Re: [PATCH] pinctrl: stm32: set default gpio line names using pin names

[Alexandre TORGUE <alexandre.torgue@foss.st.com>]

Hi

On 6/20/23 12:43, Valentin Caron wrote:
> Add stm32_pctrl_get_desc_pin_from_gpio function to find a stm32 pin
> descriptor which is matching with a gpio.
> Most of the time pin number is equal to pin index in array. So the first
> part of the function is useful to speed up.
> 
> And during gpio bank register, we set default gpio names with pin names.
> 
> Signed-off-by: Valentin Caron <valentin.caron@foss.st.com>
> ---

Acked-by: Alexandre TORGUE <alexandre.torgue@foss.st.com>

>   drivers/pinctrl/stm32/pinctrl-stm32.c | 35 +++++++++++++++++++++++++++
>   1 file changed, 35 insertions(+)
> 
> diff --git a/drivers/pinctrl/stm32/pinctrl-stm32.c b/drivers/pinctrl/stm32/pinctrl-stm32.c
> index 4b97bd00191b..eedbb9b97a65 100644
> --- a/drivers/pinctrl/stm32/pinctrl-stm32.c
> +++ b/drivers/pinctrl/stm32/pinctrl-stm32.c
> @@ -1275,6 +1275,28 @@ static const struct pinconf_ops stm32_pconf_ops = {
>   	.pin_config_dbg_show	= stm32_pconf_dbg_show,
>   };
>   
> +static struct stm32_desc_pin *stm32_pctrl_get_desc_pin_from_gpio(struct stm32_pinctrl *pctl,
> +								 struct stm32_gpio_bank *bank,
> +								 unsigned int offset)
> +{
> +	unsigned int stm32_pin_nb = bank->bank_nr * STM32_GPIO_PINS_PER_BANK + offset;
> +	struct stm32_desc_pin *pin_desc;
> +	int i;
> +
> +	/* With few exceptions (e.g. bank 'Z'), pin number matches with pin index in array */
> +	pin_desc = pctl->pins + stm32_pin_nb;
> +	if (pin_desc->pin.number == stm32_pin_nb)
> +		return pin_desc;
> +
> +	/* Otherwise, loop all array to find the pin with the right number */
> +	for (i = 0; i < pctl->npins; i++) {
> +		pin_desc = pctl->pins + i;
> +		if (pin_desc->pin.number == stm32_pin_nb)
> +			return pin_desc;
> +	}
> +	return NULL;
> +}
> +
>   static int stm32_gpiolib_register_bank(struct stm32_pinctrl *pctl, struct fwnode_handle *fwnode)
>   {
>   	struct stm32_gpio_bank *bank = &pctl->banks[pctl->nbanks];
> @@ -1285,6 +1307,8 @@ static int stm32_gpiolib_register_bank(struct stm32_pinctrl *pctl, struct fwnode
>   	struct resource res;
>   	int npins = STM32_GPIO_PINS_PER_BANK;
>   	int bank_nr, err, i = 0;
> +	struct stm32_desc_pin *stm32_pin;
> +	char **names;
>   
>   	if (!IS_ERR(bank->rstc))
>   		reset_control_deassert(bank->rstc);
> @@ -1354,6 +1378,17 @@ static int stm32_gpiolib_register_bank(struct stm32_pinctrl *pctl, struct fwnode
>   		}
>   	}
>   
> +	names = devm_kcalloc(dev, npins, sizeof(char *), GFP_KERNEL);
> +	for (i = 0; i < npins; i++) {
> +		stm32_pin = stm32_pctrl_get_desc_pin_from_gpio(pctl, bank, i);
> +		if (stm32_pin && stm32_pin->pin.name)
> +			names[i] = devm_kasprintf(dev, GFP_KERNEL, "%s", stm32_pin->pin.name);
> +		else
> +			names[i] = NULL;
> +	}
> +
> +	bank->gpio_chip.names = (const char * const *)names;
> +
>   	err = gpiochip_add_data(&bank->gpio_chip, bank);
>   	if (err) {
>   		dev_err(dev, "Failed to add gpiochip(%d)!\n", bank_nr);