cpu/sam0_common: add cpu_pm_cb_enter()/leave()

This allows to implement needed work-arounds surrounding sleep on
a per-MCU basis.

cpu/sam0_common/include/periph_cpu_common.h

@@ -367,6 +367,20 @@ void gpio_pm_cb_enter(int deep);
  */
 void gpio_pm_cb_leave(int deep);
 
+/**
+ * @brief   Called before the power management enters a power mode
+ *
+ * @param[in] deep
+ */
+void cpu_pm_cb_enter(int deep);
+
+/**
+ * @brief   Called after the power management left a power mode
+ *
+ * @param[in] deep
+ */
+void cpu_pm_cb_leave(int deep);
+
 /**
  * @brief   Wrapper for cortexm_sleep calling power management callbacks
  *
@@ -378,8 +392,12 @@ static inline void sam0_cortexm_sleep(int deep)
     gpio_pm_cb_enter(deep);
 #endif
 
+    cpu_pm_cb_enter(deep);
+
     cortexm_sleep(deep);
 
+    cpu_pm_cb_leave(deep);
+
 #ifdef MODULE_PERIPH_GPIO
     gpio_pm_cb_leave(deep);
 #endif

cpu/samd21/cpu.c

@@ -90,6 +90,18 @@ uint32_t sam0_gclk_freq(uint8_t id)
     }
 }
 
+void cpu_pm_cb_enter(int deep)
+{
+    (void) deep;
+    /* will be called before entering sleep */
+}
+
+void cpu_pm_cb_leave(int deep)
+{
+    (void) deep;
+    /* will be called after wake-up */
+}
+
 /**
  * @brief   Configure clock sources and the cpu frequency
  */

cpu/samd5x/cpu.c

@@ -144,6 +144,18 @@ uint32_t sam0_gclk_freq(uint8_t id)
     }
 }
 
+void cpu_pm_cb_enter(int deep)
+{
+    (void) deep;
+    /* will be called before entering sleep */
+}
+
+void cpu_pm_cb_leave(int deep)
+{
+    (void) deep;
+    /* will be called after wake-up */
+}
+
 /**
  * @brief Initialize the CPU, set IRQ priorities, clocks
  */

cpu/saml1x/cpu.c

@@ -99,6 +99,18 @@ uint32_t sam0_gclk_freq(uint8_t id)
     }
 }
 
+void cpu_pm_cb_enter(int deep)
+{
+    (void) deep;
+    /* will be called before entering sleep */
+}
+
+void cpu_pm_cb_leave(int deep)
+{
+    (void) deep;
+    /* will be called after wake-up */
+}
+
 /**
  * @brief Initialize the CPU, set IRQ priorities, clocks
  */

cpu/saml21/cpu.c

@@ -126,6 +126,19 @@ static void _dfll_setup(void)
     NVMCTRL->CTRLB.reg |= NVMCTRL_CTRLB_RWS(3);
 #endif
 }
+
+void cpu_pm_cb_enter(int deep)
+{
+    (void) deep;
+    /* will be called before entering sleep */
+}
+
+void cpu_pm_cb_leave(int deep)
+{
+    (void) deep;
+    /* will be called after wake-up */
+}
+
 /**
  * @brief Initialize the CPU, set IRQ priorities, clocks
  */