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 {} /* Terminating entry */ 87 }; 88 89 /* 90 * Get the Nth GPIO number from the ACPI object. 91 */ 92 static int soc_button_lookup_gpio(struct device *dev, int acpi_index, 93 int *gpio_ret, int *irq_ret) 94 { 95 struct gpio_desc *desc; 96 97 desc = gpiod_get_index(dev, NULL, acpi_index, GPIOD_ASIS); 98 if (IS_ERR(desc)) 99 return PTR_ERR(desc); 100 101 *gpio_ret = desc_to_gpio(desc); 102 *irq_ret = gpiod_to_irq(desc); 103 104 gpiod_put(desc); 105 106 return 0; 107 } 108 109 static struct platform_device * 110 soc_button_device_create(struct platform_device *pdev, 111 const struct soc_button_info *button_info, 112 bool autorepeat) 113 { 114 const struct soc_button_info *info; 115 struct platform_device *pd; 116 struct gpio_keys_button *gpio_keys; 117 struct gpio_keys_platform_data *gpio_keys_pdata; 118 int error, gpio, irq; 119 int n_buttons = 0; 120 121 for (info = button_info; info->name; info++) 122 if (info->autorepeat == autorepeat) 123 n_buttons++; 124 125 gpio_keys_pdata = devm_kzalloc(&pdev->dev, 126 sizeof(*gpio_keys_pdata) + 127 sizeof(*gpio_keys) * n_buttons, 128 GFP_KERNEL); 129 if (!gpio_keys_pdata) 130 return ERR_PTR(-ENOMEM); 131 132 gpio_keys = (void *)(gpio_keys_pdata + 1); 133 n_buttons = 0; 134 135 for (info = button_info; info->name; info++) { 136 if (info->autorepeat != autorepeat) 137 continue; 138 139 error = soc_button_lookup_gpio(&pdev->dev, info->acpi_index, &gpio, &irq); 140 if (error || irq < 0) { 141 /* 142 * Skip GPIO if not present. Note we deliberately 143 * ignore -EPROBE_DEFER errors here. On some devices 144 * Intel is using so called virtual GPIOs which are not 145 * GPIOs at all but some way for AML code to check some 146 * random status bits without need a custom opregion. 147 * In some cases the resources table we parse points to 148 * such a virtual GPIO, since these are not real GPIOs 149 * we do not have a driver for these so they will never 150 * show up, therefore we ignore -EPROBE_DEFER. 151 */ 152 continue; 153 } 154 155 /* See dmi_use_low_level_irq[] comment */ 156 if (!autorepeat && dmi_check_system(dmi_use_low_level_irq)) { 157 irq_set_irq_type(irq, IRQ_TYPE_LEVEL_LOW); 158 gpio_keys[n_buttons].irq = irq; 159 gpio_keys[n_buttons].gpio = -ENOENT; 160 } else { 161 gpio_keys[n_buttons].gpio = gpio; 162 } 163 164 gpio_keys[n_buttons].type = info->event_type; 165 gpio_keys[n_buttons].code = info->event_code; 166 gpio_keys[n_buttons].active_low = info->active_low; 167 gpio_keys[n_buttons].desc = info->name; 168 gpio_keys[n_buttons].wakeup = info->wakeup; 169 /* These devices often use cheap buttons, use 50 ms debounce */ 170 gpio_keys[n_buttons].debounce_interval = 50; 171 n_buttons++; 172 } 173 174 if (n_buttons == 0) { 175 error = -ENODEV; 176 goto err_free_mem; 177 } 178 179 gpio_keys_pdata->buttons = gpio_keys; 180 gpio_keys_pdata->nbuttons = n_buttons; 181 gpio_keys_pdata->rep = autorepeat; 182 183 pd = platform_device_register_resndata(&pdev->dev, "gpio-keys", 184 PLATFORM_DEVID_AUTO, NULL, 0, 185 gpio_keys_pdata, 186 sizeof(*gpio_keys_pdata)); 187 error = PTR_ERR_OR_ZERO(pd); 188 if (error) { 189 dev_err(&pdev->dev, 190 "failed registering gpio-keys: %d\n", error); 191 goto err_free_mem; 192 } 193 194 return pd; 195 196 err_free_mem: 197 devm_kfree(&pdev->dev, gpio_keys_pdata); 198 return ERR_PTR(error); 199 } 200 201 static int soc_button_get_acpi_object_int(const union acpi_object *obj) 202 { 203 if (obj->type != ACPI_TYPE_INTEGER) 204 return -1; 205 206 return obj->integer.value; 207 } 208 209 /* Parse a single ACPI0011 _DSD button descriptor */ 210 static int soc_button_parse_btn_desc(struct device *dev, 211 const union acpi_object *desc, 212 int collection_uid, 213 struct soc_button_info *info) 214 { 215 int upage, usage; 216 217 if (desc->type != ACPI_TYPE_PACKAGE || 218 desc->package.count != 5 || 219 /* First byte should be 1 (control) */ 220 soc_button_get_acpi_object_int(&desc->package.elements[0]) != 1 || 221 /* Third byte should be collection uid */ 222 soc_button_get_acpi_object_int(&desc->package.elements[2]) != 223 collection_uid) { 224 dev_err(dev, "Invalid ACPI Button Descriptor\n"); 225 return -ENODEV; 226 } 227 228 info->event_type = EV_KEY; 229 info->active_low = true; 230 info->acpi_index = 231 soc_button_get_acpi_object_int(&desc->package.elements[1]); 232 upage = soc_button_get_acpi_object_int(&desc->package.elements[3]); 233 usage = soc_button_get_acpi_object_int(&desc->package.elements[4]); 234 235 /* 236 * The UUID: fa6bd625-9ce8-470d-a2c7-b3ca36c4282e descriptors use HID 237 * usage page and usage codes, but otherwise the device is not HID 238 * compliant: it uses one irq per button instead of generating HID 239 * input reports and some buttons should generate wakeups where as 240 * others should not, so we cannot use the HID subsystem. 241 * 242 * Luckily all devices only use a few usage page + usage combinations, 243 * so we can simply check for the known combinations here. 244 */ 245 if (upage == 0x01 && usage == 0x81) { 246 info->name = "power"; 247 info->event_code = KEY_POWER; 248 info->wakeup = true; 249 } else if (upage == 0x01 && usage == 0xca) { 250 info->name = "rotation lock switch"; 251 info->event_type = EV_SW; 252 info->event_code = SW_ROTATE_LOCK; 253 } else if (upage == 0x07 && usage == 0xe3) { 254 info->name = "home"; 255 info->event_code = KEY_LEFTMETA; 256 info->wakeup = true; 257 } else if (upage == 0x0c && usage == 0xe9) { 258 info->name = "volume_up"; 259 info->event_code = KEY_VOLUMEUP; 260 info->autorepeat = true; 261 } else if (upage == 0x0c && usage == 0xea) { 262 info->name = "volume_down"; 263 info->event_code = KEY_VOLUMEDOWN; 264 info->autorepeat = true; 265 } else { 266 dev_warn(dev, "Unknown button index %d upage %02x usage %02x, ignoring\n", 267 info->acpi_index, upage, usage); 268 info->name = "unknown"; 269 info->event_code = KEY_RESERVED; 270 } 271 272 return 0; 273 } 274 275 /* ACPI0011 _DSD btns descriptors UUID: fa6bd625-9ce8-470d-a2c7-b3ca36c4282e */ 276 static const u8 btns_desc_uuid[16] = { 277 0x25, 0xd6, 0x6b, 0xfa, 0xe8, 0x9c, 0x0d, 0x47, 278 0xa2, 0xc7, 0xb3, 0xca, 0x36, 0xc4, 0x28, 0x2e 279 }; 280 281 /* Parse ACPI0011 _DSD button descriptors */ 282 static struct soc_button_info *soc_button_get_button_info(struct device *dev) 283 { 284 struct acpi_buffer buf = { ACPI_ALLOCATE_BUFFER }; 285 const union acpi_object *desc, *el0, *uuid, *btns_desc = NULL; 286 struct soc_button_info *button_info; 287 acpi_status status; 288 int i, btn, collection_uid = -1; 289 290 status = acpi_evaluate_object_typed(ACPI_HANDLE(dev), "_DSD", NULL, 291 &buf, ACPI_TYPE_PACKAGE); 292 if (ACPI_FAILURE(status)) { 293 dev_err(dev, "ACPI _DSD object not found\n"); 294 return ERR_PTR(-ENODEV); 295 } 296 297 /* Look for the Button Descriptors UUID */ 298 desc = buf.pointer; 299 for (i = 0; (i + 1) < desc->package.count; i += 2) { 300 uuid = &desc->package.elements[i]; 301 302 if (uuid->type != ACPI_TYPE_BUFFER || 303 uuid->buffer.length != 16 || 304 desc->package.elements[i + 1].type != ACPI_TYPE_PACKAGE) { 305 break; 306 } 307 308 if (memcmp(uuid->buffer.pointer, btns_desc_uuid, 16) == 0) { 309 btns_desc = &desc->package.elements[i + 1]; 310 break; 311 } 312 } 313 314 if (!btns_desc) { 315 dev_err(dev, "ACPI Button Descriptors not found\n"); 316 button_info = ERR_PTR(-ENODEV); 317 goto out; 318 } 319 320 /* The first package describes the collection */ 321 el0 = &btns_desc->package.elements[0]; 322 if (el0->type == ACPI_TYPE_PACKAGE && 323 el0->package.count == 5 && 324 /* First byte should be 0 (collection) */ 325 soc_button_get_acpi_object_int(&el0->package.elements[0]) == 0 && 326 /* Third byte should be 0 (top level collection) */ 327 soc_button_get_acpi_object_int(&el0->package.elements[2]) == 0) { 328 collection_uid = soc_button_get_acpi_object_int( 329 &el0->package.elements[1]); 330 } 331 if (collection_uid == -1) { 332 dev_err(dev, "Invalid Button Collection Descriptor\n"); 333 button_info = ERR_PTR(-ENODEV); 334 goto out; 335 } 336 337 /* There are package.count - 1 buttons + 1 terminating empty entry */ 338 button_info = devm_kcalloc(dev, btns_desc->package.count, 339 sizeof(*button_info), GFP_KERNEL); 340 if (!button_info) { 341 button_info = ERR_PTR(-ENOMEM); 342 goto out; 343 } 344 345 /* Parse the button descriptors */ 346 for (i = 1, btn = 0; i < btns_desc->package.count; i++, btn++) { 347 if (soc_button_parse_btn_desc(dev, 348 &btns_desc->package.elements[i], 349 collection_uid, 350 &button_info[btn])) { 351 button_info = ERR_PTR(-ENODEV); 352 goto out; 353 } 354 } 355 356 out: 357 kfree(buf.pointer); 358 return button_info; 359 } 360 361 static int soc_button_remove(struct platform_device *pdev) 362 { 363 struct soc_button_data *priv = platform_get_drvdata(pdev); 364 365 int i; 366 367 for (i = 0; i < BUTTON_TYPES; i++) 368 if (priv->children[i]) 369 platform_device_unregister(priv->children[i]); 370 371 return 0; 372 } 373 374 static int soc_button_probe(struct platform_device *pdev) 375 { 376 struct device *dev = &pdev->dev; 377 const struct soc_device_data *device_data; 378 const struct soc_button_info *button_info; 379 struct soc_button_data *priv; 380 struct platform_device *pd; 381 int i; 382 int error; 383 384 device_data = acpi_device_get_match_data(dev); 385 if (device_data && device_data->check) { 386 error = device_data->check(dev); 387 if (error) 388 return error; 389 } 390 391 if (device_data && device_data->button_info) { 392 button_info = device_data->button_info; 393 } else { 394 button_info = soc_button_get_button_info(dev); 395 if (IS_ERR(button_info)) 396 return PTR_ERR(button_info); 397 } 398 399 error = gpiod_count(dev, NULL); 400 if (error < 0) { 401 dev_dbg(dev, "no GPIO attached, ignoring...\n"); 402 return -ENODEV; 403 } 404 405 priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL); 406 if (!priv) 407 return -ENOMEM; 408 409 platform_set_drvdata(pdev, priv); 410 411 for (i = 0; i < BUTTON_TYPES; i++) { 412 pd = soc_button_device_create(pdev, button_info, i == 0); 413 if (IS_ERR(pd)) { 414 error = PTR_ERR(pd); 415 if (error != -ENODEV) { 416 soc_button_remove(pdev); 417 return error; 418 } 419 continue; 420 } 421 422 priv->children[i] = pd; 423 } 424 425 if (!priv->children[0] && !priv->children[1]) 426 return -ENODEV; 427 428 if (!device_data || !device_data->button_info) 429 devm_kfree(dev, button_info); 430 431 return 0; 432 } 433 434 /* 435 * Definition of buttons on the tablet. The ACPI index of each button 436 * is defined in section 2.8.7.2 of "Windows ACPI Design Guide for SoC 437 * Platforms" 438 */ 439 static const struct soc_button_info soc_button_PNP0C40[] = { 440 { "power", 0, EV_KEY, KEY_POWER, false, true, true }, 441 { "home", 1, EV_KEY, KEY_LEFTMETA, false, true, true }, 442 { "volume_up", 2, EV_KEY, KEY_VOLUMEUP, true, false, true }, 443 { "volume_down", 3, EV_KEY, KEY_VOLUMEDOWN, true, false, true }, 444 { "rotation_lock", 4, EV_KEY, KEY_ROTATE_LOCK_TOGGLE, false, false, true }, 445 { } 446 }; 447 448 static const struct soc_device_data soc_device_PNP0C40 = { 449 .button_info = soc_button_PNP0C40, 450 }; 451 452 static const struct soc_button_info soc_button_INT33D3[] = { 453 { "tablet_mode", 0, EV_SW, SW_TABLET_MODE, false, false, false }, 454 { } 455 }; 456 457 static const struct soc_device_data soc_device_INT33D3 = { 458 .button_info = soc_button_INT33D3, 459 }; 460 461 /* 462 * Special device check for Surface Book 2 and Surface Pro (2017). 463 * Both, the Surface Pro 4 (surfacepro3_button.c) and the above mentioned 464 * devices use MSHW0040 for power and volume buttons, however the way they 465 * have to be addressed differs. Make sure that we only load this drivers 466 * for the correct devices by checking the OEM Platform Revision provided by 467 * the _DSM method. 468 */ 469 #define MSHW0040_DSM_REVISION 0x01 470 #define MSHW0040_DSM_GET_OMPR 0x02 // get OEM Platform Revision 471 static const guid_t MSHW0040_DSM_UUID = 472 GUID_INIT(0x6fd05c69, 0xcde3, 0x49f4, 0x95, 0xed, 0xab, 0x16, 0x65, 473 0x49, 0x80, 0x35); 474 475 static int soc_device_check_MSHW0040(struct device *dev) 476 { 477 acpi_handle handle = ACPI_HANDLE(dev); 478 union acpi_object *result; 479 u64 oem_platform_rev = 0; // valid revisions are nonzero 480 481 // get OEM platform revision 482 result = acpi_evaluate_dsm_typed(handle, &MSHW0040_DSM_UUID, 483 MSHW0040_DSM_REVISION, 484 MSHW0040_DSM_GET_OMPR, NULL, 485 ACPI_TYPE_INTEGER); 486 487 if (result) { 488 oem_platform_rev = result->integer.value; 489 ACPI_FREE(result); 490 } 491 492 /* 493 * If the revision is zero here, the _DSM evaluation has failed. This 494 * indicates that we have a Pro 4 or Book 1 and this driver should not 495 * be used. 496 */ 497 if (oem_platform_rev == 0) 498 return -ENODEV; 499 500 dev_dbg(dev, "OEM Platform Revision %llu\n", oem_platform_rev); 501 502 return 0; 503 } 504 505 /* 506 * Button infos for Microsoft Surface Book 2 and Surface Pro (2017). 507 * Obtained from DSDT/testing. 508 */ 509 static const struct soc_button_info soc_button_MSHW0040[] = { 510 { "power", 0, EV_KEY, KEY_POWER, false, true, true }, 511 { "volume_up", 2, EV_KEY, KEY_VOLUMEUP, true, false, true }, 512 { "volume_down", 4, EV_KEY, KEY_VOLUMEDOWN, true, false, true }, 513 { } 514 }; 515 516 static const struct soc_device_data soc_device_MSHW0040 = { 517 .button_info = soc_button_MSHW0040, 518 .check = soc_device_check_MSHW0040, 519 }; 520 521 static const struct acpi_device_id soc_button_acpi_match[] = { 522 { "PNP0C40", (unsigned long)&soc_device_PNP0C40 }, 523 { "INT33D3", (unsigned long)&soc_device_INT33D3 }, 524 { "ID9001", (unsigned long)&soc_device_INT33D3 }, 525 { "ACPI0011", 0 }, 526 527 /* Microsoft Surface Devices (5th and 6th generation) */ 528 { "MSHW0040", (unsigned long)&soc_device_MSHW0040 }, 529 530 { } 531 }; 532 533 MODULE_DEVICE_TABLE(acpi, soc_button_acpi_match); 534 535 static struct platform_driver soc_button_driver = { 536 .probe = soc_button_probe, 537 .remove = soc_button_remove, 538 .driver = { 539 .name = KBUILD_MODNAME, 540 .acpi_match_table = ACPI_PTR(soc_button_acpi_match), 541 }, 542 }; 543 module_platform_driver(soc_button_driver); 544 545 MODULE_LICENSE("GPL"); 546