Commit Graph

762 Commits

Author SHA1 Message Date
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