I2C-EEPROM读写应用程序

/*************************************************************************** copyright : (C) by 2003-2004 Stefano Barbato email : stefano@codesink.org $Id: 24cXX.h,v 1.6 2004/02/29 11:05:28 tat Exp $ ***************************************************************************/ /*************************************************************************** * * * 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. * * * ***************************************************************************/ #include <stdio.h> #include <fcntl.h> #include <unistd.h> #include <stdlib.h> #include <linux/fs.h> #include <sys/types.h> #include <sys/ioctl.h> #include <errno.h> #include <assert.h> #include <string.h> #include "24cXX.h" /* static inline __s32 i2c_smbus_access(int file, char read_write, __u8 command, int size, union i2c_smbus_data *data) { struct i2c_smbus_ioctl_data args; args.read_write = read_write; args.command = command; args.size = size; args.data = data; return ioctl(file,I2C_SMBUS,&args); } static inline __s32 i2c_smbus_write_quick(int file, __u8 value) { return i2c_smbus_access(file,value,0,I2C_SMBUS_QUICK,NULL); } static inline __s32 i2c_smbus_read_byte(int file) { union i2c_smbus_data data; if (i2c_smbus_access(file,I2C_SMBUS_READ,0,I2C_SMBUS_BYTE,&data)) return -1; else return 0x0FF & data.byte; } static inline __s32 i2c_smbus_write_byte(int file, __u8 value) { return i2c_smbus_access(file,I2C_SMBUS_WRITE,value, I2C_SMBUS_BYTE,NULL); } static inline __s32 i2c_smbus_read_byte_data(int file, __u8 command) { union i2c_smbus_data data; if (i2c_smbus_access(file,I2C_SMBUS_READ,command, I2C_SMBUS_BYTE_DATA,&data)) return -1; else return 0x0FF & data.byte; } static inline __s32 i2c_smbus_write_byte_data(int file, __u8 command, __u8 value) { union i2c_smbus_data data; data.byte = value; return i2c_smbus_access(file,I2C_SMBUS_WRITE,command, I2C_SMBUS_BYTE_DATA, &data); } static inline __s32 i2c_smbus_read_word_data(int file, __u8 command) { union i2c_smbus_data data; if (i2c_smbus_access(file,I2C_SMBUS_READ,command, I2C_SMBUS_WORD_DATA,&data)) return -1; else return 0x0FFFF & data.word; } static inline __s32 i2c_smbus_write_word_data(int file, __u8 command, __u16 value) { union i2c_smbus_data data; data.word = value; return i2c_smbus_access(file,I2C_SMBUS_WRITE,command, I2C_SMBUS_WORD_DATA, &data); } static inline __s32 i2c_smbus_process_call(int file, __u8 command, __u16 value) { union i2c_smbus_data data; data.word = value; if (i2c_smbus_access(file,I2C_SMBUS_WRITE,command, I2C_SMBUS_PROC_CALL,&data)) return -1; else return 0x0FFFF & data.word; } // Returns the number of read bytes static inline __s32 i2c_smbus_read_block_data(int file, __u8 command, __u8 *values) { union i2c_smbus_data data; int i; if (i2c_smbus_access(file,I2C_SMBUS_READ,command, I2C_SMBUS_BLOCK_DATA,&data)) return -1; else { for (i = 1; i <= data.block[0]; i++) values[i-1] = data.block[i]; return data.block[0]; } } static inline __s32 i2c_smbus_write_block_data(int file, __u8 command, __u8 length, __u8 *values) { union i2c_smbus_data data; int i; if (length > 32) length = 32; for (i = 1; i <= length; i++) data.block[i] = values[i-1]; data.block[0] = length; return i2c_smbus_access(file,I2C_SMBUS_WRITE,command, I2C_SMBUS_BLOCK_DATA, &data); } // Returns the number of read bytes static inline __s32 i2c_smbus_read_i2c_block_data(int file, __u8 command, __u8 *values) { union i2c_smbus_data data; int i; if (i2c_smbus_access(file,I2C_SMBUS_READ,command, I2C_SMBUS_I2C_BLOCK_DATA,&data)) return -1; else { for (i = 1; i <= data.block[0]; i++) values[i-1] = data.block[i]; return data.block[0]; } } static inline __s32 i2c_smbus_write_i2c_block_data(int file, __u8 command, __u8 length, __u8 *values) { union i2c_smbus_data data; int i; if (length > 32) length = 32; for (i = 1; i <= length; i++) data.block[i] = values[i-1]; data.block[0] = length; return i2c_smbus_access(file,I2C_SMBUS_WRITE,command, I2C_SMBUS_I2C_BLOCK_DATA, &data); } Returns the number of read bytes static inline __s32 i2c_smbus_block_process_call(int file, __u8 command, __u8 length, __u8 *values) { union i2c_smbus_data data; int i; if (length > 32) length = 32; for (i = 1; i <= length; i++) data.block[i] = values[i-1]; data.block[0] = length; if (i2c_smbus_access(file,I2C_SMBUS_WRITE,command, I2C_SMBUS_BLOCK_PROC_CALL,&data)) return -1; else { for (i = 1; i <= data.block[0]; i++) values[i-1] = data.block[i]; return data.block[0]; } } */ static int i2c_write_1b(struct eeprom *e, __u8 buf) { int r; // we must simulate a plain I2C byte write with SMBus functions r = i2c_smbus_write_byte(e->fd, buf); if(r < 0) fprintf(stderr, "Error i2c_write_1b: %s\n", strerror(errno)); usleep(10); return r; } static int i2c_write_2b(struct eeprom *e, __u8 buf[2]) { int r; // we must simulate a plain I2C byte write with SMBus functions r = i2c_smbus_write_byte_data(e->fd, buf[0], buf[1]); if(r < 0) fprintf(stderr, "Error i2c_write_2b: %s\n", strerror(errno)); usleep(10); return r; } static int i2c_write_3b(struct eeprom *e, __u8 buf[3]) { int r; // we must simulate a plain I2C byte write with SMBus functions // the __u16 data field will be byte swapped by the SMBus protocol r = i2c_smbus_write_word_data(e->fd, buf[0], buf[2] << 8 | buf[1]); if(r < 0) fprintf(stderr, "Error i2c_write_3b: %s\n", strerror(errno)); usleep(10); return r; } #define CHECK_I2C_FUNC( var, label ) \ do { if(0 == (var & label)) { \ fprintf(stderr, "\nError: " \ #label " function is required. Program halted.\n\n"); \ exit(1); } \ } while(0); int eeprom_open(char *dev_fqn, int addr, int type, struct eeprom* e) { int funcs, fd, r; e->fd = e->addr = 0; e->dev = 0; fd = open(dev_fqn, O_RDWR); if(fd <= 0) { fprintf(stderr, "Error eeprom_open: %s\n", strerror(errno)); return -1; } // get funcs list if((r = ioctl(fd, I2C_FUNCS, &funcs) < 0)) { fprintf(stderr, "Error eeprom_open: %s\n", strerror(errno)); return -1; } // check for req funcs CHECK_I2C_FUNC( funcs, I2C_FUNC_SMBUS_READ_BYTE ); CHECK_I2C_FUNC( funcs, I2C_FUNC_SMBUS_WRITE_BYTE ); CHECK_I2C_FUNC( funcs, I2C_FUNC_SMBUS_READ_BYTE_DATA ); CHECK_I2C_FUNC( funcs, I2C_FUNC_SMBUS_WRITE_BYTE_DATA ); CHECK_I2C_FUNC( funcs, I2C_FUNC_SMBUS_READ_WORD_DATA ); CHECK_I2C_FUNC( funcs, I2C_FUNC_SMBUS_WRITE_WORD_DATA ); // set working device if( ( r = ioctl(fd, I2C_SLAVE, addr)) < 0) { fprintf(stderr, "Error eeprom_open: %s\n", strerror(errno)); return -1; } e->fd = fd; e->addr = addr; e->dev = dev_fqn; e->type = type; return 0; } int eeprom_close(struct eeprom *e) { close(e->fd); e->fd = -1; e->dev = 0; e->type = EEPROM_TYPE_UNKNOWN; return 0; } #if 0 int eeprom_24c32_write_byte(struct eeprom *e, __u16 mem_addr, __u8 data) { __u8 buf[3] = { (mem_addr >> 8) & 0x00ff, mem_