Messages in this thread Patch in this message |  | | From | Wenhua Lin <> | | Subject | [PATCH V2 3/6] pwm: sprd: Optimize the calculation method of duty | | Date | Thu, 25 Jan 2024 10:55:30 +0800 |
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Use DIV_ROUND_CLOSEST_ULL to avoid overflow and improve accuracy when calculating duty.
Signed-off-by: Wenhua Lin <Wenhua.Lin@unisoc.com> --- drivers/pwm/pwm-sprd.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/pwm/pwm-sprd.c b/drivers/pwm/pwm-sprd.c index cc54aa77c7e6..8de3f9e154ce 100644 --- a/drivers/pwm/pwm-sprd.c +++ b/drivers/pwm/pwm-sprd.c @@ -156,7 +156,8 @@ static int sprd_pwm_config(struct sprd_pwm_chip *spc, struct pwm_device *pwm, * given settings (MOD and input clock). */ mod = spc->mod[pwm->hwpwm]; - duty = duty_ns * mod / period_ns; + tmp = (u64)duty_ns * mod; + duty = DIV_ROUND_CLOSEST_ULL(tmp, period_ns); tmp = (u64)chn->clk_rate * period_ns; do_div(tmp, NSEC_PER_SEC); -- 2.17.1
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