[PATCH] pinctrl: mtmips: support requesting different functions for same group

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On 26.07.2023 03:48, Shiji Yang wrote:
> Sometimes pinctrl consumers may request different functions for the
> same pin group in different situations. This patch can help to reset
> the group function flag when requesting a different function.
> 
> Signed-off-by: Shiji Yang <yangshiji66 at outlook.com>
> ---
>   drivers/pinctrl/mediatek/pinctrl-mtmips.c | 21 +++++++++++++++++----
>   1 file changed, 17 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/pinctrl/mediatek/pinctrl-mtmips.c b/drivers/pinctrl/mediatek/pinctrl-mtmips.c
> index efd77b6c5..e5e085915 100644
> --- a/drivers/pinctrl/mediatek/pinctrl-mtmips.c
> +++ b/drivers/pinctrl/mediatek/pinctrl-mtmips.c
> @@ -123,11 +123,24 @@ static int mtmips_pmx_group_enable(struct pinctrl_dev *pctrldev,
>   	int i;
>   	int shift;
>   
> -	/* dont allow double use */
> +	/*
> +	 * for the same pin group, if request a different function,
> +	 * then clear the group function flag and continue, else exit.
> +	 */
>   	if (p->groups[group].enabled) {
> -		dev_err(p->dev, "%s is already enabled\n",
> -			p->groups[group].name);
> -		return 0;
> +		for (i = 0; i < p->groups[group].func_count; i++) {
> +			if (p->groups[group].func[i].enabled == 1) {
> +				if (!strcmp(p->func[func]->name,
> +					p->groups[group].func[i].name))
> +					return 0;
> +				p->groups[group].func[i].enabled = 0;
> +				break;
> +			}
> +		}
> +
> +		/* exit if request the "gpio" function again */
> +		if (i == p->groups[group].func_count && func == 0)
> +			return 0;

Could you help me understand why? The @gpio_request_enable operation is 
not properly implemented on this driver so this check would never be 
true, no?

Even if it was, this makes it so that if a pin group is already given a 
function (meaning the pin group is enabled), it will never be given the 
gpio function when requested, unless I understand it wrong.

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