root/drivers/input/keyboard/cros_ec_keyb.c

DEFINITIONS

1. cros_ec_keyb_has_ghosting
2. cros_ec_keyb_process
3. cros_ec_keyb_report_bs
4. cros_ec_keyb_work
5. cros_ec_keyb_compute_valid_keys
6. cros_ec_keyb_info
7. cros_ec_keyb_query_switches
8. cros_ec_keyb_resume
9. cros_ec_keyb_register_bs
10. cros_ec_keyb_register_matrix
11. cros_ec_keyb_probe
12. cros_ec_keyb_remove

   1 // SPDX-License-Identifier: GPL-2.0
   2 // ChromeOS EC keyboard driver
   3 //
   4 // Copyright (C) 2012 Google, Inc.
   5 //
   6 // This driver uses the ChromeOS EC byte-level message-based protocol for
   7 // communicating the keyboard state (which keys are pressed) from a keyboard EC
   8 // to the AP over some bus (such as i2c, lpc, spi).  The EC does debouncing,
   9 // but everything else (including deghosting) is done here.  The main
  10 // motivation for this is to keep the EC firmware as simple as possible, since
  11 // it cannot be easily upgraded and EC flash/IRAM space is relatively
  12 // expensive.
  13 
  14 #include <linux/module.h>
  15 #include <linux/bitops.h>
  16 #include <linux/i2c.h>
  17 #include <linux/input.h>
  18 #include <linux/interrupt.h>
  19 #include <linux/kernel.h>
  20 #include <linux/notifier.h>
  21 #include <linux/platform_device.h>
  22 #include <linux/slab.h>
  23 #include <linux/sysrq.h>
  24 #include <linux/input/matrix_keypad.h>
  25 #include <linux/platform_data/cros_ec_commands.h>
  26 #include <linux/platform_data/cros_ec_proto.h>
  27 
  28 #include <asm/unaligned.h>
  29 
  30 /*
  31  * @rows: Number of rows in the keypad
  32  * @cols: Number of columns in the keypad
  33  * @row_shift: log2 or number of rows, rounded up
  34  * @keymap_data: Matrix keymap data used to convert to keyscan values
  35  * @ghost_filter: true to enable the matrix key-ghosting filter
  36  * @valid_keys: bitmap of existing keys for each matrix column
  37  * @old_kb_state: bitmap of keys pressed last scan
  38  * @dev: Device pointer
  39  * @ec: Top level ChromeOS device to use to talk to EC
  40  * @idev: The input device for the matrix keys.
  41  * @bs_idev: The input device for non-matrix buttons and switches (or NULL).
  42  * @notifier: interrupt event notifier for transport devices
  43  */
  44 struct cros_ec_keyb {
  45         unsigned int rows;
  46         unsigned int cols;
  47         int row_shift;
  48         const struct matrix_keymap_data *keymap_data;
  49         bool ghost_filter;
  50         uint8_t *valid_keys;
  51         uint8_t *old_kb_state;
  52 
  53         struct device *dev;
  54         struct cros_ec_device *ec;
  55 
  56         struct input_dev *idev;
  57         struct input_dev *bs_idev;
  58         struct notifier_block notifier;
  59 };
  60 
  61 
  62 /**
  63  * cros_ec_bs_map - Struct mapping Linux keycodes to EC button/switch bitmap
  64  * #defines
  65  *
  66  * @ev_type: The type of the input event to generate (e.g., EV_KEY).
  67  * @code: A linux keycode
  68  * @bit: A #define like EC_MKBP_POWER_BUTTON or EC_MKBP_LID_OPEN
  69  * @inverted: If the #define and EV_SW have opposite meanings, this is true.
  70  *            Only applicable to switches.
  71  */
  72 struct cros_ec_bs_map {
  73         unsigned int ev_type;
  74         unsigned int code;
  75         u8 bit;
  76         bool inverted;
  77 };
  78 
  79 /* cros_ec_keyb_bs - Map EC button/switch #defines into kernel ones */
  80 static const struct cros_ec_bs_map cros_ec_keyb_bs[] = {
  81         /* Buttons */
  82         {
  83                 .ev_type        = EV_KEY,
  84                 .code           = KEY_POWER,
  85                 .bit            = EC_MKBP_POWER_BUTTON,
  86         },
  87         {
  88                 .ev_type        = EV_KEY,
  89                 .code           = KEY_VOLUMEUP,
  90                 .bit            = EC_MKBP_VOL_UP,
  91         },
  92         {
  93                 .ev_type        = EV_KEY,
  94                 .code           = KEY_VOLUMEDOWN,
  95                 .bit            = EC_MKBP_VOL_DOWN,
  96         },
  97 
  98         /* Switches */
  99         {
 100                 .ev_type        = EV_SW,
 101                 .code           = SW_LID,
 102                 .bit            = EC_MKBP_LID_OPEN,
 103                 .inverted       = true,
 104         },
 105         {
 106                 .ev_type        = EV_SW,
 107                 .code           = SW_TABLET_MODE,
 108                 .bit            = EC_MKBP_TABLET_MODE,
 109         },
 110 };
 111 
 112 /*
 113  * Returns true when there is at least one combination of pressed keys that
 114  * results in ghosting.
 115  */
 116 static bool cros_ec_keyb_has_ghosting(struct cros_ec_keyb *ckdev, uint8_t *buf)
 117 {
 118         int col1, col2, buf1, buf2;
 119         struct device *dev = ckdev->dev;
 120         uint8_t *valid_keys = ckdev->valid_keys;
 121 
 122         /*
 123          * Ghosting happens if for any pressed key X there are other keys
 124          * pressed both in the same row and column of X as, for instance,
 125          * in the following diagram:
 126          *
 127          * . . Y . g .
 128          * . . . . . .
 129          * . . . . . .
 130          * . . X . Z .
 131          *
 132          * In this case only X, Y, and Z are pressed, but g appears to be
 133          * pressed too (see Wikipedia).
 134          */
 135         for (col1 = 0; col1 < ckdev->cols; col1++) {
 136                 buf1 = buf[col1] & valid_keys[col1];
 137                 for (col2 = col1 + 1; col2 < ckdev->cols; col2++) {
 138                         buf2 = buf[col2] & valid_keys[col2];
 139                         if (hweight8(buf1 & buf2) > 1) {
 140                                 dev_dbg(dev, "ghost found at: B[%02d]:0x%02x & B[%02d]:0x%02x",
 141                                         col1, buf1, col2, buf2);
 142                                 return true;
 143                         }
 144                 }
 145         }
 146 
 147         return false;
 148 }
 149 
 150 
 151 /*
 152  * Compares the new keyboard state to the old one and produces key
 153  * press/release events accordingly.  The keyboard state is 13 bytes (one byte
 154  * per column)
 155  */
 156 static void cros_ec_keyb_process(struct cros_ec_keyb *ckdev,
 157                          uint8_t *kb_state, int len)
 158 {
 159         struct input_dev *idev = ckdev->idev;
 160         int col, row;
 161         int new_state;
 162         int old_state;
 163 
 164         if (ckdev->ghost_filter && cros_ec_keyb_has_ghosting(ckdev, kb_state)) {
 165                 /*
 166                  * Simple-minded solution: ignore this state. The obvious
 167                  * improvement is to only ignore changes to keys involved in
 168                  * the ghosting, but process the other changes.
 169                  */
 170                 dev_dbg(ckdev->dev, "ghosting found\n");
 171                 return;
 172         }
 173 
 174         for (col = 0; col < ckdev->cols; col++) {
 175                 for (row = 0; row < ckdev->rows; row++) {
 176                         int pos = MATRIX_SCAN_CODE(row, col, ckdev->row_shift);
 177                         const unsigned short *keycodes = idev->keycode;
 178 
 179                         new_state = kb_state[col] & (1 << row);
 180                         old_state = ckdev->old_kb_state[col] & (1 << row);
 181                         if (new_state != old_state) {
 182                                 dev_dbg(ckdev->dev,
 183                                         "changed: [r%d c%d]: byte %02x\n",
 184                                         row, col, new_state);
 185 
 186                                 input_report_key(idev, keycodes[pos],
 187                                                  new_state);
 188                         }
 189                 }
 190                 ckdev->old_kb_state[col] = kb_state[col];
 191         }
 192         input_sync(ckdev->idev);
 193 }
 194 
 195 /**
 196  * cros_ec_keyb_report_bs - Report non-matrixed buttons or switches
 197  *
 198  * This takes a bitmap of buttons or switches from the EC and reports events,
 199  * syncing at the end.
 200  *
 201  * @ckdev: The keyboard device.
 202  * @ev_type: The input event type (e.g., EV_KEY).
 203  * @mask: A bitmap of buttons from the EC.
 204  */
 205 static void cros_ec_keyb_report_bs(struct cros_ec_keyb *ckdev,
 206                                    unsigned int ev_type, u32 mask)
 207 
 208 {
 209         struct input_dev *idev = ckdev->bs_idev;
 210         int i;
 211 
 212         for (i = 0; i < ARRAY_SIZE(cros_ec_keyb_bs); i++) {
 213                 const struct cros_ec_bs_map *map = &cros_ec_keyb_bs[i];
 214 
 215                 if (map->ev_type != ev_type)
 216                         continue;
 217 
 218                 input_event(idev, ev_type, map->code,
 219                             !!(mask & BIT(map->bit)) ^ map->inverted);
 220         }
 221         input_sync(idev);
 222 }
 223 
 224 static int cros_ec_keyb_work(struct notifier_block *nb,
 225                              unsigned long queued_during_suspend, void *_notify)
 226 {
 227         struct cros_ec_keyb *ckdev = container_of(nb, struct cros_ec_keyb,
 228                                                   notifier);
 229         uint8_t mkbp_event_type = ckdev->ec->event_data.event_type &
 230                                   EC_MKBP_EVENT_TYPE_MASK;
 231         u32 val;
 232         unsigned int ev_type;
 233 
 234         /*
 235          * If not wake enabled, discard key state changes during
 236          * suspend. Switches will be re-checked in
 237          * cros_ec_keyb_resume() to be sure nothing is lost.
 238          */
 239         if (queued_during_suspend && !device_may_wakeup(ckdev->dev))
 240                 return NOTIFY_OK;
 241 
 242         switch (mkbp_event_type) {
 243         case EC_MKBP_EVENT_KEY_MATRIX:
 244                 pm_wakeup_event(ckdev->dev, 0);
 245 
 246                 if (ckdev->ec->event_size != ckdev->cols) {
 247                         dev_err(ckdev->dev,
 248                                 "Discarded incomplete key matrix event.\n");
 249                         return NOTIFY_OK;
 250                 }
 251 
 252                 cros_ec_keyb_process(ckdev,
 253                                      ckdev->ec->event_data.data.key_matrix,
 254                                      ckdev->ec->event_size);
 255                 break;
 256 
 257         case EC_MKBP_EVENT_SYSRQ:
 258                 pm_wakeup_event(ckdev->dev, 0);
 259 
 260                 val = get_unaligned_le32(&ckdev->ec->event_data.data.sysrq);
 261                 dev_dbg(ckdev->dev, "sysrq code from EC: %#x\n", val);
 262                 handle_sysrq(val);
 263                 break;
 264 
 265         case EC_MKBP_EVENT_BUTTON:
 266         case EC_MKBP_EVENT_SWITCH:
 267                 pm_wakeup_event(ckdev->dev, 0);
 268 
 269                 if (mkbp_event_type == EC_MKBP_EVENT_BUTTON) {
 270                         val = get_unaligned_le32(
 271                                         &ckdev->ec->event_data.data.buttons);
 272                         ev_type = EV_KEY;
 273                 } else {
 274                         val = get_unaligned_le32(
 275                                         &ckdev->ec->event_data.data.switches);
 276                         ev_type = EV_SW;
 277                 }
 278                 cros_ec_keyb_report_bs(ckdev, ev_type, val);
 279                 break;
 280 
 281         default:
 282                 return NOTIFY_DONE;
 283         }
 284 
 285         return NOTIFY_OK;
 286 }
 287 
 288 /*
 289  * Walks keycodes flipping bit in buffer COLUMNS deep where bit is ROW.  Used by
 290  * ghosting logic to ignore NULL or virtual keys.
 291  */
 292 static void cros_ec_keyb_compute_valid_keys(struct cros_ec_keyb *ckdev)
 293 {
 294         int row, col;
 295         int row_shift = ckdev->row_shift;
 296         unsigned short *keymap = ckdev->idev->keycode;
 297         unsigned short code;
 298 
 299         BUG_ON(ckdev->idev->keycodesize != sizeof(*keymap));
 300 
 301         for (col = 0; col < ckdev->cols; col++) {
 302                 for (row = 0; row < ckdev->rows; row++) {
 303                         code = keymap[MATRIX_SCAN_CODE(row, col, row_shift)];
 304                         if (code && (code != KEY_BATTERY))
 305                                 ckdev->valid_keys[col] |= 1 << row;
 306                 }
 307                 dev_dbg(ckdev->dev, "valid_keys[%02d] = 0x%02x\n",
 308                         col, ckdev->valid_keys[col]);
 309         }
 310 }
 311 
 312 /**
 313  * cros_ec_keyb_info - Wrap the EC command EC_CMD_MKBP_INFO
 314  *
 315  * This wraps the EC_CMD_MKBP_INFO, abstracting out all of the marshalling and
 316  * unmarshalling and different version nonsense into something simple.
 317  *
 318  * @ec_dev: The EC device
 319  * @info_type: Either EC_MKBP_INFO_SUPPORTED or EC_MKBP_INFO_CURRENT.
 320  * @event_type: Either EC_MKBP_EVENT_BUTTON or EC_MKBP_EVENT_SWITCH.  Actually
 321  *              in some cases this could be EC_MKBP_EVENT_KEY_MATRIX or
 322  *              EC_MKBP_EVENT_HOST_EVENT too but we don't use in this driver.
 323  * @result: Where we'll store the result; a union
 324  * @result_size: The size of the result.  Expected to be the size of one of
 325  *               the elements in the union.
 326  *
 327  * Returns 0 if no error or -error upon error.
 328  */
 329 static int cros_ec_keyb_info(struct cros_ec_device *ec_dev,
 330                              enum ec_mkbp_info_type info_type,
 331                              enum ec_mkbp_event event_type,
 332                              union ec_response_get_next_data *result,
 333                              size_t result_size)
 334 {
 335         struct ec_params_mkbp_info *params;
 336         struct cros_ec_command *msg;
 337         int ret;
 338 
 339         msg = kzalloc(sizeof(*msg) + max_t(size_t, result_size,
 340                                            sizeof(*params)), GFP_KERNEL);
 341         if (!msg)
 342                 return -ENOMEM;
 343 
 344         msg->command = EC_CMD_MKBP_INFO;
 345         msg->version = 1;
 346         msg->outsize = sizeof(*params);
 347         msg->insize = result_size;
 348         params = (struct ec_params_mkbp_info *)msg->data;
 349         params->info_type = info_type;
 350         params->event_type = event_type;
 351 
 352         ret = cros_ec_cmd_xfer(ec_dev, msg);
 353         if (ret < 0) {
 354                 dev_warn(ec_dev->dev, "Transfer error %d/%d: %d\n",
 355                          (int)info_type, (int)event_type, ret);
 356         } else if (msg->result == EC_RES_INVALID_VERSION) {
 357                 /* With older ECs we just return 0 for everything */
 358                 memset(result, 0, result_size);
 359                 ret = 0;
 360         } else if (msg->result != EC_RES_SUCCESS) {
 361                 dev_warn(ec_dev->dev, "Error getting info %d/%d: %d\n",
 362                          (int)info_type, (int)event_type, msg->result);
 363                 ret = -EPROTO;
 364         } else if (ret != result_size) {
 365                 dev_warn(ec_dev->dev, "Wrong size %d/%d: %d != %zu\n",
 366                          (int)info_type, (int)event_type,
 367                          ret, result_size);
 368                 ret = -EPROTO;
 369         } else {
 370                 memcpy(result, msg->data, result_size);
 371                 ret = 0;
 372         }
 373 
 374         kfree(msg);
 375 
 376         return ret;
 377 }
 378 
 379 /**
 380  * cros_ec_keyb_query_switches - Query the state of switches and report
 381  *
 382  * This will ask the EC about the current state of switches and report to the
 383  * kernel.  Note that we don't query for buttons because they are more
 384  * transitory and we'll get an update on the next release / press.
 385  *
 386  * @ckdev: The keyboard device
 387  *
 388  * Returns 0 if no error or -error upon error.
 389  */
 390 static int cros_ec_keyb_query_switches(struct cros_ec_keyb *ckdev)
 391 {
 392         struct cros_ec_device *ec_dev = ckdev->ec;
 393         union ec_response_get_next_data event_data = {};
 394         int ret;
 395 
 396         ret = cros_ec_keyb_info(ec_dev, EC_MKBP_INFO_CURRENT,
 397                                 EC_MKBP_EVENT_SWITCH, &event_data,
 398                                 sizeof(event_data.switches));
 399         if (ret)
 400                 return ret;
 401 
 402         cros_ec_keyb_report_bs(ckdev, EV_SW,
 403                                get_unaligned_le32(&event_data.switches));
 404 
 405         return 0;
 406 }
 407 
 408 /**
 409  * cros_ec_keyb_resume - Resume the keyboard
 410  *
 411  * We use the resume notification as a chance to query the EC for switches.
 412  *
 413  * @dev: The keyboard device
 414  *
 415  * Returns 0 if no error or -error upon error.
 416  */
 417 static __maybe_unused int cros_ec_keyb_resume(struct device *dev)
 418 {
 419         struct cros_ec_keyb *ckdev = dev_get_drvdata(dev);
 420 
 421         if (ckdev->bs_idev)
 422                 return cros_ec_keyb_query_switches(ckdev);
 423 
 424         return 0;
 425 }
 426 
 427 /**
 428  * cros_ec_keyb_register_bs - Register non-matrix buttons/switches
 429  *
 430  * Handles all the bits of the keyboard driver related to non-matrix buttons
 431  * and switches, including asking the EC about which are present and telling
 432  * the kernel to expect them.
 433  *
 434  * If this device has no support for buttons and switches we'll return no error
 435  * but the ckdev->bs_idev will remain NULL when this function exits.
 436  *
 437  * @ckdev: The keyboard device
 438  *
 439  * Returns 0 if no error or -error upon error.
 440  */
 441 static int cros_ec_keyb_register_bs(struct cros_ec_keyb *ckdev)
 442 {
 443         struct cros_ec_device *ec_dev = ckdev->ec;
 444         struct device *dev = ckdev->dev;
 445         struct input_dev *idev;
 446         union ec_response_get_next_data event_data = {};
 447         const char *phys;
 448         u32 buttons;
 449         u32 switches;
 450         int ret;
 451         int i;
 452 
 453         ret = cros_ec_keyb_info(ec_dev, EC_MKBP_INFO_SUPPORTED,
 454                                 EC_MKBP_EVENT_BUTTON, &event_data,
 455                                 sizeof(event_data.buttons));
 456         if (ret)
 457                 return ret;
 458         buttons = get_unaligned_le32(&event_data.buttons);
 459 
 460         ret = cros_ec_keyb_info(ec_dev, EC_MKBP_INFO_SUPPORTED,
 461                                 EC_MKBP_EVENT_SWITCH, &event_data,
 462                                 sizeof(event_data.switches));
 463         if (ret)
 464                 return ret;
 465         switches = get_unaligned_le32(&event_data.switches);
 466 
 467         if (!buttons && !switches)
 468                 return 0;
 469 
 470         /*
 471          * We call the non-matrix buttons/switches 'input1', if present.
 472          * Allocate phys before input dev, to ensure correct tear-down
 473          * ordering.
 474          */
 475         phys = devm_kasprintf(dev, GFP_KERNEL, "%s/input1", ec_dev->phys_name);
 476         if (!phys)
 477                 return -ENOMEM;
 478 
 479         idev = devm_input_allocate_device(dev);
 480         if (!idev)
 481                 return -ENOMEM;
 482 
 483         idev->name = "cros_ec_buttons";
 484         idev->phys = phys;
 485         __set_bit(EV_REP, idev->evbit);
 486 
 487         idev->id.bustype = BUS_VIRTUAL;
 488         idev->id.version = 1;
 489         idev->id.product = 0;
 490         idev->dev.parent = dev;
 491 
 492         input_set_drvdata(idev, ckdev);
 493         ckdev->bs_idev = idev;
 494 
 495         for (i = 0; i < ARRAY_SIZE(cros_ec_keyb_bs); i++) {
 496                 const struct cros_ec_bs_map *map = &cros_ec_keyb_bs[i];
 497 
 498                 if ((map->ev_type == EV_KEY && (buttons & BIT(map->bit))) ||
 499                     (map->ev_type == EV_SW && (switches & BIT(map->bit))))
 500                         input_set_capability(idev, map->ev_type, map->code);
 501         }
 502 
 503         ret = cros_ec_keyb_query_switches(ckdev);
 504         if (ret) {
 505                 dev_err(dev, "cannot query switches\n");
 506                 return ret;
 507         }
 508 
 509         ret = input_register_device(ckdev->bs_idev);
 510         if (ret) {
 511                 dev_err(dev, "cannot register input device\n");
 512                 return ret;
 513         }
 514 
 515         return 0;
 516 }
 517 
 518 /**
 519  * cros_ec_keyb_register_bs - Register matrix keys
 520  *
 521  * Handles all the bits of the keyboard driver related to matrix keys.
 522  *
 523  * @ckdev: The keyboard device
 524  *
 525  * Returns 0 if no error or -error upon error.
 526  */
 527 static int cros_ec_keyb_register_matrix(struct cros_ec_keyb *ckdev)
 528 {
 529         struct cros_ec_device *ec_dev = ckdev->ec;
 530         struct device *dev = ckdev->dev;
 531         struct input_dev *idev;
 532         const char *phys;
 533         int err;
 534 
 535         err = matrix_keypad_parse_properties(dev, &ckdev->rows, &ckdev->cols);
 536         if (err)
 537                 return err;
 538 
 539         ckdev->valid_keys = devm_kzalloc(dev, ckdev->cols, GFP_KERNEL);
 540         if (!ckdev->valid_keys)
 541                 return -ENOMEM;
 542 
 543         ckdev->old_kb_state = devm_kzalloc(dev, ckdev->cols, GFP_KERNEL);
 544         if (!ckdev->old_kb_state)
 545                 return -ENOMEM;
 546 
 547         /*
 548          * We call the keyboard matrix 'input0'. Allocate phys before input
 549          * dev, to ensure correct tear-down ordering.
 550          */
 551         phys = devm_kasprintf(dev, GFP_KERNEL, "%s/input0", ec_dev->phys_name);
 552         if (!phys)
 553                 return -ENOMEM;
 554 
 555         idev = devm_input_allocate_device(dev);
 556         if (!idev)
 557                 return -ENOMEM;
 558 
 559         idev->name = CROS_EC_DEV_NAME;
 560         idev->phys = phys;
 561         __set_bit(EV_REP, idev->evbit);
 562 
 563         idev->id.bustype = BUS_VIRTUAL;
 564         idev->id.version = 1;
 565         idev->id.product = 0;
 566         idev->dev.parent = dev;
 567 
 568         ckdev->ghost_filter = of_property_read_bool(dev->of_node,
 569                                         "google,needs-ghost-filter");
 570 
 571         err = matrix_keypad_build_keymap(NULL, NULL, ckdev->rows, ckdev->cols,
 572                                          NULL, idev);
 573         if (err) {
 574                 dev_err(dev, "cannot build key matrix\n");
 575                 return err;
 576         }
 577 
 578         ckdev->row_shift = get_count_order(ckdev->cols);
 579 
 580         input_set_capability(idev, EV_MSC, MSC_SCAN);
 581         input_set_drvdata(idev, ckdev);
 582         ckdev->idev = idev;
 583         cros_ec_keyb_compute_valid_keys(ckdev);
 584 
 585         err = input_register_device(ckdev->idev);
 586         if (err) {
 587                 dev_err(dev, "cannot register input device\n");
 588                 return err;
 589         }
 590 
 591         return 0;
 592 }
 593 
 594 static int cros_ec_keyb_probe(struct platform_device *pdev)
 595 {
 596         struct cros_ec_device *ec = dev_get_drvdata(pdev->dev.parent);
 597         struct device *dev = &pdev->dev;
 598         struct cros_ec_keyb *ckdev;
 599         int err;
 600 
 601         if (!dev->of_node)
 602                 return -ENODEV;
 603 
 604         ckdev = devm_kzalloc(dev, sizeof(*ckdev), GFP_KERNEL);
 605         if (!ckdev)
 606                 return -ENOMEM;
 607 
 608         ckdev->ec = ec;
 609         ckdev->dev = dev;
 610         dev_set_drvdata(dev, ckdev);
 611 
 612         err = cros_ec_keyb_register_matrix(ckdev);
 613         if (err) {
 614                 dev_err(dev, "cannot register matrix inputs: %d\n", err);
 615                 return err;
 616         }
 617 
 618         err = cros_ec_keyb_register_bs(ckdev);
 619         if (err) {
 620                 dev_err(dev, "cannot register non-matrix inputs: %d\n", err);
 621                 return err;
 622         }
 623 
 624         ckdev->notifier.notifier_call = cros_ec_keyb_work;
 625         err = blocking_notifier_chain_register(&ckdev->ec->event_notifier,
 626                                                &ckdev->notifier);
 627         if (err) {
 628                 dev_err(dev, "cannot register notifier: %d\n", err);
 629                 return err;
 630         }
 631 
 632         device_init_wakeup(ckdev->dev, true);
 633         return 0;
 634 }
 635 
 636 static int cros_ec_keyb_remove(struct platform_device *pdev)
 637 {
 638         struct cros_ec_keyb *ckdev = dev_get_drvdata(&pdev->dev);
 639 
 640         blocking_notifier_chain_unregister(&ckdev->ec->event_notifier,
 641                                            &ckdev->notifier);
 642 
 643         return 0;
 644 }
 645 
 646 #ifdef CONFIG_OF
 647 static const struct of_device_id cros_ec_keyb_of_match[] = {
 648         { .compatible = "google,cros-ec-keyb" },
 649         {},
 650 };
 651 MODULE_DEVICE_TABLE(of, cros_ec_keyb_of_match);
 652 #endif
 653 
 654 static SIMPLE_DEV_PM_OPS(cros_ec_keyb_pm_ops, NULL, cros_ec_keyb_resume);
 655 
 656 static struct platform_driver cros_ec_keyb_driver = {
 657         .probe = cros_ec_keyb_probe,
 658         .remove = cros_ec_keyb_remove,
 659         .driver = {
 660                 .name = "cros-ec-keyb",
 661                 .of_match_table = of_match_ptr(cros_ec_keyb_of_match),
 662                 .pm = &cros_ec_keyb_pm_ops,
 663         },
 664 };
 665 
 666 module_platform_driver(cros_ec_keyb_driver);
 667 
 668 MODULE_LICENSE("GPL v2");
 669 MODULE_DESCRIPTION("ChromeOS EC keyboard driver");
 670 MODULE_ALIAS("platform:cros-ec-keyb");