linux-toradex.git/include/linux/pwm.h, branch v3.14.3

pwm: Add sysfs interface

2013-06-21T09:32:51+00:00

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 
Cc: Thierry Reding 
Cc: Lars Poeschel 
Cc: Ryan Mallon 
Cc: Rob Landley 
Signed-off-by: Thierry Reding

Merge tag 'for-3.9-rc1' of git://gitorious.org/linux-pwm/linux-pwm

2013-02-26T17:34:29+00:00

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 devm_of_pwm_get() as exported API for users

2013-02-02T01:47:05+00:00

When booted with DT users can use devm version of of_pwm_get() to benefit
from automatic resource release.

Signed-off-by: Peter Ujfalusi 
Acked-by: Thierry Reding 
Signed-off-by: Bryan Wu

pwm: core: Rename of_pwm_request() to of_pwm_get() and export it

2013-02-02T01:47:05+00:00

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 
Acked-by: Thierry Reding 
Signed-off-by: Bryan Wu

pwm: Correct parameter name in header for *pwm_get() functions

2013-02-02T01:47:05+00:00

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 
Ackedy-by: Thierry Reding 
Signed-off-by: Bryan Wu

pwm: Add pwm_can_sleep() as exported API to users

2013-01-30T08:12:18+00:00

Calls to some external PWM chips can sleep. To help users,
add pwm_can_sleep() API.

Cc: Thierry Reding 
Cc: Peter Ujfalusi 
Signed-off-by: Florian Vaussard 
Reviewed-by: Peter Ujfalusi 
Signed-off-by: Thierry Reding

pwm: Device tree support for PWM polarity

2012-11-22T21:47:12+00:00

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 
Acked-by: Grant Likely 
Signed-off-by: Thierry Reding

pwm: Fix compilation error when CONFIG_PWM is not defined

2012-09-20T10:52:02+00:00

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 
Signed-off-by: Tushar Behera 
Signed-off-by: Thierry Reding

pwm: add devm_pwm_get() and devm_pwm_put()

2012-09-10T15:05:45+00:00

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 
Signed-off-by: Thierry Reding

pwm: Add support for configuring the PWM polarity

2012-09-10T15:05:44+00:00

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 
Signed-off-by: Thierry Reding