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| author | Sean Young <sean@mess.org> | 2019-06-03 10:00:58 +0100 |
|---|---|---|
| committer | Thierry Reding <thierry.reding@gmail.com> | 2019-06-26 11:39:12 +0200 |
| commit | 11fc4edc483bea8bf0efa0cc726886d2342f6fa6 (patch) | |
| tree | 19f3bdfc1f4cc7971343688f35770b629c28b5c9 /drivers/pwm/pwm-stm32-lp.c | |
| parent | 3f467ebe9e898c6ceec5334d92bccac2bd9bc7d2 (diff) | |
| download | linux-stable-11fc4edc483bea8bf0efa0cc726886d2342f6fa6.tar.gz linux-stable-11fc4edc483bea8bf0efa0cc726886d2342f6fa6.tar.bz2 linux-stable-11fc4edc483bea8bf0efa0cc726886d2342f6fa6.zip | |
pwm: bcm2835: Improve precision of PWM
If sending IR with carrier of 455kHz using the pwm-ir-tx driver, the
carrier ends up being 476kHz. The clock is set to bcm2835-pwm with a
rate of 10MHz.
A carrier of 455kHz has a period of 2198ns, but the arithmetic truncates
this to 2100ns rather than 2200ns. So, use DIV_ROUND_CLOSEST() to reduce
rounding errors, and we have a much more accurate carrier of 454.5kHz.
Reported-by: Andreas Christ <andreas@christ-faesch.ch>
Signed-off-by: Sean Young <sean@mess.org>
Acked-by: Stefan Wahren <wahrenst@gmx.net>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
Diffstat (limited to 'drivers/pwm/pwm-stm32-lp.c')
0 files changed, 0 insertions, 0 deletions