drivers/i2c/i2c_core.c

   1 /*
   2  * Copyright (C) 2009 Sergey Kubushyn <[email protected]>
   3  *
   4  * (C) Copyright 2012
   5  * Heiko Schocher, DENX Software Engineering, [email protected].
   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         default:
 142                 printf("%s: wrong mux id: %d\n", __func__, mux_id);
 143                 return -1;
 144         }
 145
 146         ret = adap->write(adap, chip, 0, 0, &buf, 1);
 147         if (ret)
 148                 printf("%s: could not set mux: id: %d chip: %x channel: %d\n",
 149                        __func__, mux_id, chip, channel);
 150         return ret;
 151 }
 152
 153 static int i2c_mux_set_all(void)
 154 {
 155         struct i2c_bus_hose *i2c_bus_tmp = &i2c_bus[I2C_BUS];
 156         int i;
 157
 158         /* Connect requested bus if behind muxes */
 159         if (i2c_bus_tmp->next_hop[0].chip != 0) {
 160                 /* Set all muxes along the path to that bus */
 161                 for (i = 0; i < CONFIG_SYS_I2C_MAX_HOPS; i++) {
 162                         int     ret;
 163
 164                         if (i2c_bus_tmp->next_hop[i].chip == 0)
 165                                 break;
 166
 167                         ret = i2c_mux_set(I2C_ADAP,
 168                                         i2c_bus_tmp->next_hop[i].mux.id,
 169                                         i2c_bus_tmp->next_hop[i].chip,
 170                                         i2c_bus_tmp->next_hop[i].channel);
 171                         if (ret != 0)
 172                                 return ret;
 173                 }
 174         }
 175         return 0;
 176 }
 177
 178 static int i2c_mux_disconnet_all(void)
 179 {
 180         struct  i2c_bus_hose *i2c_bus_tmp = &i2c_bus[I2C_BUS];
 181         int     i;
 182         uint8_t buf;
 183
 184         if (I2C_ADAP->init_done == 0)
 185                 return 0;
 186
 187         /* Disconnect current bus (turn off muxes if any) */
 188         if ((i2c_bus_tmp->next_hop[0].chip != 0) &&
 189             (I2C_ADAP->init_done != 0)) {
 190                 i = CONFIG_SYS_I2C_MAX_HOPS;
 191                 do {
 192                         uint8_t chip;
 193                         int ret;
 194
 195                         chip = i2c_bus_tmp->next_hop[--i].chip;
 196                         if (chip == 0)
 197                                 continue;
 198
 199                         ret = I2C_ADAP->write(I2C_ADAP, chip, 0, 0, &buf, 1);
 200                         if (ret != 0) {
 201                                 printf("i2c: mux diconnect error\n");
 202                                 return ret;
 203                         }
 204                 } while (i > 0);
 205         }
 206
 207         return 0;
 208 }
 209 #endif
 210
 211 /*
 212  * i2c_init_bus():
 213  * ---------------
 214  *
 215  * Initializes one bus. Will initialize the parent adapter. No current bus
 216  * changes, no mux (if any) setup.
 217  */
 218 static void i2c_init_bus(unsigned int bus_no, int speed, int slaveaddr)
 219 {
 220         if (bus_no >= CONFIG_SYS_NUM_I2C_BUSES)
 221                 return;
 222
 223         I2C_ADAP->init(I2C_ADAP, speed, slaveaddr);
 224
 225         if (gd->flags & GD_FLG_RELOC) {
 226                 I2C_ADAP->init_done = 1;
 227                 I2C_ADAP->speed = speed;
 228                 I2C_ADAP->slaveaddr = slaveaddr;
 229         }
 230 }
 231
 232 /* implement possible board specific board init */
 233 static void __def_i2c_init_board(void)
 234 {
 235 }
 236 void i2c_init_board(void)
 237         __attribute__((weak, alias("__def_i2c_init_board")));
 238
 239 /*
 240  * i2c_init_all():
 241  *
 242  * not longer needed, will deleted. Actual init the SPD_BUS
 243  * for compatibility.
 244  * i2c_adap[] must be initialized beforehead with function pointers and
 245  * data, including speed and slaveaddr.
 246  */
 247 void i2c_init_all(void)
 248 {
 249         i2c_init_board();
 250         i2c_set_bus_num(CONFIG_SYS_SPD_BUS_NUM);
 251         return;
 252 }
 253
 254 /*
 255  * i2c_get_bus_num():
 256  * ------------------
 257  *
 258  *  Returns index of currently active I2C bus.  Zero-based.
 259  */
 260 unsigned int i2c_get_bus_num(void)
 261 {
 262         return gd->cur_i2c_bus;
 263 }
 264
 265 /*
 266  * i2c_set_bus_num():
 267  * ------------------
 268  *
 269  *  Change the active I2C bus. Subsequent read/write calls will
 270  *  go to this one. Sets all of the muxes in a proper condition
 271  *  if that bus is behind muxes.
 272  *  If previously selected bus is behind the muxes turns off all the
 273  *  muxes along the path to that bus.
 274  *
 275  *      bus - bus index, zero based
 276  *
 277  *      Returns: 0 on success, not 0 on failure
 278  */
 279 int i2c_set_bus_num(unsigned int bus)
 280 {
 281         int max = ll_entry_count(struct i2c_adapter, i2c);
 282
 283         if (I2C_ADAPTER(bus) >= max) {
 284                 printf("Error, wrong i2c adapter %d max %d possible\n",
 285                        I2C_ADAPTER(bus), max);
 286                 return -2;
 287         }
 288 #ifndef CONFIG_SYS_I2C_DIRECT_BUS
 289         if (bus >= CONFIG_SYS_NUM_I2C_BUSES)
 290                 return -1;
 291 #endif
 292
 293         if ((bus == I2C_BUS) && (I2C_ADAP->init_done > 0))
 294                 return 0;
 295
 296 #ifndef CONFIG_SYS_I2C_DIRECT_BUS
 297         i2c_mux_disconnet_all();
 298 #endif
 299
 300         gd->cur_i2c_bus = bus;
 301         if (I2C_ADAP->init_done == 0)
 302                 i2c_init_bus(bus, I2C_ADAP->speed, I2C_ADAP->slaveaddr);
 303
 304 #ifndef CONFIG_SYS_I2C_DIRECT_BUS
 305         i2c_mux_set_all();
 306 #endif
 307         return 0;
 308 }
 309
 310 /*
 311  * Probe the given I2C chip address.  Returns 0 if a chip responded,
 312  * not 0 on failure.
 313  */
 314 int i2c_probe(uint8_t chip)
 315 {
 316         return I2C_ADAP->probe(I2C_ADAP, chip);
 317 }
 318
 319 /*
 320  * Read/Write interface:
 321  *   chip:    I2C chip address, range 0..127
 322  *   addr:    Memory (register) address within the chip
 323  *   alen:    Number of bytes to use for addr (typically 1, 2 for larger
 324  *              memories, 0 for register type devices with only one
 325  *              register)
 326  *   buffer:  Where to read/write the data
 327  *   len:     How many bytes to read/write
 328  *
 329  *   Returns: 0 on success, not 0 on failure
 330  */
 331 int i2c_read(uint8_t chip, unsigned int addr, int alen,
 332                                 uint8_t *buffer, int len)
 333 {
 334         return I2C_ADAP->read(I2C_ADAP, chip, addr, alen, buffer, len);
 335 }
 336
 337 int i2c_write(uint8_t chip, unsigned int addr, int alen,
 338                                 uint8_t *buffer, int len)
 339 {
 340         return I2C_ADAP->write(I2C_ADAP, chip, addr, alen, buffer, len);
 341 }
 342
 343 unsigned int i2c_set_bus_speed(unsigned int speed)
 344 {
 345         unsigned int ret;
 346
 347         if (I2C_ADAP->set_bus_speed == NULL)
 348                 return 0;
 349         ret = I2C_ADAP->set_bus_speed(I2C_ADAP, speed);
 350         if (gd->flags & GD_FLG_RELOC)
 351                 I2C_ADAP->speed = ret;
 352
 353         return ret;
 354 }
 355
 356 unsigned int i2c_get_bus_speed(void)
 357 {
 358         struct i2c_adapter *cur = I2C_ADAP;
 359         return cur->speed;
 360 }
 361
 362 uint8_t i2c_reg_read(uint8_t addr, uint8_t reg)
 363 {
 364         uint8_t buf;
 365
 366 #ifdef CONFIG_8xx
 367         /* MPC8xx needs this.  Maybe one day we can get rid of it. */
 368         /* maybe it is now the time for it ... */
 369         i2c_set_bus_num(i2c_get_bus_num());
 370 #endif
 371         i2c_read(addr, reg, 1, &buf, 1);
 372
 373 #ifdef DEBUG
 374         printf("%s: bus=%d addr=0x%02x, reg=0x%02x, val=0x%02x\n",
 375                __func__, i2c_get_bus_num(), addr, reg, buf);
 376 #endif
 377
 378         return buf;
 379 }
 380
 381 void i2c_reg_write(uint8_t addr, uint8_t reg, uint8_t val)
 382 {
 383 #ifdef CONFIG_8xx
 384         /* MPC8xx needs this.  Maybe one day we can get rid of it. */
 385         /* maybe it is now the time for it ... */
 386         i2c_set_bus_num(i2c_get_bus_num());
 387 #endif
 388
 389 #ifdef DEBUG
 390         printf("%s: bus=%d addr=0x%02x, reg=0x%02x, val=0x%02x\n",
 391                __func__, i2c_get_bus_num(), addr, reg, val);
 392 #endif
 393
 394         i2c_write(addr, reg, 1, &val, 1);
 395 }
 396
 397 void __i2c_init(int speed, int slaveaddr)
 398 {
 399         i2c_init_bus(i2c_get_bus_num(), speed, slaveaddr);
 400 }
 401 void i2c_init(int speed, int slaveaddr)
 402         __attribute__((weak, alias("__i2c_init")));