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Subject[PATCH v1 1/2] pwm: bcm-iproc: handle clk_get_rate() return
Date
Handle clk_get_rate() returning <= 0 condition to avoid
possible division by zero.

Fixes: daa5abc41c80 ("pwm: Add support for Broadcom iProc PWM controller")
Signed-off-by: Rayagonda Kokatanur <rayagonda.kokatanur@broadcom.com>
---
drivers/pwm/pwm-bcm-iproc.c | 32 +++++++++++++++++++-------------
1 file changed, 19 insertions(+), 13 deletions(-)

diff --git a/drivers/pwm/pwm-bcm-iproc.c b/drivers/pwm/pwm-bcm-iproc.c
index 1f829edd8ee7..8bbd2a04fead 100644
--- a/drivers/pwm/pwm-bcm-iproc.c
+++ b/drivers/pwm/pwm-bcm-iproc.c
@@ -99,19 +99,25 @@ static void iproc_pwmc_get_state(struct pwm_chip *chip, struct pwm_device *pwm,
else
state->polarity = PWM_POLARITY_INVERSED;

- value = readl(ip->base + IPROC_PWM_PRESCALE_OFFSET);
- prescale = value >> IPROC_PWM_PRESCALE_SHIFT(pwm->hwpwm);
- prescale &= IPROC_PWM_PRESCALE_MAX;
-
- multi = NSEC_PER_SEC * (prescale + 1);
-
- value = readl(ip->base + IPROC_PWM_PERIOD_OFFSET(pwm->hwpwm));
- tmp = (value & IPROC_PWM_PERIOD_MAX) * multi;
- state->period = div64_u64(tmp, rate);
-
- value = readl(ip->base + IPROC_PWM_DUTY_CYCLE_OFFSET(pwm->hwpwm));
- tmp = (value & IPROC_PWM_PERIOD_MAX) * multi;
- state->duty_cycle = div64_u64(tmp, rate);
+ if (rate == 0) {
+ state->period = 0;
+ state->duty_cycle = 0;
+ } else {
+ value = readl(ip->base + IPROC_PWM_PRESCALE_OFFSET);
+ prescale = value >> IPROC_PWM_PRESCALE_SHIFT(pwm->hwpwm);
+ prescale &= IPROC_PWM_PRESCALE_MAX;
+
+ multi = NSEC_PER_SEC * (prescale + 1);
+
+ value = readl(ip->base + IPROC_PWM_PERIOD_OFFSET(pwm->hwpwm));
+ tmp = (value & IPROC_PWM_PERIOD_MAX) * multi;
+ state->period = div64_u64(tmp, rate);
+
+ value = readl(ip->base +
+ IPROC_PWM_DUTY_CYCLE_OFFSET(pwm->hwpwm));
+ tmp = (value & IPROC_PWM_PERIOD_MAX) * multi;
+ state->duty_cycle = div64_u64(tmp, rate);
+ }
}

static int iproc_pwmc_apply(struct pwm_chip *chip, struct pwm_device *pwm,
--
2.17.1
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