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author | Linus Torvalds <torvalds@linux-foundation.org> | 2022-06-01 10:49:11 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2022-06-01 10:49:11 -0700 |
commit | 8eca6b0a647aabea3d1d2907dd6245fc436f98e7 (patch) | |
tree | 2741247faff78d81fca6d7337a679c210a7e5a89 /Documentation/driver-api | |
parent | 68e6134bb70ab20e9f7c36c1ae7dc96b8ed778ae (diff) | |
parent | 3d593b6e80ad2c911b5645af28d83eabb96e7c1b (diff) | |
download | linux-stable-8eca6b0a647aabea3d1d2907dd6245fc436f98e7.tar.gz linux-stable-8eca6b0a647aabea3d1d2907dd6245fc436f98e7.tar.bz2 linux-stable-8eca6b0a647aabea3d1d2907dd6245fc436f98e7.zip |
Merge tag 'pwm/for-5.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/thierry.reding/linux-pwm
Pull pwm updates from Thierry Reding:
"Quite a large number of conversions this time around, courtesy of Uwe
who has been working tirelessly on these. No drivers of the legacy API
are left at this point, so as a next step the old API can be removed.
Support is added for a few new devices such as the Xilinx AXI timer-
based PWMs and the PWM IP found on Sunplus SoCs.
Other than that, there's a number of fixes, cleanups and optimizations"
* tag 'pwm/for-5.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/thierry.reding/linux-pwm: (43 commits)
pwm: pwm-cros-ec: Add channel type support
dt-bindings: google,cros-ec-pwm: Add the new -type compatible
dt-bindings: Add mfd/cros_ec definitions
pwm: Document that the pinstate of a disabled PWM isn't reliable
pwm: twl-led: Implement .apply() callback
pwm: lpc18xx: Implement .apply() callback
pwm: mediatek: Implement .apply() callback
pwm: lpc32xx: Implement .apply() callback
pwm: tegra: Implement .apply() callback
pwm: stmpe: Implement .apply() callback
pwm: sti: Implement .apply() callback
pwm: pwm-mediatek: Add support for MediaTek Helio X10 MT6795
dt-bindings: pwm: pwm-mediatek: Add documentation for MT6795 SoC
pwm: tegra: Optimize period calculation
pwm: renesas-tpu: Improve precision of period and duty_cycle calculation
pwm: renesas-tpu: Improve maths to compute register settings
pwm: renesas-tpu: Rename variables to match the usual naming
pwm: renesas-tpu: Implement .apply() callback
pwm: renesas-tpu: Make use of devm functions
pwm: renesas-tpu: Make use of dev_err_probe()
...
Diffstat (limited to 'Documentation/driver-api')
-rw-r--r-- | Documentation/driver-api/pwm.rst | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/Documentation/driver-api/pwm.rst b/Documentation/driver-api/pwm.rst index ccb06e485756..fd26c3d895b6 100644 --- a/Documentation/driver-api/pwm.rst +++ b/Documentation/driver-api/pwm.rst @@ -49,6 +49,12 @@ After being requested, a PWM has to be configured using:: This API controls both the PWM period/duty_cycle config and the enable/disable state. + +As a consumer, don't rely on the output's state for a disabled PWM. If it's +easily possible, drivers are supposed to emit the inactive state, but some +drivers cannot. If you rely on getting the inactive state, use .duty_cycle=0, +.enabled=true. + There is also a usage_power setting: If set, the PWM driver is only required to maintain the power output but has more freedom regarding signal form. If supported by the driver, the signal can be optimized, for example to improve |