xref: /linux/samples/hidraw/hid-example.c (revision c54ea4918c2b7722d7242ea53271356501988a9b)
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 /* Unix */
18 #include <sys/ioctl.h>
19 #include <sys/types.h>
20 #include <sys/stat.h>
21 #include <fcntl.h>
22 #include <unistd.h>
23 
24 /* C */
25 #include <stdio.h>
26 #include <string.h>
27 #include <stdlib.h>
28 #include <errno.h>
29 
30 const char *bus_str(int bus);
31 
32 int main(int argc, char **argv)
33 {
34 	int fd;
35 	int i, res, desc_size = 0;
36 	char buf[256];
37 	struct hidraw_report_descriptor rpt_desc;
38 	struct hidraw_devinfo info;
39 
40 	/* Open the Device with non-blocking reads. In real life,
41 	   don't use a hard coded path; use libudev instead. */
42 	fd = open("/dev/hidraw0", O_RDWR|O_NONBLOCK);
43 
44 	if (fd < 0) {
45 		perror("Unable to open device");
46 		return 1;
47 	}
48 
49 	memset(&rpt_desc, 0x0, sizeof(rpt_desc));
50 	memset(&info, 0x0, sizeof(info));
51 	memset(buf, 0x0, sizeof(buf));
52 
53 	/* Get Report Descriptor Size */
54 	res = ioctl(fd, HIDIOCGRDESCSIZE, &desc_size);
55 	if (res < 0)
56 		perror("HIDIOCGRDESCSIZE");
57 	else
58 		printf("Report Descriptor Size: %d\n", desc_size);
59 
60 	/* Get Report Descriptor */
61 	rpt_desc.size = desc_size;
62 	res = ioctl(fd, HIDIOCGRDESC, &rpt_desc);
63 	if (res < 0) {
64 		perror("HIDIOCGRDESC");
65 	} else {
66 		printf("Report Descriptor:\n");
67 		for (i = 0; i < rpt_desc.size; i++)
68 			printf("%hhx ", rpt_desc.value[i]);
69 		puts("\n");
70 	}
71 
72 	/* Get Raw Name */
73 	res = ioctl(fd, HIDIOCGRAWNAME(256), buf);
74 	if (res < 0)
75 		perror("HIDIOCGRAWNAME");
76 	else
77 		printf("Raw Name: %s\n", buf);
78 
79 	/* Get Physical Location */
80 	res = ioctl(fd, HIDIOCGRAWPHYS(256), buf);
81 	if (res < 0)
82 		perror("HIDIOCGRAWPHYS");
83 	else
84 		printf("Raw Phys: %s\n", buf);
85 
86 	/* Get Raw Info */
87 	res = ioctl(fd, HIDIOCGRAWINFO, &info);
88 	if (res < 0) {
89 		perror("HIDIOCGRAWINFO");
90 	} else {
91 		printf("Raw Info:\n");
92 		printf("\tbustype: %d (%s)\n",
93 			info.bustype, bus_str(info.bustype));
94 		printf("\tvendor: 0x%04hx\n", info.vendor);
95 		printf("\tproduct: 0x%04hx\n", info.product);
96 	}
97 
98 	/* Set Feature */
99 	buf[0] = 0x9; /* Report Number */
100 	buf[1] = 0xff;
101 	buf[2] = 0xff;
102 	buf[3] = 0xff;
103 	res = ioctl(fd, HIDIOCSFEATURE(4), buf);
104 	if (res < 0)
105 		perror("HIDIOCSFEATURE");
106 	else
107 		printf("ioctl HIDIOCGFEATURE returned: %d\n", res);
108 
109 	/* Get Feature */
110 	buf[0] = 0x9; /* Report Number */
111 	res = ioctl(fd, HIDIOCGFEATURE(256), buf);
112 	if (res < 0) {
113 		perror("HIDIOCGFEATURE");
114 	} else {
115 		printf("ioctl HIDIOCGFEATURE returned: %d\n", res);
116 		printf("Report data (not containing the report number):\n\t");
117 		for (i = 0; i < res; i++)
118 			printf("%hhx ", buf[i]);
119 		puts("\n");
120 	}
121 
122 	/* Send a Report to the Device */
123 	buf[0] = 0x1; /* Report Number */
124 	buf[1] = 0x77;
125 	res = write(fd, buf, 2);
126 	if (res < 0) {
127 		printf("Error: %d\n", errno);
128 		perror("write");
129 	} else {
130 		printf("write() wrote %d bytes\n", res);
131 	}
132 
133 	/* Get a report from the device */
134 	res = read(fd, buf, 16);
135 	if (res < 0) {
136 		perror("read");
137 	} else {
138 		printf("read() read %d bytes:\n\t", res);
139 		for (i = 0; i < res; i++)
140 			printf("%hhx ", buf[i]);
141 		puts("\n");
142 	}
143 	close(fd);
144 	return 0;
145 }
146 
147 const char *
148 bus_str(int bus)
149 {
150 	switch (bus) {
151 	case BUS_USB:
152 		return "USB";
153 		break;
154 	case BUS_HIL:
155 		return "HIL";
156 		break;
157 	case BUS_BLUETOOTH:
158 		return "Bluetooth";
159 		break;
160 	case BUS_VIRTUAL:
161 		return "Virtual";
162 		break;
163 	default:
164 		return "Other";
165 		break;
166 	}
167 }
168