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2009-06-28Merge branch 'for-linus' of git://git.o-hand.com/linux-rpurdie-ledsLinus Torvalds
* 'for-linus' of git://git.o-hand.com/linux-rpurdie-leds: leds: Futher document blink_set leds: Add options to have GPIO LEDs start on or keep their state leds: LED driver for National Semiconductor LP3944 Funlight Chip leds: pca9532 - Indent using tabs, not spaces. leds: Remove an orphan Kconfig entry leds: Further document parameters for blink_set() leds: alix-leds2 fixed for Award BIOS leds: leds-gpio - fix a section mismatch leds: add the sysfs interface into the leds-bd2802 driver for changing wave pattern and led current. leds: change the license information leds: fix led-bd2802 errors while resuming
2009-06-23leds: Add options to have GPIO LEDs start on or keep their stateTrent Piepho
There already is a "default-on" trigger but there are problems with it. For one, it's a inefficient way to do it and requires led trigger support to be compiled in. But the real reason is that is produces a glitch on the LED. The GPIO is allocate with the LED *off*, then *later* when the trigger runs it is turned back on. If the LED was already on via the GPIO's reset default or action of the firmware, this produces a glitch where the LED goes from on to off to on. While normally this is fast enough that it wouldn't be noticeable to a human observer, there are still serious problems. One is that there may be something else on the GPIO line, like a hardware alarm or watchdog, that is fast enough to notice the glitch. Another is that the kernel may panic before the LED is turned back on, thus hanging with the LED in the wrong state. This is not just speculation, but actually happened to me with an embedded system that has an LED which should turn off when the kernel finishes booting, which was left in the incorrect state due to a bug in the OF LED binding code. We also let GPIO LEDs get their initial value from whatever the current state of the GPIO line is. On some systems the LEDs are put into some state by the firmware or hardware before Linux boots, and it is desired to have them keep this state which is otherwise unknown to Linux. This requires that the underlying GPIO driver support reading the value of output GPIOs. Some drivers support this and some do not. The platform device binding gains a field in the platform data "default_state" that controls this. There are three constants defined to select from on, off, or keeping the current state. The OpenFirmware binding uses a property named "default-state" that can be set to "on", "off", or "keep". The default if the property isn't present is off. Signed-off-by: Trent Piepho <xyzzy@speakeasy.org> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Wolfram Sang <w.sang@pengutronix.de> Acked-by: Sean MacLennan <smaclennan@pikatech.com> Signed-off-by: Richard Purdie <rpurdie@linux.intel.com>
2009-06-23powerpc: Refactor device tree bindingKumar Gala
Split device tree binding out of booting-without-of.txt and put them into their own files per binding. Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
2009-04-06leds: Add openfirmware platform device supportTrent Piepho
Add bindings to support LEDs defined as of_platform devices in addition to the existing bindings for platform devices. New options in Kconfig allow the platform binding code and/or the of_platform code to be turned on. The of_platform code is of course only available on archs that have OF support. The existing probe and remove methods are refactored to use new functions create_gpio_led(), to create and register one led, and delete_gpio_led(), to unregister and free one led. The new probe and remove methods for the of_platform driver can then share most of the common probe and remove code with the platform driver. The suspend and resume methods aren't shared, but they are very short. The actual led driving code is the same for LEDs created by either binding. The OF bindings are based on patch by Anton Vorontsov <avorontsov@ru.mvista.com>. They have been extended to allow multiple LEDs per device. Signed-off-by: Trent Piepho <tpiepho@freescale.com> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Sean MacLennan <smaclennan@pikatech.com> Signed-off-by: Richard Purdie <rpurdie@linux.intel.com>
2008-07-16powerpc: add FHCI USB, FSL MCU, FSL UPM and GPIO LEDs bindingsAnton Vorontsov
This patch adds few bindings for the new drivers to be submitted through the appropriate maintainers. Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com> Signed-off-by: Kumar Gala <galak@kernel.crashing.org>