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 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 struct cec_adapter { 148 struct module *owner; 149 char name[32]; 150 struct cec_devnode devnode; 151 struct mutex lock; 152 struct rc_dev *rc; 153 154 struct list_head transmit_queue; 155 unsigned int transmit_queue_sz; 156 struct list_head wait_queue; 157 struct cec_data *transmitting; 158 159 struct task_struct *kthread_config; 160 struct completion config_completion; 161 162 struct task_struct *kthread; 163 wait_queue_head_t kthread_waitq; 164 wait_queue_head_t waitq; 165 166 const struct cec_adap_ops *ops; 167 void *priv; 168 u32 capabilities; 169 u8 available_log_addrs; 170 171 u16 phys_addr; 172 bool needs_hpd; 173 bool is_configuring; 174 bool is_configured; 175 bool cec_pin_is_high; 176 u8 last_initiator; 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 input_phys[32]; 202 }; 203 204 static inline void *cec_get_drvdata(const struct cec_adapter *adap) 205 { 206 return adap->priv; 207 } 208 209 static inline bool cec_has_log_addr(const struct cec_adapter *adap, u8 log_addr) 210 { 211 return adap->log_addrs.log_addr_mask & (1 << log_addr); 212 } 213 214 static inline bool cec_is_sink(const struct cec_adapter *adap) 215 { 216 return adap->phys_addr == 0; 217 } 218 219 /** 220 * cec_is_registered() - is the CEC adapter registered? 221 * 222 * @adap: the CEC adapter, may be NULL. 223 * 224 * Return: true if the adapter is registered, false otherwise. 225 */ 226 static inline bool cec_is_registered(const struct cec_adapter *adap) 227 { 228 return adap && adap->devnode.registered; 229 } 230 231 #define cec_phys_addr_exp(pa) \ 232 ((pa) >> 12), ((pa) >> 8) & 0xf, ((pa) >> 4) & 0xf, (pa) & 0xf 233 234 struct edid; 235 236 #if IS_REACHABLE(CONFIG_CEC_CORE) 237 struct cec_adapter *cec_allocate_adapter(const struct cec_adap_ops *ops, 238 void *priv, const char *name, u32 caps, u8 available_las); 239 int cec_register_adapter(struct cec_adapter *adap, struct device *parent); 240 void cec_unregister_adapter(struct cec_adapter *adap); 241 void cec_delete_adapter(struct cec_adapter *adap); 242 243 int cec_s_log_addrs(struct cec_adapter *adap, struct cec_log_addrs *log_addrs, 244 bool block); 245 void cec_s_phys_addr(struct cec_adapter *adap, u16 phys_addr, 246 bool block); 247 void cec_s_phys_addr_from_edid(struct cec_adapter *adap, 248 const struct edid *edid); 249 int cec_transmit_msg(struct cec_adapter *adap, struct cec_msg *msg, 250 bool block); 251 252 /* Called by the adapter */ 253 void cec_transmit_done_ts(struct cec_adapter *adap, u8 status, 254 u8 arb_lost_cnt, u8 nack_cnt, u8 low_drive_cnt, 255 u8 error_cnt, ktime_t ts); 256 257 static inline void cec_transmit_done(struct cec_adapter *adap, u8 status, 258 u8 arb_lost_cnt, u8 nack_cnt, 259 u8 low_drive_cnt, u8 error_cnt) 260 { 261 cec_transmit_done_ts(adap, status, arb_lost_cnt, nack_cnt, 262 low_drive_cnt, error_cnt, ktime_get()); 263 } 264 /* 265 * Simplified version of cec_transmit_done for hardware that doesn't retry 266 * failed transmits. So this is always just one attempt in which case 267 * the status is sufficient. 268 */ 269 void cec_transmit_attempt_done_ts(struct cec_adapter *adap, 270 u8 status, ktime_t ts); 271 272 static inline void cec_transmit_attempt_done(struct cec_adapter *adap, 273 u8 status) 274 { 275 cec_transmit_attempt_done_ts(adap, status, ktime_get()); 276 } 277 278 void cec_received_msg_ts(struct cec_adapter *adap, 279 struct cec_msg *msg, ktime_t ts); 280 281 static inline void cec_received_msg(struct cec_adapter *adap, 282 struct cec_msg *msg) 283 { 284 cec_received_msg_ts(adap, msg, ktime_get()); 285 } 286 287 /** 288 * cec_queue_pin_cec_event() - queue a CEC pin event with a given timestamp. 289 * 290 * @adap: pointer to the cec adapter 291 * @is_high: when true the CEC pin is high, otherwise it is low 292 * @dropped_events: when true some events were dropped 293 * @ts: the timestamp for this event 294 * 295 */ 296 void cec_queue_pin_cec_event(struct cec_adapter *adap, bool is_high, 297 bool dropped_events, ktime_t ts); 298 299 /** 300 * cec_queue_pin_hpd_event() - queue a pin event with a given timestamp. 301 * 302 * @adap: pointer to the cec adapter 303 * @is_high: when true the HPD pin is high, otherwise it is low 304 * @ts: the timestamp for this event 305 * 306 */ 307 void cec_queue_pin_hpd_event(struct cec_adapter *adap, bool is_high, ktime_t ts); 308 309 /** 310 * cec_queue_pin_5v_event() - queue a pin event with a given timestamp. 311 * 312 * @adap: pointer to the cec adapter 313 * @is_high: when true the 5V pin is high, otherwise it is low 314 * @ts: the timestamp for this event 315 * 316 */ 317 void cec_queue_pin_5v_event(struct cec_adapter *adap, bool is_high, ktime_t ts); 318 319 /** 320 * cec_get_edid_phys_addr() - find and return the physical address 321 * 322 * @edid: pointer to the EDID data 323 * @size: size in bytes of the EDID data 324 * @offset: If not %NULL then the location of the physical address 325 * bytes in the EDID will be returned here. This is set to 0 326 * if there is no physical address found. 327 * 328 * Return: the physical address or CEC_PHYS_ADDR_INVALID if there is none. 329 */ 330 u16 cec_get_edid_phys_addr(const u8 *edid, unsigned int size, 331 unsigned int *offset); 332 333 #else 334 335 static inline int cec_register_adapter(struct cec_adapter *adap, 336 struct device *parent) 337 { 338 return 0; 339 } 340 341 static inline void cec_unregister_adapter(struct cec_adapter *adap) 342 { 343 } 344 345 static inline void cec_delete_adapter(struct cec_adapter *adap) 346 { 347 } 348 349 static inline void cec_s_phys_addr(struct cec_adapter *adap, u16 phys_addr, 350 bool block) 351 { 352 } 353 354 static inline void cec_s_phys_addr_from_edid(struct cec_adapter *adap, 355 const struct edid *edid) 356 { 357 } 358 359 static inline u16 cec_get_edid_phys_addr(const u8 *edid, unsigned int size, 360 unsigned int *offset) 361 { 362 if (offset) 363 *offset = 0; 364 return CEC_PHYS_ADDR_INVALID; 365 } 366 367 #endif 368 369 /** 370 * cec_phys_addr_invalidate() - set the physical address to INVALID 371 * 372 * @adap: the CEC adapter 373 * 374 * This is a simple helper function to invalidate the physical 375 * address. 376 */ 377 static inline void cec_phys_addr_invalidate(struct cec_adapter *adap) 378 { 379 cec_s_phys_addr(adap, CEC_PHYS_ADDR_INVALID, false); 380 } 381 382 /** 383 * cec_get_edid_spa_location() - find location of the Source Physical Address 384 * 385 * @edid: the EDID 386 * @size: the size of the EDID 387 * 388 * This EDID is expected to be a CEA-861 compliant, which means that there are 389 * at least two blocks and one or more of the extensions blocks are CEA-861 390 * blocks. 391 * 392 * The returned location is guaranteed to be <= size-2. 393 * 394 * This is an inline function since it is used by both CEC and V4L2. 395 * Ideally this would go in a module shared by both, but it is overkill to do 396 * that for just a single function. 397 */ 398 static inline unsigned int cec_get_edid_spa_location(const u8 *edid, 399 unsigned int size) 400 { 401 unsigned int blocks = size / 128; 402 unsigned int block; 403 u8 d; 404 405 /* Sanity check: at least 2 blocks and a multiple of the block size */ 406 if (blocks < 2 || size % 128) 407 return 0; 408 409 /* 410 * If there are fewer extension blocks than the size, then update 411 * 'blocks'. It is allowed to have more extension blocks than the size, 412 * since some hardware can only read e.g. 256 bytes of the EDID, even 413 * though more blocks are present. The first CEA-861 extension block 414 * should normally be in block 1 anyway. 415 */ 416 if (edid[0x7e] + 1 < blocks) 417 blocks = edid[0x7e] + 1; 418 419 for (block = 1; block < blocks; block++) { 420 unsigned int offset = block * 128; 421 422 /* Skip any non-CEA-861 extension blocks */ 423 if (edid[offset] != 0x02 || edid[offset + 1] != 0x03) 424 continue; 425 426 /* search Vendor Specific Data Block (tag 3) */ 427 d = edid[offset + 2] & 0x7f; 428 /* Check if there are Data Blocks */ 429 if (d <= 4) 430 continue; 431 if (d > 4) { 432 unsigned int i = offset + 4; 433 unsigned int end = offset + d; 434 435 /* Note: 'end' is always < 'size' */ 436 do { 437 u8 tag = edid[i] >> 5; 438 u8 len = edid[i] & 0x1f; 439 440 if (tag == 3 && len >= 5 && i + len <= end && 441 edid[i + 1] == 0x03 && 442 edid[i + 2] == 0x0c && 443 edid[i + 3] == 0x00) 444 return i + 4; 445 i += len + 1; 446 } while (i < end); 447 } 448 } 449 return 0; 450 } 451 452 #endif /* _MEDIA_CEC_H */ 453