1 /* 2 * (C) Copyright 2001 3 * Gerald Van Baren, Custom IDEAS, vanbaren@cideas.com. 4 * 5 * See file CREDITS for list of people who contributed to this 6 * project. 7 * 8 * This program is free software; you can redistribute it and/or 9 * modify it under the terms of the GNU General Public License as 10 * published by the Free Software Foundation; either version 2 of 11 * the License, or (at your option) any later version. 12 * 13 * This program is distributed in the hope that it will be useful, 14 * but WITHOUT ANY WARRANTY; without even the implied warranty of 15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 16 * GNU General Public License for more details. 17 * 18 * You should have received a copy of the GNU General Public License 19 * along with this program; if not, write to the Free Software 20 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, 21 * MA 02111-1307 USA 22 * 23 * The original I2C interface was 24 * (C) 2000 by Paolo Scaffardi (arsenio@tin.it) 25 * AIRVENT SAM s.p.a - RIMINI(ITALY) 26 * but has been changed substantially. 27 */ 28 29 #ifndef _I2C_H_ 30 #define _I2C_H_ 31 32 /* 33 * WARNING WARNING WARNING WARNING WARNING WARNING WARNING WARNING 34 * 35 * The implementation MUST NOT use static or global variables if the 36 * I2C routines are used to read SDRAM configuration information 37 * because this is done before the memories are initialized. Limited 38 * use of stack-based variables are OK (the initial stack size is 39 * limited). 40 * 41 * WARNING WARNING WARNING WARNING WARNING WARNING WARNING WARNING 42 */ 43 44 /* 45 * Configuration items. 46 */ 47 #define I2C_RXTX_LEN 128 /* maximum tx/rx buffer length */ 48 49 /* 50 * Initialization, must be called once on start up, may be called 51 * repeatedly to change the speed and slave addresses. 52 */ 53 void i2c_init(int speed, int slaveaddr); 54 #ifdef CFG_I2C_INIT_BOARD 55 void i2c_init_board(void); 56 #endif 57 58 /* 59 * Probe the given I2C chip address. Returns 0 if a chip responded, 60 * not 0 on failure. 61 */ 62 int i2c_probe(uchar chip); 63 64 /* 65 * Read/Write interface: 66 * chip: I2C chip address, range 0..127 67 * addr: Memory (register) address within the chip 68 * alen: Number of bytes to use for addr (typically 1, 2 for larger 69 * memories, 0 for register type devices with only one 70 * register) 71 * buffer: Where to read/write the data 72 * len: How many bytes to read/write 73 * 74 * Returns: 0 on success, not 0 on failure 75 */ 76 int i2c_read(uchar chip, uint addr, int alen, uchar *buffer, int len); 77 int i2c_write(uchar chip, uint addr, int alen, uchar *buffer, int len); 78 79 /* 80 * Utility routines to read/write registers. 81 */ 82 uchar i2c_reg_read (uchar chip, uchar reg); 83 void i2c_reg_write(uchar chip, uchar reg, uchar val); 84 85 #endif /* _I2C_H_ */ 86