canbus: canopen: add object dictionary storage

Add support for storing the CANopen object dictionary to non-volatile
storage.

This fixes #15278.

Signed-off-by: Henrik Brix Andersen <hebad@vestas.com>

include/canbus/canopen.h

@@ -0,0 +1,97 @@
+/*
+ * Copyright (c) 2019 Vestas Wind Systems A/S
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+/**
+ * @brief CANopen Network Stack
+ * @defgroup canopen CANopen Network Stack
+ * @ingroup CAN
+ * @{
+ */
+
+#ifndef ZEPHYR_INCLUDE_CANOPEN_H_
+#define ZEPHYR_INCLUDE_CANOPEN_H_
+
+#include <CANopen.h>
+#include <CO_Emergency.h>
+#include <CO_SDO.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/**
+ * @brief CANopen object dictionary storage types.
+ */
+enum canopen_storage {
+	CANOPEN_STORAGE_RAM,
+	CANOPEN_STORAGE_ROM,
+	CANOPEN_STORAGE_EEPROM,
+};
+
+/**
+ * @brief Attach CANopen object dictionary storage handlers.
+ *
+ * Attach CANopen storage handler functions to object dictionary
+ * indexes 0x1010 (Store parameters) and 0x1011 (Restore default
+ * parameters). This function must be called after calling CANopenNode
+ * `CO_init()`.
+ *
+ * The handlers will save object dictionary entries of type @ref
+ * CANOPEN_STORAGE_ROM to non-volatile storage when a CANopen SDO
+ * client writes 0x65766173 ('s', 'a', 'v', 'e' from LSB to MSB) to
+ * object dictionary index 0x1010 sub-index 1.
+ *
+ * Object dictionary entries of types @ref CANOPEN_STORAGE_ROM (and
+ * optionally @ref CANOPEN_STORAGE_EEPROM) will be deleted from
+ * non-volatile storage when a CANopen SDO client writes 0x64616F6C
+ * ('l', 'o', 'a', 'd' from LSB to MSB) to object dictionary index
+ * 0x1011 sub-index 1.
+ *
+ * Object dictionary entries of type @ref CANOPEN_STORAGE_EEPROM may be
+ * saved by the application by periodically calling @ref
+ * canopen_storage_save().
+ *
+ * Object dictionary entries of type @ref CANOPEN_STORAGE_RAM are
+ * never saved to non-volatile storage.
+ *
+ * @param sdo CANopenNode SDO server object
+ * @param em  CANopenNode Emergency object
+ */
+void canopen_storage_attach(CO_SDO_t *sdo, CO_EM_t *em);
+
+/**
+ * @brief Save CANopen object dictionary entries to non-volatile storage.
+ *
+ * Save object dictionary entries of a given type to non-volatile
+ * storage.
+ *
+ * @param storage CANopen object dictionary entry type
+ *
+ * @return 0 if successful, negative errno code if failure
+ */
+int canopen_storage_save(enum canopen_storage storage);
+
+/**
+ * @brief Erase CANopen object dictionary entries from non-volatile storage.
+ *
+ * Erase object dictionary entries of a given type from non-volatile
+ * storage.
+ *
+ * @param storage CANopen object dictionary entry type
+ *
+ * @return 0 if successful, negative errno code if failure
+ */
+int canopen_storage_erase(enum canopen_storage storage);
+
+#ifdef __cplusplus
+}
+#endif
+
+/**
+ * @}
+ */
+
+#endif /* ZEPHYR_INCLUDE_CANOPEN_H_ */