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

devices on the bus.

Reviewed by:	bms, stas
Obtained from:	Semihalf

4 files changed, 810 insertions, 0 deletions

diff --git a/usr.sbin/Makefile b/usr.sbin/Makefile
index 26da845..5a4efcc 100644
--- a/usr.sbin/Makefile
+++ b/usr.sbin/Makefile
@@ -65,6 +65,7 @@ SUBDIR=	${_ac} \
 	getpmac \
 	gstat \
 	${_gssd} \
+	i2c \
 	ifmcstat \
 	inetd \
 	iostat \
diff --git a/usr.sbin/i2c/Makefile b/usr.sbin/i2c/Makefile
new file mode 100644
index 0000000..9f377e6
--- /dev/null
+++ b/usr.sbin/i2c/Makefile
@@ -0,0 +1,8 @@
+# $FreeBSD$
+
+PROG=	i2c
+MAN=	i2c.8
+
+WARNS?=	2
+
+.include <bsd.prog.mk>
diff --git a/usr.sbin/i2c/i2c.8 b/usr.sbin/i2c/i2c.8
new file mode 100644
index 0000000..0067be7
--- /dev/null
+++ b/usr.sbin/i2c/i2c.8
@@ -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 .
diff --git a/usr.sbin/i2c/i2c.c b/usr.sbin/i2c/i2c.c
new file mode 100644
index 0000000..c0b3663
--- /dev/null
+++ b/usr.sbin/i2c/i2c.c
@@ -0,0 +1,633 @@
+/*-
+ * 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);
+}