diff --git a/src/atsam/sam4e_afec.c b/src/atsam/sam4e_afec.c
index 0e1c60ac..002e092f 100644
--- a/src/atsam/sam4e_afec.c
+++ b/src/atsam/sam4e_afec.c
@@ -179,7 +179,8 @@ gpio_adc_sample(struct gpio_adc g)
     afec->AFE_CR = AFE_CR_START;
 
 need_delay:
-    return ADC_FREQ_MAX * 10000ULL / CONFIG_CLOCK_FREQ; // about 400 mcu clock cycles or 40 afec cycles
+    // about 400 mcu clock cycles or 40 afec cycles
+    return ADC_FREQ_MAX * 10000ULL / CONFIG_CLOCK_FREQ;
 }
 
 // Read a value; use only after gpio_adc_sample() returns zero
diff --git a/src/atsam/sam4s_sysinit.c b/src/atsam/sam4s_sysinit.c
index 41a2dcfe..f31cf7ac 100644
--- a/src/atsam/sam4s_sysinit.c
+++ b/src/atsam/sam4s_sysinit.c
@@ -11,7 +11,8 @@
                              | CKGR_PLLAR_DIVA(0x1U))
 #define SYS_BOARD_MCKR      (PMC_MCKR_PRES_CLK_2 | PMC_MCKR_CSS_PLLA_CLK)
 
-#define SYS_CKGR_MOR_KEY_VALUE CKGR_MOR_KEY(0x37) /* Key to unlock MOR register */
+/* Key to unlock MOR register */
+#define SYS_CKGR_MOR_KEY_VALUE CKGR_MOR_KEY(0x37)
 
 uint32_t SystemCoreClock = CHIP_FREQ_MAINCK_RC_4MHZ;
 
@@ -23,7 +24,8 @@ void SystemInit( void )
     /* Initialize main oscillator */
     if ( !(PMC->CKGR_MOR & CKGR_MOR_MOSCSEL) )
     {
-        PMC->CKGR_MOR = SYS_CKGR_MOR_KEY_VALUE | SYS_BOARD_OSCOUNT | CKGR_MOR_MOSCRCEN | CKGR_MOR_MOSCXTEN;
+        PMC->CKGR_MOR = (SYS_CKGR_MOR_KEY_VALUE | SYS_BOARD_OSCOUNT
+                         | CKGR_MOR_MOSCRCEN | CKGR_MOR_MOSCXTEN);
 
         while ( !(PMC->PMC_SR & PMC_SR_MOSCXTS) )
         {
@@ -31,13 +33,16 @@ void SystemInit( void )
     }
 
     /* Switch to 3-20MHz Xtal oscillator */
-    PMC->CKGR_MOR = SYS_CKGR_MOR_KEY_VALUE | SYS_BOARD_OSCOUNT | CKGR_MOR_MOSCRCEN | CKGR_MOR_MOSCXTEN | CKGR_MOR_MOSCSEL;
+    PMC->CKGR_MOR = (SYS_CKGR_MOR_KEY_VALUE | SYS_BOARD_OSCOUNT
+                     | CKGR_MOR_MOSCRCEN | CKGR_MOR_MOSCXTEN
+                     | CKGR_MOR_MOSCSEL);
 
     while ( !(PMC->PMC_SR & PMC_SR_MOSCSELS) )
     {
     }
 
-    PMC->PMC_MCKR = (PMC->PMC_MCKR & ~(uint32_t)PMC_MCKR_CSS_Msk) | PMC_MCKR_CSS_MAIN_CLK;
+    PMC->PMC_MCKR = ((PMC->PMC_MCKR & ~(uint32_t)PMC_MCKR_CSS_Msk)
+                     | PMC_MCKR_CSS_MAIN_CLK);
 
     while ( !(PMC->PMC_SR & PMC_SR_MCKRDY) )
     {
@@ -50,7 +55,8 @@ void SystemInit( void )
     }
 
     /* Switch to main clock */
-    PMC->PMC_MCKR = (SYS_BOARD_MCKR & ~PMC_MCKR_CSS_Msk) | PMC_MCKR_CSS_MAIN_CLK;
+    PMC->PMC_MCKR = ((SYS_BOARD_MCKR & ~PMC_MCKR_CSS_Msk)
+                     | PMC_MCKR_CSS_MAIN_CLK);
     while ( !(PMC->PMC_SR & PMC_SR_MCKRDY) )
     {
     }