xref: /linux/samples/hidraw/hid-example.c (revision ca55b2fef3a9373fcfc30f82fd26bc7fccbda732)
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 	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 
161 const char *
162 bus_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