1/* SPDX-License-Identifier: GPL-2.0+ */ 2/* 3 * Surface System Aggregator Module (SSAM) controller interface. 4 * 5 * Main communication interface for the SSAM EC. Provides a controller 6 * managing access and communication to and from the SSAM EC, as well as main 7 * communication structures and definitions. 8 * 9 * Copyright (C) 2019-2020 Maximilian Luz <luzmaximilian@gmail.com> 10 */ 11 12#ifndef _LINUX_SURFACE_AGGREGATOR_CONTROLLER_H 13#define _LINUX_SURFACE_AGGREGATOR_CONTROLLER_H 14 15#include <linux/completion.h> 16#include <linux/device.h> 17#include <linux/types.h> 18 19#include <linux/surface_aggregator/serial_hub.h> 20 21 22/* -- Main data types and definitions --------------------------------------- */ 23 24/** 25 * enum ssam_event_flags - Flags for enabling/disabling SAM events 26 * @SSAM_EVENT_SEQUENCED: The event will be sent via a sequenced data frame. 27 */ 28enum ssam_event_flags { 29 SSAM_EVENT_SEQUENCED = BIT(0), 30}; 31 32/** 33 * struct ssam_event - SAM event sent from the EC to the host. 34 * @target_category: Target category of the event source. See &enum ssam_ssh_tc. 35 * @target_id: Target ID of the event source. 36 * @command_id: Command ID of the event. 37 * @instance_id: Instance ID of the event source. 38 * @length: Length of the event payload in bytes. 39 * @data: Event payload data. 40 */ 41struct ssam_event { 42 u8 target_category; 43 u8 target_id; 44 u8 command_id; 45 u8 instance_id; 46 u16 length; 47 u8 data[]; 48}; 49 50/** 51 * enum ssam_request_flags - Flags for SAM requests. 52 * 53 * @SSAM_REQUEST_HAS_RESPONSE: 54 * Specifies that the request expects a response. If not set, the request 55 * will be directly completed after its underlying packet has been 56 * transmitted. If set, the request transport system waits for a response 57 * of the request. 58 * 59 * @SSAM_REQUEST_UNSEQUENCED: 60 * Specifies that the request should be transmitted via an unsequenced 61 * packet. If set, the request must not have a response, meaning that this 62 * flag and the %SSAM_REQUEST_HAS_RESPONSE flag are mutually exclusive. 63 */ 64enum ssam_request_flags { 65 SSAM_REQUEST_HAS_RESPONSE = BIT(0), 66 SSAM_REQUEST_UNSEQUENCED = BIT(1), 67}; 68 69/** 70 * struct ssam_request - SAM request description. 71 * @target_category: Category of the request's target. See &enum ssam_ssh_tc. 72 * @target_id: ID of the request's target. 73 * @command_id: Command ID of the request. 74 * @instance_id: Instance ID of the request's target. 75 * @flags: Flags for the request. See &enum ssam_request_flags. 76 * @length: Length of the request payload in bytes. 77 * @payload: Request payload data. 78 * 79 * This struct fully describes a SAM request with payload. It is intended to 80 * help set up the actual transport struct, e.g. &struct ssam_request_sync, 81 * and specifically its raw message data via ssam_request_write_data(). 82 */ 83struct ssam_request { 84 u8 target_category; 85 u8 target_id; 86 u8 command_id; 87 u8 instance_id; 88 u16 flags; 89 u16 length; 90 const u8 *payload; 91}; 92 93/** 94 * struct ssam_response - Response buffer for SAM request. 95 * @capacity: Capacity of the buffer, in bytes. 96 * @length: Length of the actual data stored in the memory pointed to by 97 * @pointer, in bytes. Set by the transport system. 98 * @pointer: Pointer to the buffer's memory, storing the response payload data. 99 */ 100struct ssam_response { 101 size_t capacity; 102 size_t length; 103 u8 *pointer; 104}; 105 106struct ssam_controller; 107 108struct ssam_controller *ssam_get_controller(void); 109struct ssam_controller *ssam_client_bind(struct device *client); 110int ssam_client_link(struct ssam_controller *ctrl, struct device *client); 111 112struct device *ssam_controller_device(struct ssam_controller *c); 113 114struct ssam_controller *ssam_controller_get(struct ssam_controller *c); 115void ssam_controller_put(struct ssam_controller *c); 116 117void ssam_controller_statelock(struct ssam_controller *c); 118void ssam_controller_stateunlock(struct ssam_controller *c); 119 120ssize_t ssam_request_write_data(struct ssam_span *buf, 121 struct ssam_controller *ctrl, 122 const struct ssam_request *spec); 123 124 125/* -- Synchronous request interface. ---------------------------------------- */ 126 127/** 128 * struct ssam_request_sync - Synchronous SAM request struct. 129 * @base: Underlying SSH request. 130 * @comp: Completion used to signal full completion of the request. After the 131 * request has been submitted, this struct may only be modified or 132 * deallocated after the completion has been signaled. 133 * request has been submitted, 134 * @resp: Buffer to store the response. 135 * @status: Status of the request, set after the base request has been 136 * completed or has failed. 137 */ 138struct ssam_request_sync { 139 struct ssh_request base; 140 struct completion comp; 141 struct ssam_response *resp; 142 int status; 143}; 144 145int ssam_request_sync_alloc(size_t payload_len, gfp_t flags, 146 struct ssam_request_sync **rqst, 147 struct ssam_span *buffer); 148 149void ssam_request_sync_free(struct ssam_request_sync *rqst); 150 151int ssam_request_sync_init(struct ssam_request_sync *rqst, 152 enum ssam_request_flags flags); 153 154/** 155 * ssam_request_sync_set_data - Set message data of a synchronous request. 156 * @rqst: The request. 157 * @ptr: Pointer to the request message data. 158 * @len: Length of the request message data. 159 * 160 * Set the request message data of a synchronous request. The provided buffer 161 * needs to live until the request has been completed. 162 */ 163static inline void ssam_request_sync_set_data(struct ssam_request_sync *rqst, 164 u8 *ptr, size_t len) 165{ 166 ssh_request_set_data(&rqst->base, ptr, len); 167} 168 169/** 170 * ssam_request_sync_set_resp - Set response buffer of a synchronous request. 171 * @rqst: The request. 172 * @resp: The response buffer. 173 * 174 * Sets the response buffer of a synchronous request. This buffer will store 175 * the response of the request after it has been completed. May be %NULL if no 176 * response is expected. 177 */ 178static inline void ssam_request_sync_set_resp(struct ssam_request_sync *rqst, 179 struct ssam_response *resp) 180{ 181 rqst->resp = resp; 182} 183 184int ssam_request_sync_submit(struct ssam_controller *ctrl, 185 struct ssam_request_sync *rqst); 186 187/** 188 * ssam_request_sync_wait - Wait for completion of a synchronous request. 189 * @rqst: The request to wait for. 190 * 191 * Wait for completion and release of a synchronous request. After this 192 * function terminates, the request is guaranteed to have left the transport 193 * system. After successful submission of a request, this function must be 194 * called before accessing the response of the request, freeing the request, 195 * or freeing any of the buffers associated with the request. 196 * 197 * This function must not be called if the request has not been submitted yet 198 * and may lead to a deadlock/infinite wait if a subsequent request submission 199 * fails in that case, due to the completion never triggering. 200 * 201 * Return: Returns the status of the given request, which is set on completion 202 * of the packet. This value is zero on success and negative on failure. 203 */ 204static inline int ssam_request_sync_wait(struct ssam_request_sync *rqst) 205{ 206 wait_for_completion(&rqst->comp); 207 return rqst->status; 208} 209 210int ssam_request_sync(struct ssam_controller *ctrl, 211 const struct ssam_request *spec, 212 struct ssam_response *rsp); 213 214int ssam_request_sync_with_buffer(struct ssam_controller *ctrl, 215 const struct ssam_request *spec, 216 struct ssam_response *rsp, 217 struct ssam_span *buf); 218 219/** 220 * ssam_request_sync_onstack - Execute a synchronous request on the stack. 221 * @ctrl: The controller via which the request is submitted. 222 * @rqst: The request specification. 223 * @rsp: The response buffer. 224 * @payload_len: The (maximum) request payload length. 225 * 226 * Allocates a synchronous request with specified payload length on the stack, 227 * fully initializes it via the provided request specification, submits it, 228 * and finally waits for its completion before returning its status. This 229 * helper macro essentially allocates the request message buffer on the stack 230 * and then calls ssam_request_sync_with_buffer(). 231 * 232 * Note: The @payload_len parameter specifies the maximum payload length, used 233 * for buffer allocation. The actual payload length may be smaller. 234 * 235 * Return: Returns the status of the request or any failure during setup, i.e. 236 * zero on success and a negative value on failure. 237 */ 238#define ssam_request_sync_onstack(ctrl, rqst, rsp, payload_len) \ 239 ({ \ 240 u8 __data[SSH_COMMAND_MESSAGE_LENGTH(payload_len)]; \ 241 struct ssam_span __buf = { &__data[0], ARRAY_SIZE(__data) }; \ 242 \ 243 ssam_request_sync_with_buffer(ctrl, rqst, rsp, &__buf); \ 244 }) 245 246/** 247 * __ssam_retry - Retry request in case of I/O errors or timeouts. 248 * @request: The request function to execute. Must return an integer. 249 * @n: Number of tries. 250 * @args: Arguments for the request function. 251 * 252 * Executes the given request function, i.e. calls @request. In case the 253 * request returns %-EREMOTEIO (indicates I/O error) or %-ETIMEDOUT (request 254 * or underlying packet timed out), @request will be re-executed again, up to 255 * @n times in total. 256 * 257 * Return: Returns the return value of the last execution of @request. 258 */ 259#define __ssam_retry(request, n, args...) \ 260 ({ \ 261 int __i, __s = 0; \ 262 \ 263 for (__i = (n); __i > 0; __i--) { \ 264 __s = request(args); \ 265 if (__s != -ETIMEDOUT && __s != -EREMOTEIO) \ 266 break; \ 267 } \ 268 __s; \ 269 }) 270 271/** 272 * ssam_retry - Retry request in case of I/O errors or timeouts up to three 273 * times in total. 274 * @request: The request function to execute. Must return an integer. 275 * @args: Arguments for the request function. 276 * 277 * Executes the given request function, i.e. calls @request. In case the 278 * request returns %-EREMOTEIO (indicates I/O error) or -%ETIMEDOUT (request 279 * or underlying packet timed out), @request will be re-executed again, up to 280 * three times in total. 281 * 282 * See __ssam_retry() for a more generic macro for this purpose. 283 * 284 * Return: Returns the return value of the last execution of @request. 285 */ 286#define ssam_retry(request, args...) \ 287 __ssam_retry(request, 3, args) 288 289/** 290 * struct ssam_request_spec - Blue-print specification of SAM request. 291 * @target_category: Category of the request's target. See &enum ssam_ssh_tc. 292 * @target_id: ID of the request's target. 293 * @command_id: Command ID of the request. 294 * @instance_id: Instance ID of the request's target. 295 * @flags: Flags for the request. See &enum ssam_request_flags. 296 * 297 * Blue-print specification for a SAM request. This struct describes the 298 * unique static parameters of a request (i.e. type) without specifying any of 299 * its instance-specific data (e.g. payload). It is intended to be used as base 300 * for defining simple request functions via the 301 * ``SSAM_DEFINE_SYNC_REQUEST_x()`` family of macros. 302 */ 303struct ssam_request_spec { 304 u8 target_category; 305 u8 target_id; 306 u8 command_id; 307 u8 instance_id; 308 u8 flags; 309}; 310 311/** 312 * struct ssam_request_spec_md - Blue-print specification for multi-device SAM 313 * request. 314 * @target_category: Category of the request's target. See &enum ssam_ssh_tc. 315 * @command_id: Command ID of the request. 316 * @flags: Flags for the request. See &enum ssam_request_flags. 317 * 318 * Blue-print specification for a multi-device SAM request, i.e. a request 319 * that is applicable to multiple device instances, described by their 320 * individual target and instance IDs. This struct describes the unique static 321 * parameters of a request (i.e. type) without specifying any of its 322 * instance-specific data (e.g. payload) and without specifying any of its 323 * device specific IDs (i.e. target and instance ID). It is intended to be 324 * used as base for defining simple multi-device request functions via the 325 * ``SSAM_DEFINE_SYNC_REQUEST_MD_x()`` and ``SSAM_DEFINE_SYNC_REQUEST_CL_x()`` 326 * families of macros. 327 */ 328struct ssam_request_spec_md { 329 u8 target_category; 330 u8 command_id; 331 u8 flags; 332}; 333 334/** 335 * SSAM_DEFINE_SYNC_REQUEST_N() - Define synchronous SAM request function 336 * with neither argument nor return value. 337 * @name: Name of the generated function. 338 * @spec: Specification (&struct ssam_request_spec) defining the request. 339 * 340 * Defines a function executing the synchronous SAM request specified by 341 * @spec, with the request having neither argument nor return value. The 342 * generated function takes care of setting up the request struct and buffer 343 * allocation, as well as execution of the request itself, returning once the 344 * request has been fully completed. The required transport buffer will be 345 * allocated on the stack. 346 * 347 * The generated function is defined as ``int name(struct ssam_controller 348 * *ctrl)``, returning the status of the request, which is zero on success and 349 * negative on failure. The ``ctrl`` parameter is the controller via which the 350 * request is being sent. 351 * 352 * Refer to ssam_request_sync_onstack() for more details on the behavior of 353 * the generated function. 354 */ 355#define SSAM_DEFINE_SYNC_REQUEST_N(name, spec...) \ 356 int name(struct ssam_controller *ctrl) \ 357 { \ 358 struct ssam_request_spec s = (struct ssam_request_spec)spec; \ 359 struct ssam_request rqst; \ 360 \ 361 rqst.target_category = s.target_category; \ 362 rqst.target_id = s.target_id; \ 363 rqst.command_id = s.command_id; \ 364 rqst.instance_id = s.instance_id; \ 365 rqst.flags = s.flags; \ 366 rqst.length = 0; \ 367 rqst.payload = NULL; \ 368 \ 369 return ssam_request_sync_onstack(ctrl, &rqst, NULL, 0); \ 370 } 371 372/** 373 * SSAM_DEFINE_SYNC_REQUEST_W() - Define synchronous SAM request function with 374 * argument. 375 * @name: Name of the generated function. 376 * @atype: Type of the request's argument. 377 * @spec: Specification (&struct ssam_request_spec) defining the request. 378 * 379 * Defines a function executing the synchronous SAM request specified by 380 * @spec, with the request taking an argument of type @atype and having no 381 * return value. The generated function takes care of setting up the request 382 * struct, buffer allocation, as well as execution of the request itself, 383 * returning once the request has been fully completed. The required transport 384 * buffer will be allocated on the stack. 385 * 386 * The generated function is defined as ``int name(struct ssam_controller 387 * *ctrl, const atype *arg)``, returning the status of the request, which is 388 * zero on success and negative on failure. The ``ctrl`` parameter is the 389 * controller via which the request is sent. The request argument is specified 390 * via the ``arg`` pointer. 391 * 392 * Refer to ssam_request_sync_onstack() for more details on the behavior of 393 * the generated function. 394 */ 395#define SSAM_DEFINE_SYNC_REQUEST_W(name, atype, spec...) \ 396 int name(struct ssam_controller *ctrl, const atype *arg) \ 397 { \ 398 struct ssam_request_spec s = (struct ssam_request_spec)spec; \ 399 struct ssam_request rqst; \ 400 \ 401 rqst.target_category = s.target_category; \ 402 rqst.target_id = s.target_id; \ 403 rqst.command_id = s.command_id; \ 404 rqst.instance_id = s.instance_id; \ 405 rqst.flags = s.flags; \ 406 rqst.length = sizeof(atype); \ 407 rqst.payload = (u8 *)arg; \ 408 \ 409 return ssam_request_sync_onstack(ctrl, &rqst, NULL, \ 410 sizeof(atype)); \ 411 } 412 413/** 414 * SSAM_DEFINE_SYNC_REQUEST_R() - Define synchronous SAM request function with 415 * return value. 416 * @name: Name of the generated function. 417 * @rtype: Type of the request's return value. 418 * @spec: Specification (&struct ssam_request_spec) defining the request. 419 * 420 * Defines a function executing the synchronous SAM request specified by 421 * @spec, with the request taking no argument but having a return value of 422 * type @rtype. The generated function takes care of setting up the request 423 * and response structs, buffer allocation, as well as execution of the 424 * request itself, returning once the request has been fully completed. The 425 * required transport buffer will be allocated on the stack. 426 * 427 * The generated function is defined as ``int name(struct ssam_controller 428 * *ctrl, rtype *ret)``, returning the status of the request, which is zero on 429 * success and negative on failure. The ``ctrl`` parameter is the controller 430 * via which the request is sent. The request's return value is written to the 431 * memory pointed to by the ``ret`` parameter. 432 * 433 * Refer to ssam_request_sync_onstack() for more details on the behavior of 434 * the generated function. 435 */ 436#define SSAM_DEFINE_SYNC_REQUEST_R(name, rtype, spec...) \ 437 int name(struct ssam_controller *ctrl, rtype *ret) \ 438 { \ 439 struct ssam_request_spec s = (struct ssam_request_spec)spec; \ 440 struct ssam_request rqst; \ 441 struct ssam_response rsp; \ 442 int status; \ 443 \ 444 rqst.target_category = s.target_category; \ 445 rqst.target_id = s.target_id; \ 446 rqst.command_id = s.command_id; \ 447 rqst.instance_id = s.instance_id; \ 448 rqst.flags = s.flags | SSAM_REQUEST_HAS_RESPONSE; \ 449 rqst.length = 0; \ 450 rqst.payload = NULL; \ 451 \ 452 rsp.capacity = sizeof(rtype); \ 453 rsp.length = 0; \ 454 rsp.pointer = (u8 *)ret; \ 455 \ 456 status = ssam_request_sync_onstack(ctrl, &rqst, &rsp, 0); \ 457 if (status) \ 458 return status; \ 459 \ 460 if (rsp.length != sizeof(rtype)) { \ 461 struct device *dev = ssam_controller_device(ctrl); \ 462 dev_err(dev, \ 463 "rqst: invalid response length, expected %zu, got %zu (tc: %#04x, cid: %#04x)", \ 464 sizeof(rtype), rsp.length, rqst.target_category,\ 465 rqst.command_id); \ 466 return -EIO; \ 467 } \ 468 \ 469 return 0; \ 470 } 471 472/** 473 * SSAM_DEFINE_SYNC_REQUEST_MD_N() - Define synchronous multi-device SAM 474 * request function with neither argument nor return value. 475 * @name: Name of the generated function. 476 * @spec: Specification (&struct ssam_request_spec_md) defining the request. 477 * 478 * Defines a function executing the synchronous SAM request specified by 479 * @spec, with the request having neither argument nor return value. Device 480 * specifying parameters are not hard-coded, but instead must be provided to 481 * the function. The generated function takes care of setting up the request 482 * struct, buffer allocation, as well as execution of the request itself, 483 * returning once the request has been fully completed. The required transport 484 * buffer will be allocated on the stack. 485 * 486 * The generated function is defined as ``int name(struct ssam_controller 487 * *ctrl, u8 tid, u8 iid)``, returning the status of the request, which is 488 * zero on success and negative on failure. The ``ctrl`` parameter is the 489 * controller via which the request is sent, ``tid`` the target ID for the 490 * request, and ``iid`` the instance ID. 491 * 492 * Refer to ssam_request_sync_onstack() for more details on the behavior of 493 * the generated function. 494 */ 495#define SSAM_DEFINE_SYNC_REQUEST_MD_N(name, spec...) \ 496 int name(struct ssam_controller *ctrl, u8 tid, u8 iid) \ 497 { \ 498 struct ssam_request_spec_md s = (struct ssam_request_spec_md)spec; \ 499 struct ssam_request rqst; \ 500 \ 501 rqst.target_category = s.target_category; \ 502 rqst.target_id = tid; \ 503 rqst.command_id = s.command_id; \ 504 rqst.instance_id = iid; \ 505 rqst.flags = s.flags; \ 506 rqst.length = 0; \ 507 rqst.payload = NULL; \ 508 \ 509 return ssam_request_sync_onstack(ctrl, &rqst, NULL, 0); \ 510 } 511 512/** 513 * SSAM_DEFINE_SYNC_REQUEST_MD_W() - Define synchronous multi-device SAM 514 * request function with argument. 515 * @name: Name of the generated function. 516 * @atype: Type of the request's argument. 517 * @spec: Specification (&struct ssam_request_spec_md) defining the request. 518 * 519 * Defines a function executing the synchronous SAM request specified by 520 * @spec, with the request taking an argument of type @atype and having no 521 * return value. Device specifying parameters are not hard-coded, but instead 522 * must be provided to the function. The generated function takes care of 523 * setting up the request struct, buffer allocation, as well as execution of 524 * the request itself, returning once the request has been fully completed. 525 * The required transport buffer will be allocated on the stack. 526 * 527 * The generated function is defined as ``int name(struct ssam_controller 528 * *ctrl, u8 tid, u8 iid, const atype *arg)``, returning the status of the 529 * request, which is zero on success and negative on failure. The ``ctrl`` 530 * parameter is the controller via which the request is sent, ``tid`` the 531 * target ID for the request, and ``iid`` the instance ID. The request argument 532 * is specified via the ``arg`` pointer. 533 * 534 * Refer to ssam_request_sync_onstack() for more details on the behavior of 535 * the generated function. 536 */ 537#define SSAM_DEFINE_SYNC_REQUEST_MD_W(name, atype, spec...) \ 538 int name(struct ssam_controller *ctrl, u8 tid, u8 iid, const atype *arg)\ 539 { \ 540 struct ssam_request_spec_md s = (struct ssam_request_spec_md)spec; \ 541 struct ssam_request rqst; \ 542 \ 543 rqst.target_category = s.target_category; \ 544 rqst.target_id = tid; \ 545 rqst.command_id = s.command_id; \ 546 rqst.instance_id = iid; \ 547 rqst.flags = s.flags; \ 548 rqst.length = sizeof(atype); \ 549 rqst.payload = (u8 *)arg; \ 550 \ 551 return ssam_request_sync_onstack(ctrl, &rqst, NULL, \ 552 sizeof(atype)); \ 553 } 554 555/** 556 * SSAM_DEFINE_SYNC_REQUEST_MD_R() - Define synchronous multi-device SAM 557 * request function with return value. 558 * @name: Name of the generated function. 559 * @rtype: Type of the request's return value. 560 * @spec: Specification (&struct ssam_request_spec_md) defining the request. 561 * 562 * Defines a function executing the synchronous SAM request specified by 563 * @spec, with the request taking no argument but having a return value of 564 * type @rtype. Device specifying parameters are not hard-coded, but instead 565 * must be provided to the function. The generated function takes care of 566 * setting up the request and response structs, buffer allocation, as well as 567 * execution of the request itself, returning once the request has been fully 568 * completed. The required transport buffer will be allocated on the stack. 569 * 570 * The generated function is defined as ``int name(struct ssam_controller 571 * *ctrl, u8 tid, u8 iid, rtype *ret)``, returning the status of the request, 572 * which is zero on success and negative on failure. The ``ctrl`` parameter is 573 * the controller via which the request is sent, ``tid`` the target ID for the 574 * request, and ``iid`` the instance ID. The request's return value is written 575 * to the memory pointed to by the ``ret`` parameter. 576 * 577 * Refer to ssam_request_sync_onstack() for more details on the behavior of 578 * the generated function. 579 */ 580#define SSAM_DEFINE_SYNC_REQUEST_MD_R(name, rtype, spec...) \ 581 int name(struct ssam_controller *ctrl, u8 tid, u8 iid, rtype *ret) \ 582 { \ 583 struct ssam_request_spec_md s = (struct ssam_request_spec_md)spec; \ 584 struct ssam_request rqst; \ 585 struct ssam_response rsp; \ 586 int status; \ 587 \ 588 rqst.target_category = s.target_category; \ 589 rqst.target_id = tid; \ 590 rqst.command_id = s.command_id; \ 591 rqst.instance_id = iid; \ 592 rqst.flags = s.flags | SSAM_REQUEST_HAS_RESPONSE; \ 593 rqst.length = 0; \ 594 rqst.payload = NULL; \ 595 \ 596 rsp.capacity = sizeof(rtype); \ 597 rsp.length = 0; \ 598 rsp.pointer = (u8 *)ret; \ 599 \ 600 status = ssam_request_sync_onstack(ctrl, &rqst, &rsp, 0); \ 601 if (status) \ 602 return status; \ 603 \ 604 if (rsp.length != sizeof(rtype)) { \ 605 struct device *dev = ssam_controller_device(ctrl); \ 606 dev_err(dev, \ 607 "rqst: invalid response length, expected %zu, got %zu (tc: %#04x, cid: %#04x)", \ 608 sizeof(rtype), rsp.length, rqst.target_category,\ 609 rqst.command_id); \ 610 return -EIO; \ 611 } \ 612 \ 613 return 0; \ 614 } 615 616 617/* -- Event notifier/callbacks. --------------------------------------------- */ 618 619#define SSAM_NOTIF_STATE_SHIFT 2 620#define SSAM_NOTIF_STATE_MASK ((1 << SSAM_NOTIF_STATE_SHIFT) - 1) 621 622/** 623 * enum ssam_notif_flags - Flags used in return values from SSAM notifier 624 * callback functions. 625 * 626 * @SSAM_NOTIF_HANDLED: 627 * Indicates that the notification has been handled. This flag should be 628 * set by the handler if the handler can act/has acted upon the event 629 * provided to it. This flag should not be set if the handler is not a 630 * primary handler intended for the provided event. 631 * 632 * If this flag has not been set by any handler after the notifier chain 633 * has been traversed, a warning will be emitted, stating that the event 634 * has not been handled. 635 * 636 * @SSAM_NOTIF_STOP: 637 * Indicates that the notifier traversal should stop. If this flag is 638 * returned from a notifier callback, notifier chain traversal will 639 * immediately stop and any remaining notifiers will not be called. This 640 * flag is automatically set when ssam_notifier_from_errno() is called 641 * with a negative error value. 642 */ 643enum ssam_notif_flags { 644 SSAM_NOTIF_HANDLED = BIT(0), 645 SSAM_NOTIF_STOP = BIT(1), 646}; 647 648struct ssam_event_notifier; 649 650typedef u32 (*ssam_notifier_fn_t)(struct ssam_event_notifier *nf, 651 const struct ssam_event *event); 652 653/** 654 * struct ssam_notifier_block - Base notifier block for SSAM event 655 * notifications. 656 * @node: The node for the list of notifiers. 657 * @fn: The callback function of this notifier. This function takes the 658 * respective notifier block and event as input and should return 659 * a notifier value, which can either be obtained from the flags 660 * provided in &enum ssam_notif_flags, converted from a standard 661 * error value via ssam_notifier_from_errno(), or a combination of 662 * both (e.g. ``ssam_notifier_from_errno(e) | SSAM_NOTIF_HANDLED``). 663 * @priority: Priority value determining the order in which notifier callbacks 664 * will be called. A higher value means higher priority, i.e. the 665 * associated callback will be executed earlier than other (lower 666 * priority) callbacks. 667 */ 668struct ssam_notifier_block { 669 struct list_head node; 670 ssam_notifier_fn_t fn; 671 int priority; 672}; 673 674/** 675 * ssam_notifier_from_errno() - Convert standard error value to notifier 676 * return code. 677 * @err: The error code to convert, must be negative (in case of failure) or 678 * zero (in case of success). 679 * 680 * Return: Returns the notifier return value obtained by converting the 681 * specified @err value. In case @err is negative, the %SSAM_NOTIF_STOP flag 682 * will be set, causing notifier call chain traversal to abort. 683 */ 684static inline u32 ssam_notifier_from_errno(int err) 685{ 686 if (WARN_ON(err > 0) || err == 0) 687 return 0; 688 else 689 return ((-err) << SSAM_NOTIF_STATE_SHIFT) | SSAM_NOTIF_STOP; 690} 691 692/** 693 * ssam_notifier_to_errno() - Convert notifier return code to standard error 694 * value. 695 * @ret: The notifier return value to convert. 696 * 697 * Return: Returns the negative error value encoded in @ret or zero if @ret 698 * indicates success. 699 */ 700static inline int ssam_notifier_to_errno(u32 ret) 701{ 702 return -(ret >> SSAM_NOTIF_STATE_SHIFT); 703} 704 705 706/* -- Event/notification registry. ------------------------------------------ */ 707 708/** 709 * struct ssam_event_registry - Registry specification used for enabling events. 710 * @target_category: Target category for the event registry requests. 711 * @target_id: Target ID for the event registry requests. 712 * @cid_enable: Command ID for the event-enable request. 713 * @cid_disable: Command ID for the event-disable request. 714 * 715 * This struct describes a SAM event registry via the minimal collection of 716 * SAM IDs specifying the requests to use for enabling and disabling an event. 717 * The individual event to be enabled/disabled itself is specified via &struct 718 * ssam_event_id. 719 */ 720struct ssam_event_registry { 721 u8 target_category; 722 u8 target_id; 723 u8 cid_enable; 724 u8 cid_disable; 725}; 726 727/** 728 * struct ssam_event_id - Unique event ID used for enabling events. 729 * @target_category: Target category of the event source. 730 * @instance: Instance ID of the event source. 731 * 732 * This struct specifies the event to be enabled/disabled via an externally 733 * provided registry. It does not specify the registry to be used itself, this 734 * is done via &struct ssam_event_registry. 735 */ 736struct ssam_event_id { 737 u8 target_category; 738 u8 instance; 739}; 740 741/** 742 * enum ssam_event_mask - Flags specifying how events are matched to notifiers. 743 * 744 * @SSAM_EVENT_MASK_NONE: 745 * Run the callback for any event with matching target category. Do not 746 * do any additional filtering. 747 * 748 * @SSAM_EVENT_MASK_TARGET: 749 * In addition to filtering by target category, only execute the notifier 750 * callback for events with a target ID matching to the one of the 751 * registry used for enabling/disabling the event. 752 * 753 * @SSAM_EVENT_MASK_INSTANCE: 754 * In addition to filtering by target category, only execute the notifier 755 * callback for events with an instance ID matching to the instance ID 756 * used when enabling the event. 757 * 758 * @SSAM_EVENT_MASK_STRICT: 759 * Do all the filtering above. 760 */ 761enum ssam_event_mask { 762 SSAM_EVENT_MASK_TARGET = BIT(0), 763 SSAM_EVENT_MASK_INSTANCE = BIT(1), 764 765 SSAM_EVENT_MASK_NONE = 0, 766 SSAM_EVENT_MASK_STRICT = 767 SSAM_EVENT_MASK_TARGET 768 | SSAM_EVENT_MASK_INSTANCE, 769}; 770 771/** 772 * SSAM_EVENT_REGISTRY() - Define a new event registry. 773 * @tc: Target category for the event registry requests. 774 * @tid: Target ID for the event registry requests. 775 * @cid_en: Command ID for the event-enable request. 776 * @cid_dis: Command ID for the event-disable request. 777 * 778 * Return: Returns the &struct ssam_event_registry specified by the given 779 * parameters. 780 */ 781#define SSAM_EVENT_REGISTRY(tc, tid, cid_en, cid_dis) \ 782 ((struct ssam_event_registry) { \ 783 .target_category = (tc), \ 784 .target_id = (tid), \ 785 .cid_enable = (cid_en), \ 786 .cid_disable = (cid_dis), \ 787 }) 788 789#define SSAM_EVENT_REGISTRY_SAM \ 790 SSAM_EVENT_REGISTRY(SSAM_SSH_TC_SAM, 0x01, 0x0b, 0x0c) 791 792#define SSAM_EVENT_REGISTRY_KIP \ 793 SSAM_EVENT_REGISTRY(SSAM_SSH_TC_KIP, 0x02, 0x27, 0x28) 794 795#define SSAM_EVENT_REGISTRY_REG \ 796 SSAM_EVENT_REGISTRY(SSAM_SSH_TC_REG, 0x02, 0x01, 0x02) 797 798/** 799 * struct ssam_event_notifier - Notifier block for SSAM events. 800 * @base: The base notifier block with callback function and priority. 801 * @event: The event for which this block will receive notifications. 802 * @event.reg: Registry via which the event will be enabled/disabled. 803 * @event.id: ID specifying the event. 804 * @event.mask: Flags determining how events are matched to the notifier. 805 * @event.flags: Flags used for enabling the event. 806 */ 807struct ssam_event_notifier { 808 struct ssam_notifier_block base; 809 810 struct { 811 struct ssam_event_registry reg; 812 struct ssam_event_id id; 813 enum ssam_event_mask mask; 814 u8 flags; 815 } event; 816}; 817 818int ssam_notifier_register(struct ssam_controller *ctrl, 819 struct ssam_event_notifier *n); 820 821int ssam_notifier_unregister(struct ssam_controller *ctrl, 822 struct ssam_event_notifier *n); 823 824#endif /* _LINUX_SURFACE_AGGREGATOR_CONTROLLER_H */ 825