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 *)addr;
  60                 /* i2c_probe() */
  61                 addr = (unsigned long)i2c_adap_p->probe;
  62                 addr += gd->reloc_off;
  63                 i2c_adap_p->probe = (void *)addr;
  64                 /* i2c_read() */
  65                 addr = (unsigned long)i2c_adap_p->read;
  66                 addr += gd->reloc_off;
  67                 i2c_adap_p->read = (void *)addr;
  68                 /* i2c_write() */
  69                 addr = (unsigned long)i2c_adap_p->write;
  70                 addr += gd->reloc_off;
  71                 i2c_adap_p->write = (void *)addr;
  72                 /* i2c_set_bus_speed() */
  73                 addr = (unsigned long)i2c_adap_p->set_bus_speed;
  74                 addr += gd->reloc_off;
  75                 i2c_adap_p->set_bus_speed = (void *)addr;
  76                 /* name */
  77                 addr = (unsigned long)i2c_adap_p->name;
  78                 addr += gd->reloc_off;
  79                 i2c_adap_p->name = (char *)addr;
  80                 tmp++;
  81                 i2c_adap_p = tmp;
  82         }
  83 #endif
  84 }
  85
  86 #ifndef CONFIG_SYS_I2C_DIRECT_BUS
  87 /*
  88  * i2c_mux_set()
  89  * -------------
  90  *
  91  * This turns on the given channel on I2C multiplexer chip connected to
  92  * a given I2C adapter directly or via other multiplexers. In the latter
  93  * case the entire multiplexer chain must be initialized first starting
  94  * with the one connected directly to the adapter. When disabling a chain
  95  * muxes must be programmed in reverse order, starting with the one
  96  * farthest from the adapter.
  97  *
  98  * mux_id is the multiplexer chip type from defined in i2c.h. So far only
  99  * NXP (Philips) PCA954x multiplexers are supported. Switches are NOT
 100  * supported (anybody uses them?)
 101  */
 102
 103 static int i2c_mux_set(struct i2c_adapter *adap, int mux_id, int chip,
 104                         int channel)
 105 {
 106         uint8_t buf;
 107         int ret;
 108
 109         /* channel < 0 - turn off the mux */
 110         if (channel < 0) {
 111                 buf = 0;
 112                 ret = adap->write(adap, chip, 0, 0, &buf, 1);
 113                 if (ret)
 114                         printf("%s: Could not turn off the mux.\n", __func__);
 115                 return ret;
 116         }
 117
 118         switch (mux_id) {
 119         case I2C_MUX_PCA9540_ID:
 120         case I2C_MUX_PCA9542_ID:
 121                 if (channel > 1)
 122                         return -1;
 123                 buf = (uint8_t)((channel & 0x01) | (1 << 2));
 124                 break;
 125         case I2C_MUX_PCA9544_ID:
 126                 if (channel > 3)
 127                         return -1;
 128                 buf = (uint8_t)((channel & 0x03) | (1 << 2));
 129                 break;
 130         case I2C_MUX_PCA9547_ID:
 131                 if (channel > 7)
 132                         return -1;
 133                 buf = (uint8_t)((channel & 0x07) | (1 << 3));
 134                 break;
 135         case I2C_MUX_PCA9548_ID:
 136                 if (channel > 7)
 137                         return -1;
 138                 buf = (uint8_t)(0x01 << channel);
 139                 break;
 140         default:
 141                 printf("%s: wrong mux id: %d\n", __func__, mux_id);
 142                 return -1;
 143         }
 144
 145         ret = adap->write(adap, chip, 0, 0, &buf, 1);
 146         if (ret)
 147                 printf("%s: could not set mux: id: %d chip: %x channel: %d\n",
 148                        __func__, mux_id, chip, channel);
 149         return ret;
 150 }
 151
 152 static int i2c_mux_set_all(void)
 153 {
 154         struct i2c_bus_hose *i2c_bus_tmp = &i2c_bus[I2C_BUS];
 155         int i;
 156
 157         /* Connect requested bus if behind muxes */
 158         if (i2c_bus_tmp->next_hop[0].chip != 0) {
 159                 /* Set all muxes along the path to that bus */
 160                 for (i = 0; i < CONFIG_SYS_I2C_MAX_HOPS; i++) {
 161                         int     ret;
 162
 163                         if (i2c_bus_tmp->next_hop[i].chip == 0)
 164                                 break;
 165
 166                         ret = i2c_mux_set(I2C_ADAP,
 167                                         i2c_bus_tmp->next_hop[i].mux.id,
 168                                         i2c_bus_tmp->next_hop[i].chip,
 169                                         i2c_bus_tmp->next_hop[i].channel);
 170                         if (ret != 0)
 171                                 return ret;
 172                 }
 173         }
 174         return 0;
 175 }
 176
 177 static int i2c_mux_disconnect_all(void)
 178 {
 179         struct  i2c_bus_hose *i2c_bus_tmp = &i2c_bus[I2C_BUS];
 180         int     i;
 181         uint8_t buf = 0;
 182
 183         if (I2C_ADAP->init_done == 0)
 184                 return 0;
 185
 186         /* Disconnect current bus (turn off muxes if any) */
 187         if ((i2c_bus_tmp->next_hop[0].chip != 0) &&
 188             (I2C_ADAP->init_done != 0)) {
 189                 i = CONFIG_SYS_I2C_MAX_HOPS;
 190                 do {
 191                         uint8_t chip;
 192                         int ret;
 193
 194                         chip = i2c_bus_tmp->next_hop[--i].chip;
 195                         if (chip == 0)
 196                                 continue;
 197
 198                         ret = I2C_ADAP->write(I2C_ADAP, chip, 0, 0, &buf, 1);
 199                         if (ret != 0) {
 200                                 printf("i2c: mux disconnect error\n");
 201                                 return ret;
 202                         }
 203                 } while (i > 0);
 204         }
 205
 206         return 0;
 207 }
 208 #endif
 209
 210 /*
 211  * i2c_init_bus():
 212  * ---------------
 213  *
 214  * Initializes one bus. Will initialize the parent adapter. No current bus
 215  * changes, no mux (if any) setup.
 216  */
 217 static void i2c_init_bus(unsigned int bus_no, int speed, int slaveaddr)
 218 {
 219         if (bus_no >= CONFIG_SYS_NUM_I2C_BUSES)
 220                 return;
 221
 222         I2C_ADAP->init(I2C_ADAP, speed, slaveaddr);
 223
 224         if (gd->flags & GD_FLG_RELOC) {
 225                 I2C_ADAP->init_done = 1;
 226                 I2C_ADAP->speed = speed;
 227                 I2C_ADAP->slaveaddr = slaveaddr;
 228         }
 229 }
 230
 231 /* implement possible board specific board init */
 232 __weak void i2c_init_board(void)
 233 {
 234 }
 235
 236 /*
 237  * i2c_init_all():
 238  *
 239  * not longer needed, will deleted. Actual init the SPD_BUS
 240  * for compatibility.
 241  * i2c_adap[] must be initialized beforehead with function pointers and
 242  * data, including speed and slaveaddr.
 243  */
 244 void i2c_init_all(void)
 245 {
 246         i2c_init_board();
 247         i2c_set_bus_num(CONFIG_SYS_SPD_BUS_NUM);
 248         return;
 249 }
 250
 251 /*
 252  * i2c_get_bus_num():
 253  * ------------------
 254  *
 255  *  Returns index of currently active I2C bus.  Zero-based.
 256  */
 257 unsigned int i2c_get_bus_num(void)
 258 {
 259         return gd->cur_i2c_bus;
 260 }
 261
 262 /*
 263  * i2c_set_bus_num():
 264  * ------------------
 265  *
 266  *  Change the active I2C bus. Subsequent read/write calls will
 267  *  go to this one. Sets all of the muxes in a proper condition
 268  *  if that bus is behind muxes.
 269  *  If previously selected bus is behind the muxes turns off all the
 270  *  muxes along the path to that bus.
 271  *
 272  *      bus - bus index, zero based
 273  *
 274  *      Returns: 0 on success, not 0 on failure
 275  */
 276 int i2c_set_bus_num(unsigned int bus)
 277 {
 278         int max;
 279
 280         if ((bus == I2C_BUS) && (I2C_ADAP->init_done > 0))
 281                 return 0;
 282
 283 #ifndef CONFIG_SYS_I2C_DIRECT_BUS
 284         if (bus >= CONFIG_SYS_NUM_I2C_BUSES)
 285                 return -1;
 286 #endif
 287
 288         max = ll_entry_count(struct i2c_adapter, i2c);
 289         if (I2C_ADAPTER(bus) >= max) {
 290                 printf("Error, wrong i2c adapter %d max %d possible\n",
 291                        I2C_ADAPTER(bus), max);
 292                 return -2;
 293         }
 294
 295 #ifndef CONFIG_SYS_I2C_DIRECT_BUS
 296         i2c_mux_disconnect_all();
 297 #endif
 298
 299         gd->cur_i2c_bus = bus;
 300         if (I2C_ADAP->init_done == 0)
 301                 i2c_init_bus(bus, I2C_ADAP->speed, I2C_ADAP->slaveaddr);
 302
 303 #ifndef CONFIG_SYS_I2C_DIRECT_BUS
 304         i2c_mux_set_all();
 305 #endif
 306         return 0;
 307 }
 308
 309 /*
 310  * Probe the given I2C chip address.  Returns 0 if a chip responded,
 311  * not 0 on failure.
 312  */
 313 int i2c_probe(uint8_t chip)
 314 {
 315         return I2C_ADAP->probe(I2C_ADAP, chip);
 316 }
 317
 318 /*
 319  * Read/Write interface:
 320  *   chip:    I2C chip address, range 0..127
 321  *   addr:    Memory (register) address within the chip
 322  *   alen:    Number of bytes to use for addr (typically 1, 2 for larger
 323  *              memories, 0 for register type devices with only one
 324  *              register)
 325  *   buffer:  Where to read/write the data
 326  *   len:     How many bytes to read/write
 327  *
 328  *   Returns: 0 on success, not 0 on failure
 329  */
 330 int i2c_read(uint8_t chip, unsigned int addr, int alen,
 331                                 uint8_t *buffer, int len)
 332 {
 333         return I2C_ADAP->read(I2C_ADAP, chip, addr, alen, buffer, len);
 334 }
 335
 336 int i2c_write(uint8_t chip, unsigned int addr, int alen,
 337                                 uint8_t *buffer, int len)
 338 {
 339         return I2C_ADAP->write(I2C_ADAP, chip, addr, alen, buffer, len);
 340 }
 341
 342 unsigned int i2c_set_bus_speed(unsigned int speed)
 343 {
 344         unsigned int ret;
 345
 346         if (I2C_ADAP->set_bus_speed == NULL)
 347                 return 0;
 348         ret = I2C_ADAP->set_bus_speed(I2C_ADAP, speed);
 349         if (gd->flags & GD_FLG_RELOC)
 350                 I2C_ADAP->speed = (ret == 0) ? speed : 0;
 351
 352         return ret;
 353 }
 354
 355 unsigned int i2c_get_bus_speed(void)
 356 {
 357         struct i2c_adapter *cur = I2C_ADAP;
 358         return cur->speed;
 359 }
 360
 361 uint8_t i2c_reg_read(uint8_t addr, uint8_t reg)
 362 {
 363         uint8_t buf;
 364
 365 #ifdef CONFIG_8xx
 366         /* MPC8xx needs this.  Maybe one day we can get rid of it. */
 367         /* maybe it is now the time for it ... */
 368         i2c_set_bus_num(i2c_get_bus_num());
 369 #endif
 370         i2c_read(addr, reg, 1, &buf, 1);
 371
 372 #ifdef DEBUG
 373         printf("%s: bus=%d addr=0x%02x, reg=0x%02x, val=0x%02x\n",
 374                __func__, i2c_get_bus_num(), addr, reg, buf);
 375 #endif
 376
 377         return buf;
 378 }
 379
 380 void i2c_reg_write(uint8_t addr, uint8_t reg, uint8_t val)
 381 {
 382 #ifdef CONFIG_8xx
 383         /* MPC8xx needs this.  Maybe one day we can get rid of it. */
 384         /* maybe it is now the time for it ... */
 385         i2c_set_bus_num(i2c_get_bus_num());
 386 #endif
 387
 388 #ifdef DEBUG
 389         printf("%s: bus=%d addr=0x%02x, reg=0x%02x, val=0x%02x\n",
 390                __func__, i2c_get_bus_num(), addr, reg, val);
 391 #endif
 392
 393         i2c_write(addr, reg, 1, &val, 1);
 394 }
 395
 396 __weak void i2c_init(int speed, int slaveaddr)
 397 {
 398         i2c_init_bus(i2c_get_bus_num(), speed, slaveaddr);
 399 }