From 16b0c0ce83ec3f8bf96de69b1c84214cacc39416 Mon Sep 17 00:00:00 2001 From: Axel Lin 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 Acked-by: Stefano Babic Acked-by: Heiko Schocher --- 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