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 */ 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_configured)(struct cec_adapter *adap, bool configured); 122 int (*adap_transmit)(struct cec_adapter *adap, u8 attempts, 123 u32 signal_free_time, struct cec_msg *msg); 124 void (*adap_status)(struct cec_adapter *adap, struct seq_file *file); 125 void (*adap_free)(struct cec_adapter *adap); 126 127 /* Error injection callbacks */ 128 int (*error_inj_show)(struct cec_adapter *adap, struct seq_file *sf); 129 bool (*error_inj_parse_line)(struct cec_adapter *adap, char *line); 130 131 /* High-level CEC message callback */ 132 int (*received)(struct cec_adapter *adap, struct cec_msg *msg); 133 }; 134 135 /* 136 * The minimum message length you can receive (excepting poll messages) is 2. 137 * With a transfer rate of at most 36 bytes per second this makes 18 messages 138 * per second worst case. 139 * 140 * We queue at most 3 seconds worth of received messages. The CEC specification 141 * requires that messages are replied to within a second, so 3 seconds should 142 * give more than enough margin. Since most messages are actually more than 2 143 * bytes, this is in practice a lot more than 3 seconds. 144 */ 145 #define CEC_MAX_MSG_RX_QUEUE_SZ (18 * 3) 146 147 /* 148 * The transmit queue is limited to 1 second worth of messages (worst case). 149 * Messages can be transmitted by userspace and kernel space. But for both it 150 * makes no sense to have a lot of messages queued up. One second seems 151 * reasonable. 152 */ 153 #define CEC_MAX_MSG_TX_QUEUE_SZ (18 * 1) 154 155 /** 156 * struct cec_adapter - cec adapter structure 157 * @owner: module owner 158 * @name: name of the CEC adapter 159 * @devnode: device node for the /dev/cecX device 160 * @lock: mutex controlling access to this structure 161 * @rc: remote control device 162 * @transmit_queue: queue of pending transmits 163 * @transmit_queue_sz: number of pending transmits 164 * @wait_queue: queue of transmits waiting for a reply 165 * @transmitting: CEC messages currently being transmitted 166 * @transmit_in_progress: true if a transmit is in progress 167 * @transmit_in_progress_aborted: true if a transmit is in progress is to be 168 * aborted. This happens if the logical address is 169 * invalidated while the transmit is ongoing. In that 170 * case the transmit will finish, but will not retransmit 171 * and be marked as ABORTED. 172 * @xfer_timeout_ms: the transfer timeout in ms. 173 * If 0, then timeout after 2.1 ms. 174 * @kthread_config: kthread used to configure a CEC adapter 175 * @config_completion: used to signal completion of the config kthread 176 * @kthread: main CEC processing thread 177 * @kthread_waitq: main CEC processing wait_queue 178 * @ops: cec adapter ops 179 * @priv: cec driver's private data 180 * @capabilities: cec adapter capabilities 181 * @available_log_addrs: maximum number of available logical addresses 182 * @phys_addr: the current physical address 183 * @needs_hpd: if true, then the HDMI HotPlug Detect pin must be high 184 * in order to transmit or receive CEC messages. This is usually a HW 185 * limitation. 186 * @is_enabled: the CEC adapter is enabled 187 * @is_configuring: the CEC adapter is configuring (i.e. claiming LAs) 188 * @must_reconfigure: while configuring, the PA changed, so reclaim LAs 189 * @is_configured: the CEC adapter is configured (i.e. has claimed LAs) 190 * @cec_pin_is_high: if true then the CEC pin is high. Only used with the 191 * CEC pin framework. 192 * @adap_controls_phys_addr: if true, then the CEC adapter controls the 193 * physical address, i.e. the CEC hardware can detect HPD changes and 194 * read the EDID and is not dependent on an external HDMI driver. 195 * Drivers that need this can set this field to true after the 196 * cec_allocate_adapter() call. 197 * @last_initiator: the initiator of the last transmitted message. 198 * @monitor_all_cnt: number of filehandles monitoring all msgs 199 * @monitor_pin_cnt: number of filehandles monitoring pin changes 200 * @follower_cnt: number of filehandles in follower mode 201 * @cec_follower: filehandle of the exclusive follower 202 * @cec_initiator: filehandle of the exclusive initiator 203 * @passthrough: if true, then the exclusive follower is in 204 * passthrough mode. 205 * @log_addrs: current logical addresses 206 * @conn_info: current connector info 207 * @tx_timeouts: number of transmit timeouts 208 * @notifier: CEC notifier 209 * @pin: CEC pin status struct 210 * @cec_dir: debugfs cec directory 211 * @status_file: debugfs cec status file 212 * @error_inj_file: debugfs cec error injection file 213 * @sequence: transmit sequence counter 214 * @input_phys: remote control input_phys name 215 * 216 * This structure represents a cec adapter. 217 */ 218 struct cec_adapter { 219 struct module *owner; 220 char name[32]; 221 struct cec_devnode devnode; 222 struct mutex lock; 223 struct rc_dev *rc; 224 225 struct list_head transmit_queue; 226 unsigned int transmit_queue_sz; 227 struct list_head wait_queue; 228 struct cec_data *transmitting; 229 bool transmit_in_progress; 230 bool transmit_in_progress_aborted; 231 unsigned int xfer_timeout_ms; 232 233 struct task_struct *kthread_config; 234 struct completion config_completion; 235 236 struct task_struct *kthread; 237 wait_queue_head_t kthread_waitq; 238 239 const struct cec_adap_ops *ops; 240 void *priv; 241 u32 capabilities; 242 u8 available_log_addrs; 243 244 u16 phys_addr; 245 bool needs_hpd; 246 bool is_enabled; 247 bool is_configuring; 248 bool must_reconfigure; 249 bool is_configured; 250 bool cec_pin_is_high; 251 bool adap_controls_phys_addr; 252 u8 last_initiator; 253 u32 monitor_all_cnt; 254 u32 monitor_pin_cnt; 255 u32 follower_cnt; 256 struct cec_fh *cec_follower; 257 struct cec_fh *cec_initiator; 258 bool passthrough; 259 struct cec_log_addrs log_addrs; 260 struct cec_connector_info conn_info; 261 262 u32 tx_timeouts; 263 264 #ifdef CONFIG_CEC_NOTIFIER 265 struct cec_notifier *notifier; 266 #endif 267 #ifdef CONFIG_CEC_PIN 268 struct cec_pin *pin; 269 #endif 270 271 struct dentry *cec_dir; 272 273 u32 sequence; 274 275 char input_phys[32]; 276 }; 277 278 static inline void *cec_get_drvdata(const struct cec_adapter *adap) 279 { 280 return adap->priv; 281 } 282 283 static inline bool cec_has_log_addr(const struct cec_adapter *adap, u8 log_addr) 284 { 285 return adap->log_addrs.log_addr_mask & (1 << log_addr); 286 } 287 288 static inline bool cec_is_sink(const struct cec_adapter *adap) 289 { 290 return adap->phys_addr == 0; 291 } 292 293 /** 294 * cec_is_registered() - is the CEC adapter registered? 295 * 296 * @adap: the CEC adapter, may be NULL. 297 * 298 * Return: true if the adapter is registered, false otherwise. 299 */ 300 static inline bool cec_is_registered(const struct cec_adapter *adap) 301 { 302 return adap && adap->devnode.registered; 303 } 304 305 #define cec_phys_addr_exp(pa) \ 306 ((pa) >> 12), ((pa) >> 8) & 0xf, ((pa) >> 4) & 0xf, (pa) & 0xf 307 308 struct edid; 309 struct drm_connector; 310 311 #if IS_REACHABLE(CONFIG_CEC_CORE) 312 struct cec_adapter *cec_allocate_adapter(const struct cec_adap_ops *ops, 313 void *priv, const char *name, u32 caps, u8 available_las); 314 int cec_register_adapter(struct cec_adapter *adap, struct device *parent); 315 void cec_unregister_adapter(struct cec_adapter *adap); 316 void cec_delete_adapter(struct cec_adapter *adap); 317 318 int cec_s_log_addrs(struct cec_adapter *adap, struct cec_log_addrs *log_addrs, 319 bool block); 320 void cec_s_phys_addr(struct cec_adapter *adap, u16 phys_addr, 321 bool block); 322 void cec_s_phys_addr_from_edid(struct cec_adapter *adap, 323 const struct edid *edid); 324 void cec_s_conn_info(struct cec_adapter *adap, 325 const struct cec_connector_info *conn_info); 326 int cec_transmit_msg(struct cec_adapter *adap, struct cec_msg *msg, 327 bool block); 328 329 /* Called by the adapter */ 330 void cec_transmit_done_ts(struct cec_adapter *adap, u8 status, 331 u8 arb_lost_cnt, u8 nack_cnt, u8 low_drive_cnt, 332 u8 error_cnt, ktime_t ts); 333 334 static inline void cec_transmit_done(struct cec_adapter *adap, u8 status, 335 u8 arb_lost_cnt, u8 nack_cnt, 336 u8 low_drive_cnt, u8 error_cnt) 337 { 338 cec_transmit_done_ts(adap, status, arb_lost_cnt, nack_cnt, 339 low_drive_cnt, error_cnt, ktime_get()); 340 } 341 /* 342 * Simplified version of cec_transmit_done for hardware that doesn't retry 343 * failed transmits. So this is always just one attempt in which case 344 * the status is sufficient. 345 */ 346 void cec_transmit_attempt_done_ts(struct cec_adapter *adap, 347 u8 status, ktime_t ts); 348 349 static inline void cec_transmit_attempt_done(struct cec_adapter *adap, 350 u8 status) 351 { 352 cec_transmit_attempt_done_ts(adap, status, ktime_get()); 353 } 354 355 void cec_received_msg_ts(struct cec_adapter *adap, 356 struct cec_msg *msg, ktime_t ts); 357 358 static inline void cec_received_msg(struct cec_adapter *adap, 359 struct cec_msg *msg) 360 { 361 cec_received_msg_ts(adap, msg, ktime_get()); 362 } 363 364 /** 365 * cec_queue_pin_cec_event() - queue a CEC pin event with a given timestamp. 366 * 367 * @adap: pointer to the cec adapter 368 * @is_high: when true the CEC pin is high, otherwise it is low 369 * @dropped_events: when true some events were dropped 370 * @ts: the timestamp for this event 371 * 372 */ 373 void cec_queue_pin_cec_event(struct cec_adapter *adap, bool is_high, 374 bool dropped_events, ktime_t ts); 375 376 /** 377 * cec_queue_pin_hpd_event() - queue a pin event with a given timestamp. 378 * 379 * @adap: pointer to the cec adapter 380 * @is_high: when true the HPD pin is high, otherwise it is low 381 * @ts: the timestamp for this event 382 * 383 */ 384 void cec_queue_pin_hpd_event(struct cec_adapter *adap, bool is_high, ktime_t ts); 385 386 /** 387 * cec_queue_pin_5v_event() - queue a pin event with a given timestamp. 388 * 389 * @adap: pointer to the cec adapter 390 * @is_high: when true the 5V pin is high, otherwise it is low 391 * @ts: the timestamp for this event 392 * 393 */ 394 void cec_queue_pin_5v_event(struct cec_adapter *adap, bool is_high, ktime_t ts); 395 396 /** 397 * cec_get_edid_phys_addr() - find and return the physical address 398 * 399 * @edid: pointer to the EDID data 400 * @size: size in bytes of the EDID data 401 * @offset: If not %NULL then the location of the physical address 402 * bytes in the EDID will be returned here. This is set to 0 403 * if there is no physical address found. 404 * 405 * Return: the physical address or CEC_PHYS_ADDR_INVALID if there is none. 406 */ 407 u16 cec_get_edid_phys_addr(const u8 *edid, unsigned int size, 408 unsigned int *offset); 409 410 void cec_fill_conn_info_from_drm(struct cec_connector_info *conn_info, 411 const struct drm_connector *connector); 412 413 #else 414 415 static inline int cec_register_adapter(struct cec_adapter *adap, 416 struct device *parent) 417 { 418 return 0; 419 } 420 421 static inline void cec_unregister_adapter(struct cec_adapter *adap) 422 { 423 } 424 425 static inline void cec_delete_adapter(struct cec_adapter *adap) 426 { 427 } 428 429 static inline void cec_s_phys_addr(struct cec_adapter *adap, u16 phys_addr, 430 bool block) 431 { 432 } 433 434 static inline void cec_s_phys_addr_from_edid(struct cec_adapter *adap, 435 const struct edid *edid) 436 { 437 } 438 439 static inline u16 cec_get_edid_phys_addr(const u8 *edid, unsigned int size, 440 unsigned int *offset) 441 { 442 if (offset) 443 *offset = 0; 444 return CEC_PHYS_ADDR_INVALID; 445 } 446 447 static inline void cec_s_conn_info(struct cec_adapter *adap, 448 const struct cec_connector_info *conn_info) 449 { 450 } 451 452 static inline void 453 cec_fill_conn_info_from_drm(struct cec_connector_info *conn_info, 454 const struct drm_connector *connector) 455 { 456 memset(conn_info, 0, sizeof(*conn_info)); 457 } 458 459 #endif 460 461 /** 462 * cec_phys_addr_invalidate() - set the physical address to INVALID 463 * 464 * @adap: the CEC adapter 465 * 466 * This is a simple helper function to invalidate the physical 467 * address. 468 */ 469 static inline void cec_phys_addr_invalidate(struct cec_adapter *adap) 470 { 471 cec_s_phys_addr(adap, CEC_PHYS_ADDR_INVALID, false); 472 } 473 474 /** 475 * cec_get_edid_spa_location() - find location of the Source Physical Address 476 * 477 * @edid: the EDID 478 * @size: the size of the EDID 479 * 480 * This EDID is expected to be a CEA-861 compliant, which means that there are 481 * at least two blocks and one or more of the extensions blocks are CEA-861 482 * blocks. 483 * 484 * The returned location is guaranteed to be <= size-2. 485 * 486 * This is an inline function since it is used by both CEC and V4L2. 487 * Ideally this would go in a module shared by both, but it is overkill to do 488 * that for just a single function. 489 */ 490 static inline unsigned int cec_get_edid_spa_location(const u8 *edid, 491 unsigned int size) 492 { 493 unsigned int blocks = size / 128; 494 unsigned int block; 495 u8 d; 496 497 /* Sanity check: at least 2 blocks and a multiple of the block size */ 498 if (blocks < 2 || size % 128) 499 return 0; 500 501 /* 502 * If there are fewer extension blocks than the size, then update 503 * 'blocks'. It is allowed to have more extension blocks than the size, 504 * since some hardware can only read e.g. 256 bytes of the EDID, even 505 * though more blocks are present. The first CEA-861 extension block 506 * should normally be in block 1 anyway. 507 */ 508 if (edid[0x7e] + 1 < blocks) 509 blocks = edid[0x7e] + 1; 510 511 for (block = 1; block < blocks; block++) { 512 unsigned int offset = block * 128; 513 514 /* Skip any non-CEA-861 extension blocks */ 515 if (edid[offset] != 0x02 || edid[offset + 1] != 0x03) 516 continue; 517 518 /* search Vendor Specific Data Block (tag 3) */ 519 d = edid[offset + 2] & 0x7f; 520 /* Check if there are Data Blocks */ 521 if (d <= 4) 522 continue; 523 if (d > 4) { 524 unsigned int i = offset + 4; 525 unsigned int end = offset + d; 526 527 /* Note: 'end' is always < 'size' */ 528 do { 529 u8 tag = edid[i] >> 5; 530 u8 len = edid[i] & 0x1f; 531 532 if (tag == 3 && len >= 5 && i + len <= end && 533 edid[i + 1] == 0x03 && 534 edid[i + 2] == 0x0c && 535 edid[i + 3] == 0x00) 536 return i + 4; 537 i += len + 1; 538 } while (i < end); 539 } 540 } 541 return 0; 542 } 543 544 #endif /* _MEDIA_CEC_H */ 545