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Introduce the I2C diagnostic utility. It let's discover and inspect slave

Browse Source 
devices on the bus.

Reviewed by:	bms, stas
Obtained from:	Semihalf
This commit is contained in:
Rafal Jaworowski 2009-01-26 14:00:50 +00:00
parent 1aef11be0e
commit 477f656bb9
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=187712
4 changed files with 810 additions and 0 deletions
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1
usr.sbin/Makefile
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@ -65,6 +65,7 @@ SUBDIR= ${_ac} \
getpmac \
gstat \
${_gssd} \
i2c \
ifmcstat \
inetd \
iostat \

8
usr.sbin/i2c/Makefile Normal file
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@ -0,0 +1,8 @@
# $FreeBSD$
PROG= i2c
MAN= i2c.8
WARNS?= 2
.include <bsd.prog.mk>

168
usr.sbin/i2c/i2c.8 Normal file
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@ -0,0 +1,168 @@
.\"
.\" Copyright (C) 2008-2009 Semihalf, Michal Hajduk and Bartlomiej Sieka
.\" All rights reserved.
.\"
.\" Redistribution and use in source and binary forms, with or without
.\" modification, are permitted provided that the following conditions
.\" are met:
.\" 1. Redistributions of source code must retain the above copyright
.\" notice, this list of conditions and the following disclaimer.
.\" 2. Redistributions in binary form must reproduce the above copyright
.\" notice, this list of conditions and the following disclaimer in the
.\" documentation and/or other materials provided with the distribution.
.\"
.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
.\" ARE DISCLAIMED. IN NO EVENT SHALL AUTHOR OR CONTRIBUTORS BE LIABLE
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
.\" SUCH DAMAGE.
.\"
.\" $FreeBSD$
.\"
.Dd Jan 23, 2009
.Dt I2C 8
.Os
.Sh NAME
.Nm i2c
.Nd test I2C bus and slave devices
.Sh SYNOPSIS
.Nm
.Cm -a Ar address
.Op Fl f Ar device
.Op Fl d Ar r|w
.Op Fl w Ar 0|8|16
.Op Fl o Ar offset
.Op Fl c Ar count
.Op Fl m Ar ss|rs|no
.Op Fl b
.Op Fl v
.Nm
.Cm -s
.Op Fl f Ar device
.Op Fl n Ar skip_addr
.Op Fl v
.Nm
.Cm -r
.Op Fl f Ar device
.Op Fl v
.Sh DESCRIPTION
The
.Nm
utility can be used to perform raw data transfers (read or write) with devices
on the I2C bus. It can also scan the bus for available devices and reset the
I2C controller.
.Pp
The options are as follows:
.Bl -tag -width ".Fl d Ar direction"
.It Fl a Ar address
7-bit address on the I2C device to operate on (hex).
.It Fl b
binary mode - when performing a read operation, the data read from the device
is output in binary format on stdout; when doing a write, the binary data to
be written to the device is read from stdin.
.It Fl c Ar count
number of bytes to transfer (dec).
.It Fl d Ar r|w
transfer direction: r - read, w - write.
.It Fl f Ar device
I2C bus to use (default is /dev/iic0).
.It Fl m Ar ss|rs|no
addressing mode, i.e., I2C bus operations performed after the offset for the
transfer has been written to the device and before the actual read/write
operation. rs - repeated start; ss - stop start; no - none.
.It Fl n Ar skip_addr
skip address - address(es) to be skipped during bus scan.
The are two ways to specify addresses to ignore: by range 'a..b' or
using selected addresses 'a:b:c'. This option is available only when "-s" is
used.
.It Fl o Ar offset
offset within the device for data transfer (hex).
.It Fl r
reset the controller.
.It Fl s
scan the bus for devices.
.It Fl v
be verbose
.It Fl w Ar 0|8|16
device addressing width (in bits).
.El
.Sh WARNINGS
Great care must be taken when manipulating slave I2C devices with the
.Nm
utility. Often times important configuration data for the system is kept in
non-volatile but write enabled memories located on the I2C bus, for example
Ethernet hardware addresses, RAM module parameters (SPD), processor reset
configuration word etc.
.Pp
It is very easy to render the whole system unusable when such configuration
data is deleted or altered, so use the
.Dq -d w
(write) command only if you know exactly what you are doing.
.Pp
Also avoid ungraceful interrupting of an ongoing transaction on the I2C bus,
as it can lead to potentially dangerous effects. Consider the following
scenario: when the host CPU is reset (for whatever reason) in the middle of a
started I2C transaction, the I2C slave device could be left in write mode
waiting for data or offset to arrive. When the CPU reinitializes itself and
talks to this I2C slave device again, the commands and other control info it
sends are treated by the slave device as data or offset it was waiting for,
and there's great potential for corruption if such a write is performed.
.Sh EXAMPLES
.Pp
.Bl -bullet
.It
Scan the default bus (/dev/iic0) for devices:
.Pp
i2c -s
.It
Scan the default bus (/dev/iic0) for devices and skip addresses 0x56 and
0x45.
.Pp
i2c -s -n 0x56:0x45
.It
Scan the default bus (/dev/iic0) for devices and skip address range
0x34 to 0x56.
.Pp
i2c -s -n 0x34..0x56
.It
Read 8 bytes of data from device at address 0x56 (e.g., an EEPROM):
.Pp
i2c -a 0x56 -d r -c 8
.It
Write 16 bytes of data from file data.bin to device 0x56 at offset 0x10:
.Pp
i2c -a 0x56 -d w -c 16 -o 0x10 -b < data.bin
.It
Copy 4 bytes between two EEPROMs (0x56 on /dev/iic1 to 0x57 on /dev/iic0):
.Pp
i2c -a 0x56 -f /dev/iic1 -d r -c 0x4 -b | i2c -a 0x57 -f /dev/iic0 -d w -c 4 -b
.It
Reset the controller:
.Pp
i2c -f /dev/iic1 -r
.El
.Sh SEE ALSO
.Xr iic 4 ,
.Xr iicbus 4
.Sh HISTORY
The
.Nm
utility appeared in
.Fx 8.0 .
.Sh AUTHORS
.An -nosplit
The
.Nm
utility and this manual page were written by
.An Bartlomiej Sieka
.Aq tur@semihalf.com
and
.An Michal Hajduk
.Aq mih@semihalf.com .

633
usr.sbin/i2c/i2c.c Normal file
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/*-
* Copyright (C) 2008-2009 Semihalf, Michal Hajduk and Bartlomiej Sieka
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <err.h>
#include <errno.h>
#include <sysexits.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <stdarg.h>
#include <unistd.h>
#include <sys/ioctl.h>
#include <dev/iicbus/iic.h>
#define I2C_DEV "/dev/iic0"
#define I2C_MODE_NOTSET 0
#define I2C_MODE_NONE 1
#define I2C_MODE_STOP_START 2
#define I2C_MODE_REPEATED_START 3
struct options {
int width;
int count;
int verbose;
int addr_set;
int binary;
int scan;
int skip;
int reset;
int mode;
char dir;
uint32_t addr;
uint32_t off;
};
struct skip_range {
int start;
int end;
};
__dead2 static void
usage(void)
{
fprintf(stderr, "usage: %s -a addr [-f device] [-d [r|w]] [-o offset] "
"[-w [0|8|16]] [-c count] [-m [ss|rs|no]] [-b] [-v]\n",
getprogname());
fprintf(stderr, " %s -s [-f device] [-n skip_addr] -v\n",
getprogname());
fprintf(stderr, " %s -r [-f device] -v\n", getprogname());
exit(EX_USAGE);
}
static struct skip_range
skip_get_range(char *skip_addr)
{
struct skip_range addr_range;
char *token;
addr_range.start = 0;
addr_range.end = 0;
token = strsep(&skip_addr, "..");
if (token) {
addr_range.start = strtoul(token, 0, 16);
token = strsep(&skip_addr, "..");
if ((token != NULL) && !atoi(token)) {
token = strsep(&skip_addr, "..");
if (token)
addr_range.end = strtoul(token, 0, 16);
}
}
return (addr_range);
}
/* Parse the string to get hex 7 bits addresses */
static int
skip_get_tokens(char *skip_addr, int *sk_addr, int max_index)
{
char *token;
int i;
for (i = 0; i < max_index; i++) {
token = strsep(&skip_addr, ":");
if (token == NULL)
break;
sk_addr[i] = strtoul(token, 0, 16);
}
return (i);
}
static int
scan_bus(struct iiccmd cmd, char *dev, int skip, char *skip_addr)
{
struct skip_range addr_range = { 0, 0 };
int *tokens, fd, error, i, index, j;
int len = 0, do_skip = 0, no_range = 1;
fd = open(dev, O_RDWR);
if (fd == -1) {
fprintf(stderr, "Error opening I2C controller (%s) for "
"scanning: %s\n", dev, strerror(errno));
return (EX_NOINPUT);
}
if (skip) {
len = strlen(skip_addr);
if (strstr(skip_addr, "..") != NULL) {
addr_range = skip_get_range(skip_addr);
no_range = 0;
} else {
tokens = (int *)malloc((len / 2 + 1) * sizeof(int));
if (tokens == NULL) {
fprintf(stderr, "Error allocating tokens "
"buffer\n");
goto out;
}
index = skip_get_tokens(skip_addr, tokens,
len / 2 + 1);
}
if (!no_range && (addr_range.start > addr_range.end)) {
fprintf(stderr, "Skip address out of range\n");
goto out;
}
}
printf("Scanning I2C devices on %s: ", dev);
for (i = 1; i < 127; i++) {
if (skip && ( addr_range.start < addr_range.end)) {
if (i >= addr_range.start && i <= addr_range.end)
continue;
} else if (skip && no_range)
for (j = 0; j < index; j++) {
if (tokens[j] == i) {
do_skip = 1;
break;
}
}
if (do_skip) {
do_skip = 0;
continue;
}
cmd.slave = i << 1;
cmd.last = 1;
cmd.count = 0;
error = ioctl(fd, I2CRSTCARD, &cmd);
if (error)
goto out;
cmd.slave = i << 1;
cmd.last = 1;
error = ioctl(fd, I2CSTART, &cmd);
if (!error)
printf("%x ", i);
cmd.slave = i << 1;
cmd.last = 1;
error = ioctl(fd, I2CSTOP, &cmd);
}
printf("\n");
error = ioctl(fd, I2CRSTCARD, &cmd);
out:
close(fd);
if (skip && no_range)
free(tokens);
if (error) {
fprintf(stderr, "Error scanning I2C controller (%s): %s\n",
dev, strerror(errno));
return (EX_NOINPUT);
} else
return (EX_OK);
}
static int
reset_bus(struct iiccmd cmd, char *dev)
{
int fd, error;
fd = open(dev, O_RDWR);
if (fd == -1) {
fprintf(stderr, "Error opening I2C controller (%s) for "
"resetting: %s\n", dev, strerror(errno));
return (EX_NOINPUT);
}
printf("Resetting I2C controller on %s: ", dev);
error = ioctl(fd, I2CRSTCARD, &cmd);
close (fd);
if (error) {
printf("error: %s\n", strerror(errno));
return (EX_IOERR);
} else {
printf("OK\n");
return (EX_OK);
}
}
static char *
prepare_buf(int size, uint32_t off)
{
char *buf;
buf = malloc(size);
if (buf == NULL)
return (buf);
if (size == 1)
buf[0] = off & 0xff;
else if (size == 2) {
buf[0] = (off >> 8) & 0xff;
buf[1] = off & 0xff;
}
return (buf);
}
static int
i2c_write(char *dev, struct options i2c_opt, char *i2c_buf)
{
struct iiccmd cmd;
int ch, i, error, fd, bufsize;
char *err_msg, *buf;
/*
* Read data to be written to the chip from stdin
*/
if (i2c_opt.verbose && !i2c_opt.binary)
fprintf(stderr, "Enter %u bytes of data: ", i2c_opt.count);
for (i = 0; i < i2c_opt.count; i++) {
ch = getchar();
if (ch == EOF) {
free(i2c_buf);
err(1, "not enough data, exiting\n");
}
i2c_buf[i] = ch;
}
fd = open(dev, O_RDWR);
if (fd == -1) {
free(i2c_buf);
err(1, "open failed");
}
/*
* Write offset where the data will go
*/
cmd.slave = i2c_opt.addr;
error = ioctl(fd, I2CSTART, &cmd);
if (error == -1) {
err_msg = "ioctl: error sending start condition";
goto err1;
}
if (i2c_opt.width) {
bufsize = i2c_opt.width / 8;
buf = prepare_buf(bufsize, i2c_opt.off);
if (buf == NULL) {
err_msg = "error: offset malloc";
goto err1;
}
cmd.count = bufsize;
cmd.buf = buf;
error = ioctl(fd, I2CWRITE, &cmd);
free(buf);
if (error == -1) {
err_msg = "ioctl: error when write offset";
goto err1;
}
}
/* Mode - stop start */
if (i2c_opt.mode == I2C_MODE_STOP_START) {
cmd.slave = i2c_opt.addr;
error = ioctl(fd, I2CSTOP, &cmd);
if (error == -1) {
err_msg = "ioctl: error sending stop condition";
goto err2;
}
cmd.slave = i2c_opt.addr;
error = ioctl(fd, I2CSTART, &cmd);
if (error == -1) {
err_msg = "ioctl: error sending start condition";
goto err1;
}
}
/* Mode - repeated start */
if (i2c_opt.mode == I2C_MODE_REPEATED_START) {
cmd.slave = i2c_opt.addr;
error = ioctl(fd, I2CRPTSTART, &cmd);
if (error == -1) {
err_msg = "ioctl: error sending repeated start "
"condition";
goto err1;
}
}
/*
* Write the data
*/
cmd.count = i2c_opt.count;
cmd.buf = i2c_buf;
cmd.last = 0;
error = ioctl(fd, I2CWRITE, &cmd);
if (error == -1) {
err_msg = "ioctl: error when write";
goto err1;
}
cmd.slave = i2c_opt.addr;
error = ioctl(fd, I2CSTOP, &cmd);
if (error == -1) {
err_msg = "ioctl: error sending stop condition";
goto err2;
}
close(fd);
return (0);
err1:
cmd.slave = i2c_opt.addr;
error = ioctl(fd, I2CSTOP, &cmd);
if (error == -1)
fprintf(stderr, "error sending stop condtion\n");
err2:
if (err_msg)
fprintf(stderr, err_msg);
close(fd);
return (1);
}
static int
i2c_read(char *dev, struct options i2c_opt, char *i2c_buf)
{
struct iiccmd cmd;
int i, fd, error, bufsize;
char *err_msg, data = 0, *buf;
fd = open(dev, O_RDWR);
if (fd == -1)
err(1, "open failed");
bzero(&cmd, sizeof(cmd));
if (i2c_opt.width) {
cmd.slave = i2c_opt.addr;
cmd.count = 1;
cmd.last = 0;
cmd.buf = &data;
error = ioctl(fd, I2CSTART, &cmd);
if (error == -1) {
err_msg = "ioctl: error sending start condition";
goto err1;
}
bufsize = i2c_opt.width / 8;
buf = prepare_buf(bufsize, i2c_opt.off);
if (buf == NULL) {
err_msg = "error: offset malloc";
goto err1;
}
cmd.count = bufsize;
cmd.buf = buf;
cmd.last = 0;
error = ioctl(fd, I2CWRITE, &cmd);
free(buf);
if (error == -1) {
err_msg = "ioctl: error when write offset";
goto err1;
}
if (i2c_opt.mode == I2C_MODE_STOP_START) {
cmd.slave = i2c_opt.addr;
error = ioctl(fd, I2CSTOP, &cmd);
if (error == -1)
goto err2;
}
}
cmd.slave = i2c_opt.addr;
cmd.count = 1;
cmd.last = 0;
cmd.buf = &data;
if (i2c_opt.mode == I2C_MODE_STOP_START) {
error = ioctl(fd, I2CSTART, &cmd);
if (error == -1) {
err_msg = "ioctl: error sending start condition";
goto err1;
}
} else if (i2c_opt.mode == I2C_MODE_REPEATED_START) {
error = ioctl(fd, I2CRPTSTART, &cmd);
if (error == -1) {
err_msg = "ioctl: error sending repeated start "
"condition";
goto err1;
}
}
error = ioctl(fd, I2CSTOP, &cmd);
if (error == -1)
goto err2;
for (i = 0; i < i2c_opt.count; i++) {
error = read(fd, &i2c_buf[i], 1);
if (error == -1) {
err_msg = "ioctl: error while reading";
goto err1;
}
}
close(fd);
return (0);
err1:
cmd.slave = i2c_opt.addr;
error = ioctl(fd, I2CSTOP, &cmd);
if (error == -1)
fprintf(stderr, "error sending stop condtion\n");
err2:
if (err_msg)
fprintf(stderr, err_msg);
close(fd);
return (1);
}
int
main(int argc, char** argv)
{
struct iiccmd cmd;
struct options i2c_opt;
char *dev, *skip_addr, *err_msg, *i2c_buf;
int error, chunk_size, i, j, ch;
errno = 0;
error = 0;
/* Line-break the output every chunk_size bytes */
chunk_size = 16;
dev = I2C_DEV;
err_msg = NULL;
/* Default values */
i2c_opt.addr_set = 0;
i2c_opt.off = 0;
i2c_opt.verbose = 0;
i2c_opt.dir = 'r'; /* direction = read */
i2c_opt.width = 8;
i2c_opt.count = 1;
i2c_opt.binary = 0; /* ASCII text output */
i2c_opt.scan = 0; /* no bus scan */
i2c_opt.skip = 0; /* scan all addresses */
i2c_opt.reset = 0; /* no bus reset */
i2c_opt.mode = I2C_MODE_NOTSET;
while ((ch = getopt(argc, argv, "a:f:d:o:w:c:m:n:sbvrh")) != -1) {
switch(ch) {
case 'a':
i2c_opt.addr = (strtoul(optarg, 0, 16) << 1);
if (i2c_opt.addr == 0 && errno == EINVAL)
i2c_opt.addr_set = 0;
else
i2c_opt.addr_set = 1;
break;
case 'f':
dev = optarg;
break;
case 'd':
i2c_opt.dir = optarg[0];
break;
case 'o':
i2c_opt.off = strtoul(optarg, 0, 16);
if (i2c_opt.off == 0 && errno == EINVAL)
error = 1;
break;
case 'w':
i2c_opt.width = atoi(optarg);
break;
case 'c':
i2c_opt.count = atoi(optarg);
break;
case 'm':
if (!strcmp(optarg, "no"))
i2c_opt.mode = I2C_MODE_NONE;
else if (!strcmp(optarg, "ss"))
i2c_opt.mode = I2C_MODE_STOP_START;
else if (!strcmp(optarg, "rs"))
i2c_opt.mode = I2C_MODE_REPEATED_START;
else
usage();
break;
case 'n':
i2c_opt.skip = 1;
skip_addr = optarg;
break;
case 's':
i2c_opt.scan = 1;
break;
case 'b':
i2c_opt.binary = 1;
break;
case 'v':
i2c_opt.verbose = 1;
break;
case 'r':
i2c_opt.reset = 1;
break;
case 'h':
default:
usage();
}
}
argc -= optind;
argv += optind;
/* Set default mode if option -m is not specified */
if (i2c_opt.mode == I2C_MODE_NOTSET) {
if (i2c_opt.dir == 'r')
i2c_opt.mode = I2C_MODE_STOP_START;
else if (i2c_opt.dir == 'w')
i2c_opt.mode = I2C_MODE_NONE;
}
/* Basic sanity check of command line arguments */
if (i2c_opt.scan) {
if (i2c_opt.addr_set)
usage();
} else if (i2c_opt.reset) {
if (i2c_opt.addr_set)
usage();
} else if (error) {
usage();
} else if ((i2c_opt.dir == 'r' || i2c_opt.dir == 'w')) {
if ((i2c_opt.addr_set == 0) ||
!(i2c_opt.width == 0 || i2c_opt.width == 8 ||
i2c_opt.width == 16))
usage();
}
if (i2c_opt.verbose)
fprintf(stderr, "dev: %s, addr: 0x%x, r/w: %c, "
"offset: 0x%02x, width: %u, count: %u\n", dev,
i2c_opt.addr >> 1, i2c_opt.dir, i2c_opt.off,
i2c_opt.width, i2c_opt.count);
if (i2c_opt.scan)
exit(scan_bus(cmd, dev, i2c_opt.skip, skip_addr));
if (i2c_opt.reset)
exit(reset_bus(cmd, dev));
i2c_buf = malloc(i2c_opt.count);
if (i2c_buf == NULL)
err(1, "data malloc");
if (i2c_opt.dir == 'w') {
error = i2c_write(dev, i2c_opt, i2c_buf);
if (error) {
free(i2c_buf);
return (1);
}
}
if (i2c_opt.dir == 'r') {
error = i2c_read(dev, i2c_opt, i2c_buf);
if (error) {
free(i2c_buf);
return (1);
}
}
if (i2c_opt.verbose)
fprintf(stderr, "\nData %s (hex):\n", i2c_opt.dir == 'r' ?
"read" : "written");
i = 0;
j = 0;
while (i < i2c_opt.count) {
if (i2c_opt.verbose || (i2c_opt.dir == 'r' &&
!i2c_opt.binary))
fprintf (stderr, "%02hhx ", i2c_buf[i++]);
if (i2c_opt.dir == 'r' && i2c_opt.binary) {
fprintf(stdout, "%c", i2c_buf[j++]);
if(!i2c_opt.verbose)
i++;
}
if (!i2c_opt.verbose && (i2c_opt.dir == 'w'))
break;
if ((i % chunk_size) == 0)
fprintf(stderr, "\n");
}
if ((i % chunk_size) != 0)
fprintf(stderr, "\n");
free(i2c_buf);
return (0);
}