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wdenk1f045212002-03-10 14:37:15 +00001/*
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 */
53void 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 */
59int 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 */
73int i2c_read(uchar chip, uint addr, int alen, uchar *buffer, int len);
74int i2c_write(uchar chip, uint addr, int alen, uchar *buffer, int len);
75
76/*
77 * Utility routines to read/write registers.
78 */
79uchar i2c_reg_read (uchar chip, uchar reg);
80void i2c_reg_write(uchar chip, uchar reg, uchar val);
81
82#endif /* _I2C_H_ */