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>

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>
Axel Lin · Stefano Babic
1 parent 53940a5079
Showing 1 changed file with 12 additions and 0 deletions Side-by-side Diff
drivers/pwm/pwm-imx.c
@@ -18,6 +18,9 @@
 {
 	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 @@
 	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 @@
 {
 	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;
 }
@@ -54,6 +63,9 @@
 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);
 }
...	...	@@ -18,6 +18,9 @@
18	18	{
19	19	struct pwm_regs pwm = (struct pwm_regs )pwm_id_to_reg(pwm_id);
20	20
	21	+ if (!pwm)
	22	+ return -1;
	23	+
21	24	writel(0, &pwm->ir);
22	25	return 0;
23	26	}
...	...	@@ -28,6 +31,9 @@
28	31	unsigned long period_cycles, duty_cycles, prescale;
29	32	u32 cr;
30	33
	34	+ if (!pwm)
	35	+ return -1;
	36	+
31	37	pwm_imx_get_parms(period_ns, duty_ns, &period_cycles, &duty_cycles,
32	38	&prescale);
33	39
...	...	@@ -47,6 +53,9 @@
47	53	{
48	54	struct pwm_regs pwm = (struct pwm_regs )pwm_id_to_reg(pwm_id);
49	55
	56	+ if (!pwm)
	57	+ return -1;
	58	+
50	59	setbits_le32(&pwm->cr, PWMCR_EN);
51	60	return 0;
52	61	}
...	...	@@ -54,6 +63,9 @@
54	63	void pwm_disable(int pwm_id)
55	64	{
56	65	struct pwm_regs pwm = (struct pwm_regs )pwm_id_to_reg(pwm_id);
	66	+
	67	+ if (!pwm)
	68	+ return;
57	69
58	70	clrbits_le32(&pwm->cr, PWMCR_EN);
59	71	}