xtensa/esp32s2: add support for shutdown handlers

arch/xtensa/src/esp32s2/esp32s2_systemreset.c

@@ -31,11 +31,88 @@
 
 #include "xtensa.h"
 #include "hardware/esp32s2_rtccntl.h"
+#include "esp32s2_systemreset.h"
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+#define SHUTDOWN_HANDLERS_NO 4
+
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+
+static shutdown_handler_t shutdown_handlers[SHUTDOWN_HANDLERS_NO];
 
 /****************************************************************************
  * Public Functions
  ****************************************************************************/
 
+/****************************************************************************
+ * Name: esp32s2_register_shutdown_handler
+ *
+ * Description:
+ *   This function allows you to register a handler that gets invoked before
+ *   the application is restarted.
+ *
+ * Input Parameters:
+ *   handler - Function to execute on restart
+ *
+ * Returned Value:
+ *   OK on success (positive non-zero values are cmd-specific)
+ *   Negated errno returned on failure.
+ *
+ ****************************************************************************/
+
+int esp32s2_register_shutdown_handler(shutdown_handler_t handler)
+{
+  for (int i = 0; i < SHUTDOWN_HANDLERS_NO; i++)
+    {
+      if (shutdown_handlers[i] == handler)
+        {
+          return -EEXIST;
+        }
+      else if (shutdown_handlers[i] == NULL)
+        {
+          shutdown_handlers[i] = handler;
+          return OK;
+        }
+    }
+
+  return -ENOMEM;
+}
+
+/****************************************************************************
+ * Name: esp32s2_unregister_shutdown_handler
+ *
+ * Description:
+ *   This function allows you to unregister a handler which was previously
+ *   registered using up_register_shutdown_handler function.
+ *
+ * Input Parameters:
+ *   handler - Function to execute on restart
+ *
+ * Returned Value:
+ *   OK on success (positive non-zero values are cmd-specific)
+ *   Negated errno returned on failure.
+ *
+ ****************************************************************************/
+
+int esp32s2_unregister_shutdown_handler(shutdown_handler_t handler)
+{
+  for (int i = 0; i < SHUTDOWN_HANDLERS_NO; i++)
+    {
+      if (shutdown_handlers[i] == handler)
+        {
+          shutdown_handlers[i] = NULL;
+          return OK;
+        }
+    }
+
+  return -EINVAL;
+}
+
 /****************************************************************************
  * Name: up_systemreset
  *

arch/xtensa/src/esp32s2/esp32s2_systemreset.h

@@ -0,0 +1,105 @@
+/****************************************************************************
+ * arch/xtensa/src/esp32s2/esp32s2_systemreset.h
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.  The
+ * ASF licenses this file to you 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.
+ *
+ ****************************************************************************/
+
+#ifndef __ARCH_XTENSA_SRC_ESP32S3_ESP32S3_SYSTEMRESET_H
+#define __ARCH_XTENSA_SRC_ESP32S3_ESP32S3_SYSTEMRESET_H
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#ifndef __ASSEMBLY__
+
+#include <stdint.h>
+
+#undef EXTERN
+#if defined(__cplusplus)
+#define EXTERN extern "C"
+extern "C"
+{
+#else
+#define EXTERN extern
+#endif
+
+/****************************************************************************
+ * Public Types
+ ****************************************************************************/
+
+/* Shutdown handler type */
+
+typedef void (*shutdown_handler_t)(void);
+
+/****************************************************************************
+ * Public Function Prototypes
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: esp32s2_register_shutdown_handler
+ *
+ * Description:
+ *   This function allows you to register a handler that gets invoked before
+ *   the application is restarted.
+ *
+ * Input Parameters:
+ *   handler - Function to execute on restart
+ *
+ * Returned Value:
+ *   OK on success (positive non-zero values are cmd-specific)
+ *   Negated errno returned on failure.
+ *
+ ****************************************************************************/
+
+int esp32s2_register_shutdown_handler(shutdown_handler_t handler);
+
+/****************************************************************************
+ * Name: esp32s2_unregister_shutdown_handler
+ *
+ * Description:
+ *   This function allows you to unregister a handler which was previously
+ *   registered using up_register_shutdown_handler function.
+ *
+ * Input Parameters:
+ *   handler - Function to execute on restart
+ *
+ * Returned Value:
+ *   OK on success (positive non-zero values are cmd-specific)
+ *   Negated errno returned on failure.
+ *
+ ****************************************************************************/
+
+int esp32s2_unregister_shutdown_handler(shutdown_handler_t handler);
+
+/****************************************************************************
+ * Name: up_shutdown_handler
+ *
+ * Description:
+ *   Process all registered shutdown callback functions.
+ *
+ ****************************************************************************/
+
+void up_shutdown_handler(void);
+
+#ifdef __cplusplus
+}
+#endif
+#undef EXTERN
+
+#endif /* __ASSEMBLY__ */
+#endif /* __ARCH_XTENSA_SRC_ESP32S2_ESP32S2_SYSTEMRESET_H */