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 * @registered: the device was correctly registered
30 * @unregistered: the device was unregistered
31 * @fhs_lock: lock to control access to the filehandle list
32 * @fhs: the list of open filehandles (cec_fh)
33 *
34 * This structure represents a cec-related device node.
35 *
36 * The @parent is a physical device. It must be set by core or device drivers
37 * before registering the node.
38 */
39 struct cec_devnode {
40 /* sysfs */
41 struct device dev;
42 struct cdev cdev;
43
44 /* device info */
45 int minor;
46 bool registered;
47 bool unregistered;
48 struct list_head fhs;
49 struct mutex lock;
50 };
51
52 struct cec_adapter;
53 struct cec_data;
54 struct cec_pin;
55 struct cec_notifier;
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 /**
148 * struct cec_adapter - cec adapter structure
149 * @owner: module owner
150 * @name: name of the CEC adapter
151 * @devnode: device node for the /dev/cecX device
152 * @lock: mutex controlling access to this structure
153 * @rc: remote control device
154 * @transmit_queue: queue of pending transmits
155 * @transmit_queue_sz: number of pending transmits
156 * @wait_queue: queue of transmits waiting for a reply
157 * @transmitting: CEC messages currently being transmitted
158 * @transmit_in_progress: true if a transmit is in progress
159 * @kthread_config: kthread used to configure a CEC adapter
160 * @config_completion: used to signal completion of the config kthread
161 * @kthread: main CEC processing thread
162 * @kthread_waitq: main CEC processing wait_queue
163 * @ops: cec adapter ops
164 * @priv: cec driver's private data
165 * @capabilities: cec adapter capabilities
166 * @available_log_addrs: maximum number of available logical addresses
167 * @phys_addr: the current physical address
168 * @needs_hpd: if true, then the HDMI HotPlug Detect pin must be high
169 * in order to transmit or receive CEC messages. This is usually a HW
170 * limitation.
171 * @is_configuring: the CEC adapter is configuring (i.e. claiming LAs)
172 * @is_configured: the CEC adapter is configured (i.e. has claimed LAs)
173 * @cec_pin_is_high: if true then the CEC pin is high. Only used with the
174 * CEC pin framework.
175 * @adap_controls_phys_addr: if true, then the CEC adapter controls the
176 * physical address, i.e. the CEC hardware can detect HPD changes and
177 * read the EDID and is not dependent on an external HDMI driver.
178 * Drivers that need this can set this field to true after the
179 * cec_allocate_adapter() call.
180 * @last_initiator: the initiator of the last transmitted message.
181 * @monitor_all_cnt: number of filehandles monitoring all msgs
182 * @monitor_pin_cnt: number of filehandles monitoring pin changes
183 * @follower_cnt: number of filehandles in follower mode
184 * @cec_follower: filehandle of the exclusive follower
185 * @cec_initiator: filehandle of the exclusive initiator
186 * @passthrough: if true, then the exclusive follower is in
187 * passthrough mode.
188 * @log_addrs: current logical addresses
189 * @conn_info: current connector info
190 * @tx_timeouts: number of transmit timeouts
191 * @notifier: CEC notifier
192 * @pin: CEC pin status struct
193 * @cec_dir: debugfs cec directory
194 * @status_file: debugfs cec status file
195 * @error_inj_file: debugfs cec error injection file
196 * @sequence: transmit sequence counter
197 * @input_phys: remote control input_phys name
198 *
199 * This structure represents a cec adapter.
200 */
201 struct cec_adapter {
202 struct module *owner;
203 char name[32];
204 struct cec_devnode devnode;
205 struct mutex lock;
206 struct rc_dev *rc;
207
208 struct list_head transmit_queue;
209 unsigned int transmit_queue_sz;
210 struct list_head wait_queue;
211 struct cec_data *transmitting;
212 bool transmit_in_progress;
213
214 struct task_struct *kthread_config;
215 struct completion config_completion;
216
217 struct task_struct *kthread;
218 wait_queue_head_t kthread_waitq;
219
220 const struct cec_adap_ops *ops;
221 void *priv;
222 u32 capabilities;
223 u8 available_log_addrs;
224
225 u16 phys_addr;
226 bool needs_hpd;
227 bool is_configuring;
228 bool is_configured;
229 bool cec_pin_is_high;
230 bool adap_controls_phys_addr;
231 u8 last_initiator;
232 u32 monitor_all_cnt;
233 u32 monitor_pin_cnt;
234 u32 follower_cnt;
235 struct cec_fh *cec_follower;
236 struct cec_fh *cec_initiator;
237 bool passthrough;
238 struct cec_log_addrs log_addrs;
239 struct cec_connector_info conn_info;
240
241 u32 tx_timeouts;
242
243 #ifdef CONFIG_CEC_NOTIFIER
244 struct cec_notifier *notifier;
245 #endif
246 #ifdef CONFIG_CEC_PIN
247 struct cec_pin *pin;
248 #endif
249
250 struct dentry *cec_dir;
251
252 u32 sequence;
253
254 char input_phys[32];
255 };
256
cec_get_drvdata(const struct cec_adapter * adap)257 static inline void *cec_get_drvdata(const struct cec_adapter *adap)
258 {
259 return adap->priv;
260 }
261
cec_has_log_addr(const struct cec_adapter * adap,u8 log_addr)262 static inline bool cec_has_log_addr(const struct cec_adapter *adap, u8 log_addr)
263 {
264 return adap->log_addrs.log_addr_mask & (1 << log_addr);
265 }
266
cec_is_sink(const struct cec_adapter * adap)267 static inline bool cec_is_sink(const struct cec_adapter *adap)
268 {
269 return adap->phys_addr == 0;
270 }
271
272 /**
273 * cec_is_registered() - is the CEC adapter registered?
274 *
275 * @adap: the CEC adapter, may be NULL.
276 *
277 * Return: true if the adapter is registered, false otherwise.
278 */
cec_is_registered(const struct cec_adapter * adap)279 static inline bool cec_is_registered(const struct cec_adapter *adap)
280 {
281 return adap && adap->devnode.registered;
282 }
283
284 #define cec_phys_addr_exp(pa) \
285 ((pa) >> 12), ((pa) >> 8) & 0xf, ((pa) >> 4) & 0xf, (pa) & 0xf
286
287 struct edid;
288 struct drm_connector;
289
290 #if IS_REACHABLE(CONFIG_CEC_CORE)
291 struct cec_adapter *cec_allocate_adapter(const struct cec_adap_ops *ops,
292 void *priv, const char *name, u32 caps, u8 available_las);
293 int cec_register_adapter(struct cec_adapter *adap, struct device *parent);
294 void cec_unregister_adapter(struct cec_adapter *adap);
295 void cec_delete_adapter(struct cec_adapter *adap);
296
297 int cec_s_log_addrs(struct cec_adapter *adap, struct cec_log_addrs *log_addrs,
298 bool block);
299 void cec_s_phys_addr(struct cec_adapter *adap, u16 phys_addr,
300 bool block);
301 void cec_s_phys_addr_from_edid(struct cec_adapter *adap,
302 const struct edid *edid);
303 void cec_s_conn_info(struct cec_adapter *adap,
304 const struct cec_connector_info *conn_info);
305 int cec_transmit_msg(struct cec_adapter *adap, struct cec_msg *msg,
306 bool block);
307
308 /* Called by the adapter */
309 void cec_transmit_done_ts(struct cec_adapter *adap, u8 status,
310 u8 arb_lost_cnt, u8 nack_cnt, u8 low_drive_cnt,
311 u8 error_cnt, ktime_t ts);
312
cec_transmit_done(struct cec_adapter * adap,u8 status,u8 arb_lost_cnt,u8 nack_cnt,u8 low_drive_cnt,u8 error_cnt)313 static inline void cec_transmit_done(struct cec_adapter *adap, u8 status,
314 u8 arb_lost_cnt, u8 nack_cnt,
315 u8 low_drive_cnt, u8 error_cnt)
316 {
317 cec_transmit_done_ts(adap, status, arb_lost_cnt, nack_cnt,
318 low_drive_cnt, error_cnt, ktime_get());
319 }
320 /*
321 * Simplified version of cec_transmit_done for hardware that doesn't retry
322 * failed transmits. So this is always just one attempt in which case
323 * the status is sufficient.
324 */
325 void cec_transmit_attempt_done_ts(struct cec_adapter *adap,
326 u8 status, ktime_t ts);
327
cec_transmit_attempt_done(struct cec_adapter * adap,u8 status)328 static inline void cec_transmit_attempt_done(struct cec_adapter *adap,
329 u8 status)
330 {
331 cec_transmit_attempt_done_ts(adap, status, ktime_get());
332 }
333
334 void cec_received_msg_ts(struct cec_adapter *adap,
335 struct cec_msg *msg, ktime_t ts);
336
cec_received_msg(struct cec_adapter * adap,struct cec_msg * msg)337 static inline void cec_received_msg(struct cec_adapter *adap,
338 struct cec_msg *msg)
339 {
340 cec_received_msg_ts(adap, msg, ktime_get());
341 }
342
343 /**
344 * cec_queue_pin_cec_event() - queue a CEC pin event with a given timestamp.
345 *
346 * @adap: pointer to the cec adapter
347 * @is_high: when true the CEC pin is high, otherwise it is low
348 * @dropped_events: when true some events were dropped
349 * @ts: the timestamp for this event
350 *
351 */
352 void cec_queue_pin_cec_event(struct cec_adapter *adap, bool is_high,
353 bool dropped_events, ktime_t ts);
354
355 /**
356 * cec_queue_pin_hpd_event() - queue a pin event with a given timestamp.
357 *
358 * @adap: pointer to the cec adapter
359 * @is_high: when true the HPD pin is high, otherwise it is low
360 * @ts: the timestamp for this event
361 *
362 */
363 void cec_queue_pin_hpd_event(struct cec_adapter *adap, bool is_high, ktime_t ts);
364
365 /**
366 * cec_queue_pin_5v_event() - queue a pin event with a given timestamp.
367 *
368 * @adap: pointer to the cec adapter
369 * @is_high: when true the 5V pin is high, otherwise it is low
370 * @ts: the timestamp for this event
371 *
372 */
373 void cec_queue_pin_5v_event(struct cec_adapter *adap, bool is_high, ktime_t ts);
374
375 /**
376 * cec_get_edid_phys_addr() - find and return the physical address
377 *
378 * @edid: pointer to the EDID data
379 * @size: size in bytes of the EDID data
380 * @offset: If not %NULL then the location of the physical address
381 * bytes in the EDID will be returned here. This is set to 0
382 * if there is no physical address found.
383 *
384 * Return: the physical address or CEC_PHYS_ADDR_INVALID if there is none.
385 */
386 u16 cec_get_edid_phys_addr(const u8 *edid, unsigned int size,
387 unsigned int *offset);
388
389 void cec_fill_conn_info_from_drm(struct cec_connector_info *conn_info,
390 const struct drm_connector *connector);
391
392 #else
393
cec_register_adapter(struct cec_adapter * adap,struct device * parent)394 static inline int cec_register_adapter(struct cec_adapter *adap,
395 struct device *parent)
396 {
397 return 0;
398 }
399
cec_unregister_adapter(struct cec_adapter * adap)400 static inline void cec_unregister_adapter(struct cec_adapter *adap)
401 {
402 }
403
cec_delete_adapter(struct cec_adapter * adap)404 static inline void cec_delete_adapter(struct cec_adapter *adap)
405 {
406 }
407
cec_s_phys_addr(struct cec_adapter * adap,u16 phys_addr,bool block)408 static inline void cec_s_phys_addr(struct cec_adapter *adap, u16 phys_addr,
409 bool block)
410 {
411 }
412
cec_s_phys_addr_from_edid(struct cec_adapter * adap,const struct edid * edid)413 static inline void cec_s_phys_addr_from_edid(struct cec_adapter *adap,
414 const struct edid *edid)
415 {
416 }
417
cec_get_edid_phys_addr(const u8 * edid,unsigned int size,unsigned int * offset)418 static inline u16 cec_get_edid_phys_addr(const u8 *edid, unsigned int size,
419 unsigned int *offset)
420 {
421 if (offset)
422 *offset = 0;
423 return CEC_PHYS_ADDR_INVALID;
424 }
425
cec_s_conn_info(struct cec_adapter * adap,const struct cec_connector_info * conn_info)426 static inline void cec_s_conn_info(struct cec_adapter *adap,
427 const struct cec_connector_info *conn_info)
428 {
429 }
430
431 static inline void
cec_fill_conn_info_from_drm(struct cec_connector_info * conn_info,const struct drm_connector * connector)432 cec_fill_conn_info_from_drm(struct cec_connector_info *conn_info,
433 const struct drm_connector *connector)
434 {
435 memset(conn_info, 0, sizeof(*conn_info));
436 }
437
438 #endif
439
440 /**
441 * cec_phys_addr_invalidate() - set the physical address to INVALID
442 *
443 * @adap: the CEC adapter
444 *
445 * This is a simple helper function to invalidate the physical
446 * address.
447 */
cec_phys_addr_invalidate(struct cec_adapter * adap)448 static inline void cec_phys_addr_invalidate(struct cec_adapter *adap)
449 {
450 cec_s_phys_addr(adap, CEC_PHYS_ADDR_INVALID, false);
451 }
452
453 /**
454 * cec_get_edid_spa_location() - find location of the Source Physical Address
455 *
456 * @edid: the EDID
457 * @size: the size of the EDID
458 *
459 * This EDID is expected to be a CEA-861 compliant, which means that there are
460 * at least two blocks and one or more of the extensions blocks are CEA-861
461 * blocks.
462 *
463 * The returned location is guaranteed to be <= size-2.
464 *
465 * This is an inline function since it is used by both CEC and V4L2.
466 * Ideally this would go in a module shared by both, but it is overkill to do
467 * that for just a single function.
468 */
cec_get_edid_spa_location(const u8 * edid,unsigned int size)469 static inline unsigned int cec_get_edid_spa_location(const u8 *edid,
470 unsigned int size)
471 {
472 unsigned int blocks = size / 128;
473 unsigned int block;
474 u8 d;
475
476 /* Sanity check: at least 2 blocks and a multiple of the block size */
477 if (blocks < 2 || size % 128)
478 return 0;
479
480 /*
481 * If there are fewer extension blocks than the size, then update
482 * 'blocks'. It is allowed to have more extension blocks than the size,
483 * since some hardware can only read e.g. 256 bytes of the EDID, even
484 * though more blocks are present. The first CEA-861 extension block
485 * should normally be in block 1 anyway.
486 */
487 if (edid[0x7e] + 1 < blocks)
488 blocks = edid[0x7e] + 1;
489
490 for (block = 1; block < blocks; block++) {
491 unsigned int offset = block * 128;
492
493 /* Skip any non-CEA-861 extension blocks */
494 if (edid[offset] != 0x02 || edid[offset + 1] != 0x03)
495 continue;
496
497 /* search Vendor Specific Data Block (tag 3) */
498 d = edid[offset + 2] & 0x7f;
499 /* Check if there are Data Blocks */
500 if (d <= 4)
501 continue;
502 if (d > 4) {
503 unsigned int i = offset + 4;
504 unsigned int end = offset + d;
505
506 /* Note: 'end' is always < 'size' */
507 do {
508 u8 tag = edid[i] >> 5;
509 u8 len = edid[i] & 0x1f;
510
511 if (tag == 3 && len >= 5 && i + len <= end &&
512 edid[i + 1] == 0x03 &&
513 edid[i + 2] == 0x0c &&
514 edid[i + 3] == 0x00)
515 return i + 4;
516 i += len + 1;
517 } while (i < end);
518 }
519 }
520 return 0;
521 }
522
523 #endif /* _MEDIA_CEC_H */
524