Re: [PATCH v4 2/2] [media] atmel-isc: DT binding for Image Sensor Controller driver

Wu, Songjun
2016-06-12T09:36:55Z

On 6/12/2016 15:23, Boris Brezillon wrote:
> On Sun, 12 Jun 2016 11:04:27 +0800
> "Wu, Songjun" <songjun.wu-AIFe0yeh4nAAvxtiuMwx3w@public.gmane.org> wrote:
>
>> On 6/9/2016 05:57, Boris Brezillon wrote:
>>> On Tue, 7 Jun 2016 15:11:53 +0800
>>> Songjun Wu <songjun.wu-AIFe0yeh4nAAvxtiuMwx3w@public.gmane.org> wrote:
>>>
>>>> DT binding documentation for ISC driver.
>>>>
>>>> Signed-off-by: Songjun Wu <songjun.wu-AIFe0yeh4nAAvxtiuMwx3w@public.gmane.org>
>>>> ---
>>>>
>>>> Changes in v4:
>>>> - Remove the isc clock nodes.
>>>>
>>>> Changes in v3:
>>>> - Remove the 'atmel,sensor-preferred'.
>>>> - Modify the isc clock node according to the Rob's remarks.
>>>>
>>>> Changes in v2:
>>>> - Remove the unit address of the endpoint.
>>>> - Add the unit address to the clock node.
>>>> - Avoid using underscores in node names.
>>>> - Drop the "0x" in the unit address of the i2c node.
>>>> - Modify the description of 'atmel,sensor-preferred'.
>>>> - Add the description for the ISC internal clock.
>>>>
>>>> .../devicetree/bindings/media/atmel-isc.txt | 69 ++++++++++++++++++++++
>>>> 1 file changed, 69 insertions(+)
>>>> create mode 100644 Documentation/devicetree/bindings/media/atmel-isc.txt
>>>>
>>>> diff --git a/Documentation/devicetree/bindings/media/atmel-isc.txt b/Documentation/devicetree/bindings/media/atmel-isc.txt
>>>> new file mode 100644
>>>> index 0000000..3f83524
>>>> --- /dev/null
>>>> +++ b/Documentation/devicetree/bindings/media/atmel-isc.txt
>>>> @@ -0,0 +1,69 @@
>>>> +Atmel Image Sensor Controller (ISC)
>>>> +----------------------------------------------
>>>> +
>>>> +Required properties for ISC:
>>>> +- compatible
>>>> + Must be "atmel,sama5d2-isc".
>>>> +- reg
>>>> + Physical base address and length of the registers set for the device.
>>>> +- interrupts
>>>> + Should contain IRQ line for the ISC.
>>>> +- clocks
>>>> + List of clock specifiers, corresponding to entries in
>>>> + the clock-names property;
>>>> + Please refer to clock-bindings.txt.
>>>> +- clock-names
>>>> + Required elements: "hclock".
>>>> +- #clock-cells
>>>> + Should be 0.
>>>> +- clock-output-names
>>>> + Should contain the name of the clock driving the sensor master clock.
>>>> +- pinctrl-names, pinctrl-0
>>>> + Please refer to pinctrl-bindings.txt.
>>>> +
>>>> +
>>>> +ISC supports a single port node with parallel bus. It should contain one
>>>> +'port' child node with child 'endpoint' node. Please refer to the bindings
>>>> +defined in Documentation/devicetree/bindings/media/video-interfaces.txt.
>>>> +
>>>> +Example:
>>>> +isc: isc@f0008000 {
>>>> + compatible = "atmel,sama5d2-isc";
>>>> + reg = <0xf0008000 0x4000>;
>>>> + interrupts = <46 IRQ_TYPE_LEVEL_HIGH 5>;
>>>> + clocks = <&isc_clk>, <&iscck>, <&isc_gclk>;
>>>> + clock-names = "hclock";
>>>
>>> You have 3 clocks here and only one name. Are you sure this example is
>>> actually working?
>>>
>> The isc_clk is mandatory, but the other two clocks are optional, so I
>> did not give their name. This example is tested.
>> Should I add the name for the other two clocks?
>
> It only works here because you're using these clocks as the parents of
> the ispck ismck clocks, but that's an implementation detail, and
> consumer are usually referencing their clocks by name. So yes, I'd
> recommend specifying names here, even if it's not strictly required by
> your current implementation.
>
Accept. The clock names will be specified.
Thank you.

>>
>>>> + #clock-cells = <0>;
>>>> + clock-output-names = "isc-mck";
>>>> +
>>>> + port {
>>>> + #address-cells = <1>;
>>>> + #size-cells = <0>;
>>>> +
>>>> + isc_0: endpoint {
>>>> + remote-endpoint = <&ov7740_0>;
>>>> + hsync-active = <1>;
>>>> + vsync-active = <0>;
>>>> + pclk-sample = <1>;
>>>> + };
>>>> + };
>>>> +
>>>> +
>>>> +};
>>>> +
>>>> +i2c1: i2c@fc028000 {
>>>> + ov7740: camera@21 {
>>>> + compatible = "ovti,ov7740";
>>>> + reg = <0x21>;
>>>> +
>>>> + clocks = <&isc>;
>>>> + clock-names = "xvclk";
>>>> + assigned-clocks = <&isc>;
>>>> + assigned-clock-rates = <24000000>;
>>>> +
>>>> + port {
>>>> + ov7740_0: endpoint {
>>>> + remote-endpoint = <&isc_0>;
>>>> + };
>>>> + };
>>>> +};
>>>
>>>
>>>