diff options
| author | Linus Torvalds <torvalds@linux-foundation.org> | 2025-07-28 23:17:46 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2025-07-28 23:17:46 -0700 |
| commit | f38b7512903a50eaeb300e9c8d9448187dd3959c (patch) | |
| tree | 79e246940ae5352845e5ca116f44fcb5d4943d1a /Documentation/driver-api | |
| parent | 0262163136de813894cb172aa8ccf762b92e5fd7 (diff) | |
| parent | 68b9272ca7ac948b71aba482ef8244dee8032f46 (diff) | |
| download | linux-f38b7512903a50eaeb300e9c8d9448187dd3959c.tar.gz | |
Merge tag 'pwm/for-6.17-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/ukleinek/linux
Pull pwm updates from Uwe Kleine-König:
"Apart from the usual mix of new drivers (pwm-argon-fan-hat), adding
support for variants to existing drivers, minor improvements to both
drivers and docs, device tree documenation updates, the noteworthy
changes are:
- A hwmon companion driver to pwm-mc33xs2410 living in drivers/hwmon
and acked by Guenter Roeck
- chardev support for PWM devices. This leverages atomic PWM updates
to userspace and at the same time simplifies and accelerates PWM
configuration changes"
* tag 'pwm/for-6.17-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/ukleinek/linux: (35 commits)
pwm: raspberrypi-poe: Fix spelling mistake "Firwmware" -> "Firmware"
hwmon: add support for MC33XS2410 hardware monitoring
pwm: mc33xs2410: add hwmon support
pwm: img: Remove redundant pm_runtime_mark_last_busy() calls
pwm: Expose PWM_WFHWSIZE in public header
dt-bindings: pwm: Convert lpc32xx-pwm.txt to yaml format
docs: pwm: Adapt Locking paragraph to reality
pwm: twl-led: Drop driver local locking
pwm: sun4i: Drop driver local locking
pwm: sti: Drop driver local locking
pwm: microchip-core: Drop driver local locking
pwm: lpc18xx-sct: Drop driver local locking
pwm: fsl-ftm: Drop driver local locking
pwm: clps711x: Drop driver local locking
pwm: atmel: Drop driver local locking
pwm: argon-fan-hat: Add Argon40 Fan HAT support
dt-bindings: pwm: argon40,fan-hat: Document Argon40 Fan HAT
dt-bindings: vendor-prefixes: Document Argon40
pwm: pwm-mediatek: Add support for PWM IP V3.0.2 in MT6991/MT8196
pwm: pwm-mediatek: Pass PWM_CK_26M_SEL from platform data
...
Diffstat (limited to 'Documentation/driver-api')
| -rw-r--r-- | Documentation/driver-api/pwm.rst | 13 |
1 files changed, 9 insertions, 4 deletions
diff --git a/Documentation/driver-api/pwm.rst b/Documentation/driver-api/pwm.rst index b41b1c56477f3d..0d27a40f581879 100644 --- a/Documentation/driver-api/pwm.rst +++ b/Documentation/driver-api/pwm.rst @@ -173,10 +173,15 @@ Locking ------- The PWM core list manipulations are protected by a mutex, so pwm_get() -and pwm_put() may not be called from an atomic context. Currently the -PWM core does not enforce any locking to pwm_enable(), pwm_disable() and -pwm_config(), so the calling context is currently driver specific. This -is an issue derived from the former barebone API and should be fixed soon. +and pwm_put() may not be called from an atomic context. +Most functions in the PWM consumer API might sleep and so must not be called +from atomic context. The notable exception is pwm_apply_atomic() which has the +same semantics as pwm_apply_might_sleep() but can be called from atomic context. +(The price for that is that it doesn't work for all PWM devices, use +pwm_might_sleep() to check if a given PWM supports atomic operation. + +Locking in the PWM core ensures that callbacks related to a single chip are +serialized. Helpers ------- |