/*
i2cset.c - A user-space program to write an I2C register.
Copyright (C) 2001-2003 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.h>
#include <linux/i2c-dev.h>
#include <i2c/smbus.h>
#include "i2cbusses.h"
#include "util.h"
#include "../version.h"
static void help(void) __attribute__ ((noreturn));
static void help(void)
{
fprintf(stderr,
"Usage: i2cset [-f] [-y] [-m MASK] [-r] I2CBUS CHIP-ADDRESS DATA-ADDRESS [VALUE] ... [MODE]\n"
" I2CBUS is an integer or an I2C bus name\n"
" ADDRESS is an integer (0x03 - 0x77)\n"
" MODE is one of:\n"
" c (byte, no value)\n"
" b (byte data, default)\n"
" w (word data)\n"
" i (I2C block data)\n"
" s (SMBus block data)\n"
" Append p for SMBus PEC\n");
exit(1);
}
static int check_funcs(int file, int size, int pec)
{
unsigned long funcs;
/* check adapter functionality */
if (ioctl(file, I2C_FUNCS, &funcs) < 0) {
fprintf(stderr, "Error: Could not get the adapter "
"functionality matrix: %s\n", strerror(errno));
return -1;
}
switch (size) {
case I2C_SMBUS_BYTE:
if (!(funcs & I2C_FUNC_SMBUS_WRITE_BYTE)) {
fprintf(stderr, MISSING_FUNC_FMT, "SMBus send byte");
return -1;
}
break;
case I2C_SMBUS_BYTE_DATA:
if (!(funcs & I2C_FUNC_SMBUS_WRITE_BYTE_DATA)) {
fprintf(stderr, MISSING_FUNC_FMT, "SMBus write byte");
return -1;
}
break;
case I2C_SMBUS_WORD_DATA:
if (!(funcs & I2C_FUNC_SMBUS_WRITE_WORD_DATA)) {
fprintf(stderr, MISSING_FUNC_FMT, "SMBus write word");
return -1;
}
break;
case I2C_SMBUS_BLOCK_DATA:
if (!(funcs & I2C_FUNC_SMBUS_WRITE_BLOCK_DATA)) {
fprintf(stderr, MISSING_FUNC_FMT, "SMBus block write");
return -1;
}
break;
case I2C_SMBUS_I2C_BLOCK_DATA:
if (!(funcs & I2C_FUNC_SMBUS_WRITE_I2C_BLOCK)) {
fprintf(stderr, MISSING_FUNC_FMT, "I2C block write");
return -1;
}
break;
}
if (pec
&& !(funcs & (I2C_FUNC_SMBUS_PEC | I2C_FUNC_I2C))) {
fprintf(stderr, "Warning: Adapter does "
"not seem to support PEC\n");
}
return 0;
}
static int confirm(const char *filename, int address, int size, int daddress,
int value, int vmask, const unsigned char *block, int len,
int pec)
{
int dont = 0;
fprintf(stderr, "WARNING! This program can confuse your I2C "
"bus, cause data loss and worse!\n");
if (address >= 0x50 && address <= 0x57) {
fprintf(stderr, "DANGEROUS! Writing to a serial "
"EEPROM on a memory DIMM\nmay render your "
"memory USELESS and make your system "
"UNBOOTABLE!\n");
dont++;
}
fprintf(stderr, "I will write to device file %s, chip address "
"0x%02x, data address\n0x%02x, ", filename, address, daddress);
if (size == I2C_SMBUS_BYTE)
fprintf(stderr, "no data.\n");
else if (size == I2C_SMBUS_BLOCK_DATA ||
size == I2C_SMBUS_I2C_BLOCK_DATA) {
int i;
fprintf(stderr, "data");
for (i = 0; i < len; i++)
fprintf(stderr, " 0x%02x", block[i]);
fprintf(stderr, ", mode %s.\n", size == I2C_SMBUS_BLOCK_DATA
? "smbus block" : "i2c block");
} else
fprintf(stderr, "data 0x%02x%s, mode %s.\n", value,
vmask ? " (masked)" : "",
size == I2C_SMBUS_BYTE_DATA ? "byte" : "word");
if (pec)
fprintf(stderr, "PEC checking enabled.\n");
fprintf(stderr, "Continue? [%s] ", dont ? "y/N" : "Y/n");
fflush(stderr);
if (!user_ack(!dont)) {
fprintf(stderr, "Aborting on user request.\n");
return 0;
}
return 1;
}
int main(int argc, char *argv[])
{
char *end;
const char *maskp = NULL;
int res, i2cbus, address, size, file;
int value, daddress, vmask = 0;
char filename[20];
int pec = 0;
int flags = 0;
int force = 0, yes = 0, version = 0, readback = 0;
unsigned char block[I2C_SMBUS_BLOCK_MAX];
int len;
/* handle (optional) flags first */
while (1+flags < argc && argv[1+flags][0] == '-') {
switch (argv[1+flags][1]) {
case 'V': version = 1; break;
case 'f': force = 1; break;
case 'y': yes = 1; break;
case 'm':
if (2+flags < argc)
maskp = argv[2+flags];
flags++;
break;
case 'r': readback = 1; break;
default:
fprintf(stderr, "Error: Unsupported option "
"\"%s\"!\n", argv[1+flags]);
help();
exit(1);
}
flags++;
}
if (version) {
fprintf(stderr, "i2cset version %s\n", VERSION);
exit(0);
}
if (argc < flags + 4)
help();
i2cbus = lookup_i2c_bus(argv[flags+1]);
if (i2cbus < 0)
help();
address = parse_i2c_address(argv[flags+2]);
if (address < 0)
help();
daddress = strtol(argv[flags+3], &end, 0);
if (*end || daddress < 0 || daddress > 0xff) {
fprintf(stderr, "Error: Data address invalid!\n");
help();
}
/* check for command/mode */
if (argc == flags + 4) {
/* Implicit "c" */
size = I2C_SMBUS_BYTE;
} else if (argc == flags + 5) {
/* "c", "cp", or implicit "b" */
if (!strcmp(argv[flags+4], "c")
|| !strcmp(argv[flags+4], "cp")) {
size = I2C_SMBUS_BYTE;
pec = argv[flags+4][1] == 'p';
} else {
size = I2C_SMBUS_BYTE_DATA;
}
} else {
/* All other commands */
if (strlen(argv[argc-1]) > 2
|| (strlen(argv[argc-1]) == 2 && argv[argc-1][1] != 'p')) {
fprintf(stderr, "Error: Invalid mode '%s'!\n", argv[argc-1]);
help();
}
switch (argv[argc-1][0]) {
case 'b': size = I2C_SMBUS_BYTE_DATA; break;
case 'w': size = I2C_SMBUS_WORD_DATA; break;
case 's': size = I2C_SMBUS_BLOCK_DATA; break;
case 'i': size = I2C_SMBUS_I2C_BLOCK_DATA; break;
default:
fprintf(stderr, "Error: Invalid mode '%s'!\n", argv[argc-1]);
help();
}
pec = argv[argc-1][1] == 'p';
if (size == I2C_SMBUS_BLOCK_DATA || size == I2C_SMBUS_I2C_BLOCK_DATA) {
if (pec && size == I2C_SMBUS_I2C_BLOCK_DATA) {
fprintf(stderr, "Error: PEC not supported for I2C block writes!\n");
help();
}
if (maskp) {
fprintf(stderr, "Error: Mask not supported for block writes!\n");
help();
}
if (argc > (int)sizeof(block) + flags + 5) {
fprintf(stderr, "Error: Too many arguments!\n");
help();
}
} else if (argc != flags + 6) {
fprintf(stderr, "Error: Too many arguments!\n");
help();
}
}
len = 0; /* Must always initialize len since it is passed to confirm() */
/* read values from command line */
switch (size) {
case I2C_SMBUS_BYTE_DATA:
case I2C_SMBUS_WORD_DATA:
value = strtol(argv[flags+4], &end, 0);
if (*end || value < 0) {
fprintf(stderr, "Error: Data value invalid!\n");
help();
}
if ((size == I2C_SMBUS_BYTE_DATA && value > 0xff)
|| (size == I2C_SMBUS_WORD_DATA && value > 0xffff)) {
fprintf(stderr, "Error: Data value out of range!\n");
help();
}
break;
case I2C_SMBUS_BLOCK_DATA:
case I2C_SMBUS_I2C_BLOCK_DATA:
for (len = 0; len + flags + 5 < argc; len++) {
value = strtol(argv[flags + len + 4], &end, 0);
if (*end || value < 0) {
fprintf(stderr, "Error: Data value invalid!\n");
help();
}
if (value > 0xff) {
fprintf(stderr, "Error: Data value out of range!\n");
help();
}
block[len] = value;
}
value = -1;
break;
default:
value = -1;
break;
}
if (maskp) {
vmask = strtol(maskp, &end, 0);
if (*end || vmask == 0) {
fprintf(stderr, "Error: Data value mask invalid!\n");
help();
}
if (((size == I2C_SMBUS_BYTE || size == I2C_SMBUS_BYTE_DATA)
&& vmask > 0xff) || vmask > 0xffff) {
fprintf(stderr, "Error: Data value mask out of range!\n");
help();
}
}
file = open_i2c_dev(i2cbus, filename, sizeof(filename), 0);
if (file < 0
|| check_funcs(file, size, pec)
|| set_slave_addr(file, address, force))
exit(1);
if (!yes && !confirm(filename, address, size, daddress,
value, vmask, block, len, pec))
exit(0);
if (vmask) {
int oldvalue;
switch (size) {
case I2C_SMBUS_BYTE:
oldvalue = i2c_smbus_read_byte(file);
break;
case I2C_SMBUS_WORD_DATA:
oldvalue = i2c_smbus_read_word_data(file, daddress);
break;
default:
oldvalue = i2c_smbus_read_byte_data(file, daddress);
}
if (oldvalue < 0) {
fprintf(stderr, "Error: Failed to read old value\n");
exit(1);
}
value = (value & vmask) | (oldvalue & ~vmask);
if (!yes) {
fprintf(stderr, "Old value 0x%0*x, write mask "
"0x%0*x: Will write 0x%0*x to register "
"0x%02x\n",
size == I2C_SMBUS_WORD_DATA ? 4 : 2, oldvalue,
size == I2C_SMBUS_WORD_DATA ? 4 : 2, vmask,
size == I2C_SMBUS_WORD_DATA ? 4 : 2, value,
daddress);
fprintf(stderr, "Continue? [Y/n] ");
fflush(stderr);
if (!user_ack(1)) {
fprintf(stderr, "Aborting on user request.\n");
exit(0);
}
}
}
if (pec && ioctl(file, I2C_PEC, 1) < 0) {
fprintf(stderr, "Error: Could not set PEC: %s\n",
strerror(errno));
close(file);
exit(1);
}
switch (size) {
case I2C_SMBUS_BYTE:
res = i2c_smbus_write_byte(file, daddress);
break;
case I2C_SMBUS_WORD_DATA:
res = i2c_smbus_write_word_data(file, daddress, value);
break;
case I2C_SMBUS_BLOCK_DATA:
res = i2c_smbus_write_block_data(file, daddress, len, block);
break;
case I2C_SMBUS_I2C_BLOCK_DATA:
res = i2c_smbus_write_i2c_block_data(file, daddress, len, block);
break;
default: /* I2C_SMBUS_BYTE_DATA */
res = i2c_smbus_write_byte_data(file, daddress, value);
break;
}
if (res < 0) {
fprintf(stderr, "Error: Write failed\n");
close(file);
exit(1);
}
if (pec) {
if (ioctl(file, I2C_PEC, 0) < 0) {
fprintf(stderr, "Error: Could not clear PEC: %s\n",
strerror(errno));
close(file);
exit(1);
}
}
if (!readback) { /* We're done */
close(file);
exit(0);
}
switch (size) {
case I2C_SMBUS_BYTE:
res = i2c_smbus_read_byte(file);
value = daddress;
break;
case I2C_SMBUS_WORD_DATA:
res = i2c_smbus_read_word_data(file, daddress);
break;
default: /* I2C_SMBUS_BYTE_DATA */
res = i2c_smbus_read_byte_data(file, daddress);
}
close(file);
if (res < 0) {
printf("Warning - readback failed\n");
} else
if (res != value) {
printf("Warning - data mismatch - wrote "
"0x%0*x, read back 0x%0*x\n",
size == I2C_SMBUS_WORD_DATA ? 4 : 2, value,
size == I2C_SMBUS_WORD_DATA ? 4 : 2, res);
} else {
printf("Value 0x%0*x written, readback matched\n",
size == I2C_SMBUS_WORD_DATA ? 4 : 2, value);
}
exit(0);
}