/* $NetBSD: i2cscan.c,v 1.5 2015/11/26 17:31:56 hubertf Exp $ */
/*-
* Copyright (c) 2011, 2013 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Paul Goyette and Jared McNeill
*
* 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 NETBSD FOUNDATION, INC. 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 THE FOUNDATION 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>
__RCSID("$NetBSD: i2cscan.c,v 1.5 2015/11/26 17:31:56 hubertf Exp $");
#include <sys/types.h>
#include <sys/ioctl.h>
#include <err.h>
#include <errno.h>
#include <fcntl.h>
#include <paths.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <dev/i2c/i2c_io.h>
#define MODE_DEFAULT 0
#define MODE_READ 1
__dead static void
usage(void)
{
fprintf(stderr, "usage: %s [-r] i2cdev\n", getprogname());
exit(EXIT_FAILURE);
}
static int
iic_smbus_quick_write(int fd, i2c_addr_t addr, int flags)
{
i2c_ioctl_exec_t iie;
iie.iie_op = I2C_OP_WRITE_WITH_STOP;
iie.iie_addr = addr;
iie.iie_cmd = NULL;
iie.iie_cmdlen = 0;
iie.iie_buf = NULL;
iie.iie_buflen = 0;
if (ioctl(fd, I2C_IOCTL_EXEC, &iie) == -1)
return errno;
return 0;
}
static int
iic_smbus_receive_byte(int fd, i2c_addr_t addr, uint8_t *valp, int flags)
{
i2c_ioctl_exec_t iie;
iie.iie_op = I2C_OP_READ_WITH_STOP;
iie.iie_addr = addr;
iie.iie_cmd = NULL;
iie.iie_cmdlen = 0;
iie.iie_buf = valp;
iie.iie_buflen = 1;
if (ioctl(fd, I2C_IOCTL_EXEC, &iie) == -1)
return errno;
return 0;
}
static void
do_i2c_scan(const char *dname, int fd, int mode)
{
int error;
int found = 0;
i2c_addr_t addr;
uint8_t val;
for (addr = 0x09; addr < 0x78; addr++) {
/*
* Skip certain i2c addresses:
* 0x00 General Call / START
* 0x01 CBUS Address
* 0x02 Different Bus format
* 0x03 - 0x07 Reserved
* 0x08 Host Address
* 0x0c Alert Response Address
* 0x28 ACCESS.Bus host
* 0x37 ACCESS.Bus default address
* 0x48 - 0x4b Prototypes
* 0x61 Device Default Address
* 0x78 - 0x7b 10-bit addresses
* 0x7c - 0x7f Reserved
*
* Some of these are skipped by judicious selection
* of the range of the above for (;;) statement.
*
* if (addr <= 0x08 || addr >= 0x78)
* continue;
*/
if (addr == 0x0c || addr == 0x28 || addr == 0x37 ||
addr == 0x61 || (addr & 0x7c) == 0x48)
continue;
/*
* Use SMBus quick_write command to detect most
* addresses; should avoid hanging the bus on
* some write-only devices (like clocks that show
* up at address 0x69)
*
* XXX The quick_write() is allegedly known to
* XXX corrupt the Atmel AT24RF08 EEPROM found
* XXX on some IBM Thinkpads!
*/
printf("\r%s: scanning 0x%02x", dname, addr);
fflush(stdout);
if ((addr & 0xf8) == 0x30 ||
(addr & 0xf0) == 0x50 ||
mode == MODE_READ)
error = iic_smbus_receive_byte(fd, addr, &val, 0);
else
error = iic_smbus_quick_write(fd, addr, 0);
if (error == 0) {
printf("\r%s: found device at 0x%02x\n",
dname, addr);
++found;
}
}
if (found == 0)
printf("\r%s: no devices found\n", dname);
else
printf("\r%s: %d devices found\n", dname, found);
}
int
main(int argc, char *argv[])
{
int fd;
int ch, rflag;
int mode;
char *dev;
char devn[32];
setprogname(*argv);
rflag = 0;
while ((ch = getopt(argc, argv, "r")) != -1)
switch (ch) {
case 'r':
rflag = 1;
break;
default:
break;
}
argv += optind;
argc -= optind;
if (rflag)
mode = MODE_READ;
else
mode = MODE_DEFAULT;
if (*argv == NULL)
usage();
dev = argv[0];
if (strncmp(_PATH_DEV, dev, sizeof(_PATH_DEV) - 1)) {
(void)snprintf(devn, sizeof(devn), "%s%s", _PATH_DEV, dev);
dev = devn;
}
fd = open(dev, O_RDWR);
if (fd == -1)
err(EXIT_FAILURE, "couldn't open %s", *argv);
do_i2c_scan(*argv, fd, mode);
close(fd);
return EXIT_SUCCESS;
}
