xref: /openbmc/linux/samples/hidraw/hid-example.c (revision b6bec26c)
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  * If you need this, please have your distro update the kernel headers.
22  */
23 #ifndef HIDIOCSFEATURE
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 
51 	/* Open the Device with non-blocking reads. In real life,
52 	   don't use a hard coded path; use libudev instead. */
53 	fd = open("/dev/hidraw0", O_RDWR|O_NONBLOCK);
54 
55 	if (fd < 0) {
56 		perror("Unable to open device");
57 		return 1;
58 	}
59 
60 	memset(&rpt_desc, 0x0, sizeof(rpt_desc));
61 	memset(&info, 0x0, sizeof(info));
62 	memset(buf, 0x0, sizeof(buf));
63 
64 	/* Get Report Descriptor Size */
65 	res = ioctl(fd, HIDIOCGRDESCSIZE, &desc_size);
66 	if (res < 0)
67 		perror("HIDIOCGRDESCSIZE");
68 	else
69 		printf("Report Descriptor Size: %d\n", desc_size);
70 
71 	/* Get Report Descriptor */
72 	rpt_desc.size = desc_size;
73 	res = ioctl(fd, HIDIOCGRDESC, &rpt_desc);
74 	if (res < 0) {
75 		perror("HIDIOCGRDESC");
76 	} else {
77 		printf("Report Descriptor:\n");
78 		for (i = 0; i < rpt_desc.size; i++)
79 			printf("%hhx ", rpt_desc.value[i]);
80 		puts("\n");
81 	}
82 
83 	/* Get Raw Name */
84 	res = ioctl(fd, HIDIOCGRAWNAME(256), buf);
85 	if (res < 0)
86 		perror("HIDIOCGRAWNAME");
87 	else
88 		printf("Raw Name: %s\n", buf);
89 
90 	/* Get Physical Location */
91 	res = ioctl(fd, HIDIOCGRAWPHYS(256), buf);
92 	if (res < 0)
93 		perror("HIDIOCGRAWPHYS");
94 	else
95 		printf("Raw Phys: %s\n", buf);
96 
97 	/* Get Raw Info */
98 	res = ioctl(fd, HIDIOCGRAWINFO, &info);
99 	if (res < 0) {
100 		perror("HIDIOCGRAWINFO");
101 	} else {
102 		printf("Raw Info:\n");
103 		printf("\tbustype: %d (%s)\n",
104 			info.bustype, bus_str(info.bustype));
105 		printf("\tvendor: 0x%04hx\n", info.vendor);
106 		printf("\tproduct: 0x%04hx\n", info.product);
107 	}
108 
109 	/* Set Feature */
110 	buf[0] = 0x9; /* Report Number */
111 	buf[1] = 0xff;
112 	buf[2] = 0xff;
113 	buf[3] = 0xff;
114 	res = ioctl(fd, HIDIOCSFEATURE(4), buf);
115 	if (res < 0)
116 		perror("HIDIOCSFEATURE");
117 	else
118 		printf("ioctl HIDIOCGFEATURE returned: %d\n", res);
119 
120 	/* Get Feature */
121 	buf[0] = 0x9; /* Report Number */
122 	res = ioctl(fd, HIDIOCGFEATURE(256), buf);
123 	if (res < 0) {
124 		perror("HIDIOCGFEATURE");
125 	} else {
126 		printf("ioctl HIDIOCGFEATURE returned: %d\n", res);
127 		printf("Report data (not containing the report number):\n\t");
128 		for (i = 0; i < res; i++)
129 			printf("%hhx ", buf[i]);
130 		puts("\n");
131 	}
132 
133 	/* Send a Report to the Device */
134 	buf[0] = 0x1; /* Report Number */
135 	buf[1] = 0x77;
136 	res = write(fd, buf, 2);
137 	if (res < 0) {
138 		printf("Error: %d\n", errno);
139 		perror("write");
140 	} else {
141 		printf("write() wrote %d bytes\n", res);
142 	}
143 
144 	/* Get a report from the device */
145 	res = read(fd, buf, 16);
146 	if (res < 0) {
147 		perror("read");
148 	} else {
149 		printf("read() read %d bytes:\n\t", res);
150 		for (i = 0; i < res; i++)
151 			printf("%hhx ", buf[i]);
152 		puts("\n");
153 	}
154 	close(fd);
155 	return 0;
156 }
157 
158 const char *
159 bus_str(int bus)
160 {
161 	switch (bus) {
162 	case BUS_USB:
163 		return "USB";
164 		break;
165 	case BUS_HIL:
166 		return "HIL";
167 		break;
168 	case BUS_BLUETOOTH:
169 		return "Bluetooth";
170 		break;
171 	case BUS_VIRTUAL:
172 		return "Virtual";
173 		break;
174 	default:
175 		return "Other";
176 		break;
177 	}
178 }
179