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freebsd-dev/usr.sbin/i2c/i2c.c
Ian Lepore a30555576c Add a new 'tr' (transfer) mode to i2c(8) to support more i2c controllers. 
Some i2c controller hardware does not provide a way to do individual START,
REPEAT-START and STOP actions on the i2c bus.  Instead, they can only do
a complete transfer as a single operation.  Typically they can do either
START-data-STOP or START-data-REPEATSTART-data-STOP.  In the i2c driver
framework, this corresponds to the iicbus_transfer method.  In the userland
interface they are initiated with the I2CRDWR ioctl command.

These changes add a new 'tr' mode which can be specified with the '-m'
command line option.  This mode should work on all hardware; when an i2c
controller driver doesn't directly support the iicbus_transfer method,
code in the i2c driver framework uses the lower-level START/REPEAT/STOP
methods to implement the transfer.  After this new mode has gotten some
testing on various hardware, the 'tr' mode should probably become the
new default mode.

PR:		189914
2019-05-22 21:06:10 +00:00

800 lines
17 KiB
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/*-
* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
*
* 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
#define I2C_MODE_TRANSFER 4
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 [tr|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 iic_msg rdmsg;
struct iic_rdwr_data rdwrdata;
struct skip_range addr_range = { 0, 0 };
int *tokens, fd, error, i, index, j;
int len = 0, do_skip = 0, no_range = 1, num_found = 0, use_read_xfer = 0;
uint8_t rdbyte;
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);
start_over:
if (use_read_xfer) {
fprintf(stderr,
"Hardware may not support START/STOP scanning; "
"trying less-reliable read method.\n");
}
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) {
fprintf(stderr, "Controller reset failed\n");
goto out;
}
if (use_read_xfer) {
rdmsg.buf = &rdbyte;
rdmsg.len = 1;
rdmsg.flags = IIC_M_RD;
rdmsg.slave = i << 1;
rdwrdata.msgs = &rdmsg;
rdwrdata.nmsgs = 1;
error = ioctl(fd, I2CRDWR, &rdwrdata);
} else {
cmd.slave = i << 1;
cmd.last = 1;
error = ioctl(fd, I2CSTART, &cmd);
if (errno == ENODEV || errno == EOPNOTSUPP) {
/* If START not supported try reading. */
use_read_xfer = 1;
goto start_over;
}
ioctl(fd, I2CSTOP);
}
if (error == 0) {
++num_found;
printf("%02x ", i);
}
}
/*
* If we found nothing, maybe START is not supported and returns a
* generic error code such as EIO or ENXIO, so try again using reads.
*/
if (num_found == 0) {
if (!use_read_xfer) {
use_read_xfer = 1;
goto start_over;
}
printf("<none found>");
}
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 error, fd, bufsize;
char *err_msg, *buf;
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;
}
} else {
bufsize = 0;
buf = NULL;
}
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 writing offset";
goto err1;
}
}
error = ioctl(fd, I2CSTOP);
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 writing";
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 writing 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 writing";
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 writing";
goto err1;
}
break;
}
error = ioctl(fd, I2CSTOP);
if (error == -1) {
err_msg = "ioctl: error sending stop condition";
goto err2;
}
close(fd);
return (0);
err1:
error = ioctl(fd, I2CSTOP);
if (error == -1)
fprintf(stderr, "error sending stop condition\n");
err2:
if (err_msg)
fprintf(stderr, "%s\n", err_msg);
close(fd);
return (1);
}
static int
i2c_read(char *dev, struct options i2c_opt, char *i2c_buf)
{
struct iiccmd cmd;
int 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 writing offset";
goto err1;
}
if (i2c_opt.mode == I2C_MODE_STOP_START) {
error = ioctl(fd, I2CSTOP);
if (error == -1) {
err_msg = "error sending stop condition";
goto err2;
}
}
}
cmd.slave = i2c_opt.addr | 1;
cmd.count = 1;
cmd.last = 0;
cmd.buf = &data;
if (i2c_opt.mode == I2C_MODE_STOP_START || i2c_opt.width == 0) {
error = ioctl(fd, I2CSTART, &cmd);
if (error == -1) {
err_msg = "ioctl: error sending start condition";
goto err2;
}
} 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;
}
}
cmd.count = i2c_opt.count;
cmd.buf = i2c_buf;
cmd.last = 1;
error = ioctl(fd, I2CREAD, &cmd);
if (error == -1) {
err_msg = "ioctl: error while reading";
goto err1;
}
error = ioctl(fd, I2CSTOP);
if (error == -1) {
err_msg = "error sending stop condtion\n";
goto err2;
}
close(fd);
return (0);
err1:
error = ioctl(fd, I2CSTOP);
if (error == -1)
fprintf(stderr, "error sending stop condition\n");
err2:
if (err_msg)
fprintf(stderr, "%s\n", err_msg);
close(fd);
return (1);
}
/*
* i2c_rdwr_transfer() - use I2CRDWR to conduct a complete i2c transfer.
*
* Some i2c hardware is unable to provide direct control over START, REPEAT-
* START, and STOP operations. Such hardware can only perform a complete
* START-<data>-STOP or START-<data>-REPEAT-START-<data>-STOP sequence as a
* single operation. The driver framework refers to this sequence as a
* "transfer" so we call it "transfer mode". We assemble either one or two
* iic_msg structures to describe the IO operations, and hand them off to the
* driver to be handled as a single transfer.
*/
static int
i2c_rdwr_transfer(char *dev, struct options i2c_opt, char *i2c_buf)
{
struct iic_msg msgs[2];
struct iic_rdwr_data xfer;
int fd, i;
union {
uint8_t buf[2];
uint8_t off8;
uint16_t off16;
} off;
i = 0;
if (i2c_opt.width > 0) {
msgs[i].flags = IIC_M_WR | IIC_M_NOSTOP;
msgs[i].slave = i2c_opt.addr;
msgs[i].buf = off.buf;
if (i2c_opt.width == 8) {
off.off8 = (uint8_t)i2c_opt.off;
msgs[i].len = 1;
} else {
off.off16 = (uint16_t)i2c_opt.off;
msgs[i].len = 2;
}
++i;
}
/*
* If the transfer direction is write and we did a write of the offset
* above, then we need to elide the start; this transfer is just more
* writing that follows the one started above. For a read, we always do
* a start; if we did an offset write above it'll be a repeat-start
* because of the NOSTOP flag used above.
*/
if (i2c_opt.dir == 'w')
msgs[i].flags = IIC_M_WR | (i > 0) ? IIC_M_NOSTART : 0;
else
msgs[i].flags = IIC_M_RD;
msgs[i].slave = i2c_opt.addr;
msgs[i].len = i2c_opt.count;
msgs[i].buf = i2c_buf;
++i;
xfer.msgs = msgs;
xfer.nmsgs = i;
if ((fd = open(dev, O_RDWR)) == -1)
err(1, "open(%s) failed", dev);
if (ioctl(fd, I2CRDWR, &xfer) == -1 )
err(1, "ioctl(I2CRDWR) failed");
close(fd);
return (0);
}
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 if (!strcmp(optarg, "tr"))
i2c_opt.mode = I2C_MODE_TRANSFER;
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");
/*
* For a write, read the data to be written to the chip from stdin.
*/
if (i2c_opt.dir == 'w') {
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;
}
}
if (i2c_opt.mode == I2C_MODE_TRANSFER)
error = i2c_rdwr_transfer(dev, i2c_opt, i2c_buf);
else if (i2c_opt.dir == 'w')
error = i2c_write(dev, i2c_opt, i2c_buf);
else
error = i2c_read(dev, i2c_opt, i2c_buf);
if (error != 0) {
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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