drivers/video/backlight/platform_lcd.c

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

File Facts

System
Linux kernel
Corpus path
drivers/video/backlight/platform_lcd.c
Extension
.c
Size
3151 bytes
Lines
143
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 platform_lcd {
	struct device		*us;
	struct lcd_device	*lcd;
	struct plat_lcd_data	*pdata;

	unsigned int		 power;
	unsigned int		 suspended:1;
};

static inline struct platform_lcd *to_our_lcd(struct lcd_device *lcd)
{
	return lcd_get_data(lcd);
}

static int platform_lcd_get_power(struct lcd_device *lcd)
{
	struct platform_lcd *plcd = to_our_lcd(lcd);

	return plcd->power;
}

static int platform_lcd_set_power(struct lcd_device *lcd, int power)
{
	struct platform_lcd *plcd = to_our_lcd(lcd);
	int lcd_power = 1;

	if (power == LCD_POWER_OFF || plcd->suspended)
		lcd_power = 0;

	plcd->pdata->set_power(plcd->pdata, lcd_power);
	plcd->power = power;

	return 0;
}

static bool platform_lcd_controls_device(struct lcd_device *lcd, struct device *display_device)
{
	struct platform_lcd *plcd = to_our_lcd(lcd);

	return plcd->us->parent == display_device;
}

static const struct lcd_ops platform_lcd_ops = {
	.get_power		= platform_lcd_get_power,
	.set_power		= platform_lcd_set_power,
	.controls_device	= platform_lcd_controls_device,
};

static int platform_lcd_probe(struct platform_device *pdev)
{
	struct plat_lcd_data *pdata;
	struct platform_lcd *plcd;
	struct device *dev = &pdev->dev;
	int err;

	pdata = dev_get_platdata(&pdev->dev);
	if (!pdata) {
		dev_err(dev, "no platform data supplied\n");
		return -EINVAL;
	}

	if (pdata->probe) {
		err = pdata->probe(pdata);
		if (err)
			return err;
	}

	plcd = devm_kzalloc(&pdev->dev, sizeof(struct platform_lcd),
			    GFP_KERNEL);
	if (!plcd)
		return -ENOMEM;

	plcd->us = dev;
	plcd->pdata = pdata;
	plcd->lcd = devm_lcd_device_register(&pdev->dev, dev_name(dev), dev,
						plcd, &platform_lcd_ops);
	if (IS_ERR(plcd->lcd)) {
		dev_err(dev, "cannot register lcd device\n");
		return PTR_ERR(plcd->lcd);
	}

	platform_set_drvdata(pdev, plcd);
	platform_lcd_set_power(plcd->lcd, LCD_POWER_REDUCED);

	return 0;
}

#ifdef CONFIG_PM_SLEEP
static int platform_lcd_suspend(struct device *dev)
{

Annotation

Implementation Notes