1 // SPDX-License-Identifier: GPL-2.0+ 2 /* 3 * Surface System Aggregator Module (SSAM) client device registry. 4 * 5 * Registry for non-platform/non-ACPI SSAM client devices, i.e. devices that 6 * cannot be auto-detected. Provides device-hubs and performs instantiation 7 * for these devices. 8 * 9 * Copyright (C) 2020-2021 Maximilian Luz <luzmaximilian@gmail.com> 10 */ 11 12 #include <linux/acpi.h> 13 #include <linux/kernel.h> 14 #include <linux/limits.h> 15 #include <linux/module.h> 16 #include <linux/platform_device.h> 17 #include <linux/property.h> 18 #include <linux/types.h> 19 #include <linux/workqueue.h> 20 21 #include <linux/surface_aggregator/controller.h> 22 #include <linux/surface_aggregator/device.h> 23 24 25 /* -- Device registry. ------------------------------------------------------ */ 26 27 /* 28 * SSAM device names follow the SSAM module alias, meaning they are prefixed 29 * with 'ssam:', followed by domain, category, target ID, instance ID, and 30 * function, each encoded as two-digit hexadecimal, separated by ':'. In other 31 * words, it follows the scheme 32 * 33 * ssam:dd:cc:tt:ii:ff 34 * 35 * Where, 'dd', 'cc', 'tt', 'ii', and 'ff' are the two-digit hexadecimal 36 * values mentioned above, respectively. 37 */ 38 39 /* Root node. */ 40 static const struct software_node ssam_node_root = { 41 .name = "ssam_platform_hub", 42 }; 43 44 /* Base device hub (devices attached to Surface Book 3 base). */ 45 static const struct software_node ssam_node_hub_base = { 46 .name = "ssam:00:00:02:00:00", 47 .parent = &ssam_node_root, 48 }; 49 50 /* AC adapter. */ 51 static const struct software_node ssam_node_bat_ac = { 52 .name = "ssam:01:02:01:01:01", 53 .parent = &ssam_node_root, 54 }; 55 56 /* Primary battery. */ 57 static const struct software_node ssam_node_bat_main = { 58 .name = "ssam:01:02:01:01:00", 59 .parent = &ssam_node_root, 60 }; 61 62 /* Secondary battery (Surface Book 3). */ 63 static const struct software_node ssam_node_bat_sb3base = { 64 .name = "ssam:01:02:02:01:00", 65 .parent = &ssam_node_hub_base, 66 }; 67 68 /* Platform profile / performance-mode device. */ 69 static const struct software_node ssam_node_tmp_pprof = { 70 .name = "ssam:01:03:01:00:01", 71 .parent = &ssam_node_root, 72 }; 73 74 /* DTX / detachment-system device (Surface Book 3). */ 75 static const struct software_node ssam_node_bas_dtx = { 76 .name = "ssam:01:11:01:00:00", 77 .parent = &ssam_node_root, 78 }; 79 80 /* HID keyboard. */ 81 static const struct software_node ssam_node_hid_main_keyboard = { 82 .name = "ssam:01:15:02:01:00", 83 .parent = &ssam_node_root, 84 }; 85 86 /* HID touchpad. */ 87 static const struct software_node ssam_node_hid_main_touchpad = { 88 .name = "ssam:01:15:02:03:00", 89 .parent = &ssam_node_root, 90 }; 91 92 /* HID device instance 5 (unknown HID device). */ 93 static const struct software_node ssam_node_hid_main_iid5 = { 94 .name = "ssam:01:15:02:05:00", 95 .parent = &ssam_node_root, 96 }; 97 98 /* HID keyboard (base hub). */ 99 static const struct software_node ssam_node_hid_base_keyboard = { 100 .name = "ssam:01:15:02:01:00", 101 .parent = &ssam_node_hub_base, 102 }; 103 104 /* HID touchpad (base hub). */ 105 static const struct software_node ssam_node_hid_base_touchpad = { 106 .name = "ssam:01:15:02:03:00", 107 .parent = &ssam_node_hub_base, 108 }; 109 110 /* HID device instance 5 (unknown HID device, base hub). */ 111 static const struct software_node ssam_node_hid_base_iid5 = { 112 .name = "ssam:01:15:02:05:00", 113 .parent = &ssam_node_hub_base, 114 }; 115 116 /* HID device instance 6 (unknown HID device, base hub). */ 117 static const struct software_node ssam_node_hid_base_iid6 = { 118 .name = "ssam:01:15:02:06:00", 119 .parent = &ssam_node_hub_base, 120 }; 121 122 /* 123 * Devices for 5th- and 6th-generations models: 124 * - Surface Book 2, 125 * - Surface Laptop 1 and 2, 126 * - Surface Pro 5 and 6. 127 */ 128 static const struct software_node *ssam_node_group_gen5[] = { 129 &ssam_node_root, 130 &ssam_node_tmp_pprof, 131 NULL, 132 }; 133 134 /* Devices for Surface Book 3. */ 135 static const struct software_node *ssam_node_group_sb3[] = { 136 &ssam_node_root, 137 &ssam_node_hub_base, 138 &ssam_node_bat_ac, 139 &ssam_node_bat_main, 140 &ssam_node_bat_sb3base, 141 &ssam_node_tmp_pprof, 142 &ssam_node_bas_dtx, 143 &ssam_node_hid_base_keyboard, 144 &ssam_node_hid_base_touchpad, 145 &ssam_node_hid_base_iid5, 146 &ssam_node_hid_base_iid6, 147 NULL, 148 }; 149 150 /* Devices for Surface Laptop 3 and 4. */ 151 static const struct software_node *ssam_node_group_sl3[] = { 152 &ssam_node_root, 153 &ssam_node_bat_ac, 154 &ssam_node_bat_main, 155 &ssam_node_tmp_pprof, 156 &ssam_node_hid_main_keyboard, 157 &ssam_node_hid_main_touchpad, 158 &ssam_node_hid_main_iid5, 159 NULL, 160 }; 161 162 /* Devices for Surface Laptop Go. */ 163 static const struct software_node *ssam_node_group_slg1[] = { 164 &ssam_node_root, 165 &ssam_node_bat_ac, 166 &ssam_node_bat_main, 167 &ssam_node_tmp_pprof, 168 NULL, 169 }; 170 171 /* Devices for Surface Pro 7 and Surface Pro 7+. */ 172 static const struct software_node *ssam_node_group_sp7[] = { 173 &ssam_node_root, 174 &ssam_node_bat_ac, 175 &ssam_node_bat_main, 176 &ssam_node_tmp_pprof, 177 NULL, 178 }; 179 180 181 /* -- Device registry helper functions. ------------------------------------- */ 182 183 static int ssam_uid_from_string(const char *str, struct ssam_device_uid *uid) 184 { 185 u8 d, tc, tid, iid, fn; 186 int n; 187 188 n = sscanf(str, "ssam:%hhx:%hhx:%hhx:%hhx:%hhx", &d, &tc, &tid, &iid, &fn); 189 if (n != 5) 190 return -EINVAL; 191 192 uid->domain = d; 193 uid->category = tc; 194 uid->target = tid; 195 uid->instance = iid; 196 uid->function = fn; 197 198 return 0; 199 } 200 201 static int ssam_hub_remove_devices_fn(struct device *dev, void *data) 202 { 203 if (!is_ssam_device(dev)) 204 return 0; 205 206 ssam_device_remove(to_ssam_device(dev)); 207 return 0; 208 } 209 210 static void ssam_hub_remove_devices(struct device *parent) 211 { 212 device_for_each_child_reverse(parent, NULL, ssam_hub_remove_devices_fn); 213 } 214 215 static int ssam_hub_add_device(struct device *parent, struct ssam_controller *ctrl, 216 struct fwnode_handle *node) 217 { 218 struct ssam_device_uid uid; 219 struct ssam_device *sdev; 220 int status; 221 222 status = ssam_uid_from_string(fwnode_get_name(node), &uid); 223 if (status) 224 return status; 225 226 sdev = ssam_device_alloc(ctrl, uid); 227 if (!sdev) 228 return -ENOMEM; 229 230 sdev->dev.parent = parent; 231 sdev->dev.fwnode = node; 232 233 status = ssam_device_add(sdev); 234 if (status) 235 ssam_device_put(sdev); 236 237 return status; 238 } 239 240 static int ssam_hub_add_devices(struct device *parent, struct ssam_controller *ctrl, 241 struct fwnode_handle *node) 242 { 243 struct fwnode_handle *child; 244 int status; 245 246 fwnode_for_each_child_node(node, child) { 247 /* 248 * Try to add the device specified in the firmware node. If 249 * this fails with -EINVAL, the node does not specify any SSAM 250 * device, so ignore it and continue with the next one. 251 */ 252 253 status = ssam_hub_add_device(parent, ctrl, child); 254 if (status && status != -EINVAL) 255 goto err; 256 } 257 258 return 0; 259 err: 260 ssam_hub_remove_devices(parent); 261 return status; 262 } 263 264 265 /* -- SSAM base-hub driver. ------------------------------------------------- */ 266 267 /* 268 * Some devices (especially battery) may need a bit of time to be fully usable 269 * after being (re-)connected. This delay has been determined via 270 * experimentation. 271 */ 272 #define SSAM_BASE_UPDATE_CONNECT_DELAY msecs_to_jiffies(2500) 273 274 enum ssam_base_hub_state { 275 SSAM_BASE_HUB_UNINITIALIZED, 276 SSAM_BASE_HUB_CONNECTED, 277 SSAM_BASE_HUB_DISCONNECTED, 278 }; 279 280 struct ssam_base_hub { 281 struct ssam_device *sdev; 282 283 enum ssam_base_hub_state state; 284 struct delayed_work update_work; 285 286 struct ssam_event_notifier notif; 287 }; 288 289 SSAM_DEFINE_SYNC_REQUEST_R(ssam_bas_query_opmode, u8, { 290 .target_category = SSAM_SSH_TC_BAS, 291 .target_id = 0x01, 292 .command_id = 0x0d, 293 .instance_id = 0x00, 294 }); 295 296 #define SSAM_BAS_OPMODE_TABLET 0x00 297 #define SSAM_EVENT_BAS_CID_CONNECTION 0x0c 298 299 static int ssam_base_hub_query_state(struct ssam_base_hub *hub, enum ssam_base_hub_state *state) 300 { 301 u8 opmode; 302 int status; 303 304 status = ssam_retry(ssam_bas_query_opmode, hub->sdev->ctrl, &opmode); 305 if (status < 0) { 306 dev_err(&hub->sdev->dev, "failed to query base state: %d\n", status); 307 return status; 308 } 309 310 if (opmode != SSAM_BAS_OPMODE_TABLET) 311 *state = SSAM_BASE_HUB_CONNECTED; 312 else 313 *state = SSAM_BASE_HUB_DISCONNECTED; 314 315 return 0; 316 } 317 318 static ssize_t ssam_base_hub_state_show(struct device *dev, struct device_attribute *attr, 319 char *buf) 320 { 321 struct ssam_base_hub *hub = dev_get_drvdata(dev); 322 bool connected = hub->state == SSAM_BASE_HUB_CONNECTED; 323 324 return sysfs_emit(buf, "%d\n", connected); 325 } 326 327 static struct device_attribute ssam_base_hub_attr_state = 328 __ATTR(state, 0444, ssam_base_hub_state_show, NULL); 329 330 static struct attribute *ssam_base_hub_attrs[] = { 331 &ssam_base_hub_attr_state.attr, 332 NULL, 333 }; 334 335 static const struct attribute_group ssam_base_hub_group = { 336 .attrs = ssam_base_hub_attrs, 337 }; 338 339 static void ssam_base_hub_update_workfn(struct work_struct *work) 340 { 341 struct ssam_base_hub *hub = container_of(work, struct ssam_base_hub, update_work.work); 342 struct fwnode_handle *node = dev_fwnode(&hub->sdev->dev); 343 enum ssam_base_hub_state state; 344 int status = 0; 345 346 status = ssam_base_hub_query_state(hub, &state); 347 if (status) 348 return; 349 350 if (hub->state == state) 351 return; 352 hub->state = state; 353 354 if (hub->state == SSAM_BASE_HUB_CONNECTED) 355 status = ssam_hub_add_devices(&hub->sdev->dev, hub->sdev->ctrl, node); 356 else 357 ssam_hub_remove_devices(&hub->sdev->dev); 358 359 if (status) 360 dev_err(&hub->sdev->dev, "failed to update base-hub devices: %d\n", status); 361 } 362 363 static u32 ssam_base_hub_notif(struct ssam_event_notifier *nf, const struct ssam_event *event) 364 { 365 struct ssam_base_hub *hub = container_of(nf, struct ssam_base_hub, notif); 366 unsigned long delay; 367 368 if (event->command_id != SSAM_EVENT_BAS_CID_CONNECTION) 369 return 0; 370 371 if (event->length < 1) { 372 dev_err(&hub->sdev->dev, "unexpected payload size: %u\n", event->length); 373 return 0; 374 } 375 376 /* 377 * Delay update when the base is being connected to give devices/EC 378 * some time to set up. 379 */ 380 delay = event->data[0] ? SSAM_BASE_UPDATE_CONNECT_DELAY : 0; 381 382 schedule_delayed_work(&hub->update_work, delay); 383 384 /* 385 * Do not return SSAM_NOTIF_HANDLED: The event should be picked up and 386 * consumed by the detachment system driver. We're just a (more or less) 387 * silent observer. 388 */ 389 return 0; 390 } 391 392 static int __maybe_unused ssam_base_hub_resume(struct device *dev) 393 { 394 struct ssam_base_hub *hub = dev_get_drvdata(dev); 395 396 schedule_delayed_work(&hub->update_work, 0); 397 return 0; 398 } 399 static SIMPLE_DEV_PM_OPS(ssam_base_hub_pm_ops, NULL, ssam_base_hub_resume); 400 401 static int ssam_base_hub_probe(struct ssam_device *sdev) 402 { 403 struct ssam_base_hub *hub; 404 int status; 405 406 hub = devm_kzalloc(&sdev->dev, sizeof(*hub), GFP_KERNEL); 407 if (!hub) 408 return -ENOMEM; 409 410 hub->sdev = sdev; 411 hub->state = SSAM_BASE_HUB_UNINITIALIZED; 412 413 hub->notif.base.priority = INT_MAX; /* This notifier should run first. */ 414 hub->notif.base.fn = ssam_base_hub_notif; 415 hub->notif.event.reg = SSAM_EVENT_REGISTRY_SAM; 416 hub->notif.event.id.target_category = SSAM_SSH_TC_BAS, 417 hub->notif.event.id.instance = 0, 418 hub->notif.event.mask = SSAM_EVENT_MASK_NONE; 419 hub->notif.event.flags = SSAM_EVENT_SEQUENCED; 420 421 INIT_DELAYED_WORK(&hub->update_work, ssam_base_hub_update_workfn); 422 423 ssam_device_set_drvdata(sdev, hub); 424 425 status = ssam_notifier_register(sdev->ctrl, &hub->notif); 426 if (status) 427 return status; 428 429 status = sysfs_create_group(&sdev->dev.kobj, &ssam_base_hub_group); 430 if (status) 431 goto err; 432 433 schedule_delayed_work(&hub->update_work, 0); 434 return 0; 435 436 err: 437 ssam_notifier_unregister(sdev->ctrl, &hub->notif); 438 cancel_delayed_work_sync(&hub->update_work); 439 ssam_hub_remove_devices(&sdev->dev); 440 return status; 441 } 442 443 static void ssam_base_hub_remove(struct ssam_device *sdev) 444 { 445 struct ssam_base_hub *hub = ssam_device_get_drvdata(sdev); 446 447 sysfs_remove_group(&sdev->dev.kobj, &ssam_base_hub_group); 448 449 ssam_notifier_unregister(sdev->ctrl, &hub->notif); 450 cancel_delayed_work_sync(&hub->update_work); 451 ssam_hub_remove_devices(&sdev->dev); 452 } 453 454 static const struct ssam_device_id ssam_base_hub_match[] = { 455 { SSAM_VDEV(HUB, 0x02, SSAM_ANY_IID, 0x00) }, 456 { }, 457 }; 458 459 static struct ssam_device_driver ssam_base_hub_driver = { 460 .probe = ssam_base_hub_probe, 461 .remove = ssam_base_hub_remove, 462 .match_table = ssam_base_hub_match, 463 .driver = { 464 .name = "surface_aggregator_base_hub", 465 .probe_type = PROBE_PREFER_ASYNCHRONOUS, 466 .pm = &ssam_base_hub_pm_ops, 467 }, 468 }; 469 470 471 /* -- SSAM platform/meta-hub driver. ---------------------------------------- */ 472 473 static const struct acpi_device_id ssam_platform_hub_match[] = { 474 /* Surface Pro 4, 5, and 6 (OMBR < 0x10) */ 475 { "MSHW0081", (unsigned long)ssam_node_group_gen5 }, 476 477 /* Surface Pro 6 (OMBR >= 0x10) */ 478 { "MSHW0111", (unsigned long)ssam_node_group_gen5 }, 479 480 /* Surface Pro 7 */ 481 { "MSHW0116", (unsigned long)ssam_node_group_sp7 }, 482 483 /* Surface Pro 7+ */ 484 { "MSHW0119", (unsigned long)ssam_node_group_sp7 }, 485 486 /* Surface Book 2 */ 487 { "MSHW0107", (unsigned long)ssam_node_group_gen5 }, 488 489 /* Surface Book 3 */ 490 { "MSHW0117", (unsigned long)ssam_node_group_sb3 }, 491 492 /* Surface Laptop 1 */ 493 { "MSHW0086", (unsigned long)ssam_node_group_gen5 }, 494 495 /* Surface Laptop 2 */ 496 { "MSHW0112", (unsigned long)ssam_node_group_gen5 }, 497 498 /* Surface Laptop 3 (13", Intel) */ 499 { "MSHW0114", (unsigned long)ssam_node_group_sl3 }, 500 501 /* Surface Laptop 3 (15", AMD) and 4 (15", AMD) */ 502 { "MSHW0110", (unsigned long)ssam_node_group_sl3 }, 503 504 /* Surface Laptop 4 (13", Intel) */ 505 { "MSHW0250", (unsigned long)ssam_node_group_sl3 }, 506 507 /* Surface Laptop Go 1 */ 508 { "MSHW0118", (unsigned long)ssam_node_group_slg1 }, 509 510 { }, 511 }; 512 MODULE_DEVICE_TABLE(acpi, ssam_platform_hub_match); 513 514 static int ssam_platform_hub_probe(struct platform_device *pdev) 515 { 516 const struct software_node **nodes; 517 struct ssam_controller *ctrl; 518 struct fwnode_handle *root; 519 int status; 520 521 nodes = (const struct software_node **)acpi_device_get_match_data(&pdev->dev); 522 if (!nodes) 523 return -ENODEV; 524 525 /* 526 * As we're adding the SSAM client devices as children under this device 527 * and not the SSAM controller, we need to add a device link to the 528 * controller to ensure that we remove all of our devices before the 529 * controller is removed. This also guarantees proper ordering for 530 * suspend/resume of the devices on this hub. 531 */ 532 ctrl = ssam_client_bind(&pdev->dev); 533 if (IS_ERR(ctrl)) 534 return PTR_ERR(ctrl) == -ENODEV ? -EPROBE_DEFER : PTR_ERR(ctrl); 535 536 status = software_node_register_node_group(nodes); 537 if (status) 538 return status; 539 540 root = software_node_fwnode(&ssam_node_root); 541 if (!root) { 542 software_node_unregister_node_group(nodes); 543 return -ENOENT; 544 } 545 546 set_secondary_fwnode(&pdev->dev, root); 547 548 status = ssam_hub_add_devices(&pdev->dev, ctrl, root); 549 if (status) { 550 set_secondary_fwnode(&pdev->dev, NULL); 551 software_node_unregister_node_group(nodes); 552 } 553 554 platform_set_drvdata(pdev, nodes); 555 return status; 556 } 557 558 static int ssam_platform_hub_remove(struct platform_device *pdev) 559 { 560 const struct software_node **nodes = platform_get_drvdata(pdev); 561 562 ssam_hub_remove_devices(&pdev->dev); 563 set_secondary_fwnode(&pdev->dev, NULL); 564 software_node_unregister_node_group(nodes); 565 return 0; 566 } 567 568 static struct platform_driver ssam_platform_hub_driver = { 569 .probe = ssam_platform_hub_probe, 570 .remove = ssam_platform_hub_remove, 571 .driver = { 572 .name = "surface_aggregator_platform_hub", 573 .acpi_match_table = ssam_platform_hub_match, 574 .probe_type = PROBE_PREFER_ASYNCHRONOUS, 575 }, 576 }; 577 578 579 /* -- Module initialization. ------------------------------------------------ */ 580 581 static int __init ssam_device_hub_init(void) 582 { 583 int status; 584 585 status = platform_driver_register(&ssam_platform_hub_driver); 586 if (status) 587 return status; 588 589 status = ssam_device_driver_register(&ssam_base_hub_driver); 590 if (status) 591 platform_driver_unregister(&ssam_platform_hub_driver); 592 593 return status; 594 } 595 module_init(ssam_device_hub_init); 596 597 static void __exit ssam_device_hub_exit(void) 598 { 599 ssam_device_driver_unregister(&ssam_base_hub_driver); 600 platform_driver_unregister(&ssam_platform_hub_driver); 601 } 602 module_exit(ssam_device_hub_exit); 603 604 MODULE_AUTHOR("Maximilian Luz <luzmaximilian@gmail.com>"); 605 MODULE_DESCRIPTION("Device-registry for Surface System Aggregator Module"); 606 MODULE_LICENSE("GPL"); 607