1 /* $NetBSD: i2cscan.c,v 1.4 2013/07/10 15:18:54 tcort Exp $ */
2
3 /*-
4 * Copyright (c) 2011, 2013 The NetBSD Foundation, Inc.
5 * All rights reserved.
6 *
7 * This code is derived from software contributed to The NetBSD Foundation
8 * by Paul Goyette and Jared McNeill
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29 * POSSIBILITY OF SUCH DAMAGE.
30 */
31
32 #include <sys/cdefs.h>
33 __RCSID("$NetBSD: i2cscan.c,v 1.4 2013/07/10 15:18:54 tcort Exp $");
34
35 #include <sys/types.h>
36 #include <sys/ioctl.h>
37
38 #include <err.h>
39 #include <errno.h>
40 #include <fcntl.h>
41 #include <stdio.h>
42 #include <stdlib.h>
43 #include <unistd.h>
44
45 #include <dev/i2c/i2c_io.h>
46
47 #define MODE_DEFAULT 0
48 #define MODE_READ 1
49
50 __dead static void
usage(void)51 usage(void)
52 {
53 fprintf(stderr, "usage: %s [-r] <i2cdev>\n", getprogname());
54 exit(EXIT_FAILURE);
55 }
56
57 static int
iic_smbus_quick_write(int fd,i2c_addr_t addr,int flags)58 iic_smbus_quick_write(int fd, i2c_addr_t addr, int flags)
59 {
60 i2c_ioctl_exec_t iie;
61
62 iie.iie_op = I2C_OP_WRITE_WITH_STOP;
63 iie.iie_addr = addr;
64 iie.iie_cmd = NULL;
65 iie.iie_cmdlen = 0;
66 iie.iie_buf = NULL;
67 iie.iie_buflen = 0;
68
69 if (ioctl(fd, I2C_IOCTL_EXEC, &iie) == -1)
70 return errno;
71 return 0;
72 }
73
74 static int
iic_smbus_receive_byte(int fd,i2c_addr_t addr,uint8_t * valp,int flags)75 iic_smbus_receive_byte(int fd, i2c_addr_t addr, uint8_t *valp, int flags)
76 {
77 i2c_ioctl_exec_t iie;
78
79 iie.iie_op = I2C_OP_READ_WITH_STOP;
80 iie.iie_addr = addr;
81 iie.iie_cmd = NULL;
82 iie.iie_cmdlen = 0;
83 iie.iie_buf = valp;
84 iie.iie_buflen = 1;
85
86 if (ioctl(fd, I2C_IOCTL_EXEC, &iie) == -1)
87 return errno;
88 return 0;
89
90 }
91
92 static void
do_i2c_scan(const char * dname,int fd,int mode)93 do_i2c_scan(const char *dname, int fd, int mode)
94 {
95 int error;
96 int found = 0;
97 i2c_addr_t addr;
98 uint8_t val;
99
100 for (addr = 0x09; addr < 0x78; addr++) {
101 /*
102 * Skip certain i2c addresses:
103 * 0x00 General Call / START
104 * 0x01 CBUS Address
105 * 0x02 Different Bus format
106 * 0x03 - 0x07 Reserved
107 * 0x08 Host Address
108 * 0x0c Alert Response Address
109 * 0x28 ACCESS.Bus host
110 * 0x37 ACCESS.Bus default address
111 * 0x48 - 0x4b Prototypes
112 * 0x61 Device Default Address
113 * 0x78 - 0x7b 10-bit addresses
114 * 0x7c - 0x7f Reserved
115 *
116 * Some of these are skipped by judicious selection
117 * of the range of the above for (;;) statement.
118 *
119 * if (addr <= 0x08 || addr >= 0x78)
120 * continue;
121 */
122 if (addr == 0x0c || addr == 0x28 || addr == 0x37 ||
123 addr == 0x61 || (addr & 0x7c) == 0x48)
124 continue;
125
126 /*
127 * Use SMBus quick_write command to detect most
128 * addresses; should avoid hanging the bus on
129 * some write-only devices (like clocks that show
130 * up at address 0x69)
131 *
132 * XXX The quick_write() is allegedly known to
133 * XXX corrupt the Atmel AT24RF08 EEPROM found
134 * XXX on some IBM Thinkpads!
135 */
136 printf("\r%s: scanning 0x%02x", dname, addr);
137 fflush(stdout);
138 if ((addr & 0xf8) == 0x30 ||
139 (addr & 0xf0) == 0x50 ||
140 mode == MODE_READ)
141 error = iic_smbus_receive_byte(fd, addr, &val, 0);
142 else
143 error = iic_smbus_quick_write(fd, addr, 0);
144 if (error == 0) {
145 printf("\r%s: found device at 0x%02x\n",
146 dname, addr);
147 ++found;
148 }
149 }
150 if (found == 0)
151 printf("\r%s: no devices found\n", dname);
152 else
153 printf("\r%s: %d devices found\n", dname, found);
154 }
155
156 int
main(int argc,char * argv[])157 main(int argc, char *argv[])
158 {
159 int fd;
160 int ch, rflag;
161 int mode;
162
163 setprogname(*argv);
164
165 rflag = 0;
166
167 while ((ch = getopt(argc, argv, "r")) != -1)
168 switch (ch) {
169 case 'r':
170 rflag = 1;
171 break;
172 default:
173 break;
174 }
175 argv += optind;
176 argc -= optind;
177
178 if (rflag)
179 mode = MODE_READ;
180 else
181 mode = MODE_DEFAULT;
182
183 if (*argv == NULL)
184 usage();
185
186 fd = open(*argv, O_RDWR);
187 if (fd == -1)
188 err(EXIT_FAILURE, "couldn't open %s", *argv);
189
190 do_i2c_scan(*argv, fd, mode);
191
192 close(fd);
193
194 return EXIT_SUCCESS;
195 }
196