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 #define CEC_CAP_DEFAULTS (CEC_CAP_LOG_ADDRS | CEC_CAP_TRANSMIT | \
22 CEC_CAP_PASSTHROUGH | CEC_CAP_RC)
23
24 /**
25 * struct cec_devnode - cec device node
26 * @dev: cec device
27 * @cdev: cec character device
28 * @minor: device node minor number
29 * @lock: lock to serialize open/release and registration
30 * @registered: the device was correctly registered
31 * @unregistered: the device was unregistered
32 * @lock_fhs: lock to control access to @fhs
33 * @fhs: the list of open filehandles (cec_fh)
34 *
35 * This structure represents a cec-related device node.
36 *
37 * To add or remove filehandles from @fhs the @lock must be taken first,
38 * followed by @lock_fhs. It is safe to access @fhs if either lock is held.
39 *
40 * The @parent is a physical device. It must be set by core or device drivers
41 * before registering the node.
42 */
43 struct cec_devnode {
44 /* sysfs */
45 struct device dev;
46 struct cdev cdev;
47
48 /* device info */
49 int minor;
50 /* serialize open/release and registration */
51 struct mutex lock;
52 bool registered;
53 bool unregistered;
54 /* protect access to fhs */
55 struct mutex lock_fhs;
56 struct list_head fhs;
57 };
58
59 struct cec_adapter;
60 struct cec_data;
61 struct cec_pin;
62 struct cec_notifier;
63
64 struct cec_data {
65 struct list_head list;
66 struct list_head xfer_list;
67 struct cec_adapter *adap;
68 struct cec_msg msg;
69 struct cec_fh *fh;
70 struct delayed_work work;
71 struct completion c;
72 u8 attempts;
73 bool blocking;
74 bool completed;
75 };
76
77 struct cec_msg_entry {
78 struct list_head list;
79 struct cec_msg msg;
80 };
81
82 struct cec_event_entry {
83 struct list_head list;
84 struct cec_event ev;
85 };
86
87 #define CEC_NUM_CORE_EVENTS 2
88 #define CEC_NUM_EVENTS CEC_EVENT_PIN_5V_HIGH
89
90 struct cec_fh {
91 struct list_head list;
92 struct list_head xfer_list;
93 struct cec_adapter *adap;
94 u8 mode_initiator;
95 u8 mode_follower;
96
97 /* Events */
98 wait_queue_head_t wait;
99 struct mutex lock;
100 struct list_head events[CEC_NUM_EVENTS]; /* queued events */
101 u16 queued_events[CEC_NUM_EVENTS];
102 unsigned int total_queued_events;
103 struct cec_event_entry core_events[CEC_NUM_CORE_EVENTS];
104 struct list_head msgs; /* queued messages */
105 unsigned int queued_msgs;
106 };
107
108 #define CEC_SIGNAL_FREE_TIME_RETRY 3
109 #define CEC_SIGNAL_FREE_TIME_NEW_INITIATOR 5
110 #define CEC_SIGNAL_FREE_TIME_NEXT_XFER 7
111
112 /* The nominal data bit period is 2.4 ms */
113 #define CEC_FREE_TIME_TO_USEC(ft) ((ft) * 2400)
114
115 struct cec_adap_ops {
116 /* Low-level callbacks */
117 int (*adap_enable)(struct cec_adapter *adap, bool enable);
118 int (*adap_monitor_all_enable)(struct cec_adapter *adap, bool enable);
119 int (*adap_monitor_pin_enable)(struct cec_adapter *adap, bool enable);
120 int (*adap_log_addr)(struct cec_adapter *adap, u8 logical_addr);
121 void (*adap_configured)(struct cec_adapter *adap, bool configured);
122 int (*adap_transmit)(struct cec_adapter *adap, u8 attempts,
123 u32 signal_free_time, struct cec_msg *msg);
124 void (*adap_status)(struct cec_adapter *adap, struct seq_file *file);
125 void (*adap_free)(struct cec_adapter *adap);
126
127 /* Error injection callbacks */
128 int (*error_inj_show)(struct cec_adapter *adap, struct seq_file *sf);
129 bool (*error_inj_parse_line)(struct cec_adapter *adap, char *line);
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 /**
156 * struct cec_adapter - cec adapter structure
157 * @owner: module owner
158 * @name: name of the CEC adapter
159 * @devnode: device node for the /dev/cecX device
160 * @lock: mutex controlling access to this structure
161 * @rc: remote control device
162 * @transmit_queue: queue of pending transmits
163 * @transmit_queue_sz: number of pending transmits
164 * @wait_queue: queue of transmits waiting for a reply
165 * @transmitting: CEC messages currently being transmitted
166 * @transmit_in_progress: true if a transmit is in progress
167 * @transmit_in_progress_aborted: true if a transmit is in progress is to be
168 * aborted. This happens if the logical address is
169 * invalidated while the transmit is ongoing. In that
170 * case the transmit will finish, but will not retransmit
171 * and be marked as ABORTED.
172 * @xfer_timeout_ms: the transfer timeout in ms.
173 * If 0, then timeout after 2.1 ms.
174 * @kthread_config: kthread used to configure a CEC adapter
175 * @config_completion: used to signal completion of the config kthread
176 * @kthread: main CEC processing thread
177 * @kthread_waitq: main CEC processing wait_queue
178 * @ops: cec adapter ops
179 * @priv: cec driver's private data
180 * @capabilities: cec adapter capabilities
181 * @available_log_addrs: maximum number of available logical addresses
182 * @phys_addr: the current physical address
183 * @needs_hpd: if true, then the HDMI HotPlug Detect pin must be high
184 * in order to transmit or receive CEC messages. This is usually a HW
185 * limitation.
186 * @is_enabled: the CEC adapter is enabled
187 * @is_configuring: the CEC adapter is configuring (i.e. claiming LAs)
188 * @must_reconfigure: while configuring, the PA changed, so reclaim LAs
189 * @is_configured: the CEC adapter is configured (i.e. has claimed LAs)
190 * @cec_pin_is_high: if true then the CEC pin is high. Only used with the
191 * CEC pin framework.
192 * @adap_controls_phys_addr: if true, then the CEC adapter controls the
193 * physical address, i.e. the CEC hardware can detect HPD changes and
194 * read the EDID and is not dependent on an external HDMI driver.
195 * Drivers that need this can set this field to true after the
196 * cec_allocate_adapter() call.
197 * @last_initiator: the initiator of the last transmitted message.
198 * @monitor_all_cnt: number of filehandles monitoring all msgs
199 * @monitor_pin_cnt: number of filehandles monitoring pin changes
200 * @follower_cnt: number of filehandles in follower mode
201 * @cec_follower: filehandle of the exclusive follower
202 * @cec_initiator: filehandle of the exclusive initiator
203 * @passthrough: if true, then the exclusive follower is in
204 * passthrough mode.
205 * @log_addrs: current logical addresses
206 * @conn_info: current connector info
207 * @tx_timeouts: number of transmit timeouts
208 * @notifier: CEC notifier
209 * @pin: CEC pin status struct
210 * @cec_dir: debugfs cec directory
211 * @status_file: debugfs cec status file
212 * @error_inj_file: debugfs cec error injection file
213 * @sequence: transmit sequence counter
214 * @input_phys: remote control input_phys name
215 *
216 * This structure represents a cec adapter.
217 */
218 struct cec_adapter {
219 struct module *owner;
220 char name[32];
221 struct cec_devnode devnode;
222 struct mutex lock;
223 struct rc_dev *rc;
224
225 struct list_head transmit_queue;
226 unsigned int transmit_queue_sz;
227 struct list_head wait_queue;
228 struct cec_data *transmitting;
229 bool transmit_in_progress;
230 bool transmit_in_progress_aborted;
231 unsigned int xfer_timeout_ms;
232
233 struct task_struct *kthread_config;
234 struct completion config_completion;
235
236 struct task_struct *kthread;
237 wait_queue_head_t kthread_waitq;
238
239 const struct cec_adap_ops *ops;
240 void *priv;
241 u32 capabilities;
242 u8 available_log_addrs;
243
244 u16 phys_addr;
245 bool needs_hpd;
246 bool is_enabled;
247 bool is_configuring;
248 bool must_reconfigure;
249 bool is_configured;
250 bool cec_pin_is_high;
251 bool adap_controls_phys_addr;
252 u8 last_initiator;
253 u32 monitor_all_cnt;
254 u32 monitor_pin_cnt;
255 u32 follower_cnt;
256 struct cec_fh *cec_follower;
257 struct cec_fh *cec_initiator;
258 bool passthrough;
259 struct cec_log_addrs log_addrs;
260 struct cec_connector_info conn_info;
261
262 u32 tx_timeouts;
263
264 #ifdef CONFIG_CEC_NOTIFIER
265 struct cec_notifier *notifier;
266 #endif
267 #ifdef CONFIG_CEC_PIN
268 struct cec_pin *pin;
269 #endif
270
271 struct dentry *cec_dir;
272
273 u32 sequence;
274
275 char input_phys[32];
276 };
277
cec_get_drvdata(const struct cec_adapter * adap)278 static inline void *cec_get_drvdata(const struct cec_adapter *adap)
279 {
280 return adap->priv;
281 }
282
cec_has_log_addr(const struct cec_adapter * adap,u8 log_addr)283 static inline bool cec_has_log_addr(const struct cec_adapter *adap, u8 log_addr)
284 {
285 return adap->log_addrs.log_addr_mask & (1 << log_addr);
286 }
287
cec_is_sink(const struct cec_adapter * adap)288 static inline bool cec_is_sink(const struct cec_adapter *adap)
289 {
290 return adap->phys_addr == 0;
291 }
292
293 /**
294 * cec_is_registered() - is the CEC adapter registered?
295 *
296 * @adap: the CEC adapter, may be NULL.
297 *
298 * Return: true if the adapter is registered, false otherwise.
299 */
cec_is_registered(const struct cec_adapter * adap)300 static inline bool cec_is_registered(const struct cec_adapter *adap)
301 {
302 return adap && adap->devnode.registered;
303 }
304
305 #define cec_phys_addr_exp(pa) \
306 ((pa) >> 12), ((pa) >> 8) & 0xf, ((pa) >> 4) & 0xf, (pa) & 0xf
307
308 struct edid;
309 struct drm_connector;
310
311 #if IS_REACHABLE(CONFIG_CEC_CORE)
312 struct cec_adapter *cec_allocate_adapter(const struct cec_adap_ops *ops,
313 void *priv, const char *name, u32 caps, u8 available_las);
314 int cec_register_adapter(struct cec_adapter *adap, struct device *parent);
315 void cec_unregister_adapter(struct cec_adapter *adap);
316 void cec_delete_adapter(struct cec_adapter *adap);
317
318 int cec_s_log_addrs(struct cec_adapter *adap, struct cec_log_addrs *log_addrs,
319 bool block);
320 void cec_s_phys_addr(struct cec_adapter *adap, u16 phys_addr,
321 bool block);
322 void cec_s_phys_addr_from_edid(struct cec_adapter *adap,
323 const struct edid *edid);
324 void cec_s_conn_info(struct cec_adapter *adap,
325 const struct cec_connector_info *conn_info);
326 int cec_transmit_msg(struct cec_adapter *adap, struct cec_msg *msg,
327 bool block);
328
329 /* Called by the adapter */
330 void cec_transmit_done_ts(struct cec_adapter *adap, u8 status,
331 u8 arb_lost_cnt, u8 nack_cnt, u8 low_drive_cnt,
332 u8 error_cnt, ktime_t ts);
333
cec_transmit_done(struct cec_adapter * adap,u8 status,u8 arb_lost_cnt,u8 nack_cnt,u8 low_drive_cnt,u8 error_cnt)334 static inline void cec_transmit_done(struct cec_adapter *adap, u8 status,
335 u8 arb_lost_cnt, u8 nack_cnt,
336 u8 low_drive_cnt, u8 error_cnt)
337 {
338 cec_transmit_done_ts(adap, status, arb_lost_cnt, nack_cnt,
339 low_drive_cnt, error_cnt, ktime_get());
340 }
341 /*
342 * Simplified version of cec_transmit_done for hardware that doesn't retry
343 * failed transmits. So this is always just one attempt in which case
344 * the status is sufficient.
345 */
346 void cec_transmit_attempt_done_ts(struct cec_adapter *adap,
347 u8 status, ktime_t ts);
348
cec_transmit_attempt_done(struct cec_adapter * adap,u8 status)349 static inline void cec_transmit_attempt_done(struct cec_adapter *adap,
350 u8 status)
351 {
352 cec_transmit_attempt_done_ts(adap, status, ktime_get());
353 }
354
355 void cec_received_msg_ts(struct cec_adapter *adap,
356 struct cec_msg *msg, ktime_t ts);
357
cec_received_msg(struct cec_adapter * adap,struct cec_msg * msg)358 static inline void cec_received_msg(struct cec_adapter *adap,
359 struct cec_msg *msg)
360 {
361 cec_received_msg_ts(adap, msg, ktime_get());
362 }
363
364 /**
365 * cec_queue_pin_cec_event() - queue a CEC pin event with a given timestamp.
366 *
367 * @adap: pointer to the cec adapter
368 * @is_high: when true the CEC pin is high, otherwise it is low
369 * @dropped_events: when true some events were dropped
370 * @ts: the timestamp for this event
371 *
372 */
373 void cec_queue_pin_cec_event(struct cec_adapter *adap, bool is_high,
374 bool dropped_events, ktime_t ts);
375
376 /**
377 * cec_queue_pin_hpd_event() - queue a pin event with a given timestamp.
378 *
379 * @adap: pointer to the cec adapter
380 * @is_high: when true the HPD pin is high, otherwise it is low
381 * @ts: the timestamp for this event
382 *
383 */
384 void cec_queue_pin_hpd_event(struct cec_adapter *adap, bool is_high, ktime_t ts);
385
386 /**
387 * cec_queue_pin_5v_event() - queue a pin event with a given timestamp.
388 *
389 * @adap: pointer to the cec adapter
390 * @is_high: when true the 5V pin is high, otherwise it is low
391 * @ts: the timestamp for this event
392 *
393 */
394 void cec_queue_pin_5v_event(struct cec_adapter *adap, bool is_high, ktime_t ts);
395
396 /**
397 * cec_get_edid_phys_addr() - find and return the physical address
398 *
399 * @edid: pointer to the EDID data
400 * @size: size in bytes of the EDID data
401 * @offset: If not %NULL then the location of the physical address
402 * bytes in the EDID will be returned here. This is set to 0
403 * if there is no physical address found.
404 *
405 * Return: the physical address or CEC_PHYS_ADDR_INVALID if there is none.
406 */
407 u16 cec_get_edid_phys_addr(const u8 *edid, unsigned int size,
408 unsigned int *offset);
409
410 void cec_fill_conn_info_from_drm(struct cec_connector_info *conn_info,
411 const struct drm_connector *connector);
412
413 #else
414
cec_register_adapter(struct cec_adapter * adap,struct device * parent)415 static inline int cec_register_adapter(struct cec_adapter *adap,
416 struct device *parent)
417 {
418 return 0;
419 }
420
cec_unregister_adapter(struct cec_adapter * adap)421 static inline void cec_unregister_adapter(struct cec_adapter *adap)
422 {
423 }
424
cec_delete_adapter(struct cec_adapter * adap)425 static inline void cec_delete_adapter(struct cec_adapter *adap)
426 {
427 }
428
cec_s_phys_addr(struct cec_adapter * adap,u16 phys_addr,bool block)429 static inline void cec_s_phys_addr(struct cec_adapter *adap, u16 phys_addr,
430 bool block)
431 {
432 }
433
cec_s_phys_addr_from_edid(struct cec_adapter * adap,const struct edid * edid)434 static inline void cec_s_phys_addr_from_edid(struct cec_adapter *adap,
435 const struct edid *edid)
436 {
437 }
438
cec_get_edid_phys_addr(const u8 * edid,unsigned int size,unsigned int * offset)439 static inline u16 cec_get_edid_phys_addr(const u8 *edid, unsigned int size,
440 unsigned int *offset)
441 {
442 if (offset)
443 *offset = 0;
444 return CEC_PHYS_ADDR_INVALID;
445 }
446
cec_s_conn_info(struct cec_adapter * adap,const struct cec_connector_info * conn_info)447 static inline void cec_s_conn_info(struct cec_adapter *adap,
448 const struct cec_connector_info *conn_info)
449 {
450 }
451
452 static inline void
cec_fill_conn_info_from_drm(struct cec_connector_info * conn_info,const struct drm_connector * connector)453 cec_fill_conn_info_from_drm(struct cec_connector_info *conn_info,
454 const struct drm_connector *connector)
455 {
456 memset(conn_info, 0, sizeof(*conn_info));
457 }
458
459 #endif
460
461 /**
462 * cec_phys_addr_invalidate() - set the physical address to INVALID
463 *
464 * @adap: the CEC adapter
465 *
466 * This is a simple helper function to invalidate the physical
467 * address.
468 */
cec_phys_addr_invalidate(struct cec_adapter * adap)469 static inline void cec_phys_addr_invalidate(struct cec_adapter *adap)
470 {
471 cec_s_phys_addr(adap, CEC_PHYS_ADDR_INVALID, false);
472 }
473
474 /**
475 * cec_get_edid_spa_location() - find location of the Source Physical Address
476 *
477 * @edid: the EDID
478 * @size: the size of the EDID
479 *
480 * This EDID is expected to be a CEA-861 compliant, which means that there are
481 * at least two blocks and one or more of the extensions blocks are CEA-861
482 * blocks.
483 *
484 * The returned location is guaranteed to be <= size-2.
485 *
486 * This is an inline function since it is used by both CEC and V4L2.
487 * Ideally this would go in a module shared by both, but it is overkill to do
488 * that for just a single function.
489 */
cec_get_edid_spa_location(const u8 * edid,unsigned int size)490 static inline unsigned int cec_get_edid_spa_location(const u8 *edid,
491 unsigned int size)
492 {
493 unsigned int blocks = size / 128;
494 unsigned int block;
495 u8 d;
496
497 /* Sanity check: at least 2 blocks and a multiple of the block size */
498 if (blocks < 2 || size % 128)
499 return 0;
500
501 /*
502 * If there are fewer extension blocks than the size, then update
503 * 'blocks'. It is allowed to have more extension blocks than the size,
504 * since some hardware can only read e.g. 256 bytes of the EDID, even
505 * though more blocks are present. The first CEA-861 extension block
506 * should normally be in block 1 anyway.
507 */
508 if (edid[0x7e] + 1 < blocks)
509 blocks = edid[0x7e] + 1;
510
511 for (block = 1; block < blocks; block++) {
512 unsigned int offset = block * 128;
513
514 /* Skip any non-CEA-861 extension blocks */
515 if (edid[offset] != 0x02 || edid[offset + 1] != 0x03)
516 continue;
517
518 /* search Vendor Specific Data Block (tag 3) */
519 d = edid[offset + 2] & 0x7f;
520 /* Check if there are Data Blocks */
521 if (d <= 4)
522 continue;
523 if (d > 4) {
524 unsigned int i = offset + 4;
525 unsigned int end = offset + d;
526
527 /* Note: 'end' is always < 'size' */
528 do {
529 u8 tag = edid[i] >> 5;
530 u8 len = edid[i] & 0x1f;
531
532 if (tag == 3 && len >= 5 && i + len <= end &&
533 edid[i + 1] == 0x03 &&
534 edid[i + 2] == 0x0c &&
535 edid[i + 3] == 0x00)
536 return i + 4;
537 i += len + 1;
538 } while (i < end);
539 }
540 }
541 return 0;
542 }
543
544 #endif /* _MEDIA_CEC_H */
545