samples/hidraw/hid-example.c

   1 /*
   2  * Hidraw Userspace Example
   3  *
   4  * Copyright (c) 2010 Alan Ott <alan@signal11.us>
   5  * Copyright (c) 2010 Signal 11 Software
   6  *
   7  * The code may be used by anyone for any purpose,
   8  * and can serve as a starting point for developing
   9  * applications using hidraw.
  10  */
  11
  12 /* Linux */
  13 #include <linux/types.h>
  14 #include <linux/input.h>
  15 #include <linux/hidraw.h>
  16
  17 /*
  18  * Ugly hack to work around failing compilation on systems that don't
  19  * yet populate new version of hidraw.h to userspace.
  20  */
  21 #ifndef HIDIOCSFEATURE
  22 #warning Please have your distro update the userspace kernel headers
  23 #define HIDIOCSFEATURE(len)    _IOC(_IOC_WRITE|_IOC_READ, 'H', 0x06, len)
  24 #define HIDIOCGFEATURE(len)    _IOC(_IOC_WRITE|_IOC_READ, 'H', 0x07, len)
  25 #endif
  26
  27 /* Unix */
  28 #include <sys/ioctl.h>
  29 #include <sys/types.h>
  30 #include <sys/stat.h>
  31 #include <fcntl.h>
  32 #include <unistd.h>
  33
  34 /* C */
  35 #include <stdio.h>
  36 #include <string.h>
  37 #include <stdlib.h>
  38 #include <errno.h>
  39
  40 const char *bus_str(int bus);
  41
  42 int main(int argc, char **argv)
  43 {
  44         int fd;
  45         int i, res, desc_size = 0;
  46         char buf[256];
  47         struct hidraw_report_descriptor rpt_desc;
  48         struct hidraw_devinfo info;
  49         char *device = "/dev/hidraw0";
  50
  51         if (argc > 1)
  52                 device = argv[1];
  53
  54         /* Open the Device with non-blocking reads. In real life,
  55            don't use a hard coded path; use libudev instead. */
  56         fd = open(device, O_RDWR|O_NONBLOCK);
  57
  58         if (fd < 0) {
  59                 perror("Unable to open device");
  60                 return 1;
  61         }
  62
  63         memset(&rpt_desc, 0x0, sizeof(rpt_desc));
  64         memset(&info, 0x0, sizeof(info));
  65         memset(buf, 0x0, sizeof(buf));
  66
  67         /* Get Report Descriptor Size */
  68         res = ioctl(fd, HIDIOCGRDESCSIZE, &desc_size);
  69         if (res < 0)
  70                 perror("HIDIOCGRDESCSIZE");
  71         else
  72                 printf("Report Descriptor Size: %d\n", desc_size);
  73
  74         /* Get Report Descriptor */
  75         rpt_desc.size = desc_size;
  76         res = ioctl(fd, HIDIOCGRDESC, &rpt_desc);
  77         if (res < 0) {
  78                 perror("HIDIOCGRDESC");
  79         } else {
  80                 printf("Report Descriptor:\n");
  81                 for (i = 0; i < rpt_desc.size; i++)
  82                         printf("%hhx ", rpt_desc.value[i]);
  83                 puts("\n");
  84         }
  85
  86         /* Get Raw Name */
  87         res = ioctl(fd, HIDIOCGRAWNAME(256), buf);
  88         if (res < 0)
  89                 perror("HIDIOCGRAWNAME");
  90         else
  91                 printf("Raw Name: %s\n", buf);
  92
  93         /* Get Physical Location */
  94         res = ioctl(fd, HIDIOCGRAWPHYS(256), buf);
  95         if (res < 0)
  96                 perror("HIDIOCGRAWPHYS");
  97         else
  98                 printf("Raw Phys: %s\n", buf);
  99
 100         /* Get Raw Info */
 101         res = ioctl(fd, HIDIOCGRAWINFO, &info);
 102         if (res < 0) {
 103                 perror("HIDIOCGRAWINFO");
 104         } else {
 105                 printf("Raw Info:\n");
 106                 printf("\tbustype: %d (%s)\n",
 107                         info.bustype, bus_str(info.bustype));
 108                 printf("\tvendor: 0x%04hx\n", info.vendor);
 109                 printf("\tproduct: 0x%04hx\n", info.product);
 110         }
 111
 112         /* Set Feature */
 113         buf[0] = 0x9; /* Report Number */
 114         buf[1] = 0xff;
 115         buf[2] = 0xff;
 116         buf[3] = 0xff;
 117         res = ioctl(fd, HIDIOCSFEATURE(4), buf);
 118         if (res < 0)
 119                 perror("HIDIOCSFEATURE");
 120         else
 121                 printf("ioctl HIDIOCGFEATURE returned: %d\n", res);
 122
 123         /* Get Feature */
 124         buf[0] = 0x9; /* Report Number */
 125         res = ioctl(fd, HIDIOCGFEATURE(256), buf);
 126         if (res < 0) {
 127                 perror("HIDIOCGFEATURE");
 128         } else {
 129                 printf("ioctl HIDIOCGFEATURE returned: %d\n", res);
 130                 printf("Report data (not containing the report number):\n\t");
 131                 for (i = 0; i < res; i++)
 132                         printf("%hhx ", buf[i]);
 133                 puts("\n");
 134         }
 135
 136         /* Send a Report to the Device */
 137         buf[0] = 0x1; /* Report Number */
 138         buf[1] = 0x77;
 139         res = write(fd, buf, 2);
 140         if (res < 0) {
 141                 printf("Error: %d\n", errno);
 142                 perror("write");
 143         } else {
 144                 printf("write() wrote %d bytes\n", res);
 145         }
 146
 147         /* Get a report from the device */
 148         res = read(fd, buf, 16);
 149         if (res < 0) {
 150                 perror("read");
 151         } else {
 152                 printf("read() read %d bytes:\n\t", res);
 153                 for (i = 0; i < res; i++)
 154                         printf("%hhx ", buf[i]);
 155                 puts("\n");
 156         }
 157         close(fd);
 158         return 0;
 159 }
 160
 161 const char *
 162 bus_str(int bus)
 163 {
 164         switch (bus) {
 165         case BUS_USB:
 166                 return "USB";
 167                 break;
 168         case BUS_HIL:
 169                 return "HIL";
 170                 break;
 171         case BUS_BLUETOOTH:
 172                 return "Bluetooth";
 173                 break;
 174         case BUS_VIRTUAL:
 175                 return "Virtual";
 176                 break;
 177         default:
 178                 return "Other";
 179                 break;
 180         }
 181 }