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