diff options
| author | Uwe Kleine-König <u.kleine-koenig@baylibre.com> | 2025-04-08 16:23:54 +0200 |
|---|---|---|
| committer | Uwe Kleine-König <ukleinek@kernel.org> | 2025-04-17 11:52:13 +0200 |
| commit | e463b05d10da12b13d03f41a407e2ad043af158f (patch) | |
| tree | f0596f758dfb46fb2b99250cae7e88887efcfb22 | |
| parent | bd897149e40cb5c95f3d8546108035d1ea167db5 (diff) | |
pwm: Better document return value of pwm_round_waveform_might_sleep()
Better explain how pwm_round_waveform_might_sleep() (and so the
respective lowlevel driver callback) is supposed to round and the
meaning of the return value.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@baylibre.com>
Link: https://lore.kernel.org/r/db84abf1e82e4498fc0e7c318d2673771d0039fe.1744120697.git.ukleinek@kernel.org
[ukleinek: Fix a rst formatting issue reported by Stephen Rothwell]
Signed-off-by: Uwe Kleine-König <ukleinek@kernel.org>
| -rw-r--r-- | drivers/pwm/core.c | 8 |
1 files changed, 6 insertions, 2 deletions
diff --git a/drivers/pwm/core.c b/drivers/pwm/core.c index 59cc8792e312..079964961bd8 100644 --- a/drivers/pwm/core.c +++ b/drivers/pwm/core.c @@ -229,8 +229,12 @@ static int __pwm_write_waveform(struct pwm_chip *chip, struct pwm_device *pwm, c * these two calls and the waveform determined by * pwm_round_waveform_might_sleep() cannot be implemented any more. * - * Returns 0 on success, 1 if there is no valid hardware configuration matching - * the input waveform under the PWM rounding rules or a negative errno. + * Usually all values passed in @wf are rounded down to the nearest possible + * value (in the order period_length_ns, duty_length_ns and then + * duty_offset_ns). Only if this isn't possible, a value might grow. + * + * Returns 0 on success, 1 if at least one value had to be rounded up or a + * negative errno. */ int pwm_round_waveform_might_sleep(struct pwm_device *pwm, struct pwm_waveform *wf) { |