Add a more scalable mechanism for the FreeRTOS tick- and idle hooks; idle handler now uses WAITI to reduce power

components/esp32/freertos_hooks.c

@@ -0,0 +1,81 @@
+#include <stdint.h>
+#include <stdlib.h>
+#include <stdbool.h>
+#include "esp_attr.h"
+#include "esp_freertos_hooks.h"
+
+//We use just a static array here because it's not expected many components will need
+//an idle or tick hook.
+#define MAX_HOOKS 8
+
+static esp_freertos_idle_cb_t idle_cb[MAX_HOOKS]={0};
+static esp_freertos_tick_cb_t tick_cb[MAX_HOOKS]={0};
+
+void IRAM_ATTR esp_vApplicationTickHook() 
+{
+    int n;
+    for (n=0; n<MAX_HOOKS; n++) {
+        if (tick_cb[n]!=NULL) {
+            tick_cb[n]();
+        }
+    }
+}
+
+void esp_vApplicationIdleHook() 
+{
+    bool doWait=true;
+    bool r;
+    int n;
+    for (n=0; n<MAX_HOOKS; n++) {
+        if (idle_cb[n]!=NULL) {
+            r=idle_cb[n]();
+            if (!r) doWait=false;
+        }
+    }
+    if (doWait) {
+        //Wait for whatever interrupt comes next... this should save some power.
+        asm("waiti 0");
+    }
+}
+
+
+esp_err_t esp_register_freertos_idle_hook(esp_freertos_idle_cb_t new_idle_cb) 
+{
+    int n;
+    for (n=0; n<MAX_HOOKS; n++) {
+        if (idle_cb[n]==NULL) {
+            idle_cb[n]=new_idle_cb;
+            return ESP_OK;
+        }
+    }
+    return ESP_ERR_NO_MEM;
+}
+
+esp_err_t esp_register_freertos_tick_hook(esp_freertos_tick_cb_t new_tick_cb) 
+{
+    int n;
+    for (n=0; n<MAX_HOOKS; n++) {
+        if (tick_cb[n]==NULL) {
+            tick_cb[n]=new_tick_cb;
+            return ESP_OK;
+        }
+    }
+    return ESP_ERR_NO_MEM;
+}
+
+void esp_deregister_freertos_idle_hook(esp_freertos_idle_cb_t old_idle_cb)
+{
+    int n;
+    for (n=0; n<MAX_HOOKS; n++) {
+        if (idle_cb[n]==old_idle_cb) idle_cb[n]=NULL;
+    }
+}
+
+void esp_deregister_freertos_tick_hook(esp_freertos_tick_cb_t old_tick_cb)
+{
+    int n;
+    for (n=0; n<MAX_HOOKS; n++) {
+        if (tick_cb[n]==old_tick_cb) tick_cb[n]=NULL;
+    }
+}
+

components/esp32/include/esp_freertos_hooks.h

@@ -0,0 +1,58 @@
+#ifndef ESP_FREERTOS_HOOKS_H
+#define ESP_FREERTOS_HOOKS_H
+
+#include <stdbool.h>
+#include "esp_err.h"
+
+
+/*
+ Definitions for the tickhook and idlehook callbacks
+*/
+typedef bool (*esp_freertos_idle_cb_t)();
+typedef void (*esp_freertos_tick_cb_t)();
+
+/**
+  * @brief  Register a callback to be called on the freertos idle hook
+  *         The callback should return true if it's okay for the core to
+  *         sleep until an interrupt (or FreeRTOS tick) happens and false
+  *         if it should be called again as fast as possible.
+  *
+  * @param  esp_freertos_idle_cb_t new_idle_cb : Callback to be called
+  *
+  * @return ESP_OK : Callback registered
+  * @return ESP_ERR_NO_MEM : No more space to register hook
+  */
+esp_err_t esp_register_freertos_idle_hook(esp_freertos_idle_cb_t new_idle_cb);
+
+/**
+  * @brief  Register a callback to be called on the freertos tick hook
+  *
+  * @param  esp_freertos_tick_cb_t new_tick_cb : Callback to be called
+  *
+  * @return ESP_OK : Callback registered
+  * @return ESP_ERR_NO_MEM : No more space to register hook
+  */
+esp_err_t esp_register_freertos_tick_hook(esp_freertos_tick_cb_t tick_cb);
+
+
+/**
+  * @brief  Unregister an idle callback registered earlier
+  *
+  * @param  esp_freertos_idle_cb_t new_idle_cb : Callback to be unregistered
+  *
+  * @return void
+  */
+void esp_deregister_freertos_idle_hook(esp_freertos_idle_cb_t old_idle_cb);
+
+
+/**
+  * @brief  Unregister a tick callback registered earlier
+  *
+  * @param  esp_freertos_idle_cb_t new_idle_cb : Callback to be unregistered
+  *
+  * @return void
+  */
+void esp_deregister_freertos_tick_hook(esp_freertos_tick_cb_t old_tick_cb);
+
+
+#endif

components/esp32/int_wdt.c

@@ -25,6 +25,7 @@
 #include "esp_err.h"
 #include "esp_intr.h"
 #include "esp_attr.h"
+#include "esp_freertos_hooks.h"
 #include "soc/timer_group_struct.h"
 #include "soc/timer_group_reg.h"
 
@@ -36,38 +37,12 @@
 #define WDT_INT_NUM 24
 
 
-void esp_int_wdt_init() {
-    TIMERG1.wdt_wprotect=TIMG_WDT_WKEY_VALUE;
-    TIMERG1.wdt_config0.sys_reset_length=7;                 //3.2uS
-    TIMERG1.wdt_config0.cpu_reset_length=7;                 //3.2uS
-    TIMERG1.wdt_config0.level_int_en=1;
-    TIMERG1.wdt_config0.stg0=TIMG_WDT_STG_SEL_INT;          //1st stage timeout: interrupt
-    TIMERG1.wdt_config0.stg1=TIMG_WDT_STG_SEL_RESET_SYSTEM; //2nd stage timeout: reset system
-    TIMERG1.wdt_config1.clk_prescale=80*500;                //Prescaler: wdt counts in ticks of 0.5mS
-    //The timer configs initially are set to 5 seconds, to make sure the CPU can start up. The tick hook sets
-    //it to their actual value.
-    TIMERG1.wdt_config2=10000;
-    TIMERG1.wdt_config3=10000;
-    TIMERG1.wdt_config0.en=1;
-    TIMERG1.wdt_feed=1;
-    TIMERG1.wdt_wprotect=0;
-    TIMERG1.int_clr_timers.wdt=1;
-    TIMERG1.int_ena.wdt=1;
-    ESP_INTR_DISABLE(WDT_INT_NUM);
-    intr_matrix_set(xPortGetCoreID(), ETS_TG1_WDT_LEVEL_INTR_SOURCE, WDT_INT_NUM);
-    //We do not register a handler for the interrupt because it is interrupt level 4 which
-    //is not servicable from C. Instead, xtensa_vectors.S has a call to the panic handler for
-    //this interrupt.
-    ESP_INTR_ENABLE(WDT_INT_NUM);
-}
-
-
 //Take care: the tick hook can also be called before esp_int_wdt_init() is called.
 #if CONFIG_INT_WDT_CHECK_CPU1
 //Not static; the ISR assembly checks this.
 bool int_wdt_app_cpu_ticked=false;
 
-void IRAM_ATTR vApplicationTickHook(void) {
+static void IRAM_ATTR tick_hook(void) {
     if (xPortGetCoreID()!=0) {
         int_wdt_app_cpu_ticked=true;
     } else {
@@ -83,7 +58,7 @@ void IRAM_ATTR vApplicationTickHook(void) {
     }
 }
 #else
-void IRAM_ATTR vApplicationTickHook(void) {
+static void IRAM_ATTR tick_hook(void) {
     if (xPortGetCoreID()!=0) return;
     TIMERG1.wdt_wprotect=TIMG_WDT_WKEY_VALUE;
     TIMERG1.wdt_config2=CONFIG_INT_WDT_TIMEOUT_MS*2;        //Set timeout before interrupt
@@ -93,4 +68,33 @@ void IRAM_ATTR vApplicationTickHook(void) {
 }
 #endif
 
+
+void esp_int_wdt_init() {
+    TIMERG1.wdt_wprotect=TIMG_WDT_WKEY_VALUE;
+    TIMERG1.wdt_config0.sys_reset_length=7;                 //3.2uS
+    TIMERG1.wdt_config0.cpu_reset_length=7;                 //3.2uS
+    TIMERG1.wdt_config0.level_int_en=1;
+    TIMERG1.wdt_config0.stg0=TIMG_WDT_STG_SEL_INT;          //1st stage timeout: interrupt
+    TIMERG1.wdt_config0.stg1=TIMG_WDT_STG_SEL_RESET_SYSTEM; //2nd stage timeout: reset system
+    TIMERG1.wdt_config1.clk_prescale=80*500;                //Prescaler: wdt counts in ticks of 0.5mS
+    //The timer configs initially are set to 5 seconds, to make sure the CPU can start up. The tick hook sets
+    //it to their actual value.
+    TIMERG1.wdt_config2=10000;
+    TIMERG1.wdt_config3=10000;
+    TIMERG1.wdt_config0.en=1;
+    TIMERG1.wdt_feed=1;
+    TIMERG1.wdt_wprotect=0;
+    TIMERG1.int_clr_timers.wdt=1;
+    TIMERG1.int_ena.wdt=1;
+    esp_register_freertos_tick_hook(tick_hook);
+    ESP_INTR_DISABLE(WDT_INT_NUM);
+    intr_matrix_set(xPortGetCoreID(), ETS_TG1_WDT_LEVEL_INTR_SOURCE, WDT_INT_NUM);
+    //We do not register a handler for the interrupt because it is interrupt level 4 which
+    //is not servicable from C. Instead, xtensa_vectors.S has a call to the panic handler for
+    //this interrupt.
+    ESP_INTR_ENABLE(WDT_INT_NUM);
+}
+
+
+
 #endif

components/esp32/task_wdt.c

@@ -26,6 +26,7 @@
 #include "esp_err.h"
 #include "esp_intr.h"
 #include "esp_attr.h"
+#include "esp_freertos_hooks.h"
 #include "soc/timer_group_struct.h"
 #include "soc/timer_group_reg.h"
 #include "esp_log.h"
@@ -140,6 +141,18 @@ void esp_task_wdt_delete() {
     }
 }
 
+
+#if CONFIG_TASK_WDT_CHECK_IDLE_TASK
+static bool idle_hook(void) {
+#if !CONFIG_TASK_WDT_CHECK_IDLE_TASK_CPU1
+    if (xPortGetCoreID()!=0) return;
+#endif
+    esp_task_wdt_feed();
+    return true;
+}
+#endif
+
+
 void esp_task_wdt_init() {
     TIMERG0.wdt_wprotect=TIMG_WDT_WKEY_VALUE;
     TIMERG0.wdt_config0.sys_reset_length=7;                 //3.2uS
@@ -153,6 +166,9 @@ void esp_task_wdt_init() {
     TIMERG0.wdt_config0.en=1;
     TIMERG0.wdt_feed=1;
     TIMERG0.wdt_wprotect=0;
+#if CONFIG_TASK_WDT_CHECK_IDLE_TASK
+    esp_register_freertos_idle_hook(idle_hook);
+#endif
     ESP_INTR_DISABLE(ETS_T0_WDT_INUM);
     intr_matrix_set(xPortGetCoreID(), ETS_TG0_WDT_LEVEL_INTR_SOURCE, ETS_T0_WDT_INUM);
     xt_set_interrupt_handler(ETS_T0_WDT_INUM, task_wdt_isr, NULL);
@@ -161,13 +177,5 @@ void esp_task_wdt_init() {
     ESP_INTR_ENABLE(ETS_T0_WDT_INUM);
 }
 
-#if CONFIG_TASK_WDT_CHECK_IDLE_TASK
-void vApplicationIdleHook(void) {
-#if !CONFIG_TASK_WDT_CHECK_IDLE_TASK_CPU1
-    if (xPortGetCoreID()!=0) return;
-#endif
-    esp_task_wdt_feed();
-}
-#endif
 
 #endif

components/freertos/Kconfig

@@ -141,6 +141,35 @@ config FREERTOS_ISR_STACKSIZE
         The interrupt handlers have their own stack. The size of the stack can be defined here. 
         Each processor has its own stack, so the total size occupied will be twice this.
 
+config FREERTOS_LEGACY_HOOKS
+    bool "Use FreeRTOS legacy hooks"
+    default n
+    help
+        FreeRTOS offers a number of hooks/callback functions that are called when a timer
+        tick happens, the idle thread runs etc. esp-idf replaces these by runtime registerable
+        hooks using the esp_register_freertos_xxx_hook system, but for legacy reasons the old
+        hooks can also still be enabled. Please enable this only if you have code that for some
+        reason can't be migrated to the esp_register_freertos_xxx_hook system.
+
+if FREERTOS_LEGACY_HOOKS
+
+config FREERTOS_LEGACY_IDLE_HOOK
+    bool "Enable legacy idle hook"
+    default n
+    help
+        If enabled, FreeRTOS will call a function called vApplicationIdleHook when the idle thread
+        on a CPU is running. Please make sure your code defines such a function.
+
+config FREERTOS_LEGACY_TICK_HOOK
+    bool "Enable legacy tick hook"
+    default n
+    help
+        If enabled, FreeRTOS will call a function called vApplicationTickHook when a FreeRTOS
+        tick is executed. Please make sure your code defines such a function.
+
+endif #FREERTOS_LEGACY_HOOKS
+
+
 menuconfig FREERTOS_DEBUG_INTERNALS
     bool "Debug FreeRTOS internals"
     default n

components/freertos/include/freertos/FreeRTOSConfig.h

@@ -152,9 +152,9 @@
  *----------------------------------------------------------*/
 
 #define configUSE_PREEMPTION			1
-#define configUSE_IDLE_HOOK				( CONFIG_TASK_WDT_CHECK_IDLE_TASK )
+#define configUSE_IDLE_HOOK				( CONFIG_FREERTOS_LEGACY_IDLE_HOOK )
 
-#define configUSE_TICK_HOOK				( CONFIG_INT_WDT )
+#define configUSE_TICK_HOOK				( CONFIG_FREERTOS_LEGACY_TICK_HOOK )
 
 #define configTICK_RATE_HZ				( CONFIG_FREERTOS_HZ )
 

components/freertos/tasks.c

@@ -476,6 +476,7 @@ to its original value when it is released. */
 #if configUSE_TICK_HOOK > 0
 	extern void vApplicationTickHook( void );
 #endif
+extern void esp_vApplicationTickHook( void );
 
 #if  portFIRST_TASK_HOOK
 	extern void vPortFirstTaskHook(TaskFunction_t taskfn);
@@ -2360,22 +2361,21 @@ BaseType_t xSwitchRequired = pdFALSE;
 		  We can't really calculate what we need, that's done on core 0... just assume we need a switch.
 		  ToDo: Make this more intelligent? -- JD
 		*/
-		//We do need the tick hook to satisfy the int watchdog.
-		#if ( configUSE_TICK_HOOK == 1 )
 		{
 			/* Guard against the tick hook being called when the pended tick
 			count is being unwound (when the scheduler is being unlocked). */
 			if( ( uxSchedulerSuspended[ xPortGetCoreID() ] != ( UBaseType_t ) pdFALSE ) || uxPendedTicks == ( UBaseType_t ) 0U )
 			{
+				#if ( configUSE_TICK_HOOK == 1 )
 				vApplicationTickHook();
+				#endif /* configUSE_TICK_HOOK */
+				esp_vApplicationTickHook();
 			}
 			else
 			{
 				mtCOVERAGE_TEST_MARKER();
 			}
 		}
-		#endif /* configUSE_TICK_HOOK */
-
 
 		return pdTRUE;
 	}
@@ -2506,20 +2506,21 @@ BaseType_t xSwitchRequired = pdFALSE;
 		}
 		#endif /* ( ( configUSE_PREEMPTION == 1 ) && ( configUSE_TIME_SLICING == 1 ) ) */
 
-		#if ( configUSE_TICK_HOOK == 1 )
 		{
 			/* Guard against the tick hook being called when the pended tick
 			count is being unwound (when the scheduler is being unlocked). */
 			if( uxPendedTicks == ( UBaseType_t ) 0U )
 			{
+				#if ( configUSE_TICK_HOOK == 1 )
 				vApplicationTickHook();
+				#endif /* configUSE_TICK_HOOK */
+				esp_vApplicationTickHook();
 			}
 			else
 			{
 				mtCOVERAGE_TEST_MARKER();
 			}
 		}
-		#endif /* configUSE_TICK_HOOK */
 		taskEXIT_CRITICAL_ISR(&xTaskQueueMutex);
 	}
 	else
@@ -2533,6 +2534,7 @@ BaseType_t xSwitchRequired = pdFALSE;
 			vApplicationTickHook();
 		}
 		#endif
+		esp_vApplicationTickHook();
 	}
 
 	#if ( configUSE_PREEMPTION == 1 )
@@ -3270,6 +3272,12 @@ static portTASK_FUNCTION( prvIdleTask, pvParameters )
 			vApplicationIdleHook();
 		}
 		#endif /* configUSE_IDLE_HOOK */
+		{
+			/* Call the esp-idf hook system */
+			extern void esp_vApplicationIdleHook( void );
+			esp_vApplicationIdleHook();
+		}
+
 
 		/* This conditional compilation should use inequality to 0, not equality
 		to 1.  This is to ensure portSUPPRESS_TICKS_AND_SLEEP() is called when