| Support for the OPTi 82C931 chip |
| -------------------------------- |
| Note: parts of this README file apply also to other |
| cards that use the mad16 driver. |
| |
| Some items in this README file are based on features |
| added to the sound driver after Linux-2.1.91 was out. |
| By the time of writing this I do not know which official |
| kernel release will include these features. |
| Please do not report inconsistencies on older Linux |
| kernels. |
| |
| The OPTi 82C931 is supported in its non-PnP mode. |
| Usually you do not need to set jumpers, etc. The sound driver |
| will check the card status and if it is required it will |
| force the card into a mode in which it can be programmed. |
| |
| If you have another OS installed on your computer it is recommended |
| that Linux and the other OS use the same resources. |
| |
| Also, it is recommended that resources specified in /etc/modprobe.conf |
| and resources specified in /etc/isapnp.conf agree. |
| |
| Compiling the sound driver |
| -------------------------- |
| I highly recommend that you build a modularized sound driver. |
| This document does not cover a sound-driver which is built in |
| the kernel. |
| |
| Sound card support should be enabled as a module (chose m). |
| Answer 'm' for these items: |
| Generic OPL2/OPL3 FM synthesizer support (CONFIG_SOUND_ADLIB) |
| Microsoft Sound System support (CONFIG_SOUND_MSS) |
| Support for OPTi MAD16 and/or Mozart based cards (CONFIG_SOUND_MAD16) |
| FM synthesizer (YM3812/OPL-3) support (CONFIG_SOUND_YM3812) |
| |
| The configuration menu may ask for addresses, IRQ lines or DMA |
| channels. If the card is used as a module the module loading |
| options will override these values. |
| |
| For the OPTi 931 you can answer 'n' to: |
| Support MIDI in older MAD16 based cards (requires SB) (CONFIG_SOUND_MAD16_OLDCARD) |
| If you do need MIDI support in a Mozart or C928 based card you |
| need to answer 'm' to the above question. In that case you will |
| also need to answer 'm' to: |
| '100% Sound Blaster compatibles (SB16/32/64, ESS, Jazz16) support' (CONFIG_SOUND_SB) |
| |
| Go on and compile your kernel and modules. Install the modules. Run depmod -a. |
| |
| Using isapnptools |
| ----------------- |
| In most systems with a PnP BIOS you do not need to use isapnp. The |
| initialization provided by the BIOS is sufficient for the driver |
| to pick up the card and continue initialization. |
| |
| If that fails, or if you have other PnP cards, you need to use isapnp |
| to initialize the card. |
| This was tested with isapnptools-1.11 but I recommend that you use |
| isapnptools-1.13 (or newer). Run pnpdump to dump the information |
| about your PnP cards. Then edit the resulting file and select |
| the options of your choice. This file is normally installed as |
| /etc/isapnp.conf. |
| |
| The driver has one limitation with respect to I/O port resources: |
| IO3 base must be 0x0E0C. Although isapnp allows other ports, this |
| address is hard-coded into the driver. |
| |
| Using kmod and autoloading the sound driver |
| ------------------------------------------- |
| Comment: as of linux-2.1.90 kmod is replacing kerneld. |
| The config file '/etc/modprobe.conf' is used as before. |
| |
| This is the sound part of my /etc/modprobe.conf file. |
| Following that I will explain each line. |
| |
| alias mixer0 mad16 |
| alias audio0 mad16 |
| alias midi0 mad16 |
| alias synth0 opl3 |
| options sb mad16=1 |
| options mad16 irq=10 dma=0 dma16=1 io=0x530 joystick=1 cdtype=0 |
| options opl3 io=0x388 |
| install mad16 /sbin/modprobe -i mad16 && /sbin/ad1848_mixer_reroute 14 8 15 3 16 6 |
| |
| If you have an MPU daughtercard or onboard MPU you will want to add to the |
| "options mad16" line - eg |
| |
| options mad16 irq=5 dma=0 dma16=3 io=0x530 mpu_io=0x330 mpu_irq=9 |
| |
| To set the I/O and IRQ of the MPU. |
| |
| |
| Explain: |
| |
| alias mixer0 mad16 |
| alias audio0 mad16 |
| alias midi0 mad16 |
| alias synth0 opl3 |
| |
| When any sound device is opened the kernel requests auto-loading |
| of char-major-14. There is a built-in alias that translates this |
| request to loading the main sound module. |
| |
| The sound module in its turn will request loading of a sub-driver |
| for mixer, audio, midi or synthesizer device. The first 3 are |
| supported by the mad16 driver. The synth device is supported |
| by the opl3 driver. |
| |
| There is currently no way to autoload the sound device driver |
| if more than one card is installed. |
| |
| options sb mad16=1 |
| |
| This is left for historical reasons. If you enable the |
| config option 'Support MIDI in older MAD16 based cards (requires SB)' |
| or if you use an older mad16 driver it will force loading of the |
| SoundBlaster driver. This option tells the SB driver not to look |
| for a SB card but to wait for the mad16 driver. |
| |
| options mad16 irq=10 dma=0 dma16=1 io=0x530 joystick=1 cdtype=0 |
| options opl3 io=0x388 |
| |
| post-install mad16 /sbin/ad1848_mixer_reroute 14 8 15 3 16 6 |
| |
| This sets resources and options for the mad16 and opl3 drivers. |
| I use two DMA channels (only one is required) to enable full duplex. |
| joystick=1 enables the joystick port. cdtype=0 disables the cd port. |
| You can also set mpu_io and mpu_irq in the mad16 options for the |
| uart401 driver. |
| |
| This tells modprobe to run /sbin/ad1848_mixer_reroute after |
| mad16 is successfully loaded and initialized. The source |
| for ad1848_mixer_reroute is appended to the end of this readme |
| file. It is impossible for the sound driver to know the actual |
| connections to the mixer. The 3 inputs intended for cd, synth |
| and line-in are mapped to the generic inputs line1, line2 and |
| line3. This program reroutes these mixer channels to their |
| right names (note the right mapping depends on the actual sound |
| card that you use). |
| The numeric parameters mean: |
| 14=line1 8=cd - reroute line1 to the CD input. |
| 15=line2 3=synth - reroute line2 to the synthesizer input. |
| 16=line3 6=line - reroute line3 to the line input. |
| For reference on other input names look at the file |
| /usr/include/linux/soundcard.h. |
| |
| Using a joystick |
| ----------------- |
| You must enable a joystick in the mad16 options. (also |
| in /etc/isapnp.conf if you use it). |
| Tested with regular analog joysticks. |
| |
| A CDROM drive connected to the sound card |
| ----------------------------------------- |
| The 82C931 chip has support only for secondary ATAPI cdrom. |
| (cdtype=8). Loading the mad16 driver resets the C931 chip |
| and if a cdrom was already mounted it may cause a complete |
| system hang. Do not use the sound card if you have an alternative. |
| If you do use the sound card it is important that you load |
| the mad16 driver (use "modprobe mad16" to prevent auto-unloading) |
| before the cdrom is accessed the first time. |
| |
| Using the sound driver built-in to the kernel may help here, but... |
| Most new systems have a PnP BIOS and also two IDE controllers. |
| The IDE controller on the sound card may be needed only on older |
| systems (which have only one IDE controller) but these systems |
| also do not have a PnP BIOS - requiring isapnptools and a modularized |
| driver. |
| |
| Known problems |
| -------------- |
| 1. See the section on "A CDROM drive connected to the sound card". |
| |
| 2. On my system the codec cannot capture companded sound samples. |
| (eg., recording from /dev/audio). When any companded capture is |
| requested I get stereo-16 bit samples instead. Playback of |
| companded samples works well. Apparently this problem is not common |
| to all C931 based cards. I do not know how to identify cards that |
| have this problem. |
| |
| Source for ad1848_mixer_reroute.c |
| --------------------------------- |
| #include <stdio.h> |
| #include <fcntl.h> |
| #include <linux/soundcard.h> |
| |
| static char *mixer_names[SOUND_MIXER_NRDEVICES] = |
| SOUND_DEVICE_LABELS; |
| |
| int |
| main(int argc, char **argv) { |
| int val, from, to; |
| int i, fd; |
| |
| fd = open("/dev/mixer", O_RDWR); |
| if(fd < 0) { |
| perror("/dev/mixer"); |
| return 1; |
| } |
| |
| for(i = 2; i < argc; i += 2) { |
| from = atoi(argv[i-1]); |
| to = atoi(argv[i]); |
| |
| if(to == SOUND_MIXER_NONE) |
| fprintf(stderr, "%s: turning off mixer %s\n", |
| argv[0], mixer_names[to]); |
| else |
| fprintf(stderr, "%s: rerouting mixer %s to %s\n", |
| argv[0], mixer_names[from], mixer_names[to]); |
| |
| val = from << 8 | to; |
| |
| if(ioctl(fd, SOUND_MIXER_PRIVATE2, &val)) { |
| perror("AD1848 mixer reroute"); |
| return 1; |
| } |
| } |
| |
| return 0; |
| } |
| |