drivers/hid/i2c-hid/i2c-hid-of-goodix.c

Source file repositories/reference/linux-study-clean/drivers/hid/i2c-hid/i2c-hid-of-goodix.c

File Facts

System
Linux kernel
Corpus path
drivers/hid/i2c-hid/i2c-hid-of-goodix.c
Extension
.c
Size
3895 bytes
Lines
140
Domain
Driver Families
Bucket
drivers/hid
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 goodix_i2c_hid_timing_data {
	unsigned int post_gpio_reset_delay_ms;
	unsigned int post_power_delay_ms;
};

struct i2c_hid_of_goodix {
	struct i2chid_ops ops;

	struct regulator *vdd;
	struct regulator *vddio;
	struct gpio_desc *reset_gpio;
	bool no_reset_during_suspend;
	const struct goodix_i2c_hid_timing_data *timings;
};

static int goodix_i2c_hid_power_up(struct i2chid_ops *ops)
{
	struct i2c_hid_of_goodix *ihid_goodix =
		container_of(ops, struct i2c_hid_of_goodix, ops);
	int ret;

	/*
	 * We assert reset GPIO here (instead of during power-down) to ensure
	 * the device will have a clean state after powering up, just like the
	 * normal scenarios will have.
	 */
	if (ihid_goodix->no_reset_during_suspend)
		gpiod_set_value_cansleep(ihid_goodix->reset_gpio, 1);

	ret = regulator_enable(ihid_goodix->vdd);
	if (ret)
		return ret;

	ret = regulator_enable(ihid_goodix->vddio);
	if (ret)
		return ret;

	if (ihid_goodix->timings->post_power_delay_ms)
		msleep(ihid_goodix->timings->post_power_delay_ms);

	gpiod_set_value_cansleep(ihid_goodix->reset_gpio, 0);
	if (ihid_goodix->timings->post_gpio_reset_delay_ms)
		msleep(ihid_goodix->timings->post_gpio_reset_delay_ms);

	return 0;
}

static void goodix_i2c_hid_power_down(struct i2chid_ops *ops)
{
	struct i2c_hid_of_goodix *ihid_goodix =
		container_of(ops, struct i2c_hid_of_goodix, ops);

	if (!ihid_goodix->no_reset_during_suspend)
		gpiod_set_value_cansleep(ihid_goodix->reset_gpio, 1);

	regulator_disable(ihid_goodix->vddio);
	regulator_disable(ihid_goodix->vdd);
}

static int i2c_hid_of_goodix_probe(struct i2c_client *client)
{
	struct i2c_hid_of_goodix *ihid_goodix;

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

	ihid_goodix->ops.power_up = goodix_i2c_hid_power_up;
	ihid_goodix->ops.power_down = goodix_i2c_hid_power_down;

	/* Start out with reset asserted */
	ihid_goodix->reset_gpio =
		devm_gpiod_get_optional(&client->dev, "reset", GPIOD_OUT_HIGH);
	if (IS_ERR(ihid_goodix->reset_gpio))
		return PTR_ERR(ihid_goodix->reset_gpio);

	ihid_goodix->vdd = devm_regulator_get(&client->dev, "vdd");
	if (IS_ERR(ihid_goodix->vdd))
		return PTR_ERR(ihid_goodix->vdd);

	ihid_goodix->vddio = devm_regulator_get(&client->dev, "mainboard-vddio");
	if (IS_ERR(ihid_goodix->vddio))
		return PTR_ERR(ihid_goodix->vddio);

	ihid_goodix->no_reset_during_suspend =
		of_property_read_bool(client->dev.of_node, "goodix,no-reset-during-suspend");

	ihid_goodix->timings = device_get_match_data(&client->dev);

Annotation

Implementation Notes