| Message ID | cover.1722261050.git.u.kleine-koenig@baylibre.com |
|---|---|
| Headers | show |
| Series | pwm: New abstraction and userspace API | expand |
On Mon, Jul 29, 2024 at 04:34:16PM +0200, Uwe Kleine-König wrote: > Hello, > > here comes v3 of the series to add support for duty offset in PWM > waveforms. For a single PWM output there is no gain, but if you have a > chip with two (or more) outputs and both operate with the same period, > you can generate an output like: > > > ______ ______ ______ ______ > PWM #0 ___/ \_______/ \_______/ \_______/ \_______ > __ __ __ __ > PWM #1 _____/ \___________/ \___________/ \___________/ \_________ > ^ ^ ^ ^ > > Changes since v2, which is available from > https://lore.kernel.org/linux-pwm/cover.1721040875.git.u.kleine-koenig@baylibre.com > include: > > - Degrade a dev_alert() to dev_warn() on feedback by David Lechner > > - Improvement of various comments (partly in reply to David Lechner) > > - Add _ns suffixes for members of pwm_waveform, thanks David for that suggestion. > > - Rebased to v6.11-rc1 + pwm/for-next. > > Because of these changes I didn't add Trevor's Reviewed-by tag for patch > #3. > > I kept the BUG_ONs. There are a few check_patch warnings about it, but I still > prefer these given that it is safe they don't trigger without further (bogus) > code changes and when they trigger crashing early is better than stack > corruption. Also checkpatch tells > WARNING: Comparisons should place the constant on the right side of the test > #158: FILE: drivers/pwm/core.c:262: > + BUG_ON(WFHWSIZE < ops->sizeof_wfhw); > > But as the BUG_ON is about WFHWSIZE being wrong, this order is OK. > > There are a few more checkpatch warnings about line lengths. Breaking > the criticised lines further hurts readability IMHO, so I kept them. It > gets a bit better once stm32_pwm_mul_u64_u64_div_u64_roundup() is > implemented (without the stm32_pwm prefix) alongside > mul_u64_u64_div_u64() in lib/math/div64.c, but I don't want to wait for > that. I will address that once Nicolas's patch improving precision of > mul_u64_u64_div_u64() landed. (Hmm, it's not in next any more since > next-20240724, before it was 3cc8bf1a81efde105d8e57398cf8554b57768777 + > dbbe95af0fad2a9d22a4b910cfc4b87949d61a3c). > > Best regards > Uwe > > Uwe Kleine-König (8): > pwm: Simplify pwm_capture() > pwm: Add more locking > pwm: New abstraction for PWM waveforms > pwm: Provide new consumer API functions for waveforms > pwm: Add support for pwmchip devices for faster and easier userspace > access > pwm: Add tracing for waveform callbacks > pwm: axi-pwmgen: Implementation of the waveform callbacks > pwm: stm32: Implementation of the waveform callbacks I applied patch #1 which is a harmless cleanup for now. I will wait a bit for the rest of the series, as during August I won't be able to react to fall-outs reliably and quickly. I plan to apply this series with PWM_IOCTL_GET_NUM_PWMS dropped directly after the next merge window for cooking in next as long as possible. Best regards Uwe
Hello, here comes v3 of the series to add support for duty offset in PWM waveforms. For a single PWM output there is no gain, but if you have a chip with two (or more) outputs and both operate with the same period, you can generate an output like: ______ ______ ______ ______ PWM #0 ___/ \_______/ \_______/ \_______/ \_______ __ __ __ __ PWM #1 _____/ \___________/ \___________/ \___________/ \_________ ^ ^ ^ ^ Changes since v2, which is available from https://lore.kernel.org/linux-pwm/cover.1721040875.git.u.kleine-koenig@baylibre.com include: - Degrade a dev_alert() to dev_warn() on feedback by David Lechner - Improvement of various comments (partly in reply to David Lechner) - Add _ns suffixes for members of pwm_waveform, thanks David for that suggestion. - Rebased to v6.11-rc1 + pwm/for-next. Because of these changes I didn't add Trevor's Reviewed-by tag for patch #3. I kept the BUG_ONs. There are a few check_patch warnings about it, but I still prefer these given that it is safe they don't trigger without further (bogus) code changes and when they trigger crashing early is better than stack corruption. Also checkpatch tells WARNING: Comparisons should place the constant on the right side of the test #158: FILE: drivers/pwm/core.c:262: + BUG_ON(WFHWSIZE < ops->sizeof_wfhw); But as the BUG_ON is about WFHWSIZE being wrong, this order is OK. There are a few more checkpatch warnings about line lengths. Breaking the criticised lines further hurts readability IMHO, so I kept them. It gets a bit better once stm32_pwm_mul_u64_u64_div_u64_roundup() is implemented (without the stm32_pwm prefix) alongside mul_u64_u64_div_u64() in lib/math/div64.c, but I don't want to wait for that. I will address that once Nicolas's patch improving precision of mul_u64_u64_div_u64() landed. (Hmm, it's not in next any more since next-20240724, before it was 3cc8bf1a81efde105d8e57398cf8554b57768777 + dbbe95af0fad2a9d22a4b910cfc4b87949d61a3c). Best regards Uwe Uwe Kleine-König (8): pwm: Simplify pwm_capture() pwm: Add more locking pwm: New abstraction for PWM waveforms pwm: Provide new consumer API functions for waveforms pwm: Add support for pwmchip devices for faster and easier userspace access pwm: Add tracing for waveform callbacks pwm: axi-pwmgen: Implementation of the waveform callbacks pwm: stm32: Implementation of the waveform callbacks drivers/pwm/core.c | 809 +++++++++++++++++++++++++++++++++-- drivers/pwm/pwm-axi-pwmgen.c | 154 +++++-- drivers/pwm/pwm-stm32.c | 607 ++++++++++++++++---------- include/linux/pwm.h | 58 ++- include/trace/events/pwm.h | 134 +++++- include/uapi/linux/pwm.h | 25 ++ 6 files changed, 1479 insertions(+), 308 deletions(-) create mode 100644 include/uapi/linux/pwm.h base-commit: b9b6bd3dcceed371829a022caeb6b51cb9f67be9