LXR linux/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
  41const char *bus_str(int bus);
  42
  43int 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:\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
 162const char *
 163bus_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}
 183