drivers/i2c/i2c_core.c

   1 /*
   2  * Copyright (C) 2009 Sergey Kubushyn <ksi@koi8.net>
   3  *
   4  * (C) Copyright 2012
   5  * Heiko Schocher, DENX Software Engineering, hs@denx.de.
   6  *
   7  * Multibus/multiadapter I2C core functions (wrappers)
   8  *
   9  * SPDX-License-Identifier:     GPL-2.0+
  10  */
  11 #include <common.h>
  12 #include <i2c.h>
  13
  14 struct i2c_adapter *i2c_get_adapter(int index)
  15 {
  16         struct i2c_adapter *i2c_adap_p = ll_entry_start(struct i2c_adapter,
  17                                                 i2c);
  18         int max = ll_entry_count(struct i2c_adapter, i2c);
  19         int i;
  20
  21         if (index >= max) {
  22                 printf("Error, wrong i2c adapter %d max %d possible\n",
  23                        index, max);
  24                 return i2c_adap_p;
  25         }
  26         if (index == 0)
  27                 return i2c_adap_p;
  28
  29         for (i = 0; i < index; i++)
  30                 i2c_adap_p++;
  31
  32         return i2c_adap_p;
  33 }
  34
  35 #if !defined(CONFIG_SYS_I2C_DIRECT_BUS)
  36 struct i2c_bus_hose i2c_bus[CONFIG_SYS_NUM_I2C_BUSES] =
  37                         CONFIG_SYS_I2C_BUSES;
  38 #endif
  39
  40 DECLARE_GLOBAL_DATA_PTR;
  41
  42 void i2c_reloc_fixup(void)
  43 {
  44 #if defined(CONFIG_NEEDS_MANUAL_RELOC)
  45         struct i2c_adapter *i2c_adap_p = ll_entry_start(struct i2c_adapter,
  46                                                 i2c);
  47         struct i2c_adapter *tmp = i2c_adap_p;
  48         int max = ll_entry_count(struct i2c_adapter, i2c);
  49         int             i;
  50         unsigned long   addr;
  51
  52         if (gd->reloc_off == 0)
  53                 return;
  54
  55         for (i = 0; i < max; i++) {
  56                 /* adapter itself */
  57                 addr = (unsigned long)i2c_adap_p;
  58                 addr += gd->reloc_off;
  59                 i2c_adap_p = (struct i2c_adapter *)addr;
  60                 /* i2c_init() */
  61                 addr = (unsigned long)i2c_adap_p->init;
  62                 addr += gd->reloc_off;
  63                 i2c_adap_p->init = (void (*)(int, int))addr;
  64                 /* i2c_probe() */
  65                 addr = (unsigned long)i2c_adap_p->probe;
  66                 addr += gd->reloc_off;
  67                 i2c_adap_p->probe = (int (*)(uint8_t))addr;
  68                 /* i2c_read() */
  69                 addr = (unsigned long)i2c_adap_p->read;
  70                 addr += gd->reloc_off;
  71                 i2c_adap_p->read = (int (*)(uint8_t, uint, int, uint8_t *,
  72                                         int))addr;
  73                 /* i2c_write() */
  74                 addr = (unsigned long)i2c_adap_p->write;
  75                 addr += gd->reloc_off;
  76                 i2c_adap_p->write = (int (*)(uint8_t, uint, int, uint8_t *,
  77                                         int))addr;
  78                 /* i2c_set_bus_speed() */
  79                 addr = (unsigned long)i2c_adap_p->set_bus_speed;
  80                 addr += gd->reloc_off;
  81                 i2c_adap_p->set_bus_speed = (uint (*)(uint))addr;
  82                 /* name */
  83                 addr = (unsigned long)i2c_adap_p->name;
  84                 addr += gd->reloc_off;
  85                 i2c_adap_p->name = (char *)addr;
  86                 tmp++;
  87                 i2c_adap_p = tmp;
  88         }
  89 #endif
  90 }
  91
  92 #ifndef CONFIG_SYS_I2C_DIRECT_BUS
  93 /*
  94  * i2c_mux_set()
  95  * -------------
  96  *
  97  * This turns on the given channel on I2C multiplexer chip connected to
  98  * a given I2C adapter directly or via other multiplexers. In the latter
  99  * case the entire multiplexer chain must be initialized first starting
 100  * with the one connected directly to the adapter. When disabling a chain
 101  * muxes must be programmed in reverse order, starting with the one
 102  * farthest from the adapter.
 103  *
 104  * mux_id is the multiplexer chip type from defined in i2c.h. So far only
 105  * NXP (Philips) PCA954x multiplexers are supported. Switches are NOT
 106  * supported (anybody uses them?)
 107  */
 108
 109 static int i2c_mux_set(struct i2c_adapter *adap, int mux_id, int chip,
 110                         int channel)
 111 {
 112         uint8_t buf;
 113         int ret;
 114
 115         /* channel < 0 - turn off the mux */
 116         if (channel < 0) {
 117                 buf = 0;
 118                 ret = adap->write(adap, chip, 0, 0, &buf, 1);
 119                 if (ret)
 120                         printf("%s: Could not turn off the mux.\n", __func__);
 121                 return ret;
 122         }
 123
 124         switch (mux_id) {
 125         case I2C_MUX_PCA9540_ID:
 126         case I2C_MUX_PCA9542_ID:
 127                 if (channel > 1)
 128                         return -1;
 129                 buf = (uint8_t)((channel & 0x01) | (1 << 2));
 130                 break;
 131         case I2C_MUX_PCA9544_ID:
 132                 if (channel > 3)
 133                         return -1;
 134                 buf = (uint8_t)((channel & 0x03) | (1 << 2));
 135                 break;
 136         case I2C_MUX_PCA9547_ID:
 137                 if (channel > 7)
 138                         return -1;
 139                 buf = (uint8_t)((channel & 0x07) | (1 << 3));
 140                 break;
 141         case I2C_MUX_PCA9548_ID:
 142                 if (channel > 7)
 143                         return -1;
 144                 buf = (uint8_t)(0x01 << channel);
 145                 break;
 146         default:
 147                 printf("%s: wrong mux id: %d\n", __func__, mux_id);
 148                 return -1;
 149         }
 150
 151         ret = adap->write(adap, chip, 0, 0, &buf, 1);
 152         if (ret)
 153                 printf("%s: could not set mux: id: %d chip: %x channel: %d\n",
 154                        __func__, mux_id, chip, channel);
 155         return ret;
 156 }
 157
 158 static int i2c_mux_set_all(void)
 159 {
 160         struct i2c_bus_hose *i2c_bus_tmp = &i2c_bus[I2C_BUS];
 161         int i;
 162
 163         /* Connect requested bus if behind muxes */
 164         if (i2c_bus_tmp->next_hop[0].chip != 0) {
 165                 /* Set all muxes along the path to that bus */
 166                 for (i = 0; i < CONFIG_SYS_I2C_MAX_HOPS; i++) {
 167                         int     ret;
 168
 169                         if (i2c_bus_tmp->next_hop[i].chip == 0)
 170                                 break;
 171
 172                         ret = i2c_mux_set(I2C_ADAP,
 173                                         i2c_bus_tmp->next_hop[i].mux.id,
 174                                         i2c_bus_tmp->next_hop[i].chip,
 175                                         i2c_bus_tmp->next_hop[i].channel);
 176                         if (ret != 0)
 177                                 return ret;
 178                 }
 179         }
 180         return 0;
 181 }
 182
 183 static int i2c_mux_disconnet_all(void)
 184 {
 185         struct  i2c_bus_hose *i2c_bus_tmp = &i2c_bus[I2C_BUS];
 186         int     i;
 187         uint8_t buf;
 188
 189         if (I2C_ADAP->init_done == 0)
 190                 return 0;
 191
 192         /* Disconnect current bus (turn off muxes if any) */
 193         if ((i2c_bus_tmp->next_hop[0].chip != 0) &&
 194             (I2C_ADAP->init_done != 0)) {
 195                 i = CONFIG_SYS_I2C_MAX_HOPS;
 196                 do {
 197                         uint8_t chip;
 198                         int ret;
 199
 200                         chip = i2c_bus_tmp->next_hop[--i].chip;
 201                         if (chip == 0)
 202                                 continue;
 203
 204                         ret = I2C_ADAP->write(I2C_ADAP, chip, 0, 0, &buf, 1);
 205                         if (ret != 0) {
 206                                 printf("i2c: mux diconnect error\n");
 207                                 return ret;
 208                         }
 209                 } while (i > 0);
 210         }
 211
 212         return 0;
 213 }
 214 #endif
 215
 216 /*
 217  * i2c_init_bus():
 218  * ---------------
 219  *
 220  * Initializes one bus. Will initialize the parent adapter. No current bus
 221  * changes, no mux (if any) setup.
 222  */
 223 static void i2c_init_bus(unsigned int bus_no, int speed, int slaveaddr)
 224 {
 225         if (bus_no >= CONFIG_SYS_NUM_I2C_BUSES)
 226                 return;
 227
 228         I2C_ADAP->init(I2C_ADAP, speed, slaveaddr);
 229
 230         if (gd->flags & GD_FLG_RELOC) {
 231                 I2C_ADAP->init_done = 1;
 232                 I2C_ADAP->speed = speed;
 233                 I2C_ADAP->slaveaddr = slaveaddr;
 234         }
 235 }
 236
 237 /* implement possible board specific board init */
 238 static void __def_i2c_init_board(void)
 239 {
 240 }
 241 void i2c_init_board(void)
 242         __attribute__((weak, alias("__def_i2c_init_board")));
 243
 244 /*
 245  * i2c_init_all():
 246  *
 247  * not longer needed, will deleted. Actual init the SPD_BUS
 248  * for compatibility.
 249  * i2c_adap[] must be initialized beforehead with function pointers and
 250  * data, including speed and slaveaddr.
 251  */
 252 void i2c_init_all(void)
 253 {
 254         i2c_init_board();
 255         i2c_set_bus_num(CONFIG_SYS_SPD_BUS_NUM);
 256         return;
 257 }
 258
 259 /*
 260  * i2c_get_bus_num():
 261  * ------------------
 262  *
 263  *  Returns index of currently active I2C bus.  Zero-based.
 264  */
 265 unsigned int i2c_get_bus_num(void)
 266 {
 267         return gd->cur_i2c_bus;
 268 }
 269
 270 /*
 271  * i2c_set_bus_num():
 272  * ------------------
 273  *
 274  *  Change the active I2C bus. Subsequent read/write calls will
 275  *  go to this one. Sets all of the muxes in a proper condition
 276  *  if that bus is behind muxes.
 277  *  If previously selected bus is behind the muxes turns off all the
 278  *  muxes along the path to that bus.
 279  *
 280  *      bus - bus index, zero based
 281  *
 282  *      Returns: 0 on success, not 0 on failure
 283  */
 284 int i2c_set_bus_num(unsigned int bus)
 285 {
 286         int max = ll_entry_count(struct i2c_adapter, i2c);
 287
 288         if (I2C_ADAPTER(bus) >= max) {
 289                 printf("Error, wrong i2c adapter %d max %d possible\n",
 290                        I2C_ADAPTER(bus), max);
 291                 return -2;
 292         }
 293 #ifndef CONFIG_SYS_I2C_DIRECT_BUS
 294         if (bus >= CONFIG_SYS_NUM_I2C_BUSES)
 295                 return -1;
 296 #endif
 297
 298         if ((bus == I2C_BUS) && (I2C_ADAP->init_done > 0))
 299                 return 0;
 300
 301 #ifndef CONFIG_SYS_I2C_DIRECT_BUS
 302         i2c_mux_disconnet_all();
 303 #endif
 304
 305         gd->cur_i2c_bus = bus;
 306         if (I2C_ADAP->init_done == 0)
 307                 i2c_init_bus(bus, I2C_ADAP->speed, I2C_ADAP->slaveaddr);
 308
 309 #ifndef CONFIG_SYS_I2C_DIRECT_BUS
 310         i2c_mux_set_all();
 311 #endif
 312         return 0;
 313 }
 314
 315 /*
 316  * Probe the given I2C chip address.  Returns 0 if a chip responded,
 317  * not 0 on failure.
 318  */
 319 int i2c_probe(uint8_t chip)
 320 {
 321         return I2C_ADAP->probe(I2C_ADAP, chip);
 322 }
 323
 324 /*
 325  * Read/Write interface:
 326  *   chip:    I2C chip address, range 0..127
 327  *   addr:    Memory (register) address within the chip
 328  *   alen:    Number of bytes to use for addr (typically 1, 2 for larger
 329  *              memories, 0 for register type devices with only one
 330  *              register)
 331  *   buffer:  Where to read/write the data
 332  *   len:     How many bytes to read/write
 333  *
 334  *   Returns: 0 on success, not 0 on failure
 335  */
 336 int i2c_read(uint8_t chip, unsigned int addr, int alen,
 337                                 uint8_t *buffer, int len)
 338 {
 339         return I2C_ADAP->read(I2C_ADAP, chip, addr, alen, buffer, len);
 340 }
 341
 342 int i2c_write(uint8_t chip, unsigned int addr, int alen,
 343                                 uint8_t *buffer, int len)
 344 {
 345         return I2C_ADAP->write(I2C_ADAP, chip, addr, alen, buffer, len);
 346 }
 347
 348 unsigned int i2c_set_bus_speed(unsigned int speed)
 349 {
 350         unsigned int ret;
 351
 352         if (I2C_ADAP->set_bus_speed == NULL)
 353                 return 0;
 354         ret = I2C_ADAP->set_bus_speed(I2C_ADAP, speed);
 355         if (gd->flags & GD_FLG_RELOC)
 356                 I2C_ADAP->speed = ret;
 357
 358         return ret;
 359 }
 360
 361 unsigned int i2c_get_bus_speed(void)
 362 {
 363         struct i2c_adapter *cur = I2C_ADAP;
 364         return cur->speed;
 365 }
 366
 367 uint8_t i2c_reg_read(uint8_t addr, uint8_t reg)
 368 {
 369         uint8_t buf;
 370
 371 #ifdef CONFIG_8xx
 372         /* MPC8xx needs this.  Maybe one day we can get rid of it. */
 373         /* maybe it is now the time for it ... */
 374         i2c_set_bus_num(i2c_get_bus_num());
 375 #endif
 376         i2c_read(addr, reg, 1, &buf, 1);
 377
 378 #ifdef DEBUG
 379         printf("%s: bus=%d addr=0x%02x, reg=0x%02x, val=0x%02x\n",
 380                __func__, i2c_get_bus_num(), addr, reg, buf);
 381 #endif
 382
 383         return buf;
 384 }
 385
 386 void i2c_reg_write(uint8_t addr, uint8_t reg, uint8_t val)
 387 {
 388 #ifdef CONFIG_8xx
 389         /* MPC8xx needs this.  Maybe one day we can get rid of it. */
 390         /* maybe it is now the time for it ... */
 391         i2c_set_bus_num(i2c_get_bus_num());
 392 #endif
 393
 394 #ifdef DEBUG
 395         printf("%s: bus=%d addr=0x%02x, reg=0x%02x, val=0x%02x\n",
 396                __func__, i2c_get_bus_num(), addr, reg, val);
 397 #endif
 398
 399         i2c_write(addr, reg, 1, &val, 1);
 400 }
 401
 402 void __i2c_init(int speed, int slaveaddr)
 403 {
 404         i2c_init_bus(i2c_get_bus_num(), speed, slaveaddr);
 405 }
 406 void i2c_init(int speed, int slaveaddr)
 407         __attribute__((weak, alias("__i2c_init")));