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 51 usage(void) 52 { 53 fprintf(stderr, "usage: %s [-r] <i2cdev>\n", getprogname()); 54 exit(EXIT_FAILURE); 55 } 56 57 static int 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 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 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 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