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 #include <media/cec-notifier.h> 21 22 #define CEC_CAP_DEFAULTS (CEC_CAP_LOG_ADDRS | CEC_CAP_TRANSMIT | \ 23 CEC_CAP_PASSTHROUGH | CEC_CAP_RC) 24 25 /** 26 * struct cec_devnode - cec device node 27 * @dev: cec device 28 * @cdev: cec character device 29 * @minor: device node minor number 30 * @registered: the device was correctly registered 31 * @unregistered: the device was unregistered 32 * @fhs_lock: lock to control access to the filehandle list 33 * @fhs: the list of open filehandles (cec_fh) 34 * 35 * This structure represents a cec-related device node. 36 * 37 * The @parent is a physical device. It must be set by core or device drivers 38 * before registering the node. 39 */ 40 struct cec_devnode { 41 /* sysfs */ 42 struct device dev; 43 struct cdev cdev; 44 45 /* device info */ 46 int minor; 47 bool registered; 48 bool unregistered; 49 struct list_head fhs; 50 struct mutex lock; 51 }; 52 53 struct cec_adapter; 54 struct cec_data; 55 struct cec_pin; 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 new_initiator; 67 bool blocking; 68 bool completed; 69 }; 70 71 struct cec_msg_entry { 72 struct list_head list; 73 struct cec_msg msg; 74 }; 75 76 struct cec_event_entry { 77 struct list_head list; 78 struct cec_event ev; 79 }; 80 81 #define CEC_NUM_CORE_EVENTS 2 82 #define CEC_NUM_EVENTS CEC_EVENT_PIN_HPD_HIGH 83 84 struct cec_fh { 85 struct list_head list; 86 struct list_head xfer_list; 87 struct cec_adapter *adap; 88 u8 mode_initiator; 89 u8 mode_follower; 90 91 /* Events */ 92 wait_queue_head_t wait; 93 struct mutex lock; 94 struct list_head events[CEC_NUM_EVENTS]; /* queued events */ 95 u16 queued_events[CEC_NUM_EVENTS]; 96 unsigned int total_queued_events; 97 struct cec_event_entry core_events[CEC_NUM_CORE_EVENTS]; 98 struct list_head msgs; /* queued messages */ 99 unsigned int queued_msgs; 100 }; 101 102 #define CEC_SIGNAL_FREE_TIME_RETRY 3 103 #define CEC_SIGNAL_FREE_TIME_NEW_INITIATOR 5 104 #define CEC_SIGNAL_FREE_TIME_NEXT_XFER 7 105 106 /* The nominal data bit period is 2.4 ms */ 107 #define CEC_FREE_TIME_TO_USEC(ft) ((ft) * 2400) 108 109 struct cec_adap_ops { 110 /* Low-level callbacks */ 111 int (*adap_enable)(struct cec_adapter *adap, bool enable); 112 int (*adap_monitor_all_enable)(struct cec_adapter *adap, bool enable); 113 int (*adap_monitor_pin_enable)(struct cec_adapter *adap, bool enable); 114 int (*adap_log_addr)(struct cec_adapter *adap, u8 logical_addr); 115 int (*adap_transmit)(struct cec_adapter *adap, u8 attempts, 116 u32 signal_free_time, struct cec_msg *msg); 117 void (*adap_status)(struct cec_adapter *adap, struct seq_file *file); 118 void (*adap_free)(struct cec_adapter *adap); 119 120 /* Error injection callbacks */ 121 int (*error_inj_show)(struct cec_adapter *adap, struct seq_file *sf); 122 bool (*error_inj_parse_line)(struct cec_adapter *adap, char *line); 123 124 /* High-level CEC message callback */ 125 int (*received)(struct cec_adapter *adap, struct cec_msg *msg); 126 }; 127 128 /* 129 * The minimum message length you can receive (excepting poll messages) is 2. 130 * With a transfer rate of at most 36 bytes per second this makes 18 messages 131 * per second worst case. 132 * 133 * We queue at most 3 seconds worth of received messages. The CEC specification 134 * requires that messages are replied to within a second, so 3 seconds should 135 * give more than enough margin. Since most messages are actually more than 2 136 * bytes, this is in practice a lot more than 3 seconds. 137 */ 138 #define CEC_MAX_MSG_RX_QUEUE_SZ (18 * 3) 139 140 /* 141 * The transmit queue is limited to 1 second worth of messages (worst case). 142 * Messages can be transmitted by userspace and kernel space. But for both it 143 * makes no sense to have a lot of messages queued up. One second seems 144 * reasonable. 145 */ 146 #define CEC_MAX_MSG_TX_QUEUE_SZ (18 * 1) 147 148 struct cec_adapter { 149 struct module *owner; 150 char name[32]; 151 struct cec_devnode devnode; 152 struct mutex lock; 153 struct rc_dev *rc; 154 155 struct list_head transmit_queue; 156 unsigned int transmit_queue_sz; 157 struct list_head wait_queue; 158 struct cec_data *transmitting; 159 160 struct task_struct *kthread_config; 161 struct completion config_completion; 162 163 struct task_struct *kthread; 164 wait_queue_head_t kthread_waitq; 165 wait_queue_head_t waitq; 166 167 const struct cec_adap_ops *ops; 168 void *priv; 169 u32 capabilities; 170 u8 available_log_addrs; 171 172 u16 phys_addr; 173 bool needs_hpd; 174 bool is_configuring; 175 bool is_configured; 176 bool cec_pin_is_high; 177 u32 monitor_all_cnt; 178 u32 monitor_pin_cnt; 179 u32 follower_cnt; 180 struct cec_fh *cec_follower; 181 struct cec_fh *cec_initiator; 182 bool passthrough; 183 struct cec_log_addrs log_addrs; 184 185 u32 tx_timeouts; 186 187 #ifdef CONFIG_CEC_NOTIFIER 188 struct cec_notifier *notifier; 189 #endif 190 #ifdef CONFIG_CEC_PIN 191 struct cec_pin *pin; 192 #endif 193 194 struct dentry *cec_dir; 195 struct dentry *status_file; 196 struct dentry *error_inj_file; 197 198 u16 phys_addrs[15]; 199 u32 sequence; 200 201 char device_name[32]; 202 char input_phys[32]; 203 char input_drv[32]; 204 }; 205 206 static inline void *cec_get_drvdata(const struct cec_adapter *adap) 207 { 208 return adap->priv; 209 } 210 211 static inline bool cec_has_log_addr(const struct cec_adapter *adap, u8 log_addr) 212 { 213 return adap->log_addrs.log_addr_mask & (1 << log_addr); 214 } 215 216 static inline bool cec_is_sink(const struct cec_adapter *adap) 217 { 218 return adap->phys_addr == 0; 219 } 220 221 /** 222 * cec_is_registered() - is the CEC adapter registered? 223 * 224 * @adap: the CEC adapter, may be NULL. 225 * 226 * Return: true if the adapter is registered, false otherwise. 227 */ 228 static inline bool cec_is_registered(const struct cec_adapter *adap) 229 { 230 return adap && adap->devnode.registered; 231 } 232 233 #define cec_phys_addr_exp(pa) \ 234 ((pa) >> 12), ((pa) >> 8) & 0xf, ((pa) >> 4) & 0xf, (pa) & 0xf 235 236 struct edid; 237 238 #if IS_REACHABLE(CONFIG_CEC_CORE) 239 struct cec_adapter *cec_allocate_adapter(const struct cec_adap_ops *ops, 240 void *priv, const char *name, u32 caps, u8 available_las); 241 int cec_register_adapter(struct cec_adapter *adap, struct device *parent); 242 void cec_unregister_adapter(struct cec_adapter *adap); 243 void cec_delete_adapter(struct cec_adapter *adap); 244 245 int cec_s_log_addrs(struct cec_adapter *adap, struct cec_log_addrs *log_addrs, 246 bool block); 247 void cec_s_phys_addr(struct cec_adapter *adap, u16 phys_addr, 248 bool block); 249 void cec_s_phys_addr_from_edid(struct cec_adapter *adap, 250 const struct edid *edid); 251 int cec_transmit_msg(struct cec_adapter *adap, struct cec_msg *msg, 252 bool block); 253 254 /* Called by the adapter */ 255 void cec_transmit_done_ts(struct cec_adapter *adap, u8 status, 256 u8 arb_lost_cnt, u8 nack_cnt, u8 low_drive_cnt, 257 u8 error_cnt, ktime_t ts); 258 259 static inline void cec_transmit_done(struct cec_adapter *adap, u8 status, 260 u8 arb_lost_cnt, u8 nack_cnt, 261 u8 low_drive_cnt, u8 error_cnt) 262 { 263 cec_transmit_done_ts(adap, status, arb_lost_cnt, nack_cnt, 264 low_drive_cnt, error_cnt, ktime_get()); 265 } 266 /* 267 * Simplified version of cec_transmit_done for hardware that doesn't retry 268 * failed transmits. So this is always just one attempt in which case 269 * the status is sufficient. 270 */ 271 void cec_transmit_attempt_done_ts(struct cec_adapter *adap, 272 u8 status, ktime_t ts); 273 274 static inline void cec_transmit_attempt_done(struct cec_adapter *adap, 275 u8 status) 276 { 277 cec_transmit_attempt_done_ts(adap, status, ktime_get()); 278 } 279 280 void cec_received_msg_ts(struct cec_adapter *adap, 281 struct cec_msg *msg, ktime_t ts); 282 283 static inline void cec_received_msg(struct cec_adapter *adap, 284 struct cec_msg *msg) 285 { 286 cec_received_msg_ts(adap, msg, ktime_get()); 287 } 288 289 /** 290 * cec_queue_pin_cec_event() - queue a CEC pin event with a given timestamp. 291 * 292 * @adap: pointer to the cec adapter 293 * @is_high: when true the CEC pin is high, otherwise it is low 294 * @dropped_events: when true some events were dropped 295 * @ts: the timestamp for this event 296 * 297 */ 298 void cec_queue_pin_cec_event(struct cec_adapter *adap, bool is_high, 299 bool dropped_events, ktime_t ts); 300 301 /** 302 * cec_queue_pin_hpd_event() - queue a pin event with a given timestamp. 303 * 304 * @adap: pointer to the cec adapter 305 * @is_high: when true the HPD pin is high, otherwise it is low 306 * @ts: the timestamp for this event 307 * 308 */ 309 void cec_queue_pin_hpd_event(struct cec_adapter *adap, bool is_high, ktime_t ts); 310 311 /** 312 * cec_get_edid_phys_addr() - find and return the physical address 313 * 314 * @edid: pointer to the EDID data 315 * @size: size in bytes of the EDID data 316 * @offset: If not %NULL then the location of the physical address 317 * bytes in the EDID will be returned here. This is set to 0 318 * if there is no physical address found. 319 * 320 * Return: the physical address or CEC_PHYS_ADDR_INVALID if there is none. 321 */ 322 u16 cec_get_edid_phys_addr(const u8 *edid, unsigned int size, 323 unsigned int *offset); 324 325 /** 326 * cec_set_edid_phys_addr() - find and set the physical address 327 * 328 * @edid: pointer to the EDID data 329 * @size: size in bytes of the EDID data 330 * @phys_addr: the new physical address 331 * 332 * This function finds the location of the physical address in the EDID 333 * and fills in the given physical address and updates the checksum 334 * at the end of the EDID block. It does nothing if the EDID doesn't 335 * contain a physical address. 336 */ 337 void cec_set_edid_phys_addr(u8 *edid, unsigned int size, u16 phys_addr); 338 339 /** 340 * cec_phys_addr_for_input() - calculate the PA for an input 341 * 342 * @phys_addr: the physical address of the parent 343 * @input: the number of the input port, must be between 1 and 15 344 * 345 * This function calculates a new physical address based on the input 346 * port number. For example: 347 * 348 * PA = 0.0.0.0 and input = 2 becomes 2.0.0.0 349 * 350 * PA = 3.0.0.0 and input = 1 becomes 3.1.0.0 351 * 352 * PA = 3.2.1.0 and input = 5 becomes 3.2.1.5 353 * 354 * PA = 3.2.1.3 and input = 5 becomes f.f.f.f since it maxed out the depth. 355 * 356 * Return: the new physical address or CEC_PHYS_ADDR_INVALID. 357 */ 358 u16 cec_phys_addr_for_input(u16 phys_addr, u8 input); 359 360 /** 361 * cec_phys_addr_validate() - validate a physical address from an EDID 362 * 363 * @phys_addr: the physical address to validate 364 * @parent: if not %NULL, then this is filled with the parents PA. 365 * @port: if not %NULL, then this is filled with the input port. 366 * 367 * This validates a physical address as read from an EDID. If the 368 * PA is invalid (such as 1.0.1.0 since '0' is only allowed at the end), 369 * then it will return -EINVAL. 370 * 371 * The parent PA is passed into %parent and the input port is passed into 372 * %port. For example: 373 * 374 * PA = 0.0.0.0: has parent 0.0.0.0 and input port 0. 375 * 376 * PA = 1.0.0.0: has parent 0.0.0.0 and input port 1. 377 * 378 * PA = 3.2.0.0: has parent 3.0.0.0 and input port 2. 379 * 380 * PA = f.f.f.f: has parent f.f.f.f and input port 0. 381 * 382 * Return: 0 if the PA is valid, -EINVAL if not. 383 */ 384 int cec_phys_addr_validate(u16 phys_addr, u16 *parent, u16 *port); 385 386 #else 387 388 static inline int cec_register_adapter(struct cec_adapter *adap, 389 struct device *parent) 390 { 391 return 0; 392 } 393 394 static inline void cec_unregister_adapter(struct cec_adapter *adap) 395 { 396 } 397 398 static inline void cec_delete_adapter(struct cec_adapter *adap) 399 { 400 } 401 402 static inline void cec_s_phys_addr(struct cec_adapter *adap, u16 phys_addr, 403 bool block) 404 { 405 } 406 407 static inline void cec_s_phys_addr_from_edid(struct cec_adapter *adap, 408 const struct edid *edid) 409 { 410 } 411 412 static inline u16 cec_get_edid_phys_addr(const u8 *edid, unsigned int size, 413 unsigned int *offset) 414 { 415 if (offset) 416 *offset = 0; 417 return CEC_PHYS_ADDR_INVALID; 418 } 419 420 static inline void cec_set_edid_phys_addr(u8 *edid, unsigned int size, 421 u16 phys_addr) 422 { 423 } 424 425 static inline u16 cec_phys_addr_for_input(u16 phys_addr, u8 input) 426 { 427 return CEC_PHYS_ADDR_INVALID; 428 } 429 430 static inline int cec_phys_addr_validate(u16 phys_addr, u16 *parent, u16 *port) 431 { 432 if (parent) 433 *parent = phys_addr; 434 if (port) 435 *port = 0; 436 return 0; 437 } 438 439 #endif 440 441 /** 442 * cec_phys_addr_invalidate() - set the physical address to INVALID 443 * 444 * @adap: the CEC adapter 445 * 446 * This is a simple helper function to invalidate the physical 447 * address. 448 */ 449 static inline void cec_phys_addr_invalidate(struct cec_adapter *adap) 450 { 451 cec_s_phys_addr(adap, CEC_PHYS_ADDR_INVALID, false); 452 } 453 454 #endif /* _MEDIA_CEC_H */ 455