Re: [PATCH v5 7/7] ARM: dts: sun9i: Switch to the AC100 RTC clock outputs for osc32k

From: Chen-Yu Tsai
Date: Mon Jul 11 2016 - 22:03:25 EST


On Mon, Jul 11, 2016 at 2:50 PM, Maxime Ripard
<maxime.ripard@xxxxxxxxxxxxxxxxxx> wrote:
> Hi,
>
> On Fri, Jul 08, 2016 at 10:33:42PM +0800, Chen-Yu Tsai wrote:
>> The 32.768 kHz clock inside the A80 SoC is fed from an external source,
>> typically the AC100 RTC module.
>>
>> Make the osc32k placeholder a fixed-factor clock so board dts files can
>> specify its source.
>>
>> Signed-off-by: Chen-Yu Tsai <wens@xxxxxxxx>
>> ---
>> Changes since v4: none
>> Changes since v3: none
>> Changes since v2: none
>> Changes since v1: none
>> ---
>> arch/arm/boot/dts/sun9i-a80-cubieboard4.dts | 5 +++++
>> arch/arm/boot/dts/sun9i-a80-optimus.dts | 5 +++++
>> arch/arm/boot/dts/sun9i-a80.dtsi | 9 +++------
>> 3 files changed, 13 insertions(+), 6 deletions(-)
>>
>> diff --git a/arch/arm/boot/dts/sun9i-a80-cubieboard4.dts b/arch/arm/boot/dts/sun9i-a80-cubieboard4.dts
>> index cf2f4b72a841..04b014603659 100644
>> --- a/arch/arm/boot/dts/sun9i-a80-cubieboard4.dts
>> +++ b/arch/arm/boot/dts/sun9i-a80-cubieboard4.dts
>> @@ -103,6 +103,11 @@
>> allwinner,drive = <SUN4I_PINCTRL_40_MA>;
>> };
>>
>> +&osc32k {
>> + /* osc32k input is from AC100 */
>> + clocks = <&ac100_rtc 0>;
>> +};
>> +
>
> I'm guessing that an unresolved dependency when the driver has not
> loaded yet, or is not even compiled ?
>
> How is it working then?

I assume the clk framework will leave it unresolved and unusable.
Also it seems that none of existing clks use it as a parent by
default. I will need to check the remaining unimplemented ones
though.

ChenYu