[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <20240122081754.17058-4-Wenhua.Lin@unisoc.com>
Date: Mon, 22 Jan 2024 16:17:51 +0800
From: Wenhua Lin <Wenhua.Lin@...soc.com>
To: Uwe Kleine-König <u.kleine-koenig@...gutronix.de>
CC: Orson Zhai <orsonzhai@...il.com>,
Baolin Wang
<baolin.wang@...ux.alibaba.com>,
Chunyan Zhang <zhang.lyra@...il.com>, <linux-pwm@...r.kernel.org>,
<linux-kernel@...r.kernel.org>, wenhua lin
<wenhua.lin1994@...il.com>,
Wenhua Lin <Wenhua.Lin@...soc.com>,
Xiongpeng Wu
<xiongpeng.wu@...soc.com>,
zhaochen su <zhaochen.su29@...il.com>,
Zhaochen Su
<Zhaochen.Su@...soc.com>,
Xiaolong Wang <Xiaolong.Wang@...soc.com>
Subject: [PATCH 3/6] pwm: sprd: Optimize the calculation method of duty
Use DIV_ROUND_CLOSEST_ULL to avoid overflow and improve accuracy
when calculating duty.
Signed-off-by: Wenhua Lin <Wenhua.Lin@...soc.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 411e91891c6d..22793e2b8707 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
Powered by blists - more mailing lists