dynamic_electrocardiograph_ble_server/zble_nus_c.c

/**
 * Copyright (c) 2012 - 2021, Nordic Semiconductor ASA
 *
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without modification,
 * are permitted provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright notice, this
 *    list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form, except as embedded into a Nordic
 *    Semiconductor ASA integrated circuit in a product or a software update for
 *    such product, must reproduce the above copyright notice, this list of
 *    conditions and the following disclaimer in the documentation and/or other
 *    materials provided with the distribution.
 *
 * 3. Neither the name of Nordic Semiconductor ASA nor the names of its
 *    contributors may be used to endorse or promote products derived from this
 *    software without specific prior written permission.
 *
 * 4. This software, with or without modification, must only be used with a
 *    Nordic Semiconductor ASA integrated circuit.
 *
 * 5. Any software provided in binary form under this license must not be reverse
 *    engineered, decompiled, modified and/or disassembled.
 *
 * THIS SOFTWARE IS PROVIDED BY NORDIC SEMICONDUCTOR ASA "AS IS" AND ANY EXPRESS
 * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY, NONINFRINGEMENT, AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL NORDIC SEMICONDUCTOR ASA OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
 * GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 */
#include "sdk_common.h"
#if NRF_MODULE_ENABLED(BLE_NUS_C)
#include <stdlib.h>

#include "app_error.h"
#include "ble.h"
#include "ble_gattc.h"
#include "ble_srv_common.h"
#include "zble_nus_c.h"

#define NRF_LOG_MODULE_NAME ble_nus_c
#include "nrf_log.h"
NRF_LOG_MODULE_REGISTER();

/**@brief Function for intercepting the errors of GATTC and the BLE GATT Queue.
 *
 * @param[in] nrf_error   Error code.
 * @param[in] p_ctx       Parameter from the event handler.
 * @param[in] conn_handle Connection handle.
 */
static void gatt_error_handler(uint32_t nrf_error, void *p_ctx, uint16_t conn_handle) {
  ble_nus_c_t *p_ble_nus_c = (ble_nus_c_t *)p_ctx;

  NRF_LOG_DEBUG("A GATT Client error has occurred on conn_handle: 0X%X", conn_handle);

  if (p_ble_nus_c->error_handler != NULL) {
    p_ble_nus_c->error_handler(nrf_error);
  }
}

void ble_nus_c_on_db_disc_evt(ble_nus_c_t *p_ble_nus_c, ble_db_discovery_evt_t *p_evt) {
  ble_nus_c_evt_t nus_c_evt;
  memset(&nus_c_evt, 0, sizeof(ble_nus_c_evt_t));

  ble_gatt_db_char_t *p_chars = p_evt->params.discovered_db.charateristics;

  // Check if the NUS was discovered.
  if ((p_evt->evt_type == BLE_DB_DISCOVERY_COMPLETE) && (p_evt->params.discovered_db.srv_uuid.uuid == BLE_UUID_NUS_SERVICE) && (p_evt->params.discovered_db.srv_uuid.type == p_ble_nus_c->uuid_type)) {
    for (uint32_t i = 0; i < p_evt->params.discovered_db.char_count; i++) {
      switch (p_chars[i].characteristic.uuid.uuid) {
        case BLE_UUID_NUS_RX_CHARACTERISTIC:
          nus_c_evt.handles.nus_rx_handle = p_chars[i].characteristic.handle_value;
          break;
        case BLE_UUID_NUS_TX_CHARACTERISTIC:
          nus_c_evt.handles.nus_tx_handle      = p_chars[i].characteristic.handle_value;
          nus_c_evt.handles.nus_tx_cccd_handle = p_chars[i].cccd_handle;
          break;
        case BLE_UUID_NUS_TX_CHARACTERISTIC_2:
          nus_c_evt.handles.nus_tx_handle_2      = p_chars[i].characteristic.handle_value;
          nus_c_evt.handles.nus_tx_cccd_handle_2 = p_chars[i].cccd_handle;
          break;

        default:
          break;
      }
    }
    if (p_ble_nus_c->evt_handler != NULL) {
      nus_c_evt.conn_handle = p_evt->conn_handle;
      nus_c_evt.evt_type    = BLE_NUS_C_EVT_DISCOVERY_COMPLETE;
      p_ble_nus_c->evt_handler(p_ble_nus_c, &nus_c_evt);
    }
  }
}

/**@brief     Function for handling Handle Value Notification received from the SoftDevice.
 *
 * @details   This function uses the Handle Value Notification received from the SoftDevice
 *            and checks if it is a notification of the NUS TX characteristic from the peer.
 *            If it is, this function decodes the data and sends it to the application.
 *
 * @param[in] p_ble_nus_c Pointer to the NUS Client structure.
 * @param[in] p_ble_evt   Pointer to the BLE event received.
 */
static void on_hvx(ble_nus_c_t *p_ble_nus_c, ble_evt_t const *p_ble_evt) {
  // HVX can only occur from client sending.
  if ((p_ble_nus_c->handles.nus_tx_handle != BLE_GATT_HANDLE_INVALID) && (p_ble_evt->evt.gattc_evt.params.hvx.handle == p_ble_nus_c->handles.nus_tx_handle) && (p_ble_nus_c->evt_handler != NULL)) {
    ble_nus_c_evt_t ble_nus_c_evt;

    ble_nus_c_evt.evt_type = BLE_NUS_C_EVT_NUS_TX_EVT;
    ble_nus_c_evt.p_data   = (uint8_t *)p_ble_evt->evt.gattc_evt.params.hvx.data;
    ble_nus_c_evt.data_len = p_ble_evt->evt.gattc_evt.params.hvx.len;

    p_ble_nus_c->evt_handler(p_ble_nus_c, &ble_nus_c_evt);
    NRF_LOG_DEBUG("Client sending data.");
  }

  if ((p_ble_nus_c->handles.nus_tx_handle_2 != BLE_GATT_HANDLE_INVALID) && (p_ble_evt->evt.gattc_evt.params.hvx.handle == p_ble_nus_c->handles.nus_tx_handle_2) && (p_ble_nus_c->evt_handler != NULL)) {
    ble_nus_c_evt_t ble_nus_c_evt;

    // ble_nus_c_evt.evt_type = BLE_NUS_C_EVT_NUS_TX_EVT_2;
    ble_nus_c_evt.evt_type = BLE_NUS_C_EVT_NUS_TX_EVT;
    ble_nus_c_evt.p_data   = (uint8_t *)p_ble_evt->evt.gattc_evt.params.hvx.data;
    ble_nus_c_evt.data_len = p_ble_evt->evt.gattc_evt.params.hvx.len;

    p_ble_nus_c->evt_handler(p_ble_nus_c, &ble_nus_c_evt);
    NRF_LOG_DEBUG("Client sending data.");
  }
}

uint32_t ble_nus_c_init(ble_nus_c_t *p_ble_nus_c, ble_nus_c_init_t *p_ble_nus_c_init) {
  uint32_t      err_code;
  ble_uuid_t    uart_uuid;
  ble_uuid128_t nus_base_uuid = NUS_BASE_UUID;

  VERIFY_PARAM_NOT_NULL(p_ble_nus_c);
  VERIFY_PARAM_NOT_NULL(p_ble_nus_c_init);
  VERIFY_PARAM_NOT_NULL(p_ble_nus_c_init->p_gatt_queue);

  err_code = sd_ble_uuid_vs_add(&nus_base_uuid, &p_ble_nus_c->uuid_type);
  VERIFY_SUCCESS(err_code);

  uart_uuid.type = p_ble_nus_c->uuid_type;
  uart_uuid.uuid = BLE_UUID_NUS_SERVICE;

  p_ble_nus_c->conn_handle             = BLE_CONN_HANDLE_INVALID;
  p_ble_nus_c->evt_handler             = p_ble_nus_c_init->evt_handler;
  p_ble_nus_c->error_handler           = p_ble_nus_c_init->error_handler;
  p_ble_nus_c->handles.nus_tx_handle   = BLE_GATT_HANDLE_INVALID;
  p_ble_nus_c->handles.nus_tx_handle_2 = BLE_GATT_HANDLE_INVALID;
  p_ble_nus_c->handles.nus_rx_handle   = BLE_GATT_HANDLE_INVALID;
  p_ble_nus_c->p_gatt_queue            = p_ble_nus_c_init->p_gatt_queue;

  return ble_db_discovery_evt_register(&uart_uuid);
}

void ble_nus_c_on_ble_evt(ble_evt_t const *p_ble_evt, void *p_context) {
  ble_nus_c_t *p_ble_nus_c = (ble_nus_c_t *)p_context;

  if ((p_ble_nus_c == NULL) || (p_ble_evt == NULL)) {
    return;
  }

  if ((p_ble_nus_c->conn_handle == BLE_CONN_HANDLE_INVALID) || (p_ble_nus_c->conn_handle != p_ble_evt->evt.gap_evt.conn_handle)) {
    return;
  }

  switch (p_ble_evt->header.evt_id) {
    case BLE_GATTC_EVT_HVX:
      on_hvx(p_ble_nus_c, p_ble_evt);
      break;

    case BLE_GAP_EVT_DISCONNECTED:
      if (p_ble_evt->evt.gap_evt.conn_handle == p_ble_nus_c->conn_handle && p_ble_nus_c->evt_handler != NULL) {
        ble_nus_c_evt_t nus_c_evt;

        nus_c_evt.evt_type = BLE_NUS_C_EVT_DISCONNECTED;

        p_ble_nus_c->conn_handle = BLE_CONN_HANDLE_INVALID;
        p_ble_nus_c->evt_handler(p_ble_nus_c, &nus_c_evt);
      }
      break;

    default:
      // No implementation needed.
      break;
  }
}

/**@brief Function for creating a message for writing to the CCCD. */
static uint32_t cccd_configure(ble_nus_c_t *p_ble_nus_c, bool notification_enable) {
  nrf_ble_gq_req_t cccd_req;
  uint8_t          cccd[BLE_CCCD_VALUE_LEN];
  uint16_t         cccd_val = notification_enable ? BLE_GATT_HVX_NOTIFICATION : 0;

  memset(&cccd_req, 0, sizeof(nrf_ble_gq_req_t));

  cccd[0] = LSB_16(cccd_val);
  cccd[1] = MSB_16(cccd_val);

  cccd_req.type                        = NRF_BLE_GQ_REQ_GATTC_WRITE;
  cccd_req.error_handler.cb            = gatt_error_handler;
  cccd_req.error_handler.p_ctx         = p_ble_nus_c;
  cccd_req.params.gattc_write.handle   = p_ble_nus_c->handles.nus_tx_cccd_handle;
  cccd_req.params.gattc_write.len      = BLE_CCCD_VALUE_LEN;
  cccd_req.params.gattc_write.offset   = 0;
  cccd_req.params.gattc_write.p_value  = cccd;
  cccd_req.params.gattc_write.write_op = BLE_GATT_OP_WRITE_REQ;
  cccd_req.params.gattc_write.flags    = BLE_GATT_EXEC_WRITE_FLAG_PREPARED_WRITE;

  return nrf_ble_gq_item_add(p_ble_nus_c->p_gatt_queue, &cccd_req, p_ble_nus_c->conn_handle);
}

static uint32_t cccd_configure_2(ble_nus_c_t *p_ble_nus_c, bool notification_enable) {
  nrf_ble_gq_req_t cccd_req;
  uint8_t          cccd[BLE_CCCD_VALUE_LEN];
  uint16_t         cccd_val = notification_enable ? BLE_GATT_HVX_NOTIFICATION : 0;

  memset(&cccd_req, 0, sizeof(nrf_ble_gq_req_t));

  cccd[0] = LSB_16(cccd_val);
  cccd[1] = MSB_16(cccd_val);

  cccd_req.type                        = NRF_BLE_GQ_REQ_GATTC_WRITE;
  cccd_req.error_handler.cb            = gatt_error_handler;
  cccd_req.error_handler.p_ctx         = p_ble_nus_c;
  cccd_req.params.gattc_write.handle   = p_ble_nus_c->handles.nus_tx_cccd_handle_2;
  cccd_req.params.gattc_write.len      = BLE_CCCD_VALUE_LEN;
  cccd_req.params.gattc_write.offset   = 0;
  cccd_req.params.gattc_write.p_value  = cccd;
  cccd_req.params.gattc_write.write_op = BLE_GATT_OP_WRITE_REQ;
  cccd_req.params.gattc_write.flags    = BLE_GATT_EXEC_WRITE_FLAG_PREPARED_WRITE;

  return nrf_ble_gq_item_add(p_ble_nus_c->p_gatt_queue, &cccd_req, p_ble_nus_c->conn_handle);
}

uint32_t ble_nus_c_tx_notif_enable(ble_nus_c_t *p_ble_nus_c) {
  VERIFY_PARAM_NOT_NULL(p_ble_nus_c);

  if ((p_ble_nus_c->conn_handle == BLE_CONN_HANDLE_INVALID) || (p_ble_nus_c->handles.nus_tx_cccd_handle == BLE_GATT_HANDLE_INVALID)) {
    return NRF_ERROR_INVALID_STATE;
  }
  if ((p_ble_nus_c->conn_handle == BLE_CONN_HANDLE_INVALID) || (p_ble_nus_c->handles.nus_tx_cccd_handle_2 == BLE_GATT_HANDLE_INVALID)) {
    return NRF_ERROR_INVALID_STATE;
  }
  cccd_configure(p_ble_nus_c, true);
  return cccd_configure_2(p_ble_nus_c, true);
}

uint32_t ble_nus_c_string_send(ble_nus_c_t *p_ble_nus_c, uint8_t *p_string, uint16_t length) {
  VERIFY_PARAM_NOT_NULL(p_ble_nus_c);

  nrf_ble_gq_req_t write_req;

  memset(&write_req, 0, sizeof(nrf_ble_gq_req_t));

  if (length > BLE_NUS_MAX_DATA_LEN) {
    NRF_LOG_WARNING("Content too long.");
    return NRF_ERROR_INVALID_PARAM;
  }
  if (p_ble_nus_c->conn_handle == BLE_CONN_HANDLE_INVALID) {
    NRF_LOG_WARNING("Connection handle invalid.");
    return NRF_ERROR_INVALID_STATE;
  }

  write_req.type                        = NRF_BLE_GQ_REQ_GATTC_WRITE;
  write_req.error_handler.cb            = gatt_error_handler;
  write_req.error_handler.p_ctx         = p_ble_nus_c;
  write_req.params.gattc_write.handle   = p_ble_nus_c->handles.nus_rx_handle;
  write_req.params.gattc_write.len      = length;
  write_req.params.gattc_write.offset   = 0;
  write_req.params.gattc_write.p_value  = p_string;
  write_req.params.gattc_write.write_op = BLE_GATT_OP_WRITE_CMD;
  write_req.params.gattc_write.flags    = BLE_GATT_EXEC_WRITE_FLAG_PREPARED_WRITE;

  return nrf_ble_gq_item_add(p_ble_nus_c->p_gatt_queue, &write_req, p_ble_nus_c->conn_handle);
}

uint32_t ble_nus_c_handles_assign(ble_nus_c_t *p_ble_nus, uint16_t conn_handle, ble_nus_c_handles_t const *p_peer_handles) {
  VERIFY_PARAM_NOT_NULL(p_ble_nus);

  p_ble_nus->conn_handle = conn_handle;
  if (p_peer_handles != NULL) {
    p_ble_nus->handles.nus_tx_cccd_handle   = p_peer_handles->nus_tx_cccd_handle;
    p_ble_nus->handles.nus_tx_handle        = p_peer_handles->nus_tx_handle;
    p_ble_nus->handles.nus_tx_cccd_handle_2 = p_peer_handles->nus_tx_cccd_handle_2;
    p_ble_nus->handles.nus_tx_handle_2      = p_peer_handles->nus_tx_handle_2;

    p_ble_nus->handles.nus_rx_handle = p_peer_handles->nus_rx_handle;
  }
  return nrf_ble_gq_conn_handle_register(p_ble_nus->p_gatt_queue, conn_handle);
}

#endif