xref: /openbmc/linux/include/media/demux.h (revision fdbeb962)
1 /*
2  * demux.h
3  *
4  * The Kernel Digital TV Demux kABI defines a driver-internal interface for
5  * registering low-level, hardware specific driver to a hardware independent
6  * demux layer.
7  *
8  * Copyright (c) 2002 Convergence GmbH
9  *
10  * based on code:
11  * Copyright (c) 2000 Nokia Research Center
12  *                    Tampere, FINLAND
13  *
14  * This program is free software; you can redistribute it and/or
15  * modify it under the terms of the GNU Lesser General Public License
16  * as published by the Free Software Foundation; either version 2.1
17  * of the License, or (at your option) any later version.
18  *
19  * This program is distributed in the hope that it will be useful,
20  * but WITHOUT ANY WARRANTY; without even the implied warranty of
21  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
22  * GNU General Public License for more details.
23  *
24  */
25 
26 #ifndef __DEMUX_H
27 #define __DEMUX_H
28 
29 #include <linux/types.h>
30 #include <linux/errno.h>
31 #include <linux/list.h>
32 #include <linux/time.h>
33 #include <linux/dvb/dmx.h>
34 
35 /*
36  * Common definitions
37  */
38 
39 /*
40  * DMX_MAX_FILTER_SIZE: Maximum length (in bytes) of a section/PES filter.
41  */
42 
43 #ifndef DMX_MAX_FILTER_SIZE
44 #define DMX_MAX_FILTER_SIZE 18
45 #endif
46 
47 /*
48  * DMX_MAX_SECFEED_SIZE: Maximum length (in bytes) of a private section feed
49  * filter.
50  */
51 
52 #ifndef DMX_MAX_SECTION_SIZE
53 #define DMX_MAX_SECTION_SIZE 4096
54 #endif
55 #ifndef DMX_MAX_SECFEED_SIZE
56 #define DMX_MAX_SECFEED_SIZE (DMX_MAX_SECTION_SIZE + 188)
57 #endif
58 
59 /*
60  * TS packet reception
61  */
62 
63 /**
64  * enum ts_filter_type - filter type bitmap for dmx_ts_feed.set\(\)
65  *
66  * @TS_PACKET:		Send TS packets (188 bytes) to callback (default).
67  * @TS_PAYLOAD_ONLY:	In case TS_PACKET is set, only send the TS payload
68  *			(<=184 bytes per packet) to callback
69  * @TS_DECODER:		Send stream to built-in decoder (if present).
70  * @TS_DEMUX:		In case TS_PACKET is set, send the TS to the demux
71  *			device, not to the dvr device
72  */
73 enum ts_filter_type {
74 	TS_PACKET = 1,
75 	TS_PAYLOAD_ONLY = 2,
76 	TS_DECODER = 4,
77 	TS_DEMUX = 8,
78 };
79 
80 /**
81  * struct dmx_ts_feed - Structure that contains a TS feed filter
82  *
83  * @is_filtering:	Set to non-zero when filtering in progress
84  * @parent:		pointer to struct dmx_demux
85  * @priv:		pointer to private data of the API client
86  * @set:		sets the TS filter
87  * @start_filtering:	starts TS filtering
88  * @stop_filtering:	stops TS filtering
89  *
90  * A TS feed is typically mapped to a hardware PID filter on the demux chip.
91  * Using this API, the client can set the filtering properties to start/stop
92  * filtering TS packets on a particular TS feed.
93  */
94 struct dmx_ts_feed {
95 	int is_filtering;
96 	struct dmx_demux *parent;
97 	void *priv;
98 	int (*set)(struct dmx_ts_feed *feed,
99 		   u16 pid,
100 		   int type,
101 		   enum dmx_ts_pes pes_type,
102 		   ktime_t timeout);
103 	int (*start_filtering)(struct dmx_ts_feed *feed);
104 	int (*stop_filtering)(struct dmx_ts_feed *feed);
105 };
106 
107 /*
108  * Section reception
109  */
110 
111 /**
112  * struct dmx_section_filter - Structure that describes a section filter
113  *
114  * @filter_value: Contains up to 16 bytes (128 bits) of the TS section header
115  *		  that will be matched by the section filter
116  * @filter_mask:  Contains a 16 bytes (128 bits) filter mask with the bits
117  *		  specified by @filter_value that will be used on the filter
118  *		  match logic.
119  * @filter_mode:  Contains a 16 bytes (128 bits) filter mode.
120  * @parent:	  Back-pointer to struct dmx_section_feed.
121  * @priv:	  Pointer to private data of the API client.
122  *
123  *
124  * The @filter_mask controls which bits of @filter_value are compared with
125  * the section headers/payload. On a binary value of 1 in filter_mask, the
126  * corresponding bits are compared. The filter only accepts sections that are
127  * equal to filter_value in all the tested bit positions.
128  */
129 struct dmx_section_filter {
130 	u8 filter_value[DMX_MAX_FILTER_SIZE];
131 	u8 filter_mask[DMX_MAX_FILTER_SIZE];
132 	u8 filter_mode[DMX_MAX_FILTER_SIZE];
133 	struct dmx_section_feed *parent;
134 
135 	void *priv;
136 };
137 
138 /**
139  * struct dmx_section_feed - Structure that contains a section feed filter
140  *
141  * @is_filtering:	Set to non-zero when filtering in progress
142  * @parent:		pointer to struct dmx_demux
143  * @priv:		pointer to private data of the API client
144  * @check_crc:		If non-zero, check the CRC values of filtered sections.
145  * @set:		sets the section filter
146  * @allocate_filter:	This function is used to allocate a section filter on
147  *			the demux. It should only be called when no filtering
148  *			is in progress on this section feed. If a filter cannot
149  *			be allocated, the function fails with -ENOSPC.
150  * @release_filter:	This function releases all the resources of a
151  *			previously allocated section filter. The function
152  *			should not be called while filtering is in progress
153  *			on this section feed. After calling this function,
154  *			the caller should not try to dereference the filter
155  *			pointer.
156  * @start_filtering:	starts section filtering
157  * @stop_filtering:	stops section filtering
158  *
159  * A TS feed is typically mapped to a hardware PID filter on the demux chip.
160  * Using this API, the client can set the filtering properties to start/stop
161  * filtering TS packets on a particular TS feed.
162  */
163 struct dmx_section_feed {
164 	int is_filtering;
165 	struct dmx_demux *parent;
166 	void *priv;
167 
168 	int check_crc;
169 
170 	/* private: Used internally at dvb_demux.c */
171 	u32 crc_val;
172 
173 	u8 *secbuf;
174 	u8 secbuf_base[DMX_MAX_SECFEED_SIZE];
175 	u16 secbufp, seclen, tsfeedp;
176 
177 	/* public: */
178 	int (*set)(struct dmx_section_feed *feed,
179 		   u16 pid,
180 		   int check_crc);
181 	int (*allocate_filter)(struct dmx_section_feed *feed,
182 			       struct dmx_section_filter **filter);
183 	int (*release_filter)(struct dmx_section_feed *feed,
184 			      struct dmx_section_filter *filter);
185 	int (*start_filtering)(struct dmx_section_feed *feed);
186 	int (*stop_filtering)(struct dmx_section_feed *feed);
187 };
188 
189 /**
190  * typedef dmx_ts_cb - DVB demux TS filter callback function prototype
191  *
192  * @buffer1:		Pointer to the start of the filtered TS packets.
193  * @buffer1_length:	Length of the TS data in buffer1.
194  * @buffer2:		Pointer to the tail of the filtered TS packets, or NULL.
195  * @buffer2_length:	Length of the TS data in buffer2.
196  * @source:		Indicates which TS feed is the source of the callback.
197  * @buffer_flags:	Address where buffer flags are stored. Those are
198  *			used to report discontinuity users via DVB
199  *			memory mapped API, as defined by
200  *			&enum dmx_buffer_flags.
201  *
202  * This function callback prototype, provided by the client of the demux API,
203  * is called from the demux code. The function is only called when filtering
204  * on a TS feed has been enabled using the start_filtering\(\) function at
205  * the &dmx_demux.
206  * Any TS packets that match the filter settings are copied to a circular
207  * buffer. The filtered TS packets are delivered to the client using this
208  * callback function.
209  * It is expected that the @buffer1 and @buffer2 callback parameters point to
210  * addresses within the circular buffer, but other implementations are also
211  * possible. Note that the called party should not try to free the memory
212  * the @buffer1 and @buffer2 parameters point to.
213  *
214  * When this function is called, the @buffer1 parameter typically points to
215  * the start of the first undelivered TS packet within a circular buffer.
216  * The @buffer2 buffer parameter is normally NULL, except when the received
217  * TS packets have crossed the last address of the circular buffer and
218  * "wrapped" to the beginning of the buffer. In the latter case the @buffer1
219  * parameter would contain an address within the circular buffer, while the
220  * @buffer2 parameter would contain the first address of the circular buffer.
221  * The number of bytes delivered with this function (i.e. @buffer1_length +
222  * @buffer2_length) is usually equal to the value of callback_length parameter
223  * given in the set() function, with one exception: if a timeout occurs before
224  * receiving callback_length bytes of TS data, any undelivered packets are
225  * immediately delivered to the client by calling this function. The timeout
226  * duration is controlled by the set() function in the TS Feed API.
227  *
228  * If a TS packet is received with errors that could not be fixed by the
229  * TS-level forward error correction (FEC), the Transport_error_indicator
230  * flag of the TS packet header should be set. The TS packet should not be
231  * discarded, as the error can possibly be corrected by a higher layer
232  * protocol. If the called party is slow in processing the callback, it
233  * is possible that the circular buffer eventually fills up. If this happens,
234  * the demux driver should discard any TS packets received while the buffer
235  * is full and return -EOVERFLOW.
236  *
237  * The type of data returned to the callback can be selected by the
238  * &dmx_ts_feed.@set function. The type parameter decides if the raw
239  * TS packet (TS_PACKET) or just the payload (TS_PACKET|TS_PAYLOAD_ONLY)
240  * should be returned. If additionally the TS_DECODER bit is set the stream
241  * will also be sent to the hardware MPEG decoder.
242  *
243  * Return:
244  *
245  * - 0, on success;
246  *
247  * - -EOVERFLOW, on buffer overflow.
248  */
249 typedef int (*dmx_ts_cb)(const u8 *buffer1,
250 			 size_t buffer1_length,
251 			 const u8 *buffer2,
252 			 size_t buffer2_length,
253 			 struct dmx_ts_feed *source,
254 			 u32 *buffer_flags);
255 
256 /**
257  * typedef dmx_section_cb - DVB demux TS filter callback function prototype
258  *
259  * @buffer1:		Pointer to the start of the filtered section, e.g.
260  *			within the circular buffer of the demux driver.
261  * @buffer1_len:	Length of the filtered section data in @buffer1,
262  *			including headers and CRC.
263  * @buffer2:		Pointer to the tail of the filtered section data,
264  *			or NULL. Useful to handle the wrapping of a
265  *			circular buffer.
266  * @buffer2_len:	Length of the filtered section data in @buffer2,
267  *			including headers and CRC.
268  * @source:		Indicates which section feed is the source of the
269  *			callback.
270  * @buffer_flags:	Address where buffer flags are stored. Those are
271  *			used to report discontinuity users via DVB
272  *			memory mapped API, as defined by
273  *			&enum dmx_buffer_flags.
274  *
275  * This function callback prototype, provided by the client of the demux API,
276  * is called from the demux code. The function is only called when
277  * filtering of sections has been enabled using the function
278  * &dmx_ts_feed.@start_filtering. When the demux driver has received a
279  * complete section that matches at least one section filter, the client
280  * is notified via this callback function. Normally this function is called
281  * for each received section; however, it is also possible to deliver
282  * multiple sections with one callback, for example when the system load
283  * is high. If an error occurs while receiving a section, this
284  * function should be called with the corresponding error type set in the
285  * success field, whether or not there is data to deliver. The Section Feed
286  * implementation should maintain a circular buffer for received sections.
287  * However, this is not necessary if the Section Feed API is implemented as
288  * a client of the TS Feed API, because the TS Feed implementation then
289  * buffers the received data. The size of the circular buffer can be
290  * configured using the &dmx_ts_feed.@set function in the Section Feed API.
291  * If there is no room in the circular buffer when a new section is received,
292  * the section must be discarded. If this happens, the value of the success
293  * parameter should be DMX_OVERRUN_ERROR on the next callback.
294  */
295 typedef int (*dmx_section_cb)(const u8 *buffer1,
296 			      size_t buffer1_len,
297 			      const u8 *buffer2,
298 			      size_t buffer2_len,
299 			      struct dmx_section_filter *source,
300 			      u32 *buffer_flags);
301 
302 /*
303  * DVB Front-End
304  */
305 
306 /**
307  * enum dmx_frontend_source - Used to identify the type of frontend
308  *
309  * @DMX_MEMORY_FE:	The source of the demux is memory. It means that
310  *			the MPEG-TS to be filtered comes from userspace,
311  *			via write() syscall.
312  *
313  * @DMX_FRONTEND_0:	The source of the demux is a frontend connected
314  *			to the demux.
315  */
316 enum dmx_frontend_source {
317 	DMX_MEMORY_FE,
318 	DMX_FRONTEND_0,
319 };
320 
321 /**
322  * struct dmx_frontend - Structure that lists the frontends associated with
323  *			 a demux
324  *
325  * @connectivity_list:	List of front-ends that can be connected to a
326  *			particular demux;
327  * @source:		Type of the frontend.
328  *
329  * FIXME: this structure should likely be replaced soon by some
330  *	media-controller based logic.
331  */
332 struct dmx_frontend {
333 	struct list_head connectivity_list;
334 	enum dmx_frontend_source source;
335 };
336 
337 /*
338  * MPEG-2 TS Demux
339  */
340 
341 /**
342  * enum dmx_demux_caps - MPEG-2 TS Demux capabilities bitmap
343  *
344  * @DMX_TS_FILTERING:		set if TS filtering is supported;
345  * @DMX_SECTION_FILTERING:	set if section filtering is supported;
346  * @DMX_MEMORY_BASED_FILTERING:	set if write() available.
347  *
348  * Those flags are OR'ed in the &dmx_demux.capabilities field
349  */
350 enum dmx_demux_caps {
351 	DMX_TS_FILTERING = 1,
352 	DMX_SECTION_FILTERING = 4,
353 	DMX_MEMORY_BASED_FILTERING = 8,
354 };
355 
356 /*
357  * Demux resource type identifier.
358  */
359 
360 /**
361  * DMX_FE_ENTRY - Casts elements in the list of registered
362  *		  front-ends from the generic type struct list_head
363  *		  to the type * struct dmx_frontend
364  *
365  * @list: list of struct dmx_frontend
366  */
367 #define DMX_FE_ENTRY(list) \
368 	list_entry(list, struct dmx_frontend, connectivity_list)
369 
370 /**
371  * struct dmx_demux - Structure that contains the demux capabilities and
372  *		      callbacks.
373  *
374  * @capabilities: Bitfield of capability flags.
375  *
376  * @frontend: Front-end connected to the demux
377  *
378  * @priv: Pointer to private data of the API client
379  *
380  * @open: This function reserves the demux for use by the caller and, if
381  *	necessary, initializes the demux. When the demux is no longer needed,
382  *	the function @close should be called. It should be possible for
383  *	multiple clients to access the demux at the same time. Thus, the
384  *	function implementation should increment the demux usage count when
385  *	@open is called and decrement it when @close is called.
386  *	The @demux function parameter contains a pointer to the demux API and
387  *	instance data.
388  *	It returns:
389  *	0 on success;
390  *	-EUSERS, if maximum usage count was reached;
391  *	-EINVAL, on bad parameter.
392  *
393  * @close: This function reserves the demux for use by the caller and, if
394  *	necessary, initializes the demux. When the demux is no longer needed,
395  *	the function @close should be called. It should be possible for
396  *	multiple clients to access the demux at the same time. Thus, the
397  *	function implementation should increment the demux usage count when
398  *	@open is called and decrement it when @close is called.
399  *	The @demux function parameter contains a pointer to the demux API and
400  *	instance data.
401  *	It returns:
402  *	0 on success;
403  *	-ENODEV, if demux was not in use (e. g. no users);
404  *	-EINVAL, on bad parameter.
405  *
406  * @write: This function provides the demux driver with a memory buffer
407  *	containing TS packets. Instead of receiving TS packets from the DVB
408  *	front-end, the demux driver software will read packets from memory.
409  *	Any clients of this demux with active TS, PES or Section filters will
410  *	receive filtered data via the Demux callback API (see 0). The function
411  *	returns when all the data in the buffer has been consumed by the demux.
412  *	Demux hardware typically cannot read TS from memory. If this is the
413  *	case, memory-based filtering has to be implemented entirely in software.
414  *	The @demux function parameter contains a pointer to the demux API and
415  *	instance data.
416  *	The @buf function parameter contains a pointer to the TS data in
417  *	kernel-space memory.
418  *	The @count function parameter contains the length of the TS data.
419  *	It returns:
420  *	0 on success;
421  *	-ERESTARTSYS, if mutex lock was interrupted;
422  *	-EINTR, if a signal handling is pending;
423  *	-ENODEV, if demux was removed;
424  *	-EINVAL, on bad parameter.
425  *
426  * @allocate_ts_feed: Allocates a new TS feed, which is used to filter the TS
427  *	packets carrying a certain PID. The TS feed normally corresponds to a
428  *	hardware PID filter on the demux chip.
429  *	The @demux function parameter contains a pointer to the demux API and
430  *	instance data.
431  *	The @feed function parameter contains a pointer to the TS feed API and
432  *	instance data.
433  *	The @callback function parameter contains a pointer to the callback
434  *	function for passing received TS packet.
435  *	It returns:
436  *	0 on success;
437  *	-ERESTARTSYS, if mutex lock was interrupted;
438  *	-EBUSY, if no more TS feeds is available;
439  *	-EINVAL, on bad parameter.
440  *
441  * @release_ts_feed: Releases the resources allocated with @allocate_ts_feed.
442  *	Any filtering in progress on the TS feed should be stopped before
443  *	calling this function.
444  *	The @demux function parameter contains a pointer to the demux API and
445  *	instance data.
446  *	The @feed function parameter contains a pointer to the TS feed API and
447  *	instance data.
448  *	It returns:
449  *	0 on success;
450  *	-EINVAL on bad parameter.
451  *
452  * @allocate_section_feed: Allocates a new section feed, i.e. a demux resource
453  *	for filtering and receiving sections. On platforms with hardware
454  *	support for section filtering, a section feed is directly mapped to
455  *	the demux HW. On other platforms, TS packets are first PID filtered in
456  *	hardware and a hardware section filter then emulated in software. The
457  *	caller obtains an API pointer of type dmx_section_feed_t as an out
458  *	parameter. Using this API the caller can set filtering parameters and
459  *	start receiving sections.
460  *	The @demux function parameter contains a pointer to the demux API and
461  *	instance data.
462  *	The @feed function parameter contains a pointer to the TS feed API and
463  *	instance data.
464  *	The @callback function parameter contains a pointer to the callback
465  *	function for passing received TS packet.
466  *	It returns:
467  *	0 on success;
468  *	-EBUSY, if no more TS feeds is available;
469  *	-EINVAL, on bad parameter.
470  *
471  * @release_section_feed: Releases the resources allocated with
472  *	@allocate_section_feed, including allocated filters. Any filtering in
473  *	progress on the section feed should be stopped before calling this
474  *	function.
475  *	The @demux function parameter contains a pointer to the demux API and
476  *	instance data.
477  *	The @feed function parameter contains a pointer to the TS feed API and
478  *	instance data.
479  *	It returns:
480  *	0 on success;
481  *	-EINVAL, on bad parameter.
482  *
483  * @add_frontend: Registers a connectivity between a demux and a front-end,
484  *	i.e., indicates that the demux can be connected via a call to
485  *	@connect_frontend to use the given front-end as a TS source. The
486  *	client of this function has to allocate dynamic or static memory for
487  *	the frontend structure and initialize its fields before calling this
488  *	function. This function is normally called during the driver
489  *	initialization. The caller must not free the memory of the frontend
490  *	struct before successfully calling @remove_frontend.
491  *	The @demux function parameter contains a pointer to the demux API and
492  *	instance data.
493  *	The @frontend function parameter contains a pointer to the front-end
494  *	instance data.
495  *	It returns:
496  *	0 on success;
497  *	-EINVAL, on bad parameter.
498  *
499  * @remove_frontend: Indicates that the given front-end, registered by a call
500  *	to @add_frontend, can no longer be connected as a TS source by this
501  *	demux. The function should be called when a front-end driver or a demux
502  *	driver is removed from the system. If the front-end is in use, the
503  *	function fails with the return value of -EBUSY. After successfully
504  *	calling this function, the caller can free the memory of the frontend
505  *	struct if it was dynamically allocated before the @add_frontend
506  *	operation.
507  *	The @demux function parameter contains a pointer to the demux API and
508  *	instance data.
509  *	The @frontend function parameter contains a pointer to the front-end
510  *	instance data.
511  *	It returns:
512  *	0 on success;
513  *	-ENODEV, if the front-end was not found,
514  *	-EINVAL, on bad parameter.
515  *
516  * @get_frontends: Provides the APIs of the front-ends that have been
517  *	registered for this demux. Any of the front-ends obtained with this
518  *	call can be used as a parameter for @connect_frontend. The include
519  *	file demux.h contains the macro DMX_FE_ENTRY() for converting an
520  *	element of the generic type struct &list_head * to the type
521  *	struct &dmx_frontend *. The caller must not free the memory of any of
522  *	the elements obtained via this function call.
523  *	The @demux function parameter contains a pointer to the demux API and
524  *	instance data.
525  *	It returns a struct list_head pointer to the list of front-end
526  *	interfaces, or NULL in the case of an empty list.
527  *
528  * @connect_frontend: Connects the TS output of the front-end to the input of
529  *	the demux. A demux can only be connected to a front-end registered to
530  *	the demux with the function @add_frontend. It may or may not be
531  *	possible to connect multiple demuxes to the same front-end, depending
532  *	on the capabilities of the HW platform. When not used, the front-end
533  *	should be released by calling @disconnect_frontend.
534  *	The @demux function parameter contains a pointer to the demux API and
535  *	instance data.
536  *	The @frontend function parameter contains a pointer to the front-end
537  *	instance data.
538  *	It returns:
539  *	0 on success;
540  *	-EINVAL, on bad parameter.
541  *
542  * @disconnect_frontend: Disconnects the demux and a front-end previously
543  *	connected by a @connect_frontend call.
544  *	The @demux function parameter contains a pointer to the demux API and
545  *	instance data.
546  *	It returns:
547  *	0 on success;
548  *	-EINVAL on bad parameter.
549  *
550  * @get_pes_pids: Get the PIDs for DMX_PES_AUDIO0, DMX_PES_VIDEO0,
551  *	DMX_PES_TELETEXT0, DMX_PES_SUBTITLE0 and DMX_PES_PCR0.
552  *	The @demux function parameter contains a pointer to the demux API and
553  *	instance data.
554  *	The @pids function parameter contains an array with five u16 elements
555  *	where the PIDs will be stored.
556  *	It returns:
557  *	0 on success;
558  *	-EINVAL on bad parameter.
559  */
560 struct dmx_demux {
561 	enum dmx_demux_caps capabilities;
562 	struct dmx_frontend *frontend;
563 	void *priv;
564 	int (*open)(struct dmx_demux *demux);
565 	int (*close)(struct dmx_demux *demux);
566 	int (*write)(struct dmx_demux *demux, const char __user *buf,
567 		     size_t count);
568 	int (*allocate_ts_feed)(struct dmx_demux *demux,
569 				struct dmx_ts_feed **feed,
570 				dmx_ts_cb callback);
571 	int (*release_ts_feed)(struct dmx_demux *demux,
572 			       struct dmx_ts_feed *feed);
573 	int (*allocate_section_feed)(struct dmx_demux *demux,
574 				     struct dmx_section_feed **feed,
575 				     dmx_section_cb callback);
576 	int (*release_section_feed)(struct dmx_demux *demux,
577 				    struct dmx_section_feed *feed);
578 	int (*add_frontend)(struct dmx_demux *demux,
579 			    struct dmx_frontend *frontend);
580 	int (*remove_frontend)(struct dmx_demux *demux,
581 			       struct dmx_frontend *frontend);
582 	struct list_head *(*get_frontends)(struct dmx_demux *demux);
583 	int (*connect_frontend)(struct dmx_demux *demux,
584 				struct dmx_frontend *frontend);
585 	int (*disconnect_frontend)(struct dmx_demux *demux);
586 
587 	int (*get_pes_pids)(struct dmx_demux *demux, u16 *pids);
588 
589 	/* private: */
590 
591 	/*
592 	 * Only used at av7110, to read some data from firmware.
593 	 * As this was never documented, we have no clue about what's
594 	 * there, and its usage on other drivers aren't encouraged.
595 	 */
596 	int (*get_stc)(struct dmx_demux *demux, unsigned int num,
597 		       u64 *stc, unsigned int *base);
598 };
599 
600 #endif /* #ifndef __DEMUX_H */
601