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 30.Os 31.Sh NAME 32.Nm pcm , 33.Nm snd 34.Nd FreeBSD PCM audio device driver 35.Sh SYNOPSIS 36For a card with bridge driver support, and a PnP card: 37.Cd "device pcm" 38.Pp 39For a card without bridge driver support, and a non-PnP card, 40the following lines may be required in 41.Pa /boot/device.hints : 42.Cd hint.pcm.0.at="isa" 43.Cd hint.pcm.0.irq="5" 44.Cd hint.pcm.0.drq="1" 45.Cd hint.pcm.0.flags="0x0" 46.Sh DESCRIPTION 47The 48.Nm 49driver provides support for PCM audio play and capture. 50This driver 51also supports various PCI and WSS/MSS compatible ISA sound cards, and 52AC97 mixer. 53True full duplex operation is available on most cards. 54.Pp 55If your sound card is supported by a bridge driver, 56.Nm 57driver works 58in conjunction with the bridge driver. 59.Pp 60Apart from the usual parameters, the flags field is used to specify 61the secondary DMA channel (generally used for capture in full duplex 62cards). Flags are set to 0 for cards not using a secondary DMA 63channel, or to 0x10 + C to specify channel C. 64.Pp 65The driver works best with WSS/MSS cards, which have a very clean 66architecture and an orthogonal set of features. 67They also happen to be 68among the cheapest audio cards on the market. 69.Pp 70The driver does its best to recognize the installed hardware and drive 71it correctly, so that you don't have to give too many details in 72.Pa /boot/device.hints . 73For PCI and ISA PnP cards this is actually easy 74since they identify themselves. 75For legacy ISA cards, the driver looks 76for MSS cards at addresses 0x530 and 0x604 (obviously, unless overridden 77in 78.Pa /boot/device.hints ) . 79.Sh IOCTL 80The driver supports most of the Voxware ioctls(), and most 81applications work unmodified (including popular mpeg players and linux 82binaries). A few 83differences exist (the most important one is the ability to use 84memory-mapped access to the audio buffers). As a consequence, some 85applications may need to be recompiled with a slightly modified 86audio module. 87See 88.In sys/soundcard.h 89for a complete list of the supported ioctls. 90.Sh SUPPORTED CARDS 91Below we include a list of supported codecs/cards. 92If your sound card 93is not listed here, it may be supported by a bridge driver. 94.Bl -tag -width 2m 95.It CS4237, CS4236, CS4232, CS4231 (ISA) 96All these cards work perfectly in full duplex using the MSS mode. 97This chipset is used, among others, on the A/Open AW35 and AW32, on 98some Intel motherboards, and (the CS4231) on some non-PnP cards. 99.Pp 100The CS4232 is reported as buggy in the Voxware documentation but 101I am not sure if this is true. 102On one of my Intel motherboards, 103capture does not work simply because the capture DMA channel is 104not wired to the ISA DMA controller. 105.It Yamaha OPL-SAx (ISA) 106Works perfectly in all modes. 107This chip is used in several PnP cards, 108but also (in non-PnP mode) on motherboards and laptops (e.g. the 109Toshiba Libretto). 110.It OPTi931 (ISA) 111The chip is buggy, but the driver has many workarounds to make it work 112in full duplex because for some time these were the only full duplex 113cards I could find. u-law formats uses U8 format internally because of 114a bug in the chip. 115.It Trident 4DWave DX/NX (PCI) 116.It ENSONIQ AudioPCI ES1370/1371 (PCI) 117Creative Labs SoundBlaster PCI is supported as well. 118.It ESS Solo-1/1E (PCI) 119.It NeoMagic 256AV/ZX (PCI) 120.El 121.Sh FILES 122The following commonly used symbolic links to real device nodes 123should be present: 124.Pp 125.Bl -tag -width /dev/sequencer -compact 126.It Pa /dev/audio 127Sparc-compatible audio device 128.It Pa /dev/dsp 129Digitized voice device 130.It Pa /dev/dspW 131Like 132.Pa /dev/dsp , 133but 16 bits per sample 134.It Pa /dev/midi 135Raw midi access device 136.It Pa /dev/mixer 137Control port mixer device 138.It Pa /dev/music 139Level 2 sequencer interface 140.It Pa /dev/sequencer 141Sequencer device 142.It Pa /dev/pss 143Programmable device interface 144.El 145.Pp 146Each symbolic link refers to a device node of the same name, 147but with a unit number appended. 148The unit number for each device matches the unit number of the 149device probed at boot time. 150Device probe messages can be examined with the 151.Xr dmesg 8 152utility. 153.Sh DIAGNOSTICS AND TROUBLESHOOTING 154.Bl -tag -width 2m 155.It ac97: dac not ready 156AC97 codec is not likely to be accompanied with the sound card. 157.It unsupported subdevice XX 158A device node is not created properly. 159.El 160.Sh BUGS 161Some features of your cards (e.g. global volume control) might not 162be supported on all devices. 163.Sh HISTORY 164The 165.Nm 166device driver first appeared in 167.Fx 2.2.6 , 168rewritten in 169.Fx 4.0 . 170.Sh SEE ALSO 171.Xr csa 4 , 172.Xr gusc 4 , 173.Xr sbc 4 , 174.Xr devfs 5 175.Sh AUTHORS 176.An Luigi Rizzo Aq luigi@iet.unipi.it 177initially wrote the 178.Nm 179device driver and this manual page. 180.An Cameron Grant Aq gandalf@vilnya.demon.co.uk 181totally revised the device driver. 182.An Seigo Tanimura Aq tanimura@r.dl.itc.u-tokyo.ac.jp 183revised this manual page. 184