diff options
| author | Stefan Wahren <wahrenst@gmx.net> | 2019-08-24 16:09:47 +0200 |
|---|---|---|
| committer | Thierry Reding <thierry.reding@gmail.com> | 2019-09-21 01:23:24 +0200 |
| commit | 7e9713af316187f323b25ebf7eb1a8f03425e7e9 (patch) | |
| tree | c1ac2e079816199282863b70bcf9cebd3ec56723 /drivers/pwm/pwm-bcm2835.c | |
| parent | pwm: bcm2835: Suppress error message for invalid period_ns (diff) | |
| download | linux-7e9713af316187f323b25ebf7eb1a8f03425e7e9.tar.xz linux-7e9713af316187f323b25ebf7eb1a8f03425e7e9.zip | |
pwm: bcm2835: Fix period_ns range check
The range check for period_ns was written under assumption of a fixed
PWM clock. With clk-bcm2835 driver the PWM clock is a dynamic one.
So fix this by doing the range check on the period register value.
Signed-off-by: Stefan Wahren <wahrenst@gmx.net>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
Diffstat (limited to 'drivers/pwm/pwm-bcm2835.c')
| -rw-r--r-- | drivers/pwm/pwm-bcm2835.c | 9 |
1 files changed, 5 insertions, 4 deletions
diff --git a/drivers/pwm/pwm-bcm2835.c b/drivers/pwm/pwm-bcm2835.c index 52763063c100..2c82386c0ebf 100644 --- a/drivers/pwm/pwm-bcm2835.c +++ b/drivers/pwm/pwm-bcm2835.c @@ -21,7 +21,7 @@ #define PERIOD(x) (((x) * 0x10) + 0x10) #define DUTY(x) (((x) * 0x10) + 0x14) -#define MIN_PERIOD 108 /* 9.2 MHz max. PWM clock */ +#define PERIOD_MIN 0x2 struct bcm2835_pwm { struct pwm_chip chip; @@ -64,6 +64,7 @@ static int bcm2835_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm, struct bcm2835_pwm *pc = to_bcm2835_pwm(chip); unsigned long rate = clk_get_rate(pc->clk); unsigned long scaler; + u32 period; if (!rate) { dev_err(pc->dev, "failed to get clock rate\n"); @@ -71,14 +72,14 @@ static int bcm2835_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm, } scaler = DIV_ROUND_CLOSEST(NSEC_PER_SEC, rate); + period = DIV_ROUND_CLOSEST(period_ns, scaler); - if (period_ns <= MIN_PERIOD) + if (period < PERIOD_MIN) return -EINVAL; writel(DIV_ROUND_CLOSEST(duty_ns, scaler), pc->base + DUTY(pwm->hwpwm)); - writel(DIV_ROUND_CLOSEST(period_ns, scaler), - pc->base + PERIOD(pwm->hwpwm)); + writel(period, pc->base + PERIOD(pwm->hwpwm)); return 0; } |