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
  50         /* Open the Device with non-blocking reads. In real life,
  51            don't use a hard coded path; use libudev instead. */
  52         fd = open("/dev/hidraw0", O_RDWR|O_NONBLOCK);
  53
  54         if (fd < 0) {
  55                 perror("Unable to open device");
  56                 return 1;
  57         }
  58
  59         memset(&rpt_desc, 0x0, sizeof(rpt_desc));
  60         memset(&info, 0x0, sizeof(info));
  61         memset(buf, 0x0, sizeof(buf));
  62
  63         /* Get Report Descriptor Size */
  64         res = ioctl(fd, HIDIOCGRDESCSIZE, &desc_size);
  65         if (res < 0)
  66                 perror("HIDIOCGRDESCSIZE");
  67         else
  68                 printf("Report Descriptor Size: %d\n", desc_size);
  69
  70         /* Get Report Descriptor */
  71         rpt_desc.size = desc_size;
  72         res = ioctl(fd, HIDIOCGRDESC, &rpt_desc);
  73         if (res < 0) {
  74                 perror("HIDIOCGRDESC");
  75         } else {
  76                 printf("Report Descriptor:\n");
  77                 for (i = 0; i < rpt_desc.size; i++)
  78                         printf("%hhx ", rpt_desc.value[i]);
  79                 puts("\n");
  80         }
  81
  82         /* Get Raw Name */
  83         res = ioctl(fd, HIDIOCGRAWNAME(256), buf);
  84         if (res < 0)
  85                 perror("HIDIOCGRAWNAME");
  86         else
  87                 printf("Raw Name: %s\n", buf);
  88
  89         /* Get Physical Location */
  90         res = ioctl(fd, HIDIOCGRAWPHYS(256), buf);
  91         if (res < 0)
  92                 perror("HIDIOCGRAWPHYS");
  93         else
  94                 printf("Raw Phys: %s\n", buf);
  95
  96         /* Get Raw Info */
  97         res = ioctl(fd, HIDIOCGRAWINFO, &info);
  98         if (res < 0) {
  99                 perror("HIDIOCGRAWINFO");
 100         } else {
 101                 printf("Raw Info:\n");
 102                 printf("\tbustype: %d (%s)\n",
 103                         info.bustype, bus_str(info.bustype));
 104                 printf("\tvendor: 0x%04hx\n", info.vendor);
 105                 printf("\tproduct: 0x%04hx\n", info.product);
 106         }
 107
 108         /* Set Feature */
 109         buf[0] = 0x9; /* Report Number */
 110         buf[1] = 0xff;
 111         buf[2] = 0xff;
 112         buf[3] = 0xff;
 113         res = ioctl(fd, HIDIOCSFEATURE(4), buf);
 114         if (res < 0)
 115                 perror("HIDIOCSFEATURE");
 116         else
 117                 printf("ioctl HIDIOCGFEATURE returned: %d\n", res);
 118
 119         /* Get Feature */
 120         buf[0] = 0x9; /* Report Number */
 121         res = ioctl(fd, HIDIOCGFEATURE(256), buf);
 122         if (res < 0) {
 123                 perror("HIDIOCGFEATURE");
 124         } else {
 125                 printf("ioctl HIDIOCGFEATURE returned: %d\n", res);
 126                 printf("Report data (not containing the report number):\n\t");
 127                 for (i = 0; i < res; i++)
 128                         printf("%hhx ", buf[i]);
 129                 puts("\n");
 130         }
 131
 132         /* Send a Report to the Device */
 133         buf[0] = 0x1; /* Report Number */
 134         buf[1] = 0x77;
 135         res = write(fd, buf, 2);
 136         if (res < 0) {
 137                 printf("Error: %d\n", errno);
 138                 perror("write");
 139         } else {
 140                 printf("write() wrote %d bytes\n", res);
 141         }
 142
 143         /* Get a report from the device */
 144         res = read(fd, buf, 16);
 145         if (res < 0) {
 146                 perror("read");
 147         } else {
 148                 printf("read() read %d bytes:\n\t", res);
 149                 for (i = 0; i < res; i++)
 150                         printf("%hhx ", buf[i]);
 151                 puts("\n");
 152         }
 153         close(fd);
 154         return 0;
 155 }
 156
 157 const char *
 158 bus_str(int bus)
 159 {
 160         switch (bus) {
 161         case BUS_USB:
 162                 return "USB";
 163                 break;
 164         case BUS_HIL:
 165                 return "HIL";
 166                 break;
 167         case BUS_BLUETOOTH:
 168                 return "Bluetooth";
 169                 break;
 170         case BUS_VIRTUAL:
 171                 return "Virtual";
 172                 break;
 173         default:
 174                 return "Other";
 175                 break;
 176         }
 177 }