[v3,8/9] gpio: gpio-mm: Migrate to regmap API

The regmap API supports IO port accessors so we can take advantage of
regmap abstractions rather than handling access to the device registers
directly in the driver. The gpio-mm module is migrated to the new i8255
library interface leveraging the gpio-regmap API.

Suggested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: William Breathitt Gray <william.gray@linaro.org>
---
 drivers/gpio/gpio-gpio-mm.c | 153 +++++++-----------------------------
 1 file changed, 29 insertions(+), 124 deletions(-)

On Tue, Nov 22, 2022 at 02:11:05AM -0500, William Breathitt Gray wrote:
> The regmap API supports IO port accessors so we can take advantage of
> regmap abstractions rather than handling access to the device registers
> directly in the driver. The gpio-mm module is migrated to the new i8255
> library interface leveraging the gpio-regmap API.

Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

(see also below)

> Suggested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
> Signed-off-by: William Breathitt Gray <william.gray@linaro.org>
> ---
>  drivers/gpio/gpio-gpio-mm.c | 153 +++++++-----------------------------
>  1 file changed, 29 insertions(+), 124 deletions(-)
> 
> diff --git a/drivers/gpio/gpio-gpio-mm.c b/drivers/gpio/gpio-gpio-mm.c
> index 2689671b6b01..ba8847485660 100644
> --- a/drivers/gpio/gpio-gpio-mm.c
> +++ b/drivers/gpio/gpio-gpio-mm.c
> @@ -8,13 +8,13 @@
>   */
>  #include <linux/device.h>
>  #include <linux/errno.h>
> -#include <linux/gpio/driver.h>
> -#include <linux/io.h>
>  #include <linux/ioport.h>
>  #include <linux/isa.h>
>  #include <linux/kernel.h>
>  #include <linux/module.h>
>  #include <linux/moduleparam.h>
> +#include <linux/regmap.h>
> +#include <linux/types.h>
>  
>  #include "gpio-i8255.h"
>  
> @@ -30,83 +30,22 @@ MODULE_PARM_DESC(base, "Diamond Systems GPIO-MM base addresses");
>  
>  #define GPIOMM_NUM_PPI 2
>  
> -/**
> - * struct gpiomm_gpio - GPIO device private data structure
> - * @chip:		instance of the gpio_chip
> - * @ppi_state:		Programmable Peripheral Interface group states
> - * @ppi:		Programmable Peripheral Interface groups
> - */
> -struct gpiomm_gpio {
> -	struct gpio_chip chip;
> -	struct i8255_state ppi_state[GPIOMM_NUM_PPI];
> -	struct i8255 __iomem *ppi;
> +static const struct regmap_range gpiomm_volatile_ranges[] = {
> +	i8255_volatile_regmap_range(0x0), i8255_volatile_regmap_range(0x4),
> +};
> +static const struct regmap_access_table gpiomm_volatile_table = {
> +	.yes_ranges = gpiomm_volatile_ranges,
> +	.n_yes_ranges = ARRAY_SIZE(gpiomm_volatile_ranges),
> +};
> +static const struct regmap_config gpiomm_regmap_config = {
> +	.reg_bits = 8,
> +	.reg_stride = 1,
> +	.val_bits = 8,
> +	.io_port = true,
> +	.max_register = 0x7,
> +	.volatile_table = &gpiomm_volatile_table,
> +	.cache_type = REGCACHE_FLAT,
>  };
> -
> -static int gpiomm_gpio_get_direction(struct gpio_chip *chip,
> -	unsigned int offset)
> -{
> -	struct gpiomm_gpio *const gpiommgpio = gpiochip_get_data(chip);
> -
> -	if (i8255_get_direction(gpiommgpio->ppi_state, offset))
> -		return GPIO_LINE_DIRECTION_IN;
> -
> -	return GPIO_LINE_DIRECTION_OUT;
> -}
> -
> -static int gpiomm_gpio_direction_input(struct gpio_chip *chip,
> -	unsigned int offset)
> -{
> -	struct gpiomm_gpio *const gpiommgpio = gpiochip_get_data(chip);
> -
> -	i8255_direction_input(gpiommgpio->ppi, gpiommgpio->ppi_state, offset);
> -
> -	return 0;
> -}
> -
> -static int gpiomm_gpio_direction_output(struct gpio_chip *chip,
> -	unsigned int offset, int value)
> -{
> -	struct gpiomm_gpio *const gpiommgpio = gpiochip_get_data(chip);
> -
> -	i8255_direction_output(gpiommgpio->ppi, gpiommgpio->ppi_state, offset,
> -			       value);
> -
> -	return 0;
> -}
> -
> -static int gpiomm_gpio_get(struct gpio_chip *chip, unsigned int offset)
> -{
> -	struct gpiomm_gpio *const gpiommgpio = gpiochip_get_data(chip);
> -
> -	return i8255_get(gpiommgpio->ppi, offset);
> -}
> -
> -static int gpiomm_gpio_get_multiple(struct gpio_chip *chip, unsigned long *mask,
> -	unsigned long *bits)
> -{
> -	struct gpiomm_gpio *const gpiommgpio = gpiochip_get_data(chip);
> -
> -	i8255_get_multiple(gpiommgpio->ppi, mask, bits, chip->ngpio);
> -
> -	return 0;
> -}
> -
> -static void gpiomm_gpio_set(struct gpio_chip *chip, unsigned int offset,
> -	int value)
> -{
> -	struct gpiomm_gpio *const gpiommgpio = gpiochip_get_data(chip);
> -
> -	i8255_set(gpiommgpio->ppi, gpiommgpio->ppi_state, offset, value);
> -}
> -
> -static void gpiomm_gpio_set_multiple(struct gpio_chip *chip,
> -	unsigned long *mask, unsigned long *bits)
> -{
> -	struct gpiomm_gpio *const gpiommgpio = gpiochip_get_data(chip);
> -
> -	i8255_set_multiple(gpiommgpio->ppi, gpiommgpio->ppi_state, mask, bits,
> -			   chip->ngpio);
> -}
>  
>  #define GPIOMM_NGPIO 48
>  static const char *gpiomm_names[GPIOMM_NGPIO] = {
> @@ -120,30 +59,11 @@ static const char *gpiomm_names[GPIOMM_NGPIO] = {
>  	"Port 2C2", "Port 2C3", "Port 2C4", "Port 2C5", "Port 2C6", "Port 2C7",
>  };
>  
> -static void gpiomm_init_dio(struct i8255 __iomem *const ppi,
> -			    struct i8255_state *const ppi_state)
> -{
> -	const unsigned long ngpio = 24;
> -	const unsigned long mask = GENMASK(ngpio - 1, 0);
> -	const unsigned long bits = 0;
> -	unsigned long i;
> -
> -	/* Initialize all GPIO to output 0 */
> -	for (i = 0; i < GPIOMM_NUM_PPI; i++) {
> -		i8255_mode0_output(&ppi[i]);
> -		i8255_set_multiple(&ppi[i], &ppi_state[i], &mask, &bits, ngpio);
> -	}
> -}
> -
>  static int gpiomm_probe(struct device *dev, unsigned int id)
>  {
> -	struct gpiomm_gpio *gpiommgpio;
>  	const char *const name = dev_name(dev);
> -	int err;
> -
> -	gpiommgpio = devm_kzalloc(dev, sizeof(*gpiommgpio), GFP_KERNEL);
> -	if (!gpiommgpio)
> -		return -ENOMEM;

> +	struct i8255_regmap_config config = {0};

{} will be okay as well.

> +	void __iomem *regs;
>  
>  	if (!devm_request_region(dev, base[id], GPIOMM_EXTENT, name)) {
>  		dev_err(dev, "Unable to lock port addresses (0x%X-0x%X)\n",
> @@ -151,34 +71,19 @@ static int gpiomm_probe(struct device *dev, unsigned int id)
>  		return -EBUSY;
>  	}
>  
> -	gpiommgpio->ppi = devm_ioport_map(dev, base[id], GPIOMM_EXTENT);
> -	if (!gpiommgpio->ppi)
> +	regs = devm_ioport_map(dev, base[id], GPIOMM_EXTENT);
> +	if (!regs)
>  		return -ENOMEM;
>  
> -	gpiommgpio->chip.label = name;
> -	gpiommgpio->chip.parent = dev;
> -	gpiommgpio->chip.owner = THIS_MODULE;
> -	gpiommgpio->chip.base = -1;
> -	gpiommgpio->chip.ngpio = GPIOMM_NGPIO;
> -	gpiommgpio->chip.names = gpiomm_names;
> -	gpiommgpio->chip.get_direction = gpiomm_gpio_get_direction;
> -	gpiommgpio->chip.direction_input = gpiomm_gpio_direction_input;
> -	gpiommgpio->chip.direction_output = gpiomm_gpio_direction_output;
> -	gpiommgpio->chip.get = gpiomm_gpio_get;
> -	gpiommgpio->chip.get_multiple = gpiomm_gpio_get_multiple;
> -	gpiommgpio->chip.set = gpiomm_gpio_set;
> -	gpiommgpio->chip.set_multiple = gpiomm_gpio_set_multiple;
> -
> -	i8255_state_init(gpiommgpio->ppi_state, GPIOMM_NUM_PPI);
> -	gpiomm_init_dio(gpiommgpio->ppi, gpiommgpio->ppi_state);
> -
> -	err = devm_gpiochip_add_data(dev, &gpiommgpio->chip, gpiommgpio);
> -	if (err) {
> -		dev_err(dev, "GPIO registering failed (%d)\n", err);
> -		return err;
> -	}
> +	config.map = devm_regmap_init_mmio(dev, regs, &gpiomm_regmap_config);
> +	if (IS_ERR(config.map))
> +		return PTR_ERR(config.map);
> +
> +	config.parent = dev;
> +	config.num_ppi = GPIOMM_NUM_PPI;
> +	config.names = gpiomm_names;
>  
> -	return 0;
> +	return devm_i8255_regmap_register(dev, &config);
>  }
>  
>  static struct isa_driver gpiomm_driver = {
> -- 
> 2.38.1
>