基于龙芯2K1000适配RTL8821AENF模块(wifi+蓝牙)

  之前适配的intel8265模块有点小贵，这里再适配另一款wifi模块RTL8821。经验在上一篇文章可以参考基于龙芯2K1000适配WIFI模块(型号：Intel 8265NGW)，这里主要记录一些新问题。并且将此模块的蓝牙功能驱动一下。

1 wifi功能

首先确保模块及电路是没有问题的，用命令查看一下，RTL8821AE能被识别：

[loongson@localhost ~]$ lspci -v
04:00.0 USB controller: Renesas Technology Corp. uPD720201 USB 3.0 Host Controller (rev 03) (prog-if 30 [XHCI])
    Flags: bus master, fast devsel, latency 0, IRQ 138
    Memory at 40400000 (64-bit, non-prefetchable) [size=8K]
    Capabilities: <access denied>
    Kernel driver in use: xhci_hcd

08:00.0 Network controller: Realtek Semiconductor Co., Ltd. RTL8821AE 802.11ac PCIe Wireless Network Adapter
    Subsystem: Realtek Semiconductor Co., Ltd. Device 2162
    Flags: bus master, fast devsel, latency 0, IRQ 42
    I/O ports at 6000 [size=256]
    Memory at 40300000 (64-bit, non-prefetchable) [size=16K]
    Capabilities: <access denied>

1.1 linux3.10

环境：pmon+linux3.10+loongnix1.0
正如适配Intel 8265NGW模块文章写道，需要改动的不多，主要在内核里选中以下参数就可以使用了，不做过多描述：

Device Drivers > Network device support > Wireless LAN > Realtek rtlwifi family of devices > Realtek RTL8821AE/RTL8812AE Wireless Network Adapter

1.2 linux4.19

环境：uboot+linux4.19+buildroot
内核选上：

Device Drivers > Network device support > Wireless LAN > Realtek rtlwifi family of devices > Realtek RTL8821AE/RTL8812AE Wireless Network Adapter

问题：

[    3.516805] pci 0000:08:00.0: [10ec:8821] type 00 class 0x028000
[    3.553800] rtl8821ae: Using firmware rtlwifi/rtl8821aefw_29.bin
[    3.559951] rtl8821ae 0000:08:00.0: Direct firmware load for rtlwifi/rtl8821aefw_29.bin failed with error -2
[    3.569869] rtl8821ae: Using firmware rtlwifi/rtl8821aefw_wowlan.bin
[    3.569916] rtl8821ae 0000:08:00.0: Direct firmware load for rtlwifi/rtl8821aefw.bin failed with error -2
[    3.576351] rtl8821ae 0000:08:00.0: Direct firmware load for rtlwifi/rtl8821aefw_wowlan.bin failed with error -2
[    3.585882] rtlwifi: Loading alternative firmware rtlwifi/rtl8821aefw.bin
[    3.613334] rtl8821ae 0000:08:00.0: Direct firmware load for rtlwifi/rtl8821aefw.bin failed with error -2
[    3.623117] rtlwifi: Loading alternative firmware rtlwifi/rtl8821aefw.bin

还是老问题，缺少固件。这里呢，省事的方法,就是按适配intel 8265那样直接加个固件。但是呢，这种方式移植性不大好。

方法1：固件编进内核

还是简叙以下做法：
内核：

Device Drivers > Generic Driver Options > Firmware loader >
添加：rtlwifi/rtl8821aefw_29.bin

这个会从ubuntu中load固件，编译显示为：

  MK_FW   firmware/rtlwifi/rtl8821aefw_29.bin.gen.S
  AS      firmware/rtlwifi/rtl8821aefw_29.bin.gen.o

更新内核启动后：

# ifconfig -a

wlan0     Link encap:Ethernet  HWaddr 90:DE:80:0D:C6:92  
          UP BROADCAST MULTICAST  MTU:1500  Metric:1
          RX packets:0 errors:0 dropped:0 overruns:0 frame:0
          TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:0 (0.0 B)  TX bytes:0 (0.0 B)

方法2：加载用户空间驱动

1、内核修改
改为：

疑问：内核加载用户层的固件在那个目录下呢？
内核函数drivers/base/firmware_loader/main.c做了说明，在以下4个任意目录可以了：

static const char * const fw_path[] = {
        fw_path_para,
        "/lib/firmware/updates/" UTS_RELEASE,   //#define UTS_RELEASE "4.19.161+"
        "/lib/firmware/updates",
        "/lib/firmware/" UTS_RELEASE,
        "/lib/firmware"
};

2、buildroot修改
buildroot选择：

Target packages > Hardware handling > Firmware > WiFi firmware
[*] Intel iwlwifi 8265   //使8265模块 wifi能用，单纯RTL8821不需要选此项
[*] Realtek 88xx
Target packages > Hardware handling > Firmware > Bluetooth firmware
[*] Intel Wireless Bluetooth  //使8265模块 蓝牙能用，单纯RTL8821不需要选此项

启动：

[   67.610715] iwlwifi 0000:08:00.0: loaded firmware version 36.9f0a2d68.0 op_mode iwlmvm
[   67.627500] iwlwifi 0000:08:00.0: Detected Intel(R) Dual Band Wireless AC 8265, REV=0x230
[   67.712574] iwlwifi 0000:08:00.0: base HW address: 84:5c:f3:26:e9:31

编完更新，内核和固件就可以用了，恩，就是这么简单。

发现1：wifi固件加载貌似是周期轮询的，60秒左右一次。

# [   66.741710] Bluetooth: hci0: Failed to load Intel firmware file (-11)
[   66.748863] cfg80211: failed to load regulatory.db
[   66.838347] iwlwifi 0000:08:00.0: Direct firmware load for iwlwifi-8265-35.ucode failed with error -2
[   66.847665] iwlwifi 0000:08:00.0: Falling back to syfs fallback for: iwlwifi-8265-35.ucode  //从8265-35开始加载，恰好固件库里没有8265-35
[   95.344391] usb 2-2: USB disconnect, device number 2
[  128.181612] iwlwifi 0000:08:00.0: Direct firmware load for iwlwifi-8265-34.ucode failed with error -2
[  128.190987] iwlwifi 0000:08:00.0: Falling back to syfs fallback for: iwlwifi-8265-34.ucode

发现2：intel 8265NGW模块驱动是从8265-35开始加载的，但是正好固件库没有这个，按顺序要到第二次循环才加载上8265-34。验证一下。
执行：cp /lib/firmware/iwlwifi-8265-36.ucode /lib/firmware/iwlwifi-8265-35.ucode

[   67.610715] iwlwifi 0000:08:00.0: loaded firmware version 36.9f0a2d68.0 op_mode iwlmvm
[   67.627500] iwlwifi 0000:08:00.0: Detected Intel(R) Dual Band Wireless AC 8265, REV=0x230
[   67.712574] iwlwifi 0000:08:00.0: base HW address: 84:5c:f3:26:e9:31

发现3：蓝牙固件加载是启动时候加载的

# hciconfig hci0 up
[   70.975989] Bluetooth: hci0: Bootloader revision 0.0 build 26 week 38 2015
[   70.984973] Bluetooth: hci0: Device revision is 16
[   70.989824] Bluetooth: hci0: Secure boot is enabled
[   70.994865] Bluetooth: hci0: OTP lock is enabled
[   70.999574] Bluetooth: hci0: API lock is enabled
[   71.004279] Bluetooth: hci0: Debug lock is disabled
[   71.009245] Bluetooth: hci0: Minimum firmware build 1 week 10 2014
[   71.153604] Bluetooth: hci0: Found device firmware: intel/ibt-12-16.sfi
[   75.954954] Bluetooth: hci0: Waiting for firmware download to complete
[   75.961650] Bluetooth: hci0: Firmware loaded in 4870698 usecs
[   75.967734] Bluetooth: hci0: Waiting for device to boot
[   75.980958] Bluetooth: hci0: Device booted in 12987 usecs
[   75.989040] Bluetooth: hci0: Found Intel DDC parameters: intel/ibt-12-16.ddc
[   76.001966] Bluetooth: hci0: Applying Intel DDC parameters completed

wifi使用

搜索wifi：

# ifconfig wlan0 up
# ifconfig
wlan0     Link encap:Ethernet  HWaddr 90:DE:80:0D:C6:92  
          UP BROADCAST MULTICAST  MTU:1500  Metric:1
          RX packets:0 errors:0 dropped:0 overruns:0 frame:0
          TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:0 (0.0 B)  TX bytes:0 (0.0 B)

# iwlist wlan0 scan
wlan0     Scan completed :
          Cell 01 - Address: 32:B3:17:9A:13:03
                    Channel:1
                    Frequency:2.412 GHz (Channel 1)
                    Quality=50/70  Signal level=-60 dBm  
                    Encryption key:on
                    ESSID:"HUAWEI P40 Pro"
                    Bit Rates:1 Mb/s; 2 Mb/s; 5.5 Mb/s; 6 Mb/s; 9 Mb/s
                              11 Mb/s; 12 Mb/s; 18 Mb/s
                    Bit Rates:24 Mb/s; 36 Mb/s; 48 Mb/s; 54 Mb/s
                    Mode:Master
                    Extra:tsf=000000017887a733
                    Extra: Last beacon: 6ms ago
                    IE: Unknown: 000E485541574549205034302050726F
          ......

####联网：

# iwconfig wlan0 essid "USTC-WW" key "3132333435"
# ifconfig wlan0 up
# [   33.354528] wlan0: authenticate with d8:49:0b:b4:bb:90
[   33.368038] wlan0: send auth to d8:49:0b:b4:bb:90 (try 1/3)
[   33.380880] wlan0: authenticated
[   33.384200] iwlwifi 0000:08:00.0 wlan0: disabling HE/HT/VHT due to WEP/TKIP use
[   33.391799] wlan0: associate with d8:49:0b:b4:bb:90 (try 1/3)
[   33.408333] wlan0: RX AssocResp from d8:49:0b:b4:bb:90 (capab=0x1031 status=0 aid=1)
[   33.418203] wlan0: associated
udhcpc -i wlan0
udhcpc: started, v1.29.3
udhcpc: sending discover
udhcpc: sending select for 10.100.2.42
udhcpc: lease of 10.100.2.42 obtained, lease time 3600
deleting routers
adding dns 202.102.192.68
adding dns 114.114.114.114

问题1：调试要么先设置密码，然后再启动网卡！要么up之后设置密码还要down和up一遍才能分配到mac地址等信息。

问题2：一定要接小天线，否则信号不好也分配不到mac，如果分配mac失败，请记得用iwlist wlan0 scan检查一下

问题3：确保wifi名称和密码是否输入错误，这里就是调试输入了错误的密码，当时做了一堆无用功，对报错log一顿乱搜

# iwconfig wlan0 essid "USTC-WW" key "313233343536" //密码错了
Error for wireless request "Set Encode" (8B2A) :
    SET failed on device wlan0 ; Invalid argument.

2 蓝牙功能

确保蓝牙接口正常：

lsusb:
Bus 002 Device 003: ID 0930:022f Toshiba Corp.

2.1 linux3.10

环境：pmon+linux3.10+loongnix1.0
内核选中：

  CONFIG_BT=y                                                      
  CONFIG_BT_RFCOMM=y                                                      
  CONFIG_BT_RFCOMM_TTY=y                                             
  CONFIG_BT_HCIBTUSB=y

问题：

Failed to open RFKILL control device

解决：

Networking support > RF switch subsystem support

使用：

使用之前必须执行hciconfig hci0 up启动蓝牙设备
这里有个很好的蓝牙调试参考链接：
Bluetooth (简体中文)

[root@localhost loongson]# bluetoothctl
[NEW] Controller 90:DE:80:0D:C6:93 localhost.localdomain [default]
[NEW] Device 6C:AB:31:D7:BE:0E iPhone
[bluetooth]# default-agent
No agent is registered
[bluetooth]# power on
Changing power on succeeded
[bluetooth]# scan on
Discovery started
[CHG] Controller 90:DE:80:0D:C6:93 Discovering: yes
[NEW] Device 7E:43:74:A7:FB:EB 7E-43-74-A7-FB-EB
...
[CHG] Device 78:7B:79:D7:1D:8E RSSI: -56
[bluetooth]# scan off
[CHG] Device 70:66:55:9B:FB:8C RSSI is nil
...
[CHG] Device 7E:43:74:A7:FB:EB RSSI is nil
Discovery stopped
[CHG] Controller 90:DE:80:0D:C6:93 Discovering: no
[bluetooth]# pair 6C:AB:31:D7:BE:0E
Attempting to pair with 6C:AB:31:D7:BE:0E
Failed to pair: org.bluez.Error.AlreadyExists
[bluetooth]# trust 6C:AB:31:D7:BE:0E
[CHG] Device 6C:AB:31:D7:BE:0E Trusted: yes
Changing 6C:AB:31:D7:BE:0E trust succeeded
[bluetooth]# connect 6C:AB:31:D7:BE:0E
Attempting to connect to 6C:AB:31:D7:BE:0E
[CHG] Device 6C:AB:31:D7:BE:0E Connected: yes
Connection successful

2.2 linux4.19

环境：uboot+linux4.19+buildroot

内核：

RTL8821模块蓝牙不需要额外的固件，直接按照linux3.10选中配置参数即可。
intel 8265模模块需要蓝牙固件，可以编进内核，也可以用加载用户空间的固件，这里不再赘述。

buildroot：

选中以下参数：

BR2_PACKAGE_DBUS_GLIB=y
BR2_PACKAGE_LIBUSB=y
BR2_PACKAGE_BLUEZ5_UTILS=y
BR2_PACKAGE_BLUEZ5_UTILS_CLIENT=y
BR2_PACKAGE_BLUEZ5_UTILS_DEPRECATED=y
BR2_PACKAGE_UTIL_LINUX_RFKILL=y

更新之后，系统启动之后还需要执行：
1、启动bluetoothd
/usr/libexec/bluetooth/bluetoothd -n &
2、启动蓝牙
hciconfig hci0 up
3、连接调试
bluetoothctl
常用的几个命令如下：
具体可以查阅Bluetooth (简体中文)
power on
scan on
scan off
trust xx:xx:xx:xx:xx:xx
pair xx:xx:xx:xx:xx:xx
connect xx:xx:xx:xx:xx:xx

问题1：第一步必须先执行power on否则执行其他指令会失败，如下：

[bluetooth]# discoverable on
Failed to set discoverable on: org.bluez.Error.Failed
[bluetooth]# power on
Changing power on succeeded
[CHG] Controller 84:5C:F3:26:E9:35 Powered: yes
[bluetooth]# discoverable on
Changing discoverable on succeeded
[CHG] Controller 84:5C:F3:26:E9:35 Discoverable: yes

问题2：已配对成功过，如果是初次配对是显示成功的信息，这里只要trust就行了

[bluetooth]# pair 0C:83:9A:B6:9C:8C
Attempting to pair with 0C:83:9A:B6:9C:8C
Failed to pair: org.bluez.Error.AlreadyExists
[bluetooth]# trust 0C:83:9A:B6:9C:8C
[CHG] Device 0C:83:9A:B6:9C:8C Trusted: yes
Changing 0C:83:9A:B6:9C:8C trust succeeded

问题3：到这里基本上就可以和手机配对了，但是总是连接不上。

[bluetooth]# connect 0C:83:9A:B6:9C:8C
Attempting to connect to 0C:83:9A:B6:9C:8C
bluetoothd[1402]: a2dp-source profile connect failed for 0C:83:9A:B6:9C:8C: Protocol not available
Failed to connect: org.bluez.Error.Failed

这个问题耗了我很长时间，大多都说要支持pulseaudio。这里附上一个让能连接手机蓝牙的解决方案参考：linux 蓝牙开发调试（rtl8821cs模块）
借助 blue-alsa工具：

最终能连上我手机的步骤：
1、hciconfig hci0 up
2、/usr/libexec/bluetooth/bluetoothd -n &
3、bluealsa -p a2dp-sink &
4、bluetoothctl
power on
scan on
scan off
trust xx:xx:xx:xx:xx:xx
pair xx:xx:xx:xx:xx:xx
connect xx:xx:xx:xx:xx:xx
结果如下：

[bluetooth]# connect 6C:AB:31:D7:BE:0E
Attempting to connect to 6C:AB:31:D7:BE:0E
[CHG] Device 6C:AB:31:D7:BE:0E Connected: yes
Connection successful
[iPhone]# bluetoothd[1434]: Can't open input device: No such file or directory (2)
bluetoothd[1434]: AVRCP: failed to init uinput for 6C:AB:31:D7:BE:0E
[CHG] Device 6C:AB:31:D7:BE:0E ServicesResolved: yes

学海无涯！！！