Re: [PATCH 1/2] dt-bindings: ata: add DT bindings for ahci-dm816 SATA controller

[Neil Armstrong <narmstrong@baylibre.com>]

On 03/13/2017 06:27 PM, Sergei Shtylyov wrote:
> On 03/13/2017 08:08 PM, Bartosz Golaszewski wrote:
> 
>>>> Add DT bindings for the onboard SATA controller present on the DM816x
>>>> SoCs.
>>>>
>>>> Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
>>>> ---
>>>>  Documentation/devicetree/bindings/ata/ahci-dm816.txt | 20
>>>> ++++++++++++++++++++
>>>>  1 file changed, 20 insertions(+)
>>>>  create mode 100644 Documentation/devicetree/bindings/ata/ahci-dm816.txt
>>>>
>>>> diff --git a/Documentation/devicetree/bindings/ata/ahci-dm816.txt
>>>> b/Documentation/devicetree/bindings/ata/ahci-dm816.txt
>>>> new file mode 100644
>>>> index 0000000..b87ed5a
>>>> --- /dev/null
>>>> +++ b/Documentation/devicetree/bindings/ata/ahci-dm816.txt
>>>> @@ -0,0 +1,20 @@
>>>> +Device tree binding for the TI DM816 AHCI SATA Controller
>>>> +---------------------------------------------------------
>>>> +
>>>> +Required properties:
>>>> +  - compatible: must be "ti,dm816-ahci"
>>>> +  - reg: physical base address and size of the register region used by
>>>> +         the controller (as defined by the AHCI 1.1 standard)
>>>> +  - interrupts: interrupt specifier (refer to the interrupt binding)
>>>> +  - clocks: clock specifiers (refer to the clock binding); two clocks
>>>
>>>
>>>    There should be a phandle preceding the clock specifier, all new such
>>> props are different to the old "interrupts" (which had phandle in a separate
>>> "interrupt-parent" prop).
> 
>> I'm afraid I don't understand - could you point me to an example?
> 
>    Have you read Documentation/devicetree/bindings/clock/clock-bindings.txt, on clock consumers?
>    In fact, your own example below doesn't have clock specifiers, only phandles.

Hi Sergei,

I think it's perfectly clear since he mentions the "clock bindings", so it's clear the clocks
property must conform to the bindings described in the clock/clock-bindings.txt file.
The term "specifier" is alone not very clear, but it used as is in plenty of other
bindings files about this clocks property (i.e imx-sata.txt, ahci-fsl-qoriq.txt, ahci-ceva.txt).

And it's perfectly allowed to only have a single phandle without any arguments, as described
in the clock bindings actually.

Thanks,
Neil

> 
>>>> +            must be specified: the functional clock and an external
>>>> +            reference clock
>>>> +
>>>> +Example:
>>>> +
>>>> +       sata: sata@4a140000 {
>>>> +               compatible = "ti,dm816-ahci";
>>>> +               reg = <0x4a140000 0xffff>;
> [...]
>>>> +               interrupts = <16>;
>>>> +               clocks = <&sysclk5_ck>, <&sata_refclk>;
>>>> +       };
>>>>
> 
>> Thanks,
>> Bartosz Golaszewski
> 
> MBR, Sergei
>