Re: [PATCHv2 5/6] pinctrl: mcp23s08: add pinconf support

[Enric Balletbo i Serra]

On 27/04/17 16:19, Sebastian Reichel wrote:
> mcp23xxx device have configurable 100k pullup resistors. This adds
> support for enabling them using pinctrl's pinconf interface.
> 
> Signed-off-by: Sebastian Reichel <sebastian.reichel@xxxxxxxxxxxxxxx>
> ---
>  drivers/pinctrl/Kconfig            |   1 +
>  drivers/pinctrl/pinctrl-mcp23s08.c | 199 ++++++++++++++++++++++++++++++++-----
>  2 files changed, 176 insertions(+), 24 deletions(-)
> 
> diff --git a/drivers/pinctrl/Kconfig b/drivers/pinctrl/Kconfig
> index cccff799a88a..2ff95fe3017d 100644
> --- a/drivers/pinctrl/Kconfig
> +++ b/drivers/pinctrl/Kconfig
> @@ -142,6 +142,7 @@ config PINCTRL_MCP23S08
>  	select GPIOLIB_IRQCHIP
>  	select REGMAP_I2C if I2C
>  	select REGMAP_SPI if SPI_MASTER
> +	select GENERIC_PINCONF
>  	help
>  	  SPI/I2C driver for Microchip MCP23S08/MCP23S17/MCP23008/MCP23017
>  	  I/O expanders.
> diff --git a/drivers/pinctrl/pinctrl-mcp23s08.c b/drivers/pinctrl/pinctrl-mcp23s08.c
> index 2a57d024481d..8aacedcf814c 100644
> --- a/drivers/pinctrl/pinctrl-mcp23s08.c
> +++ b/drivers/pinctrl/pinctrl-mcp23s08.c
> @@ -24,6 +24,9 @@
>  #include <linux/of_irq.h>
>  #include <linux/of_device.h>
>  #include <linux/regmap.h>
> +#include <linux/pinctrl/pinctrl.h>
> +#include <linux/pinctrl/pinconf.h>
> +#include <linux/pinctrl/pinconf-generic.h>
>  
>  /**
>   * MCP types supported by driver
> @@ -77,6 +80,9 @@ struct mcp23s08 {
>  
>  	struct regmap		*regmap;
>  	struct device		*dev;
> +
> +	struct pinctrl_dev	*pctldev;
> +	struct pinctrl_desc	pinctrl_desc;
>  };
>  
>  static const struct regmap_config mcp23x08_regmap = {
> @@ -96,6 +102,158 @@ static const struct regmap_config mcp23x17_regmap = {
>  	.val_format_endian = REGMAP_ENDIAN_LITTLE,
>  };
>  
> +static int mcp_read(struct mcp23s08 *mcp, unsigned int reg, unsigned int *val)
> +{
> +	return regmap_read(mcp->regmap, reg << mcp->reg_shift, val);
> +}
> +
> +static int mcp_write(struct mcp23s08 *mcp, unsigned int reg, unsigned int val)
> +{
> +	return regmap_write(mcp->regmap, reg << mcp->reg_shift, val);
> +}
> +
> +static int mcp_set_bit(struct mcp23s08 *mcp, unsigned int reg,
> +		       unsigned int pin, bool enabled)
> +{
> +	u16 val  = enabled ? 0xffff : 0x0000;
> +	u16 mask = BIT(pin);
> +	return regmap_update_bits(mcp->regmap, reg << mcp->reg_shift,
> +				  mask, val);
> +}
> +
> +static int mcp_update_cache(struct mcp23s08 *mcp)
> +{
> +	int ret, reg, i;
> +
> +	for (i = 0; i < ARRAY_SIZE(mcp->cache); i++) {
> +		ret = mcp_read(mcp, i, &reg);
> +		if (ret < 0)
> +			return ret;
> +		mcp->cache[i] = reg;
> +	}
> +
> +	return 0;
> +}
> +
> +static const struct pinctrl_pin_desc mcp23x08_pins[] = {
> +	PINCTRL_PIN(0, "gpio0"),
> +	PINCTRL_PIN(1, "gpio1"),
> +	PINCTRL_PIN(2, "gpio2"),
> +	PINCTRL_PIN(3, "gpio3"),
> +	PINCTRL_PIN(4, "gpio4"),
> +	PINCTRL_PIN(5, "gpio5"),
> +	PINCTRL_PIN(6, "gpio6"),
> +	PINCTRL_PIN(7, "gpio7"),
> +};
> +
> +static const struct pinctrl_pin_desc mcp23x17_pins[] = {
> +	PINCTRL_PIN(0, "gpio0"),
> +	PINCTRL_PIN(1, "gpio1"),
> +	PINCTRL_PIN(2, "gpio2"),
> +	PINCTRL_PIN(3, "gpio3"),
> +	PINCTRL_PIN(4, "gpio4"),
> +	PINCTRL_PIN(5, "gpio5"),
> +	PINCTRL_PIN(6, "gpio6"),
> +	PINCTRL_PIN(7, "gpio7"),
> +	PINCTRL_PIN(8, "gpio8"),
> +	PINCTRL_PIN(9, "gpio9"),
> +	PINCTRL_PIN(10, "gpio10"),
> +	PINCTRL_PIN(11, "gpio11"),
> +	PINCTRL_PIN(12, "gpio12"),
> +	PINCTRL_PIN(13, "gpio13"),
> +	PINCTRL_PIN(14, "gpio14"),
> +	PINCTRL_PIN(15, "gpio15"),
> +};
> +
> +static int mcp_pinctrl_get_groups_count(struct pinctrl_dev *pctldev)
> +{
> +	return 0;
> +}
> +
> +static const char *mcp_pinctrl_get_group_name(struct pinctrl_dev *pctldev,
> +						unsigned int group)
> +{
> +	return NULL;
> +}
> +
> +static int mcp_pinctrl_get_group_pins(struct pinctrl_dev *pctldev,
> +					unsigned int group,
> +					const unsigned int **pins,
> +					unsigned int *num_pins)
> +{
> +	return -ENOTSUPP;
> +}
> +
> +static const struct pinctrl_ops mcp_pinctrl_ops = {
> +	.get_groups_count = mcp_pinctrl_get_groups_count,
> +	.get_group_name = mcp_pinctrl_get_group_name,
> +	.get_group_pins = mcp_pinctrl_get_group_pins,
> +#ifdef CONFIG_OF
> +	.dt_node_to_map = pinconf_generic_dt_node_to_map_pin,
> +	.dt_free_map = pinconf_generic_dt_free_map,
> +#endif
> +};
> +
> +static int mcp_pinconf_get(struct pinctrl_dev *pctldev, unsigned int pin,
> +			      unsigned long *config)
> +{
> +	struct mcp23s08 *mcp = pinctrl_dev_get_drvdata(pctldev);
> +	enum pin_config_param param = pinconf_to_config_param(*config);
> +	unsigned int data, status;
> +	int ret;
> +
> +	switch (param) {
> +	case PIN_CONFIG_BIAS_PULL_UP:
> +		ret = mcp_read(mcp, MCP_GPPU, &data);
> +		if (ret < 0)
> +			return ret;
> +		status = (data & BIT(pin)) ? 1 : 0;
> +		break;
> +	default:
> +		dev_err(mcp->dev, "Invalid config param %04x\n", param);
> +		return -ENOTSUPP;
> +	}
> +
> +	*config = 0;
> +
> +	return status ? 0 : -EINVAL;
> +}
> +
> +static int mcp_pinconf_set(struct pinctrl_dev *pctldev, unsigned int pin,
> +			      unsigned long *configs, unsigned int num_configs)
> +{
> +	struct mcp23s08 *mcp = pinctrl_dev_get_drvdata(pctldev);
> +	enum pin_config_param param;
> +	u32 arg, mask;
> +	u16 val;
> +	int ret = 0;
> +	int i;
> +
> +	for (i = 0; i < num_configs; i++) {
> +		param = pinconf_to_config_param(configs[i]);
> +		arg = pinconf_to_config_argument(configs[i]);
> +
> +		switch (param) {
> +		case PIN_CONFIG_BIAS_PULL_UP:
> +			val = arg ? 0xFFFF : 0x0000;
> +			mask = BIT(pin);
> +			ret = mcp_set_bit(mcp, MCP_GPPU, pin, arg);
> +			break;
> +		default:
> +			dev_err(mcp->dev, "Invalid config param %04x\n", param);
> +			return -ENOTSUPP;
> +		}
> +	}
> +
> +	return ret;
> +}
> +
> +static const struct pinconf_ops mcp_pinconf_ops = {
> +	.pin_config_get = mcp_pinconf_get,
> +	.pin_config_set = mcp_pinconf_set,
> +	.is_generic = true,
> +};
> +
>  /*----------------------------------------------------------------------*/
>  
>  #ifdef CONFIG_SPI_MASTER
> @@ -158,30 +316,6 @@ static const struct regmap_bus mcp23sxx_spi_regmap = {
>  
>  #endif /* CONFIG_SPI_MASTER */
>  
> -static int mcp_read(struct mcp23s08 *mcp, unsigned int reg, unsigned int *val)
> -{
> -	return regmap_read(mcp->regmap, reg << mcp->reg_shift, val);
> -}
> -
> -static int mcp_write(struct mcp23s08 *mcp, unsigned int reg, unsigned int val)
> -{
> -	return regmap_write(mcp->regmap, reg << mcp->reg_shift, val);
> -}
> -
> -static int mcp_update_cache(struct mcp23s08 *mcp)
> -{
> -	int ret, reg, i;
> -
> -	for (i = 0; i < ARRAY_SIZE(mcp->cache); i++) {
> -		ret = mcp_read(mcp, i, &reg);
> -		if (ret < 0)
> -			return ret;
> -		mcp->cache[i] = reg;
> -	}
> -
> -	return 0;
> -}
> -
>  /*----------------------------------------------------------------------*/
>  
>  /* A given spi_device can represent up to eight mcp23sxx chips
> @@ -682,6 +816,23 @@ static int mcp23s08_probe_one(struct mcp23s08 *mcp, struct device *dev,
>  		if (ret)
>  			goto fail;
>  	}
> +
> +	mcp->pinctrl_desc.name = "mcp23xxx-pinctrl";
> +	mcp->pinctrl_desc.pctlops = &mcp_pinctrl_ops;
> +	mcp->pinctrl_desc.confops = &mcp_pinconf_ops;
> +	mcp->pinctrl_desc.npins = mcp->chip.ngpio;
> +	if (mcp->pinctrl_desc.npins == 8)
> +		mcp->pinctrl_desc.pins = mcp23x08_pins;
> +	else if (mcp->pinctrl_desc.npins == 16)
> +		mcp->pinctrl_desc.pins = mcp23x17_pins;
> +	mcp->pinctrl_desc.owner = THIS_MODULE;
> +
> +	mcp->pctldev = pinctrl_register(&mcp->pinctrl_desc, dev, mcp);
> +	if (IS_ERR(mcp->pctldev)) {
> +		ret = PTR_ERR(mcp->pctldev);
> +		goto fail;
> +	}
> +
>  fail:
>  	if (ret < 0)
>  		dev_dbg(dev, "can't setup chip %d, --> %d\n", addr, ret);
> 

Many thanks for this patch, tested on SL50 board by configuring the pins to read
the hardware revision that needs to have the pullup confifured, it works as
expected so,

Tested-by: Enric Balletbo i Serra <enric.balletbo@xxxxxxxxxxxxx>