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 #ifdef CONFIG_I2C_MULTI_BUS 50 #define MAX_I2C_BUS 2 51 #define I2C_MULTI_BUS 1 52 #else 53 #define MAX_I2C_BUS 1 54 #define I2C_MULTI_BUS 0 55 #endif 56 57 #if !defined(CONFIG_SYS_MAX_I2C_BUS) 58 #define CONFIG_SYS_MAX_I2C_BUS MAX_I2C_BUS 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 *) ATMEL_BASE_PIOA; 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 void i2c_init_board(void); 112 #ifdef CONFIG_SYS_I2C_BOARD_LATE_INIT 113 void i2c_board_late_init(void); 114 #endif 115 116 #if defined(CONFIG_I2C_MUX) 117 118 typedef struct _mux { 119 uchar chip; 120 uchar channel; 121 char *name; 122 struct _mux *next; 123 } I2C_MUX; 124 125 typedef struct _mux_device { 126 int busid; 127 I2C_MUX *mux; /* List of muxes, to reach the device */ 128 struct _mux_device *next; 129 } I2C_MUX_DEVICE; 130 131 I2C_MUX_DEVICE *i2c_mux_search_device(int id); 132 I2C_MUX_DEVICE *i2c_mux_ident_muxstring (uchar *buf); 133 int i2x_mux_select_mux(int bus); 134 int i2c_mux_ident_muxstring_f (uchar *buf); 135 #endif 136 137 /* 138 * Probe the given I2C chip address. Returns 0 if a chip responded, 139 * not 0 on failure. 140 */ 141 int i2c_probe(uchar chip); 142 143 /* 144 * Read/Write interface: 145 * chip: I2C chip address, range 0..127 146 * addr: Memory (register) address within the chip 147 * alen: Number of bytes to use for addr (typically 1, 2 for larger 148 * memories, 0 for register type devices with only one 149 * register) 150 * buffer: Where to read/write the data 151 * len: How many bytes to read/write 152 * 153 * Returns: 0 on success, not 0 on failure 154 */ 155 int i2c_read(uchar chip, uint addr, int alen, uchar *buffer, int len); 156 int i2c_write(uchar chip, uint addr, int alen, uchar *buffer, int len); 157 158 /* 159 * Utility routines to read/write registers. 160 */ 161 static inline u8 i2c_reg_read(u8 addr, u8 reg) 162 { 163 u8 buf; 164 165 #ifdef CONFIG_8xx 166 /* MPC8xx needs this. Maybe one day we can get rid of it. */ 167 i2c_init(CONFIG_SYS_I2C_SPEED, CONFIG_SYS_I2C_SLAVE); 168 #endif 169 170 #ifdef DEBUG 171 printf("%s: addr=0x%02x, reg=0x%02x\n", __func__, addr, reg); 172 #endif 173 174 i2c_read(addr, reg, 1, &buf, 1); 175 176 return buf; 177 } 178 179 static inline void i2c_reg_write(u8 addr, u8 reg, u8 val) 180 { 181 #ifdef CONFIG_8xx 182 /* MPC8xx needs this. Maybe one day we can get rid of it. */ 183 i2c_init(CONFIG_SYS_I2C_SPEED, CONFIG_SYS_I2C_SLAVE); 184 #endif 185 186 #ifdef DEBUG 187 printf("%s: addr=0x%02x, reg=0x%02x, val=0x%02x\n", 188 __func__, addr, reg, val); 189 #endif 190 191 i2c_write(addr, reg, 1, &val, 1); 192 } 193 194 /* 195 * Functions for setting the current I2C bus and its speed 196 */ 197 198 /* 199 * i2c_set_bus_num: 200 * 201 * Change the active I2C bus. Subsequent read/write calls will 202 * go to this one. 203 * 204 * bus - bus index, zero based 205 * 206 * Returns: 0 on success, not 0 on failure 207 * 208 */ 209 int i2c_set_bus_num(unsigned int bus); 210 211 /* 212 * i2c_get_bus_num: 213 * 214 * Returns index of currently active I2C bus. Zero-based. 215 */ 216 217 unsigned int i2c_get_bus_num(void); 218 219 /* 220 * i2c_set_bus_speed: 221 * 222 * Change the speed of the active I2C bus 223 * 224 * speed - bus speed in Hz 225 * 226 * Returns: 0 on success, not 0 on failure 227 * 228 */ 229 int i2c_set_bus_speed(unsigned int); 230 231 /* 232 * i2c_get_bus_speed: 233 * 234 * Returns speed of currently active I2C bus in Hz 235 */ 236 237 unsigned int i2c_get_bus_speed(void); 238 239 /* NOTE: These two functions MUST be always_inline to avoid code growth! */ 240 static inline unsigned int I2C_GET_BUS(void) __attribute__((always_inline)); 241 static inline unsigned int I2C_GET_BUS(void) 242 { 243 return I2C_MULTI_BUS ? i2c_get_bus_num() : 0; 244 } 245 246 static inline void I2C_SET_BUS(unsigned int bus) __attribute__((always_inline)); 247 static inline void I2C_SET_BUS(unsigned int bus) 248 { 249 if (I2C_MULTI_BUS) 250 i2c_set_bus_num(bus); 251 } 252 253 #endif /* _I2C_H_ */ 254