leds: Add clevo notebook LED driver

The driver supports the mail LED commonly found on different Clevo notebooks.
The driver access the LED through the i8042 hardware which is handled by
the input subsystem.

Signed-off-by: Márton Németh <nm127@freemail.hu>
Signed-off-by: Richard Purdie <rpurdie@rpsys.net>
diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig
index ec568fa..cf3a6d4 100644
--- a/drivers/leds/Kconfig
+++ b/drivers/leds/Kconfig
@@ -114,6 +114,30 @@
 	help
 	  This option enables support for the CM-X270 LEDs.
 
+config LEDS_CLEVO_MAIL
+	tristate "Mail LED on Clevo notebook (EXPERIMENTAL)"
+	depends on LEDS_CLASS && X86 && SERIO_I8042 && DMI && EXPERIMENTAL
+	help
+	  This driver makes the mail LED accessible from userspace
+	  programs through the leds subsystem. This LED have three
+	  known mode: off, blink at 0.5Hz and blink at 1Hz.
+
+	  As this LED cannot change it's brightness it blinks instead.
+	  The brightness value 0 means off, 1..127 means blink at 0.5Hz
+	  and 128..255 means blink at 1Hz.
+
+	  This module can drive the mail LED for the following notebooks:
+
+	  	Clevo D410J
+	  	Clevo D410V
+	  	Clevo D400V/D470V (not tested, but might work)
+	  	Clevo M540N
+	  	Clevo M5x0N (not tested, but might work)
+	  	Positivo Mobile (Clevo M5x0V)
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called leds-clevo-mail.
+
 comment "LED Triggers"
 
 config LEDS_TRIGGERS