3 * Gerald Van Baren, Custom IDEAS, vanbaren@cideas.com.
5 * See file CREDITS for list of people who contributed to this
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.
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.
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,
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.
33 * WARNING WARNING WARNING WARNING WARNING WARNING WARNING WARNING
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
41 * WARNING WARNING WARNING WARNING WARNING WARNING WARNING WARNING
45 * Configuration items.
47 #define I2C_RXTX_LEN 128 /* maximum tx/rx buffer length */
49 #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)
54 #define CFG_MAX_I2C_BUS 1
55 #define I2C_GET_BUS() 0
56 #define I2C_SET_BUS(a)
59 /* 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
63 #if !defined(CFG_DTT_BUS_NUM)
64 #define CFG_DTT_BUS_NUM 0
68 * Initialization, must be called once on start up, may be called
69 * repeatedly to change the speed and slave addresses.
71 void i2c_init(int speed, int slaveaddr);
72 #ifdef CFG_I2C_INIT_BOARD
73 void i2c_init_board(void);
77 * Probe the given I2C chip address. Returns 0 if a chip responded,
80 int i2c_probe(uchar chip);
83 * Read/Write interface:
84 * chip: I2C chip address, range 0..127
85 * addr: Memory (register) address within the chip
86 * alen: Number of bytes to use for addr (typically 1, 2 for larger
87 * memories, 0 for register type devices with only one
89 * buffer: Where to read/write the data
90 * len: How many bytes to read/write
92 * Returns: 0 on success, not 0 on failure
94 int i2c_read(uchar chip, uint addr, int alen, uchar *buffer, int len);
95 int i2c_write(uchar chip, uint addr, int alen, uchar *buffer, int len);
98 * Utility routines to read/write registers.
100 uchar i2c_reg_read (uchar chip, uchar reg);
101 void i2c_reg_write(uchar chip, uchar reg, uchar val);
104 * Functions for setting the current I2C bus and its speed
110 * Change the active I2C bus. Subsequent read/write calls will
113 * bus - bus index, zero based
115 * Returns: 0 on success, not 0 on failure
118 int i2c_set_bus_num(unsigned int bus);
123 * Returns index of currently active I2C bus. Zero-based.
126 unsigned int i2c_get_bus_num(void);
131 * Change the speed of the active I2C bus
133 * speed - bus speed in Hz
135 * Returns: 0 on success, not 0 on failure
138 int i2c_set_bus_speed(unsigned int);
143 * Returns speed of currently active I2C bus in Hz
146 unsigned int i2c_get_bus_speed(void);