[media] rc: gpio-ir-recv: add timeout on idle

Many decoders require a trailing space (period without IR illumination)
to be delivered before completing a decode.

Since the gpio-ir-recv driver only delivers events on gpio transitions,
a single IR symbol (caused by a quick touch on an IR remote) will not
be properly decoded without the use of a timer to flush the tail end
state of the IR receiver.

This patch initializes and uses a timer and the timeout field of rcdev
to complete the stream and allow decode.

The timeout can be overridden through the use of the LIRC_SET_REC_TIMEOUT
ioctl.

Signed-off-by: Eric Nelson <eric@nelint.com>
Acked-by: Sean Young <sean@mess.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>

diff --git a/drivers/media/rc/gpio-ir-recv.c b/drivers/media/rc/gpio-ir-recv.c
index 6050de1142a66840186837d81640b34d4d6de700..5b63b1f15cb18b4431c872923b88d1cd2c0bf764 100644 (file)
--- a/drivers/media/rc/gpio-ir-recv.c
+++ b/drivers/media/rc/gpio-ir-recv.c
@@ -30,6 +30,7 @@ struct gpio_rc_dev {
        struct rc_dev *rcdev;
        int gpio_nr;
        bool active_low;
+       struct timer_list flush_timer;
 };
 
 #ifdef CONFIG_OF
@@ -93,12 +94,26 @@ static irqreturn_t gpio_ir_recv_irq(int irq, void *dev_id)
        if (rc < 0)
                goto err_get_value;
 
+       mod_timer(&gpio_dev->flush_timer,
+                 jiffies + nsecs_to_jiffies(gpio_dev->rcdev->timeout));
+
        ir_raw_event_handle(gpio_dev->rcdev);
 
 err_get_value:
        return IRQ_HANDLED;
 }
 
+static void flush_timer(unsigned long arg)
+{
+       struct gpio_rc_dev *gpio_dev = (struct gpio_rc_dev *)arg;
+       DEFINE_IR_RAW_EVENT(ev);
+
+       ev.timeout = true;
+       ev.duration = gpio_dev->rcdev->timeout;
+       ir_raw_event_store(gpio_dev->rcdev, &ev);
+       ir_raw_event_handle(gpio_dev->rcdev);
+}
+
 static int gpio_ir_recv_probe(struct platform_device *pdev)
 {
        struct gpio_rc_dev *gpio_dev;
@@ -144,6 +159,9 @@ static int gpio_ir_recv_probe(struct platform_device *pdev)
        rcdev->input_id.version = 0x0100;
        rcdev->dev.parent = &pdev->dev;
        rcdev->driver_name = GPIO_IR_DRIVER_NAME;
+       rcdev->min_timeout = 0;
+       rcdev->timeout = IR_DEFAULT_TIMEOUT;
+       rcdev->max_timeout = 10 * IR_DEFAULT_TIMEOUT;
        if (pdata->allowed_protos)
                rcdev->allowed_protocols = pdata->allowed_protos;
        else
@@ -154,6 +172,9 @@ static int gpio_ir_recv_probe(struct platform_device *pdev)
        gpio_dev->gpio_nr = pdata->gpio_nr;
        gpio_dev->active_low = pdata->active_low;
 
+       setup_timer(&gpio_dev->flush_timer, flush_timer,
+                   (unsigned long)gpio_dev);
+
        rc = gpio_request(pdata->gpio_nr, "gpio-ir-recv");
        if (rc < 0)
                goto err_gpio_request;
@@ -196,6 +217,7 @@ static int gpio_ir_recv_remove(struct platform_device *pdev)
        struct gpio_rc_dev *gpio_dev = platform_get_drvdata(pdev);
 
        free_irq(gpio_to_irq(gpio_dev->gpio_nr), gpio_dev);
+       del_timer_sync(&gpio_dev->flush_timer);
        rc_unregister_device(gpio_dev->rcdev);
        gpio_free(gpio_dev->gpio_nr);
        kfree(gpio_dev);