ble_hts.c

/**
 * Copyright (c) 2012 - 2017, 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
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 */
/* Attention!
*  To maintain compliance with Nordic Semiconductor ASA’s Bluetooth profile
*  qualification listings, this section of source code must not be modified.
*/
#include "sdk_common.h"
#if NRF_MODULE_ENABLED(BLE_HTS)
#include "ble_hts.h"
#include <string.h>
#include "ble_l2cap.h"
#include "ble_srv_common.h"


#define OPCODE_LENGTH 1                                                           /**< Length of opcode inside Health Thermometer Measurement packet. */
#define HANDLE_LENGTH 2                                                           /**< Length of handle inside Health Thermometer Measurement packet. */
#define MAX_HTM_LEN   (BLE_GATT_ATT_MTU_DEFAULT - OPCODE_LENGTH - HANDLE_LENGTH)  /**< Maximum size of a transmitted Health Thermometer Measurement. */

// Health Thermometer Measurement flag bits
#define HTS_MEAS_FLAG_TEMP_UNITS_BIT (0x01 << 0)  /**< Temperature Units flag. */
#define HTS_MEAS_FLAG_TIME_STAMP_BIT (0x01 << 1)  /**< Time Stamp flag. */
#define HTS_MEAS_FLAG_TEMP_TYPE_BIT  (0x01 << 2)  /**< Temperature Type flag. */


/**@brief Function for handling the Connect event.
 *
 * @param[in]   p_hts       Health Thermometer Service structure.
 * @param[in]   p_ble_evt   Event received from the BLE stack.
 */
static void on_connect(ble_hts_t * p_hts, ble_evt_t * p_ble_evt)
{
    p_hts->conn_handle = p_ble_evt->evt.gatts_evt.conn_handle;
}


/**@brief Function for handling the Disconnect event.
 *
 * @param[in]   p_hts       Health Thermometer Service structure.
 * @param[in]   p_ble_evt   Event received from the BLE stack.
 */
static void on_disconnect(ble_hts_t * p_hts, ble_evt_t * p_ble_evt)
{
    UNUSED_PARAMETER(p_ble_evt);
    p_hts->conn_handle = BLE_CONN_HANDLE_INVALID;
}


/**@brief Function for handling write events to the Blood Pressure Measurement characteristic.
 *
 * @param[in]   p_hts         Health Thermometer Service structure.
 * @param[in]   p_evt_write   Write event received from the BLE stack.
 */
static void on_cccd_write(ble_hts_t * p_hts, ble_gatts_evt_write_t * p_evt_write)
{
    if (p_evt_write->len == 2)
    {
        // CCCD written, update indication state
        if (p_hts->evt_handler != NULL)
        {
            ble_hts_evt_t evt;

            if (ble_srv_is_indication_enabled(p_evt_write->data))
            {
                evt.evt_type = BLE_HTS_EVT_INDICATION_ENABLED;
            }
            else
            {
                evt.evt_type = BLE_HTS_EVT_INDICATION_DISABLED;
            }

            p_hts->evt_handler(p_hts, &evt);
        }
    }
}


/**@brief Function for handling the Write event.
 *
 * @param[in]   p_hts       Health Thermometer Service structure.
 * @param[in]   p_ble_evt   Event received from the BLE stack.
 */
static void on_write(ble_hts_t * p_hts, ble_evt_t * p_ble_evt)
{
    ble_gatts_evt_write_t * p_evt_write = &p_ble_evt->evt.gatts_evt.params.write;

    if (p_evt_write->handle == p_hts->meas_handles.cccd_handle)
    {
        on_cccd_write(p_hts, p_evt_write);
    }
}


/**@brief Function for handling the HVC event.
 *
 * @details Handles HVC events from the BLE stack.
 *
 * @param[in]   p_hts       Health Thermometer Service structure.
 * @param[in]   p_ble_evt   Event received from the BLE stack.
 */
static void on_hvc(ble_hts_t * p_hts, ble_evt_t * p_ble_evt)
{
    ble_gatts_evt_hvc_t * p_hvc = &p_ble_evt->evt.gatts_evt.params.hvc;

    if (p_hvc->handle == p_hts->meas_handles.value_handle)
    {
        ble_hts_evt_t evt;

        evt.evt_type = BLE_HTS_EVT_INDICATION_CONFIRMED;
        p_hts->evt_handler(p_hts, &evt);
    }
}


void ble_hts_on_ble_evt(ble_hts_t * p_hts, ble_evt_t * p_ble_evt)
{
    switch (p_ble_evt->header.evt_id)
    {
        case BLE_GAP_EVT_CONNECTED:
            on_connect(p_hts, p_ble_evt);
            break;

        case BLE_GAP_EVT_DISCONNECTED:
            on_disconnect(p_hts, p_ble_evt);
            break;

        case BLE_GATTS_EVT_WRITE:
            on_write(p_hts, p_ble_evt);
            break;

        case BLE_GATTS_EVT_HVC:
            on_hvc(p_hts, p_ble_evt);
            break;

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


/**@brief Function for encoding a Health Thermometer Measurement.
 *
 * @param[in]   p_hts              Health Thermometer Service structure.
 * @param[in]   p_hts_meas         Measurement to be encoded.
 * @param[out]  p_encoded_buffer   Buffer where the encoded data will be written.
 *
 * @return      Size of encoded data.
 */
static uint8_t hts_measurement_encode(ble_hts_t      * p_hts,
                                      ble_hts_meas_t * p_hts_meas,
                                      uint8_t        * p_encoded_buffer)
{
    uint8_t  flags = 0;
    uint8_t  len   = 1;
    uint32_t encoded_temp;

    // Flags field
    if (p_hts_meas->temp_in_fahr_units)
    {
        flags |= HTS_MEAS_FLAG_TEMP_UNITS_BIT;
    }
    if (p_hts_meas->time_stamp_present)
    {
        flags |= HTS_MEAS_FLAG_TIME_STAMP_BIT;
    }

    // Temperature Measurement Value field
    if (p_hts_meas->temp_in_fahr_units)
    {
        flags |= HTS_MEAS_FLAG_TEMP_UNITS_BIT;

        encoded_temp = ((p_hts_meas->temp_in_fahr.exponent << 24) & 0xFF000000) |
                       ((p_hts_meas->temp_in_fahr.mantissa <<  0) & 0x00FFFFFF);
    }
    else
    {
        encoded_temp = ((p_hts_meas->temp_in_celcius.exponent << 24) & 0xFF000000) |
                       ((p_hts_meas->temp_in_celcius.mantissa <<  0) & 0x00FFFFFF);
    }
    len += uint32_encode(encoded_temp, &p_encoded_buffer[len]);

    // Time Stamp field
    if (p_hts_meas->time_stamp_present)
    {
        flags |= HTS_MEAS_FLAG_TIME_STAMP_BIT;
        len   += ble_date_time_encode(&p_hts_meas->time_stamp, &p_encoded_buffer[len]);
    }

    // Temperature Type field
    if (p_hts_meas->temp_type_present)
    {
        flags                  |= HTS_MEAS_FLAG_TEMP_TYPE_BIT;
        p_encoded_buffer[len++] = p_hts_meas->temp_type;
    }

    // Flags field
    p_encoded_buffer[0] = flags;

    return len;
}


/**@brief Function for adding Health Thermometer Measurement characteristics.
 *
 * @param[in]   p_hts        Health Thermometer Service structure.
 * @param[in]   p_hts_init   Information needed to initialize the service.
 *
 * @return      NRF_SUCCESS on success, otherwise an error code.
 */
static uint32_t hts_measurement_char_add(ble_hts_t * p_hts, const ble_hts_init_t * p_hts_init)
{
    ble_gatts_char_md_t char_md;
    ble_gatts_attr_md_t cccd_md;
    ble_gatts_attr_t    attr_char_value;
    ble_uuid_t          ble_uuid;
    ble_gatts_attr_md_t attr_md;
    ble_hts_meas_t      initial_htm;
    uint8_t             encoded_htm[MAX_HTM_LEN];

    memset(&cccd_md, 0, sizeof(cccd_md));

    BLE_GAP_CONN_SEC_MODE_SET_OPEN(&cccd_md.read_perm);
    cccd_md.vloc = BLE_GATTS_VLOC_STACK;
    cccd_md.write_perm = p_hts_init->hts_meas_attr_md.cccd_write_perm;

    memset(&char_md, 0, sizeof(char_md));

    char_md.char_props.indicate = 1;
    char_md.p_char_user_desc    = NULL;
    char_md.p_char_pf           = NULL;
    char_md.p_user_desc_md      = NULL;
    char_md.p_cccd_md           = &cccd_md;
    char_md.p_sccd_md           = NULL;

    BLE_UUID_BLE_ASSIGN(ble_uuid, BLE_UUID_TEMPERATURE_MEASUREMENT_CHAR);

    memset(&attr_md, 0, sizeof(attr_md));

    attr_md.vloc       = BLE_GATTS_VLOC_STACK;
    attr_md.read_perm  = p_hts_init->hts_meas_attr_md.read_perm;
    attr_md.write_perm = p_hts_init->hts_meas_attr_md.write_perm;
    attr_md.rd_auth    = 0;
    attr_md.wr_auth    = 0;
    attr_md.vlen       = 1;

    memset(&attr_char_value, 0, sizeof(attr_char_value));
    memset(&initial_htm, 0, sizeof(initial_htm));

    attr_char_value.p_uuid    = &ble_uuid;
    attr_char_value.p_attr_md = &attr_md;
    attr_char_value.init_len  = hts_measurement_encode(p_hts, &initial_htm, encoded_htm);
    attr_char_value.init_offs = 0;
    attr_char_value.max_len   = MAX_HTM_LEN;
    attr_char_value.p_value   = encoded_htm;

    return sd_ble_gatts_characteristic_add(p_hts->service_handle,
                                           &char_md,
                                           &attr_char_value,
                                           &p_hts->meas_handles);
}


/**@brief Function for adding Temperature Type characteristics.
 *
 * @param[in]   p_hts        Health Thermometer Service structure.
 * @param[in]   p_hts_init   Information needed to initialize the service.
 *
 * @return      NRF_SUCCESS on success, otherwise an error code.
 */
static uint32_t hts_temp_type_char_add(ble_hts_t * p_hts, const ble_hts_init_t * p_hts_init)
{
    ble_gatts_char_md_t char_md;
    ble_gatts_attr_t    attr_char_value;
    ble_uuid_t          ble_uuid;
    ble_gatts_attr_md_t attr_md;
    uint8_t             init_value_temp_type;
    uint8_t             init_value_encoded[1];

    memset(&char_md, 0, sizeof(char_md));

    char_md.char_props.read  = 1;
    char_md.p_char_user_desc = NULL;
    char_md.p_char_pf        = NULL;
    char_md.p_user_desc_md   = NULL;
    char_md.p_cccd_md        = NULL;
    char_md.p_sccd_md        = NULL;

    BLE_UUID_BLE_ASSIGN(ble_uuid, BLE_UUID_TEMPERATURE_TYPE_CHAR);

    memset(&attr_md, 0, sizeof(attr_md));

    attr_md.vloc       = BLE_GATTS_VLOC_STACK;
    attr_md.read_perm  = p_hts_init->hts_temp_type_attr_md.read_perm;
    attr_md.write_perm = p_hts_init->hts_temp_type_attr_md.write_perm;
    attr_md.rd_auth    = 0;
    attr_md.wr_auth    = 0;
    attr_md.vlen       = 0;

    memset(&attr_char_value, 0, sizeof(attr_char_value));

    init_value_temp_type  = p_hts_init->temp_type;
    init_value_encoded[0] = init_value_temp_type;

    attr_char_value.p_uuid    = &ble_uuid;
    attr_char_value.p_attr_md = &attr_md;
    attr_char_value.init_len  = sizeof (uint8_t);
    attr_char_value.init_offs = 0;
    attr_char_value.max_len   = sizeof (uint8_t);
    attr_char_value.p_value   = init_value_encoded;

    return sd_ble_gatts_characteristic_add(p_hts->service_handle,
                                           &char_md,
                                           &attr_char_value,
                                           &p_hts->temp_type_handles);
}


uint32_t ble_hts_init(ble_hts_t * p_hts, const ble_hts_init_t * p_hts_init)
{
    uint32_t   err_code;
    ble_uuid_t ble_uuid;

    // Initialize service structure
    p_hts->evt_handler = p_hts_init->evt_handler;
    p_hts->conn_handle = BLE_CONN_HANDLE_INVALID;
    p_hts->temp_type   = p_hts_init->temp_type;

    // Add service
    BLE_UUID_BLE_ASSIGN(ble_uuid, BLE_UUID_HEALTH_THERMOMETER_SERVICE);

    err_code = sd_ble_gatts_service_add(BLE_GATTS_SRVC_TYPE_PRIMARY, &ble_uuid, &p_hts->service_handle);
    if (err_code != NRF_SUCCESS)
    {
        return err_code;
    }

    // Add measurement characteristic
    err_code = hts_measurement_char_add(p_hts, p_hts_init);
    if (err_code != NRF_SUCCESS)
    {
        return err_code;
    }

    // Add temperature type characteristic
    if (p_hts_init->temp_type_as_characteristic)
    {
        err_code = hts_temp_type_char_add(p_hts, p_hts_init);
        if (err_code != NRF_SUCCESS)
        {
            return err_code;
        }
    }

    return NRF_SUCCESS;
}


uint32_t ble_hts_measurement_send(ble_hts_t * p_hts, ble_hts_meas_t * p_hts_meas)
{
    uint32_t err_code;

    // Send value if connected
    if (p_hts->conn_handle != BLE_CONN_HANDLE_INVALID)
    {
        uint8_t                encoded_hts_meas[MAX_HTM_LEN];
        uint16_t               len;
        uint16_t               hvx_len;
        ble_gatts_hvx_params_t hvx_params;

        len     = hts_measurement_encode(p_hts, p_hts_meas, encoded_hts_meas);
        hvx_len = len;

        memset(&hvx_params, 0, sizeof(hvx_params));

        hvx_params.handle = p_hts->meas_handles.value_handle;
        hvx_params.type   = BLE_GATT_HVX_INDICATION;
        hvx_params.offset = 0;
        hvx_params.p_len  = &hvx_len;
        hvx_params.p_data = encoded_hts_meas;

        err_code = sd_ble_gatts_hvx(p_hts->conn_handle, &hvx_params);
        if ((err_code == NRF_SUCCESS) && (hvx_len != len))
        {
            err_code = NRF_ERROR_DATA_SIZE;
        }
    }
    else
    {
        err_code = NRF_ERROR_INVALID_STATE;
    }

    return err_code;
}


uint32_t ble_hts_is_indication_enabled(ble_hts_t * p_hts, bool * p_indication_enabled)
{
    uint32_t err_code;
    uint8_t  cccd_value_buf[BLE_CCCD_VALUE_LEN];
    ble_gatts_value_t gatts_value;

    // Initialize value struct.
    memset(&gatts_value, 0, sizeof(gatts_value));

    gatts_value.len     = BLE_CCCD_VALUE_LEN;
    gatts_value.offset  = 0;
    gatts_value.p_value = cccd_value_buf;

    err_code = sd_ble_gatts_value_get(p_hts->conn_handle,
                                      p_hts->meas_handles.cccd_handle,
                                      &gatts_value);
    if (err_code == NRF_SUCCESS)
    {
        *p_indication_enabled = ble_srv_is_indication_enabled(cccd_value_buf);
    }
    if (err_code == BLE_ERROR_GATTS_SYS_ATTR_MISSING)
    {
        *p_indication_enabled = false;
        return NRF_SUCCESS;
    }
    return err_code;
}
#endif // NRF_MODULE_ENABLED(BLE_HTS)