android bluetooth

最新推荐文章于 2024-03-25 10:00:00 发布

原创最新推荐文章于 2024-03-25 10:00:00 发布 · 594 阅读

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CC 4.0 BY-SA版权

本文详细解析了Android系统中蓝牙服务启动的具体实现方式，包括通过JNI调用底层蓝牙模块的enableNative函数，以及bt_enable函数中涉及的蓝牙设备初始化、蓝牙守护进程启动等关键步骤。

frameworks/base/core/jni/android_server_BluetoothService.cpp

static jint enableNative(JNIEnv *env, jobject object) {
#ifdef HAVE_BLUETOOTH
LOGV("%s", __FUNCTION__);
return bt_enable();
#endif

#ifdef __BTMTK__
native_data_t *nat = get_native_data(env, object);

    LOGI("[GAP][API] enableNative");
    if(nat)
    {
        nat->state = BTMTK_POWER_STATE_TURNING_ON;
        if (btmtk_gap_power_on(nat))
        {
            btmtk_gap_init(env, object);
   btmtk_hdp_init(env, object);
            nat->state = BTMTK_POWER_STATE_ON;
            return 0;
        }
        else
        {
            nat->state = BTMTK_POWER_STATE_OFF;
    return -1;
}
    }
#endif
    return -1;
}

./system/bluetooth/bluedroid/bluetooth.c

int bt_enable() {
LOGV(__FUNCTION__);

    int ret = -1;
    int hci_sock = -1;
    int attempt;
#ifdef RDA_BT_SUPPORT
sleep(4);
#endif

if (set_bluetooth_power(1) < 0) goto out;

    LOGI("Starting hciattach daemon");
    if (property_set("ctl.start", "hciattach") < 0) {
        LOGE("Failed to start hciattach");
        set_bluetooth_power(0);
        goto out;
    }

    // Try for 10 seconds, this can only succeed once hciattach has sent the
    // firmware and then turned on hci device via HCIUARTSETPROTO ioctl
    for (attempt = 1000; attempt > 0; attempt--) {
        hci_sock = create_hci_sock();
        if (hci_sock < 0) goto out;

ret = ioctl(hci_sock, HCIDEVUP, HCI_DEV_ID);

        LOGI("bt_enable: ret: %d, errno: %d", ret, errno);
        if (!ret) {
            break;
        } else if (errno == EALREADY) {
            LOGW("Bluetoothd already started, unexpectedly!");
            break;
        }

        close(hci_sock);
        usleep(100000); // 100 ms retry delay
    }
    if (attempt == 0) {
        LOGE("%s: Timeout waiting for HCI device to come up, error- %d, ",
            __FUNCTION__, ret);
        if (property_set("ctl.stop", "hciattach") < 0) {
            LOGE("Error stopping hciattach");
        }
        set_bluetooth_power(0);
        goto out;
    }

    LOGI("Starting bluetoothd deamon");
    if (property_set("ctl.start", "bluetoothd") < 0) {
        LOGE("Failed to start bluetoothd");
        set_bluetooth_power(0);
        goto out;
    }

ret = 0;

out:
if (hci_sock >= 0) close(hci_sock);
return ret;
}