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 <dm.h>
   9 #include <errno.h>
  10 #include <i2c.h>
  11 #include <log.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 #include <linux/delay.h>
  22 #include <linux/err.h>
  23 #include <linux/printk.h>
  24
  25 enum i2c_type {
  26         TYPE_114,
  27         TYPE_STD,
  28         TYPE_DVC,
  29 };
  30
  31 /* Information about i2c controller */
  32 struct i2c_bus {
  33         int                     id;
  34         struct reset_ctl        reset_ctl;
  35         struct clk              clk;
  36         int                     speed;
  37         int                     pinmux_config;
  38         struct i2c_control      *control;
  39         struct i2c_ctlr         *regs;
  40         enum i2c_type           type;
  41         int                     inited; /* bus is inited */
  42 };
  43
  44 static void set_packet_mode(struct i2c_bus *i2c_bus)
  45 {
  46         u32 config;
  47
  48         config = I2C_CNFG_NEW_MASTER_FSM_MASK | I2C_CNFG_PACKET_MODE_MASK;
  49
  50         if (i2c_bus->type == TYPE_DVC) {
  51                 struct dvc_ctlr *dvc = (struct dvc_ctlr *)i2c_bus->regs;
  52
  53                 writel(config, &dvc->cnfg);
  54         } else {
  55                 writel(config, &i2c_bus->regs->cnfg);
  56                 /*
  57                  * program I2C_SL_CNFG.NEWSL to ENABLE. This fixes probe
  58                  * issues, i.e., some slaves may be wrongly detected.
  59                  */
  60                 setbits_le32(&i2c_bus->regs->sl_cnfg, I2C_SL_CNFG_NEWSL_MASK);
  61         }
  62 }
  63
  64 static void i2c_reset_controller(struct i2c_bus *i2c_bus)
  65 {
  66         /* Reset I2C controller. */
  67         reset_assert(&i2c_bus->reset_ctl);
  68         udelay(1);
  69         reset_deassert(&i2c_bus->reset_ctl);
  70         udelay(1);
  71
  72         /* re-program config register to packet mode */
  73         set_packet_mode(i2c_bus);
  74 }
  75
  76 static int i2c_init_clock(struct i2c_bus *i2c_bus, unsigned rate)
  77 {
  78         int ret;
  79
  80         ret = reset_assert(&i2c_bus->reset_ctl);
  81         if (ret)
  82                 return ret;
  83         ret = clk_enable(&i2c_bus->clk);
  84         if (ret)
  85                 return ret;
  86         ret = clk_set_rate(&i2c_bus->clk, rate);
  87         if (IS_ERR_VALUE(ret))
  88                 return ret;
  89         ret = reset_deassert(&i2c_bus->reset_ctl);
  90         if (ret)
  91                 return ret;
  92
  93         return 0;
  94 }
  95
  96 static void i2c_init_controller(struct i2c_bus *i2c_bus)
  97 {
  98         if (!i2c_bus->speed)
  99                 return;
 100         debug("%s: speed=%d\n", __func__, i2c_bus->speed);
 101         /*
 102          * Use PLLP - DP-04508-001_v06 datasheet indicates a divisor of 8
 103          * here, in section 23.3.1, but in fact we seem to need a factor of
 104          * 16 to get the right frequency.
 105          */
 106         i2c_init_clock(i2c_bus, i2c_bus->speed * 2 * 8);
 107
 108         if (i2c_bus->type == TYPE_114) {
 109                 /*
 110                  * T114 I2C went to a single clock source for standard/fast and
 111                  * HS clock speeds. The new clock rate setting calculation is:
 112                  *  SCL = CLK_SOURCE.I2C /
 113                  *   (CLK_MULT_STD_FAST_MODE * (I2C_CLK_DIV_STD_FAST_MODE+1) *
 114                  *   I2C FREQUENCY DIVISOR) as per the T114 TRM (sec 30.3.1).
 115                  *
 116                  * NOTE: We do this here, after the initial clock/pll start,
 117                  * because if we read the clk_div reg before the controller
 118                  * is running, we hang, and we need it for the new calc.
 119                  */
 120                 int clk_div_stdfst_mode = readl(&i2c_bus->regs->clk_div) >> 16;
 121                 unsigned rate = CLK_MULT_STD_FAST_MODE *
 122                                 (clk_div_stdfst_mode + 1) * i2c_bus->speed * 2;
 123                 debug("%s: CLK_DIV_STD_FAST_MODE setting = %d\n", __func__,
 124                         clk_div_stdfst_mode);
 125
 126                 i2c_init_clock(i2c_bus, rate);
 127         }
 128
 129         /* Reset I2C controller. */
 130         i2c_reset_controller(i2c_bus);
 131
 132         /* Configure I2C controller. */
 133         if (i2c_bus->type == TYPE_DVC) {        /* only for DVC I2C */
 134                 struct dvc_ctlr *dvc = (struct dvc_ctlr *)i2c_bus->regs;
 135
 136                 setbits_le32(&dvc->ctrl3, DVC_CTRL_REG3_I2C_HW_SW_PROG_MASK);
 137         }
 138
 139 #ifndef CONFIG_TEGRA186
 140         funcmux_select(i2c_bus->clk.id, i2c_bus->pinmux_config);
 141 #endif
 142 }
 143
 144 static void send_packet_headers(
 145         struct i2c_bus *i2c_bus,
 146         struct i2c_trans_info *trans,
 147         u32 packet_id,
 148         bool end_with_repeated_start)
 149 {
 150         u32 data;
 151
 152         /* prepare header1: Header size = 0 Protocol = I2C, pktType = 0 */
 153         data = PROTOCOL_TYPE_I2C << PKT_HDR1_PROTOCOL_SHIFT;
 154         data |= packet_id << PKT_HDR1_PKT_ID_SHIFT;
 155         data |= i2c_bus->id << PKT_HDR1_CTLR_ID_SHIFT;
 156         writel(data, &i2c_bus->control->tx_fifo);
 157         debug("pkt header 1 sent (0x%x)\n", data);
 158
 159         /* prepare header2 */
 160         data = (trans->num_bytes - 1) << PKT_HDR2_PAYLOAD_SIZE_SHIFT;
 161         writel(data, &i2c_bus->control->tx_fifo);
 162         debug("pkt header 2 sent (0x%x)\n", data);
 163
 164         /* prepare IO specific header: configure the slave address */
 165         data = trans->address << PKT_HDR3_SLAVE_ADDR_SHIFT;
 166
 167         /* Enable Read if it is not a write transaction */
 168         if (!(trans->flags & I2C_IS_WRITE))
 169                 data |= PKT_HDR3_READ_MODE_MASK;
 170         if (end_with_repeated_start)
 171                 data |= PKT_HDR3_REPEAT_START_MASK;
 172
 173         /* Write I2C specific header */
 174         writel(data, &i2c_bus->control->tx_fifo);
 175         debug("pkt header 3 sent (0x%x)\n", data);
 176 }
 177
 178 static int wait_for_tx_fifo_empty(struct i2c_control *control)
 179 {
 180         u32 count;
 181         int timeout_us = I2C_TIMEOUT_USEC;
 182
 183         while (timeout_us >= 0) {
 184                 count = (readl(&control->fifo_status) & TX_FIFO_EMPTY_CNT_MASK)
 185                                 >> TX_FIFO_EMPTY_CNT_SHIFT;
 186                 if (count == I2C_FIFO_DEPTH)
 187                         return 1;
 188                 udelay(10);
 189                 timeout_us -= 10;
 190         }
 191
 192         return 0;
 193 }
 194
 195 static int wait_for_rx_fifo_notempty(struct i2c_control *control)
 196 {
 197         u32 count;
 198         int timeout_us = I2C_TIMEOUT_USEC;
 199
 200         while (timeout_us >= 0) {
 201                 count = (readl(&control->fifo_status) & TX_FIFO_FULL_CNT_MASK)
 202                                 >> TX_FIFO_FULL_CNT_SHIFT;
 203                 if (count)
 204                         return 1;
 205                 udelay(10);
 206                 timeout_us -= 10;
 207         }
 208
 209         return 0;
 210 }
 211
 212 static int wait_for_transfer_complete(struct i2c_control *control)
 213 {
 214         int int_status;
 215         int timeout_us = I2C_TIMEOUT_USEC;
 216
 217         while (timeout_us >= 0) {
 218                 int_status = readl(&control->int_status);
 219                 if (int_status & I2C_INT_NO_ACK_MASK)
 220                         return -int_status;
 221                 if (int_status & I2C_INT_ARBITRATION_LOST_MASK)
 222                         return -int_status;
 223                 if (int_status & I2C_INT_XFER_COMPLETE_MASK)
 224                         return 0;
 225
 226                 udelay(10);
 227                 timeout_us -= 10;
 228         }
 229
 230         return -1;
 231 }
 232
 233 static int send_recv_packets(struct i2c_bus *i2c_bus,
 234                              struct i2c_trans_info *trans)
 235 {
 236         struct i2c_control *control = i2c_bus->control;
 237         u32 int_status;
 238         u32 words;
 239         u8 *dptr;
 240         u32 local;
 241         uchar last_bytes;
 242         int error = 0;
 243         int is_write = trans->flags & I2C_IS_WRITE;
 244
 245         /* clear status from previous transaction, XFER_COMPLETE, NOACK, etc. */
 246         int_status = readl(&control->int_status);
 247         writel(int_status, &control->int_status);
 248
 249         send_packet_headers(i2c_bus, trans, 1,
 250                             trans->flags & I2C_USE_REPEATED_START);
 251
 252         words = DIV_ROUND_UP(trans->num_bytes, 4);
 253         last_bytes = trans->num_bytes & 3;
 254         dptr = trans->buf;
 255
 256         while (words) {
 257                 u32 *wptr = (u32 *)dptr;
 258
 259                 if (is_write) {
 260                         /* deal with word alignment */
 261                         if ((words == 1) && last_bytes) {
 262                                 local = 0;
 263                                 memcpy(&local, dptr, last_bytes);
 264                         } else if ((unsigned long)dptr & 3) {
 265                                 memcpy(&local, dptr, sizeof(u32));
 266                         } else {
 267                                 local = *wptr;
 268                         }
 269                         writel(local, &control->tx_fifo);
 270                         debug("pkt data sent (0x%x)\n", local);
 271                         if (!wait_for_tx_fifo_empty(control)) {
 272                                 error = -1;
 273                                 goto exit;
 274                         }
 275                 } else {
 276                         if (!wait_for_rx_fifo_notempty(control)) {
 277                                 error = -1;
 278                                 goto exit;
 279                         }
 280                         /*
 281                          * for the last word, we read into our local buffer,
 282                          * in case that caller did not provide enough buffer.
 283                          */
 284                         local = readl(&control->rx_fifo);
 285                         if ((words == 1) && last_bytes)
 286                                 memcpy(dptr, (char *)&local, last_bytes);
 287                         else if ((unsigned long)dptr & 3)
 288                                 memcpy(dptr, &local, sizeof(u32));
 289                         else
 290                                 *wptr = local;
 291                         debug("pkt data received (0x%x)\n", local);
 292                 }
 293                 words--;
 294                 dptr += sizeof(u32);
 295         }
 296
 297         if (wait_for_transfer_complete(control)) {
 298                 error = -1;
 299                 goto exit;
 300         }
 301         return 0;
 302 exit:
 303         /* error, reset the controller. */
 304         i2c_reset_controller(i2c_bus);
 305
 306         return error;
 307 }
 308
 309 static int tegra_i2c_write_data(struct i2c_bus *i2c_bus, u32 addr, u8 *data,
 310                                 u32 len, bool end_with_repeated_start)
 311 {
 312         int error;
 313         struct i2c_trans_info trans_info;
 314
 315         trans_info.address = addr;
 316         trans_info.buf = data;
 317         trans_info.flags = I2C_IS_WRITE;
 318         if (end_with_repeated_start)
 319                 trans_info.flags |= I2C_USE_REPEATED_START;
 320         trans_info.num_bytes = len;
 321         trans_info.is_10bit_address = 0;
 322
 323         error = send_recv_packets(i2c_bus, &trans_info);
 324         if (error)
 325                 debug("tegra_i2c_write_data: Error (%d) !!!\n", error);
 326
 327         return error;
 328 }
 329
 330 static int tegra_i2c_read_data(struct i2c_bus *i2c_bus, u32 addr, u8 *data,
 331                                u32 len)
 332 {
 333         int error;
 334         struct i2c_trans_info trans_info;
 335
 336         trans_info.address = addr | 1;
 337         trans_info.buf = data;
 338         trans_info.flags = 0;
 339         trans_info.num_bytes = len;
 340         trans_info.is_10bit_address = 0;
 341
 342         error = send_recv_packets(i2c_bus, &trans_info);
 343         if (error)
 344                 debug("tegra_i2c_read_data: Error (%d) !!!\n", error);
 345
 346         return error;
 347 }
 348
 349 static int tegra_i2c_set_bus_speed(struct udevice *dev, unsigned int speed)
 350 {
 351         struct i2c_bus *i2c_bus = dev_get_priv(dev);
 352
 353         i2c_bus->speed = speed;
 354         i2c_init_controller(i2c_bus);
 355
 356         return 0;
 357 }
 358
 359 static int tegra_i2c_probe(struct udevice *dev)
 360 {
 361         struct i2c_bus *i2c_bus = dev_get_priv(dev);
 362         int ret;
 363         bool is_dvc;
 364
 365         i2c_bus->id = dev_seq(dev);
 366         i2c_bus->type = dev_get_driver_data(dev);
 367         i2c_bus->regs = dev_read_addr_ptr(dev);
 368         if (!i2c_bus->regs) {
 369                 debug("%s: Cannot get regs address\n", __func__);
 370                 return -EINVAL;
 371         }
 372
 373         ret = reset_get_by_name(dev, "i2c", &i2c_bus->reset_ctl);
 374         if (ret) {
 375                 pr_err("reset_get_by_name() failed: %d\n", ret);
 376                 return ret;
 377         }
 378         ret = clk_get_by_name(dev, "div-clk", &i2c_bus->clk);
 379         if (ret) {
 380                 pr_err("clk_get_by_name() failed: %d\n", ret);
 381                 return ret;
 382         }
 383
 384 #ifndef CONFIG_TEGRA186
 385         /*
 386          * We don't have a binding for pinmux yet. Leave it out for now. So
 387          * far no one needs anything other than the default.
 388          */
 389         i2c_bus->pinmux_config = FUNCMUX_DEFAULT;
 390
 391         /*
 392          * We can't specify the pinmux config in the fdt, so I2C2 will not
 393          * work on Seaboard. It normally has no devices on it anyway.
 394          * You could add in this little hack if you need to use it.
 395          * The correct solution is a pinmux binding in the fdt.
 396          *
 397          *      if (i2c_bus->clk.id == PERIPH_ID_I2C2)
 398          *              i2c_bus->pinmux_config = FUNCMUX_I2C2_PTA;
 399          */
 400 #endif
 401
 402         is_dvc = dev_get_driver_data(dev) == TYPE_DVC;
 403         if (is_dvc) {
 404                 i2c_bus->control =
 405                         &((struct dvc_ctlr *)i2c_bus->regs)->control;
 406         } else {
 407                 i2c_bus->control = &i2c_bus->regs->control;
 408         }
 409         i2c_init_controller(i2c_bus);
 410         debug("%s: controller bus %d at %p, speed %d: ",
 411               is_dvc ? "dvc" : "i2c", dev_seq(dev), i2c_bus->regs,
 412               i2c_bus->speed);
 413
 414         return 0;
 415 }
 416
 417 /* i2c write version without the register address */
 418 static int i2c_write_data(struct i2c_bus *i2c_bus, uchar chip, uchar *buffer,
 419                           int len, bool end_with_repeated_start)
 420 {
 421         int rc;
 422
 423         debug("i2c_write_data: chip=0x%x, len=0x%x\n", chip, len);
 424         debug("write_data: ");
 425         /* use rc for counter */
 426         for (rc = 0; rc < len; ++rc)
 427                 debug(" 0x%02x", buffer[rc]);
 428         debug("\n");
 429
 430         /* Shift 7-bit address over for lower-level i2c functions */
 431         rc = tegra_i2c_write_data(i2c_bus, chip << 1, buffer, len,
 432                                   end_with_repeated_start);
 433         if (rc)
 434                 debug("i2c_write_data(): rc=%d\n", rc);
 435
 436         return rc;
 437 }
 438
 439 /* i2c read version without the register address */
 440 static int i2c_read_data(struct i2c_bus *i2c_bus, uchar chip, uchar *buffer,
 441                          int len)
 442 {
 443         int rc;
 444
 445         debug("inside i2c_read_data():\n");
 446         /* Shift 7-bit address over for lower-level i2c functions */
 447         rc = tegra_i2c_read_data(i2c_bus, chip << 1, buffer, len);
 448         if (rc) {
 449                 debug("i2c_read_data(): rc=%d\n", rc);
 450                 return rc;
 451         }
 452
 453         debug("i2c_read_data: ");
 454         /* reuse rc for counter*/
 455         for (rc = 0; rc < len; ++rc)
 456                 debug(" 0x%02x", buffer[rc]);
 457         debug("\n");
 458
 459         return 0;
 460 }
 461
 462 /* Probe to see if a chip is present. */
 463 static int tegra_i2c_probe_chip(struct udevice *bus, uint chip_addr,
 464                                 uint chip_flags)
 465 {
 466         struct i2c_bus *i2c_bus = dev_get_priv(bus);
 467         int rc;
 468         u8 reg;
 469
 470         /* Shift 7-bit address over for lower-level i2c functions */
 471         rc = tegra_i2c_write_data(i2c_bus, chip_addr << 1, &reg, sizeof(reg),
 472                                   false);
 473
 474         return rc;
 475 }
 476
 477 static int tegra_i2c_xfer(struct udevice *bus, struct i2c_msg *msg,
 478                           int nmsgs)
 479 {
 480         struct i2c_bus *i2c_bus = dev_get_priv(bus);
 481         int ret;
 482
 483         debug("i2c_xfer: %d messages\n", nmsgs);
 484         for (; nmsgs > 0; nmsgs--, msg++) {
 485                 bool next_is_read = nmsgs > 1 && (msg[1].flags & I2C_M_RD);
 486
 487                 debug("i2c_xfer: chip=0x%x, len=0x%x\n", msg->addr, msg->len);
 488                 if (msg->flags & I2C_M_RD) {
 489                         ret = i2c_read_data(i2c_bus, msg->addr, msg->buf,
 490                                             msg->len);
 491                 } else {
 492                         ret = i2c_write_data(i2c_bus, msg->addr, msg->buf,
 493                                              msg->len, next_is_read);
 494                 }
 495                 if (ret) {
 496                         debug("i2c_write: error sending\n");
 497                         return -EREMOTEIO;
 498                 }
 499         }
 500
 501         return 0;
 502 }
 503
 504 int tegra_i2c_get_dvc_bus(struct udevice **busp)
 505 {
 506         return uclass_first_device_drvdata(UCLASS_I2C, TYPE_DVC, busp);
 507 }
 508
 509 static const struct dm_i2c_ops tegra_i2c_ops = {
 510         .xfer           = tegra_i2c_xfer,
 511         .probe_chip     = tegra_i2c_probe_chip,
 512         .set_bus_speed  = tegra_i2c_set_bus_speed,
 513 };
 514
 515 static const struct udevice_id tegra_i2c_ids[] = {
 516         { .compatible = "nvidia,tegra114-i2c", .data = TYPE_114 },
 517         { .compatible = "nvidia,tegra124-i2c", .data = TYPE_114 },
 518         { .compatible = "nvidia,tegra20-i2c", .data = TYPE_STD },
 519         { .compatible = "nvidia,tegra20-i2c-dvc", .data = TYPE_DVC },
 520         { }
 521 };
 522
 523 U_BOOT_DRIVER(i2c_tegra) = {
 524         .name   = "i2c_tegra",
 525         .id     = UCLASS_I2C,
 526         .of_match = tegra_i2c_ids,
 527         .probe  = tegra_i2c_probe,
 528         .priv_auto      = sizeof(struct i2c_bus),
 529         .ops    = &tegra_i2c_ops,
 530 };