samples/hidraw/hid-example.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Hidraw Userspace Example
   4  *
   5  * Copyright (c) 2010 Alan Ott <alan@signal11.us>
   6  * Copyright (c) 2010 Signal 11 Software
   7  *
   8  * The code may be used by anyone for any purpose,
   9  * and can serve as a starting point for developing
  10  * applications using hidraw.
  11  */
  12
  13 /* Linux */
  14 #include <linux/types.h>
  15 #include <linux/input.h>
  16 #include <linux/hidraw.h>
  17
  18 /*
  19  * Ugly hack to work around failing compilation on systems that don't
  20  * yet populate new version of hidraw.h to userspace.
  21  */
  22 #ifndef HIDIOCSFEATURE
  23 #warning Please have your distro update the userspace kernel headers
  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         char *device = "/dev/hidraw0";
  51
  52         if (argc > 1)
  53                 device = argv[1];
  54
  55         /* Open the Device with non-blocking reads. In real life,
  56            don't use a hard coded path; use libudev instead. */
  57         fd = open(device, O_RDWR|O_NONBLOCK);
  58
  59         if (fd < 0) {
  60                 perror("Unable to open device");
  61                 return 1;
  62         }
  63
  64         memset(&rpt_desc, 0x0, sizeof(rpt_desc));
  65         memset(&info, 0x0, sizeof(info));
  66         memset(buf, 0x0, sizeof(buf));
  67
  68         /* Get Report Descriptor Size */
  69         res = ioctl(fd, HIDIOCGRDESCSIZE, &desc_size);
  70         if (res < 0)
  71                 perror("HIDIOCGRDESCSIZE");
  72         else
  73                 printf("Report Descriptor Size: %d\n", desc_size);
  74
  75         /* Get Report Descriptor */
  76         rpt_desc.size = desc_size;
  77         res = ioctl(fd, HIDIOCGRDESC, &rpt_desc);
  78         if (res < 0) {
  79                 perror("HIDIOCGRDESC");
  80         } else {
  81                 printf("Report Descriptor:\n");
  82                 for (i = 0; i < rpt_desc.size; i++)
  83                         printf("%hhx ", rpt_desc.value[i]);
  84                 puts("\n");
  85         }
  86
  87         /* Get Raw Name */
  88         res = ioctl(fd, HIDIOCGRAWNAME(256), buf);
  89         if (res < 0)
  90                 perror("HIDIOCGRAWNAME");
  91         else
  92                 printf("Raw Name: %s\n", buf);
  93
  94         /* Get Physical Location */
  95         res = ioctl(fd, HIDIOCGRAWPHYS(256), buf);
  96         if (res < 0)
  97                 perror("HIDIOCGRAWPHYS");
  98         else
  99                 printf("Raw Phys: %s\n", buf);
 100
 101         /* Get Raw Info */
 102         res = ioctl(fd, HIDIOCGRAWINFO, &info);
 103         if (res < 0) {
 104                 perror("HIDIOCGRAWINFO");
 105         } else {
 106                 printf("Raw Info:\n");
 107                 printf("\tbustype: %d (%s)\n",
 108                         info.bustype, bus_str(info.bustype));
 109                 printf("\tvendor: 0x%04hx\n", info.vendor);
 110                 printf("\tproduct: 0x%04hx\n", info.product);
 111         }
 112
 113         /* Set Feature */
 114         buf[0] = 0x9; /* Report Number */
 115         buf[1] = 0xff;
 116         buf[2] = 0xff;
 117         buf[3] = 0xff;
 118         res = ioctl(fd, HIDIOCSFEATURE(4), buf);
 119         if (res < 0)
 120                 perror("HIDIOCSFEATURE");
 121         else
 122                 printf("ioctl HIDIOCSFEATURE returned: %d\n", res);
 123
 124         /* Get Feature */
 125         buf[0] = 0x9; /* Report Number */
 126         res = ioctl(fd, HIDIOCGFEATURE(256), buf);
 127         if (res < 0) {
 128                 perror("HIDIOCGFEATURE");
 129         } else {
 130                 printf("ioctl HIDIOCGFEATURE returned: %d\n", res);
 131                 printf("Report data (not containing the report number):\n\t");
 132                 for (i = 0; i < res; i++)
 133                         printf("%hhx ", buf[i]);
 134                 puts("\n");
 135         }
 136
 137         /* Send a Report to the Device */
 138         buf[0] = 0x1; /* Report Number */
 139         buf[1] = 0x77;
 140         res = write(fd, buf, 2);
 141         if (res < 0) {
 142                 printf("Error: %d\n", errno);
 143                 perror("write");
 144         } else {
 145                 printf("write() wrote %d bytes\n", res);
 146         }
 147
 148         /* Get a report from the device */
 149         res = read(fd, buf, 16);
 150         if (res < 0) {
 151                 perror("read");
 152         } else {
 153                 printf("read() read %d bytes:\n\t", res);
 154                 for (i = 0; i < res; i++)
 155                         printf("%hhx ", buf[i]);
 156                 puts("\n");
 157         }
 158         close(fd);
 159         return 0;
 160 }
 161
 162 const char *
 163 bus_str(int bus)
 164 {
 165         switch (bus) {
 166         case BUS_USB:
 167                 return "USB";
 168                 break;
 169         case BUS_HIL:
 170                 return "HIL";
 171                 break;
 172         case BUS_BLUETOOTH:
 173                 return "Bluetooth";
 174                 break;
 175         case BUS_VIRTUAL:
 176                 return "Virtual";
 177                 break;
 178         default:
 179                 return "Other";
 180                 break;
 181         }
 182 }