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 static inline int I2C_SET_BUS(unsigned int bus) 59 { 60 return 0; 61 } 62 #endif 63 64 /* define the I2C bus number for RTC and DTT if not already done */ 65 #if !defined(CONFIG_SYS_RTC_BUS_NUM) 66 #define CONFIG_SYS_RTC_BUS_NUM 0 67 #endif 68 #if !defined(CONFIG_SYS_DTT_BUS_NUM) 69 #define CONFIG_SYS_DTT_BUS_NUM 0 70 #endif 71 #if !defined(CONFIG_SYS_SPD_BUS_NUM) 72 #define CONFIG_SYS_SPD_BUS_NUM 0 73 #endif 74 75 #ifndef I2C_SOFT_DECLARATIONS 76 # if defined(CONFIG_MPC8260) 77 # define I2C_SOFT_DECLARATIONS volatile ioport_t *iop = ioport_addr((immap_t *)CONFIG_SYS_IMMR, I2C_PORT); 78 # elif defined(CONFIG_8xx) 79 # define I2C_SOFT_DECLARATIONS volatile immap_t *immr = (immap_t *)CONFIG_SYS_IMMR; 80 81 # elif (defined(CONFIG_AT91RM9200) || \ 82 defined(CONFIG_AT91SAM9260) || defined(CONFIG_AT91SAM9261) || \ 83 defined(CONFIG_AT91SAM9263)) && !defined(CONFIG_AT91_LEGACY) 84 # define I2C_SOFT_DECLARATIONS at91_pio_t *pio = (at91_pio_t *) AT91_PIO_BASE; 85 # else 86 # define I2C_SOFT_DECLARATIONS 87 # endif 88 #endif 89 90 #ifdef CONFIG_8xx 91 /* Set default value for the I2C bus speed on 8xx. In the 92 * future, we'll define these in all 8xx board config files. 93 */ 94 #ifndef CONFIG_SYS_I2C_SPEED 95 #define CONFIG_SYS_I2C_SPEED 50000 96 #endif 97 #endif 98 99 /* 100 * Many boards/controllers/drivers don't support an I2C slave interface so 101 * provide a default slave address for them for use in common code. A real 102 * value for CONFIG_SYS_I2C_SLAVE should be defined for any board which does 103 * support a slave interface. 104 */ 105 #ifndef CONFIG_SYS_I2C_SLAVE 106 #define CONFIG_SYS_I2C_SLAVE 0xfe 107 #endif 108 109 /* 110 * Initialization, must be called once on start up, may be called 111 * repeatedly to change the speed and slave addresses. 112 */ 113 void i2c_init(int speed, int slaveaddr); 114 void i2c_init_board(void); 115 #ifdef CONFIG_SYS_I2C_BOARD_LATE_INIT 116 void i2c_board_late_init(void); 117 #endif 118 119 #if defined(CONFIG_I2C_MUX) 120 121 typedef struct _mux { 122 uchar chip; 123 uchar channel; 124 char *name; 125 struct _mux *next; 126 } I2C_MUX; 127 128 typedef struct _mux_device { 129 int busid; 130 I2C_MUX *mux; /* List of muxes, to reach the device */ 131 struct _mux_device *next; 132 } I2C_MUX_DEVICE; 133 134 I2C_MUX_DEVICE *i2c_mux_search_device(int id); 135 I2C_MUX_DEVICE *i2c_mux_ident_muxstring (uchar *buf); 136 int i2x_mux_select_mux(int bus); 137 int i2c_mux_ident_muxstring_f (uchar *buf); 138 #endif 139 140 /* 141 * Probe the given I2C chip address. Returns 0 if a chip responded, 142 * not 0 on failure. 143 */ 144 int i2c_probe(uchar chip); 145 146 /* 147 * Read/Write interface: 148 * chip: I2C chip address, range 0..127 149 * addr: Memory (register) address within the chip 150 * alen: Number of bytes to use for addr (typically 1, 2 for larger 151 * memories, 0 for register type devices with only one 152 * register) 153 * buffer: Where to read/write the data 154 * len: How many bytes to read/write 155 * 156 * Returns: 0 on success, not 0 on failure 157 */ 158 int i2c_read(uchar chip, uint addr, int alen, uchar *buffer, int len); 159 int i2c_write(uchar chip, uint addr, int alen, uchar *buffer, int len); 160 161 /* 162 * Utility routines to read/write registers. 163 */ 164 static inline u8 i2c_reg_read(u8 addr, u8 reg) 165 { 166 u8 buf; 167 168 #ifdef CONFIG_8xx 169 /* MPC8xx needs this. Maybe one day we can get rid of it. */ 170 i2c_init(CONFIG_SYS_I2C_SPEED, CONFIG_SYS_I2C_SLAVE); 171 #endif 172 173 #ifdef DEBUG 174 printf("%s: addr=0x%02x, reg=0x%02x\n", __func__, addr, reg); 175 #endif 176 177 i2c_read(addr, reg, 1, &buf, 1); 178 179 return buf; 180 } 181 182 static inline void i2c_reg_write(u8 addr, u8 reg, u8 val) 183 { 184 #ifdef CONFIG_8xx 185 /* MPC8xx needs this. Maybe one day we can get rid of it. */ 186 i2c_init(CONFIG_SYS_I2C_SPEED, CONFIG_SYS_I2C_SLAVE); 187 #endif 188 189 #ifdef DEBUG 190 printf("%s: addr=0x%02x, reg=0x%02x, val=0x%02x\n", 191 __func__, addr, reg, val); 192 #endif 193 194 i2c_write(addr, reg, 1, &val, 1); 195 } 196 197 /* 198 * Functions for setting the current I2C bus and its speed 199 */ 200 201 /* 202 * i2c_set_bus_num: 203 * 204 * Change the active I2C bus. Subsequent read/write calls will 205 * go to this one. 206 * 207 * bus - bus index, zero based 208 * 209 * Returns: 0 on success, not 0 on failure 210 * 211 */ 212 int i2c_set_bus_num(unsigned int bus); 213 214 /* 215 * i2c_get_bus_num: 216 * 217 * Returns index of currently active I2C bus. Zero-based. 218 */ 219 220 unsigned int i2c_get_bus_num(void); 221 222 /* 223 * i2c_set_bus_speed: 224 * 225 * Change the speed of the active I2C bus 226 * 227 * speed - bus speed in Hz 228 * 229 * Returns: 0 on success, not 0 on failure 230 * 231 */ 232 int i2c_set_bus_speed(unsigned int); 233 234 /* 235 * i2c_get_bus_speed: 236 * 237 * Returns speed of currently active I2C bus in Hz 238 */ 239 240 unsigned int i2c_get_bus_speed(void); 241 242 #endif /* _I2C_H_ */ 243