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 * @registered: the device was correctly registered 30 * @unregistered: the device was unregistered 31 * @fhs: the list of open filehandles (cec_fh) 32 * @lock: lock to control access to this structure 33 * 34 * This structure represents a cec-related device node. 35 * 36 * The @parent is a physical device. It must be set by core or device drivers 37 * before registering the node. 38 */ 39 struct cec_devnode { 40 /* sysfs */ 41 struct device dev; 42 struct cdev cdev; 43 44 /* device info */ 45 int minor; 46 bool registered; 47 bool unregistered; 48 struct list_head fhs; 49 struct mutex lock; 50 }; 51 52 struct cec_adapter; 53 struct cec_data; 54 struct cec_pin; 55 struct cec_notifier; 56 57 struct cec_data { 58 struct list_head list; 59 struct list_head xfer_list; 60 struct cec_adapter *adap; 61 struct cec_msg msg; 62 struct cec_fh *fh; 63 struct delayed_work work; 64 struct completion c; 65 u8 attempts; 66 bool blocking; 67 bool completed; 68 }; 69 70 struct cec_msg_entry { 71 struct list_head list; 72 struct cec_msg msg; 73 }; 74 75 struct cec_event_entry { 76 struct list_head list; 77 struct cec_event ev; 78 }; 79 80 #define CEC_NUM_CORE_EVENTS 2 81 #define CEC_NUM_EVENTS CEC_EVENT_PIN_5V_HIGH 82 83 struct cec_fh { 84 struct list_head list; 85 struct list_head xfer_list; 86 struct cec_adapter *adap; 87 u8 mode_initiator; 88 u8 mode_follower; 89 90 /* Events */ 91 wait_queue_head_t wait; 92 struct mutex lock; 93 struct list_head events[CEC_NUM_EVENTS]; /* queued events */ 94 u16 queued_events[CEC_NUM_EVENTS]; 95 unsigned int total_queued_events; 96 struct cec_event_entry core_events[CEC_NUM_CORE_EVENTS]; 97 struct list_head msgs; /* queued messages */ 98 unsigned int queued_msgs; 99 }; 100 101 #define CEC_SIGNAL_FREE_TIME_RETRY 3 102 #define CEC_SIGNAL_FREE_TIME_NEW_INITIATOR 5 103 #define CEC_SIGNAL_FREE_TIME_NEXT_XFER 7 104 105 /* The nominal data bit period is 2.4 ms */ 106 #define CEC_FREE_TIME_TO_USEC(ft) ((ft) * 2400) 107 108 struct cec_adap_ops { 109 /* Low-level callbacks */ 110 int (*adap_enable)(struct cec_adapter *adap, bool enable); 111 int (*adap_monitor_all_enable)(struct cec_adapter *adap, bool enable); 112 int (*adap_monitor_pin_enable)(struct cec_adapter *adap, bool enable); 113 int (*adap_log_addr)(struct cec_adapter *adap, u8 logical_addr); 114 int (*adap_transmit)(struct cec_adapter *adap, u8 attempts, 115 u32 signal_free_time, struct cec_msg *msg); 116 void (*adap_status)(struct cec_adapter *adap, struct seq_file *file); 117 void (*adap_free)(struct cec_adapter *adap); 118 119 /* Error injection callbacks */ 120 int (*error_inj_show)(struct cec_adapter *adap, struct seq_file *sf); 121 bool (*error_inj_parse_line)(struct cec_adapter *adap, char *line); 122 123 /* High-level CEC message callback */ 124 int (*received)(struct cec_adapter *adap, struct cec_msg *msg); 125 }; 126 127 /* 128 * The minimum message length you can receive (excepting poll messages) is 2. 129 * With a transfer rate of at most 36 bytes per second this makes 18 messages 130 * per second worst case. 131 * 132 * We queue at most 3 seconds worth of received messages. The CEC specification 133 * requires that messages are replied to within a second, so 3 seconds should 134 * give more than enough margin. Since most messages are actually more than 2 135 * bytes, this is in practice a lot more than 3 seconds. 136 */ 137 #define CEC_MAX_MSG_RX_QUEUE_SZ (18 * 3) 138 139 /* 140 * The transmit queue is limited to 1 second worth of messages (worst case). 141 * Messages can be transmitted by userspace and kernel space. But for both it 142 * makes no sense to have a lot of messages queued up. One second seems 143 * reasonable. 144 */ 145 #define CEC_MAX_MSG_TX_QUEUE_SZ (18 * 1) 146 147 /** 148 * struct cec_adapter - cec adapter structure 149 * @owner: module owner 150 * @name: name of the CEC adapter 151 * @devnode: device node for the /dev/cecX device 152 * @lock: mutex controlling access to this structure 153 * @rc: remote control device 154 * @transmit_queue: queue of pending transmits 155 * @transmit_queue_sz: number of pending transmits 156 * @wait_queue: queue of transmits waiting for a reply 157 * @transmitting: CEC messages currently being transmitted 158 * @transmit_in_progress: true if a transmit is in progress 159 * @kthread_config: kthread used to configure a CEC adapter 160 * @config_completion: used to signal completion of the config kthread 161 * @kthread: main CEC processing thread 162 * @kthread_waitq: main CEC processing wait_queue 163 * @ops: cec adapter ops 164 * @priv: cec driver's private data 165 * @capabilities: cec adapter capabilities 166 * @available_log_addrs: maximum number of available logical addresses 167 * @phys_addr: the current physical address 168 * @needs_hpd: if true, then the HDMI HotPlug Detect pin must be high 169 * in order to transmit or receive CEC messages. This is usually a HW 170 * limitation. 171 * @is_configuring: the CEC adapter is configuring (i.e. claiming LAs) 172 * @is_configured: the CEC adapter is configured (i.e. has claimed LAs) 173 * @cec_pin_is_high: if true then the CEC pin is high. Only used with the 174 * CEC pin framework. 175 * @adap_controls_phys_addr: if true, then the CEC adapter controls the 176 * physical address, i.e. the CEC hardware can detect HPD changes and 177 * read the EDID and is not dependent on an external HDMI driver. 178 * Drivers that need this can set this field to true after the 179 * cec_allocate_adapter() call. 180 * @last_initiator: the initiator of the last transmitted message. 181 * @monitor_all_cnt: number of filehandles monitoring all msgs 182 * @monitor_pin_cnt: number of filehandles monitoring pin changes 183 * @follower_cnt: number of filehandles in follower mode 184 * @cec_follower: filehandle of the exclusive follower 185 * @cec_initiator: filehandle of the exclusive initiator 186 * @passthrough: if true, then the exclusive follower is in 187 * passthrough mode. 188 * @log_addrs: current logical addresses 189 * @conn_info: current connector info 190 * @tx_timeouts: number of transmit timeouts 191 * @notifier: CEC notifier 192 * @pin: CEC pin status struct 193 * @cec_dir: debugfs cec directory 194 * @status_file: debugfs cec status file 195 * @error_inj_file: debugfs cec error injection file 196 * @sequence: transmit sequence counter 197 * @input_phys: remote control input_phys name 198 * 199 * This structure represents a cec adapter. 200 */ 201 struct cec_adapter { 202 struct module *owner; 203 char name[32]; 204 struct cec_devnode devnode; 205 struct mutex lock; 206 struct rc_dev *rc; 207 208 struct list_head transmit_queue; 209 unsigned int transmit_queue_sz; 210 struct list_head wait_queue; 211 struct cec_data *transmitting; 212 bool transmit_in_progress; 213 214 struct task_struct *kthread_config; 215 struct completion config_completion; 216 217 struct task_struct *kthread; 218 wait_queue_head_t kthread_waitq; 219 220 const struct cec_adap_ops *ops; 221 void *priv; 222 u32 capabilities; 223 u8 available_log_addrs; 224 225 u16 phys_addr; 226 bool needs_hpd; 227 bool is_configuring; 228 bool is_configured; 229 bool cec_pin_is_high; 230 bool adap_controls_phys_addr; 231 u8 last_initiator; 232 u32 monitor_all_cnt; 233 u32 monitor_pin_cnt; 234 u32 follower_cnt; 235 struct cec_fh *cec_follower; 236 struct cec_fh *cec_initiator; 237 bool passthrough; 238 struct cec_log_addrs log_addrs; 239 struct cec_connector_info conn_info; 240 241 u32 tx_timeouts; 242 243 #ifdef CONFIG_CEC_NOTIFIER 244 struct cec_notifier *notifier; 245 #endif 246 #ifdef CONFIG_CEC_PIN 247 struct cec_pin *pin; 248 #endif 249 250 struct dentry *cec_dir; 251 252 u32 sequence; 253 254 char input_phys[32]; 255 }; 256 257 static inline void *cec_get_drvdata(const struct cec_adapter *adap) 258 { 259 return adap->priv; 260 } 261 262 static inline bool cec_has_log_addr(const struct cec_adapter *adap, u8 log_addr) 263 { 264 return adap->log_addrs.log_addr_mask & (1 << log_addr); 265 } 266 267 static inline bool cec_is_sink(const struct cec_adapter *adap) 268 { 269 return adap->phys_addr == 0; 270 } 271 272 /** 273 * cec_is_registered() - is the CEC adapter registered? 274 * 275 * @adap: the CEC adapter, may be NULL. 276 * 277 * Return: true if the adapter is registered, false otherwise. 278 */ 279 static inline bool cec_is_registered(const struct cec_adapter *adap) 280 { 281 return adap && adap->devnode.registered; 282 } 283 284 #define cec_phys_addr_exp(pa) \ 285 ((pa) >> 12), ((pa) >> 8) & 0xf, ((pa) >> 4) & 0xf, (pa) & 0xf 286 287 struct edid; 288 struct drm_connector; 289 290 #if IS_REACHABLE(CONFIG_CEC_CORE) 291 struct cec_adapter *cec_allocate_adapter(const struct cec_adap_ops *ops, 292 void *priv, const char *name, u32 caps, u8 available_las); 293 int cec_register_adapter(struct cec_adapter *adap, struct device *parent); 294 void cec_unregister_adapter(struct cec_adapter *adap); 295 void cec_delete_adapter(struct cec_adapter *adap); 296 297 int cec_s_log_addrs(struct cec_adapter *adap, struct cec_log_addrs *log_addrs, 298 bool block); 299 void cec_s_phys_addr(struct cec_adapter *adap, u16 phys_addr, 300 bool block); 301 void cec_s_phys_addr_from_edid(struct cec_adapter *adap, 302 const struct edid *edid); 303 void cec_s_conn_info(struct cec_adapter *adap, 304 const struct cec_connector_info *conn_info); 305 int cec_transmit_msg(struct cec_adapter *adap, struct cec_msg *msg, 306 bool block); 307 308 /* Called by the adapter */ 309 void cec_transmit_done_ts(struct cec_adapter *adap, u8 status, 310 u8 arb_lost_cnt, u8 nack_cnt, u8 low_drive_cnt, 311 u8 error_cnt, ktime_t ts); 312 313 static inline void cec_transmit_done(struct cec_adapter *adap, u8 status, 314 u8 arb_lost_cnt, u8 nack_cnt, 315 u8 low_drive_cnt, u8 error_cnt) 316 { 317 cec_transmit_done_ts(adap, status, arb_lost_cnt, nack_cnt, 318 low_drive_cnt, error_cnt, ktime_get()); 319 } 320 /* 321 * Simplified version of cec_transmit_done for hardware that doesn't retry 322 * failed transmits. So this is always just one attempt in which case 323 * the status is sufficient. 324 */ 325 void cec_transmit_attempt_done_ts(struct cec_adapter *adap, 326 u8 status, ktime_t ts); 327 328 static inline void cec_transmit_attempt_done(struct cec_adapter *adap, 329 u8 status) 330 { 331 cec_transmit_attempt_done_ts(adap, status, ktime_get()); 332 } 333 334 void cec_received_msg_ts(struct cec_adapter *adap, 335 struct cec_msg *msg, ktime_t ts); 336 337 static inline void cec_received_msg(struct cec_adapter *adap, 338 struct cec_msg *msg) 339 { 340 cec_received_msg_ts(adap, msg, ktime_get()); 341 } 342 343 /** 344 * cec_queue_pin_cec_event() - queue a CEC pin event with a given timestamp. 345 * 346 * @adap: pointer to the cec adapter 347 * @is_high: when true the CEC pin is high, otherwise it is low 348 * @dropped_events: when true some events were dropped 349 * @ts: the timestamp for this event 350 * 351 */ 352 void cec_queue_pin_cec_event(struct cec_adapter *adap, bool is_high, 353 bool dropped_events, ktime_t ts); 354 355 /** 356 * cec_queue_pin_hpd_event() - queue a pin event with a given timestamp. 357 * 358 * @adap: pointer to the cec adapter 359 * @is_high: when true the HPD pin is high, otherwise it is low 360 * @ts: the timestamp for this event 361 * 362 */ 363 void cec_queue_pin_hpd_event(struct cec_adapter *adap, bool is_high, ktime_t ts); 364 365 /** 366 * cec_queue_pin_5v_event() - queue a pin event with a given timestamp. 367 * 368 * @adap: pointer to the cec adapter 369 * @is_high: when true the 5V pin is high, otherwise it is low 370 * @ts: the timestamp for this event 371 * 372 */ 373 void cec_queue_pin_5v_event(struct cec_adapter *adap, bool is_high, ktime_t ts); 374 375 /** 376 * cec_get_edid_phys_addr() - find and return the physical address 377 * 378 * @edid: pointer to the EDID data 379 * @size: size in bytes of the EDID data 380 * @offset: If not %NULL then the location of the physical address 381 * bytes in the EDID will be returned here. This is set to 0 382 * if there is no physical address found. 383 * 384 * Return: the physical address or CEC_PHYS_ADDR_INVALID if there is none. 385 */ 386 u16 cec_get_edid_phys_addr(const u8 *edid, unsigned int size, 387 unsigned int *offset); 388 389 void cec_fill_conn_info_from_drm(struct cec_connector_info *conn_info, 390 const struct drm_connector *connector); 391 392 #else 393 394 static inline int cec_register_adapter(struct cec_adapter *adap, 395 struct device *parent) 396 { 397 return 0; 398 } 399 400 static inline void cec_unregister_adapter(struct cec_adapter *adap) 401 { 402 } 403 404 static inline void cec_delete_adapter(struct cec_adapter *adap) 405 { 406 } 407 408 static inline void cec_s_phys_addr(struct cec_adapter *adap, u16 phys_addr, 409 bool block) 410 { 411 } 412 413 static inline void cec_s_phys_addr_from_edid(struct cec_adapter *adap, 414 const struct edid *edid) 415 { 416 } 417 418 static inline u16 cec_get_edid_phys_addr(const u8 *edid, unsigned int size, 419 unsigned int *offset) 420 { 421 if (offset) 422 *offset = 0; 423 return CEC_PHYS_ADDR_INVALID; 424 } 425 426 static inline void cec_s_conn_info(struct cec_adapter *adap, 427 const struct cec_connector_info *conn_info) 428 { 429 } 430 431 static inline void 432 cec_fill_conn_info_from_drm(struct cec_connector_info *conn_info, 433 const struct drm_connector *connector) 434 { 435 memset(conn_info, 0, sizeof(*conn_info)); 436 } 437 438 #endif 439 440 /** 441 * cec_phys_addr_invalidate() - set the physical address to INVALID 442 * 443 * @adap: the CEC adapter 444 * 445 * This is a simple helper function to invalidate the physical 446 * address. 447 */ 448 static inline void cec_phys_addr_invalidate(struct cec_adapter *adap) 449 { 450 cec_s_phys_addr(adap, CEC_PHYS_ADDR_INVALID, false); 451 } 452 453 /** 454 * cec_get_edid_spa_location() - find location of the Source Physical Address 455 * 456 * @edid: the EDID 457 * @size: the size of the EDID 458 * 459 * This EDID is expected to be a CEA-861 compliant, which means that there are 460 * at least two blocks and one or more of the extensions blocks are CEA-861 461 * blocks. 462 * 463 * The returned location is guaranteed to be <= size-2. 464 * 465 * This is an inline function since it is used by both CEC and V4L2. 466 * Ideally this would go in a module shared by both, but it is overkill to do 467 * that for just a single function. 468 */ 469 static inline unsigned int cec_get_edid_spa_location(const u8 *edid, 470 unsigned int size) 471 { 472 unsigned int blocks = size / 128; 473 unsigned int block; 474 u8 d; 475 476 /* Sanity check: at least 2 blocks and a multiple of the block size */ 477 if (blocks < 2 || size % 128) 478 return 0; 479 480 /* 481 * If there are fewer extension blocks than the size, then update 482 * 'blocks'. It is allowed to have more extension blocks than the size, 483 * since some hardware can only read e.g. 256 bytes of the EDID, even 484 * though more blocks are present. The first CEA-861 extension block 485 * should normally be in block 1 anyway. 486 */ 487 if (edid[0x7e] + 1 < blocks) 488 blocks = edid[0x7e] + 1; 489 490 for (block = 1; block < blocks; block++) { 491 unsigned int offset = block * 128; 492 493 /* Skip any non-CEA-861 extension blocks */ 494 if (edid[offset] != 0x02 || edid[offset + 1] != 0x03) 495 continue; 496 497 /* search Vendor Specific Data Block (tag 3) */ 498 d = edid[offset + 2] & 0x7f; 499 /* Check if there are Data Blocks */ 500 if (d <= 4) 501 continue; 502 if (d > 4) { 503 unsigned int i = offset + 4; 504 unsigned int end = offset + d; 505 506 /* Note: 'end' is always < 'size' */ 507 do { 508 u8 tag = edid[i] >> 5; 509 u8 len = edid[i] & 0x1f; 510 511 if (tag == 3 && len >= 5 && i + len <= end && 512 edid[i + 1] == 0x03 && 513 edid[i + 2] == 0x0c && 514 edid[i + 3] == 0x00) 515 return i + 4; 516 i += len + 1; 517 } while (i < end); 518 } 519 } 520 return 0; 521 } 522 523 #endif /* _MEDIA_CEC_H */ 524