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* pwm: Add sysfs interfaceH Hartley Sweeten2013-06-211-1/+28
| | | | | | | | | | | | | | | | | | | | | | | | Add a simple sysfs interface to the generic PWM framework. /sys/class/pwm/ `-- pwmchipN/ for each PWM chip |-- export (w/o) ask the kernel to export a PWM channel |-- npwm (r/o) number of PWM channels in this PWM chip |-- pwmX/ for each exported PWM channel | |-- duty_cycle (r/w) duty cycle (in nanoseconds) | |-- enable (r/w) enable/disable PWM | |-- period (r/w) period (in nanoseconds) | `-- polarity (r/w) polarity of PWM (normal/inversed) `-- unexport (w/o) return a PWM channel to the kernel Based on work by Lars Poeschel. Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com> Cc: Thierry Reding <thierry.reding@gmail.com> Cc: Lars Poeschel <poeschel@lemonage.de> Cc: Ryan Mallon <rmallon@gmail.com> Cc: Rob Landley <rob@landley.net> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
* Merge tag 'for-3.9-rc1' of git://gitorious.org/linux-pwm/linux-pwmLinus Torvalds2013-02-261-0/+10
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull PWM changes from Thierry Reding: "A new driver has been added to support the PWM mode of the timer counter blocks found on Atmel AT91 SoCs. The VT8500 driver now supports changing the PWM signal polarity and the TI drivers (EHRPWM and ECAP) gained suspend and resume functionality. User drivers can now query the core for whether access to a PWM device will sleep (if the PWM chip is on a slow bus such as I2C or SPI). The pwm-backlight driver now handles the backlight BL_CORE_FBBLANK state in addition to the FB layer's blanking states. To round things off, a few fixes and cleanups are also included" * tag 'for-3.9-rc1' of git://gitorious.org/linux-pwm/linux-pwm: pwm: twl: Use to_twl() instead of container_of() pwm: tegra: assume CONFIG_OF pwm_backlight: Validate dft_brightness in main probe function pwm: Export pwm_{set,get}_chip_data() pwm: Make Kconfig entries more consistent pwm: Add can_sleep property to drivers pwm: Add pwm_can_sleep() as exported API to users pwm-backlight: handle BL_CORE_FBBLANK state pwm: pwm-tiecap: Low power sleep support pwm: pwm-tiehrpwm: Low power sleep support pwm: pwm-tiehrpwm: Update the clock handling of pwm-tiehrpwm driver pwm: vt8500: Add polarity support pwm: vt8500: Register write busy test performed incorrectly pwm: atmel: add Timer Counter Block PWM driver
| * pwm: Add pwm_can_sleep() as exported API to usersFlorian Vaussard2013-01-301-0/+10
| | | | | | | | | | | | | | | | | | | | | | Calls to some external PWM chips can sleep. To help users, add pwm_can_sleep() API. Cc: Thierry Reding <thierry.reding@avionic-design.de> Cc: Peter Ujfalusi <peter.ujfalusi@ti.com> Signed-off-by: Florian Vaussard <florian.vaussard@epfl.ch> Reviewed-by: Peter Ujfalusi <peter.ujfalusi@ti.com> Signed-off-by: Thierry Reding <thierry.reding@avionic-design.de>
* | pwm: Add devm_of_pwm_get() as exported API for usersPeter Ujfalusi2013-02-011-0/+9
| | | | | | | | | | | | | | | | | | When booted with DT users can use devm version of of_pwm_get() to benefit from automatic resource release. Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com> Acked-by: Thierry Reding <thierry.reding@avionic-design.de> Signed-off-by: Bryan Wu <cooloney@gmail.com>
* | pwm: core: Rename of_pwm_request() to of_pwm_get() and export itPeter Ujfalusi2013-02-011-0/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Allow client driver to use of_pwm_get() to get the PWM they need. This is needed for drivers which handle more than one PWM separately, like leds-pwm driver, which have: pwmleds { compatible = "pwm-leds"; kpad { label = "omap4::keypad"; pwms = <&twl_pwm 0 7812500>; max-brightness = <127>; }; charging { label = "omap4:green:chrg"; pwms = <&twl_pwmled 0 7812500>; max-brightness = <255>; }; }; in the dts files. Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com> Acked-by: Thierry Reding <thierry.reding@avionic-design.de> Signed-off-by: Bryan Wu <cooloney@gmail.com>
* | pwm: Correct parameter name in header for *pwm_get() functionsPeter Ujfalusi2013-02-011-2/+2
|/ | | | | | | | | | To synchronize the header file definition and the actual code. In the code the consumer parameter is named as con_id, change the header file and replace consumer -> con_id in the parameter list. Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com> Ackedy-by: Thierry Reding <thierry.reding@avionic-design.de> Signed-off-by: Bryan Wu <cooloney@gmail.com>
* pwm: Device tree support for PWM polarityPhilip, Avinash2012-11-221-0/+3
| | | | | | | | | | | | | Add support for encoding PWM properties in bit encoded form with of_pwm_xlate_with_flags() function support. Platforms require platform specific PWM properties has to populate in 3rd cell of the pwm-specifier and PWM driver should also set .of_xlate support with this function. Currently PWM property polarity encoded in bit position 0 of the third cell in pwm-specifier. Signed-off-by: Philip, Avinash <avinashphilip@ti.com> Acked-by: Grant Likely <grant.likely@secretlab.ca> Signed-off-by: Thierry Reding <thierry.reding@avionic-design.de>
* pwm: Fix compilation error when CONFIG_PWM is not definedTushar Behera2012-09-201-2/+80
| | | | | | | | | Add dummy implemention of public symbols for compilation-safe inclusion of include/linux/pwm.h file when CONFIG_PWM is not defined. Reported-by: Sachin Kamat <sachin.kamat@linaro.org> Signed-off-by: Tushar Behera <tushar.behera@linaro.org> Signed-off-by: Thierry Reding <thierry.reding@avionic-design.de>
* pwm: add devm_pwm_get() and devm_pwm_put()Alexandre Courbot2012-09-101-0/+3
| | | | | | | | | Add resource managed variants of pwm_get() and pwm_put() for convenience. Code is largely inspired by the equivalent devm functions of the regulator framework. Signed-off-by: Alexandre Courbot <acourbot@nvidia.com> Signed-off-by: Thierry Reding <thierry.reding@avionic-design.de>
* pwm: Add support for configuring the PWM polarityPhilip, Avinash2012-09-101-0/+23
| | | | | | | | | | | | | | | Some hardware supports inverting the polarity of the PWM signal. This commit adds support to the PWM framework to allow users of the PWM API to configure the polarity. Note that in order to reduce complexity, changing the polarity of a PWM signal is only allowed while the PWM is disabled. A practical example where this can prove useful is to simulate inversion of the duty cycle. While inversion of polarity and duty cycle are not exactly the same, the differences for most use-cases are negligible. Signed-off-by: Philip, Avinash <avinashphilip@ti.com> Signed-off-by: Thierry Reding <thierry.reding@avionic-design.de>
* pwm: Add device tree supportThierry Reding2012-06-151-0/+6
| | | | | | | | | | This patch adds helpers to support device tree bindings for the generic PWM API. Device tree binding documentation for PWM controllers is also provided. Acked-by: Arnd Bergmann <arnd@arndb.de> Reviewed-by: Shawn Guo <shawn.guo@linaro.org> Signed-off-by: Thierry Reding <thierry.reding@avionic-design.de>
* pwm: Add table-based lookup for static mappingsThierry Reding2012-06-151-0/+22
| | | | | | | | | | | | | | | In order to get rid of the global namespace for PWM devices, this commit provides an alternative method, similar to that of the regulator or clock frameworks, for registering a static mapping for PWM devices. This works by providing a table with a provider/consumer map in the board setup code. With the new pwm_get() and pwm_put() functions available, usage of pwm_request() and pwm_free() becomes deprecated. Reviewed-by: Shawn Guo <shawn.guo@linaro.org> Reviewed-by: Mark Brown <broonie@opensource.wolfsonmicro.com> Signed-off-by: Thierry Reding <thierry.reding@avionic-design.de>
* pwm: Add debugfs interfaceThierry Reding2012-06-151-0/+6
| | | | | | | | | | This commit adds a debugfs interface that can be used to list the current internal state of the PWM devices registered with the PWM framework. Reviewed-by: Mark Brown <broonie@opensource.wolfsonmicro.com> Reviewed-by: Shawn Guo <shawn.guo@linaro.org> Signed-off-by: Thierry Reding <thierry.reding@avionic-design.de>
* pwm: Allow chips to support multiple PWMsThierry Reding2012-06-151-13/+58
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Many PWM controllers provide access to more than a single PWM output and may even share some resource among them. Allowing a PWM chip to provide multiple PWM devices enables better sharing of those resources. As a side-effect this change allows easy integration with the device tree where a given PWM can be looked up based on the PWM chip's phandle and a corresponding index. This commit modifies the PWM core to support multiple PWMs per struct pwm_chip. It achieves this in a similar way to how gpiolib works, by allowing PWM ranges to be requested dynamically (pwm_chip.base == -1) or starting at a given offset (pwm_chip.base >= 0). A chip specifies how many PWMs it controls using the npwm member. Each of the functions in the pwm_ops structure gets an additional argument that specified the PWM number (it can be converted to a per-chip index by subtracting the chip's base). The total maximum number of PWM devices is currently fixed to 1024 while the data is actually stored in a radix tree, thus saving resources if not all of them are used. Reviewed-by: Mark Brown <broonie@opensource.wolfsonmicro.com> Reviewed-by: Shawn Guo <shawn.guo@linaro.org> [eric@eukrea.com: fix error handling in pwmchip_add] Signed-off-by: Eric BĂ©nard <eric@eukrea.com> Signed-off-by: Thierry Reding <thierry.reding@avionic-design.de>
* pwm: Add PWM framework supportSascha Hauer2012-06-151-0/+38
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch adds framework support for PWM (pulse width modulation) devices. The is a barebone PWM API already in the kernel under include/linux/pwm.h, but it does not allow for multiple drivers as each of them implements the pwm_*() functions. There are other PWM framework patches around from Bill Gatliff. Unlike his framework this one does not change the existing API for PWMs so that this framework can act as a drop in replacement for the existing API. Why another framework? Several people argue that there should not be another framework for PWMs but they should be integrated into one of the existing frameworks like led or hwmon. Unlike these frameworks the PWM framework is agnostic to the purpose of the PWM. In fact, a PWM can drive a LED, but this makes the LED framework a user of a PWM, like already done in leds-pwm.c. The gpio framework also is not suitable for PWMs. Every gpio could be turned into a PWM using timer based toggling, but on the other hand not every PWM hardware device can be turned into a gpio due to the lack of hardware capabilities. This patch does not try to improve the PWM API yet, this could be done in subsequent patches. Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de> Acked-by: Kurt Van Dijck <kurt.van.dijck@eia.be> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Reviewed-by: Matthias Kaehlcke <matthias@kaehlcke.net> Reviewed-by: Mark Brown <broonie@opensource.wolfsonmicro.com> Reviewed-by: Shawn Guo <shawn.guo@linaro.org> [thierry.reding@avionic-design.de: fixup typos, kerneldoc comments] Signed-off-by: Thierry Reding <thierry.reding@avionic-design.de>
* trivial: PWM: fix of #endif commentMark Vels2009-03-301-1/+1
| | | | | Signed-off-by: Mark Vels <mark.vels@team-embedded.nl> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
* [ARM] pxa: Add bare bones PWM APIRussell King2008-05-191-0/+31
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
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