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 #if !defined(CONFIG_SYS_MAX_I2C_BUS) 51 #define CONFIG_SYS_MAX_I2C_BUS 2 52 #endif 53 #define I2C_GET_BUS() i2c_get_bus_num() 54 #define I2C_SET_BUS(a) i2c_set_bus_num(a) 55 #else 56 #define CONFIG_SYS_MAX_I2C_BUS 1 57 #define I2C_GET_BUS() 0 58 #define I2C_SET_BUS(a) 59 #endif 60 61 /* define the I2C bus number for RTC and DTT if not already done */ 62 #if !defined(CONFIG_SYS_RTC_BUS_NUM) 63 #define CONFIG_SYS_RTC_BUS_NUM 0 64 #endif 65 #if !defined(CONFIG_SYS_DTT_BUS_NUM) 66 #define CONFIG_SYS_DTT_BUS_NUM 0 67 #endif 68 #if !defined(CONFIG_SYS_SPD_BUS_NUM) 69 #define CONFIG_SYS_SPD_BUS_NUM 0 70 #endif 71 72 #ifndef I2C_SOFT_DECLARATIONS 73 # if defined(CONFIG_MPC8260) 74 # define I2C_SOFT_DECLARATIONS volatile ioport_t *iop = ioport_addr((immap_t *)CONFIG_SYS_IMMR, I2C_PORT); 75 # elif defined(CONFIG_8xx) 76 # define I2C_SOFT_DECLARATIONS volatile immap_t *immr = (immap_t *)CONFIG_SYS_IMMR; 77 # else 78 # define I2C_SOFT_DECLARATIONS 79 # endif 80 #endif 81 82 #ifdef CONFIG_8xx 83 /* Set default value for the I2C bus speed on 8xx. In the 84 * future, we'll define these in all 8xx board config files. 85 */ 86 #ifndef CONFIG_SYS_I2C_SPEED 87 #define CONFIG_SYS_I2C_SPEED 50000 88 #endif 89 #endif 90 91 /* 92 * Many boards/controllers/drivers don't support an I2C slave interface so 93 * provide a default slave address for them for use in common code. A real 94 * value for CONFIG_SYS_I2C_SLAVE should be defined for any board which does 95 * support a slave interface. 96 */ 97 #ifndef CONFIG_SYS_I2C_SLAVE 98 #define CONFIG_SYS_I2C_SLAVE 0xfe 99 #endif 100 101 /* 102 * Initialization, must be called once on start up, may be called 103 * repeatedly to change the speed and slave addresses. 104 */ 105 void i2c_init(int speed, int slaveaddr); 106 #ifdef CONFIG_SYS_I2C_INIT_BOARD 107 void i2c_init_board(void); 108 #endif 109 110 #if defined(CONFIG_I2C_MUX) 111 112 typedef struct _mux { 113 uchar chip; 114 uchar channel; 115 char *name; 116 struct _mux *next; 117 } I2C_MUX; 118 119 typedef struct _mux_device { 120 int busid; 121 I2C_MUX *mux; /* List of muxes, to reach the device */ 122 struct _mux_device *next; 123 } I2C_MUX_DEVICE; 124 125 int i2c_mux_add_device(I2C_MUX_DEVICE *dev); 126 127 I2C_MUX_DEVICE *i2c_mux_search_device(int id); 128 I2C_MUX_DEVICE *i2c_mux_ident_muxstring (uchar *buf); 129 int i2x_mux_select_mux(int bus); 130 int i2c_mux_ident_muxstring_f (uchar *buf); 131 #endif 132 133 /* 134 * Probe the given I2C chip address. Returns 0 if a chip responded, 135 * not 0 on failure. 136 */ 137 int i2c_probe(uchar chip); 138 139 /* 140 * Read/Write interface: 141 * chip: I2C chip address, range 0..127 142 * addr: Memory (register) address within the chip 143 * alen: Number of bytes to use for addr (typically 1, 2 for larger 144 * memories, 0 for register type devices with only one 145 * register) 146 * buffer: Where to read/write the data 147 * len: How many bytes to read/write 148 * 149 * Returns: 0 on success, not 0 on failure 150 */ 151 int i2c_read(uchar chip, uint addr, int alen, uchar *buffer, int len); 152 int i2c_write(uchar chip, uint addr, int alen, uchar *buffer, int len); 153 154 /* 155 * Utility routines to read/write registers. 156 */ 157 static inline u8 i2c_reg_read(u8 addr, u8 reg) 158 { 159 u8 buf; 160 161 #ifdef CONFIG_8xx 162 /* MPC8xx needs this. Maybe one day we can get rid of it. */ 163 i2c_init(CONFIG_SYS_I2C_SPEED, CONFIG_SYS_I2C_SLAVE); 164 #endif 165 166 #ifdef DEBUG 167 printf("%s: addr=0x%02x, reg=0x%02x\n", __func__, addr, reg); 168 #endif 169 170 i2c_read(addr, reg, 1, &buf, 1); 171 172 return buf; 173 } 174 175 static inline void i2c_reg_write(u8 addr, u8 reg, u8 val) 176 { 177 #ifdef CONFIG_8xx 178 /* MPC8xx needs this. Maybe one day we can get rid of it. */ 179 i2c_init(CONFIG_SYS_I2C_SPEED, CONFIG_SYS_I2C_SLAVE); 180 #endif 181 182 #ifdef DEBUG 183 printf("%s: addr=0x%02x, reg=0x%02x, val=0x%02x\n", 184 __func__, addr, reg, val); 185 #endif 186 187 i2c_write(addr, reg, 1, &val, 1); 188 } 189 190 /* 191 * Functions for setting the current I2C bus and its speed 192 */ 193 194 /* 195 * i2c_set_bus_num: 196 * 197 * Change the active I2C bus. Subsequent read/write calls will 198 * go to this one. 199 * 200 * bus - bus index, zero based 201 * 202 * Returns: 0 on success, not 0 on failure 203 * 204 */ 205 int i2c_set_bus_num(unsigned int bus); 206 207 /* 208 * i2c_get_bus_num: 209 * 210 * Returns index of currently active I2C bus. Zero-based. 211 */ 212 213 unsigned int i2c_get_bus_num(void); 214 215 /* 216 * i2c_set_bus_speed: 217 * 218 * Change the speed of the active I2C bus 219 * 220 * speed - bus speed in Hz 221 * 222 * Returns: 0 on success, not 0 on failure 223 * 224 */ 225 int i2c_set_bus_speed(unsigned int); 226 227 /* 228 * i2c_get_bus_speed: 229 * 230 * Returns speed of currently active I2C bus in Hz 231 */ 232 233 unsigned int i2c_get_bus_speed(void); 234 235 #endif /* _I2C_H_ */ 236