leds: add oneshot trigger

Add oneshot trigger to blink a led with configurale parameters via
sysfs.

Signed-off-by: Fabio Baltieri <fabio.baltieri@gmail.com>
Cc: Shuah Khan <shuahkhan@gmail.com>
Signed-off-by: Bryan Wu <bryan.wu@canonical.com>
diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig
index 12b2b55..54dd1a3 100644
--- a/drivers/leds/Kconfig
+++ b/drivers/leds/Kconfig
@@ -443,6 +443,20 @@
 
 	  If unsure, say Y.
 
+config LEDS_TRIGGER_ONESHOT
+	tristate "LED One-shot Trigger"
+	depends on LEDS_TRIGGERS
+	help
+	  This allows LEDs to blink in one-shot pulses with parameters
+	  controlled via sysfs.  It's useful to notify the user on
+	  sporadic events, when there are no clear begin and end trap points,
+	  or on dense events, where this blinks the LED at constant rate if
+	  rearmed continuously.
+
+	  It also shows how to use the led_blink_set_oneshot() function.
+
+	  If unsure, say Y.
+
 config LEDS_TRIGGER_IDE_DISK
 	bool "LED IDE Disk Trigger"
 	depends on IDE_GD_ATA