Re: [PATCH] mmc: pwrseq_simple: fix probe failure when CONFIG_RESET_GPIO is enabled

[Krzysztof Kozlowski <krzk@kernel.org>]

On 05/03/2026 11:04, Bartosz Golaszewski wrote:
> 
>>> Philipp, Krzysztof: what do you think?
>>
>> I think this is a missing feature in reset-gpio.
>> This driver could fall back to to devm_gpiod_get_array() also if
>> devm_reset_control_get_optional_shared() returns -ENOENT instead of
>> erroring out (maybe -ENOTSUPP would be a better return code for [1]?).
>>
> 
> I did not write the initial version but Krzysztof: is there any reason we only
> support a single, two-cell GPIO? Would it be problematic to support any kind of
> reset GPIO setup?

It was only due to limitation of my initial solution - see even a TODO
note in reset/core.c. I think the problem I had is that GPIO specifier
without flags (so cells=1) would mess with GPIO_LOOKUP(). And if we have
cells=3, where do the flags are? If you assume flags are last argument,
that's an implied ABI encoded in the reset core.

Well, heh, implied ABI that 2nd argument are flags is already there, so
the code is partially hacky, I agree.

So honestly I believe that GPIO core should handle all this mapping of
original reset-gpios property into platform data to reset-gpio driver.
That's the answer for your question "would it be problematic".


For reference, original patch:
https://lore.kernel.org/all/20240129115216.96479-5-krzysztof.kozlowski@linaro.org/

Best regards,
Krzysztof