drivers/gpio/gpio-regmap.c

Source file repositories/reference/linux-study-clean/drivers/gpio/gpio-regmap.c

File Facts

System
Linux kernel
Corpus path
drivers/gpio/gpio-regmap.c
Extension
.c
Size
12567 bytes
Lines
487
Domain
Driver Families
Bucket
drivers/gpio
Inferred role
Driver Families: exported/initcall integration point
Status
integration implementation candidate

Why This File Exists

Repeatable hardware-adapter layer. Deep compatibility for every driver is out of scope; this atlas records patterns, probe lifecycles, bus glue, IRQ/DMA usage, and links back to core abstractions.

Dependency Surface

Detected Declarations

Annotated Snippet

struct gpio_regmap {
	struct device *parent;
	struct regmap *regmap;
	struct gpio_chip gpio_chip;

	int reg_stride;
	int ngpio_per_reg;
	unsigned int reg_dat_base;
	unsigned int reg_set_base;
	unsigned int reg_clr_base;
	unsigned int reg_dir_in_base;
	unsigned int reg_dir_out_base;
	unsigned long *fixed_direction_mask;
	unsigned long *fixed_direction_output;

#ifdef CONFIG_REGMAP_IRQ
	int regmap_irq_line;
	struct regmap_irq_chip_data *irq_chip_data;
#endif

	int (*reg_mask_xlate)(struct gpio_regmap *gpio, unsigned int base,
			      unsigned int offset, unsigned int *reg,
			      unsigned int *mask);

	void *driver_data;
};

static unsigned int gpio_regmap_addr(unsigned int addr)
{
	if (addr == GPIO_REGMAP_ADDR_ZERO)
		return 0;

	return addr;
}

static int gpio_regmap_simple_xlate(struct gpio_regmap *gpio,
				    unsigned int base, unsigned int offset,
				    unsigned int *reg, unsigned int *mask)
{
	unsigned int line = offset % gpio->ngpio_per_reg;
	unsigned int stride = offset / gpio->ngpio_per_reg;

	*reg = base + stride * gpio->reg_stride;
	*mask = BIT(line);

	return 0;
}

static int gpio_regmap_get(struct gpio_chip *chip, unsigned int offset)
{
	struct gpio_regmap *gpio = gpiochip_get_data(chip);
	unsigned int base, val, reg, mask;
	int ret;

	/* we might not have an output register if we are input only */
	if (gpio->reg_dat_base)
		base = gpio_regmap_addr(gpio->reg_dat_base);
	else
		base = gpio_regmap_addr(gpio->reg_set_base);

	ret = gpio->reg_mask_xlate(gpio, base, offset, &reg, &mask);
	if (ret)
		return ret;

	/* ensure we don't spoil any register cache with pin input values */
	if (gpio->reg_dat_base == gpio->reg_set_base)
		ret = regmap_read_bypassed(gpio->regmap, reg, &val);
	else
		ret = regmap_read(gpio->regmap, reg, &val);
	if (ret)
		return ret;

	return !!(val & mask);
}

static int gpio_regmap_set(struct gpio_chip *chip, unsigned int offset,
			   int val)
{
	struct gpio_regmap *gpio = gpiochip_get_data(chip);
	unsigned int base = gpio_regmap_addr(gpio->reg_set_base);
	unsigned int reg, mask, mask_val;
	int ret;

	ret = gpio->reg_mask_xlate(gpio, base, offset, &reg, &mask);
	if (ret)
		return ret;

	if (val)
		mask_val = mask;
	else

Annotation

Implementation Notes