Re: [PATCH v3] pinctrl: samsung: Add support for pull-up and pull-down

[Krzysztof Kozlowski <krzysztof.kozlowski@xxxxxxxxxx>]

On 04/07/2024 06:26, Vishnu Reddy wrote:
> gpiolib framework has the implementation of setting up the
> PUD configuration for GPIO pins but there is no driver support.
> 
> Add support to handle the PUD configuration request from the
> userspace in samsung pinctrl driver.
> 
> Signed-off-by: Vishnu Reddy <vishnu.reddy@xxxxxxxxxxx>
> ---
>  drivers/pinctrl/samsung/pinctrl-exynos-arm.c | 15 ++++
>  drivers/pinctrl/samsung/pinctrl-s3c64xx.c    | 15 ++++
>  drivers/pinctrl/samsung/pinctrl-samsung.c    | 80 ++++++++++++++++++++
>  drivers/pinctrl/samsung/pinctrl-samsung.h    | 24 ++++++
>  4 files changed, 134 insertions(+)
> 
> diff --git a/drivers/pinctrl/samsung/pinctrl-exynos-arm.c b/drivers/pinctrl/samsung/pinctrl-exynos-arm.c
> index 85ddf49a5188..426d1daacef2 100644
> --- a/drivers/pinctrl/samsung/pinctrl-exynos-arm.c
> +++ b/drivers/pinctrl/samsung/pinctrl-exynos-arm.c
> @@ -40,6 +40,20 @@ static const struct samsung_pin_bank_type bank_type_alive = {
>  #define S5P_OTHERS_RET_MMC		(1 << 29)
>  #define S5P_OTHERS_RET_UART		(1 << 28)
>  
> +/*
> + * s5pv210_pud_value_init: initialize the drvdata pud_val with s5pv210 pud values
> + * s5pv210_pull_disable:	0
> + * s5pv210_pull_down_enable:	1
> + * s5pv210_pull_up_enable:	2

Please use proper defines, e.g. S5P_PIN_PUD_PULL_DISABLE


> + */
> +static void s5pv210_pud_value_init(struct samsung_pinctrl_drv_data *drvdata)
> +{
> +	unsigned int i, *pud_val = drvdata->pud_val;
> +
> +	for (i = 0; i < PUD_MAX; i++)
> +		pud_val[i] = i;

pud_val[PUD_PULL_DISABLE] = PROPER_DEFINE

> +}
> +
>  static void s5pv210_retention_disable(struct samsung_pinctrl_drv_data *drvdata)
>  {
>  	void __iomem *clk_base = (void __iomem *)drvdata->retention_ctrl->priv;
> @@ -133,6 +147,7 @@ static const struct samsung_pin_ctrl s5pv210_pin_ctrl[] __initconst = {
>  		.nr_banks	= ARRAY_SIZE(s5pv210_pin_bank),
>  		.eint_gpio_init = exynos_eint_gpio_init,
>  		.eint_wkup_init = exynos_eint_wkup_init,
> +		.pud_value_init	= s5pv210_pud_value_init,
>  		.suspend	= exynos_pinctrl_suspend,
>  		.resume		= exynos_pinctrl_resume,
>  		.retention_data	= &s5pv210_retention_data,
> diff --git a/drivers/pinctrl/samsung/pinctrl-s3c64xx.c b/drivers/pinctrl/samsung/pinctrl-s3c64xx.c
> index c5d92db4fdb1..cf57b0f16999 100644
> --- a/drivers/pinctrl/samsung/pinctrl-s3c64xx.c
> +++ b/drivers/pinctrl/samsung/pinctrl-s3c64xx.c
> @@ -255,6 +255,20 @@ static int s3c64xx_irq_get_trigger(unsigned int type)
>  	return trigger;
>  }
>  
> +/*
> + * s3c64xx_pud_value_init: initialize the drvdata pud_val with s3c64xx pud values
> + * s3c64xx_pull_disable:	0
> + * s3c64xx_pull_down_enable:	1
> + * s3c64xx_pull_up_enable:	2

Use proper defines. Comments are not the place to define magic values.


> + */
> +static void s3c64xx_pud_value_init(struct samsung_pinctrl_drv_data *drvdata)
> +{
> +	unsigned int i, *pud_val = drvdata->pud_val;
> +
> +	for (i = 0; i < PUD_MAX; i++)
> +		pud_val[i] = i;
> +}
> +
>  static void s3c64xx_irq_set_handler(struct irq_data *d, unsigned int type)
>  {
>  	/* Edge- and level-triggered interrupts need different handlers */
> @@ -797,6 +811,7 @@ static const struct samsung_pin_ctrl s3c64xx_pin_ctrl[] __initconst = {
>  		.nr_banks	= ARRAY_SIZE(s3c64xx_pin_banks0),
>  		.eint_gpio_init = s3c64xx_eint_gpio_init,
>  		.eint_wkup_init = s3c64xx_eint_eint0_init,
> +		.pud_value_init	= s3c64xx_pud_value_init,
>  	},
>  };
>  
> diff --git a/drivers/pinctrl/samsung/pinctrl-samsung.c b/drivers/pinctrl/samsung/pinctrl-samsung.c
> index 623df65a5d6f..7d7e924c1fdb 100644
> --- a/drivers/pinctrl/samsung/pinctrl-samsung.c
> +++ b/drivers/pinctrl/samsung/pinctrl-samsung.c
> @@ -997,6 +997,80 @@ static int samsung_pinctrl_unregister(struct platform_device *pdev,
>  	return 0;
>  }
>  
> +/*
> + *samsung_pud_value_init: initialize the drvdata pud_val

You use some weird style of comments. It's not kerneldoc, it's not a
proper neither useful comment. Either use proper kerneldoc (and test
it!) or drop duplicated function names. They are not helping. This
applies everywhere.


> + */
> +static void samsung_pud_value_init(struct samsung_pinctrl_drv_data *drvdata)
> +{
> +	unsigned int  *pud_val = drvdata->pud_val;
> +
> +	pud_val[PUD_PULL_DISABLE] = PIN_PUD_PULL_UP_DOWN_DISABLE;
> +	pud_val[PUD_PULL_DOWN] = PIN_PUD_PULL_DOWN_ENABLE;
> +	pud_val[PUD_PULL_UP] = PIN_PUD_PULL_UP_ENABLE;
> +}
> +
> +/*
> + * samsung_gpio_set_pud will enable or disable the pull-down and
> + * pull-up for the gpio pins in the PUD register.
> + */
> +static void samsung_gpio_set_pud(struct gpio_chip *gc, unsigned int offset,
> +				 unsigned int value)
> +{
> +	struct samsung_pin_bank *bank = gpiochip_get_data(gc);
> +	const struct samsung_pin_bank_type *type = bank->type;
> +	void __iomem *reg;
> +	unsigned int data, mask;
> +
> +	reg = bank->pctl_base + bank->pctl_offset;
> +	data = readl(reg + type->reg_offset[PINCFG_TYPE_PUD]);
> +	mask = (1 << type->fld_width[PINCFG_TYPE_PUD]) - 1;
> +	data &= ~(mask << (offset * type->fld_width[PINCFG_TYPE_PUD]));
> +	data |= value << (offset * type->fld_width[PINCFG_TYPE_PUD]);
> +	writel(data, reg + type->reg_offset[PINCFG_TYPE_PUD]);
> +}
> +
> +/*
> + * samsung_gpio_set_config will identify the type of PUD config based
> + * on the gpiolib request to enable or disable the PUD configuration.
> + */
> +static int samsung_gpio_set_config(struct gpio_chip *gc, unsigned int offset,
> +				   unsigned long config)
> +{
> +	struct samsung_pin_bank *bank = gpiochip_get_data(gc);
> +	struct samsung_pinctrl_drv_data *drvdata = bank->drvdata;
> +	unsigned int value;
> +	int ret = 0;
> +	unsigned long flags;
> +
> +	switch (pinconf_to_config_param(config)) {
> +	case PIN_CONFIG_BIAS_DISABLE:
> +		value = drvdata->pud_val[PUD_PULL_DISABLE];
> +		break;
> +	case PIN_CONFIG_BIAS_PULL_DOWN:
> +		value = drvdata->pud_val[PUD_PULL_DOWN];
> +		break;
> +	case PIN_CONFIG_BIAS_PULL_UP:
> +		value = drvdata->pud_val[PUD_PULL_UP];
> +		break;
> +	default:
> +		return -ENOTSUPP;
> +	}
> +
> +	ret = clk_enable(drvdata->pclk);
> +	if (ret) {
> +		dev_err(drvdata->dev, "failed to enable clock\n");
> +		return ret;
> +	}
> +
> +	raw_spin_lock_irqsave(&bank->slock, flags);
> +	samsung_gpio_set_pud(gc, offset, value);
> +	raw_spin_unlock_irqrestore(&bank->slock, flags);
> +
> +	clk_disable(drvdata->pclk);
> +
> +	return ret;
> +}
> +
>  static const struct gpio_chip samsung_gpiolib_chip = {
>  	.request = gpiochip_generic_request,
>  	.free = gpiochip_generic_free,
> @@ -1006,6 +1080,7 @@ static const struct gpio_chip samsung_gpiolib_chip = {
>  	.direction_output = samsung_gpio_direction_output,
>  	.to_irq = samsung_gpio_to_irq,
>  	.add_pin_ranges = samsung_add_pin_ranges,
> +	.set_config = samsung_gpio_set_config,
>  	.owner = THIS_MODULE,
>  };
>  
> @@ -1237,6 +1312,11 @@ static int samsung_pinctrl_probe(struct platform_device *pdev)
>  	if (ctrl->eint_wkup_init)
>  		ctrl->eint_wkup_init(drvdata);
>  
> +	if (ctrl->pud_value_init)
> +		ctrl->pud_value_init(drvdata);
> +	else
> +		samsung_pud_value_init(drvdata);
> +
>  	ret = samsung_gpiolib_register(pdev, drvdata);
>  	if (ret)
>  		goto err_unregister;
> diff --git a/drivers/pinctrl/samsung/pinctrl-samsung.h b/drivers/pinctrl/samsung/pinctrl-samsung.h
> index d50ba6f07d5d..61384096b6d7 100644
> --- a/drivers/pinctrl/samsung/pinctrl-samsung.h
> +++ b/drivers/pinctrl/samsung/pinctrl-samsung.h
> @@ -61,6 +61,28 @@ enum pincfg_type {
>  #define PIN_CON_FUNC_INPUT		0x0
>  #define PIN_CON_FUNC_OUTPUT		0x1
>  
> +/*
> + * Values for the pin PUD register.
> + */
> +#define PIN_PUD_PULL_UP_DOWN_DISABLE	0x0

EXYNOS_PIN_PUD_PULL_DISABLE

> +#define PIN_PUD_PULL_DOWN_ENABLE	0x1

EXYNOS_PIN_PID_PULL_DOWN

> +#define PIN_PUD_PULL_UP_ENABLE		0x3

EXYNOS_PIN_PID_PULL_UP

> +
> +/*
> + * enum pud_index: Index values to access the pud_val array in
> + *	struct samsung_pinctrl_drv_data.
> + * @PUD_PULL_DISABLE: Index for value of pud disable
> + * @PUD_PULL_DOWN: Index for the value of pull down enable
> + * @PUD_PULL_UP: Index for the value of pull up enable
> + * @PUD_MAX: Maximun value of the index

Typo: Maximum

> + */
> +enum pud_index {
> +	PUD_PULL_DISABLE,
> +	PUD_PULL_DOWN,
> +	PUD_PULL_UP,
> +	PUD_MAX,
> +};

Best regards,
Krzysztof