[PATCH 2/3] pwm: bcm2835: prevent division by zero

[Stefan Wahren]

It's possible that the pwm clock become an orphan. So better
check the result of clk_get_rate in order to prevent a division
by zero.

Signed-off-by: Stefan Wahren <stefan.wahren at i2se.com>
---
 drivers/pwm/pwm-bcm2835.c |   10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/drivers/pwm/pwm-bcm2835.c b/drivers/pwm/pwm-bcm2835.c
index 174cca9..31a6992 100644
--- a/drivers/pwm/pwm-bcm2835.c
+++ b/drivers/pwm/pwm-bcm2835.c
@@ -65,7 +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 scaler = NSEC_PER_SEC / clk_get_rate(pc->clk);
+	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",
-- 
1.7.9.5