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

[Conor Dooley]

On 08/04/2022 16:29, Conor Dooley wrote:
> 
> 
> 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?

Having thought some more about it, patches 2, 3 and the rtc part of 7
should be moved into [0] since they're fixing a binding that only
arrived in 5.18-rc1.
For the rest, make the second part of the reg optional and if it doesnt
exist just return prate for the msspll clock?

Thanks,
Conor.



[0] 
https://lore.kernel.org/linux-riscv/20220408133543.3537118-1-conor.dooley@microchip.com/