Commit Graph

15 Commits

Author SHA1 Message Date
Uwe Kleine-König 71523d1812 pwm: Ensure pwm_apply_state() doesn't modify the state argument
It is surprising for a PWM consumer when the variable holding the
requested state is modified by pwm_apply_state(). Consider for example a
driver doing:

        #define PERIOD 5000000
        #define DUTY_LITTLE 10
        ...
        struct pwm_state state = {
                .period = PERIOD,
                .duty_cycle = DUTY_LITTLE,
                .polarity = PWM_POLARITY_NORMAL,
                .enabled = true,
        };

        pwm_apply_state(mypwm, &state);
        ...
        state.duty_cycle = PERIOD / 2;
        pwm_apply_state(mypwm, &state);

For sure the second call to pwm_apply_state() should still have
state.period = PERIOD and not something the hardware driver chose for a
reason that doesn't necessarily apply to the second call.

So declare the state argument as a pointer to a const type and adapt all
drivers' .apply callbacks.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2019-09-21 03:25:10 +02:00
Linus Torvalds 6e2bbb688a pwm: Changes for v5.3-rc1
This set of changes contains a new driver for SiFive SoCs as well as
 enhancements to the core (device links are used to track dependencies
 between PWM providers and consumers, support for PWM controllers via
 ACPI, sysfs will now suspend/resume PWMs that it has claimed) and
 various existing drivers.
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Merge tag 'pwm/for-5.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/thierry.reding/linux-pwm

Pull pwm updates from Thierry Reding:
 "This set of changes contains a new driver for SiFive SoCs as well as
  enhancements to the core (device links are used to track dependencies
  between PWM providers and consumers, support for PWM controllers via
  ACPI, sysfs will now suspend/resume PWMs that it has claimed) and
  various existing drivers"

* tag 'pwm/for-5.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/thierry.reding/linux-pwm: (37 commits)
  pwm: fsl-ftm: Make sure to unlock mutex on failure
  pwm: fsl-ftm: Use write protection for prescaler & polarity
  pwm: fsl-ftm: More relaxed permissions for updating period
  pwm: atmel-hlcdc: Add compatible for SAM9X60 HLCDC's PWM
  pwm: bcm2835: Improve precision of PWM
  leds: pwm: Support ACPI via firmware-node framework
  pwm: Add support referencing PWMs from ACPI
  pwm: rcar: Remove suspend/resume support
  pwm: sysfs: Add suspend/resume support
  pwm: Add power management descriptions
  pwm: meson: Add documentation to the driver
  pwm: meson: Add support PWM_POLARITY_INVERSED when disabling
  pwm: meson: Don't cache struct pwm_state internally
  pwm: meson: Read the full hardware state in meson_pwm_get_state()
  pwm: meson: Simplify the calculation of the pre-divider and count
  pwm: meson: Move pwm_set_chip_data() to meson_pwm_request()
  pwm: meson: Add the per-channel register offsets and bits in a struct
  pwm: meson: Add the meson_pwm_channel data to struct meson_pwm
  pwm: meson: Pass struct pwm_device to meson_pwm_calc()
  pwm: meson: Don't duplicate the polarity internally
  ...
2019-07-09 08:57:45 -07:00
Claudiu Beznea da9b386492 pwm: atmel-hlcdc: Add compatible for SAM9X60 HLCDC's PWM
Add compatible string for SAM9X60 HLCDC's PWM.

Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2019-06-26 11:39:13 +02:00
Thomas Gleixner caab277b1d treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 234
Based on 1 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license version 2 as
  published by the free software foundation this program is
  distributed in the hope that it will be useful but without any
  warranty without even the implied warranty of merchantability or
  fitness for a particular purpose see the gnu general public license
  for more details you should have received a copy of the gnu general
  public license along with this program if not see http www gnu org
  licenses

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-only

has been chosen to replace the boilerplate/reference in 503 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Alexios Zavras <alexios.zavras@intel.com>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Enrico Weigelt <info@metux.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190602204653.811534538@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-19 17:09:07 +02:00
Boris Brezillon f9bb9da7c0 pwm: atmel-hlcdc: Implement the suspend/resume hooks
Implement the suspend/resume hooks to make sure the PWM device is
restored to a correct state after a suspend.

Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2017-04-06 17:45:02 +02:00
Boris Brezillon 2267517cd3 pwm: atmel-hlcdc: Convert to the atomic PWM API
Implement the ->apply() hook and drop the ->enable(), ->disable,
->set_polarity and ->config() ones.

Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Acked-by: Nicolas Ferre <nicolas.ferre@microchip.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2017-04-06 16:12:52 +02:00
Thierry Reding 8c0216f377 pwm: Remove .can_sleep from struct pwm_chip
All PWM devices have been marked as "might sleep" since v4.5, there is
no longer a need to differentiate on a per-chip basis.

Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2017-01-04 09:40:54 +01:00
Boris Brezillon cc51846ba8 pwm: atmel-hlcdc: Fix default PWM polarity
The PWM device exposed by the HLCDC IP is configured with an inverted
polarity by default. Registering the PWM chip with the normal polarity
was not a problem before commit 42e8992c58d4 ("pwm: Add core
infrastructure to allow atomic updates") because the ->set_polarity()
hook was called no matter the current polarity state, but this is no longer
the case.

Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2016-06-14 10:51:45 +02:00
Nicolas Ferre 2b8b0ef354 pwm: atmel-hlcdc: add sama5d2 SoC support.
Add sama5d2 hlcdc backlight PWM support. This chip doesn't have to deal with an
errata, so it's a simple addition of the mfd compatible string.

Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2015-10-06 16:07:28 +02:00
Luis de Bethencourt a83a6a8225 pwm: atmel-hlcdc: Fix module autoload for OF platform driver
This platform driver has a OF device ID table but the OF module alias
information is not created so module autoloading won't work.

This patch adds the missing MODULE_DEVICE_TABLE() for OF to export that
information so modules have the correct aliases built-in and autoloading
works correctly.

A longer explanation by Javier Canillas can be found here:
https://lkml.org/lkml/2015/7/30/519

Signed-off-by: Luis de Bethencourt <luisbg@osg.samsung.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2015-09-21 10:04:40 +02:00
Josh Wu 7a59382018 ARM: at91: pwm: atmel-hlcdc: Add at91sam9n12 errata
The errata for HLCDC PWM of at91sam9n12 are the same as for at91sam9x5.

Signed-off-by: Josh Wu <josh.wu@atmel.com>
Acked-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2015-09-09 15:16:01 +02:00
Nicolas Ferre 054d3e1f9a pwm: atmel-hlcdc: Add errata handling for sama5d4
sama5d4 SoC also has an errata on the HLCDC PWM. It is the same as the
sama5d3 that is forbidding the use of div1 prescaler.

Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Acked-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2015-03-11 11:59:54 +01:00
Boris BREZILLON df6922adec pwm: atmel-hlcdc: Prevent division by zero
The slow and system clock should never return a rate of zero, but this
might happen if the clocks property defined in the DT is referencing the
wrong clocks.

Prevent any division by zero from happening by testing the clk_freq
value before calling do_div().

Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2015-01-30 12:16:00 +01:00
Boris BREZILLON 39e046f2c1 pwm: atmel-hlcdc: add at91sam9x5 and sama5d3 errata handling
at91sam9x5 has an errata forbidding the use of slow clk as a clk source and
sama5d3 SoCs has another errata forbidding the use of div1 prescaler.

Take both of these erratas into account.

Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2014-12-04 11:32:36 +01:00
Boris Brezillon 2b4984bef4 pwm: add support for atmel-hlcdc-pwm device
The HLCDC IP available in some Atmel SoCs (i.e. at91sam9x5, at91sam9n12
or sama5d3 families for instance) provides a PWM device.

This driver add support for a PWM chip exposing a single PWM device (which
will most likely be used to drive a backlight device).

Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Tested-by: Anthony Harivel <anthony.harivel@emtrion.de>
Tested-by: Ludovic Desroches <ludovic.desroches@atmel.com>
Acked-by: Thierry Reding <thierry.reding@gmail.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2014-11-17 12:20:17 +01:00