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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
21static bool use_low_level_irq;
22module_param(use_low_level_irq, bool, 0444);
23MODULE_PARM_DESC(use_low_level_irq, "Use low-level triggered IRQ instead of edge triggered");
24
25struct soc_button_info {
26 const char *name;
27 int acpi_index;
28 unsigned int event_type;
29 unsigned int event_code;
30 bool autorepeat;
31 bool wakeup;
32 bool active_low;
33};
34
35struct soc_device_data {
36 const struct soc_button_info *button_info;
37 int (*check)(struct device *dev);
38};
39
40/*
41 * Some of the buttons like volume up/down are auto repeat, while others
42 * are not. To support both, we register two platform devices, and put
43 * buttons into them based on whether the key should be auto repeat.
44 */
45#define BUTTON_TYPES 2
46
47struct soc_button_data {
48 struct platform_device *children[BUTTON_TYPES];
49};
50
51/*
52 * Some 2-in-1s which use the soc_button_array driver have this ugly issue in
53 * their DSDT where the _LID method modifies the irq-type settings of the GPIOs
54 * used for the power and home buttons. The intend of this AML code is to
55 * disable these buttons when the lid is closed.
56 * The AML does this by directly poking the GPIO controllers registers. This is
57 * problematic because when re-enabling the irq, which happens whenever _LID
58 * gets called with the lid open (e.g. on boot and on resume), it sets the
59 * irq-type to IRQ_TYPE_LEVEL_LOW. Where as the gpio-keys driver programs the
60 * type to, and expects it to be, IRQ_TYPE_EDGE_BOTH.
61 * To work around this we don't set gpio_keys_button.gpio on these 2-in-1s,
62 * instead we get the irq for the GPIO ourselves, configure it as
63 * IRQ_TYPE_LEVEL_LOW (to match how the _LID AML code configures it) and pass
64 * the irq in gpio_keys_button.irq. Below is a list of affected devices.
65 */
66static const struct dmi_system_id dmi_use_low_level_irq[] = {
67 {
68 /*
69 * Acer Switch 10 SW5-012. _LID method messes with home- and
70 * power-button GPIO IRQ settings. When (re-)enabling the irq
71 * it ors in its own flags without clearing the previous set
72 * ones, leading to an irq-type of IRQ_TYPE_LEVEL_LOW |
73 * IRQ_TYPE_LEVEL_HIGH causing a continuous interrupt storm.
74 */
75 .matches = {
76 DMI_MATCH(DMI_SYS_VENDOR, "Acer"),
77 DMI_MATCH(DMI_PRODUCT_NAME, "Aspire SW5-012"),
78 },
79 },
80 {
81 /* Acer Switch V 10 SW5-017, same issue as Acer Switch 10 SW5-012. */
82 .matches = {
83 DMI_MATCH(DMI_SYS_VENDOR, "Acer"),
84 DMI_MATCH(DMI_PRODUCT_NAME, "SW5-017"),
85 },
86 },
87 {
88 /*
89 * Acer One S1003. _LID method messes with power-button GPIO
90 * IRQ settings, leading to a non working power-button.
91 */
92 .matches = {
93 DMI_MATCH(DMI_SYS_VENDOR, "Acer"),
94 DMI_MATCH(DMI_PRODUCT_NAME, "One S1003"),
95 },
96 },
97 {
98 /*
99 * Lenovo Yoga Tab2 1051F/1051L, something messes with the home-button
100 * IRQ settings, leading to a non working home-button.
101 */
102 .matches = {
103 DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
104 DMI_MATCH(DMI_PRODUCT_NAME, "60073"),
105 DMI_MATCH(DMI_PRODUCT_VERSION, "1051"),
106 },
107 },
108 {} /* Terminating entry */
109};
110
111/*
112 * Get the Nth GPIO number from the ACPI object.
113 */
114static int soc_button_lookup_gpio(struct device *dev, int acpi_index,
115 int *gpio_ret, int *irq_ret)
116{
117 struct gpio_desc *desc;
118
119 desc = gpiod_get_index(dev, NULL, acpi_index, GPIOD_ASIS);
120 if (IS_ERR(desc))
121 return PTR_ERR(desc);
122
123 *gpio_ret = desc_to_gpio(desc);
124 *irq_ret = gpiod_to_irq(desc);
125
126 gpiod_put(desc);
127
128 return 0;
129}
130
131static struct platform_device *
132soc_button_device_create(struct platform_device *pdev,
133 const struct soc_button_info *button_info,
134 bool autorepeat)
135{
136 const struct soc_button_info *info;
137 struct platform_device *pd;
138 struct gpio_keys_button *gpio_keys;
139 struct gpio_keys_platform_data *gpio_keys_pdata;
140 int error, gpio, irq;
141 int n_buttons = 0;
142
143 for (info = button_info; info->name; info++)
144 if (info->autorepeat == autorepeat)
145 n_buttons++;
146
147 gpio_keys_pdata = devm_kzalloc(&pdev->dev,
148 sizeof(*gpio_keys_pdata) +
149 sizeof(*gpio_keys) * n_buttons,
150 GFP_KERNEL);
151 if (!gpio_keys_pdata)
152 return ERR_PTR(-ENOMEM);
153
154 gpio_keys = (void *)(gpio_keys_pdata + 1);
155 n_buttons = 0;
156
157 for (info = button_info; info->name; info++) {
158 if (info->autorepeat != autorepeat)
159 continue;
160
161 error = soc_button_lookup_gpio(&pdev->dev, info->acpi_index, &gpio, &irq);
162 if (error || irq < 0) {
163 /*
164 * Skip GPIO if not present. Note we deliberately
165 * ignore -EPROBE_DEFER errors here. On some devices
166 * Intel is using so called virtual GPIOs which are not
167 * GPIOs at all but some way for AML code to check some
168 * random status bits without need a custom opregion.
169 * In some cases the resources table we parse points to
170 * such a virtual GPIO, since these are not real GPIOs
171 * we do not have a driver for these so they will never
172 * show up, therefore we ignore -EPROBE_DEFER.
173 */
174 continue;
175 }
176
177 /* See dmi_use_low_level_irq[] comment */
178 if (!autorepeat && (use_low_level_irq ||
179 dmi_check_system(dmi_use_low_level_irq))) {
180 irq_set_irq_type(irq, IRQ_TYPE_LEVEL_LOW);
181 gpio_keys[n_buttons].irq = irq;
182 gpio_keys[n_buttons].gpio = -ENOENT;
183 } else {
184 gpio_keys[n_buttons].gpio = gpio;
185 }
186
187 gpio_keys[n_buttons].type = info->event_type;
188 gpio_keys[n_buttons].code = info->event_code;
189 gpio_keys[n_buttons].active_low = info->active_low;
190 gpio_keys[n_buttons].desc = info->name;
191 gpio_keys[n_buttons].wakeup = info->wakeup;
192 /* These devices often use cheap buttons, use 50 ms debounce */
193 gpio_keys[n_buttons].debounce_interval = 50;
194 n_buttons++;
195 }
196
197 if (n_buttons == 0) {
198 error = -ENODEV;
199 goto err_free_mem;
200 }
201
202 gpio_keys_pdata->buttons = gpio_keys;
203 gpio_keys_pdata->nbuttons = n_buttons;
204 gpio_keys_pdata->rep = autorepeat;
205
206 pd = platform_device_register_resndata(&pdev->dev, "gpio-keys",
207 PLATFORM_DEVID_AUTO, NULL, 0,
208 gpio_keys_pdata,
209 sizeof(*gpio_keys_pdata));
210 error = PTR_ERR_OR_ZERO(pd);
211 if (error) {
212 dev_err(&pdev->dev,
213 "failed registering gpio-keys: %d\n", error);
214 goto err_free_mem;
215 }
216
217 return pd;
218
219err_free_mem:
220 devm_kfree(&pdev->dev, gpio_keys_pdata);
221 return ERR_PTR(error);
222}
223
224static int soc_button_get_acpi_object_int(const union acpi_object *obj)
225{
226 if (obj->type != ACPI_TYPE_INTEGER)
227 return -1;
228
229 return obj->integer.value;
230}
231
232/* Parse a single ACPI0011 _DSD button descriptor */
233static int soc_button_parse_btn_desc(struct device *dev,
234 const union acpi_object *desc,
235 int collection_uid,
236 struct soc_button_info *info)
237{
238 int upage, usage;
239
240 if (desc->type != ACPI_TYPE_PACKAGE ||
241 desc->package.count != 5 ||
242 /* First byte should be 1 (control) */
243 soc_button_get_acpi_object_int(&desc->package.elements[0]) != 1 ||
244 /* Third byte should be collection uid */
245 soc_button_get_acpi_object_int(&desc->package.elements[2]) !=
246 collection_uid) {
247 dev_err(dev, "Invalid ACPI Button Descriptor\n");
248 return -ENODEV;
249 }
250
251 info->event_type = EV_KEY;
252 info->active_low = true;
253 info->acpi_index =
254 soc_button_get_acpi_object_int(&desc->package.elements[1]);
255 upage = soc_button_get_acpi_object_int(&desc->package.elements[3]);
256 usage = soc_button_get_acpi_object_int(&desc->package.elements[4]);
257
258 /*
259 * The UUID: fa6bd625-9ce8-470d-a2c7-b3ca36c4282e descriptors use HID
260 * usage page and usage codes, but otherwise the device is not HID
261 * compliant: it uses one irq per button instead of generating HID
262 * input reports and some buttons should generate wakeups where as
263 * others should not, so we cannot use the HID subsystem.
264 *
265 * Luckily all devices only use a few usage page + usage combinations,
266 * so we can simply check for the known combinations here.
267 */
268 if (upage == 0x01 && usage == 0x81) {
269 info->name = "power";
270 info->event_code = KEY_POWER;
271 info->wakeup = true;
272 } else if (upage == 0x01 && usage == 0xca) {
273 info->name = "rotation lock switch";
274 info->event_type = EV_SW;
275 info->event_code = SW_ROTATE_LOCK;
276 } else if (upage == 0x07 && usage == 0xe3) {
277 info->name = "home";
278 info->event_code = KEY_LEFTMETA;
279 info->wakeup = true;
280 } else if (upage == 0x0c && usage == 0xe9) {
281 info->name = "volume_up";
282 info->event_code = KEY_VOLUMEUP;
283 info->autorepeat = true;
284 } else if (upage == 0x0c && usage == 0xea) {
285 info->name = "volume_down";
286 info->event_code = KEY_VOLUMEDOWN;
287 info->autorepeat = true;
288 } else {
289 dev_warn(dev, "Unknown button index %d upage %02x usage %02x, ignoring\n",
290 info->acpi_index, upage, usage);
291 info->name = "unknown";
292 info->event_code = KEY_RESERVED;
293 }
294
295 return 0;
296}
297
298/* ACPI0011 _DSD btns descriptors UUID: fa6bd625-9ce8-470d-a2c7-b3ca36c4282e */
299static const u8 btns_desc_uuid[16] = {
300 0x25, 0xd6, 0x6b, 0xfa, 0xe8, 0x9c, 0x0d, 0x47,
301 0xa2, 0xc7, 0xb3, 0xca, 0x36, 0xc4, 0x28, 0x2e
302};
303
304/* Parse ACPI0011 _DSD button descriptors */
305static struct soc_button_info *soc_button_get_button_info(struct device *dev)
306{
307 struct acpi_buffer buf = { ACPI_ALLOCATE_BUFFER };
308 const union acpi_object *desc, *el0, *uuid, *btns_desc = NULL;
309 struct soc_button_info *button_info;
310 acpi_status status;
311 int i, btn, collection_uid = -1;
312
313 status = acpi_evaluate_object_typed(ACPI_HANDLE(dev), "_DSD", NULL,
314 &buf, ACPI_TYPE_PACKAGE);
315 if (ACPI_FAILURE(status)) {
316 dev_err(dev, "ACPI _DSD object not found\n");
317 return ERR_PTR(-ENODEV);
318 }
319
320 /* Look for the Button Descriptors UUID */
321 desc = buf.pointer;
322 for (i = 0; (i + 1) < desc->package.count; i += 2) {
323 uuid = &desc->package.elements[i];
324
325 if (uuid->type != ACPI_TYPE_BUFFER ||
326 uuid->buffer.length != 16 ||
327 desc->package.elements[i + 1].type != ACPI_TYPE_PACKAGE) {
328 break;
329 }
330
331 if (memcmp(uuid->buffer.pointer, btns_desc_uuid, 16) == 0) {
332 btns_desc = &desc->package.elements[i + 1];
333 break;
334 }
335 }
336
337 if (!btns_desc) {
338 dev_err(dev, "ACPI Button Descriptors not found\n");
339 button_info = ERR_PTR(-ENODEV);
340 goto out;
341 }
342
343 /* The first package describes the collection */
344 el0 = &btns_desc->package.elements[0];
345 if (el0->type == ACPI_TYPE_PACKAGE &&
346 el0->package.count == 5 &&
347 /* First byte should be 0 (collection) */
348 soc_button_get_acpi_object_int(&el0->package.elements[0]) == 0 &&
349 /* Third byte should be 0 (top level collection) */
350 soc_button_get_acpi_object_int(&el0->package.elements[2]) == 0) {
351 collection_uid = soc_button_get_acpi_object_int(
352 &el0->package.elements[1]);
353 }
354 if (collection_uid == -1) {
355 dev_err(dev, "Invalid Button Collection Descriptor\n");
356 button_info = ERR_PTR(-ENODEV);
357 goto out;
358 }
359
360 /* There are package.count - 1 buttons + 1 terminating empty entry */
361 button_info = devm_kcalloc(dev, btns_desc->package.count,
362 sizeof(*button_info), GFP_KERNEL);
363 if (!button_info) {
364 button_info = ERR_PTR(-ENOMEM);
365 goto out;
366 }
367
368 /* Parse the button descriptors */
369 for (i = 1, btn = 0; i < btns_desc->package.count; i++, btn++) {
370 if (soc_button_parse_btn_desc(dev,
371 &btns_desc->package.elements[i],
372 collection_uid,
373 &button_info[btn])) {
374 button_info = ERR_PTR(-ENODEV);
375 goto out;
376 }
377 }
378
379out:
380 kfree(buf.pointer);
381 return button_info;
382}
383
384static int soc_button_remove(struct platform_device *pdev)
385{
386 struct soc_button_data *priv = platform_get_drvdata(pdev);
387
388 int i;
389
390 for (i = 0; i < BUTTON_TYPES; i++)
391 if (priv->children[i])
392 platform_device_unregister(priv->children[i]);
393
394 return 0;
395}
396
397static int soc_button_probe(struct platform_device *pdev)
398{
399 struct device *dev = &pdev->dev;
400 const struct soc_device_data *device_data;
401 const struct soc_button_info *button_info;
402 struct soc_button_data *priv;
403 struct platform_device *pd;
404 int i;
405 int error;
406
407 device_data = acpi_device_get_match_data(dev);
408 if (device_data && device_data->check) {
409 error = device_data->check(dev);
410 if (error)
411 return error;
412 }
413
414 if (device_data && device_data->button_info) {
415 button_info = device_data->button_info;
416 } else {
417 button_info = soc_button_get_button_info(dev);
418 if (IS_ERR(button_info))
419 return PTR_ERR(button_info);
420 }
421
422 error = gpiod_count(dev, NULL);
423 if (error < 0) {
424 dev_dbg(dev, "no GPIO attached, ignoring...\n");
425 return -ENODEV;
426 }
427
428 priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
429 if (!priv)
430 return -ENOMEM;
431
432 platform_set_drvdata(pdev, priv);
433
434 for (i = 0; i < BUTTON_TYPES; i++) {
435 pd = soc_button_device_create(pdev, button_info, i == 0);
436 if (IS_ERR(pd)) {
437 error = PTR_ERR(pd);
438 if (error != -ENODEV) {
439 soc_button_remove(pdev);
440 return error;
441 }
442 continue;
443 }
444
445 priv->children[i] = pd;
446 }
447
448 if (!priv->children[0] && !priv->children[1])
449 return -ENODEV;
450
451 if (!device_data || !device_data->button_info)
452 devm_kfree(dev, button_info);
453
454 return 0;
455}
456
457/*
458 * Definition of buttons on the tablet. The ACPI index of each button
459 * is defined in section 2.8.7.2 of "Windows ACPI Design Guide for SoC
460 * Platforms"
461 */
462static const struct soc_button_info soc_button_PNP0C40[] = {
463 { "power", 0, EV_KEY, KEY_POWER, false, true, true },
464 { "home", 1, EV_KEY, KEY_LEFTMETA, false, true, true },
465 { "volume_up", 2, EV_KEY, KEY_VOLUMEUP, true, false, true },
466 { "volume_down", 3, EV_KEY, KEY_VOLUMEDOWN, true, false, true },
467 { "rotation_lock", 4, EV_KEY, KEY_ROTATE_LOCK_TOGGLE, false, false, true },
468 { }
469};
470
471static const struct soc_device_data soc_device_PNP0C40 = {
472 .button_info = soc_button_PNP0C40,
473};
474
475static const struct soc_button_info soc_button_INT33D3[] = {
476 { "tablet_mode", 0, EV_SW, SW_TABLET_MODE, false, false, false },
477 { }
478};
479
480static const struct soc_device_data soc_device_INT33D3 = {
481 .button_info = soc_button_INT33D3,
482};
483
484/*
485 * Button info for Microsoft Surface 3 (non pro), this is indentical to
486 * the PNP0C40 info except that the home button is active-high.
487 *
488 * The Surface 3 Pro also has a MSHW0028 ACPI device, but that uses a custom
489 * version of the drivers/platform/x86/intel/hid.c 5 button array ACPI API
490 * instead. A check() callback is not necessary though as the Surface 3 Pro
491 * MSHW0028 ACPI device's resource table does not contain any GPIOs.
492 */
493static const struct soc_button_info soc_button_MSHW0028[] = {
494 { "power", 0, EV_KEY, KEY_POWER, false, true, true },
495 { "home", 1, EV_KEY, KEY_LEFTMETA, false, true, false },
496 { "volume_up", 2, EV_KEY, KEY_VOLUMEUP, true, false, true },
497 { "volume_down", 3, EV_KEY, KEY_VOLUMEDOWN, true, false, true },
498 { }
499};
500
501static const struct soc_device_data soc_device_MSHW0028 = {
502 .button_info = soc_button_MSHW0028,
503};
504
505/*
506 * Special device check for Surface Book 2 and Surface Pro (2017).
507 * Both, the Surface Pro 4 (surfacepro3_button.c) and the above mentioned
508 * devices use MSHW0040 for power and volume buttons, however the way they
509 * have to be addressed differs. Make sure that we only load this drivers
510 * for the correct devices by checking the OEM Platform Revision provided by
511 * the _DSM method.
512 */
513#define MSHW0040_DSM_REVISION 0x01
514#define MSHW0040_DSM_GET_OMPR 0x02 // get OEM Platform Revision
515static const guid_t MSHW0040_DSM_UUID =
516 GUID_INIT(0x6fd05c69, 0xcde3, 0x49f4, 0x95, 0xed, 0xab, 0x16, 0x65,
517 0x49, 0x80, 0x35);
518
519static int soc_device_check_MSHW0040(struct device *dev)
520{
521 acpi_handle handle = ACPI_HANDLE(dev);
522 union acpi_object *result;
523 u64 oem_platform_rev = 0; // valid revisions are nonzero
524
525 // get OEM platform revision
526 result = acpi_evaluate_dsm_typed(handle, &MSHW0040_DSM_UUID,
527 MSHW0040_DSM_REVISION,
528 MSHW0040_DSM_GET_OMPR, NULL,
529 ACPI_TYPE_INTEGER);
530
531 if (result) {
532 oem_platform_rev = result->integer.value;
533 ACPI_FREE(result);
534 }
535
536 /*
537 * If the revision is zero here, the _DSM evaluation has failed. This
538 * indicates that we have a Pro 4 or Book 1 and this driver should not
539 * be used.
540 */
541 if (oem_platform_rev == 0)
542 return -ENODEV;
543
544 dev_dbg(dev, "OEM Platform Revision %llu\n", oem_platform_rev);
545
546 return 0;
547}
548
549/*
550 * Button infos for Microsoft Surface Book 2 and Surface Pro (2017).
551 * Obtained from DSDT/testing.
552 */
553static const struct soc_button_info soc_button_MSHW0040[] = {
554 { "power", 0, EV_KEY, KEY_POWER, false, true, true },
555 { "volume_up", 2, EV_KEY, KEY_VOLUMEUP, true, false, true },
556 { "volume_down", 4, EV_KEY, KEY_VOLUMEDOWN, true, false, true },
557 { }
558};
559
560static const struct soc_device_data soc_device_MSHW0040 = {
561 .button_info = soc_button_MSHW0040,
562 .check = soc_device_check_MSHW0040,
563};
564
565static const struct acpi_device_id soc_button_acpi_match[] = {
566 { "PNP0C40", (unsigned long)&soc_device_PNP0C40 },
567 { "INT33D3", (unsigned long)&soc_device_INT33D3 },
568 { "ID9001", (unsigned long)&soc_device_INT33D3 },
569 { "ACPI0011", 0 },
570
571 /* Microsoft Surface Devices (3th, 5th and 6th generation) */
572 { "MSHW0028", (unsigned long)&soc_device_MSHW0028 },
573 { "MSHW0040", (unsigned long)&soc_device_MSHW0040 },
574
575 { }
576};
577
578MODULE_DEVICE_TABLE(acpi, soc_button_acpi_match);
579
580static struct platform_driver soc_button_driver = {
581 .probe = soc_button_probe,
582 .remove = soc_button_remove,
583 .driver = {
584 .name = KBUILD_MODNAME,
585 .acpi_match_table = ACPI_PTR(soc_button_acpi_match),
586 },
587};
588module_platform_driver(soc_button_driver);
589
590MODULE_LICENSE("GPL");
1/*
2 * Supports for the button array on SoC tablets originally running
3 * Windows 8.
4 *
5 * (C) Copyright 2014 Intel Corporation
6 *
7 * This program is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License
9 * as published by the Free Software Foundation; version 2
10 * of the License.
11 */
12
13#include <linux/module.h>
14#include <linux/input.h>
15#include <linux/init.h>
16#include <linux/kernel.h>
17#include <linux/acpi.h>
18#include <linux/gpio/consumer.h>
19#include <linux/gpio_keys.h>
20#include <linux/gpio.h>
21#include <linux/platform_device.h>
22
23struct soc_button_info {
24 const char *name;
25 int acpi_index;
26 unsigned int event_type;
27 unsigned int event_code;
28 bool autorepeat;
29 bool wakeup;
30};
31
32/*
33 * Some of the buttons like volume up/down are auto repeat, while others
34 * are not. To support both, we register two platform devices, and put
35 * buttons into them based on whether the key should be auto repeat.
36 */
37#define BUTTON_TYPES 2
38
39struct soc_button_data {
40 struct platform_device *children[BUTTON_TYPES];
41};
42
43/*
44 * Get the Nth GPIO number from the ACPI object.
45 */
46static int soc_button_lookup_gpio(struct device *dev, int acpi_index)
47{
48 struct gpio_desc *desc;
49 int gpio;
50
51 desc = gpiod_get_index(dev, NULL, acpi_index, GPIOD_ASIS);
52 if (IS_ERR(desc))
53 return PTR_ERR(desc);
54
55 gpio = desc_to_gpio(desc);
56
57 gpiod_put(desc);
58
59 return gpio;
60}
61
62static struct platform_device *
63soc_button_device_create(struct platform_device *pdev,
64 const struct soc_button_info *button_info,
65 bool autorepeat)
66{
67 const struct soc_button_info *info;
68 struct platform_device *pd;
69 struct gpio_keys_button *gpio_keys;
70 struct gpio_keys_platform_data *gpio_keys_pdata;
71 int n_buttons = 0;
72 int gpio;
73 int error;
74
75 for (info = button_info; info->name; info++)
76 if (info->autorepeat == autorepeat)
77 n_buttons++;
78
79 gpio_keys_pdata = devm_kzalloc(&pdev->dev,
80 sizeof(*gpio_keys_pdata) +
81 sizeof(*gpio_keys) * n_buttons,
82 GFP_KERNEL);
83 if (!gpio_keys_pdata)
84 return ERR_PTR(-ENOMEM);
85
86 gpio_keys = (void *)(gpio_keys_pdata + 1);
87 n_buttons = 0;
88
89 for (info = button_info; info->name; info++) {
90 if (info->autorepeat != autorepeat)
91 continue;
92
93 gpio = soc_button_lookup_gpio(&pdev->dev, info->acpi_index);
94 if (!gpio_is_valid(gpio))
95 continue;
96
97 gpio_keys[n_buttons].type = info->event_type;
98 gpio_keys[n_buttons].code = info->event_code;
99 gpio_keys[n_buttons].gpio = gpio;
100 gpio_keys[n_buttons].active_low = 1;
101 gpio_keys[n_buttons].desc = info->name;
102 gpio_keys[n_buttons].wakeup = info->wakeup;
103 /* These devices often use cheap buttons, use 50 ms debounce */
104 gpio_keys[n_buttons].debounce_interval = 50;
105 n_buttons++;
106 }
107
108 if (n_buttons == 0) {
109 error = -ENODEV;
110 goto err_free_mem;
111 }
112
113 gpio_keys_pdata->buttons = gpio_keys;
114 gpio_keys_pdata->nbuttons = n_buttons;
115 gpio_keys_pdata->rep = autorepeat;
116
117 pd = platform_device_alloc("gpio-keys", PLATFORM_DEVID_AUTO);
118 if (!pd) {
119 error = -ENOMEM;
120 goto err_free_mem;
121 }
122
123 error = platform_device_add_data(pd, gpio_keys_pdata,
124 sizeof(*gpio_keys_pdata));
125 if (error)
126 goto err_free_pdev;
127
128 error = platform_device_add(pd);
129 if (error)
130 goto err_free_pdev;
131
132 return pd;
133
134err_free_pdev:
135 platform_device_put(pd);
136err_free_mem:
137 devm_kfree(&pdev->dev, gpio_keys_pdata);
138 return ERR_PTR(error);
139}
140
141static int soc_button_get_acpi_object_int(const union acpi_object *obj)
142{
143 if (obj->type != ACPI_TYPE_INTEGER)
144 return -1;
145
146 return obj->integer.value;
147}
148
149/* Parse a single ACPI0011 _DSD button descriptor */
150static int soc_button_parse_btn_desc(struct device *dev,
151 const union acpi_object *desc,
152 int collection_uid,
153 struct soc_button_info *info)
154{
155 int upage, usage;
156
157 if (desc->type != ACPI_TYPE_PACKAGE ||
158 desc->package.count != 5 ||
159 /* First byte should be 1 (control) */
160 soc_button_get_acpi_object_int(&desc->package.elements[0]) != 1 ||
161 /* Third byte should be collection uid */
162 soc_button_get_acpi_object_int(&desc->package.elements[2]) !=
163 collection_uid) {
164 dev_err(dev, "Invalid ACPI Button Descriptor\n");
165 return -ENODEV;
166 }
167
168 info->event_type = EV_KEY;
169 info->acpi_index =
170 soc_button_get_acpi_object_int(&desc->package.elements[1]);
171 upage = soc_button_get_acpi_object_int(&desc->package.elements[3]);
172 usage = soc_button_get_acpi_object_int(&desc->package.elements[4]);
173
174 /*
175 * The UUID: fa6bd625-9ce8-470d-a2c7-b3ca36c4282e descriptors use HID
176 * usage page and usage codes, but otherwise the device is not HID
177 * compliant: it uses one irq per button instead of generating HID
178 * input reports and some buttons should generate wakeups where as
179 * others should not, so we cannot use the HID subsystem.
180 *
181 * Luckily all devices only use a few usage page + usage combinations,
182 * so we can simply check for the known combinations here.
183 */
184 if (upage == 0x01 && usage == 0x81) {
185 info->name = "power";
186 info->event_code = KEY_POWER;
187 info->wakeup = true;
188 } else if (upage == 0x07 && usage == 0xe3) {
189 info->name = "home";
190 info->event_code = KEY_LEFTMETA;
191 info->wakeup = true;
192 } else if (upage == 0x0c && usage == 0xe9) {
193 info->name = "volume_up";
194 info->event_code = KEY_VOLUMEUP;
195 info->autorepeat = true;
196 } else if (upage == 0x0c && usage == 0xea) {
197 info->name = "volume_down";
198 info->event_code = KEY_VOLUMEDOWN;
199 info->autorepeat = true;
200 } else {
201 dev_warn(dev, "Unknown button index %d upage %02x usage %02x, ignoring\n",
202 info->acpi_index, upage, usage);
203 info->name = "unknown";
204 info->event_code = KEY_RESERVED;
205 }
206
207 return 0;
208}
209
210/* ACPI0011 _DSD btns descriptors UUID: fa6bd625-9ce8-470d-a2c7-b3ca36c4282e */
211static const u8 btns_desc_uuid[16] = {
212 0x25, 0xd6, 0x6b, 0xfa, 0xe8, 0x9c, 0x0d, 0x47,
213 0xa2, 0xc7, 0xb3, 0xca, 0x36, 0xc4, 0x28, 0x2e
214};
215
216/* Parse ACPI0011 _DSD button descriptors */
217static struct soc_button_info *soc_button_get_button_info(struct device *dev)
218{
219 struct acpi_buffer buf = { ACPI_ALLOCATE_BUFFER };
220 const union acpi_object *desc, *el0, *uuid, *btns_desc = NULL;
221 struct soc_button_info *button_info;
222 acpi_status status;
223 int i, btn, collection_uid = -1;
224
225 status = acpi_evaluate_object_typed(ACPI_HANDLE(dev), "_DSD", NULL,
226 &buf, ACPI_TYPE_PACKAGE);
227 if (ACPI_FAILURE(status)) {
228 dev_err(dev, "ACPI _DSD object not found\n");
229 return ERR_PTR(-ENODEV);
230 }
231
232 /* Look for the Button Descriptors UUID */
233 desc = buf.pointer;
234 for (i = 0; (i + 1) < desc->package.count; i += 2) {
235 uuid = &desc->package.elements[i];
236
237 if (uuid->type != ACPI_TYPE_BUFFER ||
238 uuid->buffer.length != 16 ||
239 desc->package.elements[i + 1].type != ACPI_TYPE_PACKAGE) {
240 break;
241 }
242
243 if (memcmp(uuid->buffer.pointer, btns_desc_uuid, 16) == 0) {
244 btns_desc = &desc->package.elements[i + 1];
245 break;
246 }
247 }
248
249 if (!btns_desc) {
250 dev_err(dev, "ACPI Button Descriptors not found\n");
251 button_info = ERR_PTR(-ENODEV);
252 goto out;
253 }
254
255 /* The first package describes the collection */
256 el0 = &btns_desc->package.elements[0];
257 if (el0->type == ACPI_TYPE_PACKAGE &&
258 el0->package.count == 5 &&
259 /* First byte should be 0 (collection) */
260 soc_button_get_acpi_object_int(&el0->package.elements[0]) == 0 &&
261 /* Third byte should be 0 (top level collection) */
262 soc_button_get_acpi_object_int(&el0->package.elements[2]) == 0) {
263 collection_uid = soc_button_get_acpi_object_int(
264 &el0->package.elements[1]);
265 }
266 if (collection_uid == -1) {
267 dev_err(dev, "Invalid Button Collection Descriptor\n");
268 button_info = ERR_PTR(-ENODEV);
269 goto out;
270 }
271
272 /* There are package.count - 1 buttons + 1 terminating empty entry */
273 button_info = devm_kcalloc(dev, btns_desc->package.count,
274 sizeof(*button_info), GFP_KERNEL);
275 if (!button_info) {
276 button_info = ERR_PTR(-ENOMEM);
277 goto out;
278 }
279
280 /* Parse the button descriptors */
281 for (i = 1, btn = 0; i < btns_desc->package.count; i++, btn++) {
282 if (soc_button_parse_btn_desc(dev,
283 &btns_desc->package.elements[i],
284 collection_uid,
285 &button_info[btn])) {
286 button_info = ERR_PTR(-ENODEV);
287 goto out;
288 }
289 }
290
291out:
292 kfree(buf.pointer);
293 return button_info;
294}
295
296static int soc_button_remove(struct platform_device *pdev)
297{
298 struct soc_button_data *priv = platform_get_drvdata(pdev);
299
300 int i;
301
302 for (i = 0; i < BUTTON_TYPES; i++)
303 if (priv->children[i])
304 platform_device_unregister(priv->children[i]);
305
306 return 0;
307}
308
309static int soc_button_probe(struct platform_device *pdev)
310{
311 struct device *dev = &pdev->dev;
312 const struct acpi_device_id *id;
313 struct soc_button_info *button_info;
314 struct soc_button_data *priv;
315 struct platform_device *pd;
316 int i;
317 int error;
318
319 id = acpi_match_device(dev->driver->acpi_match_table, dev);
320 if (!id)
321 return -ENODEV;
322
323 if (!id->driver_data) {
324 button_info = soc_button_get_button_info(dev);
325 if (IS_ERR(button_info))
326 return PTR_ERR(button_info);
327 } else {
328 button_info = (struct soc_button_info *)id->driver_data;
329 }
330
331 error = gpiod_count(dev, NULL);
332 if (error < 0) {
333 dev_dbg(dev, "no GPIO attached, ignoring...\n");
334 return -ENODEV;
335 }
336
337 priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
338 if (!priv)
339 return -ENOMEM;
340
341 platform_set_drvdata(pdev, priv);
342
343 for (i = 0; i < BUTTON_TYPES; i++) {
344 pd = soc_button_device_create(pdev, button_info, i == 0);
345 if (IS_ERR(pd)) {
346 error = PTR_ERR(pd);
347 if (error != -ENODEV) {
348 soc_button_remove(pdev);
349 return error;
350 }
351 continue;
352 }
353
354 priv->children[i] = pd;
355 }
356
357 if (!priv->children[0] && !priv->children[1])
358 return -ENODEV;
359
360 if (!id->driver_data)
361 devm_kfree(dev, button_info);
362
363 return 0;
364}
365
366/*
367 * Definition of buttons on the tablet. The ACPI index of each button
368 * is defined in section 2.8.7.2 of "Windows ACPI Design Guide for SoC
369 * Platforms"
370 */
371static struct soc_button_info soc_button_PNP0C40[] = {
372 { "power", 0, EV_KEY, KEY_POWER, false, true },
373 { "home", 1, EV_KEY, KEY_LEFTMETA, false, true },
374 { "volume_up", 2, EV_KEY, KEY_VOLUMEUP, true, false },
375 { "volume_down", 3, EV_KEY, KEY_VOLUMEDOWN, true, false },
376 { "rotation_lock", 4, EV_SW, SW_ROTATE_LOCK, false, false },
377 { }
378};
379
380static const struct acpi_device_id soc_button_acpi_match[] = {
381 { "PNP0C40", (unsigned long)soc_button_PNP0C40 },
382 { "ACPI0011", 0 },
383 { }
384};
385
386MODULE_DEVICE_TABLE(acpi, soc_button_acpi_match);
387
388static struct platform_driver soc_button_driver = {
389 .probe = soc_button_probe,
390 .remove = soc_button_remove,
391 .driver = {
392 .name = KBUILD_MODNAME,
393 .acpi_match_table = ACPI_PTR(soc_button_acpi_match),
394 },
395};
396module_platform_driver(soc_button_driver);
397
398MODULE_LICENSE("GPL");