[PATCH] LEDS-One-Shot-Timer-Trigger-implementation

[Shuah Khan]

Signed-off-by: Shuah Khan <shuahkhan@xxxxxxxxx>
---
 drivers/leds/led-class.c     |    4 +-
 drivers/leds/led-core.c      |   26 +++++++++--
 drivers/leds/ledtrig-timer.c |  101 +++++++++++++++++++++++++++++------------
 3 files changed, 96 insertions(+), 35 deletions(-)

diff --git a/drivers/leds/led-class.c b/drivers/leds/led-class.c
index 5bff843..be7400a 100644
--- a/drivers/leds/led-class.c
+++ b/drivers/leds/led-class.c
@@ -107,7 +107,9 @@ static void led_timer_function(unsigned long data)
 
 	led_set_brightness(led_cdev, brightness);
 
-	mod_timer(&led_cdev->blink_timer, jiffies + msecs_to_jiffies(delay));
+	if (delay != ULONG_MAX)
+		mod_timer(&led_cdev->blink_timer,
+			jiffies + msecs_to_jiffies(delay));
 }
 
 /**
diff --git a/drivers/leds/led-core.c b/drivers/leds/led-core.c
index d686004..40685f1 100644
--- a/drivers/leds/led-core.c
+++ b/drivers/leds/led-core.c
@@ -72,17 +72,35 @@ void led_blink_set(struct led_classdev *led_cdev,
 		   unsigned long *delay_on,
 		   unsigned long *delay_off)
 {
+	unsigned long val_on;
+	unsigned long val_off;
+
 	del_timer_sync(&led_cdev->blink_timer);
 
-	if (led_cdev->blink_set &&
+	if (delay_on && delay_off && led_cdev->blink_set &&
 	    !led_cdev->blink_set(led_cdev, delay_on, delay_off))
 		return;
 
+	/* if delay_on is null, leave it on forever after delay_off period
+	   if delay_off is null, leave it off forever after delay on period */
+	if (!delay_on)
+		val_on = ULONG_MAX;
+	else
+		val_on = *delay_on;
+
+	if (!delay_off)
+		val_off = ULONG_MAX;
+	else
+		val_off = *delay_off;
+
 	/* blink with 1 Hz as default if nothing specified */
-	if (!*delay_on && !*delay_off)
-		*delay_on = *delay_off = 500;
+	if (!val_on && !val_off) {
+		val_on = val_off = 500;
+		*delay_on = 500;
+		*delay_off = 500;
+	}
 
-	led_set_software_blink(led_cdev, *delay_on, *delay_off);
+	led_set_software_blink(led_cdev, val_on, val_off);
 }
 EXPORT_SYMBOL(led_blink_set);
 
diff --git a/drivers/leds/ledtrig-timer.c b/drivers/leds/ledtrig-timer.c
index 328c64c..bfda51c 100644
--- a/drivers/leds/ledtrig-timer.c
+++ b/drivers/leds/ledtrig-timer.c
@@ -24,6 +24,9 @@ static ssize_t led_delay_on_show(struct device *dev,
 {
 	struct led_classdev *led_cdev = dev_get_drvdata(dev);
 
+	if (led_cdev->blink_delay_on == ULONG_MAX)
+		return sprintf(buf, "%s\n", "forever");
+
 	return sprintf(buf, "%lu\n", led_cdev->blink_delay_on);
 }
 
@@ -32,17 +35,25 @@ static ssize_t led_delay_on_store(struct device *dev,
 {
 	struct led_classdev *led_cdev = dev_get_drvdata(dev);
 	int ret = -EINVAL;
-	char *after;
-	unsigned long state = simple_strtoul(buf, &after, 10);
-	size_t count = after - buf;
-
-	if (isspace(*after))
-		count++;
 
-	if (count == size) {
-		led_blink_set(led_cdev, &state, &led_cdev->blink_delay_off);
-		led_cdev->blink_delay_on = state;
-		ret = count;
+	if (strncmp(buf, "forever", 7) == 0) {
+		led_blink_set(led_cdev, NULL, &led_cdev->blink_delay_off);
+		led_cdev->blink_delay_on = ULONG_MAX;
+		ret = size;
+	} else {
+		char *after;
+		unsigned long state = simple_strtoul(buf, &after, 10);
+		size_t count = after - buf;
+
+		if (isspace(*after))
+			count++;
+
+		if (count == size) {
+			led_blink_set(led_cdev, &state,
+				&led_cdev->blink_delay_off);
+			led_cdev->blink_delay_on = state;
+			ret = count;
+		}
 	}
 
 	return ret;
@@ -53,6 +64,9 @@ static ssize_t led_delay_off_show(struct device *dev,
 {
 	struct led_classdev *led_cdev = dev_get_drvdata(dev);
 
+	if (led_cdev->blink_delay_off == ULONG_MAX)
+		return sprintf(buf, "%s\n", "forever");
+
 	return sprintf(buf, "%lu\n", led_cdev->blink_delay_off);
 }
 
@@ -61,17 +75,24 @@ static ssize_t led_delay_off_store(struct device *dev,
 {
 	struct led_classdev *led_cdev = dev_get_drvdata(dev);
 	int ret = -EINVAL;
-	char *after;
-	unsigned long state = simple_strtoul(buf, &after, 10);
-	size_t count = after - buf;
 
-	if (isspace(*after))
-		count++;
-
-	if (count == size) {
-		led_blink_set(led_cdev, &led_cdev->blink_delay_on, &state);
-		led_cdev->blink_delay_off = state;
-		ret = count;
+	if (strncmp(buf, "forever", 7) == 0) {
+		led_blink_set(led_cdev, &led_cdev->blink_delay_on, NULL);
+		led_cdev->blink_delay_off = ULONG_MAX;
+	} else {
+		char *after;
+		unsigned long state = simple_strtoul(buf, &after, 10);
+		size_t count = after - buf;
+
+		if (isspace(*after))
+			count++;
+
+		if (count == size) {
+			led_blink_set(led_cdev, &led_cdev->blink_delay_on,
+				&state);
+			led_cdev->blink_delay_off = state;
+			ret = count;
+		}
 	}
 
 	return ret;
@@ -80,7 +101,7 @@ static ssize_t led_delay_off_store(struct device *dev,
 static DEVICE_ATTR(delay_on, 0644, led_delay_on_show, led_delay_on_store);
 static DEVICE_ATTR(delay_off, 0644, led_delay_off_show, led_delay_off_store);
 
-static void timer_trig_activate(struct led_classdev *led_cdev)
+static void timer_trig_activate_common(struct led_classdev *led_cdev)
 {
 	int rc;
 
@@ -91,17 +112,24 @@ static void timer_trig_activate(struct led_classdev *led_cdev)
 		return;
 	rc = device_create_file(led_cdev->dev, &dev_attr_delay_off);
 	if (rc)
-		goto err_out_delayon;
-
-	led_blink_set(led_cdev, &led_cdev->blink_delay_on,
-		      &led_cdev->blink_delay_off);
+		device_remove_file(led_cdev->dev, &dev_attr_delay_on);
 
-	led_cdev->trigger_data = (void *)1;
+	else
+		led_cdev->trigger_data = (void *)1;
+}
 
-	return;
+static void timer_trig_activate_one_shot(struct led_classdev *led_cdev)
+{
+	timer_trig_activate_common(led_cdev);
+}
 
-err_out_delayon:
-	device_remove_file(led_cdev->dev, &dev_attr_delay_on);
+static void timer_trig_activate(struct led_classdev *led_cdev)
+{
+	timer_trig_activate_common(led_cdev);
+	if (led_cdev->trigger_data) {
+		led_blink_set(led_cdev, &led_cdev->blink_delay_on,
+		      &led_cdev->blink_delay_off);
+	}
 }
 
 static void timer_trig_deactivate(struct led_classdev *led_cdev)
@@ -121,14 +149,27 @@ static struct led_trigger timer_led_trigger = {
 	.deactivate = timer_trig_deactivate,
 };
 
+static struct led_trigger one_shot_timer_led_trigger = {
+	.name     = "one-shot-timer",
+	.activate = timer_trig_activate_one_shot,
+	.deactivate = timer_trig_deactivate,
+};
+
 static int __init timer_trig_init(void)
 {
-	return led_trigger_register(&timer_led_trigger);
+	int rc = 0;
+
+	rc = led_trigger_register(&timer_led_trigger);
+	if (!rc)
+		rc = led_trigger_register(&one_shot_timer_led_trigger);
+
+	return rc;
 }
 
 static void __exit timer_trig_exit(void)
 {
 	led_trigger_unregister(&timer_led_trigger);
+	led_trigger_unregister(&one_shot_timer_led_trigger);
 }
 
 module_init(timer_trig_init);
-- 
1.7.5.4



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