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 */ 43struct 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 59struct cec_adapter; 60struct cec_data; 61struct cec_pin; 62struct cec_notifier; 63 64struct 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 77struct cec_msg_entry { 78 struct list_head list; 79 struct cec_msg msg; 80}; 81 82struct 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 90struct 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 115struct 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_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 * @notifier: CEC notifier 225 * @pin: CEC pin status struct 226 * @cec_dir: debugfs cec directory 227 * @sequence: transmit sequence counter 228 * @input_phys: remote control input_phys name 229 * 230 * This structure represents a cec adapter. 231 */ 232struct cec_adapter { 233 struct module *owner; 234 char name[32]; 235 struct cec_devnode devnode; 236 struct mutex lock; 237 struct rc_dev *rc; 238 239 struct list_head transmit_queue; 240 unsigned int transmit_queue_sz; 241 struct list_head wait_queue; 242 struct cec_data *transmitting; 243 bool transmit_in_progress; 244 bool transmit_in_progress_aborted; 245 unsigned int xfer_timeout_ms; 246 247 struct task_struct *kthread_config; 248 struct completion config_completion; 249 250 struct task_struct *kthread; 251 wait_queue_head_t kthread_waitq; 252 253 const struct cec_adap_ops *ops; 254 void *priv; 255 u32 capabilities; 256 u8 available_log_addrs; 257 258 u16 phys_addr; 259 bool needs_hpd; 260 bool is_enabled; 261 bool is_configuring; 262 bool must_reconfigure; 263 bool is_configured; 264 bool cec_pin_is_high; 265 bool adap_controls_phys_addr; 266 u8 last_initiator; 267 u32 monitor_all_cnt; 268 u32 monitor_pin_cnt; 269 u32 follower_cnt; 270 struct cec_fh *cec_follower; 271 struct cec_fh *cec_initiator; 272 bool passthrough; 273 struct cec_log_addrs log_addrs; 274 struct cec_connector_info conn_info; 275 276 u32 tx_timeout_cnt; 277 u32 tx_low_drive_cnt; 278 u32 tx_error_cnt; 279 u32 tx_arb_lost_cnt; 280 u32 tx_low_drive_log_cnt; 281 u32 tx_error_log_cnt; 282 283#ifdef CONFIG_CEC_NOTIFIER 284 struct cec_notifier *notifier; 285#endif 286#ifdef CONFIG_CEC_PIN 287 struct cec_pin *pin; 288#endif 289 290 struct dentry *cec_dir; 291 292 u32 sequence; 293 294 char input_phys[40]; 295}; 296 297static inline void *cec_get_drvdata(const struct cec_adapter *adap) 298{ 299 return adap->priv; 300} 301 302static inline bool cec_has_log_addr(const struct cec_adapter *adap, u8 log_addr) 303{ 304 return adap->log_addrs.log_addr_mask & (1 << log_addr); 305} 306 307static inline bool cec_is_sink(const struct cec_adapter *adap) 308{ 309 return adap->phys_addr == 0; 310} 311 312/** 313 * cec_is_registered() - is the CEC adapter registered? 314 * 315 * @adap: the CEC adapter, may be NULL. 316 * 317 * Return: true if the adapter is registered, false otherwise. 318 */ 319static inline bool cec_is_registered(const struct cec_adapter *adap) 320{ 321 return adap && adap->devnode.registered; 322} 323 324#define cec_phys_addr_exp(pa) \ 325 ((pa) >> 12), ((pa) >> 8) & 0xf, ((pa) >> 4) & 0xf, (pa) & 0xf 326 327struct edid; 328struct drm_connector; 329 330#if IS_REACHABLE(CONFIG_CEC_CORE) 331struct cec_adapter *cec_allocate_adapter(const struct cec_adap_ops *ops, 332 void *priv, const char *name, u32 caps, u8 available_las); 333int cec_register_adapter(struct cec_adapter *adap, struct device *parent); 334void cec_unregister_adapter(struct cec_adapter *adap); 335void cec_delete_adapter(struct cec_adapter *adap); 336 337int cec_s_log_addrs(struct cec_adapter *adap, struct cec_log_addrs *log_addrs, 338 bool block); 339void cec_s_phys_addr(struct cec_adapter *adap, u16 phys_addr, 340 bool block); 341void cec_s_phys_addr_from_edid(struct cec_adapter *adap, 342 const struct edid *edid); 343void cec_s_conn_info(struct cec_adapter *adap, 344 const struct cec_connector_info *conn_info); 345int cec_transmit_msg(struct cec_adapter *adap, struct cec_msg *msg, 346 bool block); 347 348/* Called by the adapter */ 349void cec_transmit_done_ts(struct cec_adapter *adap, u8 status, 350 u8 arb_lost_cnt, u8 nack_cnt, u8 low_drive_cnt, 351 u8 error_cnt, ktime_t ts); 352 353static inline void cec_transmit_done(struct cec_adapter *adap, u8 status, 354 u8 arb_lost_cnt, u8 nack_cnt, 355 u8 low_drive_cnt, u8 error_cnt) 356{ 357 cec_transmit_done_ts(adap, status, arb_lost_cnt, nack_cnt, 358 low_drive_cnt, error_cnt, ktime_get()); 359} 360/* 361 * Simplified version of cec_transmit_done for hardware that doesn't retry 362 * failed transmits. So this is always just one attempt in which case 363 * the status is sufficient. 364 */ 365void cec_transmit_attempt_done_ts(struct cec_adapter *adap, 366 u8 status, ktime_t ts); 367 368static inline void cec_transmit_attempt_done(struct cec_adapter *adap, 369 u8 status) 370{ 371 cec_transmit_attempt_done_ts(adap, status, ktime_get()); 372} 373 374void cec_received_msg_ts(struct cec_adapter *adap, 375 struct cec_msg *msg, ktime_t ts); 376 377static inline void cec_received_msg(struct cec_adapter *adap, 378 struct cec_msg *msg) 379{ 380 cec_received_msg_ts(adap, msg, ktime_get()); 381} 382 383/** 384 * cec_queue_pin_cec_event() - queue a CEC pin event with a given timestamp. 385 * 386 * @adap: pointer to the cec adapter 387 * @is_high: when true the CEC pin is high, otherwise it is low 388 * @dropped_events: when true some events were dropped 389 * @ts: the timestamp for this event 390 * 391 */ 392void cec_queue_pin_cec_event(struct cec_adapter *adap, bool is_high, 393 bool dropped_events, ktime_t ts); 394 395/** 396 * cec_queue_pin_hpd_event() - queue a pin event with a given timestamp. 397 * 398 * @adap: pointer to the cec adapter 399 * @is_high: when true the HPD pin is high, otherwise it is low 400 * @ts: the timestamp for this event 401 * 402 */ 403void cec_queue_pin_hpd_event(struct cec_adapter *adap, bool is_high, ktime_t ts); 404 405/** 406 * cec_queue_pin_5v_event() - queue a pin event with a given timestamp. 407 * 408 * @adap: pointer to the cec adapter 409 * @is_high: when true the 5V pin is high, otherwise it is low 410 * @ts: the timestamp for this event 411 * 412 */ 413void cec_queue_pin_5v_event(struct cec_adapter *adap, bool is_high, ktime_t ts); 414 415/** 416 * cec_get_edid_phys_addr() - find and return the physical address 417 * 418 * @edid: pointer to the EDID data 419 * @size: size in bytes of the EDID data 420 * @offset: If not %NULL then the location of the physical address 421 * bytes in the EDID will be returned here. This is set to 0 422 * if there is no physical address found. 423 * 424 * Return: the physical address or CEC_PHYS_ADDR_INVALID if there is none. 425 */ 426u16 cec_get_edid_phys_addr(const u8 *edid, unsigned int size, 427 unsigned int *offset); 428 429void cec_fill_conn_info_from_drm(struct cec_connector_info *conn_info, 430 const struct drm_connector *connector); 431 432#else 433 434static inline int cec_register_adapter(struct cec_adapter *adap, 435 struct device *parent) 436{ 437 return 0; 438} 439 440static inline void cec_unregister_adapter(struct cec_adapter *adap) 441{ 442} 443 444static inline void cec_delete_adapter(struct cec_adapter *adap) 445{ 446} 447 448static inline void cec_s_phys_addr(struct cec_adapter *adap, u16 phys_addr, 449 bool block) 450{ 451} 452 453static inline void cec_s_phys_addr_from_edid(struct cec_adapter *adap, 454 const struct edid *edid) 455{ 456} 457 458static inline u16 cec_get_edid_phys_addr(const u8 *edid, unsigned int size, 459 unsigned int *offset) 460{ 461 if (offset) 462 *offset = 0; 463 return CEC_PHYS_ADDR_INVALID; 464} 465 466static inline void cec_s_conn_info(struct cec_adapter *adap, 467 const struct cec_connector_info *conn_info) 468{ 469} 470 471static inline void 472cec_fill_conn_info_from_drm(struct cec_connector_info *conn_info, 473 const struct drm_connector *connector) 474{ 475 memset(conn_info, 0, sizeof(*conn_info)); 476} 477 478#endif 479 480/** 481 * cec_phys_addr_invalidate() - set the physical address to INVALID 482 * 483 * @adap: the CEC adapter 484 * 485 * This is a simple helper function to invalidate the physical 486 * address. 487 */ 488static inline void cec_phys_addr_invalidate(struct cec_adapter *adap) 489{ 490 cec_s_phys_addr(adap, CEC_PHYS_ADDR_INVALID, false); 491} 492 493/** 494 * cec_get_edid_spa_location() - find location of the Source Physical Address 495 * 496 * @edid: the EDID 497 * @size: the size of the EDID 498 * 499 * This EDID is expected to be a CEA-861 compliant, which means that there are 500 * at least two blocks and one or more of the extensions blocks are CEA-861 501 * blocks. 502 * 503 * The returned location is guaranteed to be <= size-2. 504 * 505 * This is an inline function since it is used by both CEC and V4L2. 506 * Ideally this would go in a module shared by both, but it is overkill to do 507 * that for just a single function. 508 */ 509static inline unsigned int cec_get_edid_spa_location(const u8 *edid, 510 unsigned int size) 511{ 512 unsigned int blocks = size / 128; 513 unsigned int block; 514 u8 d; 515 516 /* Sanity check: at least 2 blocks and a multiple of the block size */ 517 if (blocks < 2 || size % 128) 518 return 0; 519 520 /* 521 * If there are fewer extension blocks than the size, then update 522 * 'blocks'. It is allowed to have more extension blocks than the size, 523 * since some hardware can only read e.g. 256 bytes of the EDID, even 524 * though more blocks are present. The first CEA-861 extension block 525 * should normally be in block 1 anyway. 526 */ 527 if (edid[0x7e] + 1 < blocks) 528 blocks = edid[0x7e] + 1; 529 530 for (block = 1; block < blocks; block++) { 531 unsigned int offset = block * 128; 532 533 /* Skip any non-CEA-861 extension blocks */ 534 if (edid[offset] != 0x02 || edid[offset + 1] != 0x03) 535 continue; 536 537 /* search Vendor Specific Data Block (tag 3) */ 538 d = edid[offset + 2] & 0x7f; 539 /* Check if there are Data Blocks */ 540 if (d <= 4) 541 continue; 542 if (d > 4) { 543 unsigned int i = offset + 4; 544 unsigned int end = offset + d; 545 546 /* Note: 'end' is always < 'size' */ 547 do { 548 u8 tag = edid[i] >> 5; 549 u8 len = edid[i] & 0x1f; 550 551 if (tag == 3 && len >= 5 && i + len <= end && 552 edid[i + 1] == 0x03 && 553 edid[i + 2] == 0x0c && 554 edid[i + 3] == 0x00) 555 return i + 4; 556 i += len + 1; 557 } while (i < end); 558 } 559 } 560 return 0; 561} 562 563#endif /* _MEDIA_CEC_H */ 564