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
40const char *bus_str(int bus);
41
42int 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
161const char *
162bus_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}
182