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

[Krzysztof Kozlowski <krzk@kernel.org>]

Allow initialization of delays used in timer 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@kernel.org>
---

New patch in the series
---
 drivers/leds/trigger/ledtrig-timer.c | 28 ++++++++++++++++++++++++++++
 1 file changed, 28 insertions(+)

diff --git a/drivers/leds/trigger/ledtrig-timer.c b/drivers/leds/trigger/ledtrig-timer.c
index 7c14983781ee..85a4b9fc3de0 100644
--- a/drivers/leds/trigger/ledtrig-timer.c
+++ b/drivers/leds/trigger/ledtrig-timer.c
@@ -77,8 +77,36 @@ static struct attribute *timer_trig_attrs[] = {
 };
 ATTRIBUTE_GROUPS(timer_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)
+		return;
+
+	if (sscanf(pattern, "%lu %lu", &delay_on, &delay_off) == 2) {
+		led_blink_set(led_cdev, &delay_on, &delay_off);
+		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 timer_trig_activate(struct led_classdev *led_cdev)
 {
+	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;
+	}
+
 	led_blink_set(led_cdev, &led_cdev->blink_delay_on,
 		      &led_cdev->blink_delay_off);
 
-- 
2.7.4