drivers/gpio/gpio-madera.c

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

File Facts

System
Linux kernel
Corpus path
drivers/gpio/gpio-madera.c
Extension
.c
Size
5716 bytes
Lines
208
Domain
Driver Families
Bucket
drivers/gpio
Inferred role
Driver Families: implementation source
Status
source 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 madera_gpio {
	struct madera *madera;
	/* storage space for the gpio_chip we're using */
	struct gpio_chip gpio_chip;
};

static int madera_gpio_get_direction(struct gpio_chip *chip,
				     unsigned int offset)
{
	struct madera_gpio *madera_gpio = gpiochip_get_data(chip);
	struct madera *madera = madera_gpio->madera;
	unsigned int reg_offset = 2 * offset;
	unsigned int val;
	int ret;

	ret = regmap_read(madera->regmap, MADERA_GPIO1_CTRL_2 + reg_offset,
			  &val);
	if (ret < 0)
		return ret;

	if (val & MADERA_GP1_DIR_MASK)
		return GPIO_LINE_DIRECTION_IN;

	return GPIO_LINE_DIRECTION_OUT;
}

static int madera_gpio_direction_in(struct gpio_chip *chip, unsigned int offset)
{
	struct madera_gpio *madera_gpio = gpiochip_get_data(chip);
	struct madera *madera = madera_gpio->madera;
	unsigned int reg_offset = 2 * offset;

	return regmap_update_bits(madera->regmap,
				  MADERA_GPIO1_CTRL_2 + reg_offset,
				  MADERA_GP1_DIR_MASK, MADERA_GP1_DIR);
}

static int madera_gpio_get(struct gpio_chip *chip, unsigned int offset)
{
	struct madera_gpio *madera_gpio = gpiochip_get_data(chip);
	struct madera *madera = madera_gpio->madera;
	unsigned int reg_offset = 2 * offset;
	unsigned int val;
	int ret;

	ret = regmap_read(madera->regmap, MADERA_GPIO1_CTRL_1 + reg_offset,
			  &val);
	if (ret < 0)
		return ret;

	return !!(val & MADERA_GP1_LVL_MASK);
}

static int madera_gpio_direction_out(struct gpio_chip *chip,
				     unsigned int offset, int value)
{
	struct madera_gpio *madera_gpio = gpiochip_get_data(chip);
	struct madera *madera = madera_gpio->madera;
	unsigned int reg_offset = 2 * offset;
	unsigned int reg_val = value ? MADERA_GP1_LVL : 0;
	int ret;

	ret = regmap_update_bits(madera->regmap,
				 MADERA_GPIO1_CTRL_2 + reg_offset,
				 MADERA_GP1_DIR_MASK, 0);
	if (ret < 0)
		return ret;

	return regmap_update_bits(madera->regmap,
				  MADERA_GPIO1_CTRL_1 + reg_offset,
				  MADERA_GP1_LVL_MASK, reg_val);
}

static int madera_gpio_set(struct gpio_chip *chip, unsigned int offset,
			   int value)
{
	struct madera_gpio *madera_gpio = gpiochip_get_data(chip);
	struct madera *madera = madera_gpio->madera;
	unsigned int reg_offset = 2 * offset;
	unsigned int reg_val = value ? MADERA_GP1_LVL : 0;

	return regmap_update_bits(madera->regmap,
				  MADERA_GPIO1_CTRL_1 + reg_offset,
				  MADERA_GP1_LVL_MASK, reg_val);
}

static const struct gpio_chip madera_gpio_chip = {
	.label			= "madera",
	.owner			= THIS_MODULE,
	.request		= gpiochip_generic_request,

Annotation

Implementation Notes