[PATCH 5.7 147/204] pwm: bcm-iproc: handle clk_get_rate() return

Greg Kroah-Hartman
2020-08-20T12:56:26Z

From: Rayagonda Kokatanur <rayagonda.kokatanur@broadcom.com>

[ Upstream commit 6ced5ff0be8e94871ba846dfbddf69d21363f3d7 ]

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-by: Ray Jui <ray.jui@broadcom.com>
Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
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 1f829edd8ee70..d392a828fc493 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;
--
2.25.1