drivers/leds/leds-as3668.c

Source file repositories/reference/linux-study-clean/drivers/leds/leds-as3668.c

File Facts

System
Linux kernel
Corpus path
drivers/leds/leds-as3668.c
Extension
.c
Size
5465 bytes
Lines
203
Domain
Driver Families
Bucket
drivers/leds
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 as3668_led {
	struct led_classdev cdev;
	struct as3668 *chip;
	struct fwnode_handle *fwnode;
	u8 mode_mask;
	u8 current_reg;
};

struct as3668 {
	struct i2c_client *client;
	struct as3668_led leds[AS3668_MAX_LEDS];
};

static int as3668_channel_mode_set(struct as3668_led *led, u8 mode)
{
	int ret;
	u8 channel_modes;

	ret = i2c_smbus_read_byte_data(led->chip->client, AS3668_CURR_MODE_REG);
	if (ret < 0) {
		dev_err(led->cdev.dev, "failed to read channel modes\n");
		return ret;
	}
	channel_modes = (u8)ret;

	channel_modes &= ~led->mode_mask;
	channel_modes |= led->mode_mask & (AS3668_CURR_MODE_PACK(mode));

	return i2c_smbus_write_byte_data(led->chip->client, AS3668_CURR_MODE_REG, channel_modes);
}

static enum led_brightness as3668_brightness_get(struct led_classdev *cdev)
{
	struct as3668_led *led = container_of(cdev, struct as3668_led, cdev);

	return i2c_smbus_read_byte_data(led->chip->client, led->current_reg);
}

static void as3668_brightness_set(struct led_classdev *cdev, enum led_brightness brightness)
{
	struct as3668_led *led = container_of(cdev, struct as3668_led, cdev);
	int err;

	err = as3668_channel_mode_set(led, !!brightness);
	if (err)
		dev_err(cdev->dev, "failed to set channel mode: %d\n", err);

	err = i2c_smbus_write_byte_data(led->chip->client, led->current_reg, brightness);
	if (err)
		dev_err(cdev->dev, "failed to set brightness: %d\n", err);
}

static int as3668_dt_init(struct as3668 *as3668)
{
	struct device *dev = &as3668->client->dev;
	struct as3668_led *led;
	struct led_init_data init_data = {};
	int err;
	u32 reg;

	for_each_available_child_of_node_scoped(dev_of_node(dev), child) {
		err = of_property_read_u32(child, "reg", &reg);
		if (err)
			return dev_err_probe(dev, err, "failed to read 'reg' property");

		if (reg < 0 || reg >= AS3668_MAX_LEDS)
			return dev_err_probe(dev, -EINVAL,
					     "unsupported LED: %d\n", reg);

		led = &as3668->leds[reg];
		led->fwnode = of_fwnode_handle(child);

		led->current_reg = reg + AS3668_CURR1_REG;
		led->mode_mask = AS3668_CURR1_MODE_MASK << (reg * 2);
		led->chip = as3668;

		led->cdev.max_brightness = U8_MAX;
		led->cdev.brightness_get = as3668_brightness_get;
		led->cdev.brightness_set = as3668_brightness_set;

		init_data.fwnode = led->fwnode;
		init_data.default_label = ":";

		err = devm_led_classdev_register_ext(dev, &led->cdev, &init_data);
		if (err)
			return dev_err_probe(dev, err, "failed to register LED %d\n", reg);
	}

	return 0;
}

Annotation

Implementation Notes