From: Rayagonda Kokatanur <rayagonda.kokatanur@broadcom.com>
Date: Sat, 18 Jul 2020 04:46:06 +0000 (-0700)
Subject: pwm: bcm-iproc: handle clk_get_rate() return
X-Git-Tag: v4.9.233~11
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=d0883cb88a80786725d161249ea4f58d3d707374;p=platform%2Fkernel%2Flinux-amlogic.git

pwm: bcm-iproc: handle clk_get_rate() return

[ 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>
---

diff --git a/drivers/pwm/pwm-bcm-iproc.c b/drivers/pwm/pwm-bcm-iproc.c
index 31b01035d0ab..8cfba3614e60 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;