| wdenk | 1f04521 | 2002-03-10 14:37:15 +0000 | [diff] [blame] | 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 | |
| 55 | /* |
| 56 | * Probe the given I2C chip address. Returns 0 if a chip responded, |
| 57 | * not 0 on failure. |
| 58 | */ |
| 59 | int i2c_probe(uchar chip); |
| 60 | |
| 61 | /* |
| 62 | * Read/Write interface: |
| 63 | * chip: I2C chip address, range 0..127 |
| 64 | * addr: Memory (register) address within the chip |
| 65 | * alen: Number of bytes to use for addr (typically 1, 2 for larger |
| 66 | * memories, 0 for register type devices with only one |
| 67 | * register) |
| 68 | * buffer: Where to read/write the data |
| 69 | * len: How many bytes to read/write |
| 70 | * |
| 71 | * Returns: 0 on success, not 0 on failure |
| 72 | */ |
| 73 | int i2c_read(uchar chip, uint addr, int alen, uchar *buffer, int len); |
| 74 | int i2c_write(uchar chip, uint addr, int alen, uchar *buffer, int len); |
| 75 | |
| 76 | /* |
| 77 | * Utility routines to read/write registers. |
| 78 | */ |
| 79 | uchar i2c_reg_read (uchar chip, uchar reg); |
| 80 | void i2c_reg_write(uchar chip, uchar reg, uchar val); |
| 81 | |
| 82 | #endif /* _I2C_H_ */ |