drivers/video/backlight/l4f00242t03.c

Source file repositories/reference/linux-study-clean/drivers/video/backlight/l4f00242t03.c

File Facts

System
Linux kernel
Corpus path
drivers/video/backlight/l4f00242t03.c
Extension
.c
Size
6725 bytes
Lines
253
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 l4f00242t03_priv {
	struct spi_device	*spi;
	struct lcd_device	*ld;
	int lcd_state;
	struct regulator *io_reg;
	struct regulator *core_reg;
	struct gpio_desc *reset;
	struct gpio_desc *enable;
};

static void l4f00242t03_reset(struct gpio_desc *gpiod)
{
	pr_debug("l4f00242t03_reset.\n");
	gpiod_set_value(gpiod, 1);
	mdelay(100);
	gpiod_set_value(gpiod, 0);
	mdelay(10);	/* tRES >= 100us */
	gpiod_set_value(gpiod, 1);
	mdelay(20);
}

#define param(x) ((x) | 0x100)

static void l4f00242t03_lcd_init(struct spi_device *spi)
{
	struct l4f00242t03_priv *priv = spi_get_drvdata(spi);
	const u16 cmd[] = { 0x36, param(0), 0x3A, param(0x60) };
	int ret;

	dev_dbg(&spi->dev, "initializing LCD\n");

	ret = regulator_set_voltage(priv->io_reg, 1800000, 1800000);
	if (ret) {
		dev_err(&spi->dev, "failed to set the IO regulator voltage.\n");
		return;
	}
	ret = regulator_enable(priv->io_reg);
	if (ret) {
		dev_err(&spi->dev, "failed to enable the IO regulator.\n");
		return;
	}

	ret = regulator_set_voltage(priv->core_reg, 2800000, 2800000);
	if (ret) {
		dev_err(&spi->dev, "failed to set the core regulator voltage.\n");
		regulator_disable(priv->io_reg);
		return;
	}
	ret = regulator_enable(priv->core_reg);
	if (ret) {
		dev_err(&spi->dev, "failed to enable the core regulator.\n");
		regulator_disable(priv->io_reg);
		return;
	}

	l4f00242t03_reset(priv->reset);

	gpiod_set_value(priv->enable, 1);
	msleep(60);
	spi_write(spi, (const u8 *)cmd, ARRAY_SIZE(cmd) * sizeof(u16));
}

static void l4f00242t03_lcd_powerdown(struct spi_device *spi)
{
	struct l4f00242t03_priv *priv = spi_get_drvdata(spi);

	dev_dbg(&spi->dev, "Powering down LCD\n");

	gpiod_set_value(priv->enable, 0);

	regulator_disable(priv->io_reg);
	regulator_disable(priv->core_reg);
}

static int l4f00242t03_lcd_power_get(struct lcd_device *ld)
{
	struct l4f00242t03_priv *priv = lcd_get_data(ld);

	return priv->lcd_state;
}

static int l4f00242t03_lcd_power_set(struct lcd_device *ld, int power)
{
	struct l4f00242t03_priv *priv = lcd_get_data(ld);
	struct spi_device *spi = priv->spi;

	const u16 slpout = 0x11;
	const u16 dison = 0x29;

	const u16 slpin = 0x10;

Annotation

Implementation Notes