Re: [PATCH 1/3] arm64: dts: actions: add s900 clock controller nodes

[Manivannan Sadhasivam]

Hi Rob,

On 2 November 2017 at 05:36, Rob Herring <robh@xxxxxxxxxx> wrote:
> On Wed, Nov 01, 2017 at 01:24:21AM +0530, Manivannan Sadhasivam wrote:
>> This patch adds clock controller nodes for Actions Semi s900 SoC
>>
>> Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@xxxxxxxxxx>
>> ---
>>  arch/arm64/boot/dts/actions/s900.dtsi | 19 +++++++++++++++++++
>>  1 file changed, 19 insertions(+)
>>
>> diff --git a/arch/arm64/boot/dts/actions/s900.dtsi b/arch/arm64/boot/dts/actions/s900.dtsi
>> index 11406f6..c099ef1 100644
>> --- a/arch/arm64/boot/dts/actions/s900.dtsi
>> +++ b/arch/arm64/boot/dts/actions/s900.dtsi
>> @@ -5,6 +5,7 @@
>>   */
>>
>>  #include <dt-bindings/interrupt-controller/arm-gic.h>
>> +#include <dt-bindings/clock/actions,s900-clock.h>
>>
>>  / {
>>       compatible = "actions,s900";
>> @@ -88,6 +89,24 @@
>>               #clock-cells = <0>;
>>       };
>>
>> +     losc: losc {
>> +             compatible = "fixed-clock";
>> +             clock-frequency = <32768>;
>> +             #clock-cells = <0>;
>> +     };
>> +
>> +     diff_24M: diff_24M {
>> +             compatible = "fixed-clock";
>> +             clock-frequency = <24000000>;
>> +             #clock-cells = <0>;
>> +     };
>
> These 2 are inputs to the clock ctrlr? The clock controller should have
> a clocks property then.
>
Actually losc and hosc (already defined) are the sources to the clock
controller.
There isn't much documentation about diff_24M clock which seems to be only
sourcing eDP. Since, the vendor driver defined these 3 clocks (losc,
hosc, diff_24M)
as fixed rate clocks I have added them in the device tree as
"fixed-clock" nodes.

So, as per your suggestion I will add hosc and losc as clock providers for the
clock controller like below in next revision:

clocks = <&hosc>,  <&losc>;

Thanks,
Mani
>> +
>> +     clock: clock-controller@e0160000 {
>> +             compatible = "actions,s900-clock";
>> +             reg = <0 0xe0160000 0 0x1000>;
>> +             #clock-cells = <1>;
>> +     };
>> +
>>       soc {
>>               compatible = "simple-bus";
>>               #address-cells = <2>;
>> --
>> 2.7.4
>>