Re: [PATCH 6/8] counter: stm32-lptimer-cnt: add support for stm32mp25

[Krzysztof Kozlowski <krzk@kernel.org>]

On 25/02/2025 15:58, Fabrice Gasnier wrote:
> On 2/25/25 13:02, Krzysztof Kozlowski wrote:
>> On Mon, Feb 24, 2025 at 07:01:48PM +0100, Fabrice Gasnier wrote:
>>> Add support for STM32MP25 SoC. Use newly introduced compatible to handle
>>> this new HW variant, even if no major change is expected on the counter
>>> driver.
>>>
>>> Signed-off-by: Fabrice Gasnier <fabrice.gasnier@foss.st.com>
>>> ---
>>>  drivers/counter/stm32-lptimer-cnt.c | 1 +
>>>  1 file changed, 1 insertion(+)
>>>
>>> diff --git a/drivers/counter/stm32-lptimer-cnt.c b/drivers/counter/stm32-lptimer-cnt.c
>>> index b249c8647639..a5dce017c37b 100644
>>> --- a/drivers/counter/stm32-lptimer-cnt.c
>>> +++ b/drivers/counter/stm32-lptimer-cnt.c
>>> @@ -508,6 +508,7 @@ static SIMPLE_DEV_PM_OPS(stm32_lptim_cnt_pm_ops, stm32_lptim_cnt_suspend,
>>>  
>>>  static const struct of_device_id stm32_lptim_cnt_of_match[] = {
>>>  	{ .compatible = "st,stm32-lptimer-counter", },
>>> +	{ .compatible = "st,stm32mp25-lptimer-counter", },
>>
>> So fully compatible? Why this change then?
> 
> Hi Krzysztof,
> 
> I should have mentioned it in the commit message:
> 
> Currently, same feature list as on STM32MP1x is supported.
> New capture input stage is now available in the hardware. It's not added
> yet to the driver.

Which is the exact meaning of compatible. Express it properly in
bindings and driver.

> 
> The Low Power Timer (LPTIM) hardware isn't fully backward compatible,

How so? How can it work then with above ID table?


Best regards,
Krzysztof