From: Trevor Gamblin <tgamblin@baylibre.com>
To: linux-pwm@vger.kernel.org
Cc: linux-kernel@vger.kernel.org, u.kleine-koenig@pengutronix.de,
michael.hennerich@analog.com, nuno.sa@analog.com,
tgamblin@baylibre.com, dlechner@baylibre.com
Subject: [PATCH 0/2 v2] pwm: add support for duty_offset
Date: Tue, 9 Apr 2024 13:41:24 -0400 [thread overview]
Message-ID: <20240409174126.1296318-1-tgamblin@baylibre.com> (raw)
This series extends the PWM subsystem to support the duty_offset feature
found on some PWM devices. It includes a patch to enable this feature
for the axi-pwmgen driver, which can also serve as an example of how to
implement it for other devices.
The series was tested on actual hardware using a Zedboard. An
oscilloscope was used to validate that the generated PWM signals matched
the requested ones. The libpwm [1] tool was also used for testing the
char device functionality.
Note that in addition to the other patches in this series, the changes
to the axi-pwmgen driver rely on [2] and [3], which haven't been picked
up yet.
[1] https://git.kernel.org/pub/scm/linux/kernel/git/ukleinek/libpwm.git/
[2] https://lore.kernel.org/linux-pwm/20240301173343.1086332-1-tgamblin@baylibre.com/
[3] https://lore.kernel.org/linux-pwm/20240314204722.1291993-1-tgamblin@baylibre.com/
---
v2 changes:
* Address feedback for driver in v1:
* Remove supports_offset flag in pwm_chip struct, and references to it
in the axi-pwmgen driver patch
* Drop pwm_config_full patch entirely
* Don't return EINVAL when state->duty_offset + state->duty_cycle >
state->period in __pwm_apply(), since this is valid as long as
neither is greater than state->period on its own
* Add a check to disallow setting the PWM signal as inverse and a
nonzero duty_offset at the same time in __pwm_apply(), with a
comment explaining why
Link to v1 (RFC): https://lore.kernel.org/linux-pwm/20240405003025.739603-1-tgamblin@baylibre.com/
Trevor Gamblin (2):
pwm: add duty offset support
pwm: axi-pwmgen: add duty offset support
drivers/pwm/core.c | 82 +++++++++++++++++++++++++++++++++---
drivers/pwm/pwm-axi-pwmgen.c | 34 +++++++++++----
include/linux/pwm.h | 15 +++++++
include/trace/events/pwm.h | 6 ++-
4 files changed, 121 insertions(+), 16 deletions(-)
--
2.44.0
next reply other threads:[~2024-04-09 17:41 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-04-09 17:41 Trevor Gamblin [this message]
2024-04-09 17:41 ` [PATCH 1/2 v2] pwm: add duty offset support Trevor Gamblin
2024-04-09 17:41 ` [PATCH 2/2 v2] pwm: axi-pwmgen: " Trevor Gamblin
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