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 <asm/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 */
37struct 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
45static struct cbas_ec cbas_ec;
46static DEFINE_SPINLOCK(cbas_ec_lock);
47static DEFINE_MUTEX(cbas_ec_reglock);
48
49static bool cbas_parse_base_state(const void *data)
50{
51 u32 switches = get_unaligned_le32(p: data);
52
53 return !!(switches & BIT(EC_MKBP_BASE_ATTACHED));
54}
55
56static 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(data: msg->data);
85 ret = 0;
86 }
87 }
88
89 kfree(objp: msg);
90
91 return ret;
92}
93
94static 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 data: &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(dev: cbas_ec.dev) ||
109 !queued_during_suspend) {
110
111 pm_wakeup_event(dev: cbas_ec.dev, msec: 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(dev: cbas_ec.input,
124 SW_TABLET_MODE,
125 value: !base_present);
126 input_sync(dev: cbas_ec.input);
127 cbas_ec.base_present = base_present;
128 }
129
130 spin_unlock_irqrestore(lock: &cbas_ec_lock, flags);
131 }
132 }
133
134 return NOTIFY_OK;
135}
136
137static __maybe_unused int cbas_ec_resume(struct device *dev)
138{
139 struct cros_ec_device *ec = dev_get_drvdata(dev: dev->parent);
140 bool base_present;
141 int error;
142
143 error = cbas_ec_query_base(ec_dev: ec, get_state: true, state: &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(lock: &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(dev: cbas_ec.input, SW_TABLET_MODE, value: 1);
159 input_sync(dev: cbas_ec.input);
160 }
161
162 spin_unlock_irq(lock: &cbas_ec_lock);
163 }
164
165 return 0;
166}
167
168static SIMPLE_DEV_PM_OPS(cbas_ec_pm_ops, NULL, cbas_ec_resume);
169
170static 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(lock: &cbas_ec_lock);
174 cbas_ec.input = input;
175 spin_unlock_irq(lock: &cbas_ec_lock);
176}
177
178static int __cbas_ec_probe(struct platform_device *pdev)
179{
180 struct cros_ec_device *ec = dev_get_drvdata(dev: pdev->dev.parent);
181 struct input_dev *input;
182 bool base_supported;
183 int error;
184
185 error = cbas_ec_query_base(ec_dev: ec, get_state: false, state: &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(dev: 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_dev: ec, get_state: true, state: &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(dev: input, SW_TABLET_MODE,
222 value: !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(nh: &ec->event_notifier,
229 nb: &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(dev: &pdev->dev, enable: true);
237 return 0;
238}
239
240static 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
253out:
254 mutex_unlock(lock: &cbas_ec_reglock);
255 return retval;
256}
257
258static int cbas_ec_remove(struct platform_device *pdev)
259{
260 struct cros_ec_device *ec = dev_get_drvdata(dev: pdev->dev.parent);
261
262 mutex_lock(&cbas_ec_reglock);
263
264 blocking_notifier_chain_unregister(nh: &ec->event_notifier,
265 nb: &cbas_ec.notifier);
266 cbas_ec_set_input(NULL);
267
268 mutex_unlock(lock: &cbas_ec_reglock);
269 return 0;
270}
271
272static const struct acpi_device_id cbas_ec_acpi_ids[] = {
273 { "GOOG000B", 0 },
274 { }
275};
276MODULE_DEVICE_TABLE(acpi, cbas_ec_acpi_ids);
277
278#ifdef CONFIG_OF
279static const struct of_device_id cbas_ec_of_match[] = {
280 { .compatible = "google,cros-cbas" },
281 { },
282};
283MODULE_DEVICE_TABLE(of, cbas_ec_of_match);
284#endif
285
286static struct platform_driver cbas_ec_driver = {
287 .probe = cbas_ec_probe,
288 .remove = cbas_ec_remove,
289 .driver = {
290 .name = "cbas_ec",
291 .acpi_match_table = ACPI_PTR(cbas_ec_acpi_ids),
292 .of_match_table = of_match_ptr(cbas_ec_of_match),
293 .pm = &cbas_ec_pm_ops,
294 },
295};
296
297#define MAX_BRIGHTNESS 100
298
299struct hammer_kbd_leds {
300 struct led_classdev cdev;
301 struct hid_device *hdev;
302 u8 buf[2] ____cacheline_aligned;
303};
304
305static int hammer_kbd_brightness_set_blocking(struct led_classdev *cdev,
306 enum led_brightness br)
307{
308 struct hammer_kbd_leds *led = container_of(cdev,
309 struct hammer_kbd_leds,
310 cdev);
311 int ret;
312
313 led->buf[0] = 0;
314 led->buf[1] = br;
315
316 /*
317 * Request USB HID device to be in Full On mode, so that sending
318 * hardware output report and hardware raw request won't fail.
319 */
320 ret = hid_hw_power(hdev: led->hdev, PM_HINT_FULLON);
321 if (ret < 0) {
322 hid_err(led->hdev, "failed: device not resumed %d\n", ret);
323 return ret;
324 }
325
326 ret = hid_hw_output_report(hdev: led->hdev, buf: led->buf, len: sizeof(led->buf));
327 if (ret == -ENOSYS)
328 ret = hid_hw_raw_request(hdev: led->hdev, reportnum: 0, buf: led->buf,
329 len: sizeof(led->buf),
330 rtype: HID_OUTPUT_REPORT,
331 reqtype: HID_REQ_SET_REPORT);
332 if (ret < 0)
333 hid_err(led->hdev, "failed to set keyboard backlight: %d\n",
334 ret);
335
336 /* Request USB HID device back to Normal Mode. */
337 hid_hw_power(hdev: led->hdev, PM_HINT_NORMAL);
338
339 return ret;
340}
341
342static int hammer_register_leds(struct hid_device *hdev)
343{
344 struct hammer_kbd_leds *kbd_backlight;
345
346 kbd_backlight = devm_kzalloc(dev: &hdev->dev, size: sizeof(*kbd_backlight),
347 GFP_KERNEL);
348 if (!kbd_backlight)
349 return -ENOMEM;
350
351 kbd_backlight->hdev = hdev;
352 kbd_backlight->cdev.name = "hammer::kbd_backlight";
353 kbd_backlight->cdev.max_brightness = MAX_BRIGHTNESS;
354 kbd_backlight->cdev.brightness_set_blocking =
355 hammer_kbd_brightness_set_blocking;
356 kbd_backlight->cdev.flags = LED_HW_PLUGGABLE;
357
358 /* Set backlight to 0% initially. */
359 hammer_kbd_brightness_set_blocking(cdev: &kbd_backlight->cdev, br: 0);
360
361 return devm_led_classdev_register(parent: &hdev->dev, led_cdev: &kbd_backlight->cdev);
362}
363
364#define HID_UP_GOOGLEVENDOR 0xffd10000
365#define HID_VD_KBD_FOLDED 0x00000019
366#define HID_USAGE_KBD_FOLDED (HID_UP_GOOGLEVENDOR | HID_VD_KBD_FOLDED)
367
368/* HID usage for keyboard backlight (Alphanumeric display brightness) */
369#define HID_AD_BRIGHTNESS 0x00140046
370
371static int hammer_input_mapping(struct hid_device *hdev, struct hid_input *hi,
372 struct hid_field *field,
373 struct hid_usage *usage,
374 unsigned long **bit, int *max)
375{
376 if (usage->hid == HID_USAGE_KBD_FOLDED) {
377 /*
378 * We do not want to have this usage mapped as it will get
379 * mixed in with "base attached" signal and delivered over
380 * separate input device for tablet switch mode.
381 */
382 return -1;
383 }
384
385 return 0;
386}
387
388static void hammer_folded_event(struct hid_device *hdev, bool folded)
389{
390 unsigned long flags;
391
392 spin_lock_irqsave(&cbas_ec_lock, flags);
393
394 /*
395 * If we are getting events from Whiskers that means that it
396 * is attached to the lid.
397 */
398 cbas_ec.base_present = true;
399 cbas_ec.base_folded = folded;
400 hid_dbg(hdev, "%s: base: %d, folded: %d\n", __func__,
401 cbas_ec.base_present, cbas_ec.base_folded);
402
403 if (cbas_ec.input) {
404 input_report_switch(dev: cbas_ec.input, SW_TABLET_MODE, value: folded);
405 input_sync(dev: cbas_ec.input);
406 }
407
408 spin_unlock_irqrestore(lock: &cbas_ec_lock, flags);
409}
410
411static int hammer_event(struct hid_device *hid, struct hid_field *field,
412 struct hid_usage *usage, __s32 value)
413{
414 if (usage->hid == HID_USAGE_KBD_FOLDED) {
415 hammer_folded_event(hdev: hid, folded: value);
416 return 1; /* We handled this event */
417 }
418
419 return 0;
420}
421
422static bool hammer_has_usage(struct hid_device *hdev, unsigned int report_type,
423 unsigned application, unsigned usage)
424{
425 struct hid_report_enum *re = &hdev->report_enum[report_type];
426 struct hid_report *report;
427 int i, j;
428
429 list_for_each_entry(report, &re->report_list, list) {
430 if (report->application != application)
431 continue;
432
433 for (i = 0; i < report->maxfield; i++) {
434 struct hid_field *field = report->field[i];
435
436 for (j = 0; j < field->maxusage; j++)
437 if (field->usage[j].hid == usage)
438 return true;
439 }
440 }
441
442 return false;
443}
444
445static bool hammer_has_folded_event(struct hid_device *hdev)
446{
447 return hammer_has_usage(hdev, report_type: HID_INPUT_REPORT,
448 HID_GD_KEYBOARD, HID_USAGE_KBD_FOLDED);
449}
450
451static bool hammer_has_backlight_control(struct hid_device *hdev)
452{
453 return hammer_has_usage(hdev, report_type: HID_OUTPUT_REPORT,
454 HID_GD_KEYBOARD, HID_AD_BRIGHTNESS);
455}
456
457static void hammer_get_folded_state(struct hid_device *hdev)
458{
459 struct hid_report *report;
460 char *buf;
461 int len, rlen;
462 int a;
463
464 report = hdev->report_enum[HID_INPUT_REPORT].report_id_hash[0x0];
465
466 if (!report || report->maxfield < 1)
467 return;
468
469 len = hid_report_len(report) + 1;
470
471 buf = kmalloc(size: len, GFP_KERNEL);
472 if (!buf)
473 return;
474
475 rlen = hid_hw_raw_request(hdev, reportnum: report->id, buf, len, rtype: report->type, reqtype: HID_REQ_GET_REPORT);
476
477 if (rlen != len) {
478 hid_warn(hdev, "Unable to read base folded state: %d (expected %d)\n", rlen, len);
479 goto out;
480 }
481
482 for (a = 0; a < report->maxfield; a++) {
483 struct hid_field *field = report->field[a];
484
485 if (field->usage->hid == HID_USAGE_KBD_FOLDED) {
486 u32 value = hid_field_extract(hid: hdev, report: buf+1,
487 offset: field->report_offset, n: field->report_size);
488
489 hammer_folded_event(hdev, folded: value);
490 break;
491 }
492 }
493
494out:
495 kfree(objp: buf);
496}
497
498static void hammer_stop(void *hdev)
499{
500 hid_hw_stop(hdev);
501}
502
503static int hammer_probe(struct hid_device *hdev,
504 const struct hid_device_id *id)
505{
506 struct vivaldi_data *vdata;
507 int error;
508
509 vdata = devm_kzalloc(dev: &hdev->dev, size: sizeof(*vdata), GFP_KERNEL);
510 if (!vdata)
511 return -ENOMEM;
512
513 hid_set_drvdata(hdev, data: vdata);
514
515 error = hid_parse(hdev);
516 if (error)
517 return error;
518
519 error = hid_hw_start(hdev, HID_CONNECT_DEFAULT);
520 if (error)
521 return error;
522
523 error = devm_add_action(&hdev->dev, hammer_stop, hdev);
524 if (error)
525 return error;
526
527 /*
528 * We always want to poll for, and handle tablet mode events from
529 * devices that have folded usage, even when nobody has opened the input
530 * device. This also prevents the hid core from dropping early tablet
531 * mode events from the device.
532 */
533 if (hammer_has_folded_event(hdev)) {
534 hdev->quirks |= HID_QUIRK_ALWAYS_POLL;
535 error = hid_hw_open(hdev);
536 if (error)
537 return error;
538
539 hammer_get_folded_state(hdev);
540 }
541
542 if (hammer_has_backlight_control(hdev)) {
543 error = hammer_register_leds(hdev);
544 if (error)
545 hid_warn(hdev,
546 "Failed to register keyboard backlight: %d\n",
547 error);
548 }
549
550 return 0;
551}
552
553static void hammer_remove(struct hid_device *hdev)
554{
555 unsigned long flags;
556
557 if (hammer_has_folded_event(hdev)) {
558 hid_hw_close(hdev);
559
560 /*
561 * If we are disconnecting then most likely Whiskers is
562 * being removed. Even if it is not removed, without proper
563 * keyboard we should not stay in clamshell mode.
564 *
565 * The reason for doing it here and not waiting for signal
566 * from EC, is that on some devices there are high leakage
567 * on Whiskers pins and we do not detect disconnect reliably,
568 * resulting in devices being stuck in clamshell mode.
569 */
570 spin_lock_irqsave(&cbas_ec_lock, flags);
571 if (cbas_ec.input && cbas_ec.base_present) {
572 input_report_switch(dev: cbas_ec.input, SW_TABLET_MODE, value: 1);
573 input_sync(dev: cbas_ec.input);
574 }
575 cbas_ec.base_present = false;
576 spin_unlock_irqrestore(lock: &cbas_ec_lock, flags);
577 }
578
579 /* Unregistering LEDs and stopping the hardware is done via devm */
580}
581
582static const struct hid_device_id hammer_devices[] = {
583 { HID_DEVICE(BUS_USB, HID_GROUP_GENERIC,
584 USB_VENDOR_ID_GOOGLE, USB_DEVICE_ID_GOOGLE_DON) },
585 { HID_DEVICE(BUS_USB, HID_GROUP_VIVALDI,
586 USB_VENDOR_ID_GOOGLE, USB_DEVICE_ID_GOOGLE_EEL) },
587 { HID_DEVICE(BUS_USB, HID_GROUP_GENERIC,
588 USB_VENDOR_ID_GOOGLE, USB_DEVICE_ID_GOOGLE_HAMMER) },
589 { HID_DEVICE(BUS_USB, HID_GROUP_GENERIC,
590 USB_VENDOR_ID_GOOGLE, USB_DEVICE_ID_GOOGLE_JEWEL) },
591 { HID_DEVICE(BUS_USB, HID_GROUP_GENERIC,
592 USB_VENDOR_ID_GOOGLE, USB_DEVICE_ID_GOOGLE_MAGNEMITE) },
593 { HID_DEVICE(BUS_USB, HID_GROUP_GENERIC,
594 USB_VENDOR_ID_GOOGLE, USB_DEVICE_ID_GOOGLE_MASTERBALL) },
595 { HID_DEVICE(BUS_USB, HID_GROUP_GENERIC,
596 USB_VENDOR_ID_GOOGLE, USB_DEVICE_ID_GOOGLE_MOONBALL) },
597 { HID_DEVICE(BUS_USB, HID_GROUP_GENERIC,
598 USB_VENDOR_ID_GOOGLE, USB_DEVICE_ID_GOOGLE_STAFF) },
599 { HID_DEVICE(BUS_USB, HID_GROUP_GENERIC,
600 USB_VENDOR_ID_GOOGLE, USB_DEVICE_ID_GOOGLE_WAND) },
601 { HID_DEVICE(BUS_USB, HID_GROUP_GENERIC,
602 USB_VENDOR_ID_GOOGLE, USB_DEVICE_ID_GOOGLE_WHISKERS) },
603 { }
604};
605MODULE_DEVICE_TABLE(hid, hammer_devices);
606
607static struct hid_driver hammer_driver = {
608 .name = "hammer",
609 .id_table = hammer_devices,
610 .probe = hammer_probe,
611 .remove = hammer_remove,
612 .feature_mapping = vivaldi_feature_mapping,
613 .input_mapping = hammer_input_mapping,
614 .event = hammer_event,
615 .driver = {
616 .dev_groups = vivaldi_attribute_groups,
617 },
618};
619
620static int __init hammer_init(void)
621{
622 int error;
623
624 error = platform_driver_register(&cbas_ec_driver);
625 if (error)
626 return error;
627
628 error = hid_register_driver(&hammer_driver);
629 if (error) {
630 platform_driver_unregister(&cbas_ec_driver);
631 return error;
632 }
633
634 return 0;
635}
636module_init(hammer_init);
637
638static void __exit hammer_exit(void)
639{
640 hid_unregister_driver(&hammer_driver);
641 platform_driver_unregister(&cbas_ec_driver);
642}
643module_exit(hammer_exit);
644
645MODULE_LICENSE("GPL");
646

source code of linux/drivers/hid/hid-google-hammer.c