path: root/sound/oss/aedsp16.c

/*
   sound/oss/aedsp16.c

   Audio Excel DSP 16 software configuration routines
   Copyright (C) 1995,1996,1997,1998  Riccardo Facchetti (fizban@tin.it)

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 2 of the License, or
   (at your option) any later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.

 */
/*
 * Include the main OSS Lite header file. It include all the os, OSS Lite, etc
 * headers needed by this source.
 */
#include <linux/delay.h>
#include <linux/module.h>
#include <linux/init.h>
#include "sound_config.h"

/*

   READ THIS

   This module started to configure the Audio Excel DSP 16 Sound Card.
   Now works with the SC-6000 (old aedsp16) and new SC-6600 based cards.

   NOTE: I have NO idea about Audio Excel DSP 16 III. If someone owns this
   audio card and want to see the kernel support for it, please contact me.

   Audio Excel DSP 16 is an SB pro II, Microsoft Sound System and MPU-401
   compatible card.
   It is software-only configurable (no jumpers to hard-set irq/dma/mpu-irq),
   so before this module, the only way to configure the DSP under linux was
   boot the MS-DOS loading the sound.sys device driver (this driver soft-
   configure the sound board hardware by massaging someone of its registers),
   and then ctrl-alt-del to boot linux with the DSP configured by the DOS
   driver.

   This module works configuring your Audio Excel DSP 16's irq, dma and
   mpu-401-irq. The OSS Lite routines rely on the fact that if the
   hardware is there, they can detect it. The problem with AEDSP16 is
   that no hardware can be found by the probe routines if the sound card
   is not configured properly. Sometimes the kernel probe routines can find
   an SBPRO even when the card is not configured (this is the standard setup
   of the card), but the SBPRO emulation don't work well if the card is not
   properly initialized. For this reason

   aedsp16_init_board()

   routine is called before the OSS Lite probe routines try to detect the
   hardware.

   NOTE (READ THE NOTE TOO, IT CONTAIN USEFUL INFORMATIONS)

   NOTE: Now it works with SC-6000 and SC-6600 based audio cards. The new cards
   have no jumper switch at all. No more WSS or MPU-401 I/O port switches. They
   have to be configured by software.

   NOTE: The driver is merged with the new OSS Lite sound driver. It works
   as a lowlevel driver.

   The Audio Excel DSP 16 Sound Card emulates both SBPRO and MSS;
   the OSS Lite sound driver can be configured for SBPRO and MSS cards
   at the same time, but the aedsp16 can't be two cards!!
   When we configure it, we have to choose the SBPRO or the MSS emulation
   for AEDSP16. We also can install a *REAL* card of the other type (see [1]).

   NOTE: If someone can test the combination AEDSP16+MSS or AEDSP16+SBPRO
   please let me know if it works.

   The MPU-401 support can be compiled in together with one of the other
   two operating modes.

   NOTE: This is something like plug-and-play: we have only to plug
   the AEDSP16 board in the socket, and then configure and compile
   a kernel that uses the AEDSP16 software configuration capability.
   No jumper setting is needed!

   For example, if you want AEDSP16 to be an SBPro, on irq 10, dma 3
   you have just to make config the OSS Lite package, configuring
   the AEDSP16 sound card, then activating the SBPro emulation mode
   and at last configuring IRQ and DMA.
   Compile the kernel and run it.

   NOTE: This means for SC-6000 cards that you can choose irq and dma,
   but not the I/O addresses. To change I/O addresses you have to set
   them with jumpers. For SC-6600 cards you have no jumpers so you have
   to set up your full card configuration in the make config.

   You can change the irq/dma/mirq settings WITHOUT THE NEED to open
   your computer and massage the jumpers (there are no irq/dma/mirq
   jumpers to be configured anyway, only I/O BASE values have to be
   configured with jumpers)

   For some ununderstandable reason, the card default of irq 7, dma 1,
   don't work for me. Seems to be an IRQ or DMA conflict. Under heavy
   HDD work, the kernel start to erupt out a lot of messages like:

   'Sound: DMA timed out - IRQ/DRQ config error?'

   For what I can say, I have NOT any conflict at irq 7 (under linux I'm
   using the lp polling driver), and dma line 1 is unused as stated by
   /proc/dma. I can suppose this is a bug of AEDSP16. I know my hardware so
   I'm pretty sure I have not any conflict, but may be I'm wrong. Who knows!
   Anyway a setting of irq 10, dma 3 works really fine.

   NOTE: if someone can use AEDSP16 with irq 7, dma 1, please let me know
   the emulation mode, all the installed hardware and the hardware
   configuration (irq and dma settings of all the hardware).

   This init module should work with SBPRO+MSS, when one of the two is
   the AEDSP16 emulation and the other the real card. (see [1])
   For example:

   AEDSP16 (0x220) in SBPRO emu (0x220) + real MSS + other
   AEDSP16 (0x220) in MSS emu + real SBPRO (0x240) + other

   MPU401 should work. (see [2])

   [1]
       ---
       Date: Mon, 29 Jul 1997 08:35:40 +0100
       From: Mr S J Greenaway <sjg95@unixfe.rl.ac.uk>

       [...]
       Just to let you know got my Audio Excel (emulating a MSS) working
       with my original SB16, thanks for the driver!
       [...]
       ---

   [2] Not tested by me for lack of hardware.

   TODO, WISHES AND TECH

   - About I/O ports allocation -

   Request the 2x0h region (port base) in any case if we are using this card.

   NOTE: the "aedsp16 (base)" string with which we are requesting the aedsp16
   port base region (see code) does not mean necessarily that we are emulating
   sbpro.  Even if this region is the sbpro I/O ports region, we use this
   region to access the control registers of the card, and if emulating
   sbpro, I/O sbpro registers too. If we are emulating MSS, the sbpro