include/media/cec.h

   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 /* CEC_ADAP_G_CONNECTOR_INFO is available */
  22 #define CEC_CAP_CONNECTOR_INFO  (1 << 8)
  23
  24 #define CEC_CAP_DEFAULTS (CEC_CAP_LOG_ADDRS | CEC_CAP_TRANSMIT | \
  25                           CEC_CAP_PASSTHROUGH | CEC_CAP_RC)
  26
  27 /**
  28  * struct cec_devnode - cec device node
  29  * @dev:        cec device
  30  * @cdev:       cec character device
  31  * @minor:      device node minor number
  32  * @registered: the device was correctly registered
  33  * @unregistered: the device was unregistered
  34  * @fhs_lock:   lock to control access to the filehandle list
  35  * @fhs:        the list of open filehandles (cec_fh)
  36  *
  37  * This structure represents a cec-related device node.
  38  *
  39  * The @parent is a physical device. It must be set by core or device drivers
  40  * before registering the node.
  41  */
  42 struct cec_devnode {
  43         /* sysfs */
  44         struct device dev;
  45         struct cdev cdev;
  46
  47         /* device info */
  48         int minor;
  49         bool registered;
  50         bool unregistered;
  51         struct list_head fhs;
  52         struct mutex lock;
  53 };
  54
  55 struct cec_adapter;
  56 struct cec_data;
  57 struct cec_pin;
  58 struct cec_notifier;
  59
  60 struct cec_data {
  61         struct list_head list;
  62         struct list_head xfer_list;
  63         struct cec_adapter *adap;
  64         struct cec_msg msg;
  65         struct cec_fh *fh;
  66         struct delayed_work work;
  67         struct completion c;
  68         u8 attempts;
  69         bool blocking;
  70         bool completed;
  71 };
  72
  73 struct cec_msg_entry {
  74         struct list_head        list;
  75         struct cec_msg          msg;
  76 };
  77
  78 struct cec_event_entry {
  79         struct list_head        list;
  80         struct cec_event        ev;
  81 };
  82
  83 #define CEC_NUM_CORE_EVENTS 2
  84 #define CEC_NUM_EVENTS CEC_EVENT_PIN_5V_HIGH
  85
  86 struct cec_fh {
  87         struct list_head        list;
  88         struct list_head        xfer_list;
  89         struct cec_adapter      *adap;
  90         u8                      mode_initiator;
  91         u8                      mode_follower;
  92
  93         /* Events */
  94         wait_queue_head_t       wait;
  95         struct mutex            lock;
  96         struct list_head        events[CEC_NUM_EVENTS]; /* queued events */
  97         u16                     queued_events[CEC_NUM_EVENTS];
  98         unsigned int            total_queued_events;
  99         struct cec_event_entry  core_events[CEC_NUM_CORE_EVENTS];
 100         struct list_head        msgs; /* queued messages */
 101         unsigned int            queued_msgs;
 102 };
 103
 104 #define CEC_SIGNAL_FREE_TIME_RETRY              3
 105 #define CEC_SIGNAL_FREE_TIME_NEW_INITIATOR      5
 106 #define CEC_SIGNAL_FREE_TIME_NEXT_XFER          7
 107
 108 /* The nominal data bit period is 2.4 ms */
 109 #define CEC_FREE_TIME_TO_USEC(ft)               ((ft) * 2400)
 110
 111 struct cec_adap_ops {
 112         /* Low-level callbacks */
 113         int (*adap_enable)(struct cec_adapter *adap, bool enable);
 114         int (*adap_monitor_all_enable)(struct cec_adapter *adap, bool enable);
 115         int (*adap_monitor_pin_enable)(struct cec_adapter *adap, bool enable);
 116         int (*adap_log_addr)(struct cec_adapter *adap, u8 logical_addr);
 117         int (*adap_transmit)(struct cec_adapter *adap, u8 attempts,
 118                              u32 signal_free_time, struct cec_msg *msg);
 119         void (*adap_status)(struct cec_adapter *adap, struct seq_file *file);
 120         void (*adap_free)(struct cec_adapter *adap);
 121
 122         /* Error injection callbacks */
 123         int (*error_inj_show)(struct cec_adapter *adap, struct seq_file *sf);
 124         bool (*error_inj_parse_line)(struct cec_adapter *adap, char *line);
 125
 126         /* High-level CEC message callback */
 127         int (*received)(struct cec_adapter *adap, struct cec_msg *msg);
 128 };
 129
 130 /*
 131  * The minimum message length you can receive (excepting poll messages) is 2.
 132  * With a transfer rate of at most 36 bytes per second this makes 18 messages
 133  * per second worst case.
 134  *
 135  * We queue at most 3 seconds worth of received messages. The CEC specification
 136  * requires that messages are replied to within a second, so 3 seconds should
 137  * give more than enough margin. Since most messages are actually more than 2
 138  * bytes, this is in practice a lot more than 3 seconds.
 139  */
 140 #define CEC_MAX_MSG_RX_QUEUE_SZ         (18 * 3)
 141
 142 /*
 143  * The transmit queue is limited to 1 second worth of messages (worst case).
 144  * Messages can be transmitted by userspace and kernel space. But for both it
 145  * makes no sense to have a lot of messages queued up. One second seems
 146  * reasonable.
 147  */
 148 #define CEC_MAX_MSG_TX_QUEUE_SZ         (18 * 1)
 149
 150 /**
 151  * struct cec_drm_connector_info - tells which drm connector is
 152  * associated with the CEC adapter.
 153  * @card_no: drm card number
 154  * @connector_id: drm connector ID
 155  */
 156 struct cec_drm_connector_info {
 157         __u32 card_no;
 158         __u32 connector_id;
 159 };
 160
 161 #define CEC_CONNECTOR_TYPE_NO_CONNECTOR 0
 162 #define CEC_CONNECTOR_TYPE_DRM          1
 163
 164 /**
 165  * struct cec_connector_info - tells if and which connector is
 166  * associated with the CEC adapter.
 167  * @type: connector type (if any)
 168  * @drm: drm connector info
 169  */
 170 struct cec_connector_info {
 171         __u32 type;
 172         union {
 173                 struct cec_drm_connector_info drm;
 174                 __u32 raw[16];
 175         };
 176 };
 177
 178 struct cec_adapter {
 179         struct module *owner;
 180         char name[32];
 181         struct cec_devnode devnode;
 182         struct mutex lock;
 183         struct rc_dev *rc;
 184
 185         struct list_head transmit_queue;
 186         unsigned int transmit_queue_sz;
 187         struct list_head wait_queue;
 188         struct cec_data *transmitting;
 189         bool transmit_in_progress;
 190
 191         struct task_struct *kthread_config;
 192         struct completion config_completion;
 193
 194         struct task_struct *kthread;
 195         wait_queue_head_t kthread_waitq;
 196         wait_queue_head_t waitq;
 197
 198         const struct cec_adap_ops *ops;
 199         void *priv;
 200         u32 capabilities;
 201         u8 available_log_addrs;
 202
 203         u16 phys_addr;
 204         bool needs_hpd;
 205         bool is_configuring;
 206         bool is_configured;
 207         bool cec_pin_is_high;
 208         u8 last_initiator;
 209         u32 monitor_all_cnt;
 210         u32 monitor_pin_cnt;
 211         u32 follower_cnt;
 212         struct cec_fh *cec_follower;
 213         struct cec_fh *cec_initiator;
 214         bool passthrough;
 215         struct cec_log_addrs log_addrs;
 216         struct cec_connector_info conn_info;
 217
 218         u32 tx_timeouts;
 219
 220 #ifdef CONFIG_CEC_NOTIFIER
 221         struct cec_notifier *notifier;
 222 #endif
 223 #ifdef CONFIG_CEC_PIN
 224         struct cec_pin *pin;
 225 #endif
 226
 227         struct dentry *cec_dir;
 228         struct dentry *status_file;
 229         struct dentry *error_inj_file;
 230
 231         u16 phys_addrs[15];
 232         u32 sequence;
 233
 234         char input_phys[32];
 235 };
 236
 237 static inline void *cec_get_drvdata(const struct cec_adapter *adap)
 238 {
 239         return adap->priv;
 240 }
 241
 242 static inline bool cec_has_log_addr(const struct cec_adapter *adap, u8 log_addr)
 243 {
 244         return adap->log_addrs.log_addr_mask & (1 << log_addr);
 245 }
 246
 247 static inline bool cec_is_sink(const struct cec_adapter *adap)
 248 {
 249         return adap->phys_addr == 0;
 250 }
 251
 252 /**
 253  * cec_is_registered() - is the CEC adapter registered?
 254  *
 255  * @adap:       the CEC adapter, may be NULL.
 256  *
 257  * Return: true if the adapter is registered, false otherwise.
 258  */
 259 static inline bool cec_is_registered(const struct cec_adapter *adap)
 260 {
 261         return adap && adap->devnode.registered;
 262 }
 263
 264 #define cec_phys_addr_exp(pa) \
 265         ((pa) >> 12), ((pa) >> 8) & 0xf, ((pa) >> 4) & 0xf, (pa) & 0xf
 266
 267 struct edid;
 268 struct drm_connector;
 269
 270 #if IS_REACHABLE(CONFIG_CEC_CORE)
 271 struct cec_adapter *cec_allocate_adapter(const struct cec_adap_ops *ops,
 272                 void *priv, const char *name, u32 caps, u8 available_las);
 273 int cec_register_adapter(struct cec_adapter *adap, struct device *parent);
 274 void cec_unregister_adapter(struct cec_adapter *adap);
 275 void cec_delete_adapter(struct cec_adapter *adap);
 276
 277 int cec_s_log_addrs(struct cec_adapter *adap, struct cec_log_addrs *log_addrs,
 278                     bool block);
 279 void cec_s_phys_addr(struct cec_adapter *adap, u16 phys_addr,
 280                      bool block);
 281 void cec_s_phys_addr_from_edid(struct cec_adapter *adap,
 282                                const struct edid *edid);
 283 void cec_s_conn_info(struct cec_adapter *adap,
 284                      const struct cec_connector_info *conn_info);
 285 int cec_transmit_msg(struct cec_adapter *adap, struct cec_msg *msg,
 286                      bool block);
 287
 288 /* Called by the adapter */
 289 void cec_transmit_done_ts(struct cec_adapter *adap, u8 status,
 290                           u8 arb_lost_cnt, u8 nack_cnt, u8 low_drive_cnt,
 291                           u8 error_cnt, ktime_t ts);
 292
 293 static inline void cec_transmit_done(struct cec_adapter *adap, u8 status,
 294                                      u8 arb_lost_cnt, u8 nack_cnt,
 295                                      u8 low_drive_cnt, u8 error_cnt)
 296 {
 297         cec_transmit_done_ts(adap, status, arb_lost_cnt, nack_cnt,
 298                              low_drive_cnt, error_cnt, ktime_get());
 299 }
 300 /*
 301  * Simplified version of cec_transmit_done for hardware that doesn't retry
 302  * failed transmits. So this is always just one attempt in which case
 303  * the status is sufficient.
 304  */
 305 void cec_transmit_attempt_done_ts(struct cec_adapter *adap,
 306                                   u8 status, ktime_t ts);
 307
 308 static inline void cec_transmit_attempt_done(struct cec_adapter *adap,
 309                                              u8 status)
 310 {
 311         cec_transmit_attempt_done_ts(adap, status, ktime_get());
 312 }
 313
 314 void cec_received_msg_ts(struct cec_adapter *adap,
 315                          struct cec_msg *msg, ktime_t ts);
 316
 317 static inline void cec_received_msg(struct cec_adapter *adap,
 318                                     struct cec_msg *msg)
 319 {
 320         cec_received_msg_ts(adap, msg, ktime_get());
 321 }
 322
 323 /**
 324  * cec_queue_pin_cec_event() - queue a CEC pin event with a given timestamp.
 325  *
 326  * @adap:       pointer to the cec adapter
 327  * @is_high:    when true the CEC pin is high, otherwise it is low
 328  * @dropped_events: when true some events were dropped
 329  * @ts:         the timestamp for this event
 330  *
 331  */
 332 void cec_queue_pin_cec_event(struct cec_adapter *adap, bool is_high,
 333                              bool dropped_events, ktime_t ts);
 334
 335 /**
 336  * cec_queue_pin_hpd_event() - queue a pin event with a given timestamp.
 337  *
 338  * @adap:       pointer to the cec adapter
 339  * @is_high:    when true the HPD pin is high, otherwise it is low
 340  * @ts:         the timestamp for this event
 341  *
 342  */
 343 void cec_queue_pin_hpd_event(struct cec_adapter *adap, bool is_high, ktime_t ts);
 344
 345 /**
 346  * cec_queue_pin_5v_event() - queue a pin event with a given timestamp.
 347  *
 348  * @adap:       pointer to the cec adapter
 349  * @is_high:    when true the 5V pin is high, otherwise it is low
 350  * @ts:         the timestamp for this event
 351  *
 352  */
 353 void cec_queue_pin_5v_event(struct cec_adapter *adap, bool is_high, ktime_t ts);
 354
 355 /**
 356  * cec_get_edid_phys_addr() - find and return the physical address
 357  *
 358  * @edid:       pointer to the EDID data
 359  * @size:       size in bytes of the EDID data
 360  * @offset:     If not %NULL then the location of the physical address
 361  *              bytes in the EDID will be returned here. This is set to 0
 362  *              if there is no physical address found.
 363  *
 364  * Return: the physical address or CEC_PHYS_ADDR_INVALID if there is none.
 365  */
 366 u16 cec_get_edid_phys_addr(const u8 *edid, unsigned int size,
 367                            unsigned int *offset);
 368
 369 void cec_fill_conn_info_from_drm(struct cec_connector_info *conn_info,
 370                                  const struct drm_connector *connector);
 371
 372 #else
 373
 374 static inline int cec_register_adapter(struct cec_adapter *adap,
 375                                        struct device *parent)
 376 {
 377         return 0;
 378 }
 379
 380 static inline void cec_unregister_adapter(struct cec_adapter *adap)
 381 {
 382 }
 383
 384 static inline void cec_delete_adapter(struct cec_adapter *adap)
 385 {
 386 }
 387
 388 static inline void cec_s_phys_addr(struct cec_adapter *adap, u16 phys_addr,
 389                                    bool block)
 390 {
 391 }
 392
 393 static inline void cec_s_phys_addr_from_edid(struct cec_adapter *adap,
 394                                              const struct edid *edid)
 395 {
 396 }
 397
 398 static inline u16 cec_get_edid_phys_addr(const u8 *edid, unsigned int size,
 399                                          unsigned int *offset)
 400 {
 401         if (offset)
 402                 *offset = 0;
 403         return CEC_PHYS_ADDR_INVALID;
 404 }
 405
 406 static inline void cec_s_conn_info(struct cec_adapter *adap,
 407                                    const struct cec_connector_info *conn_info)
 408 {
 409 }
 410
 411 static inline void
 412 cec_fill_conn_info_from_drm(struct cec_connector_info *conn_info,
 413                             const struct drm_connector *connector)
 414 {
 415         memset(conn_info, 0, sizeof(*conn_info));
 416 }
 417
 418 #endif
 419
 420 #if IS_REACHABLE(CONFIG_CEC_CORE) && IS_ENABLED(CONFIG_CEC_NOTIFIER)
 421
 422 /**
 423  * cec_notifier_register - register a callback with the notifier
 424  * @n: the CEC notifier
 425  * @adap: the CEC adapter, passed as argument to the callback function
 426  * @callback: the callback function
 427  */
 428 void cec_notifier_register(struct cec_notifier *n,
 429                            struct cec_adapter *adap,
 430                            void (*callback)(struct cec_adapter *adap, u16 pa));
 431
 432 /**
 433  * cec_notifier_unregister - unregister the callback from the notifier.
 434  * @n: the CEC notifier
 435  */
 436 void cec_notifier_unregister(struct cec_notifier *n);
 437
 438 /**
 439  * cec_register_cec_notifier - register the notifier with the cec adapter.
 440  * @adap: the CEC adapter
 441  * @notifier: the CEC notifier
 442  */
 443 void cec_register_cec_notifier(struct cec_adapter *adap,
 444                                struct cec_notifier *notifier);
 445
 446 #else
 447
 448 static inline void
 449 cec_notifier_register(struct cec_notifier *n,
 450                       struct cec_adapter *adap,
 451                       void (*callback)(struct cec_adapter *adap, u16 pa))
 452 {
 453 }
 454
 455 static inline void cec_notifier_unregister(struct cec_notifier *n)
 456 {
 457 }
 458
 459 static inline void cec_register_cec_notifier(struct cec_adapter *adap,
 460                                              struct cec_notifier *notifier)
 461 {
 462 }
 463
 464 #endif
 465
 466 /**
 467  * cec_phys_addr_invalidate() - set the physical address to INVALID
 468  *
 469  * @adap:       the CEC adapter
 470  *
 471  * This is a simple helper function to invalidate the physical
 472  * address.
 473  */
 474 static inline void cec_phys_addr_invalidate(struct cec_adapter *adap)
 475 {
 476         cec_s_phys_addr(adap, CEC_PHYS_ADDR_INVALID, false);
 477 }
 478
 479 /**
 480  * cec_get_edid_spa_location() - find location of the Source Physical Address
 481  *
 482  * @edid: the EDID
 483  * @size: the size of the EDID
 484  *
 485  * This EDID is expected to be a CEA-861 compliant, which means that there are
 486  * at least two blocks and one or more of the extensions blocks are CEA-861
 487  * blocks.
 488  *
 489  * The returned location is guaranteed to be <= size-2.
 490  *
 491  * This is an inline function since it is used by both CEC and V4L2.
 492  * Ideally this would go in a module shared by both, but it is overkill to do
 493  * that for just a single function.
 494  */
 495 static inline unsigned int cec_get_edid_spa_location(const u8 *edid,
 496                                                      unsigned int size)
 497 {
 498         unsigned int blocks = size / 128;
 499         unsigned int block;
 500         u8 d;
 501
 502         /* Sanity check: at least 2 blocks and a multiple of the block size */
 503         if (blocks < 2 || size % 128)
 504                 return 0;
 505
 506         /*
 507          * If there are fewer extension blocks than the size, then update
 508          * 'blocks'. It is allowed to have more extension blocks than the size,
 509          * since some hardware can only read e.g. 256 bytes of the EDID, even
 510          * though more blocks are present. The first CEA-861 extension block
 511          * should normally be in block 1 anyway.
 512          */
 513         if (edid[0x7e] + 1 < blocks)
 514                 blocks = edid[0x7e] + 1;
 515
 516         for (block = 1; block < blocks; block++) {
 517                 unsigned int offset = block * 128;
 518
 519                 /* Skip any non-CEA-861 extension blocks */
 520                 if (edid[offset] != 0x02 || edid[offset + 1] != 0x03)
 521                         continue;
 522
 523                 /* search Vendor Specific Data Block (tag 3) */
 524                 d = edid[offset + 2] & 0x7f;
 525                 /* Check if there are Data Blocks */
 526                 if (d <= 4)
 527                         continue;
 528                 if (d > 4) {
 529                         unsigned int i = offset + 4;
 530                         unsigned int end = offset + d;
 531
 532                         /* Note: 'end' is always < 'size' */
 533                         do {
 534                                 u8 tag = edid[i] >> 5;
 535                                 u8 len = edid[i] & 0x1f;
 536
 537                                 if (tag == 3 && len >= 5 && i + len <= end &&
 538                                     edid[i + 1] == 0x03 &&
 539                                     edid[i + 2] == 0x0c &&
 540                                     edid[i + 3] == 0x00)
 541                                         return i + 4;
 542                                 i += len + 1;
 543                         } while (i < end);
 544                 }
 545         }
 546         return 0;
 547 }
 548
 549 #endif /* _MEDIA_CEC_H */