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 bool transmit_in_progress; 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 u8 last_initiator; 178 u32 monitor_all_cnt; 179 u32 monitor_pin_cnt; 180 u32 follower_cnt; 181 struct cec_fh *cec_follower; 182 struct cec_fh *cec_initiator; 183 bool passthrough; 184 struct cec_log_addrs log_addrs; 185 186 u32 tx_timeouts; 187 188 #ifdef CONFIG_CEC_NOTIFIER 189 struct cec_notifier *notifier; 190 #endif 191 #ifdef CONFIG_CEC_PIN 192 struct cec_pin *pin; 193 #endif 194 195 struct dentry *cec_dir; 196 struct dentry *status_file; 197 struct dentry *error_inj_file; 198 199 u16 phys_addrs[15]; 200 u32 sequence; 201 202 char input_phys[32]; 203 }; 204 205 static inline void *cec_get_drvdata(const struct cec_adapter *adap) 206 { 207 return adap->priv; 208 } 209 210 static inline bool cec_has_log_addr(const struct cec_adapter *adap, u8 log_addr) 211 { 212 return adap->log_addrs.log_addr_mask & (1 << log_addr); 213 } 214 215 static inline bool cec_is_sink(const struct cec_adapter *adap) 216 { 217 return adap->phys_addr == 0; 218 } 219 220 /** 221 * cec_is_registered() - is the CEC adapter registered? 222 * 223 * @adap: the CEC adapter, may be NULL. 224 * 225 * Return: true if the adapter is registered, false otherwise. 226 */ 227 static inline bool cec_is_registered(const struct cec_adapter *adap) 228 { 229 return adap && adap->devnode.registered; 230 } 231 232 #define cec_phys_addr_exp(pa) \ 233 ((pa) >> 12), ((pa) >> 8) & 0xf, ((pa) >> 4) & 0xf, (pa) & 0xf 234 235 struct edid; 236 237 #if IS_REACHABLE(CONFIG_CEC_CORE) 238 struct cec_adapter *cec_allocate_adapter(const struct cec_adap_ops *ops, 239 void *priv, const char *name, u32 caps, u8 available_las); 240 int cec_register_adapter(struct cec_adapter *adap, struct device *parent); 241 void cec_unregister_adapter(struct cec_adapter *adap); 242 void cec_delete_adapter(struct cec_adapter *adap); 243 244 int cec_s_log_addrs(struct cec_adapter *adap, struct cec_log_addrs *log_addrs, 245 bool block); 246 void cec_s_phys_addr(struct cec_adapter *adap, u16 phys_addr, 247 bool block); 248 void cec_s_phys_addr_from_edid(struct cec_adapter *adap, 249 const struct edid *edid); 250 int cec_transmit_msg(struct cec_adapter *adap, struct cec_msg *msg, 251 bool block); 252 253 /* Called by the adapter */ 254 void cec_transmit_done_ts(struct cec_adapter *adap, u8 status, 255 u8 arb_lost_cnt, u8 nack_cnt, u8 low_drive_cnt, 256 u8 error_cnt, ktime_t ts); 257 258 static inline void cec_transmit_done(struct cec_adapter *adap, u8 status, 259 u8 arb_lost_cnt, u8 nack_cnt, 260 u8 low_drive_cnt, u8 error_cnt) 261 { 262 cec_transmit_done_ts(adap, status, arb_lost_cnt, nack_cnt, 263 low_drive_cnt, error_cnt, ktime_get()); 264 } 265 /* 266 * Simplified version of cec_transmit_done for hardware that doesn't retry 267 * failed transmits. So this is always just one attempt in which case 268 * the status is sufficient. 269 */ 270 void cec_transmit_attempt_done_ts(struct cec_adapter *adap, 271 u8 status, ktime_t ts); 272 273 static inline void cec_transmit_attempt_done(struct cec_adapter *adap, 274 u8 status) 275 { 276 cec_transmit_attempt_done_ts(adap, status, ktime_get()); 277 } 278 279 void cec_received_msg_ts(struct cec_adapter *adap, 280 struct cec_msg *msg, ktime_t ts); 281 282 static inline void cec_received_msg(struct cec_adapter *adap, 283 struct cec_msg *msg) 284 { 285 cec_received_msg_ts(adap, msg, ktime_get()); 286 } 287 288 /** 289 * cec_queue_pin_cec_event() - queue a CEC pin event with a given timestamp. 290 * 291 * @adap: pointer to the cec adapter 292 * @is_high: when true the CEC pin is high, otherwise it is low 293 * @dropped_events: when true some events were dropped 294 * @ts: the timestamp for this event 295 * 296 */ 297 void cec_queue_pin_cec_event(struct cec_adapter *adap, bool is_high, 298 bool dropped_events, ktime_t ts); 299 300 /** 301 * cec_queue_pin_hpd_event() - queue a pin event with a given timestamp. 302 * 303 * @adap: pointer to the cec adapter 304 * @is_high: when true the HPD pin is high, otherwise it is low 305 * @ts: the timestamp for this event 306 * 307 */ 308 void cec_queue_pin_hpd_event(struct cec_adapter *adap, bool is_high, ktime_t ts); 309 310 /** 311 * cec_queue_pin_5v_event() - queue a pin event with a given timestamp. 312 * 313 * @adap: pointer to the cec adapter 314 * @is_high: when true the 5V pin is high, otherwise it is low 315 * @ts: the timestamp for this event 316 * 317 */ 318 void cec_queue_pin_5v_event(struct cec_adapter *adap, bool is_high, ktime_t ts); 319 320 /** 321 * cec_get_edid_phys_addr() - find and return the physical address 322 * 323 * @edid: pointer to the EDID data 324 * @size: size in bytes of the EDID data 325 * @offset: If not %NULL then the location of the physical address 326 * bytes in the EDID will be returned here. This is set to 0 327 * if there is no physical address found. 328 * 329 * Return: the physical address or CEC_PHYS_ADDR_INVALID if there is none. 330 */ 331 u16 cec_get_edid_phys_addr(const u8 *edid, unsigned int size, 332 unsigned int *offset); 333 334 #else 335 336 static inline int cec_register_adapter(struct cec_adapter *adap, 337 struct device *parent) 338 { 339 return 0; 340 } 341 342 static inline void cec_unregister_adapter(struct cec_adapter *adap) 343 { 344 } 345 346 static inline void cec_delete_adapter(struct cec_adapter *adap) 347 { 348 } 349 350 static inline void cec_s_phys_addr(struct cec_adapter *adap, u16 phys_addr, 351 bool block) 352 { 353 } 354 355 static inline void cec_s_phys_addr_from_edid(struct cec_adapter *adap, 356 const struct edid *edid) 357 { 358 } 359 360 static inline u16 cec_get_edid_phys_addr(const u8 *edid, unsigned int size, 361 unsigned int *offset) 362 { 363 if (offset) 364 *offset = 0; 365 return CEC_PHYS_ADDR_INVALID; 366 } 367 368 #endif 369 370 /** 371 * cec_phys_addr_invalidate() - set the physical address to INVALID 372 * 373 * @adap: the CEC adapter 374 * 375 * This is a simple helper function to invalidate the physical 376 * address. 377 */ 378 static inline void cec_phys_addr_invalidate(struct cec_adapter *adap) 379 { 380 cec_s_phys_addr(adap, CEC_PHYS_ADDR_INVALID, false); 381 } 382 383 /** 384 * cec_get_edid_spa_location() - find location of the Source Physical Address 385 * 386 * @edid: the EDID 387 * @size: the size of the EDID 388 * 389 * This EDID is expected to be a CEA-861 compliant, which means that there are 390 * at least two blocks and one or more of the extensions blocks are CEA-861 391 * blocks. 392 * 393 * The returned location is guaranteed to be <= size-2. 394 * 395 * This is an inline function since it is used by both CEC and V4L2. 396 * Ideally this would go in a module shared by both, but it is overkill to do 397 * that for just a single function. 398 */ 399 static inline unsigned int cec_get_edid_spa_location(const u8 *edid, 400 unsigned int size) 401 { 402 unsigned int blocks = size / 128; 403 unsigned int block; 404 u8 d; 405 406 /* Sanity check: at least 2 blocks and a multiple of the block size */ 407 if (blocks < 2 || size % 128) 408 return 0; 409 410 /* 411 * If there are fewer extension blocks than the size, then update 412 * 'blocks'. It is allowed to have more extension blocks than the size, 413 * since some hardware can only read e.g. 256 bytes of the EDID, even 414 * though more blocks are present. The first CEA-861 extension block 415 * should normally be in block 1 anyway. 416 */ 417 if (edid[0x7e] + 1 < blocks) 418 blocks = edid[0x7e] + 1; 419 420 for (block = 1; block < blocks; block++) { 421 unsigned int offset = block * 128; 422 423 /* Skip any non-CEA-861 extension blocks */ 424 if (edid[offset] != 0x02 || edid[offset + 1] != 0x03) 425 continue; 426 427 /* search Vendor Specific Data Block (tag 3) */ 428 d = edid[offset + 2] & 0x7f; 429 /* Check if there are Data Blocks */ 430 if (d <= 4) 431 continue; 432 if (d > 4) { 433 unsigned int i = offset + 4; 434 unsigned int end = offset + d; 435 436 /* Note: 'end' is always < 'size' */ 437 do { 438 u8 tag = edid[i] >> 5; 439 u8 len = edid[i] & 0x1f; 440 441 if (tag == 3 && len >= 5 && i + len <= end && 442 edid[i + 1] == 0x03 && 443 edid[i + 2] == 0x0c && 444 edid[i + 3] == 0x00) 445 return i + 4; 446 i += len + 1; 447 } while (i < end); 448 } 449 } 450 return 0; 451 } 452 453 #endif /* _MEDIA_CEC_H */ 454