drivers/leds/leds-ot200.c

Source file repositories/reference/linux-study-clean/drivers/leds/leds-ot200.c

File Facts

System
Linux kernel
Corpus path
drivers/leds/leds-ot200.c
Extension
.c
Size
2751 bytes
Lines
153
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 ot200_led {
	struct led_classdev cdev;
	const char *name;
	unsigned long port;
	u8 mask;
};

/*
 * The device has three leds on the back panel (led_err, led_init and led_run)
 * and can handle up to seven leds on the front panel.
 */

static struct ot200_led leds[] = {
	{
		.name = "led_run",
		.port = 0x5a,
		.mask = BIT(0),
	},
	{
		.name = "led_init",
		.port = 0x5a,
		.mask = BIT(1),
	},
	{
		.name = "led_err",
		.port = 0x5a,
		.mask = BIT(2),
	},
	{
		.name = "led_1",
		.port = 0x49,
		.mask = BIT(6),
	},
	{
		.name = "led_2",
		.port = 0x49,
		.mask = BIT(5),
	},
	{
		.name = "led_3",
		.port = 0x49,
		.mask = BIT(4),
	},
	{
		.name = "led_4",
		.port = 0x49,
		.mask = BIT(3),
	},
	{
		.name = "led_5",
		.port = 0x49,
		.mask = BIT(2),
	},
	{
		.name = "led_6",
		.port = 0x49,
		.mask = BIT(1),
	},
	{
		.name = "led_7",
		.port = 0x49,
		.mask = BIT(0),
	}
};

static DEFINE_SPINLOCK(value_lock);

/*
 * we need to store the current led states, as it is not
 * possible to read the current led state via inb().
 */
static u8 leds_back;
static u8 leds_front;

static void ot200_led_brightness_set(struct led_classdev *led_cdev,
		enum led_brightness value)
{
	struct ot200_led *led = container_of(led_cdev, struct ot200_led, cdev);
	u8 *val;
	unsigned long flags;

	spin_lock_irqsave(&value_lock, flags);

	if (led->port == 0x49)
		val = &leds_front;
	else if (led->port == 0x5a)
		val = &leds_back;
	else
		BUG();

Annotation

Implementation Notes