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 78 # elif (defined(CONFIG_AT91RM9200) || \ 79 defined(CONFIG_AT91SAM9260) || defined(CONFIG_AT91SAM9261) || \ 80 defined(CONFIG_AT91SAM9263)) && !defined(CONFIG_AT91_LEGACY) 81 # define I2C_SOFT_DECLARATIONS at91_pio_t *pio = (at91_pio_t *) AT91_PIO_BASE; 82 # else 83 # define I2C_SOFT_DECLARATIONS 84 # endif 85 #endif 86 87 #ifdef CONFIG_8xx 88 /* Set default value for the I2C bus speed on 8xx. In the 89 * future, we'll define these in all 8xx board config files. 90 */ 91 #ifndef CONFIG_SYS_I2C_SPEED 92 #define CONFIG_SYS_I2C_SPEED 50000 93 #endif 94 #endif 95 96 /* 97 * Many boards/controllers/drivers don't support an I2C slave interface so 98 * provide a default slave address for them for use in common code. A real 99 * value for CONFIG_SYS_I2C_SLAVE should be defined for any board which does 100 * support a slave interface. 101 */ 102 #ifndef CONFIG_SYS_I2C_SLAVE 103 #define CONFIG_SYS_I2C_SLAVE 0xfe 104 #endif 105 106 /* 107 * Initialization, must be called once on start up, may be called 108 * repeatedly to change the speed and slave addresses. 109 */ 110 void i2c_init(int speed, int slaveaddr); 111 #ifdef CONFIG_SYS_I2C_INIT_BOARD 112 void i2c_init_board(void); 113 #endif 114 115 #if defined(CONFIG_I2C_MUX) 116 117 typedef struct _mux { 118 uchar chip; 119 uchar channel; 120 char *name; 121 struct _mux *next; 122 } I2C_MUX; 123 124 typedef struct _mux_device { 125 int busid; 126 I2C_MUX *mux; /* List of muxes, to reach the device */ 127 struct _mux_device *next; 128 } I2C_MUX_DEVICE; 129 130 I2C_MUX_DEVICE *i2c_mux_search_device(int id); 131 I2C_MUX_DEVICE *i2c_mux_ident_muxstring (uchar *buf); 132 int i2x_mux_select_mux(int bus); 133 int i2c_mux_ident_muxstring_f (uchar *buf); 134 #endif 135 136 /* 137 * Probe the given I2C chip address. Returns 0 if a chip responded, 138 * not 0 on failure. 139 */ 140 int i2c_probe(uchar chip); 141 142 /* 143 * Read/Write interface: 144 * chip: I2C chip address, range 0..127 145 * addr: Memory (register) address within the chip 146 * alen: Number of bytes to use for addr (typically 1, 2 for larger 147 * memories, 0 for register type devices with only one 148 * register) 149 * buffer: Where to read/write the data 150 * len: How many bytes to read/write 151 * 152 * Returns: 0 on success, not 0 on failure 153 */ 154 int i2c_read(uchar chip, uint addr, int alen, uchar *buffer, int len); 155 int i2c_write(uchar chip, uint addr, int alen, uchar *buffer, int len); 156 157 /* 158 * Utility routines to read/write registers. 159 */ 160 static inline u8 i2c_reg_read(u8 addr, u8 reg) 161 { 162 u8 buf; 163 164 #ifdef CONFIG_8xx 165 /* MPC8xx needs this. Maybe one day we can get rid of it. */ 166 i2c_init(CONFIG_SYS_I2C_SPEED, CONFIG_SYS_I2C_SLAVE); 167 #endif 168 169 #ifdef DEBUG 170 printf("%s: addr=0x%02x, reg=0x%02x\n", __func__, addr, reg); 171 #endif 172 173 i2c_read(addr, reg, 1, &buf, 1); 174 175 return buf; 176 } 177 178 static inline void i2c_reg_write(u8 addr, u8 reg, u8 val) 179 { 180 #ifdef CONFIG_8xx 181 /* MPC8xx needs this. Maybe one day we can get rid of it. */ 182 i2c_init(CONFIG_SYS_I2C_SPEED, CONFIG_SYS_I2C_SLAVE); 183 #endif 184 185 #ifdef DEBUG 186 printf("%s: addr=0x%02x, reg=0x%02x, val=0x%02x\n", 187 __func__, addr, reg, val); 188 #endif 189 190 i2c_write(addr, reg, 1, &val, 1); 191 } 192 193 /* 194 * Functions for setting the current I2C bus and its speed 195 */ 196 197 /* 198 * i2c_set_bus_num: 199 * 200 * Change the active I2C bus. Subsequent read/write calls will 201 * go to this one. 202 * 203 * bus - bus index, zero based 204 * 205 * Returns: 0 on success, not 0 on failure 206 * 207 */ 208 int i2c_set_bus_num(unsigned int bus); 209 210 /* 211 * i2c_get_bus_num: 212 * 213 * Returns index of currently active I2C bus. Zero-based. 214 */ 215 216 unsigned int i2c_get_bus_num(void); 217 218 /* 219 * i2c_set_bus_speed: 220 * 221 * Change the speed of the active I2C bus 222 * 223 * speed - bus speed in Hz 224 * 225 * Returns: 0 on success, not 0 on failure 226 * 227 */ 228 int i2c_set_bus_speed(unsigned int); 229 230 /* 231 * i2c_get_bus_speed: 232 * 233 * Returns speed of currently active I2C bus in Hz 234 */ 235 236 unsigned int i2c_get_bus_speed(void); 237 238 #endif /* _I2C_H_ */ 239