drivers/i2c/tegra_i2c.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * Copyright (c) 2012 The Chromium OS Authors. All rights reserved.
   4  * Copyright (c) 2010-2011 NVIDIA Corporation
   5  *  NVIDIA Corporation <www.nvidia.com>
   6  */
   7
   8 #include <common.h>
   9 #include <dm.h>
  10 #include <errno.h>
  11 #include <i2c.h>
  12 #include <asm/io.h>
  13 #include <clk.h>
  14 #include <reset.h>
  15 #ifndef CONFIG_TEGRA186
  16 #include <asm/arch/clock.h>
  17 #include <asm/arch/funcmux.h>
  18 #endif
  19 #include <asm/arch/gpio.h>
  20 #include <asm/arch-tegra/tegra_i2c.h>
  21
  22 enum i2c_type {
  23         TYPE_114,
  24         TYPE_STD,
  25         TYPE_DVC,
  26 };
  27
  28 /* Information about i2c controller */
  29 struct i2c_bus {
  30         int                     id;
  31         struct reset_ctl        reset_ctl;
  32         struct clk              clk;
  33         int                     speed;
  34         int                     pinmux_config;
  35         struct i2c_control      *control;
  36         struct i2c_ctlr         *regs;
  37         enum i2c_type           type;
  38         int                     inited; /* bus is inited */
  39 };
  40
  41 static void set_packet_mode(struct i2c_bus *i2c_bus)
  42 {
  43         u32 config;
  44
  45         config = I2C_CNFG_NEW_MASTER_FSM_MASK | I2C_CNFG_PACKET_MODE_MASK;
  46
  47         if (i2c_bus->type == TYPE_DVC) {
  48                 struct dvc_ctlr *dvc = (struct dvc_ctlr *)i2c_bus->regs;
  49
  50                 writel(config, &dvc->cnfg);
  51         } else {
  52                 writel(config, &i2c_bus->regs->cnfg);
  53                 /*
  54                  * program I2C_SL_CNFG.NEWSL to ENABLE. This fixes probe
  55                  * issues, i.e., some slaves may be wrongly detected.
  56                  */
  57                 setbits_le32(&i2c_bus->regs->sl_cnfg, I2C_SL_CNFG_NEWSL_MASK);
  58         }
  59 }
  60
  61 static void i2c_reset_controller(struct i2c_bus *i2c_bus)
  62 {
  63         /* Reset I2C controller. */
  64         reset_assert(&i2c_bus->reset_ctl);
  65         udelay(1);
  66         reset_deassert(&i2c_bus->reset_ctl);
  67         udelay(1);
  68
  69         /* re-program config register to packet mode */
  70         set_packet_mode(i2c_bus);
  71 }
  72
  73 static int i2c_init_clock(struct i2c_bus *i2c_bus, unsigned rate)
  74 {
  75         int ret;
  76
  77         ret = reset_assert(&i2c_bus->reset_ctl);
  78         if (ret)
  79                 return ret;
  80         ret = clk_enable(&i2c_bus->clk);
  81         if (ret)
  82                 return ret;
  83         ret = clk_set_rate(&i2c_bus->clk, rate);
  84         if (IS_ERR_VALUE(ret))
  85                 return ret;
  86         ret = reset_deassert(&i2c_bus->reset_ctl);
  87         if (ret)
  88                 return ret;
  89
  90         return 0;
  91 }
  92
  93 static void i2c_init_controller(struct i2c_bus *i2c_bus)
  94 {
  95         if (!i2c_bus->speed)
  96                 return;
  97         debug("%s: speed=%d\n", __func__, i2c_bus->speed);
  98         /*
  99          * Use PLLP - DP-04508-001_v06 datasheet indicates a divisor of 8
 100          * here, in section 23.3.1, but in fact we seem to need a factor of
 101          * 16 to get the right frequency.
 102          */
 103         i2c_init_clock(i2c_bus, i2c_bus->speed * 2 * 8);
 104
 105         if (i2c_bus->type == TYPE_114) {
 106                 /*
 107                  * T114 I2C went to a single clock source for standard/fast and
 108                  * HS clock speeds. The new clock rate setting calculation is:
 109                  *  SCL = CLK_SOURCE.I2C /
 110                  *   (CLK_MULT_STD_FAST_MODE * (I2C_CLK_DIV_STD_FAST_MODE+1) *
 111                  *   I2C FREQUENCY DIVISOR) as per the T114 TRM (sec 30.3.1).
 112                  *
 113                  * NOTE: We do this here, after the initial clock/pll start,
 114                  * because if we read the clk_div reg before the controller
 115                  * is running, we hang, and we need it for the new calc.
 116                  */
 117                 int clk_div_stdfst_mode = readl(&i2c_bus->regs->clk_div) >> 16;
 118                 unsigned rate = CLK_MULT_STD_FAST_MODE *
 119                                 (clk_div_stdfst_mode + 1) * i2c_bus->speed * 2;
 120                 debug("%s: CLK_DIV_STD_FAST_MODE setting = %d\n", __func__,
 121                         clk_div_stdfst_mode);
 122
 123                 i2c_init_clock(i2c_bus, rate);
 124         }
 125
 126         /* Reset I2C controller. */
 127         i2c_reset_controller(i2c_bus);
 128
 129         /* Configure I2C controller. */
 130         if (i2c_bus->type == TYPE_DVC) {        /* only for DVC I2C */
 131                 struct dvc_ctlr *dvc = (struct dvc_ctlr *)i2c_bus->regs;
 132
 133                 setbits_le32(&dvc->ctrl3, DVC_CTRL_REG3_I2C_HW_SW_PROG_MASK);
 134         }
 135
 136 #ifndef CONFIG_TEGRA186
 137         funcmux_select(i2c_bus->clk.id, i2c_bus->pinmux_config);
 138 #endif
 139 }
 140
 141 static void send_packet_headers(
 142         struct i2c_bus *i2c_bus,
 143         struct i2c_trans_info *trans,
 144         u32 packet_id,
 145         bool end_with_repeated_start)
 146 {
 147         u32 data;
 148
 149         /* prepare header1: Header size = 0 Protocol = I2C, pktType = 0 */
 150         data = PROTOCOL_TYPE_I2C << PKT_HDR1_PROTOCOL_SHIFT;
 151         data |= packet_id << PKT_HDR1_PKT_ID_SHIFT;
 152         data |= i2c_bus->id << PKT_HDR1_CTLR_ID_SHIFT;
 153         writel(data, &i2c_bus->control->tx_fifo);
 154         debug("pkt header 1 sent (0x%x)\n", data);
 155
 156         /* prepare header2 */
 157         data = (trans->num_bytes - 1) << PKT_HDR2_PAYLOAD_SIZE_SHIFT;
 158         writel(data, &i2c_bus->control->tx_fifo);
 159         debug("pkt header 2 sent (0x%x)\n", data);
 160
 161         /* prepare IO specific header: configure the slave address */
 162         data = trans->address << PKT_HDR3_SLAVE_ADDR_SHIFT;
 163
 164         /* Enable Read if it is not a write transaction */
 165         if (!(trans->flags & I2C_IS_WRITE))
 166                 data |= PKT_HDR3_READ_MODE_MASK;
 167         if (end_with_repeated_start)
 168                 data |= PKT_HDR3_REPEAT_START_MASK;
 169
 170         /* Write I2C specific header */
 171         writel(data, &i2c_bus->control->tx_fifo);
 172         debug("pkt header 3 sent (0x%x)\n", data);
 173 }
 174
 175 static int wait_for_tx_fifo_empty(struct i2c_control *control)
 176 {
 177         u32 count;
 178         int timeout_us = I2C_TIMEOUT_USEC;
 179
 180         while (timeout_us >= 0) {
 181                 count = (readl(&control->fifo_status) & TX_FIFO_EMPTY_CNT_MASK)
 182                                 >> TX_FIFO_EMPTY_CNT_SHIFT;
 183                 if (count == I2C_FIFO_DEPTH)
 184                         return 1;
 185                 udelay(10);
 186                 timeout_us -= 10;
 187         }
 188
 189         return 0;
 190 }
 191
 192 static int wait_for_rx_fifo_notempty(struct i2c_control *control)
 193 {
 194         u32 count;
 195         int timeout_us = I2C_TIMEOUT_USEC;
 196
 197         while (timeout_us >= 0) {
 198                 count = (readl(&control->fifo_status) & TX_FIFO_FULL_CNT_MASK)
 199                                 >> TX_FIFO_FULL_CNT_SHIFT;
 200                 if (count)
 201                         return 1;
 202                 udelay(10);
 203                 timeout_us -= 10;
 204         }
 205
 206         return 0;
 207 }
 208
 209 static int wait_for_transfer_complete(struct i2c_control *control)
 210 {
 211         int int_status;
 212         int timeout_us = I2C_TIMEOUT_USEC;
 213
 214         while (timeout_us >= 0) {
 215                 int_status = readl(&control->int_status);
 216                 if (int_status & I2C_INT_NO_ACK_MASK)
 217                         return -int_status;
 218                 if (int_status & I2C_INT_ARBITRATION_LOST_MASK)
 219                         return -int_status;
 220                 if (int_status & I2C_INT_XFER_COMPLETE_MASK)
 221                         return 0;
 222
 223                 udelay(10);
 224                 timeout_us -= 10;
 225         }
 226
 227         return -1;
 228 }
 229
 230 static int send_recv_packets(struct i2c_bus *i2c_bus,
 231                              struct i2c_trans_info *trans)
 232 {
 233         struct i2c_control *control = i2c_bus->control;
 234         u32 int_status;
 235         u32 words;
 236         u8 *dptr;
 237         u32 local;
 238         uchar last_bytes;
 239         int error = 0;
 240         int is_write = trans->flags & I2C_IS_WRITE;
 241
 242         /* clear status from previous transaction, XFER_COMPLETE, NOACK, etc. */
 243         int_status = readl(&control->int_status);
 244         writel(int_status, &control->int_status);
 245
 246         send_packet_headers(i2c_bus, trans, 1,
 247                             trans->flags & I2C_USE_REPEATED_START);
 248
 249         words = DIV_ROUND_UP(trans->num_bytes, 4);
 250         last_bytes = trans->num_bytes & 3;
 251         dptr = trans->buf;
 252
 253         while (words) {
 254                 u32 *wptr = (u32 *)dptr;
 255
 256                 if (is_write) {
 257                         /* deal with word alignment */
 258                         if ((words == 1) && last_bytes) {
 259                                 local = 0;
 260                                 memcpy(&local, dptr, last_bytes);
 261                         } else if ((unsigned long)dptr & 3) {
 262                                 memcpy(&local, dptr, sizeof(u32));
 263                         } else {
 264                                 local = *wptr;
 265                         }
 266                         writel(local, &control->tx_fifo);
 267                         debug("pkt data sent (0x%x)\n", local);
 268                         if (!wait_for_tx_fifo_empty(control)) {
 269                                 error = -1;
 270                                 goto exit;
 271                         }
 272                 } else {
 273                         if (!wait_for_rx_fifo_notempty(control)) {
 274                                 error = -1;
 275                                 goto exit;
 276                         }
 277                         /*
 278                          * for the last word, we read into our local buffer,
 279                          * in case that caller did not provide enough buffer.
 280                          */
 281                         local = readl(&control->rx_fifo);
 282                         if ((words == 1) && last_bytes)
 283                                 memcpy(dptr, (char *)&local, last_bytes);
 284                         else if ((unsigned long)dptr & 3)
 285                                 memcpy(dptr, &local, sizeof(u32));
 286                         else
 287                                 *wptr = local;
 288                         debug("pkt data received (0x%x)\n", local);
 289                 }
 290                 words--;
 291                 dptr += sizeof(u32);
 292         }
 293
 294         if (wait_for_transfer_complete(control)) {
 295                 error = -1;
 296                 goto exit;
 297         }
 298         return 0;
 299 exit:
 300         /* error, reset the controller. */
 301         i2c_reset_controller(i2c_bus);
 302
 303         return error;
 304 }
 305
 306 static int tegra_i2c_write_data(struct i2c_bus *i2c_bus, u32 addr, u8 *data,
 307                                 u32 len, bool end_with_repeated_start)
 308 {
 309         int error;
 310         struct i2c_trans_info trans_info;
 311
 312         trans_info.address = addr;
 313         trans_info.buf = data;
 314         trans_info.flags = I2C_IS_WRITE;
 315         if (end_with_repeated_start)
 316                 trans_info.flags |= I2C_USE_REPEATED_START;
 317         trans_info.num_bytes = len;
 318         trans_info.is_10bit_address = 0;
 319
 320         error = send_recv_packets(i2c_bus, &trans_info);
 321         if (error)
 322                 debug("tegra_i2c_write_data: Error (%d) !!!\n", error);
 323
 324         return error;
 325 }
 326
 327 static int tegra_i2c_read_data(struct i2c_bus *i2c_bus, u32 addr, u8 *data,
 328                                u32 len)
 329 {
 330         int error;
 331         struct i2c_trans_info trans_info;
 332
 333         trans_info.address = addr | 1;
 334         trans_info.buf = data;
 335         trans_info.flags = 0;
 336         trans_info.num_bytes = len;
 337         trans_info.is_10bit_address = 0;
 338
 339         error = send_recv_packets(i2c_bus, &trans_info);
 340         if (error)
 341                 debug("tegra_i2c_read_data: Error (%d) !!!\n", error);
 342
 343         return error;
 344 }
 345
 346 static int tegra_i2c_set_bus_speed(struct udevice *dev, unsigned int speed)
 347 {
 348         struct i2c_bus *i2c_bus = dev_get_priv(dev);
 349
 350         i2c_bus->speed = speed;
 351         i2c_init_controller(i2c_bus);
 352
 353         return 0;
 354 }
 355
 356 static int tegra_i2c_probe(struct udevice *dev)
 357 {
 358         struct i2c_bus *i2c_bus = dev_get_priv(dev);
 359         int ret;
 360         bool is_dvc;
 361
 362         i2c_bus->id = dev->seq;
 363         i2c_bus->type = dev_get_driver_data(dev);
 364         i2c_bus->regs = (struct i2c_ctlr *)dev_read_addr(dev);
 365         if ((ulong)i2c_bus->regs == FDT_ADDR_T_NONE) {
 366                 debug("%s: Cannot get regs address\n", __func__);
 367                 return -EINVAL;
 368         }
 369
 370         ret = reset_get_by_name(dev, "i2c", &i2c_bus->reset_ctl);
 371         if (ret) {
 372                 pr_err("reset_get_by_name() failed: %d\n", ret);
 373                 return ret;
 374         }
 375         ret = clk_get_by_name(dev, "div-clk", &i2c_bus->clk);
 376         if (ret) {
 377                 pr_err("clk_get_by_name() failed: %d\n", ret);
 378                 return ret;
 379         }
 380
 381 #ifndef CONFIG_TEGRA186
 382         /*
 383          * We don't have a binding for pinmux yet. Leave it out for now. So
 384          * far no one needs anything other than the default.
 385          */
 386         i2c_bus->pinmux_config = FUNCMUX_DEFAULT;
 387
 388         /*
 389          * We can't specify the pinmux config in the fdt, so I2C2 will not
 390          * work on Seaboard. It normally has no devices on it anyway.
 391          * You could add in this little hack if you need to use it.
 392          * The correct solution is a pinmux binding in the fdt.
 393          *
 394          *      if (i2c_bus->clk.id == PERIPH_ID_I2C2)
 395          *              i2c_bus->pinmux_config = FUNCMUX_I2C2_PTA;
 396          */
 397 #endif
 398
 399         is_dvc = dev_get_driver_data(dev) == TYPE_DVC;
 400         if (is_dvc) {
 401                 i2c_bus->control =
 402                         &((struct dvc_ctlr *)i2c_bus->regs)->control;
 403         } else {
 404                 i2c_bus->control = &i2c_bus->regs->control;
 405         }
 406         i2c_init_controller(i2c_bus);
 407         debug("%s: controller bus %d at %p, speed %d: ",
 408               is_dvc ? "dvc" : "i2c", dev->seq, i2c_bus->regs, i2c_bus->speed);
 409
 410         return 0;
 411 }
 412
 413 /* i2c write version without the register address */
 414 static int i2c_write_data(struct i2c_bus *i2c_bus, uchar chip, uchar *buffer,
 415                           int len, bool end_with_repeated_start)
 416 {
 417         int rc;
 418
 419         debug("i2c_write_data: chip=0x%x, len=0x%x\n", chip, len);
 420         debug("write_data: ");
 421         /* use rc for counter */
 422         for (rc = 0; rc < len; ++rc)
 423                 debug(" 0x%02x", buffer[rc]);
 424         debug("\n");
 425
 426         /* Shift 7-bit address over for lower-level i2c functions */
 427         rc = tegra_i2c_write_data(i2c_bus, chip << 1, buffer, len,
 428                                   end_with_repeated_start);
 429         if (rc)
 430                 debug("i2c_write_data(): rc=%d\n", rc);
 431
 432         return rc;
 433 }
 434
 435 /* i2c read version without the register address */
 436 static int i2c_read_data(struct i2c_bus *i2c_bus, uchar chip, uchar *buffer,
 437                          int len)
 438 {
 439         int rc;
 440
 441         debug("inside i2c_read_data():\n");
 442         /* Shift 7-bit address over for lower-level i2c functions */
 443         rc = tegra_i2c_read_data(i2c_bus, chip << 1, buffer, len);
 444         if (rc) {
 445                 debug("i2c_read_data(): rc=%d\n", rc);
 446                 return rc;
 447         }
 448
 449         debug("i2c_read_data: ");
 450         /* reuse rc for counter*/
 451         for (rc = 0; rc < len; ++rc)
 452                 debug(" 0x%02x", buffer[rc]);
 453         debug("\n");
 454
 455         return 0;
 456 }
 457
 458 /* Probe to see if a chip is present. */
 459 static int tegra_i2c_probe_chip(struct udevice *bus, uint chip_addr,
 460                                 uint chip_flags)
 461 {
 462         struct i2c_bus *i2c_bus = dev_get_priv(bus);
 463         int rc;
 464         u8 reg;
 465
 466         /* Shift 7-bit address over for lower-level i2c functions */
 467         rc = tegra_i2c_write_data(i2c_bus, chip_addr << 1, &reg, sizeof(reg),
 468                                   false);
 469
 470         return rc;
 471 }
 472
 473 static int tegra_i2c_xfer(struct udevice *bus, struct i2c_msg *msg,
 474                           int nmsgs)
 475 {
 476         struct i2c_bus *i2c_bus = dev_get_priv(bus);
 477         int ret;
 478
 479         debug("i2c_xfer: %d messages\n", nmsgs);
 480         for (; nmsgs > 0; nmsgs--, msg++) {
 481                 bool next_is_read = nmsgs > 1 && (msg[1].flags & I2C_M_RD);
 482
 483                 debug("i2c_xfer: chip=0x%x, len=0x%x\n", msg->addr, msg->len);
 484                 if (msg->flags & I2C_M_RD) {
 485                         ret = i2c_read_data(i2c_bus, msg->addr, msg->buf,
 486                                             msg->len);
 487                 } else {
 488                         ret = i2c_write_data(i2c_bus, msg->addr, msg->buf,
 489                                              msg->len, next_is_read);
 490                 }
 491                 if (ret) {
 492                         debug("i2c_write: error sending\n");
 493                         return -EREMOTEIO;
 494                 }
 495         }
 496
 497         return 0;
 498 }
 499
 500 int tegra_i2c_get_dvc_bus(struct udevice **busp)
 501 {
 502         struct udevice *bus;
 503
 504         for (uclass_first_device(UCLASS_I2C, &bus);
 505              bus;
 506              uclass_next_device(&bus)) {
 507                 if (dev_get_driver_data(bus) == TYPE_DVC) {
 508                         *busp = bus;
 509                         return 0;
 510                 }
 511         }
 512
 513         return -ENODEV;
 514 }
 515
 516 static const struct dm_i2c_ops tegra_i2c_ops = {
 517         .xfer           = tegra_i2c_xfer,
 518         .probe_chip     = tegra_i2c_probe_chip,
 519         .set_bus_speed  = tegra_i2c_set_bus_speed,
 520 };
 521
 522 static const struct udevice_id tegra_i2c_ids[] = {
 523         { .compatible = "nvidia,tegra114-i2c", .data = TYPE_114 },
 524         { .compatible = "nvidia,tegra20-i2c", .data = TYPE_STD },
 525         { .compatible = "nvidia,tegra20-i2c-dvc", .data = TYPE_DVC },
 526         { }
 527 };
 528
 529 U_BOOT_DRIVER(i2c_tegra) = {
 530         .name   = "i2c_tegra",
 531         .id     = UCLASS_I2C,
 532         .of_match = tegra_i2c_ids,
 533         .probe  = tegra_i2c_probe,
 534         .priv_auto_alloc_size = sizeof(struct i2c_bus),
 535         .ops    = &tegra_i2c_ops,
 536 };