drivers/gpio/gpio-wcd934x.c

Source file repositories/reference/linux-study-clean/drivers/gpio/gpio-wcd934x.c

File Facts

System
Linux kernel
Corpus path
drivers/gpio/gpio-wcd934x.c
Extension
.c
Size
3249 bytes
Lines
129
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 wcd_gpio_data {
	struct regmap *map;
	struct gpio_chip chip;
};

static int wcd_gpio_get_direction(struct gpio_chip *chip, unsigned int pin)
{
	struct wcd_gpio_data *data = gpiochip_get_data(chip);
	unsigned int value;
	int ret;

	ret = regmap_read(data->map, WCD_REG_DIR_CTL_OFFSET, &value);
	if (ret < 0)
		return ret;

	if (value & WCD_PIN_MASK(pin))
		return GPIO_LINE_DIRECTION_OUT;

	return GPIO_LINE_DIRECTION_IN;
}

static int wcd_gpio_direction_input(struct gpio_chip *chip, unsigned int pin)
{
	struct wcd_gpio_data *data = gpiochip_get_data(chip);

	return regmap_update_bits(data->map, WCD_REG_DIR_CTL_OFFSET,
				  WCD_PIN_MASK(pin), 0);
}

static int wcd_gpio_direction_output(struct gpio_chip *chip, unsigned int pin,
				     int val)
{
	struct wcd_gpio_data *data = gpiochip_get_data(chip);
	int ret;

	ret = regmap_update_bits(data->map, WCD_REG_DIR_CTL_OFFSET,
				 WCD_PIN_MASK(pin), WCD_PIN_MASK(pin));
	if (ret)
		return ret;

	return regmap_update_bits(data->map, WCD_REG_VAL_CTL_OFFSET,
				  WCD_PIN_MASK(pin),
				  val ? WCD_PIN_MASK(pin) : 0);
}

static int wcd_gpio_get(struct gpio_chip *chip, unsigned int pin)
{
	struct wcd_gpio_data *data = gpiochip_get_data(chip);
	unsigned int value;

	regmap_read(data->map, WCD_REG_VAL_CTL_OFFSET, &value);

	return !!(value & WCD_PIN_MASK(pin));
}

static int wcd_gpio_set(struct gpio_chip *chip, unsigned int pin, int val)
{
	struct wcd_gpio_data *data = gpiochip_get_data(chip);

	return regmap_update_bits(data->map, WCD_REG_VAL_CTL_OFFSET,
				  WCD_PIN_MASK(pin),
				  val ? WCD_PIN_MASK(pin) : 0);
}

static int wcd_gpio_probe(struct platform_device *pdev)
{
	struct device *dev = &pdev->dev;
	struct wcd_gpio_data *data;
	struct gpio_chip *chip;

	data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
	if (!data)
		return -ENOMEM;

	data->map = dev_get_regmap(dev->parent, NULL);
	if (!data->map) {
		dev_err(dev, "%s: failed to get regmap\n", __func__);
		return  -EINVAL;
	}

	chip = &data->chip;
	chip->direction_input  = wcd_gpio_direction_input;
	chip->direction_output = wcd_gpio_direction_output;
	chip->get_direction = wcd_gpio_get_direction;
	chip->get = wcd_gpio_get;
	chip->set = wcd_gpio_set;
	chip->parent = dev;
	chip->base = -1;
	chip->ngpio = WCD934X_NPINS;
	chip->label = dev_name(dev);

Annotation

Implementation Notes