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