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freebsd-skq/usr.sbin/i2c/i2c.c
zbb 3eb40986b7 Perform I2C transmission in a single burst when mode is "none" or not set 
Some more automated I2C controllers cannot explicitly create
START/STOP/etc. conditions on the bus.
Instead, the correct condition is set automatically according
to the pending transfer status.
This particular behavior can cause trouble if some I2C slave
requires sending address offset within the chip followed by
the actual data or command. In that case we cannot assume that
the driver will not STOP immediately after sending
offset.

To avoid that, do not split offset transfer from data transfer
for default transmission modes and do exactly that if requested
in command line (stop-start and repeated-start modes).
This more generic approach should cover special cases like
the one described.

Reviewed by:   imp
Submitted by:  Marcin Mazurek <mma@semihalf.com>
Obtained from: Semihalf
2015-09-15 11:21:16 +00:00

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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");
error = -1;
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");
error = -1;
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");
}
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;
}
}
switch(i2c_opt.mode) {
case I2C_MODE_STOP_START:
/*
* Write offset where the data will go
*/
if (i2c_opt.width) {
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;
}
}
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;
}
/*
* 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;
}
break;
case I2C_MODE_REPEATED_START:
/*
* Write offset where the data will go
*/
if (i2c_opt.width) {
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;
}
}
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;
}
break;
case I2C_MODE_NONE: /* fall through */
default:
buf = realloc(buf, bufsize + i2c_opt.count);
if (buf == NULL) {
err_msg = "error: data malloc";
goto err1;
}
memcpy(buf + bufsize, i2c_buf, i2c_opt.count);
/*
* Write offset and data
*/
cmd.count = bufsize + i2c_opt.count;
cmd.buf = buf;
cmd.last = 0;
error = ioctl(fd, I2CWRITE, &cmd);
free(buf);
if (error == -1) {
err_msg = "ioctl: error when write";
goto err1;
}
break;
}
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, "%s", 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) {
err_msg = "error sending stop condtion\n";
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) {
err_msg = "error sending stop condtion\n";
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, "%s", err_msg);
close(fd);
return (1);
}
int
main(int argc, char** argv)
{
struct iiccmd cmd;
struct options i2c_opt;
char *dev, *skip_addr, *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;
/* 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);
}
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