1 /* 2 * cec - HDMI Consumer Electronics Control support header 3 * 4 * Copyright 2016 Cisco Systems, Inc. and/or its affiliates. All rights reserved. 5 * 6 * This program is free software; you may redistribute it and/or modify 7 * it under the terms of the GNU General Public License as published by 8 * the Free Software Foundation; version 2 of the License. 9 * 10 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, 11 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF 12 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND 13 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS 14 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN 15 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN 16 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE 17 * SOFTWARE. 18 */ 19 20 #ifndef _MEDIA_CEC_H 21 #define _MEDIA_CEC_H 22 23 #include <linux/poll.h> 24 #include <linux/fs.h> 25 #include <linux/debugfs.h> 26 #include <linux/device.h> 27 #include <linux/cdev.h> 28 #include <linux/kthread.h> 29 #include <linux/timer.h> 30 #include <linux/cec-funcs.h> 31 #include <media/rc-core.h> 32 #include <media/cec-notifier.h> 33 34 #define CEC_CAP_DEFAULTS (CEC_CAP_LOG_ADDRS | CEC_CAP_TRANSMIT | \ 35 CEC_CAP_PASSTHROUGH | CEC_CAP_RC) 36 37 /** 38 * struct cec_devnode - cec device node 39 * @dev: cec device 40 * @cdev: cec character device 41 * @minor: device node minor number 42 * @registered: the device was correctly registered 43 * @unregistered: the device was unregistered 44 * @fhs_lock: lock to control access to the filehandle list 45 * @fhs: the list of open filehandles (cec_fh) 46 * 47 * This structure represents a cec-related device node. 48 * 49 * The @parent is a physical device. It must be set by core or device drivers 50 * before registering the node. 51 */ 52 struct cec_devnode { 53 /* sysfs */ 54 struct device dev; 55 struct cdev cdev; 56 57 /* device info */ 58 int minor; 59 bool registered; 60 bool unregistered; 61 struct list_head fhs; 62 struct mutex lock; 63 }; 64 65 struct cec_adapter; 66 struct cec_data; 67 struct cec_pin; 68 69 struct cec_data { 70 struct list_head list; 71 struct list_head xfer_list; 72 struct cec_adapter *adap; 73 struct cec_msg msg; 74 struct cec_fh *fh; 75 struct delayed_work work; 76 struct completion c; 77 u8 attempts; 78 bool new_initiator; 79 bool blocking; 80 bool completed; 81 }; 82 83 struct cec_msg_entry { 84 struct list_head list; 85 struct cec_msg msg; 86 }; 87 88 struct cec_event_entry { 89 struct list_head list; 90 struct cec_event ev; 91 }; 92 93 #define CEC_NUM_CORE_EVENTS 2 94 #define CEC_NUM_EVENTS CEC_EVENT_PIN_CEC_HIGH 95 96 struct cec_fh { 97 struct list_head list; 98 struct list_head xfer_list; 99 struct cec_adapter *adap; 100 u8 mode_initiator; 101 u8 mode_follower; 102 103 /* Events */ 104 wait_queue_head_t wait; 105 struct mutex lock; 106 struct list_head events[CEC_NUM_EVENTS]; /* queued events */ 107 u8 queued_events[CEC_NUM_EVENTS]; 108 unsigned int total_queued_events; 109 struct cec_event_entry core_events[CEC_NUM_CORE_EVENTS]; 110 struct list_head msgs; /* queued messages */ 111 unsigned int queued_msgs; 112 }; 113 114 #define CEC_SIGNAL_FREE_TIME_RETRY 3 115 #define CEC_SIGNAL_FREE_TIME_NEW_INITIATOR 5 116 #define CEC_SIGNAL_FREE_TIME_NEXT_XFER 7 117 118 /* The nominal data bit period is 2.4 ms */ 119 #define CEC_FREE_TIME_TO_USEC(ft) ((ft) * 2400) 120 121 struct cec_adap_ops { 122 /* Low-level callbacks */ 123 int (*adap_enable)(struct cec_adapter *adap, bool enable); 124 int (*adap_monitor_all_enable)(struct cec_adapter *adap, bool enable); 125 int (*adap_log_addr)(struct cec_adapter *adap, u8 logical_addr); 126 int (*adap_transmit)(struct cec_adapter *adap, u8 attempts, 127 u32 signal_free_time, struct cec_msg *msg); 128 void (*adap_status)(struct cec_adapter *adap, struct seq_file *file); 129 void (*adap_free)(struct cec_adapter *adap); 130 131 /* High-level CEC message callback */ 132 int (*received)(struct cec_adapter *adap, struct cec_msg *msg); 133 }; 134 135 /* 136 * The minimum message length you can receive (excepting poll messages) is 2. 137 * With a transfer rate of at most 36 bytes per second this makes 18 messages 138 * per second worst case. 139 * 140 * We queue at most 3 seconds worth of received messages. The CEC specification 141 * requires that messages are replied to within a second, so 3 seconds should 142 * give more than enough margin. Since most messages are actually more than 2 143 * bytes, this is in practice a lot more than 3 seconds. 144 */ 145 #define CEC_MAX_MSG_RX_QUEUE_SZ (18 * 3) 146 147 /* 148 * The transmit queue is limited to 1 second worth of messages (worst case). 149 * Messages can be transmitted by userspace and kernel space. But for both it 150 * makes no sense to have a lot of messages queued up. One second seems 151 * reasonable. 152 */ 153 #define CEC_MAX_MSG_TX_QUEUE_SZ (18 * 1) 154 155 struct cec_adapter { 156 struct module *owner; 157 char name[32]; 158 struct cec_devnode devnode; 159 struct mutex lock; 160 struct rc_dev *rc; 161 162 struct list_head transmit_queue; 163 unsigned int transmit_queue_sz; 164 struct list_head wait_queue; 165 struct cec_data *transmitting; 166 167 struct task_struct *kthread_config; 168 struct completion config_completion; 169 170 struct task_struct *kthread; 171 wait_queue_head_t kthread_waitq; 172 wait_queue_head_t waitq; 173 174 const struct cec_adap_ops *ops; 175 void *priv; 176 u32 capabilities; 177 u8 available_log_addrs; 178 179 u16 phys_addr; 180 bool needs_hpd; 181 bool is_configuring; 182 bool is_configured; 183 bool cec_pin_is_high; 184 u32 monitor_all_cnt; 185 u32 monitor_pin_cnt; 186 u32 follower_cnt; 187 struct cec_fh *cec_follower; 188 struct cec_fh *cec_initiator; 189 bool passthrough; 190 struct cec_log_addrs log_addrs; 191 192 u32 tx_timeouts; 193 194 #ifdef CONFIG_MEDIA_CEC_RC 195 bool rc_repeating; 196 int rc_last_scancode; 197 u64 rc_last_keypress; 198 #endif 199 #ifdef CONFIG_CEC_NOTIFIER 200 struct cec_notifier *notifier; 201 #endif 202 #ifdef CONFIG_CEC_PIN 203 struct cec_pin *pin; 204 #endif 205 206 struct dentry *cec_dir; 207 struct dentry *status_file; 208 209 u16 phys_addrs[15]; 210 u32 sequence; 211 212 char device_name[32]; 213 char input_phys[32]; 214 char input_drv[32]; 215 }; 216 217 static inline void *cec_get_drvdata(const struct cec_adapter *adap) 218 { 219 return adap->priv; 220 } 221 222 static inline bool cec_has_log_addr(const struct cec_adapter *adap, u8 log_addr) 223 { 224 return adap->log_addrs.log_addr_mask & (1 << log_addr); 225 } 226 227 static inline bool cec_is_sink(const struct cec_adapter *adap) 228 { 229 return adap->phys_addr == 0; 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 * @ts: the timestamp for this event 294 * 295 */ 296 void cec_queue_pin_cec_event(struct cec_adapter *adap, 297 bool is_high, ktime_t ts); 298 299 /** 300 * cec_get_edid_phys_addr() - find and return the physical address 301 * 302 * @edid: pointer to the EDID data 303 * @size: size in bytes of the EDID data 304 * @offset: If not %NULL then the location of the physical address 305 * bytes in the EDID will be returned here. This is set to 0 306 * if there is no physical address found. 307 * 308 * Return: the physical address or CEC_PHYS_ADDR_INVALID if there is none. 309 */ 310 u16 cec_get_edid_phys_addr(const u8 *edid, unsigned int size, 311 unsigned int *offset); 312 313 /** 314 * cec_set_edid_phys_addr() - find and set the physical address 315 * 316 * @edid: pointer to the EDID data 317 * @size: size in bytes of the EDID data 318 * @phys_addr: the new physical address 319 * 320 * This function finds the location of the physical address in the EDID 321 * and fills in the given physical address and updates the checksum 322 * at the end of the EDID block. It does nothing if the EDID doesn't 323 * contain a physical address. 324 */ 325 void cec_set_edid_phys_addr(u8 *edid, unsigned int size, u16 phys_addr); 326 327 /** 328 * cec_phys_addr_for_input() - calculate the PA for an input 329 * 330 * @phys_addr: the physical address of the parent 331 * @input: the number of the input port, must be between 1 and 15 332 * 333 * This function calculates a new physical address based on the input 334 * port number. For example: 335 * 336 * PA = 0.0.0.0 and input = 2 becomes 2.0.0.0 337 * 338 * PA = 3.0.0.0 and input = 1 becomes 3.1.0.0 339 * 340 * PA = 3.2.1.0 and input = 5 becomes 3.2.1.5 341 * 342 * PA = 3.2.1.3 and input = 5 becomes f.f.f.f since it maxed out the depth. 343 * 344 * Return: the new physical address or CEC_PHYS_ADDR_INVALID. 345 */ 346 u16 cec_phys_addr_for_input(u16 phys_addr, u8 input); 347 348 /** 349 * cec_phys_addr_validate() - validate a physical address from an EDID 350 * 351 * @phys_addr: the physical address to validate 352 * @parent: if not %NULL, then this is filled with the parents PA. 353 * @port: if not %NULL, then this is filled with the input port. 354 * 355 * This validates a physical address as read from an EDID. If the 356 * PA is invalid (such as 1.0.1.0 since '0' is only allowed at the end), 357 * then it will return -EINVAL. 358 * 359 * The parent PA is passed into %parent and the input port is passed into 360 * %port. For example: 361 * 362 * PA = 0.0.0.0: has parent 0.0.0.0 and input port 0. 363 * 364 * PA = 1.0.0.0: has parent 0.0.0.0 and input port 1. 365 * 366 * PA = 3.2.0.0: has parent 3.0.0.0 and input port 2. 367 * 368 * PA = f.f.f.f: has parent f.f.f.f and input port 0. 369 * 370 * Return: 0 if the PA is valid, -EINVAL if not. 371 */ 372 int cec_phys_addr_validate(u16 phys_addr, u16 *parent, u16 *port); 373 374 #else 375 376 static inline int cec_register_adapter(struct cec_adapter *adap, 377 struct device *parent) 378 { 379 return 0; 380 } 381 382 static inline void cec_unregister_adapter(struct cec_adapter *adap) 383 { 384 } 385 386 static inline void cec_delete_adapter(struct cec_adapter *adap) 387 { 388 } 389 390 static inline void cec_s_phys_addr(struct cec_adapter *adap, u16 phys_addr, 391 bool block) 392 { 393 } 394 395 static inline void cec_s_phys_addr_from_edid(struct cec_adapter *adap, 396 const struct edid *edid) 397 { 398 } 399 400 static inline u16 cec_get_edid_phys_addr(const u8 *edid, unsigned int size, 401 unsigned int *offset) 402 { 403 if (offset) 404 *offset = 0; 405 return CEC_PHYS_ADDR_INVALID; 406 } 407 408 static inline void cec_set_edid_phys_addr(u8 *edid, unsigned int size, 409 u16 phys_addr) 410 { 411 } 412 413 static inline u16 cec_phys_addr_for_input(u16 phys_addr, u8 input) 414 { 415 return CEC_PHYS_ADDR_INVALID; 416 } 417 418 static inline int cec_phys_addr_validate(u16 phys_addr, u16 *parent, u16 *port) 419 { 420 return 0; 421 } 422 423 #endif 424 425 /** 426 * cec_phys_addr_invalidate() - set the physical address to INVALID 427 * 428 * @adap: the CEC adapter 429 * 430 * This is a simple helper function to invalidate the physical 431 * address. 432 */ 433 static inline void cec_phys_addr_invalidate(struct cec_adapter *adap) 434 { 435 cec_s_phys_addr(adap, CEC_PHYS_ADDR_INVALID, false); 436 } 437 438 #endif /* _MEDIA_CEC_H */ 439