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 #if defined(CONFIG_I2C_MULTI_BUS) 50 #define CONFIG_SYS_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 CONFIG_SYS_MAX_I2C_BUS 1 55 #define I2C_GET_BUS() 0 56 #define I2C_SET_BUS(a) 57 #endif 58 59 /* define the I2C bus number for RTC and DTT if not already done */ 60 #if !defined(CONFIG_SYS_RTC_BUS_NUM) 61 #define CONFIG_SYS_RTC_BUS_NUM 0 62 #endif 63 #if !defined(CONFIG_SYS_DTT_BUS_NUM) 64 #define CONFIG_SYS_DTT_BUS_NUM 0 65 #endif 66 #if !defined(CONFIG_SYS_SPD_BUS_NUM) 67 #define CONFIG_SYS_SPD_BUS_NUM 0 68 #endif 69 70 #ifndef I2C_SOFT_DECLARATIONS 71 # if defined(CONFIG_MPC8260) 72 # define I2C_SOFT_DECLARATIONS volatile ioport_t *iop = ioport_addr((immap_t *)CONFIG_SYS_IMMR, I2C_PORT); 73 # elif defined(CONFIG_8xx) 74 # define I2C_SOFT_DECLARATIONS volatile immap_t *immr = (immap_t *)CONFIG_SYS_IMMR; 75 # else 76 # define I2C_SOFT_DECLARATIONS 77 # endif 78 #endif 79 /* 80 * Initialization, must be called once on start up, may be called 81 * repeatedly to change the speed and slave addresses. 82 */ 83 void i2c_init(int speed, int slaveaddr); 84 #ifdef CONFIG_SYS_I2C_INIT_BOARD 85 void i2c_init_board(void); 86 #endif 87 88 #if defined(CONFIG_I2C_MUX) 89 90 typedef struct _mux { 91 uchar chip; 92 uchar channel; 93 char *name; 94 struct _mux *next; 95 } I2C_MUX; 96 97 typedef struct _mux_device { 98 int busid; 99 I2C_MUX *mux; /* List of muxes, to reach the device */ 100 struct _mux_device *next; 101 } I2C_MUX_DEVICE; 102 103 int i2c_mux_add_device(I2C_MUX_DEVICE *dev); 104 105 I2C_MUX_DEVICE *i2c_mux_search_device(int id); 106 I2C_MUX_DEVICE *i2c_mux_ident_muxstring (uchar *buf); 107 int i2x_mux_select_mux(int bus); 108 int i2c_mux_ident_muxstring_f (uchar *buf); 109 #endif 110 111 /* 112 * Probe the given I2C chip address. Returns 0 if a chip responded, 113 * not 0 on failure. 114 */ 115 int i2c_probe(uchar chip); 116 117 /* 118 * Read/Write interface: 119 * chip: I2C chip address, range 0..127 120 * addr: Memory (register) address within the chip 121 * alen: Number of bytes to use for addr (typically 1, 2 for larger 122 * memories, 0 for register type devices with only one 123 * register) 124 * buffer: Where to read/write the data 125 * len: How many bytes to read/write 126 * 127 * Returns: 0 on success, not 0 on failure 128 */ 129 int i2c_read(uchar chip, uint addr, int alen, uchar *buffer, int len); 130 int i2c_write(uchar chip, uint addr, int alen, uchar *buffer, int len); 131 132 /* 133 * Utility routines to read/write registers. 134 */ 135 uchar i2c_reg_read (uchar chip, uchar reg); 136 void i2c_reg_write(uchar chip, uchar reg, uchar val); 137 138 /* 139 * Functions for setting the current I2C bus and its speed 140 */ 141 142 /* 143 * i2c_set_bus_num: 144 * 145 * Change the active I2C bus. Subsequent read/write calls will 146 * go to this one. 147 * 148 * bus - bus index, zero based 149 * 150 * Returns: 0 on success, not 0 on failure 151 * 152 */ 153 int i2c_set_bus_num(unsigned int bus); 154 155 /* 156 * i2c_get_bus_num: 157 * 158 * Returns index of currently active I2C bus. Zero-based. 159 */ 160 161 unsigned int i2c_get_bus_num(void); 162 163 /* 164 * i2c_set_bus_speed: 165 * 166 * Change the speed of the active I2C bus 167 * 168 * speed - bus speed in Hz 169 * 170 * Returns: 0 on success, not 0 on failure 171 * 172 */ 173 int i2c_set_bus_speed(unsigned int); 174 175 /* 176 * i2c_get_bus_speed: 177 * 178 * Returns speed of currently active I2C bus in Hz 179 */ 180 181 unsigned int i2c_get_bus_speed(void); 182 183 #endif /* _I2C_H_ */ 184