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