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

[Chen-Yu Tsai]

On Tue, Jul 12, 2016 at 10:02 AM, Chen-Yu Tsai <wens@xxxxxxxx> wrote:
> 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.

On the latest sunxi-next kernel, one clock is clocked from osc32k, which
becomes an orphaned clock:

   clock                         enable_cnt  prepare_cnt        rate
accuracy   phase
----------------------------------------------------------------------------------------
 osc24M                                   6            6    24000000
       0 0
    r_ir                                  1            1     8000000
       0 0
 r_1wire                                  0            0           0
       0 0

r_ir is clocked from osc32k by default, but the clk_set_rate call in the
IR driver seems to forces it to reparent to the working osc24M clock.

So I think we're good here. Can you merge the 3 remaining dts patches?

Thanks
ChenYu