Re: [PATCH 1/2] media: dt-bindings: Add ST VD56G3 camera sensor binding
From: Sylvain Petinot
Date: Fri May 03 2024 - 04:42:06 EST
Hi Sakari,
Thanks for the review.
On 4/24/2024 10:46 PM, Sakari Ailus wrote:
> Hi Sylvain,
>
> Thanks for the patch.
>
> On Wed, Apr 17, 2024 at 03:34:52PM +0200, Sylvain Petinot wrote:
>> Add devicetree bindings Documentation for ST VD56G3 & ST VD66GY camera
>> sensors. Update MAINTAINERS file.
>>
>> Signed-off-by: Sylvain Petinot <sylvain.petinot@xxxxxxxxxxx>
>> ---
>> .../bindings/media/i2c/st,st-vd56g3.yaml | 143 ++++++++++++++++++
>> MAINTAINERS | 9 ++
>> 2 files changed, 152 insertions(+)
>> create mode 100644 Documentation/devicetree/bindings/media/i2c/st,st-vd56g3.yaml
>>
>> diff --git a/Documentation/devicetree/bindings/media/i2c/st,st-vd56g3.yaml b/Documentation/devicetree/bindings/media/i2c/st,st-vd56g3.yaml
>> new file mode 100644
>> index 000000000000..6792c02fea5c
>> --- /dev/null
>> +++ b/Documentation/devicetree/bindings/media/i2c/st,st-vd56g3.yaml
>> @@ -0,0 +1,143 @@
>> +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
>> +# Copyright (c) 2024 STMicroelectronics SA.
>> +%YAML 1.2
>> +---
>> +$id: http://devicetree.org/schemas/media/i2c/st,st-vd56g3.yaml#
>> +$schema: http://devicetree.org/meta-schemas/core.yaml#
>> +
>> +title: STMicroelectronics VD56G3 Global Shutter Image Sensor
>> +
>> +maintainers:
>> + - Benjamin Mugnier <benjamin.mugnier@xxxxxxxxxxx>
>> + - Sylvain Petinot <sylvain.petinot@xxxxxxxxxxx>
>> +
>> +description: |-
>
>> + The STMicroelectronics VD56G3 is a 1.5 M pixel global shutter image sensor
>> + with an active array size of 1124 x 1364 (portrait orientation).
>> + It is programmable through I2C, the address is fixed to 0x10.
>> + The sensor output is available via CSI-2, which is configured as either 1 or
>> + 2 data lanes.
>
> The flow of the text could be improved by wrapping the text before 80
> columns (not earlier). Most editors can do this.
Sure, will be fixed in V2.
>
>> + The sensor provides 8 GPIOS that can be used for either
>> + - frame synchronization (Master: out-sync or Slave: in-sync)
>> + - external LED signal (synchronized with sensor integration periods)
>> +
>> +properties:
>> + compatible:
>> + enum:
>> + - st,st-vd56g3
>> + - st,st-vd66gy
>> + description:
>> + Two variants are availables; VD56G3 is a monochrome sensor while VD66GY
>> + is a colour variant.
>> +
>> + reg:
>> + maxItems: 1
>> +
>> + clocks:
>> + maxItems: 1
>> +
>> + VCORE-supply:
>> + description: Digital core power supply (1.15V)
>> +
>> + VDDIO-supply:
>> + description: Digital IO power supply (1.8V)
>> +
>> + VANA-supply:
>> + description: Analog power supply (2.8V)
>> +
>> + reset-gpios:
>> + description: Sensor reset active low GPIO (XSHUTDOWN)
>> + maxItems: 1
>> +
>> + st,leds:
>> + description:
>> + Sensor's GPIOs used for external LED control.
>> + Signal being the enveloppe of the integration time.
>> + $ref: /schemas/types.yaml#/definitions/uint32-array
>> + minItems: 1
>> + maxItems: 8
>> + items:
>> + minimum: 0
>> + maximum: 7
>> +
>> + port:
>> + $ref: /schemas/graph.yaml#/$defs/port-base
>> +
>> + properties:
>> + endpoint:
>> + $ref: /schemas/media/video-interfaces.yaml#
>> + unevaluatedProperties: false
>> +
>> + properties:
>> + clock-lanes:
>> + const: 0
>
> If the clock lane is always zero, you can drop the property.
I added it to be consistent with the data-lanes that can be
reordered/swapped. But yes, it serves nothing.
Does it make sense to keep the corresponding dev_err() message in the
driver ?
>
>> +
>> + data-lanes:
>> + minItems: 1
>> + maxItems: 2
>> + items:
>> + enum: [1, 2]
>> +
>> + link-frequencies:
>> + minItems: 1
>> + maxItems: 1
>> + items:
>> + enum: [402000000, 750000000]
>
> Is this a property of the sensor or the driver? Presumably the driver?
>
> What about the input clock frequency?
Here are the HW constraints :
- Input clock must be in [6Mhz-27Mhz]
- By design, Pll Clock must target 804Mhz : the driver set some
prediv/mult to achieve this
- Then the MIPI frequency can be configured in the range [125Mhz-750Mhz]
That being said, the common usage (and what is implemented in the
driver) is :
- 1 data lane -> MIPI freq = 750Mhz
- 2 data lanes -> MIPI freq = 402Mhz
>
>> +
>> + lane-polarities:
>> + minItems: 1
>> + maxItems: 3
>> + items:
>> + enum: [0, 1]
>
> The items are already in video-interfaces.yaml.
Ok, will be dropped for V2.
>
>> + description: Any lane can be inverted or not.
>> +
>> + required:
>> + - clock-lanes
>> + - data-lanes
>> + - link-frequencies
>> +
>> +required:
>> + - compatible
>> + - reg
>> + - clocks
>> + - VCORE-supply
>> + - VDDIO-supply
>> + - VANA-supply
>> + - reset-gpios
>> + - port
>> +
>> +additionalProperties: false
>> +
>> +examples:
>> + - |
>> + #include <dt-bindings/gpio/gpio.h>
>> +
>> + i2c {
>> + #address-cells = <1>;
>> + #size-cells = <0>;
>> +
>> + vd56g3: camera-sensor@10 {
>> + compatible = "st,st-vd56g3";
>> + reg = <0x10>;
>> +
>> + clocks = <&camera_clk_12M>;
>> +
>> + VCORE-supply = <&camera_vcore_v1v15>;
>> + VDDIO-supply = <&camera_vddio_v1v8>;
>> + VANA-supply = <&camera_vana_v2v8>;
>> +
>> + reset-gpios = <&gpio 5 GPIO_ACTIVE_LOW>;
>> + st,leds = <6>;
>> +
>> + port {
>> + vd56g3_ep: endpoint {
>> + clock-lanes = <0>;
>> + data-lanes = <1 2>;
>> + link-frequencies =
>> + /bits/ 64 <402000000>;
>
> No need for a newline after "=".
Thanks.
>
>> + remote-endpoint = <&csiphy0_ep>;
>> + };
>> + };
>> + };
>> + };
>> +...
>> diff --git a/MAINTAINERS b/MAINTAINERS
>> index 7c121493f43d..991e65627e18 100644
>> --- a/MAINTAINERS
>> +++ b/MAINTAINERS
>> @@ -20868,6 +20868,15 @@ S: Maintained
>> F: Documentation/hwmon/stpddc60.rst
>> F: drivers/hwmon/pmbus/stpddc60.c
>>
>> +ST VD56G3 DRIVER
>> +M: Benjamin Mugnier <benjamin.mugnier@xxxxxxxxxxx>
>> +M: Sylvain Petinot <sylvain.petinot@xxxxxxxxxxx>
>> +L: linux-media@xxxxxxxxxxxxxxx
>> +S: Maintained
>> +T: git git://linuxtv.org/media_tree.git
>> +F: Documentation/devicetree/bindings/media/i2c/st,st-vd56g3.yaml
>> +F: drivers/media/i2c/st-vd56g3.c
>> +
>> ST VGXY61 DRIVER
>> M: Benjamin Mugnier <benjamin.mugnier@xxxxxxxxxxx>
>> M: Sylvain Petinot <sylvain.petinot@xxxxxxxxxxx>
>
--
Sylvain