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