Merge pull request #13722 from jue89/feature/ztimer_pm-layered

sys/ztimer: add power management for ztimer clocks

sys/include/ztimer.h

@@ -223,6 +223,11 @@
 extern "C" {
 #endif
 
+/**
+ * @brief   Disables interaction with pm_layered for a clock
+ */
+#define ZTIMER_CLOCK_NO_REQUIRED_PM_MODE (UINT8_MAX)
+
 /**
  * @brief ztimer_base_t forward declaration
  */
@@ -297,6 +302,9 @@ struct ztimer_clock {
     uint32_t lower_last;            /**< timer value at last now() call     */
     ztimer_now_t checkpoint;        /**< cumulated time at last now() call  */
 #endif
+#if MODULE_PM_LAYERED || DOXYGEN
+    uint8_t required_pm_mode;       /**< min. pm mode required for the clock to run */
+#endif
 };
 
 /**
@@ -374,16 +382,6 @@ int ztimer_msg_receive_timeout(ztimer_clock_t *clock, msg_t *msg,
  /* created with dist/tools/define2u16.py */
 #define MSG_ZTIMER 0xc83e   /**< msg type used by ztimer_msg_receive_timeout */
 
-/*
- * @brief ztimer_now() for extending timers
- *
- * @internal
- *
- * @param[in]   clock          ztimer clock to operate on
- * @return  Current count on the clock @p clock
- */
-ztimer_now_t _ztimer_now_extend(ztimer_clock_t *clock);
-
 /**
  * @brief ztimer_now() for extending timers
  *

sys/ztimer/auto_init.c

@@ -86,6 +86,14 @@
 #define CONFIG_ZTIMER_USEC_WIDTH (32)
 #endif
 
+#ifndef CONFIG_ZTIMER_USEC_REQUIRED_PM_MODE
+#define CONFIG_ZTIMER_USEC_REQUIRED_PM_MODE ZTIMER_CLOCK_NO_REQUIRED_PM_MODE
+#endif
+
+#ifndef CONFIG_ZTIMER_MSEC_REQUIRED_PM_MODE
+#define CONFIG_ZTIMER_MSEC_REQUIRED_PM_MODE ZTIMER_CLOCK_NO_REQUIRED_PM_MODE
+#endif
+
 #if MODULE_ZTIMER_USEC
 #  if CONFIG_ZTIMER_USEC_TYPE_PERIPH_TIMER
 static ztimer_periph_timer_t _ztimer_periph_timer_usec = { .min = CONFIG_ZTIMER_USEC_MIN };
@@ -160,6 +168,11 @@ void ztimer_init(void)
             CONFIG_ZTIMER_USEC_ADJUST);
     ZTIMER_USEC->adjust = CONFIG_ZTIMER_USEC_ADJUST;
 #  endif
+#  ifdef MODULE_PM_LAYERED
+    LOG_DEBUG("ztimer_init(): ZTIMER_USEC setting required_pm_mode to %i\n",
+            CONFIG_ZTIMER_USEC_REQUIRED_PM_MODE);
+    ZTIMER_USEC->required_pm_mode = CONFIG_ZTIMER_USEC_REQUIRED_PM_MODE;
+#  endif
 #endif
 
 #ifdef ZTIMER_RTT_INIT
@@ -180,5 +193,10 @@ void ztimer_init(void)
             CONFIG_ZTIMER_MSEC_ADJUST);
     ZTIMER_MSEC->adjust = CONFIG_ZTIMER_MSEC_ADJUST;
 #  endif
+#  ifdef MODULE_PM_LAYERED
+    LOG_DEBUG("ztimer_init(): ZTIMER_MSEC setting required_pm_mode to %i\n",
+            CONFIG_ZTIMER_MSEC_REQUIRED_PM_MODE);
+    ZTIMER_MSEC->required_pm_mode = CONFIG_ZTIMER_MSEC_REQUIRED_PM_MODE;
+#  endif
 #endif
 }

sys/ztimer/core.c

@@ -27,6 +27,9 @@
 
 #include "kernel_defines.h"
 #include "irq.h"
+#ifdef MODULE_PM_LAYERED
+#include "pm_layered.h"
+#endif
 #include "ztimer.h"
 
 #define ENABLE_DEBUG (0)
@@ -106,6 +109,13 @@ static void _add_entry_to_list(ztimer_clock_t *clock, ztimer_base_t *entry)
 
     ztimer_base_t *list = &clock->list;
 
+#ifdef MODULE_PM_LAYERED
+    /* First timer on the clock's linked list */
+    if (list->next == NULL && clock->required_pm_mode != ZTIMER_CLOCK_NO_REQUIRED_PM_MODE) {
+        pm_block(clock->required_pm_mode);
+    }
+#endif
+
     /* Jump past all entries which are set to an earlier target than the new entry */
     while (list->next) {
         ztimer_base_t *list_entry = list->next;
@@ -223,6 +233,13 @@ static void _del_entry_from_list(ztimer_clock_t *clock, ztimer_base_t *entry)
         }
         list = list->next;
     }
+
+#ifdef MODULE_PM_LAYERED
+    /* The last timer just got removed from the clock's linked list */
+    if (clock->list.next == NULL && clock->required_pm_mode != ZTIMER_CLOCK_NO_REQUIRED_PM_MODE) {
+        pm_unblock(clock->required_pm_mode);
+    }
+#endif
 }
 
 static ztimer_t *_now_next(ztimer_clock_t *clock)
@@ -232,7 +249,13 @@ static ztimer_t *_now_next(ztimer_clock_t *clock)
     if (entry && (entry->offset == 0)) {
         clock->list.next = entry->next;
         if (!entry->next) {
+            /* The last timer just got removed from the clock's linked list */
             clock->last = NULL;
+#ifdef MODULE_PM_LAYERED
+            if (clock->required_pm_mode != ZTIMER_CLOCK_NO_REQUIRED_PM_MODE) {
+                pm_unblock(clock->required_pm_mode);
+            }
+#endif
         }
         return (ztimer_t*)entry;
     }