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