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Based on kernel version 3.16. Page generated on 2014-08-06 21:41 EST.

1	Software Interface ALSA-DSP MADI Driver 
2	
3	(translated from German, so no good English ;-), 
4	2004 - winfried ritsch
5	
6	
7	
8	 Full functionality has been added to the driver. Since some of
9	 the Controls and startup-options  are ALSA-Standard and only the
10	 special Controls are described and discussed below.
11	
12	
13	 hardware functionality:
14	
15	   
16	   Audio transmission:
17	
18	     number of channels --  depends on transmission mode
19	
20			The number of channels chosen is from 1..Nmax. The reason to
21			use for a lower number of channels is only resource allocation,
22			since unused DMA channels are disabled and less memory is
23			allocated. So also the throughput of the PCI system can be
24			scaled. (Only important for low performance boards).
25	
26	       Single Speed -- 1..64 channels 
27	
28			 (Note: Choosing the 56channel mode for transmission or as
29			 receiver, only 56 are transmitted/received over the MADI, but
30			 all 64 channels are available for the mixer, so channel count
31			 for the driver)
32	
33	       Double Speed -- 1..32 channels
34	
35			 Note: Choosing the 56-channel mode for
36			 transmission/receive-mode , only 28 are transmitted/received
37			 over the MADI, but all 32 channels are available for the mixer,
38			 so channel count for the driver
39	
40	
41	       Quad Speed -- 1..16 channels 
42	
43			 Note: Choosing the 56-channel mode for
44			 transmission/receive-mode , only 14 are transmitted/received
45			 over the MADI, but all 16 channels are available for the mixer,
46			 so channel count for the driver
47	
48	     Format -- signed 32 Bit Little Endian (SNDRV_PCM_FMTBIT_S32_LE)
49	
50	     Sample Rates --
51	
52	       Single Speed -- 32000, 44100, 48000
53	
54	       Double Speed -- 64000, 88200, 96000 (untested)
55	
56	       Quad Speed -- 128000, 176400, 192000 (untested)
57	
58	     access-mode -- MMAP (memory mapped), Not interleaved
59	     (PCM_NON-INTERLEAVED)
60	
61	     buffer-sizes -- 64,128,256,512,1024,2048,8192 Samples
62	
63	     fragments -- 2
64	
65	     Hardware-pointer -- 2 Modi
66	
67	
68			 The Card supports the readout of the actual Buffer-pointer,
69			 where DMA reads/writes. Since of the bulk mode of PCI it is only
70			 64 Byte accurate. SO it is not really usable for the
71			 ALSA-mid-level functions (here the buffer-ID gives a better
72			 result), but if MMAP is used by the application. Therefore it
73			 can be configured at load-time with the parameter
74			 precise-pointer.
75	
76	
77			 (Hint: Experimenting I found that the pointer is maximum 64 to
78			 large never to small. So if you subtract 64 you always have a
79			 safe pointer for writing, which is used on this mode inside
80			 ALSA. In theory now you can get now a latency as low as 16
81			 Samples, which is a quarter of the interrupt possibilities.)
82	
83	       Precise Pointer -- off
84						interrupt used for pointer-calculation
85	
86	       Precise Pointer -- on
87						hardware pointer used.
88	
89	   Controller:
90	
91	
92		  Since DSP-MADI-Mixer has 8152 Fader, it does not make sense to
93		  use the standard mixer-controls, since this would break most of
94		  (especially graphic) ALSA-Mixer GUIs. So Mixer control has be
95		  provided by a 2-dimensional controller using the
96		  hwdep-interface. 
97	
98	     Also all 128+256 Peak and RMS-Meter can be accessed via the
99	     hwdep-interface. Since it could be a performance problem always
100	     copying and converting Peak and RMS-Levels even if you just need
101	     one, I decided to export the hardware structure, so that of
102	     needed some driver-guru can implement a memory-mapping of mixer
103	     or peak-meters over ioctl, or also to do only copying and no
104	     conversion. A test-application shows the usage of the controller.
105	
106	    Latency Controls --- not implemented !!!
107	
108	
109		   Note: Within the windows-driver the latency is accessible of a
110		   control-panel, but buffer-sizes are controlled with ALSA from
111		   hwparams-calls and should not be changed in run-state, I did not
112		   implement it here.
113	
114	
115	    System Clock -- suspended !!!!
116	
117	        Name -- "System Clock Mode"
118	
119	        Access -- Read Write
120	
121	        Values -- "Master" "Slave"
122	
123	
124			  !!!! This is a hardware-function but is in conflict with the
125			  Clock-source controller, which is a kind of ALSA-standard. I
126			  makes sense to set the card to a special mode (master at some
127			  frequency or slave), since even not using an Audio-application
128			  a studio should have working synchronisations setup. So use
129			  Clock-source-controller instead !!!!
130	
131	    Clock Source  
132	
133	       Name -- "Sample Clock Source"
134	
135	       Access -- Read Write
136	
137	       Values -- "AutoSync", "Internal 32.0 kHz", "Internal 44.1 kHz",
138	       "Internal 48.0 kHz", "Internal 64.0 kHz", "Internal 88.2 kHz",
139	       "Internal 96.0 kHz"
140	
141			 Choose between Master at a specific Frequency and so also the
142			 Speed-mode or Slave (Autosync). Also see  "Preferred Sync Ref"
143	
144	
145	       !!!! This is no pure hardware function but was implemented by
146	       ALSA by some ALSA-drivers before, so I use it also. !!!
147	
148	
149	    Preferred Sync Ref
150	
151	       Name -- "Preferred Sync Reference"
152	
153	       Access -- Read Write
154	
155	       Values -- "Word" "MADI"
156	
157	
158			 Within the Auto-sync-Mode the preferred Sync Source can be
159			 chosen. If it is not available another is used if possible.
160	
161			 Note: Since MADI has a much higher bit-rate than word-clock, the
162			 card should synchronise better in MADI Mode. But since the
163			 RME-PLL is very good, there are almost no problems with
164			 word-clock too. I never found a difference.
165	
166	
167	    TX 64 channel --- 
168	
169	       Name -- "TX 64 channels mode"
170	
171	       Access -- Read Write
172	
173	       Values -- 0 1
174	
175			 Using 64-channel-modus (1) or 56-channel-modus for
176			 MADI-transmission (0).
177	
178	
179			 Note: This control is for output only. Input-mode is detected
180			 automatically from hardware sending MADI.
181	
182	
183	    Clear TMS ---
184	
185	       Name -- "Clear Track Marker"
186	
187	       Access -- Read Write
188	
189	       Values -- 0 1
190	
191	
192			 Don't use to lower 5 Audio-bits on AES as additional Bits.
193	        
194	
195	    Safe Mode oder Auto Input --- 
196	
197	       Name -- "Safe Mode"
198	
199	       Access -- Read Write
200	
201	       Values -- 0 1
202	
203	       (default on)
204	
205			 If on (1), then if either the optical or coaxial connection
206			 has a failure, there is a takeover to the working one, with no
207			 sample failure. Its only useful if you use the second as a
208			 backup connection.
209	
210	    Input --- 
211	
212	       Name -- "Input Select"
213	
214	       Access -- Read Write
215	
216	       Values -- optical coaxial
217	
218	
219			 Choosing the Input, optical or coaxial. If Safe-mode is active,
220			 this is the preferred Input.
221	
222	-------------- Mixer ----------------------
223	
224	    Mixer
225	
226	       Name -- "Mixer"
227	
228	       Access -- Read Write
229	
230	       Values - <channel-number 0-127> <Value 0-65535>
231	
232	
233			 Here as a first value the channel-index is taken to get/set the
234			 corresponding mixer channel, where 0-63 are the input to output
235			 fader and 64-127 the playback to outputs fader. Value 0
236			 is channel muted 0 and 32768 an amplification of  1.
237	
238	    Chn 1-64
239	
240	       fast mixer for the ALSA-mixer utils. The diagonal of the
241	       mixer-matrix is implemented from playback to output.
242	       
243	
244	    Line Out
245	
246	       Name  -- "Line Out"
247	
248	       Access -- Read Write
249	
250	       Values -- 0 1
251	
252			 Switching on and off the analog out, which has nothing to do
253			 with mixing or routing. the analog outs reflects channel 63,64.
254	
255	
256	--- information (only read access):
257	 
258	    Sample Rate
259	
260	       Name -- "System Sample Rate"
261	
262	       Access -- Read-only
263	
264			 getting the sample rate.
265	
266	
267	    External Rate measured
268	
269	       Name -- "External Rate"
270	
271	       Access -- Read only
272	
273	
274			 Should be "Autosync Rate", but Name used is
275			 ALSA-Scheme. External Sample frequency liked used on Autosync is
276			 reported.
277	
278	
279	    MADI Sync Status
280	
281	       Name -- "MADI Sync Lock Status"
282	
283	       Access -- Read
284	
285	       Values -- 0,1,2
286	
287	       MADI-Input is 0=Unlocked, 1=Locked, or 2=Synced.
288	
289	
290	    Word Clock Sync Status
291	
292	       Name -- "Word Clock Lock Status"
293	
294	       Access -- Read
295	
296	       Values -- 0,1,2
297	
298	       Word Clock Input is 0=Unlocked, 1=Locked, or 2=Synced.
299	
300	    AutoSync
301	
302	       Name -- "AutoSync Reference"
303	
304	       Access -- Read
305	
306	       Values -- "WordClock", "MADI", "None"
307	
308			 Sync-Reference is either "WordClock", "MADI" or none.
309	
310	   RX 64ch --- noch nicht implementiert
311	
312	       MADI-Receiver is in 64 channel mode oder 56 channel mode.
313	
314	
315	   AB_inp   --- not tested 
316	
317			 Used input for Auto-Input.
318	
319	
320	   actual Buffer Position --- not implemented
321	
322		   !!! this is a ALSA internal function, so no control is used !!!
323	
324	
325	
326	Calling Parameter:
327	
328	   index int array (min = 1, max = 8), 
329	     "Index value for RME HDSPM interface." card-index within ALSA
330	
331	     note: ALSA-standard
332	
333	   id string array (min = 1, max = 8), 
334	     "ID string for RME HDSPM interface."
335	
336	     note: ALSA-standard
337	
338	   enable int array (min = 1, max = 8), 
339	     "Enable/disable specific HDSPM sound-cards."
340	
341	     note: ALSA-standard
342	
343	   precise_ptr int array (min = 1, max = 8), 
344	     "Enable precise pointer, or disable."
345	
346	     note: Use only when the application supports this (which is a special case).
347	
348	   line_outs_monitor int array (min = 1, max = 8), 
349	     "Send playback streams to analog outs by default."
350	
351	
352		  note: each playback channel is mixed to the same numbered output
353		  channel (routed). This is against the ALSA-convention, where all
354		  channels have to be muted on after loading the driver, but was
355		  used before on other cards, so i historically use it again)
356	
357	
358	
359	   enable_monitor int array (min = 1, max = 8), 
360	     "Enable Analog Out on Channel 63/64 by default."
361	
362	      note: here the analog output is enabled (but not routed).
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