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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/platform_device.h>
21
22/*
23 * Definition of buttons on the tablet. The ACPI index of each button
24 * is defined in section 2.8.7.2 of "Windows ACPI Design Guide for SoC
25 * Platforms"
26 */
27#define MAX_NBUTTONS 5
28
29struct soc_button_info {
30 const char *name;
31 int acpi_index;
32 unsigned int event_type;
33 unsigned int event_code;
34 bool autorepeat;
35 bool wakeup;
36};
37
38/*
39 * Some of the buttons like volume up/down are auto repeat, while others
40 * are not. To support both, we register two platform devices, and put
41 * buttons into them based on whether the key should be auto repeat.
42 */
43#define BUTTON_TYPES 2
44
45struct soc_button_data {
46 struct platform_device *children[BUTTON_TYPES];
47};
48
49/*
50 * Get the Nth GPIO number from the ACPI object.
51 */
52static int soc_button_lookup_gpio(struct device *dev, int acpi_index)
53{
54 struct gpio_desc *desc;
55 int gpio;
56
57 desc = gpiod_get_index(dev, KBUILD_MODNAME, acpi_index, GPIOD_ASIS);
58 if (IS_ERR(desc))
59 return PTR_ERR(desc);
60
61 gpio = desc_to_gpio(desc);
62
63 gpiod_put(desc);
64
65 return gpio;
66}
67
68static struct platform_device *
69soc_button_device_create(struct platform_device *pdev,
70 const struct soc_button_info *button_info,
71 bool autorepeat)
72{
73 const struct soc_button_info *info;
74 struct platform_device *pd;
75 struct gpio_keys_button *gpio_keys;
76 struct gpio_keys_platform_data *gpio_keys_pdata;
77 int n_buttons = 0;
78 int gpio;
79 int error;
80
81 gpio_keys_pdata = devm_kzalloc(&pdev->dev,
82 sizeof(*gpio_keys_pdata) +
83 sizeof(*gpio_keys) * MAX_NBUTTONS,
84 GFP_KERNEL);
85 if (!gpio_keys_pdata)
86 return ERR_PTR(-ENOMEM);
87
88 gpio_keys = (void *)(gpio_keys_pdata + 1);
89
90 for (info = button_info; info->name; info++) {
91 if (info->autorepeat != autorepeat)
92 continue;
93
94 gpio = soc_button_lookup_gpio(&pdev->dev, info->acpi_index);
95 if (gpio < 0)
96 continue;
97
98 gpio_keys[n_buttons].type = info->event_type;
99 gpio_keys[n_buttons].code = info->event_code;
100 gpio_keys[n_buttons].gpio = gpio;
101 gpio_keys[n_buttons].active_low = 1;
102 gpio_keys[n_buttons].desc = info->name;
103 gpio_keys[n_buttons].wakeup = info->wakeup;
104 n_buttons++;
105 }
106
107 if (n_buttons == 0) {
108 error = -ENODEV;
109 goto err_free_mem;
110 }
111
112 gpio_keys_pdata->buttons = gpio_keys;
113 gpio_keys_pdata->nbuttons = n_buttons;
114 gpio_keys_pdata->rep = autorepeat;
115
116 pd = platform_device_alloc("gpio-keys", PLATFORM_DEVID_AUTO);
117 if (!pd) {
118 error = -ENOMEM;
119 goto err_free_mem;
120 }
121
122 error = platform_device_add_data(pd, gpio_keys_pdata,
123 sizeof(*gpio_keys_pdata));
124 if (error)
125 goto err_free_pdev;
126
127 error = platform_device_add(pd);
128 if (error)
129 goto err_free_pdev;
130
131 return pd;
132
133err_free_pdev:
134 platform_device_put(pd);
135err_free_mem:
136 devm_kfree(&pdev->dev, gpio_keys_pdata);
137 return ERR_PTR(error);
138}
139
140static int soc_button_remove(struct platform_device *pdev)
141{
142 struct soc_button_data *priv = platform_get_drvdata(pdev);
143
144 int i;
145
146 for (i = 0; i < BUTTON_TYPES; i++)
147 if (priv->children[i])
148 platform_device_unregister(priv->children[i]);
149
150 return 0;
151}
152
153static int soc_button_probe(struct platform_device *pdev)
154{
155 struct device *dev = &pdev->dev;
156 const struct acpi_device_id *id;
157 struct soc_button_info *button_info;
158 struct soc_button_data *priv;
159 struct platform_device *pd;
160 int i;
161 int error;
162
163 id = acpi_match_device(dev->driver->acpi_match_table, dev);
164 if (!id)
165 return -ENODEV;
166
167 button_info = (struct soc_button_info *)id->driver_data;
168
169 priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
170 if (!priv)
171 return -ENOMEM;
172
173 platform_set_drvdata(pdev, priv);
174
175 for (i = 0; i < BUTTON_TYPES; i++) {
176 pd = soc_button_device_create(pdev, button_info, i == 0);
177 if (IS_ERR(pd)) {
178 error = PTR_ERR(pd);
179 if (error != -ENODEV) {
180 soc_button_remove(pdev);
181 return error;
182 }
183 continue;
184 }
185
186 priv->children[i] = pd;
187 }
188
189 if (!priv->children[0] && !priv->children[1])
190 return -ENODEV;
191
192 return 0;
193}
194
195static struct soc_button_info soc_button_PNP0C40[] = {
196 { "power", 0, EV_KEY, KEY_POWER, false, true },
197 { "home", 1, EV_KEY, KEY_LEFTMETA, false, true },
198 { "volume_up", 2, EV_KEY, KEY_VOLUMEUP, true, false },
199 { "volume_down", 3, EV_KEY, KEY_VOLUMEDOWN, true, false },
200 { "rotation_lock", 4, EV_SW, SW_ROTATE_LOCK, false, false },
201 { }
202};
203
204static const struct acpi_device_id soc_button_acpi_match[] = {
205 { "PNP0C40", (unsigned long)soc_button_PNP0C40 },
206 { }
207};
208
209MODULE_DEVICE_TABLE(acpi, soc_button_acpi_match);
210
211static struct platform_driver soc_button_driver = {
212 .probe = soc_button_probe,
213 .remove = soc_button_remove,
214 .driver = {
215 .name = KBUILD_MODNAME,
216 .acpi_match_table = ACPI_PTR(soc_button_acpi_match),
217 },
218};
219module_platform_driver(soc_button_driver);
220
221MODULE_LICENSE("GPL");
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/kernel.h>
13#include <linux/acpi.h>
14#include <linux/gpio/consumer.h>
15#include <linux/gpio_keys.h>
16#include <linux/gpio.h>
17#include <linux/platform_device.h>
18
19struct soc_button_info {
20 const char *name;
21 int acpi_index;
22 unsigned int event_type;
23 unsigned int event_code;
24 bool autorepeat;
25 bool wakeup;
26};
27
28struct soc_device_data {
29 const struct soc_button_info *button_info;
30 int (*check)(struct device *dev);
31};
32
33/*
34 * Some of the buttons like volume up/down are auto repeat, while others
35 * are not. To support both, we register two platform devices, and put
36 * buttons into them based on whether the key should be auto repeat.
37 */
38#define BUTTON_TYPES 2
39
40struct soc_button_data {
41 struct platform_device *children[BUTTON_TYPES];
42};
43
44/*
45 * Get the Nth GPIO number from the ACPI object.
46 */
47static int soc_button_lookup_gpio(struct device *dev, int acpi_index)
48{
49 struct gpio_desc *desc;
50 int gpio;
51
52 desc = gpiod_get_index(dev, NULL, acpi_index, GPIOD_ASIS);
53 if (IS_ERR(desc))
54 return PTR_ERR(desc);
55
56 gpio = desc_to_gpio(desc);
57
58 gpiod_put(desc);
59
60 return gpio;
61}
62
63static struct platform_device *
64soc_button_device_create(struct platform_device *pdev,
65 const struct soc_button_info *button_info,
66 bool autorepeat)
67{
68 const struct soc_button_info *info;
69 struct platform_device *pd;
70 struct gpio_keys_button *gpio_keys;
71 struct gpio_keys_platform_data *gpio_keys_pdata;
72 int n_buttons = 0;
73 int gpio;
74 int error;
75
76 for (info = button_info; info->name; info++)
77 if (info->autorepeat == autorepeat)
78 n_buttons++;
79
80 gpio_keys_pdata = devm_kzalloc(&pdev->dev,
81 sizeof(*gpio_keys_pdata) +
82 sizeof(*gpio_keys) * n_buttons,
83 GFP_KERNEL);
84 if (!gpio_keys_pdata)
85 return ERR_PTR(-ENOMEM);
86
87 gpio_keys = (void *)(gpio_keys_pdata + 1);
88 n_buttons = 0;
89
90 for (info = button_info; info->name; info++) {
91 if (info->autorepeat != autorepeat)
92 continue;
93
94 gpio = soc_button_lookup_gpio(&pdev->dev, info->acpi_index);
95 if (!gpio_is_valid(gpio)) {
96 /*
97 * Skip GPIO if not present. Note we deliberately
98 * ignore -EPROBE_DEFER errors here. On some devices
99 * Intel is using so called virtual GPIOs which are not
100 * GPIOs at all but some way for AML code to check some
101 * random status bits without need a custom opregion.
102 * In some cases the resources table we parse points to
103 * such a virtual GPIO, since these are not real GPIOs
104 * we do not have a driver for these so they will never
105 * show up, therefore we ignore -EPROBE_DEFER.
106 */
107 continue;
108 }
109
110 gpio_keys[n_buttons].type = info->event_type;
111 gpio_keys[n_buttons].code = info->event_code;
112 gpio_keys[n_buttons].gpio = gpio;
113 gpio_keys[n_buttons].active_low = 1;
114 gpio_keys[n_buttons].desc = info->name;
115 gpio_keys[n_buttons].wakeup = info->wakeup;
116 /* These devices often use cheap buttons, use 50 ms debounce */
117 gpio_keys[n_buttons].debounce_interval = 50;
118 n_buttons++;
119 }
120
121 if (n_buttons == 0) {
122 error = -ENODEV;
123 goto err_free_mem;
124 }
125
126 gpio_keys_pdata->buttons = gpio_keys;
127 gpio_keys_pdata->nbuttons = n_buttons;
128 gpio_keys_pdata->rep = autorepeat;
129
130 pd = platform_device_register_resndata(&pdev->dev, "gpio-keys",
131 PLATFORM_DEVID_AUTO, NULL, 0,
132 gpio_keys_pdata,
133 sizeof(*gpio_keys_pdata));
134 error = PTR_ERR_OR_ZERO(pd);
135 if (error) {
136 dev_err(&pdev->dev,
137 "failed registering gpio-keys: %d\n", error);
138 goto err_free_mem;
139 }
140
141 return pd;
142
143err_free_mem:
144 devm_kfree(&pdev->dev, gpio_keys_pdata);
145 return ERR_PTR(error);
146}
147
148static int soc_button_get_acpi_object_int(const union acpi_object *obj)
149{
150 if (obj->type != ACPI_TYPE_INTEGER)
151 return -1;
152
153 return obj->integer.value;
154}
155
156/* Parse a single ACPI0011 _DSD button descriptor */
157static int soc_button_parse_btn_desc(struct device *dev,
158 const union acpi_object *desc,
159 int collection_uid,
160 struct soc_button_info *info)
161{
162 int upage, usage;
163
164 if (desc->type != ACPI_TYPE_PACKAGE ||
165 desc->package.count != 5 ||
166 /* First byte should be 1 (control) */
167 soc_button_get_acpi_object_int(&desc->package.elements[0]) != 1 ||
168 /* Third byte should be collection uid */
169 soc_button_get_acpi_object_int(&desc->package.elements[2]) !=
170 collection_uid) {
171 dev_err(dev, "Invalid ACPI Button Descriptor\n");
172 return -ENODEV;
173 }
174
175 info->event_type = EV_KEY;
176 info->acpi_index =
177 soc_button_get_acpi_object_int(&desc->package.elements[1]);
178 upage = soc_button_get_acpi_object_int(&desc->package.elements[3]);
179 usage = soc_button_get_acpi_object_int(&desc->package.elements[4]);
180
181 /*
182 * The UUID: fa6bd625-9ce8-470d-a2c7-b3ca36c4282e descriptors use HID
183 * usage page and usage codes, but otherwise the device is not HID
184 * compliant: it uses one irq per button instead of generating HID
185 * input reports and some buttons should generate wakeups where as
186 * others should not, so we cannot use the HID subsystem.
187 *
188 * Luckily all devices only use a few usage page + usage combinations,
189 * so we can simply check for the known combinations here.
190 */
191 if (upage == 0x01 && usage == 0x81) {
192 info->name = "power";
193 info->event_code = KEY_POWER;
194 info->wakeup = true;
195 } else if (upage == 0x01 && usage == 0xca) {
196 info->name = "rotation lock switch";
197 info->event_type = EV_SW;
198 info->event_code = SW_ROTATE_LOCK;
199 } else if (upage == 0x07 && usage == 0xe3) {
200 info->name = "home";
201 info->event_code = KEY_LEFTMETA;
202 info->wakeup = true;
203 } else if (upage == 0x0c && usage == 0xe9) {
204 info->name = "volume_up";
205 info->event_code = KEY_VOLUMEUP;
206 info->autorepeat = true;
207 } else if (upage == 0x0c && usage == 0xea) {
208 info->name = "volume_down";
209 info->event_code = KEY_VOLUMEDOWN;
210 info->autorepeat = true;
211 } else {
212 dev_warn(dev, "Unknown button index %d upage %02x usage %02x, ignoring\n",
213 info->acpi_index, upage, usage);
214 info->name = "unknown";
215 info->event_code = KEY_RESERVED;
216 }
217
218 return 0;
219}
220
221/* ACPI0011 _DSD btns descriptors UUID: fa6bd625-9ce8-470d-a2c7-b3ca36c4282e */
222static const u8 btns_desc_uuid[16] = {
223 0x25, 0xd6, 0x6b, 0xfa, 0xe8, 0x9c, 0x0d, 0x47,
224 0xa2, 0xc7, 0xb3, 0xca, 0x36, 0xc4, 0x28, 0x2e
225};
226
227/* Parse ACPI0011 _DSD button descriptors */
228static struct soc_button_info *soc_button_get_button_info(struct device *dev)
229{
230 struct acpi_buffer buf = { ACPI_ALLOCATE_BUFFER };
231 const union acpi_object *desc, *el0, *uuid, *btns_desc = NULL;
232 struct soc_button_info *button_info;
233 acpi_status status;
234 int i, btn, collection_uid = -1;
235
236 status = acpi_evaluate_object_typed(ACPI_HANDLE(dev), "_DSD", NULL,
237 &buf, ACPI_TYPE_PACKAGE);
238 if (ACPI_FAILURE(status)) {
239 dev_err(dev, "ACPI _DSD object not found\n");
240 return ERR_PTR(-ENODEV);
241 }
242
243 /* Look for the Button Descriptors UUID */
244 desc = buf.pointer;
245 for (i = 0; (i + 1) < desc->package.count; i += 2) {
246 uuid = &desc->package.elements[i];
247
248 if (uuid->type != ACPI_TYPE_BUFFER ||
249 uuid->buffer.length != 16 ||
250 desc->package.elements[i + 1].type != ACPI_TYPE_PACKAGE) {
251 break;
252 }
253
254 if (memcmp(uuid->buffer.pointer, btns_desc_uuid, 16) == 0) {
255 btns_desc = &desc->package.elements[i + 1];
256 break;
257 }
258 }
259
260 if (!btns_desc) {
261 dev_err(dev, "ACPI Button Descriptors not found\n");
262 button_info = ERR_PTR(-ENODEV);
263 goto out;
264 }
265
266 /* The first package describes the collection */
267 el0 = &btns_desc->package.elements[0];
268 if (el0->type == ACPI_TYPE_PACKAGE &&
269 el0->package.count == 5 &&
270 /* First byte should be 0 (collection) */
271 soc_button_get_acpi_object_int(&el0->package.elements[0]) == 0 &&
272 /* Third byte should be 0 (top level collection) */
273 soc_button_get_acpi_object_int(&el0->package.elements[2]) == 0) {
274 collection_uid = soc_button_get_acpi_object_int(
275 &el0->package.elements[1]);
276 }
277 if (collection_uid == -1) {
278 dev_err(dev, "Invalid Button Collection Descriptor\n");
279 button_info = ERR_PTR(-ENODEV);
280 goto out;
281 }
282
283 /* There are package.count - 1 buttons + 1 terminating empty entry */
284 button_info = devm_kcalloc(dev, btns_desc->package.count,
285 sizeof(*button_info), GFP_KERNEL);
286 if (!button_info) {
287 button_info = ERR_PTR(-ENOMEM);
288 goto out;
289 }
290
291 /* Parse the button descriptors */
292 for (i = 1, btn = 0; i < btns_desc->package.count; i++, btn++) {
293 if (soc_button_parse_btn_desc(dev,
294 &btns_desc->package.elements[i],
295 collection_uid,
296 &button_info[btn])) {
297 button_info = ERR_PTR(-ENODEV);
298 goto out;
299 }
300 }
301
302out:
303 kfree(buf.pointer);
304 return button_info;
305}
306
307static int soc_button_remove(struct platform_device *pdev)
308{
309 struct soc_button_data *priv = platform_get_drvdata(pdev);
310
311 int i;
312
313 for (i = 0; i < BUTTON_TYPES; i++)
314 if (priv->children[i])
315 platform_device_unregister(priv->children[i]);
316
317 return 0;
318}
319
320static int soc_button_probe(struct platform_device *pdev)
321{
322 struct device *dev = &pdev->dev;
323 const struct soc_device_data *device_data;
324 const struct soc_button_info *button_info;
325 struct soc_button_data *priv;
326 struct platform_device *pd;
327 int i;
328 int error;
329
330 device_data = acpi_device_get_match_data(dev);
331 if (device_data && device_data->check) {
332 error = device_data->check(dev);
333 if (error)
334 return error;
335 }
336
337 if (device_data && device_data->button_info) {
338 button_info = device_data->button_info;
339 } else {
340 button_info = soc_button_get_button_info(dev);
341 if (IS_ERR(button_info))
342 return PTR_ERR(button_info);
343 }
344
345 error = gpiod_count(dev, NULL);
346 if (error < 0) {
347 dev_dbg(dev, "no GPIO attached, ignoring...\n");
348 return -ENODEV;
349 }
350
351 priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
352 if (!priv)
353 return -ENOMEM;
354
355 platform_set_drvdata(pdev, priv);
356
357 for (i = 0; i < BUTTON_TYPES; i++) {
358 pd = soc_button_device_create(pdev, button_info, i == 0);
359 if (IS_ERR(pd)) {
360 error = PTR_ERR(pd);
361 if (error != -ENODEV) {
362 soc_button_remove(pdev);
363 return error;
364 }
365 continue;
366 }
367
368 priv->children[i] = pd;
369 }
370
371 if (!priv->children[0] && !priv->children[1])
372 return -ENODEV;
373
374 if (!device_data || !device_data->button_info)
375 devm_kfree(dev, button_info);
376
377 return 0;
378}
379
380/*
381 * Definition of buttons on the tablet. The ACPI index of each button
382 * is defined in section 2.8.7.2 of "Windows ACPI Design Guide for SoC
383 * Platforms"
384 */
385static const struct soc_button_info soc_button_PNP0C40[] = {
386 { "power", 0, EV_KEY, KEY_POWER, false, true },
387 { "home", 1, EV_KEY, KEY_LEFTMETA, false, true },
388 { "volume_up", 2, EV_KEY, KEY_VOLUMEUP, true, false },
389 { "volume_down", 3, EV_KEY, KEY_VOLUMEDOWN, true, false },
390 { "rotation_lock", 4, EV_KEY, KEY_ROTATE_LOCK_TOGGLE, false, false },
391 { }
392};
393
394static const struct soc_device_data soc_device_PNP0C40 = {
395 .button_info = soc_button_PNP0C40,
396};
397
398/*
399 * Special device check for Surface Book 2 and Surface Pro (2017).
400 * Both, the Surface Pro 4 (surfacepro3_button.c) and the above mentioned
401 * devices use MSHW0040 for power and volume buttons, however the way they
402 * have to be addressed differs. Make sure that we only load this drivers
403 * for the correct devices by checking the OEM Platform Revision provided by
404 * the _DSM method.
405 */
406#define MSHW0040_DSM_REVISION 0x01
407#define MSHW0040_DSM_GET_OMPR 0x02 // get OEM Platform Revision
408static const guid_t MSHW0040_DSM_UUID =
409 GUID_INIT(0x6fd05c69, 0xcde3, 0x49f4, 0x95, 0xed, 0xab, 0x16, 0x65,
410 0x49, 0x80, 0x35);
411
412static int soc_device_check_MSHW0040(struct device *dev)
413{
414 acpi_handle handle = ACPI_HANDLE(dev);
415 union acpi_object *result;
416 u64 oem_platform_rev = 0; // valid revisions are nonzero
417
418 // get OEM platform revision
419 result = acpi_evaluate_dsm_typed(handle, &MSHW0040_DSM_UUID,
420 MSHW0040_DSM_REVISION,
421 MSHW0040_DSM_GET_OMPR, NULL,
422 ACPI_TYPE_INTEGER);
423
424 if (result) {
425 oem_platform_rev = result->integer.value;
426 ACPI_FREE(result);
427 }
428
429 /*
430 * If the revision is zero here, the _DSM evaluation has failed. This
431 * indicates that we have a Pro 4 or Book 1 and this driver should not
432 * be used.
433 */
434 if (oem_platform_rev == 0)
435 return -ENODEV;
436
437 dev_dbg(dev, "OEM Platform Revision %llu\n", oem_platform_rev);
438
439 return 0;
440}
441
442/*
443 * Button infos for Microsoft Surface Book 2 and Surface Pro (2017).
444 * Obtained from DSDT/testing.
445 */
446static const struct soc_button_info soc_button_MSHW0040[] = {
447 { "power", 0, EV_KEY, KEY_POWER, false, true },
448 { "volume_up", 2, EV_KEY, KEY_VOLUMEUP, true, false },
449 { "volume_down", 4, EV_KEY, KEY_VOLUMEDOWN, true, false },
450 { }
451};
452
453static const struct soc_device_data soc_device_MSHW0040 = {
454 .button_info = soc_button_MSHW0040,
455 .check = soc_device_check_MSHW0040,
456};
457
458static const struct acpi_device_id soc_button_acpi_match[] = {
459 { "PNP0C40", (unsigned long)&soc_device_PNP0C40 },
460 { "ACPI0011", 0 },
461
462 /* Microsoft Surface Devices (5th and 6th generation) */
463 { "MSHW0040", (unsigned long)&soc_device_MSHW0040 },
464
465 { }
466};
467
468MODULE_DEVICE_TABLE(acpi, soc_button_acpi_match);
469
470static struct platform_driver soc_button_driver = {
471 .probe = soc_button_probe,
472 .remove = soc_button_remove,
473 .driver = {
474 .name = KBUILD_MODNAME,
475 .acpi_match_table = ACPI_PTR(soc_button_acpi_match),
476 },
477};
478module_platform_driver(soc_button_driver);
479
480MODULE_LICENSE("GPL");