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/debugfs.h> 14 #include <linux/device.h> 15 #include <linux/cdev.h> 16 #include <linux/kthread.h> 17 #include <linux/timer.h> 18 #include <linux/cec-funcs.h> 19 #include <media/rc-core.h> 20 21 #define CEC_CAP_DEFAULTS (CEC_CAP_LOG_ADDRS | CEC_CAP_TRANSMIT | \ 22 CEC_CAP_PASSTHROUGH | CEC_CAP_RC) 23 24 /** 25 * struct cec_devnode - cec device node 26 * @dev: cec device 27 * @cdev: cec character device 28 * @minor: device node minor number 29 * @lock: lock to serialize open/release and registration 30 * @registered: the device was correctly registered 31 * @unregistered: the device was unregistered 32 * @lock_fhs: lock to control access to @fhs 33 * @fhs: the list of open filehandles (cec_fh) 34 * 35 * This structure represents a cec-related device node. 36 * 37 * To add or remove filehandles from @fhs the @lock must be taken first, 38 * followed by @lock_fhs. It is safe to access @fhs if either lock is held. 39 * 40 * The @parent is a physical device. It must be set by core or device drivers 41 * before registering the node. 42 */ 43 struct cec_devnode { 44 /* sysfs */ 45 struct device dev; 46 struct cdev cdev; 47 48 /* device info */ 49 int minor; 50 /* serialize open/release and registration */ 51 struct mutex lock; 52 bool registered; 53 bool unregistered; 54 /* protect access to fhs */ 55 struct mutex lock_fhs; 56 struct list_head fhs; 57 }; 58 59 struct cec_adapter; 60 struct cec_data; 61 struct cec_pin; 62 struct cec_notifier; 63 64 struct cec_data { 65 struct list_head list; 66 struct list_head xfer_list; 67 struct cec_adapter *adap; 68 struct cec_msg msg; 69 struct cec_fh *fh; 70 struct delayed_work work; 71 struct completion c; 72 u8 attempts; 73 bool blocking; 74 bool completed; 75 }; 76 77 struct cec_msg_entry { 78 struct list_head list; 79 struct cec_msg msg; 80 }; 81 82 struct cec_event_entry { 83 struct list_head list; 84 struct cec_event ev; 85 }; 86 87 #define CEC_NUM_CORE_EVENTS 2 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 cec_event_entry core_events[CEC_NUM_CORE_EVENTS]; 104 struct list_head msgs; /* queued messages */ 105 unsigned int queued_msgs; 106 }; 107 108 #define CEC_SIGNAL_FREE_TIME_RETRY 3 109 #define CEC_SIGNAL_FREE_TIME_NEW_INITIATOR 5 110 #define CEC_SIGNAL_FREE_TIME_NEXT_XFER 7 111 112 /* The nominal data bit period is 2.4 ms */ 113 #define CEC_FREE_TIME_TO_USEC(ft) ((ft) * 2400) 114 115 struct cec_adap_ops { 116 /* Low-level callbacks, called with adap->lock held */ 117 int (*adap_enable)(struct cec_adapter *adap, bool enable); 118 int (*adap_monitor_all_enable)(struct cec_adapter *adap, bool enable); 119 int (*adap_monitor_pin_enable)(struct cec_adapter *adap, bool enable); 120 int (*adap_log_addr)(struct cec_adapter *adap, u8 logical_addr); 121 void (*adap_unconfigured)(struct cec_adapter *adap); 122 int (*adap_transmit)(struct cec_adapter *adap, u8 attempts, 123 u32 signal_free_time, struct cec_msg *msg); 124 void (*adap_nb_transmit_canceled)(struct cec_adapter *adap, 125 const struct cec_msg *msg); 126 void (*adap_status)(struct cec_adapter *adap, struct seq_file *file); 127 void (*adap_free)(struct cec_adapter *adap); 128 129 /* Error injection callbacks, called without adap->lock held */ 130 int (*error_inj_show)(struct cec_adapter *adap, struct seq_file *sf); 131 bool (*error_inj_parse_line)(struct cec_adapter *adap, char *line); 132 133 /* High-level CEC message callback, called without adap->lock held */ 134 void (*configured)(struct cec_adapter *adap); 135 int (*received)(struct cec_adapter *adap, struct cec_msg *msg); 136 }; 137 138 /* 139 * The minimum message length you can receive (excepting poll messages) is 2. 140 * With a transfer rate of at most 36 bytes per second this makes 18 messages 141 * per second worst case. 142 * 143 * We queue at most 3 seconds worth of received messages. The CEC specification 144 * requires that messages are replied to within a second, so 3 seconds should 145 * give more than enough margin. Since most messages are actually more than 2 146 * bytes, this is in practice a lot more than 3 seconds. 147 */ 148 #define CEC_MAX_MSG_RX_QUEUE_SZ (18 * 3) 149 150 /* 151 * The transmit queue is limited to 1 second worth of messages (worst case). 152 * Messages can be transmitted by userspace and kernel space. But for both it 153 * makes no sense to have a lot of messages queued up. One second seems 154 * reasonable. 155 */ 156 #define CEC_MAX_MSG_TX_QUEUE_SZ (18 * 1) 157 158 /** 159 * struct cec_adapter - cec adapter structure 160 * @owner: module owner 161 * @name: name of the CEC adapter 162 * @devnode: device node for the /dev/cecX device 163 * @lock: mutex controlling access to this structure 164 * @rc: remote control device 165 * @transmit_queue: queue of pending transmits 166 * @transmit_queue_sz: number of pending transmits 167 * @wait_queue: queue of transmits waiting for a reply 168 * @transmitting: CEC messages currently being transmitted 169 * @transmit_in_progress: true if a transmit is in progress 170 * @transmit_in_progress_aborted: true if a transmit is in progress is to be 171 * aborted. This happens if the logical address is 172 * invalidated while the transmit is ongoing. In that 173 * case the transmit will finish, but will not retransmit 174 * and be marked as ABORTED. 175 * @xfer_timeout_ms: the transfer timeout in ms. 176 * If 0, then timeout after 2.1 ms. 177 * @kthread_config: kthread used to configure a CEC adapter 178 * @config_completion: used to signal completion of the config kthread 179 * @kthread: main CEC processing thread 180 * @kthread_waitq: main CEC processing wait_queue 181 * @ops: cec adapter ops 182 * @priv: cec driver's private data 183 * @capabilities: cec adapter capabilities 184 * @available_log_addrs: maximum number of available logical addresses 185 * @phys_addr: the current physical address 186 * @needs_hpd: if true, then the HDMI HotPlug Detect pin must be high 187 * in order to transmit or receive CEC messages. This is usually a HW 188 * limitation. 189 * @is_enabled: the CEC adapter is enabled 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_timeouts: number of transmit timeouts 211 * @notifier: CEC notifier 212 * @pin: CEC pin status struct 213 * @cec_dir: debugfs cec directory 214 * @status_file: debugfs cec status file 215 * @error_inj_file: debugfs cec error injection file 216 * @sequence: transmit sequence counter 217 * @input_phys: remote control input_phys name 218 * 219 * This structure represents a cec adapter. 220 */ 221 struct cec_adapter { 222 struct module *owner; 223 char name[32]; 224 struct cec_devnode devnode; 225 struct mutex lock; 226 struct rc_dev *rc; 227 228 struct list_head transmit_queue; 229 unsigned int transmit_queue_sz; 230 struct list_head wait_queue; 231 struct cec_data *transmitting; 232 bool transmit_in_progress; 233 bool transmit_in_progress_aborted; 234 unsigned int xfer_timeout_ms; 235 236 struct task_struct *kthread_config; 237 struct completion config_completion; 238 239 struct task_struct *kthread; 240 wait_queue_head_t kthread_waitq; 241 242 const struct cec_adap_ops *ops; 243 void *priv; 244 u32 capabilities; 245 u8 available_log_addrs; 246 247 u16 phys_addr; 248 bool needs_hpd; 249 bool is_enabled; 250 bool is_configuring; 251 bool must_reconfigure; 252 bool is_configured; 253 bool cec_pin_is_high; 254 bool adap_controls_phys_addr; 255 u8 last_initiator; 256 u32 monitor_all_cnt; 257 u32 monitor_pin_cnt; 258 u32 follower_cnt; 259 struct cec_fh *cec_follower; 260 struct cec_fh *cec_initiator; 261 bool passthrough; 262 struct cec_log_addrs log_addrs; 263 struct cec_connector_info conn_info; 264 265 u32 tx_timeouts; 266 267 #ifdef CONFIG_CEC_NOTIFIER 268 struct cec_notifier *notifier; 269 #endif 270 #ifdef CONFIG_CEC_PIN 271 struct cec_pin *pin; 272 #endif 273 274 struct dentry *cec_dir; 275 276 u32 sequence; 277 278 char input_phys[32]; 279 }; 280 281 static inline void *cec_get_drvdata(const struct cec_adapter *adap) 282 { 283 return adap->priv; 284 } 285 286 static inline bool cec_has_log_addr(const struct cec_adapter *adap, u8 log_addr) 287 { 288 return adap->log_addrs.log_addr_mask & (1 << log_addr); 289 } 290 291 static inline bool cec_is_sink(const struct cec_adapter *adap) 292 { 293 return adap->phys_addr == 0; 294 } 295 296 /** 297 * cec_is_registered() - is the CEC adapter registered? 298 * 299 * @adap: the CEC adapter, may be NULL. 300 * 301 * Return: true if the adapter is registered, false otherwise. 302 */ 303 static inline bool cec_is_registered(const struct cec_adapter *adap) 304 { 305 return adap && adap->devnode.registered; 306 } 307 308 #define cec_phys_addr_exp(pa) \ 309 ((pa) >> 12), ((pa) >> 8) & 0xf, ((pa) >> 4) & 0xf, (pa) & 0xf 310 311 struct edid; 312 struct drm_connector; 313 314 #if IS_REACHABLE(CONFIG_CEC_CORE) 315 struct cec_adapter *cec_allocate_adapter(const struct cec_adap_ops *ops, 316 void *priv, const char *name, u32 caps, u8 available_las); 317 int cec_register_adapter(struct cec_adapter *adap, struct device *parent); 318 void cec_unregister_adapter(struct cec_adapter *adap); 319 void cec_delete_adapter(struct cec_adapter *adap); 320 321 int cec_s_log_addrs(struct cec_adapter *adap, struct cec_log_addrs *log_addrs, 322 bool block); 323 void cec_s_phys_addr(struct cec_adapter *adap, u16 phys_addr, 324 bool block); 325 void cec_s_phys_addr_from_edid(struct cec_adapter *adap, 326 const struct edid *edid); 327 void cec_s_conn_info(struct cec_adapter *adap, 328 const struct cec_connector_info *conn_info); 329 int cec_transmit_msg(struct cec_adapter *adap, struct cec_msg *msg, 330 bool block); 331 332 /* Called by the adapter */ 333 void cec_transmit_done_ts(struct cec_adapter *adap, u8 status, 334 u8 arb_lost_cnt, u8 nack_cnt, u8 low_drive_cnt, 335 u8 error_cnt, ktime_t ts); 336 337 static inline void cec_transmit_done(struct cec_adapter *adap, u8 status, 338 u8 arb_lost_cnt, u8 nack_cnt, 339 u8 low_drive_cnt, u8 error_cnt) 340 { 341 cec_transmit_done_ts(adap, status, arb_lost_cnt, nack_cnt, 342 low_drive_cnt, error_cnt, ktime_get()); 343 } 344 /* 345 * Simplified version of cec_transmit_done for hardware that doesn't retry 346 * failed transmits. So this is always just one attempt in which case 347 * the status is sufficient. 348 */ 349 void cec_transmit_attempt_done_ts(struct cec_adapter *adap, 350 u8 status, ktime_t ts); 351 352 static inline void cec_transmit_attempt_done(struct cec_adapter *adap, 353 u8 status) 354 { 355 cec_transmit_attempt_done_ts(adap, status, ktime_get()); 356 } 357 358 void cec_received_msg_ts(struct cec_adapter *adap, 359 struct cec_msg *msg, ktime_t ts); 360 361 static inline void cec_received_msg(struct cec_adapter *adap, 362 struct cec_msg *msg) 363 { 364 cec_received_msg_ts(adap, msg, ktime_get()); 365 } 366 367 /** 368 * cec_queue_pin_cec_event() - queue a CEC pin event with a given timestamp. 369 * 370 * @adap: pointer to the cec adapter 371 * @is_high: when true the CEC pin is high, otherwise it is low 372 * @dropped_events: when true some events were dropped 373 * @ts: the timestamp for this event 374 * 375 */ 376 void cec_queue_pin_cec_event(struct cec_adapter *adap, bool is_high, 377 bool dropped_events, ktime_t ts); 378 379 /** 380 * cec_queue_pin_hpd_event() - queue a pin event with a given timestamp. 381 * 382 * @adap: pointer to the cec adapter 383 * @is_high: when true the HPD pin is high, otherwise it is low 384 * @ts: the timestamp for this event 385 * 386 */ 387 void cec_queue_pin_hpd_event(struct cec_adapter *adap, bool is_high, ktime_t ts); 388 389 /** 390 * cec_queue_pin_5v_event() - queue a pin event with a given timestamp. 391 * 392 * @adap: pointer to the cec adapter 393 * @is_high: when true the 5V pin is high, otherwise it is low 394 * @ts: the timestamp for this event 395 * 396 */ 397 void cec_queue_pin_5v_event(struct cec_adapter *adap, bool is_high, ktime_t ts); 398 399 /** 400 * cec_get_edid_phys_addr() - find and return the physical address 401 * 402 * @edid: pointer to the EDID data 403 * @size: size in bytes of the EDID data 404 * @offset: If not %NULL then the location of the physical address 405 * bytes in the EDID will be returned here. This is set to 0 406 * if there is no physical address found. 407 * 408 * Return: the physical address or CEC_PHYS_ADDR_INVALID if there is none. 409 */ 410 u16 cec_get_edid_phys_addr(const u8 *edid, unsigned int size, 411 unsigned int *offset); 412 413 void cec_fill_conn_info_from_drm(struct cec_connector_info *conn_info, 414 const struct drm_connector *connector); 415 416 #else 417 418 static inline int cec_register_adapter(struct cec_adapter *adap, 419 struct device *parent) 420 { 421 return 0; 422 } 423 424 static inline void cec_unregister_adapter(struct cec_adapter *adap) 425 { 426 } 427 428 static inline void cec_delete_adapter(struct cec_adapter *adap) 429 { 430 } 431 432 static inline void cec_s_phys_addr(struct cec_adapter *adap, u16 phys_addr, 433 bool block) 434 { 435 } 436 437 static inline void cec_s_phys_addr_from_edid(struct cec_adapter *adap, 438 const struct edid *edid) 439 { 440 } 441 442 static inline u16 cec_get_edid_phys_addr(const u8 *edid, unsigned int size, 443 unsigned int *offset) 444 { 445 if (offset) 446 *offset = 0; 447 return CEC_PHYS_ADDR_INVALID; 448 } 449 450 static inline void cec_s_conn_info(struct cec_adapter *adap, 451 const struct cec_connector_info *conn_info) 452 { 453 } 454 455 static inline void 456 cec_fill_conn_info_from_drm(struct cec_connector_info *conn_info, 457 const struct drm_connector *connector) 458 { 459 memset(conn_info, 0, sizeof(*conn_info)); 460 } 461 462 #endif 463 464 /** 465 * cec_phys_addr_invalidate() - set the physical address to INVALID 466 * 467 * @adap: the CEC adapter 468 * 469 * This is a simple helper function to invalidate the physical 470 * address. 471 */ 472 static inline void cec_phys_addr_invalidate(struct cec_adapter *adap) 473 { 474 cec_s_phys_addr(adap, CEC_PHYS_ADDR_INVALID, false); 475 } 476 477 /** 478 * cec_get_edid_spa_location() - find location of the Source Physical Address 479 * 480 * @edid: the EDID 481 * @size: the size of the EDID 482 * 483 * This EDID is expected to be a CEA-861 compliant, which means that there are 484 * at least two blocks and one or more of the extensions blocks are CEA-861 485 * blocks. 486 * 487 * The returned location is guaranteed to be <= size-2. 488 * 489 * This is an inline function since it is used by both CEC and V4L2. 490 * Ideally this would go in a module shared by both, but it is overkill to do 491 * that for just a single function. 492 */ 493 static inline unsigned int cec_get_edid_spa_location(const u8 *edid, 494 unsigned int size) 495 { 496 unsigned int blocks = size / 128; 497 unsigned int block; 498 u8 d; 499 500 /* Sanity check: at least 2 blocks and a multiple of the block size */ 501 if (blocks < 2 || size % 128) 502 return 0; 503 504 /* 505 * If there are fewer extension blocks than the size, then update 506 * 'blocks'. It is allowed to have more extension blocks than the size, 507 * since some hardware can only read e.g. 256 bytes of the EDID, even 508 * though more blocks are present. The first CEA-861 extension block 509 * should normally be in block 1 anyway. 510 */ 511 if (edid[0x7e] + 1 < blocks) 512 blocks = edid[0x7e] + 1; 513 514 for (block = 1; block < blocks; block++) { 515 unsigned int offset = block * 128; 516 517 /* Skip any non-CEA-861 extension blocks */ 518 if (edid[offset] != 0x02 || edid[offset + 1] != 0x03) 519 continue; 520 521 /* search Vendor Specific Data Block (tag 3) */ 522 d = edid[offset + 2] & 0x7f; 523 /* Check if there are Data Blocks */ 524 if (d <= 4) 525 continue; 526 if (d > 4) { 527 unsigned int i = offset + 4; 528 unsigned int end = offset + d; 529 530 /* Note: 'end' is always < 'size' */ 531 do { 532 u8 tag = edid[i] >> 5; 533 u8 len = edid[i] & 0x1f; 534 535 if (tag == 3 && len >= 5 && i + len <= end && 536 edid[i + 1] == 0x03 && 537 edid[i + 2] == 0x0c && 538 edid[i + 3] == 0x00) 539 return i + 4; 540 i += len + 1; 541 } while (i < end); 542 } 543 } 544 return 0; 545 } 546 547 #endif /* _MEDIA_CEC_H */ 548