1 /* SPDX-License-Identifier: GPL-2.0-only */ 2 /* 3 * cec - HDMI Consumer Electronics Control support header 4 * 5 * Copyright 2016 Cisco Systems, Inc. and/or its affiliates. All rights reserved. 6 */ 7 8 #ifndef _MEDIA_CEC_H 9 #define _MEDIA_CEC_H 10 11 #include <linux/poll.h> 12 #include <linux/fs.h> 13 #include <linux/device.h> 14 #include <linux/cdev.h> 15 #include <linux/kthread.h> 16 #include <linux/timer.h> 17 #include <linux/cec-funcs.h> 18 #include <media/rc-core.h> 19 20 #define CEC_CAP_DEFAULTS (CEC_CAP_LOG_ADDRS | CEC_CAP_TRANSMIT | \ 21 CEC_CAP_PASSTHROUGH | CEC_CAP_RC) 22 23 /** 24 * struct cec_devnode - cec device node 25 * @dev: cec device 26 * @cdev: cec character device 27 * @minor: device node minor number 28 * @lock: lock to serialize open/release and registration 29 * @registered: the device was correctly registered 30 * @unregistered: the device was unregistered 31 * @lock_fhs: lock to control access to @fhs 32 * @fhs: the list of open filehandles (cec_fh) 33 * 34 * This structure represents a cec-related device node. 35 * 36 * To add or remove filehandles from @fhs the @lock must be taken first, 37 * followed by @lock_fhs. It is safe to access @fhs if either lock is held. 38 * 39 * The @parent is a physical device. It must be set by core or device drivers 40 * before registering the node. 41 */ 42 struct cec_devnode { 43 /* sysfs */ 44 struct device dev; 45 struct cdev cdev; 46 47 /* device info */ 48 int minor; 49 /* serialize open/release and registration */ 50 struct mutex lock; 51 bool registered; 52 bool unregistered; 53 /* protect access to fhs */ 54 struct mutex lock_fhs; 55 struct list_head fhs; 56 }; 57 58 struct cec_adapter; 59 struct cec_data; 60 struct cec_pin; 61 struct cec_notifier; 62 63 struct cec_data { 64 struct list_head list; 65 struct list_head xfer_list; 66 struct cec_adapter *adap; 67 struct cec_msg msg; 68 u8 match_len; 69 u8 match_reply[5]; 70 struct cec_fh *fh; 71 struct delayed_work work; 72 struct completion c; 73 u8 attempts; 74 bool blocking; 75 bool completed; 76 }; 77 78 struct cec_msg_entry { 79 struct list_head list; 80 struct cec_msg msg; 81 }; 82 83 struct cec_event_entry { 84 struct list_head list; 85 struct cec_event ev; 86 }; 87 88 #define CEC_NUM_EVENTS CEC_EVENT_PIN_5V_HIGH 89 90 struct cec_fh { 91 struct list_head list; 92 struct list_head xfer_list; 93 struct cec_adapter *adap; 94 u8 mode_initiator; 95 u8 mode_follower; 96 97 /* Events */ 98 wait_queue_head_t wait; 99 struct mutex lock; 100 struct list_head events[CEC_NUM_EVENTS]; /* queued events */ 101 u16 queued_events[CEC_NUM_EVENTS]; 102 unsigned int total_queued_events; 103 struct list_head msgs; /* queued messages */ 104 unsigned int queued_msgs; 105 }; 106 107 #define CEC_SIGNAL_FREE_TIME_RETRY 3 108 #define CEC_SIGNAL_FREE_TIME_NEW_INITIATOR 5 109 #define CEC_SIGNAL_FREE_TIME_NEXT_XFER 7 110 111 /* The nominal data bit period is 2.4 ms */ 112 #define CEC_FREE_TIME_TO_USEC(ft) ((ft) * 2400) 113 114 struct cec_adap_ops { 115 /* Low-level callbacks, called with adap->lock held */ 116 int (*adap_enable)(struct cec_adapter *adap, bool enable); 117 int (*adap_monitor_all_enable)(struct cec_adapter *adap, bool enable); 118 int (*adap_monitor_pin_enable)(struct cec_adapter *adap, bool enable); 119 int (*adap_log_addr)(struct cec_adapter *adap, u8 logical_addr); 120 void (*adap_unconfigured)(struct cec_adapter *adap); 121 int (*adap_transmit)(struct cec_adapter *adap, u8 attempts, 122 u32 signal_free_time, struct cec_msg *msg); 123 void (*adap_nb_transmit_canceled)(struct cec_adapter *adap, 124 const struct cec_msg *msg); 125 void (*adap_status)(struct cec_adapter *adap, struct seq_file *file); 126 void (*adap_free)(struct cec_adapter *adap); 127 128 /* Error injection callbacks, called without adap->lock held */ 129 int (*error_inj_show)(struct cec_adapter *adap, struct seq_file *sf); 130 bool (*error_inj_parse_line)(struct cec_adapter *adap, char *line); 131 132 /* High-level CEC message callback, called without adap->lock held */ 133 void (*configured)(struct cec_adapter *adap); 134 int (*received)(struct cec_adapter *adap, struct cec_msg *msg); 135 }; 136 137 /* 138 * The minimum message length you can receive (excepting poll messages) is 2. 139 * With a transfer rate of at most 36 bytes per second this makes 18 messages 140 * per second worst case. 141 * 142 * We queue at most 3 seconds worth of received messages. The CEC specification 143 * requires that messages are replied to within a second, so 3 seconds should 144 * give more than enough margin. Since most messages are actually more than 2 145 * bytes, this is in practice a lot more than 3 seconds. 146 */ 147 #define CEC_MAX_MSG_RX_QUEUE_SZ (18 * 3) 148 149 /* 150 * The transmit queue is limited to 1 second worth of messages (worst case). 151 * Messages can be transmitted by userspace and kernel space. But for both it 152 * makes no sense to have a lot of messages queued up. One second seems 153 * reasonable. 154 */ 155 #define CEC_MAX_MSG_TX_QUEUE_SZ (18 * 1) 156 157 /** 158 * struct cec_adapter - cec adapter structure 159 * @owner: module owner 160 * @name: name of the CEC adapter 161 * @devnode: device node for the /dev/cecX device 162 * @lock: mutex controlling access to this structure 163 * @rc: remote control device 164 * @transmit_queue: queue of pending transmits 165 * @transmit_queue_sz: number of pending transmits 166 * @wait_queue: queue of transmits waiting for a reply 167 * @transmitting: CEC messages currently being transmitted 168 * @transmit_in_progress: true if a transmit is in progress 169 * @transmit_in_progress_aborted: true if a transmit is in progress is to be 170 * aborted. This happens if the logical address is 171 * invalidated while the transmit is ongoing. In that 172 * case the transmit will finish, but will not retransmit 173 * and be marked as ABORTED. 174 * @xfer_timeout_ms: the transfer timeout in ms. 175 * If 0, then timeout after 2100 ms. 176 * @kthread_config: kthread used to configure a CEC adapter 177 * @config_completion: used to signal completion of the config kthread 178 * @kthread: main CEC processing thread 179 * @kthread_waitq: main CEC processing wait_queue 180 * @ops: cec adapter ops 181 * @priv: cec driver's private data 182 * @capabilities: cec adapter capabilities 183 * @available_log_addrs: maximum number of available logical addresses 184 * @phys_addr: the current physical address 185 * @needs_hpd: if true, then the HDMI HotPlug Detect pin must be high 186 * in order to transmit or receive CEC messages. This is usually a HW 187 * limitation. 188 * @is_enabled: the CEC adapter is enabled 189 * @is_claiming_log_addrs: true if cec_claim_log_addrs() is running 190 * @is_configuring: the CEC adapter is configuring (i.e. claiming LAs) 191 * @must_reconfigure: while configuring, the PA changed, so reclaim LAs 192 * @is_configured: the CEC adapter is configured (i.e. has claimed LAs) 193 * @cec_pin_is_high: if true then the CEC pin is high. Only used with the 194 * CEC pin framework. 195 * @adap_controls_phys_addr: if true, then the CEC adapter controls the 196 * physical address, i.e. the CEC hardware can detect HPD changes and 197 * read the EDID and is not dependent on an external HDMI driver. 198 * Drivers that need this can set this field to true after the 199 * cec_allocate_adapter() call. 200 * @last_initiator: the initiator of the last transmitted message. 201 * @monitor_all_cnt: number of filehandles monitoring all msgs 202 * @monitor_pin_cnt: number of filehandles monitoring pin changes 203 * @follower_cnt: number of filehandles in follower mode 204 * @cec_follower: filehandle of the exclusive follower 205 * @cec_initiator: filehandle of the exclusive initiator 206 * @passthrough: if true, then the exclusive follower is in 207 * passthrough mode. 208 * @log_addrs: current logical addresses 209 * @conn_info: current connector info 210 * @tx_timeout_cnt: count the number of Timed Out transmits. 211 * Reset to 0 when this is reported in cec_adap_status(). 212 * @tx_low_drive_cnt: count the number of Low Drive transmits. 213 * Reset to 0 when this is reported in cec_adap_status(). 214 * @tx_error_cnt: count the number of Error transmits. 215 * Reset to 0 when this is reported in cec_adap_status(). 216 * @tx_arb_lost_cnt: count the number of Arb Lost transmits. 217 * Reset to 0 when this is reported in cec_adap_status(). 218 * @tx_low_drive_log_cnt: number of logged Low Drive transmits since the 219 * adapter was enabled. Used to avoid flooding the kernel 220 * log if this happens a lot. 221 * @tx_error_log_cnt: number of logged Error transmits since the adapter was 222 * enabled. Used to avoid flooding the kernel log if this 223 * happens a lot. 224 * @error_inj_tx_timeouts: error injection: the next @error_inj_tx_timeouts 225 * transmits will time out. 226 * @notifier: CEC notifier 227 * @pin: CEC pin status struct 228 * @cec_dir: debugfs cec directory 229 * @sequence: transmit sequence counter 230 * @input_phys: remote control input_phys name 231 * 232 * This structure represents a cec adapter. 233 */ 234 struct cec_adapter { 235 struct module *owner; 236 char name[32]; 237 struct cec_devnode devnode; 238 struct mutex lock; 239 struct rc_dev *rc; 240 241 struct list_head transmit_queue; 242 unsigned int transmit_queue_sz; 243 struct list_head wait_queue; 244 struct cec_data *transmitting; 245 bool transmit_in_progress; 246 bool transmit_in_progress_aborted; 247 unsigned int xfer_timeout_ms; 248 249 struct task_struct *kthread_config; 250 struct completion config_completion; 251 252 struct task_struct *kthread; 253 wait_queue_head_t kthread_waitq; 254 255 const struct cec_adap_ops *ops; 256 void *priv; 257 u32 capabilities; 258 u8 available_log_addrs; 259 260 u16 phys_addr; 261 bool needs_hpd; 262 bool is_enabled; 263 bool is_claiming_log_addrs; 264 bool is_configuring; 265 bool must_reconfigure; 266 bool is_configured; 267 bool cec_pin_is_high; 268 bool adap_controls_phys_addr; 269 u8 last_initiator; 270 u32 monitor_all_cnt; 271 u32 monitor_pin_cnt; 272 u32 follower_cnt; 273 struct cec_fh *cec_follower; 274 struct cec_fh *cec_initiator; 275 bool passthrough; 276 struct cec_log_addrs log_addrs; 277 struct cec_connector_info conn_info; 278 279 u32 tx_timeout_cnt; 280 u32 tx_low_drive_cnt; 281 u32 tx_error_cnt; 282 u32 tx_arb_lost_cnt; 283 u32 tx_low_drive_log_cnt; 284 u32 tx_error_log_cnt; 285 286 u32 error_inj_tx_timeouts; 287 288 #ifdef CONFIG_CEC_NOTIFIER 289 struct cec_notifier *notifier; 290 #endif 291 #ifdef CONFIG_CEC_PIN 292 struct cec_pin *pin; 293 #endif 294 295 struct dentry *cec_dir; 296 297 u32 sequence; 298 299 char input_phys[40]; 300 }; 301 302 static inline int cec_get_device(struct cec_adapter *adap) 303 { 304 struct cec_devnode *devnode = &adap->devnode; 305 306 /* 307 * Check if the cec device is available. This needs to be done with 308 * the devnode->lock held to prevent an open/unregister race: 309 * without the lock, the device could be unregistered and freed between 310 * the devnode->registered check and get_device() calls, leading to 311 * a crash. 312 */ 313 mutex_lock(&devnode->lock); 314 /* 315 * return ENODEV if the cec device has been removed 316 * already or if it is not registered anymore. 317 */ 318 if (!devnode->registered) { 319 mutex_unlock(&devnode->lock); 320 return -ENODEV; 321 } 322 /* and increase the device refcount */ 323 get_device(&devnode->dev); 324 mutex_unlock(&devnode->lock); 325 return 0; 326 } 327 328 static inline void cec_put_device(struct cec_adapter *adap) 329 { 330 put_device(&adap->devnode.dev); 331 } 332 333 static inline void *cec_get_drvdata(const struct cec_adapter *adap) 334 { 335 return adap->priv; 336 } 337 338 static inline bool cec_has_log_addr(const struct cec_adapter *adap, u8 log_addr) 339 { 340 return adap->log_addrs.log_addr_mask & (1 << log_addr); 341 } 342 343 static inline bool cec_is_sink(const struct cec_adapter *adap) 344 { 345 return adap->phys_addr == 0; 346 } 347 348 /** 349 * cec_is_registered() - is the CEC adapter registered? 350 * 351 * @adap: the CEC adapter, may be NULL. 352 * 353 * Return: true if the adapter is registered, false otherwise. 354 */ 355 static inline bool cec_is_registered(const struct cec_adapter *adap) 356 { 357 return adap && adap->devnode.registered; 358 } 359 360 #define cec_phys_addr_exp(pa) \ 361 ((pa) >> 12), ((pa) >> 8) & 0xf, ((pa) >> 4) & 0xf, (pa) & 0xf 362 363 struct edid; 364 struct drm_connector; 365 366 #if IS_REACHABLE(CONFIG_CEC_CORE) 367 struct cec_adapter *cec_allocate_adapter(const struct cec_adap_ops *ops, 368 void *priv, const char *name, u32 caps, u8 available_las); 369 int cec_register_adapter(struct cec_adapter *adap, struct device *parent); 370 void cec_unregister_adapter(struct cec_adapter *adap); 371 void cec_delete_adapter(struct cec_adapter *adap); 372 373 int cec_s_log_addrs(struct cec_adapter *adap, struct cec_log_addrs *log_addrs, 374 bool block); 375 void cec_s_phys_addr(struct cec_adapter *adap, u16 phys_addr, 376 bool block); 377 void cec_s_phys_addr_from_edid(struct cec_adapter *adap, 378 const struct edid *edid); 379 void cec_s_conn_info(struct cec_adapter *adap, 380 const struct cec_connector_info *conn_info); 381 int cec_transmit_msg(struct cec_adapter *adap, struct cec_msg *msg, 382 bool block); 383 384 /* Called by the adapter */ 385 void cec_transmit_done_ts(struct cec_adapter *adap, u8 status, 386 u8 arb_lost_cnt, u8 nack_cnt, u8 low_drive_cnt, 387 u8 error_cnt, ktime_t ts); 388 389 static inline void cec_transmit_done(struct cec_adapter *adap, u8 status, 390 u8 arb_lost_cnt, u8 nack_cnt, 391 u8 low_drive_cnt, u8 error_cnt) 392 { 393 cec_transmit_done_ts(adap, status, arb_lost_cnt, nack_cnt, 394 low_drive_cnt, error_cnt, ktime_get()); 395 } 396 /* 397 * Simplified version of cec_transmit_done for hardware that doesn't retry 398 * failed transmits. So this is always just one attempt in which case 399 * the status is sufficient. 400 */ 401 void cec_transmit_attempt_done_ts(struct cec_adapter *adap, 402 u8 status, ktime_t ts); 403 404 static inline void cec_transmit_attempt_done(struct cec_adapter *adap, 405 u8 status) 406 { 407 cec_transmit_attempt_done_ts(adap, status, ktime_get()); 408 } 409 410 void cec_received_msg_ts(struct cec_adapter *adap, 411 struct cec_msg *msg, ktime_t ts); 412 413 static inline void cec_received_msg(struct cec_adapter *adap, 414 struct cec_msg *msg) 415 { 416 cec_received_msg_ts(adap, msg, ktime_get()); 417 } 418 419 /** 420 * cec_queue_pin_cec_event() - queue a CEC pin event with a given timestamp. 421 * 422 * @adap: pointer to the cec adapter 423 * @is_high: when true the CEC pin is high, otherwise it is low 424 * @dropped_events: when true some events were dropped 425 * @ts: the timestamp for this event 426 * 427 */ 428 void cec_queue_pin_cec_event(struct cec_adapter *adap, bool is_high, 429 bool dropped_events, ktime_t ts); 430 431 /** 432 * cec_queue_pin_hpd_event() - queue a pin event with a given timestamp. 433 * 434 * @adap: pointer to the cec adapter 435 * @is_high: when true the HPD pin is high, otherwise it is low 436 * @ts: the timestamp for this event 437 * 438 */ 439 void cec_queue_pin_hpd_event(struct cec_adapter *adap, bool is_high, ktime_t ts); 440 441 /** 442 * cec_queue_pin_5v_event() - queue a pin event with a given timestamp. 443 * 444 * @adap: pointer to the cec adapter 445 * @is_high: when true the 5V pin is high, otherwise it is low 446 * @ts: the timestamp for this event 447 * 448 */ 449 void cec_queue_pin_5v_event(struct cec_adapter *adap, bool is_high, ktime_t ts); 450 451 /** 452 * cec_get_edid_phys_addr() - find and return the physical address 453 * 454 * @edid: pointer to the EDID data 455 * @size: size in bytes of the EDID data 456 * @offset: If not %NULL then the location of the physical address 457 * bytes in the EDID will be returned here. This is set to 0 458 * if there is no physical address found. 459 * 460 * Return: the physical address or CEC_PHYS_ADDR_INVALID if there is none. 461 */ 462 u16 cec_get_edid_phys_addr(const u8 *edid, unsigned int size, 463 unsigned int *offset); 464 465 void cec_fill_conn_info_from_drm(struct cec_connector_info *conn_info, 466 const struct drm_connector *connector); 467 468 #else 469 470 static inline int cec_register_adapter(struct cec_adapter *adap, 471 struct device *parent) 472 { 473 return 0; 474 } 475 476 static inline void cec_unregister_adapter(struct cec_adapter *adap) 477 { 478 } 479 480 static inline void cec_delete_adapter(struct cec_adapter *adap) 481 { 482 } 483 484 static inline void cec_s_phys_addr(struct cec_adapter *adap, u16 phys_addr, 485 bool block) 486 { 487 } 488 489 static inline void cec_s_phys_addr_from_edid(struct cec_adapter *adap, 490 const struct edid *edid) 491 { 492 } 493 494 static inline u16 cec_get_edid_phys_addr(const u8 *edid, unsigned int size, 495 unsigned int *offset) 496 { 497 if (offset) 498 *offset = 0; 499 return CEC_PHYS_ADDR_INVALID; 500 } 501 502 static inline void cec_s_conn_info(struct cec_adapter *adap, 503 const struct cec_connector_info *conn_info) 504 { 505 } 506 507 static inline void 508 cec_fill_conn_info_from_drm(struct cec_connector_info *conn_info, 509 const struct drm_connector *connector) 510 { 511 memset(conn_info, 0, sizeof(*conn_info)); 512 } 513 514 #endif 515 516 /** 517 * cec_phys_addr_invalidate() - set the physical address to INVALID 518 * 519 * @adap: the CEC adapter 520 * 521 * This is a simple helper function to invalidate the physical 522 * address. 523 */ 524 static inline void cec_phys_addr_invalidate(struct cec_adapter *adap) 525 { 526 cec_s_phys_addr(adap, CEC_PHYS_ADDR_INVALID, false); 527 } 528 529 /** 530 * cec_get_edid_spa_location() - find location of the Source Physical Address 531 * 532 * @edid: the EDID 533 * @size: the size of the EDID 534 * 535 * This EDID is expected to be a CEA-861 compliant, which means that there are 536 * at least two blocks and one or more of the extensions blocks are CEA-861 537 * blocks. 538 * 539 * The returned location is guaranteed to be <= size-2. 540 * 541 * This is an inline function since it is used by both CEC and V4L2. 542 * Ideally this would go in a module shared by both, but it is overkill to do 543 * that for just a single function. 544 */ 545 static inline unsigned int cec_get_edid_spa_location(const u8 *edid, 546 unsigned int size) 547 { 548 unsigned int blocks = size / 128; 549 unsigned int block; 550 u8 d; 551 552 /* Sanity check: at least 2 blocks and a multiple of the block size */ 553 if (blocks < 2 || size % 128) 554 return 0; 555 556 /* 557 * If there are fewer extension blocks than the size, then update 558 * 'blocks'. It is allowed to have more extension blocks than the size, 559 * since some hardware can only read e.g. 256 bytes of the EDID, even 560 * though more blocks are present. The first CEA-861 extension block 561 * should normally be in block 1 anyway. 562 */ 563 if (edid[0x7e] + 1 < blocks) 564 blocks = edid[0x7e] + 1; 565 566 for (block = 1; block < blocks; block++) { 567 unsigned int offset = block * 128; 568 569 /* Skip any non-CEA-861 extension blocks */ 570 if (edid[offset] != 0x02 || edid[offset + 1] != 0x03) 571 continue; 572 573 /* search Vendor Specific Data Block (tag 3) */ 574 d = edid[offset + 2] & 0x7f; 575 /* Check if there are Data Blocks */ 576 if (d <= 4) 577 continue; 578 if (d > 4) { 579 unsigned int i = offset + 4; 580 unsigned int end = offset + d; 581 582 /* Note: 'end' is always < 'size' */ 583 do { 584 u8 tag = edid[i] >> 5; 585 u8 len = edid[i] & 0x1f; 586 587 if (tag == 3 && len >= 5 && i + len <= end && 588 edid[i + 1] == 0x03 && 589 edid[i + 2] == 0x0c && 590 edid[i + 3] == 0x00) 591 return i + 4; 592 i += len + 1; 593 } while (i < end); 594 } 595 } 596 return 0; 597 } 598 599 #endif /* _MEDIA_CEC_H */ 600