1 // SPDX-License-Identifier: GPL-2.0+ 2 /* 3 * HID driver for Google Hammer device. 4 * 5 * Copyright (c) 2017 Google Inc. 6 * Author: Wei-Ning Huang <wnhuang@google.com> 7 */ 8 9 /* 10 * This program is free software; you can redistribute it and/or modify it 11 * under the terms of the GNU General Public License as published by the Free 12 * Software Foundation; either version 2 of the License, or (at your option) 13 * any later version. 14 */ 15 16 #include <linux/acpi.h> 17 #include <linux/hid.h> 18 #include <linux/input/vivaldi-fmap.h> 19 #include <linux/leds.h> 20 #include <linux/module.h> 21 #include <linux/of.h> 22 #include <linux/platform_data/cros_ec_commands.h> 23 #include <linux/platform_data/cros_ec_proto.h> 24 #include <linux/platform_device.h> 25 #include <linux/pm_wakeup.h> 26 #include <linux/unaligned.h> 27 28 #include "hid-ids.h" 29 #include "hid-vivaldi-common.h" 30 31 /* 32 * C(hrome)B(ase)A(ttached)S(witch) - switch exported by Chrome EC and reporting 33 * state of the "Whiskers" base - attached or detached. Whiskers USB device also 34 * reports position of the keyboard - folded or not. Combining base state and 35 * position allows us to generate proper "Tablet mode" events. 36 */ 37 struct cbas_ec { 38 struct device *dev; /* The platform device (EC) */ 39 struct input_dev *input; 40 bool base_present; 41 bool base_folded; 42 struct notifier_block notifier; 43 }; 44 45 static struct cbas_ec cbas_ec; 46 static DEFINE_SPINLOCK(cbas_ec_lock); 47 static DEFINE_MUTEX(cbas_ec_reglock); 48 cbas_parse_base_state(const void * data)49 static bool cbas_parse_base_state(const void *data) 50 { 51 u32 switches = get_unaligned_le32(data); 52 53 return !!(switches & BIT(EC_MKBP_BASE_ATTACHED)); 54 } 55 cbas_ec_query_base(struct cros_ec_device * ec_dev,bool get_state,bool * state)56 static int cbas_ec_query_base(struct cros_ec_device *ec_dev, bool get_state, 57 bool *state) 58 { 59 struct ec_params_mkbp_info *params; 60 struct cros_ec_command *msg; 61 int ret; 62 63 msg = kzalloc(struct_size(msg, data, max(sizeof(u32), sizeof(*params))), 64 GFP_KERNEL); 65 if (!msg) 66 return -ENOMEM; 67 68 msg->command = EC_CMD_MKBP_INFO; 69 msg->version = 1; 70 msg->outsize = sizeof(*params); 71 msg->insize = sizeof(u32); 72 params = (struct ec_params_mkbp_info *)msg->data; 73 params->info_type = get_state ? 74 EC_MKBP_INFO_CURRENT : EC_MKBP_INFO_SUPPORTED; 75 params->event_type = EC_MKBP_EVENT_SWITCH; 76 77 ret = cros_ec_cmd_xfer_status(ec_dev, msg); 78 if (ret >= 0) { 79 if (ret != sizeof(u32)) { 80 dev_warn(ec_dev->dev, "wrong result size: %d != %zu\n", 81 ret, sizeof(u32)); 82 ret = -EPROTO; 83 } else { 84 *state = cbas_parse_base_state(msg->data); 85 ret = 0; 86 } 87 } 88 89 kfree(msg); 90 91 return ret; 92 } 93 cbas_ec_notify(struct notifier_block * nb,unsigned long queued_during_suspend,void * _notify)94 static int cbas_ec_notify(struct notifier_block *nb, 95 unsigned long queued_during_suspend, 96 void *_notify) 97 { 98 struct cros_ec_device *ec = _notify; 99 unsigned long flags; 100 bool base_present; 101 102 if (ec->event_data.event_type == EC_MKBP_EVENT_SWITCH) { 103 base_present = cbas_parse_base_state( 104 &ec->event_data.data.switches); 105 dev_dbg(cbas_ec.dev, 106 "%s: base: %d\n", __func__, base_present); 107 108 if (device_may_wakeup(cbas_ec.dev) || 109 !queued_during_suspend) { 110 111 pm_wakeup_event(cbas_ec.dev, 0); 112 113 spin_lock_irqsave(&cbas_ec_lock, flags); 114 115 /* 116 * While input layer dedupes the events, we do not want 117 * to disrupt the state reported by the base by 118 * overriding it with state reported by the LID. Only 119 * report changes, as we assume that on attach the base 120 * is not folded. 121 */ 122 if (base_present != cbas_ec.base_present) { 123 input_report_switch(cbas_ec.input, 124 SW_TABLET_MODE, 125 !base_present); 126 input_sync(cbas_ec.input); 127 cbas_ec.base_present = base_present; 128 } 129 130 spin_unlock_irqrestore(&cbas_ec_lock, flags); 131 } 132 } 133 134 return NOTIFY_OK; 135 } 136 cbas_ec_resume(struct device * dev)137 static __maybe_unused int cbas_ec_resume(struct device *dev) 138 { 139 struct cros_ec_device *ec = dev_get_drvdata(dev->parent); 140 bool base_present; 141 int error; 142 143 error = cbas_ec_query_base(ec, true, &base_present); 144 if (error) { 145 dev_warn(dev, "failed to fetch base state on resume: %d\n", 146 error); 147 } else { 148 spin_lock_irq(&cbas_ec_lock); 149 150 cbas_ec.base_present = base_present; 151 152 /* 153 * Only report if base is disconnected. If base is connected, 154 * it will resend its state on resume, and we'll update it 155 * in hammer_event(). 156 */ 157 if (!cbas_ec.base_present) { 158 input_report_switch(cbas_ec.input, SW_TABLET_MODE, 1); 159 input_sync(cbas_ec.input); 160 } 161 162 spin_unlock_irq(&cbas_ec_lock); 163 } 164 165 return 0; 166 } 167 168 static SIMPLE_DEV_PM_OPS(cbas_ec_pm_ops, NULL, cbas_ec_resume); 169 cbas_ec_set_input(struct input_dev * input)170 static void cbas_ec_set_input(struct input_dev *input) 171 { 172 /* Take the lock so hammer_event() does not race with us here */ 173 spin_lock_irq(&cbas_ec_lock); 174 cbas_ec.input = input; 175 spin_unlock_irq(&cbas_ec_lock); 176 } 177 __cbas_ec_probe(struct platform_device * pdev)178 static int __cbas_ec_probe(struct platform_device *pdev) 179 { 180 struct cros_ec_device *ec = dev_get_drvdata(pdev->dev.parent); 181 struct input_dev *input; 182 bool base_supported; 183 int error; 184 185 error = cbas_ec_query_base(ec, false, &base_supported); 186 if (error) 187 return error; 188 189 if (!base_supported) 190 return -ENXIO; 191 192 input = devm_input_allocate_device(&pdev->dev); 193 if (!input) 194 return -ENOMEM; 195 196 input->name = "Whiskers Tablet Mode Switch"; 197 input->id.bustype = BUS_HOST; 198 199 input_set_capability(input, EV_SW, SW_TABLET_MODE); 200 201 error = input_register_device(input); 202 if (error) { 203 dev_err(&pdev->dev, "cannot register input device: %d\n", 204 error); 205 return error; 206 } 207 208 /* Seed the state */ 209 error = cbas_ec_query_base(ec, true, &cbas_ec.base_present); 210 if (error) { 211 dev_err(&pdev->dev, "cannot query base state: %d\n", error); 212 return error; 213 } 214 215 if (!cbas_ec.base_present) 216 cbas_ec.base_folded = false; 217 218 dev_dbg(&pdev->dev, "%s: base: %d, folded: %d\n", __func__, 219 cbas_ec.base_present, cbas_ec.base_folded); 220 221 input_report_switch(input, SW_TABLET_MODE, 222 !cbas_ec.base_present || cbas_ec.base_folded); 223 224 cbas_ec_set_input(input); 225 226 cbas_ec.dev = &pdev->dev; 227 cbas_ec.notifier.notifier_call = cbas_ec_notify; 228 error = blocking_notifier_chain_register(&ec->event_notifier, 229 &cbas_ec.notifier); 230 if (error) { 231 dev_err(&pdev->dev, "cannot register notifier: %d\n", error); 232 cbas_ec_set_input(NULL); 233 return error; 234 } 235 236 device_init_wakeup(&pdev->dev, true); 237 return 0; 238 } 239 cbas_ec_probe(struct platform_device * pdev)240 static int cbas_ec_probe(struct platform_device *pdev) 241 { 242 int retval; 243 244 mutex_lock(&cbas_ec_reglock); 245 246 if (cbas_ec.input) { 247 retval = -EBUSY; 248 goto out; 249 } 250 251 retval = __cbas_ec_probe(pdev); 252 253 out: 254 mutex_unlock(&cbas_ec_reglock); 255 return retval; 256 } 257 cbas_ec_remove(struct platform_device * pdev)258 static void cbas_ec_remove(struct platform_device *pdev) 259 { 260 struct cros_ec_device *ec = dev_get_drvdata(pdev->dev.parent); 261 262 mutex_lock(&cbas_ec_reglock); 263 264 blocking_notifier_chain_unregister(&ec->event_notifier, 265 &cbas_ec.notifier); 266 cbas_ec_set_input(NULL); 267 268 mutex_unlock(&cbas_ec_reglock); 269 } 270 271 static const struct acpi_device_id cbas_ec_acpi_ids[] = { 272 { "GOOG000B", 0 }, 273 { } 274 }; 275 MODULE_DEVICE_TABLE(acpi, cbas_ec_acpi_ids); 276 277 #ifdef CONFIG_OF 278 static const struct of_device_id cbas_ec_of_match[] = { 279 { .compatible = "google,cros-cbas" }, 280 { }, 281 }; 282 MODULE_DEVICE_TABLE(of, cbas_ec_of_match); 283 #endif 284 285 static struct platform_driver cbas_ec_driver = { 286 .probe = cbas_ec_probe, 287 .remove_new = cbas_ec_remove, 288 .driver = { 289 .name = "cbas_ec", 290 .acpi_match_table = ACPI_PTR(cbas_ec_acpi_ids), 291 .of_match_table = of_match_ptr(cbas_ec_of_match), 292 .pm = &cbas_ec_pm_ops, 293 }, 294 }; 295 296 #define MAX_BRIGHTNESS 100 297 298 struct hammer_kbd_leds { 299 struct led_classdev cdev; 300 struct hid_device *hdev; 301 u8 buf[2] ____cacheline_aligned; 302 }; 303 hammer_kbd_brightness_set_blocking(struct led_classdev * cdev,enum led_brightness br)304 static int hammer_kbd_brightness_set_blocking(struct led_classdev *cdev, 305 enum led_brightness br) 306 { 307 struct hammer_kbd_leds *led = container_of(cdev, 308 struct hammer_kbd_leds, 309 cdev); 310 int ret; 311 312 led->buf[0] = 0; 313 led->buf[1] = br; 314 315 /* 316 * Request USB HID device to be in Full On mode, so that sending 317 * hardware output report and hardware raw request won't fail. 318 */ 319 ret = hid_hw_power(led->hdev, PM_HINT_FULLON); 320 if (ret < 0) { 321 hid_err(led->hdev, "failed: device not resumed %d\n", ret); 322 return ret; 323 } 324 325 ret = hid_hw_output_report(led->hdev, led->buf, sizeof(led->buf)); 326 if (ret == -ENOSYS) 327 ret = hid_hw_raw_request(led->hdev, 0, led->buf, 328 sizeof(led->buf), 329 HID_OUTPUT_REPORT, 330 HID_REQ_SET_REPORT); 331 if (ret < 0) 332 hid_err(led->hdev, "failed to set keyboard backlight: %d\n", 333 ret); 334 335 /* Request USB HID device back to Normal Mode. */ 336 hid_hw_power(led->hdev, PM_HINT_NORMAL); 337 338 return ret; 339 } 340 hammer_register_leds(struct hid_device * hdev)341 static int hammer_register_leds(struct hid_device *hdev) 342 { 343 struct hammer_kbd_leds *kbd_backlight; 344 345 kbd_backlight = devm_kzalloc(&hdev->dev, sizeof(*kbd_backlight), 346 GFP_KERNEL); 347 if (!kbd_backlight) 348 return -ENOMEM; 349 350 kbd_backlight->hdev = hdev; 351 kbd_backlight->cdev.name = "hammer::kbd_backlight"; 352 kbd_backlight->cdev.max_brightness = MAX_BRIGHTNESS; 353 kbd_backlight->cdev.brightness_set_blocking = 354 hammer_kbd_brightness_set_blocking; 355 kbd_backlight->cdev.flags = LED_HW_PLUGGABLE; 356 357 /* Set backlight to 0% initially. */ 358 hammer_kbd_brightness_set_blocking(&kbd_backlight->cdev, 0); 359 360 return devm_led_classdev_register(&hdev->dev, &kbd_backlight->cdev); 361 } 362 363 #define HID_UP_GOOGLEVENDOR 0xffd10000 364 #define HID_VD_KBD_FOLDED 0x00000019 365 #define HID_USAGE_KBD_FOLDED (HID_UP_GOOGLEVENDOR | HID_VD_KBD_FOLDED) 366 367 /* HID usage for keyboard backlight (Alphanumeric display brightness) */ 368 #define HID_AD_BRIGHTNESS 0x00140046 369 hammer_input_mapping(struct hid_device * hdev,struct hid_input * hi,struct hid_field * field,struct hid_usage * usage,unsigned long ** bit,int * max)370 static int hammer_input_mapping(struct hid_device *hdev, struct hid_input *hi, 371 struct hid_field *field, 372 struct hid_usage *usage, 373 unsigned long **bit, int *max) 374 { 375 if (usage->hid == HID_USAGE_KBD_FOLDED) { 376 /* 377 * We do not want to have this usage mapped as it will get 378 * mixed in with "base attached" signal and delivered over 379 * separate input device for tablet switch mode. 380 */ 381 return -1; 382 } 383 384 return 0; 385 } 386 hammer_folded_event(struct hid_device * hdev,bool folded)387 static void hammer_folded_event(struct hid_device *hdev, bool folded) 388 { 389 unsigned long flags; 390 391 spin_lock_irqsave(&cbas_ec_lock, flags); 392 393 /* 394 * If we are getting events from Whiskers that means that it 395 * is attached to the lid. 396 */ 397 cbas_ec.base_present = true; 398 cbas_ec.base_folded = folded; 399 hid_dbg(hdev, "%s: base: %d, folded: %d\n", __func__, 400 cbas_ec.base_present, cbas_ec.base_folded); 401 402 if (cbas_ec.input) { 403 input_report_switch(cbas_ec.input, SW_TABLET_MODE, folded); 404 input_sync(cbas_ec.input); 405 } 406 407 spin_unlock_irqrestore(&cbas_ec_lock, flags); 408 } 409 hammer_event(struct hid_device * hid,struct hid_field * field,struct hid_usage * usage,__s32 value)410 static int hammer_event(struct hid_device *hid, struct hid_field *field, 411 struct hid_usage *usage, __s32 value) 412 { 413 if (usage->hid == HID_USAGE_KBD_FOLDED) { 414 hammer_folded_event(hid, value); 415 return 1; /* We handled this event */ 416 } 417 418 return 0; 419 } 420 hammer_has_folded_event(struct hid_device * hdev)421 static bool hammer_has_folded_event(struct hid_device *hdev) 422 { 423 return !!hid_find_field(hdev, HID_INPUT_REPORT, 424 HID_GD_KEYBOARD, HID_USAGE_KBD_FOLDED); 425 } 426 hammer_has_backlight_control(struct hid_device * hdev)427 static bool hammer_has_backlight_control(struct hid_device *hdev) 428 { 429 return !!hid_find_field(hdev, HID_OUTPUT_REPORT, 430 HID_GD_KEYBOARD, HID_AD_BRIGHTNESS); 431 } 432 hammer_get_folded_state(struct hid_device * hdev)433 static void hammer_get_folded_state(struct hid_device *hdev) 434 { 435 struct hid_report *report; 436 char *buf; 437 int len, rlen; 438 int a; 439 440 report = hdev->report_enum[HID_INPUT_REPORT].report_id_hash[0x0]; 441 442 if (!report || report->maxfield < 1) 443 return; 444 445 len = hid_report_len(report) + 1; 446 447 buf = kmalloc(len, GFP_KERNEL); 448 if (!buf) 449 return; 450 451 rlen = hid_hw_raw_request(hdev, report->id, buf, len, report->type, HID_REQ_GET_REPORT); 452 453 if (rlen != len) { 454 hid_warn(hdev, "Unable to read base folded state: %d (expected %d)\n", rlen, len); 455 goto out; 456 } 457 458 for (a = 0; a < report->maxfield; a++) { 459 struct hid_field *field = report->field[a]; 460 461 if (field->usage->hid == HID_USAGE_KBD_FOLDED) { 462 u32 value = hid_field_extract(hdev, buf+1, 463 field->report_offset, field->report_size); 464 465 hammer_folded_event(hdev, value); 466 break; 467 } 468 } 469 470 out: 471 kfree(buf); 472 } 473 hammer_stop(void * hdev)474 static void hammer_stop(void *hdev) 475 { 476 hid_hw_stop(hdev); 477 } 478 hammer_probe(struct hid_device * hdev,const struct hid_device_id * id)479 static int hammer_probe(struct hid_device *hdev, 480 const struct hid_device_id *id) 481 { 482 struct vivaldi_data *vdata; 483 int error; 484 485 vdata = devm_kzalloc(&hdev->dev, sizeof(*vdata), GFP_KERNEL); 486 if (!vdata) 487 return -ENOMEM; 488 489 hid_set_drvdata(hdev, vdata); 490 491 error = hid_parse(hdev); 492 if (error) 493 return error; 494 495 error = hid_hw_start(hdev, HID_CONNECT_DEFAULT); 496 if (error) 497 return error; 498 499 error = devm_add_action(&hdev->dev, hammer_stop, hdev); 500 if (error) 501 return error; 502 503 /* 504 * We always want to poll for, and handle tablet mode events from 505 * devices that have folded usage, even when nobody has opened the input 506 * device. This also prevents the hid core from dropping early tablet 507 * mode events from the device. 508 */ 509 if (hammer_has_folded_event(hdev)) { 510 hdev->quirks |= HID_QUIRK_ALWAYS_POLL; 511 error = hid_hw_open(hdev); 512 if (error) 513 return error; 514 515 hammer_get_folded_state(hdev); 516 } 517 518 if (hammer_has_backlight_control(hdev)) { 519 error = hammer_register_leds(hdev); 520 if (error) 521 hid_warn(hdev, 522 "Failed to register keyboard backlight: %d\n", 523 error); 524 } 525 526 return 0; 527 } 528 hammer_remove(struct hid_device * hdev)529 static void hammer_remove(struct hid_device *hdev) 530 { 531 unsigned long flags; 532 533 if (hammer_has_folded_event(hdev)) { 534 hid_hw_close(hdev); 535 536 /* 537 * If we are disconnecting then most likely Whiskers is 538 * being removed. Even if it is not removed, without proper 539 * keyboard we should not stay in clamshell mode. 540 * 541 * The reason for doing it here and not waiting for signal 542 * from EC, is that on some devices there are high leakage 543 * on Whiskers pins and we do not detect disconnect reliably, 544 * resulting in devices being stuck in clamshell mode. 545 */ 546 spin_lock_irqsave(&cbas_ec_lock, flags); 547 if (cbas_ec.input && cbas_ec.base_present) { 548 input_report_switch(cbas_ec.input, SW_TABLET_MODE, 1); 549 input_sync(cbas_ec.input); 550 } 551 cbas_ec.base_present = false; 552 spin_unlock_irqrestore(&cbas_ec_lock, flags); 553 } 554 555 /* Unregistering LEDs and stopping the hardware is done via devm */ 556 } 557 558 static const struct hid_device_id hammer_devices[] = { 559 { HID_DEVICE(BUS_USB, HID_GROUP_GENERIC, 560 USB_VENDOR_ID_GOOGLE, USB_DEVICE_ID_GOOGLE_DON) }, 561 { HID_DEVICE(BUS_USB, HID_GROUP_VIVALDI, 562 USB_VENDOR_ID_GOOGLE, USB_DEVICE_ID_GOOGLE_EEL) }, 563 { HID_DEVICE(BUS_USB, HID_GROUP_GENERIC, 564 USB_VENDOR_ID_GOOGLE, USB_DEVICE_ID_GOOGLE_HAMMER) }, 565 { HID_DEVICE(BUS_USB, HID_GROUP_GENERIC, 566 USB_VENDOR_ID_GOOGLE, USB_DEVICE_ID_GOOGLE_JEWEL) }, 567 { HID_DEVICE(BUS_USB, HID_GROUP_GENERIC, 568 USB_VENDOR_ID_GOOGLE, USB_DEVICE_ID_GOOGLE_MAGNEMITE) }, 569 { HID_DEVICE(BUS_USB, HID_GROUP_GENERIC, 570 USB_VENDOR_ID_GOOGLE, USB_DEVICE_ID_GOOGLE_MASTERBALL) }, 571 { HID_DEVICE(BUS_USB, HID_GROUP_GENERIC, 572 USB_VENDOR_ID_GOOGLE, USB_DEVICE_ID_GOOGLE_MOONBALL) }, 573 { HID_DEVICE(BUS_USB, HID_GROUP_GENERIC, 574 USB_VENDOR_ID_GOOGLE, USB_DEVICE_ID_GOOGLE_STAFF) }, 575 { HID_DEVICE(BUS_USB, HID_GROUP_GENERIC, 576 USB_VENDOR_ID_GOOGLE, USB_DEVICE_ID_GOOGLE_WAND) }, 577 { HID_DEVICE(BUS_USB, HID_GROUP_GENERIC, 578 USB_VENDOR_ID_GOOGLE, USB_DEVICE_ID_GOOGLE_WHISKERS) }, 579 { } 580 }; 581 MODULE_DEVICE_TABLE(hid, hammer_devices); 582 583 static struct hid_driver hammer_driver = { 584 .name = "hammer", 585 .id_table = hammer_devices, 586 .probe = hammer_probe, 587 .remove = hammer_remove, 588 .feature_mapping = vivaldi_feature_mapping, 589 .input_mapping = hammer_input_mapping, 590 .event = hammer_event, 591 .driver = { 592 .dev_groups = vivaldi_attribute_groups, 593 }, 594 }; 595 hammer_init(void)596 static int __init hammer_init(void) 597 { 598 int error; 599 600 error = platform_driver_register(&cbas_ec_driver); 601 if (error) 602 return error; 603 604 error = hid_register_driver(&hammer_driver); 605 if (error) { 606 platform_driver_unregister(&cbas_ec_driver); 607 return error; 608 } 609 610 return 0; 611 } 612 module_init(hammer_init); 613 hammer_exit(void)614 static void __exit hammer_exit(void) 615 { 616 hid_unregister_driver(&hammer_driver); 617 platform_driver_unregister(&cbas_ec_driver); 618 } 619 module_exit(hammer_exit); 620 621 MODULE_DESCRIPTION("HID driver for Google Hammer device."); 622 MODULE_LICENSE("GPL"); 623