1// SPDX-License-Identifier: GPL-2.0+
2/*
3 *  Intel Virtual Button driver for Windows 8.1+
4 *
5 *  Copyright (C) 2016 AceLan Kao <acelan.kao@canonical.com>
6 *  Copyright (C) 2016 Alex Hung <alex.hung@canonical.com>
7 */
8
9#include <linux/acpi.h>
10#include <linux/dmi.h>
11#include <linux/input.h>
12#include <linux/input/sparse-keymap.h>
13#include <linux/kernel.h>
14#include <linux/module.h>
15#include <linux/platform_device.h>
16#include <linux/suspend.h>
17#include "../dual_accel_detect.h"
18
19/* Returned when NOT in tablet mode on some HP Stream x360 11 models */
20#define VGBS_TABLET_MODE_FLAG_ALT	0x10
21/* When NOT in tablet mode, VGBS returns with the flag 0x40 */
22#define VGBS_TABLET_MODE_FLAG		0x40
23#define VGBS_DOCK_MODE_FLAG		0x80
24
25#define VGBS_TABLET_MODE_FLAGS (VGBS_TABLET_MODE_FLAG | VGBS_TABLET_MODE_FLAG_ALT)
26
27MODULE_LICENSE("GPL");
28MODULE_AUTHOR("AceLan Kao");
29
30static const struct acpi_device_id intel_vbtn_ids[] = {
31	{"INT33D6", 0},
32	{"", 0},
33};
34MODULE_DEVICE_TABLE(acpi, intel_vbtn_ids);
35
36/* In theory, these are HID usages. */
37static const struct key_entry intel_vbtn_keymap[] = {
38	{ KE_KEY, 0xC0, { KEY_POWER } },	/* power key press */
39	{ KE_IGNORE, 0xC1, { KEY_POWER } },	/* power key release */
40	{ KE_KEY, 0xC2, { KEY_LEFTMETA } },		/* 'Windows' key press */
41	{ KE_KEY, 0xC3, { KEY_LEFTMETA } },		/* 'Windows' key release */
42	{ KE_KEY, 0xC4, { KEY_VOLUMEUP } },		/* volume-up key press */
43	{ KE_IGNORE, 0xC5, { KEY_VOLUMEUP } },		/* volume-up key release */
44	{ KE_KEY, 0xC6, { KEY_VOLUMEDOWN } },		/* volume-down key press */
45	{ KE_IGNORE, 0xC7, { KEY_VOLUMEDOWN } },	/* volume-down key release */
46	{ KE_KEY,    0xC8, { KEY_ROTATE_LOCK_TOGGLE } },	/* rotate-lock key press */
47	{ KE_KEY,    0xC9, { KEY_ROTATE_LOCK_TOGGLE } },	/* rotate-lock key release */
48	{ KE_END }
49};
50
51static const struct key_entry intel_vbtn_switchmap[] = {
52	/*
53	 * SW_DOCK should only be reported for docking stations, but DSDTs using the
54	 * intel-vbtn code, always seem to use this for 2-in-1s / convertibles and set
55	 * SW_DOCK=1 when in laptop-mode (in tandem with setting SW_TABLET_MODE=0).
56	 * This causes userspace to think the laptop is docked to a port-replicator
57	 * and to disable suspend-on-lid-close, which is undesirable.
58	 * Map the dock events to KEY_IGNORE to avoid this broken SW_DOCK reporting.
59	 */
60	{ KE_IGNORE, 0xCA, { .sw = { SW_DOCK, 1 } } },		/* Docked */
61	{ KE_IGNORE, 0xCB, { .sw = { SW_DOCK, 0 } } },		/* Undocked */
62	{ KE_SW,     0xCC, { .sw = { SW_TABLET_MODE, 1 } } },	/* Tablet */
63	{ KE_SW,     0xCD, { .sw = { SW_TABLET_MODE, 0 } } },	/* Laptop */
64	{ KE_END }
65};
66
67struct intel_vbtn_priv {
68	struct input_dev *buttons_dev;
69	struct input_dev *switches_dev;
70	bool dual_accel;
71	bool has_buttons;
72	bool has_switches;
73	bool wakeup_mode;
74};
75
76static void detect_tablet_mode(struct device *dev)
77{
78	struct intel_vbtn_priv *priv = dev_get_drvdata(dev);
79	acpi_handle handle = ACPI_HANDLE(dev);
80	unsigned long long vgbs;
81	acpi_status status;
82	int m;
83
84	status = acpi_evaluate_integer(handle, "VGBS", NULL, &vgbs);
85	if (ACPI_FAILURE(status))
86		return;
87
88	m = !(vgbs & VGBS_TABLET_MODE_FLAGS);
89	input_report_switch(priv->switches_dev, SW_TABLET_MODE, m);
90	m = (vgbs & VGBS_DOCK_MODE_FLAG) ? 1 : 0;
91	input_report_switch(priv->switches_dev, SW_DOCK, m);
92
93	input_sync(priv->switches_dev);
94}
95
96/*
97 * Note this unconditionally creates the 2 input_dev-s and sets up
98 * the sparse-keymaps. Only the registration is conditional on
99 * have_buttons / have_switches. This is done so that the notify
100 * handler can always call sparse_keymap_entry_from_scancode()
101 * on the input_dev-s do determine the event type.
102 */
103static int intel_vbtn_input_setup(struct platform_device *device)
104{
105	struct intel_vbtn_priv *priv = dev_get_drvdata(&device->dev);
106	int ret;
107
108	priv->buttons_dev = devm_input_allocate_device(&device->dev);
109	if (!priv->buttons_dev)
110		return -ENOMEM;
111
112	ret = sparse_keymap_setup(priv->buttons_dev, intel_vbtn_keymap, NULL);
113	if (ret)
114		return ret;
115
116	priv->buttons_dev->dev.parent = &device->dev;
117	priv->buttons_dev->name = "Intel Virtual Buttons";
118	priv->buttons_dev->id.bustype = BUS_HOST;
119
120	if (priv->has_buttons) {
121		ret = input_register_device(priv->buttons_dev);
122		if (ret)
123			return ret;
124	}
125
126	priv->switches_dev = devm_input_allocate_device(&device->dev);
127	if (!priv->switches_dev)
128		return -ENOMEM;
129
130	ret = sparse_keymap_setup(priv->switches_dev, intel_vbtn_switchmap, NULL);
131	if (ret)
132		return ret;
133
134	priv->switches_dev->dev.parent = &device->dev;
135	priv->switches_dev->name = "Intel Virtual Switches";
136	priv->switches_dev->id.bustype = BUS_HOST;
137
138	if (priv->has_switches) {
139		ret = input_register_device(priv->switches_dev);
140		if (ret)
141			return ret;
142	}
143
144	return 0;
145}
146
147static void notify_handler(acpi_handle handle, u32 event, void *context)
148{
149	struct platform_device *device = context;
150	struct intel_vbtn_priv *priv = dev_get_drvdata(&device->dev);
151	unsigned int val = !(event & 1); /* Even=press, Odd=release */
152	const struct key_entry *ke, *ke_rel;
153	struct input_dev *input_dev;
154	bool autorelease;
155	int ret;
156
157	if ((ke = sparse_keymap_entry_from_scancode(priv->buttons_dev, event))) {
158		if (!priv->has_buttons) {
159			dev_warn(&device->dev, "Warning: received 0x%02x button event on a device without buttons, please report this.\n",
160				 event);
161			return;
162		}
163		input_dev = priv->buttons_dev;
164	} else if ((ke = sparse_keymap_entry_from_scancode(priv->switches_dev, event))) {
165		if (!priv->has_switches) {
166			/* See dual_accel_detect.h for more info */
167			if (priv->dual_accel)
168				return;
169
170			dev_info(&device->dev, "Registering Intel Virtual Switches input-dev after receiving a switch event\n");
171			ret = input_register_device(priv->switches_dev);
172			if (ret)
173				return;
174
175			priv->has_switches = true;
176		}
177		input_dev = priv->switches_dev;
178	} else {
179		dev_dbg(&device->dev, "unknown event index 0x%x\n", event);
180		return;
181	}
182
183	if (priv->wakeup_mode) {
184		pm_wakeup_hard_event(&device->dev);
185
186		/*
187		 * Skip reporting an evdev event for button wake events,
188		 * mirroring how the drivers/acpi/button.c code skips this too.
189		 */
190		if (ke->type == KE_KEY)
191			return;
192	}
193
194	/*
195	 * Even press events are autorelease if there is no corresponding odd
196	 * release event, or if the odd event is KE_IGNORE.
197	 */
198	ke_rel = sparse_keymap_entry_from_scancode(input_dev, event | 1);
199	autorelease = val && (!ke_rel || ke_rel->type == KE_IGNORE);
200
201	sparse_keymap_report_event(input_dev, event, val, autorelease);
202}
203
204/*
205 * There are several laptops (non 2-in-1) models out there which support VGBS,
206 * but simply always return 0, which we translate to SW_TABLET_MODE=1. This in
207 * turn causes userspace (libinput) to suppress events from the builtin
208 * keyboard and touchpad, making the laptop essentially unusable.
209 *
210 * Since the problem of wrongly reporting SW_TABLET_MODE=1 in combination
211 * with libinput, leads to a non-usable system. Where as OTOH many people will
212 * not even notice when SW_TABLET_MODE is not being reported, a DMI based allow
213 * list is used here. This list mainly matches on the chassis-type of 2-in-1s.
214 *
215 * There are also some 2-in-1s which use the intel-vbtn ACPI interface to report
216 * SW_TABLET_MODE with a chassis-type of 8 ("Portable") or 10 ("Notebook"),
217 * these are matched on a per model basis, since many normal laptops with a
218 * possible broken VGBS ACPI-method also use these chassis-types.
219 */
220static const struct dmi_system_id dmi_switches_allow_list[] = {
221	{
222		.matches = {
223			DMI_EXACT_MATCH(DMI_CHASSIS_TYPE, "31" /* Convertible */),
224		},
225	},
226	{
227		.matches = {
228			DMI_EXACT_MATCH(DMI_CHASSIS_TYPE, "32" /* Detachable */),
229		},
230	},
231	{
232		.matches = {
233			DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
234			DMI_MATCH(DMI_PRODUCT_NAME, "Venue 11 Pro 7130"),
235		},
236	},
237	{
238		.matches = {
239			DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
240			DMI_MATCH(DMI_PRODUCT_NAME, "HP Pavilion 13 x360 PC"),
241		},
242	},
243	{
244		.matches = {
245			DMI_MATCH(DMI_SYS_VENDOR, "Acer"),
246			DMI_MATCH(DMI_PRODUCT_NAME, "Switch SA5-271"),
247		},
248	},
249	{
250		.matches = {
251			DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
252			DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron 7352"),
253		},
254	},
255	{} /* Array terminator */
256};
257
258static bool intel_vbtn_has_switches(acpi_handle handle, bool dual_accel)
259{
260	/* See dual_accel_detect.h for more info */
261	if (dual_accel)
262		return false;
263
264	if (!dmi_check_system(dmi_switches_allow_list))
265		return false;
266
267	return acpi_has_method(handle, "VGBS");
268}
269
270static int intel_vbtn_probe(struct platform_device *device)
271{
272	acpi_handle handle = ACPI_HANDLE(&device->dev);
273	bool dual_accel, has_buttons, has_switches;
274	struct intel_vbtn_priv *priv;
275	acpi_status status;
276	int err;
277
278	dual_accel = dual_accel_detect();
279	has_buttons = acpi_has_method(handle, "VBDL");
280	has_switches = intel_vbtn_has_switches(handle, dual_accel);
281
282	if (!has_buttons && !has_switches) {
283		dev_warn(&device->dev, "failed to read Intel Virtual Button driver\n");
284		return -ENODEV;
285	}
286
287	priv = devm_kzalloc(&device->dev, sizeof(*priv), GFP_KERNEL);
288	if (!priv)
289		return -ENOMEM;
290	dev_set_drvdata(&device->dev, priv);
291
292	priv->dual_accel = dual_accel;
293	priv->has_buttons = has_buttons;
294	priv->has_switches = has_switches;
295
296	err = intel_vbtn_input_setup(device);
297	if (err) {
298		pr_err("Failed to setup Intel Virtual Button\n");
299		return err;
300	}
301
302	status = acpi_install_notify_handler(handle,
303					     ACPI_DEVICE_NOTIFY,
304					     notify_handler,
305					     device);
306	if (ACPI_FAILURE(status))
307		return -EBUSY;
308
309	if (has_buttons) {
310		status = acpi_evaluate_object(handle, "VBDL", NULL, NULL);
311		if (ACPI_FAILURE(status))
312			dev_err(&device->dev, "Error VBDL failed with ACPI status %d\n", status);
313	}
314	// Check switches after buttons since VBDL may have side effects.
315	if (has_switches)
316		detect_tablet_mode(&device->dev);
317
318	device_init_wakeup(&device->dev, true);
319	/*
320	 * In order for system wakeup to work, the EC GPE has to be marked as
321	 * a wakeup one, so do that here (this setting will persist, but it has
322	 * no effect until the wakeup mask is set for the EC GPE).
323	 */
324	acpi_ec_mark_gpe_for_wake();
325	return 0;
326}
327
328static void intel_vbtn_remove(struct platform_device *device)
329{
330	acpi_handle handle = ACPI_HANDLE(&device->dev);
331
332	device_init_wakeup(&device->dev, false);
333	acpi_remove_notify_handler(handle, ACPI_DEVICE_NOTIFY, notify_handler);
334}
335
336static int intel_vbtn_pm_prepare(struct device *dev)
337{
338	if (device_may_wakeup(dev)) {
339		struct intel_vbtn_priv *priv = dev_get_drvdata(dev);
340
341		priv->wakeup_mode = true;
342	}
343	return 0;
344}
345
346static void intel_vbtn_pm_complete(struct device *dev)
347{
348	struct intel_vbtn_priv *priv = dev_get_drvdata(dev);
349
350	priv->wakeup_mode = false;
351}
352
353static int intel_vbtn_pm_resume(struct device *dev)
354{
355	struct intel_vbtn_priv *priv = dev_get_drvdata(dev);
356
357	intel_vbtn_pm_complete(dev);
358
359	if (priv->has_switches)
360		detect_tablet_mode(dev);
361
362	return 0;
363}
364
365static const struct dev_pm_ops intel_vbtn_pm_ops = {
366	.prepare = intel_vbtn_pm_prepare,
367	.complete = intel_vbtn_pm_complete,
368	.resume = intel_vbtn_pm_resume,
369	.restore = intel_vbtn_pm_resume,
370	.thaw = intel_vbtn_pm_resume,
371};
372
373static struct platform_driver intel_vbtn_pl_driver = {
374	.driver = {
375		.name = "intel-vbtn",
376		.acpi_match_table = intel_vbtn_ids,
377		.pm = &intel_vbtn_pm_ops,
378	},
379	.probe = intel_vbtn_probe,
380	.remove_new = intel_vbtn_remove,
381};
382
383static acpi_status __init
384check_acpi_dev(acpi_handle handle, u32 lvl, void *context, void **rv)
385{
386	const struct acpi_device_id *ids = context;
387	struct acpi_device *dev = acpi_fetch_acpi_dev(handle);
388
389	if (dev && acpi_match_device_ids(dev, ids) == 0)
390		if (!IS_ERR_OR_NULL(acpi_create_platform_device(dev, NULL)))
391			dev_info(&dev->dev,
392				 "intel-vbtn: created platform device\n");
393
394	return AE_OK;
395}
396
397static int __init intel_vbtn_init(void)
398{
399	acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
400			    ACPI_UINT32_MAX, check_acpi_dev, NULL,
401			    (void *)intel_vbtn_ids, NULL);
402
403	return platform_driver_register(&intel_vbtn_pl_driver);
404}
405module_init(intel_vbtn_init);
406
407static void __exit intel_vbtn_exit(void)
408{
409	platform_driver_unregister(&intel_vbtn_pl_driver);
410}
411module_exit(intel_vbtn_exit);
412