Commit Graph

856 Commits

Author SHA1 Message Date
Uwe Kleine-König aef1a3799b pwm: imx27: Fix rounding behavior
To not trigger the warnings provided by CONFIG_PWM_DEBUG

 - use up-rounding in .get_state()
 - don't divide by the result of a division
 - don't use the rounded counter value for the period length to calculate
   the counter value for the duty cycle

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2020-06-02 15:50:52 +02:00
Rasmus Villemoes cad0f29606 pwm: rockchip: Simplify rockchip_pwm_get_state()
The way state->enabled is computed is rather convoluted and hard to
read - both branches of the if() actually do the exact same thing. So
remove the if(), and further simplify "<boolean condition> ? true :
false" to "<boolean condition>".

Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2020-06-02 15:50:52 +02:00
Navid Emamdoost ca162ce981 pwm: img: Call pm_runtime_put() in pm_runtime_get_sync() failed case
Even in failed case of pm_runtime_get_sync(), the usage_count is
incremented. In order to keep the usage_count with correct value call
appropriate pm_runtime_put().

Signed-off-by: Navid Emamdoost <navid.emamdoost@gmail.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2020-06-02 15:50:51 +02:00
Sandipan Patra 1d7796bdb6 pwm: tegra: Support dynamic clock frequency configuration
Added support for dynamic clock freq configuration in PWM kernel driver.
Earlier the PWM driver used to cache boot time clock rate by PWM clock
parent during probe. Hence dynamically changing PWM frequency was not
possible for all the possible ranges. With this change, dynamic
calculation is enabled and it is able to set the requested period from
sysfs knob provided the value is supported by clock source.

Changes mainly have 2 parts:
  - Tegra186 and later chips [1]
  - Tegra210 and prior chips [2]

For [1] - Changes implemented to set pwm period dynamically and also
          checks added to allow only if requested period(ns) is below or
          equals to higher range.

For [2] - Only checks if the requested period(ns) is below or equals to
          higher range defined by max clock limit. The limitation in
          Tegra210 or prior chips are due to the reason of having only
          one PWM controller supporting multiple channels. But later
          chips have multiple PWM controller instances each having
          single channel support.

Signed-off-by: Sandipan Patra <spatra@nvidia.com>
Reviewed-by: Jon Hunter <jonathanh@nvidia.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2020-06-02 14:25:37 +02:00
Paul Cercueil 74db728c0b pwm: jz4740: Add support for the JZ4725B
The PWM hardware in the JZ4725B works the same as in the JZ4740, but has
only six channels available.

Signed-off-by: Paul Cercueil <paul@crapouillou.net>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2020-06-02 14:24:57 +02:00
Paul Cercueil a020f22a4f pwm: jz4740: Make PWM start with the active part
The PWM in Ingenic SoCs starts in inactive state until the internal
timer reaches the duty value, then becomes active until the timer
reaches the period value. In theory, we should then use (period - duty)
as the real duty value, as a high duty value would otherwise result in
the PWM pin being inactive most of the time.

This is the reason why the duty value was inverted in the driver until
now, but it still had the problem that it would not start with the
active part.

To address this remaining issue, the common trick is to invert the
duty, and invert the polarity when the PWM is enabled.

Since the duty was already inverted, and we invert it again, we now
program the hardware for the requested duty, and simply invert the
polarity when the PWM is enabled.

Signed-off-by: Paul Cercueil <paul@crapouillou.net>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2020-06-02 14:24:26 +02:00
Paul Cercueil 9017dc4fbd pwm: jz4740: Enhance precision in calculation of duty cycle
Calculating the hardware value for the duty from the hardware value of
the period resulted in a precision loss versus calculating it from the
clock rate directly.

(Also remove a cast that doesn't really need to be here)

Fixes: f6b8a57000 ("pwm: Add Ingenic JZ4740 support")
Cc: <stable@vger.kernel.org>
Suggested-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Paul Cercueil <paul@crapouillou.net>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2020-06-02 14:24:00 +02:00
Paul Cercueil b48d49e0d5 pwm: jz4740: Drop dependency on MACH_INGENIC
Depending on MACH_INGENIC prevent us from creating a generic kernel that
works on more than one MIPS board. Instead, we just depend on MIPS being
set.

Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Paul Cercueil <paul@crapouillou.net>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2020-06-02 14:23:42 +02:00
Hans de Goede 01aa905d47 pwm: lpss: Fix get_state runtime-pm reference handling
Before commit cfc4c189bc ("pwm: Read initial hardware state at request
time"), a driver's get_state callback would get called once per PWM from
pwmchip_add().

pwm-lpss' runtime-pm code was relying on this, getting a runtime-pm ref for
PWMs which are enabled at probe time from within its get_state callback,
before enabling runtime-pm.

The change to calling get_state at request time causes a number of
problems:

1. PWMs enabled at probe time may get runtime suspended before they are
requested, causing e.g. a LCD backlight controlled by the PWM to turn off.

2. When the request happens when the PWM has been runtime suspended, the
ctrl register will read all 1 / 0xffffffff, causing get_state to store
bogus values in the pwm_state.

3. get_state was using an async pm_runtime_get() call, because it assumed
that runtime-pm has not been enabled yet. If shortly after the request an
apply call is made, then the pwm_lpss_is_updating() check may trigger
because the resume triggered by the pm_runtime_get() call is not complete
yet, so the ctrl register still reads all 1 / 0xffffffff.

This commit fixes these issues by moving the initial pm_runtime_get() call
for PWMs which are enabled at probe time to the pwm_lpss_probe() function;
and by making get_state take a runtime-pm ref before reading the ctrl reg.

BugLink: https://bugzilla.redhat.com/show_bug.cgi?id=1828927
Fixes: cfc4c189bc ("pwm: Read initial hardware state at request time")
Cc: stable@vger.kernel.org
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2020-06-02 14:21:42 +02:00
Peter Vasil 856c45d8c1 pwm: sun4i: Support direct clock output on Allwinner A64
Allwinner A64 is capable of a direct clock output on PWM (see A64 User
Manual chapter 3.10). Add support for this in the sun4i PWM driver.

Signed-off-by: Peter Vasil <peter.vasil@gmail.com>
Acked-by: Maxime Ripard <mripard@kernel.org>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2020-06-02 14:20:11 +02:00
Jeff LaBundy 6f0841a819 pwm: Add support for Azoteq IQS620A PWM generator
This patch adds support for the Azoteq IQS620A, capable of generating
a 1-kHz PWM output with duty cycle between ~0.4% and 100% (inclusive).

Signed-off-by: Jeff LaBundy <jeff@labundy.com>
Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2020-04-14 16:02:28 +02:00
Christophe JAILLET db539cb928 pwm: Add missing '\n' in log messages
Message logged by 'dev_xxx()' or 'pr_xxx()' should end with a '\n'.

Fixes: 3ad1f3a332 ("pwm: Implement some checks for lowlevel drivers")
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2020-04-14 15:57:51 +02:00
Sven Van Asbroeck 9cc5f232a4 pwm: pca9685: Fix PWM/GPIO inter-operation
This driver allows pwms to be requested as gpios via gpiolib. Obviously,
it should not be allowed to request a GPIO when its corresponding PWM is
already requested (and vice versa). So it requires some exclusion code.

Given that the PWMm and GPIO cores are not synchronized with respect to
each other, this exclusion code will also require proper
synchronization.

Such a mechanism was in place, but was inadvertently removed by Uwe's
clean-up in commit e926b12c61 ("pwm: Clear chip_data in pwm_put()").

Upon revisiting the synchronization mechanism, we found that
theoretically, it could allow two threads to successfully request
conflicting PWMs/GPIOs.

Replace with a bitmap which tracks PWMs in-use, plus a mutex. As long as
PWM and GPIO's respective request/free functions modify the in-use
bitmap while holding the mutex, proper synchronization will be
guaranteed.

Reported-by: YueHaibing <yuehaibing@huawei.com>
Fixes: e926b12c61 ("pwm: Clear chip_data in pwm_put()")
Cc: Mika Westerberg <mika.westerberg@linux.intel.com>
Cc: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Cc: YueHaibing <yuehaibing@huawei.com>
Link: https://lkml.org/lkml/2019/5/31/963
Signed-off-by: Sven Van Asbroeck <TheSven73@gmail.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
[cg: Tested on an i.MX6Q board with two NXP PCA9685 chips]
Tested-by: Clemens Gruber <clemens.gruber@pqgruber.com>
Reviewed-by: Sven Van Asbroeck <TheSven73@gmail.com> # cg's rebase
Link: https://lore.kernel.org/lkml/20200330160238.GD2817345@ulmo/
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2020-04-03 21:41:42 +02:00
Jason Yan 374c1104eb pwm: Make pwm_apply_state_debug() static
Fix the following gcc warning:

    drivers/pwm/core.c:467:6: warning: symbol 'pwm_apply_state_debug' was
        not declared. Should it be static?

Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Jason Yan <yanaijie@huawei.com>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2020-04-03 21:41:09 +02:00
Colin Ian King 437fb760d0 pwm: meson: Remove redundant assignment to variable fin_freq
The variable fin_freq is being initialized with a value that is never
read and it is being updated later with a new value. The initialization
is redundant and can be removed.

Addresses-Coverity: ("Unused value")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2020-04-03 21:40:56 +02:00
Paul Cercueil a2005fc791 pwm: jz4740: Allow selection of PWM channels 0 and 1
The TCU channels 0 and 1 were previously reserved for system tasks, and
thus unavailable for PWM.

Signed-off-by: Paul Cercueil <paul@crapouillou.net>
Tested-by: Mathieu Malaterre <malat@debian.org>
Tested-by: Artur Rojek <contact@artur-rojek.eu>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2020-03-30 18:03:10 +02:00
Paul Cercueil c2693514a0 pwm: jz4740: Obtain regmap from parent node
The TCU registers are shared between a handful of drivers, accessing
them through the same regmap.

While this driver is devicetree-compatible, it is never (as of now)
probed from devicetree, so this change does not introduce a ABI problem
with current devicetree files.

Signed-off-by: Paul Cercueil <paul@crapouillou.net>
Tested-by: Mathieu Malaterre <malat@debian.org>
Tested-by: Artur Rojek <contact@artur-rojek.eu>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2020-03-30 18:03:09 +02:00
Paul Cercueil 485b56f08f pwm: jz4740: Improve algorithm of clock calculation
The previous algorithm hardcoded details about how the TCU clocks work.
The new algorithm will use clk_round_rate to find the perfect clock rate
for the PWM channel.

This code relies on the fact that clk_round_rate() will always round
down, which is not a valid assumption given by the clk API, but only
happens to be true with the clk drivers used for Ingenic SoCs.

Right now, there is no alternative as the clk API does not have a
round-down function (and won't have one for a while), but if it ever
comes to light, a round-down function should be used instead.

Signed-off-by: Paul Cercueil <paul@crapouillou.net>
Tested-by: Mathieu Malaterre <malat@debian.org>
Tested-by: Artur Rojek <contact@artur-rojek.eu>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2020-03-30 18:03:09 +02:00
Paul Cercueil ce1f9cece0 pwm: jz4740: Use clocks from TCU driver
The ingenic-timer "TCU" driver provides us with clocks, that can be
(un)gated, reparented or reclocked from devicetree, instead of having
these settings hardcoded in this driver.

The new code now uses a clk pointer per PWM (instead of a clk per
pwm-chip before). So the pointer is stored in per-pwm data now.
The calls to arch-specific timer code is replaced with standard
clock API calls to start and stop each channel's clock.

While this driver is devicetree-compatible, it is never (as of now)
probed from devicetree, so this change does not introduce a ABI problem
with current devicetree files.

Signed-off-by: Paul Cercueil <paul@crapouillou.net>
Tested-by: Mathieu Malaterre <malat@debian.org>
Tested-by: Artur Rojek <contact@artur-rojek.eu>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2020-03-30 18:03:09 +02:00
Pascal Roeleven d3817a6470 pwm: sun4i: Remove redundant needs_delay
'needs_delay' does now always evaluate to true, so remove all
occurrences.

Signed-off-by: Pascal Roeleven <dev@pascalroeleven.nl>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2020-03-30 18:03:08 +02:00
Lokesh Vutla 6b28fb6f3c pwm: omap-dmtimer: Implement .apply callback
Implement .apply callback and drop the legacy callbacks(enable, disable,
config, set_polarity). In .apply() check for the current hardware status
before changing the PWM configuration.

Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com>
Tested-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2020-03-30 18:03:08 +02:00
Lokesh Vutla e793eef806 pwm: omap-dmtimer: Do not disable PWM before changing period/duty_cycle
Only the Timer control register(TCLR) cannot be updated when the timer
is running. Registers like Counter register (TCRR), loader register
(TLDR) and match register (TMAR) can be updated while the counter is
running. Since TCLR is not updated in pwm_omap_dmtimer_config(), do not
stop the timer for period/duty_cycle update.

Tested-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2020-03-30 18:03:07 +02:00
Lokesh Vutla 867beb60d1 pwm: omap-dmtimer: Fix PWM enabling sequence
To configure DM timer in PWM mode the following needs to be set in
OMAP_TIMER_CTRL_REG using set_pwm callback:
- Set toggle mode on PORTIMERPWM output pin
- Set trigger on overflow and match on PORTIMERPWM output pin.
- Set auto reload

This is a one time configuration and needs to be set before the start of
the DM timer. But the current driver tries to set the same configuration
for every period/duty cycle update, which is not needed. So move the PWM
setup before enabling timer and do not update it in
pwm_omap_dmtimer_config().

Tested-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2020-03-30 18:03:07 +02:00
Lokesh Vutla 348fb6f7fb pwm: omap-dmtimer: Update description for PWM OMAP DM timer
Update the description with a brief about how PWM is generated using
OMAP DM timer and add limitations for the PWM generations. Also add a
link to the reference manual.

Suggested-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2020-03-30 18:03:06 +02:00
Lokesh Vutla 54091b5f19 pwm: omap-dmtimer: Drop unused header file
pwm_omap_dmtimer.h is used only:
- to typedef struct omap_dm_timer to pwm_omap_dmtimer
- for macro PWM_OMAP_DMTIMER_TRIGGER_OVERFLOW_AND_COMPARE
Rest of the file is pretty mush unsed. So reuse omap_dm_timer
and OMAP_TIMER_TRIGGER_OVERFLOW_AND_COMPARE in pwm-omap-dmtimer.c
and delete the header file.

Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2020-03-30 18:03:06 +02:00
Geert Uytterhoeven a1098c13a3 pwm: renesas-tpu: Drop confusing registered message
During device probe, the message

    TPU PWM -1 registered

is printed.

While the "-1" looks suspicious, it is perfectly normal for a device
instantiated from DT.

Remove the message, as there are no non-DT users left, and other drivers
don't print such messages either.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2020-03-30 18:03:06 +02:00
Geert Uytterhoeven d5a3c7a453 pwm: renesas-tpu: Fix late Runtime PM enablement
Runtime PM should be enabled before calling pwmchip_add(), as PWM users
can appear immediately after the PWM chip has been added.
Likewise, Runtime PM should always be disabled after the removal of the
PWM chip, even if the latter failed.

Fixes: 99b82abb0a ("pwm: Add Renesas TPU PWM driver")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2020-03-30 18:03:05 +02:00
Geert Uytterhoeven 1451a3eed2 pwm: rcar: Fix late Runtime PM enablement
Runtime PM should be enabled before calling pwmchip_add(), as PWM users
can appear immediately after the PWM chip has been added.
Likewise, Runtime PM should be disabled after the removal of the PWM
chip.

Fixes: ed6c1476bf ("pwm: Add support for R-Car PWM Timer")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2020-03-30 18:03:05 +02:00
Krzysztof Kozlowski b33d232e61 pwm: meson: Fix confusing indentation
Fix indentation of return block.  Smatch warning:
    drivers/pwm/pwm-meson.c:139 meson_pwm_request() warn: inconsistent indenting

Reported-by: kbuild test robot <lkp@intel.com>
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Acked-by: Neil Armstrong <narmstrong@baylibre.com>
Fixes: 211ed63075 ("pwm: Add support for Meson PWM Controller")
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2020-03-30 18:03:05 +02:00
Rishi Gupta a37507d5bf pwm: pca9685: Use gpio core provided macro GPIO_LINE_DIRECTION_OUT
GPIO core recently added macro to uniformly specify direction of a GPIO
line, so use it.

Signed-off-by: Rishi Gupta <gupt21@gmail.com>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2020-03-30 18:03:04 +02:00
Rishi Gupta 408a7591d9 pwm: pca9685: Replace CONFIG_PM with __maybe_unused
The __maybe_unused attribute is preferred over CONFIG_PM to prevent
potential build time issues. This commit replaces CONFIG_PM with this
attribute.

Signed-off-by: Rishi Gupta <gupt21@gmail.com>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2020-03-30 18:03:04 +02:00
Sandipan Patra 2d0c08fcd6 pwm: tegra: Add support for Tegra194
Tegra194 has multiple PWM controllers with each having only one output.

Also the maxmimum frequency is higher than earlier SoCs.

Add support for Tegra194 and specify the number of PWM outputs and
maximum supported frequency using device tree match data.

Signed-off-by: Sandipan Patra <spatra@nvidia.com>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: Laxman Dewangan <ldewangan@nvidia.com>
Acked-by: Rob Herring <robh@kernel.org>
Acked-by: Jon Hunter <jonathanh@nvidia.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2020-03-30 18:03:04 +02:00
Krzysztof Kozlowski e96c0ff4b1 pwm: Enable compile testing for some of drivers
Some of the PWM drivers can be compile tested to increase build
coverage.

The Meson PWM driver requires COMMON_CLK dependency.

Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Acked-by: Florian Fainelli <f.fainelli@gmail.com> # For Broadcoam
Reviewed-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com> # For Meson
Acked-by: Claudiu Beznea <claudiu.beznea@microchip.com> # For Atmel
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2020-03-30 18:03:03 +02:00
Matthias Schiffer 69ee15f1b7 pwm: pca9685: Remove unused duty_cycle struct element
duty_cycle was only set, never read.

Signed-off-by: Matthias Schiffer <matthias.schiffer@ew.tq-group.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2020-03-30 16:55:27 +02:00
Anson Huang cef6df8bcd pwm: mxs: Remove unused include of of_address.h
There is nothing in use from of_address.h, remove it.

Signed-off-by: Anson Huang <Anson.Huang@nxp.com>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2020-03-30 16:55:27 +02:00
Anson Huang cf7987320a pwm: imx27: Remove unused include of of_device.h
There is nothing in use from of_device.h, remove it.

Signed-off-by: Anson Huang <Anson.Huang@nxp.com>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2020-03-30 16:55:26 +02:00
Anson Huang c0adbd1cdf pwm: imx-tpm: Remove unused includes
There is nothing in use from log2.h/of_address.h, remove them.

Signed-off-by: Anson Huang <Anson.Huang@nxp.com>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2020-03-30 16:55:26 +02:00
Uwe Kleine-König 3ad1f3a332 pwm: Implement some checks for lowlevel drivers
There are some expectations which the callbacks provided by lowlevel
drivers should fulfill. Implement checks that help driver authors to get
these semantics right. As these have some overhead the checks can be
disabled using a Kconfig setting.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2020-03-30 16:55:26 +02:00
Uwe Kleine-König 2cb5cd90f4 pwm: imx27: Ensure clocks being on iff the PWM is on
Up to now the .probe() function didn't enable clocks and relied on the
core to call the .get_state() callback to have the clock running. The
latter enabled the needed clocks and kept them running if the PWM wass
enabled.

This only works correctly if the .get_state() callback is called exactly
once and this single call happens before unused clocks are disabled by
the clk core.

The former wasn't true for a short period while commit 01ccf903ed
("pwm: Let pwm_get_state() return the last implemented state") applied
and not reverted yet and might become wrong in the future.

The latter isn't true any more since commit cfc4c189bc ("pwm: Read
initial hardware state at request time") which results in a running PWM
being stopped at boot time if for example the consumer lives in a kernel
module that is only loaded after the clk core disabled unused clocks.

So ensure .probe() is left with the clocks on if the PWM is running and
.get_state() disables everything it enabled.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2020-03-30 16:55:26 +02:00
Uwe Kleine-König 4563654fdd pwm: imx27: Don't disable clocks at device remove time
The .remove() callback is not supposed to modify hardware state. This is
in the responsibility of the PWM consumer.

After the PWM was disabled the clocks are off (apart from a bug that is
fixed in the next patch), so unbinding the driver either stops the PWM
(which it should not) or disables already disabled clocks yielding
warnings from the clk core.

So just drop the call to disable the clocks. (Which BTW was also in the
wrong order because the call makes the PWM unfunctional and so should
have come only after pwmchip_remove()).

Fixes: 9f4c8f9607 ("pwm: imx: Add ipg clock operation")
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2020-03-30 16:55:25 +02:00
Uwe Kleine-König aad4e530c2 pwm: imx27: Simplify helper function to enable and disable clocks
pwm_imx27_clk_prepare_enable() took a pointer to a struct pwm_chip just
to convert it to a struct pwm_imx27_chip pointer while all callers
already have the latter. Ditto for pwm_imx27_clk_disable_unprepare().

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2020-03-30 16:55:25 +02:00
Uwe Kleine-König 15d4dbd601 pwm: imx27: Fix clock handling in pwm_imx27_apply()
pwm_imx27_apply() enables the clocks if the previous PWM state was
disabled. Given that the clocks are supposed to be left on iff the PWM
is running, the decision to disable the clocks at the end of the
function must not depend on the previous state.

Without this fix the enable count of the two affected clocks increases
by one whenever ->apply() changes from one disabled state to another.

Fixes: bd88d319ab ("pwm: imx27: Unconditionally write state to hardware")
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2020-03-30 16:55:25 +02:00
Florian Fainelli 2c25b07e5e pwm: bcm2835: Dynamically allocate base
The newer 2711 and 7211 chips have two PWM controllers and failure to
dynamically allocate the PWM base would prevent the second PWM
controller instance being probed for succeeding with an -EEXIST error
from alloc_pwms().

Fixes: e5a06dc5ac ("pwm: Add BCM2835 PWM driver")
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reviewed-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2020-03-30 16:55:25 +02:00
Lokesh Vutla 02e6d546e3 clocksource/drivers/timer-ti-dm: Enable autoreload in set_pwm
dm timer ops set_load() api allows to configure the load value and to
set the auto reload feature. But auto reload feature is independent of
load value and should be part of configuring pwm. This way pwm can be
disabled by disabling auto reload feature using set_pwm() so that the
current pwm cycle will be completed. Else pwm disabling causes the
cycle to be stopped abruptly.

Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com>
Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20200305082715.15861-7-lokeshvutla@ti.com
2020-03-16 12:40:51 +01:00
yu kuai 9871abffc8 pwm: Remove set but not set variable 'pwm'
Fixes gcc '-Wunused-but-set-variable' warning:

	drivers/pwm/pwm-pca9685.c: In function ‘pca9685_pwm_gpio_free’:
	drivers/pwm/pwm-pca9685.c:162:21: warning: variable ‘pwm’ set but not used [-Wunused-but-set-variable]

It is never used, and so can be removed. In that case, hold and release
the lock 'pca->lock' can be removed since nothing will be done between
them.

Fixes: e926b12c61 ("pwm: Clear chip_data in pwm_put()")
Signed-off-by: yu kuai <yukuai3@huawei.com>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2020-01-20 15:40:49 +01:00
Thierry Reding 413c2a110d pwm: sun4i: Initialize variables before use
GCC can't always determine that the duty, period and prescaler values
are initialized when returning from sun4i_pwm_calculate(), so help out a
little by initializing them to 0.

Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2020-01-20 15:22:37 +01:00
Fabrice Gasnier 0c73201c5c pwm: stm32: Remove automatic output enable
Don't use AOE (automatic output enable) by default. In case of break
events, PWM is automatically re-enabled on next PWM cycle otherwise.

Signed-off-by: Fabrice Gasnier <fabrice.gasnier@st.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2020-01-20 13:47:36 +01:00
Uwe Kleine-König f6003f9482 pwm: sun4i: Narrow scope of local variable
The variable pval is only used in a single block in the function
sun4i_pwm_calculate(). So declare it in a more local scope to simplify
the function for humans and compilers.

While at it also simplify assignment to pval.

While the diffstat for this patch is negative for this patch I still
thing the advantage of having a narrower scope is beneficial.

In my compiler / .config setup (gcc 8.2.1, arm/imx_v6_v7_defconfig +
COMPILE_TEST + PWM_SUN4I) this change doesn't result in any binary
changes.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2020-01-20 13:22:42 +01:00
Florian Fainelli fdf47ff69d pwm: bcm2835: Allow building for ARCH_BRCMSTB
BCM7211 is supported using ARCH_BRCMSTB and uses this PWM controller
driver, make it possible to build it.

Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2020-01-20 13:21:44 +01:00
Anson Huang a368c34340 pwm: imx27: Eliminate error message for defer probe
For defer probe error, no need to output error message which
will cause confusion.

Signed-off-by: Anson Huang <Anson.Huang@nxp.com>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2020-01-20 13:20:21 +01:00
Gustavo A. R. Silva cba8d3bfdc pwm: sun4i: Fix inconsistent IS_ERR and PTR_ERR
Fix inconsistent IS_ERR and PTR_ERR in sun4i_pwm_probe().

The proper pointers to be passed as arguments are pwm->clk and pwm->bus_clk.

This bug was detected with the help of Coccinelle.

Fixes: b8d74644f3 ("pwm: sun4i: Prefer "mod" clock to unnamed")
Fixes: 5b090b430d ("pwm: sun4i: Add an optional probe for bus clock")
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2020-01-20 13:19:50 +01:00
Clément Péron 3e954d9626 pwm: sun4i: Move pwm_calculate() out of spin_lock()
pwm_calculate() calls clk_get_rate() while holding a spin_lock().

This create an issue as clk_get_rate() may sleep.

Move pwm_calculate() out of this spin_lock().

Fixes: c32c5c50d4 ("pwm: sun4i: Switch to atomic PWM")
Reported-by: Alexander Finger <alex.mobigo@gmail.com>
Sugested-by: Vasily Khoruzhick <anarsoul@gmail.com>
Tested-by: Alexander Finger <alex.mobigo@gmail.com>
Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Clément Péron <peron.clem@gmail.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2020-01-20 13:17:33 +01:00
Uwe Kleine-König 9f2919e9b4 pwm: omap-dmtimer: Allow compiling with COMPILE_TEST
The dependency on OMAP_DM_TIMER is only a runtime dependency. Also
OMAP_DM_TIMER cannot be enabled without ARCH_OMAP being enabled.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2020-01-20 12:32:59 +01:00
Uwe Kleine-König c7cb3a1dd5 pwm: omap-dmtimer: put_device() after of_find_device_by_node()
This was found by coccicheck:

	drivers/pwm/pwm-omap-dmtimer.c:304:2-8: ERROR: missing put_device;
	call of_find_device_by_node on line 255, but without a corresponding
	object release within this function.

Reported-by: Markus Elfring <elfring@users.sourceforge.net>
Fixes: 6604c6556d ("pwm: Add PWM driver for OMAP using dual-mode timers")
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2020-01-20 12:32:37 +01:00
Uwe Kleine-König c4cf7aa57e pwm: omap-dmtimer: Simplify error handling
Instead of doing error handling in the middle of ->probe(), move error
handling and freeing the reference to timer to the end.

This fixes a resource leak as dm_timer wasn't freed when allocating
*omap failed.

Implementation note: The put: label was never reached without a goto and
ret being unequal to 0, so the removed return statement is fine.

Fixes: 6604c6556d ("pwm: Add PWM driver for OMAP using dual-mode timers")
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2020-01-20 12:31:19 +01:00
Uwe Kleine-König 43efdc8f0e pwm: omap-dmtimer: Remove PWM chip in .remove before making it unfunctional
In the old code (e.g.) mutex_destroy() was called before
pwmchip_remove(). Between these two calls it is possible that a PWM
callback is used which tries to grab the mutex.

Fixes: 6604c6556d ("pwm: Add PWM driver for OMAP using dual-mode timers")
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2020-01-20 12:29:34 +01:00
Uwe Kleine-König 1188829abc pwm: Implement tracing for .get_state() and .apply_state()
This allows to log all calls to the driver's lowlevel functions which
simplifies debugging in some cases.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2020-01-20 12:28:37 +01:00
Uwe Kleine-König af4fab8bed pwm: rcar: Document inability to set duty_cycle = 0
When .apply() is called with state->duty_cycle = 0 the duty_ns parameter
to rcar_pwm_set_counter() is 0 which results in ph being 0 and
rcar_pwm_set_counter() returning -EINVAL.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reviewed-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2020-01-20 12:22:30 +01:00
Uwe Kleine-König bca900829d pwm: rcar: Drop useless call to pwm_get_state()
pwm_get_state has no side effects and the resulting pwm_state is unused.
So drop the call to pwm_get_state() and the local variable from
rcar_pwm_apply().

The call was introduced in commit 7f68ce8287 ("pwm: rcar: Add support
"atomic" API") and already then was useless.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reviewed-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2020-01-20 12:21:49 +01:00
Krzysztof Kozlowski f24e564129 pwm: Fix minor Kconfig whitespace issues
Remove double whitespace after "config" keyword.

Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2020-01-08 13:56:02 +01:00
Uwe Kleine-König 651b510a74 pwm: atmel: Implement .get_state()
This function reads back the configured parameters from the hardware. As
.apply() rounds down (mostly) I'm rounding up in .get_state() to achieve
that applying a state just read from hardware is a no-op.

Signed-off-by: Uwe Kleine-König <uwe@kleine-koenig.org>
Acked-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2020-01-08 13:47:46 +01:00
Uwe Kleine-König 02afb811e0 pwm: atmel: Use register accessors for channels
This makes it a bit easier when instrumenting register access to only
have to add code in one place.

Signed-off-by: Uwe Kleine-König <uwe@kleine-koenig.org>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2020-01-08 13:44:51 +01:00
Uwe Kleine-König 998d189a81 pwm: atmel: Document known weaknesses of both hardware and software
This documents the my findings while reading through the driver and the
reference manual.

Signed-off-by: Uwe Kleine-König <uwe@kleine-koenig.org>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2020-01-08 13:44:08 +01:00
Uwe Kleine-König 2101c878f7 pwm: atmel: Replace loop in prescale calculation by ad-hoc calculation
The calculated values are the same with the modified algorithm. The only
difference is that the calculation is a bit more efficient.

Acked-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Signed-off-by: Uwe Kleine-König <uwe@kleine-koenig.org>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2020-01-08 13:43:39 +01:00
Uwe Kleine-König ff55e7a314 pwm: atmel: Use a constant for maximum prescale value
The maximal prescale value is 10 for all supported variants. So drop the
member in the variant description and introduce a global constant
instead.

This reduces the size of the variant descriptions and the .apply()
callback can be compiled a bit more effectively.

Acked-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Signed-off-by: Uwe Kleine-König <uwe@kleine-koenig.org>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2020-01-08 13:43:00 +01:00
Uwe Kleine-König 3c269ba6d8 pwm: atmel: Add a hint where to find hardware documentation
Most Microchip (formerly Atmel) chips have publicly available manuals.
A comprehensive list is already contained in the documentation folder.
Reference this list in the header of the driver to allow reviewers to
find the relevant manuals.

Signed-off-by: Uwe Kleine-König <uwe@kleine-koenig.org>
Acked-by: Nicolas Ferre <nicolas.ferre@microchip.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2020-01-08 13:42:40 +01:00
Rasmus Villemoes 3c64ed74d6 pwm: mxs: Avoid a division in mxs_pwm_apply()
Since the divisor is not a compile-time constant (unless gcc somehow
decided to unroll the loop PERIOD_CDIV_MAX times), this does a
somewhat expensive 32/32 division. Replace that with a right shift.

We still have a 64/32 division just below, but at least in that
case the divisor is compile-time constant.

Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2020-01-08 13:35:12 +01:00
Rasmus Villemoes 2cf0f6fece pwm: mxs: Add support for inverse polarity
If I'm reading of_pwm_xlate_with_flags() right, existing device trees
that set #pwm-cells = 2 will continue to work.

Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2020-01-08 13:33:37 +01:00
Rasmus Villemoes ebbfb1592c pwm: mxs: Remove legacy methods
Since we now have ->apply(), these are no longer relevant.

Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2020-01-08 13:33:11 +01:00
Rasmus Villemoes bf29c2ff82 pwm: mxs: Implement ->apply()
In preparation for supporting setting the polarity, switch the driver
to support the ->apply() method.

Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2020-01-08 13:32:47 +01:00
Jernej Skrabec fdd2c12e37 pwm: sun4i: Add support for H6 PWM
Now that sun4i PWM driver supports deasserting reset line and enabling
bus clock, support for H6 PWM can be added.

Note that while H6 PWM has two channels, only first one is wired to
output pin. Second channel is used as a clock source to companion AC200
chip which is bundled into same package.

Signed-off-by: Jernej Skrabec <jernej.skrabec@siol.net>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Clément Péron <peron.clem@gmail.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2020-01-08 12:50:42 +01:00
Jernej Skrabec 9f28e95b52 pwm: sun4i: Add support to output source clock directly
PWM core has an option to bypass whole logic and output unchanged source
clock as PWM output. This is achieved by enabling bypass bit.

Note that when bypass is enabled, no other setting has any meaning, not
even enable bit.

This mode of operation is needed to achieve high enough frequency to
serve as clock source for AC200 chip which is integrated into same
package as H6 SoC.

Signed-off-by: Jernej Skrabec <jernej.skrabec@siol.net>
Signed-off-by: Clément Péron <peron.clem@gmail.com>
Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2020-01-08 12:50:41 +01:00
Clément Péron fa4d817846 pwm: sun4i: Always calculate params when applying new parameters
Bypass mode will require to be re-calculated when the pwm state
is changed.

Remove the condition so pwm_sun4i_calculate is always called.

Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Clément Péron <peron.clem@gmail.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2020-01-08 12:48:33 +01:00
Jernej Skrabec 5b090b430d pwm: sun4i: Add an optional probe for bus clock
H6 PWM core needs bus clock to be enabled in order to work.

Add an optional probe for it.

Signed-off-by: Jernej Skrabec <jernej.skrabec@siol.net>
Signed-off-by: Clément Péron <peron.clem@gmail.com>
Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2020-01-08 12:48:19 +01:00
Clément Péron b8d74644f3 pwm: sun4i: Prefer "mod" clock to unnamed
New device tree bindings called the source clock of the module
"mod" when several clocks are defined.

Try to get a clock called "mod" if nothing is found try to get
an unnamed clock.

Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Clément Péron <peron.clem@gmail.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2020-01-08 12:48:05 +01:00
Jernej Skrabec a7fe985633 pwm: sun4i: Add an optional probe for reset line
H6 PWM core needs deasserted reset line in order to work.

Add an optional probe for it.

Signed-off-by: Jernej Skrabec <jernej.skrabec@siol.net>
Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Clément Péron <peron.clem@gmail.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2020-01-08 12:47:26 +01:00
Thierry Reding bd88d319ab pwm: imx27: Unconditionally write state to hardware
The i.MX driver currently uses a shortcut and doesn't write all of the
state through to the hardware when the PWM is disabled. This causes an
inconsistent state to be read back by consumers with the result of them
malfunctioning.

Fix this by always writing the full state through to the hardware
registers so that the correct state can always be read back.

Tested-by: Michal Vokáč <michal.vokac@ysoft.com>
Tested-by: Adam Ford <aford173@gmail.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2019-12-09 10:05:46 +01:00
Thierry Reding a3597d6c89 pwm: imx27: Cache duty cycle register value
The hardware register containing the duty cycle value cannot be accessed
when the PWM is disabled. This causes the ->get_state() callback to read
back a duty cycle value of 0, which can confuse consumer drivers.

Tested-by: Michal Vokáč <michal.vokac@ysoft.com>
Tested-by: Adam Ford <aford173@gmail.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2019-12-09 10:05:43 +01:00
Thierry Reding 1db37f9561 pwm: cros-ec: Cache duty cycle value
The ChromeOS embedded controller doesn't differentiate between disabled
and duty cycle being 0. In order not to potentially confuse consumers,
cache the duty cycle and return the cached value instead of the real
value when the PWM is disabled.

Tested-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2019-12-09 10:05:42 +01:00
Thierry Reding cfc4c189bc pwm: Read initial hardware state at request time
Drivers that support reading the hardware state (using ->get_state())
may want to rely on per-PWM data to do so. Defer reading the hardware
state for the first time until the PWM has been requested and after
drivers have had a chance to allocate per-PWM data.

Conceptually this is also a more natural place to read the hardware
state because the PWM core doesn't need to know the hardware state of a
PWM unless there is a user for it. This also ensures that the state is
read everytime a user requests a PWM. If the PWM changes between users
for some reason, the PWM core will reload the state from hardware and
keep its copy of the state up-to-date.

Tested-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Tested-by: Michal Vokáč <michal.vokac@ysoft.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2019-12-09 10:05:41 +01:00
Linus Torvalds d9e48dc2a7 pwm: Changes for v5.5-rc1
Various changes and minor fixes across a couple of drivers.
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Merge tag 'pwm/for-5.5-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/thierry.reding/linux-pwm

Pull pwm updates from Thierry Reding:
 "Various changes and minor fixes across a couple of drivers"

* tag 'pwm/for-5.5-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/thierry.reding/linux-pwm:
  pwm: stm32: Pass breakinput instead of its values
  pwm: stm32: Remove clutter from ternary operator
  pwm: stm32: Validate breakinput data from DT
  pwm: Update comment on struct pwm_ops::apply
  pwm: sun4i: Fix incorrect calculation of duty_cycle/period
  pwm: stm32: Add power management support
  pwm: stm32: Split breakinput apply routine to ease PM support
  dt-bindings: pwm-stm32: Document pinctrl sleep state
  pwm: sun4i: Drop redundant assignment to variable pval
  dt-bindings: pwm: mediatek: Remove gratuitous compatible string for MT7629
2019-12-05 11:28:14 -08:00
Greg Kroah-Hartman f0cb9b5dfd Merge 5.4-rc7 into staging-next
We want the staging fixes in here, and it resolves some merge issues.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-11-11 06:23:37 +01:00
Uwe Kleine-König 24906a41ee pwm: bcm-iproc: Prevent unloading the driver module while in use
The owner member of struct pwm_ops must be set to THIS_MODULE to
increase the reference count of the module such that the module cannot
be removed while its code is in use.

Fixes: daa5abc41c ("pwm: Add support for Broadcom iProc PWM controller")
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2019-11-08 18:38:06 +01:00
Thierry Reding 9e1b4999a1 pwm: stm32: Pass breakinput instead of its values
Instead of passing the individual values of the breakpoint, pass a
pointer to the breakpoint.

Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2019-10-21 16:50:05 +02:00
Thierry Reding 8e53622594 pwm: stm32: Remove clutter from ternary operator
Remove usage of the ternary operator to assign values for register
fields. Instead, parameterize the register and field offset macros
and pass the index to them.

This removes clutter and improves readability.

Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2019-10-21 16:50:05 +02:00
Thierry Reding 8dfa620e3d pwm: stm32: Validate breakinput data from DT
Both index and level can only be either 0 or 1 and the filter value is
limited to values between (and including) 0 and 15. Validate that the
device tree node contains values that are within these ranges.

Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2019-10-21 16:50:04 +02:00
Ondrej Jirman 50cc7e3e4f pwm: sun4i: Fix incorrect calculation of duty_cycle/period
Since 5.4-rc1, pwm_apply_state calls ->get_state after ->apply
if available, and this revealed an issue with integer precision
when calculating duty_cycle and period for the currently set
state in ->get_state callback.

This issue manifested in broken backlight on several Allwinner
based devices.

Previously this worked, because ->apply updated the passed state
directly.

Fixes: deb9c462f4 ("pwm: sun4i: Don't update the state for the caller of pwm_apply_state")
Signed-off-by: Ondrej Jirman <megous@megous.com>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2019-10-21 16:50:02 +02:00
Fabrice Gasnier 2d3aa06b5d pwm: stm32: Add power management support
Add suspend/resume PM sleep ops. When going to low power, enforce the PWM
channel isn't active. Let the PWM consumers disable it during their own
suspend sequence, see [1]. So, perform a check here, and handle the
pinctrl states. Also restore the break inputs upon resume, as registers
content may be lost when going to low power mode.

[1] https://lkml.org/lkml/2019/2/5/770

Signed-off-by: Fabrice Gasnier <fabrice.gasnier@st.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2019-10-21 16:50:01 +02:00
Fabrice Gasnier 0f9d2ecba8 pwm: stm32: Split breakinput apply routine to ease PM support
Split breakinput routine that configures STM32 timers 'break' safety
feature upon probe, into two routines:
- stm32_pwm_apply_breakinputs() sets all the break inputs into registers.
- stm32_pwm_probe_breakinputs() probes the device tree break input settings
  before calling stm32_pwm_apply_breakinputs()

This is a precursor patch to ease PM support. Registers content may get
lost during low power. So, break input settings applied upon probe need
to be restored upon resume (e.g. by calling stm32_pwm_apply_breakinputs()).

Signed-off-by: Fabrice Gasnier <fabrice.gasnier@st.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2019-10-21 16:50:00 +02:00
Colin Ian King 1b98ad3b3b pwm: sun4i: Drop redundant assignment to variable pval
Variable pval is being assigned a value that is never read. The
assignment is redundant and hence can be removed.

Addresses-Coverity: ("Unused value")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2019-10-21 16:49:58 +02:00
Thierry Reding 40a6b9a009 Revert "pwm: Let pwm_get_state() return the last implemented state"
It turns out that commit 01ccf903ed ("pwm: Let pwm_get_state() return
the last implemented state") causes backlight failures on a number of
boards. The reason is that some of the drivers do not write the full
state through to the hardware registers, which means that ->get_state()
subsequently does not return the correct state. Consumers which rely on
pwm_get_state() returning the current state will therefore get confused
and subsequently try to program a bad state.

Before this change can be made, existing drivers need to be more
carefully audited and fixed to behave as the framework expects. Until
then, keep the original behaviour of returning the software state that
was applied rather than reading the state back from hardware.

Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Tested-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Tested-by: Michal Vokáč <michal.vokac@ysoft.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2019-10-21 16:48:52 +02:00
David Lechner 7cabf9251a bus/ti-pwmss: move TI PWMSS driver from PWM to bus subsystem
The TI PWMSS driver is a simple bus driver for providing power
power management for the PWM peripherals on TI AM33xx SoCs, namely
eCAP, eHRPWM and eQEP. The eQEP is a counter rather than a PWM, so
it does not make sense to have the bus driver in the PWM subsystem
since the PWMSS is not exclusive to PWM devices.

Signed-off-by: David Lechner <david@lechnology.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
2019-10-17 21:17:42 +01:00
Linus Torvalds e37e3bc7e2 pwm: Changes for v5.4-rc1
Besides one new driver being added for the PWM controller found in
 various Spreadtrum SoCs, this series of changes brings a slew of, mostly
 minor, fixes and cleanups for existing drivers, as well as some
 enhancements to the core code.
 
 Lastly, Uwe is added to the PWM subsystem entry of the MAINTAINERS file,
 making official his role as a reviewer.
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Merge tag 'pwm/for-5.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/thierry.reding/linux-pwm

Pull pwm updates from Thierry Reding:
 "Besides one new driver being added for the PWM controller found in
  various Spreadtrum SoCs, this series of changes brings a slew of,
  mostly minor, fixes and cleanups for existing drivers, as well as some
  enhancements to the core code.

  Lastly, Uwe is added to the PWM subsystem entry of the MAINTAINERS
  file, making official his role as a reviewer"

* tag 'pwm/for-5.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/thierry.reding/linux-pwm: (34 commits)
  MAINTAINERS: Add myself as reviewer for the PWM subsystem
  MAINTAINERS: Add patchwork link for PWM entry
  MAINTAINERS: Add a selection of PWM related keywords to the PWM entry
  pwm: mediatek: Add MT7629 compatible string
  dt-bindings: pwm: Update bindings for MT7629 SoC
  pwm: mediatek: Update license and switch to SPDX tag
  pwm: mediatek: Use pwm_mediatek as common prefix
  pwm: mediatek: Allocate the clks array dynamically
  pwm: mediatek: Remove the has_clks field
  pwm: mediatek: Drop the check for of_device_get_match_data()
  pwm: atmel: Consolidate driver data initialization
  pwm: atmel: Remove unneeded check for match data
  pwm: atmel: Remove platform_device_id and use only dt bindings
  pwm: stm32-lp: Add check in case requested period cannot be achieved
  pwm: Ensure pwm_apply_state() doesn't modify the state argument
  pwm: fsl-ftm: Don't update the state for the caller of pwm_apply_state()
  pwm: sun4i: Don't update the state for the caller of pwm_apply_state()
  pwm: rockchip: Don't update the state for the caller of pwm_apply_state()
  pwm: Let pwm_get_state() return the last implemented state
  pwm: Introduce local struct pwm_chip in pwm_apply_state()
  ...
2019-09-27 12:19:47 -07:00
Sam Shih 715d14da67 pwm: mediatek: Add MT7629 compatible string
This adds pwm support for MT7629, and separate mt7629 compatible string
from mt7622

Signed-off-by: Sam Shih <sam.shih@mediatek.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2019-09-26 13:27:50 +02:00
Sam Shih 4bea6dd5be pwm: mediatek: Update license and switch to SPDX tag
Add SPDX identifiers to pwm-mediatek.c. Update MODULE_LICENSE to
correctly reflect the GNU General Public License v2.0.

Signed-off-by: Ryder Lee <ryder.lee@mediatek.com>
Signed-off-by: Sam Shih <sam.shih@mediatek.com>
Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2019-09-25 09:49:15 +02:00
Sam Shih 2503781c97 pwm: mediatek: Use pwm_mediatek as common prefix
Use pwm_mediatek as common prefix to match the filename. No functional
change intended.

Signed-off-by: Ryder Lee <ryder.lee@mediatek.com>
Signed-off-by: Sam Shih <sam.shih@mediatek.com>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2019-09-25 09:49:15 +02:00
Sam Shih efecdeb82f pwm: mediatek: Allocate the clks array dynamically
Instead of using fixed size of arrays, allocate the memory for them
based on the number of PWMs specified for each SoC generation.

Signed-off-by: Ryder Lee <ryder.lee@mediatek.com>
Signed-off-by: Sam Shih <sam.shih@mediatek.com>
Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2019-09-25 09:49:15 +02:00
Sam Shih 61aa258ab1 pwm: mediatek: Remove the has_clks field
We can use fixed clocks to repair mt7628 PWM during configure from
userspace. The SoC is legacy MIPS and has no complex clock tree. Because
we can get the clock frequency for period calculation from fixed clocks
specified in DT, we can remove the has_clock field, and directly use
devm_clk_get() and clk_get_rate().

Signed-off-by: Ryder Lee <ryder.lee@mediatek.com>
Signed-off-by: Sam Shih <sam.shih@mediatek.com>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2019-09-25 09:48:58 +02:00
Sam Shih e6c7c258f0 pwm: mediatek: Drop the check for of_device_get_match_data()
This patch drop the check for of_device_get_match_data. Due to the only
way call driver probe is compatible match. The data pointer which points
to the SoC specify data is directly set by driver, and it should not be
NULL in our case. We can safety remove the check for the result of
of_device_get_match_data().

Signed-off-by: Ryder Lee <ryder.lee@mediatek.com>
Signed-off-by: Sam Shih <sam.shih@mediatek.com>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2019-09-21 03:25:11 +02:00
Thierry Reding 9193c16e5a pwm: atmel: Consolidate driver data initialization
This helps readability by separating the driver-specific bits from the
PWM framework bits.

Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2019-09-21 03:25:11 +02:00