diff --git a/arch/arm/src/samv7/sam_pwm.c b/arch/arm/src/samv7/sam_pwm.c
index a47fd6d3e41..6fd40119c7a 100644
--- a/arch/arm/src/samv7/sam_pwm.c
+++ b/arch/arm/src/samv7/sam_pwm.c
@@ -147,7 +147,7 @@ static struct sam_pwm_s g_pwm0 =
 {
   .ops = &g_pwmops,
   .channels = g_pwm0_channels,
-  .channels_num = 4,
+  .channels_num = PWM0_NCHANNELS,
   .frequency = 0,
   .base = SAM_PWM0_BASE,
 };
@@ -191,7 +191,7 @@ static struct sam_pwm_s g_pwm1 =
 {
   .ops = &g_pwmops,
   .channels = g_pwm1_channels,
-  .channels_num = 4,
+  .channels_num = PWM1_NCHANNELS,
   .frequency = 0,
   .base = SAM_PWM1_BASE,
 };
diff --git a/arch/arm/src/samv7/sam_pwm.h b/arch/arm/src/samv7/sam_pwm.h
index ca17af95cac..d8fb1e1ebd5 100644
--- a/arch/arm/src/samv7/sam_pwm.h
+++ b/arch/arm/src/samv7/sam_pwm.h
@@ -36,6 +36,60 @@
  * Pre-processor Definitions
  ****************************************************************************/
 
+#ifdef CONFIG_SAMV7_PWM0_CH0
+#define PWM0_CH0 1
+#else
+#define PWM0_CH0 0
+#endif
+
+#ifdef CONFIG_SAMV7_PWM0_CH1
+#define PWM0_CH1 1
+#else
+#define PWM0_CH1 0
+#endif
+
+#ifdef CONFIG_SAMV7_PWM0_CH2
+#define PWM0_CH2 1
+#else
+#define PWM0_CH2 0
+#endif
+
+#ifdef CONFIG_SAMV7_PWM0_CH3
+#define PWM0_CH3 1
+#else
+#define PWM0_CH3 0
+#endif
+
+#define PWM0_NCHANNELS (PWM0_CH0 + PWM0_CH1 + \
+                        PWM0_CH2 + PWM0_CH3)
+
+#ifdef CONFIG_SAMV7_PWM1_CH0
+#define PWM1_CH0 1
+#else
+#define PWM1_CH0 0
+#endif
+
+#ifdef CONFIG_SAMV7_PWM1_CH1
+#define PWM1_CH1 1
+#else
+#define PWM1_CH1 0
+#endif
+
+#ifdef CONFIG_SAMV7_PWM1_CH2
+#define PWM1_CH2 1
+#else
+#define PWM1_CH2 0
+#endif
+
+#ifdef CONFIG_SAMV7_PWM1_CH3
+#define PWM1_CH3 1
+#else
+#define PWM1_CH3 0
+#endif
+
+#define PWM1_NCHANNELS (PWM1_CH0 + PWM1_CH1 + \
+                        PWM1_CH2 + PWM1_CH3)
+
 /****************************************************************************
  * Public Function Prototypes
  ****************************************************************************/