If we change the inverted attribute to another value, the LED will not be inverted until we change the GPIO state. Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@holoscopio.com> Cc: Samuel R. C. Vale <srcvale@holoscopio.com> Cc: Richard Purdie <rpurdie@rpsys.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When setting the same GPIO number, multiple IRQ shared requests will be done without freing the previous request. It will also try to free a failed request or an already freed IRQ if 0 was written to the gpio file. All these oops and leaks were fixed with the following solution: keep the previous allocated GPIO (if any) still allocated in case the new request fails. The alternative solution would desallocate the previous allocated GPIO and set gpio as 0. Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@holoscopio.com> Signed-off-by: Samuel R. C. Vale <srcvale@holoscopio.com> Cc: Richard Purdie <rpurdie@rpsys.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Yoichi Yuasa <yuasa@linux-mips.org> Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
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>
LEDs driver for National Semiconductor LP3944 Funlight Chip http://www.national.com/pf/LP/LP3944.html This helper chip can drive up to 8 leds, with two programmable DIM modes; it could even be used as a gpio expander but this driver assumes it is used as a led controller. The DIM modes are used to set _blink_ patterns for leds, the pattern is specified supplying two parameters: - period: from 0s to 1.6s - duty cycle: percentage of the period the led is on, from 0 to 100 LP3944 can be found on Motorola A910 smartphone, where it drives the rgb leds, the camera flash light and the displays backlights. Signed-off-by: Antonio Ospite <ospite@studenti.unina.it> Signed-off-by: Richard Purdie <rpurdie@linux.intel.com>
Indent using tabs, not spaces. Signed-off-by: Antonio Ospite <ospite@studenti.unina.it> Acked-by: Riku Voipio <riku.voipio@iki.fi> Signed-off-by: Richard Purdie <rpurdie@linux.intel.com>
Remove an orphan Kconfig entry (LEDS_LP5521) Signed-off-by: Richard Purdie <rpurdie@linux.intel.com>
Add initialisation of GPIO ports for compatibility with boards with Award BIOS (e.g. ALIX.3D3). Signed-off-by: Tobias Mueller <Tobias_Mueller@twam.info> Reviewed-by: Constantin Baranov <const@mimas.ru> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Richard Purdie <rpurdie@linux.intel.com>
WARNING: drivers/leds/leds-gpio.o(.text+0x153): Section mismatch in reference from the function gpio_led_probe() to the function .devinit.text:create_gpio_led() The function gpio_led_probe() references the function __devinit create_gpio_led(). This is often because gpio_led_probe lacks a __devinit annotation or the annotation of create_gpio_led is wrong. Signed-off-by: Zhenwen Xu <helight.xu@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Richard Purdie <rpurdie@linux.intel.com>
Allow the user application to change the wave pattern and led current by 'wave_pattern' and 'rgb_current' sysfs files. Signed-off-by: Kim Kyuwon <q1.kim@samsung.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Richard Purdie <rpurdie@linux.intel.com>