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pwm: imx: Prevent NULL pointer dereference

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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>
This commit is contained in:
Axel Lin 2015-05-23 15:16:48 +08:00 committed by Stefano Babic
parent 53940a5079
commit 16b0c0ce83
1 changed files with 12 additions and 0 deletions
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12
drivers/pwm/pwm-imx.c
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@ -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); struct pwm_regs *pwm = (struct pwm_regs *)pwm_id_to_reg(pwm_id);
if (!pwm)
return -1;
writel(0, &pwm->ir); writel(0, &pwm->ir);
return 0; 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; unsigned long period_cycles, duty_cycles, prescale;
u32 cr; u32 cr;
if (!pwm)
return -1;
pwm_imx_get_parms(period_ns, duty_ns, &period_cycles, &duty_cycles, pwm_imx_get_parms(period_ns, duty_ns, &period_cycles, &duty_cycles,
&prescale); &prescale);
@ -47,6 +53,9 @@ int pwm_enable(int pwm_id)
{ {
struct pwm_regs *pwm = (struct pwm_regs *)pwm_id_to_reg(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); setbits_le32(&pwm->cr, PWMCR_EN);
return 0; 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); struct pwm_regs *pwm = (struct pwm_regs *)pwm_id_to_reg(pwm_id);
if (!pwm)
return;
clrbits_le32(&pwm->cr, PWMCR_EN); clrbits_le32(&pwm->cr, PWMCR_EN);
} }