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