diff options
Diffstat (limited to 'drivers/pwm/pwm-tegra.c')
| -rw-r--r-- | drivers/pwm/pwm-tegra.c | 15 |
1 files changed, 13 insertions, 2 deletions
diff --git a/drivers/pwm/pwm-tegra.c b/drivers/pwm/pwm-tegra.c index dad9978c9186..249dc0193297 100644 --- a/drivers/pwm/pwm-tegra.c +++ b/drivers/pwm/pwm-tegra.c @@ -145,8 +145,19 @@ static int tegra_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm, * source clock rate as required_clk_rate, PWM controller will * be able to configure the requested period. */ - required_clk_rate = - (NSEC_PER_SEC / period_ns) << PWM_DUTY_WIDTH; + required_clk_rate = DIV_ROUND_UP_ULL((u64)NSEC_PER_SEC << PWM_DUTY_WIDTH, + period_ns); + + if (required_clk_rate > clk_round_rate(pc->clk, required_clk_rate)) + /* + * required_clk_rate is a lower bound for the input + * rate; for lower rates there is no value for PWM_SCALE + * that yields a period less than or equal to the + * requested period. Hence, for lower rates, double the + * required_clk_rate to get a clock rate that can meet + * the requested period. + */ + required_clk_rate *= 2; err = dev_pm_opp_set_rate(pc->dev, required_clk_rate); if (err < 0) |