drivers/video/backlight/lv5207lp.c

Source file repositories/reference/linux-study-clean/drivers/video/backlight/lv5207lp.c

File Facts

System
Linux kernel
Corpus path
drivers/video/backlight/lv5207lp.c
Extension
.c
Size
3983 bytes
Lines
153
Domain
Driver Families
Bucket
drivers/video
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 lv5207lp {
	struct i2c_client *client;
	struct backlight_device *backlight;
	struct lv5207lp_platform_data *pdata;
};

static int lv5207lp_write(struct lv5207lp *lv, u8 reg, u8 data)
{
	return i2c_smbus_write_byte_data(lv->client, reg, data);
}

static int lv5207lp_backlight_update_status(struct backlight_device *backlight)
{
	struct lv5207lp *lv = bl_get_data(backlight);
	int brightness = backlight_get_brightness(backlight);

	if (brightness) {
		lv5207lp_write(lv, LV5207LP_CTRL1,
			       LV5207LP_CPSW | LV5207LP_C10 | LV5207LP_CKSW);
		lv5207lp_write(lv, LV5207LP_CTRL2,
			       LV5207LP_MSW | LV5207LP_MLED4 |
			       (brightness - 1));
	} else {
		lv5207lp_write(lv, LV5207LP_CTRL1, 0);
		lv5207lp_write(lv, LV5207LP_CTRL2, 0);
	}

	return 0;
}

static bool lv5207lp_backlight_controls_device(struct backlight_device *backlight,
					       struct device *display_dev)
{
	struct lv5207lp *lv = bl_get_data(backlight);

	return !lv->pdata->dev || lv->pdata->dev == display_dev;
}

static const struct backlight_ops lv5207lp_backlight_ops = {
	.options	 = BL_CORE_SUSPENDRESUME,
	.update_status	 = lv5207lp_backlight_update_status,
	.controls_device = lv5207lp_backlight_controls_device,
};

static int lv5207lp_probe(struct i2c_client *client)
{
	struct lv5207lp_platform_data *pdata = dev_get_platdata(&client->dev);
	struct backlight_device *backlight;
	struct backlight_properties props;
	struct lv5207lp *lv;

	if (pdata == NULL) {
		dev_err(&client->dev, "No platform data supplied\n");
		return -EINVAL;
	}

	if (!i2c_check_functionality(client->adapter,
				     I2C_FUNC_SMBUS_BYTE_DATA)) {
		dev_warn(&client->dev,
			 "I2C adapter doesn't support I2C_FUNC_SMBUS_BYTE\n");
		return -EIO;
	}

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

	lv->client = client;
	lv->pdata = pdata;

	memset(&props, 0, sizeof(props));
	props.type = BACKLIGHT_RAW;
	props.max_brightness = min_t(unsigned int, pdata->max_value,
				     LV5207LP_MAX_BRIGHTNESS);
	props.brightness = clamp_t(unsigned int, pdata->def_value, 0,
				   props.max_brightness);

	backlight = devm_backlight_device_register(&client->dev,
				dev_name(&client->dev), &lv->client->dev,
				lv, &lv5207lp_backlight_ops, &props);
	if (IS_ERR(backlight)) {
		dev_err(&client->dev, "failed to register backlight\n");
		return PTR_ERR(backlight);
	}

	backlight_update_status(backlight);
	i2c_set_clientdata(client, backlight);

	return 0;
}

Annotation

Implementation Notes