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path: root/drivers/pwm/pwm-bcm2835.c
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Diffstat (limited to 'drivers/pwm/pwm-bcm2835.c')
-rw-r--r--drivers/pwm/pwm-bcm2835.c19
1 files changed, 10 insertions, 9 deletions
diff --git a/drivers/pwm/pwm-bcm2835.c b/drivers/pwm/pwm-bcm2835.c
index f6fe0b922e1e..91e24f01b54e 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");
@@ -71,17 +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) {
- dev_err(pc->dev, "period %d not supported, minimum %d\n",
- 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;
}
@@ -155,8 +153,11 @@ static int bcm2835_pwm_probe(struct platform_device *pdev)
pc->clk = devm_clk_get(&pdev->dev, NULL);
if (IS_ERR(pc->clk)) {
- dev_err(&pdev->dev, "clock not found: %ld\n", PTR_ERR(pc->clk));
- return PTR_ERR(pc->clk);
+ ret = PTR_ERR(pc->clk);
+ if (ret != -EPROBE_DEFER)
+ dev_err(&pdev->dev, "clock not found: %d\n", ret);
+
+ return ret;
}
ret = clk_prepare_enable(pc->clk);