xref: /linux/drivers/platform/x86/intel/vbtn.c (revision 9ca12e50a48c100e3bda3e5152d2181f4a6649e2)
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/cleanup.h>
11 #include <linux/dmi.h>
12 #include <linux/input.h>
13 #include <linux/input/sparse-keymap.h>
14 #include <linux/kernel.h>
15 #include <linux/module.h>
16 #include <linux/mutex.h>
17 #include <linux/platform_device.h>
18 #include <linux/suspend.h>
19 #include "../dual_accel_detect.h"
20 
21 /* Returned when NOT in tablet mode on some HP Stream x360 11 models */
22 #define VGBS_TABLET_MODE_FLAG_ALT	0x10
23 /* When NOT in tablet mode, VGBS returns with the flag 0x40 */
24 #define VGBS_TABLET_MODE_FLAG		0x40
25 #define VGBS_DOCK_MODE_FLAG		0x80
26 
27 #define VGBS_TABLET_MODE_FLAGS (VGBS_TABLET_MODE_FLAG | VGBS_TABLET_MODE_FLAG_ALT)
28 
29 MODULE_DESCRIPTION("Intel Virtual Button driver");
30 MODULE_LICENSE("GPL");
31 MODULE_AUTHOR("AceLan Kao");
32 
33 static const struct acpi_device_id intel_vbtn_ids[] = {
34 	{"INT33D6", 0},
35 	{"", 0},
36 };
37 MODULE_DEVICE_TABLE(acpi, intel_vbtn_ids);
38 
39 /* In theory, these are HID usages. */
40 static const struct key_entry intel_vbtn_keymap[] = {
41 	{ KE_KEY, 0xC0, { KEY_POWER } },	/* power key press */
42 	{ KE_IGNORE, 0xC1, { KEY_POWER } },	/* power key release */
43 	{ KE_KEY, 0xC2, { KEY_LEFTMETA } },		/* 'Windows' key press */
44 	{ KE_KEY, 0xC3, { KEY_LEFTMETA } },		/* 'Windows' key release */
45 	{ KE_KEY, 0xC4, { KEY_VOLUMEUP } },		/* volume-up key press */
46 	{ KE_IGNORE, 0xC5, { KEY_VOLUMEUP } },		/* volume-up key release */
47 	{ KE_KEY, 0xC6, { KEY_VOLUMEDOWN } },		/* volume-down key press */
48 	{ KE_IGNORE, 0xC7, { KEY_VOLUMEDOWN } },	/* volume-down key release */
49 	{ KE_KEY,    0xC8, { KEY_ROTATE_LOCK_TOGGLE } },	/* rotate-lock key press */
50 	{ KE_KEY,    0xC9, { KEY_ROTATE_LOCK_TOGGLE } },	/* rotate-lock key release */
51 	{ KE_END }
52 };
53 
54 static const struct key_entry intel_vbtn_switchmap[] = {
55 	/*
56 	 * SW_DOCK should only be reported for docking stations, but DSDTs using the
57 	 * intel-vbtn code, always seem to use this for 2-in-1s / convertibles and set
58 	 * SW_DOCK=1 when in laptop-mode (in tandem with setting SW_TABLET_MODE=0).
59 	 * This causes userspace to think the laptop is docked to a port-replicator
60 	 * and to disable suspend-on-lid-close, which is undesirable.
61 	 * Map the dock events to KEY_IGNORE to avoid this broken SW_DOCK reporting.
62 	 */
63 	{ KE_IGNORE, 0xCA, { .sw = { SW_DOCK, 1 } } },		/* Docked */
64 	{ KE_IGNORE, 0xCB, { .sw = { SW_DOCK, 0 } } },		/* Undocked */
65 	{ KE_SW,     0xCC, { .sw = { SW_TABLET_MODE, 1 } } },	/* Tablet */
66 	{ KE_SW,     0xCD, { .sw = { SW_TABLET_MODE, 0 } } },	/* Laptop */
67 	{ KE_END }
68 };
69 
70 struct intel_vbtn_priv {
71 	struct mutex mutex; /* Avoid notify_handler() racing with itself */
72 	struct input_dev *buttons_dev;
73 	struct input_dev *switches_dev;
74 	bool dual_accel;
75 	bool has_buttons;
76 	bool has_switches;
77 	bool wakeup_mode;
78 };
79 
80 static void detect_tablet_mode(struct device *dev)
81 {
82 	struct intel_vbtn_priv *priv = dev_get_drvdata(dev);
83 	acpi_handle handle = ACPI_HANDLE(dev);
84 	unsigned long long vgbs;
85 	acpi_status status;
86 	int m;
87 
88 	status = acpi_evaluate_integer(handle, "VGBS", NULL, &vgbs);
89 	if (ACPI_FAILURE(status))
90 		return;
91 
92 	m = !(vgbs & VGBS_TABLET_MODE_FLAGS);
93 	input_report_switch(priv->switches_dev, SW_TABLET_MODE, m);
94 	m = (vgbs & VGBS_DOCK_MODE_FLAG) ? 1 : 0;
95 	input_report_switch(priv->switches_dev, SW_DOCK, m);
96 
97 	input_sync(priv->switches_dev);
98 }
99 
100 /*
101  * Note this unconditionally creates the 2 input_dev-s and sets up
102  * the sparse-keymaps. Only the registration is conditional on
103  * have_buttons / have_switches. This is done so that the notify
104  * handler can always call sparse_keymap_entry_from_scancode()
105  * on the input_dev-s do determine the event type.
106  */
107 static int intel_vbtn_input_setup(struct platform_device *device)
108 {
109 	struct intel_vbtn_priv *priv = dev_get_drvdata(&device->dev);
110 	int ret;
111 
112 	priv->buttons_dev = devm_input_allocate_device(&device->dev);
113 	if (!priv->buttons_dev)
114 		return -ENOMEM;
115 
116 	ret = sparse_keymap_setup(priv->buttons_dev, intel_vbtn_keymap, NULL);
117 	if (ret)
118 		return ret;
119 
120 	priv->buttons_dev->dev.parent = &device->dev;
121 	priv->buttons_dev->name = "Intel Virtual Buttons";
122 	priv->buttons_dev->id.bustype = BUS_HOST;
123 
124 	if (priv->has_buttons) {
125 		ret = input_register_device(priv->buttons_dev);
126 		if (ret)
127 			return ret;
128 	}
129 
130 	priv->switches_dev = devm_input_allocate_device(&device->dev);
131 	if (!priv->switches_dev)
132 		return -ENOMEM;
133 
134 	ret = sparse_keymap_setup(priv->switches_dev, intel_vbtn_switchmap, NULL);
135 	if (ret)
136 		return ret;
137 
138 	priv->switches_dev->dev.parent = &device->dev;
139 	priv->switches_dev->name = "Intel Virtual Switches";
140 	priv->switches_dev->id.bustype = BUS_HOST;
141 
142 	if (priv->has_switches) {
143 		ret = input_register_device(priv->switches_dev);
144 		if (ret)
145 			return ret;
146 	}
147 
148 	return 0;
149 }
150 
151 static void notify_handler(acpi_handle handle, u32 event, void *context)
152 {
153 	struct platform_device *device = context;
154 	struct intel_vbtn_priv *priv = dev_get_drvdata(&device->dev);
155 	unsigned int val = !(event & 1); /* Even=press, Odd=release */
156 	const struct key_entry *ke, *ke_rel;
157 	struct input_dev *input_dev;
158 	bool autorelease;
159 	int ret;
160 
161 	guard(mutex)(&priv->mutex);
162 
163 	if ((ke = sparse_keymap_entry_from_scancode(priv->buttons_dev, event))) {
164 		if (!priv->has_buttons) {
165 			dev_warn(&device->dev, "Warning: received 0x%02x button event on a device without buttons, please report this.\n",
166 				 event);
167 			return;
168 		}
169 		input_dev = priv->buttons_dev;
170 	} else if ((ke = sparse_keymap_entry_from_scancode(priv->switches_dev, event))) {
171 		if (!priv->has_switches) {
172 			/* See dual_accel_detect.h for more info */
173 			if (priv->dual_accel)
174 				return;
175 
176 			dev_info(&device->dev, "Registering Intel Virtual Switches input-dev after receiving a switch event\n");
177 			ret = input_register_device(priv->switches_dev);
178 			if (ret)
179 				return;
180 
181 			priv->has_switches = true;
182 		}
183 		input_dev = priv->switches_dev;
184 	} else {
185 		dev_dbg(&device->dev, "unknown event index 0x%x\n", event);
186 		return;
187 	}
188 
189 	if (priv->wakeup_mode) {
190 		pm_wakeup_hard_event(&device->dev);
191 
192 		/*
193 		 * Skip reporting an evdev event for button wake events,
194 		 * mirroring how the drivers/acpi/button.c code skips this too.
195 		 */
196 		if (ke->type == KE_KEY)
197 			return;
198 	}
199 
200 	/*
201 	 * Even press events are autorelease if there is no corresponding odd
202 	 * release event, or if the odd event is KE_IGNORE.
203 	 */
204 	ke_rel = sparse_keymap_entry_from_scancode(input_dev, event | 1);
205 	autorelease = val && (!ke_rel || ke_rel->type == KE_IGNORE);
206 
207 	sparse_keymap_report_event(input_dev, event, val, autorelease);
208 }
209 
210 /*
211  * There are several laptops (non 2-in-1) models out there which support VGBS,
212  * but simply always return 0, which we translate to SW_TABLET_MODE=1. This in
213  * turn causes userspace (libinput) to suppress events from the builtin
214  * keyboard and touchpad, making the laptop essentially unusable.
215  *
216  * Since the problem of wrongly reporting SW_TABLET_MODE=1 in combination
217  * with libinput, leads to a non-usable system. Where as OTOH many people will
218  * not even notice when SW_TABLET_MODE is not being reported, a DMI based allow
219  * list is used here. This list mainly matches on the chassis-type of 2-in-1s.
220  *
221  * There are also some 2-in-1s which use the intel-vbtn ACPI interface to report
222  * SW_TABLET_MODE with a chassis-type of 8 ("Portable") or 10 ("Notebook"),
223  * these are matched on a per model basis, since many normal laptops with a
224  * possible broken VGBS ACPI-method also use these chassis-types.
225  */
226 static const struct dmi_system_id dmi_switches_allow_list[] = {
227 	{
228 		.matches = {
229 			DMI_EXACT_MATCH(DMI_CHASSIS_TYPE, "31" /* Convertible */),
230 		},
231 	},
232 	{
233 		.matches = {
234 			DMI_EXACT_MATCH(DMI_CHASSIS_TYPE, "32" /* Detachable */),
235 		},
236 	},
237 	{
238 		.matches = {
239 			DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
240 			DMI_MATCH(DMI_PRODUCT_NAME, "Venue 11 Pro 7130"),
241 		},
242 	},
243 	{
244 		.matches = {
245 			DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
246 			DMI_MATCH(DMI_PRODUCT_NAME, "HP Pavilion 13 x360 PC"),
247 		},
248 	},
249 	{
250 		.matches = {
251 			DMI_MATCH(DMI_SYS_VENDOR, "Acer"),
252 			DMI_MATCH(DMI_PRODUCT_NAME, "Switch SA5-271"),
253 		},
254 	},
255 	{
256 		.matches = {
257 			DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
258 			DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron 7352"),
259 		},
260 	},
261 	{} /* Array terminator */
262 };
263 
264 static bool intel_vbtn_has_switches(acpi_handle handle, bool dual_accel)
265 {
266 	/* See dual_accel_detect.h for more info */
267 	if (dual_accel)
268 		return false;
269 
270 	if (!dmi_check_system(dmi_switches_allow_list))
271 		return false;
272 
273 	return acpi_has_method(handle, "VGBS");
274 }
275 
276 static int intel_vbtn_probe(struct platform_device *device)
277 {
278 	acpi_handle handle = ACPI_HANDLE(&device->dev);
279 	bool dual_accel, has_buttons, has_switches;
280 	struct intel_vbtn_priv *priv;
281 	acpi_status status;
282 	int err;
283 
284 	dual_accel = dual_accel_detect();
285 	has_buttons = acpi_has_method(handle, "VBDL");
286 	has_switches = intel_vbtn_has_switches(handle, dual_accel);
287 
288 	if (!has_buttons && !has_switches) {
289 		dev_warn(&device->dev, "failed to read Intel Virtual Button driver\n");
290 		return -ENODEV;
291 	}
292 
293 	priv = devm_kzalloc(&device->dev, sizeof(*priv), GFP_KERNEL);
294 	if (!priv)
295 		return -ENOMEM;
296 	dev_set_drvdata(&device->dev, priv);
297 
298 	err = devm_mutex_init(&device->dev, &priv->mutex);
299 	if (err)
300 		return err;
301 
302 	priv->dual_accel = dual_accel;
303 	priv->has_buttons = has_buttons;
304 	priv->has_switches = has_switches;
305 
306 	err = intel_vbtn_input_setup(device);
307 	if (err) {
308 		pr_err("Failed to setup Intel Virtual Button\n");
309 		return err;
310 	}
311 
312 	status = acpi_install_notify_handler(handle,
313 					     ACPI_DEVICE_NOTIFY,
314 					     notify_handler,
315 					     device);
316 	if (ACPI_FAILURE(status))
317 		return -EBUSY;
318 
319 	if (has_buttons) {
320 		status = acpi_evaluate_object(handle, "VBDL", NULL, NULL);
321 		if (ACPI_FAILURE(status))
322 			dev_err(&device->dev, "Error VBDL failed with ACPI status %d\n", status);
323 	}
324 	// Check switches after buttons since VBDL may have side effects.
325 	if (has_switches)
326 		detect_tablet_mode(&device->dev);
327 
328 	device_init_wakeup(&device->dev, true);
329 	/*
330 	 * In order for system wakeup to work, the EC GPE has to be marked as
331 	 * a wakeup one, so do that here (this setting will persist, but it has
332 	 * no effect until the wakeup mask is set for the EC GPE).
333 	 */
334 	acpi_ec_mark_gpe_for_wake();
335 	return 0;
336 }
337 
338 static void intel_vbtn_remove(struct platform_device *device)
339 {
340 	acpi_handle handle = ACPI_HANDLE(&device->dev);
341 
342 	device_init_wakeup(&device->dev, false);
343 	acpi_remove_notify_handler(handle, ACPI_DEVICE_NOTIFY, notify_handler);
344 }
345 
346 static int intel_vbtn_pm_prepare(struct device *dev)
347 {
348 	if (device_may_wakeup(dev)) {
349 		struct intel_vbtn_priv *priv = dev_get_drvdata(dev);
350 
351 		priv->wakeup_mode = true;
352 	}
353 	return 0;
354 }
355 
356 static void intel_vbtn_pm_complete(struct device *dev)
357 {
358 	struct intel_vbtn_priv *priv = dev_get_drvdata(dev);
359 
360 	priv->wakeup_mode = false;
361 }
362 
363 static int intel_vbtn_pm_resume(struct device *dev)
364 {
365 	struct intel_vbtn_priv *priv = dev_get_drvdata(dev);
366 
367 	intel_vbtn_pm_complete(dev);
368 
369 	if (priv->has_switches)
370 		detect_tablet_mode(dev);
371 
372 	return 0;
373 }
374 
375 static const struct dev_pm_ops intel_vbtn_pm_ops = {
376 	.prepare = intel_vbtn_pm_prepare,
377 	.complete = intel_vbtn_pm_complete,
378 	.resume = intel_vbtn_pm_resume,
379 	.restore = intel_vbtn_pm_resume,
380 	.thaw = intel_vbtn_pm_resume,
381 };
382 
383 static struct platform_driver intel_vbtn_pl_driver = {
384 	.driver = {
385 		.name = "intel-vbtn",
386 		.acpi_match_table = intel_vbtn_ids,
387 		.pm = &intel_vbtn_pm_ops,
388 	},
389 	.probe = intel_vbtn_probe,
390 	.remove_new = intel_vbtn_remove,
391 };
392 
393 static acpi_status __init
394 check_acpi_dev(acpi_handle handle, u32 lvl, void *context, void **rv)
395 {
396 	const struct acpi_device_id *ids = context;
397 	struct acpi_device *dev = acpi_fetch_acpi_dev(handle);
398 
399 	if (dev && acpi_match_device_ids(dev, ids) == 0)
400 		if (!IS_ERR_OR_NULL(acpi_create_platform_device(dev, NULL)))
401 			dev_info(&dev->dev,
402 				 "intel-vbtn: created platform device\n");
403 
404 	return AE_OK;
405 }
406 
407 static int __init intel_vbtn_init(void)
408 {
409 	acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
410 			    ACPI_UINT32_MAX, check_acpi_dev, NULL,
411 			    (void *)intel_vbtn_ids, NULL);
412 
413 	return platform_driver_register(&intel_vbtn_pl_driver);
414 }
415 module_init(intel_vbtn_init);
416 
417 static void __exit intel_vbtn_exit(void)
418 {
419 	platform_driver_unregister(&intel_vbtn_pl_driver);
420 }
421 module_exit(intel_vbtn_exit);
422