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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
Stefan Roese79b2d0b2007-02-20 10:27:08 +010049#if defined(CONFIG_I2C_MULTI_BUS)
50#define CFG_MAX_I2C_BUS 2
51#define I2C_GET_BUS() i2c_get_bus_num()
52#define I2C_SET_BUS(a) i2c_set_bus_num(a)
53#else
54#define CFG_MAX_I2C_BUS 1
55#define I2C_GET_BUS() 0
56#define I2C_SET_BUS(a)
57#endif
58
Stefan Roese8c120452007-03-01 07:03:25 +010059/* define the I2C bus number for RTC and DTT if not already done */
60#if !defined(CFG_RTC_BUS_NUM)
61#define CFG_RTC_BUS_NUM 0
62#endif
63#if !defined(CFG_DTT_BUS_NUM)
64#define CFG_DTT_BUS_NUM 0
65#endif
Matthias Fuchsd8a8ea52007-03-08 16:20:32 +010066#if !defined(CFG_SPD_BUS_NUM)
67#define CFG_SPD_BUS_NUM 0
68#endif
Stefan Roese8c120452007-03-01 07:03:25 +010069
wdenk1f045212002-03-10 14:37:15 +000070/*
71 * Initialization, must be called once on start up, may be called
72 * repeatedly to change the speed and slave addresses.
73 */
74void i2c_init(int speed, int slaveaddr);
wdenk06d01db2003-03-14 20:47:52 +000075#ifdef CFG_I2C_INIT_BOARD
76void i2c_init_board(void);
77#endif
wdenk1f045212002-03-10 14:37:15 +000078
79/*
80 * Probe the given I2C chip address. Returns 0 if a chip responded,
81 * not 0 on failure.
82 */
83int i2c_probe(uchar chip);
84
85/*
86 * Read/Write interface:
87 * chip: I2C chip address, range 0..127
88 * addr: Memory (register) address within the chip
89 * alen: Number of bytes to use for addr (typically 1, 2 for larger
90 * memories, 0 for register type devices with only one
91 * register)
92 * buffer: Where to read/write the data
93 * len: How many bytes to read/write
94 *
95 * Returns: 0 on success, not 0 on failure
96 */
97int i2c_read(uchar chip, uint addr, int alen, uchar *buffer, int len);
98int i2c_write(uchar chip, uint addr, int alen, uchar *buffer, int len);
99
100/*
101 * Utility routines to read/write registers.
102 */
103uchar i2c_reg_read (uchar chip, uchar reg);
104void i2c_reg_write(uchar chip, uchar reg, uchar val);
105
Ben Warrenbb99ad62006-09-07 16:50:54 -0400106/*
107 * Functions for setting the current I2C bus and its speed
108 */
109
110/*
111 * i2c_set_bus_num:
112 *
113 * Change the active I2C bus. Subsequent read/write calls will
114 * go to this one.
115 *
Wolfgang Denk53677ef2008-05-20 16:00:29 +0200116 * bus - bus index, zero based
Ben Warrenbb99ad62006-09-07 16:50:54 -0400117 *
Wolfgang Denk53677ef2008-05-20 16:00:29 +0200118 * Returns: 0 on success, not 0 on failure
Ben Warrenbb99ad62006-09-07 16:50:54 -0400119 *
120 */
Timur Tabi9ca880a2006-10-31 21:23:16 -0600121int i2c_set_bus_num(unsigned int bus);
Ben Warrenbb99ad62006-09-07 16:50:54 -0400122
123/*
124 * i2c_get_bus_num:
125 *
126 * Returns index of currently active I2C bus. Zero-based.
127 */
128
Timur Tabi9ca880a2006-10-31 21:23:16 -0600129unsigned int i2c_get_bus_num(void);
Ben Warrenbb99ad62006-09-07 16:50:54 -0400130
131/*
132 * i2c_set_bus_speed:
133 *
134 * Change the speed of the active I2C bus
135 *
Wolfgang Denk53677ef2008-05-20 16:00:29 +0200136 * speed - bus speed in Hz
Ben Warrenbb99ad62006-09-07 16:50:54 -0400137 *
Wolfgang Denk53677ef2008-05-20 16:00:29 +0200138 * Returns: 0 on success, not 0 on failure
Ben Warrenbb99ad62006-09-07 16:50:54 -0400139 *
140 */
Timur Tabi9ca880a2006-10-31 21:23:16 -0600141int i2c_set_bus_speed(unsigned int);
Ben Warrenbb99ad62006-09-07 16:50:54 -0400142
143/*
144 * i2c_get_bus_speed:
145 *
146 * Returns speed of currently active I2C bus in Hz
147 */
148
Timur Tabi9ca880a2006-10-31 21:23:16 -0600149unsigned int i2c_get_bus_speed(void);
Ben Warrenbb99ad62006-09-07 16:50:54 -0400150
wdenk1f045212002-03-10 14:37:15 +0000151#endif /* _I2C_H_ */