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Subject[PATCH v3] pwm: bcm-iproc: handle clk_get_rate() return
Date
From: Rayagonda Kokatanur <rayagonda.kokatanur@broadcom.com>

Handle clk_get_rate() returning 0 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>
Signed-off-by: Scott Branden <scott.branden@broadcom.com>
Reviewed-off-by: Ray Jui <ray.jui@broadcom.com>

---
Changes from v2: update commit message to remove <= condition
as clk_get_rate only returns value >= 0
---
drivers/pwm/pwm-bcm-iproc.c | 9 +++++++--
1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/drivers/pwm/pwm-bcm-iproc.c b/drivers/pwm/pwm-bcm-iproc.c
index 1f829edd8ee7..d392a828fc49 100644
--- a/drivers/pwm/pwm-bcm-iproc.c
+++ b/drivers/pwm/pwm-bcm-iproc.c
@@ -85,8 +85,6 @@ static void iproc_pwmc_get_state(struct pwm_chip *chip, struct pwm_device *pwm,
u64 tmp, multi, rate;
u32 value, prescale;

- rate = clk_get_rate(ip->clk);
-
value = readl(ip->base + IPROC_PWM_CTRL_OFFSET);

if (value & BIT(IPROC_PWM_CTRL_EN_SHIFT(pwm->hwpwm)))
@@ -99,6 +97,13 @@ static void iproc_pwmc_get_state(struct pwm_chip *chip, struct pwm_device *pwm,
else
state->polarity = PWM_POLARITY_INVERSED;

+ rate = clk_get_rate(ip->clk);
+ if (rate == 0) {
+ state->period = 0;
+ state->duty_cycle = 0;
+ return;
+ }
+
value = readl(ip->base + IPROC_PWM_PRESCALE_OFFSET);
prescale = value >> IPROC_PWM_PRESCALE_SHIFT(pwm->hwpwm);
prescale &= IPROC_PWM_PRESCALE_MAX;
--
2.17.1
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