blob: 07b3d97e7ffde3a78d95ffe2926588fb5449d16f [file] [log] [blame]
/*
i2cdetect.c - a user-space program to scan for I2C devices
Copyright (C) 1999-2004 Frodo Looijaard <frodol@dds.nl>, and
Mark D. Studebaker <mdsxyz123@yahoo.com>
Copyright (C) 2004-2012 Jean Delvare <jdelvare@suse.de>
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
MA 02110-1301 USA.
*/
#include <sys/ioctl.h>
#include <errno.h>
#include <string.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <linux/i2c-dev.h>
#include "i2cbusses.h"
#include "../version.h"
#define MODE_AUTO 0
#define MODE_QUICK 1
#define MODE_READ 2
#define MODE_FUNC 3
static void help(void)
{
fprintf(stderr,
"Usage: i2cdetect [-y] [-a] [-q|-r] I2CBUS [FIRST LAST]\n"
" i2cdetect -F I2CBUS\n"
" i2cdetect -l\n"
" I2CBUS is an integer or an I2C bus name\n"
" If provided, FIRST and LAST limit the probing range.\n");
}
static int scan_i2c_bus(int file, int mode, int first, int last)
{
int i, j;
int res;
printf(" 0 1 2 3 4 5 6 7 8 9 a b c d e f\n");
for (i = 0; i < 128; i += 16) {
printf("%02x: ", i);
for(j = 0; j < 16; j++) {
fflush(stdout);
/* Skip unwanted addresses */
if (i+j < first || i+j > last) {
printf(" ");
continue;
}
/* Set slave address */
if (ioctl(file, I2C_SLAVE, i+j) < 0) {
if (errno == EBUSY) {
printf("UU ");
continue;
} else {
fprintf(stderr, "Error: Could not set "
"address to 0x%02x: %s\n", i+j,
strerror(errno));
return -1;
}
}
/* Probe this address */
switch (mode) {
case MODE_QUICK:
/* This is known to corrupt the Atmel AT24RF08
EEPROM */
res = i2c_smbus_write_quick(file,
I2C_SMBUS_WRITE);
break;
case MODE_READ:
/* This is known to lock SMBus on various
write-only chips (mainly clock chips) */
res = i2c_smbus_read_byte(file);
break;
default:
if ((i+j >= 0x30 && i+j <= 0x37)
|| (i+j >= 0x50 && i+j <= 0x5F))
res = i2c_smbus_read_byte(file);
else
res = i2c_smbus_write_quick(file,
I2C_SMBUS_WRITE);
}
if (res < 0)
printf("-- ");
else
printf("%02x ", i+j);
}
printf("\n");
}
return 0;
}
struct func
{
long value;
const char* name;
};
static const struct func all_func[] = {
{ .value = I2C_FUNC_I2C,
.name = "I2C" },
{ .value = I2C_FUNC_SMBUS_QUICK,
.name = "SMBus Quick Command" },
{ .value = I2C_FUNC_SMBUS_WRITE_BYTE,
.name = "SMBus Send Byte" },
{ .value = I2C_FUNC_SMBUS_READ_BYTE,
.name = "SMBus Receive Byte" },
{ .value = I2C_FUNC_SMBUS_WRITE_BYTE_DATA,
.name = "SMBus Write Byte" },
{ .value = I2C_FUNC_SMBUS_READ_BYTE_DATA,
.name = "SMBus Read Byte" },
{ .value = I2C_FUNC_SMBUS_WRITE_WORD_DATA,
.name = "SMBus Write Word" },
{ .value = I2C_FUNC_SMBUS_READ_WORD_DATA,
.name = "SMBus Read Word" },
{ .value = I2C_FUNC_SMBUS_PROC_CALL,
.name = "SMBus Process Call" },
{ .value = I2C_FUNC_SMBUS_WRITE_BLOCK_DATA,
.name = "SMBus Block Write" },
{ .value = I2C_FUNC_SMBUS_READ_BLOCK_DATA,
.name = "SMBus Block Read" },
{ .value = I2C_FUNC_SMBUS_BLOCK_PROC_CALL,
.name = "SMBus Block Process Call" },
{ .value = I2C_FUNC_SMBUS_PEC,
.name = "SMBus PEC" },
{ .value = I2C_FUNC_SMBUS_WRITE_I2C_BLOCK,
.name = "I2C Block Write" },
{ .value = I2C_FUNC_SMBUS_READ_I2C_BLOCK,
.name = "I2C Block Read" },
{ .value = 0, .name = "" }
};
static void print_functionality(unsigned long funcs)
{
int i;
for (i = 0; all_func[i].value; i++) {
printf("%-32s %s\n", all_func[i].name,
(funcs & all_func[i].value) ? "yes" : "no");
}
}
/*
* Print the installed i2c busses. The format is those of Linux 2.4's
* /proc/bus/i2c for historical compatibility reasons.
*/
static void print_i2c_busses(void)
{
struct i2c_adap *adapters;
int count;
adapters = gather_i2c_busses();
if (adapters == NULL) {
fprintf(stderr, "Error: Out of memory!\n");
return;
}
for (count = 0; adapters[count].name; count++) {
printf("i2c-%d\t%-10s\t%-32s\t%s\n",
adapters[count].nr, adapters[count].funcs,
adapters[count].name, adapters[count].algo);
}
free_adapters(adapters);
}
int main(int argc, char *argv[])
{
char *end;
int i2cbus, file, res;
char filename[20];
unsigned long funcs;
int mode = MODE_AUTO;
int first = 0x03, last = 0x77;
int flags = 0;
int yes = 0, version = 0, list = 0;
/* handle (optional) flags first */
while (1+flags < argc && argv[1+flags][0] == '-') {
switch (argv[1+flags][1]) {
case 'V': version = 1; break;
case 'y': yes = 1; break;
case 'l': list = 1; break;
case 'F':
if (mode != MODE_AUTO && mode != MODE_FUNC) {
fprintf(stderr, "Error: Different modes "
"specified!\n");
exit(1);
}
mode = MODE_FUNC;
break;
case 'r':
if (mode == MODE_QUICK) {
fprintf(stderr, "Error: Different modes "
"specified!\n");
exit(1);
}
mode = MODE_READ;
break;
case 'q':
if (mode == MODE_READ) {
fprintf(stderr, "Error: Different modes "
"specified!\n");
exit(1);
}
mode = MODE_QUICK;
break;
case 'a':
first = 0x00;
last = 0x7F;
break;
default:
fprintf(stderr, "Error: Unsupported option "
"\"%s\"!\n", argv[1+flags]);
help();
exit(1);
}
flags++;
}
if (version) {
fprintf(stderr, "i2cdetect version %s\n", VERSION);
exit(0);
}
if (list) {
print_i2c_busses();
exit(0);
}
if (argc < flags + 2) {
fprintf(stderr, "Error: No i2c-bus specified!\n");
help();
exit(1);
}
i2cbus = lookup_i2c_bus(argv[flags+1]);
if (i2cbus < 0) {
help();
exit(1);
}
/* read address range if present */
if (argc == flags + 4 && mode != MODE_FUNC) {
int tmp;
tmp = strtol(argv[flags+2], &end, 0);
if (*end) {
fprintf(stderr, "Error: FIRST argment not a "
"number!\n");
help();
exit(1);
}
if (tmp < first || tmp > last) {
fprintf(stderr, "Error: FIRST argument out of range "
"(0x%02x-0x%02x)!\n", first, last);
help();
exit(1);
}
first = tmp;
tmp = strtol(argv[flags+3], &end, 0);
if (*end) {
fprintf(stderr, "Error: LAST argment not a "
"number!\n");
help();
exit(1);
}
if (tmp < first || tmp > last) {
fprintf(stderr, "Error: LAST argument out of range "
"(0x%02x-0x%02x)!\n", first, last);
help();
exit(1);
}
last = tmp;
} else if (argc != flags + 2) {
help();
exit(1);
}
file = open_i2c_dev(i2cbus, filename, sizeof(filename), 0);
if (file < 0) {
exit(1);
}
if (ioctl(file, I2C_FUNCS, &funcs) < 0) {
fprintf(stderr, "Error: Could not get the adapter "
"functionality matrix: %s\n", strerror(errno));
close(file);
exit(1);
}
/* Special case, we only list the implemented functionalities */
if (mode == MODE_FUNC) {
close(file);
printf("Functionalities implemented by %s:\n", filename);
print_functionality(funcs);
exit(0);
}
if (mode != MODE_READ && !(funcs & I2C_FUNC_SMBUS_QUICK)) {
fprintf(stderr, "Error: Can't use SMBus Quick Write command "
"on this bus\n");
close(file);
exit(1);
}
if (mode != MODE_QUICK && !(funcs & I2C_FUNC_SMBUS_READ_BYTE)) {
fprintf(stderr, "Error: Can't use SMBus Read Byte command "
"on this bus\n");
close(file);
exit(1);
}
if (!yes) {
char s[2];
fprintf(stderr, "WARNING! This program can confuse your I2C "
"bus, cause data loss and worse!\n");
fprintf(stderr, "I will probe file %s%s.\n", filename,
mode==MODE_QUICK?" using quick write commands":
mode==MODE_READ?" using read byte commands":"");
fprintf(stderr, "I will probe address range 0x%02x-0x%02x.\n",
first, last);
fprintf(stderr, "Continue? [Y/n] ");
fflush(stderr);
if (!fgets(s, 2, stdin)
|| (s[0] != '\n' && s[0] != 'y' && s[0] != 'Y')) {
fprintf(stderr, "Aborting on user request.\n");
exit(0);
}
}
res = scan_i2c_bus(file, mode, first, last);
close(file);
exit(res?1:0);
}