drivers/mfd/cros_ec_spi.c

   1 /*
   2  * ChromeOS EC multi-function device (SPI)
   3  *
   4  * Copyright (C) 2012 Google, Inc
   5  *
   6  * This software is licensed under the terms of the GNU General Public
   7  * License version 2, as published by the Free Software Foundation, and
   8  * may be copied, distributed, and modified under those terms.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  */
  15
  16 #include <linux/delay.h>
  17 #include <linux/kernel.h>
  18 #include <linux/module.h>
  19 #include <linux/mfd/cros_ec.h>
  20 #include <linux/mfd/cros_ec_commands.h>
  21 #include <linux/of.h>
  22 #include <linux/platform_device.h>
  23 #include <linux/slab.h>
  24 #include <linux/spi/spi.h>
  25
  26
  27 /* The header byte, which follows the preamble */
  28 #define EC_MSG_HEADER                   0xec
  29
  30 /*
  31  * Number of EC preamble bytes we read at a time. Since it takes
  32  * about 400-500us for the EC to respond there is not a lot of
  33  * point in tuning this. If the EC could respond faster then
  34  * we could increase this so that might expect the preamble and
  35  * message to occur in a single transaction. However, the maximum
  36  * SPI transfer size is 256 bytes, so at 5MHz we need a response
  37  * time of perhaps <320us (200 bytes / 1600 bits).
  38  */
  39 #define EC_MSG_PREAMBLE_COUNT           32
  40
  41 /*
  42  * Allow for a long time for the EC to respond.  We support i2c
  43  * tunneling and support fairly long messages for the tunnel (249
  44  * bytes long at the moment).  If we're talking to a 100 kHz device
  45  * on the other end and need to transfer ~256 bytes, then we need:
  46  *  10 us/bit * ~10 bits/byte * ~256 bytes = ~25ms
  47  *
  48  * We'll wait 4 times that to handle clock stretching and other
  49  * paranoia.
  50  *
  51  * It's pretty unlikely that we'll really see a 249 byte tunnel in
  52  * anything other than testing.  If this was more common we might
  53  * consider having slow commands like this require a GET_STATUS
  54  * wait loop.  The 'flash write' command would be another candidate
  55  * for this, clocking in at 2-3ms.
  56  */
  57 #define EC_MSG_DEADLINE_MS              100
  58
  59 /*
  60   * Time between raising the SPI chip select (for the end of a
  61   * transaction) and dropping it again (for the next transaction).
  62   * If we go too fast, the EC will miss the transaction. We know that we
  63   * need at least 70 us with the 16 MHz STM32 EC, so go with 200 us to be
  64   * safe.
  65   */
  66 #define EC_SPI_RECOVERY_TIME_NS (200 * 1000)
  67
  68 /**
  69  * struct cros_ec_spi - information about a SPI-connected EC
  70  *
  71  * @spi: SPI device we are connected to
  72  * @last_transfer_ns: time that we last finished a transfer, or 0 if there
  73  *      if no record
  74  * @start_of_msg_delay: used to set the delay_usecs on the spi_transfer that
  75  *      is sent when we want to turn on CS at the start of a transaction.
  76  * @end_of_msg_delay: used to set the delay_usecs on the spi_transfer that
  77  *      is sent when we want to turn off CS at the end of a transaction.
  78  */
  79 struct cros_ec_spi {
  80         struct spi_device *spi;
  81         s64 last_transfer_ns;
  82         unsigned int start_of_msg_delay;
  83         unsigned int end_of_msg_delay;
  84 };
  85
  86 static void debug_packet(struct device *dev, const char *name, u8 *ptr,
  87                          int len)
  88 {
  89 #ifdef DEBUG
  90         int i;
  91
  92         dev_dbg(dev, "%s: ", name);
  93         for (i = 0; i < len; i++)
  94                 pr_cont(" %02x", ptr[i]);
  95
  96         pr_cont("\n");
  97 #endif
  98 }
  99
 100 static int terminate_request(struct cros_ec_device *ec_dev)
 101 {
 102         struct cros_ec_spi *ec_spi = ec_dev->priv;
 103         struct spi_message msg;
 104         struct spi_transfer trans;
 105         int ret;
 106
 107         /*
 108          * Turn off CS, possibly adding a delay to ensure the rising edge
 109          * doesn't come too soon after the end of the data.
 110          */
 111         spi_message_init(&msg);
 112         memset(&trans, 0, sizeof(trans));
 113         trans.delay_usecs = ec_spi->end_of_msg_delay;
 114         spi_message_add_tail(&trans, &msg);
 115
 116         ret = spi_sync_locked(ec_spi->spi, &msg);
 117
 118         /* Reset end-of-response timer */
 119         ec_spi->last_transfer_ns = ktime_get_ns();
 120         if (ret < 0) {
 121                 dev_err(ec_dev->dev,
 122                         "cs-deassert spi transfer failed: %d\n",
 123                         ret);
 124         }
 125
 126         return ret;
 127 }
 128
 129 /**
 130  * receive_n_bytes - receive n bytes from the EC.
 131  *
 132  * Assumes buf is a pointer into the ec_dev->din buffer
 133  */
 134 static int receive_n_bytes(struct cros_ec_device *ec_dev, u8 *buf, int n)
 135 {
 136         struct cros_ec_spi *ec_spi = ec_dev->priv;
 137         struct spi_transfer trans;
 138         struct spi_message msg;
 139         int ret;
 140
 141         BUG_ON(buf - ec_dev->din + n > ec_dev->din_size);
 142
 143         memset(&trans, 0, sizeof(trans));
 144         trans.cs_change = 1;
 145         trans.rx_buf = buf;
 146         trans.len = n;
 147
 148         spi_message_init(&msg);
 149         spi_message_add_tail(&trans, &msg);
 150         ret = spi_sync_locked(ec_spi->spi, &msg);
 151         if (ret < 0)
 152                 dev_err(ec_dev->dev, "spi transfer failed: %d\n", ret);
 153
 154         return ret;
 155 }
 156
 157 /**
 158  * cros_ec_spi_receive_packet - Receive a packet from the EC.
 159  *
 160  * This function has two phases: reading the preamble bytes (since if we read
 161  * data from the EC before it is ready to send, we just get preamble) and
 162  * reading the actual message.
 163  *
 164  * The received data is placed into ec_dev->din.
 165  *
 166  * @ec_dev: ChromeOS EC device
 167  * @need_len: Number of message bytes we need to read
 168  */
 169 static int cros_ec_spi_receive_packet(struct cros_ec_device *ec_dev,
 170                                       int need_len)
 171 {
 172         struct ec_host_response *response;
 173         u8 *ptr, *end;
 174         int ret;
 175         unsigned long deadline;
 176         int todo;
 177
 178         BUG_ON(ec_dev->din_size < EC_MSG_PREAMBLE_COUNT);
 179
 180         /* Receive data until we see the header byte */
 181         deadline = jiffies + msecs_to_jiffies(EC_MSG_DEADLINE_MS);
 182         while (true) {
 183                 unsigned long start_jiffies = jiffies;
 184
 185                 ret = receive_n_bytes(ec_dev,
 186                                       ec_dev->din,
 187                                       EC_MSG_PREAMBLE_COUNT);
 188                 if (ret < 0)
 189                         return ret;
 190
 191                 ptr = ec_dev->din;
 192                 for (end = ptr + EC_MSG_PREAMBLE_COUNT; ptr != end; ptr++) {
 193                         if (*ptr == EC_SPI_FRAME_START) {
 194                                 dev_dbg(ec_dev->dev, "msg found at %zd\n",
 195                                         ptr - ec_dev->din);
 196                                 break;
 197                         }
 198                 }
 199                 if (ptr != end)
 200                         break;
 201
 202                 /*
 203                  * Use the time at the start of the loop as a timeout.  This
 204                  * gives us one last shot at getting the transfer and is useful
 205                  * in case we got context switched out for a while.
 206                  */
 207                 if (time_after(start_jiffies, deadline)) {
 208                         dev_warn(ec_dev->dev, "EC failed to respond in time\n");
 209                         return -ETIMEDOUT;
 210                 }
 211         }
 212
 213         /*
 214          * ptr now points to the header byte. Copy any valid data to the
 215          * start of our buffer
 216          */
 217         todo = end - ++ptr;
 218         BUG_ON(todo < 0 || todo > ec_dev->din_size);
 219         todo = min(todo, need_len);
 220         memmove(ec_dev->din, ptr, todo);
 221         ptr = ec_dev->din + todo;
 222         dev_dbg(ec_dev->dev, "need %d, got %d bytes from preamble\n",
 223                 need_len, todo);
 224         need_len -= todo;
 225
 226         /* If the entire response struct wasn't read, get the rest of it. */
 227         if (todo < sizeof(*response)) {
 228                 ret = receive_n_bytes(ec_dev, ptr, sizeof(*response) - todo);
 229                 if (ret < 0)
 230                         return -EBADMSG;
 231                 ptr += (sizeof(*response) - todo);
 232                 todo = sizeof(*response);
 233         }
 234
 235         response = (struct ec_host_response *)ec_dev->din;
 236
 237         /* Abort if data_len is too large. */
 238         if (response->data_len > ec_dev->din_size)
 239                 return -EMSGSIZE;
 240
 241         /* Receive data until we have it all */
 242         while (need_len > 0) {
 243                 /*
 244                  * We can't support transfers larger than the SPI FIFO size
 245                  * unless we have DMA. We don't have DMA on the ISP SPI ports
 246                  * for Exynos. We need a way of asking SPI driver for
 247                  * maximum-supported transfer size.
 248                  */
 249                 todo = min(need_len, 256);
 250                 dev_dbg(ec_dev->dev, "loop, todo=%d, need_len=%d, ptr=%zd\n",
 251                         todo, need_len, ptr - ec_dev->din);
 252
 253                 ret = receive_n_bytes(ec_dev, ptr, todo);
 254                 if (ret < 0)
 255                         return ret;
 256
 257                 ptr += todo;
 258                 need_len -= todo;
 259         }
 260
 261         dev_dbg(ec_dev->dev, "loop done, ptr=%zd\n", ptr - ec_dev->din);
 262
 263         return 0;
 264 }
 265
 266 /**
 267  * cros_ec_spi_receive_response - Receive a response from the EC.
 268  *
 269  * This function has two phases: reading the preamble bytes (since if we read
 270  * data from the EC before it is ready to send, we just get preamble) and
 271  * reading the actual message.
 272  *
 273  * The received data is placed into ec_dev->din.
 274  *
 275  * @ec_dev: ChromeOS EC device
 276  * @need_len: Number of message bytes we need to read
 277  */
 278 static int cros_ec_spi_receive_response(struct cros_ec_device *ec_dev,
 279                                         int need_len)
 280 {
 281         u8 *ptr, *end;
 282         int ret;
 283         unsigned long deadline;
 284         int todo;
 285
 286         BUG_ON(ec_dev->din_size < EC_MSG_PREAMBLE_COUNT);
 287
 288         /* Receive data until we see the header byte */
 289         deadline = jiffies + msecs_to_jiffies(EC_MSG_DEADLINE_MS);
 290         while (true) {
 291                 unsigned long start_jiffies = jiffies;
 292
 293                 ret = receive_n_bytes(ec_dev,
 294                                       ec_dev->din,
 295                                       EC_MSG_PREAMBLE_COUNT);
 296                 if (ret < 0)
 297                         return ret;
 298
 299                 ptr = ec_dev->din;
 300                 for (end = ptr + EC_MSG_PREAMBLE_COUNT; ptr != end; ptr++) {
 301                         if (*ptr == EC_SPI_FRAME_START) {
 302                                 dev_dbg(ec_dev->dev, "msg found at %zd\n",
 303                                         ptr - ec_dev->din);
 304                                 break;
 305                         }
 306                 }
 307                 if (ptr != end)
 308                         break;
 309
 310                 /*
 311                  * Use the time at the start of the loop as a timeout.  This
 312                  * gives us one last shot at getting the transfer and is useful
 313                  * in case we got context switched out for a while.
 314                  */
 315                 if (time_after(start_jiffies, deadline)) {
 316                         dev_warn(ec_dev->dev, "EC failed to respond in time\n");
 317                         return -ETIMEDOUT;
 318                 }
 319         }
 320
 321         /*
 322          * ptr now points to the header byte. Copy any valid data to the
 323          * start of our buffer
 324          */
 325         todo = end - ++ptr;
 326         BUG_ON(todo < 0 || todo > ec_dev->din_size);
 327         todo = min(todo, need_len);
 328         memmove(ec_dev->din, ptr, todo);
 329         ptr = ec_dev->din + todo;
 330         dev_dbg(ec_dev->dev, "need %d, got %d bytes from preamble\n",
 331                  need_len, todo);
 332         need_len -= todo;
 333
 334         /* Receive data until we have it all */
 335         while (need_len > 0) {
 336                 /*
 337                  * We can't support transfers larger than the SPI FIFO size
 338                  * unless we have DMA. We don't have DMA on the ISP SPI ports
 339                  * for Exynos. We need a way of asking SPI driver for
 340                  * maximum-supported transfer size.
 341                  */
 342                 todo = min(need_len, 256);
 343                 dev_dbg(ec_dev->dev, "loop, todo=%d, need_len=%d, ptr=%zd\n",
 344                         todo, need_len, ptr - ec_dev->din);
 345
 346                 ret = receive_n_bytes(ec_dev, ptr, todo);
 347                 if (ret < 0)
 348                         return ret;
 349
 350                 debug_packet(ec_dev->dev, "interim", ptr, todo);
 351                 ptr += todo;
 352                 need_len -= todo;
 353         }
 354
 355         dev_dbg(ec_dev->dev, "loop done, ptr=%zd\n", ptr - ec_dev->din);
 356
 357         return 0;
 358 }
 359
 360 /**
 361  * cros_ec_pkt_xfer_spi - Transfer a packet over SPI and receive the reply
 362  *
 363  * @ec_dev: ChromeOS EC device
 364  * @ec_msg: Message to transfer
 365  */
 366 static int cros_ec_pkt_xfer_spi(struct cros_ec_device *ec_dev,
 367                                 struct cros_ec_command *ec_msg)
 368 {
 369         struct ec_host_response *response;
 370         struct cros_ec_spi *ec_spi = ec_dev->priv;
 371         struct spi_transfer trans, trans_delay;
 372         struct spi_message msg;
 373         int i, len;
 374         u8 *ptr;
 375         u8 *rx_buf;
 376         u8 sum;
 377         int ret = 0, final_ret;
 378
 379         len = cros_ec_prepare_tx(ec_dev, ec_msg);
 380         dev_dbg(ec_dev->dev, "prepared, len=%d\n", len);
 381
 382         /* If it's too soon to do another transaction, wait */
 383         if (ec_spi->last_transfer_ns) {
 384                 unsigned long delay;    /* The delay completed so far */
 385
 386                 delay = ktime_get_ns() - ec_spi->last_transfer_ns;
 387                 if (delay < EC_SPI_RECOVERY_TIME_NS)
 388                         ndelay(EC_SPI_RECOVERY_TIME_NS - delay);
 389         }
 390
 391         rx_buf = kzalloc(len, GFP_KERNEL);
 392         if (!rx_buf)
 393                 return -ENOMEM;
 394
 395         spi_bus_lock(ec_spi->spi->master);
 396
 397         /*
 398          * Leave a gap between CS assertion and clocking of data to allow the
 399          * EC time to wakeup.
 400          */
 401         spi_message_init(&msg);
 402         if (ec_spi->start_of_msg_delay) {
 403                 memset(&trans_delay, 0, sizeof(trans_delay));
 404                 trans_delay.delay_usecs = ec_spi->start_of_msg_delay;
 405                 spi_message_add_tail(&trans_delay, &msg);
 406         }
 407
 408         /* Transmit phase - send our message */
 409         memset(&trans, 0, sizeof(trans));
 410         trans.tx_buf = ec_dev->dout;
 411         trans.rx_buf = rx_buf;
 412         trans.len = len;
 413         trans.cs_change = 1;
 414         spi_message_add_tail(&trans, &msg);
 415         ret = spi_sync_locked(ec_spi->spi, &msg);
 416
 417         /* Get the response */
 418         if (!ret) {
 419                 /* Verify that EC can process command */
 420                 for (i = 0; i < len; i++) {
 421                         switch (rx_buf[i]) {
 422                         case EC_SPI_PAST_END:
 423                         case EC_SPI_RX_BAD_DATA:
 424                         case EC_SPI_NOT_READY:
 425                                 ret = -EAGAIN;
 426                                 ec_msg->result = EC_RES_IN_PROGRESS;
 427                         default:
 428                                 break;
 429                         }
 430                         if (ret)
 431                                 break;
 432                 }
 433                 if (!ret)
 434                         ret = cros_ec_spi_receive_packet(ec_dev,
 435                                         ec_msg->insize + sizeof(*response));
 436         } else {
 437                 dev_err(ec_dev->dev, "spi transfer failed: %d\n", ret);
 438         }
 439
 440         final_ret = terminate_request(ec_dev);
 441
 442         spi_bus_unlock(ec_spi->spi->master);
 443
 444         if (!ret)
 445                 ret = final_ret;
 446         if (ret < 0)
 447                 goto exit;
 448
 449         ptr = ec_dev->din;
 450
 451         /* check response error code */
 452         response = (struct ec_host_response *)ptr;
 453         ec_msg->result = response->result;
 454
 455         ret = cros_ec_check_result(ec_dev, ec_msg);
 456         if (ret)
 457                 goto exit;
 458
 459         len = response->data_len;
 460         sum = 0;
 461         if (len > ec_msg->insize) {
 462                 dev_err(ec_dev->dev, "packet too long (%d bytes, expected %d)",
 463                         len, ec_msg->insize);
 464                 ret = -EMSGSIZE;
 465                 goto exit;
 466         }
 467
 468         for (i = 0; i < sizeof(*response); i++)
 469                 sum += ptr[i];
 470
 471         /* copy response packet payload and compute checksum */
 472         memcpy(ec_msg->data, ptr + sizeof(*response), len);
 473         for (i = 0; i < len; i++)
 474                 sum += ec_msg->data[i];
 475
 476         if (sum) {
 477                 dev_err(ec_dev->dev,
 478                         "bad packet checksum, calculated %x\n",
 479                         sum);
 480                 ret = -EBADMSG;
 481                 goto exit;
 482         }
 483
 484         ret = len;
 485 exit:
 486         kfree(rx_buf);
 487         if (ec_msg->command == EC_CMD_REBOOT_EC)
 488                 msleep(EC_REBOOT_DELAY_MS);
 489
 490         return ret;
 491 }
 492
 493 /**
 494  * cros_ec_cmd_xfer_spi - Transfer a message over SPI and receive the reply
 495  *
 496  * @ec_dev: ChromeOS EC device
 497  * @ec_msg: Message to transfer
 498  */
 499 static int cros_ec_cmd_xfer_spi(struct cros_ec_device *ec_dev,
 500                                 struct cros_ec_command *ec_msg)
 501 {
 502         struct cros_ec_spi *ec_spi = ec_dev->priv;
 503         struct spi_transfer trans;
 504         struct spi_message msg;
 505         int i, len;
 506         u8 *ptr;
 507         u8 *rx_buf;
 508         int sum;
 509         int ret = 0, final_ret;
 510
 511         len = cros_ec_prepare_tx(ec_dev, ec_msg);
 512         dev_dbg(ec_dev->dev, "prepared, len=%d\n", len);
 513
 514         /* If it's too soon to do another transaction, wait */
 515         if (ec_spi->last_transfer_ns) {
 516                 unsigned long delay;    /* The delay completed so far */
 517
 518                 delay = ktime_get_ns() - ec_spi->last_transfer_ns;
 519                 if (delay < EC_SPI_RECOVERY_TIME_NS)
 520                         ndelay(EC_SPI_RECOVERY_TIME_NS - delay);
 521         }
 522
 523         rx_buf = kzalloc(len, GFP_KERNEL);
 524         if (!rx_buf)
 525                 return -ENOMEM;
 526
 527         spi_bus_lock(ec_spi->spi->master);
 528
 529         /* Transmit phase - send our message */
 530         debug_packet(ec_dev->dev, "out", ec_dev->dout, len);
 531         memset(&trans, 0, sizeof(trans));
 532         trans.tx_buf = ec_dev->dout;
 533         trans.rx_buf = rx_buf;
 534         trans.len = len;
 535         trans.cs_change = 1;
 536         spi_message_init(&msg);
 537         spi_message_add_tail(&trans, &msg);
 538         ret = spi_sync_locked(ec_spi->spi, &msg);
 539
 540         /* Get the response */
 541         if (!ret) {
 542                 /* Verify that EC can process command */
 543                 for (i = 0; i < len; i++) {
 544                         switch (rx_buf[i]) {
 545                         case EC_SPI_PAST_END:
 546                         case EC_SPI_RX_BAD_DATA:
 547                         case EC_SPI_NOT_READY:
 548                                 ret = -EAGAIN;
 549                                 ec_msg->result = EC_RES_IN_PROGRESS;
 550                         default:
 551                                 break;
 552                         }
 553                         if (ret)
 554                                 break;
 555                 }
 556                 if (!ret)
 557                         ret = cros_ec_spi_receive_response(ec_dev,
 558                                         ec_msg->insize + EC_MSG_TX_PROTO_BYTES);
 559         } else {
 560                 dev_err(ec_dev->dev, "spi transfer failed: %d\n", ret);
 561         }
 562
 563         final_ret = terminate_request(ec_dev);
 564
 565         spi_bus_unlock(ec_spi->spi->master);
 566
 567         if (!ret)
 568                 ret = final_ret;
 569         if (ret < 0)
 570                 goto exit;
 571
 572         ptr = ec_dev->din;
 573
 574         /* check response error code */
 575         ec_msg->result = ptr[0];
 576         ret = cros_ec_check_result(ec_dev, ec_msg);
 577         if (ret)
 578                 goto exit;
 579
 580         len = ptr[1];
 581         sum = ptr[0] + ptr[1];
 582         if (len > ec_msg->insize) {
 583                 dev_err(ec_dev->dev, "packet too long (%d bytes, expected %d)",
 584                         len, ec_msg->insize);
 585                 ret = -ENOSPC;
 586                 goto exit;
 587         }
 588
 589         /* copy response packet payload and compute checksum */
 590         for (i = 0; i < len; i++) {
 591                 sum += ptr[i + 2];
 592                 if (ec_msg->insize)
 593                         ec_msg->data[i] = ptr[i + 2];
 594         }
 595         sum &= 0xff;
 596
 597         debug_packet(ec_dev->dev, "in", ptr, len + 3);
 598
 599         if (sum != ptr[len + 2]) {
 600                 dev_err(ec_dev->dev,
 601                         "bad packet checksum, expected %02x, got %02x\n",
 602                         sum, ptr[len + 2]);
 603                 ret = -EBADMSG;
 604                 goto exit;
 605         }
 606
 607         ret = len;
 608 exit:
 609         kfree(rx_buf);
 610         if (ec_msg->command == EC_CMD_REBOOT_EC)
 611                 msleep(EC_REBOOT_DELAY_MS);
 612
 613         return ret;
 614 }
 615
 616 static void cros_ec_spi_dt_probe(struct cros_ec_spi *ec_spi, struct device *dev)
 617 {
 618         struct device_node *np = dev->of_node;
 619         u32 val;
 620         int ret;
 621
 622         ret = of_property_read_u32(np, "google,cros-ec-spi-pre-delay", &val);
 623         if (!ret)
 624                 ec_spi->start_of_msg_delay = val;
 625
 626         ret = of_property_read_u32(np, "google,cros-ec-spi-msg-delay", &val);
 627         if (!ret)
 628                 ec_spi->end_of_msg_delay = val;
 629 }
 630
 631 static int cros_ec_spi_probe(struct spi_device *spi)
 632 {
 633         struct device *dev = &spi->dev;
 634         struct cros_ec_device *ec_dev;
 635         struct cros_ec_spi *ec_spi;
 636         int err;
 637
 638         spi->bits_per_word = 8;
 639         spi->mode = SPI_MODE_0;
 640         err = spi_setup(spi);
 641         if (err < 0)
 642                 return err;
 643
 644         ec_spi = devm_kzalloc(dev, sizeof(*ec_spi), GFP_KERNEL);
 645         if (ec_spi == NULL)
 646                 return -ENOMEM;
 647         ec_spi->spi = spi;
 648         ec_dev = devm_kzalloc(dev, sizeof(*ec_dev), GFP_KERNEL);
 649         if (!ec_dev)
 650                 return -ENOMEM;
 651
 652         /* Check for any DT properties */
 653         cros_ec_spi_dt_probe(ec_spi, dev);
 654
 655         spi_set_drvdata(spi, ec_dev);
 656         ec_dev->dev = dev;
 657         ec_dev->priv = ec_spi;
 658         ec_dev->irq = spi->irq;
 659         ec_dev->cmd_xfer = cros_ec_cmd_xfer_spi;
 660         ec_dev->pkt_xfer = cros_ec_pkt_xfer_spi;
 661         ec_dev->phys_name = dev_name(&ec_spi->spi->dev);
 662         ec_dev->din_size = EC_MSG_PREAMBLE_COUNT +
 663                            sizeof(struct ec_host_response) +
 664                            sizeof(struct ec_response_get_protocol_info);
 665         ec_dev->dout_size = sizeof(struct ec_host_request);
 666
 667
 668         err = cros_ec_register(ec_dev);
 669         if (err) {
 670                 dev_err(dev, "cannot register EC\n");
 671                 return err;
 672         }
 673
 674         device_init_wakeup(&spi->dev, true);
 675
 676         return 0;
 677 }
 678
 679 static int cros_ec_spi_remove(struct spi_device *spi)
 680 {
 681         struct cros_ec_device *ec_dev;
 682
 683         ec_dev = spi_get_drvdata(spi);
 684         cros_ec_remove(ec_dev);
 685
 686         return 0;
 687 }
 688
 689 #ifdef CONFIG_PM_SLEEP
 690 static int cros_ec_spi_suspend(struct device *dev)
 691 {
 692         struct cros_ec_device *ec_dev = dev_get_drvdata(dev);
 693
 694         return cros_ec_suspend(ec_dev);
 695 }
 696
 697 static int cros_ec_spi_resume(struct device *dev)
 698 {
 699         struct cros_ec_device *ec_dev = dev_get_drvdata(dev);
 700
 701         return cros_ec_resume(ec_dev);
 702 }
 703 #endif
 704
 705 static SIMPLE_DEV_PM_OPS(cros_ec_spi_pm_ops, cros_ec_spi_suspend,
 706                          cros_ec_spi_resume);
 707
 708 static const struct of_device_id cros_ec_spi_of_match[] = {
 709         { .compatible = "google,cros-ec-spi", },
 710         { /* sentinel */ },
 711 };
 712 MODULE_DEVICE_TABLE(of, cros_ec_spi_of_match);
 713
 714 static const struct spi_device_id cros_ec_spi_id[] = {
 715         { "cros-ec-spi", 0 },
 716         { }
 717 };
 718 MODULE_DEVICE_TABLE(spi, cros_ec_spi_id);
 719
 720 static struct spi_driver cros_ec_driver_spi = {
 721         .driver = {
 722                 .name   = "cros-ec-spi",
 723                 .of_match_table = of_match_ptr(cros_ec_spi_of_match),
 724                 .pm     = &cros_ec_spi_pm_ops,
 725         },
 726         .probe          = cros_ec_spi_probe,
 727         .remove         = cros_ec_spi_remove,
 728         .id_table       = cros_ec_spi_id,
 729 };
 730
 731 module_spi_driver(cros_ec_driver_spi);
 732
 733 MODULE_LICENSE("GPL v2");
 734 MODULE_DESCRIPTION("ChromeOS EC multi function device (SPI)");