drivers/gpio/gpio-tpic2810.c

Source file repositories/reference/linux-study-clean/drivers/gpio/gpio-tpic2810.c

File Facts

System
Linux kernel
Corpus path
drivers/gpio/gpio-tpic2810.c
Extension
.c
Size
3067 bytes
Lines
133
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 tpic2810 {
	struct gpio_chip chip;
	struct i2c_client *client;
	u8 buffer;
	struct mutex lock;
};

static int tpic2810_set(struct gpio_chip *chip, unsigned int offset, int value);

static int tpic2810_get_direction(struct gpio_chip *chip,
				  unsigned offset)
{
	/* This device always output */
	return GPIO_LINE_DIRECTION_OUT;
}

static int tpic2810_direction_output(struct gpio_chip *chip,
				     unsigned offset, int value)
{
	/* This device always output */
	return tpic2810_set(chip, offset, value);
}

static void tpic2810_set_mask_bits(struct gpio_chip *chip, u8 mask, u8 bits)
{
	struct tpic2810 *gpio = gpiochip_get_data(chip);
	u8 buffer;
	int err;

	mutex_lock(&gpio->lock);

	buffer = gpio->buffer & ~mask;
	buffer |= (mask & bits);

	err = i2c_smbus_write_byte_data(gpio->client, TPIC2810_WS_COMMAND,
					buffer);
	if (!err)
		gpio->buffer = buffer;

	mutex_unlock(&gpio->lock);
}

static int tpic2810_set(struct gpio_chip *chip, unsigned int offset, int value)
{
	tpic2810_set_mask_bits(chip, BIT(offset), value ? BIT(offset) : 0);

	return 0;
}

static int tpic2810_set_multiple(struct gpio_chip *chip, unsigned long *mask,
				 unsigned long *bits)
{
	tpic2810_set_mask_bits(chip, *mask, *bits);

	return 0;
}

static const struct gpio_chip template_chip = {
	.label			= "tpic2810",
	.owner			= THIS_MODULE,
	.get_direction		= tpic2810_get_direction,
	.direction_output	= tpic2810_direction_output,
	.set			= tpic2810_set,
	.set_multiple		= tpic2810_set_multiple,
	.base			= -1,
	.ngpio			= 8,
	.can_sleep		= true,
};

static const struct of_device_id tpic2810_of_match_table[] = {
	{ .compatible = "ti,tpic2810" },
	{ /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, tpic2810_of_match_table);

static int tpic2810_probe(struct i2c_client *client)
{
	struct tpic2810 *gpio;

	gpio = devm_kzalloc(&client->dev, sizeof(*gpio), GFP_KERNEL);
	if (!gpio)
		return -ENOMEM;

	gpio->chip = template_chip;
	gpio->chip.parent = &client->dev;

	gpio->client = client;

	mutex_init(&gpio->lock);

Annotation

Implementation Notes