drivers/platform/chrome/cros_ec_ishtp.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 // ISHTP interface for ChromeOS Embedded Controller
   3 //
   4 // Copyright (c) 2019, Intel Corporation.
   5 //
   6 // ISHTP client driver for talking to the Chrome OS EC firmware running
   7 // on Intel Integrated Sensor Hub (ISH) using the ISH Transport protocol
   8 // (ISH-TP).
   9
  10 #include <linux/delay.h>
  11 #include <linux/module.h>
  12 #include <linux/pci.h>
  13 #include <linux/platform_data/cros_ec_commands.h>
  14 #include <linux/platform_data/cros_ec_proto.h>
  15 #include <linux/intel-ish-client-if.h>
  16
  17 #include "cros_ec.h"
  18
  19 /*
  20  * ISH TX/RX ring buffer pool size
  21  *
  22  * The AP->ISH messages and corresponding ISH->AP responses are
  23  * serialized. We need 1 TX and 1 RX buffer for these.
  24  *
  25  * The MKBP ISH->AP events are serialized. We need one additional RX
  26  * buffer for them.
  27  */
  28 #define CROS_ISH_CL_TX_RING_SIZE                8
  29 #define CROS_ISH_CL_RX_RING_SIZE                8
  30
  31 /* ISH CrOS EC Host Commands */
  32 enum cros_ec_ish_channel {
  33         CROS_EC_COMMAND = 1,                    /* AP->ISH message */
  34         CROS_MKBP_EVENT = 2,                    /* ISH->AP events */
  35 };
  36
  37 /*
  38  * ISH firmware timeout for 1 message send failure is 1Hz, and the
  39  * firmware will retry 2 times, so 3Hz is used for timeout.
  40  */
  41 #define ISHTP_SEND_TIMEOUT                      (3 * HZ)
  42
  43 /* ISH Transport CrOS EC ISH client unique GUID */
  44 static const struct ishtp_device_id cros_ec_ishtp_id_table[] = {
  45         { .guid = GUID_INIT(0x7b7154d0, 0x56f4, 0x4bdc,
  46                   0xb0, 0xd8, 0x9e, 0x7c, 0xda, 0xe0, 0xd6, 0xa0), },
  47         { }
  48 };
  49 MODULE_DEVICE_TABLE(ishtp, cros_ec_ishtp_id_table);
  50
  51 struct header {
  52         u8 channel;
  53         u8 status;
  54         u8 token;
  55         u8 reserved;
  56 } __packed;
  57
  58 struct cros_ish_out_msg {
  59         struct header hdr;
  60         struct ec_host_request ec_request;
  61 } __packed;
  62
  63 struct cros_ish_in_msg {
  64         struct header hdr;
  65         struct ec_host_response ec_response;
  66 } __packed;
  67
  68 #define IN_MSG_EC_RESPONSE_PREAMBLE                                     \
  69         offsetof(struct cros_ish_in_msg, ec_response)
  70
  71 #define OUT_MSG_EC_REQUEST_PREAMBLE                                     \
  72         offsetof(struct cros_ish_out_msg, ec_request)
  73
  74 #define cl_data_to_dev(client_data) ishtp_device((client_data)->cl_device)
  75
  76 /*
  77  * The Read-Write Semaphore is used to prevent message TX or RX while
  78  * the ishtp client is being initialized or undergoing reset.
  79  *
  80  * The readers are the kernel function calls responsible for IA->ISH
  81  * and ISH->AP messaging.
  82  *
  83  * The writers are .reset() and .probe() function.
  84  */
  85 static DECLARE_RWSEM(init_lock);
  86
  87 /**
  88  * struct response_info - Encapsulate firmware response related
  89  * information for passing between function ish_send() and
  90  * process_recv() callback.
  91  *
  92  * @data: Copy the data received from firmware here.
  93  * @max_size: Max size allocated for the @data buffer. If the received
  94  * data exceeds this value, we log an error.
  95  * @size: Actual size of data received from firmware.
  96  * @error: 0 for success, negative error code for a failure in process_recv().
  97  * @token: Expected token for response that we are waiting on.
  98  * @received: Set to true on receiving a valid firmware response to host command
  99  * @wait_queue: Wait queue for host to wait for firmware response.
 100  */
 101 struct response_info {
 102         void *data;
 103         size_t max_size;
 104         size_t size;
 105         int error;
 106         u8 token;
 107         bool received;
 108         wait_queue_head_t wait_queue;
 109 };
 110
 111 /**
 112  * struct ishtp_cl_data - Encapsulate per ISH TP Client.
 113  *
 114  * @cros_ish_cl: ISHTP firmware client instance.
 115  * @cl_device: ISHTP client device instance.
 116  * @response: Response info passing between ish_send() and process_recv().
 117  * @work_ishtp_reset: Work queue reset handling.
 118  * @work_ec_evt: Work queue for EC events.
 119  * @ec_dev: CrOS EC MFD device.
 120  *
 121  * This structure is used to store per client data.
 122  */
 123 struct ishtp_cl_data {
 124         struct ishtp_cl *cros_ish_cl;
 125         struct ishtp_cl_device *cl_device;
 126
 127         /*
 128          * Used for passing firmware response information between
 129          * ish_send() and process_recv() callback.
 130          */
 131         struct response_info response;
 132
 133         struct work_struct work_ishtp_reset;
 134         struct work_struct work_ec_evt;
 135         struct cros_ec_device *ec_dev;
 136 };
 137
 138 /**
 139  * ish_evt_handler - ISH to AP event handler
 140  * @work: Work struct
 141  */
 142 static void ish_evt_handler(struct work_struct *work)
 143 {
 144         struct ishtp_cl_data *client_data =
 145                 container_of(work, struct ishtp_cl_data, work_ec_evt);
 146
 147         cros_ec_irq_thread(0, client_data->ec_dev);
 148 }
 149
 150 /**
 151  * ish_send() - Send message from host to firmware
 152  *
 153  * @client_data: Client data instance
 154  * @out_msg: Message buffer to be sent to firmware
 155  * @out_size: Size of out going message
 156  * @in_msg: Message buffer where the incoming data is copied. This buffer
 157  * is allocated by calling
 158  * @in_size: Max size of incoming message
 159  *
 160  * Return: Number of bytes copied in the in_msg on success, negative
 161  * error code on failure.
 162  */
 163 static int ish_send(struct ishtp_cl_data *client_data,
 164                     u8 *out_msg, size_t out_size,
 165                     u8 *in_msg, size_t in_size)
 166 {
 167         static u8 next_token;
 168         int rv;
 169         struct header *out_hdr = (struct header *)out_msg;
 170         struct ishtp_cl *cros_ish_cl = client_data->cros_ish_cl;
 171
 172         dev_dbg(cl_data_to_dev(client_data),
 173                 "%s: channel=%02u status=%02u\n",
 174                 __func__, out_hdr->channel, out_hdr->status);
 175
 176         /* Setup for incoming response */
 177         client_data->response.data = in_msg;
 178         client_data->response.max_size = in_size;
 179         client_data->response.error = 0;
 180         client_data->response.token = next_token++;
 181         client_data->response.received = false;
 182
 183         out_hdr->token = client_data->response.token;
 184
 185         rv = ishtp_cl_send(cros_ish_cl, out_msg, out_size);
 186         if (rv) {
 187                 dev_err(cl_data_to_dev(client_data),
 188                         "ishtp_cl_send error %d\n", rv);
 189                 return rv;
 190         }
 191
 192         wait_event_interruptible_timeout(client_data->response.wait_queue,
 193                                          client_data->response.received,
 194                                          ISHTP_SEND_TIMEOUT);
 195         if (!client_data->response.received) {
 196                 dev_err(cl_data_to_dev(client_data),
 197                         "Timed out for response to host message\n");
 198                 return -ETIMEDOUT;
 199         }
 200
 201         if (client_data->response.error < 0)
 202                 return client_data->response.error;
 203
 204         return client_data->response.size;
 205 }
 206
 207 /**
 208  * process_recv() - Received and parse incoming packet
 209  * @cros_ish_cl: Client instance to get stats
 210  * @rb_in_proc: Host interface message buffer
 211  * @timestamp: Timestamp of when parent callback started
 212  *
 213  * Parse the incoming packet. If it is a response packet then it will
 214  * update per instance flags and wake up the caller waiting to for the
 215  * response. If it is an event packet then it will schedule event work.
 216  */
 217 static void process_recv(struct ishtp_cl *cros_ish_cl,
 218                          struct ishtp_cl_rb *rb_in_proc, ktime_t timestamp)
 219 {
 220         size_t data_len = rb_in_proc->buf_idx;
 221         struct ishtp_cl_data *client_data =
 222                 ishtp_get_client_data(cros_ish_cl);
 223         struct device *dev = cl_data_to_dev(client_data);
 224         struct cros_ish_in_msg *in_msg =
 225                 (struct cros_ish_in_msg *)rb_in_proc->buffer.data;
 226
 227         /* Proceed only if reset or init is not in progress */
 228         if (!down_read_trylock(&init_lock)) {
 229                 /* Free the buffer */
 230                 ishtp_cl_io_rb_recycle(rb_in_proc);
 231                 dev_warn(dev,
 232                          "Host is not ready to receive incoming messages\n");
 233                 return;
 234         }
 235
 236         /*
 237          * All firmware messages contain a header. Check the buffer size
 238          * before accessing elements inside.
 239          */
 240         if (!rb_in_proc->buffer.data) {
 241                 dev_warn(dev, "rb_in_proc->buffer.data returned null");
 242                 client_data->response.error = -EBADMSG;
 243                 goto end_error;
 244         }
 245
 246         if (data_len < sizeof(struct header)) {
 247                 dev_err(dev, "data size %zu is less than header %zu\n",
 248                         data_len, sizeof(struct header));
 249                 client_data->response.error = -EMSGSIZE;
 250                 goto end_error;
 251         }
 252
 253         dev_dbg(dev, "channel=%02u status=%02u\n",
 254                 in_msg->hdr.channel, in_msg->hdr.status);
 255
 256         switch (in_msg->hdr.channel) {
 257         case CROS_EC_COMMAND:
 258                 if (client_data->response.received) {
 259                         dev_err(dev,
 260                                 "Previous firmware message not yet processed\n");
 261                         goto end_error;
 262                 }
 263
 264                 if (client_data->response.token != in_msg->hdr.token) {
 265                         dev_err_ratelimited(dev,
 266                                             "Dropping old response token %d\n",
 267                                             in_msg->hdr.token);
 268                         goto end_error;
 269                 }
 270
 271                 /* Sanity check */
 272                 if (!client_data->response.data) {
 273                         dev_err(dev,
 274                                 "Receiving buffer is null. Should be allocated by calling function\n");
 275                         client_data->response.error = -EINVAL;
 276                         goto error_wake_up;
 277                 }
 278
 279                 if (data_len > client_data->response.max_size) {
 280                         dev_err(dev,
 281                                 "Received buffer size %zu is larger than allocated buffer %zu\n",
 282                                 data_len, client_data->response.max_size);
 283                         client_data->response.error = -EMSGSIZE;
 284                         goto error_wake_up;
 285                 }
 286
 287                 if (in_msg->hdr.status) {
 288                         dev_err(dev, "firmware returned status %d\n",
 289                                 in_msg->hdr.status);
 290                         client_data->response.error = -EIO;
 291                         goto error_wake_up;
 292                 }
 293
 294                 /* Update the actual received buffer size */
 295                 client_data->response.size = data_len;
 296
 297                 /*
 298                  * Copy the buffer received in firmware response for the
 299                  * calling thread.
 300                  */
 301                 memcpy(client_data->response.data,
 302                        rb_in_proc->buffer.data, data_len);
 303
 304 error_wake_up:
 305                 /* Free the buffer since we copied data or didn't need it */
 306                 ishtp_cl_io_rb_recycle(rb_in_proc);
 307                 rb_in_proc = NULL;
 308
 309                 /* Set flag before waking up the caller */
 310                 client_data->response.received = true;
 311
 312                 /* Wake the calling thread */
 313                 wake_up_interruptible(&client_data->response.wait_queue);
 314
 315                 break;
 316
 317         case CROS_MKBP_EVENT:
 318                 /* Free the buffer. This is just an event without data */
 319                 ishtp_cl_io_rb_recycle(rb_in_proc);
 320                 rb_in_proc = NULL;
 321                 /*
 322                  * Set timestamp from beginning of function since we actually
 323                  * got an incoming MKBP event
 324                  */
 325                 client_data->ec_dev->last_event_time = timestamp;
 326                 schedule_work(&client_data->work_ec_evt);
 327
 328                 break;
 329
 330         default:
 331                 dev_err(dev, "Invalid channel=%02d\n", in_msg->hdr.channel);
 332         }
 333
 334 end_error:
 335         /* Free the buffer if we already haven't */
 336         if (rb_in_proc)
 337                 ishtp_cl_io_rb_recycle(rb_in_proc);
 338
 339         up_read(&init_lock);
 340 }
 341
 342 /**
 343  * ish_event_cb() - bus driver callback for incoming message
 344  * @cl_device: ISHTP client device for which this message is targeted.
 345  *
 346  * Remove the packet from the list and process the message by calling
 347  * process_recv.
 348  */
 349 static void ish_event_cb(struct ishtp_cl_device *cl_device)
 350 {
 351         struct ishtp_cl_rb *rb_in_proc;
 352         struct ishtp_cl *cros_ish_cl = ishtp_get_drvdata(cl_device);
 353         ktime_t timestamp;
 354
 355         /*
 356          * Take timestamp as close to hardware interrupt as possible for sensor
 357          * timestamps.
 358          */
 359         timestamp = cros_ec_get_time_ns();
 360
 361         while ((rb_in_proc = ishtp_cl_rx_get_rb(cros_ish_cl)) != NULL) {
 362                 /* Decide what to do with received data */
 363                 process_recv(cros_ish_cl, rb_in_proc, timestamp);
 364         }
 365 }
 366
 367 /**
 368  * cros_ish_init() - Init function for ISHTP client
 369  * @cros_ish_cl: ISHTP client instance
 370  * @reset: true if called from reset handler
 371  *
 372  * This function complete the initializtion of the client.
 373  *
 374  * Return: 0 for success, negative error code for failure.
 375  */
 376 static int cros_ish_init(struct ishtp_cl *cros_ish_cl, bool reset)
 377 {
 378         int rv;
 379         struct ishtp_cl_data *client_data = ishtp_get_client_data(cros_ish_cl);
 380
 381         rv = ishtp_cl_establish_connection(cros_ish_cl,
 382                                            &cros_ec_ishtp_id_table[0].guid,
 383                                            CROS_ISH_CL_TX_RING_SIZE,
 384                                            CROS_ISH_CL_RX_RING_SIZE,
 385                                            reset);
 386         if (rv) {
 387                 dev_err(cl_data_to_dev(client_data),
 388                         "client connect fail\n");
 389                 goto err_cl_disconnect;
 390         }
 391
 392         ishtp_register_event_cb(client_data->cl_device, ish_event_cb);
 393         return 0;
 394
 395 err_cl_disconnect:
 396         ishtp_cl_destroy_connection(cros_ish_cl, reset);
 397         return rv;
 398 }
 399
 400 /**
 401  * cros_ish_deinit() - Deinit function for ISHTP client
 402  * @cros_ish_cl: ISHTP client instance
 403  *
 404  * Unlink and free cros_ec client
 405  */
 406 static void cros_ish_deinit(struct ishtp_cl *cros_ish_cl)
 407 {
 408         ishtp_cl_destroy_connection(cros_ish_cl, false);
 409
 410         /* Disband and free all Tx and Rx client-level rings */
 411         ishtp_cl_free(cros_ish_cl);
 412 }
 413
 414 /**
 415  * prepare_cros_ec_rx() - Check & prepare receive buffer
 416  * @ec_dev: CrOS EC MFD device.
 417  * @in_msg: Incoming message buffer
 418  * @msg: cros_ec command used to send & receive data
 419  *
 420  * Return: 0 for success, negative error code for failure.
 421  *
 422  * Check the received buffer. Convert to cros_ec_command format.
 423  */
 424 static int prepare_cros_ec_rx(struct cros_ec_device *ec_dev,
 425                               const struct cros_ish_in_msg *in_msg,
 426                               struct cros_ec_command *msg)
 427 {
 428         u8 sum = 0;
 429         int i, rv, offset;
 430
 431         /* Check response error code */
 432         msg->result = in_msg->ec_response.result;
 433         rv = cros_ec_check_result(ec_dev, msg);
 434         if (rv < 0)
 435                 return rv;
 436
 437         if (in_msg->ec_response.data_len > msg->insize) {
 438                 dev_err(ec_dev->dev, "Packet too long (%d bytes, expected %d)",
 439                         in_msg->ec_response.data_len, msg->insize);
 440                 return -ENOSPC;
 441         }
 442
 443         /* Copy response packet payload and compute checksum */
 444         for (i = 0; i < sizeof(struct ec_host_response); i++)
 445                 sum += ((u8 *)in_msg)[IN_MSG_EC_RESPONSE_PREAMBLE + i];
 446
 447         offset = sizeof(struct cros_ish_in_msg);
 448         for (i = 0; i < in_msg->ec_response.data_len; i++)
 449                 sum += msg->data[i] = ((u8 *)in_msg)[offset + i];
 450
 451         if (sum) {
 452                 dev_dbg(ec_dev->dev, "Bad received packet checksum %d\n", sum);
 453                 return -EBADMSG;
 454         }
 455
 456         return 0;
 457 }
 458
 459 static int cros_ec_pkt_xfer_ish(struct cros_ec_device *ec_dev,
 460                                 struct cros_ec_command *msg)
 461 {
 462         int rv;
 463         struct ishtp_cl *cros_ish_cl = ec_dev->priv;
 464         struct ishtp_cl_data *client_data = ishtp_get_client_data(cros_ish_cl);
 465         struct device *dev = cl_data_to_dev(client_data);
 466         struct cros_ish_in_msg *in_msg = (struct cros_ish_in_msg *)ec_dev->din;
 467         struct cros_ish_out_msg *out_msg =
 468                 (struct cros_ish_out_msg *)ec_dev->dout;
 469         size_t in_size = sizeof(struct cros_ish_in_msg) + msg->insize;
 470         size_t out_size = sizeof(struct cros_ish_out_msg) + msg->outsize;
 471
 472         /* Sanity checks */
 473         if (in_size > ec_dev->din_size) {
 474                 dev_err(dev,
 475                         "Incoming payload size %zu is too large for ec_dev->din_size %d\n",
 476                         in_size, ec_dev->din_size);
 477                 return -EMSGSIZE;
 478         }
 479
 480         if (out_size > ec_dev->dout_size) {
 481                 dev_err(dev,
 482                         "Outgoing payload size %zu is too large for ec_dev->dout_size %d\n",
 483                         out_size, ec_dev->dout_size);
 484                 return -EMSGSIZE;
 485         }
 486
 487         /* Proceed only if reset-init is not in progress */
 488         if (!down_read_trylock(&init_lock)) {
 489                 dev_warn(dev,
 490                          "Host is not ready to send messages to ISH. Try again\n");
 491                 return -EAGAIN;
 492         }
 493
 494         /* Prepare the package to be sent over ISH TP */
 495         out_msg->hdr.channel = CROS_EC_COMMAND;
 496         out_msg->hdr.status = 0;
 497
 498         ec_dev->dout += OUT_MSG_EC_REQUEST_PREAMBLE;
 499         rv = cros_ec_prepare_tx(ec_dev, msg);
 500         if (rv < 0)
 501                 goto end_error;
 502         ec_dev->dout -= OUT_MSG_EC_REQUEST_PREAMBLE;
 503
 504         dev_dbg(dev,
 505                 "out_msg: struct_ver=0x%x checksum=0x%x command=0x%x command_ver=0x%x data_len=0x%x\n",
 506                 out_msg->ec_request.struct_version,
 507                 out_msg->ec_request.checksum,
 508                 out_msg->ec_request.command,
 509                 out_msg->ec_request.command_version,
 510                 out_msg->ec_request.data_len);
 511
 512         /* Send command to ISH EC firmware and read response */
 513         rv = ish_send(client_data,
 514                       (u8 *)out_msg, out_size,
 515                       (u8 *)in_msg, in_size);
 516         if (rv < 0)
 517                 goto end_error;
 518
 519         rv = prepare_cros_ec_rx(ec_dev, in_msg, msg);
 520         if (rv)
 521                 goto end_error;
 522
 523         rv = in_msg->ec_response.data_len;
 524
 525         dev_dbg(dev,
 526                 "in_msg: struct_ver=0x%x checksum=0x%x result=0x%x data_len=0x%x\n",
 527                 in_msg->ec_response.struct_version,
 528                 in_msg->ec_response.checksum,
 529                 in_msg->ec_response.result,
 530                 in_msg->ec_response.data_len);
 531
 532 end_error:
 533         if (msg->command == EC_CMD_REBOOT_EC)
 534                 msleep(EC_REBOOT_DELAY_MS);
 535
 536         up_read(&init_lock);
 537
 538         return rv;
 539 }
 540
 541 static int cros_ec_dev_init(struct ishtp_cl_data *client_data)
 542 {
 543         struct cros_ec_device *ec_dev;
 544         struct device *dev = cl_data_to_dev(client_data);
 545
 546         ec_dev = devm_kzalloc(dev, sizeof(*ec_dev), GFP_KERNEL);
 547         if (!ec_dev)
 548                 return -ENOMEM;
 549
 550         client_data->ec_dev = ec_dev;
 551         dev->driver_data = ec_dev;
 552
 553         ec_dev->dev = dev;
 554         ec_dev->priv = client_data->cros_ish_cl;
 555         ec_dev->cmd_xfer = NULL;
 556         ec_dev->pkt_xfer = cros_ec_pkt_xfer_ish;
 557         ec_dev->phys_name = dev_name(dev);
 558         ec_dev->din_size = sizeof(struct cros_ish_in_msg) +
 559                            sizeof(struct ec_response_get_protocol_info);
 560         ec_dev->dout_size = sizeof(struct cros_ish_out_msg);
 561
 562         return cros_ec_register(ec_dev);
 563 }
 564
 565 static void reset_handler(struct work_struct *work)
 566 {
 567         int rv;
 568         struct device *dev;
 569         struct ishtp_cl *cros_ish_cl;
 570         struct ishtp_cl_data *client_data =
 571                 container_of(work, struct ishtp_cl_data, work_ishtp_reset);
 572
 573         /* Lock for reset to complete */
 574         down_write(&init_lock);
 575
 576         cros_ish_cl = client_data->cros_ish_cl;
 577
 578         ishtp_cl_destroy_connection(cros_ish_cl, true);
 579
 580         rv = cros_ish_init(cros_ish_cl, true);
 581         if (rv) {
 582                 dev_err(cl_data_to_dev(client_data), "Reset Failed\n");
 583                 up_write(&init_lock);
 584                 return;
 585         }
 586
 587         /* Refresh ec_dev device pointers */
 588         client_data->ec_dev->priv = client_data->cros_ish_cl;
 589         dev = cl_data_to_dev(client_data);
 590         dev->driver_data = client_data->ec_dev;
 591
 592         dev_info(cl_data_to_dev(client_data), "Chrome EC ISH reset done\n");
 593
 594         up_write(&init_lock);
 595 }
 596
 597 /**
 598  * cros_ec_ishtp_probe() - ISHTP client driver probe callback
 599  * @cl_device: ISHTP client device instance
 600  *
 601  * Return: 0 for success, negative error code for failure.
 602  */
 603 static int cros_ec_ishtp_probe(struct ishtp_cl_device *cl_device)
 604 {
 605         int rv;
 606         struct ishtp_cl *cros_ish_cl;
 607         struct ishtp_cl_data *client_data =
 608                 devm_kzalloc(ishtp_device(cl_device),
 609                              sizeof(*client_data), GFP_KERNEL);
 610         if (!client_data)
 611                 return -ENOMEM;
 612
 613         /* Lock for initialization to complete */
 614         down_write(&init_lock);
 615
 616         cros_ish_cl = ishtp_cl_allocate(cl_device);
 617         if (!cros_ish_cl) {
 618                 rv = -ENOMEM;
 619                 goto end_ishtp_cl_alloc_error;
 620         }
 621
 622         ishtp_set_drvdata(cl_device, cros_ish_cl);
 623         ishtp_set_client_data(cros_ish_cl, client_data);
 624         client_data->cros_ish_cl = cros_ish_cl;
 625         client_data->cl_device = cl_device;
 626
 627         init_waitqueue_head(&client_data->response.wait_queue);
 628
 629         INIT_WORK(&client_data->work_ishtp_reset,
 630                   reset_handler);
 631         INIT_WORK(&client_data->work_ec_evt,
 632                   ish_evt_handler);
 633
 634         rv = cros_ish_init(cros_ish_cl, false);
 635         if (rv)
 636                 goto end_ishtp_cl_init_error;
 637
 638         ishtp_get_device(cl_device);
 639
 640         up_write(&init_lock);
 641
 642         /* Register croc_ec_dev mfd */
 643         rv = cros_ec_dev_init(client_data);
 644         if (rv) {
 645                 down_write(&init_lock);
 646                 goto end_cros_ec_dev_init_error;
 647         }
 648
 649         return 0;
 650
 651 end_cros_ec_dev_init_error:
 652         ishtp_cl_destroy_connection(cros_ish_cl, false);
 653         ishtp_put_device(cl_device);
 654 end_ishtp_cl_init_error:
 655         ishtp_cl_free(cros_ish_cl);
 656 end_ishtp_cl_alloc_error:
 657         up_write(&init_lock);
 658         return rv;
 659 }
 660
 661 /**
 662  * cros_ec_ishtp_remove() - ISHTP client driver remove callback
 663  * @cl_device: ISHTP client device instance
 664  *
 665  * Return: 0
 666  */
 667 static void cros_ec_ishtp_remove(struct ishtp_cl_device *cl_device)
 668 {
 669         struct ishtp_cl *cros_ish_cl = ishtp_get_drvdata(cl_device);
 670         struct ishtp_cl_data *client_data = ishtp_get_client_data(cros_ish_cl);
 671
 672         cancel_work_sync(&client_data->work_ishtp_reset);
 673         cancel_work_sync(&client_data->work_ec_evt);
 674         cros_ish_deinit(cros_ish_cl);
 675         ishtp_put_device(cl_device);
 676 }
 677
 678 /**
 679  * cros_ec_ishtp_reset() - ISHTP client driver reset callback
 680  * @cl_device: ISHTP client device instance
 681  *
 682  * Return: 0
 683  */
 684 static int cros_ec_ishtp_reset(struct ishtp_cl_device *cl_device)
 685 {
 686         struct ishtp_cl *cros_ish_cl = ishtp_get_drvdata(cl_device);
 687         struct ishtp_cl_data *client_data = ishtp_get_client_data(cros_ish_cl);
 688
 689         schedule_work(&client_data->work_ishtp_reset);
 690
 691         return 0;
 692 }
 693
 694 /**
 695  * cros_ec_ishtp_suspend() - ISHTP client driver suspend callback
 696  * @device: device instance
 697  *
 698  * Return: 0 for success, negative error code for failure.
 699  */
 700 static int __maybe_unused cros_ec_ishtp_suspend(struct device *device)
 701 {
 702         struct ishtp_cl_device *cl_device = ishtp_dev_to_cl_device(device);
 703         struct ishtp_cl *cros_ish_cl = ishtp_get_drvdata(cl_device);
 704         struct ishtp_cl_data *client_data = ishtp_get_client_data(cros_ish_cl);
 705
 706         return cros_ec_suspend(client_data->ec_dev);
 707 }
 708
 709 /**
 710  * cros_ec_ishtp_resume() - ISHTP client driver resume callback
 711  * @device: device instance
 712  *
 713  * Return: 0 for success, negative error code for failure.
 714  */
 715 static int __maybe_unused cros_ec_ishtp_resume(struct device *device)
 716 {
 717         struct ishtp_cl_device *cl_device = ishtp_dev_to_cl_device(device);
 718         struct ishtp_cl *cros_ish_cl = ishtp_get_drvdata(cl_device);
 719         struct ishtp_cl_data *client_data = ishtp_get_client_data(cros_ish_cl);
 720
 721         return cros_ec_resume(client_data->ec_dev);
 722 }
 723
 724 static SIMPLE_DEV_PM_OPS(cros_ec_ishtp_pm_ops, cros_ec_ishtp_suspend,
 725                          cros_ec_ishtp_resume);
 726
 727 static struct ishtp_cl_driver   cros_ec_ishtp_driver = {
 728         .name = "cros_ec_ishtp",
 729         .id = cros_ec_ishtp_id_table,
 730         .probe = cros_ec_ishtp_probe,
 731         .remove = cros_ec_ishtp_remove,
 732         .reset = cros_ec_ishtp_reset,
 733         .driver = {
 734                 .pm = &cros_ec_ishtp_pm_ops,
 735         },
 736 };
 737
 738 static int __init cros_ec_ishtp_mod_init(void)
 739 {
 740         return ishtp_cl_driver_register(&cros_ec_ishtp_driver, THIS_MODULE);
 741 }
 742
 743 static void __exit cros_ec_ishtp_mod_exit(void)
 744 {
 745         ishtp_cl_driver_unregister(&cros_ec_ishtp_driver);
 746 }
 747
 748 module_init(cros_ec_ishtp_mod_init);
 749 module_exit(cros_ec_ishtp_mod_exit);
 750
 751 MODULE_DESCRIPTION("ChromeOS EC ISHTP Client Driver");
 752 MODULE_AUTHOR("Rushikesh S Kadam <rushikesh.s.kadam@intel.com>");
 753
 754 MODULE_LICENSE("GPL v2");