miscutils/i2c_tools.c

   1 /* vi: set sw=4 ts=4: */
   2 /*
   3  * Minimal i2c-tools implementation for busybox.
   4  * Parts of code ported from i2c-tools:
   5  *              http://www.lm-sensors.org/wiki/I2CTools.
   6  *
   7  * Copyright (C) 2014 by Bartosz Golaszewski <bartekgola@gmail.com>
   8  *
   9  * Licensed under GPLv2 or later, see file LICENSE in this source tree.
  10  */
  11
  12 //config:config I2CGET
  13 //config:       bool "i2cget (5.6 kb)"
  14 //config:       default y
  15 //config:       select PLATFORM_LINUX
  16 //config:       help
  17 //config:       Read from I2C/SMBus chip registers.
  18 //config:
  19 //config:config I2CSET
  20 //config:       bool "i2cset (6.9 kb)"
  21 //config:       default y
  22 //config:       select PLATFORM_LINUX
  23 //config:       help
  24 //config:       Set I2C registers.
  25 //config:
  26 //config:config I2CDUMP
  27 //config:       bool "i2cdump (7.2 kb)"
  28 //config:       default y
  29 //config:       select PLATFORM_LINUX
  30 //config:       help
  31 //config:       Examine I2C registers.
  32 //config:
  33 //config:config I2CDETECT
  34 //config:       bool "i2cdetect (7.2 kb)"
  35 //config:       default y
  36 //config:       select PLATFORM_LINUX
  37 //config:       help
  38 //config:       Detect I2C chips.
  39 //config:
  40
  41 //applet:IF_I2CGET(APPLET(i2cget, BB_DIR_USR_SBIN, BB_SUID_DROP))
  42 //applet:IF_I2CSET(APPLET(i2cset, BB_DIR_USR_SBIN, BB_SUID_DROP))
  43 //applet:IF_I2CDUMP(APPLET(i2cdump, BB_DIR_USR_SBIN, BB_SUID_DROP))
  44 //applet:IF_I2CDETECT(APPLET(i2cdetect, BB_DIR_USR_SBIN, BB_SUID_DROP))
  45 /* not NOEXEC: if hw operation stalls, use less memory in "hung" process */
  46
  47 //kbuild:lib-$(CONFIG_I2CGET) += i2c_tools.o
  48 //kbuild:lib-$(CONFIG_I2CSET) += i2c_tools.o
  49 //kbuild:lib-$(CONFIG_I2CDUMP) += i2c_tools.o
  50 //kbuild:lib-$(CONFIG_I2CDETECT) += i2c_tools.o
  51
  52 /*
  53  * Unsupported stuff:
  54  *
  55  * - upstream i2c-tools can also look-up i2c busses by name, we only accept
  56  *   numbers,
  57  * - bank and bankreg parameters for i2cdump are not supported because of
  58  *   their limited usefulness (see i2cdump manual entry for more info),
  59  * - i2cdetect doesn't look for bus info in /proc as it does in upstream, but
  60  *   it shouldn't be a problem in modern kernels.
  61  */
  62
  63 #include "libbb.h"
  64 #include "common_bufsiz.h"
  65
  66 #include <linux/i2c.h>
  67 #include <linux/i2c-dev.h>
  68
  69 #define I2CDUMP_NUM_REGS                256
  70
  71 #define I2CDETECT_MODE_AUTO             0
  72 #define I2CDETECT_MODE_QUICK            1
  73 #define I2CDETECT_MODE_READ             2
  74
  75 /*
  76  * This is needed for ioctl_or_perror_and_die() since it only accepts pointers.
  77  */
  78 static ALWAYS_INLINE void *itoptr(int i)
  79 {
  80         return (void*)(intptr_t)i;
  81 }
  82
  83 static int32_t i2c_smbus_access(int fd, char read_write, uint8_t cmd,
  84                                 int size, union i2c_smbus_data *data)
  85 {
  86         struct i2c_smbus_ioctl_data args;
  87
  88         args.read_write = read_write;
  89         args.command = cmd;
  90         args.size = size;
  91         args.data = data;
  92
  93         return ioctl(fd, I2C_SMBUS, &args);
  94 }
  95
  96 static int32_t i2c_smbus_read_byte(int fd)
  97 {
  98         union i2c_smbus_data data;
  99         int err;
 100
 101         err = i2c_smbus_access(fd, I2C_SMBUS_READ, 0, I2C_SMBUS_BYTE, &data);
 102         if (err < 0)
 103                 return err;
 104
 105         return data.byte;
 106 }
 107
 108 #if ENABLE_I2CGET || ENABLE_I2CSET || ENABLE_I2CDUMP
 109 static int32_t i2c_smbus_write_byte(int fd, uint8_t val)
 110 {
 111         return i2c_smbus_access(fd, I2C_SMBUS_WRITE,
 112                                 val, I2C_SMBUS_BYTE, NULL);
 113 }
 114
 115 static int32_t i2c_smbus_read_byte_data(int fd, uint8_t cmd)
 116 {
 117         union i2c_smbus_data data;
 118         int err;
 119
 120         err = i2c_smbus_access(fd, I2C_SMBUS_READ, cmd,
 121                                I2C_SMBUS_BYTE_DATA, &data);
 122         if (err < 0)
 123                 return err;
 124
 125         return data.byte;
 126 }
 127
 128 static int32_t i2c_smbus_read_word_data(int fd, uint8_t cmd)
 129 {
 130         union i2c_smbus_data data;
 131         int err;
 132
 133         err = i2c_smbus_access(fd, I2C_SMBUS_READ, cmd,
 134                                I2C_SMBUS_WORD_DATA, &data);
 135         if (err < 0)
 136                 return err;
 137
 138         return data.word;
 139 }
 140 #endif /* ENABLE_I2CGET || ENABLE_I2CSET || ENABLE_I2CDUMP */
 141
 142 #if ENABLE_I2CSET
 143 static int32_t i2c_smbus_write_byte_data(int file,
 144                                          uint8_t cmd, uint8_t value)
 145 {
 146         union i2c_smbus_data data;
 147
 148         data.byte = value;
 149
 150         return i2c_smbus_access(file, I2C_SMBUS_WRITE, cmd,
 151                                 I2C_SMBUS_BYTE_DATA, &data);
 152 }
 153
 154 static int32_t i2c_smbus_write_word_data(int file, uint8_t cmd, uint16_t value)
 155 {
 156         union i2c_smbus_data data;
 157
 158         data.word = value;
 159
 160         return i2c_smbus_access(file, I2C_SMBUS_WRITE, cmd,
 161                                 I2C_SMBUS_WORD_DATA, &data);
 162 }
 163
 164 static int32_t i2c_smbus_write_block_data(int file, uint8_t cmd,
 165                                    uint8_t length, const uint8_t *values)
 166 {
 167         union i2c_smbus_data data;
 168
 169         if (length > I2C_SMBUS_BLOCK_MAX)
 170                 length = I2C_SMBUS_BLOCK_MAX;
 171
 172         memcpy(data.block+1, values, length);
 173         data.block[0] = length;
 174
 175         return i2c_smbus_access(file, I2C_SMBUS_WRITE, cmd,
 176                                 I2C_SMBUS_BLOCK_DATA, &data);
 177 }
 178
 179 static int32_t i2c_smbus_write_i2c_block_data(int file, uint8_t cmd,
 180                                        uint8_t length, const uint8_t *values)
 181 {
 182         union i2c_smbus_data data;
 183
 184         if (length > I2C_SMBUS_BLOCK_MAX)
 185                 length = I2C_SMBUS_BLOCK_MAX;
 186
 187         memcpy(data.block+1, values, length);
 188         data.block[0] = length;
 189
 190         return i2c_smbus_access(file, I2C_SMBUS_WRITE, cmd,
 191                                 I2C_SMBUS_I2C_BLOCK_BROKEN, &data);
 192 }
 193 #endif /* ENABLE_I2CSET */
 194
 195 #if ENABLE_I2CDUMP
 196 /*
 197  * Returns the number of bytes read, vals must hold at
 198  * least I2C_SMBUS_BLOCK_MAX bytes.
 199  */
 200 static int32_t i2c_smbus_read_block_data(int fd, uint8_t cmd, uint8_t *vals)
 201 {
 202         union i2c_smbus_data data;
 203         int i, err;
 204
 205         err = i2c_smbus_access(fd, I2C_SMBUS_READ, cmd,
 206                                I2C_SMBUS_BLOCK_DATA, &data);
 207         if (err < 0)
 208                 return err;
 209
 210         for (i = 1; i <= data.block[0]; i++)
 211                 *vals++ = data.block[i];
 212         return data.block[0];
 213 }
 214
 215 static int32_t i2c_smbus_read_i2c_block_data(int fd, uint8_t cmd,
 216                                              uint8_t len, uint8_t *vals)
 217 {
 218         union i2c_smbus_data data;
 219         int i, err;
 220
 221         if (len > I2C_SMBUS_BLOCK_MAX)
 222                 len = I2C_SMBUS_BLOCK_MAX;
 223         data.block[0] = len;
 224
 225         err = i2c_smbus_access(fd, I2C_SMBUS_READ, cmd,
 226                                len == 32 ? I2C_SMBUS_I2C_BLOCK_BROKEN :
 227                                            I2C_SMBUS_I2C_BLOCK_DATA, &data);
 228         if (err < 0)
 229                 return err;
 230
 231         for (i = 1; i <= data.block[0]; i++)
 232                 *vals++ = data.block[i];
 233         return data.block[0];
 234 }
 235 #endif /* ENABLE_I2CDUMP */
 236
 237 #if ENABLE_I2CDETECT
 238 static int32_t i2c_smbus_write_quick(int fd, uint8_t val)
 239 {
 240         return i2c_smbus_access(fd, val, 0, I2C_SMBUS_QUICK, NULL);
 241 }
 242 #endif /* ENABLE_I2CDETECT */
 243
 244 static int i2c_bus_lookup(const char *bus_str)
 245 {
 246         return xstrtou_range(bus_str, 10, 0, 0xfffff);
 247 }
 248
 249 #if ENABLE_I2CGET || ENABLE_I2CSET || ENABLE_I2CDUMP
 250 static int i2c_parse_bus_addr(const char *addr_str)
 251 {
 252         /* Slave address must be in range 0x03 - 0x77. */
 253         return xstrtou_range(addr_str, 16, 0x03, 0x77);
 254 }
 255
 256 static void i2c_set_pec(int fd, int pec)
 257 {
 258         ioctl_or_perror_and_die(fd, I2C_PEC,
 259                                 itoptr(pec ? 1 : 0),
 260                                 "can't set PEC");
 261 }
 262
 263 static void i2c_set_slave_addr(int fd, int addr, int force)
 264 {
 265         ioctl_or_perror_and_die(fd, force ? I2C_SLAVE_FORCE : I2C_SLAVE,
 266                                 itoptr(addr),
 267                                 "can't set address to 0x%02x", addr);
 268 }
 269 #endif /* ENABLE_I2CGET || ENABLE_I2CSET || ENABLE_I2CDUMP */
 270
 271 #if ENABLE_I2CGET || ENABLE_I2CSET
 272 static int i2c_parse_data_addr(const char *data_addr)
 273 {
 274         /* Data address must be an 8 bit integer. */
 275         return xstrtou_range(data_addr, 16, 0, 0xff);
 276 }
 277 #endif /* ENABLE_I2CGET || ENABLE_I2CSET */
 278
 279 /*
 280  * Opens the device file associated with given i2c bus.
 281  *
 282  * Upstream i2c-tools also support opening devices by i2c bus name
 283  * but we drop it here for size reduction.
 284  */
 285 static int i2c_dev_open(int i2cbus)
 286 {
 287         char filename[sizeof("/dev/i2c-%d") + sizeof(int)*3];
 288         int fd;
 289
 290         sprintf(filename, "/dev/i2c-%d", i2cbus);
 291         fd = open(filename, O_RDWR);
 292         if (fd < 0) {
 293                 if (errno == ENOENT) {
 294                         filename[8] = '/'; /* change to "/dev/i2c/%d" */
 295                         fd = xopen(filename, O_RDWR);
 296                 } else {
 297                         bb_perror_msg_and_die("can't open '%s'", filename);
 298                 }
 299         }
 300
 301         return fd;
 302 }
 303
 304 /* Size reducing helpers for xxx_check_funcs(). */
 305 static void get_funcs_matrix(int fd, unsigned long *funcs)
 306 {
 307         ioctl_or_perror_and_die(fd, I2C_FUNCS, funcs,
 308                         "can't get adapter functionality matrix");
 309 }
 310
 311 #if ENABLE_I2CGET || ENABLE_I2CSET || ENABLE_I2CDUMP
 312 static void check_funcs_test_end(int funcs, int pec, const char *err)
 313 {
 314         if (pec && !(funcs & (I2C_FUNC_SMBUS_PEC | I2C_FUNC_I2C)))
 315                 bb_error_msg("warning: adapter does not support PEC");
 316
 317         if (err)
 318                 bb_error_msg_and_die(
 319                         "adapter has no %s capability", err);
 320 }
 321 #endif /* ENABLE_I2CGET || ENABLE_I2CSET || ENABLE_I2CDUMP */
 322
 323 /*
 324  * The below functions emit an error message and exit if the adapter doesn't
 325  * support desired functionalities.
 326  */
 327 #if ENABLE_I2CGET || ENABLE_I2CDUMP
 328 static void check_read_funcs(int fd, int mode, int data_addr, int pec)
 329 {
 330         unsigned long funcs;
 331         const char *err = NULL;
 332
 333         get_funcs_matrix(fd, &funcs);
 334         switch (mode) {
 335         case I2C_SMBUS_BYTE:
 336                 if (!(funcs & I2C_FUNC_SMBUS_READ_BYTE)) {
 337                         err = "SMBus receive byte";
 338                         break;
 339                 }
 340                 if (data_addr >= 0 && !(funcs & I2C_FUNC_SMBUS_WRITE_BYTE))
 341                         err = "SMBus send byte";
 342                 break;
 343         case I2C_SMBUS_BYTE_DATA:
 344                 if (!(funcs & I2C_FUNC_SMBUS_READ_BYTE_DATA))
 345                         err = "SMBus read byte";
 346                 break;
 347         case I2C_SMBUS_WORD_DATA:
 348                 if (!(funcs & I2C_FUNC_SMBUS_READ_WORD_DATA))
 349                         err = "SMBus read word";
 350                 break;
 351 #if ENABLE_I2CDUMP
 352         case I2C_SMBUS_BLOCK_DATA:
 353                 if (!(funcs & I2C_FUNC_SMBUS_READ_BLOCK_DATA))
 354                         err = "SMBus block read";
 355                 break;
 356
 357         case I2C_SMBUS_I2C_BLOCK_DATA:
 358                 if (!(funcs & I2C_FUNC_SMBUS_READ_I2C_BLOCK))
 359                         err = "I2C block read";
 360                 break;
 361 #endif /* ENABLE_I2CDUMP */
 362         default:
 363                 bb_error_msg_and_die("internal error");
 364         }
 365         check_funcs_test_end(funcs, pec, err);
 366 }
 367 #endif /* ENABLE_I2CGET || ENABLE_I2CDUMP */
 368
 369 #if ENABLE_I2CSET
 370 static void check_write_funcs(int fd, int mode, int pec)
 371 {
 372         unsigned long funcs;
 373         const char *err = NULL;
 374
 375         get_funcs_matrix(fd, &funcs);
 376         switch (mode) {
 377         case I2C_SMBUS_BYTE:
 378                 if (!(funcs & I2C_FUNC_SMBUS_WRITE_BYTE))
 379                         err = "SMBus send byte";
 380                 break;
 381
 382         case I2C_SMBUS_BYTE_DATA:
 383                 if (!(funcs & I2C_FUNC_SMBUS_WRITE_BYTE_DATA))
 384                         err = "SMBus write byte";
 385                 break;
 386
 387         case I2C_SMBUS_WORD_DATA:
 388                 if (!(funcs & I2C_FUNC_SMBUS_WRITE_WORD_DATA))
 389                         err = "SMBus write word";
 390                 break;
 391
 392         case I2C_SMBUS_BLOCK_DATA:
 393                 if (!(funcs & I2C_FUNC_SMBUS_WRITE_BLOCK_DATA))
 394                         err = "SMBus block write";
 395                 break;
 396         case I2C_SMBUS_I2C_BLOCK_DATA:
 397                 if (!(funcs & I2C_FUNC_SMBUS_WRITE_I2C_BLOCK))
 398                         err = "I2C block write";
 399                 break;
 400         }
 401         check_funcs_test_end(funcs, pec, err);
 402 }
 403 #endif /* ENABLE_I2CSET */
 404
 405 static void confirm_or_abort(void)
 406 {
 407         fprintf(stderr, "Continue? [y/N] ");
 408         fflush_all();
 409         if (!bb_ask_confirmation())
 410                 bb_error_msg_and_die("aborting");
 411 }
 412
 413 /*
 414  * Return only if user confirms the action, abort otherwise.
 415  *
 416  * The messages displayed here are much less elaborate than their i2c-tools
 417  * counterparts - this is done for size reduction.
 418  */
 419 static void confirm_action(int bus_addr, int mode, int data_addr, int pec)
 420 {
 421         bb_error_msg("WARNING! This program can confuse your I2C bus");
 422
 423         /* Don't let the user break his/her EEPROMs */
 424         if (bus_addr >= 0x50 && bus_addr <= 0x57 && pec) {
 425                 bb_error_msg_and_die("this is I2C not smbus - using PEC on I2C "
 426                         "devices may result in data loss, aborting");
 427         }
 428
 429         if (mode == I2C_SMBUS_BYTE && data_addr >= 0 && pec)
 430                 bb_error_msg("WARNING! May interpret a write byte command "
 431                         "with PEC as a write byte data command");
 432
 433         if (pec)
 434                 bb_error_msg("PEC checking enabled");
 435
 436         confirm_or_abort();
 437 }
 438
 439 #if ENABLE_I2CGET
 440 //usage:#define i2cget_trivial_usage
 441 //usage:       "[-f] [-y] BUS CHIP-ADDRESS [DATA-ADDRESS [MODE]]"
 442 //usage:#define i2cget_full_usage "\n\n"
 443 //usage:       "Read from I2C/SMBus chip registers\n"
 444 //usage:     "\n        I2CBUS  i2c bus number"
 445 //usage:     "\n        ADDRESS 0x03 - 0x77"
 446 //usage:     "\nMODE is:"
 447 //usage:     "\n        b       read byte data (default)"
 448 //usage:     "\n        w       read word data"
 449 //usage:     "\n        c       write byte/read byte"
 450 //usage:     "\n        Append p for SMBus PEC"
 451 //usage:     "\n"
 452 //usage:     "\n        -f      force access"
 453 //usage:     "\n        -y      disable interactive mode"
 454 int i2cget_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
 455 int i2cget_main(int argc UNUSED_PARAM, char **argv)
 456 {
 457         const unsigned opt_f = (1 << 0), opt_y = (1 << 1);
 458
 459         int bus_num, bus_addr, data_addr = -1, status;
 460         int mode = I2C_SMBUS_BYTE, pec = 0, fd;
 461         unsigned opts;
 462
 463         opts = getopt32(argv, "^" "fy" "\0" "-2:?4"/*from 2 to 4 args*/);
 464         argv += optind;
 465
 466         bus_num = i2c_bus_lookup(argv[0]);
 467         bus_addr = i2c_parse_bus_addr(argv[1]);
 468
 469         if (argv[2]) {
 470                 data_addr = i2c_parse_data_addr(argv[2]);
 471                 mode = I2C_SMBUS_BYTE_DATA;
 472                 if (argv[3]) {
 473                         switch (argv[3][0]) {
 474                         case 'b':       /* Already set */               break;
 475                         case 'w':       mode = I2C_SMBUS_WORD_DATA;     break;
 476                         case 'c':       mode = I2C_SMBUS_BYTE;          break;
 477                         default:
 478                                 bb_error_msg("invalid mode");
 479                                 bb_show_usage();
 480                         }
 481                         pec = argv[3][1] == 'p';
 482                 }
 483         }
 484
 485         fd = i2c_dev_open(bus_num);
 486         check_read_funcs(fd, mode, data_addr, pec);
 487         i2c_set_slave_addr(fd, bus_addr, opts & opt_f);
 488
 489         if (!(opts & opt_y))
 490                 confirm_action(bus_addr, mode, data_addr, pec);
 491
 492         if (pec)
 493                 i2c_set_pec(fd, 1);
 494
 495         switch (mode) {
 496         case I2C_SMBUS_BYTE:
 497                 if (data_addr >= 0) {
 498                         status = i2c_smbus_write_byte(fd, data_addr);
 499                         if (status < 0)
 500                                 bb_error_msg("warning - write failed");
 501                 }
 502                 status = i2c_smbus_read_byte(fd);
 503                 break;
 504         case I2C_SMBUS_WORD_DATA:
 505                 status = i2c_smbus_read_word_data(fd, data_addr);
 506                 break;
 507         default: /* I2C_SMBUS_BYTE_DATA */
 508                 status = i2c_smbus_read_byte_data(fd, data_addr);
 509         }
 510         close(fd);
 511
 512         if (status < 0)
 513                 bb_perror_msg_and_die("read failed");
 514
 515         printf("0x%0*x\n", mode == I2C_SMBUS_WORD_DATA ? 4 : 2, status);
 516
 517         return 0;
 518 }
 519 #endif /* ENABLE_I2CGET */
 520
 521 #if ENABLE_I2CSET
 522 //usage:#define i2cset_trivial_usage
 523 //usage:       "[-f] [-y] [-m MASK] BUS CHIP-ADDR DATA-ADDR [VALUE] ... [MODE]"
 524 //usage:#define i2cset_full_usage "\n\n"
 525 //usage:       "Set I2C registers\n"
 526 //usage:     "\n        I2CBUS  i2c bus number"
 527 //usage:     "\n        ADDRESS 0x03 - 0x77"
 528 //usage:     "\nMODE is:"
 529 //usage:     "\n        c       byte, no value"
 530 //usage:     "\n        b       byte data (default)"
 531 //usage:     "\n        w       word data"
 532 //usage:     "\n        i       I2C block data"
 533 //usage:     "\n        s       SMBus block data"
 534 //usage:     "\n        Append p for SMBus PEC"
 535 //usage:     "\n"
 536 //usage:     "\n        -f      force access"
 537 //usage:     "\n        -y      disable interactive mode"
 538 //usage:     "\n        -r      read back and compare the result"
 539 //usage:     "\n        -m MASK mask specifying which bits to write"
 540 int i2cset_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
 541 int i2cset_main(int argc, char **argv)
 542 {
 543         const unsigned opt_f = (1 << 0), opt_y = (1 << 1),
 544                               opt_m = (1 << 2), opt_r = (1 << 3);
 545
 546         int bus_num, bus_addr, data_addr, mode = I2C_SMBUS_BYTE, pec = 0;
 547         int val, blen = 0, mask = 0, fd, status;
 548         unsigned char block[I2C_SMBUS_BLOCK_MAX];
 549         char *opt_m_arg = NULL;
 550         unsigned opts;
 551
 552         opts = getopt32(argv, "^" "fym:r" "\0" "-3"/*from 3 to ? args*/, &opt_m_arg);
 553         argv += optind;
 554         argc -= optind;
 555
 556         bus_num = i2c_bus_lookup(argv[0]);
 557         bus_addr = i2c_parse_bus_addr(argv[1]);
 558         data_addr = i2c_parse_data_addr(argv[2]);
 559
 560         if (argv[3]) {
 561                 if (!argv[4] && argv[3][0] != 'c') {
 562                         mode = I2C_SMBUS_BYTE_DATA; /* Implicit b */
 563                 } else {
 564                         switch (argv[argc-1][0]) {
 565                         case 'c': /* Already set */                     break;
 566                         case 'b': mode = I2C_SMBUS_BYTE_DATA;           break;
 567                         case 'w': mode = I2C_SMBUS_WORD_DATA;           break;
 568                         case 's': mode = I2C_SMBUS_BLOCK_DATA;          break;
 569                         case 'i': mode = I2C_SMBUS_I2C_BLOCK_DATA;      break;
 570                         default:
 571                                 bb_error_msg("invalid mode");
 572                                 bb_show_usage();
 573                         }
 574
 575                         pec = argv[argc-1][1] == 'p';
 576                         if (mode == I2C_SMBUS_BLOCK_DATA ||
 577                                         mode == I2C_SMBUS_I2C_BLOCK_DATA) {
 578                                 if (pec && mode == I2C_SMBUS_I2C_BLOCK_DATA)
 579                                         bb_error_msg_and_die(
 580                                                 "PEC not supported for I2C "
 581                                                 "block writes");
 582                                 if (opts & opt_m)
 583                                         bb_error_msg_and_die(
 584                                                 "mask not supported for block "
 585                                                 "writes");
 586                         }
 587                 }
 588         }
 589
 590         /* Prepare the value(s) to be written according to current mode. */
 591         switch (mode) {
 592         case I2C_SMBUS_BYTE_DATA:
 593                 val = xstrtou_range(argv[3], 0, 0, 0xff);
 594                 break;
 595         case I2C_SMBUS_WORD_DATA:
 596                 val = xstrtou_range(argv[3], 0, 0, 0xffff);
 597                 break;
 598         case I2C_SMBUS_BLOCK_DATA:
 599         case I2C_SMBUS_I2C_BLOCK_DATA:
 600                 for (blen = 3; blen < (argc - 1); blen++)
 601                         block[blen] = xstrtou_range(argv[blen], 0, 0, 0xff);
 602                 val = -1;
 603                 break;
 604         default:
 605                 val = -1;
 606                 break;
 607         }
 608
 609         if (opts & opt_m) {
 610                 mask = xstrtou_range(opt_m_arg, 0, 0,
 611                                 (mode == I2C_SMBUS_BYTE ||
 612                                  mode == I2C_SMBUS_BYTE_DATA) ? 0xff : 0xffff);
 613         }
 614
 615         fd = i2c_dev_open(bus_num);
 616         check_write_funcs(fd, mode, pec);
 617         i2c_set_slave_addr(fd, bus_addr, opts & opt_f);
 618
 619         if (!(opts & opt_y))
 620                 confirm_action(bus_addr, mode, data_addr, pec);
 621
 622         /*
 623          * If we're using mask - read the current value here and adjust the
 624          * value to be written.
 625          */
 626         if (opts & opt_m) {
 627                 int tmpval;
 628
 629                 switch (mode) {
 630                 case I2C_SMBUS_BYTE:
 631                         tmpval = i2c_smbus_read_byte(fd);
 632                         break;
 633                 case I2C_SMBUS_WORD_DATA:
 634                         tmpval = i2c_smbus_read_word_data(fd, data_addr);
 635                         break;
 636                 default:
 637                         tmpval = i2c_smbus_read_byte_data(fd, data_addr);
 638                 }
 639
 640                 if (tmpval < 0)
 641                         bb_perror_msg_and_die("can't read old value");
 642
 643                 val = (val & mask) | (tmpval & ~mask);
 644
 645                 if (!(opts & opt_y)) {
 646                         bb_error_msg("old value 0x%0*x, write mask "
 647                                 "0x%0*x, will write 0x%0*x to register "
 648                                 "0x%02x",
 649                                 mode == I2C_SMBUS_WORD_DATA ? 4 : 2, tmpval,
 650                                 mode == I2C_SMBUS_WORD_DATA ? 4 : 2, mask,
 651                                 mode == I2C_SMBUS_WORD_DATA ? 4 : 2, val,
 652                                 data_addr);
 653                         confirm_or_abort();
 654                 }
 655         }
 656
 657         if (pec)
 658                 i2c_set_pec(fd, 1);
 659
 660         switch (mode) {
 661         case I2C_SMBUS_BYTE:
 662                 status = i2c_smbus_write_byte(fd, data_addr);
 663                 break;
 664         case I2C_SMBUS_WORD_DATA:
 665                 status = i2c_smbus_write_word_data(fd, data_addr, val);
 666                 break;
 667         case I2C_SMBUS_BLOCK_DATA:
 668                 status = i2c_smbus_write_block_data(fd, data_addr,
 669                                                     blen, block);
 670                 break;
 671         case I2C_SMBUS_I2C_BLOCK_DATA:
 672                 status = i2c_smbus_write_i2c_block_data(fd, data_addr,
 673                                                         blen, block);
 674                 break;
 675         default: /* I2C_SMBUS_BYTE_DATA */
 676                 status = i2c_smbus_write_byte_data(fd, data_addr, val);
 677                 break;
 678         }
 679         if (status < 0)
 680                 bb_perror_msg_and_die("write failed");
 681
 682         if (pec)
 683                 i2c_set_pec(fd, 0); /* Clear PEC. */
 684
 685         /* No readback required - we're done. */
 686         if (!(opts & opt_r))
 687                 return 0;
 688
 689         switch (mode) {
 690         case I2C_SMBUS_BYTE:
 691                 status = i2c_smbus_read_byte(fd);
 692                 val = data_addr;
 693                 break;
 694         case I2C_SMBUS_WORD_DATA:
 695                 status = i2c_smbus_read_word_data(fd, data_addr);
 696                 break;
 697         default: /* I2C_SMBUS_BYTE_DATA */
 698                 status = i2c_smbus_read_byte_data(fd, data_addr);
 699         }
 700
 701         if (status < 0) {
 702                 puts("Warning - readback failed");
 703         } else
 704         if (status != val) {
 705                 printf("Warning - data mismatch - wrote "
 706                        "0x%0*x, read back 0x%0*x\n",
 707                        mode == I2C_SMBUS_WORD_DATA ? 4 : 2, val,
 708                        mode == I2C_SMBUS_WORD_DATA ? 4 : 2, status);
 709         } else {
 710                 printf("Value 0x%0*x written, readback matched\n",
 711                        mode == I2C_SMBUS_WORD_DATA ? 4 : 2, val);
 712         }
 713
 714         return 0;
 715 }
 716 #endif /* ENABLE_I2CSET */
 717
 718 #if ENABLE_I2CDUMP
 719 static int read_block_data(int buf_fd, int mode, int *block)
 720 {
 721         uint8_t cblock[I2C_SMBUS_BLOCK_MAX + I2CDUMP_NUM_REGS];
 722         int res, blen = 0, tmp, i;
 723
 724         if (mode == I2C_SMBUS_BLOCK_DATA) {
 725                 blen = i2c_smbus_read_block_data(buf_fd, 0, cblock);
 726                 if (blen <= 0)
 727                         goto fail;
 728         } else {
 729                 for (res = 0; res < I2CDUMP_NUM_REGS; res += tmp) {
 730                         tmp = i2c_smbus_read_i2c_block_data(
 731                                         buf_fd, res, I2C_SMBUS_BLOCK_MAX,
 732                                         cblock + res);
 733                         if (tmp <= 0) {
 734                                 blen = tmp;
 735                                 goto fail;
 736                         }
 737                 }
 738
 739                 if (res >= I2CDUMP_NUM_REGS)
 740                         res = I2CDUMP_NUM_REGS;
 741
 742                 for (i = 0; i < res; i++)
 743                         block[i] = cblock[i];
 744
 745                 if (mode != I2C_SMBUS_BLOCK_DATA)
 746                         for (i = res; i < I2CDUMP_NUM_REGS; i++)
 747                                 block[i] = -1;
 748         }
 749
 750         return blen;
 751
 752  fail:
 753         bb_error_msg_and_die("block read failed: %d", blen);
 754 }
 755
 756 /* Dump all but word data. */
 757 static void dump_data(int bus_fd, int mode, unsigned first,
 758                       unsigned last, int *block, int blen)
 759 {
 760         int i, j, res;
 761
 762         puts("     0  1  2  3  4  5  6  7  8  9  a  b  c  d  e  f"
 763              "    0123456789abcdef");
 764
 765         for (i = 0; i < I2CDUMP_NUM_REGS; i += 0x10) {
 766                 if (mode == I2C_SMBUS_BLOCK_DATA && i >= blen)
 767                         break;
 768                 if (i/16 < first/16)
 769                         continue;
 770                 if (i/16 > last/16)
 771                         break;
 772
 773                 printf("%02x: ", i);
 774                 for (j = 0; j < 16; j++) {
 775                         fflush_all();
 776                         /* Skip unwanted registers */
 777                         if (i+j < first || i+j > last) {
 778                                 printf("   ");
 779                                 if (mode == I2C_SMBUS_WORD_DATA) {
 780                                         printf("   ");
 781                                         j++;
 782                                 }
 783                                 continue;
 784                         }
 785
 786                         switch (mode) {
 787                         case I2C_SMBUS_BYTE_DATA:
 788                                 res = i2c_smbus_read_byte_data(bus_fd, i+j);
 789                                 block[i+j] = res;
 790                                 break;
 791                         case I2C_SMBUS_WORD_DATA:
 792                                 res = i2c_smbus_read_word_data(bus_fd, i+j);
 793                                 if (res < 0) {
 794                                         block[i+j] = res;
 795                                         block[i+j+1] = res;
 796                                 } else {
 797                                         block[i+j] = res & 0xff;
 798                                         block[i+j+1] = res >> 8;
 799                                 }
 800                                 break;
 801                         case I2C_SMBUS_BYTE:
 802                                 res = i2c_smbus_read_byte(bus_fd);
 803                                 block[i+j] = res;
 804                                 break;
 805                         default:
 806                                 res = block[i+j];
 807                         }
 808
 809                         if (mode == I2C_SMBUS_BLOCK_DATA &&
 810                             i+j >= blen) {
 811                                 printf("   ");
 812                         } else if (res < 0) {
 813                                 printf("XX ");
 814                                 if (mode == I2C_SMBUS_WORD_DATA)
 815                                         printf("XX ");
 816                         } else {
 817                                 printf("%02x ", block[i+j]);
 818                                 if (mode == I2C_SMBUS_WORD_DATA)
 819                                         printf("%02x ", block[i+j+1]);
 820                         }
 821
 822                         if (mode == I2C_SMBUS_WORD_DATA)
 823                                 j++;
 824                 }
 825                 printf("   ");
 826
 827                 for (j = 0; j < 16; j++) {
 828                         if (mode == I2C_SMBUS_BLOCK_DATA && i+j >= blen)
 829                                 break;
 830                         /* Skip unwanted registers */
 831                         if (i+j < first || i+j > last) {
 832                                 bb_putchar(' ');
 833                                 continue;
 834                         }
 835
 836                         res = block[i+j];
 837                         if (res < 0) {
 838                                 bb_putchar('X');
 839                         } else if (res == 0x00 || res == 0xff) {
 840                                 bb_putchar('.');
 841                         } else if (res < 32 || res >= 127) {
 842                                 bb_putchar('?');
 843                         } else {
 844                                 bb_putchar(res);
 845                         }
 846                 }
 847                 bb_putchar('\n');
 848         }
 849 }
 850
 851 static void dump_word_data(int bus_fd, unsigned first, unsigned last)
 852 {
 853         int i, j, rv;
 854
 855         /* Word data. */
 856         puts("     0,8  1,9  2,a  3,b  4,c  5,d  6,e  7,f");
 857         for (i = 0; i < 256; i += 8) {
 858                 if (i/8 < first/8)
 859                         continue;
 860                 if (i/8 > last/8)
 861                         break;
 862
 863                 printf("%02x: ", i);
 864                 for (j = 0; j < 8; j++) {
 865                         /* Skip unwanted registers. */
 866                         if (i+j < first || i+j > last) {
 867                                 printf("     ");
 868                                 continue;
 869                         }
 870
 871                         rv = i2c_smbus_read_word_data(bus_fd, i+j);
 872                         if (rv < 0)
 873                                 printf("XXXX ");
 874                         else
 875                                 printf("%04x ", rv & 0xffff);
 876                 }
 877                 bb_putchar('\n');
 878         }
 879 }
 880
 881 //usage:#define i2cdump_trivial_usage
 882 //usage:       "[-f] [-r FIRST-LAST] [-y] BUS ADDR [MODE]"
 883 //usage:#define i2cdump_full_usage "\n\n"
 884 //usage:       "Examine I2C registers\n"
 885 //usage:     "\n        I2CBUS  i2c bus number"
 886 //usage:     "\n        ADDRESS 0x03 - 0x77"
 887 //usage:     "\nMODE is:"
 888 //usage:     "\n        b       byte (default)"
 889 //usage:     "\n        w       word"
 890 //usage:     "\n        W       word on even register addresses"
 891 //usage:     "\n        i       I2C block"
 892 //usage:     "\n        s       SMBus block"
 893 //usage:     "\n        c       consecutive byte"
 894 //usage:     "\n        Append p for SMBus PEC"
 895 //usage:     "\n"
 896 //usage:     "\n        -f      force access"
 897 //usage:     "\n        -y      disable interactive mode"
 898 //usage:     "\n        -r      limit the number of registers being accessed"
 899 int i2cdump_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
 900 int i2cdump_main(int argc UNUSED_PARAM, char **argv)
 901 {
 902         const unsigned opt_f = (1 << 0), opt_y = (1 << 1),
 903                               opt_r = (1 << 2);
 904
 905         int bus_num, bus_addr, mode = I2C_SMBUS_BYTE_DATA, even = 0, pec = 0;
 906         unsigned first = 0x00, last = 0xff, opts;
 907         int block[I2CDUMP_NUM_REGS];
 908         char *opt_r_str, *dash;
 909         int fd, res;
 910
 911         opts = getopt32(argv, "^"
 912                 "fyr:"
 913                 "\0" "-2:?3" /* from 2 to 3 args */,
 914                 &opt_r_str
 915         );
 916         argv += optind;
 917
 918         bus_num = i2c_bus_lookup(argv[0]);
 919         bus_addr = i2c_parse_bus_addr(argv[1]);
 920
 921         if (argv[2]) {
 922                 switch (argv[2][0]) {
 923                 case 'b': /* Already set. */                    break;
 924                 case 'c': mode = I2C_SMBUS_BYTE;                break;
 925                 case 'w': mode = I2C_SMBUS_WORD_DATA;           break;
 926                 case 'W':
 927                         mode = I2C_SMBUS_WORD_DATA;
 928                         even = 1;
 929                         break;
 930                 case 's': mode = I2C_SMBUS_BLOCK_DATA;          break;
 931                 case 'i': mode = I2C_SMBUS_I2C_BLOCK_DATA;      break;
 932                 default:
 933                         bb_error_msg_and_die("invalid mode");
 934                 }
 935
 936                 if (argv[2][1] == 'p') {
 937                         if (argv[2][0] == 'W' || argv[2][0] == 'i') {
 938                                 bb_error_msg_and_die(
 939                                         "pec not supported for -W and -i");
 940                         } else {
 941                                 pec = 1;
 942                         }
 943                 }
 944         }
 945
 946         if (opts & opt_r) {
 947                 first = strtol(opt_r_str, &dash, 0);
 948                 if (dash == opt_r_str || *dash != '-' || first > 0xff)
 949                         bb_error_msg_and_die("invalid range");
 950                 last = xstrtou_range(++dash, 0, first, 0xff);
 951
 952                 /* Range is not available for every mode. */
 953                 switch (mode) {
 954                 case I2C_SMBUS_BYTE:
 955                 case I2C_SMBUS_BYTE_DATA:
 956                         break;
 957                 case I2C_SMBUS_WORD_DATA:
 958                         if (!even || (!(first % 2) && last % 2))
 959                                 break;
 960                         /* Fall through */
 961                 default:
 962                         bb_error_msg_and_die(
 963                                 "range not compatible with selected mode");
 964                 }
 965         }
 966
 967         fd = i2c_dev_open(bus_num);
 968         check_read_funcs(fd, mode, -1 /* data_addr */, pec);
 969         i2c_set_slave_addr(fd, bus_addr, opts & opt_f);
 970
 971         if (pec)
 972                 i2c_set_pec(fd, 1);
 973
 974         if (!(opts & opt_y))
 975                 confirm_action(bus_addr, mode, -1 /* data_addr */, pec);
 976
 977         /* All but word data. */
 978         if (mode != I2C_SMBUS_WORD_DATA || even) {
 979                 int blen = 0;
 980
 981                 if (mode == I2C_SMBUS_BLOCK_DATA || mode == I2C_SMBUS_I2C_BLOCK_DATA)
 982                         blen = read_block_data(fd, mode, block);
 983
 984                 if (mode == I2C_SMBUS_BYTE) {
 985                         res = i2c_smbus_write_byte(fd, first);
 986                         if (res < 0)
 987                                 bb_perror_msg_and_die("write start address");
 988                 }
 989
 990                 dump_data(fd, mode, first, last, block, blen);
 991         } else {
 992                 dump_word_data(fd, first, last);
 993         }
 994
 995         return 0;
 996 }
 997 #endif /* ENABLE_I2CDUMP */
 998
 999 #if ENABLE_I2CDETECT
1000 enum adapter_type {
1001         ADT_DUMMY = 0,
1002         ADT_ISA,
1003         ADT_I2C,
1004         ADT_SMBUS,
1005 };
1006
1007 struct adap_desc {
1008         const char *funcs;
1009         const char *algo;
1010 };
1011
1012 static const struct adap_desc adap_descs[] = {
1013         { .funcs        = "dummy",
1014           .algo         = "Dummy bus", },
1015         { .funcs        = "isa",
1016           .algo         = "ISA bus", },
1017         { .funcs        = "i2c",
1018           .algo         = "I2C adapter", },
1019         { .funcs        = "smbus",
1020           .algo         = "SMBus adapter", },
1021 };
1022
1023 struct i2c_func
1024 {
1025         long value;
1026         const char* name;
1027 };
1028
1029 static const struct i2c_func i2c_funcs_tab[] = {
1030         { .value = I2C_FUNC_I2C,
1031           .name = "I2C" },
1032         { .value = I2C_FUNC_SMBUS_QUICK,
1033           .name = "SMBus quick command" },
1034         { .value = I2C_FUNC_SMBUS_WRITE_BYTE,
1035           .name = "SMBus send byte" },
1036         { .value = I2C_FUNC_SMBUS_READ_BYTE,
1037           .name = "SMBus receive byte" },
1038         { .value = I2C_FUNC_SMBUS_WRITE_BYTE_DATA,
1039           .name = "SMBus write byte" },
1040         { .value = I2C_FUNC_SMBUS_READ_BYTE_DATA,
1041           .name = "SMBus read byte" },
1042         { .value = I2C_FUNC_SMBUS_WRITE_WORD_DATA,
1043           .name = "SMBus write word" },
1044         { .value = I2C_FUNC_SMBUS_READ_WORD_DATA,
1045           .name = "SMBus read word" },
1046         { .value = I2C_FUNC_SMBUS_PROC_CALL,
1047           .name = "SMBus process call" },
1048         { .value = I2C_FUNC_SMBUS_WRITE_BLOCK_DATA,
1049           .name = "SMBus block write" },
1050         { .value = I2C_FUNC_SMBUS_READ_BLOCK_DATA,
1051           .name = "SMBus block read" },
1052         { .value = I2C_FUNC_SMBUS_BLOCK_PROC_CALL,
1053           .name = "SMBus block process call" },
1054         { .value = I2C_FUNC_SMBUS_PEC,
1055           .name = "SMBus PEC" },
1056         { .value = I2C_FUNC_SMBUS_WRITE_I2C_BLOCK,
1057           .name = "I2C block write" },
1058         { .value = I2C_FUNC_SMBUS_READ_I2C_BLOCK,
1059           .name = "I2C block read" },
1060         { .value = 0, .name = NULL }
1061 };
1062
1063 static enum adapter_type i2cdetect_get_funcs(int bus)
1064 {
1065         enum adapter_type ret;
1066         unsigned long funcs;
1067         int fd;
1068
1069         fd = i2c_dev_open(bus);
1070
1071         get_funcs_matrix(fd, &funcs);
1072         if (funcs & I2C_FUNC_I2C)
1073                 ret = ADT_I2C;
1074         else if (funcs & (I2C_FUNC_SMBUS_BYTE |
1075                           I2C_FUNC_SMBUS_BYTE_DATA |
1076                           I2C_FUNC_SMBUS_WORD_DATA))
1077                 ret = ADT_SMBUS;
1078         else
1079                 ret = ADT_DUMMY;
1080
1081         close(fd);
1082
1083         return ret;
1084 }
1085
1086 static void NORETURN list_i2c_busses_and_exit(void)
1087 {
1088         const char *const i2cdev_path = "/sys/class/i2c-dev";
1089
1090         char path[NAME_MAX], name[128];
1091         struct dirent *de, *subde;
1092         enum adapter_type adt;
1093         DIR *dir, *subdir;
1094         int rv, bus;
1095         char *pos;
1096         FILE *fp;
1097
1098         /*
1099          * XXX Upstream i2cdetect also looks for i2c bus info in /proc/bus/i2c,
1100          * but we won't bother since it's only useful on older kernels (before
1101          * 2.6.5). We expect sysfs to be present and mounted at /sys/.
1102          */
1103
1104         dir = xopendir(i2cdev_path);
1105         while ((de = readdir(dir))) {
1106                 if (de->d_name[0] == '.')
1107                         continue;
1108
1109                 /* Simple version for ISA chips. */
1110                 snprintf(path, NAME_MAX, "%s/%s/name",
1111                          i2cdev_path, de->d_name);
1112                 fp = fopen(path, "r");
1113                 if (fp == NULL) {
1114                         snprintf(path, NAME_MAX,
1115                                  "%s/%s/device/name",
1116                                  i2cdev_path, de->d_name);
1117                         fp = fopen(path, "r");
1118                 }
1119
1120                 /* Non-ISA chips require the hard-way. */
1121                 if (fp == NULL) {
1122                         snprintf(path, NAME_MAX,
1123                                  "%s/%s/device/name",
1124                                  i2cdev_path, de->d_name);
1125                         subdir = opendir(path);
1126                         if (subdir == NULL)
1127                                 continue;
1128
1129                         while ((subde = readdir(subdir))) {
1130                                 if (subde->d_name[0] == '.')
1131                                         continue;
1132
1133                                 if (is_prefixed_with(subde->d_name, "i2c-")) {
1134                                         snprintf(path, NAME_MAX,
1135                                                  "%s/%s/device/%s/name",
1136                                                  i2cdev_path, de->d_name,
1137                                                  subde->d_name);
1138                                         fp = fopen(path, "r");
1139                                         break;
1140                                 }
1141                         }
1142                 }
1143
1144                 if (fp != NULL) {
1145                         /*
1146                          * Get the rest of the info and display a line
1147                          * for a single bus.
1148                          */
1149                         memset(name, 0, sizeof(name));
1150                         pos = fgets(name, sizeof(name), fp);
1151                         fclose(fp);
1152                         if (pos == NULL)
1153                                 continue;
1154
1155                         pos = strchr(name, '\n');
1156                         if (pos != NULL)
1157                                 *pos = '\0';
1158
1159                         rv = sscanf(de->d_name, "i2c-%d", &bus);
1160                         if (rv != 1)
1161                                 continue;
1162
1163                         if (is_prefixed_with(name, "ISA"))
1164                                 adt = ADT_ISA;
1165                         else
1166                                 adt = i2cdetect_get_funcs(bus);
1167
1168                         printf(
1169                                 "i2c-%d\t%-10s\t%-32s\t%s\n",
1170                                 bus, adap_descs[adt].funcs,
1171                                 name, adap_descs[adt].algo);
1172                 }
1173         }
1174
1175         exit(EXIT_SUCCESS);
1176 }
1177
1178 static void NORETURN no_support(const char *cmd)
1179 {
1180         bb_error_msg_and_die("bus doesn't support %s", cmd);
1181 }
1182
1183 static void will_skip(const char *cmd)
1184 {
1185         bb_error_msg(
1186                 "warning: can't use %s command, "
1187                 "will skip some addresses", cmd);
1188 }
1189
1190 //usage:#define i2cdetect_trivial_usage
1191 //usage:       "[-F I2CBUS] [-l] [-y] [-a] [-q|-r] I2CBUS [FIRST LAST]"
1192 //usage:#define i2cdetect_full_usage "\n\n"
1193 //usage:       "Detect I2C chips.\n"
1194 //usage:     "\n        I2CBUS  i2c bus number"
1195 //usage:     "\n        FIRST and LAST limit the probing range"
1196 //usage:     "\n"
1197 //usage:     "\n        -l      output list of installed busses"
1198 //usage:     "\n        -y      disable interactive mode"
1199 //usage:     "\n        -a      force scanning of non-regular addresses"
1200 //usage:     "\n        -q      use smbus quick write commands for probing (default)"
1201 //usage:     "\n        -r      use smbus read byte commands for probing"
1202 //usage:     "\n        -F      display list of functionalities"
1203 int i2cdetect_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
1204 int i2cdetect_main(int argc UNUSED_PARAM, char **argv)
1205 {
1206         const unsigned opt_y = (1 << 0), opt_a = (1 << 1),
1207                               opt_q = (1 << 2), opt_r = (1 << 3),
1208                               opt_F = (1 << 4), opt_l = (1 << 5);
1209
1210         int fd, bus_num, i, j, mode = I2CDETECT_MODE_AUTO, status, cmd;
1211         unsigned first = 0x03, last = 0x77, opts;
1212         unsigned long funcs;
1213
1214         opts = getopt32(argv, "^"
1215                         "yaqrFl"
1216                         "\0"
1217                         "q--r:r--q:"/*mutually exclusive*/ "?3"/*up to 3 args*/
1218         );
1219         argv += optind;
1220
1221         if (opts & opt_l)
1222                 list_i2c_busses_and_exit();
1223
1224         if (!argv[0])
1225                 bb_show_usage();
1226
1227         bus_num = i2c_bus_lookup(argv[0]);
1228         fd = i2c_dev_open(bus_num);
1229         get_funcs_matrix(fd, &funcs);
1230
1231         if (opts & opt_F) {
1232                 /* Only list the functionalities. */
1233                 printf("Functionalities implemented by bus #%d\n", bus_num);
1234                 for (i = 0; i2c_funcs_tab[i].value; i++) {
1235                         printf("%-32s %s\n", i2c_funcs_tab[i].name,
1236                                funcs & i2c_funcs_tab[i].value ? "yes" : "no");
1237                 }
1238
1239                 return EXIT_SUCCESS;
1240         }
1241
1242         if (opts & opt_r)
1243                 mode = I2CDETECT_MODE_READ;
1244         else if (opts & opt_q)
1245                 mode = I2CDETECT_MODE_QUICK;
1246
1247         if (opts & opt_a) {
1248                 first = 0x00;
1249                 last = 0x7f;
1250         }
1251
1252         /* Read address range. */
1253         if (argv[1]) {
1254                 first = xstrtou_range(argv[1], 16, first, last);
1255                 if (argv[2])
1256                         last = xstrtou_range(argv[2], 16, first, last);
1257         }
1258
1259         if (!(funcs & (I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_READ_BYTE))) {
1260                 no_support("detection commands");
1261         } else
1262         if (mode == I2CDETECT_MODE_QUICK && !(funcs & I2C_FUNC_SMBUS_QUICK)) {
1263                 no_support("SMBus quick write");
1264         } else
1265         if (mode == I2CDETECT_MODE_READ && !(funcs & I2C_FUNC_SMBUS_READ_BYTE)) {
1266                 no_support("SMBus receive byte");
1267         }
1268
1269         if (mode == I2CDETECT_MODE_AUTO) {
1270                 if (!(funcs & I2C_FUNC_SMBUS_QUICK))
1271                         will_skip("SMBus quick write");
1272                 if (!(funcs & I2C_FUNC_SMBUS_READ_BYTE))
1273                         will_skip("SMBus receive byte");
1274         }
1275
1276         if (!(opts & opt_y))
1277                 confirm_action(-1, -1, -1, 0);
1278
1279         puts("     0  1  2  3  4  5  6  7  8  9  a  b  c  d  e  f");
1280         for (i = 0; i < 128; i += 16) {
1281                 printf("%02x: ", i);
1282                 for (j = 0; j < 16; j++) {
1283                         fflush_all();
1284
1285                         cmd = mode;
1286                         if (mode == I2CDETECT_MODE_AUTO) {
1287                                 if ((i+j >= 0x30 && i+j <= 0x37) ||
1288                                     (i+j >= 0x50 && i+j <= 0x5F))
1289                                         cmd = I2CDETECT_MODE_READ;
1290                                 else
1291                                         cmd = I2CDETECT_MODE_QUICK;
1292                         }
1293
1294                         /* Skip unwanted addresses. */
1295                         if (i+j < first
1296                          || i+j > last
1297                          || (cmd == I2CDETECT_MODE_READ && !(funcs & I2C_FUNC_SMBUS_READ_BYTE))
1298                          || (cmd == I2CDETECT_MODE_QUICK && !(funcs & I2C_FUNC_SMBUS_QUICK)))
1299                         {
1300                                 printf("   ");
1301                                 continue;
1302                         }
1303
1304                         status = ioctl(fd, I2C_SLAVE, itoptr(i + j));
1305                         if (status < 0) {
1306                                 if (errno == EBUSY) {
1307                                         printf("UU ");
1308                                         continue;
1309                                 }
1310
1311                                 bb_perror_msg_and_die(
1312                                         "can't set address to 0x%02x", i + j);
1313                         }
1314
1315                         switch (cmd) {
1316                         case I2CDETECT_MODE_READ:
1317                                 /*
1318                                  * This is known to lock SMBus on various
1319                                  * write-only chips (mainly clock chips).
1320                                  */
1321                                 status = i2c_smbus_read_byte(fd);
1322                                 break;
1323                         default: /* I2CDETECT_MODE_QUICK: */
1324                                 /*
1325                                  * This is known to corrupt the Atmel
1326                                  * AT24RF08 EEPROM.
1327                                  */
1328                                 status = i2c_smbus_write_quick(fd,
1329                                                                I2C_SMBUS_WRITE);
1330                                 break;
1331                         }
1332
1333                         if (status < 0)
1334                                 printf("-- ");
1335                         else
1336                                 printf("%02x ", i+j);
1337                 }
1338                 bb_putchar('\n');
1339         }
1340
1341         return 0;
1342 }
1343 #endif /* ENABLE_I2CDETECT */