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Documentation / sound / oss / Opti

Based on kernel version 2.6.26. Page generated on 2008-07-16 21:13 EST.

1	Support for the OPTi 82C931 chip
2	--------------------------------
3	Note: parts of this README file apply also to other
4	cards that use the mad16 driver.
5	
6	Some items in this README file are based on features
7	added to the sound driver after Linux-2.1.91 was out.
8	By the time of writing this I do not know which official
9	kernel release will include these features.
10	Please do not report inconsistencies on older Linux
11	kernels.
12	
13	The OPTi 82C931 is supported in its non-PnP mode.
14	Usually you do not need to set jumpers, etc. The sound driver
15	will check the card status and if it is required it will
16	force the card into a mode in which it can be programmed.
17	
18	If you have another OS installed on your computer it is recommended
19	that Linux and the other OS use the same resources.
20	
21	Also, it is recommended that resources specified in /etc/modprobe.conf
22	and resources specified in /etc/isapnp.conf agree.
23	
24	Compiling the sound driver
25	--------------------------
26	I highly recommend that you build a modularized sound driver.
27	This document does not cover a sound-driver which is built in
28	the kernel.
29	
30	Sound card support should be enabled as a module (chose m).
31	Answer 'm' for  these items:
32	  Generic OPL2/OPL3 FM synthesizer support		(CONFIG_SOUND_ADLIB)
33	  Microsoft Sound System support			(CONFIG_SOUND_MSS)
34	  Support for OPTi MAD16 and/or Mozart based cards	(CONFIG_SOUND_MAD16)
35	  FM synthesizer (YM3812/OPL-3) support			(CONFIG_SOUND_YM3812)
36	
37	The configuration menu may ask for addresses, IRQ lines or DMA
38	channels. If the card is used as a module the module loading
39	options will override these values.
40	
41	For the OPTi 931 you can answer 'n' to:
42	  Support MIDI in older MAD16 based cards (requires SB)	(CONFIG_SOUND_MAD16_OLDCARD)
43	If you do need MIDI support in a Mozart or C928 based card you
44	need to answer 'm' to the above question. In that case you will
45	also need to answer 'm' to:
46	  '100% Sound Blaster compatibles (SB16/32/64, ESS, Jazz16) support' (CONFIG_SOUND_SB)
47	
48	Go on and compile your kernel and modules. Install the modules. Run depmod -a.
49	
50	Using isapnptools
51	-----------------
52	In most systems with a PnP BIOS you do not need to use isapnp. The
53	initialization provided by the BIOS is sufficient for the driver
54	to pick up the card and continue initialization.
55	
56	If that fails, or if you have other PnP cards, you need to use isapnp
57	to initialize the card.
58	This was tested with isapnptools-1.11 but I recommend that you use
59	isapnptools-1.13 (or newer). Run pnpdump to dump the information
60	about your PnP cards. Then edit the resulting file and select
61	the options of your choice. This file is normally installed as
62	/etc/isapnp.conf.
63	
64	The driver has one limitation with respect to I/O port resources:
65	IO3 base must be 0x0E0C.  Although isapnp allows other ports, this
66	address is hard-coded into the driver.
67	
68	Using kmod and autoloading the sound driver
69	-------------------------------------------
70	Comment: as of linux-2.1.90 kmod is replacing kerneld.
71	The config file '/etc/modprobe.conf' is used as before.
72	
73	This is the sound part of my /etc/modprobe.conf file.
74	Following that I will explain each line.
75	
76	alias mixer0 mad16
77	alias audio0 mad16
78	alias midi0  mad16
79	alias synth0 opl3
80	options sb mad16=1
81	options mad16 irq=10 dma=0 dma16=1 io=0x530 joystick=1 cdtype=0
82	options opl3 io=0x388
83	install mad16 /sbin/modprobe -i mad16 && /sbin/ad1848_mixer_reroute 14 8 15 3 16 6
84	
85	If you have an MPU daughtercard or onboard MPU you will want to add to the
86	"options mad16" line - eg 
87	
88	options mad16 irq=5 dma=0 dma16=3 io=0x530 mpu_io=0x330 mpu_irq=9
89	
90	To set the I/O and IRQ of the MPU.
91	
92	
93	Explain:
94	
95	alias mixer0 mad16
96	alias audio0 mad16
97	alias midi0  mad16
98	alias synth0 opl3
99	
100	When any sound device is opened the kernel requests auto-loading
101	of char-major-14. There is a built-in alias that translates this
102	request to loading the main sound module.
103	
104	The sound module in its turn will request loading of a sub-driver
105	for mixer, audio, midi or synthesizer device. The first 3 are
106	supported by the mad16 driver. The synth device is supported
107	by the opl3 driver.
108	
109	There is currently no way to autoload the sound device driver
110	if more than one card is installed.
111	
112	options sb mad16=1
113	
114	This is left for historical reasons. If you enable the
115	config option 'Support MIDI in older MAD16 based cards (requires SB)'
116	or if you use an older mad16 driver it will force loading of the
117	SoundBlaster driver. This option tells the SB driver not to look
118	for a SB card but to wait for the mad16 driver.
119	
120	options mad16 irq=10 dma=0 dma16=1 io=0x530 joystick=1 cdtype=0
121	options opl3 io=0x388
122	
123	post-install mad16 /sbin/ad1848_mixer_reroute 14 8 15 3 16 6
124	
125	This sets resources and options for the mad16 and opl3 drivers.
126	I use two DMA channels (only one is required) to enable full duplex.
127	joystick=1 enables the joystick port. cdtype=0 disables the cd port.
128	You can also set mpu_io and mpu_irq in the mad16 options for the
129	uart401 driver.
130	
131	This tells modprobe to run /sbin/ad1848_mixer_reroute after
132	mad16 is successfully loaded and initialized. The source
133	for ad1848_mixer_reroute is appended to the end of this readme
134	file. It is impossible for the sound driver to know the actual
135	connections to the mixer. The 3 inputs intended for cd, synth
136	and line-in are mapped to the generic inputs line1, line2 and
137	line3. This program reroutes these mixer channels to their
138	right names (note the right mapping depends on the actual sound
139	card that you use).
140	The numeric parameters mean:
141	 14=line1 8=cd    - reroute line1 to the CD input.
142	 15=line2 3=synth - reroute line2 to the synthesizer input.
143	 16=line3 6=line  - reroute line3 to the line input.
144	For reference on other input names look at the file
145	/usr/include/linux/soundcard.h.
146	
147	Using a joystick
148	-----------------
149	You must enable a joystick in the mad16 options. (also
150	in /etc/isapnp.conf if you use it).
151	Tested with regular analog joysticks.
152	
153	A CDROM drive connected to the sound card
154	-----------------------------------------
155	The 82C931 chip has support only for secondary ATAPI cdrom.
156	(cdtype=8). Loading the mad16 driver resets the C931 chip
157	and if a cdrom was already mounted it may cause a complete
158	system hang. Do not use the sound card if you have an alternative.
159	If you do use the sound card it is important that you load
160	the mad16 driver (use "modprobe mad16" to prevent auto-unloading)
161	before the cdrom is accessed the first time.
162	
163	Using the sound driver built-in to the kernel may help here, but...
164	Most new systems have a PnP BIOS and also two IDE controllers.
165	The IDE controller on the sound card may be needed only on older
166	systems (which have only one IDE controller) but these systems
167	also do not have a PnP BIOS - requiring isapnptools and a modularized
168	driver.
169	
170	Known problems
171	--------------
172	1. See the section on "A CDROM drive connected to the sound card".
173	
174	2. On my system the codec cannot capture companded sound samples.
175	   (eg., recording from /dev/audio). When any companded capture is
176	   requested I get stereo-16 bit samples instead. Playback of
177	   companded samples works well. Apparently this problem is not common
178	   to all C931 based cards. I do not know how to identify cards that
179	   have this problem.
180	
181	Source for ad1848_mixer_reroute.c
182	---------------------------------
183	#include <stdio.h>
184	#include <fcntl.h>
185	#include <linux/soundcard.h>
186	
187	static char *mixer_names[SOUND_MIXER_NRDEVICES] =
188		SOUND_DEVICE_LABELS;
189	
190	int
191	main(int argc, char **argv) {
192		int val, from, to;
193		int i, fd;
194	
195		fd = open("/dev/mixer", O_RDWR);
196		if(fd < 0) {
197			perror("/dev/mixer");
198			return 1;
199		}
200	
201		for(i = 2; i < argc; i += 2) {
202			from = atoi(argv[i-1]);
203			to = atoi(argv[i]);
204	
205			if(to == SOUND_MIXER_NONE)
206				fprintf(stderr, "%s: turning off mixer %s\n",
207					argv[0], mixer_names[to]);
208			else
209				fprintf(stderr, "%s: rerouting mixer %s to %s\n",
210					argv[0], mixer_names[from], mixer_names[to]);
211	
212			val = from << 8 | to;
213	
214			if(ioctl(fd, SOUND_MIXER_PRIVATE2, &val)) {
215				perror("AD1848 mixer reroute");
216				return 1;
217			}
218		}
219	
220		return 0;
221	}
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