root/lm-sensors/trunk/prog/dump/i2cset.c @ 4432

/*
    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) 2004-2005  Jean Delvare <khali@linux-fr.org>

    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., 675 Mass Ave, Cambridge, MA 02139, USA.
*/

#include <errno.h>
#include <string.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include "i2cbusses.h"
#include "util.h"
#include "i2c-dev.h"
#include "version.h"

void help(void) __attribute__ ((noreturn));

void help(void)
{
        fprintf(stderr, "Syntax: i2cset [-f] [-y] I2CBUS CHIP-ADDRESS DATA-ADDRESS "
                "VALUE [MODE] [MASK]\n"
                "        i2cset -V\n"
                "  MODE is 'b[yte]' or 'w[ord]' (default b)\n"
                "  Append 'p' to MODE for PEC checking\n"
                "  I2CBUS is an integer\n");
        print_i2c_busses(0);
        exit(1);
}

int main(int argc, char *argv[])
{
        char *end;
        int res, i2cbus, address, size, file;
        int value, daddress, vmask = 0;
        int e1;
        char filename[20];
        unsigned long funcs;
        int pec = 0;
        int flags = 0;
        int force = 0, yes = 0, version = 0;

        /* 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;
                default:
                        fprintf(stderr, "Warning: Unsupported flag "
                                "\"-%c\"!\n", argv[1+flags][1]);
                        help();
                        exit(1);
                }
                flags++;
        }

        if (version) {
                fprintf(stderr, "i2cset version %s\n", LM_VERSION);
                exit(0);
        }

        if (argc < flags + 5)
                help();

        i2cbus = strtol(argv[flags+1], &end, 0);
        if (*end || i2cbus < 0 || i2cbus > 0x3f) {
                fprintf(stderr, "Error: I2CBUS argument invalid!\n");
                help();
        }

        address = strtol(argv[flags+2], &end, 0);
        if (*end || address < 0 || address > 0x7f) {
                fprintf(stderr, "Error: Chip address invalid!\n");
                help();
        }

        daddress = strtol(argv[flags+3], &end, 0);
        if (*end || daddress < 0 || daddress > 0xff) {
                fprintf(stderr, "Error: Data address invalid!\n");
                help();
        }

        value = strtol(argv[flags+4], &end, 0);
        if (*end) {
                fprintf(stderr, "Error: Data value invalid!\n");
                help();
        }

        if (argc < flags + 6) {
                fprintf(stderr, "No size specified (using byte-data access)\n");
                size = I2C_SMBUS_BYTE_DATA;
        } else if (argv[flags+5][0] == 'b') {
                size = I2C_SMBUS_BYTE_DATA;
                pec = argv[flags+5][1] == 'p';
        } else if (argv[flags+5][0] == 'w') {
                size = I2C_SMBUS_WORD_DATA;
                pec = argv[flags+5][1] == 'p';
        } else {
                fprintf(stderr, "Error: Invalid mode!\n");
                help();
        }

        if (argc >= flags + 7) {
                vmask = strtol(argv[flags+6], &end, 0);
                if (*end || vmask == 0) {
                        fprintf(stderr, "Error: Data value mask invalid!\n");
                        help();
                }
        }

        if (value < 0
         || (size == I2C_SMBUS_BYTE_DATA && value > 0xff)
         || (size == I2C_SMBUS_WORD_DATA && value > 0xffff)) {
                fprintf(stderr, "Error: Data value out of range!\n");
                help();
        }

        file = open_i2c_dev(i2cbus, filename, 0);
        if (file < 0) {
                exit(1);
        }

        /* check adapter functionality */
        if (ioctl(file, I2C_FUNCS, &funcs) < 0) {
                fprintf(stderr, "Error: Could not get the adapter "
                        "functionality matrix: %s\n", strerror(errno));
                exit(1);
        }

        switch (size) {
        case I2C_SMBUS_BYTE_DATA:
                if (!(funcs & I2C_FUNC_SMBUS_WRITE_BYTE_DATA)) {
                        fprintf(stderr, "Error: Adapter for i2c bus %d does "
                                "not have byte write capability\n", i2cbus);
                        exit(1);
                }
                break;

        case I2C_SMBUS_WORD_DATA:
                if (!(funcs & I2C_FUNC_SMBUS_WRITE_WORD_DATA)) {
                        fprintf(stderr, "Error: Adapter for i2c bus %d does "
                                "not have word write capability\n", i2cbus);
                        exit(1);
                }
                break;
        }

        if (set_slave_addr(file, address, force) < 0)
                exit(1);

        if (!yes) {
                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 = 1;
                }

                fprintf(stderr, "I will write to device file %s, chip address "
                        "0x%02x, data address\n0x%02x, data 0x%02x%s, mode "
                        "%s.\n", filename, address, daddress, 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");
                        exit(0);
                }
        }

        if (vmask) {
                int oldvalue;

                if (size == I2C_SMBUS_WORD_DATA) {
                        oldvalue = i2c_smbus_read_word_data(file, daddress);
                } else {
                        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) {
                if (ioctl(file, I2C_PEC, 1) < 0) {
                        fprintf(stderr, "Error: Could not set PEC: %s\n",
                                strerror(errno));
                        exit(1);
                }
                if (!(funcs & (I2C_FUNC_SMBUS_HWPEC_CALC | I2C_FUNC_I2C))) {
                        fprintf(stderr, "Warning: Adapter for i2c bus %d does "
                                "not seem to actually support PEC\n", i2cbus);
                }
        }

        e1 = 0;
        if (size == I2C_SMBUS_WORD_DATA) {
                res = i2c_smbus_write_word_data(file, daddress, value);
        } else {
                res = i2c_smbus_write_byte_data(file, daddress, value);
        }
        if (res < 0) {
                fprintf(stderr, "Warning - write failed\n");
                e1++;
        }

        if (pec) {
                if (ioctl(file, I2C_PEC, 0) < 0) {
                        fprintf(stderr, "Error: Could not clear PEC: %s\n",
                                strerror(errno));
                        close(file);
                        exit(e1);
                }
        }

        if (size == I2C_SMBUS_WORD_DATA) {
                res = i2c_smbus_read_word_data(file, daddress);
        } else {
                res = i2c_smbus_read_byte_data(file, daddress);
        }
        close(file);

        if (res < 0) {
                fprintf(stderr, "Warning - readback failed\n");
                e1++;
        } else
        if (res != value) {
                e1++;
                fprintf(stderr, "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 {
                fprintf(stderr, "Value 0x%0*x written, readback matched\n",
                        size == I2C_SMBUS_WORD_DATA ? 4 : 2, value);
        }

        exit(e1);
}