This is the exact same thing as the 'alloc_obj()' version, only much
smaller because there are a lot fewer users of the *alloc_flex()
interface.
As with alloc_obj() version, this was done entirely with mindless brute
force, using the same script, except using 'flex' in the pattern rather
than 'objs*'.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This was done entirely with mindless brute force, using
git grep -l '\<k[vmz]*alloc_objs*(.*, GFP_KERNEL)' |
xargs sed -i 's/\(alloc_objs*(.*\), GFP_KERNEL)/\1)/'
to convert the new alloc_obj() users that had a simple GFP_KERNEL
argument to just drop that argument.
Note that due to the extreme simplicity of the scripting, any slightly
more complex cases spread over multiple lines would not be triggered:
they definitely exist, but this covers the vast bulk of the cases, and
the resulting diff is also then easier to check automatically.
For the same reason the 'flex' versions will be done as a separate
conversion.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This is the result of running the Coccinelle script from
scripts/coccinelle/api/kmalloc_objs.cocci. The script is designed to
avoid scalar types (which need careful case-by-case checking), and
instead replace kmalloc-family calls that allocate struct or union
object instances:
Single allocations: kmalloc(sizeof(TYPE), ...)
are replaced with: kmalloc_obj(TYPE, ...)
Array allocations: kmalloc_array(COUNT, sizeof(TYPE), ...)
are replaced with: kmalloc_objs(TYPE, COUNT, ...)
Flex array allocations: kmalloc(struct_size(PTR, FAM, COUNT), ...)
are replaced with: kmalloc_flex(*PTR, FAM, COUNT, ...)
(where TYPE may also be *VAR)
The resulting allocations no longer return "void *", instead returning
"TYPE *".
Signed-off-by: Kees Cook <kees@kernel.org>
copy_to_user() returns the number of bytes not copied, thus if there is
a problem a positive number. However the ioctl callback is supposed to
return a negative error code on error.
This error is a unfortunate as strictly speaking it became ABI with the
introduction of pwm character devices. However I never saw the issue in
real life -- I found this by code inspection -- and it only affects an
error case where readonly memory is passed to the ioctls or the address
mapping changes while the ioctl is active. Also there are already error
cases returning negative values, so the calling code must be prepared to
see such values already.
Fixes: 9c06f26ba5 ("pwm: Add support for pwmchip devices for faster and easier userspace access")
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@baylibre.com>
Link: https://patch.msgid.link/20260119151325.571857-2-u.kleine-koenig@baylibre.com
Signed-off-by: Uwe Kleine-König <ukleinek@kernel.org>
The upcoming Rust abstraction layer for the PWM subsystem uses a custom
`dev->release` handler to safely manage the lifetime of its driver
data.
To prevent leaking the memory of the `struct pwm_chip` (allocated by
`pwmchip_alloc`), this custom handler must also call the original
`pwmchip_release` function to complete the cleanup.
Make `pwmchip_release` a global, exported function so that it can be
called from the Rust FFI bridge. This involves removing the `static`
keyword, adding a prototype to the public header, and exporting the
symbol.
Reviewed-by: Elle Rhumsaa <elle@weathered-steel.dev>
Signed-off-by: Michal Wilczynski <m.wilczynski@samsung.com>
Link: https://patch.msgid.link/20251016-rust-next-pwm-working-fan-for-sending-v16-1-a5df2405d2bd@samsung.com
Signed-off-by: Uwe Kleine-König <ukleinek@kernel.org>
A PWM is a more general concept than an output-only GPIO. When using
duty_length = period_length the PWM looks like an active GPIO, with
duty_length = 0 like an inactive GPIO. With the waveform abstraction
there is enough control over the configuration to ensure that PWMs that
cannot generate a constant signal at both levels error out.
The pwm-pca9685 driver already provides a gpio chip. When this driver is
converted to the waveform callbacks, the gpio part can just be dropped.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@baylibre.com>
Reviewed-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Link: https://lore.kernel.org/r/20250717151117.1828585-2-u.kleine-koenig@baylibre.com
Signed-off-by: Uwe Kleine-König <ukleinek@kernel.org>
When a PWM is requested to be disabled, the result is unspecified, the only
intention is to save some power. So skip all checks in this case.
All but two checks already only triggered for states with .enabled = true.
The first resulted in some false positive diagnostics, the other checked
for a condition that depending on hardware might not be implementable.
Similar if the lowlevel driver disabled the hardware this might be a valid
reaction and with .enabled = false all other state parameters are
unreliable, so skip further tests in this case, too.
All later usages of .enabled can be assumed to yield true, and so several
if conditions can be simplified.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@baylibre.com>
Link: https://lore.kernel.org/r/16d29212b09b66c286c1232b1ab0ec0f8d510aae.1751994988.git.u.kleine-koenig@baylibre.com
Signed-off-by: Uwe Kleine-König <ukleinek@kernel.org>
The WFHWSIZE constant defines the maximum size for the hardware-specific
waveform representation buffer. It is currently local to
drivers/pwm/core.c, which makes it inaccessible to external tools like
bindgen.
Move the constant to include/linux/pwm.h to make it part of the public
API. As part of this change, rename it to PWM_WFHWSIZE to follow
standard kernel conventions for namespacing macros in public headers.
This allows bindgen to automatically generate a corresponding constant
for the Rust PWM abstractions, ensuring the value remains synchronized
between the C core and Rust code and preventing future maintenance
issues.
Signed-off-by: Michal Wilczynski <m.wilczynski@samsung.com>
Link: https://lore.kernel.org/r/20250702-rust-next-pwm-working-fan-for-sending-v7-1-67ef39ff1d29@samsung.com
Signed-off-by: Uwe Kleine-König <ukleinek@kernel.org>
With this change each pwmchip defining the new-style waveform callbacks
can be accessed from userspace via a character device. Compared to the
sysfs-API this is faster and allows to pass the whole configuration in a
single ioctl allowing atomic application and thus reducing glitches.
On an STM32MP13 I see:
root@DistroKit:~ time pwmtestperf
real 0m 1.27s
user 0m 0.02s
sys 0m 1.21s
root@DistroKit:~ rm /dev/pwmchip0
root@DistroKit:~ time pwmtestperf
real 0m 3.61s
user 0m 0.27s
sys 0m 3.26s
pwmtestperf does essentially:
for i in 0 .. 50000:
pwm_set_waveform(duty_length_ns=i, period_length_ns=50000, duty_offset_ns=0)
and in the presence of /dev/pwmchip0 is uses the ioctls introduced here,
without that device it uses /sys/class/pwm/pwmchip0.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@baylibre.com>
Link: https://lore.kernel.org/r/ad4a4e49ae3f8ea81e23cac1ac12b338c3bf5c5b.1746010245.git.u.kleine-koenig@baylibre.com
Signed-off-by: Uwe Kleine-König <ukleinek@kernel.org>
Commit 9dd42d019e ("pwm: Allow pwm state transitions from an invalid
state") intended to allow some state transitions that were not allowed
before. The idea is sane and back then I also got the code comment
right, but the check for enabled is bogus. This resulted in state
transitions for enabled states to be allowed to have invalid duty/period
settings and thus it can happen that low-level drivers get requests for
invalid states🙄.
Invert the check to allow state transitions for disabled states only.
Fixes: 9dd42d019e ("pwm: Allow pwm state transitions from an invalid state")
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@baylibre.com>
Link: https://lore.kernel.org/r/20250704172416.626433-2-u.kleine-koenig@baylibre.com
Cc: stable@vger.kernel.org
Signed-off-by: Uwe Kleine-König <ukleinek@kernel.org>
While telling the caller of pwm_set_waveform_might_sleep() if the
request was completed by rounding down only or (some) rounding up gives
additional information, it makes usage this function needlessly hard and
the additional information is not used. A prove for that is that
currently both users of this function just pass the returned value up to
their caller even though a positive value isn't intended there.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@baylibre.com>
Link: https://lore.kernel.org/r/528cc3bbd9e35dea8646b1bcc0fbfe6c498bb4ed.1746010245.git.u.kleine-koenig@baylibre.com
Signed-off-by: Uwe Kleine-König <ukleinek@kernel.org>
Waveform parameters are supposed to be rounded down to the next value
possible for the hardware. However when a requested value is too small,
.round_waveform_tohw() is supposed to pick the next bigger value and
return 1. Let pwm_set_waveform() behave in the same way.
This creates consistency between pwm_set_waveform_might_sleep() with
exact=false and pwm_round_waveform_might_sleep() +
pwm_set_waveform_might_sleep() with exact=true.
The PWM_DEBUG rounding check has to be adapted to only trigger if no
uprounding happend.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@baylibre.com>
Tested-by: Trevor Gamblin <tgamblin@baylibre.com>
Link: https://lore.kernel.org/r/353dc6ae31be815e41fd3df89c257127ca0d1a09.1743844730.git.u.kleine-koenig@baylibre.com
Signed-off-by: Uwe Kleine-König <ukleinek@kernel.org>
