summaryrefslogtreecommitdiffstats
path: root/drivers/input/misc/soc_button_array.c
blob: cb6ec59a045d4097cdffbcc5fa219c03059d583f (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
// SPDX-License-Identifier: GPL-2.0-only
/*
 * Supports for the button array on SoC tablets originally running
 * Windows 8.
 *
 * (C) Copyright 2014 Intel Corporation
 */

#include <linux/module.h>
#include <linux/input.h>
#include <linux/init.h>
#include <linux/irq.h>
#include <linux/kernel.h>
#include <linux/acpi.h>
#include <linux/dmi.h>
#include <linux/gpio/consumer.h>
#include <linux/gpio_keys.h>
#include <linux/gpio.h>
#include <linux/platform_device.h>

struct soc_button_info {
	const char *name;
	int acpi_index;
	unsigned int event_type;
	unsigned int event_code;
	bool autorepeat;
	bool wakeup;
	bool active_low;
};

struct soc_device_data {
	const struct soc_button_info *button_info;
	int (*check)(struct device *dev);
};

/*
 * Some of the buttons like volume up/down are auto repeat, while others
 * are not. To support both, we register two platform devices, and put
 * buttons into them based on whether the key should be auto repeat.
 */
#define BUTTON_TYPES	2

struct soc_button_data {
	struct platform_device *children[BUTTON_TYPES];
};

/*
 * Some 2-in-1s which use the soc_button_array driver have this ugly issue in
 * their DSDT where the _LID method modifies the irq-type settings of the GPIOs
 * used for the power and home buttons. The intend of this AML code is to
 * disable these buttons when the lid is closed.
 * The AML does this by directly poking the GPIO controllers registers. This is
 * problematic because when re-enabling the irq, which happens whenever _LID
 * gets called with the lid open (e.g. on boot and on resume), it sets the
 * irq-type to IRQ_TYPE_LEVEL_LOW. Where as the gpio-keys driver programs the
 * type to, and expects it to be, IRQ_TYPE_EDGE_BOTH.
 * To work around this we don't set gpio_keys_button.gpio on these 2-in-1s,
 * instead we get the irq for the GPIO ourselves, configure it as
 * IRQ_TYPE_LEVEL_LOW (to match how the _LID AML code configures it) and pass
 * the irq in gpio_keys_button.irq. Below is a list of affected devices.
 */
static const struct dmi_system_id dmi_use_low_level_irq[] = {
	{
		/*
		 * Acer Switch 10 SW5-012. _LID method messes with home- and
		 * power-button GPIO IRQ settings. When (re-)enabling the irq
		 * it ors in its own flags without clearing the previous set
		 * ones, leading to an irq-type of IRQ_TYPE_LEVEL_LOW |
		 * IRQ_TYPE_LEVEL_HIGH causing a continuous interrupt storm.
		 */
		.matches = {
			DMI_MATCH(DMI_SYS_VENDOR, "Acer"),
			DMI_MATCH(DMI_PRODUCT_NAME, "Aspire SW5-012"),
		},
	},
	{
		/*
		 * Acer One S1003. _LID method messes with power-button GPIO
		 * IRQ settings, leading to a non working power-button.
		 */
		.matches = {
			DMI_MATCH(DMI_SYS_VENDOR, "Acer"),
			DMI_MATCH(DMI_PRODUCT_NAME, "One S1003"),
		},
	},
	{
		/*
		 * Lenovo Yoga Tab2 1051L, something messes with the home-button
		 * IRQ settings, leading to a non working home-button.
		 */
		.matches = {
			DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
			DMI_MATCH(DMI_PRODUCT_NAME, "60073"),
			DMI_MATCH(DMI_PRODUCT_VERSION, "1051L"),
		},
	},
	{} /* Terminating entry */
};

/*
 * Get the Nth GPIO number from the ACPI object.
 */
static int soc_button_lookup_gpio(struct device *dev, int acpi_index,
				  int *gpio_ret, int *irq_ret)
{
	struct gpio_desc *desc;

	desc = gpiod_get_index(dev, NULL, acpi_index, GPIOD_ASIS);
	if (IS_ERR(desc))
		return PTR_ERR(desc);

	*gpio_ret = desc_to_gpio(desc);
	*irq_ret = gpiod_to_irq(desc);

	gpiod_put(desc);

	return 0;
}

static struct platform_device *
soc_button_device_create(struct platform_device *pdev,
			 const struct soc_button_info *button_info,
			 bool autorepeat)
{
	const struct soc_button_info *info;
	struct platform_device *pd;
	struct gpio_keys_button *gpio_keys;
	struct gpio_keys_platform_data *gpio_keys_pdata;
	int error, gpio, irq;
	int n_buttons = 0;

	for (info = button_info; info->name; info++)
		if (info->autorepeat == autorepeat)
			n_buttons++;

	gpio_keys_pdata = devm_kzalloc(&pdev->dev,
				       sizeof(*gpio_keys_pdata) +
					sizeof(*gpio_keys) * n_buttons,
				       GFP_KERNEL);
	if (!gpio_keys_pdata)
		return ERR_PTR(-ENOMEM);

	gpio_keys = (void *)(gpio_keys_pdata + 1);
	n_buttons = 0;

	for (info = button_info; info->name; info++) {
		if (info->autorepeat != autorepeat)
			continue;

		error = soc_button_lookup_gpio(&pdev->dev, info->acpi_index, &gpio, &irq);
		if (error || irq < 0) {
			/*
			 * Skip GPIO if not present. Note we deliberately
			 * ignore -EPROBE_DEFER errors here. On some devices
			 * Intel is using so called virtual GPIOs which are not
			 * GPIOs at all but some way for AML code to check some
			 * random status bits without need a custom opregion.
			 * In some cases the resources table we parse points to
			 * such a virtual GPIO, since these are not real GPIOs
			 * we do not have a driver for these so they will never
			 * show up, therefore we ignore -EPROBE_DEFER.
			 */
			continue;
		}

		/* See dmi_use_low_level_irq[] comment */
		if (!autorepeat && dmi_check_system(dmi_use_low_level_irq)) {
			irq_set_irq_type(irq, IRQ_TYPE_LEVEL_LOW);
			gpio_keys[n_buttons].irq = irq;
			gpio_keys[n_buttons].gpio = -ENOENT;
		} else {
			gpio_keys[n_buttons].gpio = gpio;
		}

		gpio_keys[n_buttons].type = info->event_type;
		gpio_keys[n_buttons].code = info->event_code;
		gpio_keys[n_buttons].active_low = info->active_low;
		gpio_keys[n_buttons].desc = info->name;
		gpio_keys[n_buttons].wakeup = info->wakeup;
		/* These devices often use cheap buttons, use 50 ms debounce */
		gpio_keys[n_buttons].debounce_interval = 50;
		n_buttons++;
	}

	if (n_buttons == 0) {
		error = -ENODEV;
		goto err_free_mem;
	}

	gpio_keys_pdata->buttons = gpio_keys;
	gpio_keys_pdata->nbuttons = n_buttons;
	gpio_keys_pdata->rep = autorepeat;

	pd = platform_device_register_resndata(&pdev->dev, "gpio-keys",
					       PLATFORM_DEVID_AUTO, NULL, 0,
					       gpio_keys_pdata,
					       sizeof(*gpio_keys_pdata));
	error = PTR_ERR_OR_ZERO(pd);
	if (error) {
		dev_err(&pdev->dev,
			"failed registering gpio-keys: %d\n", error);
		goto err_free_mem;
	}

	return pd;

err_free_mem:
	devm_kfree(&pdev->dev, gpio_keys_pdata);
	return ERR_PTR(error);
}

static int soc_button_get_acpi_object_int(const union acpi_object *obj)
{
	if (obj->type != ACPI_TYPE_INTEGER)
		return -1;

	return obj->integer.value;
}

/* Parse a single ACPI0011 _DSD button descriptor */
static int soc_button_parse_btn_desc(struct device *dev,
				     const union acpi_object *desc,
				     int collection_uid,
				     struct soc_button_info *info)
{
	int upage, usage;

	if (desc->type != ACPI_TYPE_PACKAGE ||
	    desc->package.count != 5 ||
	    /* First byte should be 1 (control) */
	    soc_button_get_acpi_object_int(&desc->package.elements[0]) != 1 ||
	    /* Third byte should be collection uid */
	    soc_button_get_acpi_object_int(&desc->package.elements[2]) !=
							    collection_uid) {
		dev_err(dev, "Invalid ACPI Button Descriptor\n");
		return -ENODEV;
	}

	info->event_type = EV_KEY;
	info->active_low = true;
	info->acpi_index =
		soc_button_get_acpi_object_int(&desc->package.elements[1]);
	upage = soc_button_get_acpi_object_int(&desc->package.elements[3]);
	usage = soc_button_get_acpi_object_int(&desc->package.elements[4]);

	/*
	 * The UUID: fa6bd625-9ce8-470d-a2c7-b3ca36c4282e descriptors use HID
	 * usage page and usage codes, but otherwise the device is not HID
	 * compliant: it uses one irq per button instead of generating HID
	 * input reports and some buttons should generate wakeups where as
	 * others should not, so we cannot use the HID subsystem.
	 *
	 * Luckily all devices only use a few usage page + usage combinations,
	 * so we can simply check for the known combinations here.
	 */
	if (upage == 0x01 && usage == 0x81) {
		info->name = "power";
		info->event_code = KEY_POWER;
		info->wakeup = true;
	} else if (upage == 0x01 && usage == 0xca) {
		info->name = "rotation lock switch";
		info->event_type = EV_SW;
		info->event_code = SW_ROTATE_LOCK;
	} else if (upage == 0x07 && usage == 0xe3) {
		info->name = "home";
		info->event_code = KEY_LEFTMETA;
		info->wakeup = true;
	} else if (upage == 0x0c && usage == 0xe9) {
		info->name = "volume_up";
		info->event_code = KEY_VOLUMEUP;
		info->autorepeat = true;
	} else if (upage == 0x0c && usage == 0xea) {
		info->name = "volume_down";
		info->event_code = KEY_VOLUMEDOWN;
		info->autorepeat = true;
	} else {
		dev_warn(dev, "Unknown button index %d upage %02x usage %02x, ignoring\n",
			 info->acpi_index, upage, usage);
		info->name = "unknown";
		info->event_code = KEY_RESERVED;
	}

	return 0;
}

/* ACPI0011 _DSD btns descriptors UUID: fa6bd625-9ce8-470d-a2c7-b3ca36c4282e */
static const u8 btns_desc_uuid[16] = {
	0x25, 0xd6, 0x6b, 0xfa, 0xe8, 0x9c, 0x0d, 0x47,
	0xa2, 0xc7, 0xb3, 0xca, 0x36, 0xc4, 0x28, 0x2e
};

/* Parse ACPI0011 _DSD button descriptors */
static struct soc_button_info *soc_button_get_button_info(struct device *dev)
{
	struct acpi_buffer buf = { ACPI_ALLOCATE_BUFFER };
	const union acpi_object *desc, *el0, *uuid, *btns_desc = NULL;
	struct soc_button_info *button_info;
	acpi_status status;
	int i, btn, collection_uid = -1;

	status = acpi_evaluate_object_typed(ACPI_HANDLE(dev), "_DSD", NULL,
					    &buf, ACPI_TYPE_PACKAGE);
	if (ACPI_FAILURE(status)) {
		dev_err(dev, "ACPI _DSD object not found\n");
		return ERR_PTR(-ENODEV);
	}

	/* Look for the Button Descriptors UUID */
	desc = buf.pointer;
	for (i = 0; (i + 1) < desc->package.count; i += 2) {
		uuid = &desc->package.elements[i];

		if (uuid->type != ACPI_TYPE_BUFFER ||
		    uuid->buffer.length != 16 ||
		    desc->package.elements[i + 1].type != ACPI_TYPE_PACKAGE) {
			break;
		}

		if (memcmp(uuid->buffer.pointer, btns_desc_uuid, 16) == 0) {
			btns_desc = &desc->package.elements[i + 1];
			break;
		}
	}

	if (!btns_desc) {
		dev_err(dev, "ACPI Button Descriptors not found\n");
		button_info = ERR_PTR(-ENODEV);
		goto out;
	}

	/* The first package describes the collection */
	el0 = &btns_desc->package.elements[0];
	if (el0->type == ACPI_TYPE_PACKAGE &&
	    el0->package.count == 5 &&
	    /* First byte should be 0 (collection) */
	    soc_button_get_acpi_object_int(&el0->package.elements[0]) == 0 &&
	    /* Third byte should be 0 (top level collection) */
	    soc_button_get_acpi_object_int(&el0->package.elements[2]) == 0) {
		collection_uid = soc_button_get_acpi_object_int(
						&el0->package.elements[1]);
	}
	if (collection_uid == -1) {
		dev_err(dev, "Invalid Button Collection Descriptor\n");
		button_info = ERR_PTR(-ENODEV);
		goto out;
	}

	/* There are package.count - 1 buttons + 1 terminating empty entry */
	button_info = devm_kcalloc(dev, btns_desc->package.count,
				   sizeof(*button_info), GFP_KERNEL);
	if (!button_info) {
		button_info = ERR_PTR(-ENOMEM);
		goto out;
	}

	/* Parse the button descriptors */
	for (i = 1, btn = 0; i < btns_desc->package.count; i++, btn++) {
		if (soc_button_parse_btn_desc(dev,
					      &btns_desc->package.elements[i],
					      collection_uid,
					      &button_info[btn])) {
			button_info = ERR_PTR(-ENODEV);
			goto out;
		}
	}

out:
	kfree(buf.pointer);
	return button_info;
}

static int soc_button_remove(struct platform_device *pdev)
{
	struct soc_button_data *priv = platform_get_drvdata(pdev);

	int i;

	for (i = 0; i < BUTTON_TYPES; i++)
		if (priv->children[i])
			platform_device_unregister(priv->children[i]);

	return 0;
}

static int soc_button_probe(struct platform_device *pdev)
{
	struct device *dev = &pdev->dev;
	const struct soc_device_data *device_data;
	const struct soc_button_info *button_info;
	struct soc_button_data *priv;
	struct platform_device *pd;
	int i;
	int error;

	device_data = acpi_device_get_match_data(dev);
	if (device_data && device_data->check) {
		error = device_data->check(dev);
		if (error)
			return error;
	}

	if (device_data && device_data->button_info) {
		button_info = device_data->button_info;
	} else {
		button_info = soc_button_get_button_info(dev);
		if (IS_ERR(button_info))
			return PTR_ERR(button_info);
	}

	error = gpiod_count(dev, NULL);
	if (error < 0) {
		dev_dbg(dev, "no GPIO attached, ignoring...\n");
		return -ENODEV;
	}

	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
	if (!priv)
		return -ENOMEM;

	platform_set_drvdata(pdev, priv);

	for (i = 0; i < BUTTON_TYPES; i++) {
		pd = soc_button_device_create(pdev, button_info, i == 0);
		if (IS_ERR(pd)) {
			error = PTR_ERR(pd);
			if (error != -ENODEV) {
				soc_button_remove(pdev);
				return error;
			}
			continue;
		}

		priv->children[i] = pd;
	}

	if (!priv->children[0] && !priv->children[1])
		return -ENODEV;

	if (!device_data || !device_data->button_info)
		devm_kfree(dev, button_info);

	return 0;
}

/*
 * Definition of buttons on the tablet. The ACPI index of each button
 * is defined in section 2.8.7.2 of "Windows ACPI Design Guide for SoC
 * Platforms"
 */
static const struct soc_button_info soc_button_PNP0C40[] = {
	{ "power", 0, EV_KEY, KEY_POWER, false, true, true },
	{ "home", 1, EV_KEY, KEY_LEFTMETA, false, true, true },
	{ "volume_up", 2, EV_KEY, KEY_VOLUMEUP, true, false, true },
	{ "volume_down", 3, EV_KEY, KEY_VOLUMEDOWN, true, false, true },
	{ "rotation_lock", 4, EV_KEY, KEY_ROTATE_LOCK_TOGGLE, false, false, true },
	{ }
};

static const struct soc_device_data soc_device_PNP0C40 = {
	.button_info = soc_button_PNP0C40,
};

static const struct soc_button_info soc_button_INT33D3[] = {
	{ "tablet_mode", 0, EV_SW, SW_TABLET_MODE, false, false, false },
	{ }
};

static const struct soc_device_data soc_device_INT33D3 = {
	.button_info = soc_button_INT33D3,
};

/*
 * Special device check for Surface Book 2 and Surface Pro (2017).
 * Both, the Surface Pro 4 (surfacepro3_button.c) and the above mentioned
 * devices use MSHW0040 for power and volume buttons, however the way they
 * have to be addressed differs. Make sure that we only load this drivers
 * for the correct devices by checking the OEM Platform Revision provided by
 * the _DSM method.
 */
#define MSHW0040_DSM_REVISION		0x01
#define MSHW0040_DSM_GET_OMPR		0x02	// get OEM Platform Revision
static const guid_t MSHW0040_DSM_UUID =
	GUID_INIT(0x6fd05c69, 0xcde3, 0x49f4, 0x95, 0xed, 0xab, 0x16, 0x65,
		  0x49, 0x80, 0x35);

static int soc_device_check_MSHW0040(struct device *dev)
{
	acpi_handle handle = ACPI_HANDLE(dev);
	union acpi_object *result;
	u64 oem_platform_rev = 0;	// valid revisions are nonzero

	// get OEM platform revision
	result = acpi_evaluate_dsm_typed(handle, &MSHW0040_DSM_UUID,
					 MSHW0040_DSM_REVISION,
					 MSHW0040_DSM_GET_OMPR, NULL,
					 ACPI_TYPE_INTEGER);

	if (result) {
		oem_platform_rev = result->integer.value;
		ACPI_FREE(result);
	}

	/*
	 * If the revision is zero here, the _DSM evaluation has failed. This
	 * indicates that we have a Pro 4 or Book 1 and this driver should not
	 * be used.
	 */
	if (oem_platform_rev == 0)
		return -ENODEV;

	dev_dbg(dev, "OEM Platform Revision %llu\n", oem_platform_rev);

	return 0;
}

/*
 * Button infos for Microsoft Surface Book 2 and Surface Pro (2017).
 * Obtained from DSDT/testing.
 */
static const struct soc_button_info soc_button_MSHW0040[] = {
	{ "power", 0, EV_KEY, KEY_POWER, false, true, true },
	{ "volume_up", 2, EV_KEY, KEY_VOLUMEUP, true, false, true },
	{ "volume_down", 4, EV_KEY, KEY_VOLUMEDOWN, true, false, true },
	{ }
};

static const struct soc_device_data soc_device_MSHW0040 = {
	.button_info = soc_button_MSHW0040,
	.check = soc_device_check_MSHW0040,
};

static const struct acpi_device_id soc_button_acpi_match[] = {
	{ "PNP0C40", (unsigned long)&soc_device_PNP0C40 },
	{ "INT33D3", (unsigned long)&soc_device_INT33D3 },
	{ "ID9001", (unsigned long)&soc_device_INT33D3 },
	{ "ACPI0011", 0 },

	/* Microsoft Surface Devices (5th and 6th generation) */
	{ "MSHW0040", (unsigned long)&soc_device_MSHW0040 },

	{ }
};

MODULE_DEVICE_TABLE(acpi, soc_button_acpi_match);

static struct platform_driver soc_button_driver = {
	.probe          = soc_button_probe,
	.remove		= soc_button_remove,
	.driver		= {
		.name = KBUILD_MODNAME,
		.acpi_match_table = ACPI_PTR(soc_button_acpi_match),
	},
};
module_platform_driver(soc_button_driver);

MODULE_LICENSE("GPL");