Merge tag 'leds_for_4.11' of git://git.kernel.org/pub/scm/linux/kernel/git/j.anaszewski/linux-leds

Pull LED updates from Jacek Anaszewski:
 "New features and improvements:

   - add new optional brightness_hw_changed attribute for the LEDs that
     may have their brightness level changed autonomously (outside of
     kernel control) by hardware / firmware. The attribute supports
     userspace notifications through POLLPRI events

   - add led_brightness_hw_mon tool that demonstrates how to use the
     aforementioned feature

   - add LED_ON enum for LEDs that can be only turned on/off, and don't
     allow setting other brightness levels

   - allow for adjusting heartbeat trigger blink brightness level

  Fixes and cleanups:

   - avoid harmless maybe-uninitialized warning in leds-ktd2692.c

   - add context to the existing example entries in common LED bindings
     to make the documentation more clear"

* tag 'leds_for_4.11' of git://git.kernel.org/pub/scm/linux/kernel/git/j.anaszewski/linux-leds:
  leds: ledtrig-heartbeat: Make top brightness adjustable
  tools/leds: Add led_hw_brightness_mon program
  leds: class: Add new optional brightness_hw_changed attribute
  leds: ktd2692: avoid harmless maybe-uninitialized warning
  leds: add LED_ON brightness as boolean value
  DT: leds: Improve examples by adding some context

1 files changed, 17 insertions, 0 deletions

diff --git a/Documentation/ABI/testing/sysfs-class-led b/Documentation/ABI/testing/sysfs-class-led
index 491cdeedc195..5f67f7ab277b 100644
--- a/Documentation/ABI/testing/sysfs-class-led
+++ b/Documentation/ABI/testing/sysfs-class-led
@@ -23,6 +23,23 @@ Description:
 		If the LED does not support different brightness levels, this
 		should be 1.
 
+What:		/sys/class/leds/<led>/brightness_hw_changed
+Date:		January 2017
+KernelVersion:	4.11
+Description:
+		Last hardware set brightness level for this LED. Some LEDs
+		may be changed autonomously by hardware/firmware. Only LEDs
+		where this happens and the driver can detect this, will have
+		this file.
+
+		This file supports poll() to detect when the hardware changes
+		the brightness.
+
+		Reading this file will return the last brightness level set
+		by the hardware, this may be different from the current
+		brightness. Reading this file when no hw brightness change
+		event has happened will return an ENODATA error.
+
 What:		/sys/class/leds/<led>/trigger
 Date:		March 2006
 KernelVersion:	2.6.17