Commit graph

1063 commits

Author SHA1 Message Date
Uwe Kleine-König
3d2813fb17 pwm: lpc32xx: Don't modify HW state in .probe() after the PWM chip was registered
This fixes a race condition: After pwmchip_add() is called there might
already be a consumer and then modifying the hardware behind the
consumer's back is bad. So set the default before.

(Side-note: I don't know what this register setting actually does, if
this modifies the polarity there is an inconsistency because the
inversed polarity isn't considered if the PWM is already running during
.probe().)

Fixes: acfd92fdfb ("pwm: lpc32xx: Set PWM_PIN_LEVEL bit to default value")
Cc: Sylvain Lemieux <slemieux@tycoint.com>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2021-09-02 21:38:35 +02:00
Uwe Kleine-König
eb41f33458 pwm: ab8500: Fix register offset calculation to not depend on probe order
The assumption that lead to commit 5e5da1e9fb ("pwm: ab8500:
Explicitly allocate pwm chip base dynamically") was wrong: The
pwm-ab8500 devices are not directly instantiated from device tree, but
from the ab8500 mfd driver. So the pdev->id isn't -1, but a number
between 1 and 3. Now that pwmchip ids are always allocated dynamically,
this cannot easily be reverted.

Introduce a new member in the driver data struct that tracks the
hardware id and use this to calculate the register offset.

Side-note: Using chip->base to calculate the offset was never robust
because if there was already a PWM with id 1 at the time ab8500-pwm.1
was probed, the associated pwmchip would get assigned chip->base = 2 (or
something bigger).

Fixes: 5e5da1e9fb ("pwm: ab8500: Explicitly allocate pwm chip base dynamically")
Fixes: 6173f8f4ed ("pwm: Move AB8500 PWM driver to PWM framework")
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2021-09-02 21:35:09 +02:00
Uwe Kleine-König
52eaba4ced pwm: atmel: Rework tracking updates pending in hardware
This improves the driver's behavior in several ways:

 - The lock is held for shorter periods and so a channel that is currently
   waited for doesn't block disabling another channel.

 - It's easier to understand because the procedure is split into more
   semantic units and documentation is improved

 - A channel is only set to pending when such an event is actually
   scheduled in hardware (by writing the CUPD register).

 - Also wait in .get_state() to report the last configured state instead
   of (maybe) the previous one. This fixes the read back duty cycle and so
   prevents a warning being emitted when PWM_DEBUG is on.

Tested on an AriettaG25.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2021-09-02 21:35:09 +02:00
Uwe Kleine-König
f4a8e31ed8 pwm: ep93xx: Ensure configuring period and duty_cycle isn't wrongly skipped
As the last call to ep93xx_pwm_apply() might have exited early if
state->enabled was false, the values for period and duty_cycle stored in
pwm->state might not have been written to hardware and it must be
ensured that they are configured before enabling the PWM.

Fixes: 6d45374af5 ("pwm: ep93xx: Implement .apply callback")
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2021-07-08 16:09:30 +02:00
Uwe Kleine-König
7d6d4aaf28 pwm: berlin: Ensure configuring period and duty_cycle isn't wrongly skipped
As the last call to berlin_pwm_apply() might have exited early if
state->enabled was false, the values for period and duty_cycle stored in
pwm->state might not have been written to hardware and it must be
ensured that they are configured before enabling the PWM.

Fixes: 30dffb42fc ("pwm: berlin: Implement .apply() callback")
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2021-07-08 16:09:17 +02:00
Uwe Kleine-König
25f70b8f3d pwm: tiecap: Ensure configuring period and duty_cycle isn't wrongly skipped
As the last call to ecap_pwm_apply() might have exited early if
state->enabled was false, the values for period and duty_cycle stored in
pwm->state might not have been written to hardware and it must be
ensured that they are configured before enabling the PWM.

Fixes: 0ca7acd847 ("pwm: tiecap: Implement .apply() callback")
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2021-07-08 16:08:54 +02:00
Uwe Kleine-König
fe8255f80b pwm: spear: Ensure configuring period and duty_cycle isn't wrongly skipped
As the last call to spear_pwm_apply() might have exited early if
state->enabled was false, the values for period and duty_cycle stored in
pwm->state might not have been written to hardware and it must be
ensured that they are configured before enabling the PWM.

Fixes: 98761ce4b9 ("pwm: spear: Implement .apply() callback")
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2021-07-08 16:08:38 +02:00
Uwe Kleine-König
65e2e6c1c2 pwm: sprd: Ensure configuring period and duty_cycle isn't wrongly skipped
As the last call to sprd_pwm_apply() might have exited early if
state->enabled was false, the values for period and duty_cycle stored in
pwm->state might not have been written to hardware and it must be
ensured that they are configured before enabling the PWM.

Fixes: 8aae4b02e8 ("pwm: sprd: Add Spreadtrum PWM support")
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2021-07-08 16:08:08 +02:00
Colin Ian King
bebedf2bb4 pwm: Remove redundant assignment to pointer pwm
The pointer pwm 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>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2021-07-07 21:43:32 +02:00
Colin Ian King
96e45e5202 pwm: ep93xx: Fix read of uninitialized variable ret
There is a potential path in function ep93xx_pwm_apply where ret is
never assigned a value and it is checked for an error code. Fix this
by ensuring ret is zero'd in the success path to avoid this issue.

Addresses-Coverity: ("Uninitialized scalar variable")
Fixes: f6ef94edf0f6 ("pwm: ep93xx: Unfold legacy callbacks into ep93xx_pwm_apply()")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2021-06-30 19:12:21 +02:00
Alexander Sverdlin
b235f8a39f pwm: ep93xx: Prepare clock before using it
Use clk_prepare_enable()/clk_disable_unprepare() in preparation for switch
to Common Clock Framework.

Signed-off-by: Alexander Sverdlin <alexander.sverdlin@gmail.com>
Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2021-06-30 19:12:20 +02:00
Uwe Kleine-König
72cce47fe8 pwm: ep93xx: Unfold legacy callbacks into ep93xx_pwm_apply()
This just puts the implementation of ep93xx_pwm_disable(),
ep93xx_pwm_enable() and ep93xx_pwm_config() into their only caller.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2021-06-30 19:12:20 +02:00
Uwe Kleine-König
6d45374af5 pwm: ep93xx: Implement .apply callback
To ease review this reuses the formerly implemented callbacks.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2021-06-30 19:12:20 +02:00
Uwe Kleine-König
868f13bdea pwm: vt8500: Only unprepare the clock after the pwmchip was removed
Until pwmchip_remove() returns the PWM is supposed to work, so
pwmchip_remove() must be called before the clock is stopped.

The return value of pwmchip_remove doesn't need to be checked because
it returns zero anyhow and I plan to make it return void soon.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2021-06-30 19:12:20 +02:00
Uwe Kleine-König
fb2cb3bff9 pwm: vt8500: Drop if with an always false condition
vt8500_pwm_remove() is only called after vt8500_pwm_probe() returned
successfully. In this case driver data was set to a non-NULL value
and so chip can never be NULL.

While touching this code also put declaration and assignment in a single
line.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2021-06-30 19:12:20 +02:00
Uwe Kleine-König
2f1a3bd451 pwm: tegra: Assert reset only after the PWM was unregistered
The driver is supposed to stay functional until pwmchip_remove()
returns. So the reset must be asserted only after that.

pwmchip_remove() always returns 0, so the return code can be ignored
which keeps the tegra_pwm_remove() a bit simpler.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2021-06-30 19:12:20 +02:00
Uwe Kleine-König
3b8b571fcc pwm: tegra: Don't needlessly enable and disable the clock in .remove()
There is no reason to enable the PWM clock just to assert the reset
control. (If the reset control depends on the clock this is a bug and
probably it doesn't because in .probe() the reset is deasserted without
the clock being enabled.)

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2021-06-30 19:12:20 +02:00
Uwe Kleine-König
86f7fa71cd pwm: tegra: Don't modify HW state in .remove callback
A consumer is expected to disable a PWM before calling pwm_put(). And if
they didn't there is hopefully a good reason (or the consumer needs
fixing). Also if disabling an enabled PWM was the right thing to do,
this should better be done in the framework instead of in each low level
driver.

So drop the hardware modification from the .remove() callback.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2021-06-30 19:12:20 +02:00
Uwe Kleine-König
c1b8ac969f pwm: tegra: Drop an if block with an always false condition
tegra_pwm_remove() is only called after tegra_pwm_probe() successfully
completed. In this case platform_set_drvdata() was called with a
non-NULL value and so platform_get_drvdata(pdev) cannot return NULL.

Returning an error code from a platform_driver's remove function is
ignored anyway, so it's a good thing this exit path is gone.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2021-06-30 19:12:20 +02:00
Andy Shevchenko
9ae241d06e pwm: core: Simplify some devm_*pwm*() functions
Use devm_add_action_or_reset() instead of devres_alloc() and
devres_add(), which works the same. This will simplify the
code. There is no functional changes.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2021-06-30 19:12:19 +02:00
Andy Shevchenko
c333b936c1 pwm: core: Remove unused devm_pwm_put()
There are no users and seems no will come of the devm_pwm_put().
Remove the function.

While at it, slightly update documentation.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2021-06-30 19:12:19 +02:00
Andy Shevchenko
e625fb70a6 pwm: core: Unify fwnode checks in the module
Historically we have two different approaches on how to check type of fwnode.
Unify them using the latest and greatest fwnode related APIs.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2021-06-30 19:12:19 +02:00
Andy Shevchenko
e5c38ba9f2 pwm: core: Reuse fwnode_to_pwmchip() in ACPI case
In ACPI case we may use matching by fwnode as provided via
fwnode_to_pwmchip(). This makes device_to_pwmchip() not needed
anymore.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2021-06-30 19:12:19 +02:00
Andy Shevchenko
ca06616b1e pwm: core: Convert to use fwnode for matching
When we traverse the list of the registered PWM controllers,
use fwnode to match. This will help for further cleanup.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2021-06-30 19:12:19 +02:00
Uwe Kleine-König
76982e478d pwm: sprd: Don't check the return code of pwmchip_remove()
pwmchip_remove() returns always 0. Don't use the value to make it
possible to eventually change the function to return void. This is a
good thing as pwmchip_remove() is usually called from a remove function
(mostly for platform devices) and their return value is ignored by the
device core anyhow.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2021-06-30 19:12:18 +02:00
Zou Wei
fde25294df pwm: img: Fix PM reference leak in img_pwm_enable()
pm_runtime_get_sync will increment pm usage counter even it failed.
Forgetting to putting operation will result in reference leak here.
Fix it by replacing it with pm_runtime_resume_and_get to keep usage
counter balanced.

Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Zou Wei <zou_wei@huawei.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2021-06-30 19:12:18 +02:00
Uwe Kleine-König
b63d60b2ea pwm: pxa: Always use the same variable name for driver data
In most functions the driver data variable is called pc. Do the same in
the two remaining functions.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2021-06-30 19:12:18 +02:00
Uwe Kleine-König
81b7c173e3 pwm: pxa: Drop if with an always false condition
The .remove() function is only called after .probe() returned
successfully. In this case platform_set_drvdata() was called with a
non-NULL argument and so platfrom_get_drvdata() returns the same
non-NULL value.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2021-06-30 19:12:18 +02:00
Uwe Kleine-König
0512f0503b pwm: berlin: Don't check the return code of pwmchip_remove()
pwmchip_remove() always returns 0. Don't use the value to make it
possible to eventually change the function to return void. This is a
good thing as pwmchip_remove() is usually called from a remove function
(mostly for platform devices) and their return value is ignored by the
device core anyhow.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2021-06-30 19:12:18 +02:00
Uwe Kleine-König
30dffb42fc pwm: berlin: Implement .apply() callback
To eventually get rid of all legacy drivers convert this driver to the
modern world implementing .apply(). This just pushes down a slightly
optimized variant of how legacy drivers are handled in the core.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2021-06-30 19:12:18 +02:00
Uwe Kleine-König
3f3e805177 pwm: berlin: use consistent naming for variables
A struct berlin_pwm_chip * is now always called "bpc" (instead of "pwm"
which is usually used for struct pwm_device * or "chip" which is usually
used for struct pwm_chip *). The struct pwm_device * variables were
named "pwm_dev" or "pwm"; they are now always called "pwm".

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2021-06-30 19:12:17 +02:00
Uwe Kleine-König
0ca7acd847 pwm: tiecap: Implement .apply() callback
To eventually get rid of all legacy drivers convert this driver to the
modern world implementing .apply(). This just pushes down a slightly
optimized variant of how legacy drivers are handled in the core.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2021-06-28 13:28:24 +02:00
Uwe Kleine-König
ec67fba92e pwm: tiecap: Drop .free() callback
ecap_pwm_free is only called when a consumer releases the PWM (using
pwm_put() or pwm_free()). The consumer is expected to disable the PWM
before doing that. It's not clear if a warning about that is justified, but
if it is this is independent of the actual driver and can better be done in
the core. Also if there is a good reason it's wrong to disable the hardware
and so the call to pm_runtime_put_sync() should be dropped. Moreover there
is no matching pwm_runtime_get call and so the runtime usage counter might
become negative.

Fixes: 8e0cb05b3b ("pwm: pwm-tiecap: PWM driver support for ECAP APWM")
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2021-06-28 13:28:11 +02:00
Uwe Kleine-König
ad5e085c63 pwm: Drop irrelevant error path from pwmchip_remove()
Since the PWM core uses device links (commit b2c200e3f2 ("pwm: Add
consumer device link")) each consumer driver that requested the PWMs is
already gone. If they called pwm_put() (as they should) the
PWMF_REQUESTED bit is not set. If they failed (which is a bug) the
PWMF_REQUESTED bit might still be set, but the driver that cared is
gone, so nothing bad happens if the PWM chip goes away even if the
PWMF_REQUESTED is still present.

So the check can be dropped.

With this change pwmchip_remove() returns always 0, so lowlevel drivers
don't need to check the return code any more. Once all drivers dropped
this check this function can be changed to return void.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2021-06-28 13:27:01 +02:00
Uwe Kleine-König
66a03c4fd9 pwm: crc: Simplify using devm_pwmchip_add()
With devm_pwmchip_add() we can drop pwmchip_remove() from the device
remove callback. The latter can then go away, too and as this is the
only user of platform_get_drvdata(), the respective call to
platform_set_drvdata() can go, too.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2021-06-28 13:25:04 +02:00
Uwe Kleine-König
f7edeb4023 pwm: imx1: Simplify using devm_pwmchip_add()
With devm_pwmchip_add() we can drop pwmchip_remove() from the device
remove callback. The latter can then go away, too and as this is the
only user of platform_get_drvdata(), the respective call to
platform_set_drvdata() can go, too.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2021-06-28 13:24:45 +02:00
Uwe Kleine-König
1bc6ea31cb pwm: imx1: Don't disable clocks at device remove time
The .remove() callback disables clocks that were not enabled in
.probe(). So just probing and then unbinding the driver results in a clk
enable imbalance.

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>
2021-06-28 13:24:25 +02:00
Uwe Kleine-König
9c6a02e6d5 pwm: clps711x: Simplify using devm_pwmchip_add()
With devm_pwmchip_add() we can drop pwmchip_remove() from the device
remove callback. The latter can then go away, too and as this is the
only user of platform_get_drvdata(), the respective call to
platform_set_drvdata() can go, too.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2021-06-28 13:23:11 +02:00
Uwe Kleine-König
f41227eb8f pwm: meson: Simplify using devm_pwmchip_add()
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2021-06-28 13:22:07 +02:00
Uwe Kleine-König
d1e487b7a3 pwm: lpss: Simplify using devm_pwmchip_add()
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2021-06-28 13:18:25 +02:00
Uwe Kleine-König
bcda91bf86 pwm: Add a device-managed function to add PWM chips
This potentially simplifies low-level PWM drivers.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2021-06-28 13:17:48 +02:00
Clemens Gruber
79dd354fe1 pwm: pca9685: Add error messages for failed regmap calls
Regmap operations can fail if the underlying subsystem is not working
properly (e.g. hogged I2C bus, etc.)
As this is useful information for the user, print an error message if it
happens.
Let probe fail if the first regmap_read or the first regmap_write fails.

Signed-off-by: Clemens Gruber <clemens.gruber@pqgruber.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2021-06-04 11:43:54 +02:00
Clemens Gruber
6d6e705027 pwm: pca9685: Restrict period change for enabled PWMs
Previously, the last used PWM channel could change the global prescale
setting, even if other channels are already in use.

Fix it by only allowing the first enabled PWM to change the global
chip-wide prescale setting. If there is more than one channel in use,
the prescale settings resulting from the chosen periods must match.

GPIOs do not count as enabled PWMs as they are not using the prescaler
and can't change it.

Signed-off-by: Clemens Gruber <clemens.gruber@pqgruber.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2021-06-04 11:43:53 +02:00
Clemens Gruber
ae16db1fd3 pwm: pca9685: Support new usage_power setting in PWM state
If usage_power is set, the pca9685 driver will phase shift the
individual channels relative to their channel number. This improves EMI
because the enabled channels no longer turn on at the same time, while
still maintaining the configured duty cycle / power output.

Signed-off-by: Clemens Gruber <clemens.gruber@pqgruber.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2021-06-04 11:43:52 +02:00
Clemens Gruber
9e40ee18a1 pwm: core: Support new usage_power setting in PWM state
If usage_power is set, the PWM driver is only required to maintain
the power output but has more freedom regarding signal form.

If supported, the signal can be optimized, for example to
improve EMI by phase shifting individual channels.

Signed-off-by: Clemens Gruber <clemens.gruber@pqgruber.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2021-06-04 11:43:52 +02:00
Uwe Kleine-König
98761ce4b9 pwm: spear: Implement .apply() callback
Just using the previous callbacks to implment a similar procedure as the
legacy handling in the core.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2021-05-25 18:43:10 +02:00
Uwe Kleine-König
da0dea8912 pwm: spear: Free resources only after pwmchip_remove()
Before pwmchip_remove() returns the PWM is expected to be functional. So
remove the pwmchip before disabling the clocks. The check for
pwmchip_remove()'s return value is dropped as this function returns
effectively always 0 and returning an error in a remove callback is
useless anyhow (as the device core ignores it and drops devm allocated
resources).

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2021-05-25 18:42:54 +02:00
Uwe Kleine-König
b601a18f12 pwm: spear: Don't modify HW state in .remove callback
A consumer is expected to disable a PWM before calling pwm_put(). And if
they didn't there is hopefully a good reason (or the consumer needs
fixing). Also if disabling an enabled PWM was the right thing to do,
this should better be done in the framework instead of in each low level
driver.

So drop the hardware modification from the .remove() callback.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2021-05-25 18:42:25 +02:00
Uwe Kleine-König
937efa29e7 pwm: visconti: Fix and simplify period calculation
With the original code a request for period = 65536000 ns and period =
32768000 ns yields the same register settings (which results in 32768000
ns) because the value for pwmc0 was miscalculated.

Also simplify using that fls(0) is 0.

Fixes: 721b595744 ("pwm: visconti: Add Toshiba Visconti SoC PWM support")
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: Nobuhiro Iwamatsu <nobuhiro1.iwamatsu@toshiba.co.jp>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2021-05-25 18:29:40 +02:00
Uwe Kleine-König
e9fdf122cf pwm: Simplify all drivers with explicit of_pwm_n_cells = 3
With the previous commit there is no need for the lowlevel driver any
more to specify it it uses two or three cells. So simplify accordingly.

The only non-trival change affects the pwm-rockchip driver: It used to only
support three cells if the hardware supports polarity. Now the default
number depends on the device tree which has to match hardware anyhow
(and if it doesn't the error is just a bit delayed as a PWM handle with
an inverted setting is catched when pwm_apply_state() is called).

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2021-05-25 18:19:15 +02:00
Uwe Kleine-König
69230cfac3 pwm: Autodetect default value for of_pwm_n_cells from device tree
This allows to simplify all drivers that use three pwm-cells.
The only ugly side effect is that if a driver specified of_pwm_n_cells = 2
it suddenly supports device trees that use #pwm-cells = <3>. This however
isn't a bad thing because the driver doesn't need explicit support for
three cells as the core handles all the details. Also there is no such
in-tree driver.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2021-05-25 18:18:25 +02:00
Uwe Kleine-König
5447e78336 pwm: Drop of_pwm_simple_xlate() in favour of of_pwm_xlate_with_flags()
Since the previous commit the latter function can do everything that the
former does. So simplify accordingly.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2021-05-25 18:18:07 +02:00
Uwe Kleine-König
cf38c978cf pwm: Make of_pwm_xlate_with_flags() work with #pwm-cells = <2>
The two functions of_pwm_simple_xlate() and of_pwm_xlate_with_flags()
are quite similar. of_pwm_simple_xlate() only supports two-cell PWM
specifiers while of_pwm_xlate_with_flags() only supports PWM specifiers
with 3 or more cells. The latter can easily be modified to behave
identically to of_pwm_simple_xlate() for two-cell PWM specifiers. This
is implemented here and allows to drop of_pwm_simple_xlate() in the next
commit.

There is a small detail that is different now in the two-cell specifier
case in of_pwm_xlate_with_flags(): pwm->args.polarity is unconditionally
initialized to PWM_POLARITY_NORMAL in the latter. I didn't find a case
where this matters and doing that explicitly is the more robust
approach.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
[thierry.reding@gmail.com: fix up checkpatch warnings]
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2021-05-25 18:13:51 +02:00
Linus Torvalds
7b9df264f0 pwm: Changes for v5.13-rc1
This set of changes adds support for the PWM controller found on Toshiba
 Visconti SoCs and converts a couple of drivers to the atomic API.
 
 There's also a bunch of cleanups and minor fixes across the board.
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Merge tag 'pwm/for-5.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/thierry.reding/linux-pwm

Pull pwm updates from Thierry Reding:
 "This adds support for the PWM controller found on Toshiba Visconti
  SoCs and converts a couple of drivers to the atomic API.

  There's also a bunch of cleanups and minor fixes across the board"

* tag 'pwm/for-5.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/thierry.reding/linux-pwm: (35 commits)
  pwm: Reword docs about pwm_apply_state()
  pwm: atmel: Improve duty cycle calculation in .apply()
  pwm: atmel: Fix duty cycle calculation in .get_state()
  pwm: visconti: Add Toshiba Visconti SoC PWM support
  dt-bindings: pwm: Add bindings for Toshiba Visconti PWM Controller
  arm64: dts: rockchip: Remove clock-names from PWM nodes
  ARM: dts: rockchip: Remove clock-names from PWM nodes
  dt-bindings: pwm: rockchip: Add more compatible strings
  dt-bindings: pwm: Convert pwm-rockchip.txt to YAML
  pwm: mediatek: Remove unused function
  pwm: pca9685: Improve runtime PM behavior
  pwm: pca9685: Support hardware readout
  pwm: pca9685: Switch to atomic API
  pwm: lpss: Don't modify HW state in .remove callback
  pwm: sti: Free resources only after pwmchip_remove()
  pwm: sti: Don't modify HW state in .remove callback
  pwm: lpc3200: Don't modify HW state in .remove callback
  pwm: lpc18xx-sct: Free resources only after pwmchip_remove()
  pwm: bcm-kona: Don't modify HW state in .remove callback
  pwm: bcm2835: Free resources only after pwmchip_remove()
  ...
2021-05-05 12:53:16 -07:00
Linus Torvalds
71a5cc28e8 - Core Frameworks
- Add support for Software Nodes to MFD Core
    - Remove support for Device Properties from MFD Core
    - Use standard APIs in MFD Core
 
  - New Drivers
    - Add support for ROHM BD9576MUF and BD9573MUF PMICs
    - Add support for Netronix Embedded Controller, PWM and RTC
    - Add support for Actions Semi ATC260x PMICs and OnKey
 
  - New Device Support
    - Add support for DG1 PCIe Graphics Card to Intel PMT
    - Add support for ROHM BD71815 PMIC to ROHM BD71828
    - Add support for Tolino Shine 2 HD to Netronix Embedded Controller
    - Add support for AX10 BMC Secure Updates to Intel M10 BMC
 
  - Removed Device Support
    - Remove Arizona Extcon support from MFD
    - Remove ST-E AB8500 Power Supply code from MFD
    - Remove AB3100 altogether
 
  - New Functionality
    - Add support for SMBus and I2C modes to Dialog DA9063
    - Switch to using Software Nodes in Intel (various)
 
  - New/converted Device Tree bindings; rohm,bd71815-pmic, rohm,bd9576-pmic,
                                        netronix,ntxec, actions,atc260x,
 				       ricoh,rn5t618, qcom-pm8xxx
 
 - Fix-ups
    - Fix error handling/path; intel_pmt
    - Simplify code; rohm-bd718x7, ab8500-core, intel-m10-bmc
    - Trivial clean-ups (reordering, spelling); rohm-generic, rn5t618, max8997
    - Use correct data-type; db8500-prcmu
    - Remove superfluous code; lp87565, intel_quark_i2c_gpi, lpc_sch, twl
    - Use generic APIs/defines; lm3533-core, intel_quark_i2c_gpio
    - Regmap related fix-ups; intel-m10-bmc, sec-core
    - Reorder resource freeing during remove; intel_quark_i2c_gpio
    - Make table indexing more robust; intel_quark_i2c_gpio
    - Fix reference imbalances; arizona-irq
    - Staticify and (un)constify things; arizona-spi, stmpe, ene-kb3930,
                                         intel-lpss-acpi, intel-lpss-pci,
                                         atc260x-i2c, intel_quark_i2c_gpio
 
  - Bug Fixes
    - Fix incorrect (register) values; intel-m10-bmc
    - Kconfig related fixes; ABX500_CORE
    - Do not clear the Auto Reload Register; stm32-timers
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Merge tag 'mfd-next-5.13' of git://git.kernel.org/pub/scm/linux/kernel/git/lee/mfd

Pull MFD updates from Lee Jones:
 "Core Framework:
   - Add support for Software Nodes to MFD Core
   - Remove support for Device Properties from MFD Core
   - Use standard APIs in MFD Core

  New Drivers:
   - Add support for ROHM BD9576MUF and BD9573MUF PMICs
   - Add support for Netronix Embedded Controller, PWM and RTC
   - Add support for Actions Semi ATC260x PMICs and OnKey

  New Device Support:
   - Add support for DG1 PCIe Graphics Card to Intel PMT
   - Add support for ROHM BD71815 PMIC to ROHM BD71828
   - Add support for Tolino Shine 2 HD to Netronix Embedded Controller
   - Add support for AX10 BMC Secure Updates to Intel M10 BMC

  Removed Device Support:
   - Remove Arizona Extcon support from MFD
   - Remove ST-E AB8500 Power Supply code from MFD
   - Remove AB3100 altogether

  New Functionality:
   - Add support for SMBus and I2C modes to Dialog DA9063
   - Switch to using Software Nodes in Intel (various)

  New/converted Device Tree bindings:
   - rohm bd71815-pmic, rohm bd9576-pmic, netronix ntxec, actions
     atc260x, ricoh rn5t618, qcom pm8xxx

- Fix-ups:
   - Fix error handling/path; intel_pmt
   - Simplify code; rohm-bd718x7, ab8500-core, intel-m10-bmc
   - Trivial clean-ups (reordering, spelling); rohm-generic, rn5t618,
     max8997
   - Use correct data-type; db8500-prcmu
   - Remove superfluous code; lp87565, intel_quark_i2c_gpi, lpc_sch, twl
   - Use generic APIs/defines; lm3533-core, intel_quark_i2c_gpio
   - Regmap related fix-ups; intel-m10-bmc, sec-core
   - Reorder resource freeing during remove; intel_quark_i2c_gpio
   - Make table indexing more robust; intel_quark_i2c_gpio
   - Fix reference imbalances; arizona-irq
   - Staticify and (un)constify things; arizona-spi, stmpe, ene-kb3930,
     intel-lpss-acpi, intel-lpss-pci, atc260x-i2c, intel_quark_i2c_gpio

  Bug Fixes:
   - Fix incorrect (register) values; intel-m10-bmc
   - Kconfig related fixes; ABX500_CORE
   - Do not clear the Auto Reload Register; stm32-timers"

* tag 'mfd-next-5.13' of git://git.kernel.org/pub/scm/linux/kernel/git/lee/mfd: (84 commits)
  mfd: intel-m10-bmc: Add support for MAX10 BMC Secure Updates
  Revert "mfd: max8997: Add of_compatible to Extcon and Charger mfd_cell"
  mfd: twl: Remove unused inline function twl4030charger_usb_en()
  dt-bindings: mfd: Convert pm8xxx bindings to yaml
  dt-bindings: mfd: Add compatible for pmk8350 rtc
  i2c: designware: Get rid of legacy platform data
  mfd: intel_quark_i2c_gpio: Convert I²C to use software nodes
  mfd: lpc_sch: Partially revert "Add support for Intel Quark X1000"
  mfd: arizona: Fix rumtime PM imbalance on error
  mfd: max8997: Replace 8998 with 8997
  mfd: core: Use acpi_find_child_device() for child devices lookup
  mfd: intel_quark_i2c_gpio: Don't play dirty trick with const
  mfd: intel_quark_i2c_gpio: Enable MSI interrupt
  mfd: intel_quark_i2c_gpio: Reuse BAR definitions for MFD cell indexing
  mfd: ntxec: Support for EC in Tolino Shine 2 HD
  mfd: stm32-timers: Avoid clearing auto reload register
  mfd: intel_quark_i2c_gpio: Replace I²C speeds with descriptive definitions
  mfd: intel_quark_i2c_gpio: Remove unused struct device member
  mfd: intel_quark_i2c_gpio: Unregister resources in reversed order
  mfd: Kconfig: ABX500_CORE should depend on ARCH_U8500
  ...
2021-04-28 15:59:13 -07:00
Uwe Kleine-König
8035e6c66a pwm: atmel: Improve duty cycle calculation in .apply()
In the calculation of the register value determining the duty cycle the
requested period is used instead of the actually implemented period which
results in suboptimal settings.

The following example assumes an input clock of 133333333 Hz on one of
the SoCs with 16 bit period.

When the following state is to be applied:

        .period = 414727681
        .duty_cycle = 652806

the following register values used to be  calculated:

        PRES = 10
        CPRD = 54000
        CDTY = 53916

which yields an actual duty cycle of a bit more than 645120 ns.

The setting

        PRES = 10
        CPRD = 54000
        CDTY = 53915

however yields a duty of 652800 ns which is between the current result
and the requested value and so is a better approximation.

The reason for this error is that for the calculation of CDTY the
requested period was used instead of the actually implemented one.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2021-04-23 19:05:31 +02:00
Uwe Kleine-König
453e8b3d8e pwm: atmel: Fix duty cycle calculation in .get_state()
The CDTY register contains the number of inactive cycles. .apply() does
this correctly, however .get_state() got this wrong.

Fixes: 651b510a74 ("pwm: atmel: Implement .get_state()")
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2021-04-23 19:05:31 +02:00
Nobuhiro Iwamatsu
721b595744 pwm: visconti: Add Toshiba Visconti SoC PWM support
Add driver for the PWM controller on Toshiba Visconti ARM SoC.

Signed-off-by: Nobuhiro Iwamatsu <nobuhiro1.iwamatsu@toshiba.co.jp>
Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
[thierry.reding@gmail.com: fix up a couple of checkpatch warnings]
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2021-04-23 19:05:13 +02:00
Jiapeng Chong
0b638f5032 pwm: mediatek: Remove unused function
Fix the following clang warning:

drivers/pwm/pwm-mediatek.c:110:19: warning: unused function
'pwm_mediatek_readl' [-Wunused-function].

Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Signed-off-by: Jiapeng Chong <jiapeng.chong@linux.alibaba.com>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2021-04-23 18:47:45 +02:00
Clemens Gruber
9e6fd830ab pwm: pca9685: Improve runtime PM behavior
The chip does not come out of POR in active state but in sleep state.
To be sure (in case the bootloader woke it up) we force it to sleep in
probe.

If runtime PM is disabled, we instead wake the chip in .probe and put it
to sleep in .remove.

Signed-off-by: Clemens Gruber <clemens.gruber@pqgruber.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2021-04-23 18:45:49 +02:00
Clemens Gruber
8f4768a56b pwm: pca9685: Support hardware readout
Implement .get_state to read-out the current hardware state.

The hardware readout may return slightly different values than those
that were set in apply due to the limited range of possible prescale and
counter register values.

Also note that although the datasheet mentions 200 Hz as default
frequency when using the internal 25 MHz oscillator, the calculated
period from the default prescaler register setting of 30 is 5079040ns.

Signed-off-by: Clemens Gruber <clemens.gruber@pqgruber.com>
Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2021-04-23 18:45:14 +02:00
Clemens Gruber
9af1fba33b pwm: pca9685: Switch to atomic API
The switch to the atomic API goes hand in hand with a few fixes to
previously experienced issues:
- The duty cycle is no longer lost after disable/enable (previously the
  OFF registers were cleared in disable and the user was required to
  call config to restore the duty cycle settings)
- If one sets a period resulting in the same prescale register value,
  the sleep and write to the register is now skipped
- Previously, only the full ON bit was toggled in GPIO mode (and full
  OFF cleared if set to high), which could result in both full OFF and
  full ON not being set and on=0, off=0, which is not allowed according
  to the datasheet
- The OFF registers were reset to 0 in probe, which could lead to the
  forbidden on=0, off=0. Fixed by resetting to POR default (full OFF)

Signed-off-by: Clemens Gruber <clemens.gruber@pqgruber.com>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2021-04-23 18:44:55 +02:00
Uwe Kleine-König
64d7d074ac pwm: lpss: Don't modify HW state in .remove callback
A consumer is expected to disable a PWM before calling pwm_put(). And if
they didn't there is hopefully a good reason (or the consumer needs
fixing). Also if disabling an enabled PWM was the right thing to do,
this should better be done in the framework instead of in each low level
driver.

So drop the hardware modification from the .remove() callback.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2021-04-09 15:21:18 +02:00
Uwe Kleine-König
0e719e8ca3 pwm: sti: Free resources only after pwmchip_remove()
Before pwmchip_remove() returns the PWM is expected to be functional. So
remove the pwmchip before disabling the clocks.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2021-04-09 14:46:58 +02:00
Uwe Kleine-König
a9ea2e793e pwm: sti: Don't modify HW state in .remove callback
A consumer is expected to disable a PWM before calling pwm_put(). And if
they didn't there is hopefully a good reason (or the consumer needs
fixing). Also if disabling an enabled PWM was the right thing to do,
this should better be done in the framework instead of in each low level
driver.

So drop the hardware modification from the .remove() callback.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2021-04-09 14:46:27 +02:00
Uwe Kleine-König
13ef0414c8 pwm: lpc3200: Don't modify HW state in .remove callback
A consumer is expected to disable a PWM before calling pwm_put(). And if
they didn't there is hopefully a good reason (or the consumer needs
fixing). Also if disabling an enabled PWM was the right thing to do,
this should better be done in the framework instead of in each low level
driver.

So drop the hardware modification from the .remove() callback.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: Vladimir Zapolskiy <vz@mleia.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2021-04-09 14:45:11 +02:00
Uwe Kleine-König
d58a484e7c pwm: lpc18xx-sct: Free resources only after pwmchip_remove()
Before pwmchip_remove() returns the PWM is expected to be functional. So
remove the pwmchip before disabling the clock.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: Vladimir Zapolskiy <vz@mleia.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2021-04-09 14:44:37 +02:00
Uwe Kleine-König
819e82460a pwm: bcm-kona: Don't modify HW state in .remove callback
A consumer is expected to disable a PWM before calling pwm_put(). And if
they didn't there is hopefully a good reason (or the consumer needs
fixing.) Also if disabling an enabled PWM was the right thing to do, this
should better be done in the framework instead of in each low level driver.

So drop the hardware modification from the .remove() callback.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2021-04-09 14:44:12 +02:00
Uwe Kleine-König
3c817469a5 pwm: bcm2835: Free resources only after pwmchip_remove()
Before pwmchip_remove() returns the PWM is expected to be functional. So
remove the pwmchip before disabling the clock.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2021-04-09 14:33:39 +02:00
Uwe Kleine-König
d4ac3917bc pwm: bcm-iproc: Free resources only after pwmchip_remove()
Before pwmchip_remove() returns the PWM is expected to be functional. So
remove the pwmchip before disabling the clock.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2021-04-09 14:33:10 +02:00
Uwe Kleine-König
89c6f31460 pwm: atmel: Free resources only after pwmchip_remove()
Before pwmchip_remove() returns the PWM is expected to be functional. So
remove the pwmchip before disabling the clock.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2021-04-09 14:31:08 +02:00
Nicolas Saenz Julienne
79caa362ea pwm: Add Raspberry Pi Firmware based PWM bus
Adds support to control the PWM bus available in official Raspberry Pi
PoE HAT. Only RPi's co-processor has access to it, so commands have to
be sent through RPi's firmware mailbox interface.

Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: Thierry Reding <thierry.reding@gmail.com>
2021-03-22 17:59:52 +01:00
Uwe Kleine-König
9666cec380 pwm: Drop function pwmchip_add_with_polarity()
pwmchip_add() only calls pwmchip_add_with_polarity() and nothing else. All
other users of pwmchip_add_with_polarity() are gone. So drop
pwmchip_add_with_polarity() and move the code instead to pwmchip_add().

The initial assignment to pwm->state.polarity is dropped. In every correct
usage of the PWM API this value is overwritten later anyhow.

Signed-off-by: Uwe Kleine-König <uwe@kleine-koenig.org>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2021-03-22 12:31:32 +01:00
Uwe Kleine-König
965ebe39c9 pwm: atmel-hlcdc: Use pwmchip_add() instead of pwmchip_add_with_polarity()
The only side effect of this change is that pwm->state.polarity is
initialized to PWM_POLARITY_NORMAL instead of PWM_POLARITY_INVERSED.
However all other members of pwm->state are uninitialized and consumers
are expected to provide the right polarity (either by setting it explicitly
or by using a helper like pwm_init_state() that overwrites .polarity
anyhow with a value independent of the initial value).

Signed-off-by: Uwe Kleine-König <uwe@kleine-koenig.org>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2021-03-22 12:19:08 +01:00
Uwe Kleine-König
fc423f29f7 pwm: bcm-kona: Use pwmchip_add() instead of pwmchip_add_with_polarity()
The only side effect of this change is that pwm->state.polarity is
initialized to PWM_POLARITY_NORMAL instead of PWM_POLARITY_INVERSED.
However all other members of pwm->state are uninitialized and consumers
are expected to provide the right polarity (either by setting it explicitly
or by using a helper like pwm_init_state() that overwrites .polarity
anyhow with a value independent of the initial value).

The eventual goal is to remove pwmchip_add_with_polarity() and so simplify
the data flow in the PWM core.

Signed-off-by: Uwe Kleine-König <uwe@kleine-koenig.org>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2021-03-22 12:18:54 +01:00
Uwe Kleine-König
9f0f6107e0 pwm: cros-ec: Refuse requests with unsupported polarity
The driver only supports normal polarity and so should refuse requests
for inversed polarity.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2021-03-22 12:08:06 +01:00
Uwe Kleine-König
09081c9ba6 pwm: sprd: Refuse requests with unsupported polarity
The driver only supports normal polarity and so should refuse requests
for inversed polarity.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: Chunyan Zhang <zhang.lyra@gmail.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2021-03-22 12:07:26 +01:00
Uwe Kleine-König
c77e99f434 pwm: atmel-tcb: Only free resources after pwm_chip_remove() returned
Otherwise the PWM stops working before the PWM core and its consumers
are aware the device is going away.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2021-03-22 12:06:45 +01:00
Uwe Kleine-König
30882cf130 pwm: atmel-tcb: Implement .apply callback
This is just pushing down the core's compat code down into the driver using
the legacy callback nearly unchanged. The call to .enable() was just
dropped from .config() because .apply() calls it unconditionally.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2021-03-22 12:06:26 +01:00
Uwe Kleine-König
d58cb0ee51 pwm: Return -EINVAL for old-style drivers without .set_polarity callback
Since commit 2b1c1a5d51 ("pwm: Use -EINVAL for unsupported polarity")
all drivers implementing the apply callback are unified to return
-EINVAL if an unsupported polarity is requested. Do the same in the
compat code for old-style drivers.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2021-03-22 11:55:20 +01:00
Uwe Kleine-König
f9a8ee8c8b pwm: Always allocate PWM chip base ID dynamically
Since commit 5e5da1e9fb ("pwm: ab8500: Explicitly allocate pwm chip
base dynamically") all drivers use dynamic ID allocation explicitly. New
drivers are supposed to do the same, so remove support for driver
specified base IDs and drop all assignments in the low-level drivers.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2021-03-22 11:53:00 +01:00
Fabio Estevam
5a43c201c9 pwm: imx-tpm: Use a single line for error message
There is no need to split the dev_err() call in three lines.

Use a single line to improve readability.

Signed-off-by: Fabio Estevam <festevam@gmail.com>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2021-03-22 11:49:46 +01:00
Uwe Kleine-König
acf3402d83 pwm: ab8500: Implement .apply instead of .config, .enable and .disable
To eventually get rid of all legacy drivers convert this driver to the
modern world implementing .apply().

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2021-03-22 11:48:49 +01:00
Uwe Kleine-König
ca0d2fb790 pwm: bcm2835: Improve period and duty cycle calculation
With an input clk rate bigger than 2000000000, scaler would have been
zero which then would have resulted in a division by zero.

Also the originally implemented algorithm divided by the result of a
division. This nearly always looses precision. Consider a requested period
of 1000000 ns. With an input clock frequency of 32786885 Hz the hardware
was configured with an actual period of 983869.007 ns (PERIOD = 32258)
while the hardware can provide 1000003.508 ns (PERIOD = 32787).
And note if the input clock frequency was 32786886 Hz instead, the hardware
was configured to 1016656.477 ns (PERIOD = 33333) while the optimal
setting results in 1000003.477 ns (PERIOD = 32787).

This patch implements proper range checking and only divides once for
the calculation of period (and similar for duty_cycle).

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reviewed-by: Lino Sanfilippo <LinoSanfilippo@gmx.de>
Tested-by: Lino Sanfilippo <LinoSanfilippo@gmx.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2021-03-22 11:48:07 +01:00
Jonathan Neuschäfer
9fc0486f94 pwm: ntxec: Add driver for PWM function in Netronix EC
The Netronix EC provides a PWM output which is used for the backlight
on some ebook readers. This patches adds a driver for the PWM output.

The .get_state callback is not implemented, because the PWM state can't
be read back from the hardware.

Signed-off-by: Jonathan Neuschäfer <j.neuschaefer@gmx.net>
Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: Thierry Reding <thierry.reding@gmail.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
2021-03-10 11:06:30 +00:00
Linus Torvalds
2c87f7a38f pwm: Changes for v5.12-rc1
The ZTE ZX platform is being removed, so the PWM driver is no longer
 needed and removed as well. Other than that this contains a small set of
 fixes and cleanups across a couple of drivers.
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Merge tag 'pwm/for-5.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/thierry.reding/linux-pwm

Pull pwm updates from Thierry Reding:
 "The ZTE ZX platform is being removed, so the PWM driver is no longer
  needed and removed as well.

  Other than that this contains a small set of fixes and cleanups across
  a couple of drivers"

* tag 'pwm/for-5.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/thierry.reding/linux-pwm:
  pwm: lpc18xx-sct: remove unneeded semicolon
  pwm: iqs620a: Correct a stale state variable
  pwm: iqs620a: Fix overflow and optimize calculations
  pwm: rockchip: Enable clock before calling clk_get_rate()
  pwm: rockchip: Eliminate potential race condition when probing
  pwm: rockchip: Replace "bus clk" with "PWM clk"
  pwm: rockchip: rockchip_pwm_probe(): Remove superfluous clk_unprepare()
  pwm: rockchip: Enable APB clock during register access while probing
  pwm: Remove ZTE ZX driver
2021-02-25 12:23:49 -08:00
Yang Li
9a9dd7e473 pwm: lpc18xx-sct: remove unneeded semicolon
Eliminate the following coccicheck warning:
./drivers/pwm/pwm-lpc18xx-sct.c:292:2-3: Unneeded semicolon

Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Signed-off-by: Yang Li <yang.lee@linux.alibaba.com>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: Vladimir Zapolskiy <vz@mleia.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2021-02-22 15:20:43 +01:00
Jeff LaBundy
28208c7b4a pwm: iqs620a: Correct a stale state variable
If duty cycle is first set to a value that is sufficiently high to
enable the output (e.g. 10000 ns) but then lowered to a value that
is quantized to zero (e.g. 1000 ns), the output is disabled as the
device cannot drive a constant zero (as expected).

However if the device is later re-initialized due to watchdog bite,
the output is re-enabled at the next-to-last duty cycle (10000 ns).
This is because the iqs620_pwm->out_en flag unconditionally tracks
state->enabled instead of what was actually written to the device.

To solve this problem, use one state variable that encodes all 257
states of the output (duty_scale) with 0 representing tri-state, 1
representing the minimum available duty cycle and 256 representing
100% duty cycle.

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>
2021-02-22 15:18:50 +01:00
Uwe Kleine-König
72d6b2459d pwm: iqs620a: Fix overflow and optimize calculations
If state->duty_cycle is 0x100000000000000, the previous calculation of
duty_scale overflows and yields a duty cycle ratio of 0% instead of
100%. Fix this by clamping the requested duty cycle to the maximal
possible duty cycle first. This way it is possible to use a native
integer division instead of a (depending on the architecture) more
expensive 64bit division.

With this change in place duty_scale cannot be bigger than 256 which
allows to simplify the calculation of duty_val.

Fixes: 6f0841a819 ("pwm: Add support for Azoteq IQS620A PWM generator")
Tested-by: Jeff LaBundy <jeff@labundy.com>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2021-02-22 15:18:36 +01:00
Simon South
11be938ae0 pwm: rockchip: Enable clock before calling clk_get_rate()
The documentation for clk_get_rate() in include/linux/clk.h states the
function's result is valid only for a clock source that has been
enabled. However, the Rockchip PWM driver uses this function in two places
to query the rate of a clock without first ensuring it is enabled.

Fix this by modifying rockchip_pwm_get_state() and rockchip_pwm_apply() so
they enable a device's PWM clock before querying its rate (in the latter
case, the querying is actually done in rockchip_pwm_config()) and disable
the clock again before returning.

Reported-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Simon South <simon@simonsouth.net>
Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2021-01-20 18:13:32 +01:00
Simon South
d21ba5d621 pwm: rockchip: Eliminate potential race condition when probing
Commit 48cf973cae ("pwm: rockchip: Avoid glitches on already running
PWMs") introduced a potential race condition in rockchip_pwm_probe(): A
consumer could enable an inactive PWM, or disable a running one, between
rockchip_pwm_probe() registering the device via pwmchip_add() and checking
whether it is enabled (to determine whether it was started by a
bootloader). This could result in a device's PWM clock being either enabled
once more than necessary, potentially causing it to continue running when
no longer needed, or disabled once more than necessary, producing a warning
from the kernel.

Eliminate these possibilities by modifying rockchip_pwm_probe() so it
checks whether a device is enabled before registering it rather than after.

Fixes: 48cf973cae ("pwm: rockchip: Avoid glitches on already running PWMs")
Reported-by: Trent Piepho <tpiepho@gmail.com>
Signed-off-by: Simon South <simon@simonsouth.net>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2021-01-20 18:13:15 +01:00
Simon South
c9f809d0db pwm: rockchip: Replace "bus clk" with "PWM clk"
Clarify the Rockchip PWM driver's error messages by referring to the clock
that operates a PWM device as the "PWM" clock, matching its name in the
device tree, rather than the "bus" clock (which is especially misleading in
the case of devices that also use a separate clock for bus access).

Suggested-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Simon South <simon@simonsouth.net>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2021-01-20 18:12:59 +01:00
Simon South
d5d8d67586 pwm: rockchip: rockchip_pwm_probe(): Remove superfluous clk_unprepare()
If rockchip_pwm_probe() fails to register a PWM device it calls
clk_unprepare() for the device's PWM clock, without having first disabled
the clock and before jumping to an error handler that also unprepares
it. This is likely to produce warnings from the kernel about the clock
being unprepared when it is still enabled, and then being unprepared when
it has already been unprepared.

Prevent these warnings by removing this unnecessary call to
clk_unprepare().

Fixes: 48cf973cae ("pwm: rockchip: Avoid glitches on already running PWMs")
Signed-off-by: Simon South <simon@simonsouth.net>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2021-01-20 18:12:46 +01:00
Simon South
d9b657a5cd pwm: rockchip: Enable APB clock during register access while probing
Commit 457f74abbe ("pwm: rockchip: Keep enabled PWMs running while
probing") modified rockchip_pwm_probe() to access a PWM device's registers
directly to check whether or not the device is enabled, but did not also
change the function so it first enables the device's APB clock to be
certain the device can respond. This risks hanging the kernel on systems
with PWM devices that use more than a single clock.

Avoid this by enabling the device's APB clock before accessing its
registers (and disabling the clock when register access is complete).

Fixes: 457f74abbe ("pwm: rockchip: Keep enabled PWMs running while probing")
Reported-by: Thierry Reding <thierry.reding@gmail.com>
Suggested-by: Trent Piepho <tpiepho@gmail.com>
Signed-off-by: Simon South <simon@simonsouth.net>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2021-01-20 18:12:31 +01:00
Arnd Bergmann
a2bc9b21fd pwm: Remove ZTE ZX driver
The ZTE ZX platform is getting removed, so this driver is no longer
needed.

Cc: Jun Nie <jun.nie@linaro.org>
Cc: Shawn Guo <shawnguo@kernel.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2021-01-20 17:16:52 +01:00
Linus Torvalds
d56154c7e8 pwm: Changes for v5.11-rc1
This is a fairly big release cycle from the PWM framework's point of
 view. There's a large patcheset here which converts drivers to use the
 new devm_platform_ioremap_resource() helper and a bunch of minor fixes
 to existing drivers. Some of the existing drivers also add support for
 more hardware, such as Atmel SAMA 5D2 and Mediatek MT8183.
 
 Finally there's a couple of new drivers for Intel Keem Bay and LGM SoCs
 as well as the DesignWare PWM controller.
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Merge tag 'pwm/for-5.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/thierry.reding/linux-pwm

Pull pwm updates from Thierry Reding:
 "This is a fairly big release cycle from the PWM framework's point of
  view.

  There's a large patcheset here which converts drivers to use the new
  devm_platform_ioremap_resource() helper and a bunch of minor fixes to
  existing drivers. Some of the existing drivers also add support for
  more hardware, such as Atmel SAMA 5D2 and Mediatek MT8183.

  Finally there's a couple of new drivers for Intel Keem Bay and LGM
  SoCs as well as the DesignWare PWM controller"

* tag 'pwm/for-5.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/thierry.reding/linux-pwm: (66 commits)
  pwm: sun4i: Remove erroneous else branch
  pwm: sl28cpld: Set driver data before registering the PWM chip
  pwm: Remove unused function pwmchip_add_inversed()
  pwm: imx27: Fix overflow for bigger periods
  pwm: bcm2835: Support apply function for atomic configuration
  pwm: keembay: Fix build failure with -Os
  pwm: core: Use octal permission
  pwm: lpss: Make compilable with COMPILE_TEST
  pwm: Fix dependencies on HAS_IOMEM
  pwm: Use -EINVAL for unsupported polarity
  pwm: sti: Remove unnecessary blank line
  pwm: sti: Avoid conditional gotos
  pwm: Add PWM fan controller driver for LGM SoC
  Add DT bindings YAML schema for PWM fan controller of LGM SoC
  pwm: Add DesignWare PWM Controller Driver
  dt-bindings: pwm: mtk-disp: add MT8167 SoC binding
  pwm: mediatek: Add MT8183 SoC support
  pwm: mediatek: Always use bus clock
  dt-bindings: pwm: pwm-mediatek: Add documentation for MT8183 SoC
  pwm: Add PWM driver for Intel Keem Bay
  ...
2020-12-19 11:51:32 -08:00
Thierry Reding
6eefb79d6f pwm: sun4i: Remove erroneous else branch
Commit d3817a6470 ("pwm: sun4i: Remove redundant needs_delay") changed
the logic of an else branch so that the PWM_EN and PWM_CLK_GATING bits
are now cleared if the PWM is to be disabled, whereas previously the
condition was always false, and hence the branch never got executed.

This code is reported causing backlight issues on boards based on the
Allwinner A20 SoC. Fix this by removing the else branch, which restores
the behaviour prior to the offending commit.

Note that the PWM_EN and PWM_CLK_GATING bits still get cleared later in
sun4i_pwm_apply() if the PWM is to be disabled.

Fixes: d3817a6470 ("pwm: sun4i: Remove redundant needs_delay")
Reported-by: Taras Galchenko <tpgalchenko@gmail.com>
Suggested-by: Taras Galchenko <tpgalchenko@gmail.com>
Tested-by: Taras Galchenko <tpgalchenko@gmail.com>
Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2020-12-17 14:23:49 +01:00
Thierry Reding
edf7f80e78 pwm: sl28cpld: Set driver data before registering the PWM chip
It is good practice to set the driver data before registering a device
with a subsystem because the subsystem or the driver core may call back
into the driver implementation. This is not currently an issue, but to
prevent future changes from causing this to break unexpectedly, make
sure that the driver data is set before the PWM chip registration.

Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2020-12-17 14:19:02 +01:00
Uwe Kleine-König
1ce65396e6 pwm: imx27: Fix overflow for bigger periods
The second parameter of do_div is an u32 and NSEC_PER_SEC * prescale
overflows this for bigger periods. Assuming the usual pwm input clk rate
of 66 MHz this happens starting at requested period > 606060 ns.

Splitting the division into two operations doesn't loose any precision.
It doesn't need to be feared that c / NSEC_PER_SEC doesn't fit into the
unsigned long variable "duty_cycles" because in this case the assignment
above to period_cycles would already have been overflowing as
period >= duty_cycle and then the calculation is moot anyhow.

Fixes: aef1a3799b ("pwm: imx27: Fix rounding behavior")
Signed-off-by: Uwe Kleine-König <uwe@kleine-koenig.org>
Tested-by: Johannes Pointner <johannes.pointner@br-automation.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2020-12-17 14:19:01 +01:00
Lino Sanfilippo
2f81b51d0d pwm: bcm2835: Support apply function for atomic configuration
Use the newer .apply function of pwm_ops instead of .config, .enable,
.disable and .set_polarity. This guarantees atomic changes of the pwm
controller configuration. It also reduces the size of the driver.

Since now period is a 64 bit value, add an extra check to reject periods
that exceed the possible max value for the 32 bit register.

This has been tested on a Raspberry PI 4.

Signed-off-by: Lino Sanfilippo <LinoSanfilippo@gmx.de>
Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2020-12-17 14:19:01 +01:00