Logitech Unifying Receiver

罗技 Unifying 接收器是无线设备的接收器，可同时连接最多六个兼容鼠标及键盘。 和该接收器一组的输入设备已预先配对，并能即插即用。而针对额外的输入设备，罗技仅提供 Windows 软件以供配对。 不过 Benjamin Tissoires 在 kernel mailing list 发表了一支程序，令 Linux 下也有其功能。

编译 unifying_pair

此程序亦可于 AUR 找到。

首先确定系统已安装了 C 编译器。

# pacman -S gcc 

将下列代码复制到文件并命名，假设名为 unifying_pair.c。

/*
* Copyright 2011 Benjamin Tissoires 
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program.  If not, see .
*/

#include <linux/input.h>
#include <linux/hidraw.h>
#include <sys/ioctl.h>
#include <fcntl.h>
#include <unistd.h>
#include <stdio.h>
#include <errno.h>

#define USB_VENDOR_ID_LOGITECH                  (__u32)0x046d
#define USB_DEVICE_ID_UNIFYING_RECEIVER         (__s16)0xc52b
#define USB_DEVICE_ID_UNIFYING_RECEIVER_2       (__s16)0xc532

int main(int argc, char **argv)
{
       int fd;
       int res;
       struct hidraw_devinfo info;
       char magic_sequence[] = {0x10, 0xFF, 0x80, 0xB2, 0x01, 0x00, 0x00};

       if (argc == 1) {
               errno = EINVAL;
               perror("No hidraw device given");
               return 1;
       }

       /* Open the Device with non-blocking reads. */
       fd = open(argv[1], O_RDWR|O_NONBLOCK);

       if (fd < 0) {
               perror("Unable to open device");
               return 1;
       }

       /* Get Raw Info */
       res = ioctl(fd, HIDIOCGRAWINFO, &info);
       if (res < 0) {
               perror("error while getting info from device");
       } else {
               if (info.bustype != BUS_USB ||
                   info.vendor != USB_VENDOR_ID_LOGITECH ||
                   (info.product != USB_DEVICE_ID_UNIFYING_RECEIVER &&
                    info.product != USB_DEVICE_ID_UNIFYING_RECEIVER_2)) {
                       errno = EPERM;
                       perror("The given device is not a Logitech "
                               "Unifying Receiver");
                       return 1;
               }
       }

       /* Send the magic sequence to the Device */
       res = write(fd, magic_sequence, sizeof(magic_sequence));
       if (res < 0) {
               printf("Error: %d\n", errno);
               perror("write");
       } else if (res == sizeof(magic_sequence)) {
               printf("The receiver is ready to pair a new device.\n"
               "Switch your device on to pair it.\n");
       } else {
               errno = ENOMEM;
               printf("write: %d were written instead of %ld.\n", res,
                       sizeof(magic_sequence));
               perror("write");
       }
       close(fd);
       return 0;
}

将原始码编译成可执行档 unifying_pair：

$ gcc -o unifying_pair unifying_pair.c

兼容设备配对

下一步需要查找接收器设备的位置，因此观察下列命令的输出

$ cat /sys/class/hidraw/hidrawX/device/uevent |grep NAME

(你必须把 X 替换成系统上存在的整数) 直到找到 Logitech USB Receiver 为止(在此假设 X 恰为 0)

$ cat /sys/class/hidraw/hidraw0/device/uevent |grep NAME
  HID_NAME=Logitech USB Receiver

如果想要配对的设备现在是开着时，关掉并执行适才编译过的程序，以合适的设备做为其参数：

# ./unifying_pair /dev/hidraw0

若顺利该程序会告知你打开欲配对的设备，且该设备应该也会正常运作。

Known Problems

Keyboard Layout via xorg.conf

With kernel 3.2 the Unifying Receiver got its own kernel module hid_logitech_dj which does not work flawlessly together with keyboard layout setting set via xorg.conf. A temporary workaround is to use xorg-setxkbmap^包 and set the layout manually. For example for a German layout with no deadkeys one has to execute:

$ setxkbmap -layout de -variant nodeadkeys

To automate this process one could add this line to xinitrc.