summaryrefslogtreecommitdiff
path: root/include/media/cec.h
blob: 603f2fa08f625e044fcfc9bf35f627446fdeefc5 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
/* SPDX-License-Identifier: GPL-2.0-only */
/*
 * cec - HDMI Consumer Electronics Control support header
 *
 * Copyright 2016 Cisco Systems, Inc. and/or its affiliates. All rights reserved.
 */

#ifndef _MEDIA_CEC_H
#define _MEDIA_CEC_H

#include <linux/poll.h>
#include <linux/fs.h>
#include <linux/debugfs.h>
#include <linux/device.h>
#include <linux/cdev.h>
#include <linux/kthread.h>
#include <linux/timer.h>
#include <linux/cec-funcs.h>
#include <media/rc-core.h>
#include <media/cec-notifier.h>

#define CEC_CAP_DEFAULTS (CEC_CAP_LOG_ADDRS | CEC_CAP_TRANSMIT | \
			  CEC_CAP_PASSTHROUGH | CEC_CAP_RC)

/**
 * struct cec_devnode - cec device node
 * @dev:	cec device
 * @cdev:	cec character device
 * @minor:	device node minor number
 * @registered:	the device was correctly registered
 * @unregistered: the device was unregistered
 * @fhs_lock:	lock to control access to the filehandle list
 * @fhs:	the list of open filehandles (cec_fh)
 *
 * This structure represents a cec-related device node.
 *
 * The @parent is a physical device. It must be set by core or device drivers
 * before registering the node.
 */
struct cec_devnode {
	/* sysfs */
	struct device dev;
	struct cdev cdev;

	/* device info */
	int minor;
	bool registered;
	bool unregistered;
	struct list_head fhs;
	struct mutex lock;
};

struct cec_adapter;
struct cec_data;
struct cec_pin;

struct cec_data {
	struct list_head list;
	struct list_head xfer_list;
	struct cec_adapter *adap;
	struct cec_msg msg;
	struct cec_fh *fh;
	struct delayed_work work;
	struct completion c;
	u8 attempts;
	bool new_initiator;
	bool blocking;
	bool completed;
};

struct cec_msg_entry {
	struct list_head	list;
	struct cec_msg		msg;
};

struct cec_event_entry {
	struct list_head	list;
	struct cec_event	ev;
};

#define CEC_NUM_CORE_EVENTS 2
#define CEC_NUM_EVENTS CEC_EVENT_PIN_5V_HIGH

struct cec_fh {
	struct list_head	list;
	struct list_head	xfer_list;
	struct cec_adapter	*adap;
	u8			mode_initiator;
	u8			mode_follower;

	/* Events */
	wait_queue_head_t	wait;
	struct mutex		lock;
	struct list_head	events[CEC_NUM_EVENTS]; /* queued events */
	u16			queued_events[CEC_NUM_EVENTS];
	unsigned int		total_queued_events;
	struct cec_event_entry	core_events[CEC_NUM_CORE_EVENTS];
	struct list_head	msgs; /* queued messages */
	unsigned int		queued_msgs;
};

#define CEC_SIGNAL_FREE_TIME_RETRY		3
#define CEC_SIGNAL_FREE_TIME_NEW_INITIATOR	5
#define CEC_SIGNAL_FREE_TIME_NEXT_XFER		7

/* The nominal data bit period is 2.4 ms */
#define CEC_FREE_TIME_TO_USEC(ft)		((ft) * 2400)

struct cec_adap_ops {
	/* Low-level callbacks */
	int (*adap_enable)(struct cec_adapter *adap, bool enable);
	int (*adap_monitor_all_enable)(struct cec_adapter *adap, bool enable);
	int (*adap_monitor_pin_enable)(struct cec_adapter *adap, bool enable);
	int (*adap_log_addr)(struct cec_adapter *adap, u8 logical_addr);
	int (*adap_transmit)(struct cec_adapter *adap, u8 attempts,
			     u32 signal_free_time, struct cec_msg *msg);
	void (*adap_status)(struct cec_adapter *adap, struct seq_file *file);
	void (*adap_free)(struct cec_adapter *adap);

	/* Error injection callbacks */
	int (*error_inj_show)(struct cec_adapter *adap, struct seq_file *sf);
	bool (*error_inj_parse_line)(struct cec_adapter *adap, char *line);

	/* High-level CEC message callback */
	int (*received)(struct cec_adapter *adap, struct cec_msg *msg);
};

/*
 * The minimum message length you can receive (excepting poll messages) is 2.
 * With a transfer rate of at most 36 bytes per second this makes 18 messages
 * per second worst case.
 *
 * We queue at most 3 seconds worth of received messages. The CEC specification
 * requires that messages are replied to within a second, so 3 seconds should
 * give more than enough margin. Since most messages are actually more than 2
 * bytes, this is in practice a lot more than 3 seconds.
 */
#define CEC_MAX_MSG_RX_QUEUE_SZ		(18 * 3)

/*
 * The transmit queue is limited to 1 second worth of messages (worst case).
 * Messages can be transmitted by userspace and kernel space. But for both it
 * makes no sense to have a lot of messages queued up. One second seems
 * reasonable.
 */
#define CEC_MAX_MSG_TX_QUEUE_SZ		(18 * 1)

struct cec_adapter {
	struct module *owner;
	char name[32];
	struct cec_devnode devnode;
	struct mutex lock;
	struct rc_dev *rc;

	struct list_head transmit_queue;
	unsigned int transmit_queue_sz;
	struct list_head wait_queue;
	struct cec_data *transmitting;

	struct task_struct *kthread_config;
	struct completion config_completion;

	struct task_struct *kthread;
	wait_queue_head_t kthread_waitq;
	wait_queue_head_t waitq;

	const struct cec_adap_ops *ops;
	void *priv;
	u32 capabilities;
	u8 available_log_addrs;

	u16 phys_addr;
	bool needs_hpd;
	bool is_configuring;
	bool is_configured;
	bool cec_pin_is_high;
	u32 monitor_all_cnt;
	u32 monitor_pin_cnt;
	u32 follower_cnt;
	struct cec_fh *cec_follower;
	struct cec_fh *cec_initiator;
	bool passthrough;
	struct cec_log_addrs log_addrs;

	u32 tx_timeouts;

#ifdef CONFIG_CEC_NOTIFIER
	struct cec_notifier *notifier;
#endif
#ifdef CONFIG_CEC_PIN
	struct cec_pin *pin;
#endif

	struct dentry *cec_dir;
	struct dentry *status_file;
	struct dentry *error_inj_file;

	u16 phys_addrs[15];
	u32 sequence;

	char device_name[32];
	char input_phys[32];
	char input_drv[32];
};

static inline void *cec_get_drvdata(const struct cec_adapter *adap)
{
	return adap->priv;
}

static inline bool cec_has_log_addr(const struct cec_adapter *adap, u8 log_addr)
{
	return adap->log_addrs.log_addr_mask & (1 << log_addr);
}

static inline bool cec_is_sink(const struct cec_adapter *adap)
{
	return adap->phys_addr == 0;
}

/**
 * cec_is_registered() - is the CEC adapter registered?
 *
 * @adap:	the CEC adapter, may be NULL.
 *
 * Return: true if the adapter is registered, false otherwise.
 */
static inline bool cec_is_registered(const struct cec_adapter *adap)
{
	return adap && adap->devnode.registered;
}

#define cec_phys_addr_exp(pa) \
	((pa) >> 12), ((pa) >> 8) & 0xf, ((pa) >> 4) & 0xf, (pa) & 0xf

struct edid;

#if IS_REACHABLE(CONFIG_CEC_CORE)
struct cec_adapter *cec_allocate_adapter(const struct cec_adap_ops *ops,
		void *priv, const char *name, u32 caps, u8 available_las);
int cec_register_adapter(struct cec_adapter *adap, struct device *parent);
void cec_unregister_adapter(struct cec_adapter *adap);
void cec_delete_adapter(struct cec_adapter *adap);

int cec_s_log_addrs(struct cec_adapter *adap, struct cec_log_addrs *log_addrs,
		    bool block);
void cec_s_phys_addr(struct cec_adapter *adap, u16 phys_addr,
		     bool block);
void cec_s_phys_addr_from_edid(struct cec_adapter *adap,
			       const struct edid *edid);
int cec_transmit_msg(struct cec_adapter *adap, struct cec_msg *msg,
		     bool block);

/* Called by the adapter */
void cec_transmit_done_ts(struct cec_adapter *adap, u8 status,
			  u8 arb_lost_cnt, u8 nack_cnt, u8 low_drive_cnt,
			  u8 error_cnt, ktime_t ts);

static inline void cec_transmit_done(struct cec_adapter *adap, u8 status,
				     u8 arb_lost_cnt, u8 nack_cnt,
				     u8 low_drive_cnt, u8 error_cnt)
{
	cec_transmit_done_ts(adap, status, arb_lost_cnt, nack_cnt,
			     low_drive_cnt, error_cnt, ktime_get());
}
/*
 * Simplified version of cec_transmit_done for hardware that doesn't retry
 * failed transmits. So this is always just one attempt in which case
 * the status is sufficient.
 */
void cec_transmit_attempt_done_ts(struct cec_adapter *adap,
				  u8 status, ktime_t ts);

static inline void cec_transmit_attempt_done(struct cec_adapter *adap,
					     u8 status)
{
	cec_transmit_attempt_done_ts(adap, status, ktime_get());
}

void cec_received_msg_ts(struct cec_adapter *adap,
			 struct cec_msg *msg, ktime_t ts);

static inline void cec_received_msg(struct cec_adapter *adap,
				    struct cec_msg *msg)
{
	cec_received_msg_ts(adap, msg, ktime_get());
}

/**
 * cec_queue_pin_cec_event() - queue a CEC pin event with a given timestamp.
 *
 * @adap:	pointer to the cec adapter
 * @is_high:	when true the CEC pin is high, otherwise it is low
 * @dropped_events: when true some events were dropped
 * @ts:		the timestamp for this event
 *
 */
void cec_queue_pin_cec_event(struct cec_adapter *adap, bool is_high,
			     bool dropped_events, ktime_t ts);

/**
 * cec_queue_pin_hpd_event() - queue a pin event with a given timestamp.
 *
 * @adap:	pointer to the cec adapter
 * @is_high:	when true the HPD pin is high, otherwise it is low
 * @ts:		the timestamp for this event
 *
 */
void cec_queue_pin_hpd_event(struct cec_adapter *adap, bool is_high, ktime_t ts);

/**
 * cec_queue_pin_5v_event() - queue a pin event with a given timestamp.
 *
 * @adap:	pointer to the cec adapter
 * @is_high:	when true the 5V pin is high, otherwise it is low
 * @ts:		the timestamp for this event
 *
 */
void cec_queue_pin_5v_event(struct cec_adapter *adap, bool is_high, ktime_t ts);

/**
 * cec_get_edid_phys_addr() - find and return the physical address
 *
 * @edid:	pointer to the EDID data
 * @size:	size in bytes of the EDID data
 * @offset:	If not %NULL then the location of the physical address
 *		bytes in the EDID will be returned here. This is set to 0
 *		if there is no physical address found.
 *
 * Return: the physical address or CEC_PHYS_ADDR_INVALID if there is none.
 */
u16 cec_get_edid_phys_addr(const u8 *edid, unsigned int size,
			   unsigned int *offset);

/**
 * cec_set_edid_phys_addr() - find and set the physical address
 *
 * @edid:	pointer to the EDID data
 * @size:	size in bytes of the EDID data
 * @phys_addr:	the new physical address
 *
 * This function finds the location of the physical address in the EDID
 * and fills in the given physical address and updates the checksum
 * at the end of the EDID block. It does nothing if the EDID doesn't
 * contain a physical address.
 */
void cec_set_edid_phys_addr(u8 *edid, unsigned int size, u16 phys_addr);

/**
 * cec_phys_addr_for_input() - calculate the PA for an input
 *
 * @phys_addr:	the physical address of the parent
 * @input:	the number of the input port, must be between 1 and 15
 *
 * This function calculates a new physical address based on the input
 * port number. For example:
 *
 * PA = 0.0.0.0 and input = 2 becomes 2.0.0.0
 *
 * PA = 3.0.0.0 and input = 1 becomes 3.1.0.0
 *
 * PA = 3.2.1.0 and input = 5 becomes 3.2.1.5
 *
 * PA = 3.2.1.3 and input = 5 becomes f.f.f.f since it maxed out the depth.
 *
 * Return: the new physical address or CEC_PHYS_ADDR_INVALID.
 */
u16 cec_phys_addr_for_input(u16 phys_addr, u8 input);

/**
 * cec_phys_addr_validate() - validate a physical address from an EDID
 *
 * @phys_addr:	the physical address to validate
 * @parent:	if not %NULL, then this is filled with the parents PA.
 * @port:	if not %NULL, then this is filled with the input port.
 *
 * This validates a physical address as read from an EDID. If the
 * PA is invalid (such as 1.0.1.0 since '0' is only allowed at the end),
 * then it will return -EINVAL.
 *
 * The parent PA is passed into %parent and the input port is passed into
 * %port. For example:
 *
 * PA = 0.0.0.0: has parent 0.0.0.0 and input port 0.
 *
 * PA = 1.0.0.0: has parent 0.0.0.0 and input port 1.
 *
 * PA = 3.2.0.0: has parent 3.0.0.0 and input port 2.
 *
 * PA = f.f.f.f: has parent f.f.f.f and input port 0.
 *
 * Return: 0 if the PA is valid, -EINVAL if not.
 */
int cec_phys_addr_validate(u16 phys_addr, u16 *parent, u16 *port);

#else

static inline int cec_register_adapter(struct cec_adapter *adap,
				       struct device *parent)
{
	return 0;
}

static inline void cec_unregister_adapter(struct cec_adapter *adap)
{
}

static inline void cec_delete_adapter(struct cec_adapter *adap)
{
}

static inline void cec_s_phys_addr(struct cec_adapter *adap, u16 phys_addr,
				   bool block)
{
}

static inline void cec_s_phys_addr_from_edid(struct cec_adapter *adap,
					     const struct edid *edid)
{
}

static inline u16 cec_get_edid_phys_addr(const u8 *edid, unsigned int size,
					 unsigned int *offset)
{
	if (offset)
		*offset = 0;
	return CEC_PHYS_ADDR_INVALID;
}

static inline void cec_set_edid_phys_addr(u8 *edid, unsigned int size,
					  u16 phys_addr)
{
}

static inline u16 cec_phys_addr_for_input(u16 phys_addr, u8 input)
{
	return CEC_PHYS_ADDR_INVALID;
}

static inline int cec_phys_addr_validate(u16 phys_addr, u16 *parent, u16 *port)
{
	if (parent)
		*parent = phys_addr;
	if (port)
		*port = 0;
	return 0;
}

#endif

/**
 * cec_phys_addr_invalidate() - set the physical address to INVALID
 *
 * @adap:	the CEC adapter
 *
 * This is a simple helper function to invalidate the physical
 * address.
 */
static inline void cec_phys_addr_invalidate(struct cec_adapter *adap)
{
	cec_s_phys_addr(adap, CEC_PHYS_ADDR_INVALID, false);
}

/**
 * cec_get_edid_spa_location() - find location of the Source Physical Address
 *
 * @edid: the EDID
 * @size: the size of the EDID
 *
 * This EDID is expected to be a CEA-861 compliant, which means that there are
 * at least two blocks and one or more of the extensions blocks are CEA-861
 * blocks.
 *
 * The returned location is guaranteed to be <= size-2.
 *
 * This is an inline function since it is used by both CEC and V4L2.
 * Ideally this would go in a module shared by both, but it is overkill to do
 * that for just a single function.
 */
static inline unsigned int cec_get_edid_spa_location(const u8 *edid,
						     unsigned int size)
{
	unsigned int blocks = size / 128;
	unsigned int block;
	u8 d;

	/* Sanity check: at least 2 blocks and a multiple of the block size */
	if (blocks < 2 || size % 128)
		return 0;

	/*
	 * If there are fewer extension blocks than the size, then update
	 * 'blocks'. It is allowed to have more extension blocks than the size,
	 * since some hardware can only read e.g. 256 bytes of the EDID, even
	 * though more blocks are present. The first CEA-861 extension block
	 * should normally be in block 1 anyway.
	 */
	if (edid[0x7e] + 1 < blocks)
		blocks = edid[0x7e] + 1;

	for (block = 1; block < blocks; block++) {
		unsigned int offset = block * 128;

		/* Skip any non-CEA-861 extension blocks */
		if (edid[offset] != 0x02 || edid[offset + 1] != 0x03)
			continue;

		/* search Vendor Specific Data Block (tag 3) */
		d = edid[offset + 2] & 0x7f;
		/* Check if there are Data Blocks */
		if (d <= 4)
			continue;
		if (d > 4) {
			unsigned int i = offset + 4;
			unsigned int end = offset + d;

			/* Note: 'end' is always < 'size' */
			do {
				u8 tag = edid[i] >> 5;
				u8 len = edid[i] & 0x1f;

				if (tag == 3 && len >= 5 && i + len <= end &&
				    edid[i + 1] == 0x03 &&
				    edid[i + 2] == 0x0c &&
				    edid[i + 3] == 0x00)
					return i + 4;
				i += len + 1;
			} while (i < end);
		}
	}
	return 0;
}

#endif /* _MEDIA_CEC_H */