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