xref: /linux/drivers/hid/hid-appletb-kbd.c (revision 8fa7292fee5c5240402371ea89ab285ec856c916)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Apple Touch Bar Keyboard Mode Driver
4  *
5  * Copyright (c) 2017-2018 Ronald Tschalär
6  * Copyright (c) 2022-2023 Kerem Karabay <kekrby@gmail.com>
7  * Copyright (c) 2024-2025 Aditya Garg <gargaditya08@live.com>
8  */
9 
10 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
11 
12 #include <linux/hid.h>
13 #include <linux/usb.h>
14 #include <linux/input.h>
15 #include <linux/sysfs.h>
16 #include <linux/bitops.h>
17 #include <linux/module.h>
18 #include <linux/string.h>
19 #include <linux/backlight.h>
20 #include <linux/timer.h>
21 #include <linux/input/sparse-keymap.h>
22 
23 #include "hid-ids.h"
24 
25 #define APPLETB_KBD_MODE_ESC	0
26 #define APPLETB_KBD_MODE_FN	1
27 #define APPLETB_KBD_MODE_SPCL	2
28 #define APPLETB_KBD_MODE_OFF	3
29 #define APPLETB_KBD_MODE_MAX	APPLETB_KBD_MODE_OFF
30 
31 #define APPLETB_DEVID_KEYBOARD	1
32 #define APPLETB_DEVID_TRACKPAD	2
33 
34 #define HID_USAGE_MODE		0x00ff0004
35 
36 static int appletb_tb_def_mode = APPLETB_KBD_MODE_SPCL;
37 module_param_named(mode, appletb_tb_def_mode, int, 0444);
38 MODULE_PARM_DESC(mode, "Default touchbar mode:\n"
39 			 "    0 - escape key only\n"
40 			 "    1 - function-keys\n"
41 			 "    [2] - special keys");
42 
43 static bool appletb_tb_fn_toggle = true;
44 module_param_named(fntoggle, appletb_tb_fn_toggle, bool, 0644);
45 MODULE_PARM_DESC(fntoggle, "Switch between Fn and media controls on pressing Fn key");
46 
47 static bool appletb_tb_autodim = true;
48 module_param_named(autodim, appletb_tb_autodim, bool, 0644);
49 MODULE_PARM_DESC(autodim, "Automatically dim and turn off the Touch Bar after some time");
50 
51 static int appletb_tb_dim_timeout = 60;
52 module_param_named(dim_timeout, appletb_tb_dim_timeout, int, 0644);
53 MODULE_PARM_DESC(dim_timeout, "Dim timeout in sec");
54 
55 static int appletb_tb_idle_timeout = 15;
56 module_param_named(idle_timeout, appletb_tb_idle_timeout, int, 0644);
57 MODULE_PARM_DESC(idle_timeout, "Idle timeout in sec");
58 
59 struct appletb_kbd {
60 	struct hid_field *mode_field;
61 	struct input_handler inp_handler;
62 	struct input_handle kbd_handle;
63 	struct input_handle tpd_handle;
64 	struct backlight_device *backlight_dev;
65 	struct timer_list inactivity_timer;
66 	bool has_dimmed;
67 	bool has_turned_off;
68 	u8 saved_mode;
69 	u8 current_mode;
70 };
71 
72 static const struct key_entry appletb_kbd_keymap[] = {
73 	{ KE_KEY, KEY_ESC, { KEY_ESC } },
74 	{ KE_KEY, KEY_F1,  { KEY_BRIGHTNESSDOWN } },
75 	{ KE_KEY, KEY_F2,  { KEY_BRIGHTNESSUP } },
76 	{ KE_KEY, KEY_F3,  { KEY_RESERVED } },
77 	{ KE_KEY, KEY_F4,  { KEY_RESERVED } },
78 	{ KE_KEY, KEY_F5,  { KEY_KBDILLUMDOWN } },
79 	{ KE_KEY, KEY_F6,  { KEY_KBDILLUMUP } },
80 	{ KE_KEY, KEY_F7,  { KEY_PREVIOUSSONG } },
81 	{ KE_KEY, KEY_F8,  { KEY_PLAYPAUSE } },
82 	{ KE_KEY, KEY_F9,  { KEY_NEXTSONG } },
83 	{ KE_KEY, KEY_F10, { KEY_MUTE } },
84 	{ KE_KEY, KEY_F11, { KEY_VOLUMEDOWN } },
85 	{ KE_KEY, KEY_F12, { KEY_VOLUMEUP } },
86 	{ KE_END, 0 }
87 };
88 
89 static int appletb_kbd_set_mode(struct appletb_kbd *kbd, u8 mode)
90 {
91 	struct hid_report *report = kbd->mode_field->report;
92 	struct hid_device *hdev = report->device;
93 	int ret;
94 
95 	ret = hid_hw_power(hdev, PM_HINT_FULLON);
96 	if (ret) {
97 		hid_err(hdev, "Device didn't resume (%pe)\n", ERR_PTR(ret));
98 		return ret;
99 	}
100 
101 	ret = hid_set_field(kbd->mode_field, 0, mode);
102 	if (ret) {
103 		hid_err(hdev, "Failed to set mode field to %u (%pe)\n", mode, ERR_PTR(ret));
104 		goto power_normal;
105 	}
106 
107 	hid_hw_request(hdev, report, HID_REQ_SET_REPORT);
108 
109 	kbd->current_mode = mode;
110 
111 power_normal:
112 	hid_hw_power(hdev, PM_HINT_NORMAL);
113 
114 	return ret;
115 }
116 
117 static ssize_t mode_show(struct device *dev,
118 			 struct device_attribute *attr, char *buf)
119 {
120 	struct appletb_kbd *kbd = dev_get_drvdata(dev);
121 
122 	return sysfs_emit(buf, "%d\n", kbd->current_mode);
123 }
124 
125 static ssize_t mode_store(struct device *dev,
126 			  struct device_attribute *attr,
127 			  const char *buf, size_t size)
128 {
129 	struct appletb_kbd *kbd = dev_get_drvdata(dev);
130 	u8 mode;
131 	int ret;
132 
133 	ret = kstrtou8(buf, 0, &mode);
134 	if (ret)
135 		return ret;
136 
137 	if (mode > APPLETB_KBD_MODE_MAX)
138 		return -EINVAL;
139 
140 	ret = appletb_kbd_set_mode(kbd, mode);
141 
142 	return ret < 0 ? ret : size;
143 }
144 static DEVICE_ATTR_RW(mode);
145 
146 static struct attribute *appletb_kbd_attrs[] = {
147 	&dev_attr_mode.attr,
148 	NULL
149 };
150 ATTRIBUTE_GROUPS(appletb_kbd);
151 
152 static int appletb_tb_key_to_slot(unsigned int code)
153 {
154 	switch (code) {
155 	case KEY_ESC:
156 		return 0;
157 	case KEY_F1 ... KEY_F10:
158 		return code - KEY_F1 + 1;
159 	case KEY_F11 ... KEY_F12:
160 		return code - KEY_F11 + 11;
161 
162 	default:
163 		return -EINVAL;
164 	}
165 }
166 
167 static void appletb_inactivity_timer(struct timer_list *t)
168 {
169 	struct appletb_kbd *kbd = from_timer(kbd, t, inactivity_timer);
170 
171 	if (kbd->backlight_dev && appletb_tb_autodim) {
172 		if (!kbd->has_dimmed) {
173 			backlight_device_set_brightness(kbd->backlight_dev, 1);
174 			kbd->has_dimmed = true;
175 			mod_timer(&kbd->inactivity_timer, jiffies + msecs_to_jiffies(appletb_tb_idle_timeout * 1000));
176 		} else if (!kbd->has_turned_off) {
177 			backlight_device_set_brightness(kbd->backlight_dev, 0);
178 			kbd->has_turned_off = true;
179 		}
180 	}
181 }
182 
183 static void reset_inactivity_timer(struct appletb_kbd *kbd)
184 {
185 	if (kbd->backlight_dev && appletb_tb_autodim) {
186 		if (kbd->has_dimmed || kbd->has_turned_off) {
187 			backlight_device_set_brightness(kbd->backlight_dev, 2);
188 			kbd->has_dimmed = false;
189 			kbd->has_turned_off = false;
190 		}
191 		mod_timer(&kbd->inactivity_timer, jiffies + msecs_to_jiffies(appletb_tb_dim_timeout * 1000));
192 	}
193 }
194 
195 static int appletb_kbd_hid_event(struct hid_device *hdev, struct hid_field *field,
196 				      struct hid_usage *usage, __s32 value)
197 {
198 	struct appletb_kbd *kbd = hid_get_drvdata(hdev);
199 	struct key_entry *translation;
200 	struct input_dev *input;
201 	int slot;
202 
203 	if ((usage->hid & HID_USAGE_PAGE) != HID_UP_KEYBOARD || usage->type != EV_KEY)
204 		return 0;
205 
206 	input = field->hidinput->input;
207 
208 	/*
209 	 * Skip non-touch-bar keys.
210 	 *
211 	 * Either the touch bar itself or usbhid generate a slew of key-down
212 	 * events for all the meta keys. None of which we're at all interested
213 	 * in.
214 	 */
215 	slot = appletb_tb_key_to_slot(usage->code);
216 	if (slot < 0)
217 		return 0;
218 
219 	reset_inactivity_timer(kbd);
220 
221 	translation = sparse_keymap_entry_from_scancode(input, usage->code);
222 
223 	if (translation && kbd->current_mode == APPLETB_KBD_MODE_SPCL) {
224 		input_event(input, usage->type, translation->keycode, value);
225 
226 		return 1;
227 	}
228 
229 	return kbd->current_mode == APPLETB_KBD_MODE_OFF;
230 }
231 
232 static void appletb_kbd_inp_event(struct input_handle *handle, unsigned int type,
233 			      unsigned int code, int value)
234 {
235 	struct appletb_kbd *kbd = handle->private;
236 
237 	reset_inactivity_timer(kbd);
238 
239 	if (type == EV_KEY && code == KEY_FN && appletb_tb_fn_toggle &&
240 		(kbd->current_mode == APPLETB_KBD_MODE_SPCL ||
241 		 kbd->current_mode == APPLETB_KBD_MODE_FN)) {
242 		if (value == 1) {
243 			kbd->saved_mode = kbd->current_mode;
244 			appletb_kbd_set_mode(kbd, kbd->current_mode == APPLETB_KBD_MODE_SPCL
245 						? APPLETB_KBD_MODE_FN : APPLETB_KBD_MODE_SPCL);
246 		} else if (value == 0) {
247 			if (kbd->saved_mode != kbd->current_mode)
248 				appletb_kbd_set_mode(kbd, kbd->saved_mode);
249 		}
250 	}
251 }
252 
253 static int appletb_kbd_inp_connect(struct input_handler *handler,
254 			       struct input_dev *dev,
255 			       const struct input_device_id *id)
256 {
257 	struct appletb_kbd *kbd = handler->private;
258 	struct input_handle *handle;
259 	int rc;
260 
261 	if (id->driver_info == APPLETB_DEVID_KEYBOARD) {
262 		handle = &kbd->kbd_handle;
263 		handle->name = "tbkbd";
264 	} else if (id->driver_info == APPLETB_DEVID_TRACKPAD) {
265 		handle = &kbd->tpd_handle;
266 		handle->name = "tbtpd";
267 	} else {
268 		return -ENOENT;
269 	}
270 
271 	if (handle->dev)
272 		return -EEXIST;
273 
274 	handle->open = 0;
275 	handle->dev = input_get_device(dev);
276 	handle->handler = handler;
277 	handle->private = kbd;
278 
279 	rc = input_register_handle(handle);
280 	if (rc)
281 		goto err_free_dev;
282 
283 	rc = input_open_device(handle);
284 	if (rc)
285 		goto err_unregister_handle;
286 
287 	return 0;
288 
289  err_unregister_handle:
290 	input_unregister_handle(handle);
291  err_free_dev:
292 	input_put_device(handle->dev);
293 	handle->dev = NULL;
294 	return rc;
295 }
296 
297 static void appletb_kbd_inp_disconnect(struct input_handle *handle)
298 {
299 	input_close_device(handle);
300 	input_unregister_handle(handle);
301 
302 	input_put_device(handle->dev);
303 	handle->dev = NULL;
304 }
305 
306 static int appletb_kbd_input_configured(struct hid_device *hdev, struct hid_input *hidinput)
307 {
308 	int idx;
309 	struct input_dev *input = hidinput->input;
310 
311 	/*
312 	 * Clear various input capabilities that are blindly set by the hid
313 	 * driver (usbkbd.c)
314 	 */
315 	memset(input->evbit, 0, sizeof(input->evbit));
316 	memset(input->keybit, 0, sizeof(input->keybit));
317 	memset(input->ledbit, 0, sizeof(input->ledbit));
318 
319 	__set_bit(EV_REP, input->evbit);
320 
321 	sparse_keymap_setup(input, appletb_kbd_keymap, NULL);
322 
323 	for (idx = 0; appletb_kbd_keymap[idx].type != KE_END; idx++)
324 		input_set_capability(input, EV_KEY, appletb_kbd_keymap[idx].code);
325 
326 	return 0;
327 }
328 
329 static const struct input_device_id appletb_kbd_input_devices[] = {
330 	{
331 		.flags = INPUT_DEVICE_ID_MATCH_BUS |
332 			INPUT_DEVICE_ID_MATCH_VENDOR |
333 			INPUT_DEVICE_ID_MATCH_KEYBIT,
334 		.bustype = BUS_USB,
335 		.vendor = USB_VENDOR_ID_APPLE,
336 		.keybit = { [BIT_WORD(KEY_FN)] = BIT_MASK(KEY_FN) },
337 		.driver_info = APPLETB_DEVID_KEYBOARD,
338 	},
339 	{
340 		.flags = INPUT_DEVICE_ID_MATCH_BUS |
341 			INPUT_DEVICE_ID_MATCH_VENDOR |
342 			INPUT_DEVICE_ID_MATCH_KEYBIT,
343 		.bustype = BUS_USB,
344 		.vendor = USB_VENDOR_ID_APPLE,
345 		.keybit = { [BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH) },
346 		.driver_info = APPLETB_DEVID_TRACKPAD,
347 	},
348 	{ }
349 };
350 
351 static bool appletb_kbd_match_internal_device(struct input_handler *handler,
352 					  struct input_dev *inp_dev)
353 {
354 	struct device *dev = &inp_dev->dev;
355 
356 	/* in kernel: dev && !is_usb_device(dev) */
357 	while (dev && !(dev->type && dev->type->name &&
358 			!strcmp(dev->type->name, "usb_device")))
359 		dev = dev->parent;
360 
361 	/*
362 	 * Apple labels all their internal keyboards and trackpads as such,
363 	 * instead of maintaining an ever expanding list of product-id's we
364 	 * just look at the device's product name.
365 	 */
366 	if (dev)
367 		return !!strstr(to_usb_device(dev)->product, "Internal Keyboard");
368 
369 	return false;
370 }
371 
372 static int appletb_kbd_probe(struct hid_device *hdev, const struct hid_device_id *id)
373 {
374 	struct appletb_kbd *kbd;
375 	struct device *dev = &hdev->dev;
376 	struct hid_field *mode_field;
377 	int ret;
378 
379 	ret = hid_parse(hdev);
380 	if (ret)
381 		return dev_err_probe(dev, ret, "HID parse failed\n");
382 
383 	mode_field = hid_find_field(hdev, HID_OUTPUT_REPORT,
384 				    HID_GD_KEYBOARD, HID_USAGE_MODE);
385 	if (!mode_field)
386 		return -ENODEV;
387 
388 	kbd = devm_kzalloc(dev, sizeof(*kbd), GFP_KERNEL);
389 	if (!kbd)
390 		return -ENOMEM;
391 
392 	kbd->mode_field = mode_field;
393 
394 	ret = hid_hw_start(hdev, HID_CONNECT_HIDINPUT);
395 	if (ret)
396 		return dev_err_probe(dev, ret, "HID hw start failed\n");
397 
398 	ret = hid_hw_open(hdev);
399 	if (ret) {
400 		dev_err_probe(dev, ret, "HID hw open failed\n");
401 		goto stop_hw;
402 	}
403 
404 	kbd->backlight_dev = backlight_device_get_by_name("appletb_backlight");
405 	if (!kbd->backlight_dev) {
406 		dev_err_probe(dev, -ENODEV, "Failed to get backlight device\n");
407 	} else {
408 		backlight_device_set_brightness(kbd->backlight_dev, 2);
409 		timer_setup(&kbd->inactivity_timer, appletb_inactivity_timer, 0);
410 		mod_timer(&kbd->inactivity_timer, jiffies + msecs_to_jiffies(appletb_tb_dim_timeout * 1000));
411 	}
412 
413 	kbd->inp_handler.event = appletb_kbd_inp_event;
414 	kbd->inp_handler.connect = appletb_kbd_inp_connect;
415 	kbd->inp_handler.disconnect = appletb_kbd_inp_disconnect;
416 	kbd->inp_handler.name = "appletb";
417 	kbd->inp_handler.id_table = appletb_kbd_input_devices;
418 	kbd->inp_handler.match = appletb_kbd_match_internal_device;
419 	kbd->inp_handler.private = kbd;
420 
421 	ret = input_register_handler(&kbd->inp_handler);
422 	if (ret) {
423 		dev_err_probe(dev, ret, "Unable to register keyboard handler\n");
424 		goto close_hw;
425 	}
426 
427 	ret = appletb_kbd_set_mode(kbd, appletb_tb_def_mode);
428 	if (ret) {
429 		dev_err_probe(dev, ret, "Failed to set touchbar mode\n");
430 		goto close_hw;
431 	}
432 
433 	hid_set_drvdata(hdev, kbd);
434 
435 	return 0;
436 
437 close_hw:
438 	hid_hw_close(hdev);
439 stop_hw:
440 	hid_hw_stop(hdev);
441 	return ret;
442 }
443 
444 static void appletb_kbd_remove(struct hid_device *hdev)
445 {
446 	struct appletb_kbd *kbd = hid_get_drvdata(hdev);
447 
448 	appletb_kbd_set_mode(kbd, APPLETB_KBD_MODE_OFF);
449 
450 	input_unregister_handler(&kbd->inp_handler);
451 	timer_delete_sync(&kbd->inactivity_timer);
452 
453 	hid_hw_close(hdev);
454 	hid_hw_stop(hdev);
455 }
456 
457 #ifdef CONFIG_PM
458 static int appletb_kbd_suspend(struct hid_device *hdev, pm_message_t msg)
459 {
460 	struct appletb_kbd *kbd = hid_get_drvdata(hdev);
461 
462 	kbd->saved_mode = kbd->current_mode;
463 	appletb_kbd_set_mode(kbd, APPLETB_KBD_MODE_OFF);
464 
465 	return 0;
466 }
467 
468 static int appletb_kbd_reset_resume(struct hid_device *hdev)
469 {
470 	struct appletb_kbd *kbd = hid_get_drvdata(hdev);
471 
472 	appletb_kbd_set_mode(kbd, kbd->saved_mode);
473 
474 	return 0;
475 }
476 #endif
477 
478 static const struct hid_device_id appletb_kbd_hid_ids[] = {
479 	/* MacBook Pro's 2018, 2019, with T2 chip: iBridge Display */
480 	{ HID_USB_DEVICE(USB_VENDOR_ID_APPLE, USB_DEVICE_ID_APPLE_TOUCHBAR_DISPLAY) },
481 	{ }
482 };
483 MODULE_DEVICE_TABLE(hid, appletb_kbd_hid_ids);
484 
485 static struct hid_driver appletb_kbd_hid_driver = {
486 	.name = "hid-appletb-kbd",
487 	.id_table = appletb_kbd_hid_ids,
488 	.probe = appletb_kbd_probe,
489 	.remove = appletb_kbd_remove,
490 	.event = appletb_kbd_hid_event,
491 	.input_configured = appletb_kbd_input_configured,
492 #ifdef CONFIG_PM
493 	.suspend = appletb_kbd_suspend,
494 	.reset_resume = appletb_kbd_reset_resume,
495 #endif
496 	.driver.dev_groups = appletb_kbd_groups,
497 };
498 module_hid_driver(appletb_kbd_hid_driver);
499 
500 /* The backlight driver should be loaded before the keyboard driver is initialised */
501 MODULE_SOFTDEP("pre: hid_appletb_bl");
502 
503 MODULE_AUTHOR("Ronald Tschalär");
504 MODULE_AUTHOR("Kerem Karabay <kekrby@gmail.com>");
505 MODULE_AUTHOR("Aditya Garg <gargaditya08@live.com>");
506 MODULE_DESCRIPTION("MacBook Pro Touch Bar Keyboard Mode driver");
507 MODULE_LICENSE("GPL");
508