drivers/media/rc/gpio-ir-recv.c

Source file repositories/reference/linux-study-clean/drivers/media/rc/gpio-ir-recv.c

File Facts

System
Linux kernel
Corpus path
drivers/media/rc/gpio-ir-recv.c
Extension
.c
Size
5378 bytes
Lines
215
Domain
Driver Families
Bucket
drivers/media
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 gpio_rc_dev {
	struct rc_dev *rcdev;
	struct gpio_desc *gpiod;
	int irq;
	struct device *pmdev;
	struct pm_qos_request qos;
};

static irqreturn_t gpio_ir_recv_irq(int irq, void *dev_id)
{
	int val;
	struct gpio_rc_dev *gpio_dev = dev_id;
	struct device *pmdev = gpio_dev->pmdev;

	/*
	 * For some cpuidle systems, not all:
	 * Respond to interrupt taking more latency when cpu in idle.
	 * Invoke asynchronous pm runtime get from interrupt context,
	 * this may introduce a millisecond delay to call resume callback,
	 * where to disable cpuilde.
	 *
	 * Two issues lead to fail to decode first frame, one is latency to
	 * respond to interrupt, another is delay introduced by async api.
	 */
	if (pmdev)
		pm_runtime_get(pmdev);

	val = gpiod_get_value(gpio_dev->gpiod);
	if (val >= 0)
		ir_raw_event_store_edge(gpio_dev->rcdev, val == 1);

	if (pmdev)
		pm_runtime_put_autosuspend(pmdev);

	return IRQ_HANDLED;
}

static int gpio_ir_recv_probe(struct platform_device *pdev)
{
	struct device *dev = &pdev->dev;
	struct device_node *np = dev->of_node;
	struct gpio_rc_dev *gpio_dev;
	struct rc_dev *rcdev;
	u32 period = 0;
	int rc;

	if (!np)
		return -ENODEV;

	gpio_dev = devm_kzalloc(dev, sizeof(*gpio_dev), GFP_KERNEL);
	if (!gpio_dev)
		return -ENOMEM;

	gpio_dev->gpiod = devm_gpiod_get(dev, NULL, GPIOD_IN);
	if (IS_ERR(gpio_dev->gpiod))
		return dev_err_probe(dev, PTR_ERR(gpio_dev->gpiod),
				     "error getting gpio\n");
	gpio_dev->irq = gpiod_to_irq(gpio_dev->gpiod);
	if (gpio_dev->irq < 0)
		return gpio_dev->irq;

	rcdev = devm_rc_allocate_device(dev, RC_DRIVER_IR_RAW);
	if (!rcdev)
		return -ENOMEM;

	rcdev->priv = gpio_dev;
	rcdev->device_name = GPIO_IR_DEVICE_NAME;
	rcdev->input_phys = GPIO_IR_DEVICE_NAME "/input0";
	rcdev->input_id.bustype = BUS_HOST;
	rcdev->input_id.vendor = 0x0001;
	rcdev->input_id.product = 0x0001;
	rcdev->input_id.version = 0x0100;
	rcdev->dev.parent = dev;
	rcdev->driver_name = KBUILD_MODNAME;
	rcdev->min_timeout = 1;
	rcdev->timeout = IR_DEFAULT_TIMEOUT;
	rcdev->max_timeout = 10 * IR_DEFAULT_TIMEOUT;
	rcdev->allowed_protocols = RC_PROTO_BIT_ALL_IR_DECODER;
	rcdev->map_name = of_get_property(np, "linux,rc-map-name", NULL);
	if (!rcdev->map_name)
		rcdev->map_name = RC_MAP_EMPTY;

	gpio_dev->rcdev = rcdev;
	if (of_property_read_bool(np, "wakeup-source"))
		device_init_wakeup(dev, true);

	rc = devm_rc_register_device(dev, rcdev);
	if (rc < 0) {
		dev_err(dev, "failed to register rc device (%d)\n", rc);
		return rc;

Annotation

Implementation Notes