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 a button event on a device without buttons, please report this.\n");
160			return;
161		}
162		input_dev = priv->buttons_dev;
163	} else if ((ke = sparse_keymap_entry_from_scancode(priv->switches_dev, event))) {
164		if (!priv->has_switches) {
165			/* See dual_accel_detect.h for more info */
166			if (priv->dual_accel)
167				return;
168
169			dev_info(&device->dev, "Registering Intel Virtual Switches input-dev after receiving a switch event\n");
170			ret = input_register_device(priv->switches_dev);
171			if (ret)
172				return;
173
174			priv->has_switches = true;
175		}
176		input_dev = priv->switches_dev;
177	} else {
178		dev_dbg(&device->dev, "unknown event index 0x%x\n", event);
179		return;
180	}
181
182	if (priv->wakeup_mode) {
183		pm_wakeup_hard_event(&device->dev);
184
185		/*
186		 * Skip reporting an evdev event for button wake events,
187		 * mirroring how the drivers/acpi/button.c code skips this too.
188		 */
189		if (ke->type == KE_KEY)
190			return;
191	}
192
193	/*
194	 * Even press events are autorelease if there is no corresponding odd
195	 * release event, or if the odd event is KE_IGNORE.
196	 */
197	ke_rel = sparse_keymap_entry_from_scancode(input_dev, event | 1);
198	autorelease = val && (!ke_rel || ke_rel->type == KE_IGNORE);
199
200	sparse_keymap_report_event(input_dev, event, val, autorelease);
201}
202
203/*
204 * There are several laptops (non 2-in-1) models out there which support VGBS,
205 * but simply always return 0, which we translate to SW_TABLET_MODE=1. This in
206 * turn causes userspace (libinput) to suppress events from the builtin
207 * keyboard and touchpad, making the laptop essentially unusable.
208 *
209 * Since the problem of wrongly reporting SW_TABLET_MODE=1 in combination
210 * with libinput, leads to a non-usable system. Where as OTOH many people will
211 * not even notice when SW_TABLET_MODE is not being reported, a DMI based allow
212 * list is used here. This list mainly matches on the chassis-type of 2-in-1s.
213 *
214 * There are also some 2-in-1s which use the intel-vbtn ACPI interface to report
215 * SW_TABLET_MODE with a chassis-type of 8 ("Portable") or 10 ("Notebook"),
216 * these are matched on a per model basis, since many normal laptops with a
217 * possible broken VGBS ACPI-method also use these chassis-types.
218 */
219static const struct dmi_system_id dmi_switches_allow_list[] = {
220	{
221		.matches = {
222			DMI_EXACT_MATCH(DMI_CHASSIS_TYPE, "31" /* Convertible */),
223		},
224	},
225	{
226		.matches = {
227			DMI_EXACT_MATCH(DMI_CHASSIS_TYPE, "32" /* Detachable */),
228		},
229	},
230	{
231		.matches = {
232			DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
233			DMI_MATCH(DMI_PRODUCT_NAME, "Venue 11 Pro 7130"),
234		},
235	},
236	{
237		.matches = {
238			DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
239			DMI_MATCH(DMI_PRODUCT_NAME, "HP Pavilion 13 x360 PC"),
240		},
241	},
242	{
243		.matches = {
244			DMI_MATCH(DMI_SYS_VENDOR, "Acer"),
245			DMI_MATCH(DMI_PRODUCT_NAME, "Switch SA5-271"),
246		},
247	},
248	{
249		.matches = {
250			DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
251			DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron 7352"),
252		},
253	},
254	{} /* Array terminator */
255};
256
257static bool intel_vbtn_has_switches(acpi_handle handle, bool dual_accel)
258{
259	/* See dual_accel_detect.h for more info */
260	if (dual_accel)
261		return false;
262
263	if (!dmi_check_system(dmi_switches_allow_list))
264		return false;
265
266	return acpi_has_method(handle, "VGBS");
267}
268
269static int intel_vbtn_probe(struct platform_device *device)
270{
271	acpi_handle handle = ACPI_HANDLE(&device->dev);
272	bool dual_accel, has_buttons, has_switches;
273	struct intel_vbtn_priv *priv;
274	acpi_status status;
275	int err;
276
277	dual_accel = dual_accel_detect();
278	has_buttons = acpi_has_method(handle, "VBDL");
279	has_switches = intel_vbtn_has_switches(handle, dual_accel);
280
281	if (!has_buttons && !has_switches) {
282		dev_warn(&device->dev, "failed to read Intel Virtual Button driver\n");
283		return -ENODEV;
284	}
285
286	priv = devm_kzalloc(&device->dev, sizeof(*priv), GFP_KERNEL);
287	if (!priv)
288		return -ENOMEM;
289	dev_set_drvdata(&device->dev, priv);
290
291	priv->dual_accel = dual_accel;
292	priv->has_buttons = has_buttons;
293	priv->has_switches = has_switches;
294
295	err = intel_vbtn_input_setup(device);
296	if (err) {
297		pr_err("Failed to setup Intel Virtual Button\n");
298		return err;
299	}
300
301	status = acpi_install_notify_handler(handle,
302					     ACPI_DEVICE_NOTIFY,
303					     notify_handler,
304					     device);
305	if (ACPI_FAILURE(status))
306		return -EBUSY;
307
308	if (has_buttons) {
309		status = acpi_evaluate_object(handle, "VBDL", NULL, NULL);
310		if (ACPI_FAILURE(status))
311			dev_err(&device->dev, "Error VBDL failed with ACPI status %d\n", status);
312	}
313	// Check switches after buttons since VBDL may have side effects.
314	if (has_switches)
315		detect_tablet_mode(&device->dev);
316
317	device_init_wakeup(&device->dev, true);
318	/*
319	 * In order for system wakeup to work, the EC GPE has to be marked as
320	 * a wakeup one, so do that here (this setting will persist, but it has
321	 * no effect until the wakeup mask is set for the EC GPE).
322	 */
323	acpi_ec_mark_gpe_for_wake();
324	return 0;
325}
326
327static void intel_vbtn_remove(struct platform_device *device)
328{
329	acpi_handle handle = ACPI_HANDLE(&device->dev);
330
331	device_init_wakeup(&device->dev, false);
332	acpi_remove_notify_handler(handle, ACPI_DEVICE_NOTIFY, notify_handler);
333}
334
335static int intel_vbtn_pm_prepare(struct device *dev)
336{
337	if (device_may_wakeup(dev)) {
338		struct intel_vbtn_priv *priv = dev_get_drvdata(dev);
339
340		priv->wakeup_mode = true;
341	}
342	return 0;
343}
344
345static void intel_vbtn_pm_complete(struct device *dev)
346{
347	struct intel_vbtn_priv *priv = dev_get_drvdata(dev);
348
349	priv->wakeup_mode = false;
350}
351
352static int intel_vbtn_pm_resume(struct device *dev)
353{
354	struct intel_vbtn_priv *priv = dev_get_drvdata(dev);
355
356	intel_vbtn_pm_complete(dev);
357
358	if (priv->has_switches)
359		detect_tablet_mode(dev);
360
361	return 0;
362}
363
364static const struct dev_pm_ops intel_vbtn_pm_ops = {
365	.prepare = intel_vbtn_pm_prepare,
366	.complete = intel_vbtn_pm_complete,
367	.resume = intel_vbtn_pm_resume,
368	.restore = intel_vbtn_pm_resume,
369	.thaw = intel_vbtn_pm_resume,
370};
371
372static struct platform_driver intel_vbtn_pl_driver = {
373	.driver = {
374		.name = "intel-vbtn",
375		.acpi_match_table = intel_vbtn_ids,
376		.pm = &intel_vbtn_pm_ops,
377	},
378	.probe = intel_vbtn_probe,
379	.remove_new = intel_vbtn_remove,
380};
381
382static acpi_status __init
383check_acpi_dev(acpi_handle handle, u32 lvl, void *context, void **rv)
384{
385	const struct acpi_device_id *ids = context;
386	struct acpi_device *dev = acpi_fetch_acpi_dev(handle);
387
388	if (dev && acpi_match_device_ids(dev, ids) == 0)
389		if (!IS_ERR_OR_NULL(acpi_create_platform_device(dev, NULL)))
390			dev_info(&dev->dev,
391				 "intel-vbtn: created platform device\n");
392
393	return AE_OK;
394}
395
396static int __init intel_vbtn_init(void)
397{
398	acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
399			    ACPI_UINT32_MAX, check_acpi_dev, NULL,
400			    (void *)intel_vbtn_ids, NULL);
401
402	return platform_driver_register(&intel_vbtn_pl_driver);
403}
404module_init(intel_vbtn_init);
405
406static void __exit intel_vbtn_exit(void)
407{
408	platform_driver_unregister(&intel_vbtn_pl_driver);
409}
410module_exit(intel_vbtn_exit);
411