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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.c18
1 files changed, 12 insertions, 6 deletions
diff --git a/drivers/pwm/pwm-bcm2835.c b/drivers/pwm/pwm-bcm2835.c
index b4c7f956b6fa..c5dbf16d810b 100644
--- a/drivers/pwm/pwm-bcm2835.c
+++ b/drivers/pwm/pwm-bcm2835.c
@@ -29,7 +29,6 @@
struct bcm2835_pwm {
struct pwm_chip chip;
struct device *dev;
- unsigned long scaler;
void __iomem *base;
struct clk *clk;
};
@@ -66,6 +65,15 @@ static int bcm2835_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
int duty_ns, int period_ns)
{
struct bcm2835_pwm *pc = to_bcm2835_pwm(chip);
+ unsigned long rate = clk_get_rate(pc->clk);
+ unsigned long scaler;
+
+ if (!rate) {
+ dev_err(pc->dev, "failed to get clock rate\n");
+ return -EINVAL;
+ }
+
+ scaler = NSEC_PER_SEC / rate;
if (period_ns <= MIN_PERIOD) {
dev_err(pc->dev, "period %d not supported, minimum %d\n",
@@ -73,8 +81,8 @@ static int bcm2835_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
return -EINVAL;
}
- writel(duty_ns / pc->scaler, pc->base + DUTY(pwm->hwpwm));
- writel(period_ns / pc->scaler, pc->base + PERIOD(pwm->hwpwm));
+ writel(duty_ns / scaler, pc->base + DUTY(pwm->hwpwm));
+ writel(period_ns / scaler, pc->base + PERIOD(pwm->hwpwm));
return 0;
}
@@ -156,8 +164,6 @@ static int bcm2835_pwm_probe(struct platform_device *pdev)
if (ret)
return ret;
- pc->scaler = NSEC_PER_SEC / clk_get_rate(pc->clk);
-
pc->chip.dev = &pdev->dev;
pc->chip.ops = &bcm2835_pwm_ops;
pc->chip.npwm = 2;
@@ -200,6 +206,6 @@ static struct platform_driver bcm2835_pwm_driver = {
};
module_platform_driver(bcm2835_pwm_driver);
-MODULE_AUTHOR("Bart Tanghe <bart.tanghe@thomasmore.be");
+MODULE_AUTHOR("Bart Tanghe <bart.tanghe@thomasmore.be>");
MODULE_DESCRIPTION("Broadcom BCM2835 PWM driver");
MODULE_LICENSE("GPL v2");