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 adds an optional device tree node "flush-ms" which, if
present, will use a jiffie-based timer to complete the last pulse
stream and allow decode.
The "flush-ms" value should be chosen with a value that will convert
well to jiffies (multiples of 10 are good).
Signed-off-by: Eric Nelson <eric@xxxxxxxxxx>
---
.../devicetree/bindings/media/gpio-ir-receiver.txt | 1 +
drivers/media/rc/gpio-ir-recv.c | 39 ++++++++++++++++++----
include/media/gpio-ir-recv.h | 1 +
3 files changed, 34 insertions(+), 7 deletions(-)
diff --git a/Documentation/devicetree/bindings/media/gpio-ir-receiver.txt b/Documentation/devicetree/bindings/media/gpio-ir-receiver.txt
index 56e726e..13ff92d 100644
--- a/Documentation/devicetree/bindings/media/gpio-ir-receiver.txt
+++ b/Documentation/devicetree/bindings/media/gpio-ir-receiver.txt
@@ -6,6 +6,7 @@ Required properties:
Optional properties:
- linux,rc-map-name: Linux specific remote control map name.
+ - flush-ms: time for final flush of 'space' pulse (period with no IR)
Example node:
diff --git a/drivers/media/rc/gpio-ir-recv.c b/drivers/media/rc/gpio-ir-recv.c
index 7dbc9ca..e3c353e 100644
--- a/drivers/media/rc/gpio-ir-recv.c
+++ b/drivers/media/rc/gpio-ir-recv.c
@@ -29,7 +29,9 @@
struct gpio_rc_dev {
struct rc_dev *rcdev;
int gpio_nr;
+ int flush_jiffies;
bool active_low;
+ struct timer_list flush_timer;
};
#ifdef CONFIG_OF
@@ -42,6 +44,7 @@ static int gpio_ir_recv_get_devtree_pdata(struct device *dev,
struct device_node *np = dev->of_node;
enum of_gpio_flags flags;
int gpio;
+ u32 flush_ms = 0;
gpio = of_get_gpio_flags(np, 0, &flags);
if (gpio < 0) {
@@ -50,6 +53,9 @@ static int gpio_ir_recv_get_devtree_pdata(struct device *dev,
return gpio;
}
+ of_property_read_u32(np, "flush-ms", &flush_ms);
+ pdata->flush_jiffies = msecs_to_jiffies(flush_ms);
+
pdata->gpio_nr = gpio;
pdata->active_low = (flags & OF_GPIO_ACTIVE_LOW);
/* probe() takes care of map_name == NULL or allowed_protos == 0 */
@@ -71,9 +77,8 @@ MODULE_DEVICE_TABLE(of, gpio_ir_recv_of_match);
#endif
-static irqreturn_t gpio_ir_recv_irq(int irq, void *dev_id)
+static void flush_gp(struct gpio_rc_dev *gpio_dev)
{
- struct gpio_rc_dev *gpio_dev = dev_id;
int gval;
int rc = 0;
enum raw_event_type type = IR_SPACE;
@@ -81,7 +86,7 @@ static irqreturn_t gpio_ir_recv_irq(int irq, void *dev_id)
gval = gpio_get_value(gpio_dev->gpio_nr);
if (gval < 0)
- goto err_get_value;
+ return;
if (gpio_dev->active_low)
gval = !gval;
@@ -90,15 +95,30 @@ static irqreturn_t gpio_ir_recv_irq(int irq, void *dev_id)
type = IR_PULSE;
rc = ir_raw_event_store_edge(gpio_dev->rcdev, type);
- if (rc < 0)
- goto err_get_value;
+ if (rc >= 0)
+ ir_raw_event_handle(gpio_dev->rcdev);
+}
- ir_raw_event_handle(gpio_dev->rcdev);
+static irqreturn_t gpio_ir_recv_irq(int irq, void *dev_id)
+{
+ struct gpio_rc_dev *gpio_dev = dev_id;
+
+ flush_gp(gpio_dev);
+
+ if (gpio_dev->flush_jiffies)
+ mod_timer(&gpio_dev->flush_timer,
+ jiffies + gpio_dev->flush_jiffies);
-err_get_value:
return IRQ_HANDLED;
}
+static void flush_timer(unsigned long arg)
+{
+ struct gpio_rc_dev *gpio_dev = (struct gpio_rc_dev *)arg;
+
+ flush_gp(gpio_dev);
+}
+
static int gpio_ir_recv_probe(struct platform_device *pdev)
{
struct gpio_rc_dev *gpio_dev;
@@ -152,8 +172,13 @@ static int gpio_ir_recv_probe(struct platform_device *pdev)
gpio_dev->rcdev = rcdev;
gpio_dev->gpio_nr = pdata->gpio_nr;
+ gpio_dev->flush_jiffies = pdata->flush_jiffies;
gpio_dev->active_low = pdata->active_low;
+ init_timer(&gpio_dev->flush_timer);
+ gpio_dev->flush_timer.function = flush_timer;
+ gpio_dev->flush_timer.data = (unsigned long)gpio_dev;
+
rc = gpio_request(pdata->gpio_nr, "gpio-ir-recv");
if (rc < 0)
goto err_gpio_request;
diff --git a/include/media/gpio-ir-recv.h b/include/media/gpio-ir-recv.h
index 0142736..88fae78 100644
--- a/include/media/gpio-ir-recv.h
+++ b/include/media/gpio-ir-recv.h
@@ -17,6 +17,7 @@ struct gpio_ir_recv_platform_data {
int gpio_nr;
bool active_low;
u64 allowed_protos;
+ int flush_jiffies;
const char *map_name;
};
--
2.5.1
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