Re: [PATCH] pinctrl: bcm2835: Use bcm2835 gpio_chip label for bcm2711

[Stefan Wahren <stefan.wahren@i2se.com>]

Hi Lukas,

Am 15.02.22 um 06:52 schrieb Lukas Wunner:
> Commit b1d84a3d0a26 ("pinctrl: bcm2835: Add support for all GPIOs on
> BCM2711") used a different label for the bcm2711 gpio_chip vis-à-vis
> the bcm2835.
>
> That breaks compatibility for GPIO_LOOKUP_IDX() and GPIO_HOG() clauses
> when porting from older Raspberry Pi Compute Modules to the CM4 or CM4S.

i've some questions:

could you explain the breakage more in detail, is it kernel or user space?

A little bit off topic, but what is this CM4S? Is it special version of
the CM4? Can you provide a link or something?

>
> The name change seems unwarranted given it's essentially the same
> hardware, so use the old name instead.

I disagree at this point. The pinctrl of bcm2835 and bcm2711 are
different. For example the bcm2835 has only 54 GPIOs while the bcm2711
has 58.

Best regards

>
> For consistency, modify the pinctrl_desc and pinctrl_gpio_range names
> as well.  (It looks like they're only used by debugfs.)
>
> Signed-off-by: Lukas Wunner <lukas@wunner.de>
> Cc: Stefan Wahren <stefan.wahren@i2se.com>
> ---
>  drivers/pinctrl/bcm/pinctrl-bcm2835.c | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/pinctrl/bcm/pinctrl-bcm2835.c b/drivers/pinctrl/bcm/pinctrl-bcm2835.c
> index 47e433e09c5c..41d0f32b9d66 100644
> --- a/drivers/pinctrl/bcm/pinctrl-bcm2835.c
> +++ b/drivers/pinctrl/bcm/pinctrl-bcm2835.c
> @@ -375,7 +375,7 @@ static const struct gpio_chip bcm2835_gpio_chip = {
>  };
>  
>  static const struct gpio_chip bcm2711_gpio_chip = {
> -	.label = "pinctrl-bcm2711",
> +	.label = MODULE_NAME,
>  	.owner = THIS_MODULE,
>  	.request = gpiochip_generic_request,
>  	.free = gpiochip_generic_free,
> @@ -1134,7 +1134,7 @@ static const struct pinctrl_desc bcm2835_pinctrl_desc = {
>  };
>  
>  static const struct pinctrl_desc bcm2711_pinctrl_desc = {
> -	.name = "pinctrl-bcm2711",
> +	.name = MODULE_NAME,
>  	.pins = bcm2835_gpio_pins,
>  	.npins = BCM2711_NUM_GPIOS,
>  	.pctlops = &bcm2835_pctl_ops,
> @@ -1149,7 +1149,7 @@ static const struct pinctrl_gpio_range bcm2835_pinctrl_gpio_range = {
>  };
>  
>  static const struct pinctrl_gpio_range bcm2711_pinctrl_gpio_range = {
> -	.name = "pinctrl-bcm2711",
> +	.name = MODULE_NAME,
>  	.npins = BCM2711_NUM_GPIOS,
>  };
>