The .remove() callback for a platform driver returns an int which makes
many driver authors wrongly assume it's possible to do error handling by
returning an error code. However the value returned is (mostly) ignored
and this typically results in resource leaks. To improve here there is a
quest to make the remove callback return void. In the first step of this
quest all drivers are converted to .remove_new() which already returns
void.
Trivially convert this driver from always returning zero in the remove
callback to the void returning variant.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reviewed-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
pwmchip_remove() returns always 0. Don't use the value to make it
possible to eventually change the function to return void. Also the
driver core ignores the return value of atmel_hlcdc_pwm_remove()
and considers the device removed anyhow.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
With the previous commit there is no need for the lowlevel driver any
more to specify it it uses two or three cells. So simplify accordingly.
The only non-trival change affects the pwm-rockchip driver: It used to only
support three cells if the hardware supports polarity. Now the default
number depends on the device tree which has to match hardware anyhow
(and if it doesn't the error is just a bit delayed as a PWM handle with
an inverted setting is catched when pwm_apply_state() is called).
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
The only side effect of this change is that pwm->state.polarity is
initialized to PWM_POLARITY_NORMAL instead of PWM_POLARITY_INVERSED.
However all other members of pwm->state are uninitialized and consumers
are expected to provide the right polarity (either by setting it explicitly
or by using a helper like pwm_init_state() that overwrites .polarity
anyhow with a value independent of the initial value).
Signed-off-by: Uwe Kleine-König <uwe@kleine-koenig.org>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
Since commit 5e5da1e9fb ("pwm: ab8500: Explicitly allocate pwm chip
base dynamically") all drivers use dynamic ID allocation explicitly. New
drivers are supposed to do the same, so remove support for driver
specified base IDs and drop all assignments in the low-level drivers.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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>
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
...
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
Uwe Kleine-König