linux-toradex.git/Documentation/ABI/testing/sysfs-class-led, branch v5.0 Linux kernel for Apalis and Colibri modules leds: class: Add new optional brightness_hw_changed attribute 2017-01-29T18:59:42+00:00 Hans de Goede hdegoede@redhat.com 2017-01-29T13:42:52+00:00 0cb8eb30d425d2d2ae28ab630596c44a158784c4 Some LEDs may have their brightness level changed autonomously (outside of kernel control) by hardware / firmware. This commit adds support for an optional brightness_hw_changed attribute to signal such changes to userspace (if a driver can detect them): 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. Drivers which want to support this, simply add LED_BRIGHT_HW_CHANGED to their flags field and call led_classdev_notify_brightness_hw_changed() with the hardware set brightness when they detect a hardware / firmware triggered brightness change. Signed-off-by: Hans de Goede <hdegoede@redhat.com> Acked-by: Pavel Machek <pavel@ucw.cz> Signed-off-by: Jacek Anaszewski <jacek.anaszewski@gmail.com> 
Some LEDs may have their brightness level changed autonomously
(outside of kernel control) by hardware / firmware. This commit
adds support for an optional brightness_hw_changed attribute to
signal such changes to userspace (if a driver can detect them):

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.

Drivers which want to support this, simply add LED_BRIGHT_HW_CHANGED to
their flags field and call led_classdev_notify_brightness_hw_changed()
with the hardware set brightness when they detect a hardware / firmware
triggered brightness change.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Jacek Anaszewski <jacek.anaszewski@gmail.com>
cleanup LED documentation and make it match reality 2016-11-22T11:07:03+00:00 Pavel Machek pavel@ucw.cz 2016-10-03T08:10:50+00:00 ed25e9cae1ab8e84556c9413fd5de0a9da8f3657 sysfs-class-led fails to mention some important details. Also fix led vs LED and english. Signed-off-by: Pavel Machek <pavel@ucw.cz> Signed-off-by: Jacek Anaszewski <j.anaszewski@samsung.com> 
sysfs-class-led fails to mention some important details. Also fix led
vs LED and english.

Signed-off-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Jacek Anaszewski <j.anaszewski@samsung.com>
Documentation: move oneshot trigger attributes documentation to ABI 2016-08-29T13:06:32+00:00 Rafał Miłecki rafal@milecki.pl 2016-08-26T14:19:36+00:00 1f70cb4045cba47287fed3ba98dadc7187f13ef8 Documentation of sysfs interface should be in ABI in the first place. This moves relevant part of documentation and mentions where to look for it. Fix trivial typos whilst we are at it. Signed-off-by: Rafał Miłecki <rafal@milecki.pl> Signed-off-by: Jacek Anaszewski <j.anaszewski@samsung.com> 
Documentation of sysfs interface should be in ABI in the first place.
This moves relevant part of documentation and mentions where to look for
it.
Fix trivial typos whilst we are at it.

Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
Signed-off-by: Jacek Anaszewski <j.anaszewski@samsung.com>
Fix common misspellings 2011-03-31T14:26:23+00:00 Lucas De Marchi lucas.demarchi@profusion.mobi 2011-03-31T01:57:33+00:00 25985edcedea6396277003854657b5f3cb31a628 Fixes generated by 'codespell' and manually reviewed. Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi> 
Fixes generated by 'codespell' and manually reviewed.

Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
leds: add output inversion option to backlight trigger 2011-01-13T16:03:06+00:00 Janusz Krzysztofik jkrzyszt@tis.icnet.pl 2011-01-13T00:59:20+00:00 9f9455ae710786bd11625d501567f4f783fedea5 Extend the LED backlight tirgger driver with an option that allows for inverting the trigger output polarity. With the invertion option provided, I (ab)use the backlight trigger for driving a LED that indicates LCD display blank condtition on my Amstrad Delta videophone. Since the machine has no dedicated power LED, it was not possible to distinguish if the display was blanked, or the machine was turned off, without touching it. The invert sysfs control is patterned after a similiar function of the GPIO trigger driver. [akpm@linux-foundation.org: make output match input, tighten input checking] [akpm@linux-foundation.org: make output match input, tighten input checking] Signed-off-by: Janusz Krzysztofik <jkrzyszt@tis.icnet.pl> Cc: Paul Mundt <lethal@linux-sh.org> Acked-by: Richard Purdie <richard.purdie@linuxfoundation.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> 
Extend the LED backlight tirgger driver with an option that allows for
inverting the trigger output polarity.

With the invertion option provided, I (ab)use the backlight trigger for
driving a LED that indicates LCD display blank condtition on my Amstrad
Delta videophone.  Since the machine has no dedicated power LED, it was
not possible to distinguish if the display was blanked, or the machine was
turned off, without touching it.

The invert sysfs control is patterned after a similiar function of the GPIO
trigger driver.

[akpm@linux-foundation.org: make output match input, tighten input checking]
[akpm@linux-foundation.org: make output match input, tighten input checking]
Signed-off-by: Janusz Krzysztofik <jkrzyszt@tis.icnet.pl>
Cc: Paul Mundt <lethal@linux-sh.org>
Acked-by: Richard Purdie <richard.purdie@linuxfoundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
led: document sysfs interface 2009-08-28T19:21:12+00:00 Corentin Chary corentincj@iksaif.net 2009-08-28T12:56:45+00:00 5f634c6527249275df4199a294ee9cec2f3ff3b1 Also fix Documentation/led-class.txt, the acceptable range of values for brightness is 0-max_brightness, not 0-255. Cc: Richard Purdie <rpurdie@rpsys.net> Signed-off-by: Corentin Chary <corentincj@iksaif.net> Signed-off-by: Len Brown <len.brown@intel.com> 
Also fix Documentation/led-class.txt, the acceptable
range of values for brightness is 0-max_brightness, not 0-255.

Cc: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: Corentin Chary <corentincj@iksaif.net>
Signed-off-by: Len Brown <len.brown@intel.com>