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>
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>
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>
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>
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>
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>
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>
'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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
