PATCH: Add Kahlua audio from 2.4

[Alan Cox]

This is slightly weird. Its a legacy sound blaster device living
in non PCI space driven by SMM magic glue controlling real invisible
hardware.

diff -u --new-file --recursive --exclude-from /usr/src/exclude linux-2.5.75/sound/oss/kahlua.c linux-2.5.75-ac1/sound/oss/kahlua.c
--- linux-2.5.75/sound/oss/kahlua.c	1970-01-01 01:00:00.000000000 +0100
+++ linux-2.5.75-ac1/sound/oss/kahlua.c	2003-07-11 16:47:05.000000000 +0100
@@ -0,0 +1,230 @@
+/*
+ *	Initialisation code for Cyrix/NatSemi VSA1 softaudio
+ *
+ *	(C) Copyright 2003 Red Hat Inc <[e-mail]>
+ *
+ * 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.
+ *
+ * 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, 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.
+ *
+ * For the avoidance of doubt the "preferred form" of this code is one which
+ * is in an open non patent encumbered format. Where cryptographic key signing
+ * forms part of the process of creating an executable the information
+ * including keys needed to generate an equivalently functional executable
+ * are deemed to be part of the source code.
+ *
+ * TO DO:
+ *	Investigate whether we can portably support Cognac (5520) in the
+ *	same manner.
+ */
+
+#include <linux/config.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/pci.h>
+
+#include "sound_config.h"
+
+#include "sb.h"
+
+/*
+ *	Read a soundblaster compatible mixer register.
+ *	In this case we are actually reading an SMI trap
+ *	not real hardware.
+ */
+
+static u8 __devinit mixer_read(unsigned long io, u8 reg)
+{
+	outb(reg, io + 4);
+	udelay(20);
+	reg = inb(io + 5);
+	udelay(20);
+	return reg;
+}
+
+static int __devinit probe_one(struct pci_dev *pdev, const struct pci_device_id *ent)
+{
+	struct address_info *hw_config;
+	unsigned long base;
+	void *mem;
+	unsigned long io;
+	u16 map;
+	u8 irq, dma8, dma16;
+	int oldquiet;
+	extern int sb_be_quiet;
+		
+	base = pci_resource_start(pdev, 0);
+	if(base == 0UL)
+		return 1;
+	
+	mem = ioremap(base, 128);
+	if(mem == 0UL)
+		return 1;
+	map = readw(mem + 0x18);	/* Read the SMI enables */
+	iounmap(mem);
+	
+	/* Map bits
+		0:1	* 0x20 + 0x200 = sb base
+		2	sb enable
+		3	adlib enable
+		5	MPU enable 0x330
+		6	MPU enable 0x300
+		
+	   The other bits may be used internally so must be masked */
+
+	io = 0x220 + 0x20 * (map & 3);	   
+	
+	if(map & (1<<2))
+		printk(KERN_INFO "kahlua: XpressAudio at 0x%lx\n", io);
+	else
+		return 1;
+		
+	if(map & (1<<5))
+		printk(KERN_INFO "kahlua: MPU at 0x300\n");
+	else if(map & (1<<6))
+		printk(KERN_INFO "kahlua: MPU at 0x330\n");
+	
+	irq = mixer_read(io, 0x80) & 0x0F;
+	dma8 = mixer_read(io, 0x81);
+
+	// printk("IRQ=%x MAP=%x DMA=%x\n", irq, map, dma8);
+	
+	if(dma8 & 0x20)
+		dma16 = 5;
+	else if(dma8 & 0x40)
+		dma16 = 6;
+	else if(dma8 & 0x80)
+		dma16 = 7;
+	else
+	{
+		printk(KERN_ERR "kahlua: No 16bit DMA enabled.\n");
+		return 1;
+	}
+		
+	if(dma8 & 0x01)
+		dma8 = 0;
+	else if(dma8 & 0x02)
+		dma8 = 1;
+	else if(dma8 & 0x08)
+		dma8 = 3;
+	else
+	{
+		printk(KERN_ERR "kahlua: No 8bit DMA enabled.\n");
+		return 1;
+	}
+	
+	if(irq & 1)
+		irq = 9;
+	else if(irq & 2)
+		irq = 5;
+	else if(irq & 4)
+		irq = 7;
+	else if(irq & 8)
+		irq = 10;
+	else
+	{
+		printk(KERN_ERR "kahlua: SB IRQ not set.\n");
+		return 1;
+	}
+	
+	printk(KERN_INFO "kahlua: XpressAudio on IRQ %d, DMA %d, %d\n",
+		irq, dma8, dma16);
+	
+	hw_config = kmalloc(sizeof(struct address_info), GFP_KERNEL);
+	if(hw_config == NULL)
+	{
+		printk(KERN_ERR "kahlua: out of memory.\n");
+		return 1;
+	}
+	memset(hw_config, 0, sizeof(*hw_config));
+	
+	pci_set_drvdata(pdev, hw_config);
+	
+	hw_config->io_base = io;
+	hw_config->irq = irq;
+	hw_config->dma = dma8;
+	hw_config->dma2 = dma16;
+	hw_config->name = "Cyrix XpressAudio";
+	hw_config->driver_use_1 = SB_NO_MIDI | SB_PCI_IRQ;
+	
+	if(sb_dsp_detect(hw_config, 0, 0, NULL)==0)
+	{
+		printk(KERN_ERR "kahlua: audio not responding.\n");
+		return 1;
+	}
+
+	oldquiet = sb_be_quiet;	
+	sb_be_quiet = 1;
+	if(sb_dsp_init(hw_config, THIS_MODULE))
+	{
+		sb_be_quiet = oldquiet;
+		pci_set_drvdata(pdev, NULL);
+		kfree(hw_config);
+		return 1;
+	}
+	sb_be_quiet = oldquiet;
+	
+	return 0;
+}
+
+static void __devexit remove_one(struct pci_dev *pdev)
+{
+	struct address_info *hw_config = pci_get_drvdata(pdev);
+	sb_dsp_unload(hw_config, 0);
+	pci_set_drvdata(pdev, NULL);
+	kfree(hw_config);
+}
+
+MODULE_AUTHOR("Alan Cox");
+MODULE_DESCRIPTION("Kahlua VSA1 PCI Audio");
+MODULE_LICENSE("GPL");
+
+/*
+ *	5530 only. The 5510/5520 decode is different.
+ */
+
+static struct pci_device_id id_tbl[] __devinitdata = {
+	{ PCI_VENDOR_ID_CYRIX, PCI_DEVICE_ID_CYRIX_5530_AUDIO, PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0 },
+	{ }
+};
+
+MODULE_DEVICE_TABLE(pci, id_tbl);
+
+static struct pci_driver kahlua_driver = {
+	name:		"kahlua",
+	id_table:	id_tbl,
+	probe:		probe_one,
+	remove:         __devexit_p(remove_one),
+};
+
+
+static int __init kahlua_init_module(void)
+{
+	printk(KERN_INFO "Cyrix Kahlua VSA1 XpressAudio support (c) Copyright 2003 Red Hat Inc\n");
+	return pci_module_init(&kahlua_driver);
+}
+
+static void __devexit kahlua_cleanup_module(void)
+{
+	return pci_unregister_driver(&kahlua_driver);
+}
+
+
+module_init(kahlua_init_module);
+module_exit(kahlua_cleanup_module);
+