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