[PATCH v1 0/7] Add rtc refclk support for PolarFire SoC

Conor Dooley mail at conchuod.ie
Fri Apr 8 08:29:28 PDT 2022



On 08/04/2022 15:57, Krzysztof Kozlowski wrote:
> On 08/04/2022 16:36, Conor Dooley wrote:
>> Hey,
>> As I mentioned in my fixes for 5.18 [0], found out that the reference
>> clock for the rtc is actually missing from the clock driver (and the
>> dt binding).
>>
>> Currently the mpfs clock driver uses a reference clock called the
>> "msspll", set in the device tree, as the parent for the cpu/axi/ahb
>> (config) clocks. The frequency of the msspll is determined by the FPGA
>> bitstream & the bootloader configures the clock to match the bitstream.
>> The real reference is provided by a 100 or 125 MHz off chip oscillator.
>>
>> However, the msspll clock is not actually the parent of all clocks on
>> the system - the reference clock for the rtc/mtimer actually has the
>> off chip oscillator as its parent.
>>
>> This series enables reading the rate of the msspll clock, converts
>> the refclock in the device tree to the external reference & adds
>> the missing rtc reference clock.
>>
>> I assume it is okay not to add fixes tags for the rtc dt binding?
>> Since the clock was previously missing, the binding is wrong, but
>> idk if that qualifies as a fix?
> 
> Usually ABI breakage, even if accepted, should be be tagged as fix
> because it is clearly then a break of other peoples' trees...
> 

That means either a) do something messy in the clock driver or b) mark
the whole series as fixes (and roll it into [0]).

The second option seems far more sensible to me, do you agree?



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