1.\" 2.\" Copyright (c) 1998, Luigi Rizzo 3.\" All rights reserved. 4.\" 5.\" Redistribution and use in source and binary forms, with or without 6.\" modification, are permitted provided that the following conditions 7.\" are met: 8.\" 1. Redistributions of source code must retain the above copyright 9.\" notice, this list of conditions and the following disclaimer. 10.\" 2. Redistributions in binary form must reproduce the above copyright 11.\" notice, this list of conditions and the following disclaimer in the 12.\" documentation and/or other materials provided with the distribution. 13.\" 14.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17.\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24.\" SUCH DAMAGE. 25.\" 26.\" $FreeBSD$ 27.\" 28.Dd June 3, 1998 29.Dt PCM 4 i386 30.Os FreeBSD 31.Sh NAME 32.Nm pcm 33.Nd FreeBSD audio device driver 34.Sh SYNOPSIS 35.Cd "device pcm0 at isa? port? irq 5 drq 1 flags 0x15" 36.Sh DESCRIPTION 37The 38.Nm pcm 39driver provides support for various ISA sound cards that are compatible 40with the WSS/MSS specs, or with the SBPro and SB16. Only audio 41capture/playback is supported by the driver, and true full duplex 42operation is available on most cards. 43.Pp 44Apart from the usual parameters, the flags field is used to specify 45the secondary DMA channel (generally used for capture in full duplex 46cards). Flags are set to 0 for cards not using a secondary DMA 47channel, or to 0x10 + C to specify channel C. 48.Pp 49PnP audio cards are also supported using the 50.Nm pnp 51support which is available in FreeBSD starting from release 2.2.6. 52See the 53.Xr pnp 4 54manpage for more information. In particular, remember that unit 55numbers for (recognized) 56PnP cards are assigned after the legacy ISA devices, and that the 57actual resources (port, irq and drq) used by the driver are read from 58the PnP configuration and not from the "device pcm0" line. 59So, if you have the following line in your kernel config file: 60.Pp 61.Cd "device pcm0 ..." 62.Pp 63your first PnP audio card will be unit #1, i.e. it will be accessible 64as /dev/audio1, /dev/dsp1, etc. 65Many applications default to using /dev/audio, but appropriate 66symlinks will be created as a side-effect of the the following command: 67.Pp 68.Cd cd /dev 69.Cd ./MAKEDEV snd1 70.Pp 71The driver works best with WSS/MSS cards, which have a very clean 72architecture and an orthogonal set of features. They also happen to be 73among the cheapest audio cards on the market. 74Other cards such as SB and ESS have a more complex internal 75architecture, and often no documentation available. As a consequence, 76support for these cards is slightly worse. 77.Pp 78The driver does its best to recognize the installed harware and drive 79it correctly, so that you don't have to give too many details in the 80kernel config files. For PnP cards this is actually easy since they 81identify themselves. For legacy ISA cards, the driver first looks for 82MSS cards at addresses 0x530 and 0x604, then for SB 83cards at 0x220 and 0x240 (obviously, unless overridden in the kernel 84config file by specifying an address). 85 86.Sh IOCTL 87The driver supports most of the Voxware ioctls(), and most 88applications work unmodified (including popular mpeg players and linux 89binaries). A few 90differences exist (the most important one is the ability to use 91memory-mapped access to the audio buffers). As a consequence, some 92applications may need to be recompiled with a slightly modified 93audio module. See /usr/include/machine/soundcard.h for a complete 94list of the supported ioctls. 95 96.Sh SUPPORTED CARDS 97.Pp 98Below we include a list of supported codecs/cards, including, if 99possible, the pnp configuration information where applicable 100(we give default parameters, your actual resources may vary). 101 102.Bl -tag -width 2m % begin list 103.It CS4237, CS4236, CS4232, CS4231 104.Cd "pnp 1 0 os enable port0 0x534 port2 0x220 irq0 5 drq0 1 drq1 3" 105.Pp 106All these cards work perfectly in full duplex using the MSS mode. 107This chipset is used, among others, on the A/Open AW35 and AW32, on 108some Intel motherboards, and (the CS4231) on some non-PnP cards. 109.Pp 110The CS4232 is reported as buggy in the Voxware documentation but 111I am not sure if this is true. On one of my Intel motherboards, 112capture does not work simply because the capture DMA channel is 113not wired to the ISA DMA controller. 114 115.It GUSPnP 116.Cd "pnp 1 0 os enable port0 0x220 port1 0x320 port2 0x32c irq0 5 drq0 7 drq1 5" 117.Pp 118Supported in full duplex using the MSS mode. The GUSPnP does not use a 119real CS4231, and I suspect a bug in the emulation when operating 120with mu-law format. Since the card is discontinued, I did not bother 121to include special code to set the card in "Mode3" (where mu-law is 122known to work) and rather I use U8 format internally, and do the 123conversion in software within the driver. This loses resolution, 124so you should use 16-bit modes with this card when possible. 125 126.It Yamaha OPL-SAx 127.Cd "pnp 1 0 os enable port0 0x220 port1 0x530 port2 0x388 port3 0x370 irq0 5 drq0 1 drq1 3" 128.Pp 129Works perfectly in all modes. This chip is used in several PnP cards, 130but also (in non-PnP mode) on motherboards and laptops (e.g. the 131Toshiba Libretto). 132 133.It OPTi931 134.Cd "pnp 1 1 os enable port0 0x534 port2 0x220 port3 0xe0d irq0 10 drq0 1 drq1 6" 135.Pp 136The chip is buggy, but the driver has many workarounds to make it work 137in full duplex because for some time these were the only full duplex 138cards I could find. u-law formats uses U8 format internally because of 139a bug in the chip. 140 141.It SB16, Vibra16C, and old SB16/AWExx cards 142.Cd "pnp 1 0 os enable port0 0x220 irq0 5 drq0 1 drq1 5" 143.Pp 144These codecs have limited full duplex capabilities, by doing 8-bit 145in one direction and 16-bit in the other one. The driver supports this 146mode of operation but keep in mind that it is not a supported mode of 147operation from CreativeLabs. 148 149.It Vibra16X and newer SB16/AWExx cards 150.Cd "pnp 1 0 os enable port0 0x220 irq0 5 drq0 1 drq1 3" 151.Pp 152Recently CreativeLabs has changed the codec (DSP) and the new one is 153somewhat different from the old one. The most apparent difference is 154the use of two 8-bit DMA channels, which seems to have broken our full 155duplex support. Maybe one can achieve full duplex by making use of the 156wavetable to play audio, but since this driver does not support the 157wavetable you have to stick with half duplex. 158 159.It SBPro and clones 160This is the default mode of operation for most other cards. We have 161only limited (and possibly buggy) support for them: 8-bit, half 162duplex, even if the hardware in some cases (e.g. ESS chips) might do more. 163.El 164.Pp 165.Sh DIAGNOSTICS AND TROUBLESHOOTING 166.Bl -tag -width 2m 167.It "This is XXX but LDN Y is disabled" 168.Pp 169This means that the bios has left the PnP device disabled, and you 170have to enable it manually booting with "-c" and giving the pnp 171configuration shown above. 172.It "pcmX: unit not configured, perhaps you want pcmY ?" 173This means that you are using the wrong unit. Generally this happens 174when you are using a PnP card without creating the symlinks to the 175correct unit. Re-create the symlinks (and possibly also the device 176entries) in the /dev directory to point to the right one. 177 178.It "timeout flushing dbuf_out ..." 179This means a problem in the configuration of the card (specifically, 180in the DMA channel) or (much less likely) in the driver, which has 181not recognized the card correctly. Check the DMA channel used for 182capture. 183 184.It capture does not work 185This usually happens when the input dma channel is misconfigured. 186 187.El 188.Sh BUGS 189Due to lack of documentation, 190SB16 support is not very good. Also, mixer support is not complete, 191and some features of your cards (e.g. global volume control) might not 192be supported on all devices. 193.Sh HISTORY 194The 195.Nm pcm 196device driver first appeared in 197.Fx 2.2.6 198.Sh AUTHORS 199The 200.Nm 201device driver and this manual page were written by 202.An Luigi Rizzo Aq luigi@iet.unipi.it 203