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 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, "1051L"), 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 * Special device check for Surface Book 2 and Surface Pro (2017). 474 * Both, the Surface Pro 4 (surfacepro3_button.c) and the above mentioned 475 * devices use MSHW0040 for power and volume buttons, however the way they 476 * have to be addressed differs. Make sure that we only load this drivers 477 * for the correct devices by checking the OEM Platform Revision provided by 478 * the _DSM method. 479 */ 480 #define MSHW0040_DSM_REVISION 0x01 481 #define MSHW0040_DSM_GET_OMPR 0x02 // get OEM Platform Revision 482 static const guid_t MSHW0040_DSM_UUID = 483 GUID_INIT(0x6fd05c69, 0xcde3, 0x49f4, 0x95, 0xed, 0xab, 0x16, 0x65, 484 0x49, 0x80, 0x35); 485 486 static int soc_device_check_MSHW0040(struct device *dev) 487 { 488 acpi_handle handle = ACPI_HANDLE(dev); 489 union acpi_object *result; 490 u64 oem_platform_rev = 0; // valid revisions are nonzero 491 492 // get OEM platform revision 493 result = acpi_evaluate_dsm_typed(handle, &MSHW0040_DSM_UUID, 494 MSHW0040_DSM_REVISION, 495 MSHW0040_DSM_GET_OMPR, NULL, 496 ACPI_TYPE_INTEGER); 497 498 if (result) { 499 oem_platform_rev = result->integer.value; 500 ACPI_FREE(result); 501 } 502 503 /* 504 * If the revision is zero here, the _DSM evaluation has failed. This 505 * indicates that we have a Pro 4 or Book 1 and this driver should not 506 * be used. 507 */ 508 if (oem_platform_rev == 0) 509 return -ENODEV; 510 511 dev_dbg(dev, "OEM Platform Revision %llu\n", oem_platform_rev); 512 513 return 0; 514 } 515 516 /* 517 * Button infos for Microsoft Surface Book 2 and Surface Pro (2017). 518 * Obtained from DSDT/testing. 519 */ 520 static const struct soc_button_info soc_button_MSHW0040[] = { 521 { "power", 0, EV_KEY, KEY_POWER, false, true, true }, 522 { "volume_up", 2, EV_KEY, KEY_VOLUMEUP, true, false, true }, 523 { "volume_down", 4, EV_KEY, KEY_VOLUMEDOWN, true, false, true }, 524 { } 525 }; 526 527 static const struct soc_device_data soc_device_MSHW0040 = { 528 .button_info = soc_button_MSHW0040, 529 .check = soc_device_check_MSHW0040, 530 }; 531 532 static const struct acpi_device_id soc_button_acpi_match[] = { 533 { "PNP0C40", (unsigned long)&soc_device_PNP0C40 }, 534 { "INT33D3", (unsigned long)&soc_device_INT33D3 }, 535 { "ID9001", (unsigned long)&soc_device_INT33D3 }, 536 { "ACPI0011", 0 }, 537 538 /* Microsoft Surface Devices (5th and 6th generation) */ 539 { "MSHW0040", (unsigned long)&soc_device_MSHW0040 }, 540 541 { } 542 }; 543 544 MODULE_DEVICE_TABLE(acpi, soc_button_acpi_match); 545 546 static struct platform_driver soc_button_driver = { 547 .probe = soc_button_probe, 548 .remove = soc_button_remove, 549 .driver = { 550 .name = KBUILD_MODNAME, 551 .acpi_match_table = ACPI_PTR(soc_button_acpi_match), 552 }, 553 }; 554 module_platform_driver(soc_button_driver); 555 556 MODULE_LICENSE("GPL"); 557