WDT: implement interrupt wdt and task wdt for ESP32-C2

ESP32-C2 has a single group timer, thus it will use it for the interrupt watchdog,
which is more critical than the task watchdog. The latter is implement in
software thanks to the `esp_timer`component.

.gitlab/ci/target-test.yml

@@ -980,7 +980,7 @@ UT_S2_SDSPI:
 
 UT_C2:
   extends: .unit_test_esp32c2_template
-  parallel: 21
+  parallel: 22
   tags:
     - ESP32C2_IDF
     - UT_T1_1

components/esp_event/test/test_event.c

@@ -22,8 +22,6 @@
 #include "test_utils.h"
 
 
-#if !TEMPORARY_DISABLED_FOR_TARGETS(ESP32C2)
-//IDF-4035
 static const char* TAG = "test_event";
 
 #define TEST_CONFIG_ITEMS_TO_REGISTER        5
@@ -2021,4 +2019,3 @@ TEST_CASE("can post events from interrupt handler", "[event]")
 }
 
 #endif // CONFIG_ESP_EVENT_POST_FROM_ISR
-#endif //!TEMPORARY_DISABLED_FOR_TARGETS(ESP32C2)

components/esp_hw_support/sleep_modes.c

@@ -47,6 +47,7 @@
 #include "esp_private/sleep_retention.h"
 #include "esp_private/esp_clk.h"
 #include "esp_private/startup_internal.h"
+#include "esp_private/esp_task_wdt.h"
 
 #ifdef CONFIG_IDF_TARGET_ESP32
 #include "esp32/rom/cache.h"
@@ -662,6 +663,13 @@ static inline bool can_power_down_vddsdio(const uint32_t vddsdio_pd_sleep_durati
 
 esp_err_t esp_light_sleep_start(void)
 {
+#if CONFIG_ESP_TASK_WDT_USE_ESP_TIMER
+    esp_err_t timerret = ESP_OK;
+
+    /* If a task watchdog timer is running, we have to stop it. */
+    timerret = esp_task_wdt_stop();
+#endif // CONFIG_ESP_TASK_WDT_USE_ESP_TIMER
+
     s_config.ccount_ticks_record = esp_cpu_get_cycle_count();
     static portMUX_TYPE light_sleep_lock = portMUX_INITIALIZER_UNLOCKED;
     portENTER_CRITICAL(&light_sleep_lock);
@@ -820,6 +828,14 @@ esp_err_t esp_light_sleep_start(void)
     }
     portEXIT_CRITICAL(&light_sleep_lock);
     s_config.sleep_time_overhead_out = (esp_cpu_get_cycle_count() - s_config.ccount_ticks_record) / (esp_clk_cpu_freq() / 1000000ULL);
+
+#if CONFIG_ESP_TASK_WDT_USE_ESP_TIMER
+    /* Restart the Task Watchdog timer as it was stopped before sleeping. */
+    if (timerret == ESP_OK) {
+        esp_task_wdt_restart();
+    }
+#endif // CONFIG_ESP_TASK_WDT_USE_ESP_TIMER
+
     return err;
 }
 

components/esp_pm/linker.lf

@@ -32,7 +32,7 @@ entries:
         freertos_hooks:esp_vApplicationIdleHook (noflash)
     if PM_SLP_IRAM_OPT = y:
         task_wdt:idle_hook_cb (noflash)
-        task_wdt:reset_hw_timer (noflash)
+        task_wdt:task_wdt_timer_feed (noflash)
         task_wdt:find_entry_and_check_all_reset (noflash)
         task_wdt:find_entry_from_task_handle_and_check_all_reset (noflash)
         task_wdt:esp_task_wdt_reset (noflash)
@@ -42,6 +42,9 @@ entries:
 archive: libesp_timer.a
 entries:
     if PM_SLP_IRAM_OPT = y:
+        # esp_timer_feed is called from task_wdt_timer_feed, so put it
+        # in IRAM if task_wdt_timer_feed itself is in IRAM.
+        esp_timer:esp_timer_feed (noflash)
         if ESP_TIMER_IMPL_TG0_LAC = y:
             esp_timer_impl_lac:esp_timer_impl_lock (noflash)
             esp_timer_impl_lac:esp_timer_impl_unlock (noflash)

components/esp_system/CMakeLists.txt

@@ -21,11 +21,14 @@ else()
             "startup.c"
             "system_time.c"
             "stack_check.c"
-            "task_wdt.c"
             "ubsan.c"
             "xt_wdt.c"
             "debug_stubs.c")
 
+    if(CONFIG_ESP_TASK_WDT)
+        list(APPEND srcs "task_wdt.c")
+    endif()
+
     if(CONFIG_ESP_SYSTEM_USE_EH_FRAME)
         list(APPEND srcs "eh_frame_parser.c")
     endif()

components/esp_system/Kconfig

@@ -367,7 +367,6 @@ menu "ESP System Settings"
 
     config ESP_INT_WDT
         bool "Interrupt watchdog"
-        default n if IDF_TARGET_ESP32C2 # add support in IDF-4114
         default y
         help
             This watchdog timer can detect if the FreeRTOS tick interrupt has not been called for a certain time,
@@ -392,18 +391,35 @@ menu "ESP System Settings"
             Also detect if interrupts on CPU 1 are disabled for too long.
 
     config ESP_TASK_WDT
-        bool "Initialize Task Watchdog Timer on startup"
+        bool "Enable Task Watchdog Timer"
         default y
         select FREERTOS_ENABLE_TASK_SNAPSHOT
         help
             The Task Watchdog Timer can be used to make sure individual tasks are still
-            running. Enabling this option will cause the Task Watchdog Timer to be
-            initialized automatically at startup. The Task Watchdog timer can be
-            initialized after startup as well (see Task Watchdog Timer API Reference)
+            running. Enabling this option will enable the Task Watchdog Timer. It can be
+            either initialized automatically at startup or initialized after startup
+            (see Task Watchdog Timer API Reference)
+
+    config ESP_TASK_WDT_USE_ESP_TIMER
+        # Software implementation of Task Watchdog, handy for targets with only a single
+        # Timer Group, such as the ESP32-C2
+        bool
+        depends on ESP_TASK_WDT
+        default y if IDF_TARGET_ESP32C2
+        default n if !IDF_TARGET_ESP32C2
+        select ESP_TIMER_SUPPORTS_ISR_DISPATCH_METHOD
+
+    config ESP_TASK_WDT_INIT
+        bool "Initialize Task Watchdog Timer on startup"
+        depends on ESP_TASK_WDT
+        default y
+        help
+            Enabling this option will cause the Task Watchdog Timer to be initialized
+            automatically at startup.
 
     config ESP_TASK_WDT_PANIC
         bool "Invoke panic handler on Task Watchdog timeout"
-        depends on ESP_TASK_WDT
+        depends on ESP_TASK_WDT_INIT
         default n
         help
             If this option is enabled, the Task Watchdog Timer will be configured to
@@ -412,7 +428,7 @@ menu "ESP System Settings"
 
     config ESP_TASK_WDT_TIMEOUT_S
         int "Task Watchdog timeout period (seconds)"
-        depends on ESP_TASK_WDT
+        depends on ESP_TASK_WDT_INIT
         range 1 60
         default 5
         help
@@ -421,7 +437,7 @@ menu "ESP System Settings"
 
     config ESP_TASK_WDT_CHECK_IDLE_TASK_CPU0
         bool "Watch CPU0 Idle Task"
-        depends on ESP_TASK_WDT
+        depends on ESP_TASK_WDT_INIT
         default y
         help
             If this option is enabled, the Task Watchdog Timer will watch the CPU0
@@ -432,10 +448,10 @@ menu "ESP System Settings"
 
     config ESP_TASK_WDT_CHECK_IDLE_TASK_CPU1
         bool "Watch CPU1 Idle Task"
-        depends on ESP_TASK_WDT && !FREERTOS_UNICORE
+        depends on ESP_TASK_WDT_INIT && !FREERTOS_UNICORE
         default y
         help
-            If this option is enabled, the Task Wtachdog Timer will wach the CPU1
+            If this option is enabled, the Task Watchdog Timer will wach the CPU1
             Idle Task.
 
     config ESP_XT_WDT

components/esp_system/crosscore_int.c

@@ -96,12 +96,14 @@ static void IRAM_ATTR esp_crosscore_isr(void *arg) {
         esp_backtrace_print(100);
     }
 
+#if CONFIG_ESP_TASK_WDT
     if (my_reason_val & REASON_TWDT_ABORT) {
         extern void task_wdt_timeout_abort_xtensa(bool);
         /* Called from a crosscore interrupt, thus, we are not the core that received
          * the TWDT interrupt, call the function with `false` as a parameter. */
         task_wdt_timeout_abort_xtensa(false);
     }
+#endif // CONFIG_ESP_TASK_WDT
 #endif // CONFIG_IDF_TARGET_ARCH_XTENSA
 }
 
@@ -171,7 +173,9 @@ void IRAM_ATTR esp_crosscore_int_send_print_backtrace(int core_id)
     esp_crosscore_int_send(core_id, REASON_PRINT_BACKTRACE);
 }
 
+#if CONFIG_ESP_TASK_WDT
 void IRAM_ATTR esp_crosscore_int_send_twdt_abort(int core_id) {
     esp_crosscore_int_send(core_id, REASON_TWDT_ABORT);
 }
+#endif // CONFIG_ESP_TASK_WDT
 #endif

components/esp_system/include/esp_private/esp_int_wdt.h

@@ -6,10 +6,32 @@
 
 #pragma once
 
+#include "system_internal.h"
+#include "soc/periph_defs.h"
+
 #ifdef __cplusplus
 extern "C" {
 #endif
 
+#if SOC_TIMER_GROUPS > 1
+
+/* If we have two hardware timer groups, use the second one for interrupt watchdog. */
+#define WDT_LEVEL_INTR_SOURCE   ETS_TG1_WDT_LEVEL_INTR_SOURCE
+#define IWDT_PRESCALER          MWDT1_TICK_PRESCALER   // Tick period of 500us if WDT source clock is 80MHz
+#define IWDT_TICKS_PER_US       MWDT1_TICKS_PER_US
+#define IWDT_INSTANCE           WDT_MWDT1
+#define IWDT_INITIAL_TIMEOUT_S  5
+
+#else
+
+#define WDT_LEVEL_INTR_SOURCE   ETS_TG0_WDT_LEVEL_INTR_SOURCE
+#define IWDT_PRESCALER          MWDT0_TICK_PRESCALER   // Tick period of 500us if WDT source clock is 80MHz
+#define IWDT_TICKS_PER_US       MWDT0_TICKS_PER_US
+#define IWDT_INSTANCE           WDT_MWDT0
+#define IWDT_INITIAL_TIMEOUT_S  5
+
+#endif // SOC_TIMER_GROUPS > 1
+
 /**
  * @brief Initialize the non-CPU-specific parts of interrupt watchdog.
  *

components/esp_system/include/esp_private/esp_task_wdt.h

@@ -0,0 +1,46 @@
+/*
+ * SPDX-FileCopyrightText: 2015-2022 Espressif Systems (Shanghai) CO LTD
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#pragma once
+
+#include "sdkconfig.h"
+#include "esp_err.h"
+
+#if CONFIG_ESP_TASK_WDT
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/**
+ * @brief   Stop the Task Watchdog Timer (TWDT)
+ *
+ * This function will temporarily stop the timer until it is restarted/resumed by a call to esp_task_wdt_restart().
+
+ * @note esp_task_wdt_stop() must not be called by multiple tasks simultaneously.
+ * @return
+ *  - ESP_OK: TWDT successfully stopped
+ *  - Other: Failed to stop the TWDT
+ */
+esp_err_t esp_task_wdt_stop(void);
+
+/**
+ * @brief   Restart the Task Watchdog Timer (TWDT)
+ *
+ * This function will restart/resume the timer after it has been stopped by esp_task_wdt_stop().
+
+ * @note esp_task_wdt_restart() must not be called by multiple tasks simultaneously.
+ * @return
+ *  - ESP_OK: TWDT successfully stopped
+ *  - Other: Failed to stop the TWDT
+ */
+esp_err_t esp_task_wdt_restart(void);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif // CONFIG_ESP_TASK_WDT

components/esp_system/include/esp_private/system_internal.h

@@ -1,16 +1,8 @@
-// Copyright 2018 Espressif Systems (Shanghai) PTE LTD
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
+/*
+ * SPDX-FileCopyrightText: 2018-2022 Espressif Systems (Shanghai) CO LTD
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
 
 #pragma once
 
@@ -20,11 +12,25 @@ extern "C" {
 
 #include "esp_system.h"
 
+#if !CONFIG_ESP_TASK_WDT_USE_ESP_TIMER
+
+/* All the targets that have more than one timer group are using
+ * APB clock by default, which frequency is 80MHz.
+ * Thus, we can determine the default parameter for the prescaler here */
 #define MWDT0_TICK_PRESCALER    40000
 #define MWDT0_TICKS_PER_US      500
 #define MWDT1_TICK_PRESCALER    40000
 #define MWDT1_TICKS_PER_US      500
 
+#else
+
+/* The targets that have a single timer group use XTAL clock as the
+ * default clock. XTAL clock frequency is 40MHz. */
+#define MWDT0_TICK_PRESCALER    20000
+#define MWDT0_TICKS_PER_US      500
+
+#endif
+
 /**
  * @brief  Internal function to restart PRO and APP CPUs.
  *

components/esp_system/include/esp_task_wdt.h

@@ -36,7 +36,8 @@ typedef struct esp_task_wdt_user_handle_s * esp_task_wdt_user_handle_t;
  * this function will update the TWDT's current configuration. This funciton will also subscribe the idle tasks if
  * configured to do so. For other tasks, users can subscribe them using esp_task_wdt_add() or esp_task_wdt_add_user().
  *
- * @note esp_task_wdt_init() must only be called after the scheduler is started
+ * @note esp_task_wdt_init() must only be called after the scheduler is started. Moreover, it must not be called by
+ *       multiple tasks simultaneously.
  * @param[in] config Configuration structure
  * @return
  *  - ESP_OK: Initialization was successful
@@ -51,6 +52,7 @@ esp_err_t esp_task_wdt_init(const esp_task_wdt_config_t *config);
  * are still subscribed to the TWDT, or when the TWDT is already deinitialized, will result in an error code being
  * returned.
  *
+ * @note esp_task_wdt_deinit() must not be called by multiple tasks simultaneously.
  * @return
  *  - ESP_OK: TWDT successfully deinitialized
  *  - Other: Failed to deinitialize TWDT
@@ -150,6 +152,16 @@ esp_err_t esp_task_wdt_delete_user(esp_task_wdt_user_handle_t user_handle);
  */
 esp_err_t esp_task_wdt_status(TaskHandle_t task_handle);
 
+/**
+ * @brief User ISR callback placeholder
+ *
+ * This function is called by task_wdt_isr function (ISR for when TWDT times out). It can be defined in user code to
+ * handle TWDT events.
+ *
+ * @note It has the same limitations as the interrupt function. Do not use ESP_LOGx functions inside.
+ */
+void __attribute__((weak)) esp_task_wdt_isr_user_handler(void);
+
 #ifdef __cplusplus
 }
 #endif