This function is not supposed to be used any more since commit
c748a6d77c ("pwm: Rename pwm_apply_state() to
pwm_apply_might_sleep()") that is included in v6.8-rc1. Two kernel
releases should be enough for everyone to adapt, so drop the old
function that was introduced as a compatibility stub for the transition.
Signed-off-by: Uwe Kleine-König <ukleinek@kernel.org>
Define all pwm core's symbols in the namespace "PWM". The necessary
module import statement is just added to the main header, this way every
file that knows about the public functions automatically has this
namespace available.
Thanks to Biju Das for pointing out a cut'n'paste failure in my initial
patch.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@baylibre.com>
Link: https://lore.kernel.org/r/20240607160012.1206874-2-u.kleine-koenig@baylibre.com
Signed-off-by: Uwe Kleine-König <ukleinek@kernel.org>
It's required to not free the memory underlying a requested PWM
while a consumer still has a reference to it. While currently a pwm_chip
doesn't live long enough in all cases, linking the struct pwm to the
pwm_chip results in the right lifetime as soon as the pwmchip is living
long enough. This happens with the following commits.
Note this is a breaking change for all pwm drivers that don't use
pwmchip_alloc().
Reviewed-by: Gustavo A. R. Silva <gustavoars@kernel.org> # for struct_size() and __counted_by()
Link: https://lore.kernel.org/r/7e9e958841f049026c0023b309cc9deecf0ab61d.1710670958.git.u.kleine-koenig@pengutronix.de
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
With the upcoming restructuring having all in a single file simplifies
things a bit. The relevant and somewhat visible changes are:
- Some dropped prototypes from include/linux/pwm.h that were only
necessary that core.c has a declaration of the symbols defined in
sysfs.c. The respective functions are static now.
- The pwm class now also exists if CONFIG_SYSFS isn't enabled. Having
CONFIG_SYSFS is not very relevant today, but even without it the
class and device stuff still provides lifetime tracking.
- Both files had an initcall, these are merged into a single one now.
Instead of a big #ifdef block for CONFIG_DEBUG_FS, a single
if (IS_ENABLED(CONFIG_DEBUG_FS)) is used now. This increases compile
coverage a bit and is a tad nicer on the eyes.
Link: https://lore.kernel.org/r/9e2d39a5280d7dda5bfc6682a8aef510148635b2.1710670958.git.u.kleine-koenig@pengutronix.de
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
This function allocates a struct pwm_chip and driver data. Compared to
the status quo the split into pwm_chip and driver data is new, otherwise
it doesn't change anything relevant (yet).
The intention is that after all drivers are switched to use this
allocation function, its possible to add a struct device to struct
pwm_chip to properly track the latter's lifetime without touching all
drivers again. Proper lifetime tracking is a necessary precondition to
introduce character device support for PWMs (that implements atomic
setting and doesn't suffer from the sysfs overhead of the /sys/class/pwm
userspace support).
The new function pwmchip_priv() (obviously?) only works for chips
allocated with pwmchip_alloc().
Link: https://lore.kernel.org/r/9577d6053a5a52536057dc8654ff567181c2da82.1707900770.git.u.kleine-koenig@pengutronix.de
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Currently a pwm_chip stores in its struct device *dev member a pointer
to the parent device. Preparing a change that embeds a full struct
device in struct pwm_chip, this accessor function should be used in all
drivers directly accessing chip->dev now. This way struct pwm_chip and
this new function can be changed without having to touch all drivers in
the same change set.
Make use of this function in the framework's core sources.
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/r/cc30090d2f9762bed9854a55612144bccc910781.1707900770.git.u.kleine-koenig@pengutronix.de
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
In order to make the transition to the new pwm_apply_might_sleep() a bit
smoother, add a compatibility stub. This will prevent new calls to the
old function introduced via other subsystems from breaking builds. Once
the next merge window has closed we can take another stab at removing
the stub.
Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
These functions are unused. Also I think there is no valid use case
where these are correct to be called. So drop them.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
Some PWM devices require sleeping, for example if the pwm device is
connected over I2C. However, many PWM devices could be used from atomic
context, e.g. memory mapped PWM. This is useful for, for example, the
pwm-ir-tx driver which requires precise timing. Sleeping causes havoc
with the generated IR signal.
Since not all PWM devices can support atomic context, we also add a
pwm_might_sleep() function to check if is not supported.
Signed-off-by: Sean Young <sean@mess.org>
Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
According to Documentation/dev-tools/checkpatch.rst ENOTSUPP is
not recommended and EOPNOTSUPP should be used instead.
Signed-off-by: Sean Young <sean@mess.org>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
In order to introduce a pwm api which can be used from atomic context,
we will need two functions for applying pwm changes:
int pwm_apply_might_sleep(struct pwm *, struct pwm_state *);
int pwm_apply_atomic(struct pwm *, struct pwm_state *);
This commit just deals with renaming pwm_apply_state(), a following
commit will introduce the pwm_apply_atomic() function.
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: Guenter Roeck <linux@roeck-us.net>
Acked-by: Mark Brown <broonie@kernel.org>
Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> # for input
Acked-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Jani Nikula <jani.nikula@intel.com>
Acked-by: Lee Jones <lee@kernel.org>
Signed-off-by: Sean Young <sean@mess.org>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
Commit c572f3b9c8b7 ("pwm: Replace PWM chip unique base by unique ID")
changed the members of struct pwm_chip, but failed to update the
documentation accordingly. Catch up and document the new member and drop
description for the two removed ones.
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
Traditionally each PWM device had a unique ID stored in the "pwm" member
of struct pwm_device. However this number was hardly used and dropped
in the previous commit. To identify a certain PWM you're supposed to use
the chip's ID and the hwpwm of the PWM device now.
With the PWM chip base gone PWM chips can get their IDs better and
simpler using an idr.
This is expected to change the numbering of PWM chips, but nothing
should rely on the numbering anyhow.
Other than that the side effects are:
- The PWM chip IDs are smaller and in most cases consecutive.
- The ordering in /sys/kernel/debug/pwm is ordered by ascending PWM
chip ID.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
These enums are passed to set/test_bit(). The set/test_bit() functions
take a bit number instead of a shifted value. Passing a shifted value
is a double shift bug like doing BIT(BIT(1)). The double shift bug
doesn't cause a problem here because we are only checking 0 and 1 but
if the value was 5 or above then it can lead to a buffer overflow.
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reviewed-by: Sam Protsenko <semen.protsenko@linaro.org>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
Most variables of type struct pwm_chip * are named "chip", there are
only three outliers called "pc". Change these three to "chip", too, for
consistency.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
Since commit 5a7fbe452a ("backlight: pwm_bl: Drop support for legacy PWM
probing") the last user of pwm_request() and pwm_free() is gone. So remove
these functions that were deprecated over 10 years ago in commit
8138d2ddbc ("pwm: Add table-based lookup for static mappings").
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
[thierry.reding@gmail.com: clean up a bit after removal]
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
Pull pwm updates from Thierry Reding:
"Various changes across the board, mostly improvements and cleanups"
* tag 'pwm/for-6.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/thierry.reding/linux-pwm: (42 commits)
pwm: pca9685: Convert to i2c's .probe_new()
pwm: sun4i: Propagate errors in .get_state() to the caller
pwm: Handle .get_state() failures
pwm: sprd: Propagate errors in .get_state() to the caller
pwm: rockchip: Propagate errors in .get_state() to the caller
pwm: mtk-disp: Propagate errors in .get_state() to the caller
pwm: imx27: Propagate errors in .get_state() to the caller
pwm: cros-ec: Propagate errors in .get_state() to the caller
pwm: crc: Propagate errors in .get_state() to the caller
leds: qcom-lpg: Propagate errors in .get_state() to the caller
drm/bridge: ti-sn65dsi86: Propagate errors in .get_state() to the caller
pwm/tracing: Also record trace events for failed API calls
pwm: Make .get_state() callback return an error code
pwm: pxa: Enable for MMP platform
pwm: pxa: Add reference manual link and limitations
pwm: pxa: Use abrupt shutdown mode
pwm: pxa: Remove clk enable/disable from pxa_pwm_config
pwm: pxa: Set duty cycle to 0 when disabling PWM
pwm: pxa: Remove pxa_pwm_enable/disable
pwm: mediatek: Add support for MT7986
...
.get_state() might fail in some cases. To make it possible that a driver
signals such a failure change the prototype of .get_state() to return an
error code.
This patch was created using coccinelle and the following semantic patch:
@p1@
identifier getstatefunc;
identifier driver;
@@
struct pwm_ops driver = {
...,
.get_state = getstatefunc
,...
};
@p2@
identifier p1.getstatefunc;
identifier chip, pwm, state;
@@
-void
+int
getstatefunc(struct pwm_chip *chip, struct pwm_device *pwm, struct pwm_state *state)
{
...
- return;
+ return 0;
...
}
plus the actual change of the prototype in include/linux/pwm.h (plus some
manual fixing of indentions and empty lines).
So for now all drivers return success unconditionally. They are adapted
in the following patches to make the changes easier reviewable.
Reviewed-by: Heiko Stuebner <heiko@sntech.de>
Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Reviewed-by: Tzung-Bi Shih <tzungbi@kernel.org>
Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
Reviewed-by: Nobuhiro Iwamatsu <nobuhiro1.iwamatsu@toshiba.co.jp>
Reviewed-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
Acked-by: Douglas Anderson <dianders@chromium.org>
Acked-by: Jernej Skrabec <jernej.skrabec@gmail.com>
Acked-by: Pavel Machek <pavel@ucw.cz>
Acked-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://lore.kernel.org/r/20221130152148.2769768-2-u.kleine-koenig@pengutronix.de
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
There are no drivers left providing the legacy callbacks. So drop
support for these.
If this commit breaks your out-of-tree pwm driver, look at e.g. commit
ec00cd5e63 ("pwm: renesas-tpu: Implement .apply() callback") for an
example of the needed conversion for your driver.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
At least some implementations sleep. So mark pwm_apply_state() with a
might_sleep() to make callers aware. In the worst case this uncovers a
valid atomic user, then we revert this patch and at least gained some more
knowledge and then can work on a concept similar to
gpio_get_value/gpio_get_value_cansleep.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
The normal implementations of these functions make use of mutexes. To
make it obvious that these functions might sleep also add annotations to
the dummy implementations in the !CONFIG_PWM case.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
Since some time pwmchip_remove() always returns 0 so the return value
isn't usefull. Now that all callers are converted to ignore its value
the 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>
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>
Given that lowlevel drivers usually cannot implement exactly what a
consumer requests with pwm_apply_state() there is some rounding
involved.
pwm_get_state() returns the setting that was requested most recently by
the consumer (opposed to what was actually implemented in hardware in
reply to the last request). Clarify this in the function kerneldoc.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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>
This is only defined with CONFIG_PWM unset and was introduced together
with pwmchip_add_with_polarity() (which is only defined with CONFIG_PWM
enabled). I guess the series that introduced pwmchip_add_with_polarity()
had a different concept in earlier revisions and the !CONFIG_PWM part
was just not updated accordingly.
Given that there is no implementation for pwmchip_add_with_polarity()
without CONFIG_PWM, just drop pwmchip_add_inversed() instead of renaming
it to pwmchip_add_with_polarity().
Signed-off-by: Uwe Kleine-König <uwe@kleine-koenig.org>
Acked-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
Because period and duty cycle are defined as ints with units of
nanoseconds, the maximum time duration that can be set is limited to
~2.147 seconds. Change their definitions to u64 in the structs of the
PWM framework so that higher durations may be set.
Also use the right format specifiers in debug prints in both core.c,
pwm-stm32-lp.c as well as video/fbdev/ssd1307fb.c.
Reported-by: kbuild test robot <lkp@intel.com>
Signed-off-by: Guru Das Srinagesh <gurus@codeaurora.org>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
There are some expectations which the callbacks provided by lowlevel
drivers should fulfill. Implement checks that help driver authors to get
these semantics right. As these have some overhead the checks can be
disabled using a Kconfig setting.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
