text: /*
   * SPDX-FileCopyrightText: 2016-2021 Espressif Systems (Shanghai) CO LTD
   *
   * SPDX-License-Identifier: Apache-2.0
   */
  
  #ifndef _MB_CONTROLLER_SLAVE_H
  #define _MB_CONTROLLER_SLAVE_H
  
  #include "driver/uart.h"    // for uart defines
  #include "errno.h"          // for errno
  #include "sys/queue.h"      // for list
  #include "esp_log.h"        // for log write
  #include "string.h"         // for strerror()
  
  #include "esp_modbus_slave.h"    // for public type defines
  #include "esp_modbus_callbacks.h"   // for callback functions
  
  /* ----------------------- Defines ------------------------------------------*/
  #define MB_INST_MIN_SIZE                    (2) // The minimal size of Modbus registers area in bytes
  #define MB_INST_MAX_SIZE                    (65535 * 2) // The maximum size of Modbus area in bytes
  
  #define MB_CONTROLLER_NOTIFY_QUEUE_SIZE     (CONFIG_FMB_CONTROLLER_NOTIFY_QUEUE_SIZE) // Number of messages in parameter notification queue
  #define MB_CONTROLLER_NOTIFY_TIMEOUT        (pdMS_TO_TICKS(CONFIG_FMB_CONTROLLER_NOTIFY_TIMEOUT)) // notification timeout
  
  #define MB_SLAVE_TAG "MB_CONTROLLER_SLAVE"
  
  #define MB_SLAVE_CHECK(a, ret_val, str, ...) \
      if (!(a)) { \
          ESP_LOGE(MB_SLAVE_TAG, "%s(%u): " str, __FUNCTION__, __LINE__, ##__VA_ARGS__); \
          return (ret_val); \
      }
  
  #define MB_SLAVE_ASSERT(con) do { \
          if (!(con)) { ESP_LOGE(MB_SLAVE_TAG, "assert errno:%d, errno_str: !(%s)", errno, strerror(errno)); assert(0 && #con); } \
      } while (0)
  
  /**
   * @brief Device communication parameters for master
   */
  typedef struct {
      mb_mode_type_t mode;                    /*!< Modbus communication mode */
      uint8_t slave_addr;                     /*!< Slave address field */
      uart_port_t port;                       /*!< Modbus communication port (UART) number */
      uint32_t baudrate;                      /*!< Modbus baudrate */
      uart_parity_t parity;                   /*!< Modbus UART parity settings */
  } mb_slave_comm_info_t;
  
  /**
   * @brief Modbus area descriptor list item
   */
  typedef struct mb_descr_entry_s{
      uint16_t start_offset;                  /*!< Modbus start address for area descriptor */
      mb_param_type_t type;                   /*!< Type of storage area descriptor */
      void* p_data;                           /*!< Instance address for storage area descriptor */
      size_t size;                            /*!< Instance size for area descriptor (bytes) */
      LIST_ENTRY(mb_descr_entry_s) entries;    /*!< The Modbus area descriptor entry */
  } mb_descr_entry_t;
  
  /**
   * @brief Modbus controller handler structure
   */
  typedef struct {
      mb_port_type_t port_type;                           /*!< port type */
      mb_communication_info_t mbs_comm;                   /*!< communication info */
      TaskHandle_t mbs_task_handle;                       /*!< task handle */
      EventGroupHandle_t mbs_event_group;                 /*!< controller event group */
      QueueHandle_t mbs_notification_queue_handle;        /*!< controller notification queue */
      LIST_HEAD(mbs_area_descriptors_, mb_descr_entry_s) mbs_area_descriptors[MB_PARAM_COUNT]; /*!< register area descriptors */
  } mb_slave_options_t;
  
  typedef mb_event_group_t (*iface_check_event)(mb_event_group_t);          /*!< Interface method check_event */
  typedef esp_err_t (*iface_get_param_info)(mb_param_info_t*, uint32_t);    /*!< Interface method get_param_info */
  typedef esp_err_t (*iface_set_descriptor)(mb_register_area_descriptor_t); /*!< Interface method set_descriptor */
  
  /**
   * @brief Request mode for parameter to use in data dictionary
   */
  typedef struct
  {
      mb_slave_options_t opts;                                    /*!< Modbus slave options */
  
      // Functional pointers to internal static functions of the implementation (public interface methods)
      iface_init init;                        /*!< Interface method init */
      iface_destroy destroy;                  /*!< Interface method destroy */
      iface_setup setup;                      /*!< Interface method setup */
      iface_start start;                      /*!< Interface method start */
      iface_check_event check_event;          /*!< Interface method check_event */
      iface_get_param_info get_param_info;    /*!< Interface method get_param_info */
      iface_set_descriptor set_descriptor;    /*!< Interface method set_descriptor */
  
      // Modbus register calback function pointers
      reg_discrete_cb slave_reg_cb_discrete;  /*!< Stack callback discrete rw method */
      reg_input_cb slave_reg_cb_input;        /*!< Stack callback input rw method */
      reg_holding_cb slave_reg_cb_holding;    /*!< Stack callback holding rw method */
      reg_coils_cb slave_reg_cb_coils;        /*!< Stack callback coils rw method */
  } mb_slave_interface_t;
  
  #endif
  