1 /* $NetBSD: i2cscan.c,v 1.5 2015/11/26 17:31:56 hubertf 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 1.5 2015/11/26 17:31:56 hubertf 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 <paths.h> 42 #include <stdio.h> 43 #include <stdlib.h> 44 #include <string.h> 45 #include <unistd.h> 46 47 #include <dev/i2c/i2c_io.h> 48 49 #define MODE_DEFAULT 0 50 #define MODE_READ 1 51 52 __dead static void 53 usage(void) 54 { 55 fprintf(stderr, "usage: %s [-r] i2cdev\n", getprogname()); 56 exit(EXIT_FAILURE); 57 } 58 59 static int 60 iic_smbus_quick_write(int fd, i2c_addr_t addr, int flags) 61 { 62 i2c_ioctl_exec_t iie; 63 64 iie.iie_op = I2C_OP_WRITE_WITH_STOP; 65 iie.iie_addr = addr; 66 iie.iie_cmd = NULL; 67 iie.iie_cmdlen = 0; 68 iie.iie_buf = NULL; 69 iie.iie_buflen = 0; 70 71 if (ioctl(fd, I2C_IOCTL_EXEC, &iie) == -1) 72 return errno; 73 return 0; 74 } 75 76 static int 77 iic_smbus_receive_byte(int fd, i2c_addr_t addr, uint8_t *valp, int flags) 78 { 79 i2c_ioctl_exec_t iie; 80 81 iie.iie_op = I2C_OP_READ_WITH_STOP; 82 iie.iie_addr = addr; 83 iie.iie_cmd = NULL; 84 iie.iie_cmdlen = 0; 85 iie.iie_buf = valp; 86 iie.iie_buflen = 1; 87 88 if (ioctl(fd, I2C_IOCTL_EXEC, &iie) == -1) 89 return errno; 90 return 0; 91 92 } 93 94 static void 95 do_i2c_scan(const char *dname, int fd, int mode) 96 { 97 int error; 98 int found = 0; 99 i2c_addr_t addr; 100 uint8_t val; 101 102 for (addr = 0x09; addr < 0x78; addr++) { 103 /* 104 * Skip certain i2c addresses: 105 * 0x00 General Call / START 106 * 0x01 CBUS Address 107 * 0x02 Different Bus format 108 * 0x03 - 0x07 Reserved 109 * 0x08 Host Address 110 * 0x0c Alert Response Address 111 * 0x28 ACCESS.Bus host 112 * 0x37 ACCESS.Bus default address 113 * 0x48 - 0x4b Prototypes 114 * 0x61 Device Default Address 115 * 0x78 - 0x7b 10-bit addresses 116 * 0x7c - 0x7f Reserved 117 * 118 * Some of these are skipped by judicious selection 119 * of the range of the above for (;;) statement. 120 * 121 * if (addr <= 0x08 || addr >= 0x78) 122 * continue; 123 */ 124 if (addr == 0x0c || addr == 0x28 || addr == 0x37 || 125 addr == 0x61 || (addr & 0x7c) == 0x48) 126 continue; 127 128 /* 129 * Use SMBus quick_write command to detect most 130 * addresses; should avoid hanging the bus on 131 * some write-only devices (like clocks that show 132 * up at address 0x69) 133 * 134 * XXX The quick_write() is allegedly known to 135 * XXX corrupt the Atmel AT24RF08 EEPROM found 136 * XXX on some IBM Thinkpads! 137 */ 138 printf("\r%s: scanning 0x%02x", dname, addr); 139 fflush(stdout); 140 if ((addr & 0xf8) == 0x30 || 141 (addr & 0xf0) == 0x50 || 142 mode == MODE_READ) 143 error = iic_smbus_receive_byte(fd, addr, &val, 0); 144 else 145 error = iic_smbus_quick_write(fd, addr, 0); 146 if (error == 0) { 147 printf("\r%s: found device at 0x%02x\n", 148 dname, addr); 149 ++found; 150 } 151 } 152 if (found == 0) 153 printf("\r%s: no devices found\n", dname); 154 else 155 printf("\r%s: %d devices found\n", dname, found); 156 } 157 158 int 159 main(int argc, char *argv[]) 160 { 161 int fd; 162 int ch, rflag; 163 int mode; 164 char *dev; 165 char devn[32]; 166 167 setprogname(*argv); 168 169 rflag = 0; 170 171 while ((ch = getopt(argc, argv, "r")) != -1) 172 switch (ch) { 173 case 'r': 174 rflag = 1; 175 break; 176 default: 177 break; 178 } 179 argv += optind; 180 argc -= optind; 181 182 if (rflag) 183 mode = MODE_READ; 184 else 185 mode = MODE_DEFAULT; 186 187 if (*argv == NULL) 188 usage(); 189 dev = argv[0]; 190 191 if (strncmp(_PATH_DEV, dev, sizeof(_PATH_DEV) - 1)) { 192 (void)snprintf(devn, sizeof(devn), "%s%s", _PATH_DEV, dev); 193 dev = devn; 194 } 195 196 fd = open(dev, O_RDWR); 197 if (fd == -1) 198 err(EXIT_FAILURE, "couldn't open %s", *argv); 199 200 do_i2c_scan(*argv, fd, mode); 201 202 close(fd); 203 204 return EXIT_SUCCESS; 205 } 206
Indexes created Thu Sep 25 08:09:54 GMT 2025