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 #ifdef CONFIG_ACPI
272 static const struct acpi_device_id cbas_ec_acpi_ids[] = {
273 { "GOOG000B", 0 },
274 { }
275 };
276 MODULE_DEVICE_TABLE(acpi, cbas_ec_acpi_ids);
277 #endif
278
279 #ifdef CONFIG_OF
280 static const struct of_device_id cbas_ec_of_match[] = {
281 { .compatible = "google,cros-cbas" },
282 { },
283 };
284 MODULE_DEVICE_TABLE(of, cbas_ec_of_match);
285 #endif
286
287 static struct platform_driver cbas_ec_driver = {
288 .probe = cbas_ec_probe,
289 .remove = cbas_ec_remove,
290 .driver = {
291 .name = "cbas_ec",
292 .acpi_match_table = ACPI_PTR(cbas_ec_acpi_ids),
293 .of_match_table = of_match_ptr(cbas_ec_of_match),
294 .pm = &cbas_ec_pm_ops,
295 },
296 };
297
298 #define MAX_BRIGHTNESS 100
299
300 struct hammer_kbd_leds {
301 struct led_classdev cdev;
302 struct hid_device *hdev;
303 u8 buf[2] ____cacheline_aligned;
304 };
305
hammer_kbd_brightness_set_blocking(struct led_classdev * cdev,enum led_brightness br)306 static int hammer_kbd_brightness_set_blocking(struct led_classdev *cdev,
307 enum led_brightness br)
308 {
309 struct hammer_kbd_leds *led = container_of(cdev,
310 struct hammer_kbd_leds,
311 cdev);
312 int ret;
313
314 led->buf[0] = 0;
315 led->buf[1] = br;
316
317 /*
318 * Request USB HID device to be in Full On mode, so that sending
319 * hardware output report and hardware raw request won't fail.
320 */
321 ret = hid_hw_power(led->hdev, PM_HINT_FULLON);
322 if (ret < 0) {
323 hid_err(led->hdev, "failed: device not resumed %d\n", ret);
324 return ret;
325 }
326
327 ret = hid_hw_output_report(led->hdev, led->buf, sizeof(led->buf));
328 if (ret == -ENOSYS)
329 ret = hid_hw_raw_request(led->hdev, 0, led->buf,
330 sizeof(led->buf),
331 HID_OUTPUT_REPORT,
332 HID_REQ_SET_REPORT);
333 if (ret < 0)
334 hid_err(led->hdev, "failed to set keyboard backlight: %d\n",
335 ret);
336
337 /* Request USB HID device back to Normal Mode. */
338 hid_hw_power(led->hdev, PM_HINT_NORMAL);
339
340 return ret;
341 }
342
hammer_register_leds(struct hid_device * hdev)343 static int hammer_register_leds(struct hid_device *hdev)
344 {
345 struct hammer_kbd_leds *kbd_backlight;
346
347 kbd_backlight = devm_kzalloc(&hdev->dev, sizeof(*kbd_backlight),
348 GFP_KERNEL);
349 if (!kbd_backlight)
350 return -ENOMEM;
351
352 kbd_backlight->hdev = hdev;
353 kbd_backlight->cdev.name = "hammer::kbd_backlight";
354 kbd_backlight->cdev.max_brightness = MAX_BRIGHTNESS;
355 kbd_backlight->cdev.brightness_set_blocking =
356 hammer_kbd_brightness_set_blocking;
357 kbd_backlight->cdev.flags = LED_HW_PLUGGABLE;
358
359 /* Set backlight to 0% initially. */
360 hammer_kbd_brightness_set_blocking(&kbd_backlight->cdev, 0);
361
362 return devm_led_classdev_register(&hdev->dev, &kbd_backlight->cdev);
363 }
364
365 #define HID_UP_GOOGLEVENDOR 0xffd10000
366 #define HID_VD_KBD_FOLDED 0x00000019
367 #define HID_USAGE_KBD_FOLDED (HID_UP_GOOGLEVENDOR | HID_VD_KBD_FOLDED)
368
369 /* HID usage for keyboard backlight (Alphanumeric display brightness) */
370 #define HID_AD_BRIGHTNESS 0x00140046
371
hammer_input_mapping(struct hid_device * hdev,struct hid_input * hi,struct hid_field * field,struct hid_usage * usage,unsigned long ** bit,int * max)372 static int hammer_input_mapping(struct hid_device *hdev, struct hid_input *hi,
373 struct hid_field *field,
374 struct hid_usage *usage,
375 unsigned long **bit, int *max)
376 {
377 if (usage->hid == HID_USAGE_KBD_FOLDED) {
378 /*
379 * We do not want to have this usage mapped as it will get
380 * mixed in with "base attached" signal and delivered over
381 * separate input device for tablet switch mode.
382 */
383 return -1;
384 }
385
386 return 0;
387 }
388
hammer_folded_event(struct hid_device * hdev,bool folded)389 static void hammer_folded_event(struct hid_device *hdev, bool folded)
390 {
391 unsigned long flags;
392
393 spin_lock_irqsave(&cbas_ec_lock, flags);
394
395 /*
396 * If we are getting events from Whiskers that means that it
397 * is attached to the lid.
398 */
399 cbas_ec.base_present = true;
400 cbas_ec.base_folded = folded;
401 hid_dbg(hdev, "%s: base: %d, folded: %d\n", __func__,
402 cbas_ec.base_present, cbas_ec.base_folded);
403
404 if (cbas_ec.input) {
405 input_report_switch(cbas_ec.input, SW_TABLET_MODE, folded);
406 input_sync(cbas_ec.input);
407 }
408
409 spin_unlock_irqrestore(&cbas_ec_lock, flags);
410 }
411
hammer_event(struct hid_device * hid,struct hid_field * field,struct hid_usage * usage,__s32 value)412 static int hammer_event(struct hid_device *hid, struct hid_field *field,
413 struct hid_usage *usage, __s32 value)
414 {
415 if (usage->hid == HID_USAGE_KBD_FOLDED) {
416 hammer_folded_event(hid, value);
417 return 1; /* We handled this event */
418 }
419
420 return 0;
421 }
422
hammer_has_folded_event(struct hid_device * hdev)423 static bool hammer_has_folded_event(struct hid_device *hdev)
424 {
425 return !!hid_find_field(hdev, HID_INPUT_REPORT,
426 HID_GD_KEYBOARD, HID_USAGE_KBD_FOLDED);
427 }
428
hammer_has_backlight_control(struct hid_device * hdev)429 static bool hammer_has_backlight_control(struct hid_device *hdev)
430 {
431 return !!hid_find_field(hdev, HID_OUTPUT_REPORT,
432 HID_GD_KEYBOARD, HID_AD_BRIGHTNESS);
433 }
434
hammer_get_folded_state(struct hid_device * hdev)435 static void hammer_get_folded_state(struct hid_device *hdev)
436 {
437 struct hid_report *report;
438 char *buf;
439 int len, rlen;
440 int a;
441
442 report = hdev->report_enum[HID_INPUT_REPORT].report_id_hash[0x0];
443
444 if (!report || report->maxfield < 1)
445 return;
446
447 len = hid_report_len(report) + 1;
448
449 buf = kmalloc(len, GFP_KERNEL);
450 if (!buf)
451 return;
452
453 rlen = hid_hw_raw_request(hdev, report->id, buf, len, report->type, HID_REQ_GET_REPORT);
454
455 if (rlen != len) {
456 hid_warn(hdev, "Unable to read base folded state: %d (expected %d)\n", rlen, len);
457 goto out;
458 }
459
460 for (a = 0; a < report->maxfield; a++) {
461 struct hid_field *field = report->field[a];
462
463 if (field->usage->hid == HID_USAGE_KBD_FOLDED) {
464 u32 value = hid_field_extract(hdev, buf+1,
465 field->report_offset, field->report_size);
466
467 hammer_folded_event(hdev, value);
468 break;
469 }
470 }
471
472 out:
473 kfree(buf);
474 }
475
hammer_stop(void * hdev)476 static void hammer_stop(void *hdev)
477 {
478 hid_hw_stop(hdev);
479 }
480
hammer_probe(struct hid_device * hdev,const struct hid_device_id * id)481 static int hammer_probe(struct hid_device *hdev,
482 const struct hid_device_id *id)
483 {
484 struct vivaldi_data *vdata;
485 int error;
486
487 vdata = devm_kzalloc(&hdev->dev, sizeof(*vdata), GFP_KERNEL);
488 if (!vdata)
489 return -ENOMEM;
490
491 hid_set_drvdata(hdev, vdata);
492
493 error = hid_parse(hdev);
494 if (error)
495 return error;
496
497 error = hid_hw_start(hdev, HID_CONNECT_DEFAULT);
498 if (error)
499 return error;
500
501 error = devm_add_action(&hdev->dev, hammer_stop, hdev);
502 if (error)
503 return error;
504
505 /*
506 * We always want to poll for, and handle tablet mode events from
507 * devices that have folded usage, even when nobody has opened the input
508 * device. This also prevents the hid core from dropping early tablet
509 * mode events from the device.
510 */
511 if (hammer_has_folded_event(hdev)) {
512 hdev->quirks |= HID_QUIRK_ALWAYS_POLL;
513 error = hid_hw_open(hdev);
514 if (error)
515 return error;
516
517 hammer_get_folded_state(hdev);
518 }
519
520 if (hammer_has_backlight_control(hdev)) {
521 error = hammer_register_leds(hdev);
522 if (error)
523 hid_warn(hdev,
524 "Failed to register keyboard backlight: %d\n",
525 error);
526 }
527
528 return 0;
529 }
530
hammer_remove(struct hid_device * hdev)531 static void hammer_remove(struct hid_device *hdev)
532 {
533 unsigned long flags;
534
535 if (hammer_has_folded_event(hdev)) {
536 hid_hw_close(hdev);
537
538 /*
539 * If we are disconnecting then most likely Whiskers is
540 * being removed. Even if it is not removed, without proper
541 * keyboard we should not stay in clamshell mode.
542 *
543 * The reason for doing it here and not waiting for signal
544 * from EC, is that on some devices there are high leakage
545 * on Whiskers pins and we do not detect disconnect reliably,
546 * resulting in devices being stuck in clamshell mode.
547 */
548 spin_lock_irqsave(&cbas_ec_lock, flags);
549 if (cbas_ec.input && cbas_ec.base_present) {
550 input_report_switch(cbas_ec.input, SW_TABLET_MODE, 1);
551 input_sync(cbas_ec.input);
552 }
553 cbas_ec.base_present = false;
554 spin_unlock_irqrestore(&cbas_ec_lock, flags);
555 }
556
557 /* Unregistering LEDs and stopping the hardware is done via devm */
558 }
559
560 static const struct hid_device_id hammer_devices[] = {
561 { HID_DEVICE(BUS_USB, HID_GROUP_GENERIC,
562 USB_VENDOR_ID_GOOGLE, USB_DEVICE_ID_GOOGLE_DON) },
563 { HID_DEVICE(BUS_USB, HID_GROUP_VIVALDI,
564 USB_VENDOR_ID_GOOGLE, USB_DEVICE_ID_GOOGLE_EEL) },
565 { HID_DEVICE(BUS_USB, HID_GROUP_GENERIC,
566 USB_VENDOR_ID_GOOGLE, USB_DEVICE_ID_GOOGLE_HAMMER) },
567 { HID_DEVICE(BUS_USB, HID_GROUP_GENERIC,
568 USB_VENDOR_ID_GOOGLE, USB_DEVICE_ID_GOOGLE_JEWEL) },
569 { HID_DEVICE(BUS_USB, HID_GROUP_GENERIC,
570 USB_VENDOR_ID_GOOGLE, USB_DEVICE_ID_GOOGLE_MAGNEMITE) },
571 { HID_DEVICE(BUS_USB, HID_GROUP_GENERIC,
572 USB_VENDOR_ID_GOOGLE, USB_DEVICE_ID_GOOGLE_MASTERBALL) },
573 { HID_DEVICE(BUS_USB, HID_GROUP_GENERIC,
574 USB_VENDOR_ID_GOOGLE, USB_DEVICE_ID_GOOGLE_MOONBALL) },
575 { HID_DEVICE(BUS_USB, HID_GROUP_GENERIC,
576 USB_VENDOR_ID_GOOGLE, USB_DEVICE_ID_GOOGLE_STAFF) },
577 { HID_DEVICE(BUS_USB, HID_GROUP_GENERIC,
578 USB_VENDOR_ID_GOOGLE, USB_DEVICE_ID_GOOGLE_WAND) },
579 { HID_DEVICE(BUS_USB, HID_GROUP_GENERIC,
580 USB_VENDOR_ID_GOOGLE, USB_DEVICE_ID_GOOGLE_WHISKERS) },
581 { }
582 };
583 MODULE_DEVICE_TABLE(hid, hammer_devices);
584
585 static struct hid_driver hammer_driver = {
586 .name = "hammer",
587 .id_table = hammer_devices,
588 .probe = hammer_probe,
589 .remove = hammer_remove,
590 .feature_mapping = vivaldi_feature_mapping,
591 .input_mapping = hammer_input_mapping,
592 .event = hammer_event,
593 .driver = {
594 .dev_groups = vivaldi_attribute_groups,
595 },
596 };
597
hammer_init(void)598 static int __init hammer_init(void)
599 {
600 int error;
601
602 error = platform_driver_register(&cbas_ec_driver);
603 if (error)
604 return error;
605
606 error = hid_register_driver(&hammer_driver);
607 if (error) {
608 platform_driver_unregister(&cbas_ec_driver);
609 return error;
610 }
611
612 return 0;
613 }
614 module_init(hammer_init);
615
hammer_exit(void)616 static void __exit hammer_exit(void)
617 {
618 hid_unregister_driver(&hammer_driver);
619 platform_driver_unregister(&cbas_ec_driver);
620 }
621 module_exit(hammer_exit);
622
623 MODULE_DESCRIPTION("HID driver for Google Hammer device.");
624 MODULE_LICENSE("GPL");
625