drivers/i2c/tegra_i2c.c

   1 /*
   2  * Copyright (c) 2012 The Chromium OS Authors. All rights reserved.
   3  * Copyright (c) 2010-2011 NVIDIA Corporation
   4  *  NVIDIA Corporation <www.nvidia.com>
   5  *
   6  * SPDX-License-Identifier:     GPL-2.0+
   7  */
   8
   9 #include <common.h>
  10 #include <fdtdec.h>
  11 #include <i2c.h>
  12 #include <asm/io.h>
  13 #include <asm/arch/clock.h>
  14 #include <asm/arch/funcmux.h>
  15 #include <asm/arch/gpio.h>
  16 #include <asm/arch/pinmux.h>
  17 #include <asm/arch-tegra/clk_rst.h>
  18 #include <asm/arch-tegra/tegra_i2c.h>
  19
  20 DECLARE_GLOBAL_DATA_PTR;
  21
  22 /* Information about i2c controller */
  23 struct i2c_bus {
  24         int                     id;
  25         enum periph_id          periph_id;
  26         int                     speed;
  27         int                     pinmux_config;
  28         struct i2c_control      *control;
  29         struct i2c_ctlr         *regs;
  30         int                     is_dvc; /* DVC type, rather than I2C */
  31         int                     is_scs; /* single clock source (T114+) */
  32         int                     inited; /* bus is inited */
  33 };
  34
  35 static struct i2c_bus i2c_controllers[TEGRA_I2C_NUM_CONTROLLERS];
  36
  37 static void set_packet_mode(struct i2c_bus *i2c_bus)
  38 {
  39         u32 config;
  40
  41         config = I2C_CNFG_NEW_MASTER_FSM_MASK | I2C_CNFG_PACKET_MODE_MASK;
  42
  43         if (i2c_bus->is_dvc) {
  44                 struct dvc_ctlr *dvc = (struct dvc_ctlr *)i2c_bus->regs;
  45
  46                 writel(config, &dvc->cnfg);
  47         } else {
  48                 writel(config, &i2c_bus->regs->cnfg);
  49                 /*
  50                  * program I2C_SL_CNFG.NEWSL to ENABLE. This fixes probe
  51                  * issues, i.e., some slaves may be wrongly detected.
  52                  */
  53                 setbits_le32(&i2c_bus->regs->sl_cnfg, I2C_SL_CNFG_NEWSL_MASK);
  54         }
  55 }
  56
  57 static void i2c_reset_controller(struct i2c_bus *i2c_bus)
  58 {
  59         /* Reset I2C controller. */
  60         reset_periph(i2c_bus->periph_id, 1);
  61
  62         /* re-program config register to packet mode */
  63         set_packet_mode(i2c_bus);
  64 }
  65
  66 static void i2c_init_controller(struct i2c_bus *i2c_bus)
  67 {
  68         /*
  69          * Use PLLP - DP-04508-001_v06 datasheet indicates a divisor of 8
  70          * here, in section 23.3.1, but in fact we seem to need a factor of
  71          * 16 to get the right frequency.
  72          */
  73         clock_start_periph_pll(i2c_bus->periph_id, CLOCK_ID_PERIPH,
  74                 i2c_bus->speed * 2 * 8);
  75
  76         if (i2c_bus->is_scs) {
  77                 /*
  78                  * T114 I2C went to a single clock source for standard/fast and
  79                  * HS clock speeds. The new clock rate setting calculation is:
  80                  *  SCL = CLK_SOURCE.I2C /
  81                  *   (CLK_MULT_STD_FAST_MODE * (I2C_CLK_DIV_STD_FAST_MODE+1) *
  82                  *   I2C FREQUENCY DIVISOR) as per the T114 TRM (sec 30.3.1).
  83                  *
  84                  * NOTE: We do this here, after the initial clock/pll start,
  85                  * because if we read the clk_div reg before the controller
  86                  * is running, we hang, and we need it for the new calc.
  87                  */
  88                 int clk_div_stdfst_mode = readl(&i2c_bus->regs->clk_div) >> 16;
  89                 debug("%s: CLK_DIV_STD_FAST_MODE setting = %d\n", __func__,
  90                         clk_div_stdfst_mode);
  91
  92                 clock_start_periph_pll(i2c_bus->periph_id, CLOCK_ID_PERIPH,
  93                         CLK_MULT_STD_FAST_MODE * (clk_div_stdfst_mode + 1) *
  94                         i2c_bus->speed * 2);
  95         }
  96
  97         /* Reset I2C controller. */
  98         i2c_reset_controller(i2c_bus);
  99
 100         /* Configure I2C controller. */
 101         if (i2c_bus->is_dvc) {  /* only for DVC I2C */
 102                 struct dvc_ctlr *dvc = (struct dvc_ctlr *)i2c_bus->regs;
 103
 104                 setbits_le32(&dvc->ctrl3, DVC_CTRL_REG3_I2C_HW_SW_PROG_MASK);
 105         }
 106
 107         funcmux_select(i2c_bus->periph_id, i2c_bus->pinmux_config);
 108 }
 109
 110 static void send_packet_headers(
 111         struct i2c_bus *i2c_bus,
 112         struct i2c_trans_info *trans,
 113         u32 packet_id)
 114 {
 115         u32 data;
 116
 117         /* prepare header1: Header size = 0 Protocol = I2C, pktType = 0 */
 118         data = PROTOCOL_TYPE_I2C << PKT_HDR1_PROTOCOL_SHIFT;
 119         data |= packet_id << PKT_HDR1_PKT_ID_SHIFT;
 120         data |= i2c_bus->id << PKT_HDR1_CTLR_ID_SHIFT;
 121         writel(data, &i2c_bus->control->tx_fifo);
 122         debug("pkt header 1 sent (0x%x)\n", data);
 123
 124         /* prepare header2 */
 125         data = (trans->num_bytes - 1) << PKT_HDR2_PAYLOAD_SIZE_SHIFT;
 126         writel(data, &i2c_bus->control->tx_fifo);
 127         debug("pkt header 2 sent (0x%x)\n", data);
 128
 129         /* prepare IO specific header: configure the slave address */
 130         data = trans->address << PKT_HDR3_SLAVE_ADDR_SHIFT;
 131
 132         /* Enable Read if it is not a write transaction */
 133         if (!(trans->flags & I2C_IS_WRITE))
 134                 data |= PKT_HDR3_READ_MODE_MASK;
 135
 136         /* Write I2C specific header */
 137         writel(data, &i2c_bus->control->tx_fifo);
 138         debug("pkt header 3 sent (0x%x)\n", data);
 139 }
 140
 141 static int wait_for_tx_fifo_empty(struct i2c_control *control)
 142 {
 143         u32 count;
 144         int timeout_us = I2C_TIMEOUT_USEC;
 145
 146         while (timeout_us >= 0) {
 147                 count = (readl(&control->fifo_status) & TX_FIFO_EMPTY_CNT_MASK)
 148                                 >> TX_FIFO_EMPTY_CNT_SHIFT;
 149                 if (count == I2C_FIFO_DEPTH)
 150                         return 1;
 151                 udelay(10);
 152                 timeout_us -= 10;
 153         }
 154
 155         return 0;
 156 }
 157
 158 static int wait_for_rx_fifo_notempty(struct i2c_control *control)
 159 {
 160         u32 count;
 161         int timeout_us = I2C_TIMEOUT_USEC;
 162
 163         while (timeout_us >= 0) {
 164                 count = (readl(&control->fifo_status) & TX_FIFO_FULL_CNT_MASK)
 165                                 >> TX_FIFO_FULL_CNT_SHIFT;
 166                 if (count)
 167                         return 1;
 168                 udelay(10);
 169                 timeout_us -= 10;
 170         }
 171
 172         return 0;
 173 }
 174
 175 static int wait_for_transfer_complete(struct i2c_control *control)
 176 {
 177         int int_status;
 178         int timeout_us = I2C_TIMEOUT_USEC;
 179
 180         while (timeout_us >= 0) {
 181                 int_status = readl(&control->int_status);
 182                 if (int_status & I2C_INT_NO_ACK_MASK)
 183                         return -int_status;
 184                 if (int_status & I2C_INT_ARBITRATION_LOST_MASK)
 185                         return -int_status;
 186                 if (int_status & I2C_INT_XFER_COMPLETE_MASK)
 187                         return 0;
 188
 189                 udelay(10);
 190                 timeout_us -= 10;
 191         }
 192
 193         return -1;
 194 }
 195
 196 static int send_recv_packets(struct i2c_bus *i2c_bus,
 197                              struct i2c_trans_info *trans)
 198 {
 199         struct i2c_control *control = i2c_bus->control;
 200         u32 int_status;
 201         u32 words;
 202         u8 *dptr;
 203         u32 local;
 204         uchar last_bytes;
 205         int error = 0;
 206         int is_write = trans->flags & I2C_IS_WRITE;
 207
 208         /* clear status from previous transaction, XFER_COMPLETE, NOACK, etc. */
 209         int_status = readl(&control->int_status);
 210         writel(int_status, &control->int_status);
 211
 212         send_packet_headers(i2c_bus, trans, 1);
 213
 214         words = DIV_ROUND_UP(trans->num_bytes, 4);
 215         last_bytes = trans->num_bytes & 3;
 216         dptr = trans->buf;
 217
 218         while (words) {
 219                 u32 *wptr = (u32 *)dptr;
 220
 221                 if (is_write) {
 222                         /* deal with word alignment */
 223                         if ((unsigned)dptr & 3) {
 224                                 memcpy(&local, dptr, sizeof(u32));
 225                                 writel(local, &control->tx_fifo);
 226                                 debug("pkt data sent (0x%x)\n", local);
 227                         } else {
 228                                 writel(*wptr, &control->tx_fifo);
 229                                 debug("pkt data sent (0x%x)\n", *wptr);
 230                         }
 231                         if (!wait_for_tx_fifo_empty(control)) {
 232                                 error = -1;
 233                                 goto exit;
 234                         }
 235                 } else {
 236                         if (!wait_for_rx_fifo_notempty(control)) {
 237                                 error = -1;
 238                                 goto exit;
 239                         }
 240                         /*
 241                          * for the last word, we read into our local buffer,
 242                          * in case that caller did not provide enough buffer.
 243                          */
 244                         local = readl(&control->rx_fifo);
 245                         if ((words == 1) && last_bytes)
 246                                 memcpy(dptr, (char *)&local, last_bytes);
 247                         else if ((unsigned)dptr & 3)
 248                                 memcpy(dptr, &local, sizeof(u32));
 249                         else
 250                                 *wptr = local;
 251                         debug("pkt data received (0x%x)\n", local);
 252                 }
 253                 words--;
 254                 dptr += sizeof(u32);
 255         }
 256
 257         if (wait_for_transfer_complete(control)) {
 258                 error = -1;
 259                 goto exit;
 260         }
 261         return 0;
 262 exit:
 263         /* error, reset the controller. */
 264         i2c_reset_controller(i2c_bus);
 265
 266         return error;
 267 }
 268
 269 static int tegra_i2c_write_data(struct i2c_bus *bus, u32 addr, u8 *data,
 270                                 u32 len)
 271 {
 272         int error;
 273         struct i2c_trans_info trans_info;
 274
 275         trans_info.address = addr;
 276         trans_info.buf = data;
 277         trans_info.flags = I2C_IS_WRITE;
 278         trans_info.num_bytes = len;
 279         trans_info.is_10bit_address = 0;
 280
 281         error = send_recv_packets(bus, &trans_info);
 282         if (error)
 283                 debug("tegra_i2c_write_data: Error (%d) !!!\n", error);
 284
 285         return error;
 286 }
 287
 288 static int tegra_i2c_read_data(struct i2c_bus *bus, u32 addr, u8 *data,
 289                                u32 len)
 290 {
 291         int error;
 292         struct i2c_trans_info trans_info;
 293
 294         trans_info.address = addr | 1;
 295         trans_info.buf = data;
 296         trans_info.flags = 0;
 297         trans_info.num_bytes = len;
 298         trans_info.is_10bit_address = 0;
 299
 300         error = send_recv_packets(bus, &trans_info);
 301         if (error)
 302                 debug("tegra_i2c_read_data: Error (%d) !!!\n", error);
 303
 304         return error;
 305 }
 306
 307 #ifndef CONFIG_OF_CONTROL
 308 #error "Please enable device tree support to use this driver"
 309 #endif
 310
 311 /**
 312  * Check that a bus number is valid and return a pointer to it
 313  *
 314  * @param bus_num       Bus number to check / return
 315  * @return pointer to bus, if valid, else NULL
 316  */
 317 static struct i2c_bus *tegra_i2c_get_bus(struct i2c_adapter *adap)
 318 {
 319         struct i2c_bus *bus;
 320
 321         bus = &i2c_controllers[adap->hwadapnr];
 322         if (!bus->inited) {
 323                 debug("%s: Bus %u not available\n", __func__, adap->hwadapnr);
 324                 return NULL;
 325         }
 326
 327         return bus;
 328 }
 329
 330 static unsigned int tegra_i2c_set_bus_speed(struct i2c_adapter *adap,
 331                         unsigned int speed)
 332 {
 333         struct i2c_bus *bus;
 334
 335         bus = tegra_i2c_get_bus(adap);
 336         if (!bus)
 337                 return 0;
 338         bus->speed = speed;
 339         i2c_init_controller(bus);
 340
 341         return 0;
 342 }
 343
 344 static int i2c_get_config(const void *blob, int node, struct i2c_bus *i2c_bus)
 345 {
 346         i2c_bus->regs = (struct i2c_ctlr *)fdtdec_get_addr(blob, node, "reg");
 347
 348         /*
 349          * We don't have a binding for pinmux yet. Leave it out for now. So
 350          * far no one needs anything other than the default.
 351          */
 352         i2c_bus->pinmux_config = FUNCMUX_DEFAULT;
 353         i2c_bus->speed = fdtdec_get_int(blob, node, "clock-frequency", 0);
 354         i2c_bus->periph_id = clock_decode_periph_id(blob, node);
 355
 356         /*
 357          * We can't specify the pinmux config in the fdt, so I2C2 will not
 358          * work on Seaboard. It normally has no devices on it anyway.
 359          * You could add in this little hack if you need to use it.
 360          * The correct solution is a pinmux binding in the fdt.
 361          *
 362          *      if (i2c_bus->periph_id == PERIPH_ID_I2C2)
 363          *              i2c_bus->pinmux_config = FUNCMUX_I2C2_PTA;
 364          */
 365         if (i2c_bus->periph_id == -1)
 366                 return -FDT_ERR_NOTFOUND;
 367
 368         return 0;
 369 }
 370
 371 /*
 372  * Process a list of nodes, adding them to our list of I2C ports.
 373  *
 374  * @param blob          fdt blob
 375  * @param node_list     list of nodes to process (any <=0 are ignored)
 376  * @param count         number of nodes to process
 377  * @param is_dvc        1 if these are DVC ports, 0 if standard I2C
 378  * @param is_scs        1 if this HW uses a single clock source (T114+)
 379  * @return 0 if ok, -1 on error
 380  */
 381 static int process_nodes(const void *blob, int node_list[], int count,
 382                          int is_dvc, int is_scs)
 383 {
 384         struct i2c_bus *i2c_bus;
 385         int i;
 386
 387         /* build the i2c_controllers[] for each controller */
 388         for (i = 0; i < count; i++) {
 389                 int node = node_list[i];
 390
 391                 if (node <= 0)
 392                         continue;
 393
 394                 i2c_bus = &i2c_controllers[i];
 395                 i2c_bus->id = i;
 396
 397                 if (i2c_get_config(blob, node, i2c_bus)) {
 398                         printf("i2c_init_board: failed to decode bus %d\n", i);
 399                         return -1;
 400                 }
 401
 402                 i2c_bus->is_scs = is_scs;
 403
 404                 i2c_bus->is_dvc = is_dvc;
 405                 if (is_dvc) {
 406                         i2c_bus->control =
 407                                 &((struct dvc_ctlr *)i2c_bus->regs)->control;
 408                 } else {
 409                         i2c_bus->control = &i2c_bus->regs->control;
 410                 }
 411                 debug("%s: controller bus %d at %p, periph_id %d, speed %d: ",
 412                       is_dvc ? "dvc" : "i2c", i, i2c_bus->regs,
 413                       i2c_bus->periph_id, i2c_bus->speed);
 414                 i2c_init_controller(i2c_bus);
 415                 debug("ok\n");
 416                 i2c_bus->inited = 1;
 417
 418                 /* Mark position as used */
 419                 node_list[i] = -1;
 420         }
 421
 422         return 0;
 423 }
 424
 425 /* Sadly there is no error return from this function */
 426 void i2c_init_board(void)
 427 {
 428         int node_list[TEGRA_I2C_NUM_CONTROLLERS];
 429         const void *blob = gd->fdt_blob;
 430         int count;
 431
 432         /* First check for newer (T114+) I2C ports */
 433         count = fdtdec_find_aliases_for_id(blob, "i2c",
 434                         COMPAT_NVIDIA_TEGRA114_I2C, node_list,
 435                         TEGRA_I2C_NUM_CONTROLLERS);
 436         if (process_nodes(blob, node_list, count, 0, 1))
 437                 return;
 438
 439         /* Now get the older (T20/T30) normal I2C ports */
 440         count = fdtdec_find_aliases_for_id(blob, "i2c",
 441                         COMPAT_NVIDIA_TEGRA20_I2C, node_list,
 442                         TEGRA_I2C_NUM_CONTROLLERS);
 443         if (process_nodes(blob, node_list, count, 0, 0))
 444                 return;
 445
 446         /* Now look for dvc ports */
 447         count = fdtdec_add_aliases_for_id(blob, "i2c",
 448                         COMPAT_NVIDIA_TEGRA20_DVC, node_list,
 449                         TEGRA_I2C_NUM_CONTROLLERS);
 450         if (process_nodes(blob, node_list, count, 1, 0))
 451                 return;
 452 }
 453
 454 static void tegra_i2c_init(struct i2c_adapter *adap, int speed, int slaveaddr)
 455 {
 456         /* No i2c support prior to relocation */
 457         if (!(gd->flags & GD_FLG_RELOC))
 458                 return;
 459
 460         /* This will override the speed selected in the fdt for that port */
 461         debug("i2c_init(speed=%u, slaveaddr=0x%x)\n", speed, slaveaddr);
 462         i2c_set_bus_speed(speed);
 463 }
 464
 465 /* i2c write version without the register address */
 466 int i2c_write_data(struct i2c_bus *bus, uchar chip, uchar *buffer, int len)
 467 {
 468         int rc;
 469
 470         debug("i2c_write_data: chip=0x%x, len=0x%x\n", chip, len);
 471         debug("write_data: ");
 472         /* use rc for counter */
 473         for (rc = 0; rc < len; ++rc)
 474                 debug(" 0x%02x", buffer[rc]);
 475         debug("\n");
 476
 477         /* Shift 7-bit address over for lower-level i2c functions */
 478         rc = tegra_i2c_write_data(bus, chip << 1, buffer, len);
 479         if (rc)
 480                 debug("i2c_write_data(): rc=%d\n", rc);
 481
 482         return rc;
 483 }
 484
 485 /* i2c read version without the register address */
 486 int i2c_read_data(struct i2c_bus *bus, uchar chip, uchar *buffer, int len)
 487 {
 488         int rc;
 489
 490         debug("inside i2c_read_data():\n");
 491         /* Shift 7-bit address over for lower-level i2c functions */
 492         rc = tegra_i2c_read_data(bus, chip << 1, buffer, len);
 493         if (rc) {
 494                 debug("i2c_read_data(): rc=%d\n", rc);
 495                 return rc;
 496         }
 497
 498         debug("i2c_read_data: ");
 499         /* reuse rc for counter*/
 500         for (rc = 0; rc < len; ++rc)
 501                 debug(" 0x%02x", buffer[rc]);
 502         debug("\n");
 503
 504         return 0;
 505 }
 506
 507 /* Probe to see if a chip is present. */
 508 static int tegra_i2c_probe(struct i2c_adapter *adap, uchar chip)
 509 {
 510         struct i2c_bus *bus;
 511         int rc;
 512         uchar reg;
 513
 514         debug("i2c_probe: addr=0x%x\n", chip);
 515         bus = tegra_i2c_get_bus(adap);
 516         if (!bus)
 517                 return 1;
 518         reg = 0;
 519         rc = i2c_write_data(bus, chip, &reg, 1);
 520         if (rc) {
 521                 debug("Error probing 0x%x.\n", chip);
 522                 return 1;
 523         }
 524         return 0;
 525 }
 526
 527 static int i2c_addr_ok(const uint addr, const int alen)
 528 {
 529         /* We support 7 or 10 bit addresses, so one or two bytes each */
 530         return alen == 1 || alen == 2;
 531 }
 532
 533 /* Read bytes */
 534 static int tegra_i2c_read(struct i2c_adapter *adap, uchar chip, uint addr,
 535                         int alen, uchar *buffer, int len)
 536 {
 537         struct i2c_bus *bus;
 538         uint offset;
 539         int i;
 540
 541         debug("i2c_read: chip=0x%x, addr=0x%x, len=0x%x\n",
 542                                 chip, addr, len);
 543         bus = tegra_i2c_get_bus(adap);
 544         if (!bus)
 545                 return 1;
 546         if (!i2c_addr_ok(addr, alen)) {
 547                 debug("i2c_read: Bad address %x.%d.\n", addr, alen);
 548                 return 1;
 549         }
 550         for (offset = 0; offset < len; offset++) {
 551                 if (alen) {
 552                         uchar data[alen];
 553                         for (i = 0; i < alen; i++) {
 554                                 data[alen - i - 1] =
 555                                         (addr + offset) >> (8 * i);
 556                         }
 557                         if (i2c_write_data(bus, chip, data, alen)) {
 558                                 debug("i2c_read: error sending (0x%x)\n",
 559                                         addr);
 560                                 return 1;
 561                         }
 562                 }
 563                 if (i2c_read_data(bus, chip, buffer + offset, 1)) {
 564                         debug("i2c_read: error reading (0x%x)\n", addr);
 565                         return 1;
 566                 }
 567         }
 568
 569         return 0;
 570 }
 571
 572 /* Write bytes */
 573 static int tegra_i2c_write(struct i2c_adapter *adap, uchar chip, uint addr,
 574                         int alen, uchar *buffer, int len)
 575 {
 576         struct i2c_bus *bus;
 577         uint offset;
 578         int i;
 579
 580         debug("i2c_write: chip=0x%x, addr=0x%x, len=0x%x\n",
 581                                 chip, addr, len);
 582         bus = tegra_i2c_get_bus(adap);
 583         if (!bus)
 584                 return 1;
 585         if (!i2c_addr_ok(addr, alen)) {
 586                 debug("i2c_write: Bad address %x.%d.\n", addr, alen);
 587                 return 1;
 588         }
 589         for (offset = 0; offset < len; offset++) {
 590                 uchar data[alen + 1];
 591                 for (i = 0; i < alen; i++)
 592                         data[alen - i - 1] = (addr + offset) >> (8 * i);
 593                 data[alen] = buffer[offset];
 594                 if (i2c_write_data(bus, chip, data, alen + 1)) {
 595                         debug("i2c_write: error sending (0x%x)\n", addr);
 596                         return 1;
 597                 }
 598         }
 599
 600         return 0;
 601 }
 602
 603 int tegra_i2c_get_dvc_bus_num(void)
 604 {
 605         int i;
 606
 607         for (i = 0; i < TEGRA_I2C_NUM_CONTROLLERS; i++) {
 608                 struct i2c_bus *bus = &i2c_controllers[i];
 609
 610                 if (bus->inited && bus->is_dvc)
 611                         return i;
 612         }
 613
 614         return -1;
 615 }
 616
 617 /*
 618  * Register soft i2c adapters
 619  */
 620 U_BOOT_I2C_ADAP_COMPLETE(tegra0, tegra_i2c_init, tegra_i2c_probe,
 621                          tegra_i2c_read, tegra_i2c_write,
 622                          tegra_i2c_set_bus_speed, 100000, 0, 0)
 623 U_BOOT_I2C_ADAP_COMPLETE(tegra1, tegra_i2c_init, tegra_i2c_probe,
 624                          tegra_i2c_read, tegra_i2c_write,
 625                          tegra_i2c_set_bus_speed, 100000, 0, 1)
 626 U_BOOT_I2C_ADAP_COMPLETE(tegra2, tegra_i2c_init, tegra_i2c_probe,
 627                          tegra_i2c_read, tegra_i2c_write,
 628                          tegra_i2c_set_bus_speed, 100000, 0, 2)
 629 U_BOOT_I2C_ADAP_COMPLETE(tegra3, tegra_i2c_init, tegra_i2c_probe,
 630                          tegra_i2c_read, tegra_i2c_write,
 631                          tegra_i2c_set_bus_speed, 100000, 0, 3)