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 #ifdef CONFIG_8xx 81 /* Set default values for the I2C bus speed and slave address on 8xx. In the 82 * future, we'll define these in all 8xx board config files. 83 */ 84 #ifndef CONFIG_SYS_I2C_SPEED 85 #define CONFIG_SYS_I2C_SPEED 50000 86 #endif 87 88 #ifndef CONFIG_SYS_I2C_SLAVE 89 #define CONFIG_SYS_I2C_SLAVE 0xFE 90 #endif 91 #endif 92 93 /* 94 * Initialization, must be called once on start up, may be called 95 * repeatedly to change the speed and slave addresses. 96 */ 97 void i2c_init(int speed, int slaveaddr); 98 #ifdef CONFIG_SYS_I2C_INIT_BOARD 99 void i2c_init_board(void); 100 #endif 101 102 #if defined(CONFIG_I2C_MUX) 103 104 typedef struct _mux { 105 uchar chip; 106 uchar channel; 107 char *name; 108 struct _mux *next; 109 } I2C_MUX; 110 111 typedef struct _mux_device { 112 int busid; 113 I2C_MUX *mux; /* List of muxes, to reach the device */ 114 struct _mux_device *next; 115 } I2C_MUX_DEVICE; 116 117 int i2c_mux_add_device(I2C_MUX_DEVICE *dev); 118 119 I2C_MUX_DEVICE *i2c_mux_search_device(int id); 120 I2C_MUX_DEVICE *i2c_mux_ident_muxstring (uchar *buf); 121 int i2x_mux_select_mux(int bus); 122 int i2c_mux_ident_muxstring_f (uchar *buf); 123 #endif 124 125 /* 126 * Probe the given I2C chip address. Returns 0 if a chip responded, 127 * not 0 on failure. 128 */ 129 int i2c_probe(uchar chip); 130 131 /* 132 * Read/Write interface: 133 * chip: I2C chip address, range 0..127 134 * addr: Memory (register) address within the chip 135 * alen: Number of bytes to use for addr (typically 1, 2 for larger 136 * memories, 0 for register type devices with only one 137 * register) 138 * buffer: Where to read/write the data 139 * len: How many bytes to read/write 140 * 141 * Returns: 0 on success, not 0 on failure 142 */ 143 int i2c_read(uchar chip, uint addr, int alen, uchar *buffer, int len); 144 int i2c_write(uchar chip, uint addr, int alen, uchar *buffer, int len); 145 146 /* 147 * Utility routines to read/write registers. 148 */ 149 static inline u8 i2c_reg_read(u8 addr, u8 reg) 150 { 151 u8 buf; 152 153 #ifdef CONFIG_8xx 154 /* MPC8xx needs this. Maybe one day we can get rid of it. */ 155 i2c_init(CONFIG_SYS_I2C_SPEED, CONFIG_SYS_I2C_SLAVE); 156 #endif 157 158 #ifdef DEBUG 159 printf("%s: addr=0x%02x, reg=0x%02x\n", __func__, addr, reg); 160 #endif 161 162 #ifdef CONFIG_BLACKFIN 163 /* This ifdef will become unneccessary in a future version of the 164 * blackfin I2C driver. 165 */ 166 i2c_read(addr, reg, 0, &buf, 1); 167 #else 168 i2c_read(addr, reg, 1, &buf, 1); 169 #endif 170 171 return buf; 172 } 173 174 static inline void i2c_reg_write(u8 addr, u8 reg, u8 val) 175 { 176 #ifdef CONFIG_8xx 177 /* MPC8xx needs this. Maybe one day we can get rid of it. */ 178 i2c_init(CONFIG_SYS_I2C_SPEED, CONFIG_SYS_I2C_SLAVE); 179 #endif 180 181 #ifdef DEBUG 182 printf("%s: addr=0x%02x, reg=0x%02x, val=0x%02x\n", 183 __func__, addr, reg, val); 184 #endif 185 186 #ifdef CONFIG_BLACKFIN 187 /* This ifdef will become unneccessary in a future version of the 188 * blackfin I2C driver. 189 */ 190 i2c_write(addr, reg, 0, &val, 1); 191 #else 192 i2c_write(addr, reg, 1, &val, 1); 193 #endif 194 } 195 196 /* 197 * Functions for setting the current I2C bus and its speed 198 */ 199 200 /* 201 * i2c_set_bus_num: 202 * 203 * Change the active I2C bus. Subsequent read/write calls will 204 * go to this one. 205 * 206 * bus - bus index, zero based 207 * 208 * Returns: 0 on success, not 0 on failure 209 * 210 */ 211 int i2c_set_bus_num(unsigned int bus); 212 213 /* 214 * i2c_get_bus_num: 215 * 216 * Returns index of currently active I2C bus. Zero-based. 217 */ 218 219 unsigned int i2c_get_bus_num(void); 220 221 /* 222 * i2c_set_bus_speed: 223 * 224 * Change the speed of the active I2C bus 225 * 226 * speed - bus speed in Hz 227 * 228 * Returns: 0 on success, not 0 on failure 229 * 230 */ 231 int i2c_set_bus_speed(unsigned int); 232 233 /* 234 * i2c_get_bus_speed: 235 * 236 * Returns speed of currently active I2C bus in Hz 237 */ 238 239 unsigned int i2c_get_bus_speed(void); 240 241 #endif /* _I2C_H_ */ 242