diff options
| author | George Stark <gnstark@salutedevices.com> | 2024-04-25 20:12:53 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2024-05-30 09:44:28 +0200 |
| commit | 132fe6c1ee248cbc0e03197d417f7d40bcf07c49 (patch) | |
| tree | 0900b9a584a666d98fac1bbb80e68ce082a1c08e | |
| parent | 513202bfe4dafa086e94d80b8a68e6ab7041a35b (diff) | |
pwm: meson: Use mul_u64_u64_div_u64() for frequency calculating
[ Upstream commit 32c44e1fa921aebf8a5ef9f778534a30aab39313 ]
While calculating frequency for the given period u64 numbers are
multiplied before division what can lead to overflow in theory so use
secure mul_u64_u64_div_u64() which handles overflow correctly.
Fixes: 329db102a26d ("pwm: meson: make full use of common clock framework")
Suggested-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: George Stark <gnstark@salutedevices.com>
Link: https://lore.kernel.org/r/20240425171253.2752877-4-gnstark@salutedevices.com
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
| -rw-r--r-- | drivers/pwm/pwm-meson.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/drivers/pwm/pwm-meson.c b/drivers/pwm/pwm-meson.c index b5d5fe466999..e12b6ff70bab 100644 --- a/drivers/pwm/pwm-meson.c +++ b/drivers/pwm/pwm-meson.c @@ -175,7 +175,7 @@ static int meson_pwm_calc(struct pwm_chip *chip, struct pwm_device *pwm, dev_dbg(pwmchip_parent(chip), "fin_freq: %ld Hz\n", fin_freq); - cnt = div_u64(fin_freq * period, NSEC_PER_SEC); + cnt = mul_u64_u64_div_u64(fin_freq, period, NSEC_PER_SEC); if (cnt > 0xffff) { dev_err(pwmchip_parent(chip), "unable to get period cnt\n"); return -EINVAL; @@ -190,7 +190,7 @@ static int meson_pwm_calc(struct pwm_chip *chip, struct pwm_device *pwm, channel->hi = 0; channel->lo = cnt; } else { - duty_cnt = div_u64(fin_freq * duty, NSEC_PER_SEC); + duty_cnt = mul_u64_u64_div_u64(fin_freq, duty, NSEC_PER_SEC); dev_dbg(pwmchip_parent(chip), "duty=%llu duty_cnt=%u\n", duty, duty_cnt); |