1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Supports for the button array on SoC tablets originally running
4  * Windows 8.
5  *
6  * (C) Copyright 2014 Intel Corporation
7  */
8 
9 #include <linux/module.h>
10 #include <linux/input.h>
11 #include <linux/init.h>
12 #include <linux/irq.h>
13 #include <linux/kernel.h>
14 #include <linux/acpi.h>
15 #include <linux/dmi.h>
16 #include <linux/gpio/consumer.h>
17 #include <linux/gpio_keys.h>
18 #include <linux/gpio.h>
19 #include <linux/platform_device.h>
20 
21 struct soc_button_info {
22 	const char *name;
23 	int acpi_index;
24 	unsigned int event_type;
25 	unsigned int event_code;
26 	bool autorepeat;
27 	bool wakeup;
28 	bool active_low;
29 };
30 
31 struct soc_device_data {
32 	const struct soc_button_info *button_info;
33 	int (*check)(struct device *dev);
34 };
35 
36 /*
37  * Some of the buttons like volume up/down are auto repeat, while others
38  * are not. To support both, we register two platform devices, and put
39  * buttons into them based on whether the key should be auto repeat.
40  */
41 #define BUTTON_TYPES	2
42 
43 struct soc_button_data {
44 	struct platform_device *children[BUTTON_TYPES];
45 };
46 
47 /*
48  * Some 2-in-1s which use the soc_button_array driver have this ugly issue in
49  * their DSDT where the _LID method modifies the irq-type settings of the GPIOs
50  * used for the power and home buttons. The intend of this AML code is to
51  * disable these buttons when the lid is closed.
52  * The AML does this by directly poking the GPIO controllers registers. This is
53  * problematic because when re-enabling the irq, which happens whenever _LID
54  * gets called with the lid open (e.g. on boot and on resume), it sets the
55  * irq-type to IRQ_TYPE_LEVEL_LOW. Where as the gpio-keys driver programs the
56  * type to, and expects it to be, IRQ_TYPE_EDGE_BOTH.
57  * To work around this we don't set gpio_keys_button.gpio on these 2-in-1s,
58  * instead we get the irq for the GPIO ourselves, configure it as
59  * IRQ_TYPE_LEVEL_LOW (to match how the _LID AML code configures it) and pass
60  * the irq in gpio_keys_button.irq. Below is a list of affected devices.
61  */
62 static const struct dmi_system_id dmi_use_low_level_irq[] = {
63 	{
64 		/*
65 		 * Acer Switch 10 SW5-012. _LID method messes with home- and
66 		 * power-button GPIO IRQ settings. When (re-)enabling the irq
67 		 * it ors in its own flags without clearing the previous set
68 		 * ones, leading to an irq-type of IRQ_TYPE_LEVEL_LOW |
69 		 * IRQ_TYPE_LEVEL_HIGH causing a continuous interrupt storm.
70 		 */
71 		.matches = {
72 			DMI_MATCH(DMI_SYS_VENDOR, "Acer"),
73 			DMI_MATCH(DMI_PRODUCT_NAME, "Aspire SW5-012"),
74 		},
75 	},
76 	{
77 		/*
78 		 * Acer One S1003. _LID method messes with power-button GPIO
79 		 * IRQ settings, leading to a non working power-button.
80 		 */
81 		.matches = {
82 			DMI_MATCH(DMI_SYS_VENDOR, "Acer"),
83 			DMI_MATCH(DMI_PRODUCT_NAME, "One S1003"),
84 		},
85 	},
86 	{
87 		/*
88 		 * Lenovo Yoga Tab2 1051F/1051L, something messes with the home-button
89 		 * IRQ settings, leading to a non working home-button.
90 		 */
91 		.matches = {
92 			DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
93 			DMI_MATCH(DMI_PRODUCT_NAME, "60073"),
94 			DMI_MATCH(DMI_PRODUCT_VERSION, "1051"),
95 		},
96 	},
97 	{} /* Terminating entry */
98 };
99 
100 /*
101  * Get the Nth GPIO number from the ACPI object.
102  */
103 static int soc_button_lookup_gpio(struct device *dev, int acpi_index,
104 				  int *gpio_ret, int *irq_ret)
105 {
106 	struct gpio_desc *desc;
107 
108 	desc = gpiod_get_index(dev, NULL, acpi_index, GPIOD_ASIS);
109 	if (IS_ERR(desc))
110 		return PTR_ERR(desc);
111 
112 	*gpio_ret = desc_to_gpio(desc);
113 	*irq_ret = gpiod_to_irq(desc);
114 
115 	gpiod_put(desc);
116 
117 	return 0;
118 }
119 
120 static struct platform_device *
121 soc_button_device_create(struct platform_device *pdev,
122 			 const struct soc_button_info *button_info,
123 			 bool autorepeat)
124 {
125 	const struct soc_button_info *info;
126 	struct platform_device *pd;
127 	struct gpio_keys_button *gpio_keys;
128 	struct gpio_keys_platform_data *gpio_keys_pdata;
129 	int error, gpio, irq;
130 	int n_buttons = 0;
131 
132 	for (info = button_info; info->name; info++)
133 		if (info->autorepeat == autorepeat)
134 			n_buttons++;
135 
136 	gpio_keys_pdata = devm_kzalloc(&pdev->dev,
137 				       sizeof(*gpio_keys_pdata) +
138 					sizeof(*gpio_keys) * n_buttons,
139 				       GFP_KERNEL);
140 	if (!gpio_keys_pdata)
141 		return ERR_PTR(-ENOMEM);
142 
143 	gpio_keys = (void *)(gpio_keys_pdata + 1);
144 	n_buttons = 0;
145 
146 	for (info = button_info; info->name; info++) {
147 		if (info->autorepeat != autorepeat)
148 			continue;
149 
150 		error = soc_button_lookup_gpio(&pdev->dev, info->acpi_index, &gpio, &irq);
151 		if (error || irq < 0) {
152 			/*
153 			 * Skip GPIO if not present. Note we deliberately
154 			 * ignore -EPROBE_DEFER errors here. On some devices
155 			 * Intel is using so called virtual GPIOs which are not
156 			 * GPIOs at all but some way for AML code to check some
157 			 * random status bits without need a custom opregion.
158 			 * In some cases the resources table we parse points to
159 			 * such a virtual GPIO, since these are not real GPIOs
160 			 * we do not have a driver for these so they will never
161 			 * show up, therefore we ignore -EPROBE_DEFER.
162 			 */
163 			continue;
164 		}
165 
166 		/* See dmi_use_low_level_irq[] comment */
167 		if (!autorepeat && dmi_check_system(dmi_use_low_level_irq)) {
168 			irq_set_irq_type(irq, IRQ_TYPE_LEVEL_LOW);
169 			gpio_keys[n_buttons].irq = irq;
170 			gpio_keys[n_buttons].gpio = -ENOENT;
171 		} else {
172 			gpio_keys[n_buttons].gpio = gpio;
173 		}
174 
175 		gpio_keys[n_buttons].type = info->event_type;
176 		gpio_keys[n_buttons].code = info->event_code;
177 		gpio_keys[n_buttons].active_low = info->active_low;
178 		gpio_keys[n_buttons].desc = info->name;
179 		gpio_keys[n_buttons].wakeup = info->wakeup;
180 		/* These devices often use cheap buttons, use 50 ms debounce */
181 		gpio_keys[n_buttons].debounce_interval = 50;
182 		n_buttons++;
183 	}
184 
185 	if (n_buttons == 0) {
186 		error = -ENODEV;
187 		goto err_free_mem;
188 	}
189 
190 	gpio_keys_pdata->buttons = gpio_keys;
191 	gpio_keys_pdata->nbuttons = n_buttons;
192 	gpio_keys_pdata->rep = autorepeat;
193 
194 	pd = platform_device_register_resndata(&pdev->dev, "gpio-keys",
195 					       PLATFORM_DEVID_AUTO, NULL, 0,
196 					       gpio_keys_pdata,
197 					       sizeof(*gpio_keys_pdata));
198 	error = PTR_ERR_OR_ZERO(pd);
199 	if (error) {
200 		dev_err(&pdev->dev,
201 			"failed registering gpio-keys: %d\n", error);
202 		goto err_free_mem;
203 	}
204 
205 	return pd;
206 
207 err_free_mem:
208 	devm_kfree(&pdev->dev, gpio_keys_pdata);
209 	return ERR_PTR(error);
210 }
211 
212 static int soc_button_get_acpi_object_int(const union acpi_object *obj)
213 {
214 	if (obj->type != ACPI_TYPE_INTEGER)
215 		return -1;
216 
217 	return obj->integer.value;
218 }
219 
220 /* Parse a single ACPI0011 _DSD button descriptor */
221 static int soc_button_parse_btn_desc(struct device *dev,
222 				     const union acpi_object *desc,
223 				     int collection_uid,
224 				     struct soc_button_info *info)
225 {
226 	int upage, usage;
227 
228 	if (desc->type != ACPI_TYPE_PACKAGE ||
229 	    desc->package.count != 5 ||
230 	    /* First byte should be 1 (control) */
231 	    soc_button_get_acpi_object_int(&desc->package.elements[0]) != 1 ||
232 	    /* Third byte should be collection uid */
233 	    soc_button_get_acpi_object_int(&desc->package.elements[2]) !=
234 							    collection_uid) {
235 		dev_err(dev, "Invalid ACPI Button Descriptor\n");
236 		return -ENODEV;
237 	}
238 
239 	info->event_type = EV_KEY;
240 	info->active_low = true;
241 	info->acpi_index =
242 		soc_button_get_acpi_object_int(&desc->package.elements[1]);
243 	upage = soc_button_get_acpi_object_int(&desc->package.elements[3]);
244 	usage = soc_button_get_acpi_object_int(&desc->package.elements[4]);
245 
246 	/*
247 	 * The UUID: fa6bd625-9ce8-470d-a2c7-b3ca36c4282e descriptors use HID
248 	 * usage page and usage codes, but otherwise the device is not HID
249 	 * compliant: it uses one irq per button instead of generating HID
250 	 * input reports and some buttons should generate wakeups where as
251 	 * others should not, so we cannot use the HID subsystem.
252 	 *
253 	 * Luckily all devices only use a few usage page + usage combinations,
254 	 * so we can simply check for the known combinations here.
255 	 */
256 	if (upage == 0x01 && usage == 0x81) {
257 		info->name = "power";
258 		info->event_code = KEY_POWER;
259 		info->wakeup = true;
260 	} else if (upage == 0x01 && usage == 0xca) {
261 		info->name = "rotation lock switch";
262 		info->event_type = EV_SW;
263 		info->event_code = SW_ROTATE_LOCK;
264 	} else if (upage == 0x07 && usage == 0xe3) {
265 		info->name = "home";
266 		info->event_code = KEY_LEFTMETA;
267 		info->wakeup = true;
268 	} else if (upage == 0x0c && usage == 0xe9) {
269 		info->name = "volume_up";
270 		info->event_code = KEY_VOLUMEUP;
271 		info->autorepeat = true;
272 	} else if (upage == 0x0c && usage == 0xea) {
273 		info->name = "volume_down";
274 		info->event_code = KEY_VOLUMEDOWN;
275 		info->autorepeat = true;
276 	} else {
277 		dev_warn(dev, "Unknown button index %d upage %02x usage %02x, ignoring\n",
278 			 info->acpi_index, upage, usage);
279 		info->name = "unknown";
280 		info->event_code = KEY_RESERVED;
281 	}
282 
283 	return 0;
284 }
285 
286 /* ACPI0011 _DSD btns descriptors UUID: fa6bd625-9ce8-470d-a2c7-b3ca36c4282e */
287 static const u8 btns_desc_uuid[16] = {
288 	0x25, 0xd6, 0x6b, 0xfa, 0xe8, 0x9c, 0x0d, 0x47,
289 	0xa2, 0xc7, 0xb3, 0xca, 0x36, 0xc4, 0x28, 0x2e
290 };
291 
292 /* Parse ACPI0011 _DSD button descriptors */
293 static struct soc_button_info *soc_button_get_button_info(struct device *dev)
294 {
295 	struct acpi_buffer buf = { ACPI_ALLOCATE_BUFFER };
296 	const union acpi_object *desc, *el0, *uuid, *btns_desc = NULL;
297 	struct soc_button_info *button_info;
298 	acpi_status status;
299 	int i, btn, collection_uid = -1;
300 
301 	status = acpi_evaluate_object_typed(ACPI_HANDLE(dev), "_DSD", NULL,
302 					    &buf, ACPI_TYPE_PACKAGE);
303 	if (ACPI_FAILURE(status)) {
304 		dev_err(dev, "ACPI _DSD object not found\n");
305 		return ERR_PTR(-ENODEV);
306 	}
307 
308 	/* Look for the Button Descriptors UUID */
309 	desc = buf.pointer;
310 	for (i = 0; (i + 1) < desc->package.count; i += 2) {
311 		uuid = &desc->package.elements[i];
312 
313 		if (uuid->type != ACPI_TYPE_BUFFER ||
314 		    uuid->buffer.length != 16 ||
315 		    desc->package.elements[i + 1].type != ACPI_TYPE_PACKAGE) {
316 			break;
317 		}
318 
319 		if (memcmp(uuid->buffer.pointer, btns_desc_uuid, 16) == 0) {
320 			btns_desc = &desc->package.elements[i + 1];
321 			break;
322 		}
323 	}
324 
325 	if (!btns_desc) {
326 		dev_err(dev, "ACPI Button Descriptors not found\n");
327 		button_info = ERR_PTR(-ENODEV);
328 		goto out;
329 	}
330 
331 	/* The first package describes the collection */
332 	el0 = &btns_desc->package.elements[0];
333 	if (el0->type == ACPI_TYPE_PACKAGE &&
334 	    el0->package.count == 5 &&
335 	    /* First byte should be 0 (collection) */
336 	    soc_button_get_acpi_object_int(&el0->package.elements[0]) == 0 &&
337 	    /* Third byte should be 0 (top level collection) */
338 	    soc_button_get_acpi_object_int(&el0->package.elements[2]) == 0) {
339 		collection_uid = soc_button_get_acpi_object_int(
340 						&el0->package.elements[1]);
341 	}
342 	if (collection_uid == -1) {
343 		dev_err(dev, "Invalid Button Collection Descriptor\n");
344 		button_info = ERR_PTR(-ENODEV);
345 		goto out;
346 	}
347 
348 	/* There are package.count - 1 buttons + 1 terminating empty entry */
349 	button_info = devm_kcalloc(dev, btns_desc->package.count,
350 				   sizeof(*button_info), GFP_KERNEL);
351 	if (!button_info) {
352 		button_info = ERR_PTR(-ENOMEM);
353 		goto out;
354 	}
355 
356 	/* Parse the button descriptors */
357 	for (i = 1, btn = 0; i < btns_desc->package.count; i++, btn++) {
358 		if (soc_button_parse_btn_desc(dev,
359 					      &btns_desc->package.elements[i],
360 					      collection_uid,
361 					      &button_info[btn])) {
362 			button_info = ERR_PTR(-ENODEV);
363 			goto out;
364 		}
365 	}
366 
367 out:
368 	kfree(buf.pointer);
369 	return button_info;
370 }
371 
372 static int soc_button_remove(struct platform_device *pdev)
373 {
374 	struct soc_button_data *priv = platform_get_drvdata(pdev);
375 
376 	int i;
377 
378 	for (i = 0; i < BUTTON_TYPES; i++)
379 		if (priv->children[i])
380 			platform_device_unregister(priv->children[i]);
381 
382 	return 0;
383 }
384 
385 static int soc_button_probe(struct platform_device *pdev)
386 {
387 	struct device *dev = &pdev->dev;
388 	const struct soc_device_data *device_data;
389 	const struct soc_button_info *button_info;
390 	struct soc_button_data *priv;
391 	struct platform_device *pd;
392 	int i;
393 	int error;
394 
395 	device_data = acpi_device_get_match_data(dev);
396 	if (device_data && device_data->check) {
397 		error = device_data->check(dev);
398 		if (error)
399 			return error;
400 	}
401 
402 	if (device_data && device_data->button_info) {
403 		button_info = device_data->button_info;
404 	} else {
405 		button_info = soc_button_get_button_info(dev);
406 		if (IS_ERR(button_info))
407 			return PTR_ERR(button_info);
408 	}
409 
410 	error = gpiod_count(dev, NULL);
411 	if (error < 0) {
412 		dev_dbg(dev, "no GPIO attached, ignoring...\n");
413 		return -ENODEV;
414 	}
415 
416 	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
417 	if (!priv)
418 		return -ENOMEM;
419 
420 	platform_set_drvdata(pdev, priv);
421 
422 	for (i = 0; i < BUTTON_TYPES; i++) {
423 		pd = soc_button_device_create(pdev, button_info, i == 0);
424 		if (IS_ERR(pd)) {
425 			error = PTR_ERR(pd);
426 			if (error != -ENODEV) {
427 				soc_button_remove(pdev);
428 				return error;
429 			}
430 			continue;
431 		}
432 
433 		priv->children[i] = pd;
434 	}
435 
436 	if (!priv->children[0] && !priv->children[1])
437 		return -ENODEV;
438 
439 	if (!device_data || !device_data->button_info)
440 		devm_kfree(dev, button_info);
441 
442 	return 0;
443 }
444 
445 /*
446  * Definition of buttons on the tablet. The ACPI index of each button
447  * is defined in section 2.8.7.2 of "Windows ACPI Design Guide for SoC
448  * Platforms"
449  */
450 static const struct soc_button_info soc_button_PNP0C40[] = {
451 	{ "power", 0, EV_KEY, KEY_POWER, false, true, true },
452 	{ "home", 1, EV_KEY, KEY_LEFTMETA, false, true, true },
453 	{ "volume_up", 2, EV_KEY, KEY_VOLUMEUP, true, false, true },
454 	{ "volume_down", 3, EV_KEY, KEY_VOLUMEDOWN, true, false, true },
455 	{ "rotation_lock", 4, EV_KEY, KEY_ROTATE_LOCK_TOGGLE, false, false, true },
456 	{ }
457 };
458 
459 static const struct soc_device_data soc_device_PNP0C40 = {
460 	.button_info = soc_button_PNP0C40,
461 };
462 
463 static const struct soc_button_info soc_button_INT33D3[] = {
464 	{ "tablet_mode", 0, EV_SW, SW_TABLET_MODE, false, false, false },
465 	{ }
466 };
467 
468 static const struct soc_device_data soc_device_INT33D3 = {
469 	.button_info = soc_button_INT33D3,
470 };
471 
472 /*
473  * Button info for Microsoft Surface 3 (non pro), this is indentical to
474  * the PNP0C40 info except that the home button is active-high.
475  *
476  * The Surface 3 Pro also has a MSHW0028 ACPI device, but that uses a custom
477  * version of the drivers/platform/x86/intel/hid.c 5 button array ACPI API
478  * instead. A check() callback is not necessary though as the Surface 3 Pro
479  * MSHW0028 ACPI device's resource table does not contain any GPIOs.
480  */
481 static const struct soc_button_info soc_button_MSHW0028[] = {
482 	{ "power", 0, EV_KEY, KEY_POWER, false, true, true },
483 	{ "home", 1, EV_KEY, KEY_LEFTMETA, false, true, false },
484 	{ "volume_up", 2, EV_KEY, KEY_VOLUMEUP, true, false, true },
485 	{ "volume_down", 3, EV_KEY, KEY_VOLUMEDOWN, true, false, true },
486 	{ }
487 };
488 
489 static const struct soc_device_data soc_device_MSHW0028 = {
490 	.button_info = soc_button_MSHW0028,
491 };
492 
493 /*
494  * Special device check for Surface Book 2 and Surface Pro (2017).
495  * Both, the Surface Pro 4 (surfacepro3_button.c) and the above mentioned
496  * devices use MSHW0040 for power and volume buttons, however the way they
497  * have to be addressed differs. Make sure that we only load this drivers
498  * for the correct devices by checking the OEM Platform Revision provided by
499  * the _DSM method.
500  */
501 #define MSHW0040_DSM_REVISION		0x01
502 #define MSHW0040_DSM_GET_OMPR		0x02	// get OEM Platform Revision
503 static const guid_t MSHW0040_DSM_UUID =
504 	GUID_INIT(0x6fd05c69, 0xcde3, 0x49f4, 0x95, 0xed, 0xab, 0x16, 0x65,
505 		  0x49, 0x80, 0x35);
506 
507 static int soc_device_check_MSHW0040(struct device *dev)
508 {
509 	acpi_handle handle = ACPI_HANDLE(dev);
510 	union acpi_object *result;
511 	u64 oem_platform_rev = 0;	// valid revisions are nonzero
512 
513 	// get OEM platform revision
514 	result = acpi_evaluate_dsm_typed(handle, &MSHW0040_DSM_UUID,
515 					 MSHW0040_DSM_REVISION,
516 					 MSHW0040_DSM_GET_OMPR, NULL,
517 					 ACPI_TYPE_INTEGER);
518 
519 	if (result) {
520 		oem_platform_rev = result->integer.value;
521 		ACPI_FREE(result);
522 	}
523 
524 	/*
525 	 * If the revision is zero here, the _DSM evaluation has failed. This
526 	 * indicates that we have a Pro 4 or Book 1 and this driver should not
527 	 * be used.
528 	 */
529 	if (oem_platform_rev == 0)
530 		return -ENODEV;
531 
532 	dev_dbg(dev, "OEM Platform Revision %llu\n", oem_platform_rev);
533 
534 	return 0;
535 }
536 
537 /*
538  * Button infos for Microsoft Surface Book 2 and Surface Pro (2017).
539  * Obtained from DSDT/testing.
540  */
541 static const struct soc_button_info soc_button_MSHW0040[] = {
542 	{ "power", 0, EV_KEY, KEY_POWER, false, true, true },
543 	{ "volume_up", 2, EV_KEY, KEY_VOLUMEUP, true, false, true },
544 	{ "volume_down", 4, EV_KEY, KEY_VOLUMEDOWN, true, false, true },
545 	{ }
546 };
547 
548 static const struct soc_device_data soc_device_MSHW0040 = {
549 	.button_info = soc_button_MSHW0040,
550 	.check = soc_device_check_MSHW0040,
551 };
552 
553 static const struct acpi_device_id soc_button_acpi_match[] = {
554 	{ "PNP0C40", (unsigned long)&soc_device_PNP0C40 },
555 	{ "INT33D3", (unsigned long)&soc_device_INT33D3 },
556 	{ "ID9001", (unsigned long)&soc_device_INT33D3 },
557 	{ "ACPI0011", 0 },
558 
559 	/* Microsoft Surface Devices (3th, 5th and 6th generation) */
560 	{ "MSHW0028", (unsigned long)&soc_device_MSHW0028 },
561 	{ "MSHW0040", (unsigned long)&soc_device_MSHW0040 },
562 
563 	{ }
564 };
565 
566 MODULE_DEVICE_TABLE(acpi, soc_button_acpi_match);
567 
568 static struct platform_driver soc_button_driver = {
569 	.probe          = soc_button_probe,
570 	.remove		= soc_button_remove,
571 	.driver		= {
572 		.name = KBUILD_MODNAME,
573 		.acpi_match_table = ACPI_PTR(soc_button_acpi_match),
574 	},
575 };
576 module_platform_driver(soc_button_driver);
577 
578 MODULE_LICENSE("GPL");
579