[PATCH v3 4/5] leds: trigger: oneshot: Add initialization from Device Tree

[Krzysztof Kozlowski]

Allow initialization of delays used in oneshot trigger from Device
Tree property.

This is especially useful for embedded systems where the trigger might
be used early, before bringing up user-space.

Signed-off-by: Krzysztof Kozlowski <krzk@xxxxxxxxxx>
---

New patch in the series
---
 drivers/leds/trigger/ledtrig-oneshot.c | 31 +++++++++++++++++++++++++++++--
 1 file changed, 29 insertions(+), 2 deletions(-)

diff --git a/drivers/leds/trigger/ledtrig-oneshot.c b/drivers/leds/trigger/ledtrig-oneshot.c
index 95c9be4b6e7e..4e73a1c17a40 100644
--- a/drivers/leds/trigger/ledtrig-oneshot.c
+++ b/drivers/leds/trigger/ledtrig-oneshot.c
@@ -130,6 +130,27 @@ static struct attribute *oneshot_trig_attrs[] = {
 };
 ATTRIBUTE_GROUPS(oneshot_trig);
 
+static void pattern_init(struct led_classdev *led_cdev)
+{
+	const char *pattern;
+	unsigned long delay_on, delay_off;
+
+	pattern = led_classdev_get_default_pattern(led_cdev);
+	if (!pattern) {
+		led_cdev->blink_delay_on = DEFAULT_DELAY;
+		led_cdev->blink_delay_off = DEFAULT_DELAY;
+		return;
+	}
+
+	if (sscanf(pattern, "%lu %lu", &delay_on, &delay_off) == 2) {
+		led_cdev->blink_delay_on = delay_on;
+		led_cdev->blink_delay_off = delay_off;
+	} else {
+		dev_warn(led_cdev->dev,
+			 "Invalid value for delays pattern\n");
+	}
+}
+
 static int oneshot_trig_activate(struct led_classdev *led_cdev)
 {
 	struct oneshot_trig_data *oneshot_data;
@@ -140,8 +161,14 @@ static int oneshot_trig_activate(struct led_classdev *led_cdev)
 
 	led_set_trigger_data(led_cdev, oneshot_data);
 
-	led_cdev->blink_delay_on = DEFAULT_DELAY;
-	led_cdev->blink_delay_off = DEFAULT_DELAY;
+	if (led_cdev->flags & LED_INIT_DEFAULT_TRIGGER) {
+		pattern_init(led_cdev);
+		/*
+		 * Mark as initialized even on pattern_init() error because
+		 * any consecutive call to it would produce the same error.
+		 */
+		led_cdev->flags &= ~LED_INIT_DEFAULT_TRIGGER;
+	}
 
 	return 0;
 }
-- 
2.7.4