Re: [v2 1/3] media: dt-bindings: ov8856: Document YAML bindings

Sakari Ailus
2020-03-13T12:20:56Z

Hi Robert,

On Fri, Mar 13, 2020 at 12:03:48PM +0100, Robert Foss wrote:
> From: Dongchun Zhu <dongchun.zhu@mediatek.com>
>
> This patch adds documentation of device tree in YAML schema for the
> OV8856 CMOS image sensor.
>
> Signed-off-by: Dongchun Zhu <dongchun.zhu@mediatek.com>
> Signed-off-by: Robert Foss <robert.foss@linaro.org>
> ---
>
> - Changes since v4:
> * Fabio: Change reset-gpio to GPIO_ACTIVE_LOW, explain in description
> * Add clock-lanes property to example
> * robher: Fix syntax error in devicetree example
>
> - Changes since v3:
> * robher: Fix syntax error
> * robher: Removed maxItems
> * Fixes yaml 'make dt-binding-check' errors
>
> - Changes since v2:
> Fixes comments from from Andy, Tomasz, Sakari, Rob.
> * Convert text documentation to YAML schema.
>
> - Changes since v1:
> Fixes comments from Sakari, Tomasz
> * Add clock-frequency and link-frequencies in DT
>
> .../devicetree/bindings/media/i2c/ov8856.yaml | 133 ++++++++++++++++++
> MAINTAINERS | 1 +
> 2 files changed, 134 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/media/i2c/ov8856.yaml
>
> diff --git a/Documentation/devicetree/bindings/media/i2c/ov8856.yaml b/Documentation/devicetree/bindings/media/i2c/ov8856.yaml
> new file mode 100644
> index 000000000000..f5cb9add9277
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/media/i2c/ov8856.yaml
> @@ -0,0 +1,133 @@
> +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
> +# Copyright (c) 2019 MediaTek Inc.
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/media/i2c/ov8856.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Omnivision OV8856 CMOS Sensor Device Tree Bindings
> +
> +maintainers:
> + - Ben Kao <ben.kao@intel.com>

Is Ben aware of this?

> + - Dongchun Zhu <dongchun.zhu@mediatek.com>
> +
> +description: |-
> + The Omnivision OV8856 is a high performance, 1/4-inch, 8 megapixel, CMOS
> + image sensor that delivers 3264x2448 at 30fps. It provides full-frame,
> + sub-sampled, and windowed 10-bit MIPI images in various formats via the
> + Serial Camera Control Bus (SCCB) interface. This chip is programmable
> + through I2C and two-wire SCCB. The sensor output is available via CSI-2
> + serial data output (up to 4-lane).
> +
> +properties:
> + compatible:
> + const: ovti,ov8856
> +
> + reg:
> + maxItems: 1
> +
> + clocks:
> + maxItems: 1
> +
> + clock-names:
> + description:
> + Input clock for the sensor.
> + items:
> + - const: xvclk
> +
> + clock-frequency:
> + description:
> + Frequency of the xvclk clock in Hertz.
> +
> + dovdd-supply:
> + description:
> + Definition of the regulator used as interface power supply.
> +
> + avdd-supply:
> + description:
> + Definition of the regulator used as analog power supply.
> +
> + dvdd-supply:
> + description:
> + Definition of the regulator used as digital power supply.
> +
> + reset-gpios:
> + description:
> + The phandle and specifier for the GPIO that controls sensor reset.
> + This corresponds to the hardware pin XSHUTDOWN which is physically
> + active low.
> +
> + port:
> + type: object
> + additionalProperties: false
> + description:
> + A node containing input and output port nodes with endpoint definitions
> + as documented in
> + Documentation/devicetree/bindings/media/video-interfaces.txt
> +
> + properties:
> + endpoint:
> + type: object
> +
> + properties:
> + clock-lanes:
> + maxItems: 1
> +
> + data-lanes:
> + maxItems: 1
> +
> + remote-endpoint: true
> +
> + required:
> + - clock-lanes

Do you need the clock-lanes property, i.e. does the device support lane
reordering? If not, it should be removed.

> + - data-lanes
> + - remote-endpoint
> +
> + required:
> + - endpoint
> +
> +required:
> + - compatible
> + - reg
> + - clocks
> + - clock-names
> + - clock-frequency
> + - dovdd-supply
> + - avdd-supply
> + - dvdd-supply
> + - reset-gpios
> + - port
> +
> +additionalProperties: false
> +
> +examples:
> + - |
> + #include <dt-bindings/gpio/gpio.h>
> + #include <dt-bindings/clock/qcom,camcc-sdm845.h>
> +
> + ov8856: camera-sensor@10 {
> + compatible = "ovti,ov8856";
> + reg = <0x10>;
> + reset-gpios = <&pio 111 GPIO_ACTIVE_LOW>;
> + pinctrl-names = "default";
> + pinctrl-0 = <&clk_24m_cam>;
> +
> + clocks = <&clock_camcc CAM_CC_MCLK0_CLK>;
> + clock-names = "xvclk";
> + clock-frequency = <19200000>;
> +
> + avdd-supply = <&mt6358_vcama2_reg>;
> + dvdd-supply = <&mt6358_vcamd_reg>;
> + dovdd-supply = <&mt6358_vcamio_reg>;
> +
> + port {
> + wcam_out: endpoint {
> + remote-endpoint = <&mipi_in_wcam>;
> + clock-lanes = <0>;
> + data-lanes = <1 2 3 4>;
> + link-frequencies = /bits/ 64 <360000000 180000000>;
> + };
> + };
> + };
> +
> +...
> \ No newline at end of file
> diff --git a/MAINTAINERS b/MAINTAINERS
> index a6fbdf354d34..0f99e863978a 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -12355,6 +12355,7 @@ L: linux-media@vger.kernel.org
> T: git git://linuxtv.org/media_tree.git
> S: Maintained
> F: drivers/media/i2c/ov8856.c
> +F: Documentation/devicetree/bindings/media/i2c/ov8856.yaml
>
> OMNIVISION OV9650 SENSOR DRIVER
> M: Sakari Ailus <sakari.ailus@linux.intel.com>

--
Regards,

Sakari Ailus