From 16b0c0ce83ec3f8bf96de69b1c84214cacc39416 Mon Sep 17 00:00:00 2001
From: Axel Lin <axel.lin@ingics.com>
Date: Sat, 23 May 2015 15:16:48 +0800
Subject: [PATCH] pwm: imx: Prevent NULL pointer dereference
pwm_id_to_reg() can return NULL, so add NULL testing to prevent NULL pointer
dereference.
Signed-off-by: Axel Lin <axel.lin@ingics.com>
Acked-by: Stefano Babic <sbabic@denx.de>
Acked-by: Heiko Schocher <hs@denx.de>
---
drivers/pwm/pwm-imx.c | 12 ++++++++++++
1 file changed, 12 insertions(+)
diff --git a/drivers/pwm/pwm-imx.c b/drivers/pwm/pwm-imx.c
index 40bf027543..47799fc0d1 100644
--- a/drivers/pwm/pwm-imx.c
+++ b/drivers/pwm/pwm-imx.c
@@ -18,6 +18,9 @@ int pwm_init(int pwm_id, int div, int invert)
{
struct pwm_regs *pwm = (struct pwm_regs *)pwm_id_to_reg(pwm_id);
+ if (!pwm)
+ return -1;
+
writel(0, &pwm->ir);
return 0;
}
@@ -28,6 +31,9 @@ int pwm_config(int pwm_id, int duty_ns, int period_ns)
unsigned long period_cycles, duty_cycles, prescale;
u32 cr;
+ if (!pwm)
+ return -1;
+
pwm_imx_get_parms(period_ns, duty_ns, &period_cycles, &duty_cycles,
&prescale);
@@ -47,6 +53,9 @@ int pwm_enable(int pwm_id)
{
struct pwm_regs *pwm = (struct pwm_regs *)pwm_id_to_reg(pwm_id);
+ if (!pwm)
+ return -1;
+
setbits_le32(&pwm->cr, PWMCR_EN);
return 0;
}
@@ -55,5 +64,8 @@ void pwm_disable(int pwm_id)
{
struct pwm_regs *pwm = (struct pwm_regs *)pwm_id_to_reg(pwm_id);
+ if (!pwm)
+ return;
+
clrbits_le32(&pwm->cr, PWMCR_EN);
}
--
2.39.5