 0;
> +}
> +
> +static int __maybe_unused
> +tc358746_s_register(struct v4l2_subdev *sd, const struct v4l2_dbg_register *reg)
> +{
> +	struct tc358746 *tc358746 = to_tc358746(sd);
> +
> +	if (!pm_runtime_get_if_in_use(sd->dev))
> +		return 0;
> +
> +	tc358746_write(tc358746, (u32)reg->reg, (u32)reg->val);
> +
> +	pm_runtime_mark_last_busy(sd->dev);
> +	pm_runtime_put_sync_autosuspend(sd->dev);
> +
> +	return 0;
> +}
> +
> +static const struct v4l2_subdev_core_ops tc358746_core_ops = {
> +#ifdef CONFIG_VIDEO_ADV_DEBUG
> +	.g_register = tc358746_g_register,
> +	.s_register = tc358746_s_register,
> +#endif
> +};
> +
> +static const struct v4l2_subdev_video_ops tc358746_video_ops = {
> +	.s_stream = tc358746_s_stream,
> +};
> +
> +static const struct v4l2_subdev_pad_ops tc358746_pad_ops = {
> +	.init_cfg = tc358746_init_cfg,
> +	.enum_mbus_code = tc358746_enum_mbus_code,
> +	.set_fmt = tc358746_set_fmt,
> +	.get_fmt = v4l2_subdev_get_fmt,
> +	.link_validate = tc358746_link_validate,
> +	.get_mbus_config = tc358746_get_mbus_config,
> +};
> +
> +static const struct v4l2_subdev_ops tc358746_ops = {
> +	.core = &tc358746_core_ops,
> +	.video = &tc358746_video_ops,
> +	.pad = &tc358746_pad_ops,
> +};
> +
> +static const struct media_entity_operations tc358746_entity_ops = {
> +	.get_fwnode_pad = v4l2_subdev_get_fwnode_pad_1_to_1,
> +	.link_validate = v4l2_subdev_link_validate,
> +};
> +
> +static int tc358746_mclk_enable(struct clk_hw *hw)
> +{
> +	struct tc358746 *tc358746 = clk_hw_to_tc358746(hw);
> +	unsigned int div;
> +	u32 val;
> +	int err;
> +
> +	div = tc358746->mclk_postdiv / 2;
> +	val = MCLK_HIGH(div - 1) | MCLK_LOW(div - 1);
> +	dev_dbg(tc358746->sd.dev, "MCLKCTL: %u (0x%x)\n", val, val);
> +	err = tc358746_write(tc358746, MCLKCTL_REG, val);
> +	if (err)
> +		return err;
> +
> +	if (tc358746->mclk_prediv == 8)
> +		val = MCLKDIV(MCLKDIV_8);
> +	else if (tc358746->mclk_prediv == 4)
> +		val = MCLKDIV(MCLKDIV_4);
> +	else
> +		val = MCLKDIV(MCLKDIV_2);
> +
> +	dev_dbg(tc358746->sd.dev, "CLKCTL[MCLKDIV]: %u (0x%x)\n", val, val);
> +	return tc358746_update_bits(tc358746, CLKCTL_REG, MCLKDIV_MASK, val);
> +}
> +
> +static void tc358746_mclk_disable(struct clk_hw *hw)
> +{
> +	struct tc358746 *tc358746 = clk_hw_to_tc358746(hw);
> +
> +	tc358746_write(tc358746, MCLKCTL_REG, 0);
> +}
> +
> +static long
> +tc358746_find_mclk_settings(struct tc358746 *tc358746, unsigned long mclk_rate)
> +{
> +	unsigned long pll_rate = tc358746->pll_rate;
> +	const unsigned char prediv[] = { 2, 4, 8 };
> +	unsigned int mclk_prediv, mclk_postdiv;
> +	struct device *dev = tc358746->sd.dev;
> +	unsigned int postdiv, mclkdiv;
> +	unsigned long best_mclk_rate;
> +	unsigned int i;
> +
> +	/*
> +	 *                          MCLK-Div
> +	 *           -------------------´`---------------------
> +	 *          ´                                          `
> +	 *         +-------------+     +------------------------+
> +	 *         | MCLK-PreDiv |     |       MCLK-PostDiv     |
> +	 * PLL --> |   (2/4/8)   | --> | (mclk_low + mclk_high) | --> MCLK
> +	 *         +-------------+     +------------------------+
> +	 *
> +	 * The register value of mclk_low/high is mclk_low/high+1, i.e.:
> +	 *   mclk_low/high = 1   --> 2 MCLK-Ref Counts
> +	 *   mclk_low/high = 255 --> 256 MCLK-Ref Counts == max.
> +	 * If mclk_low and mclk_high are 0 then MCLK is disabled.
> +	 *
> +	 * Keep it simple and support 50/50 duty cycles only for now,
> +	 * so the calc will be:
> +	 *
> +	 *   MCLK = PLL / (MCLK-PreDiv * 2 * MCLK-PostDiv)
> +	 */
> +
> +	if (mclk_rate == tc358746->mclk_rate)
> +		return mclk_rate;
> +
> +	/* Highest possible rate */
> +	mclkdiv = pll_rate / mclk_rate;
> +	if (mclkdiv <= 8) {
> +		mclk_prediv = 2;
> +		mclk_postdiv = 4;
> +		best_mclk_rate = pll_rate / (2 * 4);
> +		goto out;
> +	}
> +
> +	/* First check the prediv */
> +	for (i = 0; i < ARRAY_SIZE(prediv); i++) {
> +		postdiv = mclkdiv / prediv[i];
> +
> +		if (postdiv % 2)
> +			continue;
> +
> +		if (postdiv >= 4 && postdiv <= 512) {
> +			mclk_prediv = prediv[i];
> +			mclk_postdiv = postdiv;
> +			best_mclk_rate = pll_rate / (prediv[i] * postdiv);
> +			goto out;
> +		}
> +	}
> +
> +	/* No suitable prediv found, so try to adjust the postdiv */
> +	for (postdiv = 4; postdiv <= 512; postdiv += 2) {
> +		unsigned int pre;
> +
> +		pre = mclkdiv / postdiv;
> +		if (pre == 2 || pre == 4 || pre == 8) {
> +			mclk_prediv = pre;
> +			mclk_postdiv = postdiv;
> +			best_mclk_rate = pll_rate / (pre * postdiv);
> +			goto out;
> +		}
> +	}
> +
> +	/* The MCLK <-> PLL gap is to high -> use largest possible div */
> +	mclk_prediv = 8;
> +	mclk_postdiv = 512;
> +	best_mclk_rate = pll_rate / (8 * 512);
> +
> +out:
> +	tc358746->mclk_prediv = mclk_prediv;
> +	tc358746->mclk_postdiv = mclk_postdiv;
> +	tc358746->mclk_rate = best_mclk_rate;
> +
> +	if (best_mclk_rate != mclk_rate)
> +		dev_warn(dev, "Request MCLK freq:%lu, found MCLK freq:%lu\n",
> +			 mclk_rate, best_mclk_rate);
> +
> +	dev_dbg(dev, "Found MCLK settings: freq:%lu prediv:%u postdiv:%u\n",
> +		best_mclk_rate, mclk_prediv, mclk_postdiv);
> +
> +	return best_mclk_rate;
> +}
> +
> +static unsigned long
> +tc358746_recalc_rate(struct clk_hw *hw, unsigned long parent_rate)
> +{
> +	struct tc358746 *tc358746 = clk_hw_to_tc358746(hw);
> +	unsigned int prediv, postdiv;
> +	u32 val;
> +	int err;
> +
> +	err = tc358746_read(tc358746, MCLKCTL_REG, &val);
> +	if (err)
> +		return 0;
> +
> +	postdiv = FIELD_GET(MCLK_LOW_MASK, val) + 1;
> +	postdiv += FIELD_GET(MCLK_HIGH_MASK, val) + 1;
> +
> +	err = tc358746_read(tc358746, CLKCTL_REG, &val);
> +	if (err)
> +		return 0;
> +
> +	prediv = FIELD_GET(MCLKDIV_MASK, val);
> +	if (prediv == MCLKDIV_8)
> +		prediv = 8;
> +	else if (prediv == MCLKDIV_4)
> +		prediv = 4;
> +	else
> +		prediv = 2;
> +
> +	return tc358746->pll_rate / (prediv * postdiv);
> +}
> +
> +static long tc358746_mclk_round_rate(struct clk_hw *hw, unsigned long rate,
> +				     unsigned long *parent_rate)
> +{
> +	struct tc358746 *tc358746 = clk_hw_to_tc358746(hw);
> +
> +	*parent_rate = tc358746->pll_rate;
> +
> +	return tc358746_find_mclk_settings(tc358746, rate);
> +}
> +
> +static int tc358746_mclk_set_rate(struct clk_hw *hw, unsigned long rate,
> +				  unsigned long parent_rate)
> +{
> +	struct tc358746 *tc358746 = clk_hw_to_tc358746(hw);
> +
> +	tc358746_find_mclk_settings(tc358746, rate);
> +
> +	return tc358746_mclk_enable(hw);
> +}
> +
> +static const struct clk_ops tc358746_mclk_ops = {
> +	.enable = tc358746_mclk_enable,
> +	.disable = tc358746_mclk_disable,
> +	.recalc_rate = tc358746_recalc_rate,
> +	.round_rate = tc358746_mclk_round_rate,
> +	.set_rate = tc358746_mclk_set_rate,
> +};
> +
> +static int tc358746_setup_mclk_provider(struct tc358746 *tc358746)
> +{
> +	struct clk_init_data mclk_initdata = { };
> +	struct device *dev = tc358746->sd.dev;
> +	const char *mclk_name;
> +	int err;
> +
> +	/* MCLK clk provider support is optional */
> +	if (!device_property_present(dev, "#clock-cells"))
> +		return 0;
> +
> +	/* Init to highest possibel MCLK */
> +	tc358746->mclk_postdiv = 512;
> +	tc358746->mclk_prediv = 8;
> +
> +	mclk_name = "tc358746-mclk";
> +	device_property_read_string(dev, "clock-output-names", &mclk_name);
> +
> +	mclk_initdata.name = mclk_name;
> +	mclk_initdata.ops = &tc358746_mclk_ops;
> +	tc358746->mclk_hw.init = &mclk_initdata;
> +
> +	err = devm_clk_hw_register(dev, &tc358746->mclk_hw);
> +	if (err) {
> +		dev_err(dev, "Failed to register mclk provider\n");
> +		return err;
> +	}
> +
> +	err = devm_of_clk_add_hw_provider(dev, of_clk_hw_simple_get,
> +					  &tc358746->mclk_hw);
> +	if (err)
> +		dev_err(dev, "Failed to add mclk provider\n");
> +
> +	return err;
> +}
> +
> +static int
> +tc358746_init_subdev(struct tc358746 *tc358746, struct i2c_client *client)
> +{
> +	struct v4l2_subdev *sd = &tc358746->sd;
> +	int err;
> +
> +	v4l2_i2c_subdev_init(sd, client, &tc358746_ops);
> +	sd->flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;
> +	sd->entity.function = MEDIA_ENT_F_VID_IF_BRIDGE;
> +	sd->entity.ops = &tc358746_entity_ops;
> +
> +	tc358746->pads[TC358746_SINK].flags = MEDIA_PAD_FL_SINK;
> +	tc358746->pads[TC358746_SOURCE].flags = MEDIA_PAD_FL_SOURCE;
> +	err = media_entity_pads_init(&sd->entity, TC358746_NR_PADS,
> +				     tc358746->pads);
> +	if (err)
> +		return err;
> +
> +	err = v4l2_subdev_init_finalize(sd);
> +	if (err)
> +		media_entity_cleanup(&sd->entity);
> +
> +	return err;
> +}
> +
> +static int
> +tc358746_init_output_port(struct tc358746 *tc358746, unsigned long refclk)
> +{
> +	struct device *dev = tc358746->sd.dev;
> +	struct v4l2_fwnode_endpoint *vep;
> +	unsigned long csi_link_rate;
> +	struct fwnode_handle *ep;
> +	unsigned char csi_lanes;
> +	int err;
> +
> +	ep = fwnode_graph_get_endpoint_by_id(dev_fwnode(dev), TC358746_SOURCE,
> +					     0, 0);
> +	if (!ep) {
> +		dev_err(dev, "Missing endpoint node\n");
> +		return -EINVAL;
> +	}
> +
> +	/* Currently we only support 'parallel in' -> 'csi out' */
> +	vep = &tc358746->csi_vep;
> +	vep->bus_type = V4L2_MBUS_CSI2_DPHY;
> +	err = v4l2_fwnode_endpoint_alloc_parse(ep, vep);
> +	fwnode_handle_put(ep);
> +	if (err) {
> +		dev_err(dev, "Failed to parse source endpoint\n");
> +		return err;
> +	}
> +
> +	csi_lanes = vep->bus.mipi_csi2.num_data_lanes;
> +	if (csi_lanes == 0 || csi_lanes > 4 ||
> +	    vep->nr_of_link_frequencies == 0) {
> +		dev_err(dev, "error: Invalid CSI-2 settings\n");
> +		err = -EINVAL;
> +		goto err;
> +	}
> +
> +	/* TODO: Add support to handle multiple link frequencies */
> +	csi_link_rate = (unsigned long)vep->link_frequencies[0];
> +	tc358746->pll_rate = tc358746_find_pll_settings(tc358746, refclk,
> +							csi_link_rate * 2);
> +	if (!tc358746->pll_rate) {
> +		err = -EINVAL;
> +		goto err;
> +	}
> +
> +	err = phy_mipi_dphy_get_default_config_for_hsclk(tc358746->pll_rate,
> +						csi_lanes, &tc358746->dphy_cfg);
> +	if (err)
> +		goto err;
> +
> +	tc358746->vb_size = TC358746_VB_DEFAULT_SIZE;
> +
> +	return 0;
> +
> +err:
> +	v4l2_fwnode_endpoint_free(vep);
> +
> +	return err;
> +}
> +
> +static int tc358746_init_hw(struct tc358746 *tc358746)
> +{
> +	struct device *dev = tc358746->sd.dev;
> +	unsigned int chipid;
> +	u32 val;
> +	int err;
> +
> +	err = pm_runtime_resume_and_get(dev);
> +	if (err < 0) {
> +		dev_err(dev, "Failed to resume the device\n");
> +		return err;
> +	}
> +
> +	 /* Ensure that CSI interface is put into LP-11 state */
> +	err = tc358746_sw_reset(tc358746);
> +	if (err) {
> +		pm_runtime_put_sync(dev);
> +		dev_err(dev, "Failed to reset the device\n");
> +		return err;
> +	}
> +
> +	err = tc358746_read(tc358746, CHIPID_REG, &val);
> +	pm_runtime_mark_last_busy(dev);
> +	pm_runtime_put_sync_autosuspend(dev);
> +	if (err)
> +		return -ENODEV;
> +
> +	chipid = FIELD_GET(CHIPID, val);
> +	if (chipid != 0x44) {
> +		dev_err(dev, "Invalid chipid 0x%02x\n", chipid);
> +		return -ENODEV;
> +	}
> +
> +	return 0;
> +}
> +
> +static int tc358746_init_controls(struct tc358746 *tc358746)
> +{
> +	u64 *link_frequencies = tc358746->csi_vep.link_frequencies;
> +	struct v4l2_ctrl *ctrl;
> +	int err;
> +
> +	err = v4l2_ctrl_handler_init(&tc358746->ctrl_hdl, 1);
> +	if (err)
> +		return err;
> +
> +	/*
> +	 * The driver currently supports only one link-frequency, regardless of
> +	 * the input from the firmware, see: tc358746_init_output_port(). So
> +	 * report only the first frequency from the array of possible given
> +	 * frequencies.
> +	 */
> +	ctrl = v4l2_ctrl_new_int_menu(&tc358746->ctrl_hdl, NULL,
> +				      V4L2_CID_LINK_FREQ, 0, 0,
> +				      link_frequencies);
> +	if (ctrl)
> +		ctrl->flags |= V4L2_CTRL_FLAG_READ_ONLY;
> +
> +	err = tc358746->ctrl_hdl.error;
> +	if (err) {
> +		v4l2_ctrl_handler_free(&tc358746->ctrl_hdl);
> +		return err;
> +	}
> +
> +	tc358746->sd.ctrl_handler = &tc358746->ctrl_hdl;
> +
> +	return 0;
> +}
> +
> +static int tc358746_notify_bound(struct v4l2_async_notifier *notifier,
> +				 struct v4l2_subdev *sd,
> +				 struct v4l2_async_subdev *asd)
> +{
> +	struct tc358746 *tc358746 =
> +		container_of(notifier, struct tc358746, notifier);
> +	u32 flags = MEDIA_LNK_FL_ENABLED | MEDIA_LNK_FL_IMMUTABLE;
> +	struct media_pad *sink = &tc358746->pads[TC358746_SINK];
> +
> +	return v4l2_create_fwnode_links_to_pad(sd, sink, flags);
> +}
> +
> +static const struct v4l2_async_notifier_operations tc358746_notify_ops = {
> +	.bound = tc358746_notify_bound,
> +};
> +
> +static int tc358746_async_register(struct tc358746 *tc358746)
> +{
> +	struct v4l2_fwnode_endpoint vep = {
> +		.bus_type = V4L2_MBUS_PARALLEL,
> +	};
> +	struct v4l2_async_subdev *asd;
> +	struct fwnode_handle *ep;
> +	int err;
> +
> +	ep = fwnode_graph_get_endpoint_by_id(dev_fwnode(tc358746->sd.dev),
> +					     TC358746_SINK, 0, 0);
> +	if (!ep)
> +		return -ENOTCONN;
> +
> +	err = v4l2_fwnode_endpoint_parse(ep, &vep);
> +	if (err) {
> +		fwnode_handle_put(ep);
> +		return err;
> +	}
> +
> +	v4l2_async_nf_init(&tc358746->notifier);
> +	asd = v4l2_async_nf_add_fwnode_remote(&tc358746->notifier, ep,
> +					      struct v4l2_async_subdev);
> +	fwnode_handle_put(ep);
> +
> +	if (IS_ERR(asd)) {
> +		err = PTR_ERR(asd);
> +		goto err_cleanup;
> +	}
> +
> +	tc358746->notifier.ops = &tc358746_notify_ops;
> +
> +	err = v4l2_async_subdev_nf_register(&tc358746->sd, &tc358746->notifier);
> +	if (err)
> +		goto err_cleanup;
> +
> +	tc358746->sd.fwnode = fwnode_graph_get_endpoint_by_id(
> +		dev_fwnode(tc358746->sd.dev), TC358746_SOURCE, 0, 0);
> +
> +	err = v4l2_async_register_subdev(&tc358746->sd);
> +	if (err)
> +		goto err_unregister;
> +
> +	return 0;
> +
> +err_unregister:
> +	fwnode_handle_put(tc358746->sd.fwnode);
> +	v4l2_async_nf_unregister(&tc358746->notifier);
> +err_cleanup:
> +	v4l2_async_nf_cleanup(&tc358746->notifier);
> +
> +	return err;
> +}
> +
> +static int tc358746_probe(struct i2c_client *client)
> +{
> +	struct device *dev = &client->dev;
> +	struct tc358746 *tc358746;
> +	unsigned long refclk;
> +	unsigned int i;
> +	int err;
> +
> +	tc358746 = devm_kzalloc(&client->dev, sizeof(*tc358746), GFP_KERNEL);
> +	if (!tc358746)
> +		return -ENOMEM;
> +
> +	tc358746->regmap = devm_regmap_init_i2c(client, &tc358746_regmap_config);
> +	if (IS_ERR(tc358746->regmap))
> +		return dev_err_probe(dev, PTR_ERR(tc358746->regmap),
> +				     "Failed to init regmap\n");
> +
> +	tc358746->refclk = devm_clk_get(dev, "refclk");
> +	if (IS_ERR(tc358746->refclk))
> +		return dev_err_probe(dev, PTR_ERR(tc358746->refclk),
> +				     "Failed to get refclk\n");
> +
> +	err = clk_prepare_enable(tc358746->refclk);
> +	if (err)
> +		return dev_err_probe(dev, err,
> +				     "Failed to enable refclk\n");
> +
> +	refclk = clk_get_rate(tc358746->refclk);
> +	clk_disable_unprepare(tc358746->refclk);
> +
> +	if (refclk < 6 * HZ_PER_MHZ || refclk > 40 * HZ_PER_MHZ)
> +		return dev_err_probe(dev, -EINVAL, "Invalid refclk range\n");
> +
> +	for (i = 0; i < ARRAY_SIZE(tc358746_supplies); i++)
> +		tc358746->supplies[i].supply = tc358746_supplies[i];
> +
> +	err = devm_regulator_bulk_get(dev, ARRAY_SIZE(tc358746_supplies),
> +				      tc358746->supplies);
> +	if (err)
> +		return dev_err_probe(dev, err, "Failed to get supplies\n");
> +
> +	tc358746->reset_gpio = devm_gpiod_get_optional(dev, "reset",
> +						       GPIOD_OUT_HIGH);
> +	if (IS_ERR(tc358746->reset_gpio))
> +		return dev_err_probe(dev, PTR_ERR(tc358746->reset_gpio),
> +				     "Failed to get reset-gpios\n");
> +
> +	err = tc358746_init_subdev(tc358746, client);
> +	if (err)
> +		return dev_err_probe(dev, err, "Failed to init subdev\n");
> +
> +	err = tc358746_init_output_port(tc358746, refclk);
> +	if (err)
> +		goto err_subdev;
> +
> +	/*
> +	 * Keep this order since we need the output port link-frequencies
> +	 * information.
> +	 */
> +	err = tc358746_init_controls(tc358746);
> +	if (err)
> +		goto err_fwnode;
> +
> +	dev_set_drvdata(dev, tc358746);
> +
> +	/* Set to 1sec to give the stream reconfiguration enough time */
> +	pm_runtime_set_autosuspend_delay(dev, 1000);
> +	pm_runtime_use_autosuspend(dev);
> +	pm_runtime_enable(dev);
> +
> +	err = tc358746_init_hw(tc358746);
> +	if (err)
> +		goto err_pm;
> +
> +	err = tc358746_setup_mclk_provider(tc358746);
> +	if (err)
> +		goto err_pm;
> +
> +	err = tc358746_async_register(tc358746);
> +	if (err < 0)
> +		goto err_pm;
> +
> +	dev_dbg(dev, "%s found @ 0x%x (%s)\n", client->name,
> +		client->addr, client->adapter->name);
> +
> +	return 0;
> +
> +err_pm:
> +	pm_runtime_disable(dev);
> +	pm_runtime_set_suspended(dev);
> +	pm_runtime_dont_use_autosuspend(dev);
> +	v4l2_ctrl_handler_free(&tc358746->ctrl_hdl);
> +err_fwnode:
> +	v4l2_fwnode_endpoint_free(&tc358746->csi_vep);
> +err_subdev:
> +	v4l2_subdev_cleanup(&tc358746->sd);
> +	media_entity_cleanup(&tc358746->sd.entity);
> +
> +	return err;
> +}
> +
> +static int tc358746_remove(struct i2c_client *client)
> +{
> +	struct v4l2_subdev *sd = i2c_get_clientdata(client);
> +	struct tc358746 *tc358746 = to_tc358746(sd);
> +
> +	v4l2_subdev_cleanup(sd);
> +	v4l2_ctrl_handler_free(&tc358746->ctrl_hdl);
> +	v4l2_fwnode_endpoint_free(&tc358746->csi_vep);
> +	v4l2_async_nf_unregister(&tc358746->notifier);
> +	v4l2_async_nf_cleanup(&tc358746->notifier);
> +	fwnode_handle_put(sd->fwnode);
> +	v4l2_async_unregister_subdev(sd);
> +	media_entity_cleanup(&sd->entity);
> +
> +	pm_runtime_disable(sd->dev);
> +	pm_runtime_set_suspended(sd->dev);
> +	pm_runtime_dont_use_autosuspend(sd->dev);
> +
> +	return 0;
> +}
> +
> +static int tc358746_suspend(struct device *dev)
> +{
> +	struct tc358746 *tc358746 = dev_get_drvdata(dev);
> +	int err;
> +
> +	clk_disable_unprepare(tc358746->refclk);
> +
> +	err = regulator_bulk_disable(ARRAY_SIZE(tc358746_supplies),
> +				     tc358746->supplies);
> +	if (err)
> +		clk_prepare_enable(tc358746->refclk);
> +
> +	return err;
> +}
> +
> +static int tc358746_resume(struct device *dev)
> +{
> +	struct tc358746 *tc358746 = dev_get_drvdata(dev);
> +	int err;
> +
> +	gpiod_set_value(tc358746->reset_gpio, 1);
> +
> +	err = regulator_bulk_enable(ARRAY_SIZE(tc358746_supplies),
> +				    tc358746->supplies);
> +	if (err)
> +		return err;
> +
> +	/* min. 200ns */
> +	usleep_range(10, 20);
> +
> +	gpiod_set_value(tc358746->reset_gpio, 0);
> +
> +	err = clk_prepare_enable(tc358746->refclk);
> +	if (err)
> +		goto err;
> +
> +	/* min. 700us ... 1ms */
> +	usleep_range(1000, 1500);
> +
> +	/*
> +	 * Enable the PLL here since it can be called by the clk-framework or by
> +	 * the .s_stream() callback. So this is the common place for both.
> +	 */
> +	err = tc358746_apply_pll_config(tc358746);
> +	if (err)
> +		goto err_clk;
> +
> +	return 0;
> +
> +err_clk:
> +	clk_disable_unprepare(tc358746->refclk);
> +err:
> +	regulator_bulk_disable(ARRAY_SIZE(tc358746_supplies),
> +			       tc358746->supplies);
> +	return err;
> +}
> +
> +DEFINE_RUNTIME_DEV_PM_OPS(tc358746_pm_ops, tc358746_suspend,
> +			  tc358746_resume, NULL);
> +
> +static const struct of_device_id __maybe_unused tc358746_of_match[] = {
> +	{ .compatible = "toshiba,tc358746" },
> +	{ },
> +};
> +MODULE_DEVICE_TABLE(of, tc358746_of_match);
> +
> +static struct i2c_driver tc358746_driver = {
> +	.driver = {
> +		.name = "tc358746",
> +		.pm = pm_ptr(&tc358746_pm_ops),
> +		.of_match_table = tc358746_of_match,
> +	},
> +	.probe_new = tc358746_probe,
> +	.remove = tc358746_remove,
> +};
> +
> +module_i2c_driver(tc358746_driver);
> +
> +MODULE_DESCRIPTION("Toshiba TC358746 Parallel to CSI-2 bridge driver");
> +MODULE_AUTHOR("Marco Felsch <kernel@pengutronix.de>");
> +MODULE_LICENSE("GPL");

-- 
Regards,

Laurent Pinchart

-- 
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linux-phy@lists.infradead.org
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Re: [PATCH v3 4/4] media: tc358746: add Toshiba TC358746 Parallel to CSI-2 bridge driver

[Marco Felsch]

Hi Laurent,

On 22-09-22, Laurent Pinchart wrote:
> Hi Marco,
> 
> Thank you for the patch.
> 
> On Thu, Sep 22, 2022 at 03:48:43PM +0200, Marco Felsch wrote:
> > Adding support for the TC358746 parallel <-> MIPI CSI bridge. This chip
> > supports two operating modes:
> >   1st) parallel-in -> mipi-csi out
> >   2nd) mipi-csi in -> parallel out
> > 
> > This patch only adds the support for the 1st mode.
> > 
> > Signed-off-by: Marco Felsch <m.felsch@pengutronix.de>
> > ---
> > Changelog:
> > 
> > v3:
> > - added missing static
> > - drop s/MHZ/HZ_PER_MHZ/
> > - kconfig: add "depends on PM"
> > - Add tc358746_valid_reg() for regmap.
> > - tc358746_set_fmt: fix format negotiation for pad == SOURCE
> > - tc358746_write/read: add error messages
> > - replace udelay with fsleep()
> > - tc358746_apply_misc_config: const mbusfmt
> > - tc358746_s_stream: fix comment about LP-00/11 state change
> > - tc358746_link_validate: s/sensor/source/
> > - tc358746_link_validate: s/pclk_rate/link_freq/
> > - tc358746_link_validate: fix v4l2_subdev_unlock_state()
> > - tc358746_link_validate: adapt fifo-sz comment
> > - tc358746_g/s_register: use pm_runtime_get_if_in_use
> > - tc358746_setup_mclk_provider: move to clk related location
> > - tc358746_init_hw: fix error case
> > - tc358746_init_controls: add comment
> > - tc358746_notify_bound: add MEDIA_LNK_FL_IMMUTABLE
> > - tc358746_async_register: fix error path
> > - tc358746_async_register: put sd.fwnode on error and remove
> > - tc358746_probe: increase autosuspend to 1s
> > 
> > v2:
> > - use the correct CID_LINK_FREQ control to query the sensor_pclk_rate
> > - remove now not needed tc358746_link_setup() and
> >   struct v4l2_ctrl sensor_pclk_ctrl
> > - call v4l2_subdev_link_validate_default() during link validation
> > - remove MEDIA_BUS_FMT_GBR888_1X24/YUV444 format support
> > - use subdev active_state API
> > - replace own .get_fmt with v4l2_subdev_get_fmt
> > - remove unnecessary pad checks
> > - restructure tc358746_get_format_by_code() if-case
> > - move apply_dphy_config|apply_misc_config from resume intos s_stream
> > - use goto in s_stream enable case
> > - fix error handling in suspend/resume
> > - split probe() into more sub-functions
> > ---
> >  drivers/media/i2c/Kconfig    |   17 +
> >  drivers/media/i2c/Makefile   |    1 +
> >  drivers/media/i2c/tc358746.c | 1692 ++++++++++++++++++++++++++++++++++
> >  3 files changed, 1710 insertions(+)
> >  create mode 100644 drivers/media/i2c/tc358746.c
> > 
> > diff --git a/drivers/media/i2c/Kconfig b/drivers/media/i2c/Kconfig
> > index 7806d4b81716..f85cdb94c524 100644
> > --- a/drivers/media/i2c/Kconfig
> > +++ b/drivers/media/i2c/Kconfig
> > @@ -1272,6 +1272,23 @@ config VIDEO_TC358743_CEC
> >  	  When selected the tc358743 will support the optional
> >  	  HDMI CEC feature.
> >  
> > +config VIDEO_TC358746
> > +	tristate "Toshiba TC358746 parallel-CSI2 bridge"
> > +	depends on VIDEO_DEV && PM && I2C
> > +	select VIDEO_V4L2_SUBDEV_API
> > +	select MEDIA_CONTROLLER
> > +	select V4L2_FWNODE
> > +	select GENERIC_PHY_MIPI_DPHY
> > +	select REGMAP_I2C
> > +	select COMMON_CLK
> > +	help
> > +	  Support for the Toshiba TC358746 parallel to MIPI CSI-2 bridge.
> > +	  The bridge can work in both directions but currently only the
> > +	  parallel-in / csi-out path is supported.
> > +
> > +	  To compile this driver as a module, choose M here: the
> > +	  module will be called tc358746.
> > +
> >  config VIDEO_TVP514X
> >  	tristate "Texas Instruments TVP514x video decoder"
> >  	depends on VIDEO_DEV && I2C
> > diff --git a/drivers/media/i2c/Makefile b/drivers/media/i2c/Makefile
> > index 0a2933103dd9..d1096c2ab480 100644
> > --- a/drivers/media/i2c/Makefile
> > +++ b/drivers/media/i2c/Makefile
> > @@ -118,6 +118,7 @@ obj-$(CONFIG_VIDEO_SONY_BTF_MPX) += sony-btf-mpx.o
> >  obj-$(CONFIG_VIDEO_SR030PC30) += sr030pc30.o
> >  obj-$(CONFIG_VIDEO_ST_MIPID02) += st-mipid02.o
> >  obj-$(CONFIG_VIDEO_TC358743) += tc358743.o
> > +obj-$(CONFIG_VIDEO_TC358746) += tc358746.o
> >  obj-$(CONFIG_VIDEO_TDA1997X) += tda1997x.o
> >  obj-$(CONFIG_VIDEO_TDA7432) += tda7432.o
> >  obj-$(CONFIG_VIDEO_TDA9840) += tda9840.o
> > diff --git a/drivers/media/i2c/tc358746.c b/drivers/media/i2c/tc358746.c
> > new file mode 100644
> > index 000000000000..0dcd5e0e0855
> > --- /dev/null
> > +++ b/drivers/media/i2c/tc358746.c
> > @@ -0,0 +1,1692 @@
> > +// SPDX-License-Identifier: GPL-2.0-only
> > +/*
> > + * TC358746 - Parallel <-> CSI-2 Bridge
> > + *
> > + * Copyright 2022 Marco Felsch <kernel@pengutronix.de>
> > + *
> > + * Notes:
> > + *  - Currently only 'Parallel-in -> CSI-out' mode is supported!
> > + */
> > +
> > +#include <linux/bitfield.h>
> > +#include <linux/clk.h>
> > +#include <linux/clk-provider.h>
> > +#include <linux/delay.h>
> > +#include <linux/i2c.h>
> > +#include <linux/interrupt.h>
> > +#include <linux/kernel.h>
> > +#include <linux/module.h>
> > +#include <linux/phy/phy-mipi-dphy.h>
> > +#include <linux/property.h>
> > +#include <linux/pm_runtime.h>
> > +#include <linux/regmap.h>
> > +#include <linux/units.h>
> > +#include <media/v4l2-ctrls.h>
> > +#include <media/v4l2-device.h>
> > +#include <media/v4l2-fwnode.h>
> > +#include <media/v4l2-mc.h>
> > +
> > +/* 16-bit registers */
> > +#define CHIPID_REG			0x0000
> > +#define		CHIPID			GENMASK(15, 8)
> > +
> > +#define SYSCTL_REG			0x0002
> > +#define		SRESET			BIT(0)
> > +
> > +#define CONFCTL_REG			0x0004
> > +#define		PDATAF_MASK		GENMASK(9, 8)
> > +#define		PDATAF_MODE0		0
> > +#define		PDATAF_MODE1		1
> > +#define		PDATAF_MODE2		2
> > +#define		PDATAF(val)		FIELD_PREP(PDATAF_MASK, (val))
> > +#define		PPEN			BIT(6)
> > +#define		DATALANE_MASK		GENMASK(1, 0)
> > +
> > +#define FIFOCTL_REG			0x0006
> > +#define DATAFMT_REG			0x0008
> > +#define		PDFMT(val)		FIELD_PREP(GENMASK(7, 4), (val))
> > +
> > +#define MCLKCTL_REG			0x000c
> > +#define		MCLK_HIGH_MASK		GENMASK(15, 8)
> > +#define		MCLK_LOW_MASK		GENMASK(7, 0)
> > +#define		MCLK_HIGH(val)		FIELD_PREP(MCLK_HIGH_MASK, (val))
> > +#define		MCLK_LOW(val)		FIELD_PREP(MCLK_LOW_MASK, (val))
> > +
> > +#define PLLCTL0_REG			0x0016
> > +#define		PLL_PRD_MASK		GENMASK(15, 12)
> > +#define		PLL_PRD(val)		FIELD_PREP(PLL_PRD_MASK, (val))
> > +#define		PLL_FBD_MASK		GENMASK(8, 0)
> > +#define		PLL_FBD(val)		FIELD_PREP(PLL_FBD_MASK, (val))
> > +
> > +#define PLLCTL1_REG			0x0018
> > +#define		PLL_FRS_MASK		GENMASK(11, 10)
> > +#define		PLL_FRS(val)		FIELD_PREP(PLL_FRS_MASK, (val))
> > +#define		CKEN			BIT(4)
> > +#define		RESETB			BIT(1)
> > +#define		PLL_EN			BIT(0)
> > +
> > +#define CLKCTL_REG			0x0020
> > +#define		MCLKDIV_MASK		GENMASK(3, 2)
> > +#define		MCLKDIV(val)		FIELD_PREP(MCLKDIV_MASK, (val))
> > +#define		MCLKDIV_8		0
> > +#define		MCLKDIV_4		1
> > +#define		MCLKDIV_2		2
> > +
> > +#define WORDCNT_REG			0x0022
> > +#define PP_MISC_REG			0x0032
> > +#define		FRMSTOP			BIT(15)
> > +#define		RSTPTR			BIT(14)
> > +
> > +/* 32-bit registers */
> > +#define CLW_DPHYCONTTX_REG		0x0100
> > +#define CLW_CNTRL_REG			0x0140
> > +#define D0W_CNTRL_REG			0x0144
> > +#define		LANEDISABLE		BIT(0)
> > +
> > +#define STARTCNTRL_REG			0x0204
> > +#define		START			BIT(0)
> > +
> > +#define LINEINITCNT_REG			0x0210
> > +#define LPTXTIMECNT_REG			0x0214
> > +#define TCLK_HEADERCNT_REG		0x0218
> > +#define		TCLK_ZEROCNT(val)	FIELD_PREP(GENMASK(15, 8), (val))
> > +#define		TCLK_PREPARECNT(val)	FIELD_PREP(GENMASK(6, 0), (val))
> > +
> > +#define TCLK_TRAILCNT_REG		0x021C
> > +#define THS_HEADERCNT_REG		0x0220
> > +#define		THS_ZEROCNT(val)	FIELD_PREP(GENMASK(14, 8), (val))
> > +#define		THS_PREPARECNT(val)	FIELD_PREP(GENMASK(6, 0), (val))
> > +
> > +#define TWAKEUP_REG			0x0224
> > +#define TCLK_POSTCNT_REG		0x0228
> > +#define THS_TRAILCNT_REG		0x022C
> > +#define HSTXVREGEN_REG			0x0234
> > +#define TXOPTIONCNTRL_REG		0x0238
> > +#define CSI_CONTROL_REG			0x040C
> > +#define		CSI_MODE		BIT(15)
> > +#define		TXHSMD			BIT(7)
> > +#define		NOL(val)		FIELD_PREP(GENMASK(2, 1), (val))
> > +
> > +#define CSI_CONFW_REG			0x0500
> > +#define		MODE(val)		FIELD_PREP(GENMASK(31, 29), (val))
> > +#define		MODE_SET		0x5
> > +#define		ADDRESS(val)		FIELD_PREP(GENMASK(28, 24), (val))
> > +#define		CSI_CONTROL_ADDRESS	0x3
> > +#define		DATA(val)		FIELD_PREP(GENMASK(15, 0), (val))
> > +
> > +#define CSI_START_REG			0x0518
> > +#define		STRT			BIT(0)
> > +
> > +static const struct v4l2_mbus_framefmt tc358746_def_fmt = {
> > +	.width		= 640,
> > +	.height		= 480,
> > +	.code		= MEDIA_BUS_FMT_UYVY8_2X8,
> > +	.field		= V4L2_FIELD_NONE,
> > +	.colorspace	= V4L2_COLORSPACE_DEFAULT,
> > +	.ycbcr_enc	= V4L2_YCBCR_ENC_DEFAULT,
> > +	.quantization	= V4L2_QUANTIZATION_DEFAULT,
> > +	.xfer_func	= V4L2_XFER_FUNC_DEFAULT,
> > +};
> > +
> > +static const char * const tc358746_supplies[] = {
> > +	"vddc", "vddio", "vddmipi"
> > +};
> > +
> > +enum {
> > +	TC358746_SINK,
> > +	TC358746_SOURCE,
> > +	TC358746_NR_PADS
> > +};
> > +
> > +struct tc358746 {
> > +	struct v4l2_subdev		sd;
> > +	struct media_pad		pads[TC358746_NR_PADS];
> > +	struct v4l2_async_notifier	notifier;
> > +	struct v4l2_fwnode_endpoint	csi_vep;
> > +
> > +	struct v4l2_ctrl_handler	ctrl_hdl;
> > +
> > +	struct regmap			*regmap;
> > +	struct clk			*refclk;
> > +	struct gpio_desc		*reset_gpio;
> > +	struct regulator_bulk_data	supplies[ARRAY_SIZE(tc358746_supplies)];
> > +
> > +	struct clk_hw			mclk_hw;
> > +	unsigned long			mclk_rate;
> > +	u8				mclk_prediv;
> > +	u16				mclk_postdiv;
> > +
> > +	unsigned long			pll_rate;
> > +	u8				pll_post_div;
> > +	u16				pll_pre_div;
> > +	u16				pll_mul;
> > +
> > +#define TC358746_VB_MAX_SIZE		(511 * 32)
> > +#define TC358746_VB_DEFAULT_SIZE	  (1 * 32)
> > +	unsigned int			vb_size; /* Video buffer size in bits */
> > +
> > +	struct phy_configure_opts_mipi_dphy dphy_cfg;
> > +};
> > +
> > +static inline struct tc358746 *to_tc358746(struct v4l2_subdev *sd)
> > +{
> > +	return container_of(sd, struct tc358746, sd);
> > +}
> > +
> > +static inline struct tc358746 *clk_hw_to_tc358746(struct clk_hw *hw)
> > +{
> > +	return container_of(hw, struct tc358746, mclk_hw);
> > +}
> > +
> > +struct tc358746_format {
> > +	u32		code;
> > +	bool		csi_format;
> > +	unsigned char	bus_width;
> > +	unsigned char	bpp;
> > +	/* Register values */
> > +	u8		pdformat; /* Peripheral Data Format */
> > +	u8		pdataf;   /* Parallel Data Format Option */
> > +};
> > +
> > +enum {
> > +	PDFORMAT_RAW8 = 0,
> > +	PDFORMAT_RAW10,
> > +	PDFORMAT_RAW12,
> > +	PDFORMAT_RGB888,
> > +	PDFORMAT_RGB666,
> > +	PDFORMAT_RGB565,
> > +	PDFORMAT_YUV422_8BIT,
> > +	/* RESERVED = 7 */
> > +	PDFORMAT_RAW14 = 8,
> > +	PDFORMAT_YUV422_10BIT,
> > +	PDFORMAT_YUV444,
> > +};
> > +
> > +/* Check tc358746_src_mbus_code() if you add new formats */
> > +static const struct tc358746_format tc358746_formats[] = {
> > +	{
> > +		.code = MEDIA_BUS_FMT_UYVY8_2X8,
> > +		.bus_width = 8,
> > +		.bpp = 16,
> > +		.pdformat = PDFORMAT_YUV422_8BIT,
> > +		.pdataf = PDATAF_MODE0,
> > +	}, {
> > +		.code = MEDIA_BUS_FMT_UYVY8_1X16,
> > +		.csi_format = true,
> > +		.bus_width = 16,
> > +		.bpp = 16,
> > +		.pdformat = PDFORMAT_YUV422_8BIT,
> > +		.pdataf = PDATAF_MODE1,
> > +	}, {
> > +		.code = MEDIA_BUS_FMT_YUYV8_1X16,
> > +		.csi_format = true,
> > +		.bus_width = 16,
> > +		.bpp = 16,
> > +		.pdformat = PDFORMAT_YUV422_8BIT,
> > +		.pdataf = PDATAF_MODE2,
> > +	}, {
> > +		.code = MEDIA_BUS_FMT_UYVY10_2X10,
> > +		.bus_width = 10,
> > +		.bpp = 20,
> > +		.pdformat = PDFORMAT_YUV422_10BIT,
> > +		.pdataf = PDATAF_MODE0, /* don't care */
> > +	}
> > +};
> > +
> > +/* Get n-th format for pad */
> > +static const struct tc358746_format *
> > +tc358746_get_format_by_idx(unsigned int pad, unsigned int index)
> > +{
> > +	unsigned int idx = 0;
> > +	unsigned int i;
> > +
> > +	for (i = 0; i < ARRAY_SIZE(tc358746_formats); i++) {
> > +		const struct tc358746_format *fmt = &tc358746_formats[i];
> > +
> > +		if ((pad == TC358746_SOURCE && fmt->csi_format) ||
> > +		    (pad == TC358746_SINK)) {
> > +			if (idx == index)
> > +				return fmt;
> > +			idx++;
> > +		}
> > +	}
> > +
> > +	return ERR_PTR(-EINVAL);
> > +}
> > +
> > +static const struct tc358746_format *
> > +tc358746_get_format_by_code(unsigned int pad, u32 code)
> > +{
> > +	unsigned int i;
> > +
> > +	for (i = 0; i < ARRAY_SIZE(tc358746_formats); i++) {
> > +		const struct tc358746_format *fmt = &tc358746_formats[i];
> > +
> > +		if (pad == TC358746_SINK && fmt->code == code)
> > +			return fmt;
> > +
> > +		if (pad == TC358746_SOURCE && !fmt->csi_format)
> > +			continue;
> > +
> > +		if (fmt->code == code)
> > +			return fmt;
> > +	}
> > +
> > +	return ERR_PTR(-EINVAL);
> > +}
> > +
> > +static u32 tc358746_src_mbus_code(u32 code)
> > +{
> > +	switch (code) {
> > +	case MEDIA_BUS_FMT_UYVY8_2X8:
> > +		return MEDIA_BUS_FMT_UYVY8_1X16;
> > +	case MEDIA_BUS_FMT_UYVY10_2X10:
> > +		return MEDIA_BUS_FMT_UYVY10_1X20;
> > +	default:
> > +		return code;
> > +	}
> > +}
> > +
> > +static bool tc358746_valid_reg(struct device *dev, unsigned int reg)
> > +{
> > +	switch (reg) {
> > +	case CHIPID_REG ... CSI_START_REG:
> > +		return true;
> > +	default:
> > +		return false;
> > +	}
> > +}
> > +
> > +static const struct regmap_config tc358746_regmap_config = {
> > +	.name = "tc358746",
> > +	.reg_bits = 16,
> > +	.val_bits = 16,
> > +	.max_register = CSI_START_REG,
> > +	.writeable_reg = tc358746_valid_reg,
> > +	.readable_reg = tc358746_valid_reg,
> > +	.reg_format_endian = REGMAP_ENDIAN_BIG,
> > +	.val_format_endian = REGMAP_ENDIAN_BIG,
> > +};
> > +
> > +static int tc358746_write(struct tc358746 *tc358746, u32 reg, u32 val)
> > +{
> > +	size_t count;
> > +	int err;
> > +
> > +	/* 32-bit registers starting from CLW_DPHYCONTTX */
> > +	count = reg < CLW_DPHYCONTTX_REG ? 1 : 2;
> > +
> > +	err = regmap_bulk_write(tc358746->regmap, reg, &val, count);
> > +	if (err)
> > +		dev_dbg(tc358746->sd.dev,
> > +			"Failed to write reg:0x%04x val:0x%04x\n", reg, val);
> 
> I'm not sure if the value is relevant here, but I'd add the error, it's
> useful to know what kind of I2C issue occurred. Same for read().

Yeah.. I'm not sure, since you told me to not flood the kernel log. If
someone recognised error while probing or streaming the debug will be
turned on anyways. However, I will make it a dev_err() since this
shouldnt appear normally, you're right.

> By the way, this isn't something you need to do in this driver, but I've
> found the following pattern to be useful for error handling:
> 
> static int tc358746_write(struct tc358746 *tc358746, u32 reg, u32 val, int *err)
> {
> 	size_t count;
> 	int ret;
> 
> 	if (err && *err)
> 		return *err;
> 
> 	/* 32-bit registers starting from CLW_DPHYCONTTX */
> 	count = reg < CLW_DPHYCONTTX_REG ? 1 : 2;
> 
> 	ret = regmap_bulk_write(tc358746->regmap, reg, &val, count);
> 	if (ret)
> 		dev_dbg(tc358746->sd.dev,
> 			"Failed to write reg 0x%04x: %d\n", reg, ret);
> 		if (err)
> 			*err = ret;
> 		return ret;
> 	}
> 
> 	return 0;
> }
> 
> With this, you could simplify functions such as
> tc358746_apply_dphy_config(), by initializing the local err variable to
> 0, calling 
> 
> 	tc358746_write(tc358746, ..., ..., &err);
> 
> without checking for errors, and just returning err at the end of the
> function. With the same pattern enabled in tc358746_update_bits() you
> could simplify other functions too.

Good pattern, will keep it in mind. Albeit the little magic can cause
confusion while reading e.g. tc358746_apply_dphy_config().

> > +
> > +	return err;
> > +}
> > +
> > +static int tc358746_read(struct tc358746 *tc358746, u32 reg, u32 *val)
> > +{
> > +	size_t count;
> > +	int err;
> > +
> > +	/* 32-bit registers starting from CLW_DPHYCONTTX */
> > +	count = reg < CLW_DPHYCONTTX_REG ? 1 : 2;
> > +	*val = 0;
> > +
> > +	err = regmap_bulk_read(tc358746->regmap, reg, val, count);
> > +	if (err)
> > +		dev_dbg(tc358746->sd.dev, "Failed to read reg:0x%04x\n", reg);
> > +
> > +	return err;
> > +}
> > +
> > +static int
> > +tc358746_update_bits(struct tc358746 *tc358746, u32 reg, u32 mask, u32 val)
> > +{
> > +	u32 tmp, orig;
> > +	int err;
> > +
> > +	err = tc358746_read(tc358746, reg, &orig);
> > +	if (err)
> > +		return err;
> > +
> > +	tmp = orig & ~mask;
> > +	tmp |= val & mask;
> > +
> > +	return tc358746_write(tc358746, reg, tmp);
> > +}
> > +
> > +static int tc358746_set_bits(struct tc358746 *tc358746, u32 reg, u32 bits)
> > +{
> > +	return tc358746_update_bits(tc358746, reg, bits, bits);
> > +}
> > +
> > +static int tc358746_clear_bits(struct tc358746 *tc358746, u32 reg, u32 bits)
> > +{
> > +	return tc358746_update_bits(tc358746, reg, bits, 0);
> > +}
> > +
> > +static int tc358746_sw_reset(struct tc358746 *tc358746)
> > +{
> > +	int err;
> > +
> > +	err = tc358746_set_bits(tc358746, SYSCTL_REG, SRESET);
> > +	if (err)
> > +		return err;
> > +
> > +	fsleep(10);
> > +
> > +	return tc358746_clear_bits(tc358746, SYSCTL_REG, SRESET);
> > +}
> > +
> > +static int
> > +tc358746_apply_pll_config(struct tc358746 *tc358746)
> > +{
> > +	u8 post = tc358746->pll_post_div;
> > +	u16 pre = tc358746->pll_pre_div;
> > +	u16 mul = tc358746->pll_mul;
> > +	u32 val, mask;
> > +	int err;
> > +
> > +	err = tc358746_read(tc358746, PLLCTL1_REG, &val);
> > +	if (err)
> > +		return err;
> > +
> > +	/* Don't touch the PLL if running */
> > +	if (FIELD_GET(PLL_EN, val) == 1)
> > +		return 0;
> > +
> > +	/* Pre-div and Multiplicator have a internal +1 logic */
> > +	val = PLL_PRD(pre - 1) | PLL_FBD(mul - 1);
> > +	mask = PLL_PRD_MASK | PLL_FBD_MASK;
> > +	err = tc358746_update_bits(tc358746, PLLCTL0_REG, mask, val);
> > +	if (err)
> > +		return err;
> > +
> > +	val = PLL_FRS(ilog2(post)) | RESETB | PLL_EN;
> > +	mask = PLL_FRS_MASK | RESETB | PLL_EN;
> > +	tc358746_update_bits(tc358746, PLLCTL1_REG, mask, val);
> > +	if (err)
> > +		return err;
> > +
> > +	fsleep(1000);
> > +
> > +	return tc358746_set_bits(tc358746, PLLCTL1_REG, CKEN);
> > +}
> > +
> > +static int tc358746_apply_misc_config(struct tc358746 *tc358746)
> > +{
> > +	const struct v4l2_mbus_framefmt *mbusfmt;
> > +	struct v4l2_subdev *sd = &tc358746->sd;
> > +	struct v4l2_subdev_state *sink_state;
> > +	const struct tc358746_format *fmt;
> > +	struct device *dev = sd->dev;
> > +	u32 val;
> > +	int err;
> > +
> > +	sink_state = v4l2_subdev_lock_and_get_active_state(sd);
> > +	mbusfmt = v4l2_subdev_get_pad_format(sd, sink_state, TC358746_SINK);
> > +	v4l2_subdev_unlock_state(sink_state);
> > +
> > +	fmt = tc358746_get_format_by_code(TC358746_SINK, mbusfmt->code);
> > +
> > +	/* Self defined CSI user data type id's are not supported yet */
> > +	val = PDFMT(fmt->pdformat);
> > +	dev_dbg(dev, "DATAFMT: 0x%x\n", val);
> > +	err = tc358746_write(tc358746, DATAFMT_REG, val);
> > +	if (err)
> > +		return err;
> > +
> > +	val = PDATAF(fmt->pdataf);
> > +	dev_dbg(dev, "CONFCTL[PDATAF]: 0x%x\n", fmt->pdataf);
> > +	err = tc358746_update_bits(tc358746, CONFCTL_REG, PDATAF_MASK, val);
> > +	if (err)
> > +		return err;
> > +
> > +	val = tc358746->vb_size / 32;
> > +	dev_dbg(dev, "FIFOCTL: %u (0x%x)\n", val, val);
> > +	err = tc358746_write(tc358746, FIFOCTL_REG, val);
> > +	if (err)
> > +		return err;
> > +
> > +	/* Total number of bytes for each line/width */
> > +	val = mbusfmt->width * fmt->bpp / 8;
> > +	dev_dbg(dev, "WORDCNT: %u (0x%x)\n", val, val);
> > +	return tc358746_write(tc358746, WORDCNT_REG, val);
> > +}
> > +
> > +/* Use MHz as base so the div needs no u64 */
> > +static u32 tc358746_cfg_to_cnt(unsigned int cfg_val,
> > +			       unsigned int clk_mhz,
> > +			       unsigned int time_base)
> > +{
> > +	return DIV_ROUND_UP(cfg_val * clk_mhz, time_base);
> > +}
> > +
> > +static u32 tc358746_ps_to_cnt(unsigned int cfg_val,
> > +			      unsigned int clk_mhz)
> > +{
> > +	return tc358746_cfg_to_cnt(cfg_val, clk_mhz, USEC_PER_SEC);
> > +}
> > +
> > +static u32 tc358746_us_to_cnt(unsigned int cfg_val,
> > +			      unsigned int clk_mhz)
> > +{
> > +	return tc358746_cfg_to_cnt(cfg_val, clk_mhz, 1);
> > +}
> > +
> > +static int tc358746_apply_dphy_config(struct tc358746 *tc358746)
> > +{
> > +	struct phy_configure_opts_mipi_dphy *cfg = &tc358746->dphy_cfg;
> > +	bool non_cont_clk = !!(tc358746->csi_vep.bus.mipi_csi2.flags &
> > +			       V4L2_MBUS_CSI2_NONCONTINUOUS_CLOCK);
> > +	struct device *dev = tc358746->sd.dev;
> > +	unsigned long hs_byte_clk, hf_clk;
> > +	u32 val, val2, lptxcnt;
> > +	int err;
> > +
> > +	/* The hs_byte_clk is also called SYSCLK in the excel sheet */
> > +	hs_byte_clk = cfg->hs_clk_rate / 8;
> > +	hs_byte_clk /= HZ_PER_MHZ;
> > +	hf_clk = hs_byte_clk / 2;
> > +
> > +	val = tc358746_us_to_cnt(cfg->init, hf_clk) - 1;
> > +	dev_dbg(dev, "LINEINITCNT: %u (0x%x)\n", val, val);
> > +	err = tc358746_write(tc358746, LINEINITCNT_REG, val);
> > +	if (err)
> > +		return err;
> > +
> > +	val = tc358746_ps_to_cnt(cfg->lpx, hs_byte_clk) - 1;
> > +	lptxcnt = val;
> > +	dev_dbg(dev, "LPTXTIMECNT: %u (0x%x)\n", val, val);
> > +	err = tc358746_write(tc358746, LPTXTIMECNT_REG, val);
> > +	if (err)
> > +		return err;
> > +
> > +	val = tc358746_ps_to_cnt(cfg->clk_prepare, hs_byte_clk) - 1;
> > +	val2 = tc358746_ps_to_cnt(cfg->clk_zero, hs_byte_clk) - 1;
> > +	dev_dbg(dev, "TCLK_PREPARECNT: %u (0x%x)\n", val, val);
> > +	dev_dbg(dev, "TCLK_ZEROCNT: %u (0x%x)\n", val2, val2);
> > +	dev_dbg(dev, "TCLK_HEADERCNT: 0x%x\n",
> > +		(u32)(TCLK_PREPARECNT(val) | TCLK_ZEROCNT(val2)));
> > +	err = tc358746_write(tc358746, TCLK_HEADERCNT_REG,
> > +			     TCLK_PREPARECNT(val) | TCLK_ZEROCNT(val2));
> > +	if (err)
> > +		return err;
> > +
> > +	val = tc358746_ps_to_cnt(cfg->clk_trail, hs_byte_clk);
> > +	dev_dbg(dev, "TCLK_TRAILCNT: %u (0x%x)\n", val, val);
> > +	err = tc358746_write(tc358746, TCLK_TRAILCNT_REG, val);
> > +	if (err)
> > +		return err;
> > +
> > +	val = tc358746_ps_to_cnt(cfg->hs_prepare, hs_byte_clk) - 1;
> > +	val2 = tc358746_ps_to_cnt(cfg->hs_zero, hs_byte_clk) - 1;
> > +	dev_dbg(dev, "THS_PREPARECNT: %u (0x%x)\n", val, val);
> > +	dev_dbg(dev, "THS_ZEROCNT: %u (0x%x)\n", val2, val2);
> > +	dev_dbg(dev, "THS_HEADERCNT: 0x%x\n",
> > +		(u32)(THS_PREPARECNT(val) | THS_ZEROCNT(val2)));
> > +	err = tc358746_write(tc358746, THS_HEADERCNT_REG,
> > +			     THS_PREPARECNT(val) | THS_ZEROCNT(val2));
> > +	if (err)
> > +		return err;
> > +
> > +	/* TWAKEUP > 1ms in lptxcnt steps */
> > +	val = tc358746_us_to_cnt(cfg->wakeup, hs_byte_clk);
> > +	val = val / (lptxcnt + 1) - 1;
> > +	dev_dbg(dev, "TWAKEUP: %u (0x%x)\n", val, val);
> > +	err = tc358746_write(tc358746, TWAKEUP_REG, val);
> > +	if (err)
> > +		return err;
> > +
> > +	val = tc358746_ps_to_cnt(cfg->clk_post, hs_byte_clk);
> > +	dev_dbg(dev, "TCLK_POSTCNT: %u (0x%x)\n", val, val);
> > +	err = tc358746_write(tc358746, TCLK_POSTCNT_REG, val);
> > +	if (err)
> > +		return err;
> > +
> > +	val = tc358746_ps_to_cnt(cfg->hs_trail, hs_byte_clk);
> > +	dev_dbg(dev, "THS_TRAILCNT: %u (0x%x)\n", val, val);
> > +	err = tc358746_write(tc358746, THS_TRAILCNT_REG, val);
> > +	if (err)
> > +		return err;
> > +
> > +	dev_dbg(dev, "CONTCLKMODE: %u", non_cont_clk ? 0 : 1);
> > +	return  tc358746_write(tc358746, TXOPTIONCNTRL_REG, non_cont_clk ? 0 : 1);
> 
> Extra space after return.

Okay.

> > +}
> > +
> > +#define MAX_DATA_LANES 4
> > +
> > +static int tc358746_enable_csi_lanes(struct tc358746 *tc358746, int enable)
> > +{
> > +	unsigned int lanes = tc358746->dphy_cfg.lanes;
> > +	unsigned int lane;
> > +	u32 reg, val;
> > +	int err;
> > +
> > +	err = tc358746_update_bits(tc358746, CONFCTL_REG, DATALANE_MASK,
> > +				   lanes - 1);
> > +	if (err)
> > +		return err;
> > +
> > +	/* Clock lane */
> > +	val = enable ? 0 : LANEDISABLE;
> > +	dev_dbg(tc358746->sd.dev, "CLW_CNTRL: 0x%x\n", val);
> > +	err = tc358746_write(tc358746, CLW_CNTRL_REG, val);
> > +	if (err)
> > +		return err;
> > +
> > +	for (lane = 0; lane < MAX_DATA_LANES; lane++) {
> > +		/* Data lanes */
> > +		reg = D0W_CNTRL_REG + lane * 0x4;
> > +		val = (enable && lane < lanes) ? 0 : LANEDISABLE;
> > +
> > +		dev_dbg(tc358746->sd.dev, "D%uW_CNTRL: 0x%x\n", lane, val);
> > +		err = tc358746_write(tc358746, reg, val);
> > +		if (err)
> > +			return err;
> > +	}
> > +
> > +	val = 0;
> > +	if (enable) {
> > +		/* Clock lane */
> > +		val |= BIT(0);
> > +
> > +		/* Data lanes */
> > +		for (lane = 1; lane <= lanes; lane++)
> > +			val |= BIT(lane);
> > +	}
> > +
> > +	dev_dbg(tc358746->sd.dev, "HSTXVREGEN: 0x%x\n", val);
> > +	return tc358746_write(tc358746, HSTXVREGEN_REG, val);
> > +}
> > +
> > +static int tc358746_enable_csi_module(struct tc358746 *tc358746, int enable)
> > +{
> > +	unsigned int lanes = tc358746->dphy_cfg.lanes;
> > +	int err;
> > +
> > +	/*
> > +	 * START and STRT are only reseted/disabled by sw reset. This is
> > +	 * required to put the lane state back into LP-11 state. The sw reset
> > +	 * don't reset register values.
> > +	 */
> > +	if (!enable)
> > +		return tc358746_sw_reset(tc358746);
> > +
> > +	err = tc358746_write(tc358746, STARTCNTRL_REG, START);
> > +	if (err)
> > +		return err;
> > +
> > +	err = tc358746_write(tc358746, CSI_START_REG, STRT);
> > +	if (err)
> > +		return err;
> > +
> > +	/* CSI_CONTROL_REG is only indirect accessible */
> > +	return tc358746_write(tc358746, CSI_CONFW_REG,
> > +			      MODE(MODE_SET) |
> > +			      ADDRESS(CSI_CONTROL_ADDRESS) |
> > +			      DATA(CSI_MODE | TXHSMD | NOL(lanes - 1)));
> > +}
> > +
> > +static int tc358746_enable_parallel_port(struct tc358746 *tc358746, int enable)
> > +{
> > +	int err;
> > +
> > +	if (enable) {
> > +		err = tc358746_write(tc358746, PP_MISC_REG, 0);
> > +		if (err)
> > +			return err;
> > +
> > +		return tc358746_set_bits(tc358746, CONFCTL_REG, PPEN);
> > +	}
> > +
> > +	err = tc358746_set_bits(tc358746, PP_MISC_REG, FRMSTOP);
> > +	if (err)
> > +		return err;
> > +
> > +	err = tc358746_clear_bits(tc358746, CONFCTL_REG, PPEN);
> > +	if (err)
> > +		return err;
> > +
> > +	return tc358746_set_bits(tc358746, PP_MISC_REG, RSTPTR);
> > +}
> > +
> > +static inline struct v4l2_subdev *tc358746_get_remote_sd(struct media_pad *pad)
> > +{
> > +	pad = media_pad_remote_pad_first(pad);
> > +	if (!pad)
> > +		return NULL;
> > +
> > +	return media_entity_to_v4l2_subdev(pad->entity);
> > +}
> > +
> > +static int tc358746_s_stream(struct v4l2_subdev *sd, int enable)
> > +{
> > +	struct tc358746 *tc358746 = to_tc358746(sd);
> > +	struct v4l2_subdev *src;
> > +	int err;
> > +
> > +	dev_dbg(sd->dev, "%sable\n", enable ? "en" : "dis");
> > +
> > +	src = tc358746_get_remote_sd(&tc358746->pads[TC358746_SINK]);
> > +	if (!src)
> > +		return -EPIPE;
> > +
> > +	if (enable) {
> > +		err = pm_runtime_resume_and_get(sd->dev);
> > +		if (err)
> > +			return err;
> > +
> > +		err = tc358746_apply_dphy_config(tc358746);
> > +		if (err)
> > +			goto err_out;
> > +
> > +		err = tc358746_apply_misc_config(tc358746);
> > +		if (err)
> > +			goto err_out;
> > +
> > +		err = tc358746_enable_csi_lanes(tc358746, 1);
> > +		if (err)
> > +			goto err_out;
> > +
> > +		err = tc358746_enable_csi_module(tc358746, 1);
> > +		if (err)
> > +			goto err_out;
> > +
> > +		err = tc358746_enable_parallel_port(tc358746, 1);
> > +		if (err)
> > +			goto err_out;
> > +
> > +		err = v4l2_subdev_call(src, video, s_stream, 1);
> > +		if (err)
> > +			goto err_out;
> > +
> > +		return err;
> > +
> > +err_out:
> > +		pm_runtime_mark_last_busy(sd->dev);
> > +		pm_runtime_put_sync_autosuspend(sd->dev);
> > +
> > +		return err;
> > +	}
> > +
> > +	 /*
> > +	  * The lanes must be disabled first (before the csi module) so the
> > +	  * LP-11 state is entered correctly.
> > +	  */
> 
> Wrong indentation.

Damn.. Shouldn't that be detected by checkpatch? Anyway, thanks :)

> > +	err = tc358746_enable_csi_lanes(tc358746, 0);
> > +	if (err)
> > +		return err;
> > +
> > +	err = tc358746_enable_csi_module(tc358746, 0);
> > +	if (err)
> > +		return err;
> > +
> > +	err = tc358746_enable_parallel_port(tc358746, 0);
> > +	if (err)
> > +		return err;
> > +
> > +	pm_runtime_mark_last_busy(sd->dev);
> > +	pm_runtime_put_sync_autosuspend(sd->dev);
> > +
> > +	return v4l2_subdev_call(src, video, s_stream, 0);
> > +}
> > +
> > +static int tc358746_init_cfg(struct v4l2_subdev *sd,
> > +			     struct v4l2_subdev_state *state)
> > +{
> > +	struct v4l2_mbus_framefmt *fmt;
> > +
> > +	fmt = v4l2_subdev_get_pad_format(sd, state, TC358746_SINK);
> > +	*fmt = tc358746_def_fmt;
> > +
> > +	fmt = v4l2_subdev_get_pad_format(sd, state, TC358746_SOURCE);
> > +	*fmt = tc358746_def_fmt;
> > +	fmt->code = tc358746_src_mbus_code(tc358746_def_fmt.code);
> > +
> > +	return 0;
> > +}
> > +
> > +static int tc358746_enum_mbus_code(struct v4l2_subdev *sd,
> > +				   struct v4l2_subdev_state *sd_state,
> > +				   struct v4l2_subdev_mbus_code_enum *code)
> > +{
> > +	const struct tc358746_format *fmt;
> > +
> > +	fmt = tc358746_get_format_by_idx(code->pad, code->index);
> > +	if (IS_ERR(fmt))
> > +		return PTR_ERR(fmt);
> > +
> > +	code->code = fmt->code;
> > +
> > +	return 0;
> > +}
> > +
> > +static int tc358746_set_fmt(struct v4l2_subdev *sd,
> > +			    struct v4l2_subdev_state *sd_state,
> > +			    struct v4l2_subdev_format *format)
> > +{
> > +	struct v4l2_mbus_framefmt *src_fmt, *sink_fmt;
> > +	const struct tc358746_format *fmt;
> > +
> > +	/* Source follows the sink */
> > +	if (format->pad == TC358746_SOURCE)
> > +		return v4l2_subdev_get_fmt(sd, sd_state, format);
> > +
> > +	sink_fmt = v4l2_subdev_get_pad_format(sd, sd_state, TC358746_SINK);
> > +
> > +	fmt = tc358746_get_format_by_code(format->pad, format->format.code);
> > +	if (IS_ERR(fmt))
> > +		fmt = tc358746_get_format_by_code(format->pad, tc358746_def_fmt.code);
> > +
> > +	format->format.code = fmt->code;
> > +	format->format.field = V4L2_FIELD_NONE;
> > +
> > +	dev_dbg(sd->dev, "Update format: %ux%u code:0x%x -> %ux%u code:0x%x",
> > +		sink_fmt->width, sink_fmt->height, sink_fmt->code,
> > +		format->format.width, format->format.height, format->format.code);
> > +
> > +	*sink_fmt = format->format;
> > +
> > +	src_fmt = v4l2_subdev_get_pad_format(sd, sd_state, TC358746_SOURCE);
> > +	*src_fmt = *sink_fmt;
> > +	src_fmt->code = tc358746_src_mbus_code(sink_fmt->code);
> > +
> > +	return 0;
> > +}
> > +
> > +static unsigned long tc358746_find_pll_settings(struct tc358746 *tc358746,
> > +						unsigned long refclk,
> > +						unsigned long fout)
> > +
> > +{
> > +	struct device *dev = tc358746->sd.dev;
> > +	unsigned long best_freq = 0;
> > +	u32 min_delta = 0xffffffff;
> > +	u16 prediv_max = 17;
> > +	u16 prediv_min = 1;
> > +	u16 m_best, mul;
> > +	u16 p_best, p;
> > +	u8 postdiv;
> > +
> > +	if (fout > 1000 * HZ_PER_MHZ) {
> > +		dev_err(dev, "HS-Clock above 1 Ghz are not supported\n");
> > +		return 0;
> > +	}
> > +
> > +	if (fout >= 500 * HZ_PER_MHZ)
> > +		postdiv = 1;
> > +	else if (fout >= 250 * HZ_PER_MHZ)
> > +		postdiv = 2;
> > +	else if (fout >= 125 * HZ_PER_MHZ)
> > +		postdiv = 4;
> > +	else
> > +		postdiv = 8;
> > +
> > +	for (p = prediv_min; p <= prediv_max; p++) {
> > +		unsigned long delta, fin;
> > +		u64 tmp;
> > +
> > +		fin = DIV_ROUND_CLOSEST(refclk, p);
> > +		if (fin < 4 * HZ_PER_MHZ || fin > 40 * HZ_PER_MHZ)
> > +			continue;
> > +
> > +		tmp = fout * p * postdiv;
> > +		do_div(tmp, fin);
> > +		mul = tmp;
> > +		if (mul > 511)
> > +			continue;
> > +
> > +		tmp = mul * fin;
> > +		do_div(tmp, p * postdiv);
> > +
> > +		delta = abs(fout - tmp);
> > +		if (delta < min_delta) {
> > +			p_best = p;
> > +			m_best = mul;
> > +			min_delta = delta;
> > +			best_freq = tmp;
> > +		};
> > +
> > +		if (delta == 0)
> > +			break;
> > +	};
> > +
> > +	if (!best_freq) {
> > +		dev_err(dev, "Failed find PLL frequency\n");
> > +		return 0;
> > +	}
> > +
> > +	tc358746->pll_post_div = postdiv;
> > +	tc358746->pll_pre_div = p_best;
> > +	tc358746->pll_mul = m_best;
> > +
> > +	if (best_freq != fout)
> > +		dev_warn(dev, "Request PLL freq:%lu, found PLL freq:%lu\n",
> > +			 fout, best_freq);
> > +
> > +	dev_dbg(dev, "Found PLL settings: freq:%lu prediv:%u multi:%u postdiv:%u\n",
> > +		best_freq, p_best, m_best, postdiv);
> > +
> > +	return best_freq;
> > +}
> > +
> > +#define TC358746_PRECISION 10
> > +
> > +static int
> > +tc358746_link_validate(struct v4l2_subdev *sd, struct media_link *link,
> > +		       struct v4l2_subdev_format *source_fmt,
> > +		       struct v4l2_subdev_format *sink_fmt)
> > +{
> > +	struct tc358746 *tc358746 = to_tc358746(sd);
> > +	unsigned long csi_bitrate, source_bitrate;
> > +	struct v4l2_subdev_state *sink_state;
> > +	struct v4l2_mbus_framefmt *mbusfmt;
> > +	const struct tc358746_format *fmt;
> > +	unsigned int fifo_sz, tmp, n;
> > +	struct v4l2_subdev *source;
> > +	s64 source_link_freq;
> > +	int err;
> > +
> > +	err = v4l2_subdev_link_validate_default(sd, link, source_fmt, sink_fmt);
> > +	if (err)
> > +		return err;
> > +
> > +	sink_state = v4l2_subdev_lock_and_get_active_state(sd);
> > +	mbusfmt = v4l2_subdev_get_pad_format(sd, sink_state, TC358746_SINK);
> > +
> > +	/* Check the FIFO settings */
> > +	fmt = tc358746_get_format_by_code(TC358746_SINK, mbusfmt->code);
> > +
> > +	source = media_entity_to_v4l2_subdev(link->source->entity);
> > +	source_link_freq = v4l2_get_link_freq(source->ctrl_handler, 0, 0);
> > +	if (source_link_freq <= 0) {
> > +		dev_err(tc358746->sd.dev,
> > +			"Failed to query or invalid source link frequency\n");
> > +		v4l2_subdev_unlock_state(sink_state);
> > +		/* Return -EINVAL in case of source_link_freq is 0 */
> > +		return source_link_freq ? : -EINVAL;
> > +	}
> > +	source_bitrate = source_link_freq * fmt->bus_width;
> > +
> > +	csi_bitrate = tc358746->dphy_cfg.lanes * tc358746->pll_rate;
> > +
> > +	dev_dbg(tc358746->sd.dev,
> > +		"Fifo settings params: source-bitrate:%lu csi-bitrate:%lu",
> > +		source_bitrate, csi_bitrate);
> > +
> > +	/* Avoid possible FIFO overflows */
> > +	if (csi_bitrate < source_bitrate) {
> > +		v4l2_subdev_unlock_state(sink_state);
> > +		return -EINVAL;
> > +	}
> > +
> > +	/* Best case */
> > +	if (csi_bitrate == source_bitrate) {
> > +		fifo_sz = TC358746_VB_DEFAULT_SIZE;
> > +		tc358746->vb_size = TC358746_VB_DEFAULT_SIZE;
> > +		goto out;
> > +	}
> > +
> > +	/*
> > +	 * Avoid possible FIFO underflow in case of
> > +	 * csi_bitrate > source_bitrate. For such case the chip has a internal
> > +	 * fifo which can be used to delay the line output.
> > +	 *
> > +	 * Fifo size calculation (excluding precision):
> > +	 *
> > +	 * fifo-sz, image-width - in bits
> > +	 * sbr                  - source_bitrate in bits/s
> > +	 * csir                 - csi_bitrate in bits/s
> > +	 *
> > +	 *                1               1      1
> > +	 * image-width * --- + fifo-sz * --- >= ---- * image-width
> > +	 *               sbr             sbr    csir
> 
> I still think there's something fishy here. The inequality is always
> true as csir > sbr. You will get a non-zero fifo size in your
> calculation because you artifically add an abs(), but I don't think
> that's right.
> 
> If I understand things correctly, you need to ensure that once the FIFO
> threshold is reached and the CSI-2 side starts sending data, the input
> size will keep feeding data fast enough for the FIFO to never underrun.
> 
> The FIFO level triggers the CSI-2 transmission. This means that once the
> CSI-2 transmission start, fifo-sz bits have been written to the FIFO
> already, and image-width - fifo-sz bits still need to be written. To
> avoid underruns, you need to ensure that the time required to read all
> the data (image-width) on the CSI-2 size will be higher than or equal to
> the time required to write the remaining data (image-width - fifo-sz) on
> the input side. This translates to
> 
> 	image-width / csir >= (image-width - fifo-sz) / sbr
> 	image-width * sbr / csir >= image-width - fifo-sz
> 	fifo-sz >= image-width - image-width * sbr / csir

Thanks, makes more sense, I will change the comment.

> The calculation is thus correct, but not for the right reason :-) All
> you need to fix here is the comment, not the code.
> 
> With these small issues fixed,
> 
> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

Regards,
  Marco

> > +	 *
> > +	 * fifo-sz >= abs(sbr/csir * image-width - image-width); with n = csir/sbr
> > +	 *
> > +	 * fifo-sz >= abs(image-width / n - image-width)
> > +	 *         >= image-width - image-width / n
> > +	 */
> > +
> > +	source_bitrate /= TC358746_PRECISION;
> > +	n = csi_bitrate / source_bitrate;
> > +	tmp = (mbusfmt->width * TC358746_PRECISION) / n;
> > +	fifo_sz = mbusfmt->width - tmp;
> > +	fifo_sz *= fmt->bpp;
> > +	tc358746->vb_size = round_up(fifo_sz, 32);
> > +
> > +out:
> > +	dev_dbg(tc358746->sd.dev,
> > +		"Found FIFO size[bits]:%u -> aligned to size[bits]:%u\n",
> > +		fifo_sz, tc358746->vb_size);
> > +
> > +	v4l2_subdev_unlock_state(sink_state);
> > +
> > +	return tc358746->vb_size > TC358746_VB_MAX_SIZE ? -EINVAL : 0;
> > +}
> > +
> > +static int tc358746_get_mbus_config(struct v4l2_subdev *sd, unsigned int pad,
> > +				    struct v4l2_mbus_config *config)
> > +{
> > +	struct tc358746 *tc358746 = to_tc358746(sd);
> > +
> > +	if (pad != TC358746_SOURCE)
> > +		return -EINVAL;
> > +
> > +	config->type = V4L2_MBUS_CSI2_DPHY;
> > +	config->bus.mipi_csi2 = tc358746->csi_vep.bus.mipi_csi2;
> > +
> > +	return 0;
> > +}
> > +
> > +static int __maybe_unused
> > +tc358746_g_register(struct v4l2_subdev *sd, struct v4l2_dbg_register *reg)
> > +{
> > +	struct tc358746 *tc358746 = to_tc358746(sd);
> > +
> > +	/* 32-bit registers starting from CLW_DPHYCONTTX */
> > +	reg->size = reg->reg < CLW_DPHYCONTTX_REG ? 2 : 4;
> > +
> > +	if (!pm_runtime_get_if_in_use(sd->dev))
> > +		return 0;
> > +
> > +	tc358746_read(tc358746, reg->reg, (u32 *)&reg->val);
> > +
> > +	pm_runtime_mark_last_busy(sd->dev);
> > +	pm_runtime_put_sync_autosuspend(sd->dev);
> > +
> > +	return 0;
> > +}
> > +
> > +static int __maybe_unused
> > +tc358746_s_register(struct v4l2_subdev *sd, const struct v4l2_dbg_register *reg)
> > +{
> > +	struct tc358746 *tc358746 = to_tc358746(sd);
> > +
> > +	if (!pm_runtime_get_if_in_use(sd->dev))
> > +		return 0;
> > +
> > +	tc358746_write(tc358746, (u32)reg->reg, (u32)reg->val);
> > +
> > +	pm_runtime_mark_last_busy(sd->dev);
> > +	pm_runtime_put_sync_autosuspend(sd->dev);
> > +
> > +	return 0;
> > +}
> > +
> > +static const struct v4l2_subdev_core_ops tc358746_core_ops = {
> > +#ifdef CONFIG_VIDEO_ADV_DEBUG
> > +	.g_register = tc358746_g_register,
> > +	.s_register = tc358746_s_register,
> > +#endif
> > +};
> > +
> > +static const struct v4l2_subdev_video_ops tc358746_video_ops = {
> > +	.s_stream = tc358746_s_stream,
> > +};
> > +
> > +static const struct v4l2_subdev_pad_ops tc358746_pad_ops = {
> > +	.init_cfg = tc358746_init_cfg,
> > +	.enum_mbus_code = tc358746_enum_mbus_code,
> > +	.set_fmt = tc358746_set_fmt,
> > +	.get_fmt = v4l2_subdev_get_fmt,
> > +	.link_validate = tc358746_link_validate,
> > +	.get_mbus_config = tc358746_get_mbus_config,
> > +};
> > +
> > +static const struct v4l2_subdev_ops tc358746_ops = {
> > +	.core = &tc358746_core_ops,
> > +	.video = &tc358746_video_ops,
> > +	.pad = &tc358746_pad_ops,
> > +};
> > +
> > +static const struct media_entity_operations tc358746_entity_ops = {
> > +	.get_fwnode_pad = v4l2_subdev_get_fwnode_pad_1_to_1,
> > +	.link_validate = v4l2_subdev_link_validate,
> > +};
> > +
> > +static int tc358746_mclk_enable(struct clk_hw *hw)
> > +{
> > +	struct tc358746 *tc358746 = clk_hw_to_tc358746(hw);
> > +	unsigned int div;
> > +	u32 val;
> > +	int err;
> > +
> > +	div = tc358746->mclk_postdiv / 2;
> > +	val = MCLK_HIGH(div - 1) | MCLK_LOW(div - 1);
> > +	dev_dbg(tc358746->sd.dev, "MCLKCTL: %u (0x%x)\n", val, val);
> > +	err = tc358746_write(tc358746, MCLKCTL_REG, val);
> > +	if (err)
> > +		return err;
> > +
> > +	if (tc358746->mclk_prediv == 8)
> > +		val = MCLKDIV(MCLKDIV_8);
> > +	else if (tc358746->mclk_prediv == 4)
> > +		val = MCLKDIV(MCLKDIV_4);
> > +	else
> > +		val = MCLKDIV(MCLKDIV_2);
> > +
> > +	dev_dbg(tc358746->sd.dev, "CLKCTL[MCLKDIV]: %u (0x%x)\n", val, val);
> > +	return tc358746_update_bits(tc358746, CLKCTL_REG, MCLKDIV_MASK, val);
> > +}
> > +
> > +static void tc358746_mclk_disable(struct clk_hw *hw)
> > +{
> > +	struct tc358746 *tc358746 = clk_hw_to_tc358746(hw);
> > +
> > +	tc358746_write(tc358746, MCLKCTL_REG, 0);
> > +}
> > +
> > +static long
> > +tc358746_find_mclk_settings(struct tc358746 *tc358746, unsigned long mclk_rate)
> > +{
> > +	unsigned long pll_rate = tc358746->pll_rate;
> > +	const unsigned char prediv[] = { 2, 4, 8 };
> > +	unsigned int mclk_prediv, mclk_postdiv;
> > +	struct device *dev = tc358746->sd.dev;
> > +	unsigned int postdiv, mclkdiv;
> > +	unsigned long best_mclk_rate;
> > +	unsigned int i;
> > +
> > +	/*
> > +	 *                          MCLK-Div
> > +	 *           -------------------´`---------------------
> > +	 *          ´                                          `
> > +	 *         +-------------+     +------------------------+
> > +	 *         | MCLK-PreDiv |     |       MCLK-PostDiv     |
> > +	 * PLL --> |   (2/4/8)   | --> | (mclk_low + mclk_high) | --> MCLK
> > +	 *         +-------------+     +------------------------+
> > +	 *
> > +	 * The register value of mclk_low/high is mclk_low/high+1, i.e.:
> > +	 *   mclk_low/high = 1   --> 2 MCLK-Ref Counts
> > +	 *   mclk_low/high = 255 --> 256 MCLK-Ref Counts == max.
> > +	 * If mclk_low and mclk_high are 0 then MCLK is disabled.
> > +	 *
> > +	 * Keep it simple and support 50/50 duty cycles only for now,
> > +	 * so the calc will be:
> > +	 *
> > +	 *   MCLK = PLL / (MCLK-PreDiv * 2 * MCLK-PostDiv)
> > +	 */
> > +
> > +	if (mclk_rate == tc358746->mclk_rate)
> > +		return mclk_rate;
> > +
> > +	/* Highest possible rate */
> > +	mclkdiv = pll_rate / mclk_rate;
> > +	if (mclkdiv <= 8) {
> > +		mclk_prediv = 2;
> > +		mclk_postdiv = 4;
> > +		best_mclk_rate = pll_rate / (2 * 4);
> > +		goto out;
> > +	}
> > +
> > +	/* First check the prediv */
> > +	for (i = 0; i < ARRAY_SIZE(prediv); i++) {
> > +		postdiv = mclkdiv / prediv[i];
> > +
> > +		if (postdiv % 2)
> > +			continue;
> > +
> > +		if (postdiv >= 4 && postdiv <= 512) {
> > +			mclk_prediv = prediv[i];
> > +			mclk_postdiv = postdiv;
> > +			best_mclk_rate = pll_rate / (prediv[i] * postdiv);
> > +			goto out;
> > +		}
> > +	}
> > +
> > +	/* No suitable prediv found, so try to adjust the postdiv */
> > +	for (postdiv = 4; postdiv <= 512; postdiv += 2) {
> > +		unsigned int pre;
> > +
> > +		pre = mclkdiv / postdiv;
> > +		if (pre == 2 || pre == 4 || pre == 8) {
> > +			mclk_prediv = pre;
> > +			mclk_postdiv = postdiv;
> > +			best_mclk_rate = pll_rate / (pre * postdiv);
> > +			goto out;
> > +		}
> > +	}
> > +
> > +	/* The MCLK <-> PLL gap is to high -> use largest possible div */
> > +	mclk_prediv = 8;
> > +	mclk_postdiv = 512;
> > +	best_mclk_rate = pll_rate / (8 * 512);
> > +
> > +out:
> > +	tc358746->mclk_prediv = mclk_prediv;
> > +	tc358746->mclk_postdiv = mclk_postdiv;
> > +	tc358746->mclk_rate = best_mclk_rate;
> > +
> > +	if (best_mclk_rate != mclk_rate)
> > +		dev_warn(dev, "Request MCLK freq:%lu, found MCLK freq:%lu\n",
> > +			 mclk_rate, best_mclk_rate);
> > +
> > +	dev_dbg(dev, "Found MCLK settings: freq:%lu prediv:%u postdiv:%u\n",
> > +		best_mclk_rate, mclk_prediv, mclk_postdiv);
> > +
> > +	return best_mclk_rate;
> > +}
> > +
> > +static unsigned long
> > +tc358746_recalc_rate(struct clk_hw *hw, unsigned long parent_rate)
> > +{
> > +	struct tc358746 *tc358746 = clk_hw_to_tc358746(hw);
> > +	unsigned int prediv, postdiv;
> > +	u32 val;
> > +	int err;
> > +
> > +	err = tc358746_read(tc358746, MCLKCTL_REG, &val);
> > +	if (err)
> > +		return 0;
> > +
> > +	postdiv = FIELD_GET(MCLK_LOW_MASK, val) + 1;
> > +	postdiv += FIELD_GET(MCLK_HIGH_MASK, val) + 1;
> > +
> > +	err = tc358746_read(tc358746, CLKCTL_REG, &val);
> > +	if (err)
> > +		return 0;
> > +
> > +	prediv = FIELD_GET(MCLKDIV_MASK, val);
> > +	if (prediv == MCLKDIV_8)
> > +		prediv = 8;
> > +	else if (prediv == MCLKDIV_4)
> > +		prediv = 4;
> > +	else
> > +		prediv = 2;
> > +
> > +	return tc358746->pll_rate / (prediv * postdiv);
> > +}
> > +
> > +static long tc358746_mclk_round_rate(struct clk_hw *hw, unsigned long rate,
> > +				     unsigned long *parent_rate)
> > +{
> > +	struct tc358746 *tc358746 = clk_hw_to_tc358746(hw);
> > +
> > +	*parent_rate = tc358746->pll_rate;
> > +
> > +	return tc358746_find_mclk_settings(tc358746, rate);
> > +}
> > +
> > +static int tc358746_mclk_set_rate(struct clk_hw *hw, unsigned long rate,
> > +				  unsigned long parent_rate)
> > +{
> > +	struct tc358746 *tc358746 = clk_hw_to_tc358746(hw);
> > +
> > +	tc358746_find_mclk_settings(tc358746, rate);
> > +
> > +	return tc358746_mclk_enable(hw);
> > +}
> > +
> > +static const struct clk_ops tc358746_mclk_ops = {
> > +	.enable = tc358746_mclk_enable,
> > +	.disable = tc358746_mclk_disable,
> > +	.recalc_rate = tc358746_recalc_rate,
> > +	.round_rate = tc358746_mclk_round_rate,
> > +	.set_rate = tc358746_mclk_set_rate,
> > +};
> > +
> > +static int tc358746_setup_mclk_provider(struct tc358746 *tc358746)
> > +{
> > +	struct clk_init_data mclk_initdata = { };
> > +	struct device *dev = tc358746->sd.dev;
> > +	const char *mclk_name;
> > +	int err;
> > +
> > +	/* MCLK clk provider support is optional */
> > +	if (!device_property_present(dev, "#clock-cells"))
> > +		return 0;
> > +
> > +	/* Init to highest possibel MCLK */
> > +	tc358746->mclk_postdiv = 512;
> > +	tc358746->mclk_prediv = 8;
> > +
> > +	mclk_name = "tc358746-mclk";
> > +	device_property_read_string(dev, "clock-output-names", &mclk_name);
> > +
> > +	mclk_initdata.name = mclk_name;
> > +	mclk_initdata.ops = &tc358746_mclk_ops;
> > +	tc358746->mclk_hw.init = &mclk_initdata;
> > +
> > +	err = devm_clk_hw_register(dev, &tc358746->mclk_hw);
> > +	if (err) {
> > +		dev_err(dev, "Failed to register mclk provider\n");
> > +		return err;
> > +	}
> > +
> > +	err = devm_of_clk_add_hw_provider(dev, of_clk_hw_simple_get,
> > +					  &tc358746->mclk_hw);
> > +	if (err)
> > +		dev_err(dev, "Failed to add mclk provider\n");
> > +
> > +	return err;
> > +}
> > +
> > +static int
> > +tc358746_init_subdev(struct tc358746 *tc358746, struct i2c_client *client)
> > +{
> > +	struct v4l2_subdev *sd = &tc358746->sd;
> > +	int err;
> > +
> > +	v4l2_i2c_subdev_init(sd, client, &tc358746_ops);
> > +	sd->flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;
> > +	sd->entity.function = MEDIA_ENT_F_VID_IF_BRIDGE;
> > +	sd->entity.ops = &tc358746_entity_ops;
> > +
> > +	tc358746->pads[TC358746_SINK].flags = MEDIA_PAD_FL_SINK;
> > +	tc358746->pads[TC358746_SOURCE].flags = MEDIA_PAD_FL_SOURCE;
> > +	err = media_entity_pads_init(&sd->entity, TC358746_NR_PADS,
> > +				     tc358746->pads);
> > +	if (err)
> > +		return err;
> > +
> > +	err = v4l2_subdev_init_finalize(sd);
> > +	if (err)
> > +		media_entity_cleanup(&sd->entity);
> > +
> > +	return err;
> > +}
> > +
> > +static int
> > +tc358746_init_output_port(struct tc358746 *tc358746, unsigned long refclk)
> > +{
> > +	struct device *dev = tc358746->sd.dev;
> > +	struct v4l2_fwnode_endpoint *vep;
> > +	unsigned long csi_link_rate;
> > +	struct fwnode_handle *ep;
> > +	unsigned char csi_lanes;
> > +	int err;
> > +
> > +	ep = fwnode_graph_get_endpoint_by_id(dev_fwnode(dev), TC358746_SOURCE,
> > +					     0, 0);
> > +	if (!ep) {
> > +		dev_err(dev, "Missing endpoint node\n");
> > +		return -EINVAL;
> > +	}
> > +
> > +	/* Currently we only support 'parallel in' -> 'csi out' */
> > +	vep = &tc358746->csi_vep;
> > +	vep->bus_type = V4L2_MBUS_CSI2_DPHY;
> > +	err = v4l2_fwnode_endpoint_alloc_parse(ep, vep);
> > +	fwnode_handle_put(ep);
> > +	if (err) {
> > +		dev_err(dev, "Failed to parse source endpoint\n");
> > +		return err;
> > +	}
> > +
> > +	csi_lanes = vep->bus.mipi_csi2.num_data_lanes;
> > +	if (csi_lanes == 0 || csi_lanes > 4 ||
> > +	    vep->nr_of_link_frequencies == 0) {
> > +		dev_err(dev, "error: Invalid CSI-2 settings\n");
> > +		err = -EINVAL;
> > +		goto err;
> > +	}
> > +
> > +	/* TODO: Add support to handle multiple link frequencies */
> > +	csi_link_rate = (unsigned long)vep->link_frequencies[0];
> > +	tc358746->pll_rate = tc358746_find_pll_settings(tc358746, refclk,
> > +							csi_link_rate * 2);
> > +	if (!tc358746->pll_rate) {
> > +		err = -EINVAL;
> > +		goto err;
> > +	}
> > +
> > +	err = phy_mipi_dphy_get_default_config_for_hsclk(tc358746->pll_rate,
> > +						csi_lanes, &tc358746->dphy_cfg);
> > +	if (err)
> > +		goto err;
> > +
> > +	tc358746->vb_size = TC358746_VB_DEFAULT_SIZE;
> > +
> > +	return 0;
> > +
> > +err:
> > +	v4l2_fwnode_endpoint_free(vep);
> > +
> > +	return err;
> > +}
> > +
> > +static int tc358746_init_hw(struct tc358746 *tc358746)
> > +{
> > +	struct device *dev = tc358746->sd.dev;
> > +	unsigned int chipid;
> > +	u32 val;
> > +	int err;
> > +
> > +	err = pm_runtime_resume_and_get(dev);
> > +	if (err < 0) {
> > +		dev_err(dev, "Failed to resume the device\n");
> > +		return err;
> > +	}
> > +
> > +	 /* Ensure that CSI interface is put into LP-11 state */
> > +	err = tc358746_sw_reset(tc358746);
> > +	if (err) {
> > +		pm_runtime_put_sync(dev);
> > +		dev_err(dev, "Failed to reset the device\n");
> > +		return err;
> > +	}
> > +
> > +	err = tc358746_read(tc358746, CHIPID_REG, &val);
> > +	pm_runtime_mark_last_busy(dev);
> > +	pm_runtime_put_sync_autosuspend(dev);
> > +	if (err)
> > +		return -ENODEV;
> > +
> > +	chipid = FIELD_GET(CHIPID, val);
> > +	if (chipid != 0x44) {
> > +		dev_err(dev, "Invalid chipid 0x%02x\n", chipid);
> > +		return -ENODEV;
> > +	}
> > +
> > +	return 0;
> > +}
> > +
> > +static int tc358746_init_controls(struct tc358746 *tc358746)
> > +{
> > +	u64 *link_frequencies = tc358746->csi_vep.link_frequencies;
> > +	struct v4l2_ctrl *ctrl;
> > +	int err;
> > +
> > +	err = v4l2_ctrl_handler_init(&tc358746->ctrl_hdl, 1);
> > +	if (err)
> > +		return err;
> > +
> > +	/*
> > +	 * The driver currently supports only one link-frequency, regardless of
> > +	 * the input from the firmware, see: tc358746_init_output_port(). So
> > +	 * report only the first frequency from the array of possible given
> > +	 * frequencies.
> > +	 */
> > +	ctrl = v4l2_ctrl_new_int_menu(&tc358746->ctrl_hdl, NULL,
> > +				      V4L2_CID_LINK_FREQ, 0, 0,
> > +				      link_frequencies);
> > +	if (ctrl)
> > +		ctrl->flags |= V4L2_CTRL_FLAG_READ_ONLY;
> > +
> > +	err = tc358746->ctrl_hdl.error;
> > +	if (err) {
> > +		v4l2_ctrl_handler_free(&tc358746->ctrl_hdl);
> > +		return err;
> > +	}
> > +
> > +	tc358746->sd.ctrl_handler = &tc358746->ctrl_hdl;
> > +
> > +	return 0;
> > +}
> > +
> > +static int tc358746_notify_bound(struct v4l2_async_notifier *notifier,
> > +				 struct v4l2_subdev *sd,
> > +				 struct v4l2_async_subdev *asd)
> > +{
> > +	struct tc358746 *tc358746 =
> > +		container_of(notifier, struct tc358746, notifier);
> > +	u32 flags = MEDIA_LNK_FL_ENABLED | MEDIA_LNK_FL_IMMUTABLE;
> > +	struct media_pad *sink = &tc358746->pads[TC358746_SINK];
> > +
> > +	return v4l2_create_fwnode_links_to_pad(sd, sink, flags);
> > +}
> > +
> > +static const struct v4l2_async_notifier_operations tc358746_notify_ops = {
> > +	.bound = tc358746_notify_bound,
> > +};
> > +
> > +static int tc358746_async_register(struct tc358746 *tc358746)
> > +{
> > +	struct v4l2_fwnode_endpoint vep = {
> > +		.bus_type = V4L2_MBUS_PARALLEL,
> > +	};
> > +	struct v4l2_async_subdev *asd;
> > +	struct fwnode_handle *ep;
> > +	int err;
> > +
> > +	ep = fwnode_graph_get_endpoint_by_id(dev_fwnode(tc358746->sd.dev),
> > +					     TC358746_SINK, 0, 0);
> > +	if (!ep)
> > +		return -ENOTCONN;
> > +
> > +	err = v4l2_fwnode_endpoint_parse(ep, &vep);
> > +	if (err) {
> > +		fwnode_handle_put(ep);
> > +		return err;
> > +	}
> > +
> > +	v4l2_async_nf_init(&tc358746->notifier);
> > +	asd = v4l2_async_nf_add_fwnode_remote(&tc358746->notifier, ep,
> > +					      struct v4l2_async_subdev);
> > +	fwnode_handle_put(ep);
> > +
> > +	if (IS_ERR(asd)) {
> > +		err = PTR_ERR(asd);
> > +		goto err_cleanup;
> > +	}
> > +
> > +	tc358746->notifier.ops = &tc358746_notify_ops;
> > +
> > +	err = v4l2_async_subdev_nf_register(&tc358746->sd, &tc358746->notifier);
> > +	if (err)
> > +		goto err_cleanup;
> > +
> > +	tc358746->sd.fwnode = fwnode_graph_get_endpoint_by_id(
> > +		dev_fwnode(tc358746->sd.dev), TC358746_SOURCE, 0, 0);
> > +
> > +	err = v4l2_async_register_subdev(&tc358746->sd);
> > +	if (err)
> > +		goto err_unregister;
> > +
> > +	return 0;
> > +
> > +err_unregister:
> > +	fwnode_handle_put(tc358746->sd.fwnode);
> > +	v4l2_async_nf_unregister(&tc358746->notifier);
> > +err_cleanup:
> > +	v4l2_async_nf_cleanup(&tc358746->notifier);
> > +
> > +	return err;
> > +}
> > +
> > +static int tc358746_probe(struct i2c_client *client)
> > +{
> > +	struct device *dev = &client->dev;
> > +	struct tc358746 *tc358746;
> > +	unsigned long refclk;
> > +	unsigned int i;
> > +	int err;
> > +
> > +	tc358746 = devm_kzalloc(&client->dev, sizeof(*tc358746), GFP_KERNEL);
> > +	if (!tc358746)
> > +		return -ENOMEM;
> > +
> > +	tc358746->regmap = devm_regmap_init_i2c(client, &tc358746_regmap_config);
> > +	if (IS_ERR(tc358746->regmap))
> > +		return dev_err_probe(dev, PTR_ERR(tc358746->regmap),
> > +				     "Failed to init regmap\n");
> > +
> > +	tc358746->refclk = devm_clk_get(dev, "refclk");
> > +	if (IS_ERR(tc358746->refclk))
> > +		return dev_err_probe(dev, PTR_ERR(tc358746->refclk),
> > +				     "Failed to get refclk\n");
> > +
> > +	err = clk_prepare_enable(tc358746->refclk);
> > +	if (err)
> > +		return dev_err_probe(dev, err,
> > +				     "Failed to enable refclk\n");
> > +
> > +	refclk = clk_get_rate(tc358746->refclk);
> > +	clk_disable_unprepare(tc358746->refclk);
> > +
> > +	if (refclk < 6 * HZ_PER_MHZ || refclk > 40 * HZ_PER_MHZ)
> > +		return dev_err_probe(dev, -EINVAL, "Invalid refclk range\n");
> > +
> > +	for (i = 0; i < ARRAY_SIZE(tc358746_supplies); i++)
> > +		tc358746->supplies[i].supply = tc358746_supplies[i];
> > +
> > +	err = devm_regulator_bulk_get(dev, ARRAY_SIZE(tc358746_supplies),
> > +				      tc358746->supplies);
> > +	if (err)
> > +		return dev_err_probe(dev, err, "Failed to get supplies\n");
> > +
> > +	tc358746->reset_gpio = devm_gpiod_get_optional(dev, "reset",
> > +						       GPIOD_OUT_HIGH);
> > +	if (IS_ERR(tc358746->reset_gpio))
> > +		return dev_err_probe(dev, PTR_ERR(tc358746->reset_gpio),
> > +				     "Failed to get reset-gpios\n");
> > +
> > +	err = tc358746_init_subdev(tc358746, client);
> > +	if (err)
> > +		return dev_err_probe(dev, err, "Failed to init subdev\n");
> > +
> > +	err = tc358746_init_output_port(tc358746, refclk);
> > +	if (err)
> > +		goto err_subdev;
> > +
> > +	/*
> > +	 * Keep this order since we need the output port link-frequencies
> > +	 * information.
> > +	 */
> > +	err = tc358746_init_controls(tc358746);
> > +	if (err)
> > +		goto err_fwnode;
> > +
> > +	dev_set_drvdata(dev, tc358746);
> > +
> > +	/* Set to 1sec to give the stream reconfiguration enough time */
> > +	pm_runtime_set_autosuspend_delay(dev, 1000);
> > +	pm_runtime_use_autosuspend(dev);
> > +	pm_runtime_enable(dev);
> > +
> > +	err = tc358746_init_hw(tc358746);
> > +	if (err)
> > +		goto err_pm;
> > +
> > +	err = tc358746_setup_mclk_provider(tc358746);
> > +	if (err)
> > +		goto err_pm;
> > +
> > +	err = tc358746_async_register(tc358746);
> > +	if (err < 0)
> > +		goto err_pm;
> > +
> > +	dev_dbg(dev, "%s found @ 0x%x (%s)\n", client->name,
> > +		client->addr, client->adapter->name);
> > +
> > +	return 0;
> > +
> > +err_pm:
> > +	pm_runtime_disable(dev);
> > +	pm_runtime_set_suspended(dev);
> > +	pm_runtime_dont_use_autosuspend(dev);
> > +	v4l2_ctrl_handler_free(&tc358746->ctrl_hdl);
> > +err_fwnode:
> > +	v4l2_fwnode_endpoint_free(&tc358746->csi_vep);
> > +err_subdev:
> > +	v4l2_subdev_cleanup(&tc358746->sd);
> > +	media_entity_cleanup(&tc358746->sd.entity);
> > +
> > +	return err;
> > +}
> > +
> > +static int tc358746_remove(struct i2c_client *client)
> > +{
> > +	struct v4l2_subdev *sd = i2c_get_clientdata(client);
> > +	struct tc358746 *tc358746 = to_tc358746(sd);
> > +
> > +	v4l2_subdev_cleanup(sd);
> > +	v4l2_ctrl_handler_free(&tc358746->ctrl_hdl);
> > +	v4l2_fwnode_endpoint_free(&tc358746->csi_vep);
> > +	v4l2_async_nf_unregister(&tc358746->notifier);
> > +	v4l2_async_nf_cleanup(&tc358746->notifier);
> > +	fwnode_handle_put(sd->fwnode);
> > +	v4l2_async_unregister_subdev(sd);
> > +	media_entity_cleanup(&sd->entity);
> > +
> > +	pm_runtime_disable(sd->dev);
> > +	pm_runtime_set_suspended(sd->dev);
> > +	pm_runtime_dont_use_autosuspend(sd->dev);
> > +
> > +	return 0;
> > +}
> > +
> > +static int tc358746_suspend(struct device *dev)
> > +{
> > +	struct tc358746 *tc358746 = dev_get_drvdata(dev);
> > +	int err;
> > +
> > +	clk_disable_unprepare(tc358746->refclk);
> > +
> > +	err = regulator_bulk_disable(ARRAY_SIZE(tc358746_supplies),
> > +				     tc358746->supplies);
> > +	if (err)
> > +		clk_prepare_enable(tc358746->refclk);
> > +
> > +	return err;
> > +}
> > +
> > +static int tc358746_resume(struct device *dev)
> > +{
> > +	struct tc358746 *tc358746 = dev_get_drvdata(dev);
> > +	int err;
> > +
> > +	gpiod_set_value(tc358746->reset_gpio, 1);
> > +
> > +	err = regulator_bulk_enable(ARRAY_SIZE(tc358746_supplies),
> > +				    tc358746->supplies);
> > +	if (err)
> > +		return err;
> > +
> > +	/* min. 200ns */
> > +	usleep_range(10, 20);
> > +
> > +	gpiod_set_value(tc358746->reset_gpio, 0);
> > +
> > +	err = clk_prepare_enable(tc358746->refclk);
> > +	if (err)
> > +		goto err;
> > +
> > +	/* min. 700us ... 1ms */
> > +	usleep_range(1000, 1500);
> > +
> > +	/*
> > +	 * Enable the PLL here since it can be called by the clk-framework or by
> > +	 * the .s_stream() callback. So this is the common place for both.
> > +	 */
> > +	err = tc358746_apply_pll_config(tc358746);
> > +	if (err)
> > +		goto err_clk;
> > +
> > +	return 0;
> > +
> > +err_clk:
> > +	clk_disable_unprepare(tc358746->refclk);
> > +err:
> > +	regulator_bulk_disable(ARRAY_SIZE(tc358746_supplies),
> > +			       tc358746->supplies);
> > +	return err;
> > +}
> > +
> > +DEFINE_RUNTIME_DEV_PM_OPS(tc358746_pm_ops, tc358746_suspend,
> > +			  tc358746_resume, NULL);
> > +
> > +static const struct of_device_id __maybe_unused tc358746_of_match[] = {
> > +	{ .compatible = "toshiba,tc358746" },
> > +	{ },
> > +};
> > +MODULE_DEVICE_TABLE(of, tc358746_of_match);
> > +
> > +static struct i2c_driver tc358746_driver = {
> > +	.driver = {
> > +		.name = "tc358746",
> > +		.pm = pm_ptr(&tc358746_pm_ops),
> > +		.of_match_table = tc358746_of_match,
> > +	},
> > +	.probe_new = tc358746_probe,
> > +	.remove = tc358746_remove,
> > +};
> > +
> > +module_i2c_driver(tc358746_driver);
> > +
> > +MODULE_DESCRIPTION("Toshiba TC358746 Parallel to CSI-2 bridge driver");
> > +MODULE_AUTHOR("Marco Felsch <kernel@pengutronix.de>");
> > +MODULE_LICENSE("GPL");
> 
> -- 
> Regards,
> 
> Laurent Pinchart
> 

Re: [PATCH v3 4/4] media: tc358746: add Toshiba TC358746 Parallel to CSI-2 bridge driver

[Marco Felsch]

Hi Laurent,

On 22-09-22, Laurent Pinchart wrote:
> Hi Marco,
> 
> Thank you for the patch.
> 
> On Thu, Sep 22, 2022 at 03:48:43PM +0200, Marco Felsch wrote:
> > Adding support for the TC358746 parallel <-> MIPI CSI bridge. This chip
> > supports two operating modes:
> >   1st) parallel-in -> mipi-csi out
> >   2nd) mipi-csi in -> parallel out
> > 
> > This patch only adds the support for the 1st mode.
> > 
> > Signed-off-by: Marco Felsch <m.felsch@pengutronix.de>
> > ---
> > Changelog:
> > 
> > v3:
> > - added missing static
> > - drop s/MHZ/HZ_PER_MHZ/
> > - kconfig: add "depends on PM"
> > - Add tc358746_valid_reg() for regmap.
> > - tc358746_set_fmt: fix format negotiation for pad == SOURCE
> > - tc358746_write/read: add error messages
> > - replace udelay with fsleep()
> > - tc358746_apply_misc_config: const mbusfmt
> > - tc358746_s_stream: fix comment about LP-00/11 state change
> > - tc358746_link_validate: s/sensor/source/
> > - tc358746_link_validate: s/pclk_rate/link_freq/
> > - tc358746_link_validate: fix v4l2_subdev_unlock_state()
> > - tc358746_link_validate: adapt fifo-sz comment
> > - tc358746_g/s_register: use pm_runtime_get_if_in_use
> > - tc358746_setup_mclk_provider: move to clk related location
> > - tc358746_init_hw: fix error case
> > - tc358746_init_controls: add comment
> > - tc358746_notify_bound: add MEDIA_LNK_FL_IMMUTABLE
> > - tc358746_async_register: fix error path
> > - tc358746_async_register: put sd.fwnode on error and remove
> > - tc358746_probe: increase autosuspend to 1s
> > 
> > v2:
> > - use the correct CID_LINK_FREQ control to query the sensor_pclk_rate
> > - remove now not needed tc358746_link_setup() and
> >   struct v4l2_ctrl sensor_pclk_ctrl
> > - call v4l2_subdev_link_validate_default() during link validation
> > - remove MEDIA_BUS_FMT_GBR888_1X24/YUV444 format support
> > - use subdev active_state API
> > - replace own .get_fmt with v4l2_subdev_get_fmt
> > - remove unnecessary pad checks
> > - restructure tc358746_get_format_by_code() if-case
> > - move apply_dphy_config|apply_misc_config from resume intos s_stream
> > - use goto in s_stream enable case
> > - fix error handling in suspend/resume
> > - split probe() into more sub-functions
> > ---
> >  drivers/media/i2c/Kconfig    |   17 +
> >  drivers/media/i2c/Makefile   |    1 +
> >  drivers/media/i2c/tc358746.c | 1692 ++++++++++++++++++++++++++++++++++
> >  3 files changed, 1710 insertions(+)
> >  create mode 100644 drivers/media/i2c/tc358746.c
> > 
> > diff --git a/drivers/media/i2c/Kconfig b/drivers/media/i2c/Kconfig
> > index 7806d4b81716..f85cdb94c524 100644
> > --- a/drivers/media/i2c/Kconfig
> > +++ b/drivers/media/i2c/Kconfig
> > @@ -1272,6 +1272,23 @@ config VIDEO_TC358743_CEC
> >  	  When selected the tc358743 will support the optional
> >  	  HDMI CEC feature.
> >  
> > +config VIDEO_TC358746
> > +	tristate "Toshiba TC358746 parallel-CSI2 bridge"
> > +	depends on VIDEO_DEV && PM && I2C
> > +	select VIDEO_V4L2_SUBDEV_API
> > +	select MEDIA_CONTROLLER
> > +	select V4L2_FWNODE
> > +	select GENERIC_PHY_MIPI_DPHY
> > +	select REGMAP_I2C
> > +	select COMMON_CLK
> > +	help
> > +	  Support for the Toshiba TC358746 parallel to MIPI CSI-2 bridge.
> > +	  The bridge can work in both directions but currently only the
> > +	  parallel-in / csi-out path is supported.
> > +
> > +	  To compile this driver as a module, choose M here: the
> > +	  module will be called tc358746.
> > +
> >  config VIDEO_TVP514X
> >  	tristate "Texas Instruments TVP514x video decoder"
> >  	depends on VIDEO_DEV && I2C
> > diff --git a/drivers/media/i2c/Makefile b/drivers/media/i2c/Makefile
> > index 0a2933103dd9..d1096c2ab480 100644
> > --- a/drivers/media/i2c/Makefile
> > +++ b/drivers/media/i2c/Makefile
> > @@ -118,6 +118,7 @@ obj-$(CONFIG_VIDEO_SONY_BTF_MPX) += sony-btf-mpx.o
> >  obj-$(CONFIG_VIDEO_SR030PC30) += sr030pc30.o
> >  obj-$(CONFIG_VIDEO_ST_MIPID02) += st-mipid02.o
> >  obj-$(CONFIG_VIDEO_TC358743) += tc358743.o
> > +obj-$(CONFIG_VIDEO_TC358746) += tc358746.o
> >  obj-$(CONFIG_VIDEO_TDA1997X) += tda1997x.o
> >  obj-$(CONFIG_VIDEO_TDA7432) += tda7432.o
> >  obj-$(CONFIG_VIDEO_TDA9840) += tda9840.o
> > diff --git a/drivers/media/i2c/tc358746.c b/drivers/media/i2c/tc358746.c
> > new file mode 100644
> > index 000000000000..0dcd5e0e0855
> > --- /dev/null
> > +++ b/drivers/media/i2c/tc358746.c
> > @@ -0,0 +1,1692 @@
> > +// SPDX-License-Identifier: GPL-2.0-only
> > +/*
> > + * TC358746 - Parallel <-> CSI-2 Bridge
> > + *
> > + * Copyright 2022 Marco Felsch <kernel@pengutronix.de>
> > + *
> > + * Notes:
> > + *  - Currently only 'Parallel-in -> CSI-out' mode is supported!
> > + */
> > +
> > +#include <linux/bitfield.h>
> > +#include <linux/clk.h>
> > +#include <linux/clk-provider.h>
> > +#include <linux/delay.h>
> > +#include <linux/i2c.h>
> > +#include <linux/interrupt.h>
> > +#include <linux/kernel.h>
> > +#include <linux/module.h>
> > +#include <linux/phy/phy-mipi-dphy.h>
> > +#include <linux/property.h>
> > +#include <linux/pm_runtime.h>
> > +#include <linux/regmap.h>
> > +#include <linux/units.h>
> > +#include <media/v4l2-ctrls.h>
> > +#include <media/v4l2-device.h>
> > +#include <media/v4l2-fwnode.h>
> > +#include <media/v4l2-mc.h>
> > +
> > +/* 16-bit registers */
> > +#define CHIPID_REG			0x0000
> > +#define		CHIPID			GENMASK(15, 8)
> > +
> > +#define SYSCTL_REG			0x0002
> > +#define		SRESET			BIT(0)
> > +
> > +#define CONFCTL_REG			0x0004
> > +#define		PDATAF_MASK		GENMASK(9, 8)
> > +#define		PDATAF_MODE0		0
> > +#define		PDATAF_MODE1		1
> > +#define		PDATAF_MODE2		2
> > +#define		PDATAF(val)		FIELD_PREP(PDATAF_MASK, (val))
> > +#define		PPEN			BIT(6)
> > +#define		DATALANE_MASK		GENMASK(1, 0)
> > +
> > +#define FIFOCTL_REG			0x0006
> > +#define DATAFMT_REG			0x0008
> > +#define		PDFMT(val)		FIELD_PREP(GENMASK(7, 4), (val))
> > +
> > +#define MCLKCTL_REG			0x000c
> > +#define		MCLK_HIGH_MASK		GENMASK(15, 8)
> > +#define		MCLK_LOW_MASK		GENMASK(7, 0)
> > +#define		MCLK_HIGH(val)		FIELD_PREP(MCLK_HIGH_MASK, (val))
> > +#define		MCLK_LOW(val)		FIELD_PREP(MCLK_LOW_MASK, (val))
> > +
> > +#define PLLCTL0_REG			0x0016
> > +#define		PLL_PRD_MASK		GENMASK(15, 12)
> > +#define		PLL_PRD(val)		FIELD_PREP(PLL_PRD_MASK, (val))
> > +#define		PLL_FBD_MASK		GENMASK(8, 0)
> > +#define		PLL_FBD(val)		FIELD_PREP(PLL_FBD_MASK, (val))
> > +
> > +#define PLLCTL1_REG			0x0018
> > +#define		PLL_FRS_MASK		GENMASK(11, 10)
> > +#define		PLL_FRS(val)		FIELD_PREP(PLL_FRS_MASK, (val))
> > +#define		CKEN			BIT(4)
> > +#define		RESETB			BIT(1)
> > +#define		PLL_EN			BIT(0)
> > +
> > +#define CLKCTL_REG			0x0020
> > +#define		MCLKDIV_MASK		GENMASK(3, 2)
> > +#define		MCLKDIV(val)		FIELD_PREP(MCLKDIV_MASK, (val))
> > +#define		MCLKDIV_8		0
> > +#define		MCLKDIV_4		1
> > +#define		MCLKDIV_2		2
> > +
> > +#define WORDCNT_REG			0x0022
> > +#define PP_MISC_REG			0x0032
> > +#define		FRMSTOP			BIT(15)
> > +#define		RSTPTR			BIT(14)
> > +
> > +/* 32-bit registers */
> > +#define CLW_DPHYCONTTX_REG		0x0100
> > +#define CLW_CNTRL_REG			0x0140
> > +#define D0W_CNTRL_REG			0x0144
> > +#define		LANEDISABLE		BIT(0)
> > +
> > +#define STARTCNTRL_REG			0x0204
> > +#define		START			BIT(0)
> > +
> > +#define LINEINITCNT_REG			0x0210
> > +#define LPTXTIMECNT_REG			0x0214
> > +#define TCLK_HEADERCNT_REG		0x0218
> > +#define		TCLK_ZEROCNT(val)	FIELD_PREP(GENMASK(15, 8), (val))
> > +#define		TCLK_PREPARECNT(val)	FIELD_PREP(GENMASK(6, 0), (val))
> > +
> > +#define TCLK_TRAILCNT_REG		0x021C
> > +#define THS_HEADERCNT_REG		0x0220
> > +#define		THS_ZEROCNT(val)	FIELD_PREP(GENMASK(14, 8), (val))
> > +#define		THS_PREPARECNT(val)	FIELD_PREP(GENMASK(6, 0), (val))
> > +
> > +#define TWAKEUP_REG			0x0224
> > +#define TCLK_POSTCNT_REG		0x0228
> > +#define THS_TRAILCNT_REG		0x022C
> > +#define HSTXVREGEN_REG			0x0234
> > +#define TXOPTIONCNTRL_REG		0x0238
> > +#define CSI_CONTROL_REG			0x040C
> > +#define		CSI_MODE		BIT(15)
> > +#define		TXHSMD			BIT(7)
> > +#define		NOL(val)		FIELD_PREP(GENMASK(2, 1), (val))
> > +
> > +#define CSI_CONFW_REG			0x0500
> > +#define		MODE(val)		FIELD_PREP(GENMASK(31, 29), (val))
> > +#define		MODE_SET		0x5
> > +#define		ADDRESS(val)		FIELD_PREP(GENMASK(28, 24), (val))
> > +#define		CSI_CONTROL_ADDRESS	0x3
> > +#define		DATA(val)		FIELD_PREP(GENMASK(15, 0), (val))
> > +
> > +#define CSI_START_REG			0x0518
> > +#define		STRT			BIT(0)
> > +
> > +static const struct v4l2_mbus_framefmt tc358746_def_fmt = {
> > +	.width		= 640,
> > +	.height		= 480,
> > +	.code		= MEDIA_BUS_FMT_UYVY8_2X8,
> > +	.field		= V4L2_FIELD_NONE,
> > +	.colorspace	= V4L2_COLORSPACE_DEFAULT,
> > +	.ycbcr_enc	= V4L2_YCBCR_ENC_DEFAULT,
> > +	.quantization	= V4L2_QUANTIZATION_DEFAULT,
> > +	.xfer_func	= V4L2_XFER_FUNC_DEFAULT,
> > +};
> > +
> > +static const char * const tc358746_supplies[] = {
> > +	"vddc", "vddio", "vddmipi"
> > +};
> > +
> > +enum {
> > +	TC358746_SINK,
> > +	TC358746_SOURCE,
> > +	TC358746_NR_PADS
> > +};
> > +
> > +struct tc358746 {
> > +	struct v4l2_subdev		sd;
> > +	struct media_pad		pads[TC358746_NR_PADS];
> > +	struct v4l2_async_notifier	notifier;
> > +	struct v4l2_fwnode_endpoint	csi_vep;
> > +
> > +	struct v4l2_ctrl_handler	ctrl_hdl;
> > +
> > +	struct regmap			*regmap;
> > +	struct clk			*refclk;
> > +	struct gpio_desc		*reset_gpio;
> > +	struct regulator_bulk_data	supplies[ARRAY_SIZE(tc358746_supplies)];
> > +
> > +	struct clk_hw			mclk_hw;
> > +	unsigned long			mclk_rate;
> > +	u8				mclk_prediv;
> > +	u16				mclk_postdiv;
> > +
> > +	unsigned long			pll_rate;
> > +	u8				pll_post_div;
> > +	u16				pll_pre_div;
> > +	u16				pll_mul;
> > +
> > +#define TC358746_VB_MAX_SIZE		(511 * 32)
> > +#define TC358746_VB_DEFAULT_SIZE	  (1 * 32)
> > +	unsigned int			vb_size; /* Video buffer size in bits */
> > +
> > +	struct phy_configure_opts_mipi_dphy dphy_cfg;
> > +};
> > +
> > +static inline struct tc358746 *to_tc358746(struct v4l2_subdev *sd)
> > +{
> > +	return container_of(sd, struct tc358746, sd);
> > +}
> > +
> > +static inline struct tc358746 *clk_hw_to_tc358746(struct clk_hw *hw)
> > +{
> > +	return container_of(hw, struct tc358746, mclk_hw);
> > +}
> > +
> > +struct tc358746_format {
> > +	u32		code;
> > +	bool		csi_format;
> > +	unsigned char	bus_width;
> > +	unsigned char	bpp;
> > +	/* Register values */
> > +	u8		pdformat; /* Peripheral Data Format */
> > +	u8		pdataf;   /* Parallel Data Format Option */
> > +};
> > +
> > +enum {
> > +	PDFORMAT_RAW8 = 0,
> > +	PDFORMAT_RAW10,
> > +	PDFORMAT_RAW12,
> > +	PDFORMAT_RGB888,
> > +	PDFORMAT_RGB666,
> > +	PDFORMAT_RGB565,
> > +	PDFORMAT_YUV422_8BIT,
> > +	/* RESERVED = 7 */
> > +	PDFORMAT_RAW14 = 8,
> > +	PDFORMAT_YUV422_10BIT,
> > +	PDFORMAT_YUV444,
> > +};
> > +
> > +/* Check tc358746_src_mbus_code() if you add new formats */
> > +static const struct tc358746_format tc358746_formats[] = {
> > +	{
> > +		.code = MEDIA_BUS_FMT_UYVY8_2X8,
> > +		.bus_width = 8,
> > +		.bpp = 16,
> > +		.pdformat = PDFORMAT_YUV422_8BIT,
> > +		.pdataf = PDATAF_MODE0,
> > +	}, {
> > +		.code = MEDIA_BUS_FMT_UYVY8_1X16,
> > +		.csi_format = true,
> > +		.bus_width = 16,
> > +		.bpp = 16,
> > +		.pdformat = PDFORMAT_YUV422_8BIT,
> > +		.pdataf = PDATAF_MODE1,
> > +	}, {
> > +		.code = MEDIA_BUS_FMT_YUYV8_1X16,
> > +		.csi_format = true,
> > +		.bus_width = 16,
> > +		.bpp = 16,
> > +		.pdformat = PDFORMAT_YUV422_8BIT,
> > +		.pdataf = PDATAF_MODE2,
> > +	}, {
> > +		.code = MEDIA_BUS_FMT_UYVY10_2X10,
> > +		.bus_width = 10,
> > +		.bpp = 20,
> > +		.pdformat = PDFORMAT_YUV422_10BIT,
> > +		.pdataf = PDATAF_MODE0, /* don't care */
> > +	}
> > +};
> > +
> > +/* Get n-th format for pad */
> > +static const struct tc358746_format *
> > +tc358746_get_format_by_idx(unsigned int pad, unsigned int index)
> > +{
> > +	unsigned int idx = 0;
> > +	unsigned int i;
> > +
> > +	for (i = 0; i < ARRAY_SIZE(tc358746_formats); i++) {
> > +		const struct tc358746_format *fmt = &tc358746_formats[i];
> > +
> > +		if ((pad == TC358746_SOURCE && fmt->csi_format) ||
> > +		    (pad == TC358746_SINK)) {
> > +			if (idx == index)
> > +				return fmt;
> > +			idx++;
> > +		}
> > +	}
> > +
> > +	return ERR_PTR(-EINVAL);
> > +}
> > +
> > +static const struct tc358746_format *
> > +tc358746_get_format_by_code(unsigned int pad, u32 code)
> > +{
> > +	unsigned int i;
> > +
> > +	for (i = 0; i < ARRAY_SIZE(tc358746_formats); i++) {
> > +		const struct tc358746_format *fmt = &tc358746_formats[i];
> > +
> > +		if (pad == TC358746_SINK && fmt->code == code)
> > +			return fmt;
> > +
> > +		if (pad == TC358746_SOURCE && !fmt->csi_format)
> > +			continue;
> > +
> > +		if (fmt->code == code)
> > +			return fmt;
> > +	}
> > +
> > +	return ERR_PTR(-EINVAL);
> > +}
> > +
> > +static u32 tc358746_src_mbus_code(u32 code)
> > +{
> > +	switch (code) {
> > +	case MEDIA_BUS_FMT_UYVY8_2X8:
> > +		return MEDIA_BUS_FMT_UYVY8_1X16;
> > +	case MEDIA_BUS_FMT_UYVY10_2X10:
> > +		return MEDIA_BUS_FMT_UYVY10_1X20;
> > +	default:
> > +		return code;
> > +	}
> > +}
> > +
> > +static bool tc358746_valid_reg(struct device *dev, unsigned int reg)
> > +{
> > +	switch (reg) {
> > +	case CHIPID_REG ... CSI_START_REG:
> > +		return true;
> > +	default:
> > +		return false;
> > +	}
> > +}
> > +
> > +static const struct regmap_config tc358746_regmap_config = {
> > +	.name = "tc358746",
> > +	.reg_bits = 16,
> > +	.val_bits = 16,
> > +	.max_register = CSI_START_REG,
> > +	.writeable_reg = tc358746_valid_reg,
> > +	.readable_reg = tc358746_valid_reg,
> > +	.reg_format_endian = REGMAP_ENDIAN_BIG,
> > +	.val_format_endian = REGMAP_ENDIAN_BIG,
> > +};
> > +
> > +static int tc358746_write(struct tc358746 *tc358746, u32 reg, u32 val)
> > +{
> > +	size_t count;
> > +	int err;
> > +
> > +	/* 32-bit registers starting from CLW_DPHYCONTTX */
> > +	count = reg < CLW_DPHYCONTTX_REG ? 1 : 2;
> > +
> > +	err = regmap_bulk_write(tc358746->regmap, reg, &val, count);
> > +	if (err)
> > +		dev_dbg(tc358746->sd.dev,
> > +			"Failed to write reg:0x%04x val:0x%04x\n", reg, val);
> 
> I'm not sure if the value is relevant here, but I'd add the error, it's
> useful to know what kind of I2C issue occurred. Same for read().

Yeah.. I'm not sure, since you told me to not flood the kernel log. If
someone recognised error while probing or streaming the debug will be
turned on anyways. However, I will make it a dev_err() since this
shouldnt appear normally, you're right.

> By the way, this isn't something you need to do in this driver, but I've
> found the following pattern to be useful for error handling:
> 
> static int tc358746_write(struct tc358746 *tc358746, u32 reg, u32 val, int *err)
> {
> 	size_t count;
> 	int ret;
> 
> 	if (err && *err)
> 		return *err;
> 
> 	/* 32-bit registers starting from CLW_DPHYCONTTX */
> 	count = reg < CLW_DPHYCONTTX_REG ? 1 : 2;
> 
> 	ret = regmap_bulk_write(tc358746->regmap, reg, &val, count);
> 	if (ret)
> 		dev_dbg(tc358746->sd.dev,
> 			"Failed to write reg 0x%04x: %d\n", reg, ret);
> 		if (err)
> 			*err = ret;
> 		return ret;
> 	}
> 
> 	return 0;
> }
> 
> With this, you could simplify functions such as
> tc358746_apply_dphy_config(), by initializing the local err variable to
> 0, calling 
> 
> 	tc358746_write(tc358746, ..., ..., &err);
> 
> without checking for errors, and just returning err at the end of the
> function. With the same pattern enabled in tc358746_update_bits() you
> could simplify other functions too.

Good pattern, will keep it in mind. Albeit the little magic can cause
confusion while reading e.g. tc358746_apply_dphy_config().

> > +
> > +	return err;
> > +}
> > +
> > +static int tc358746_read(struct tc358746 *tc358746, u32 reg, u32 *val)
> > +{
> > +	size_t count;
> > +	int err;
> > +
> > +	/* 32-bit registers starting from CLW_DPHYCONTTX */
> > +	count = reg < CLW_DPHYCONTTX_REG ? 1 : 2;
> > +	*val = 0;
> > +
> > +	err = regmap_bulk_read(tc358746->regmap, reg, val, count);
> > +	if (err)
> > +		dev_dbg(tc358746->sd.dev, "Failed to read reg:0x%04x\n", reg);
> > +
> > +	return err;
> > +}
> > +
> > +static int
> > +tc358746_update_bits(struct tc358746 *tc358746, u32 reg, u32 mask, u32 val)
> > +{
> > +	u32 tmp, orig;
> > +	int err;
> > +
> > +	err = tc358746_read(tc358746, reg, &orig);
> > +	if (err)
> > +		return err;
> > +
> > +	tmp = orig & ~mask;
> > +	tmp |= val & mask;
> > +
> > +	return tc358746_write(tc358746, reg, tmp);
> > +}
> > +
> > +static int tc358746_set_bits(struct tc358746 *tc358746, u32 reg, u32 bits)
> > +{
> > +	return tc358746_update_bits(tc358746, reg, bits, bits);
> > +}
> > +
> > +static int tc358746_clear_bits(struct tc358746 *tc358746, u32 reg, u32 bits)
> > +{
> > +	return tc358746_update_bits(tc358746, reg, bits, 0);
> > +}
> > +
> > +static int tc358746_sw_reset(struct tc358746 *tc358746)
> > +{
> > +	int err;
> > +
> > +	err = tc358746_set_bits(tc358746, SYSCTL_REG, SRESET);
> > +	if (err)
> > +		return err;
> > +
> > +	fsleep(10);
> > +
> > +	return tc358746_clear_bits(tc358746, SYSCTL_REG, SRESET);
> > +}
> > +
> > +static int
> > +tc358746_apply_pll_config(struct tc358746 *tc358746)
> > +{
> > +	u8 post = tc358746->pll_post_div;
> > +	u16 pre = tc358746->pll_pre_div;
> > +	u16 mul = tc358746->pll_mul;
> > +	u32 val, mask;
> > +	int err;
> > +
> > +	err = tc358746_read(tc358746, PLLCTL1_REG, &val);
> > +	if (err)
> > +		return err;
> > +
> > +	/* Don't touch the PLL if running */
> > +	if (FIELD_GET(PLL_EN, val) == 1)
> > +		return 0;
> > +
> > +	/* Pre-div and Multiplicator have a internal +1 logic */
> > +	val = PLL_PRD(pre - 1) | PLL_FBD(mul - 1);
> > +	mask = PLL_PRD_MASK | PLL_FBD_MASK;
> > +	err = tc358746_update_bits(tc358746, PLLCTL0_REG, mask, val);
> > +	if (err)
> > +		return err;
> > +
> > +	val = PLL_FRS(ilog2(post)) | RESETB | PLL_EN;
> > +	mask = PLL_FRS_MASK | RESETB | PLL_EN;
> > +	tc358746_update_bits(tc358746, PLLCTL1_REG, mask, val);
> > +	if (err)
> > +		return err;
> > +
> > +	fsleep(1000);
> > +
> > +	return tc358746_set_bits(tc358746, PLLCTL1_REG, CKEN);
> > +}
> > +
> > +static int tc358746_apply_misc_config(struct tc358746 *tc358746)
> > +{
> > +	const struct v4l2_mbus_framefmt *mbusfmt;
> > +	struct v4l2_subdev *sd = &tc358746->sd;
> > +	struct v4l2_subdev_state *sink_state;
> > +	const struct tc358746_format *fmt;
> > +	struct device *dev = sd->dev;
> > +	u32 val;
> > +	int err;
> > +
> > +	sink_state = v4l2_subdev_lock_and_get_active_state(sd);
> > +	mbusfmt = v4l2_subdev_get_pad_format(sd, sink_state, TC358746_SINK);
> > +	v4l2_subdev_unlock_state(sink_state);
> > +
> > +	fmt = tc358746_get_format_by_code(TC358746_SINK, mbusfmt->code);
> > +
> > +	/* Self defined CSI user data type id's are not supported yet */
> > +	val = PDFMT(fmt->pdformat);
> > +	dev_dbg(dev, "DATAFMT: 0x%x\n", val);
> > +	err = tc358746_write(tc358746, DATAFMT_REG, val);
> > +	if (err)
> > +		return err;
> > +
> > +	val = PDATAF(fmt->pdataf);
> > +	dev_dbg(dev, "CONFCTL[PDATAF]: 0x%x\n", fmt->pdataf);
> > +	err = tc358746_update_bits(tc358746, CONFCTL_REG, PDATAF_MASK, val);
> > +	if (err)
> > +		return err;
> > +
> > +	val = tc358746->vb_size / 32;
> > +	dev_dbg(dev, "FIFOCTL: %u (0x%x)\n", val, val);
> > +	err = tc358746_write(tc358746, FIFOCTL_REG, val);
> > +	if (err)
> > +		return err;
> > +
> > +	/* Total number of bytes for each line/width */
> > +	val = mbusfmt->width * fmt->bpp / 8;
> > +	dev_dbg(dev, "WORDCNT: %u (0x%x)\n", val, val);
> > +	return tc358746_write(tc358746, WORDCNT_REG, val);
> > +}
> > +
> > +/* Use MHz as base so the div needs no u64 */
> > +static u32 tc358746_cfg_to_cnt(unsigned int cfg_val,
> > +			       unsigned int clk_mhz,
> > +			       unsigned int time_base)
> > +{
> > +	return DIV_ROUND_UP(cfg_val * clk_mhz, time_base);
> > +}
> > +
> > +static u32 tc358746_ps_to_cnt(unsigned int cfg_val,
> > +			      unsigned int clk_mhz)
> > +{
> > +	return tc358746_cfg_to_cnt(cfg_val, clk_mhz, USEC_PER_SEC);
> > +}
> > +
> > +static u32 tc358746_us_to_cnt(unsigned int cfg_val,
> > +			      unsigned int clk_mhz)
> > +{
> > +	return tc358746_cfg_to_cnt(cfg_val, clk_mhz, 1);
> > +}
> > +
> > +static int tc358746_apply_dphy_config(struct tc358746 *tc358746)
> > +{
> > +	struct phy_configure_opts_mipi_dphy *cfg = &tc358746->dphy_cfg;
> > +	bool non_cont_clk = !!(tc358746->csi_vep.bus.mipi_csi2.flags &
> > +			       V4L2_MBUS_CSI2_NONCONTINUOUS_CLOCK);
> > +	struct device *dev = tc358746->sd.dev;
> > +	unsigned long hs_byte_clk, hf_clk;
> > +	u32 val, val2, lptxcnt;
> > +	int err;
> > +
> > +	/* The hs_byte_clk is also called SYSCLK in the excel sheet */
> > +	hs_byte_clk = cfg->hs_clk_rate / 8;
> > +	hs_byte_clk /= HZ_PER_MHZ;
> > +	hf_clk = hs_byte_clk / 2;
> > +
> > +	val = tc358746_us_to_cnt(cfg->init, hf_clk) - 1;
> > +	dev_dbg(dev, "LINEINITCNT: %u (0x%x)\n", val, val);
> > +	err = tc358746_write(tc358746, LINEINITCNT_REG, val);
> > +	if (err)
> > +		return err;
> > +
> > +	val = tc358746_ps_to_cnt(cfg->lpx, hs_byte_clk) - 1;
> > +	lptxcnt = val;
> > +	dev_dbg(dev, "LPTXTIMECNT: %u (0x%x)\n", val, val);
> > +	err = tc358746_write(tc358746, LPTXTIMECNT_REG, val);
> > +	if (err)
> > +		return err;
> > +
> > +	val = tc358746_ps_to_cnt(cfg->clk_prepare, hs_byte_clk) - 1;
> > +	val2 = tc358746_ps_to_cnt(cfg->clk_zero, hs_byte_clk) - 1;
> > +	dev_dbg(dev, "TCLK_PREPARECNT: %u (0x%x)\n", val, val);
> > +	dev_dbg(dev, "TCLK_ZEROCNT: %u (0x%x)\n", val2, val2);
> > +	dev_dbg(dev, "TCLK_HEADERCNT: 0x%x\n",
> > +		(u32)(TCLK_PREPARECNT(val) | TCLK_ZEROCNT(val2)));
> > +	err = tc358746_write(tc358746, TCLK_HEADERCNT_REG,
> > +			     TCLK_PREPARECNT(val) | TCLK_ZEROCNT(val2));
> > +	if (err)
> > +		return err;
> > +
> > +	val = tc358746_ps_to_cnt(cfg->clk_trail, hs_byte_clk);
> > +	dev_dbg(dev, "TCLK_TRAILCNT: %u (0x%x)\n", val, val);
> > +	err = tc358746_write(tc358746, TCLK_TRAILCNT_REG, val);
> > +	if (err)
> > +		return err;
> > +
> > +	val = tc358746_ps_to_cnt(cfg->hs_prepare, hs_byte_clk) - 1;
> > +	val2 = tc358746_ps_to_cnt(cfg->hs_zero, hs_byte_clk) - 1;
> > +	dev_dbg(dev, "THS_PREPARECNT: %u (0x%x)\n", val, val);
> > +	dev_dbg(dev, "THS_ZEROCNT: %u (0x%x)\n", val2, val2);
> > +	dev_dbg(dev, "THS_HEADERCNT: 0x%x\n",
> > +		(u32)(THS_PREPARECNT(val) | THS_ZEROCNT(val2)));
> > +	err = tc358746_write(tc358746, THS_HEADERCNT_REG,
> > +			     THS_PREPARECNT(val) | THS_ZEROCNT(val2));
> > +	if (err)
> > +		return err;
> > +
> > +	/* TWAKEUP > 1ms in lptxcnt steps */
> > +	val = tc358746_us_to_cnt(cfg->wakeup, hs_byte_clk);
> > +	val = val / (lptxcnt + 1) - 1;
> > +	dev_dbg(dev, "TWAKEUP: %u (0x%x)\n", val, val);
> > +	err = tc358746_write(tc358746, TWAKEUP_REG, val);
> > +	if (err)
> > +		return err;
> > +
> > +	val = tc358746_ps_to_cnt(cfg->clk_post, hs_byte_clk);
> > +	dev_dbg(dev, "TCLK_POSTCNT: %u (0x%x)\n", val, val);
> > +	err = tc358746_write(tc358746, TCLK_POSTCNT_REG, val);
> > +	if (err)
> > +		return err;
> > +
> > +	val = tc358746_ps_to_cnt(cfg->hs_trail, hs_byte_clk);
> > +	dev_dbg(dev, "THS_TRAILCNT: %u (0x%x)\n", val, val);
> > +	err = tc358746_write(tc358746, THS_TRAILCNT_REG, val);
> > +	if (err)
> > +		return err;
> > +
> > +	dev_dbg(dev, "CONTCLKMODE: %u", non_cont_clk ? 0 : 1);
> > +	return  tc358746_write(tc358746, TXOPTIONCNTRL_REG, non_cont_clk ? 0 : 1);
> 
> Extra space after return.

Okay.

> > +}
> > +
> > +#define MAX_DATA_LANES 4
> > +
> > +static int tc358746_enable_csi_lanes(struct tc358746 *tc358746, int enable)
> > +{
> > +	unsigned int lanes = tc358746->dphy_cfg.lanes;
> > +	unsigned int lane;
> > +	u32 reg, val;
> > +	int err;
> > +
> > +	err = tc358746_update_bits(tc358746, CONFCTL_REG, DATALANE_MASK,
> > +				   lanes - 1);
> > +	if (err)
> > +		return err;
> > +
> > +	/* Clock lane */
> > +	val = enable ? 0 : LANEDISABLE;
> > +	dev_dbg(tc358746->sd.dev, "CLW_CNTRL: 0x%x\n", val);
> > +	err = tc358746_write(tc358746, CLW_CNTRL_REG, val);
> > +	if (err)
> > +		return err;
> > +
> > +	for (lane = 0; lane < MAX_DATA_LANES; lane++) {
> > +		/* Data lanes */
> > +		reg = D0W_CNTRL_REG + lane * 0x4;
> > +		val = (enable && lane < lanes) ? 0 : LANEDISABLE;
> > +
> > +		dev_dbg(tc358746->sd.dev, "D%uW_CNTRL: 0x%x\n", lane, val);
> > +		err = tc358746_write(tc358746, reg, val);
> > +		if (err)
> > +			return err;
> > +	}
> > +
> > +	val = 0;
> > +	if (enable) {
> > +		/* Clock lane */
> > +		val |= BIT(0);
> > +
> > +		/* Data lanes */
> > +		for (lane = 1; lane <= lanes; lane++)
> > +			val |= BIT(lane);
> > +	}
> > +
> > +	dev_dbg(tc358746->sd.dev, "HSTXVREGEN: 0x%x\n", val);
> > +	return tc358746_write(tc358746, HSTXVREGEN_REG, val);
> > +}
> > +
> > +static int tc358746_enable_csi_module(struct tc358746 *tc358746, int enable)
> > +{
> > +	unsigned int lanes = tc358746->dphy_cfg.lanes;
> > +	int err;
> > +
> > +	/*
> > +	 * START and STRT are only reseted/disabled by sw reset. This is
> > +	 * required to put the lane state back into LP-11 state. The sw reset
> > +	 * don't reset register values.
> > +	 */
> > +	if (!enable)
> > +		return tc358746_sw_reset(tc358746);
> > +
> > +	err = tc358746_write(tc358746, STARTCNTRL_REG, START);
> > +	if (err)
> > +		return err;
> > +
> > +	err = tc358746_write(tc358746, CSI_START_REG, STRT);
> > +	if (err)
> > +		return err;
> > +
> > +	/* CSI_CONTROL_REG is only indirect accessible */
> > +	return tc358746_write(tc358746, CSI_CONFW_REG,
> > +			      MODE(MODE_SET) |
> > +			      ADDRESS(CSI_CONTROL_ADDRESS) |
> > +			      DATA(CSI_MODE | TXHSMD | NOL(lanes - 1)));
> > +}
> > +
> > +static int tc358746_enable_parallel_port(struct tc358746 *tc358746, int enable)
> > +{
> > +	int err;
> > +
> > +	if (enable) {
> > +		err = tc358746_write(tc358746, PP_MISC_REG, 0);
> > +		if (err)
> > +			return err;
> > +
> > +		return tc358746_set_bits(tc358746, CONFCTL_REG, PPEN);
> > +	}
> > +
> > +	err = tc358746_set_bits(tc358746, PP_MISC_REG, FRMSTOP);
> > +	if (err)
> > +		return err;
> > +
> > +	err = tc358746_clear_bits(tc358746, CONFCTL_REG, PPEN);
> > +	if (err)
> > +		return err;
> > +
> > +	return tc358746_set_bits(tc358746, PP_MISC_REG, RSTPTR);
> > +}
> > +
> > +static inline struct v4l2_subdev *tc358746_get_remote_sd(struct media_pad *pad)
> > +{
> > +	pad = media_pad_remote_pad_first(pad);
> > +	if (!pad)
> > +		return NULL;
> > +
> > +	return media_entity_to_v4l2_subdev(pad->entity);
> > +}
> > +
> > +static int tc358746_s_stream(struct v4l2_subdev *sd, int enable)
> > +{
> > +	struct tc358746 *tc358746 = to_tc358746(sd);
> > +	struct v4l2_subdev *src;
> > +	int err;
> > +
> > +	dev_dbg(sd->dev, "%sable\n", enable ? "en" : "dis");
> > +
> > +	src = tc358746_get_remote_sd(&tc358746->pads[TC358746_SINK]);
> > +	if (!src)
> > +		return -EPIPE;
> > +
> > +	if (enable) {
> > +		err = pm_runtime_resume_and_get(sd->dev);
> > +		if (err)
> > +			return err;
> > +
> > +		err = tc358746_apply_dphy_config(tc358746);
> > +		if (err)
> > +			goto err_out;
> > +
> > +		err = tc358746_apply_misc_config(tc358746);
> > +		if (err)
> > +			goto err_out;
> > +
> > +		err = tc358746_enable_csi_lanes(tc358746, 1);
> > +		if (err)
> > +			goto err_out;
> > +
> > +		err = tc358746_enable_csi_module(tc358746, 1);
> > +		if (err)
> > +			goto err_out;
> > +
> > +		err = tc358746_enable_parallel_port(tc358746, 1);
> > +		if (err)
> > +			goto err_out;
> > +
> > +		err = v4l2_subdev_call(src, video, s_stream, 1);
> > +		if (err)
> > +			goto err_out;
> > +
> > +		return err;
> > +
> > +err_out:
> > +		pm_runtime_mark_last_busy(sd->dev);
> > +		pm_runtime_put_sync_autosuspend(sd->dev);
> > +
> > +		return err;
> > +	}
> > +
> > +	 /*
> > +	  * The lanes must be disabled first (before the csi module) so the
> > +	  * LP-11 state is entered correctly.
> > +	  */
> 
> Wrong indentation.

Damn.. Shouldn't that be detected by checkpatch? Anyway, thanks :)

> > +	err = tc358746_enable_csi_lanes(tc358746, 0);
> > +	if (err)
> > +		return err;
> > +
> > +	err = tc358746_enable_csi_module(tc358746, 0);
> > +	if (err)
> > +		return err;
> > +
> > +	err = tc358746_enable_parallel_port(tc358746, 0);
> > +	if (err)
> > +		return err;
> > +
> > +	pm_runtime_mark_last_busy(sd->dev);
> > +	pm_runtime_put_sync_autosuspend(sd->dev);
> > +
> > +	return v4l2_subdev_call(src, video, s_stream, 0);
> > +}
> > +
> > +static int tc358746_init_cfg(struct v4l2_subdev *sd,
> > +			     struct v4l2_subdev_state *state)
> > +{
> > +	struct v4l2_mbus_framefmt *fmt;
> > +
> > +	fmt = v4l2_subdev_get_pad_format(sd, state, TC358746_SINK);
> > +	*fmt = tc358746_def_fmt;
> > +
> > +	fmt = v4l2_subdev_get_pad_format(sd, state, TC358746_SOURCE);
> > +	*fmt = tc358746_def_fmt;
> > +	fmt->code = tc358746_src_mbus_code(tc358746_def_fmt.code);
> > +
> > +	return 0;
> > +}
> > +
> > +static int tc358746_enum_mbus_code(struct v4l2_subdev *sd,
> > +				   struct v4l2_subdev_state *sd_state,
> > +				   struct v4l2_subdev_mbus_code_enum *code)
> > +{
> > +	const struct tc358746_format *fmt;
> > +
> > +	fmt = tc358746_get_format_by_idx(code->pad, code->index);
> > +	if (IS_ERR(fmt))
> > +		return PTR_ERR(fmt);
> > +
> > +	code->code = fmt->code;
> > +
> > +	return 0;
> > +}
> > +
> > +static int tc358746_set_fmt(struct v4l2_subdev *sd,
> > +			    struct v4l2_subdev_state *sd_state,
> > +			    struct v4l2_subdev_format *format)
> > +{
> > +	struct v4l2_mbus_framefmt *src_fmt, *sink_fmt;
> > +	const struct tc358746_format *fmt;
> > +
> > +	/* Source follows the sink */
> > +	if (format->pad == TC358746_SOURCE)
> > +		return v4l2_subdev_get_fmt(sd, sd_state, format);
> > +
> > +	sink_fmt = v4l2_subdev_get_pad_format(sd, sd_state, TC358746_SINK);
> > +
> > +	fmt = tc358746_get_format_by_code(format->pad, format->format.code);
> > +	if (IS_ERR(fmt))
> > +		fmt = tc358746_get_format_by_code(format->pad, tc358746_def_fmt.code);
> > +
> > +	format->format.code = fmt->code;
> > +	format->format.field = V4L2_FIELD_NONE;
> > +
> > +	dev_dbg(sd->dev, "Update format: %ux%u code:0x%x -> %ux%u code:0x%x",
> > +		sink_fmt->width, sink_fmt->height, sink_fmt->code,
> > +		format->format.width, format->format.height, format->format.code);
> > +
> > +	*sink_fmt = format->format;
> > +
> > +	src_fmt = v4l2_subdev_get_pad_format(sd, sd_state, TC358746_SOURCE);
> > +	*src_fmt = *sink_fmt;
> > +	src_fmt->code = tc358746_src_mbus_code(sink_fmt->code);
> > +
> > +	return 0;
> > +}
> > +
> > +static unsigned long tc358746_find_pll_settings(struct tc358746 *tc358746,
> > +						unsigned long refclk,
> > +						unsigned long fout)
> > +
> > +{
> > +	struct device *dev = tc358746->sd.dev;
> > +	unsigned long best_freq = 0;
> > +	u32 min_delta = 0xffffffff;
> > +	u16 prediv_max = 17;
> > +	u16 prediv_min = 1;
> > +	u16 m_best, mul;
> > +	u16 p_best, p;
> > +	u8 postdiv;
> > +
> > +	if (fout > 1000 * HZ_PER_MHZ) {
> > +		dev_err(dev, "HS-Clock above 1 Ghz are not supported\n");
> > +		return 0;
> > +	}
> > +
> > +	if (fout >= 500 * HZ_PER_MHZ)
> > +		postdiv = 1;
> > +	else if (fout >= 250 * HZ_PER_MHZ)
> > +		postdiv = 2;
> > +	else if (fout >= 125 * HZ_PER_MHZ)
> > +		postdiv = 4;
> > +	else
> > +		postdiv = 8;
> > +
> > +	for (p = prediv_min; p <= prediv_max; p++) {
> > +		unsigned long delta, fin;
> > +		u64 tmp;
> > +
> > +		fin = DIV_ROUND_CLOSEST(refclk, p);
> > +		if (fin < 4 * HZ_PER_MHZ || fin > 40 * HZ_PER_MHZ)
> > +			continue;
> > +
> > +		tmp = fout * p * postdiv;
> > +		do_div(tmp, fin);
> > +		mul = tmp;
> > +		if (mul > 511)
> > +			continue;
> > +
> > +		tmp = mul * fin;
> > +		do_div(tmp, p * postdiv);
> > +
> > +		delta = abs(fout - tmp);
> > +		if (delta < min_delta) {
> > +			p_best = p;
> > +			m_best = mul;
> > +			min_delta = delta;
> > +			best_freq = tmp;
> > +		};
> > +
> > +		if (delta == 0)
> > +			break;
> > +	};
> > +
> > +	if (!best_freq) {
> > +		dev_err(dev, "Failed find PLL frequency\n");
> > +		return 0;
> > +	}
> > +
> > +	tc358746->pll_post_div = postdiv;
> > +	tc358746->pll_pre_div = p_best;
> > +	tc358746->pll_mul = m_best;
> > +
> > +	if (best_freq != fout)
> > +		dev_warn(dev, "Request PLL freq:%lu, found PLL freq:%lu\n",
> > +			 fout, best_freq);
> > +
> > +	dev_dbg(dev, "Found PLL settings: freq:%lu prediv:%u multi:%u postdiv:%u\n",
> > +		best_freq, p_best, m_best, postdiv);
> > +
> > +	return best_freq;
> > +}
> > +
> > +#define TC358746_PRECISION 10
> > +
> > +static int
> > +tc358746_link_validate(struct v4l2_subdev *sd, struct media_link *link,
> > +		       struct v4l2_subdev_format *source_fmt,
> > +		       struct v4l2_subdev_format *sink_fmt)
> > +{
> > +	struct tc358746 *tc358746 = to_tc358746(sd);
> > +	unsigned long csi_bitrate, source_bitrate;
> > +	struct v4l2_subdev_state *sink_state;
> > +	struct v4l2_mbus_framefmt *mbusfmt;
> > +	const struct tc358746_format *fmt;
> > +	unsigned int fifo_sz, tmp, n;
> > +	struct v4l2_subdev *source;
> > +	s64 source_link_freq;
> > +	int err;
> > +
> > +	err = v4l2_subdev_link_validate_default(sd, link, source_fmt, sink_fmt);
> > +	if (err)
> > +		return err;
> > +
> > +	sink_state = v4l2_subdev_lock_and_get_active_state(sd);
> > +	mbusfmt = v4l2_subdev_get_pad_format(sd, sink_state, TC358746_SINK);
> > +
> > +	/* Check the FIFO settings */
> > +	fmt = tc358746_get_format_by_code(TC358746_SINK, mbusfmt->code);
> > +
> > +	source = media_entity_to_v4l2_subdev(link->source->entity);
> > +	source_link_freq = v4l2_get_link_freq(source->ctrl_handler, 0, 0);
> > +	if (source_link_freq <= 0) {
> > +		dev_err(tc358746->sd.dev,
> > +			"Failed to query or invalid source link frequency\n");
> > +		v4l2_subdev_unlock_state(sink_state);
> > +		/* Return -EINVAL in case of source_link_freq is 0 */
> > +		return source_link_freq ? : -EINVAL;
> > +	}
> > +	source_bitrate = source_link_freq * fmt->bus_width;
> > +
> > +	csi_bitrate = tc358746->dphy_cfg.lanes * tc358746->pll_rate;
> > +
> > +	dev_dbg(tc358746->sd.dev,
> > +		"Fifo settings params: source-bitrate:%lu csi-bitrate:%lu",
> > +		source_bitrate, csi_bitrate);
> > +
> > +	/* Avoid possible FIFO overflows */
> > +	if (csi_bitrate < source_bitrate) {
> > +		v4l2_subdev_unlock_state(sink_state);
> > +		return -EINVAL;
> > +	}
> > +
> > +	/* Best case */
> > +	if (csi_bitrate == source_bitrate) {
> > +		fifo_sz = TC358746_VB_DEFAULT_SIZE;
> > +		tc358746->vb_size = TC358746_VB_DEFAULT_SIZE;
> > +		goto out;
> > +	}
> > +
> > +	/*
> > +	 * Avoid possible FIFO underflow in case of
> > +	 * csi_bitrate > source_bitrate. For such case the chip has a internal
> > +	 * fifo which can be used to delay the line output.
> > +	 *
> > +	 * Fifo size calculation (excluding precision):
> > +	 *
> > +	 * fifo-sz, image-width - in bits
> > +	 * sbr                  - source_bitrate in bits/s
> > +	 * csir                 - csi_bitrate in bits/s
> > +	 *
> > +	 *                1               1      1
> > +	 * image-width * --- + fifo-sz * --- >= ---- * image-width
> > +	 *               sbr             sbr    csir
> 
> I still think there's something fishy here. The inequality is always
> true as csir > sbr. You will get a non-zero fifo size in your
> calculation because you artifically add an abs(), but I don't think
> that's right.
> 
> If I understand things correctly, you need to ensure that once the FIFO
> threshold is reached and the CSI-2 side starts sending data, the input
> size will keep feeding data fast enough for the FIFO to never underrun.
> 
> The FIFO level triggers the CSI-2 transmission. This means that once the
> CSI-2 transmission start, fifo-sz bits have been written to the FIFO
> already, and image-width - fifo-sz bits still need to be written. To
> avoid underruns, you need to ensure that the time required to read all
> the data (image-width) on the CSI-2 size will be higher than or equal to
> the time required to write the remaining data (image-width - fifo-sz) on
> the input side. This translates to
> 
> 	image-width / csir >= (image-width - fifo-sz) / sbr
> 	image-width * sbr / csir >= image-width - fifo-sz
> 	fifo-sz >= image-width - image-width * sbr / csir

Thanks, makes more sense, I will change the comment.

> The calculation is thus correct, but not for the right reason :-) All
> you need to fix here is the comment, not the code.
> 
> With these small issues fixed,
> 
> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

Regards,
  Marco

> > +	 *
> > +	 * fifo-sz >= abs(sbr/csir * image-width - image-width); with n = csir/sbr
> > +	 *
> > +	 * fifo-sz >= abs(image-width / n - image-width)
> > +	 *         >= image-width - image-width / n
> > +	 */
> > +
> > +	source_bitrate /= TC358746_PRECISION;
> > +	n = csi_bitrate / source_bitrate;
> > +	tmp = (mbusfmt->width * TC358746_PRECISION) / n;
> > +	fifo_sz = mbusfmt->width - tmp;
> > +	fifo_sz *= fmt->bpp;
> > +	tc358746->vb_size = round_up(fifo_sz, 32);
> > +
> > +out:
> > +	dev_dbg(tc358746->sd.dev,
> > +		"Found FIFO size[bits]:%u -> aligned to size[bits]:%u\n",
> > +		fifo_sz, tc358746->vb_size);
> > +
> > +	v4l2_subdev_unlock_state(sink_state);
> > +
> > +	return tc358746->vb_size > TC358746_VB_MAX_SIZE ? -EINVAL : 0;
> > +}
> > +
> > +static int tc358746_get_mbus_config(struct v4l2_subdev *sd, unsigned int pad,
> > +				    struct v4l2_mbus_config *config)
> > +{
> > +	struct tc358746 *tc358746 = to_tc358746(sd);
> > +
> > +	if (pad != TC358746_SOURCE)
> > +		return -EINVAL;
> > +
> > +	config->type = V4L2_MBUS_CSI2_DPHY;
> > +	config->bus.mipi_csi2 = tc358746->csi_vep.bus.mipi_csi2;
> > +
> > +	return 0;
> > +}
> > +
> > +static int __maybe_unused
> > +tc358746_g_register(struct v4l2_subdev *sd, struct v4l2_dbg_register *reg)
> > +{
> > +	struct tc358746 *tc358746 = to_tc358746(sd);
> > +
> > +	/* 32-bit registers starting from CLW_DPHYCONTTX */
> > +	reg->size = reg->reg < CLW_DPHYCONTTX_REG ? 2 : 4;
> > +
> > +	if (!pm_runtime_get_if_in_use(sd->dev))
> > +		return 0;
> > +
> > +	tc358746_read(tc358746, reg->reg, (u32 *)&reg->val);
> > +
> > +	pm_runtime_mark_last_busy(sd->dev);
> > +	pm_runtime_put_sync_autosuspend(sd->dev);
> > +
> > +	return 0;
> > +}
> > +
> > +static int __maybe_unused
> > +tc358746_s_register(struct v4l2_subdev *sd, const struct v4l2_dbg_register *reg)
> > +{
> > +	struct tc358746 *tc358746 = to_tc358746(sd);
> > +
> > +	if (!pm_runtime_get_if_in_use(sd->dev))
> > +		return 0;
> > +
> > +	tc358746_write(tc358746, (u32)reg->reg, (u32)reg->val);
> > +
> > +	pm_runtime_mark_last_busy(sd->dev);
> > +	pm_runtime_put_sync_autosuspend(sd->dev);
> > +
> > +	return 0;
> > +}
> > +
> > +static const struct v4l2_subdev_core_ops tc358746_core_ops = {
> > +#ifdef CONFIG_VIDEO_ADV_DEBUG
> > +	.g_register = tc358746_g_register,
> > +	.s_register = tc358746_s_register,
> > +#endif
> > +};
> > +
> > +static const struct v4l2_subdev_video_ops tc358746_video_ops = {
> > +	.s_stream = tc358746_s_stream,
> > +};
> > +
> > +static const struct v4l2_subdev_pad_ops tc358746_pad_ops = {
> > +	.init_cfg = tc358746_init_cfg,
> > +	.enum_mbus_code = tc358746_enum_mbus_code,
> > +	.set_fmt = tc358746_set_fmt,
> > +	.get_fmt = v4l2_subdev_get_fmt,
> > +	.link_validate = tc358746_link_validate,
> > +	.get_mbus_config = tc358746_get_mbus_config,
> > +};
> > +
> > +static const struct v4l2_subdev_ops tc358746_ops = {
> > +	.core = &tc358746_core_ops,
> > +	.video = &tc358746_video_ops,
> > +	.pad = &tc358746_pad_ops,
> > +};
> > +
> > +static const struct media_entity_operations tc358746_entity_ops = {
> > +	.get_fwnode_pad = v4l2_subdev_get_fwnode_pad_1_to_1,
> > +	.link_validate = v4l2_subdev_link_validate,
> > +};
> > +
> > +static int tc358746_mclk_enable(struct clk_hw *hw)
> > +{
> > +	struct tc358746 *tc358746 = clk_hw_to_tc358746(hw);
> > +	unsigned int div;
> > +	u32 val;
> > +	int err;
> > +
> > +	div = tc358746->mclk_postdiv / 2;
> > +	val = MCLK_HIGH(div - 1) | MCLK_LOW(div - 1);
> > +	dev_dbg(tc358746->sd.dev, "MCLKCTL: %u (0x%x)\n", val, val);
> > +	err = tc358746_write(tc358746, MCLKCTL_REG, val);
> > +	if (err)
> > +		return err;
> > +
> > +	if (tc358746->mclk_prediv == 8)
> > +		val = MCLKDIV(MCLKDIV_8);
> > +	else if (tc358746->mclk_prediv == 4)
> > +		val = MCLKDIV(MCLKDIV_4);
> > +	else
> > +		val = MCLKDIV(MCLKDIV_2);
> > +
> > +	dev_dbg(tc358746->sd.dev, "CLKCTL[MCLKDIV]: %u (0x%x)\n", val, val);
> > +	return tc358746_update_bits(tc358746, CLKCTL_REG, MCLKDIV_MASK, val);
> > +}
> > +
> > +static void tc358746_mclk_disable(struct clk_hw *hw)
> > +{
> > +	struct tc358746 *tc358746 = clk_hw_to_tc358746(hw);
> > +
> > +	tc358746_write(tc358746, MCLKCTL_REG, 0);
> > +}
> > +
> > +static long
> > +tc358746_find_mclk_settings(struct tc358746 *tc358746, unsigned long mclk_rate)
> > +{
> > +	unsigned long pll_rate = tc358746->pll_rate;
> > +	const unsigned char prediv[] = { 2, 4, 8 };
> > +	unsigned int mclk_prediv, mclk_postdiv;
> > +	struct device *dev = tc358746->sd.dev;
> > +	unsigned int postdiv, mclkdiv;
> > +	unsigned long best_mclk_rate;
> > +	unsigned int i;
> > +
> > +	/*
> > +	 *                          MCLK-Div
> > +	 *           -------------------´`---------------------
> > +	 *          ´                                          `
> > +	 *         +-------------+     +------------------------+
> > +	 *         | MCLK-PreDiv |     |       MCLK-PostDiv     |
> > +	 * PLL --> |   (2/4/8)   | --> | (mclk_low + mclk_high) | --> MCLK
> > +	 *         +-------------+     +------------------------+
> > +	 *
> > +	 * The register value of mclk_low/high is mclk_low/high+1, i.e.:
> > +	 *   mclk_low/high = 1   --> 2 MCLK-Ref Counts
> > +	 *   mclk_low/high = 255 --> 256 MCLK-Ref Counts == max.
> > +	 * If mclk_low and mclk_high are 0 then MCLK is disabled.
> > +	 *
> > +	 * Keep it simple and support 50/50 duty cycles only for now,
> > +	 * so the calc will be:
> > +	 *
> > +	 *   MCLK = PLL / (MCLK-PreDiv * 2 * MCLK-PostDiv)
> > +	 */
> > +
> > +	if (mclk_rate == tc358746->mclk_rate)
> > +		return mclk_rate;
> > +
> > +	/* Highest possible rate */
> > +	mclkdiv = pll_rate / mclk_rate;
> > +	if (mclkdiv <= 8) {
> > +		mclk_prediv = 2;
> > +		mclk_postdiv = 4;
> > +		best_mclk_rate = pll_rate / (2 * 4);
> > +		goto out;
> > +	}
> > +
> > +	/* First check the prediv */
> > +	for (i = 0; i < ARRAY_SIZE(prediv); i++) {
> > +		postdiv = mclkdiv / prediv[i];
> > +
> > +		if (postdiv % 2)
> > +			continue;
> > +
> > +		if (postdiv >= 4 && postdiv <= 512) {
> > +			mclk_prediv = prediv[i];
> > +			mclk_postdiv = postdiv;
> > +			best_mclk_rate = pll_rate / (prediv[i] * postdiv);
> > +			goto out;
> > +		}
> > +	}
> > +
> > +	/* No suitable prediv found, so try to adjust the postdiv */
> > +	for (postdiv = 4; postdiv <= 512; postdiv += 2) {
> > +		unsigned int pre;
> > +
> > +		pre = mclkdiv / postdiv;
> > +		if (pre == 2 || pre == 4 || pre == 8) {
> > +			mclk_prediv = pre;
> > +			mclk_postdiv = postdiv;
> > +			best_mclk_rate = pll_rate / (pre * postdiv);
> > +			goto out;
> > +		}
> > +	}
> > +
> > +	/* The MCLK <-> PLL gap is to high -> use largest possible div */
> > +	mclk_prediv = 8;
> > +	mclk_postdiv = 512;
> > +	best_mclk_rate = pll_rate / (8 * 512);
> > +
> > +out:
> > +	tc358746->mclk_prediv = mclk_prediv;
> > +	tc358746->mclk_postdiv = mclk_postdiv;
> > +	tc358746->mclk_rate = best_mclk_rate;
> > +
> > +	if (best_mclk_rate != mclk_rate)
> > +		dev_warn(dev, "Request MCLK freq:%lu, found MCLK freq:%lu\n",
> > +			 mclk_rate, best_mclk_rate);
> > +
> > +	dev_dbg(dev, "Found MCLK settings: freq:%lu prediv:%u postdiv:%u\n",
> > +		best_mclk_rate, mclk_prediv, mclk_postdiv);
> > +
> > +	return best_mclk_rate;
> > +}
> > +
> > +static unsigned long
> > +tc358746_recalc_rate(struct clk_hw *hw, unsigned long parent_rate)
> > +{
> > +	struct tc358746 *tc358746 = clk_hw_to_tc358746(hw);
> > +	unsigned int prediv, postdiv;
> > +	u32 val;
> > +	int err;
> > +
> > +	err = tc358746_read(tc358746, MCLKCTL_REG, &val);
> > +	if (err)
> > +		return 0;
> > +
> > +	postdiv = FIELD_GET(MCLK_LOW_MASK, val) + 1;
> > +	postdiv += FIELD_GET(MCLK_HIGH_MASK, val) + 1;
> > +
> > +	err = tc358746_read(tc358746, CLKCTL_REG, &val);
> > +	if (err)
> > +		return 0;
> > +
> > +	prediv = FIELD_GET(MCLKDIV_MASK, val);
> > +	if (prediv == MCLKDIV_8)
> > +		prediv = 8;
> > +	else if (prediv == MCLKDIV_4)
> > +		prediv = 4;
> > +	else
> > +		prediv = 2;
> > +
> > +	return tc358746->pll_rate / (prediv * postdiv);
> > +}
> > +
> > +static long tc358746_mclk_round_rate(struct clk_hw *hw, unsigned long rate,
> > +				     unsigned long *parent_rate)
> > +{
> > +	struct tc358746 *tc358746 = clk_hw_to_tc358746(hw);
> > +
> > +	*parent_rate = tc358746->pll_rate;
> > +
> > +	return tc358746_find_mclk_settings(tc358746, rate);
> > +}
> > +
> > +static int tc358746_mclk_set_rate(struct clk_hw *hw, unsigned long rate,
> > +				  unsigned long parent_rate)
> > +{
> > +	struct tc358746 *tc358746 = clk_hw_to_tc358746(hw);
> > +
> > +	tc358746_find_mclk_settings(tc358746, rate);
> > +
> > +	return tc358746_mclk_enable(hw);
> > +}
> > +
> > +static const struct clk_ops tc358746_mclk_ops = {
> > +	.enable = tc358746_mclk_enable,
> > +	.disable = tc358746_mclk_disable,
> > +	.recalc_rate = tc358746_recalc_rate,
> > +	.round_rate = tc358746_mclk_round_rate,
> > +	.set_rate = tc358746_mclk_set_rate,
> > +};
> > +
> > +static int tc358746_setup_mclk_provider(struct tc358746 *tc358746)
> > +{
> > +	struct clk_init_data mclk_initdata = { };
> > +	struct device *dev = tc358746->sd.dev;
> > +	const char *mclk_name;
> > +	int err;
> > +
> > +	/* MCLK clk provider support is optional */
> > +	if (!device_property_present(dev, "#clock-cells"))
> > +		return 0;
> > +
> > +	/* Init to highest possibel MCLK */
> > +	tc358746->mclk_postdiv = 512;
> > +	tc358746->mclk_prediv = 8;
> > +
> > +	mclk_name = "tc358746-mclk";
> > +	device_property_read_string(dev, "clock-output-names", &mclk_name);
> > +
> > +	mclk_initdata.name = mclk_name;
> > +	mclk_initdata.ops = &tc358746_mclk_ops;
> > +	tc358746->mclk_hw.init = &mclk_initdata;
> > +
> > +	err = devm_clk_hw_register(dev, &tc358746->mclk_hw);
> > +	if (err) {
> > +		dev_err(dev, "Failed to register mclk provider\n");
> > +		return err;
> > +	}
> > +
> > +	err = devm_of_clk_add_hw_provider(dev, of_clk_hw_simple_get,
> > +					  &tc358746->mclk_hw);
> > +	if (err)
> > +		dev_err(dev, "Failed to add mclk provider\n");
> > +
> > +	return err;
> > +}
> > +
> > +static int
> > +tc358746_init_subdev(struct tc358746 *tc358746, struct i2c_client *client)
> > +{
> > +	struct v4l2_subdev *sd = &tc358746->sd;
> > +	int err;
> > +
> > +	v4l2_i2c_subdev_init(sd, client, &tc358746_ops);
> > +	sd->flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;
> > +	sd->entity.function = MEDIA_ENT_F_VID_IF_BRIDGE;
> > +	sd->entity.ops = &tc358746_entity_ops;
> > +
> > +	tc358746->pads[TC358746_SINK].flags = MEDIA_PAD_FL_SINK;
> > +	tc358746->pads[TC358746_SOURCE].flags = MEDIA_PAD_FL_SOURCE;
> > +	err = media_entity_pads_init(&sd->entity, TC358746_NR_PADS,
> > +				     tc358746->pads);
> > +	if (err)
> > +		return err;
> > +
> > +	err = v4l2_subdev_init_finalize(sd);
> > +	if (err)
> > +		media_entity_cleanup(&sd->entity);
> > +
> > +	return err;
> > +}
> > +
> > +static int
> > +tc358746_init_output_port(struct tc358746 *tc358746, unsigned long refclk)
> > +{
> > +	struct device *dev = tc358746->sd.dev;
> > +	struct v4l2_fwnode_endpoint *vep;
> > +	unsigned long csi_link_rate;
> > +	struct fwnode_handle *ep;
> > +	unsigned char csi_lanes;
> > +	int err;
> > +
> > +	ep = fwnode_graph_get_endpoint_by_id(dev_fwnode(dev), TC358746_SOURCE,
> > +					     0, 0);
> > +	if (!ep) {
> > +		dev_err(dev, "Missing endpoint node\n");
> > +		return -EINVAL;
> > +	}
> > +
> > +	/* Currently we only support 'parallel in' -> 'csi out' */
> > +	vep = &tc358746->csi_vep;
> > +	vep->bus_type = V4L2_MBUS_CSI2_DPHY;
> > +	err = v4l2_fwnode_endpoint_alloc_parse(ep, vep);
> > +	fwnode_handle_put(ep);
> > +	if (err) {
> > +		dev_err(dev, "Failed to parse source endpoint\n");
> > +		return err;
> > +	}
> > +
> > +	csi_lanes = vep->bus.mipi_csi2.num_data_lanes;
> > +	if (csi_lanes == 0 || csi_lanes > 4 ||
> > +	    vep->nr_of_link_frequencies == 0) {
> > +		dev_err(dev, "error: Invalid CSI-2 settings\n");
> > +		err = -EINVAL;
> > +		goto err;
> > +	}
> > +
> > +	/* TODO: Add support to handle multiple link frequencies */
> > +	csi_link_rate = (unsigned long)vep->link_frequencies[0];
> > +	tc358746->pll_rate = tc358746_find_pll_settings(tc358746, refclk,
> > +							csi_link_rate * 2);
> > +	if (!tc358746->pll_rate) {
> > +		err = -EINVAL;
> > +		goto err;
> > +	}
> > +
> > +	err = phy_mipi_dphy_get_default_config_for_hsclk(tc358746->pll_rate,
> > +						csi_lanes, &tc358746->dphy_cfg);
> > +	if (err)
> > +		goto err;
> > +
> > +	tc358746->vb_size = TC358746_VB_DEFAULT_SIZE;
> > +
> > +	return 0;
> > +
> > +err:
> > +	v4l2_fwnode_endpoint_free(vep);
> > +
> > +	return err;
> > +}
> > +
> > +static int tc358746_init_hw(struct tc358746 *tc358746)
> > +{
> > +	struct device *dev = tc358746->sd.dev;
> > +	unsigned int chipid;
> > +	u32 val;
> > +	int err;
> > +
> > +	err = pm_runtime_resume_and_get(dev);
> > +	if (err < 0) {
> > +		dev_err(dev, "Failed to resume the device\n");
> > +		return err;
> > +	}
> > +
> > +	 /* Ensure that CSI interface is put into LP-11 state */
> > +	err = tc358746_sw_reset(tc358746);
> > +	if (err) {
> > +		pm_runtime_put_sync(dev);
> > +		dev_err(dev, "Failed to reset the device\n");
> > +		return err;
> > +	}
> > +
> > +	err = tc358746_read(tc358746, CHIPID_REG, &val);
> > +	pm_runtime_mark_last_busy(dev);
> > +	pm_runtime_put_sync_autosuspend(dev);
> > +	if (err)
> > +		return -ENODEV;
> > +
> > +	chipid = FIELD_GET(CHIPID, val);
> > +	if (chipid != 0x44) {
> > +		dev_err(dev, "Invalid chipid 0x%02x\n", chipid);
> > +		return -ENODEV;
> > +	}
> > +
> > +	return 0;
> > +}
> > +
> > +static int tc358746_init_controls(struct tc358746 *tc358746)
> > +{
> > +	u64 *link_frequencies = tc358746->csi_vep.link_frequencies;
> > +	struct v4l2_ctrl *ctrl;
> > +	int err;
> > +
> > +	err = v4l2_ctrl_handler_init(&tc358746->ctrl_hdl, 1);
> > +	if (err)
> > +		return err;
> > +
> > +	/*
> > +	 * The driver currently supports only one link-frequency, regardless of
> > +	 * the input from the firmware, see: tc358746_init_output_port(). So
> > +	 * report only the first frequency from the array of possible given
> > +	 * frequencies.
> > +	 */
> > +	ctrl = v4l2_ctrl_new_int_menu(&tc358746->ctrl_hdl, NULL,
> > +				      V4L2_CID_LINK_FREQ, 0, 0,
> > +				      link_frequencies);
> > +	if (ctrl)
> > +		ctrl->flags |= V4L2_CTRL_FLAG_READ_ONLY;
> > +
> > +	err = tc358746->ctrl_hdl.error;
> > +	if (err) {
> > +		v4l2_ctrl_handler_free(&tc358746->ctrl_hdl);
> > +		return err;
> > +	}
> > +
> > +	tc358746->sd.ctrl_handler = &tc358746->ctrl_hdl;
> > +
> > +	return 0;
> > +}
> > +
> > +static int tc358746_notify_bound(struct v4l2_async_notifier *notifier,
> > +				 struct v4l2_subdev *sd,
> > +				 struct v4l2_async_subdev *asd)
> > +{
> > +	struct tc358746 *tc358746 =
> > +		container_of(notifier, struct tc358746, notifier);
> > +	u32 flags = MEDIA_LNK_FL_ENABLED | MEDIA_LNK_FL_IMMUTABLE;
> > +	struct media_pad *sink = &tc358746->pads[TC358746_SINK];
> > +
> > +	return v4l2_create_fwnode_links_to_pad(sd, sink, flags);
> > +}
> > +
> > +static const struct v4l2_async_notifier_operations tc358746_notify_ops = {
> > +	.bound = tc358746_notify_bound,
> > +};
> > +
> > +static int tc358746_async_register(struct tc358746 *tc358746)
> > +{
> > +	struct v4l2_fwnode_endpoint vep = {
> > +		.bus_type = V4L2_MBUS_PARALLEL,
> > +	};
> > +	struct v4l2_async_subdev *asd;
> > +	struct fwnode_handle *ep;
> > +	int err;
> > +
> > +	ep = fwnode_graph_get_endpoint_by_id(dev_fwnode(tc358746->sd.dev),
> > +					     TC358746_SINK, 0, 0);
> > +	if (!ep)
> > +		return -ENOTCONN;
> > +
> > +	err = v4l2_fwnode_endpoint_parse(ep, &vep);
> > +	if (err) {
> > +		fwnode_handle_put(ep);
> > +		return err;
> > +	}
> > +
> > +	v4l2_async_nf_init(&tc358746->notifier);
> > +	asd = v4l2_async_nf_add_fwnode_remote(&tc358746->notifier, ep,
> > +					      struct v4l2_async_subdev);
> > +	fwnode_handle_put(ep);
> > +
> > +	if (IS_ERR(asd)) {
> > +		err = PTR_ERR(asd);
> > +		goto err_cleanup;
> > +	}
> > +
> > +	tc358746->notifier.ops = &tc358746_notify_ops;
> > +
> > +	err = v4l2_async_subdev_nf_register(&tc358746->sd, &tc358746->notifier);
> > +	if (err)
> > +		goto err_cleanup;
> > +
> > +	tc358746->sd.fwnode = fwnode_graph_get_endpoint_by_id(
> > +		dev_fwnode(tc358746->sd.dev), TC358746_SOURCE, 0, 0);
> > +
> > +	err = v4l2_async_register_subdev(&tc358746->sd);
> > +	if (err)
> > +		goto err_unregister;
> > +
> > +	return 0;
> > +
> > +err_unregister:
> > +	fwnode_handle_put(tc358746->sd.fwnode);
> > +	v4l2_async_nf_unregister(&tc358746->notifier);
> > +err_cleanup:
> > +	v4l2_async_nf_cleanup(&tc358746->notifier);
> > +
> > +	return err;
> > +}
> > +
> > +static int tc358746_probe(struct i2c_client *client)
> > +{
> > +	struct device *dev = &client->dev;
> > +	struct tc358746 *tc358746;
> > +	unsigned long refclk;
> > +	unsigned int i;
> > +	int err;
> > +
> > +	tc358746 = devm_kzalloc(&client->dev, sizeof(*tc358746), GFP_KERNEL);
> > +	if (!tc358746)
> > +		return -ENOMEM;
> > +
> > +	tc358746->regmap = devm_regmap_init_i2c(client, &tc358746_regmap_config);
> > +	if (IS_ERR(tc358746->regmap))
> > +		return dev_err_probe(dev, PTR_ERR(tc358746->regmap),
> > +				     "Failed to init regmap\n");
> > +
> > +	tc358746->refclk = devm_clk_get(dev, "refclk");
> > +	if (IS_ERR(tc358746->refclk))
> > +		return dev_err_probe(dev, PTR_ERR(tc358746->refclk),
> > +				     "Failed to get refclk\n");
> > +
> > +	err = clk_prepare_enable(tc358746->refclk);
> > +	if (err)
> > +		return dev_err_probe(dev, err,
> > +				     "Failed to enable refclk\n");
> > +
> > +	refclk = clk_get_rate(tc358746->refclk);
> > +	clk_disable_unprepare(tc358746->refclk);
> > +
> > +	if (refclk < 6 * HZ_PER_MHZ || refclk > 40 * HZ_PER_MHZ)
> > +		return dev_err_probe(dev, -EINVAL, "Invalid refclk range\n");
> > +
> > +	for (i = 0; i < ARRAY_SIZE(tc358746_supplies); i++)
> > +		tc358746->supplies[i].supply = tc358746_supplies[i];
> > +
> > +	err = devm_regulator_bulk_get(dev, ARRAY_SIZE(tc358746_supplies),
> > +				      tc358746->supplies);
> > +	if (err)
> > +		return dev_err_probe(dev, err, "Failed to get supplies\n");
> > +
> > +	tc358746->reset_gpio = devm_gpiod_get_optional(dev, "reset",
> > +						       GPIOD_OUT_HIGH);
> > +	if (IS_ERR(tc358746->reset_gpio))
> > +		return dev_err_probe(dev, PTR_ERR(tc358746->reset_gpio),
> > +				     "Failed to get reset-gpios\n");
> > +
> > +	err = tc358746_init_subdev(tc358746, client);
> > +	if (err)
> > +		return dev_err_probe(dev, err, "Failed to init subdev\n");
> > +
> > +	err = tc358746_init_output_port(tc358746, refclk);
> > +	if (err)
> > +		goto err_subdev;
> > +
> > +	/*
> > +	 * Keep this order since we need the output port link-frequencies
> > +	 * information.
> > +	 */
> > +	err = tc358746_init_controls(tc358746);
> > +	if (err)
> > +		goto err_fwnode;
> > +
> > +	dev_set_drvdata(dev, tc358746);
> > +
> > +	/* Set to 1sec to give the stream reconfiguration enough time */
> > +	pm_runtime_set_autosuspend_delay(dev, 1000);
> > +	pm_runtime_use_autosuspend(dev);
> > +	pm_runtime_enable(dev);
> > +
> > +	err = tc358746_init_hw(tc358746);
> > +	if (err)
> > +		goto err_pm;
> > +
> > +	err = tc358746_setup_mclk_provider(tc358746);
> > +	if (err)
> > +		goto err_pm;
> > +
> > +	err = tc358746_async_register(tc358746);
> > +	if (err < 0)
> > +		goto err_pm;
> > +
> > +	dev_dbg(dev, "%s found @ 0x%x (%s)\n", client->name,
> > +		client->addr, client->adapter->name);
> > +
> > +	return 0;
> > +
> > +err_pm:
> > +	pm_runtime_disable(dev);
> > +	pm_runtime_set_suspended(dev);
> > +	pm_runtime_dont_use_autosuspend(dev);
> > +	v4l2_ctrl_handler_free(&tc358746->ctrl_hdl);
> > +err_fwnode:
> > +	v4l2_fwnode_endpoint_free(&tc358746->csi_vep);
> > +err_subdev:
> > +	v4l2_subdev_cleanup(&tc358746->sd);
> > +	media_entity_cleanup(&tc358746->sd.entity);
> > +
> > +	return err;
> > +}
> > +
> > +static int tc358746_remove(struct i2c_client *client)
> > +{
> > +	struct v4l2_subdev *sd = i2c_get_clientdata(client);
> > +	struct tc358746 *tc358746 = to_tc358746(sd);
> > +
> > +	v4l2_subdev_cleanup(sd);
> > +	v4l2_ctrl_handler_free(&tc358746->ctrl_hdl);
> > +	v4l2_fwnode_endpoint_free(&tc358746->csi_vep);
> > +	v4l2_async_nf_unregister(&tc358746->notifier);
> > +	v4l2_async_nf_cleanup(&tc358746->notifier);
> > +	fwnode_handle_put(sd->fwnode);
> > +	v4l2_async_unregister_subdev(sd);
> > +	media_entity_cleanup(&sd->entity);
> > +
> > +	pm_runtime_disable(sd->dev);
> > +	pm_runtime_set_suspended(sd->dev);
> > +	pm_runtime_dont_use_autosuspend(sd->dev);
> > +
> > +	return 0;
> > +}
> > +
> > +static int tc358746_suspend(struct device *dev)
> > +{
> > +	struct tc358746 *tc358746 = dev_get_drvdata(dev);
> > +	int err;
> > +
> > +	clk_disable_unprepare(tc358746->refclk);
> > +
> > +	err = regulator_bulk_disable(ARRAY_SIZE(tc358746_supplies),
> > +				     tc358746->supplies);
> > +	if (err)
> > +		clk_prepare_enable(tc358746->refclk);
> > +
> > +	return err;
> > +}
> > +
> > +static int tc358746_resume(struct device *dev)
> > +{
> > +	struct tc358746 *tc358746 = dev_get_drvdata(dev);
> > +	int err;
> > +
> > +	gpiod_set_value(tc358746->reset_gpio, 1);
> > +
> > +	err = regulator_bulk_enable(ARRAY_SIZE(tc358746_supplies),
> > +				    tc358746->supplies);
> > +	if (err)
> > +		return err;
> > +
> > +	/* min. 200ns */
> > +	usleep_range(10, 20);
> > +
> > +	gpiod_set_value(tc358746->reset_gpio, 0);
> > +
> > +	err = clk_prepare_enable(tc358746->refclk);
> > +	if (err)
> > +		goto err;
> > +
> > +	/* min. 700us ... 1ms */
> > +	usleep_range(1000, 1500);
> > +
> > +	/*
> > +	 * Enable the PLL here since it can be called by the clk-framework or by
> > +	 * the .s_stream() callback. So this is the common place for both.
> > +	 */
> > +	err = tc358746_apply_pll_config(tc358746);
> > +	if (err)
> > +		goto err_clk;
> > +
> > +	return 0;
> > +
> > +err_clk:
> > +	clk_disable_unprepare(tc358746->refclk);
> > +err:
> > +	regulator_bulk_disable(ARRAY_SIZE(tc358746_supplies),
> > +			       tc358746->supplies);
> > +	return err;
> > +}
> > +
> > +DEFINE_RUNTIME_DEV_PM_OPS(tc358746_pm_ops, tc358746_suspend,
> > +			  tc358746_resume, NULL);
> > +
> > +static const struct of_device_id __maybe_unused tc358746_of_match[] = {
> > +	{ .compatible = "toshiba,tc358746" },
> > +	{ },
> > +};
> > +MODULE_DEVICE_TABLE(of, tc358746_of_match);
> > +
> > +static struct i2c_driver tc358746_driver = {
> > +	.driver = {
> > +		.name = "tc358746",
> > +		.pm = pm_ptr(&tc358746_pm_ops),
> > +		.of_match_table = tc358746_of_match,
> > +	},
> > +	.probe_new = tc358746_probe,
> > +	.remove = tc358746_remove,
> > +};
> > +
> > +module_i2c_driver(tc358746_driver);
> > +
> > +MODULE_DESCRIPTION("Toshiba TC358746 Parallel to CSI-2 bridge driver");
> > +MODULE_AUTHOR("Marco Felsch <kernel@pengutronix.de>");
> > +MODULE_LICENSE("GPL");
> 
> -- 
> Regards,
> 
> Laurent Pinchart
> 

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Re: [PATCH v3 4/4] media: tc358746: add Toshiba TC358746 Parallel to CSI-2 bridge driver

[Laurent Pinchart]

Hi Marco,

On Fri, Sep 23, 2022 at 11:27:26AM +0200, Marco Felsch wrote:
> On 22-09-22, Laurent Pinchart wrote:
> > On Thu, Sep 22, 2022 at 03:48:43PM +0200, Marco Felsch wrote:
> > > Adding support for the TC358746 parallel <-> MIPI CSI bridge. This chip
> > > supports two operating modes:
> > >   1st) parallel-in -> mipi-csi out
> > >   2nd) mipi-csi in -> parallel out
> > > 
> > > This patch only adds the support for the 1st mode.
> > > 
> > > Signed-off-by: Marco Felsch <m.felsch@pengutronix.de>
> > > ---
> > > Changelog:
> > > 
> > > v3:
> > > - added missing static
> > > - drop s/MHZ/HZ_PER_MHZ/
> > > - kconfig: add "depends on PM"
> > > - Add tc358746_valid_reg() for regmap.
> > > - tc358746_set_fmt: fix format negotiation for pad == SOURCE
> > > - tc358746_write/read: add error messages
> > > - replace udelay with fsleep()
> > > - tc358746_apply_misc_config: const mbusfmt
> > > - tc358746_s_stream: fix comment about LP-00/11 state change
> > > - tc358746_link_validate: s/sensor/source/
> > > - tc358746_link_validate: s/pclk_rate/link_freq/
> > > - tc358746_link_validate: fix v4l2_subdev_unlock_state()
> > > - tc358746_link_validate: adapt fifo-sz comment
> > > - tc358746_g/s_register: use pm_runtime_get_if_in_use
> > > - tc358746_setup_mclk_provider: move to clk related location
> > > - tc358746_init_hw: fix error case
> > > - tc358746_init_controls: add comment
> > > - tc358746_notify_bound: add MEDIA_LNK_FL_IMMUTABLE
> > > - tc358746_async_register: fix error path
> > > - tc358746_async_register: put sd.fwnode on error and remove
> > > - tc358746_probe: increase autosuspend to 1s
> > > 
> > > v2:
> > > - use the correct CID_LINK_FREQ control to query the sensor_pclk_rate
> > > - remove now not needed tc358746_link_setup() and
> > >   struct v4l2_ctrl sensor_pclk_ctrl
> > > - call v4l2_subdev_link_validate_default() during link validation
> > > - remove MEDIA_BUS_FMT_GBR888_1X24/YUV444 format support
> > > - use subdev active_state API
> > > - replace own .get_fmt with v4l2_subdev_get_fmt
> > > - remove unnecessary pad checks
> > > - restructure tc358746_get_format_by_code() if-case
> > > - move apply_dphy_config|apply_misc_config from resume intos s_stream
> > > - use goto in s_stream enable case
> > > - fix error handling in suspend/resume
> > > - split probe() into more sub-functions
> > > ---
> > >  drivers/media/i2c/Kconfig    |   17 +
> > >  drivers/media/i2c/Makefile   |    1 +
> > >  drivers/media/i2c/tc358746.c | 1692 ++++++++++++++++++++++++++++++++++
> > >  3 files changed, 1710 insertions(+)
> > >  create mode 100644 drivers/media/i2c/tc358746.c
> > > 
> > > diff --git a/drivers/media/i2c/Kconfig b/drivers/media/i2c/Kconfig
> > > index 7806d4b81716..f85cdb94c524 100644
> > > --- a/drivers/media/i2c/Kconfig
> > > +++ b/drivers/media/i2c/Kconfig
> > > @@ -1272,6 +1272,23 @@ config VIDEO_TC358743_CEC
> > >  	  When selected the tc358743 will support the optional
> > >  	  HDMI CEC feature.
> > >  
> > > +config VIDEO_TC358746
> > > +	tristate "Toshiba TC358746 parallel-CSI2 bridge"
> > > +	depends on VIDEO_DEV && PM && I2C
> > > +	select VIDEO_V4L2_SUBDEV_API
> > > +	select MEDIA_CONTROLLER
> > > +	select V4L2_FWNODE
> > > +	select GENERIC_PHY_MIPI_DPHY
> > > +	select REGMAP_I2C
> > > +	select COMMON_CLK
> > > +	help
> > > +	  Support for the Toshiba TC358746 parallel to MIPI CSI-2 bridge.
> > > +	  The bridge can work in both directions but currently only the
> > > +	  parallel-in / csi-out path is supported.
> > > +
> > > +	  To compile this driver as a module, choose M here: the
> > > +	  module will be called tc358746.
> > > +
> > >  config VIDEO_TVP514X
> > >  	tristate "Texas Instruments TVP514x video decoder"
> > >  	depends on VIDEO_DEV && I2C
> > > diff --git a/drivers/media/i2c/Makefile b/drivers/media/i2c/Makefile
> > > index 0a2933103dd9..d1096c2ab480 100644
> > > --- a/drivers/media/i2c/Makefile
> > > +++ b/drivers/media/i2c/Makefile
> > > @@ -118,6 +118,7 @@ obj-$(CONFIG_VIDEO_SONY_BTF_MPX) += sony-btf-mpx.o
> > >  obj-$(CONFIG_VIDEO_SR030PC30) += sr030pc30.o
> > >  obj-$(CONFIG_VIDEO_ST_MIPID02) += st-mipid02.o
> > >  obj-$(CONFIG_VIDEO_TC358743) += tc358743.o
> > > +obj-$(CONFIG_VIDEO_TC358746) += tc358746.o
> > >  obj-$(CONFIG_VIDEO_TDA1997X) += tda1997x.o
> > >  obj-$(CONFIG_VIDEO_TDA7432) += tda7432.o
> > >  obj-$(CONFIG_VIDEO_TDA9840) += tda9840.o
> > > diff --git a/drivers/media/i2c/tc358746.c b/drivers/media/i2c/tc358746.c
> > > new file mode 100644
> > > index 000000000000..0dcd5e0e0855
> > > --- /dev/null
> > > +++ b/drivers/media/i2c/tc358746.c
> > > @@ -0,0 +1,1692 @@
> > > +// SPDX-License-Identifier: GPL-2.0-only
> > > +/*
> > > + * TC358746 - Parallel <-> CSI-2 Bridge
> > > + *
> > > + * Copyright 2022 Marco Felsch <kernel@pengutronix.de>
> > > + *
> > > + * Notes:
> > > + *  - Currently only 'Parallel-in -> CSI-out' mode is supported!
> > > + */
> > > +
> > > +#include <linux/bitfield.h>
> > > +#include <linux/clk.h>
> > > +#include <linux/clk-provider.h>
> > > +#include <linux/delay.h>
> > > +#include <linux/i2c.h>
> > > +#include <linux/interrupt.h>
> > > +#include <linux/kernel.h>
> > > +#include <linux/module.h>
> > > +#include <linux/phy/phy-mipi-dphy.h>
> > > +#include <linux/property.h>
> > > +#include <linux/pm_runtime.h>
> > > +#include <linux/regmap.h>
> > > +#include <linux/units.h>
> > > +#include <media/v4l2-ctrls.h>
> > > +#include <media/v4l2-device.h>
> > > +#include <media/v4l2-fwnode.h>
> > > +#include <media/v4l2-mc.h>
> > > +
> > > +/* 16-bit registers */
> > > +#define CHIPID_REG			0x0000
> > > +#define		CHIPID			GENMASK(15, 8)
> > > +
> > > +#define SYSCTL_REG			0x0002
> > > +#define		SRESET			BIT(0)
> > > +
> > > +#define CONFCTL_REG			0x0004
> > > +#define		PDATAF_MASK		GENMASK(9, 8)
> > > +#define		PDATAF_MODE0		0
> > > +#define		PDATAF_MODE1		1
> > > +#define		PDATAF_MODE2		2
> > > +#define		PDATAF(val)		FIELD_PREP(PDATAF_MASK, (val))
> > > +#define		PPEN			BIT(6)
> > > +#define		DATALANE_MASK		GENMASK(1, 0)
> > > +
> > > +#define FIFOCTL_REG			0x0006
> > > +#define DATAFMT_REG			0x0008
> > > +#define		PDFMT(val)		FIELD_PREP(GENMASK(7, 4), (val))
> > > +
> > > +#define MCLKCTL_REG			0x000c
> > > +#define		MCLK_HIGH_MASK		GENMASK(15, 8)
> > > +#define		MCLK_LOW_MASK		GENMASK(7, 0)
> > > +#define		MCLK_HIGH(val)		FIELD_PREP(MCLK_HIGH_MASK, (val))
> > > +#define		MCLK_LOW(val)		FIELD_PREP(MCLK_LOW_MASK, (val))
> > > +
> > > +#define PLLCTL0_REG			0x0016
> > > +#define		PLL_PRD_MASK		GENMASK(15, 12)
> > > +#define		PLL_PRD(val)		FIELD_PREP(PLL_PRD_MASK, (val))
> > > +#define		PLL_FBD_MASK		GENMASK(8, 0)
> > > +#define		PLL_FBD(val)		FIELD_PREP(PLL_FBD_MASK, (val))
> > > +
> > > +#define PLLCTL1_REG			0x0018
> > > +#define		PLL_FRS_MASK		GENMASK(11, 10)
> > > +#define		PLL_FRS(val)		FIELD_PREP(PLL_FRS_MASK, (val))
> > > +#define		CKEN			BIT(4)
> > > +#define		RESETB			BIT(1)
> > > +#define		PLL_EN			BIT(0)
> > > +
> > > +#define CLKCTL_REG			0x0020
> > > +#define		MCLKDIV_MASK		GENMASK(3, 2)
> > > +#define		MCLKDIV(val)		FIELD_PREP(MCLKDIV_MASK, (val))
> > > +#define		MCLKDIV_8		0
> > > +#define		MCLKDIV_4		1
> > > +#define		MCLKDIV_2		2
> > > +
> > > +#define WORDCNT_REG			0x0022
> > > +#define PP_MISC_REG			0x0032
> > > +#define		FRMSTOP			BIT(15)
> > > +#define		RSTPTR			BIT(14)
> > > +
> > > +/* 32-bit registers */
> > > +#define CLW_DPHYCONTTX_REG		0x0100
> > > +#define CLW_CNTRL_REG			0x0140
> > > +#define D0W_CNTRL_REG			0x0144
> > > +#define		LANEDISABLE		BIT(0)
> > > +
> > > +#define STARTCNTRL_REG			0x0204
> > > +#define		START			BIT(0)
> > > +
> > > +#define LINEINITCNT_REG			0x0210
> > > +#define LPTXTIMECNT_REG			0x0214
> > > +#define TCLK_HEADERCNT_REG		0x0218
> > > +#define		TCLK_ZEROCNT(val)	FIELD_PREP(GENMASK(15, 8), (val))
> > > +#define		TCLK_PREPARECNT(val)	FIELD_PREP(GENMASK(6, 0), (val))
> > > +
> > > +#define TCLK_TRAILCNT_REG		0x021C
> > > +#define THS_HEADERCNT_REG		0x0220
> > > +#define		THS_ZEROCNT(val)	FIELD_PREP(GENMASK(14, 8), (val))
> > > +#define		THS_PREPARECNT(val)	FIELD_PREP(GENMASK(6, 0), (val))
> > > +
> > > +#define TWAKEUP_REG			0x0224
> > > +#define TCLK_POSTCNT_REG		0x0228
> > > +#define THS_TRAILCNT_REG		0x022C
> > > +#define HSTXVREGEN_REG			0x0234
> > > +#define TXOPTIONCNTRL_REG		0x0238
> > > +#define CSI_CONTROL_REG			0x040C
> > > +#define		CSI_MODE		BIT(15)
> > > +#define		TXHSMD			BIT(7)
> > > +#define		NOL(val)		FIELD_PREP(GENMASK(2, 1), (val))
> > > +
> > > +#define CSI_CONFW_REG			0x0500
> > > +#define		MODE(val)		FIELD_PREP(GENMASK(31, 29), (val))
> > > +#define		MODE_SET		0x5
> > > +#define		ADDRESS(val)		FIELD_PREP(GENMASK(28, 24), (val))
> > > +#define		CSI_CONTROL_ADDRESS	0x3
> > > +#define		DATA(val)		FIELD_PREP(GENMASK(15, 0), (val))
> > > +
> > > +#define CSI_START_REG			0x0518
> > > +#define		STRT			BIT(0)
> > > +
> > > +static const struct v4l2_mbus_framefmt tc358746_def_fmt = {
> > > +	.width		= 640,
> > > +	.height		= 480,
> > > +	.code		= MEDIA_BUS_FMT_UYVY8_2X8,
> > > +	.field		= V4L2_FIELD_NONE,
> > > +	.colorspace	= V4L2_COLORSPACE_DEFAULT,
> > > +	.ycbcr_enc	= V4L2_YCBCR_ENC_DEFAULT,
> > > +	.quantization	= V4L2_QUANTIZATION_DEFAULT,
> > > +	.xfer_func	= V4L2_XFER_FUNC_DEFAULT,
> > > +};
> > > +
> > > +static const char * const tc358746_supplies[] = {
> > > +	"vddc", "vddio", "vddmipi"
> > > +};
> > > +
> > > +enum {
> > > +	TC358746_SINK,
> > > +	TC358746_SOURCE,
> > > +	TC358746_NR_PADS
> > > +};
> > > +
> > > +struct tc358746 {
> > > +	struct v4l2_subdev		sd;
> > > +	struct media_pad		pads[TC358746_NR_PADS];
> > > +	struct v4l2_async_notifier	notifier;
> > > +	struct v4l2_fwnode_endpoint	csi_vep;
> > > +
> > > +	struct v4l2_ctrl_handler	ctrl_hdl;
> > > +
> > > +	struct regmap			*regmap;
> > > +	struct clk			*refclk;
> > > +	struct gpio_desc		*reset_gpio;
> > > +	struct regulator_bulk_data	supplies[ARRAY_SIZE(tc358746_supplies)];
> > > +
> > > +	struct clk_hw			mclk_hw;
> > > +	unsigned long			mclk_rate;
> > > +	u8				mclk_prediv;
> > > +	u16				mclk_postdiv;
> > > +
> > > +	unsigned long			pll_rate;
> > > +	u8				pll_post_div;
> > > +	u16				pll_pre_div;
> > > +	u16				pll_mul;
> > > +
> > > +#define TC358746_VB_MAX_SIZE		(511 * 32)
> > > +#define TC358746_VB_DEFAULT_SIZE	  (1 * 32)
> > > +	unsigned int			vb_size; /* Video buffer size in bits */
> > > +
> > > +	struct phy_configure_opts_mipi_dphy dphy_cfg;
> > > +};
> > > +
> > > +static inline struct tc358746 *to_tc358746(struct v4l2_subdev *sd)
> > > +{
> > > +	return container_of(sd, struct tc358746, sd);
> > > +}
> > > +
> > > +static inline struct tc358746 *clk_hw_to_tc358746(struct clk_hw *hw)
> > > +{
> > > +	return container_of(hw, struct tc358746, mclk_hw);
> > > +}
> > > +
> > > +struct tc358746_format {
> > > +	u32		code;
> > > +	bool		csi_format;
> > > +	unsigned char	bus_width;
> > > +	unsigned char	bpp;
> > > +	/* Register values */
> > > +	u8		pdformat; /* Peripheral Data Format */
> > > +	u8		pdataf;   /* Parallel Data Format Option */
> > > +};
> > > +
> > > +enum {
> > > +	PDFORMAT_RAW8 = 0,
> > > +	PDFORMAT_RAW10,
> > > +	PDFORMAT_RAW12,
> > > +	PDFORMAT_RGB888,
> > > +	PDFORMAT_RGB666,
> > > +	PDFORMAT_RGB565,
> > > +	PDFORMAT_YUV422_8BIT,
> > > +	/* RESERVED = 7 */
> > > +	PDFORMAT_RAW14 = 8,
> > > +	PDFORMAT_YUV422_10BIT,
> > > +	PDFORMAT_YUV444,
> > > +};
> > > +
> > > +/* Check tc358746_src_mbus_code() if you add new formats */
> > > +static const struct tc358746_format tc358746_formats[] = {
> > > +	{
> > > +		.code = MEDIA_BUS_FMT_UYVY8_2X8,
> > > +		.bus_width = 8,
> > > +		.bpp = 16,
> > > +		.pdformat = PDFORMAT_YUV422_8BIT,
> > > +		.pdataf = PDATAF_MODE0,
> > > +	}, {
> > > +		.code = MEDIA_BUS_FMT_UYVY8_1X16,
> > > +		.csi_format = true,
> > > +		.bus_width = 16,
> > > +		.bpp = 16,
> > > +		.pdformat = PDFORMAT_YUV422_8BIT,
> > > +		.pdataf = PDATAF_MODE1,
> > > +	}, {
> > > +		.code = MEDIA_BUS_FMT_YUYV8_1X16,
> > > +		.csi_format = true,
> > > +		.bus_width = 16,
> > > +		.bpp = 16,
> > > +		.pdformat = PDFORMAT_YUV422_8BIT,
> > > +		.pdataf = PDATAF_MODE2,
> > > +	}, {
> > > +		.code = MEDIA_BUS_FMT_UYVY10_2X10,
> > > +		.bus_width = 10,
> > > +		.bpp = 20,
> > > +		.pdformat = PDFORMAT_YUV422_10BIT,
> > > +		.pdataf = PDATAF_MODE0, /* don't care */
> > > +	}
> > > +};
> > > +
> > > +/* Get n-th format for pad */
> > > +static const struct tc358746_format *
> > > +tc358746_get_format_by_idx(unsigned int pad, unsigned int index)
> > > +{
> > > +	unsigned int idx = 0;
> > > +	unsigned int i;
> > > +
> > > +	for (i = 0; i < ARRAY_SIZE(tc358746_formats); i++) {
> > > +		const struct tc358746_format *fmt = &tc358746_formats[i];
> > > +
> > > +		if ((pad == TC358746_SOURCE && fmt->csi_format) ||
> > > +		    (pad == TC358746_SINK)) {
> > > +			if (idx == index)
> > > +				return fmt;
> > > +			idx++;
> > > +		}
> > > +	}
> > > +
> > > +	return ERR_PTR(-EINVAL);
> > > +}
> > > +
> > > +static const struct tc358746_format *
> > > +tc358746_get_format_by_code(unsigned int pad, u32 code)
> > > +{
> > > +	unsigned int i;
> > > +
> > > +	for (i = 0; i < ARRAY_SIZE(tc358746_formats); i++) {
> > > +		const struct tc358746_format *fmt = &tc358746_formats[i];
> > > +
> > > +		if (pad == TC358746_SINK && fmt->code == code)
> > > +			return fmt;
> > > +
> > > +		if (pad == TC358746_SOURCE && !fmt->csi_format)
> > > +			continue;
> > > +
> > > +		if (fmt->code == code)
> > > +			return fmt;
> > > +	}
> > > +
> > > +	return ERR_PTR(-EINVAL);
> > > +}
> > > +
> > > +static u32 tc358746_src_mbus_code(u32 code)
> > > +{
> > > +	switch (code) {
> > > +	case MEDIA_BUS_FMT_UYVY8_2X8:
> > > +		return MEDIA_BUS_FMT_UYVY8_1X16;
> > > +	case MEDIA_BUS_FMT_UYVY10_2X10:
> > > +		return MEDIA_BUS_FMT_UYVY10_1X20;
> > > +	default:
> > > +		return code;
> > > +	}
> > > +}
> > > +
> > > +static bool tc358746_valid_reg(struct device *dev, unsigned int reg)
> > > +{
> > > +	switch (reg) {
> > > +	case CHIPID_REG ... CSI_START_REG:
> > > +		return true;
> > > +	default:
> > > +		return false;
> > > +	}
> > > +}
> > > +
> > > +static const struct regmap_config tc358746_regmap_config = {
> > > +	.name = "tc358746",
> > > +	.reg_bits = 16,
> > > +	.val_bits = 16,
> > > +	.max_register = CSI_START_REG,
> > > +	.writeable_reg = tc358746_valid_reg,
> > > +	.readable_reg = tc358746_valid_reg,
> > > +	.reg_format_endian = REGMAP_ENDIAN_BIG,
> > > +	.val_format_endian = REGMAP_ENDIAN_BIG,
> > > +};
> > > +
> > > +static int tc358746_write(struct tc358746 *tc358746, u32 reg, u32 val)
> > > +{
> > > +	size_t count;
> > > +	int err;
> > > +
> > > +	/* 32-bit registers starting from CLW_DPHYCONTTX */
> > > +	count = reg < CLW_DPHYCONTTX_REG ? 1 : 2;
> > > +
> > > +	err = regmap_bulk_write(tc358746->regmap, reg, &val, count);
> > > +	if (err)
> > > +		dev_dbg(tc358746->sd.dev,
> > > +			"Failed to write reg:0x%04x val:0x%04x\n", reg, val);
> > 
> > I'm not sure if the value is relevant here, but I'd add the error, it's
> > useful to know what kind of I2C issue occurred. Same for read().
> 
> Yeah.. I'm not sure, since you told me to not flood the kernel log. If
> someone recognised error while probing or streaming the debug will be
> turned on anyways. However, I will make it a dev_err() since this
> shouldnt appear normally, you're right.

Sorry, I meant printing the value of the error code in the message, the
err variable. dev_err() is probably good too actually, as this isn't
meant to happen.

> > By the way, this isn't something you need to do in this driver, but I've
> > found the following pattern to be useful for error handling:
> > 
> > static int tc358746_write(struct tc358746 *tc358746, u32 reg, u32 val, int *err)
> > {
> > 	size_t count;
> > 	int ret;
> > 
> > 	if (err && *err)
> > 		return *err;
> > 
> > 	/* 32-bit registers starting from CLW_DPHYCONTTX */
> > 	count = reg < CLW_DPHYCONTTX_REG ? 1 : 2;
> > 
> > 	ret = regmap_bulk_write(tc358746->regmap, reg, &val, count);
> > 	if (ret)
> > 		dev_dbg(tc358746->sd.dev,
> > 			"Failed to write reg 0x%04x: %d\n", reg, ret);
> > 		if (err)
> > 			*err = ret;
> > 		return ret;
> > 	}
> > 
> > 	return 0;
> > }
> > 
> > With this, you could simplify functions such as
> > tc358746_apply_dphy_config(), by initializing the local err variable to
> > 0, calling 
> > 
> > 	tc358746_write(tc358746, ..., ..., &err);
> > 
> > without checking for errors, and just returning err at the end of the
> > function. With the same pattern enabled in tc358746_update_bits() you
> > could simplify other functions too.
> 
> Good pattern, will keep it in mind. Albeit the little magic can cause
> confusion while reading e.g. tc358746_apply_dphy_config().

Yes it could. It's really up to you whether you want to use it here,
elsewhere or nowhere :-) I mentioned it because I've found it very
useful in multiple drivers. Maybe regmap should even have a similar API.

> > > +
> > > +	return err;
> > > +}
> > > +
> > > +static int tc358746_read(struct tc358746 *tc358746, u32 reg, u32 *val)
> > > +{
> > > +	size_t count;
> > > +	int err;
> > > +
> > > +	/* 32-bit registers starting from CLW_DPHYCONTTX */
> > > +	count = reg < CLW_DPHYCONTTX_REG ? 1 : 2;
> > > +	*val = 0;
> > > +
> > > +	err = regmap_bulk_read(tc358746->regmap, reg, val, count);
> > > +	if (err)
> > > +		dev_dbg(tc358746->sd.dev, "Failed to read reg:0x%04x\n", reg);
> > > +
> > > +	return err;
> > > +}
> > > +
> > > +static int
> > > +tc358746_update_bits(struct tc358746 *tc358746, u32 reg, u32 mask, u32 val)
> > > +{
> > > +	u32 tmp, orig;
> > > +	int err;
> > > +
> > > +	err = tc358746_read(tc358746, reg, &orig);
> > > +	if (err)
> > > +		return err;
> > > +
> > > +	tmp = orig & ~mask;
> > > +	tmp |= val & mask;
> > > +
> > > +	return tc358746_write(tc358746, reg, tmp);
> > > +}
> > > +
> > > +static int tc358746_set_bits(struct tc358746 *tc358746, u32 reg, u32 bits)
> > > +{
> > > +	return tc358746_update_bits(tc358746, reg, bits, bits);
> > > +}
> > > +
> > > +static int tc358746_clear_bits(struct tc358746 *tc358746, u32 reg, u32 bits)
> > > +{
> > > +	return tc358746_update_bits(tc358746, reg, bits, 0);
> > > +}
> > > +
> > > +static int tc358746_sw_reset(struct tc358746 *tc358746)
> > > +{
> > > +	int err;
> > > +
> > > +	err = tc358746_set_bits(tc358746, SYSCTL_REG, SRESET);
> > > +	if (err)
> > > +		return err;
> > > +
> > > +	fsleep(10);
> > > +
> > > +	return tc358746_clear_bits(tc358746, SYSCTL_REG, SRESET);
> > > +}
> > > +
> > > +static int
> > > +tc358746_apply_pll_config(struct tc358746 *tc358746)
> > > +{
> > > +	u8 post = tc358746->pll_post_div;
> > > +	u16 pre = tc358746->pll_pre_div;
> > > +	u16 mul = tc358746->pll_mul;
> > > +	u32 val, mask;
> > > +	int err;
> > > +
> > > +	err = tc358746_read(tc358746, PLLCTL1_REG, &val);
> > > +	if (err)
> > > +		return err;
> > > +
> > > +	/* Don't touch the PLL if running */
> > > +	if (FIELD_GET(PLL_EN, val) == 1)
> > > +		return 0;
> > > +
> > > +	/* Pre-div and Multiplicator have a internal +1 logic */
> > > +	val = PLL_PRD(pre - 1) | PLL_FBD(mul - 1);
> > > +	mask = PLL_PRD_MASK | PLL_FBD_MASK;
> > > +	err = tc358746_update_bits(tc358746, PLLCTL0_REG, mask, val);
> > > +	if (err)
> > > +		return err;
> > > +
> > > +	val = PLL_FRS(ilog2(post)) | RESETB | PLL_EN;
> > > +	mask = PLL_FRS_MASK | RESETB | PLL_EN;
> > > +	tc358746_update_bits(tc358746, PLLCTL1_REG, mask, val);
> > > +	if (err)
> > > +		return err;
> > > +
> > > +	fsleep(1000);
> > > +
> > > +	return tc358746_set_bits(tc358746, PLLCTL1_REG, CKEN);
> > > +}
> > > +
> > > +static int tc358746_apply_misc_config(struct tc358746 *tc358746)
> > > +{
> > > +	const struct v4l2_mbus_framefmt *mbusfmt;
> > > +	struct v4l2_subdev *sd = &tc358746->sd;
> > > +	struct v4l2_subdev_state *sink_state;
> > > +	const struct tc358746_format *fmt;
> > > +	struct device *dev = sd->dev;
> > > +	u32 val;
> > > +	int err;
> > > +
> > > +	sink_state = v4l2_subdev_lock_and_get_active_state(sd);
> > > +	mbusfmt = v4l2_subdev_get_pad_format(sd, sink_state, TC358746_SINK);
> > > +	v4l2_subdev_unlock_state(sink_state);
> > > +
> > > +	fmt = tc358746_get_format_by_code(TC358746_SINK, mbusfmt->code);
> > > +
> > > +	/* Self defined CSI user data type id's are not supported yet */
> > > +	val = PDFMT(fmt->pdformat);
> > > +	dev_dbg(dev, "DATAFMT: 0x%x\n", val);
> > > +	err = tc358746_write(tc358746, DATAFMT_REG, val);
> > > +	if (err)
> > > +		return err;
> > > +
> > > +	val = PDATAF(fmt->pdataf);
> > > +	dev_dbg(dev, "CONFCTL[PDATAF]: 0x%x\n", fmt->pdataf);
> > > +	err = tc358746_update_bits(tc358746, CONFCTL_REG, PDATAF_MASK, val);
> > > +	if (err)
> > > +		return err;
> > > +
> > > +	val = tc358746->vb_size / 32;
> > > +	dev_dbg(dev, "FIFOCTL: %u (0x%x)\n", val, val);
> > > +	err = tc358746_write(tc358746, FIFOCTL_REG, val);
> > > +	if (err)
> > > +		return err;
> > > +
> > > +	/* Total number of bytes for each line/width */
> > > +	val = mbusfmt->width * fmt->bpp / 8;
> > > +	dev_dbg(dev, "WORDCNT: %u (0x%x)\n", val, val);
> > > +	return tc358746_write(tc358746, WORDCNT_REG, val);
> > > +}
> > > +
> > > +/* Use MHz as base so the div needs no u64 */
> > > +static u32 tc358746_cfg_to_cnt(unsigned int cfg_val,
> > > +			       unsigned int clk_mhz,
> > > +			       unsigned int time_base)
> > > +{
> > > +	return DIV_ROUND_UP(cfg_val * clk_mhz, time_base);
> > > +}
> > > +
> > > +static u32 tc358746_ps_to_cnt(unsigned int cfg_val,
> > > +			      unsigned int clk_mhz)
> > > +{
> > > +	return tc358746_cfg_to_cnt(cfg_val, clk_mhz, USEC_PER_SEC);
> > > +}
> > > +
> > > +static u32 tc358746_us_to_cnt(unsigned int cfg_val,
> > > +			      unsigned int clk_mhz)
> > > +{
> > > +	return tc358746_cfg_to_cnt(cfg_val, clk_mhz, 1);
> > > +}
> > > +
> > > +static int tc358746_apply_dphy_config(struct tc358746 *tc358746)
> > > +{
> > > +	struct phy_configure_opts_mipi_dphy *cfg = &tc358746->dphy_cfg;
> > > +	bool non_cont_clk = !!(tc358746->csi_vep.bus.mipi_csi2.flags &
> > > +			       V4L2_MBUS_CSI2_NONCONTINUOUS_CLOCK);
> > > +	struct device *dev = tc358746->sd.dev;
> > > +	unsigned long hs_byte_clk, hf_clk;
> > > +	u32 val, val2, lptxcnt;
> > > +	int err;
> > > +
> > > +	/* The hs_byte_clk is also called SYSCLK in the excel sheet */
> > > +	hs_byte_clk = cfg->hs_clk_rate / 8;
> > > +	hs_byte_clk /= HZ_PER_MHZ;
> > > +	hf_clk = hs_byte_clk / 2;
> > > +
> > > +	val = tc358746_us_to_cnt(cfg->init, hf_clk) - 1;
> > > +	dev_dbg(dev, "LINEINITCNT: %u (0x%x)\n", val, val);
> > > +	err = tc358746_write(tc358746, LINEINITCNT_REG, val);
> > > +	if (err)
> > > +		return err;
> > > +
> > > +	val = tc358746_ps_to_cnt(cfg->lpx, hs_byte_clk) - 1;
> > > +	lptxcnt = val;
> > > +	dev_dbg(dev, "LPTXTIMECNT: %u (0x%x)\n", val, val);
> > > +	err = tc358746_write(tc358746, LPTXTIMECNT_REG, val);
> > > +	if (err)
> > > +		return err;
> > > +
> > > +	val = tc358746_ps_to_cnt(cfg->clk_prepare, hs_byte_clk) - 1;
> > > +	val2 = tc358746_ps_to_cnt(cfg->clk_zero, hs_byte_clk) - 1;
> > > +	dev_dbg(dev, "TCLK_PREPARECNT: %u (0x%x)\n", val, val);
> > > +	dev_dbg(dev, "TCLK_ZEROCNT: %u (0x%x)\n", val2, val2);
> > > +	dev_dbg(dev, "TCLK_HEADERCNT: 0x%x\n",
> > > +		(u32)(TCLK_PREPARECNT(val) | TCLK_ZEROCNT(val2)));
> > > +	err = tc358746_write(tc358746, TCLK_HEADERCNT_REG,
> > > +			     TCLK_PREPARECNT(val) | TCLK_ZEROCNT(val2));
> > > +	if (err)
> > > +		return err;
> > > +
> > > +	val = tc358746_ps_to_cnt(cfg->clk_trail, hs_byte_clk);
> > > +	dev_dbg(dev, "TCLK_TRAILCNT: %u (0x%x)\n", val, val);
> > > +	err = tc358746_write(tc358746, TCLK_TRAILCNT_REG, val);
> > > +	if (err)
> > > +		return err;
> > > +
> > > +	val = tc358746_ps_to_cnt(cfg->hs_prepare, hs_byte_clk) - 1;
> > > +	val2 = tc358746_ps_to_cnt(cfg->hs_zero, hs_byte_clk) - 1;
> > > +	dev_dbg(dev, "THS_PREPARECNT: %u (0x%x)\n", val, val);
> > > +	dev_dbg(dev, "THS_ZEROCNT: %u (0x%x)\n", val2, val2);
> > > +	dev_dbg(dev, "THS_HEADERCNT: 0x%x\n",
> > > +		(u32)(THS_PREPARECNT(val) | THS_ZEROCNT(val2)));
> > > +	err = tc358746_write(tc358746, THS_HEADERCNT_REG,
> > > +			     THS_PREPARECNT(val) | THS_ZEROCNT(val2));
> > > +	if (err)
> > > +		return err;
> > > +
> > > +	/* TWAKEUP > 1ms in lptxcnt steps */
> > > +	val = tc358746_us_to_cnt(cfg->wakeup, hs_byte_clk);
> > > +	val = val / (lptxcnt + 1) - 1;
> > > +	dev_dbg(dev, "TWAKEUP: %u (0x%x)\n", val, val);
> > > +	err = tc358746_write(tc358746, TWAKEUP_REG, val);
> > > +	if (err)
> > > +		return err;
> > > +
> > > +	val = tc358746_ps_to_cnt(cfg->clk_post, hs_byte_clk);
> > > +	dev_dbg(dev, "TCLK_POSTCNT: %u (0x%x)\n", val, val);
> > > +	err = tc358746_write(tc358746, TCLK_POSTCNT_REG, val);
> > > +	if (err)
> > > +		return err;
> > > +
> > > +	val = tc358746_ps_to_cnt(cfg->hs_trail, hs_byte_clk);
> > > +	dev_dbg(dev, "THS_TRAILCNT: %u (0x%x)\n", val, val);
> > > +	err = tc358746_write(tc358746, THS_TRAILCNT_REG, val);
> > > +	if (err)
> > > +		return err;
> > > +
> > > +	dev_dbg(dev, "CONTCLKMODE: %u", non_cont_clk ? 0 : 1);
> > > +	return  tc358746_write(tc358746, TXOPTIONCNTRL_REG, non_cont_clk ? 0 : 1);
> > 
> > Extra space after return.
> 
> Okay.
> 
> > > +}
> > > +
> > > +#define MAX_DATA_LANES 4
> > > +
> > > +static int tc358746_enable_csi_lanes(struct tc358746 *tc358746, int enable)
> > > +{
> > > +	unsigned int lanes = tc358746->dphy_cfg.lanes;
> > > +	unsigned int lane;
> > > +	u32 reg, val;
> > > +	int err;
> > > +
> > > +	err = tc358746_update_bits(tc358746, CONFCTL_REG, DATALANE_MASK,
> > > +				   lanes - 1);
> > > +	if (err)
> > > +		return err;
> > > +
> > > +	/* Clock lane */
> > > +	val = enable ? 0 : LANEDISABLE;
> > > +	dev_dbg(tc358746->sd.dev, "CLW_CNTRL: 0x%x\n", val);
> > > +	err = tc358746_write(tc358746, CLW_CNTRL_REG, val);
> > > +	if (err)
> > > +		return err;
> > > +
> > > +	for (lane = 0; lane < MAX_DATA_LANES; lane++) {
> > > +		/* Data lanes */
> > > +		reg = D0W_CNTRL_REG + lane * 0x4;
> > > +		val = (enable && lane < lanes) ? 0 : LANEDISABLE;
> > > +
> > > +		dev_dbg(tc358746->sd.dev, "D%uW_CNTRL: 0x%x\n", lane, val);
> > > +		err = tc358746_write(tc358746, reg, val);
> > > +		if (err)
> > > +			return err;
> > > +	}
> > > +
> > > +	val = 0;
> > > +	if (enable) {
> > > +		/* Clock lane */
> > > +		val |= BIT(0);
> > > +
> > > +		/* Data lanes */
> > > +		for (lane = 1; lane <= lanes; lane++)
> > > +			val |= BIT(lane);
> > > +	}
> > > +
> > > +	dev_dbg(tc358746->sd.dev, "HSTXVREGEN: 0x%x\n", val);
> > > +	return tc358746_write(tc358746, HSTXVREGEN_REG, val);
> > > +}
> > > +
> > > +static int tc358746_enable_csi_module(struct tc358746 *tc358746, int enable)
> > > +{
> > > +	unsigned int lanes = tc358746->dphy_cfg.lanes;
> > > +	int err;
> > > +
> > > +	/*
> > > +	 * START and STRT are only reseted/disabled by sw reset. This is
> > > +	 * required to put the lane state back into LP-11 state. The sw reset
> > > +	 * don't reset register values.
> > > +	 */
> > > +	if (!enable)
> > > +		return tc358746_sw_reset(tc358746);
> > > +
> > > +	err = tc358746_write(tc358746, STARTCNTRL_REG, START);
> > > +	if (err)
> > > +		return err;
> > > +
> > > +	err = tc358746_write(tc358746, CSI_START_REG, STRT);
> > > +	if (err)
> > > +		return err;
> > > +
> > > +	/* CSI_CONTROL_REG is only indirect accessible */
> > > +	return tc358746_write(tc358746, CSI_CONFW_REG,
> > > +			      MODE(MODE_SET) |
> > > +			      ADDRESS(CSI_CONTROL_ADDRESS) |
> > > +			      DATA(CSI_MODE | TXHSMD | NOL(lanes - 1)));
> > > +}
> > > +
> > > +static int tc358746_enable_parallel_port(struct tc358746 *tc358746, int enable)
> > > +{
> > > +	int err;
> > > +
> > > +	if (enable) {
> > > +		err = tc358746_write(tc358746, PP_MISC_REG, 0);
> > > +		if (err)
> > > +			return err;
> > > +
> > > +		return tc358746_set_bits(tc358746, CONFCTL_REG, PPEN);
> > > +	}
> > > +
> > > +	err = tc358746_set_bits(tc358746, PP_MISC_REG, FRMSTOP);
> > > +	if (err)
> > > +		return err;
> > > +
> > > +	err = tc358746_clear_bits(tc358746, CONFCTL_REG, PPEN);
> > > +	if (err)
> > > +		return err;
> > > +
> > > +	return tc358746_set_bits(tc358746, PP_MISC_REG, RSTPTR);
> > > +}
> > > +
> > > +static inline struct v4l2_subdev *tc358746_get_remote_sd(struct media_pad *pad)
> > > +{
> > > +	pad = media_pad_remote_pad_first(pad);
> > > +	if (!pad)
> > > +		return NULL;
> > > +
> > > +	return media_entity_to_v4l2_subdev(pad->entity);
> > > +}
> > > +
> > > +static int tc358746_s_stream(struct v4l2_subdev *sd, int enable)
> > > +{
> > > +	struct tc358746 *tc358746 = to_tc358746(sd);
> > > +	struct v4l2_subdev *src;
> > > +	int err;
> > > +
> > > +	dev_dbg(sd->dev, "%sable\n", enable ? "en" : "dis");
> > > +
> > > +	src = tc358746_get_remote_sd(&tc358746->pads[TC358746_SINK]);
> > > +	if (!src)
> > > +		return -EPIPE;
> > > +
> > > +	if (enable) {
> > > +		err = pm_runtime_resume_and_get(sd->dev);
> > > +		if (err)
> > > +			return err;
> > > +
> > > +		err = tc358746_apply_dphy_config(tc358746);
> > > +		if (err)
> > > +			goto err_out;
> > > +
> > > +		err = tc358746_apply_misc_config(tc358746);
> > > +		if (err)
> > > +			goto err_out;
> > > +
> > > +		err = tc358746_enable_csi_lanes(tc358746, 1);
> > > +		if (err)
> > > +			goto err_out;
> > > +
> > > +		err = tc358746_enable_csi_module(tc358746, 1);
> > > +		if (err)
> > > +			goto err_out;
> > > +
> > > +		err = tc358746_enable_parallel_port(tc358746, 1);
> > > +		if (err)
> > > +			goto err_out;
> > > +
> > > +		err = v4l2_subdev_call(src, video, s_stream, 1);
> > > +		if (err)
> > > +			goto err_out;
> > > +
> > > +		return err;
> > > +
> > > +err_out:
> > > +		pm_runtime_mark_last_busy(sd->dev);
> > > +		pm_runtime_put_sync_autosuspend(sd->dev);
> > > +
> > > +		return err;
> > > +	}
> > > +
> > > +	 /*
> > > +	  * The lanes must be disabled first (before the csi module) so the
> > > +	  * LP-11 state is entered correctly.
> > > +	  */
> > 
> > Wrong indentation.
> 
> Damn.. Shouldn't that be detected by checkpatch? Anyway, thanks :)
> 
> > > +	err = tc358746_enable_csi_lanes(tc358746, 0);
> > > +	if (err)
> > > +		return err;
> > > +
> > > +	err = tc358746_enable_csi_module(tc358746, 0);
> > > +	if (err)
> > > +		return err;
> > > +
> > > +	err = tc358746_enable_parallel_port(tc358746, 0);
> > > +	if (err)
> > > +		return err;
> > > +
> > > +	pm_runtime_mark_last_busy(sd->dev);
> > > +	pm_runtime_put_sync_autosuspend(sd->dev);
> > > +
> > > +	return v4l2_subdev_call(src, video, s_stream, 0);
> > > +}
> > > +
> > > +static int tc358746_init_cfg(struct v4l2_subdev *sd,
> > > +			     struct v4l2_subdev_state *state)
> > > +{
> > > +	struct v4l2_mbus_framefmt *fmt;
> > > +
> > > +	fmt = v4l2_subdev_get_pad_format(sd, state, TC358746_SINK);
> > > +	*fmt = tc358746_def_fmt;
> > > +
> > > +	fmt = v4l2_subdev_get_pad_format(sd, state, TC358746_SOURCE);
> > > +	*fmt = tc358746_def_fmt;
> > > +	fmt->code = tc358746_src_mbus_code(tc358746_def_fmt.code);
> > > +
> > > +	return 0;
> > > +}
> > > +
> > > +static int tc358746_enum_mbus_code(struct v4l2_subdev *sd,
> > > +				   struct v4l2_subdev_state *sd_state,
> > > +				   struct v4l2_subdev_mbus_code_enum *code)
> > > +{
> > > +	const struct tc358746_format *fmt;
> > > +
> > > +	fmt = tc358746_get_format_by_idx(code->pad, code->index);
> > > +	if (IS_ERR(fmt))
> > > +		return PTR_ERR(fmt);
> > > +
> > > +	code->code = fmt->code;
> > > +
> > > +	return 0;
> > > +}
> > > +
> > > +static int tc358746_set_fmt(struct v4l2_subdev *sd,
> > > +			    struct v4l2_subdev_state *sd_state,
> > > +			    struct v4l2_subdev_format *format)
> > > +{
> > > +	struct v4l2_mbus_framefmt *src_fmt, *sink_fmt;
> > > +	const struct tc358746_format *fmt;
> > > +
> > > +	/* Source follows the sink */
> > > +	if (format->pad == TC358746_SOURCE)
> > > +		return v4l2_subdev_get_fmt(sd, sd_state, format);
> > > +
> > > +	sink_fmt = v4l2_subdev_get_pad_format(sd, sd_state, TC358746_SINK);
> > > +
> > > +	fmt = tc358746_get_format_by_code(format->pad, format->format.code);
> > > +	if (IS_ERR(fmt))
> > > +		fmt = tc358746_get_format_by_code(format->pad, tc358746_def_fmt.code);
> > > +
> > > +	format->format.code = fmt->code;
> > > +	format->format.field = V4L2_FIELD_NONE;
> > > +
> > > +	dev_dbg(sd->dev, "Update format: %ux%u code:0x%x -> %ux%u code:0x%x",
> > > +		sink_fmt->width, sink_fmt->height, sink_fmt->code,
> > > +		format->format.width, format->format.height, format->format.code);
> > > +
> > > +	*sink_fmt = format->format;
> > > +
> > > +	src_fmt = v4l2_subdev_get_pad_format(sd, sd_state, TC358746_SOURCE);
> > > +	*src_fmt = *sink_fmt;
> > > +	src_fmt->code = tc358746_src_mbus_code(sink_fmt->code);
> > > +
> > > +	return 0;
> > > +}
> > > +
> > > +static unsigned long tc358746_find_pll_settings(struct tc358746 *tc358746,
> > > +						unsigned long refclk,
> > > +						unsigned long fout)
> > > +
> > > +{
> > > +	struct device *dev = tc358746->sd.dev;
> > > +	unsigned long best_freq = 0;
> > > +	u32 min_delta = 0xffffffff;
> > > +	u16 prediv_max = 17;
> > > +	u16 prediv_min = 1;
> > > +	u16 m_best, mul;
> > > +	u16 p_best, p;
> > > +	u8 postdiv;
> > > +
> > > +	if (fout > 1000 * HZ_PER_MHZ) {
> > > +		dev_err(dev, "HS-Clock above 1 Ghz are not supported\n");
> > > +		return 0;
> > > +	}
> > > +
> > > +	if (fout >= 500 * HZ_PER_MHZ)
> > > +		postdiv = 1;
> > > +	else if (fout >= 250 * HZ_PER_MHZ)
> > > +		postdiv = 2;
> > > +	else if (fout >= 125 * HZ_PER_MHZ)
> > > +		postdiv = 4;
> > > +	else
> > > +		postdiv = 8;
> > > +
> > > +	for (p = prediv_min; p <= prediv_max; p++) {
> > > +		unsigned long delta, fin;
> > > +		u64 tmp;
> > > +
> > > +		fin = DIV_ROUND_CLOSEST(refclk, p);
> > > +		if (fin < 4 * HZ_PER_MHZ || fin > 40 * HZ_PER_MHZ)
> > > +			continue;
> > > +
> > > +		tmp = fout * p * postdiv;
> > > +		do_div(tmp, fin);
> > > +		mul = tmp;
> > > +		if (mul > 511)
> > > +			continue;
> > > +
> > > +		tmp = mul * fin;
> > > +		do_div(tmp, p * postdiv);
> > > +
> > > +		delta = abs(fout - tmp);
> > > +		if (delta < min_delta) {
> > > +			p_best = p;
> > > +			m_best = mul;
> > > +			min_delta = delta;
> > > +			best_freq = tmp;
> > > +		};
> > > +
> > > +		if (delta == 0)
> > > +			break;
> > > +	};
> > > +
> > > +	if (!best_freq) {
> > > +		dev_err(dev, "Failed find PLL frequency\n");
> > > +		return 0;
> > > +	}
> > > +
> > > +	tc358746->pll_post_div = postdiv;
> > > +	tc358746->pll_pre_div = p_best;
> > > +	tc358746->pll_mul = m_best;
> > > +
> > > +	if (best_freq != fout)
> > > +		dev_warn(dev, "Request PLL freq:%lu, found PLL freq:%lu\n",
> > > +			 fout, best_freq);
> > > +
> > > +	dev_dbg(dev, "Found PLL settings: freq:%lu prediv:%u multi:%u postdiv:%u\n",
> > > +		best_freq, p_best, m_best, postdiv);
> > > +
> > > +	return best_freq;
> > > +}
> > > +
> > > +#define TC358746_PRECISION 10
> > > +
> > > +static int
> > > +tc358746_link_validate(struct v4l2_subdev *sd, struct media_link *link,
> > > +		       struct v4l2_subdev_format *source_fmt,
> > > +		       struct v4l2_subdev_format *sink_fmt)
> > > +{
> > > +	struct tc358746 *tc358746 = to_tc358746(sd);
> > > +	unsigned long csi_bitrate, source_bitrate;
> > > +	struct v4l2_subdev_state *sink_state;
> > > +	struct v4l2_mbus_framefmt *mbusfmt;
> > > +	const struct tc358746_format *fmt;
> > > +	unsigned int fifo_sz, tmp, n;
> > > +	struct v4l2_subdev *source;
> > > +	s64 source_link_freq;
> > > +	int err;
> > > +
> > > +	err = v4l2_subdev_link_validate_default(sd, link, source_fmt, sink_fmt);
> > > +	if (err)
> > > +		return err;
> > > +
> > > +	sink_state = v4l2_subdev_lock_and_get_active_state(sd);
> > > +	mbusfmt = v4l2_subdev_get_pad_format(sd, sink_state, TC358746_SINK);
> > > +
> > > +	/* Check the FIFO settings */
> > > +	fmt = tc358746_get_format_by_code(TC358746_SINK, mbusfmt->code);
> > > +
> > > +	source = media_entity_to_v4l2_subdev(link->source->entity);
> > > +	source_link_freq = v4l2_get_link_freq(source->ctrl_handler, 0, 0);
> > > +	if (source_link_freq <= 0) {
> > > +		dev_err(tc358746->sd.dev,
> > > +			"Failed to query or invalid source link frequency\n");
> > > +		v4l2_subdev_unlock_state(sink_state);
> > > +		/* Return -EINVAL in case of source_link_freq is 0 */
> > > +		return source_link_freq ? : -EINVAL;
> > > +	}
> > > +	source_bitrate = source_link_freq * fmt->bus_width;
> > > +
> > > +	csi_bitrate = tc358746->dphy_cfg.lanes * tc358746->pll_rate;
> > > +
> > > +	dev_dbg(tc358746->sd.dev,
> > > +		"Fifo settings params: source-bitrate:%lu csi-bitrate:%lu",
> > > +		source_bitrate, csi_bitrate);
> > > +
> > > +	/* Avoid possible FIFO overflows */
> > > +	if (csi_bitrate < source_bitrate) {
> > > +		v4l2_subdev_unlock_state(sink_state);
> > > +		return -EINVAL;
> > > +	}
> > > +
> > > +	/* Best case */
> > > +	if (csi_bitrate == source_bitrate) {
> > > +		fifo_sz = TC358746_VB_DEFAULT_SIZE;
> > > +		tc358746->vb_size = TC358746_VB_DEFAULT_SIZE;
> > > +		goto out;
> > > +	}
> > > +
> > > +	/*
> > > +	 * Avoid possible FIFO underflow in case of
> > > +	 * csi_bitrate > source_bitrate. For such case the chip has a internal
> > > +	 * fifo which can be used to delay the line output.
> > > +	 *
> > > +	 * Fifo size calculation (excluding precision):
> > > +	 *
> > > +	 * fifo-sz, image-width - in bits
> > > +	 * sbr                  - source_bitrate in bits/s
> > > +	 * csir                 - csi_bitrate in bits/s
> > > +	 *
> > > +	 *                1               1      1
> > > +	 * image-width * --- + fifo-sz * --- >= ---- * image-width
> > > +	 *               sbr             sbr    csir
> > 
> > I still think there's something fishy here. The inequality is always
> > true as csir > sbr. You will get a non-zero fifo size in your
> > calculation because you artifically add an abs(), but I don't think
> > that's right.
> > 
> > If I understand things correctly, you need to ensure that once the FIFO
> > threshold is reached and the CSI-2 side starts sending data, the input
> > size will keep feeding data fast enough for the FIFO to never underrun.
> > 
> > The FIFO level triggers the CSI-2 transmission. This means that once the
> > CSI-2 transmission start, fifo-sz bits have been written to the FIFO
> > already, and image-width - fifo-sz bits still need to be written. To
> > avoid underruns, you need to ensure that the time required to read all
> > the data (image-width) on the CSI-2 size will be higher than or equal to
> > the time required to write the remaining data (image-width - fifo-sz) on
> > the input side. This translates to
> > 
> > 	image-width / csir >= (image-width - fifo-sz) / sbr
> > 	image-width * sbr / csir >= image-width - fifo-sz
> > 	fifo-sz >= image-width - image-width * sbr / csir
> 
> Thanks, makes more sense, I will change the comment.
> 
> > The calculation is thus correct, but not for the right reason :-) All
> > you need to fix here is the comment, not the code.
> > 
> > With these small issues fixed,
> > 
> > Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> 
> > > +	 *
> > > +	 * fifo-sz >= abs(sbr/csir * image-width - image-width); with n = csir/sbr
> > > +	 *
> > > +	 * fifo-sz >= abs(image-width / n - image-width)
> > > +	 *         >= image-width - image-width / n
> > > +	 */
> > > +
> > > +	source_bitrate /= TC358746_PRECISION;
> > > +	n = csi_bitrate / source_bitrate;
> > > +	tmp = (mbusfmt->width * TC358746_PRECISION) / n;
> > > +	fifo_sz = mbusfmt->width - tmp;
> > > +	fifo_sz *= fmt->bpp;
> > > +	tc358746->vb_size = round_up(fifo_sz, 32);
> > > +
> > > +out:
> > > +	dev_dbg(tc358746->sd.dev,
> > > +		"Found FIFO size[bits]:%u -> aligned to size[bits]:%u\n",
> > > +		fifo_sz, tc358746->vb_size);
> > > +
> > > +	v4l2_subdev_unlock_state(sink_state);
> > > +
> > > +	return tc358746->vb_size > TC358746_VB_MAX_SIZE ? -EINVAL : 0;
> > > +}
> > > +
> > > +static int tc358746_get_mbus_config(struct v4l2_subdev *sd, unsigned int pad,
> > > +				    struct v4l2_mbus_config *config)
> > > +{
> > > +	struct tc358746 *tc358746 = to_tc358746(sd);
> > > +
> > > +	if (pad != TC358746_SOURCE)
> > > +		return -EINVAL;
> > > +
> > > +	config->type = V4L2_MBUS_CSI2_DPHY;
> > > +	config->bus.mipi_csi2 = tc358746->csi_vep.bus.mipi_csi2;
> > > +
> > > +	return 0;
> > > +}
> > > +
> > > +static int __maybe_unused
> > > +tc358746_g_register(struct v4l2_subdev *sd, struct v4l2_dbg_register *reg)
> > > +{
> > > +	struct tc358746 *tc358746 = to_tc358746(sd);
> > > +
> > > +	/* 32-bit registers starting from CLW_DPHYCONTTX */
> > > +	reg->size = reg->reg < CLW_DPHYCONTTX_REG ? 2 : 4;
> > > +
> > > +	if (!pm_runtime_get_if_in_use(sd->dev))
> > > +		return 0;
> > > +
> > > +	tc358746_read(tc358746, reg->reg, (u32 *)&reg->val);
> > > +
> > > +	pm_runtime_mark_last_busy(sd->dev);
> > > +	pm_runtime_put_sync_autosuspend(sd->dev);
> > > +
> > > +	return 0;
> > > +}
> > > +
> > > +static int __maybe_unused
> > > +tc358746_s_register(struct v4l2_subdev *sd, const struct v4l2_dbg_register *reg)
> > > +{
> > > +	struct tc358746 *tc358746 = to_tc358746(sd);
> > > +
> > > +	if (!pm_runtime_get_if_in_use(sd->dev))
> > > +		return 0;
> > > +
> > > +	tc358746_write(tc358746, (u32)reg->reg, (u32)reg->val);
> > > +
> > > +	pm_runtime_mark_last_busy(sd->dev);
> > > +	pm_runtime_put_sync_autosuspend(sd->dev);
> > > +
> > > +	return 0;
> > > +}
> > > +
> > > +static const struct v4l2_subdev_core_ops tc358746_core_ops = {
> > > +#ifdef CONFIG_VIDEO_ADV_DEBUG
> > > +	.g_register = tc358746_g_register,
> > > +	.s_register = tc358746_s_register,
> > > +#endif
> > > +};
> > > +
> > > +static const struct v4l2_subdev_video_ops tc358746_video_ops = {
> > > +	.s_stream = tc358746_s_stream,
> > > +};
> > > +
> > > +static const struct v4l2_subdev_pad_ops tc358746_pad_ops = {
> > > +	.init_cfg = tc358746_init_cfg,
> > > +	.enum_mbus_code = tc358746_enum_mbus_code,
> > > +	.set_fmt = tc358746_set_fmt,
> > > +	.get_fmt = v4l2_subdev_get_fmt,
> > > +	.link_validate = tc358746_link_validate,
> > > +	.get_mbus_config = tc358746_get_mbus_config,
> > > +};
> > > +
> > > +static const struct v4l2_subdev_ops tc358746_ops = {
> > > +	.core = &tc358746_core_ops,
> > > +	.video = &tc358746_video_ops,
> > > +	.pad = &tc358746_pad_ops,
> > > +};
> > > +
> > > +static const struct media_entity_operations tc358746_entity_ops = {
> > > +	.get_fwnode_pad = v4l2_subdev_get_fwnode_pad_1_to_1,
> > > +	.link_validate = v4l2_subdev_link_validate,
> > > +};
> > > +
> > > +static int tc358746_mclk_enable(struct clk_hw *hw)
> > > +{
> > > +	struct tc358746 *tc358746 = clk_hw_to_tc358746(hw);
> > > +	unsigned int div;
> > > +	u32 val;
> > > +	int err;
> > > +
> > > +	div = tc358746->mclk_postdiv / 2;
> > > +	val = MCLK_HIGH(div - 1) | MCLK_LOW(div - 1);
> > > +	dev_dbg(tc358746->sd.dev, "MCLKCTL: %u (0x%x)\n", val, val);
> > > +	err = tc358746_write(tc358746, MCLKCTL_REG, val);
> > > +	if (err)
> > > +		return err;
> > > +
> > > +	if (tc358746->mclk_prediv == 8)
> > > +		val = MCLKDIV(MCLKDIV_8);
> > > +	else if (tc358746->mclk_prediv == 4)
> > > +		val = MCLKDIV(MCLKDIV_4);
> > > +	else
> > > +		val = MCLKDIV(MCLKDIV_2);
> > > +
> > > +	dev_dbg(tc358746->sd.dev, "CLKCTL[MCLKDIV]: %u (0x%x)\n", val, val);
> > > +	return tc358746_update_bits(tc358746, CLKCTL_REG, MCLKDIV_MASK, val);
> > > +}
> > > +
> > > +static void tc358746_mclk_disable(struct clk_hw *hw)
> > > +{
> > > +	struct tc358746 *tc358746 = clk_hw_to_tc358746(hw);
> > > +
> > > +	tc358746_write(tc358746, MCLKCTL_REG, 0);
> > > +}
> > > +
> > > +static long
> > > +tc358746_find_mclk_settings(struct tc358746 *tc358746, unsigned long mclk_rate)
> > > +{
> > > +	unsigned long pll_rate = tc358746->pll_rate;
> > > +	const unsigned char prediv[] = { 2, 4, 8 };
> > > +	unsigned int mclk_prediv, mclk_postdiv;
> > > +	struct device *dev = tc358746->sd.dev;
> > > +	unsigned int postdiv, mclkdiv;
> > > +	unsigned long best_mclk_rate;
> > > +	unsigned int i;
> > > +
> > > +	/*
> > > +	 *                          MCLK-Div
> > > +	 *           -------------------´`---------------------
> > > +	 *          ´                                          `
> > > +	 *         +-------------+     +------------------------+
> > > +	 *         | MCLK-PreDiv |     |       MCLK-PostDiv     |
> > > +	 * PLL --> |   (2/4/8)   | --> | (mclk_low + mclk_high) | --> MCLK
> > > +	 *         +-------------+     +------------------------+
> > > +	 *
> > > +	 * The register value of mclk_low/high is mclk_low/high+1, i.e.:
> > > +	 *   mclk_low/high = 1   --> 2 MCLK-Ref Counts
> > > +	 *   mclk_low/high = 255 --> 256 MCLK-Ref Counts == max.
> > > +	 * If mclk_low and mclk_high are 0 then MCLK is disabled.
> > > +	 *
> > > +	 * Keep it simple and support 50/50 duty cycles only for now,
> > > +	 * so the calc will be:
> > > +	 *
> > > +	 *   MCLK = PLL / (MCLK-PreDiv * 2 * MCLK-PostDiv)
> > > +	 */
> > > +
> > > +	if (mclk_rate == tc358746->mclk_rate)
> > > +		return mclk_rate;
> > > +
> > > +	/* Highest possible rate */
> > > +	mclkdiv = pll_rate / mclk_rate;
> > > +	if (mclkdiv <= 8) {
> > > +		mclk_prediv = 2;
> > > +		mclk_postdiv = 4;
> > > +		best_mclk_rate = pll_rate / (2 * 4);
> > > +		goto out;
> > > +	}
> > > +
> > > +	/* First check the prediv */
> > > +	for (i = 0; i < ARRAY_SIZE(prediv); i++) {
> > > +		postdiv = mclkdiv / prediv[i];
> > > +
> > > +		if (postdiv % 2)
> > > +			continue;
> > > +
> > > +		if (postdiv >= 4 && postdiv <= 512) {
> > > +			mclk_prediv = prediv[i];
> > > +			mclk_postdiv = postdiv;
> > > +			best_mclk_rate = pll_rate / (prediv[i] * postdiv);
> > > +			goto out;
> > > +		}
> > > +	}
> > > +
> > > +	/* No suitable prediv found, so try to adjust the postdiv */
> > > +	for (postdiv = 4; postdiv <= 512; postdiv += 2) {
> > > +		unsigned int pre;
> > > +
> > > +		pre = mclkdiv / postdiv;
> > > +		if (pre == 2 || pre == 4 || pre == 8) {
> > > +			mclk_prediv = pre;
> > > +			mclk_postdiv = postdiv;
> > > +			best_mclk_rate = pll_rate / (pre * postdiv);
> > > +			goto out;
> > > +		}
> > > +	}
> > > +
> > > +	/* The MCLK <-> PLL gap is to high -> use largest possible div */
> > > +	mclk_prediv = 8;
> > > +	mclk_postdiv = 512;
> > > +	best_mclk_rate = pll_rate / (8 * 512);
> > > +
> > > +out:
> > > +	tc358746->mclk_prediv = mclk_prediv;
> > > +	tc358746->mclk_postdiv = mclk_postdiv;
> > > +	tc358746->mclk_rate = best_mclk_rate;
> > > +
> > > +	if (best_mclk_rate != mclk_rate)
> > > +		dev_warn(dev, "Request MCLK freq:%lu, found MCLK freq:%lu\n",
> > > +			 mclk_rate, best_mclk_rate);
> > > +
> > > +	dev_dbg(dev, "Found MCLK settings: freq:%lu prediv:%u postdiv:%u\n",
> > > +		best_mclk_rate, mclk_prediv, mclk_postdiv);
> > > +
> > > +	return best_mclk_rate;
> > > +}
> > > +
> > > +static unsigned long
> > > +tc358746_recalc_rate(struct clk_hw *hw, unsigned long parent_rate)
> > > +{
> > > +	struct tc358746 *tc358746 = clk_hw_to_tc358746(hw);
> > > +	unsigned int prediv, postdiv;
> > > +	u32 val;
> > > +	int err;
> > > +
> > > +	err = tc358746_read(tc358746, MCLKCTL_REG, &val);
> > > +	if (err)
> > > +		return 0;
> > > +
> > > +	postdiv = FIELD_GET(MCLK_LOW_MASK, val) + 1;
> > > +	postdiv += FIELD_GET(MCLK_HIGH_MASK, val) + 1;
> > > +
> > > +	err = tc358746_read(tc358746, CLKCTL_REG, &val);
> > > +	if (err)
> > > +		return 0;
> > > +
> > > +	prediv = FIELD_GET(MCLKDIV_MASK, val);
> > > +	if (prediv == MCLKDIV_8)
> > > +		prediv = 8;
> > > +	else if (prediv == MCLKDIV_4)
> > > +		prediv = 4;
> > > +	else
> > > +		prediv = 2;
> > > +
> > > +	return tc358746->pll_rate / (prediv * postdiv);
> > > +}
> > > +
> > > +static long tc358746_mclk_round_rate(struct clk_hw *hw, unsigned long rate,
> > > +				     unsigned long *parent_rate)
> > > +{
> > > +	struct tc358746 *tc358746 = clk_hw_to_tc358746(hw);
> > > +
> > > +	*parent_rate = tc358746->pll_rate;
> > > +
> > > +	return tc358746_find_mclk_settings(tc358746, rate);
> > > +}
> > > +
> > > +static int tc358746_mclk_set_rate(struct clk_hw *hw, unsigned long rate,
> > > +				  unsigned long parent_rate)
> > > +{
> > > +	struct tc358746 *tc358746 = clk_hw_to_tc358746(hw);
> > > +
> > > +	tc358746_find_mclk_settings(tc358746, rate);
> > > +
> > > +	return tc358746_mclk_enable(hw);
> > > +}
> > > +
> > > +static const struct clk_ops tc358746_mclk_ops = {
> > > +	.enable = tc358746_mclk_enable,
> > > +	.disable = tc358746_mclk_disable,
> > > +	.recalc_rate = tc358746_recalc_rate,
> > > +	.round_rate = tc358746_mclk_round_rate,
> > > +	.set_rate = tc358746_mclk_set_rate,
> > > +};
> > > +
> > > +static int tc358746_setup_mclk_provider(struct tc358746 *tc358746)
> > > +{
> > > +	struct clk_init_data mclk_initdata = { };
> > > +	struct device *dev = tc358746->sd.dev;
> > > +	const char *mclk_name;
> > > +	int err;
> > > +
> > > +	/* MCLK clk provider support is optional */
> > > +	if (!device_property_present(dev, "#clock-cells"))
> > > +		return 0;
> > > +
> > > +	/* Init to highest possibel MCLK */
> > > +	tc358746->mclk_postdiv = 512;
> > > +	tc358746->mclk_prediv = 8;
> > > +
> > > +	mclk_name = "tc358746-mclk";
> > > +	device_property_read_string(dev, "clock-output-names", &mclk_name);
> > > +
> > > +	mclk_initdata.name = mclk_name;
> > > +	mclk_initdata.ops = &tc358746_mclk_ops;
> > > +	tc358746->mclk_hw.init = &mclk_initdata;
> > > +
> > > +	err = devm_clk_hw_register(dev, &tc358746->mclk_hw);
> > > +	if (err) {
> > > +		dev_err(dev, "Failed to register mclk provider\n");
> > > +		return err;
> > > +	}
> > > +
> > > +	err = devm_of_clk_add_hw_provider(dev, of_clk_hw_simple_get,
> > > +					  &tc358746->mclk_hw);
> > > +	if (err)
> > > +		dev_err(dev, "Failed to add mclk provider\n");
> > > +
> > > +	return err;
> > > +}
> > > +
> > > +static int
> > > +tc358746_init_subdev(struct tc358746 *tc358746, struct i2c_client *client)
> > > +{
> > > +	struct v4l2_subdev *sd = &tc358746->sd;
> > > +	int err;
> > > +
> > > +	v4l2_i2c_subdev_init(sd, client, &tc358746_ops);
> > > +	sd->flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;
> > > +	sd->entity.function = MEDIA_ENT_F_VID_IF_BRIDGE;
> > > +	sd->entity.ops = &tc358746_entity_ops;
> > > +
> > > +	tc358746->pads[TC358746_SINK].flags = MEDIA_PAD_FL_SINK;
> > > +	tc358746->pads[TC358746_SOURCE].flags = MEDIA_PAD_FL_SOURCE;
> > > +	err = media_entity_pads_init(&sd->entity, TC358746_NR_PADS,
> > > +				     tc358746->pads);
> > > +	if (err)
> > > +		return err;
> > > +
> > > +	err = v4l2_subdev_init_finalize(sd);
> > > +	if (err)
> > > +		media_entity_cleanup(&sd->entity);
> > > +
> > > +	return err;
> > > +}
> > > +
> > > +static int
> > > +tc358746_init_output_port(struct tc358746 *tc358746, unsigned long refclk)
> > > +{
> > > +	struct device *dev = tc358746->sd.dev;
> > > +	struct v4l2_fwnode_endpoint *vep;
> > > +	unsigned long csi_link_rate;
> > > +	struct fwnode_handle *ep;
> > > +	unsigned char csi_lanes;
> > > +	int err;
> > > +
> > > +	ep = fwnode_graph_get_endpoint_by_id(dev_fwnode(dev), TC358746_SOURCE,
> > > +					     0, 0);
> > > +	if (!ep) {
> > > +		dev_err(dev, "Missing endpoint node\n");
> > > +		return -EINVAL;
> > > +	}
> > > +
> > > +	/* Currently we only support 'parallel in' -> 'csi out' */
> > > +	vep = &tc358746->csi_vep;
> > > +	vep->bus_type = V4L2_MBUS_CSI2_DPHY;
> > > +	err = v4l2_fwnode_endpoint_alloc_parse(ep, vep);
> > > +	fwnode_handle_put(ep);
> > > +	if (err) {
> > > +		dev_err(dev, "Failed to parse source endpoint\n");
> > > +		return err;
> > > +	}
> > > +
> > > +	csi_lanes = vep->bus.mipi_csi2.num_data_lanes;
> > > +	if (csi_lanes == 0 || csi_lanes > 4 ||
> > > +	    vep->nr_of_link_frequencies == 0) {
> > > +		dev_err(dev, "error: Invalid CSI-2 settings\n");
> > > +		err = -EINVAL;
> > > +		goto err;
> > > +	}
> > > +
> > > +	/* TODO: Add support to handle multiple link frequencies */
> > > +	csi_link_rate = (unsigned long)vep->link_frequencies[0];
> > > +	tc358746->pll_rate = tc358746_find_pll_settings(tc358746, refclk,
> > > +							csi_link_rate * 2);
> > > +	if (!tc358746->pll_rate) {
> > > +		err = -EINVAL;
> > > +		goto err;
> > > +	}
> > > +
> > > +	err = phy_mipi_dphy_get_default_config_for_hsclk(tc358746->pll_rate,
> > > +						csi_lanes, &tc358746->dphy_cfg);
> > > +	if (err)
> > > +		goto err;
> > > +
> > > +	tc358746->vb_size = TC358746_VB_DEFAULT_SIZE;
> > > +
> > > +	return 0;
> > > +
> > > +err:
> > > +	v4l2_fwnode_endpoint_free(vep);
> > > +
> > > +	return err;
> > > +}
> > > +
> > > +static int tc358746_init_hw(struct tc358746 *tc358746)
> > > +{
> > > +	struct device *dev = tc358746->sd.dev;
> > > +	unsigned int chipid;
> > > +	u32 val;
> > > +	int err;
> > > +
> > > +	err = pm_runtime_resume_and_get(dev);
> > > +	if (err < 0) {
> > > +		dev_err(dev, "Failed to resume the device\n");
> > > +		return err;
> > > +	}
> > > +
> > > +	 /* Ensure that CSI interface is put into LP-11 state */
> > > +	err = tc358746_sw_reset(tc358746);
> > > +	if (err) {
> > > +		pm_runtime_put_sync(dev);
> > > +		dev_err(dev, "Failed to reset the device\n");
> > > +		return err;
> > > +	}
> > > +
> > > +	err = tc358746_read(tc358746, CHIPID_REG, &val);
> > > +	pm_runtime_mark_last_busy(dev);
> > > +	pm_runtime_put_sync_autosuspend(dev);
> > > +	if (err)
> > > +		return -ENODEV;
> > > +
> > > +	chipid = FIELD_GET(CHIPID, val);
> > > +	if (chipid != 0x44) {
> > > +		dev_err(dev, "Invalid chipid 0x%02x\n", chipid);
> > > +		return -ENODEV;
> > > +	}
> > > +
> > > +	return 0;
> > > +}
> > > +
> > > +static int tc358746_init_controls(struct tc358746 *tc358746)
> > > +{
> > > +	u64 *link_frequencies = tc358746->csi_vep.link_frequencies;
> > > +	struct v4l2_ctrl *ctrl;
> > > +	int err;
> > > +
> > > +	err = v4l2_ctrl_handler_init(&tc358746->ctrl_hdl, 1);
> > > +	if (err)
> > > +		return err;
> > > +
> > > +	/*
> > > +	 * The driver currently supports only one link-frequency, regardless of
> > > +	 * the input from the firmware, see: tc358746_init_output_port(). So
> > > +	 * report only the first frequency from the array of possible given
> > > +	 * frequencies.
> > > +	 */
> > > +	ctrl = v4l2_ctrl_new_int_menu(&tc358746->ctrl_hdl, NULL,
> > > +				      V4L2_CID_LINK_FREQ, 0, 0,
> > > +				      link_frequencies);
> > > +	if (ctrl)
> > > +		ctrl->flags |= V4L2_CTRL_FLAG_READ_ONLY;
> > > +
> > > +	err = tc358746->ctrl_hdl.error;
> > > +	if (err) {
> > > +		v4l2_ctrl_handler_free(&tc358746->ctrl_hdl);
> > > +		return err;
> > > +	}
> > > +
> > > +	tc358746->sd.ctrl_handler = &tc358746->ctrl_hdl;
> > > +
> > > +	return 0;
> > > +}
> > > +
> > > +static int tc358746_notify_bound(struct v4l2_async_notifier *notifier,
> > > +				 struct v4l2_subdev *sd,
> > > +				 struct v4l2_async_subdev *asd)
> > > +{
> > > +	struct tc358746 *tc358746 =
> > > +		container_of(notifier, struct tc358746, notifier);
> > > +	u32 flags = MEDIA_LNK_FL_ENABLED | MEDIA_LNK_FL_IMMUTABLE;
> > > +	struct media_pad *sink = &tc358746->pads[TC358746_SINK];
> > > +
> > > +	return v4l2_create_fwnode_links_to_pad(sd, sink, flags);
> > > +}
> > > +
> > > +static const struct v4l2_async_notifier_operations tc358746_notify_ops = {
> > > +	.bound = tc358746_notify_bound,
> > > +};
> > > +
> > > +static int tc358746_async_register(struct tc358746 *tc358746)
> > > +{
> > > +	struct v4l2_fwnode_endpoint vep = {
> > > +		.bus_type = V4L2_MBUS_PARALLEL,
> > > +	};
> > > +	struct v4l2_async_subdev *asd;
> > > +	struct fwnode_handle *ep;
> > > +	int err;
> > > +
> > > +	ep = fwnode_graph_get_endpoint_by_id(dev_fwnode(tc358746->sd.dev),
> > > +					     TC358746_SINK, 0, 0);
> > > +	if (!ep)
> > > +		return -ENOTCONN;
> > > +
> > > +	err = v4l2_fwnode_endpoint_parse(ep, &vep);
> > > +	if (err) {
> > > +		fwnode_handle_put(ep);
> > > +		return err;
> > > +	}
> > > +
> > > +	v4l2_async_nf_init(&tc358746->notifier);
> > > +	asd = v4l2_async_nf_add_fwnode_remote(&tc358746->notifier, ep,
> > > +					      struct v4l2_async_subdev);
> > > +	fwnode_handle_put(ep);
> > > +
> > > +	if (IS_ERR(asd)) {
> > > +		err = PTR_ERR(asd);
> > > +		goto err_cleanup;
> > > +	}
> > > +
> > > +	tc358746->notifier.ops = &tc358746_notify_ops;
> > > +
> > > +	err = v4l2_async_subdev_nf_register(&tc358746->sd, &tc358746->notifier);
> > > +	if (err)
> > > +		goto err_cleanup;
> > > +
> > > +	tc358746->sd.fwnode = fwnode_graph_get_endpoint_by_id(
> > > +		dev_fwnode(tc358746->sd.dev), TC358746_SOURCE, 0, 0);
> > > +
> > > +	err = v4l2_async_register_subdev(&tc358746->sd);
> > > +	if (err)
> > > +		goto err_unregister;
> > > +
> > > +	return 0;
> > > +
> > > +err_unregister:
> > > +	fwnode_handle_put(tc358746->sd.fwnode);
> > > +	v4l2_async_nf_unregister(&tc358746->notifier);
> > > +err_cleanup:
> > > +	v4l2_async_nf_cleanup(&tc358746->notifier);
> > > +
> > > +	return err;
> > > +}
> > > +
> > > +static int tc358746_probe(struct i2c_client *client)
> > > +{
> > > +	struct device *dev = &client->dev;
> > > +	struct tc358746 *tc358746;
> > > +	unsigned long refclk;
> > > +	unsigned int i;
> > > +	int err;
> > > +
> > > +	tc358746 = devm_kzalloc(&client->dev, sizeof(*tc358746), GFP_KERNEL);
> > > +	if (!tc358746)
> > > +		return -ENOMEM;
> > > +
> > > +	tc358746->regmap = devm_regmap_init_i2c(client, &tc358746_regmap_config);
> > > +	if (IS_ERR(tc358746->regmap))
> > > +		return dev_err_probe(dev, PTR_ERR(tc358746->regmap),
> > > +				     "Failed to init regmap\n");
> > > +
> > > +	tc358746->refclk = devm_clk_get(dev, "refclk");
> > > +	if (IS_ERR(tc358746->refclk))
> > > +		return dev_err_probe(dev, PTR_ERR(tc358746->refclk),
> > > +				     "Failed to get refclk\n");
> > > +
> > > +	err = clk_prepare_enable(tc358746->refclk);
> > > +	if (err)
> > > +		return dev_err_probe(dev, err,
> > > +				     "Failed to enable refclk\n");
> > > +
> > > +	refclk = clk_get_rate(tc358746->refclk);
> > > +	clk_disable_unprepare(tc358746->refclk);
> > > +
> > > +	if (refclk < 6 * HZ_PER_MHZ || refclk > 40 * HZ_PER_MHZ)
> > > +		return dev_err_probe(dev, -EINVAL, "Invalid refclk range\n");
> > > +
> > > +	for (i = 0; i < ARRAY_SIZE(tc358746_supplies); i++)
> > > +		tc358746->supplies[i].supply = tc358746_supplies[i];
> > > +
> > > +	err = devm_regulator_bulk_get(dev, ARRAY_SIZE(tc358746_supplies),
> > > +				      tc358746->supplies);
> > > +	if (err)
> > > +		return dev_err_probe(dev, err, "Failed to get supplies\n");
> > > +
> > > +	tc358746->reset_gpio = devm_gpiod_get_optional(dev, "reset",
> > > +						       GPIOD_OUT_HIGH);
> > > +	if (IS_ERR(tc358746->reset_gpio))
> > > +		return dev_err_probe(dev, PTR_ERR(tc358746->reset_gpio),
> > > +				     "Failed to get reset-gpios\n");
> > > +
> > > +	err = tc358746_init_subdev(tc358746, client);
> > > +	if (err)
> > > +		return dev_err_probe(dev, err, "Failed to init subdev\n");
> > > +
> > > +	err = tc358746_init_output_port(tc358746, refclk);
> > > +	if (err)
> > > +		goto err_subdev;
> > > +
> > > +	/*
> > > +	 * Keep this order since we need the output port link-frequencies
> > > +	 * information.
> > > +	 */
> > > +	err = tc358746_init_controls(tc358746);
> > > +	if (err)
> > > +		goto err_fwnode;
> > > +
> > > +	dev_set_drvdata(dev, tc358746);
> > > +
> > > +	/* Set to 1sec to give the stream reconfiguration enough time */
> > > +	pm_runtime_set_autosuspend_delay(dev, 1000);
> > > +	pm_runtime_use_autosuspend(dev);
> > > +	pm_runtime_enable(dev);
> > > +
> > > +	err = tc358746_init_hw(tc358746);
> > > +	if (err)
> > > +		goto err_pm;
> > > +
> > > +	err = tc358746_setup_mclk_provider(tc358746);
> > > +	if (err)
> > > +		goto err_pm;
> > > +
> > > +	err = tc358746_async_register(tc358746);
> > > +	if (err < 0)
> > > +		goto err_pm;
> > > +
> > > +	dev_dbg(dev, "%s found @ 0x%x (%s)\n", client->name,
> > > +		client->addr, client->adapter->name);
> > > +
> > > +	return 0;
> > > +
> > > +err_pm:
> > > +	pm_runtime_disable(dev);
> > > +	pm_runtime_set_suspended(dev);
> > > +	pm_runtime_dont_use_autosuspend(dev);
> > > +	v4l2_ctrl_handler_free(&tc358746->ctrl_hdl);
> > > +err_fwnode:
> > > +	v4l2_fwnode_endpoint_free(&tc358746->csi_vep);
> > > +err_subdev:
> > > +	v4l2_subdev_cleanup(&tc358746->sd);
> > > +	media_entity_cleanup(&tc358746->sd.entity);
> > > +
> > > +	return err;
> > > +}
> > > +
> > > +static int tc358746_remove(struct i2c_client *client)
> > > +{
> > > +	struct v4l2_subdev *sd = i2c_get_clientdata(client);
> > > +	struct tc358746 *tc358746 = to_tc358746(sd);
> > > +
> > > +	v4l2_subdev_cleanup(sd);
> > > +	v4l2_ctrl_handler_free(&tc358746->ctrl_hdl);
> > > +	v4l2_fwnode_endpoint_free(&tc358746->csi_vep);
> > > +	v4l2_async_nf_unregister(&tc358746->notifier);
> > > +	v4l2_async_nf_cleanup(&tc358746->notifier);
> > > +	fwnode_handle_put(sd->fwnode);
> > > +	v4l2_async_unregister_subdev(sd);
> > > +	media_entity_cleanup(&sd->entity);
> > > +
> > > +	pm_runtime_disable(sd->dev);
> > > +	pm_runtime_set_suspended(sd->dev);
> > > +	pm_runtime_dont_use_autosuspend(sd->dev);
> > > +
> > > +	return 0;
> > > +}
> > > +
> > > +static int tc358746_suspend(struct device *dev)
> > > +{
> > > +	struct tc358746 *tc358746 = dev_get_drvdata(dev);
> > > +	int err;
> > > +
> > > +	clk_disable_unprepare(tc358746->refclk);
> > > +
> > > +	err = regulator_bulk_disable(ARRAY_SIZE(tc358746_supplies),
> > > +				     tc358746->supplies);
> > > +	if (err)
> > > +		clk_prepare_enable(tc358746->refclk);
> > > +
> > > +	return err;
> > > +}
> > > +
> > > +static int tc358746_resume(struct device *dev)
> > > +{
> > > +	struct tc358746 *tc358746 = dev_get_drvdata(dev);
> > > +	int err;
> > > +
> > > +	gpiod_set_value(tc358746->reset_gpio, 1);
> > > +
> > > +	err = regulator_bulk_enable(ARRAY_SIZE(tc358746_supplies),
> > > +				    tc358746->supplies);
> > > +	if (err)
> > > +		return err;
> > > +
> > > +	/* min. 200ns */
> > > +	usleep_range(10, 20);
> > > +
> > > +	gpiod_set_value(tc358746->reset_gpio, 0);
> > > +
> > > +	err = clk_prepare_enable(tc358746->refclk);
> > > +	if (err)
> > > +		goto err;
> > > +
> > > +	/* min. 700us ... 1ms */
> > > +	usleep_range(1000, 1500);
> > > +
> > > +	/*
> > > +	 * Enable the PLL here since it can be called by the clk-framework or by
> > > +	 * the .s_stream() callback. So this is the common place for both.
> > > +	 */
> > > +	err = tc358746_apply_pll_config(tc358746);
> > > +	if (err)
> > > +		goto err_clk;
> > > +
> > > +	return 0;
> > > +
> > > +err_clk:
> > > +	clk_disable_unprepare(tc358746->refclk);
> > > +err:
> > > +	regulator_bulk_disable(ARRAY_SIZE(tc358746_supplies),
> > > +			       tc358746->supplies);
> > > +	return err;
> > > +}
> > > +
> > > +DEFINE_RUNTIME_DEV_PM_OPS(tc358746_pm_ops, tc358746_suspend,
> > > +			  tc358746_resume, NULL);
> > > +
> > > +static const struct of_device_id __maybe_unused tc358746_of_match[] = {
> > > +	{ .compatible = "toshiba,tc358746" },
> > > +	{ },
> > > +};
> > > +MODULE_DEVICE_TABLE(of, tc358746_of_match);
> > > +
> > > +static struct i2c_driver tc358746_driver = {
> > > +	.driver = {
> > > +		.name = "tc358746",
> > > +		.pm = pm_ptr(&tc358746_pm_ops),
> > > +		.of_match_table = tc358746_of_match,
> > > +	},
> > > +	.probe_new = tc358746_probe,
> > > +	.remove = tc358746_remove,
> > > +};
> > > +
> > > +module_i2c_driver(tc358746_driver);
> > > +
> > > +MODULE_DESCRIPTION("Toshiba TC358746 Parallel to CSI-2 bridge driver");
> > > +MODULE_AUTHOR("Marco Felsch <kernel@pengutronix.de>");
> > > +MODULE_LICENSE("GPL");

-- 
Regards,

Laurent Pinchart

Re: [PATCH v3 4/4] media: tc358746: add Toshiba TC358746 Parallel to CSI-2 bridge driver

[Laurent Pinchart]

Hi Marco,

On Fri, Sep 23, 2022 at 11:27:26AM +0200, Marco Felsch wrote:
> On 22-09-22, Laurent Pinchart wrote:
> > On Thu, Sep 22, 2022 at 03:48:43PM +0200, Marco Felsch wrote:
> > > Adding support for the TC358746 parallel <-> MIPI CSI bridge. This chip
> > > supports two operating modes:
> > >   1st) parallel-in -> mipi-csi out
> > >   2nd) mipi-csi in -> parallel out
> > > 
> > > This patch only adds the support for the 1st mode.
> > > 
> > > Signed-off-by: Marco Felsch <m.felsch@pengutronix.de>
> > > ---
> > > Changelog:
> > > 
> > > v3:
> > > - added missing static
> > > - drop s/MHZ/HZ_PER_MHZ/
> > > - kconfig: add "depends on PM"
> > > - Add tc358746_valid_reg() for regmap.
> > > - tc358746_set_fmt: fix format negotiation for pad == SOURCE
> > > - tc358746_write/read: add error messages
> > > - replace udelay with fsleep()
> > > - tc358746_apply_misc_config: const mbusfmt
> > > - tc358746_s_stream: fix comment about LP-00/11 state change
> > > - tc358746_link_validate: s/sensor/source/
> > > - tc358746_link_validate: s/pclk_rate/link_freq/
> > > - tc358746_link_validate: fix v4l2_subdev_unlock_state()
> > > - tc358746_link_validate: adapt fifo-sz comment
> > > - tc358746_g/s_register: use pm_runtime_get_if_in_use
> > > - tc358746_setup_mclk_provider: move to clk related location
> > > - tc358746_init_hw: fix error case
> > > - tc358746_init_controls: add comment
> > > - tc358746_notify_bound: add MEDIA_LNK_FL_IMMUTABLE
> > > - tc358746_async_register: fix error path
> > > - tc358746_async_register: put sd.fwnode on error and remove
> > > - tc358746_probe: increase autosuspend to 1s
> > > 
> > > v2:
> > > - use the correct CID_LINK_FREQ control to query the sensor_pclk_rate
> > > - remove now not needed tc358746_link_setup() and
> > >   struct v4l2_ctrl sensor_pclk_ctrl
> > > - call v4l2_subdev_link_validate_default() during link validation
> > > - remove MEDIA_BUS_FMT_GBR888_1X24/YUV444 format support
> > > - use subdev active_state API
> > > - replace own .get_fmt with v4l2_subdev_get_fmt
> > > - remove unnecessary pad checks
> > > - restructure tc358746_get_format_by_code() if-case
> > > - move apply_dphy_config|apply_misc_config from resume intos s_stream
> > > - use goto in s_stream enable case
> > > - fix error handling in suspend/resume
> > > - split probe() into more sub-functions
> > > ---
> > >  drivers/media/i2c/Kconfig    |   17 +
> > >  drivers/media/i2c/Makefile   |    1 +
> > >  drivers/media/i2c/tc358746.c | 1692 ++++++++++++++++++++++++++++++++++
> > >  3 files changed, 1710 insertions(+)
> > >  create mode 100644 drivers/media/i2c/tc358746.c
> > > 
> > > diff --git a/drivers/media/i2c/Kconfig b/drivers/media/i2c/Kconfig
> > > index 7806d4b81716..f85cdb94c524 100644
> > > --- a/drivers/media/i2c/Kconfig
> > > +++ b/drivers/media/i2c/Kconfig
> > > @@ -1272,6 +1272,23 @@ config VIDEO_TC358743_CEC
> > >  	  When selected the tc358743 will support the optional
> > >  	  HDMI CEC feature.
> > >  
> > > +config VIDEO_TC358746
> > > +	tristate "Toshiba TC358746 parallel-CSI2 bridge"
> > > +	depends on VIDEO_DEV && PM && I2C
> > > +	select VIDEO_V4L2_SUBDEV_API
> > > +	select MEDIA_CONTROLLER
> > > +	select V4L2_FWNODE
> > > +	select GENERIC_PHY_MIPI_DPHY
> > > +	select REGMAP_I2C
> > > +	select COMMON_CLK
> > > +	help
> > > +	  Support for the Toshiba TC358746 parallel to MIPI CSI-2 bridge.
> > > +	  The bridge can work in both directions but currently only the
> > > +	  parallel-in / csi-out path is supported.
> > > +
> > > +	  To compile this driver as a module, choose M here: the
> > > +	  module will be called tc358746.
> > > +
> > >  config VIDEO_TVP514X
> > >  	tristate "Texas Instruments TVP514x video decoder"
> > >  	depends on VIDEO_DEV && I2C
> > > diff --git a/drivers/media/i2c/Makefile b/drivers/media/i2c/Makefile
> > > index 0a2933103dd9..d1096c2ab480 100644
> > > --- a/drivers/media/i2c/Makefile
> > > +++ b/drivers/media/i2c/Makefile
> > > @@ -118,6 +118,7 @@ obj-$(CONFIG_VIDEO_SONY_BTF_MPX) += sony-btf-mpx.o
> > >  obj-$(CONFIG_VIDEO_SR030PC30) += sr030pc30.o
> > >  obj-$(CONFIG_VIDEO_ST_MIPID02) += st-mipid02.o
> > >  obj-$(CONFIG_VIDEO_TC358743) += tc358743.o
> > > +obj-$(CONFIG_VIDEO_TC358746) += tc358746.o
> > >  obj-$(CONFIG_VIDEO_TDA1997X) += tda1997x.o
> > >  obj-$(CONFIG_VIDEO_TDA7432) += tda7432.o
> > >  obj-$(CONFIG_VIDEO_TDA9840) += tda9840.o
> > > diff --git a/drivers/media/i2c/tc358746.c b/drivers/media/i2c/tc358746.c
> > > new file mode 100644
> > > index 000000000000..0dcd5e0e0855
> > > --- /dev/null
> > > +++ b/drivers/media/i2c/tc358746.c
> > > @@ -0,0 +1,1692 @@
> > > +// SPDX-License-Identifier: GPL-2.0-only
> > > +/*
> > > + * TC358746 - Parallel <-> CSI-2 Bridge
> > > + *
> > > + * Copyright 2022 Marco Felsch <kernel@pengutronix.de>
> > > + *
> > > + * Notes:
> > > + *  - Currently only 'Parallel-in -> CSI-out' mode is supported!
> > > + */
> > > +
> > > +#include <linux/bitfield.h>
> > > +#include <linux/clk.h>
> > > +#include <linux/clk-provider.h>
> > > +#include <linux/delay.h>
> > > +#include <linux/i2c.h>
> > > +#include <linux/interrupt.h>
> > > +#include <linux/kernel.h>
> > > +#include <linux/module.h>
> > > +#include <linux/phy/phy-mipi-dphy.h>
> > > +#include <linux/property.h>
> > > +#include <linux/pm_runtime.h>
> > > +#include <linux/regmap.h>
> > > +#include <linux/units.h>
> > > +#include <media/v4l2-ctrls.h>
> > > +#include <media/v4l2-device.h>
> > > +#include <media/v4l2-fwnode.h>
> > > +#include <media/v4l2-mc.h>
> > > +
> > > +/* 16-bit registers */
> > > +#define CHIPID_REG			0x0000
> > > +#define		CHIPID			GENMASK(15, 8)
> > > +
> > > +#define SYSCTL_REG			0x0002
> > > +#define		SRESET			BIT(0)
> > > +
> > > +#define CONFCTL_REG			0x0004
> > > +#define		PDATAF_MASK		GENMASK(9, 8)
> > > +#define		PDATAF_MODE0		0
> > > +#define		PDATAF_MODE1		1
> > > +#define		PDATAF_MODE2		2
> > > +#define		PDATAF(val)		FIELD_PREP(PDATAF_MASK, (val))
> > > +#define		PPEN			BIT(6)
> > > +#define		DATALANE_MASK		GENMASK(1, 0)
> > > +
> > > +#define FIFOCTL_REG			0x0006
> > > +#define DATAFMT_REG			0x0008
> > > +#define		PDFMT(val)		FIELD_PREP(GENMASK(7, 4), (val))
> > > +
> > > +#define MCLKCTL_REG			0x000c
> > > +#define		MCLK_HIGH_MASK		GENMASK(15, 8)
> > > +#define		MCLK_LOW_MASK		GENMASK(7, 0)
> > > +#define		MCLK_HIGH(val)		FIELD_PREP(MCLK_HIGH_MASK, (val))
> > > +#define		MCLK_LOW(val)		FIELD_PREP(MCLK_LOW_MASK, (val))
> > > +
> > > +#define PLLCTL0_REG			0x0016
> > > +#define		PLL_PRD_MASK		GENMASK(15, 12)
> > > +#define		PLL_PRD(val)		FIELD_PREP(PLL_PRD_MASK, (val))
> > > +#define		PLL_FBD_MASK		GENMASK(8, 0)
> > > +#define		PLL_FBD(val)		FIELD_PREP(PLL_FBD_MASK, (val))
> > > +
> > > +#define PLLCTL1_REG			0x0018
> > > +#define		PLL_FRS_MASK		GENMASK(11, 10)
> > > +#define		PLL_FRS(val)		FIELD_PREP(PLL_FRS_MASK, (val))
> > > +#define		CKEN			BIT(4)
> > > +#define		RESETB			BIT(1)
> > > +#define		PLL_EN			BIT(0)
> > > +
> > > +#define CLKCTL_REG			0x0020
> > > +#define		MCLKDIV_MASK		GENMASK(3, 2)
> > > +#define		MCLKDIV(val)		FIELD_PREP(MCLKDIV_MASK, (val))
> > > +#define		MCLKDIV_8		0
> > > +#define		MCLKDIV_4		1
> > > +#define		MCLKDIV_2		2
> > > +
> > > +#define WORDCNT_REG			0x0022
> > > +#define PP_MISC_REG			0x0032
> > > +#define		FRMSTOP			BIT(15)
> > > +#define		RSTPTR			BIT(14)
> > > +
> > > +/* 32-bit registers */
> > > +#define CLW_DPHYCONTTX_REG		0x0100
> > > +#define CLW_CNTRL_REG			0x0140
> > > +#define D0W_CNTRL_REG			0x0144
> > > +#define		LANEDISABLE		BIT(0)
> > > +
> > > +#define STARTCNTRL_REG			0x0204
> > > +#define		START			BIT(0)
> > > +
> > > +#define LINEINITCNT_REG			0x0210
> > > +#define LPTXTIMECNT_REG			0x0214
> > > +#define TCLK_HEADERCNT_REG		0x0218
> > > +#define		TCLK_ZEROCNT(val)	FIELD_PREP(GENMASK(15, 8), (val))
> > > +#define		TCLK_PREPARECNT(val)	FIELD_PREP(GENMASK(6, 0), (val))
> > > +
> > > +#define TCLK_TRAILCNT_REG		0x021C
> > > +#define THS_HEADERCNT_REG		0x0220
> > > +#define		THS_ZEROCNT(val)	FIELD_PREP(GENMASK(14, 8), (val))
> > > +#define		THS_PREPARECNT(val)	FIELD_PREP(GENMASK(6, 0), (val))
> > > +
> > > +#define TWAKEUP_REG			0x0224
> > > +#define TCLK_POSTCNT_REG		0x0228
> > > +#define THS_TRAILCNT_REG		0x022C
> > > +#define HSTXVREGEN_REG			0x0234
> > > +#define TXOPTIONCNTRL_REG		0x0238
> > > +#define CSI_CONTROL_REG			0x040C
> > > +#define		CSI_MODE		BIT(15)
> > > +#define		TXHSMD			BIT(7)
> > > +#define		NOL(val)		FIELD_PREP(GENMASK(2, 1), (val))
> > > +
> > > +#define CSI_CONFW_REG			0x0500
> > > +#define		MODE(val)		FIELD_PREP(GENMASK(31, 29), (val))
> > > +#define		MODE_SET		0x5
> > > +#define		ADDRESS(val)		FIELD_PREP(GENMASK(28, 24), (val))
> > > +#define		CSI_CONTROL_ADDRESS	0x3
> > > +#define		DATA(val)		FIELD_PREP(GENMASK(15, 0), (val))
> > > +
> > > +#define CSI_START_REG			0x0518
> > > +#define		STRT			BIT(0)
> > > +
> > > +static const struct v4l2_mbus_framefmt tc358746_def_fmt = {
> > > +	.width		= 640,
> > > +	.height		= 480,
> > > +	.code		= MEDIA_BUS_FMT_UYVY8_2X8,
> > > +	.field		= V4L2_FIELD_NONE,
> > > +	.colorspace	= V4L2_COLORSPACE_DEFAULT,
> > > +	.ycbcr_enc	= V4L2_YCBCR_ENC_DEFAULT,
> > > +	.quantization	= V4L2_QUANTIZATION_DEFAULT,
> > > +	.xfer_func	= V4L2_XFER_FUNC_DEFAULT,
> > > +};
> > > +
> > > +static const char * const tc358746_supplies[] = {
> > > +	"vddc", "vddio", "vddmipi"
> > > +};
> > > +
> > > +enum {
> > > +	TC358746_SINK,
> > > +	TC358746_SOURCE,
> > > +	TC358746_NR_PADS
> > > +};
> > > +
> > > +struct tc358746 {
> > > +	struct v4l2_subdev		sd;
> > > +	struct media_pad		pads[TC358746_NR_PADS];
> > > +	struct v4l2_async_notifier	notifier;
> > > +	struct v4l2_fwnode_endpoint	csi_vep;
> > > +
> > > +	struct v4l2_ctrl_handler	ctrl_hdl;
> > > +
> > > +	struct regmap			*regmap;
> > > +	struct clk			*refclk;
> > > +	struct gpio_desc		*reset_gpio;
> > > +	struct regulator_bulk_data	supplies[ARRAY_SIZE(tc358746_supplies)];
> > > +
> > > +	struct clk_hw			mclk_hw;
> > > +	unsigned long			mclk_rate;
> > > +	u8				mclk_prediv;
> > > +	u16				mclk_postdiv;
> > > +
> > > +	unsigned long			pll_rate;
> > > +	u8				pll_post_div;
> > > +	u16				pll_pre_div;
> > > +	u16				pll_mul;
> > > +
> > > +#define TC358746_VB_MAX_SIZE		(511 * 32)
> > > +#define TC358746_VB_DEFAULT_SIZE	  (1 * 32)
> > > +	unsigned int			vb_size; /* Video buffer size in bits */
> > > +
> > > +	struct phy_configure_opts_mipi_dphy dphy_cfg;
> > > +};
> > > +
> > > +static inline struct tc358746 *to_tc358746(struct v4l2_subdev *sd)
> > > +{
> > > +	return container_of(sd, struct tc358746, sd);
> > > +}
> > > +
> > > +static inline struct tc358746 *clk_hw_to_tc358746(struct clk_hw *hw)
> > > +{
> > > +	return container_of(hw, struct tc358746, mclk_hw);
> > > +}
> > > +
> > > +struct tc358746_format {
> > > +	u32		code;
> > > +	bool		csi_format;
> > > +	unsigned char	bus_width;
> > > +	unsigned char	bpp;
> > > +	/* Register values */
> > > +	u8		pdformat; /* Peripheral Data Format */
> > > +	u8		pdataf;   /* Parallel Data Format Option */
> > > +};
> > > +
> > > +enum {
> > > +	PDFORMAT_RAW8 = 0,
> > > +	PDFORMAT_RAW10,
> > > +	PDFORMAT_RAW12,
> > > +	PDFORMAT_RGB888,
> > > +	PDFORMAT_RGB666,
> > > +	PDFORMAT_RGB565,
> > > +	PDFORMAT_YUV422_8BIT,
> > > +	/* RESERVED = 7 */
> > > +	PDFORMAT_RAW14 = 8,
> > > +	PDFORMAT_YUV422_10BIT,
> > > +	PDFORMAT_YUV444,
> > > +};
> > > +
> > > +/* Check tc358746_src_mbus_code() if you add new formats */
> > > +static const struct tc358746_format tc358746_formats[] = {
> > > +	{
> > > +		.code = MEDIA_BUS_FMT_UYVY8_2X8,
> > > +		.bus_width = 8,
> > > +		.bpp = 16,
> > > +		.pdformat = PDFORMAT_YUV422_8BIT,
> > > +		.pdataf = PDATAF_MODE0,
> > > +	}, {
> > > +		.code = MEDIA_BUS_FMT_UYVY8_1X16,
> > > +		.csi_format = true,
> > > +		.bus_width = 16,
> > > +		.bpp = 16,
> > > +		.pdformat = PDFORMAT_YUV422_8BIT,
> > > +		.pdataf = PDATAF_MODE1,
> > > +	}, {
> > > +		.code = MEDIA_BUS_FMT_YUYV8_1X16,
> > > +		.csi_format = true,
> > > +		.bus_width = 16,
> > > +		.bpp = 16,
> > > +		.pdformat = PDFORMAT_YUV422_8BIT,
> > > +		.pdataf = PDATAF_MODE2,
> > > +	}, {
> > > +		.code = MEDIA_BUS_FMT_UYVY10_2X10,
> > > +		.bus_width = 10,
> > > +		.bpp = 20,
> > > +		.pdformat = PDFORMAT_YUV422_10BIT,
> > > +		.pdataf = PDATAF_MODE0, /* don't care */
> > > +	}
> > > +};
> > > +
> > > +/* Get n-th format for pad */
> > > +static const struct tc358746_format *
> > > +tc358746_get_format_by_idx(unsigned int pad, unsigned int index)
> > > +{
> > > +	unsigned int idx = 0;
> > > +	unsigned int i;
> > > +
> > > +	for (i = 0; i < ARRAY_SIZE(tc358746_formats); i++) {
> > > +		const struct tc358746_format *fmt = &tc358746_formats[i];
> > > +
> > > +		if ((pad == TC358746_SOURCE && fmt->csi_format) ||
> > > +		    (pad == TC358746_SINK)) {
> > > +			if (idx == index)
> > > +				return fmt;
> > > +			idx++;
> > > +		}
> > > +	}
> > > +
> > > +	return ERR_PTR(-EINVAL);
> > > +}
> > > +
> > > +static const struct tc358746_format *
> > > +tc358746_get_format_by_code(unsigned int pad, u32 code)
> > > +{
> > > +	unsigned int i;
> > > +
> > > +	for (i = 0; i < ARRAY_SIZE(tc358746_formats); i++) {
> > > +		const struct tc358746_format *fmt = &tc358746_formats[i];
> > > +
> > > +		if (pad == TC358746_SINK && fmt->code == code)
> > > +			return fmt;
> > > +
> > > +		if (pad == TC358746_SOURCE && !fmt->csi_format)
> > > +			continue;
> > > +
> > > +		if (fmt->code == code)
> > > +			return fmt;
> > > +	}
> > > +
> > > +	return ERR_PTR(-EINVAL);
> > > +}
> > > +
> > > +static u32 tc358746_src_mbus_code(u32 code)
> > > +{
> > > +	switch (code) {
> > > +	case MEDIA_BUS_FMT_UYVY8_2X8:
> > > +		return MEDIA_BUS_FMT_UYVY8_1X16;
> > > +	case MEDIA_BUS_FMT_UYVY10_2X10:
> > > +		return MEDIA_BUS_FMT_UYVY10_1X20;
> > > +	default:
> > > +		return code;
> > > +	}
> > > +}
> > > +
> > > +static bool tc358746_valid_reg(struct device *dev, unsigned int reg)
> > > +{
> > > +	switch (reg) {
> > > +	case CHIPID_REG ... CSI_START_REG:
> > > +		return true;
> > > +	default:
> > > +		return false;
> > > +	}
> > > +}
> > > +
> > > +static const struct regmap_config tc358746_regmap_config = {
> > > +	.name = "tc358746",
> > > +	.reg_bits = 16,
> > > +	.val_bits = 16,
> > > +	.max_register = CSI_START_REG,
> > > +	.writeable_reg = tc358746_valid_reg,
> > > +	.readable_reg = tc358746_valid_reg,
> > > +	.reg_format_endian = REGMAP_ENDIAN_BIG,
> > > +	.val_format_endian = REGMAP_ENDIAN_BIG,
> > > +};
> > > +
> > > +static int tc358746_write(struct tc358746 *tc358746, u32 reg, u32 val)
> > > +{
> > > +	size_t count;
> > > +	int err;
> > > +
> > > +	/* 32-bit registers starting from CLW_DPHYCONTTX */
> > > +	count = reg < CLW_DPHYCONTTX_REG ? 1 : 2;
> > > +
> > > +	err = regmap_bulk_write(tc358746->regmap, reg, &val, count);
> > > +	if (err)
> > > +		dev_dbg(tc358746->sd.dev,
> > > +			"Failed to write reg:0x%04x val:0x%04x\n", reg, val);
> > 
> > I'm not sure if the value is relevant here, but I'd add the error, it's
> > useful to know what kind of I2C issue occurred. Same for read().
> 
> Yeah.. I'm not sure, since you told me to not flood the kernel log. If
> someone recognised error while probing or streaming the debug will be
> turned on anyways. However, I will make it a dev_err() since this
> shouldnt appear normally, you're right.

Sorry, I meant printing the value of the error code in the message, the
err variable. dev_err() is probably good too actually, as this isn't
meant to happen.

> > By the way, this isn't something you need to do in this driver, but I've
> > found the following pattern to be useful for error handling:
> > 
> > static int tc358746_write(struct tc358746 *tc358746, u32 reg, u32 val, int *err)
> > {
> > 	size_t count;
> > 	int ret;
> > 
> > 	if (err && *err)
> > 		return *err;
> > 
> > 	/* 32-bit registers starting from CLW_DPHYCONTTX */
> > 	count = reg < CLW_DPHYCONTTX_REG ? 1 : 2;
> > 
> > 	ret = regmap_bulk_write(tc358746->regmap, reg, &val, count);
> > 	if (ret)
> > 		dev_dbg(tc358746->sd.dev,
> > 			"Failed to write reg 0x%04x: %d\n", reg, ret);
> > 		if (err)
> > 			*err = ret;
> > 		return ret;
> > 	}
> > 
> > 	return 0;
> > }
> > 
> > With this, you could simplify functions such as
> > tc358746_apply_dphy_config(), by initializing the local err variable to
> > 0, calling 
> > 
> > 	tc358746_write(tc358746, ..., ..., &err);
> > 
> > without checking for errors, and just returning err at the end of the
> > function. With the same pattern enabled in tc358746_update_bits() you
> > could simplify other functions too.
> 
> Good pattern, will keep it in mind. Albeit the little magic can cause
> confusion while reading e.g. tc358746_apply_dphy_config().

Yes it could. It's really up to you whether you want to use it here,
elsewhere or nowhere :-) I mentioned it because I've found it very
useful in multiple drivers. Maybe regmap should even have a similar API.

> > > +
> > > +	return err;
> > > +}
> > > +
> > > +static int tc358746_read(struct tc358746 *tc358746, u32 reg, u32 *val)
> > > +{
> > > +	size_t count;
> > > +	int err;
> > > +
> > > +	/* 32-bit registers starting from CLW_DPHYCONTTX */
> > > +	count = reg < CLW_DPHYCONTTX_REG ? 1 : 2;
> > > +	*val = 0;
> > > +
> > > +	err = regmap_bulk_read(tc358746->regmap, reg, val, count);
> > > +	if (err)
> > > +		dev_dbg(tc358746->sd.dev, "Failed to read reg:0x%04x\n", reg);
> > > +
> > > +	return err;
> > > +}
> > > +
> > > +static int
> > > +tc358746_update_bits(struct tc358746 *tc358746, u32 reg, u32 mask, u32 val)
> > > +{
> > > +	u32 tmp, orig;
> > > +	int err;
> > > +
> > > +	err = tc358746_read(tc358746, reg, &orig);
> > > +	if (err)
> > > +		return err;
> > > +
> > > +	tmp = orig & ~mask;
> > > +	tmp |= val & mask;
> > > +
> > > +	return tc358746_write(tc358746, reg, tmp);
> > > +}
> > > +
> > > +static int tc358746_set_bits(struct tc358746 *tc358746, u32 reg, u32 bits)
> > > +{
> > > +	return tc358746_update_bits(tc358746, reg, bits, bits);
> > > +}
> > > +
> > > +static int tc358746_clear_bits(struct tc358746 *tc358746, u32 reg, u32 bits)
> > > +{
> > > +	return tc358746_update_bits(tc358746, reg, bits, 0);
> > > +}
> > > +
> > > +static int tc358746_sw_reset(struct tc358746 *tc358746)
> > > +{
> > > +	int err;
> > > +
> > > +	err = tc358746_set_bits(tc358746, SYSCTL_REG, SRESET);
> > > +	if (err)
> > > +		return err;
> > > +
> > > +	fsleep(10);
> > > +
> > > +	return tc358746_clear_bits(tc358746, SYSCTL_REG, SRESET);
> > > +}
> > > +
> > > +static int
> > > +tc358746_apply_pll_config(struct tc358746 *tc358746)
> > > +{
> > > +	u8 post = tc358746->pll_post_div;
> > > +	u16 pre = tc358746->pll_pre_div;
> > > +	u16 mul = tc358746->pll_mul;
> > > +	u32 val, mask;
> > > +	int err;
> > > +
> > > +	err = tc358746_read(tc358746, PLLCTL1_REG, &val);
> > > +	if (err)
> > > +		return err;
> > > +
> > > +	/* Don't touch the PLL if running */
> > > +	if (FIELD_GET(PLL_EN, val) == 1)
> > > +		return 0;
> > > +
> > > +	/* Pre-div and Multiplicator have a internal +1 logic */
> > > +	val = PLL_PRD(pre - 1) | PLL_FBD(mul - 1);
> > > +	mask = PLL_PRD_MASK | PLL_FBD_MASK;
> > > +	err = tc358746_update_bits(tc358746, PLLCTL0_REG, mask, val);
> > > +	if (err)
> > > +		return err;
> > > +
> > > +	val = PLL_FRS(ilog2(post)) | RESETB | PLL_EN;
> > > +	mask = PLL_FRS_MASK | RESETB | PLL_EN;
> > > +	tc358746_update_bits(tc358746, PLLCTL1_REG, mask, val);
> > > +	if (err)
> > > +		return err;
> > > +
> > > +	fsleep(1000);
> > > +
> > > +	return tc358746_set_bits(tc358746, PLLCTL1_REG, CKEN);
> > > +}
> > > +
> > > +static int tc358746_apply_misc_config(struct tc358746 *tc358746)
> > > +{
> > > +	const struct v4l2_mbus_framefmt *mbusfmt;
> > > +	struct v4l2_subdev *sd = &tc358746->sd;
> > > +	struct v4l2_subdev_state *sink_state;
> > > +	const struct tc358746_format *fmt;
> > > +	struct device *dev = sd->dev;
> > > +	u32 val;
> > > +	int err;
> > > +
> > > +	sink_state = v4l2_subdev_lock_and_get_active_state(sd);
> > > +	mbusfmt = v4l2_subdev_get_pad_format(sd, sink_state, TC358746_SINK);
> > > +	v4l2_subdev_unlock_state(sink_state);
> > > +
> > > +	fmt = tc358746_get_format_by_code(TC358746_SINK, mbusfmt->code);
> > > +
> > > +	/* Self defined CSI user data type id's are not supported yet */
> > > +	val = PDFMT(fmt->pdformat);
> > > +	dev_dbg(dev, "DATAFMT: 0x%x\n", val);
> > > +	err = tc358746_write(tc358746, DATAFMT_REG, val);
> > > +	if (err)
> > > +		return err;
> > > +
> > > +	val = PDATAF(fmt->pdataf);
> > > +	dev_dbg(dev, "CONFCTL[PDATAF]: 0x%x\n", fmt->pdataf);
> > > +	err = tc358746_update_bits(tc358746, CONFCTL_REG, PDATAF_MASK, val);
> > > +	if (err)
> > > +		return err;
> > > +
> > > +	val = tc358746->vb_size / 32;
> > > +	dev_dbg(dev, "FIFOCTL: %u (0x%x)\n", val, val);
> > > +	err = tc358746_write(tc358746, FIFOCTL_REG, val);
> > > +	if (err)
> > > +		return err;
> > > +
> > > +	/* Total number of bytes for each line/width */
> > > +	val = mbusfmt->width * fmt->bpp / 8;
> > > +	dev_dbg(dev, "WORDCNT: %u (0x%x)\n", val, val);
> > > +	return tc358746_write(tc358746, WORDCNT_REG, val);
> > > +}
> > > +
> > > +/* Use MHz as base so the div needs no u64 */
> > > +static u32 tc358746_cfg_to_cnt(unsigned int cfg_val,
> > > +			       unsigned int clk_mhz,
> > > +			       unsigned int time_base)
> > > +{
> > > +	return DIV_ROUND_UP(cfg_val * clk_mhz, time_base);
> > > +}
> > > +
> > > +static u32 tc358746_ps_to_cnt(unsigned int cfg_val,
> > > +			      unsigned int clk_mhz)
> > > +{
> > > +	return tc358746_cfg_to_cnt(cfg_val, clk_mhz, USEC_PER_SEC);
> > > +}
> > > +
> > > +static u32 tc358746_us_to_cnt(unsigned int cfg_val,
> > > +			      unsigned int clk_mhz)
> > > +{
> > > +	return tc358746_cfg_to_cnt(cfg_val, clk_mhz, 1);
> > > +}
> > > +
> > > +static int tc358746_apply_dphy_config(struct tc358746 *tc358746)
> > > +{
> > > +	struct phy_configure_opts_mipi_dphy *cfg = &tc358746->dphy_cfg;
> > > +	bool non_cont_clk = !!(tc358746->csi_vep.bus.mipi_csi2.flags &
> > > +			       V4L2_MBUS_CSI2_NONCONTINUOUS_CLOCK);
> > > +	struct device *dev = tc358746->sd.dev;
> > > +	unsigned long hs_byte_clk, hf_clk;
> > > +	u32 val, val2, lptxcnt;
> > > +	int err;
> > > +
> > > +	/* The hs_byte_clk is also called SYSCLK in the excel sheet */
> > > +	hs_byte_clk = cfg->hs_clk_rate / 8;
> > > +	hs_byte_clk /= HZ_PER_MHZ;
> > > +	hf_clk = hs_byte_clk / 2;
> > > +
> > > +	val = tc358746_us_to_cnt(cfg->init, hf_clk) - 1;
> > > +	dev_dbg(dev, "LINEINITCNT: %u (0x%x)\n", val, val);
> > > +	err = tc358746_write(tc358746, LINEINITCNT_REG, val);
> > > +	if (err)
> > > +		return err;
> > > +
> > > +	val = tc358746_ps_to_cnt(cfg->lpx, hs_byte_clk) - 1;
> > > +	lptxcnt = val;
> > > +	dev_dbg(dev, "LPTXTIMECNT: %u (0x%x)\n", val, val);
> > > +	err = tc358746_write(tc358746, LPTXTIMECNT_REG, val);
> > > +	if (err)
> > > +		return err;
> > > +
> > > +	val = tc358746_ps_to_cnt(cfg->clk_prepare, hs_byte_clk) - 1;
> > > +	val2 = tc358746_ps_to_cnt(cfg->clk_zero, hs_byte_clk) - 1;
> > > +	dev_dbg(dev, "TCLK_PREPARECNT: %u (0x%x)\n", val, val);
> > > +	dev_dbg(dev, "TCLK_ZEROCNT: %u (0x%x)\n", val2, val2);
> > > +	dev_dbg(dev, "TCLK_HEADERCNT: 0x%x\n",
> > > +		(u32)(TCLK_PREPARECNT(val) | TCLK_ZEROCNT(val2)));
> > > +	err = tc358746_write(tc358746, TCLK_HEADERCNT_REG,
> > > +			     TCLK_PREPARECNT(val) | TCLK_ZEROCNT(val2));
> > > +	if (err)
> > > +		return err;
> > > +
> > > +	val = tc358746_ps_to_cnt(cfg->clk_trail, hs_byte_clk);
> > > +	dev_dbg(dev, "TCLK_TRAILCNT: %u (0x%x)\n", val, val);
> > > +	err = tc358746_write(tc358746, TCLK_TRAILCNT_REG, val);
> > > +	if (err)
> > > +		return err;
> > > +
> > > +	val = tc358746_ps_to_cnt(cfg->hs_prepare, hs_byte_clk) - 1;
> > > +	val2 = tc358746_ps_to_cnt(cfg->hs_zero, hs_byte_clk) - 1;
> > > +	dev_dbg(dev, "THS_PREPARECNT: %u (0x%x)\n", val, val);
> > > +	dev_dbg(dev, "THS_ZEROCNT: %u (0x%x)\n", val2, val2);
> > > +	dev_dbg(dev, "THS_HEADERCNT: 0x%x\n",
> > > +		(u32)(THS_PREPARECNT(val) | THS_ZEROCNT(val2)));
> > > +	err = tc358746_write(tc358746, THS_HEADERCNT_REG,
> > > +			     THS_PREPARECNT(val) | THS_ZEROCNT(val2));
> > > +	if (err)
> > > +		return err;
> > > +
> > > +	/* TWAKEUP > 1ms in lptxcnt steps */
> > > +	val = tc358746_us_to_cnt(cfg->wakeup, hs_byte_clk);
> > > +	val = val / (lptxcnt + 1) - 1;
> > > +	dev_dbg(dev, "TWAKEUP: %u (0x%x)\n", val, val);
> > > +	err = tc358746_write(tc358746, TWAKEUP_REG, val);
> > > +	if (err)
> > > +		return err;
> > > +
> > > +	val = tc358746_ps_to_cnt(cfg->clk_post, hs_byte_clk);
> > > +	dev_dbg(dev, "TCLK_POSTCNT: %u (0x%x)\n", val, val);
> > > +	err = tc358746_write(tc358746, TCLK_POSTCNT_REG, val);
> > > +	if (err)
> > > +		return err;
> > > +
> > > +	val = tc358746_ps_to_cnt(cfg->hs_trail, hs_byte_clk);
> > > +	dev_dbg(dev, "THS_TRAILCNT: %u (0x%x)\n", val, val);
> > > +	err = tc358746_write(tc358746, THS_TRAILCNT_REG, val);
> > > +	if (err)
> > > +		return err;
> > > +
> > > +	dev_dbg(dev, "CONTCLKMODE: %u", non_cont_clk ? 0 : 1);
> > > +	return  tc358746_write(tc358746, TXOPTIONCNTRL_REG, non_cont_clk ? 0 : 1);
> > 
> > Extra space after return.
> 
> Okay.
> 
> > > +}
> > > +
> > > +#define MAX_DATA_LANES 4
> > > +
> > > +static int tc358746_enable_csi_lanes(struct tc358746 *tc358746, int enable)
> > > +{
> > > +	unsigned int lanes = tc358746->dphy_cfg.lanes;
> > > +	unsigned int lane;
> > > +	u32 reg, val;
> > > +	int err;
> > > +
> > > +	err = tc358746_update_bits(tc358746, CONFCTL_REG, DATALANE_MASK,
> > > +				   lanes - 1);
> > > +	if (err)
> > > +		return err;
> > > +
> > > +	/* Clock lane */
> > > +	val = enable ? 0 : LANEDISABLE;
> > > +	dev_dbg(tc358746->sd.dev, "CLW_CNTRL: 0x%x\n", val);
> > > +	err = tc358746_write(tc358746, CLW_CNTRL_REG, val);
> > > +	if (err)
> > > +		return err;
> > > +
> > > +	for (lane = 0; lane < MAX_DATA_LANES; lane++) {
> > > +		/* Data lanes */
> > > +		reg = D0W_CNTRL_REG + lane * 0x4;
> > > +		val = (enable && lane < lanes) ? 0 : LANEDISABLE;
> > > +
> > > +		dev_dbg(tc358746->sd.dev, "D%uW_CNTRL: 0x%x\n", lane, val);
> > > +		err = tc358746_write(tc358746, reg, val);
> > > +		if (err)
> > > +			return err;
> > > +	}
> > > +
> > > +	val = 0;
> > > +	if (enable) {
> > > +		/* Clock lane */
> > > +		val |= BIT(0);
> > > +
> > > +		/* Data lanes */
> > > +		for (lane = 1; lane <= lanes; lane++)
> > > +			val |= BIT(lane);
> > > +	}
> > > +
> > > +	dev_dbg(tc358746->sd.dev, "HSTXVREGEN: 0x%x\n", val);
> > > +	return tc358746_write(tc358746, HSTXVREGEN_REG, val);
> > > +}
> > > +
> > > +static int tc358746_enable_csi_module(struct tc358746 *tc358746, int enable)
> > > +{
> > > +	unsigned int lanes = tc358746->dphy_cfg.lanes;
> > > +	int err;
> > > +
> > > +	/*
> > > +	 * START and STRT are only reseted/disabled by sw reset. This is
> > > +	 * required to put the lane state back into LP-11 state. The sw reset
> > > +	 * don't reset register values.
> > > +	 */
> > > +	if (!enable)
> > > +		return tc358746_sw_reset(tc358746);
> > > +
> > > +	err = tc358746_write(tc358746, STARTCNTRL_REG, START);
> > > +	if (err)
> > > +		return err;
> > > +
> > > +	err = tc358746_write(tc358746, CSI_START_REG, STRT);
> > > +	if (err)
> > > +		return err;
> > > +
> > > +	/* CSI_CONTROL_REG is only indirect accessible */
> > > +	return tc358746_write(tc358746, CSI_CONFW_REG,
> > > +			      MODE(MODE_SET) |
> > > +			      ADDRESS(CSI_CONTROL_ADDRESS) |
> > > +			      DATA(CSI_MODE | TXHSMD | NOL(lanes - 1)));
> > > +}
> > > +
> > > +static int tc358746_enable_parallel_port(struct tc358746 *tc358746, int enable)
> > > +{
> > > +	int err;
> > > +
> > > +	if (enable) {
> > > +		err = tc358746_write(tc358746, PP_MISC_REG, 0);
> > > +		if (err)
> > > +			return err;
> > > +
> > > +		return tc358746_set_bits(tc358746, CONFCTL_REG, PPEN);
> > > +	}
> > > +
> > > +	err = tc358746_set_bits(tc358746, PP_MISC_REG, FRMSTOP);
> > > +	if (err)
> > > +		return err;
> > > +
> > > +	err = tc358746_clear_bits(tc358746, CONFCTL_REG, PPEN);
> > > +	if (err)
> > > +		return err;
> > > +
> > > +	return tc358746_set_bits(tc358746, PP_MISC_REG, RSTPTR);
> > > +}
> > > +
> > > +static inline struct v4l2_subdev *tc358746_get_remote_sd(struct media_pad *pad)
> > > +{
> > > +	pad = media_pad_remote_pad_first(pad);
> > > +	if (!pad)
> > > +		return NULL;
> > > +
> > > +	return media_entity_to_v4l2_subdev(pad->entity);
> > > +}
> > > +
> > > +static int tc358746_s_stream(struct v4l2_subdev *sd, int enable)
> > > +{
> > > +	struct tc358746 *tc358746 = to_tc358746(sd);
> > > +	struct v4l2_subdev *src;
> > > +	int err;
> > > +
> > > +	dev_dbg(sd->dev, "%sable\n", enable ? "en" : "dis");
> > > +
> > > +	src = tc358746_get_remote_sd(&tc358746->pads[TC358746_SINK]);
> > > +	if (!src)
> > > +		return -EPIPE;
> > > +
> > > +	if (enable) {
> > > +		err = pm_runtime_resume_and_get(sd->dev);
> > > +		if (err)
> > > +			return err;
> > > +
> > > +		err = tc358746_apply_dphy_config(tc358746);
> > > +		if (err)
> > > +			goto err_out;
> > > +
> > > +		err = tc358746_apply_misc_config(tc358746);
> > > +		if (err)
> > > +			goto err_out;
> > > +
> > > +		err = tc358746_enable_csi_lanes(tc358746, 1);
> > > +		if (err)
> > > +			goto err_out;
> > > +
> > > +		err = tc358746_enable_csi_module(tc358746, 1);
> > > +		if (err)
> > > +			goto err_out;
> > > +
> > > +		err = tc358746_enable_parallel_port(tc358746, 1);
> > > +		if (err)
> > > +			goto err_out;
> > > +
> > > +		err = v4l2_subdev_call(src, video, s_stream, 1);
> > > +		if (err)
> > > +			goto err_out;
> > > +
> > > +		return err;
> > > +
> > > +err_out:
> > > +		pm_runtime_mark_last_busy(sd->dev);
> > > +		pm_runtime_put_sync_autosuspend(sd->dev);
> > > +
> > > +		return err;
> > > +	}
> > > +
> > > +	 /*
> > > +	  * The lanes must be disabled first (before the csi module) so the
> > > +	  * LP-11 state is entered correctly.
> > > +	  */
> > 
> > Wrong indentation.
> 
> Damn.. Shouldn't that be detected by checkpatch? Anyway, thanks :)
> 
> > > +	err = tc358746_enable_csi_lanes(tc358746, 0);
> > > +	if (err)
> > > +		return err;
> > > +
> > > +	err = tc358746_enable_csi_module(tc358746, 0);
> > > +	if (err)
> > > +		return err;
> > > +
> > > +	err = tc358746_enable_parallel_port(tc358746, 0);
> > > +	if (err)
> > > +		return err;
> > > +
> > > +	pm_runtime_mark_last_busy(sd->dev);
> > > +	pm_runtime_put_sync_autosuspend(sd->dev);
> > > +
> > > +	return v4l2_subdev_call(src, video, s_stream, 0);
> > > +}
> > > +
> > > +static int tc358746_init_cfg(struct v4l2_subdev *sd,
> > > +			     struct v4l2_subdev_state *state)
> > > +{
> > > +	struct v4l2_mbus_framefmt *fmt;
> > > +
> > > +	fmt = v4l2_subdev_get_pad_format(sd, state, TC358746_SINK);
> > > +	*fmt = tc358746_def_fmt;
> > > +
> > > +	fmt = v4l2_subdev_get_pad_format(sd, state, TC358746_SOURCE);
> > > +	*fmt = tc358746_def_fmt;
> > > +	fmt->code = tc358746_src_mbus_code(tc358746_def_fmt.code);
> > > +
> > > +	return 0;
> > > +}
> > > +
> > > +static int tc358746_enum_mbus_code(struct v4l2_subdev *sd,
> > > +				   struct v4l2_subdev_state *sd_state,
> > > +				   struct v4l2_subdev_mbus_code_enum *code)
> > > +{
> > > +	const struct tc358746_format *fmt;
> > > +
> > > +	fmt = tc358746_get_format_by_idx(code->pad, code->index);
> > > +	if (IS_ERR(fmt))
> > > +		return PTR_ERR(fmt);
> > > +
> > > +	code->code = fmt->code;
> > > +
> > > +	return 0;
> > > +}
> > > +
> > > +static int tc358746_set_fmt(struct v4l2_subdev *sd,
> > > +			    struct v4l2_subdev_state *sd_state,
> > > +			    struct v4l2_subdev_format *format)
> > > +{
> > > +	struct v4l2_mbus_framefmt *src_fmt, *sink_fmt;
> > > +	const struct tc358746_format *fmt;
> > > +
> > > +	/* Source follows the sink */
> > > +	if (format->pad == TC358746_SOURCE)
> > > +		return v4l2_subdev_get_fmt(sd, sd_state, format);
> > > +
> > > +	sink_fmt = v4l2_subdev_get_pad_format(sd, sd_state, TC358746_SINK);
> > > +
> > > +	fmt = tc358746_get_format_by_code(format->pad, format->format.code);
> > > +	if (IS_ERR(fmt))
> > > +		fmt = tc358746_get_format_by_code(format->pad, tc358746_def_fmt.code);
> > > +
> > > +	format->format.code = fmt->code;
> > > +	format->format.field = V4L2_FIELD_NONE;
> > > +
> > > +	dev_dbg(sd->dev, "Update format: %ux%u code:0x%x -> %ux%u code:0x%x",
> > > +		sink_fmt->width, sink_fmt->height, sink_fmt->code,
> > > +		format->format.width, format->format.height, format->format.code);
> > > +
> > > +	*sink_fmt = format->format;
> > > +
> > > +	src_fmt = v4l2_subdev_get_pad_format(sd, sd_state, TC358746_SOURCE);
> > > +	*src_fmt = *sink_fmt;
> > > +	src_fmt->code = tc358746_src_mbus_code(sink_fmt->code);
> > > +
> > > +	return 0;
> > > +}
> > > +
> > > +static unsigned long tc358746_find_pll_settings(struct tc358746 *tc358746,
> > > +						unsigned long refclk,
> > > +						unsigned long fout)
> > > +
> > > +{
> > > +	struct device *dev = tc358746->sd.dev;
> > > +	unsigned long best_freq = 0;
> > > +	u32 min_delta = 0xffffffff;
> > > +	u16 prediv_max = 17;
> > > +	u16 prediv_min = 1;
> > > +	u16 m_best, mul;
> > > +	u16 p_best, p;
> > > +	u8 postdiv;
> > > +
> > > +	if (fout > 1000 * HZ_PER_MHZ) {
> > > +		dev_err(dev, "HS-Clock above 1 Ghz are not supported\n");
> > > +		return 0;
> > > +	}
> > > +
> > > +	if (fout >= 500 * HZ_PER_MHZ)
> > > +		postdiv = 1;
> > > +	else if (fout >= 250 * HZ_PER_MHZ)
> > > +		postdiv = 2;
> > > +	else if (fout >= 125 * HZ_PER_MHZ)
> > > +		postdiv = 4;
> > > +	else
> > > +		postdiv = 8;
> > > +
> > > +	for (p = prediv_min; p <= prediv_max; p++) {
> > > +		unsigned long delta, fin;
> > > +		u64 tmp;
> > > +
> > > +		fin = DIV_ROUND_CLOSEST(refclk, p);
> > > +		if (fin < 4 * HZ_PER_MHZ || fin > 40 * HZ_PER_MHZ)
> > > +			continue;
> > > +
> > > +		tmp = fout * p * postdiv;
> > > +		do_div(tmp, fin);
> > > +		mul = tmp;
> > > +		if (mul > 511)
> > > +			continue;
> > > +
> > > +		tmp = mul * fin;
> > > +		do_div(tmp, p * postdiv);
> > > +
> > > +		delta = abs(fout - tmp);
> > > +		if (delta < min_delta) {
> > > +			p_best = p;
> > > +			m_best = mul;
> > > +			min_delta = delta;
> > > +			best_freq = tmp;
> > > +		};
> > > +
> > > +		if (delta == 0)
> > > +			break;
> > > +	};
> > > +
> > > +	if (!best_freq) {
> > > +		dev_err(dev, "Failed find PLL frequency\n");
> > > +		return 0;
> > > +	}
> > > +
> > > +	tc358746->pll_post_div = postdiv;
> > > +	tc358746->pll_pre_div = p_best;
> > > +	tc358746->pll_mul = m_best;
> > > +
> > > +	if (best_freq != fout)
> > > +		dev_warn(dev, "Request PLL freq:%lu, found PLL freq:%lu\n",
> > > +			 fout, best_freq);
> > > +
> > > +	dev_dbg(dev, "Found PLL settings: freq:%lu prediv:%u multi:%u postdiv:%u\n",
> > > +		best_freq, p_best, m_best, postdiv);
> > > +
> > > +	return best_freq;
> > > +}
> > > +
> > > +#define TC358746_PRECISION 10
> > > +
> > > +static int
> > > +tc358746_link_validate(struct v4l2_subdev *sd, struct media_link *link,
> > > +		       struct v4l2_subdev_format *source_fmt,
> > > +		       struct v4l2_subdev_format *sink_fmt)
> > > +{
> > > +	struct tc358746 *tc358746 = to_tc358746(sd);
> > > +	unsigned long csi_bitrate, source_bitrate;
> > > +	struct v4l2_subdev_state *sink_state;
> > > +	struct v4l2_mbus_framefmt *mbusfmt;
> > > +	const struct tc358746_format *fmt;
> > > +	unsigned int fifo_sz, tmp, n;
> > > +	struct v4l2_subdev *source;
> > > +	s64 source_link_freq;
> > > +	int err;
> > > +
> > > +	err = v4l2_subdev_link_validate_default(sd, link, source_fmt, sink_fmt);
> > > +	if (err)
> > > +		return err;
> > > +
> > > +	sink_state = v4l2_subdev_lock_and_get_active_state(sd);
> > > +	mbusfmt = v4l2_subdev_get_pad_format(sd, sink_state, TC358746_SINK);
> > > +
> > > +	/* Check the FIFO settings */
> > > +	fmt = tc358746_get_format_by_code(TC358746_SINK, mbusfmt->code);
> > > +
> > > +	source = media_entity_to_v4l2_subdev(link->source->entity);
> > > +	source_link_freq = v4l2_get_link_freq(source->ctrl_handler, 0, 0);
> > > +	if (source_link_freq <= 0) {
> > > +		dev_err(tc358746->sd.dev,
> > > +			"Failed to query or invalid source link frequency\n");
> > > +		v4l2_subdev_unlock_state(sink_state);
> > > +		/* Return -EINVAL in case of source_link_freq is 0 */
> > > +		return source_link_freq ? : -EINVAL;
> > > +	}
> > > +	source_bitrate = source_link_freq * fmt->bus_width;
> > > +
> > > +	csi_bitrate = tc358746->dphy_cfg.lanes * tc358746->pll_rate;
> > > +
> > > +	dev_dbg(tc358746->sd.dev,
> > > +		"Fifo settings params: source-bitrate:%lu csi-bitrate:%lu",
> > > +		source_bitrate, csi_bitrate);
> > > +
> > > +	/* Avoid possible FIFO overflows */
> > > +	if (csi_bitrate < source_bitrate) {
> > > +		v4l2_subdev_unlock_state(sink_state);
> > > +		return -EINVAL;
> > > +	}
> > > +
> > > +	/* Best case */
> > > +	if (csi_bitrate == source_bitrate) {
> > > +		fifo_sz = TC358746_VB_DEFAULT_SIZE;
> > > +		tc358746->vb_size = TC358746_VB_DEFAULT_SIZE;
> > > +		goto out;
> > > +	}
> > > +
> > > +	/*
> > > +	 * Avoid possible FIFO underflow in case of
> > > +	 * csi_bitrate > source_bitrate. For such case the chip has a internal
> > > +	 * fifo which can be used to delay the line output.
> > > +	 *
> > > +	 * Fifo size calculation (excluding precision):
> > > +	 *
> > > +	 * fifo-sz, image-width - in bits
> > > +	 * sbr                  - source_bitrate in bits/s
> > > +	 * csir                 - csi_bitrate in bits/s
> > > +	 *
> > > +	 *                1               1      1
> > > +	 * image-width * --- + fifo-sz * --- >= ---- * image-width
> > > +	 *               sbr             sbr    csir
> > 
> > I still think there's something fishy here. The inequality is always
> > true as csir > sbr. You will get a non-zero fifo size in your
> > calculation because you artifically add an abs(), but I don't think
> > that's right.
> > 
> > If I understand things correctly, you need to ensure that once the FIFO
> > threshold is reached and the CSI-2 side starts sending data, the input
> > size will keep feeding data fast enough for the FIFO to never underrun.
> > 
> > The FIFO level triggers the CSI-2 transmission. This means that once the
> > CSI-2 transmission start, fifo-sz bits have been written to the FIFO
> > already, and image-width - fifo-sz bits still need to be written. To
> > avoid underruns, you need to ensure that the time required to read all
> > the data (image-width) on the CSI-2 size will be higher than or equal to
> > the time required to write the remaining data (image-width - fifo-sz) on
> > the input side. This translates to
> > 
> > 	image-width / csir >= (image-width - fifo-sz) / sbr
> > 	image-width * sbr / csir >= image-width - fifo-sz
> > 	fifo-sz >= image-width - image-width * sbr / csir
> 
> Thanks, makes more sense, I will change the comment.
> 
> > The calculation is thus correct, but not for the right reason :-) All
> > you need to fix here is the comment, not the code.
> > 
> > With these small issues fixed,
> > 
> > Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> 
> > > +	 *
> > > +	 * fifo-sz >= abs(sbr/csir * image-width - image-width); with n = csir/sbr
> > > +	 *
> > > +	 * fifo-sz >= abs(image-width / n - image-width)
> > > +	 *         >= image-width - image-width / n
> > > +	 */
> > > +
> > > +	source_bitrate /= TC358746_PRECISION;
> > > +	n = csi_bitrate / source_bitrate;
> > > +	tmp = (mbusfmt->width * TC358746_PRECISION) / n;
> > > +	fifo_sz = mbusfmt->width - tmp;
> > > +	fifo_sz *= fmt->bpp;
> > > +	tc358746->vb_size = round_up(fifo_sz, 32);
> > > +
> > > +out:
> > > +	dev_dbg(tc358746->sd.dev,
> > > +		"Found FIFO size[bits]:%u -> aligned to size[bits]:%u\n",
> > > +		fifo_sz, tc358746->vb_size);
> > > +
> > > +	v4l2_subdev_unlock_state(sink_state);
> > > +
> > > +	return tc358746->vb_size > TC358746_VB_MAX_SIZE ? -EINVAL : 0;
> > > +}
> > > +
> > > +static int tc358746_get_mbus_config(struct v4l2_subdev *sd, unsigned int pad,
> > > +				    struct v4l2_mbus_config *config)
> > > +{
> > > +	struct tc358746 *tc358746 = to_tc358746(sd);
> > > +
> > > +	if (pad != TC358746_SOURCE)
> > > +		return -EINVAL;
> > > +
> > > +	config->type = V4L2_MBUS_CSI2_DPHY;
> > > +	config->bus.mipi_csi2 = tc358746->csi_vep.bus.mipi_csi2;
> > > +
> > > +	return 0;
> > > +}
> > > +
> > > +static int __maybe_unused
> > > +tc358746_g_register(struct v4l2_subdev *sd, struct v4l2_dbg_register *reg)
> > > +{
> > > +	struct tc358746 *tc358746 = to_tc358746(sd);
> > > +
> > > +	/* 32-bit registers starting from CLW_DPHYCONTTX */
> > > +	reg->size = reg->reg < CLW_DPHYCONTTX_REG ? 2 : 4;
> > > +
> > > +	if (!pm_runtime_get_if_in_use(sd->dev))
> > > +		return 0;
> > > +
> > > +	tc358746_read(tc358746, reg->reg, (u32 *)&reg->val);
> > > +
> > > +	pm_runtime_mark_last_busy(sd->dev);
> > > +	pm_runtime_put_sync_autosuspend(sd->dev);
> > > +
> > > +	return 0;
> > > +}
> > > +
> > > +static int __maybe_unused
> > > +tc358746_s_register(struct v4l2_subdev *sd, const struct v4l2_dbg_register *reg)
> > > +{
> > > +	struct tc358746 *tc358746 = to_tc358746(sd);
> > > +
> > > +	if (!pm_runtime_get_if_in_use(sd->dev))
> > > +		return 0;
> > > +
> > > +	tc358746_write(tc358746, (u32)reg->reg, (u32)reg->val);
> > > +
> > > +	pm_runtime_mark_last_busy(sd->dev);
> > > +	pm_runtime_put_sync_autosuspend(sd->dev);
> > > +
> > > +	return 0;
> > > +}
> > > +
> > > +static const struct v4l2_subdev_core_ops tc358746_core_ops = {
> > > +#ifdef CONFIG_VIDEO_ADV_DEBUG
> > > +	.g_register = tc358746_g_register,
> > > +	.s_register = tc358746_s_register,
> > > +#endif
> > > +};
> > > +
> > > +static const struct v4l2_subdev_video_ops tc358746_video_ops = {
> > > +	.s_stream = tc358746_s_stream,
> > > +};
> > > +
> > > +static const struct v4l2_subdev_pad_ops tc358746_pad_ops = {
> > > +	.init_cfg = tc358746_init_cfg,
> > > +	.enum_mbus_code = tc358746_enum_mbus_code,
> > > +	.set_fmt = tc358746_set_fmt,
> > > +	.get_fmt = v4l2_subdev_get_fmt,
> > > +	.link_validate = tc358746_link_validate,
> > > +	.get_mbus_config = tc358746_get_mbus_config,
> > > +};
> > > +
> > > +static const struct v4l2_subdev_ops tc358746_ops = {
> > > +	.core = &tc358746_core_ops,
> > > +	.video = &tc358746_video_ops,
> > > +	.pad = &tc358746_pad_ops,
> > > +};
> > > +
> > > +static const struct media_entity_operations tc358746_entity_ops = {
> > > +	.get_fwnode_pad = v4l2_subdev_get_fwnode_pad_1_to_1,
> > > +	.link_validate = v4l2_subdev_link_validate,
> > > +};
> > > +
> > > +static int tc358746_mclk_enable(struct clk_hw *hw)
> > > +{
> > > +	struct tc358746 *tc358746 = clk_hw_to_tc358746(hw);
> > > +	unsigned int div;
> > > +	u32 val;
> > > +	int err;
> > > +
> > > +	div = tc358746->mclk_postdiv / 2;
> > > +	val = MCLK_HIGH(div - 1) | MCLK_LOW(div - 1);
> > > +	dev_dbg(tc358746->sd.dev, "MCLKCTL: %u (0x%x)\n", val, val);
> > > +	err = tc358746_write(tc358746, MCLKCTL_REG, val);
> > > +	if (err)
> > > +		return err;
> > > +
> > > +	if (tc358746->mclk_prediv == 8)
> > > +		val = MCLKDIV(MCLKDIV_8);
> > > +	else if (tc358746->mclk_prediv == 4)
> > > +		val = MCLKDIV(MCLKDIV_4);
> > > +	else
> > > +		val = MCLKDIV(MCLKDIV_2);
> > > +
> > > +	dev_dbg(tc358746->sd.dev, "CLKCTL[MCLKDIV]: %u (0x%x)\n", val, val);
> > > +	return tc358746_update_bits(tc358746, CLKCTL_REG, MCLKDIV_MASK, val);
> > > +}
> > > +
> > > +static void tc358746_mclk_disable(struct clk_hw *hw)
> > > +{
> > > +	struct tc358746 *tc358746 = clk_hw_to_tc358746(hw);
> > > +
> > > +	tc358746_write(tc358746, MCLKCTL_REG, 0);
> > > +}
> > > +
> > > +static long
> > > +tc358746_find_mclk_settings(struct tc358746 *tc358746, unsigned long mclk_rate)
> > > +{
> > > +	unsigned long pll_rate = tc358746->pll_rate;
> > > +	const unsigned char prediv[] = { 2, 4, 8 };
> > > +	unsigned int mclk_prediv, mclk_postdiv;
> > > +	struct device *dev = tc358746->sd.dev;
> > > +	unsigned int postdiv, mclkdiv;
> > > +	unsigned long best_mclk_rate;
> > > +	unsigned int i;
> > > +
> > > +	/*
> > > +	 *                          MCLK-Div
> > > +	 *           -------------------´`---------------------
> > > +	 *          ´                                          `
> > > +	 *         +-------------+     +------------------------+
> > > +	 *         | MCLK-PreDiv |     |       MCLK-PostDiv     |
> > > +	 * PLL --> |   (2/4/8)   | --> | (mclk_low + mclk_high) | --> MCLK
> > > +	 *         +-------------+     +------------------------+
> > > +	 *
> > > +	 * The register value of mclk_low/high is mclk_low/high+1, i.e.:
> > > +	 *   mclk_low/high = 1   --> 2 MCLK-Ref Counts
> > > +	 *   mclk_low/high = 255 --> 256 MCLK-Ref Counts == max.
> > > +	 * If mclk_low and mclk_high are 0 then MCLK is disabled.
> > > +	 *
> > > +	 * Keep it simple and support 50/50 duty cycles only for now,
> > > +	 * so the calc will be:
> > > +	 *
> > > +	 *   MCLK = PLL / (MCLK-PreDiv * 2 * MCLK-PostDiv)
> > > +	 */
> > > +
> > > +	if (mclk_rate == tc358746->mclk_rate)
> > > +		return mclk_rate;
> > > +
> > > +	/* Highest possible rate */
> > > +	mclkdiv = pll_rate / mclk_rate;
> > > +	if (mclkdiv <= 8) {
> > > +		mclk_prediv = 2;
> > > +		mclk_postdiv = 4;
> > > +		best_mclk_rate = pll_rate / (2 * 4);
> > > +		goto out;
> > > +	}
> > > +
> > > +	/* First check the prediv */
> > > +	for (i = 0; i < ARRAY_SIZE(prediv); i++) {
> > > +		postdiv = mclkdiv / prediv[i];
> > > +
> > > +		if (postdiv % 2)
> > > +			continue;
> > > +
> > > +		if (postdiv >= 4 && postdiv <= 512) {
> > > +			mclk_prediv = prediv[i];
> > > +			mclk_postdiv = postdiv;
> > > +			best_mclk_rate = pll_rate / (prediv[i] * postdiv);
> > > +			goto out;
> > > +		}
> > > +	}
> > > +
> > > +	/* No suitable prediv found, so try to adjust the postdiv */
> > > +	for (postdiv = 4; postdiv <= 512; postdiv += 2) {
> > > +		unsigned int pre;
> > > +
> > > +		pre = mclkdiv / postdiv;
> > > +		if (pre == 2 || pre == 4 || pre == 8) {
> > > +			mclk_prediv = pre;
> > > +			mclk_postdiv = postdiv;
> > > +			best_mclk_rate = pll_rate / (pre * postdiv);
> > > +			goto out;
> > > +		}
> > > +	}
> > > +
> > > +	/* The MCLK <-> PLL gap is to high -> use largest possible div */
> > > +	mclk_prediv = 8;
> > > +	mclk_postdiv = 512;
> > > +	best_mclk_rate = pll_rate / (8 * 512);
> > > +
> > > +out:
> > > +	tc358746->mclk_prediv = mclk_prediv;
> > > +	tc358746->mclk_postdiv = mclk_postdiv;
> > > +	tc358746->mclk_rate = best_mclk_rate;
> > > +
> > > +	if (best_mclk_rate != mclk_rate)
> > > +		dev_warn(dev, "Request MCLK freq:%lu, found MCLK freq:%lu\n",
> > > +			 mclk_rate, best_mclk_rate);
> > > +
> > > +	dev_dbg(dev, "Found MCLK settings: freq:%lu prediv:%u postdiv:%u\n",
> > > +		best_mclk_rate, mclk_prediv, mclk_postdiv);
> > > +
> > > +	return best_mclk_rate;
> > > +}
> > > +
> > > +static unsigned long
> > > +tc358746_recalc_rate(struct clk_hw *hw, unsigned long parent_rate)
> > > +{
> > > +	struct tc358746 *tc358746 = clk_hw_to_tc358746(hw);
> > > +	unsigned int prediv, postdiv;
> > > +	u32 val;
> > > +	int err;
> > > +
> > > +	err = tc358746_read(tc358746, MCLKCTL_REG, &val);
> > > +	if (err)
> > > +		return 0;
> > > +
> > > +	postdiv = FIELD_GET(MCLK_LOW_MASK, val) + 1;
> > > +	postdiv += FIELD_GET(MCLK_HIGH_MASK, val) + 1;
> > > +
> > > +	err = tc358746_read(tc358746, CLKCTL_REG, &val);
> > > +	if (err)
> > > +		return 0;
> > > +
> > > +	prediv = FIELD_GET(MCLKDIV_MASK, val);
> > > +	if (prediv == MCLKDIV_8)
> > > +		prediv = 8;
> > > +	else if (prediv == MCLKDIV_4)
> > > +		prediv = 4;
> > > +	else
> > > +		prediv = 2;
> > > +
> > > +	return tc358746->pll_rate / (prediv * postdiv);
> > > +}
> > > +
> > > +static long tc358746_mclk_round_rate(struct clk_hw *hw, unsigned long rate,
> > > +				     unsigned long *parent_rate)
> > > +{
> > > +	struct tc358746 *tc358746 = clk_hw_to_tc358746(hw);
> > > +
> > > +	*parent_rate = tc358746->pll_rate;
> > > +
> > > +	return tc358746_find_mclk_settings(tc358746, rate);
> > > +}
> > > +
> > > +static int tc358746_mclk_set_rate(struct clk_hw *hw, unsigned long rate,
> > > +				  unsigned long parent_rate)
> > > +{
> > > +	struct tc358746 *tc358746 = clk_hw_to_tc358746(hw);
> > > +
> > > +	tc358746_find_mclk_settings(tc358746, rate);
> > > +
> > > +	return tc358746_mclk_enable(hw);
> > > +}
> > > +
> > > +static const struct clk_ops tc358746_mclk_ops = {
> > > +	.enable = tc358746_mclk_enable,
> > > +	.disable = tc358746_mclk_disable,
> > > +	.recalc_rate = tc358746_recalc_rate,
> > > +	.round_rate = tc358746_mclk_round_rate,
> > > +	.set_rate = tc358746_mclk_set_rate,
> > > +};
> > > +
> > > +static int tc358746_setup_mclk_provider(struct tc358746 *tc358746)
> > > +{
> > > +	struct clk_init_data mclk_initdata = { };
> > > +	struct device *dev = tc358746->sd.dev;
> > > +	const char *mclk_name;
> > > +	int err;
> > > +
> > > +	/* MCLK clk provider support is optional */
> > > +	if (!device_property_present(dev, "#clock-cells"))
> > > +		return 0;
> > > +
> > > +	/* Init to highest possibel MCLK */
> > > +	tc358746->mclk_postdiv = 512;
> > > +	tc358746->mclk_prediv = 8;
> > > +
> > > +	mclk_name = "tc358746-mclk";
> > > +	device_property_read_string(dev, "clock-output-names", &mclk_name);
> > > +
> > > +	mclk_initdata.name = mclk_name;
> > > +	mclk_initdata.ops = &tc358746_mclk_ops;
> > > +	tc358746->mclk_hw.init = &mclk_initdata;
> > > +
> > > +	err = devm_clk_hw_register(dev, &tc358746->mclk_hw);
> > > +	if (err) {
> > > +		dev_err(dev, "Failed to register mclk provider\n");
> > > +		return err;
> > > +	}
> > > +
> > > +	err = devm_of_clk_add_hw_provider(dev, of_clk_hw_simple_get,
> > > +					  &tc358746->mclk_hw);
> > > +	if (err)
> > > +		dev_err(dev, "Failed to add mclk provider\n");
> > > +
> > > +	return err;
> > > +}
> > > +
> > > +static int
> > > +tc358746_init_subdev(struct tc358746 *tc358746, struct i2c_client *client)
> > > +{
> > > +	struct v4l2_subdev *sd = &tc358746->sd;
> > > +	int err;
> > > +
> > > +	v4l2_i2c_subdev_init(sd, client, &tc358746_ops);
> > > +	sd->flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;
> > > +	sd->entity.function = MEDIA_ENT_F_VID_IF_BRIDGE;
> > > +	sd->entity.ops = &tc358746_entity_ops;
> > > +
> > > +	tc358746->pads[TC358746_SINK].flags = MEDIA_PAD_FL_SINK;
> > > +	tc358746->pads[TC358746_SOURCE].flags = MEDIA_PAD_FL_SOURCE;
> > > +	err = media_entity_pads_init(&sd->entity, TC358746_NR_PADS,
> > > +				     tc358746->pads);
> > > +	if (err)
> > > +		return err;
> > > +
> > > +	err = v4l2_subdev_init_finalize(sd);
> > > +	if (err)
> > > +		media_entity_cleanup(&sd->entity);
> > > +
> > > +	return err;
> > > +}
> > > +
> > > +static int
> > > +tc358746_init_output_port(struct tc358746 *tc358746, unsigned long refclk)
> > > +{
> > > +	struct device *dev = tc358746->sd.dev;
> > > +	struct v4l2_fwnode_endpoint *vep;
> > > +	unsigned long csi_link_rate;
> > > +	struct fwnode_handle *ep;
> > > +	unsigned char csi_lanes;
> > > +	int err;
> > > +
> > > +	ep = fwnode_graph_get_endpoint_by_id(dev_fwnode(dev), TC358746_SOURCE,
> > > +					     0, 0);
> > > +	if (!ep) {
> > > +		dev_err(dev, "Missing endpoint node\n");
> > > +		return -EINVAL;
> > > +	}
> > > +
> > > +	/* Currently we only support 'parallel in' -> 'csi out' */
> > > +	vep = &tc358746->csi_vep;
> > > +	vep->bus_type = V4L2_MBUS_CSI2_DPHY;
> > > +	err = v4l2_fwnode_endpoint_alloc_parse(ep, vep);
> > > +	fwnode_handle_put(ep);
> > > +	if (err) {
> > > +		dev_err(dev, "Failed to parse source endpoint\n");
> > > +		return err;
> > > +	}
> > > +
> > > +	csi_lanes = vep->bus.mipi_csi2.num_data_lanes;
> > > +	if (csi_lanes == 0 || csi_lanes > 4 ||
> > > +	    vep->nr_of_link_frequencies == 0) {
> > > +		dev_err(dev, "error: Invalid CSI-2 settings\n");
> > > +		err = -EINVAL;
> > > +		goto err;
> > > +	}
> > > +
> > > +	/* TODO: Add support to handle multiple link frequencies */
> > > +	csi_link_rate = (unsigned long)vep->link_frequencies[0];
> > > +	tc358746->pll_rate = tc358746_find_pll_settings(tc358746, refclk,
> > > +							csi_link_rate * 2);
> > > +	if (!tc358746->pll_rate) {
> > > +		err = -EINVAL;
> > > +		goto err;
> > > +	}
> > > +
> > > +	err = phy_mipi_dphy_get_default_config_for_hsclk(tc358746->pll_rate,
> > > +						csi_lanes, &tc358746->dphy_cfg);
> > > +	if (err)
> > > +		goto err;
> > > +
> > > +	tc358746->vb_size = TC358746_VB_DEFAULT_SIZE;
> > > +
> > > +	return 0;
> > > +
> > > +err:
> > > +	v4l2_fwnode_endpoint_free(vep);
> > > +
> > > +	return err;
> > > +}
> > > +
> > > +static int tc358746_init_hw(struct tc358746 *tc358746)
> > > +{
> > > +	struct device *dev = tc358746->sd.dev;
> > > +	unsigned int chipid;
> > > +	u32 val;
> > > +	int err;
> > > +
> > > +	err = pm_runtime_resume_and_get(dev);
> > > +	if (err < 0) {
> > > +		dev_err(dev, "Failed to resume the device\n");
> > > +		return err;
> > > +	}
> > > +
> > > +	 /* Ensure that CSI interface is put into LP-11 state */
> > > +	err = tc358746_sw_reset(tc358746);
> > > +	if (err) {
> > > +		pm_runtime_put_sync(dev);
> > > +		dev_err(dev, "Failed to reset the device\n");
> > > +		return err;
> > > +	}
> > > +
> > > +	err = tc358746_read(tc358746, CHIPID_REG, &val);
> > > +	pm_runtime_mark_last_busy(dev);
> > > +	pm_runtime_put_sync_autosuspend(dev);
> > > +	if (err)
> > > +		return -ENODEV;
> > > +
> > > +	chipid = FIELD_GET(CHIPID, val);
> > > +	if (chipid != 0x44) {
> > > +		dev_err(dev, "Invalid chipid 0x%02x\n", chipid);
> > > +		return -ENODEV;
> > > +	}
> > > +
> > > +	return 0;
> > > +}
> > > +
> > > +static int tc358746_init_controls(struct tc358746 *tc358746)
> > > +{
> > > +	u64 *link_frequencies = tc358746->csi_vep.link_frequencies;
> > > +	struct v4l2_ctrl *ctrl;
> > > +	int err;
> > > +
> > > +	err = v4l2_ctrl_handler_init(&tc358746->ctrl_hdl, 1);
> > > +	if (err)
> > > +		return err;
> > > +
> > > +	/*
> > > +	 * The driver currently supports only one link-frequency, regardless of
> > > +	 * the input from the firmware, see: tc358746_init_output_port(). So
> > > +	 * report only the first frequency from the array of possible given
> > > +	 * frequencies.
> > > +	 */
> > > +	ctrl = v4l2_ctrl_new_int_menu(&tc358746->ctrl_hdl, NULL,
> > > +				      V4L2_CID_LINK_FREQ, 0, 0,
> > > +				      link_frequencies);
> > > +	if (ctrl)
> > > +		ctrl->flags |= V4L2_CTRL_FLAG_READ_ONLY;
> > > +
> > > +	err = tc358746->ctrl_hdl.error;
> > > +	if (err) {
> > > +		v4l2_ctrl_handler_free(&tc358746->ctrl_hdl);
> > > +		return err;
> > > +	}
> > > +
> > > +	tc358746->sd.ctrl_handler = &tc358746->ctrl_hdl;
> > > +
> > > +	return 0;
> > > +}
> > > +
> > > +static int tc358746_notify_bound(struct v4l2_async_notifier *notifier,
> > > +				 struct v4l2_subdev *sd,
> > > +				 struct v4l2_async_subdev *asd)
> > > +{
> > > +	struct tc358746 *tc358746 =
> > > +		container_of(notifier, struct tc358746, notifier);
> > > +	u32 flags = MEDIA_LNK_FL_ENABLED | MEDIA_LNK_FL_IMMUTABLE;
> > > +	struct media_pad *sink = &tc358746->pads[TC358746_SINK];
> > > +
> > > +	return v4l2_create_fwnode_links_to_pad(sd, sink, flags);
> > > +}
> > > +
> > > +static const struct v4l2_async_notifier_operations tc358746_notify_ops = {
> > > +	.bound = tc358746_notify_bound,
> > > +};
> > > +
> > > +static int tc358746_async_register(struct tc358746 *tc358746)
> > > +{
> > > +	struct v4l2_fwnode_endpoint vep = {
> > > +		.bus_type = V4L2_MBUS_PARALLEL,
> > > +	};
> > > +	struct v4l2_async_subdev *asd;
> > > +	struct fwnode_handle *ep;
> > > +	int err;
> > > +
> > > +	ep = fwnode_graph_get_endpoint_by_id(dev_fwnode(tc358746->sd.dev),
> > > +					     TC358746_SINK, 0, 0);
> > > +	if (!ep)
> > > +		return -ENOTCONN;
> > > +
> > > +	err = v4l2_fwnode_endpoint_parse(ep, &vep);
> > > +	if (err) {
> > > +		fwnode_handle_put(ep);
> > > +		return err;
> > > +	}
> > > +
> > > +	v4l2_async_nf_init(&tc358746->notifier);
> > > +	asd = v4l2_async_nf_add_fwnode_remote(&tc358746->notifier, ep,
> > > +					      struct v4l2_async_subdev);
> > > +	fwnode_handle_put(ep);
> > > +
> > > +	if (IS_ERR(asd)) {
> > > +		err = PTR_ERR(asd);
> > > +		goto err_cleanup;
> > > +	}
> > > +
> > > +	tc358746->notifier.ops = &tc358746_notify_ops;
> > > +
> > > +	err = v4l2_async_subdev_nf_register(&tc358746->sd, &tc358746->notifier);
> > > +	if (err)
> > > +		goto err_cleanup;
> > > +
> > > +	tc358746->sd.fwnode = fwnode_graph_get_endpoint_by_id(
> > > +		dev_fwnode(tc358746->sd.dev), TC358746_SOURCE, 0, 0);
> > > +
> > > +	err = v4l2_async_register_subdev(&tc358746->sd);
> > > +	if (err)
> > > +		goto err_unregister;
> > > +
> > > +	return 0;
> > > +
> > > +err_unregister:
> > > +	fwnode_handle_put(tc358746->sd.fwnode);
> > > +	v4l2_async_nf_unregister(&tc358746->notifier);
> > > +err_cleanup:
> > > +	v4l2_async_nf_cleanup(&tc358746->notifier);
> > > +
> > > +	return err;
> > > +}
> > > +
> > > +static int tc358746_probe(struct i2c_client *client)
> > > +{
> > > +	struct device *dev = &client->dev;
> > > +	struct tc358746 *tc358746;
> > > +	unsigned long refclk;
> > > +	unsigned int i;
> > > +	int err;
> > > +
> > > +	tc358746 = devm_kzalloc(&client->dev, sizeof(*tc358746), GFP_KERNEL);
> > > +	if (!tc358746)
> > > +		return -ENOMEM;
> > > +
> > > +	tc358746->regmap = devm_regmap_init_i2c(client, &tc358746_regmap_config);
> > > +	if (IS_ERR(tc358746->regmap))
> > > +		return dev_err_probe(dev, PTR_ERR(tc358746->regmap),
> > > +				     "Failed to init regmap\n");
> > > +
> > > +	tc358746->refclk = devm_clk_get(dev, "refclk");
> > > +	if (IS_ERR(tc358746->refclk))
> > > +		return dev_err_probe(dev, PTR_ERR(tc358746->refclk),
> > > +				     "Failed to get refclk\n");
> > > +
> > > +	err = clk_prepare_enable(tc358746->refclk);
> > > +	if (err)
> > > +		return dev_err_probe(dev, err,
> > > +				     "Failed to enable refclk\n");
> > > +
> > > +	refclk = clk_get_rate(tc358746->refclk);
> > > +	clk_disable_unprepare(tc358746->refclk);
> > > +
> > > +	if (refclk < 6 * HZ_PER_MHZ || refclk > 40 * HZ_PER_MHZ)
> > > +		return dev_err_probe(dev, -EINVAL, "Invalid refclk range\n");
> > > +
> > > +	for (i = 0; i < ARRAY_SIZE(tc358746_supplies); i++)
> > > +		tc358746->supplies[i].supply = tc358746_supplies[i];
> > > +
> > > +	err = devm_regulator_bulk_get(dev, ARRAY_SIZE(tc358746_supplies),
> > > +				      tc358746->supplies);
> > > +	if (err)
> > > +		return dev_err_probe(dev, err, "Failed to get supplies\n");
> > > +
> > > +	tc358746->reset_gpio = devm_gpiod_get_optional(dev, "reset",
> > > +						       GPIOD_OUT_HIGH);
> > > +	if (IS_ERR(tc358746->reset_gpio))
> > > +		return dev_err_probe(dev, PTR_ERR(tc358746->reset_gpio),
> > > +				     "Failed to get reset-gpios\n");
> > > +
> > > +	err = tc358746_init_subdev(tc358746, client);
> > > +	if (err)
> > > +		return dev_err_probe(dev, err, "Failed to init subdev\n");
> > > +
> > > +	err = tc358746_init_output_port(tc358746, refclk);
> > > +	if (err)
> > > +		goto err_subdev;
> > > +
> > > +	/*
> > > +	 * Keep this order since we need the output port link-frequencies
> > > +	 * information.
> > > +	 */
> > > +	err = tc358746_init_controls(tc358746);
> > > +	if (err)
> > > +		goto err_fwnode;
> > > +
> > > +	dev_set_drvdata(dev, tc358746);
> > > +
> > > +	/* Set to 1sec to give the stream reconfiguration enough time */
> > > +	pm_runtime_set_autosuspend_delay(dev, 1000);
> > > +	pm_runtime_use_autosuspend(dev);
> > > +	pm_runtime_enable(dev);
> > > +
> > > +	err = tc358746_init_hw(tc358746);
> > > +	if (err)
> > > +		goto err_pm;
> > > +
> > > +	err = tc358746_setup_mclk_provider(tc358746);
> > > +	if (err)
> > > +		goto err_pm;
> > > +
> > > +	err = tc358746_async_register(tc358746);
> > > +	if (err < 0)
> > > +		goto err_pm;
> > > +
> > > +	dev_dbg(dev, "%s found @ 0x%x (%s)\n", client->name,
> > > +		client->addr, client->adapter->name);
> > > +
> > > +	return 0;
> > > +
> > > +err_pm:
> > > +	pm_runtime_disable(dev);
> > > +	pm_runtime_set_suspended(dev);
> > > +	pm_runtime_dont_use_autosuspend(dev);
> > > +	v4l2_ctrl_handler_free(&tc358746->ctrl_hdl);
> > > +err_fwnode:
> > > +	v4l2_fwnode_endpoint_free(&tc358746->csi_vep);
> > > +err_subdev:
> > > +	v4l2_subdev_cleanup(&tc358746->sd);
> > > +	media_entity_cleanup(&tc358746->sd.entity);
> > > +
> > > +	return err;
> > > +}
> > > +
> > > +static int tc358746_remove(struct i2c_client *client)
> > > +{
> > > +	struct v4l2_subdev *sd = i2c_get_clientdata(client);
> > > +	struct tc358746 *tc358746 = to_tc358746(sd);
> > > +
> > > +	v4l2_subdev_cleanup(sd);
> > > +	v4l2_ctrl_handler_free(&tc358746->ctrl_hdl);
> > > +	v4l2_fwnode_endpoint_free(&tc358746->csi_vep);
> > > +	v4l2_async_nf_unregister(&tc358746->notifier);
> > > +	v4l2_async_nf_cleanup(&tc358746->notifier);
> > > +	fwnode_handle_put(sd->fwnode);
> > > +	v4l2_async_unregister_subdev(sd);
> > > +	media_entity_cleanup(&sd->entity);
> > > +
> > > +	pm_runtime_disable(sd->dev);
> > > +	pm_runtime_set_suspended(sd->dev);
> > > +	pm_runtime_dont_use_autosuspend(sd->dev);
> > > +
> > > +	return 0;
> > > +}
> > > +
> > > +static int tc358746_suspend(struct device *dev)
> > > +{
> > > +	struct tc358746 *tc358746 = dev_get_drvdata(dev);
> > > +	int err;
> > > +
> > > +	clk_disable_unprepare(tc358746->refclk);
> > > +
> > > +	err = regulator_bulk_disable(ARRAY_SIZE(tc358746_supplies),
> > > +				     tc358746->supplies);
> > > +	if (err)
> > > +		clk_prepare_enable(tc358746->refclk);
> > > +
> > > +	return err;
> > > +}
> > > +
> > > +static int tc358746_resume(struct device *dev)
> > > +{
> > > +	struct tc358746 *tc358746 = dev_get_drvdata(dev);
> > > +	int err;
> > > +
> > > +	gpiod_set_value(tc358746->reset_gpio, 1);
> > > +
> > > +	err = regulator_bulk_enable(ARRAY_SIZE(tc358746_supplies),
> > > +				    tc358746->supplies);
> > > +	if (err)
> > > +		return err;
> > > +
> > > +	/* min. 200ns */
> > > +	usleep_range(10, 20);
> > > +
> > > +	gpiod_set_value(tc358746->reset_gpio, 0);
> > > +
> > > +	err = clk_prepare_enable(tc358746->refclk);
> > > +	if (err)
> > > +		goto err;
> > > +
> > > +	/* min. 700us ... 1ms */
> > > +	usleep_range(1000, 1500);
> > > +
> > > +	/*
> > > +	 * Enable the PLL here since it can be called by the clk-framework or by
> > > +	 * the .s_stream() callback. So this is the common place for both.
> > > +	 */
> > > +	err = tc358746_apply_pll_config(tc358746);
> > > +	if (err)
> > > +		goto err_clk;
> > > +
> > > +	return 0;
> > > +
> > > +err_clk:
> > > +	clk_disable_unprepare(tc358746->refclk);
> > > +err:
> > > +	regulator_bulk_disable(ARRAY_SIZE(tc358746_supplies),
> > > +			       tc358746->supplies);
> > > +	return err;
> > > +}
> > > +
> > > +DEFINE_RUNTIME_DEV_PM_OPS(tc358746_pm_ops, tc358746_suspend,
> > > +			  tc358746_resume, NULL);
> > > +
> > > +static const struct of_device_id __maybe_unused tc358746_of_match[] = {
> > > +	{ .compatible = "toshiba,tc358746" },
> > > +	{ },
> > > +};
> > > +MODULE_DEVICE_TABLE(of, tc358746_of_match);
> > > +
> > > +static struct i2c_driver tc358746_driver = {
> > > +	.driver = {
> > > +		.name = "tc358746",
> > > +		.pm = pm_ptr(&tc358746_pm_ops),
> > > +		.of_match_table = tc358746_of_match,
> > > +	},
> > > +	.probe_new = tc358746_probe,
> > > +	.remove = tc358746_remove,
> > > +};
> > > +
> > > +module_i2c_driver(tc358746_driver);
> > > +
> > > +MODULE_DESCRIPTION("Toshiba TC358746 Parallel to CSI-2 bridge driver");
> > > +MODULE_AUTHOR("Marco Felsch <kernel@pengutronix.de>");
> > > +MODULE_LICENSE("GPL");

-- 
Regards,

Laurent Pinchart

-- 
linux-phy mailing list
linux-phy@lists.infradead.org
https://lists.infradead.org/mailman/listinfo/linux-phy

Re: [PATCH v3 4/4] media: tc358746: add Toshiba TC358746 Parallel to CSI-2 bridge driver

[Marco Felsch]

On 22-09-23, Laurent Pinchart wrote:
> Hi Marco,
> 
> On Fri, Sep 23, 2022 at 11:27:26AM +0200, Marco Felsch wrote:

...

> > > > +static int tc358746_write(struct tc358746 *tc358746, u32 reg, u32 val)
> > > > +{
> > > > +	size_t count;
> > > > +	int err;
> > > > +
> > > > +	/* 32-bit registers starting from CLW_DPHYCONTTX */
> > > > +	count = reg < CLW_DPHYCONTTX_REG ? 1 : 2;
> > > > +
> > > > +	err = regmap_bulk_write(tc358746->regmap, reg, &val, count);
> > > > +	if (err)
> > > > +		dev_dbg(tc358746->sd.dev,
> > > > +			"Failed to write reg:0x%04x val:0x%04x\n", reg, val);
> > > 
> > > I'm not sure if the value is relevant here, but I'd add the error, it's
> > > useful to know what kind of I2C issue occurred. Same for read().
> > 
> > Yeah.. I'm not sure, since you told me to not flood the kernel log. If
> > someone recognised error while probing or streaming the debug will be
> > turned on anyways. However, I will make it a dev_err() since this
> > shouldnt appear normally, you're right.
> 
> Sorry, I meant printing the value of the error code in the message, the
> err variable. dev_err() is probably good too actually, as this isn't
> meant to happen.

Sorry that was my fault, I misread your comment.. Anyway since we agree
with dev_err() and I added the err value into the message, everything is
fine :)

Regards,
  Marco

Re: [PATCH v3 4/4] media: tc358746: add Toshiba TC358746 Parallel to CSI-2 bridge driver

[Marco Felsch]

On 22-09-23, Laurent Pinchart wrote:
> Hi Marco,
> 
> On Fri, Sep 23, 2022 at 11:27:26AM +0200, Marco Felsch wrote:

...

> > > > +static int tc358746_write(struct tc358746 *tc358746, u32 reg, u32 val)
> > > > +{
> > > > +	size_t count;
> > > > +	int err;
> > > > +
> > > > +	/* 32-bit registers starting from CLW_DPHYCONTTX */
> > > > +	count = reg < CLW_DPHYCONTTX_REG ? 1 : 2;
> > > > +
> > > > +	err = regmap_bulk_write(tc358746->regmap, reg, &val, count);
> > > > +	if (err)
> > > > +		dev_dbg(tc358746->sd.dev,
> > > > +			"Failed to write reg:0x%04x val:0x%04x\n", reg, val);
> > > 
> > > I'm not sure if the value is relevant here, but I'd add the error, it's
> > > useful to know what kind of I2C issue occurred. Same for read().
> > 
> > Yeah.. I'm not sure, since you told me to not flood the kernel log. If
> > someone recognised error while probing or streaming the debug will be
> > turned on anyways. However, I will make it a dev_err() since this
> > shouldnt appear normally, you're right.
> 
> Sorry, I meant printing the value of the error code in the message, the
> err variable. dev_err() is probably good too actually, as this isn't
> meant to happen.

Sorry that was my fault, I misread your comment.. Anyway since we agree
with dev_err() and I added the err value into the message, everything is
fine :)

Regards,
  Marco

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Re: [PATCH v3 4/4] media: tc358746: add Toshiba TC358746 Parallel to CSI-2 bridge driver

[Sakari Ailus]

Hi Marco,

Thanks for the update. A few small things below.

On Thu, Sep 22, 2022 at 03:48:43PM +0200, Marco Felsch wrote:
...
> +static int tc358746_apply_misc_config(struct tc358746 *tc358746)
> +{
> +	const struct v4l2_mbus_framefmt *mbusfmt;
> +	struct v4l2_subdev *sd = &tc358746->sd;
> +	struct v4l2_subdev_state *sink_state;
> +	const struct tc358746_format *fmt;
> +	struct device *dev = sd->dev;
> +	u32 val;
> +	int err;
> +
> +	sink_state = v4l2_subdev_lock_and_get_active_state(sd);
> +	mbusfmt = v4l2_subdev_get_pad_format(sd, sink_state, TC358746_SINK);
> +	v4l2_subdev_unlock_state(sink_state);
> +
> +	fmt = tc358746_get_format_by_code(TC358746_SINK, mbusfmt->code);

You can no longer access mbusfmt here as you've already unlocked subdev
state.

> +
> +	/* Self defined CSI user data type id's are not supported yet */
> +	val = PDFMT(fmt->pdformat);
> +	dev_dbg(dev, "DATAFMT: 0x%x\n", val);
> +	err = tc358746_write(tc358746, DATAFMT_REG, val);
> +	if (err)
> +		return err;
> +
> +	val = PDATAF(fmt->pdataf);
> +	dev_dbg(dev, "CONFCTL[PDATAF]: 0x%x\n", fmt->pdataf);
> +	err = tc358746_update_bits(tc358746, CONFCTL_REG, PDATAF_MASK, val);
> +	if (err)
> +		return err;
> +
> +	val = tc358746->vb_size / 32;
> +	dev_dbg(dev, "FIFOCTL: %u (0x%x)\n", val, val);
> +	err = tc358746_write(tc358746, FIFOCTL_REG, val);
> +	if (err)
> +		return err;
> +
> +	/* Total number of bytes for each line/width */
> +	val = mbusfmt->width * fmt->bpp / 8;
> +	dev_dbg(dev, "WORDCNT: %u (0x%x)\n", val, val);
> +	return tc358746_write(tc358746, WORDCNT_REG, val);
> +}

...

> +static int tc358746_s_stream(struct v4l2_subdev *sd, int enable)
> +{
> +	struct tc358746 *tc358746 = to_tc358746(sd);
> +	struct v4l2_subdev *src;
> +	int err;
> +
> +	dev_dbg(sd->dev, "%sable\n", enable ? "en" : "dis");
> +
> +	src = tc358746_get_remote_sd(&tc358746->pads[TC358746_SINK]);
> +	if (!src)
> +		return -EPIPE;
> +
> +	if (enable) {
> +		err = pm_runtime_resume_and_get(sd->dev);
> +		if (err)
> +			return err;
> +
> +		err = tc358746_apply_dphy_config(tc358746);
> +		if (err)
> +			goto err_out;
> +
> +		err = tc358746_apply_misc_config(tc358746);
> +		if (err)
> +			goto err_out;
> +
> +		err = tc358746_enable_csi_lanes(tc358746, 1);
> +		if (err)
> +			goto err_out;
> +
> +		err = tc358746_enable_csi_module(tc358746, 1);
> +		if (err)
> +			goto err_out;
> +
> +		err = tc358746_enable_parallel_port(tc358746, 1);
> +		if (err)
> +			goto err_out;
> +
> +		err = v4l2_subdev_call(src, video, s_stream, 1);
> +		if (err)
> +			goto err_out;
> +
> +		return err;

This can be return 0.

> +
> +err_out:
> +		pm_runtime_mark_last_busy(sd->dev);
> +		pm_runtime_put_sync_autosuspend(sd->dev);
> +
> +		return err;
> +	}

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Sakari Ailus

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Re: [PATCH v3 4/4] media: tc358746: add Toshiba TC358746 Parallel to CSI-2 bridge driver

[Sakari Ailus]

Hi Marco,

Thanks for the update. A few small things below.

On Thu, Sep 22, 2022 at 03:48:43PM +0200, Marco Felsch wrote:
...
> +static int tc358746_apply_misc_config(struct tc358746 *tc358746)
> +{
> +	const struct v4l2_mbus_framefmt *mbusfmt;
> +	struct v4l2_subdev *sd = &tc358746->sd;
> +	struct v4l2_subdev_state *sink_state;
> +	const struct tc358746_format *fmt;
> +	struct device *dev = sd->dev;
> +	u32 val;
> +	int err;
> +
> +	sink_state = v4l2_subdev_lock_and_get_active_state(sd);
> +	mbusfmt = v4l2_subdev_get_pad_format(sd, sink_state, TC358746_SINK);
> +	v4l2_subdev_unlock_state(sink_state);
> +
> +	fmt = tc358746_get_format_by_code(TC358746_SINK, mbusfmt->code);

You can no longer access mbusfmt here as you've already unlocked subdev
state.

> +
> +	/* Self defined CSI user data type id's are not supported yet */
> +	val = PDFMT(fmt->pdformat);
> +	dev_dbg(dev, "DATAFMT: 0x%x\n", val);
> +	err = tc358746_write(tc358746, DATAFMT_REG, val);
> +	if (err)
> +		return err;
> +
> +	val = PDATAF(fmt->pdataf);
> +	dev_dbg(dev, "CONFCTL[PDATAF]: 0x%x\n", fmt->pdataf);
> +	err = tc358746_update_bits(tc358746, CONFCTL_REG, PDATAF_MASK, val);
> +	if (err)
> +		return err;
> +
> +	val = tc358746->vb_size / 32;
> +	dev_dbg(dev, "FIFOCTL: %u (0x%x)\n", val, val);
> +	err = tc358746_write(tc358746, FIFOCTL_REG, val);
> +	if (err)
> +		return err;
> +
> +	/* Total number of bytes for each line/width */
> +	val = mbusfmt->width * fmt->bpp / 8;
> +	dev_dbg(dev, "WORDCNT: %u (0x%x)\n", val, val);
> +	return tc358746_write(tc358746, WORDCNT_REG, val);
> +}

...

> +static int tc358746_s_stream(struct v4l2_subdev *sd, int enable)
> +{
> +	struct tc358746 *tc358746 = to_tc358746(sd);
> +	struct v4l2_subdev *src;
> +	int err;
> +
> +	dev_dbg(sd->dev, "%sable\n", enable ? "en" : "dis");
> +
> +	src = tc358746_get_remote_sd(&tc358746->pads[TC358746_SINK]);
> +	if (!src)
> +		return -EPIPE;
> +
> +	if (enable) {
> +		err = pm_runtime_resume_and_get(sd->dev);
> +		if (err)
> +			return err;
> +
> +		err = tc358746_apply_dphy_config(tc358746);
> +		if (err)
> +			goto err_out;
> +
> +		err = tc358746_apply_misc_config(tc358746);
> +		if (err)
> +			goto err_out;
> +
> +		err = tc358746_enable_csi_lanes(tc358746, 1);
> +		if (err)
> +			goto err_out;
> +
> +		err = tc358746_enable_csi_module(tc358746, 1);
> +		if (err)
> +			goto err_out;
> +
> +		err = tc358746_enable_parallel_port(tc358746, 1);
> +		if (err)
> +			goto err_out;
> +
> +		err = v4l2_subdev_call(src, video, s_stream, 1);
> +		if (err)
> +			goto err_out;
> +
> +		return err;

This can be return 0.

> +
> +err_out:
> +		pm_runtime_mark_last_busy(sd->dev);
> +		pm_runtime_put_sync_autosuspend(sd->dev);
> +
> +		return err;
> +	}

-- 
Kind regards,

Sakari Ailus

Re: [PATCH v3 4/4] media: tc358746: add Toshiba TC358746 Parallel to CSI-2 bridge driver

[Marco Felsch]

Hi Sakari,

On 22-09-23, Sakari Ailus wrote:
> Hi Marco,
> 
> Thanks for the update. A few small things below.
> 
> On Thu, Sep 22, 2022 at 03:48:43PM +0200, Marco Felsch wrote:
> ...
> > +static int tc358746_apply_misc_config(struct tc358746 *tc358746)
> > +{
> > +	const struct v4l2_mbus_framefmt *mbusfmt;
> > +	struct v4l2_subdev *sd = &tc358746->sd;
> > +	struct v4l2_subdev_state *sink_state;
> > +	const struct tc358746_format *fmt;
> > +	struct device *dev = sd->dev;
> > +	u32 val;
> > +	int err;
> > +
> > +	sink_state = v4l2_subdev_lock_and_get_active_state(sd);
> > +	mbusfmt = v4l2_subdev_get_pad_format(sd, sink_state, TC358746_SINK);
> > +	v4l2_subdev_unlock_state(sink_state);
> > +
> > +	fmt = tc358746_get_format_by_code(TC358746_SINK, mbusfmt->code);
> 
> You can no longer access mbusfmt here as you've already unlocked subdev
> state.

You're right, Laurent also mentioned this but this function gets called
during .s_stream(on) so the format shouldn't be changed that late.
However since you're the 2nd with the thought, I will fix it in the v4.

> > +
> > +	/* Self defined CSI user data type id's are not supported yet */
> > +	val = PDFMT(fmt->pdformat);
> > +	dev_dbg(dev, "DATAFMT: 0x%x\n", val);
> > +	err = tc358746_write(tc358746, DATAFMT_REG, val);
> > +	if (err)
> > +		return err;
> > +
> > +	val = PDATAF(fmt->pdataf);
> > +	dev_dbg(dev, "CONFCTL[PDATAF]: 0x%x\n", fmt->pdataf);
> > +	err = tc358746_update_bits(tc358746, CONFCTL_REG, PDATAF_MASK, val);
> > +	if (err)
> > +		return err;
> > +
> > +	val = tc358746->vb_size / 32;
> > +	dev_dbg(dev, "FIFOCTL: %u (0x%x)\n", val, val);
> > +	err = tc358746_write(tc358746, FIFOCTL_REG, val);
> > +	if (err)
> > +		return err;
> > +
> > +	/* Total number of bytes for each line/width */
> > +	val = mbusfmt->width * fmt->bpp / 8;
> > +	dev_dbg(dev, "WORDCNT: %u (0x%x)\n", val, val);
> > +	return tc358746_write(tc358746, WORDCNT_REG, val);
> > +}
> 
> ...
> 
> > +static int tc358746_s_stream(struct v4l2_subdev *sd, int enable)
> > +{
> > +	struct tc358746 *tc358746 = to_tc358746(sd);
> > +	struct v4l2_subdev *src;
> > +	int err;
> > +
> > +	dev_dbg(sd->dev, "%sable\n", enable ? "en" : "dis");
> > +
> > +	src = tc358746_get_remote_sd(&tc358746->pads[TC358746_SINK]);
> > +	if (!src)
> > +		return -EPIPE;
> > +
> > +	if (enable) {
> > +		err = pm_runtime_resume_and_get(sd->dev);
> > +		if (err)
> > +			return err;
> > +
> > +		err = tc358746_apply_dphy_config(tc358746);
> > +		if (err)
> > +			goto err_out;
> > +
> > +		err = tc358746_apply_misc_config(tc358746);
> > +		if (err)
> > +			goto err_out;
> > +
> > +		err = tc358746_enable_csi_lanes(tc358746, 1);
> > +		if (err)
> > +			goto err_out;
> > +
> > +		err = tc358746_enable_csi_module(tc358746, 1);
> > +		if (err)
> > +			goto err_out;
> > +
> > +		err = tc358746_enable_parallel_port(tc358746, 1);
> > +		if (err)
> > +			goto err_out;
> > +
> > +		err = v4l2_subdev_call(src, video, s_stream, 1);
> > +		if (err)
> > +			goto err_out;
> > +
> > +		return err;
> 
> This can be return 0.

Sure.

Regards,
  Marco

> 
> > +
> > +err_out:
> > +		pm_runtime_mark_last_busy(sd->dev);
> > +		pm_runtime_put_sync_autosuspend(sd->dev);
> > +
> > +		return err;
> > +	}
> 
> -- 
> Kind regards,
> 
> Sakari Ailus
> 

Re: [PATCH v3 4/4] media: tc358746: add Toshiba TC358746 Parallel to CSI-2 bridge driver

[Marco Felsch]

Hi Sakari,

On 22-09-23, Sakari Ailus wrote:
> Hi Marco,
> 
> Thanks for the update. A few small things below.
> 
> On Thu, Sep 22, 2022 at 03:48:43PM +0200, Marco Felsch wrote:
> ...
> > +static int tc358746_apply_misc_config(struct tc358746 *tc358746)
> > +{
> > +	const struct v4l2_mbus_framefmt *mbusfmt;
> > +	struct v4l2_subdev *sd = &tc358746->sd;
> > +	struct v4l2_subdev_state *sink_state;
> > +	const struct tc358746_format *fmt;
> > +	struct device *dev = sd->dev;
> > +	u32 val;
> > +	int err;
> > +
> > +	sink_state = v4l2_subdev_lock_and_get_active_state(sd);
> > +	mbusfmt = v4l2_subdev_get_pad_format(sd, sink_state, TC358746_SINK);
> > +	v4l2_subdev_unlock_state(sink_state);
> > +
> > +	fmt = tc358746_get_format_by_code(TC358746_SINK, mbusfmt->code);
> 
> You can no longer access mbusfmt here as you've already unlocked subdev
> state.

You're right, Laurent also mentioned this but this function gets called
during .s_stream(on) so the format shouldn't be changed that late.
However since you're the 2nd with the thought, I will fix it in the v4.

> > +
> > +	/* Self defined CSI user data type id's are not supported yet */
> > +	val = PDFMT(fmt->pdformat);
> > +	dev_dbg(dev, "DATAFMT: 0x%x\n", val);
> > +	err = tc358746_write(tc358746, DATAFMT_REG, val);
> > +	if (err)
> > +		return err;
> > +
> > +	val = PDATAF(fmt->pdataf);
> > +	dev_dbg(dev, "CONFCTL[PDATAF]: 0x%x\n", fmt->pdataf);
> > +	err = tc358746_update_bits(tc358746, CONFCTL_REG, PDATAF_MASK, val);
> > +	if (err)
> > +		return err;
> > +
> > +	val = tc358746->vb_size / 32;
> > +	dev_dbg(dev, "FIFOCTL: %u (0x%x)\n", val, val);
> > +	err = tc358746_write(tc358746, FIFOCTL_REG, val);
> > +	if (err)
> > +		return err;
> > +
> > +	/* Total number of bytes for each line/width */
> > +	val = mbusfmt->width * fmt->bpp / 8;
> > +	dev_dbg(dev, "WORDCNT: %u (0x%x)\n", val, val);
> > +	return tc358746_write(tc358746, WORDCNT_REG, val);
> > +}
> 
> ...
> 
> > +static int tc358746_s_stream(struct v4l2_subdev *sd, int enable)
> > +{
> > +	struct tc358746 *tc358746 = to_tc358746(sd);
> > +	struct v4l2_subdev *src;
> > +	int err;
> > +
> > +	dev_dbg(sd->dev, "%sable\n", enable ? "en" : "dis");
> > +
> > +	src = tc358746_get_remote_sd(&tc358746->pads[TC358746_SINK]);
> > +	if (!src)
> > +		return -EPIPE;
> > +
> > +	if (enable) {
> > +		err = pm_runtime_resume_and_get(sd->dev);
> > +		if (err)
> > +			return err;
> > +
> > +		err = tc358746_apply_dphy_config(tc358746);
> > +		if (err)
> > +			goto err_out;
> > +
> > +		err = tc358746_apply_misc_config(tc358746);
> > +		if (err)
> > +			goto err_out;
> > +
> > +		err = tc358746_enable_csi_lanes(tc358746, 1);
> > +		if (err)
> > +			goto err_out;
> > +
> > +		err = tc358746_enable_csi_module(tc358746, 1);
> > +		if (err)
> > +			goto err_out;
> > +
> > +		err = tc358746_enable_parallel_port(tc358746, 1);
> > +		if (err)
> > +			goto err_out;
> > +
> > +		err = v4l2_subdev_call(src, video, s_stream, 1);
> > +		if (err)
> > +			goto err_out;
> > +
> > +		return err;
> 
> This can be return 0.

Sure.

Regards,
  Marco

> 
> > +
> > +err_out:
> > +		pm_runtime_mark_last_busy(sd->dev);
> > +		pm_runtime_put_sync_autosuspend(sd->dev);
> > +
> > +		return err;
> > +	}
> 
> -- 
> Kind regards,
> 
> Sakari Ailus
> 

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