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

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

File Facts

System
Linux kernel
Corpus path
drivers/hid/i2c-hid/i2c-hid-of.c
Extension
.c
Size
4720 bytes
Lines
172
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 i2c_hid_of {
	struct i2chid_ops ops;

	struct i2c_client *client;
	struct gpio_desc *reset_gpio;
	struct regulator_bulk_data supplies[2];
	int post_power_delay_ms;
	int post_reset_delay_ms;
};

static int i2c_hid_of_power_up(struct i2chid_ops *ops)
{
	struct i2c_hid_of *ihid_of = container_of(ops, struct i2c_hid_of, ops);
	struct device *dev = &ihid_of->client->dev;
	int ret;

	ret = regulator_bulk_enable(ARRAY_SIZE(ihid_of->supplies),
				    ihid_of->supplies);
	if (ret) {
		dev_warn(dev, "Failed to enable supplies: %d\n", ret);
		return ret;
	}

	if (ihid_of->post_power_delay_ms)
		msleep(ihid_of->post_power_delay_ms);

	gpiod_set_value_cansleep(ihid_of->reset_gpio, 0);
	if (ihid_of->post_reset_delay_ms)
		msleep(ihid_of->post_reset_delay_ms);

	return 0;
}

static void i2c_hid_of_power_down(struct i2chid_ops *ops)
{
	struct i2c_hid_of *ihid_of = container_of(ops, struct i2c_hid_of, ops);

	gpiod_set_value_cansleep(ihid_of->reset_gpio, 1);
	regulator_bulk_disable(ARRAY_SIZE(ihid_of->supplies),
			       ihid_of->supplies);
}

static int i2c_hid_of_probe(struct i2c_client *client)
{
	struct device *dev = &client->dev;
	struct i2c_hid_of *ihid_of;
	u16 hid_descriptor_address;
	u32 quirks = 0;
	int ret;
	u32 val;

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

	ihid_of->client = client;
	ihid_of->ops.power_up = i2c_hid_of_power_up;
	ihid_of->ops.power_down = i2c_hid_of_power_down;

	ret = device_property_read_u32(dev, "hid-descr-addr", &val);
	if (ret) {
		dev_err(dev, "HID register address not provided\n");
		return -ENODEV;
	}
	if (val >> 16) {
		dev_err(dev, "Bad HID register address: 0x%08x\n", val);
		return -EINVAL;
	}
	hid_descriptor_address = val;

	if (!device_property_read_u32(dev, "post-power-on-delay-ms", &val))
		ihid_of->post_power_delay_ms = val;

	/*
	 * Note this is a kernel internal device-property set by x86 platform code,
	 * this MUST not be used in devicetree files without first adding it to
	 * the DT bindings.
	 */
	if (!device_property_read_u32(dev, "post-reset-deassert-delay-ms", &val))
		ihid_of->post_reset_delay_ms = val;

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

	ihid_of->supplies[0].supply = "vdd";
	ihid_of->supplies[1].supply = "vddl";
	ret = devm_regulator_bulk_get(dev, ARRAY_SIZE(ihid_of->supplies),
				      ihid_of->supplies);

Annotation

Implementation Notes