xref: /freebsd/usr.sbin/i2c/i2c.c (revision b9f654b163bce26de79705e77b872427c9f2afa1)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3  *
4  * Copyright (C) 2008-2009 Semihalf, Michal Hajduk and Bartlomiej Sieka
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19  * ARE DISCLAIMED.  IN NO EVENT SHALL AUTHOR OR CONTRIBUTORS BE LIABLE
20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  */
28 
29 #include <sys/cdefs.h>
30 __FBSDID("$FreeBSD$");
31 
32 #include <err.h>
33 #include <errno.h>
34 #include <sysexits.h>
35 #include <fcntl.h>
36 #include <stdio.h>
37 #include <stdlib.h>
38 #include <string.h>
39 #include <stdarg.h>
40 #include <unistd.h>
41 #include <sys/ioctl.h>
42 
43 #include <dev/iicbus/iic.h>
44 
45 #define	I2C_DEV			"/dev/iic0"
46 #define	I2C_MODE_NOTSET		0
47 #define	I2C_MODE_NONE		1
48 #define	I2C_MODE_STOP_START	2
49 #define	I2C_MODE_REPEATED_START	3
50 #define	I2C_MODE_TRANSFER	4
51 
52 struct options {
53 	int	width;
54 	int	count;
55 	int	verbose;
56 	int	addr_set;
57 	int	binary;
58 	int	scan;
59 	int	skip;
60 	int	reset;
61 	int	mode;
62 	char	dir;
63 	uint32_t	addr;
64 	uint32_t	off;
65 };
66 
67 struct skip_range {
68 	int	start;
69 	int	end;
70 };
71 
72 __dead2 static void
73 usage(void)
74 {
75 
76 	fprintf(stderr, "usage: %s -a addr [-f device] [-d [r|w]] [-o offset] "
77 	    "[-w [0|8|16]] [-c count] [-m [tr|ss|rs|no]] [-b] [-v]\n",
78 	    getprogname());
79 	fprintf(stderr, "       %s -s [-f device] [-n skip_addr] -v\n",
80 	    getprogname());
81 	fprintf(stderr, "       %s -r [-f device] -v\n", getprogname());
82 	exit(EX_USAGE);
83 }
84 
85 static struct skip_range
86 skip_get_range(char *skip_addr)
87 {
88 	struct skip_range addr_range;
89 	char *token;
90 
91 	addr_range.start = 0;
92 	addr_range.end = 0;
93 
94 	token = strsep(&skip_addr, "..");
95 	if (token) {
96 		addr_range.start = strtoul(token, 0, 16);
97 		token = strsep(&skip_addr, "..");
98 		if ((token != NULL) && !atoi(token)) {
99 			token = strsep(&skip_addr, "..");
100 			if (token)
101 				addr_range.end = strtoul(token, 0, 16);
102 		}
103 	}
104 
105 	return (addr_range);
106 }
107 
108 /* Parse the string to get hex 7 bits addresses */
109 static int
110 skip_get_tokens(char *skip_addr, int *sk_addr, int max_index)
111 {
112 	char *token;
113 	int i;
114 
115 	for (i = 0; i < max_index; i++) {
116 		token = strsep(&skip_addr, ":");
117 		if (token == NULL)
118 			break;
119 		sk_addr[i] = strtoul(token, 0, 16);
120 	}
121 	return (i);
122 }
123 
124 static int
125 scan_bus(struct iiccmd cmd, char *dev, int skip, char *skip_addr)
126 {
127 	struct iic_msg rdmsg;
128 	struct iic_rdwr_data rdwrdata;
129 	struct skip_range addr_range = { 0, 0 };
130 	int *tokens, fd, error, i, index, j;
131 	int len = 0, do_skip = 0, no_range = 1, num_found = 0, use_read_xfer = 0;
132 	uint8_t rdbyte;
133 
134 	fd = open(dev, O_RDWR);
135 	if (fd == -1) {
136 		fprintf(stderr, "Error opening I2C controller (%s) for "
137 		    "scanning: %s\n", dev, strerror(errno));
138 		return (EX_NOINPUT);
139 	}
140 
141 	if (skip) {
142 		len = strlen(skip_addr);
143 		if (strstr(skip_addr, "..") != NULL) {
144 			addr_range = skip_get_range(skip_addr);
145 			no_range = 0;
146 		} else {
147 			tokens = (int *)malloc((len / 2 + 1) * sizeof(int));
148 			if (tokens == NULL) {
149 				fprintf(stderr, "Error allocating tokens "
150 				    "buffer\n");
151 				error = -1;
152 				goto out;
153 			}
154 			index = skip_get_tokens(skip_addr, tokens,
155 			    len / 2 + 1);
156 		}
157 
158 		if (!no_range && (addr_range.start > addr_range.end)) {
159 			fprintf(stderr, "Skip address out of range\n");
160 			error = -1;
161 			goto out;
162 		}
163 	}
164 
165 	printf("Scanning I2C devices on %s: ", dev);
166 
167 start_over:
168 	if (use_read_xfer) {
169 		fprintf(stderr,
170 		    "Hardware may not support START/STOP scanning; "
171 		    "trying less-reliable read method.\n");
172 	}
173 
174 	for (i = 1; i < 127; i++) {
175 
176 		if (skip && ( addr_range.start < addr_range.end)) {
177 			if (i >= addr_range.start && i <= addr_range.end)
178 				continue;
179 
180 		} else if (skip && no_range)
181 			for (j = 0; j < index; j++) {
182 				if (tokens[j] == i) {
183 					do_skip = 1;
184 					break;
185 				}
186 			}
187 
188 		if (do_skip) {
189 			do_skip = 0;
190 			continue;
191 		}
192 
193 		cmd.slave = i << 1;
194 		cmd.last = 1;
195 		cmd.count = 0;
196 		error = ioctl(fd, I2CRSTCARD, &cmd);
197 		if (error) {
198 			fprintf(stderr, "Controller reset failed\n");
199 			goto out;
200 		}
201 		if (use_read_xfer) {
202 			rdmsg.buf = &rdbyte;
203 			rdmsg.len = 1;
204 			rdmsg.flags = IIC_M_RD;
205 			rdmsg.slave = i << 1;
206 			rdwrdata.msgs = &rdmsg;
207 			rdwrdata.nmsgs = 1;
208 			error = ioctl(fd, I2CRDWR, &rdwrdata);
209 		} else {
210 			cmd.slave = i << 1;
211 			cmd.last = 1;
212 			error = ioctl(fd, I2CSTART, &cmd);
213 			if (errno == ENODEV || errno == EOPNOTSUPP) {
214 				/* If START not supported try reading. */
215 				use_read_xfer = 1;
216 				goto start_over;
217 			}
218 			ioctl(fd, I2CSTOP);
219 		}
220 		if (error == 0) {
221 			++num_found;
222 			printf("%02x ", i);
223 		}
224 	}
225 
226 	/*
227 	 * If we found nothing, maybe START is not supported and returns a
228 	 * generic error code such as EIO or ENXIO, so try again using reads.
229 	 */
230 	if (num_found == 0) {
231 		if (!use_read_xfer) {
232 			use_read_xfer = 1;
233 			goto start_over;
234 		}
235 		printf("<none found>");
236 	}
237 	printf("\n");
238 
239 	error = ioctl(fd, I2CRSTCARD, &cmd);
240 out:
241 	close(fd);
242 	if (skip && no_range)
243 		free(tokens);
244 
245 	if (error) {
246 		fprintf(stderr, "Error scanning I2C controller (%s): %s\n",
247 		    dev, strerror(errno));
248 		return (EX_NOINPUT);
249 	} else
250 		return (EX_OK);
251 }
252 
253 static int
254 reset_bus(struct iiccmd cmd, char *dev)
255 {
256 	int fd, error;
257 
258 	fd = open(dev, O_RDWR);
259 	if (fd == -1) {
260 		fprintf(stderr, "Error opening I2C controller (%s) for "
261 		    "resetting: %s\n", dev, strerror(errno));
262 		return (EX_NOINPUT);
263 	}
264 
265 	printf("Resetting I2C controller on %s: ", dev);
266 	error = ioctl(fd, I2CRSTCARD, &cmd);
267 	close (fd);
268 
269 	if (error) {
270 		printf("error: %s\n", strerror(errno));
271 		return (EX_IOERR);
272 	} else {
273 		printf("OK\n");
274 		return (EX_OK);
275 	}
276 }
277 
278 static char *
279 prepare_buf(int size, uint32_t off)
280 {
281 	char *buf;
282 
283 	buf = malloc(size);
284 	if (buf == NULL)
285 		return (buf);
286 
287 	if (size == 1)
288 		buf[0] = off & 0xff;
289 	else if (size == 2) {
290 		buf[0] = (off >> 8) & 0xff;
291 		buf[1] = off & 0xff;
292 	}
293 
294 	return (buf);
295 }
296 
297 static int
298 i2c_write(char *dev, struct options i2c_opt, char *i2c_buf)
299 {
300 	struct iiccmd cmd;
301 	int error, fd, bufsize;
302 	char *err_msg, *buf;
303 
304 	fd = open(dev, O_RDWR);
305 	if (fd == -1) {
306 		free(i2c_buf);
307 		err(1, "open failed");
308 	}
309 
310 	cmd.slave = i2c_opt.addr;
311 	error = ioctl(fd, I2CSTART, &cmd);
312 	if (error == -1) {
313 		err_msg = "ioctl: error sending start condition";
314 		goto err1;
315 	}
316 
317 	if (i2c_opt.width) {
318 		bufsize = i2c_opt.width / 8;
319 		buf = prepare_buf(bufsize, i2c_opt.off);
320 		if (buf == NULL) {
321 			err_msg = "error: offset malloc";
322 			goto err1;
323 		}
324 	} else {
325 		bufsize = 0;
326 		buf = NULL;
327 	}
328 
329 	switch(i2c_opt.mode) {
330 	case I2C_MODE_STOP_START:
331 		/*
332 		 * Write offset where the data will go
333 		 */
334 		if (i2c_opt.width) {
335 			cmd.count = bufsize;
336 			cmd.buf = buf;
337 			error = ioctl(fd, I2CWRITE, &cmd);
338 			free(buf);
339 			if (error == -1) {
340 				err_msg = "ioctl: error writing offset";
341 				goto err1;
342 			}
343 		}
344 
345 		error = ioctl(fd, I2CSTOP);
346 		if (error == -1) {
347 			err_msg = "ioctl: error sending stop condition";
348 			goto err2;
349 		}
350 		cmd.slave = i2c_opt.addr;
351 		error = ioctl(fd, I2CSTART, &cmd);
352 		if (error == -1) {
353 			err_msg = "ioctl: error sending start condition";
354 			goto err1;
355 		}
356 
357 		/*
358 		 * Write the data
359 		 */
360 		cmd.count = i2c_opt.count;
361 		cmd.buf = i2c_buf;
362 		cmd.last = 0;
363 		error = ioctl(fd, I2CWRITE, &cmd);
364 		if (error == -1) {
365 			err_msg = "ioctl: error writing";
366 			goto err1;
367 		}
368 		break;
369 
370 	case I2C_MODE_REPEATED_START:
371 		/*
372 		 * Write offset where the data will go
373 		 */
374 		if (i2c_opt.width) {
375 			cmd.count = bufsize;
376 			cmd.buf = buf;
377 			error = ioctl(fd, I2CWRITE, &cmd);
378 			free(buf);
379 			if (error == -1) {
380 				err_msg = "ioctl: error writing offset";
381 				goto err1;
382 			}
383 		}
384 
385 		cmd.slave = i2c_opt.addr;
386 		error = ioctl(fd, I2CRPTSTART, &cmd);
387 		if (error == -1) {
388 			err_msg = "ioctl: error sending repeated start "
389 			    "condition";
390 			goto err1;
391 		}
392 
393 		/*
394 		 * Write the data
395 		 */
396 		cmd.count = i2c_opt.count;
397 		cmd.buf = i2c_buf;
398 		cmd.last = 0;
399 		error = ioctl(fd, I2CWRITE, &cmd);
400 		if (error == -1) {
401 			err_msg = "ioctl: error writing";
402 			goto err1;
403 		}
404 		break;
405 
406 	case I2C_MODE_NONE: /* fall through */
407 	default:
408 		buf = realloc(buf, bufsize + i2c_opt.count);
409 		if (buf == NULL) {
410 			err_msg = "error: data malloc";
411 			goto err1;
412 		}
413 
414 		memcpy(buf + bufsize, i2c_buf, i2c_opt.count);
415 		/*
416 		 * Write offset and data
417 		 */
418 		cmd.count = bufsize + i2c_opt.count;
419 		cmd.buf = buf;
420 		cmd.last = 0;
421 		error = ioctl(fd, I2CWRITE, &cmd);
422 		free(buf);
423 		if (error == -1) {
424 			err_msg = "ioctl: error writing";
425 			goto err1;
426 		}
427 		break;
428 	}
429 	error = ioctl(fd, I2CSTOP);
430 	if (error == -1) {
431 		err_msg = "ioctl: error sending stop condition";
432 		goto err2;
433 	}
434 
435 	close(fd);
436 	return (0);
437 
438 err1:
439 	error = ioctl(fd, I2CSTOP);
440 	if (error == -1)
441 		fprintf(stderr, "error sending stop condition\n");
442 err2:
443 	if (err_msg)
444 		fprintf(stderr, "%s\n", err_msg);
445 
446 	close(fd);
447 	return (1);
448 }
449 
450 static int
451 i2c_read(char *dev, struct options i2c_opt, char *i2c_buf)
452 {
453 	struct iiccmd cmd;
454 	int fd, error, bufsize;
455 	char *err_msg, data = 0, *buf;
456 
457 	fd = open(dev, O_RDWR);
458 	if (fd == -1)
459 		err(1, "open failed");
460 
461 	bzero(&cmd, sizeof(cmd));
462 
463 	if (i2c_opt.width) {
464 		cmd.slave = i2c_opt.addr;
465 		cmd.count = 1;
466 		cmd.last = 0;
467 		cmd.buf = &data;
468 		error = ioctl(fd, I2CSTART, &cmd);
469 		if (error == -1) {
470 			err_msg = "ioctl: error sending start condition";
471 			goto err1;
472 		}
473 		bufsize = i2c_opt.width / 8;
474 		buf = prepare_buf(bufsize, i2c_opt.off);
475 		if (buf == NULL) {
476 			err_msg = "error: offset malloc";
477 			goto err1;
478 		}
479 
480 		cmd.count = bufsize;
481 		cmd.buf = buf;
482 		cmd.last = 0;
483 		error = ioctl(fd, I2CWRITE, &cmd);
484 		free(buf);
485 		if (error == -1) {
486 			err_msg = "ioctl: error writing offset";
487 			goto err1;
488 		}
489 
490 		if (i2c_opt.mode == I2C_MODE_STOP_START) {
491 			error = ioctl(fd, I2CSTOP);
492 			if (error == -1) {
493 				err_msg = "error sending stop condition";
494 				goto err2;
495 			}
496 		}
497 	}
498 	cmd.slave = i2c_opt.addr | 1;
499 	cmd.count = 1;
500 	cmd.last = 0;
501 	cmd.buf = &data;
502 	if (i2c_opt.mode == I2C_MODE_STOP_START || i2c_opt.width == 0) {
503 		error = ioctl(fd, I2CSTART, &cmd);
504 		if (error == -1) {
505 			err_msg = "ioctl: error sending start condition";
506 			goto err2;
507 		}
508 	} else if (i2c_opt.mode == I2C_MODE_REPEATED_START) {
509 		error = ioctl(fd, I2CRPTSTART, &cmd);
510 		if (error == -1) {
511 			err_msg = "ioctl: error sending repeated start "
512 			    "condition";
513 			goto err1;
514 		}
515 	}
516 
517 	cmd.count = i2c_opt.count;
518 	cmd.buf = i2c_buf;
519 	cmd.last = 1;
520 	error = ioctl(fd, I2CREAD, &cmd);
521 	if (error == -1) {
522 		err_msg = "ioctl: error while reading";
523 		goto err1;
524 	}
525 
526 	error = ioctl(fd, I2CSTOP);
527 	if (error == -1) {
528 		err_msg = "error sending stop condtion\n";
529 		goto err2;
530 	}
531 
532 	close(fd);
533 	return (0);
534 
535 err1:
536 	error = ioctl(fd, I2CSTOP);
537 	if (error == -1)
538 		fprintf(stderr, "error sending stop condition\n");
539 err2:
540 	if (err_msg)
541 		fprintf(stderr, "%s\n", err_msg);
542 
543 	close(fd);
544 	return (1);
545 }
546 
547 /*
548  * i2c_rdwr_transfer() - use I2CRDWR to conduct a complete i2c transfer.
549  *
550  * Some i2c hardware is unable to provide direct control over START, REPEAT-
551  * START, and STOP operations.  Such hardware can only perform a complete
552  * START-<data>-STOP or START-<data>-REPEAT-START-<data>-STOP sequence as a
553  * single operation.  The driver framework refers to this sequence as a
554  * "transfer" so we call it "transfer mode".  We assemble either one or two
555  * iic_msg structures to describe the IO operations, and hand them off to the
556  * driver to be handled as a single transfer.
557  */
558 static int
559 i2c_rdwr_transfer(char *dev, struct options i2c_opt, char *i2c_buf)
560 {
561 	struct iic_msg msgs[2];
562 	struct iic_rdwr_data xfer;
563 	int fd, i;
564 	union {
565 		uint8_t  buf[2];
566 		uint8_t  off8;
567 		uint16_t off16;
568 	} off;
569 
570 	i = 0;
571 	if (i2c_opt.width > 0) {
572 		msgs[i].flags = IIC_M_WR | IIC_M_NOSTOP;
573 		msgs[i].slave = i2c_opt.addr;
574 		msgs[i].buf   = off.buf;
575 		if (i2c_opt.width == 8) {
576 			off.off8 = (uint8_t)i2c_opt.off;
577 			msgs[i].len = 1;
578 		} else {
579 			off.off16 = (uint16_t)i2c_opt.off;
580 			msgs[i].len = 2;
581 		}
582 		++i;
583 	}
584 
585 	/*
586 	 * If the transfer direction is write and we did a write of the offset
587 	 * above, then we need to elide the start; this transfer is just more
588 	 * writing that follows the one started above.  For a read, we always do
589 	 * a start; if we did an offset write above it'll be a repeat-start
590 	 * because of the NOSTOP flag used above.
591 	 */
592 	if (i2c_opt.dir == 'w')
593 		msgs[i].flags = IIC_M_WR | (i > 0) ? IIC_M_NOSTART : 0;
594 	else
595 		msgs[i].flags = IIC_M_RD;
596 	msgs[i].slave = i2c_opt.addr;
597 	msgs[i].len   = i2c_opt.count;
598 	msgs[i].buf   = i2c_buf;
599 	++i;
600 
601 	xfer.msgs = msgs;
602 	xfer.nmsgs = i;
603 
604 	if ((fd = open(dev, O_RDWR)) == -1)
605 		err(1, "open(%s) failed", dev);
606 	if (ioctl(fd, I2CRDWR, &xfer) == -1 )
607 		err(1, "ioctl(I2CRDWR) failed");
608 	close(fd);
609 
610 	return (0);
611 }
612 
613 int
614 main(int argc, char** argv)
615 {
616 	struct iiccmd cmd;
617 	struct options i2c_opt;
618 	char *dev, *skip_addr, *i2c_buf;
619 	int error, chunk_size, i, j, ch;
620 
621 	errno = 0;
622 	error = 0;
623 
624 	/* Line-break the output every chunk_size bytes */
625 	chunk_size = 16;
626 
627 	dev = I2C_DEV;
628 
629 	/* Default values */
630 	i2c_opt.addr_set = 0;
631 	i2c_opt.off = 0;
632 	i2c_opt.verbose = 0;
633 	i2c_opt.dir = 'r';	/* direction = read */
634 	i2c_opt.width = 8;
635 	i2c_opt.count = 1;
636 	i2c_opt.binary = 0;	/* ASCII text output */
637 	i2c_opt.scan = 0;	/* no bus scan */
638 	i2c_opt.skip = 0;	/* scan all addresses */
639 	i2c_opt.reset = 0;	/* no bus reset */
640 	i2c_opt.mode = I2C_MODE_NOTSET;
641 
642 	while ((ch = getopt(argc, argv, "a:f:d:o:w:c:m:n:sbvrh")) != -1) {
643 		switch(ch) {
644 		case 'a':
645 			i2c_opt.addr = (strtoul(optarg, 0, 16) << 1);
646 			if (i2c_opt.addr == 0 && errno == EINVAL)
647 				i2c_opt.addr_set = 0;
648 			else
649 				i2c_opt.addr_set = 1;
650 			break;
651 		case 'f':
652 			dev = optarg;
653 			break;
654 		case 'd':
655 			i2c_opt.dir = optarg[0];
656 			break;
657 		case 'o':
658 			i2c_opt.off = strtoul(optarg, 0, 16);
659 			if (i2c_opt.off == 0 && errno == EINVAL)
660 				error = 1;
661 			break;
662 		case 'w':
663 			i2c_opt.width = atoi(optarg);
664 			break;
665 		case 'c':
666 			i2c_opt.count = atoi(optarg);
667 			break;
668 		case 'm':
669 			if (!strcmp(optarg, "no"))
670 				i2c_opt.mode = I2C_MODE_NONE;
671 			else if (!strcmp(optarg, "ss"))
672 				i2c_opt.mode = I2C_MODE_STOP_START;
673 			else if (!strcmp(optarg, "rs"))
674 				i2c_opt.mode = I2C_MODE_REPEATED_START;
675 			else if (!strcmp(optarg, "tr"))
676 				i2c_opt.mode = I2C_MODE_TRANSFER;
677 			else
678 				usage();
679 			break;
680 		case 'n':
681 			i2c_opt.skip = 1;
682 			skip_addr = optarg;
683 			break;
684 		case 's':
685 			i2c_opt.scan = 1;
686 			break;
687 		case 'b':
688 			i2c_opt.binary = 1;
689 			break;
690 		case 'v':
691 			i2c_opt.verbose = 1;
692 			break;
693 		case 'r':
694 			i2c_opt.reset = 1;
695 			break;
696 		case 'h':
697 		default:
698 			usage();
699 		}
700 	}
701 	argc -= optind;
702 	argv += optind;
703 
704 	/* Set default mode if option -m is not specified */
705 	if (i2c_opt.mode == I2C_MODE_NOTSET) {
706 		if (i2c_opt.dir == 'r')
707 			i2c_opt.mode = I2C_MODE_STOP_START;
708 		else if (i2c_opt.dir == 'w')
709 			i2c_opt.mode = I2C_MODE_NONE;
710 	}
711 
712 	/* Basic sanity check of command line arguments */
713 	if (i2c_opt.scan) {
714 		if (i2c_opt.addr_set)
715 			usage();
716 	} else if (i2c_opt.reset) {
717 		if (i2c_opt.addr_set)
718 			usage();
719 	} else if (error) {
720 		usage();
721 	} else if ((i2c_opt.dir == 'r' || i2c_opt.dir == 'w')) {
722 		if ((i2c_opt.addr_set == 0) ||
723 		    !(i2c_opt.width == 0 || i2c_opt.width == 8 ||
724 		    i2c_opt.width == 16))
725 		usage();
726 	}
727 
728 	if (i2c_opt.verbose)
729 		fprintf(stderr, "dev: %s, addr: 0x%x, r/w: %c, "
730 		    "offset: 0x%02x, width: %u, count: %u\n", dev,
731 		    i2c_opt.addr >> 1, i2c_opt.dir, i2c_opt.off,
732 		    i2c_opt.width, i2c_opt.count);
733 
734 	if (i2c_opt.scan)
735 		exit(scan_bus(cmd, dev, i2c_opt.skip, skip_addr));
736 
737 	if (i2c_opt.reset)
738 		exit(reset_bus(cmd, dev));
739 
740 	i2c_buf = malloc(i2c_opt.count);
741 	if (i2c_buf == NULL)
742 		err(1, "data malloc");
743 
744 	/*
745 	 * For a write, read the data to be written to the chip from stdin.
746 	 */
747 	if (i2c_opt.dir == 'w') {
748 		if (i2c_opt.verbose && !i2c_opt.binary)
749 			fprintf(stderr, "Enter %u bytes of data: ",
750 			    i2c_opt.count);
751 		for (i = 0; i < i2c_opt.count; i++) {
752 			ch = getchar();
753 			if (ch == EOF) {
754 				free(i2c_buf);
755 				err(1, "not enough data, exiting\n");
756 			}
757 			i2c_buf[i] = ch;
758 		}
759 	}
760 
761 	if (i2c_opt.mode == I2C_MODE_TRANSFER)
762 		error = i2c_rdwr_transfer(dev, i2c_opt, i2c_buf);
763 	else if (i2c_opt.dir == 'w')
764 		error = i2c_write(dev, i2c_opt, i2c_buf);
765 	else
766 		error = i2c_read(dev, i2c_opt, i2c_buf);
767 
768 	if (error != 0) {
769 		free(i2c_buf);
770 		return (1);
771 	}
772 
773 	if (i2c_opt.verbose)
774 		fprintf(stderr, "\nData %s (hex):\n", i2c_opt.dir == 'r' ?
775 		    "read" : "written");
776 
777 	i = 0;
778 	j = 0;
779 	while (i < i2c_opt.count) {
780 		if (i2c_opt.verbose || (i2c_opt.dir == 'r' &&
781 		    !i2c_opt.binary))
782 			fprintf (stderr, "%02hhx ", i2c_buf[i++]);
783 
784 		if (i2c_opt.dir == 'r' && i2c_opt.binary) {
785 			fprintf(stdout, "%c", i2c_buf[j++]);
786 			if(!i2c_opt.verbose)
787 				i++;
788 		}
789 		if (!i2c_opt.verbose && (i2c_opt.dir == 'w'))
790 			break;
791 		if ((i % chunk_size) == 0)
792 			fprintf(stderr, "\n");
793 	}
794 	if ((i % chunk_size) != 0)
795 		fprintf(stderr, "\n");
796 
797 	free(i2c_buf);
798 	return (0);
799 }
800