summaryrefslogtreecommitdiffstats
path: root/drivers/pwm/pwm-mediatek.c
diff options
context:
space:
mode:
Diffstat (limited to 'drivers/pwm/pwm-mediatek.c')
-rw-r--r--drivers/pwm/pwm-mediatek.c17
1 files changed, 12 insertions, 5 deletions
diff --git a/drivers/pwm/pwm-mediatek.c b/drivers/pwm/pwm-mediatek.c
index 502c366c7d7c..328c124773b2 100644
--- a/drivers/pwm/pwm-mediatek.c
+++ b/drivers/pwm/pwm-mediatek.c
@@ -135,19 +135,25 @@ static int mtk_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
{
struct mtk_pwm_chip *pc = to_mtk_pwm_chip(chip);
struct clk *clk = pc->clks[MTK_CLK_PWM1 + pwm->hwpwm];
- u32 resolution, clkdiv = 0, reg_width = PWMDWIDTH,
+ u32 clkdiv = 0, cnt_period, cnt_duty, reg_width = PWMDWIDTH,
reg_thres = PWMTHRES;
+ u64 resolution;
int ret;
ret = mtk_pwm_clk_enable(chip, pwm);
if (ret < 0)
return ret;
- resolution = NSEC_PER_SEC / clk_get_rate(clk);
+ /* Using resolution in picosecond gets accuracy higher */
+ resolution = (u64)NSEC_PER_SEC * 1000;
+ do_div(resolution, clk_get_rate(clk));
- while (period_ns / resolution > 8191) {
+ cnt_period = DIV_ROUND_CLOSEST_ULL((u64)period_ns * 1000, resolution);
+ while (cnt_period > 8191) {
resolution *= 2;
clkdiv++;
+ cnt_period = DIV_ROUND_CLOSEST_ULL((u64)period_ns * 1000,
+ resolution);
}
if (clkdiv > PWM_CLK_DIV_MAX) {
@@ -165,9 +171,10 @@ static int mtk_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
reg_thres = PWM45THRES_FIXUP;
}
+ cnt_duty = DIV_ROUND_CLOSEST_ULL((u64)duty_ns * 1000, resolution);
mtk_pwm_writel(pc, pwm->hwpwm, PWMCON, BIT(15) | clkdiv);
- mtk_pwm_writel(pc, pwm->hwpwm, reg_width, period_ns / resolution);
- mtk_pwm_writel(pc, pwm->hwpwm, reg_thres, duty_ns / resolution);
+ mtk_pwm_writel(pc, pwm->hwpwm, reg_width, cnt_period);
+ mtk_pwm_writel(pc, pwm->hwpwm, reg_thres, cnt_duty);
mtk_pwm_clk_disable(chip, pwm);
OpenPOWER on IntegriCloud