drivers/staging/greybus/svc.c

   1 /*
   2  * SVC Greybus driver.
   3  *
   4  * Copyright 2015 Google Inc.
   5  * Copyright 2015 Linaro Ltd.
   6  *
   7  * Released under the GPLv2 only.
   8  */
   9
  10 #include <linux/workqueue.h>
  11
  12 #include "greybus.h"
  13
  14 #define CPORT_FLAGS_E2EFC       (1)
  15 #define CPORT_FLAGS_CSD_N       (2)
  16 #define CPORT_FLAGS_CSV_N       (4)
  17
  18 enum gb_svc_state {
  19         GB_SVC_STATE_RESET,
  20         GB_SVC_STATE_PROTOCOL_VERSION,
  21         GB_SVC_STATE_SVC_HELLO,
  22 };
  23
  24 struct gb_svc {
  25         struct gb_connection    *connection;
  26         enum gb_svc_state       state;
  27 };
  28
  29 struct svc_hotplug {
  30         struct work_struct work;
  31         struct gb_connection *connection;
  32         struct gb_svc_intf_hotplug_request data;
  33 };
  34
  35 static struct ida greybus_svc_device_id_map;
  36
  37 /*
  38  * AP's SVC cport is required early to get messages from the SVC. This happens
  39  * even before the Endo is created and hence any modules or interfaces.
  40  *
  41  * This is a temporary connection, used only at initial bootup.
  42  */
  43 struct gb_connection *
  44 gb_ap_svc_connection_create(struct greybus_host_device *hd)
  45 {
  46         struct gb_connection *connection;
  47
  48         connection = gb_connection_create_range(hd, NULL, hd->parent,
  49                                                 GB_SVC_CPORT_ID,
  50                                                 GREYBUS_PROTOCOL_SVC,
  51                                                 GB_SVC_CPORT_ID,
  52                                                 GB_SVC_CPORT_ID + 1);
  53
  54         return connection;
  55 }
  56
  57 /*
  58  * We know endo-type and AP's interface id now, lets create a proper svc
  59  * connection (and its interface/bundle) now and get rid of the initial
  60  * 'partially' initialized one svc connection.
  61  */
  62 static struct gb_interface *
  63 gb_ap_interface_create(struct greybus_host_device *hd,
  64                        struct gb_connection *connection, u8 interface_id)
  65 {
  66         struct gb_interface *intf;
  67         struct device *dev = &hd->endo->dev;
  68
  69         intf = gb_interface_create(hd, interface_id);
  70         if (!intf) {
  71                 dev_err(dev, "%s: Failed to create interface with id %hhu\n",
  72                         __func__, interface_id);
  73                 return NULL;
  74         }
  75
  76         intf->device_id = GB_DEVICE_ID_AP;
  77         svc_update_connection(intf, connection);
  78
  79         /* Its no longer a partially initialized connection */
  80         hd->initial_svc_connection = NULL;
  81
  82         return intf;
  83 }
  84
  85 static int gb_svc_intf_device_id(struct gb_svc *svc, u8 intf_id, u8 device_id)
  86 {
  87         struct gb_svc_intf_device_id_request request;
  88
  89         request.intf_id = intf_id;
  90         request.device_id = device_id;
  91
  92         return gb_operation_sync(svc->connection, GB_SVC_TYPE_INTF_DEVICE_ID,
  93                                  &request, sizeof(request), NULL, 0);
  94 }
  95
  96 int gb_svc_intf_reset(struct gb_svc *svc, u8 intf_id)
  97 {
  98         struct gb_svc_intf_reset_request request;
  99
 100         request.intf_id = intf_id;
 101
 102         return gb_operation_sync(svc->connection, GB_SVC_TYPE_INTF_RESET,
 103                                  &request, sizeof(request), NULL, 0);
 104 }
 105 EXPORT_SYMBOL_GPL(gb_svc_intf_reset);
 106
 107 int gb_svc_connection_create(struct gb_svc *svc,
 108                                 u8 intf1_id, u16 cport1_id,
 109                                 u8 intf2_id, u16 cport2_id)
 110 {
 111         struct gb_svc_conn_create_request request;
 112
 113         request.intf1_id = intf1_id;
 114         request.cport1_id = cport1_id;
 115         request.intf2_id = intf2_id;
 116         request.cport2_id = cport2_id;
 117         /*
 118          * XXX: fix connections paramaters to TC0 and all CPort flags
 119          * for now.
 120          */
 121         request.tc = 0;
 122         request.flags = CPORT_FLAGS_CSV_N | CPORT_FLAGS_E2EFC;
 123
 124         return gb_operation_sync(svc->connection, GB_SVC_TYPE_CONN_CREATE,
 125                                  &request, sizeof(request), NULL, 0);
 126 }
 127 EXPORT_SYMBOL_GPL(gb_svc_connection_create);
 128
 129 void gb_svc_connection_destroy(struct gb_svc *svc, u8 intf1_id, u16 cport1_id,
 130                                u8 intf2_id, u16 cport2_id)
 131 {
 132         struct gb_svc_conn_destroy_request request;
 133         struct gb_connection *connection = svc->connection;
 134         int ret;
 135
 136         request.intf1_id = intf1_id;
 137         request.cport1_id = cport1_id;
 138         request.intf2_id = intf2_id;
 139         request.cport2_id = cport2_id;
 140
 141         ret = gb_operation_sync(connection, GB_SVC_TYPE_CONN_DESTROY,
 142                                 &request, sizeof(request), NULL, 0);
 143         if (ret) {
 144                 dev_err(&connection->dev,
 145                         "failed to destroy connection (%hhx:%hx %hhx:%hx) %d\n",
 146                         intf1_id, cport1_id, intf2_id, cport2_id, ret);
 147         }
 148 }
 149 EXPORT_SYMBOL_GPL(gb_svc_connection_destroy);
 150
 151 /* Creates bi-directional routes between the devices */
 152 static int gb_svc_route_create(struct gb_svc *svc, u8 intf1_id, u8 dev1_id,
 153                                u8 intf2_id, u8 dev2_id)
 154 {
 155         struct gb_svc_route_create_request request;
 156
 157         request.intf1_id = intf1_id;
 158         request.dev1_id = dev1_id;
 159         request.intf2_id = intf2_id;
 160         request.dev2_id = dev2_id;
 161
 162         return gb_operation_sync(svc->connection, GB_SVC_TYPE_ROUTE_CREATE,
 163                                  &request, sizeof(request), NULL, 0);
 164 }
 165
 166 static int gb_svc_version_request(struct gb_operation *op)
 167 {
 168         struct gb_connection *connection = op->connection;
 169         struct gb_protocol_version_response *version;
 170         struct device *dev = &connection->dev;
 171
 172         version = op->request->payload;
 173
 174         if (version->major > GB_SVC_VERSION_MAJOR) {
 175                 dev_err(&connection->dev,
 176                         "unsupported major version (%hhu > %hhu)\n",
 177                         version->major, GB_SVC_VERSION_MAJOR);
 178                 return -ENOTSUPP;
 179         }
 180
 181         connection->module_major = version->major;
 182         connection->module_minor = version->minor;
 183
 184         if (!gb_operation_response_alloc(op, sizeof(*version), GFP_KERNEL)) {
 185                 dev_err(dev, "%s: error allocating response\n",
 186                                 __func__);
 187                 return -ENOMEM;
 188         }
 189
 190         version = op->response->payload;
 191         version->major = GB_SVC_VERSION_MAJOR;
 192         version->minor = GB_SVC_VERSION_MINOR;
 193         return 0;
 194 }
 195
 196 static int gb_svc_hello(struct gb_operation *op)
 197 {
 198         struct gb_connection *connection = op->connection;
 199         struct greybus_host_device *hd = connection->hd;
 200         struct gb_svc_hello_request *hello_request;
 201         struct device *dev = &connection->dev;
 202         struct gb_interface *intf;
 203         u16 endo_id;
 204         u8 interface_id;
 205         int ret;
 206
 207         /*
 208          * SVC sends information about the endo and interface-id on the hello
 209          * request, use that to create an endo.
 210          */
 211         if (op->request->payload_size < sizeof(*hello_request)) {
 212                 dev_err(dev, "%s: Illegal size of hello request (%zu < %zu)\n",
 213                         __func__, op->request->payload_size,
 214                         sizeof(*hello_request));
 215                 return -EINVAL;
 216         }
 217
 218         hello_request = op->request->payload;
 219         endo_id = le16_to_cpu(hello_request->endo_id);
 220         interface_id = hello_request->interface_id;
 221
 222         /* Setup Endo */
 223         ret = greybus_endo_setup(hd, endo_id, interface_id);
 224         if (ret)
 225                 return ret;
 226
 227         /*
 228          * Endo and its modules are ready now, fix AP's partially initialized
 229          * svc protocol and its connection.
 230          */
 231         intf = gb_ap_interface_create(hd, connection, interface_id);
 232         if (!intf) {
 233                 gb_endo_remove(hd->endo);
 234                 return ret;
 235         }
 236
 237         return 0;
 238 }
 239
 240 /*
 241  * 'struct svc_hotplug' should be freed by svc_process_hotplug() before it
 242  * returns, irrespective of success or Failure in bringing up the module.
 243  */
 244 static void svc_process_hotplug(struct work_struct *work)
 245 {
 246         struct svc_hotplug *svc_hotplug = container_of(work, struct svc_hotplug,
 247                                                        work);
 248         struct gb_svc_intf_hotplug_request *hotplug = &svc_hotplug->data;
 249         struct gb_connection *connection = svc_hotplug->connection;
 250         struct gb_svc *svc = connection->private;
 251         struct greybus_host_device *hd = connection->hd;
 252         struct device *dev = &connection->dev;
 253         struct gb_interface *intf;
 254         u8 intf_id, device_id;
 255         int ret;
 256
 257         /*
 258          * Grab the information we need.
 259          */
 260         intf_id = hotplug->intf_id;
 261
 262         intf = gb_interface_create(hd, intf_id);
 263         if (!intf) {
 264                 dev_err(dev, "%s: Failed to create interface with id %hhu\n",
 265                         __func__, intf_id);
 266                 goto free_svc_hotplug;
 267         }
 268
 269         intf->unipro_mfg_id = le32_to_cpu(hotplug->data.unipro_mfg_id);
 270         intf->unipro_prod_id = le32_to_cpu(hotplug->data.unipro_prod_id);
 271         intf->ara_vend_id = le32_to_cpu(hotplug->data.ara_vend_id);
 272         intf->ara_prod_id = le32_to_cpu(hotplug->data.ara_prod_id);
 273
 274         /*
 275          * Create a device id for the interface:
 276          * - device id 0 (GB_DEVICE_ID_SVC) belongs to the SVC
 277          * - device id 1 (GB_DEVICE_ID_AP) belongs to the AP
 278          *
 279          * XXX Do we need to allocate device ID for SVC or the AP here? And what
 280          * XXX about an AP with multiple interface blocks?
 281          */
 282         device_id = ida_simple_get(&greybus_svc_device_id_map,
 283                                    GB_DEVICE_ID_MODULES_START, 0, GFP_KERNEL);
 284         if (device_id < 0) {
 285                 ret = device_id;
 286                 dev_err(dev, "%s: Failed to allocate device id for interface with id %hhu (%d)\n",
 287                         __func__, intf_id, ret);
 288                 goto destroy_interface;
 289         }
 290
 291         ret = gb_svc_intf_device_id(svc, intf_id, device_id);
 292         if (ret) {
 293                 dev_err(dev, "%s: Device id operation failed, interface %hhu device_id %hhu (%d)\n",
 294                         __func__, intf_id, device_id, ret);
 295                 goto ida_put;
 296         }
 297
 298         /*
 299          * Create a two-way route between the AP and the new interface
 300          */
 301         ret = gb_svc_route_create(svc, hd->endo->ap_intf_id, GB_DEVICE_ID_AP,
 302                                   intf_id, device_id);
 303         if (ret) {
 304                 dev_err(dev, "%s: Route create operation failed, interface %hhu device_id %hhu (%d)\n",
 305                         __func__, intf_id, device_id, ret);
 306                 goto ida_put;
 307         }
 308
 309         ret = gb_interface_init(intf, device_id);
 310         if (ret) {
 311                 dev_err(dev, "%s: Failed to initialize interface, interface %hhu device_id %hhu (%d)\n",
 312                         __func__, intf_id, device_id, ret);
 313                 goto svc_id_free;
 314         }
 315
 316         goto free_svc_hotplug;
 317
 318 svc_id_free:
 319         /*
 320          * XXX Should we tell SVC that this id doesn't belong to interface
 321          * XXX anymore.
 322          */
 323 ida_put:
 324         ida_simple_remove(&greybus_svc_device_id_map, device_id);
 325 destroy_interface:
 326         gb_interface_remove(hd, intf_id);
 327 free_svc_hotplug:
 328         kfree(svc_hotplug);
 329 }
 330
 331 /*
 332  * Bringing up a module can be time consuming, as that may require lots of
 333  * initialization on the module side. Over that, we may also need to download
 334  * the firmware first and flash that on the module.
 335  *
 336  * In order to make other hotplug events to not wait for all this to finish,
 337  * handle most of module hotplug stuff outside of the hotplug callback, with
 338  * help of a workqueue.
 339  */
 340 static int gb_svc_intf_hotplug_recv(struct gb_operation *op)
 341 {
 342         struct gb_message *request = op->request;
 343         struct svc_hotplug *svc_hotplug;
 344
 345         if (request->payload_size < sizeof(svc_hotplug->data)) {
 346                 dev_err(&op->connection->dev,
 347                         "%s: short hotplug request received (%zu < %zu)\n",
 348                         __func__, request->payload_size,
 349                         sizeof(svc_hotplug->data));
 350                 return -EINVAL;
 351         }
 352
 353         svc_hotplug = kmalloc(sizeof(*svc_hotplug), GFP_KERNEL);
 354         if (!svc_hotplug)
 355                 return -ENOMEM;
 356
 357         svc_hotplug->connection = op->connection;
 358         memcpy(&svc_hotplug->data, op->request->payload, sizeof(svc_hotplug->data));
 359
 360         INIT_WORK(&svc_hotplug->work, svc_process_hotplug);
 361         queue_work(system_unbound_wq, &svc_hotplug->work);
 362
 363         return 0;
 364 }
 365
 366 static int gb_svc_intf_hot_unplug_recv(struct gb_operation *op)
 367 {
 368         struct gb_message *request = op->request;
 369         struct gb_svc_intf_hot_unplug_request *hot_unplug = request->payload;
 370         struct greybus_host_device *hd = op->connection->hd;
 371         struct device *dev = &op->connection->dev;
 372         u8 device_id;
 373         struct gb_interface *intf;
 374         u8 intf_id;
 375
 376         if (request->payload_size < sizeof(*hot_unplug)) {
 377                 dev_err(&op->connection->dev,
 378                         "short hot unplug request received (%zu < %zu)\n",
 379                         request->payload_size, sizeof(*hot_unplug));
 380                 return -EINVAL;
 381         }
 382
 383         intf_id = hot_unplug->intf_id;
 384
 385         intf = gb_interface_find(hd, intf_id);
 386         if (!intf) {
 387                 dev_err(dev, "%s: Couldn't find interface for id %hhu\n",
 388                         __func__, intf_id);
 389                 return -EINVAL;
 390         }
 391
 392         device_id = intf->device_id;
 393         gb_interface_remove(hd, intf_id);
 394         ida_simple_remove(&greybus_svc_device_id_map, device_id);
 395
 396         return 0;
 397 }
 398
 399 static int gb_svc_intf_reset_recv(struct gb_operation *op)
 400 {
 401         struct gb_message *request = op->request;
 402         struct gb_svc_intf_reset_request *reset;
 403         u8 intf_id;
 404
 405         if (request->payload_size < sizeof(*reset)) {
 406                 dev_err(&op->connection->dev,
 407                         "short reset request received (%zu < %zu)\n",
 408                         request->payload_size, sizeof(*reset));
 409                 return -EINVAL;
 410         }
 411         reset = request->payload;
 412
 413         intf_id = reset->intf_id;
 414
 415         /* FIXME Reset the interface here */
 416
 417         return 0;
 418 }
 419
 420 static int gb_svc_request_recv(u8 type, struct gb_operation *op)
 421 {
 422         struct gb_connection *connection = op->connection;
 423         struct gb_svc *svc = connection->private;
 424         int ret = 0;
 425
 426         /*
 427          * SVC requests need to follow a specific order (at least initially) and
 428          * below code takes care of enforcing that. The expected order is:
 429          * - PROTOCOL_VERSION
 430          * - SVC_HELLO
 431          * - Any other request, but the earlier two.
 432          *
 433          * Incoming requests are guaranteed to be serialized and so we don't
 434          * need to protect 'state' for any races.
 435          */
 436         switch (type) {
 437         case GB_REQUEST_TYPE_PROTOCOL_VERSION:
 438                 if (svc->state != GB_SVC_STATE_RESET)
 439                         ret = -EINVAL;
 440                 break;
 441         case GB_SVC_TYPE_SVC_HELLO:
 442                 if (svc->state != GB_SVC_STATE_PROTOCOL_VERSION)
 443                         ret = -EINVAL;
 444                 break;
 445         default:
 446                 if (svc->state != GB_SVC_STATE_SVC_HELLO)
 447                         ret = -EINVAL;
 448                 break;
 449         }
 450
 451         if (ret) {
 452                 dev_warn(&connection->dev,
 453                          "unexpected SVC request 0x%02x received (state %u)\n",
 454                          type, svc->state);
 455                 return ret;
 456         }
 457
 458         switch (type) {
 459         case GB_REQUEST_TYPE_PROTOCOL_VERSION:
 460                 ret = gb_svc_version_request(op);
 461                 if (!ret)
 462                         svc->state = GB_SVC_STATE_PROTOCOL_VERSION;
 463                 return ret;
 464         case GB_SVC_TYPE_SVC_HELLO:
 465                 ret = gb_svc_hello(op);
 466                 if (!ret)
 467                         svc->state = GB_SVC_STATE_SVC_HELLO;
 468                 return ret;
 469         case GB_SVC_TYPE_INTF_HOTPLUG:
 470                 return gb_svc_intf_hotplug_recv(op);
 471         case GB_SVC_TYPE_INTF_HOT_UNPLUG:
 472                 return gb_svc_intf_hot_unplug_recv(op);
 473         case GB_SVC_TYPE_INTF_RESET:
 474                 return gb_svc_intf_reset_recv(op);
 475         default:
 476                 dev_err(&op->connection->dev,
 477                         "unsupported request: %hhu\n", type);
 478                 return -EINVAL;
 479         }
 480 }
 481
 482 static int gb_svc_connection_init(struct gb_connection *connection)
 483 {
 484         struct gb_svc *svc;
 485
 486         svc = kzalloc(sizeof(*svc), GFP_KERNEL);
 487         if (!svc)
 488                 return -ENOMEM;
 489
 490         connection->hd->svc = svc;
 491         svc->state = GB_SVC_STATE_RESET;
 492         svc->connection = connection;
 493         connection->private = svc;
 494
 495         WARN_ON(connection->hd->initial_svc_connection);
 496         connection->hd->initial_svc_connection = connection;
 497
 498         ida_init(&greybus_svc_device_id_map);
 499
 500         return 0;
 501 }
 502
 503 static void gb_svc_connection_exit(struct gb_connection *connection)
 504 {
 505         struct gb_svc *svc = connection->private;
 506
 507         connection->hd->svc = NULL;
 508         connection->private = NULL;
 509         kfree(svc);
 510 }
 511
 512 static struct gb_protocol svc_protocol = {
 513         .name                   = "svc",
 514         .id                     = GREYBUS_PROTOCOL_SVC,
 515         .major                  = GB_SVC_VERSION_MAJOR,
 516         .minor                  = GB_SVC_VERSION_MINOR,
 517         .connection_init        = gb_svc_connection_init,
 518         .connection_exit        = gb_svc_connection_exit,
 519         .request_recv           = gb_svc_request_recv,
 520         .flags                  = GB_PROTOCOL_SKIP_CONTROL_CONNECTED |
 521                                   GB_PROTOCOL_SKIP_CONTROL_DISCONNECTED |
 522                                   GB_PROTOCOL_NO_BUNDLE |
 523                                   GB_PROTOCOL_SKIP_VERSION |
 524                                   GB_PROTOCOL_SKIP_SVC_CONNECTION,
 525 };
 526 gb_builtin_protocol_driver(svc_protocol);