trezor-firmware/core/embed/ble_zephyr_fw/src/trz_nus.c

/*
 * Copyright (c) 2018 Nordic Semiconductor ASA
 *
 * SPDX-License-Identifier: LicenseRef-Nordic-5-Clause
 */

#include <zephyr/bluetooth/conn.h>
#include <zephyr/bluetooth/uuid.h>
#include <zephyr/bluetooth/gatt.h>

#include <zephyr/logging/log.h>

#include "trz_nus.h"

LOG_MODULE_REGISTER(trznus);

static struct bt_nus_cb nus_cb;


static void nus_ccc_cfg_changed(const struct bt_gatt_attr *attr,
                                uint16_t value)
{
  if (nus_cb.send_enabled) {
    LOG_DBG("Notification has been turned %s",
            value == BT_GATT_CCC_NOTIFY ? "on" : "off");
    nus_cb.send_enabled(value == BT_GATT_CCC_NOTIFY ?
                        BT_NUS_SEND_STATUS_ENABLED : BT_NUS_SEND_STATUS_DISABLED);
  }
}


static ssize_t on_receive(struct bt_conn *conn,
                          const struct bt_gatt_attr *attr,
                          const void *buf,
                          uint16_t len,
                          uint16_t offset,
                          uint8_t flags)
{
  LOG_DBG("Received data, handle %d, conn %p",
          attr->handle, (void *)conn);

  if (nus_cb.received) {
    nus_cb.received(conn, buf, len);
  }
  return len;
}

static void on_sent(struct bt_conn *conn, void *user_data)
{
  ARG_UNUSED(user_data);

  LOG_DBG("Data send, conn %p", (void *)conn);

  if (nus_cb.sent) {
    nus_cb.sent(conn);
  }
}

/* UART Service Declaration */
BT_GATT_SERVICE_DEFINE(nus_svc,
        BT_GATT_PRIMARY_SERVICE(BT_UUID_NUS_SERVICE),
        BT_GATT_CHARACTERISTIC(BT_UUID_NUS_TX, BT_GATT_CHRC_NOTIFY, BT_GATT_PERM_READ_ENCRYPT,  NULL, NULL, NULL),
        BT_GATT_CCC(nus_ccc_cfg_changed, BT_GATT_PERM_READ_ENCRYPT | BT_GATT_PERM_WRITE_ENCRYPT),
        BT_GATT_CHARACTERISTIC(BT_UUID_NUS_RX, BT_GATT_CHRC_WRITE | BT_GATT_CHRC_WRITE_WITHOUT_RESP, BT_GATT_PERM_READ_ENCRYPT | BT_GATT_PERM_WRITE_ENCRYPT, NULL, on_receive, NULL),
);

int bt_nus_init(struct bt_nus_cb *callbacks)
{
  if (callbacks) {
    nus_cb.received = callbacks->received;
    nus_cb.sent = callbacks->sent;
  }

  return 0;
}

int bt_nus_send(struct bt_conn *conn, const uint8_t *data, uint16_t len)
{
  struct bt_gatt_notify_params params = {0};
  const struct bt_gatt_attr *attr = &nus_svc.attrs[2];

  params.attr = attr;
  params.data = data;
  params.len = len;
  params.func = on_sent;

  if (conn && bt_gatt_is_subscribed(conn, attr, BT_GATT_CCC_NOTIFY)) {
    return bt_gatt_notify_cb(conn, &params);
  } else {
    return -EINVAL;
  }
}