linux/sound/pci/cs5530.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * cs5530.c - Initialisation code for Cyrix/NatSemi VSA1 softaudio
 *
 * 	(C) Copyright 2007 Ash Willis <[email protected]>
 *	(C) Copyright 2003 Red Hat Inc <[email protected]>
 *
 * This driver was ported (shamelessly ripped ;) from oss/kahlua.c but I did
 * mess with it a bit. The chip seems to have to have trouble with full duplex
 * mode. If we're recording in 8bit 8000kHz, say, and we then attempt to
 * simultaneously play back audio at 16bit 44100kHz, the device actually plays
 * back in the same format in which it is capturing. By forcing the chip to
 * always play/capture in 16/44100, we can let alsa-lib convert the samples and
 * that way we can hack up some full duplex audio. 
 * 
 * XpressAudio(tm) is used on the Cyrix MediaGX (now NatSemi Geode) systems.
 * The older version (VSA1) provides fairly good soundblaster emulation
 * although there are a couple of bugs: large DMA buffers break record,
 * and the MPU event handling seems suspect. VSA2 allows the native driver
 * to control the AC97 audio engine directly and requires a different driver.
 *
 * Thanks to National Semiconductor for providing the needed information
 * on the XpressAudio(tm) internals.
 *
 * TO DO:
 *	Investigate whether we can portably support Cognac (5520) in the
 *	same manner.
 */

#include <linux/delay.h>
#include <linux/module.h>
#include <linux/pci.h>
#include <linux/slab.h>
#include <sound/core.h>
#include <sound/sb.h>
#include <sound/initval.h>

MODULE_AUTHOR(…) …;
MODULE_DESCRIPTION(…) …;
MODULE_LICENSE(…) …;

static int index[SNDRV_CARDS] = …;
static char *id[SNDRV_CARDS] = …;
static bool enable[SNDRV_CARDS] = …;

module_param_array(…);
MODULE_PARM_DESC(…) …;
module_param_array(…);
MODULE_PARM_DESC(…) …;
module_param_array(…);
MODULE_PARM_DESC(…) …;

struct snd_cs5530 { … };

static const struct pci_device_id snd_cs5530_ids[] = …;

MODULE_DEVICE_TABLE(pci, snd_cs5530_ids);

static u8 snd_cs5530_mixer_read(unsigned long io, u8 reg)
{ … }

static int snd_cs5530_create(struct snd_card *card,
			     struct pci_dev *pci)
{ … }

static int snd_cs5530_probe(struct pci_dev *pci,
			    const struct pci_device_id *pci_id)
{ … }

static struct pci_driver cs5530_driver = …;

module_pci_driver(…) …;