Re: [PATCH 3/5] gpio: vf610: add i.MX8ULP of_device_id entry

[Krzysztof Kozlowski <krzysztof.kozlowski@xxxxxxxxxx>]

On 14/09/2023 10:48, Linus Walleij wrote:
> On Thu, Sep 14, 2023 at 7:48 AM Krzysztof Kozlowski
> <krzysztof.kozlowski@xxxxxxxxxx> wrote:
>> On 14/09/2023 04:20, Peng Fan (OSS) wrote:
>>> From: Peng Fan <peng.fan@xxxxxxx>
>>>
>>> i.MX8ULP supports two interrupts, while i.MX7ULP supports one interrupt.
>>> So from hardware perspective, they are not compatible.
>>>
>>> So add entry for i.MX8ULP.
>>>
>>> Signed-off-by: Peng Fan <peng.fan@xxxxxxx>
>>> ---
>>>  drivers/gpio/gpio-vf610.c | 1 +
>>>  1 file changed, 1 insertion(+)
>>>
>>> diff --git a/drivers/gpio/gpio-vf610.c b/drivers/gpio/gpio-vf610.c
>>> index dbc7ba0ee72c..88f7215cdf4b 100644
>>> --- a/drivers/gpio/gpio-vf610.c
>>> +++ b/drivers/gpio/gpio-vf610.c
>>> @@ -67,6 +67,7 @@ static const struct fsl_gpio_soc_data imx_data = {
>>>  static const struct of_device_id vf610_gpio_dt_ids[] = {
>>>       { .compatible = "fsl,vf610-gpio",       .data = NULL, },
>>>       { .compatible = "fsl,imx7ulp-gpio",     .data = &imx_data, },
>>> +     { .compatible = "fsl,imx8ulp-gpio",     .data = &imx_data, },
>>
>> Why? It is the same as imx7. No need.
> 
> Because compatible = "fsl,imx7ulp-gpio" is not what is going to be in the
> device tree, but compatible = "fsl,imx8ulp-gpio"?
> 
> What am I missing here? Maybe the commit message is weird.
> 

If the devices used before and are still going to use same driver data,
they look compatible from OS point of view. Therefore usually we express
such compatibility and do not add unneeded device_id entries.

Now whether the devices are truly compatible or not, I don't know and
with some recent emails I am bit confused.

Best regards,
Krzysztof