patch-2.2.16 linux/drivers/sound/trident.c

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diff -urN v2.2.15/linux/drivers/sound/trident.c linux/drivers/sound/trident.c
@@ -0,0 +1,2504 @@
+/*
+ *
+ *	Trident 4D-Wave/SiS 7018 OSS driver for Linux 2.2.x
+ *
+ *	Driver: Alan Cox <alan@redhat.com>
+ *
+ *  Built from:
+ *	Low level code: <audio@tridentmicro.com> from ALSA
+ *	Framework: Thomas Sailer <sailer@ife.ee.ethz.ch>
+ *	Extended by: Zach Brown <zab@redhat.com>  
+ *
+ *  Hacked up by:
+ *	Aaron Holtzman <aholtzma@ess.engr.uvic.ca>
+ *	Ollie Lho <ollie@sis.com.tw> SiS 7018 Audio Core Support
+ *
+ *
+ *	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.
+ *
+ *  History
+ *  v0.14.5 June 3 2000 Ollie Lho
+ *  	Misc bug fix from the Net
+ *	Backported from 2.4.0-test1 to 2.2.16 (Eric Brombaugh)
+ *  v0.14.4 May 20 2000 Aaron Holtzman
+ *  	Fix kfree'd memory access in release
+ *  	Fix race in open while looking for a free virtual channel slot
+ *  	remove open_wait wq (which appears to be unused)
+ *  v0.14.3 May 10 2000 Ollie Lho
+ *	fixed a small bug in trident_update_ptr, xmms 1.0.1 no longer uses 100% CPU
+ *  v0.14.2 Mar 29 2000 Ching Ling Lee
+ *	Add clear to silence advance in trident_update_ptr 
+ *	fix invalid data of the end of the sound
+ *  v0.14.1 Mar 24 2000 Ching Ling Lee
+ *	ALi 5451 support added, playback and recording O.K.
+ *	ALi 5451 originally developed and structured based on sonicvibes, and
+ *	suggested to merge into this file by Alan Cox.
+ *  v0.14 Mar 15 2000 Ollie Lho
+ *	5.1 channel output support with channel binding. What's the Matrix ?
+ *  v0.13.1 Mar 10 2000 Ollie Lho
+ *	few minor bugs on dual codec support, needs more testing
+ *  v0.13 Mar 03 2000 Ollie Lho
+ *	new pci_* for 2.4 kernel, back ported to 2.2
+ *  v0.12 Feb 23 2000 Ollie Lho
+ *	Preliminary Recording support
+ *  v0.11.2 Feb 19 2000 Ollie Lho
+ *	removed incomplete full-dulplex support
+ *  v0.11.1 Jan 28 2000 Ollie Lho
+ *	small bug in setting sample rate for 4d-nx (reported by Aaron)
+ *  v0.11 Jan 27 2000 Ollie Lho
+ *	DMA bug, scheduler latency, second try
+ *  v0.10 Jan 24 2000 Ollie Lho
+ *	DMA bug fixed, found kernel scheduling problem
+ *  v0.09 Jan 20 2000 Ollie Lho
+ *	Clean up of channel register access routine (prepare for channel binding)
+ *  v0.08 Jan 14 2000 Ollie Lho
+ *	Isolation of AC97 codec code
+ *  v0.07 Jan 13 2000 Ollie Lho
+ *	Get rid of ugly old low level access routines (e.g. CHRegs.lp****)
+ *  v0.06 Jan 11 2000 Ollie Lho
+ *	Preliminary support for dual (more ?) AC97 codecs
+ *  v0.05 Jan 08 2000 Luca Montecchiani <m.luca@iname.com>
+ *	adapt to 2.3.x new __setup/__init call
+ *  v0.04 Dec 31 1999 Ollie Lho
+ *	Multiple Open, using Middle Loop Interrupt to smooth playback
+ *  v0.03 Dec 24 1999 Ollie Lho
+ *	mem leak in prog_dmabuf and dealloc_dmabuf removed
+ *  v0.02 Dec 15 1999 Ollie Lho
+ *	SiS 7018 support added, playback O.K.
+ *  v0.01 Alan Cox et. al.
+ *	Initial Release in kernel 2.3.30, does not work
+ * 
+ *  ToDo
+ *	Clean up of low level channel register access code. (done)
+ *	Fix the bug on dma buffer management in update_ptr, read/write, drain_dac (done)
+ *	Dual AC97 codecs support (done)
+ *	Recording support (done)
+ *	Mmap support
+ *	"Channel Binding" ioctl extension (done)
+ *	new pci device driver interface for 2.4 kernel (done)
+ */
+
+#include <linux/config.h>
+#include <linux/module.h>
+#include <linux/version.h>
+#include <linux/string.h>
+#include <linux/ctype.h>
+#include <linux/ioport.h>
+#include <linux/sched.h>
+#include <linux/delay.h>
+#include <linux/sound.h>
+#include <linux/malloc.h>
+#include <linux/soundcard.h>
+#include <linux/pci.h>
+#include <asm/io.h>
+#include <asm/dma.h>
+#include <linux/init.h>
+#include <linux/poll.h>
+#include <asm/spinlock.h>
+#include <linux/ac97_codec.h>
+#include <asm/uaccess.h>
+#include <asm/hardirq.h>
+#include <linux/bitops.h>
+
+#include "trident.h"
+
+#define DRIVER_VERSION "0.14.5"
+
+/* magic numbers to protect our data structures */
+#define TRIDENT_CARD_MAGIC	0x5072696E /* "Prin" */
+#define TRIDENT_STATE_MAGIC	0x63657373 /* "cess" */
+
+#define TRIDENT_DMA_MASK	0x3fffffff /* DMA buffer mask for pci_alloc_consist */
+
+#define NR_HW_CH		32
+
+/* maxinum nuber of AC97 codecs connected, AC97 2.0 defined 4, but 7018 and 4D-NX only
+   have 2 SDATA_IN lines (currently) */
+#define NR_AC97		2
+
+/* minor number of /dev/dspW */
+#define SND_DEV_DSP8	3
+
+/* minor number of /dev/dspW */
+#define SND_DEV_DSP16	5 
+
+/* minor number of /dev/swmodem (temporary, experimental) */
+#define SND_DEV_SWMODEM	7
+
+static const unsigned sample_size[] = { 1, 2, 2, 4 };
+static const unsigned sample_shift[] = { 0, 1, 1, 2 };
+
+static const char invalid_magic[] = KERN_CRIT "trident: invalid magic value in %s\n";
+
+struct pci_audio_info {
+	u16 vendor;
+	u16 device;
+	char *name;
+};
+
+static struct pci_audio_info pci_audio_devices[] = {
+	{PCI_VENDOR_ID_TRIDENT, PCI_DEVICE_ID_TRIDENT_4DWAVE_DX, "Trident 4DWave DX"},
+	{PCI_VENDOR_ID_TRIDENT, PCI_DEVICE_ID_TRIDENT_4DWAVE_NX, "Trident 4DWave NX"},
+	{PCI_VENDOR_ID_SI, PCI_DEVICE_ID_SI_7018, "SiS 7018 PCI Audio"},
+	{PCI_VENDOR_ID_ALI, PCI_DEVICE_ID_ALI_5451, "ALi Audio Accelerator"}
+};
+
+/* "software" or virtual channel, an instance of opened /dev/dsp */
+struct trident_state {
+	unsigned int magic;
+	struct trident_card *card;	/* Card info */
+
+	/* file mode */
+	mode_t open_mode;
+
+	/* virtual channel number */
+	int virt;
+
+	struct dmabuf {
+		/* wave sample stuff */
+		unsigned int rate;
+		unsigned char fmt, enable;
+
+		/* hardware channel */
+		struct trident_channel *channel;
+
+		/* OSS buffer management stuff */
+		void *rawbuf;
+
+		unsigned buforder;
+		unsigned numfrag;
+		unsigned fragshift;
+
+		/* our buffer acts like a circular ring */
+		unsigned hwptr;		/* where dma last started, updated by update_ptr */
+		unsigned swptr;		/* where driver last clear/filled, updated by read/write */
+		int count;		/* bytes to be comsumed or been generated by dma machine */
+		unsigned total_bytes;	/* total bytes dmaed by hardware */
+
+		unsigned error;		/* number of over/underruns */
+		struct wait_queue *wait;	/* put process on wait queue when no more space in buffer */
+
+		/* redundant, but makes calculations easier */
+		unsigned fragsize;
+		unsigned dmasize;
+		unsigned fragsamples;
+
+		/* OSS stuff */
+		unsigned mapped:1;
+		unsigned ready:1;
+		unsigned endcleared:1;
+		unsigned update_flag;
+		unsigned ossfragshift;
+		int ossmaxfrags;
+		unsigned subdivision;
+	} dmabuf;
+};
+
+/* hardware channels */
+struct trident_channel {
+	int  num;	/* channel number */
+	u32 lba;	/* Loop Begine Address, where dma buffer starts */
+	u32 eso;	/* End Sample Offset, wehre dma buffer ends (in the unit of samples) */
+	u32 delta;	/* delta value, sample rate / 48k for playback, 48k/sample rate for recording */
+	u16 attribute;	/* control where PCM data go and come  */
+	u16 fm_vol;
+	u32 control;	/* signed/unsigned, 8/16 bits, mono/stereo */
+};
+
+struct trident_pcm_bank_address {
+	u32 start;
+	u32 stop;
+	u32 aint;
+	u32 aint_en;
+};
+static struct trident_pcm_bank_address bank_a_addrs =
+{
+	T4D_START_A,
+	T4D_STOP_A,
+	T4D_AINT_A,
+	T4D_AINTEN_A
+};
+static struct trident_pcm_bank_address bank_b_addrs =
+{
+	T4D_START_B,
+	T4D_STOP_B,
+	T4D_AINT_B,
+	T4D_AINTEN_B
+};
+struct trident_pcm_bank {
+	/* register addresses to control bank operations */
+	struct trident_pcm_bank_address *addresses;
+	/* each bank has 32 channels */
+	u32 bitmap; /* channel allocation bitmap */
+	struct trident_channel channels[32];
+};
+
+struct trident_card {
+	unsigned int magic;
+
+	/* We keep trident cards in a linked list */
+	struct trident_card *next;
+
+	/* single open lock mechanism, only used for recording */
+	struct semaphore open_sem;
+
+	/* The trident has a certain amount of cross channel interaction
+	   so we use a single per card lock */
+	spinlock_t lock;
+
+	/* PCI device stuff */
+	struct pci_audio_info *pci_info;
+	struct pci_dev * pci_dev;
+	u16 pci_id;
+	u8 revision;
+
+	/* soundcore stuff */
+	int dev_audio;
+
+	/* structures for abstraction of hardware facilities, codecs, banks and channels*/
+	struct ac97_codec *ac97_codec[NR_AC97];
+	struct trident_pcm_bank banks[NR_BANKS];
+	struct trident_state *states[NR_HW_CH];
+
+	/* hardware resources */
+	unsigned long iobase;
+	u32 irq;
+	
+	/* Function support */
+	struct trident_channel *(*alloc_pcm_channel)(struct trident_card *);
+	struct trident_channel *(*alloc_rec_pcm_channel)(struct trident_card *);
+	void (*free_pcm_channel)(struct trident_card *, int chan);
+	void (*address_interrupt)(struct trident_card *);
+};
+
+static struct trident_card *devs = NULL;
+
+static void ali_ac97_set(struct ac97_codec *codec, u8 reg, u16 val);
+static u16 ali_ac97_get(struct ac97_codec *codec, u8 reg);
+
+static void trident_ac97_set(struct ac97_codec *codec, u8 reg, u16 val);
+static u16 trident_ac97_get(struct ac97_codec *codec, u8 reg);
+
+static int trident_open_mixdev(struct inode *inode, struct file *file);
+static int trident_release_mixdev(struct inode *inode, struct file *file);
+static int trident_ioctl_mixdev(struct inode *inode, struct file *file, unsigned int cmd,
+				unsigned long arg);
+static loff_t trident_llseek(struct file *file, loff_t offset, int origin);
+
+static int trident_enable_loop_interrupts(struct trident_card * card)
+{
+	u32 global_control;
+
+	global_control = inl(TRID_REG(card, T4D_LFO_GC_CIR));
+
+	switch (card->pci_id)
+	{
+	case PCI_DEVICE_ID_SI_7018:
+		global_control |= (ENDLP_IE | MIDLP_IE| BANK_B_EN);
+		break;
+	case PCI_DEVICE_ID_ALI_5451:
+	case PCI_DEVICE_ID_TRIDENT_4DWAVE_DX:
+	case PCI_DEVICE_ID_TRIDENT_4DWAVE_NX:
+		global_control |= (ENDLP_IE | MIDLP_IE);
+		break;
+	default:
+		return FALSE;
+	}
+
+	outl(global_control, TRID_REG(card, T4D_LFO_GC_CIR));
+
+#ifdef DEBUG
+	printk("trident: Enable Loop Interrupts, globctl = 0x%08X\n",
+	       global_control);
+#endif
+	return (TRUE);
+}
+
+static int trident_disable_loop_interrupts(struct trident_card * card)
+{
+	u32 global_control;
+
+	global_control = inl(TRID_REG(card, T4D_LFO_GC_CIR));
+	global_control &= ~(ENDLP_IE | MIDLP_IE);
+	outl(global_control, TRID_REG(card, T4D_LFO_GC_CIR));
+
+#ifdef DEBUG
+	printk("trident: Disabled Loop Interrupts, globctl = 0x%08X\n",
+	       global_control);
+#endif
+	return (TRUE);
+}
+
+static void trident_enable_voice_irq(struct trident_card * card, unsigned int channel)
+{
+	unsigned int mask = 1 << (channel & 0x1f);
+	struct trident_pcm_bank *bank = &card->banks[channel >> 5];
+	u32 reg, addr = bank->addresses->aint_en;
+
+	reg = inl(TRID_REG(card, addr));
+	reg |= mask;
+	outl(reg, TRID_REG(card, addr));
+
+#ifdef DEBUG
+	reg = inl(TRID_REG(card, T4D_AINTEN_B));
+	printk("trident: enabled IRQ on channel %d, AINTEN_B = 0x%08x\n",
+	       channel, reg);
+#endif
+}
+
+static void trident_disable_voice_irq(struct trident_card * card, unsigned int channel)
+{
+	unsigned int mask = 1 << (channel & 0x1f);
+	struct trident_pcm_bank *bank = &card->banks[channel >> 5];
+	u32 reg, addr = bank->addresses->aint_en;
+	
+	reg = inl(TRID_REG(card, addr));
+	reg &= ~mask;
+	outl(reg, TRID_REG(card, addr));
+	
+	/* Ack the channel in case the interrupt was set before we disable it. */
+	outl(mask, TRID_REG(card, bank->addresses->aint));
+
+#ifdef DEBUG
+	reg = inl(TRID_REG(card, T4D_AINTEN_B));
+	printk("trident: disabled IRQ on channel %d, AINTEN_B = 0x%08x\n",
+	       channel, reg);
+#endif
+}
+
+static void trident_start_voice(struct trident_card * card, unsigned int channel)
+{
+	unsigned int mask = 1 << (channel & 0x1f);
+	struct trident_pcm_bank *bank = &card->banks[channel >> 5];
+	u32 addr = bank->addresses->start;
+
+#ifdef DEBUG
+	u32 reg;
+#endif
+
+	outl(mask, TRID_REG(card, addr));
+
+#ifdef DEBUG
+	reg = inl(TRID_REG(card, T4D_START_B));
+	printk("trident: start voice on channel %d, START_B  = 0x%08x\n",
+	       channel, reg);
+#endif
+}
+
+static void trident_stop_voice(struct trident_card * card, unsigned int channel)
+{
+	unsigned int mask = 1 << (channel & 0x1f);
+	struct trident_pcm_bank *bank = &card->banks[channel >> 5];
+	u32 addr = bank->addresses->stop;
+
+#ifdef DEBUG
+	u32 reg;
+#endif
+
+	outl(mask, TRID_REG(card, addr));
+
+#ifdef DEBUG
+	reg = inl(TRID_REG(card, T4D_STOP_B));
+	printk("trident: stop voice on channel %d,  STOP_B  = 0x%08x\n",
+	       channel, reg);
+#endif
+}
+
+static u32 trident_get_interrupt_mask (struct trident_card * card, unsigned int channel)
+{
+	struct trident_pcm_bank *bank = &card->banks[channel];
+	u32 addr = bank->addresses->aint;
+	return inl(TRID_REG(card, addr));
+}
+
+static int trident_check_channel_interrupt(struct trident_card * card, unsigned int channel)
+{
+	unsigned int mask = 1 << (channel & 0x1f);
+	u32 reg = trident_get_interrupt_mask (card, channel >> 5);
+
+#ifdef DEBUG
+	if (reg & mask)
+		printk("trident: channel %d has interrupt, AINT_B = 0x%08x\n",
+		       channel, reg);
+#endif
+	return (reg & mask) ? TRUE : FALSE;
+}
+
+static void trident_ack_channel_interrupt(struct trident_card * card, unsigned int channel)
+{
+	unsigned int mask = 1 << (channel & 0x1f);
+	struct trident_pcm_bank *bank = &card->banks[channel >> 5];
+	u32 reg, addr = bank->addresses->aint;
+
+	reg = inl(TRID_REG(card, addr));
+	reg &= mask;
+	outl(reg, TRID_REG(card, addr));
+
+#ifdef DEBUG
+	reg = inl(TRID_REG(card, T4D_AINT_B));
+	printk("trident: Ack channel %d interrupt, AINT_B = 0x%08x\n",
+	       channel, reg);
+#endif
+}
+
+static struct trident_channel * trident_alloc_pcm_channel(struct trident_card *card)
+{
+	struct trident_pcm_bank *bank;
+	int idx;
+
+	bank = &card->banks[BANK_B];
+
+	for (idx = 31; idx >= 0; idx--) {
+		if (!(bank->bitmap & (1 << idx))) {
+			struct trident_channel *channel = &bank->channels[idx];
+			bank->bitmap |= 1 << idx;
+			channel->num = idx + 32;
+			return channel;
+		}
+	}
+
+	/* no more free channels avaliable */
+	printk(KERN_ERR "trident: no more channels available on Bank B.\n");
+	return NULL;
+}
+
+static struct trident_channel *ali_alloc_pcm_channel(struct trident_card *card)
+{
+	struct trident_pcm_bank *bank;
+	int idx;
+
+	bank = &card->banks[BANK_A];
+
+	for (idx = ALI_PCM_OUT_CHANNEL_FIRST; idx <= ALI_PCM_OUT_CHANNEL_LAST ; idx++) {
+		if (!(bank->bitmap & (1 << idx))) {
+			struct trident_channel *channel = &bank->channels[idx];
+			bank->bitmap |= 1 << idx;
+			channel->num = idx;
+			return channel;
+		}
+	}
+
+	/* no more free channels avaliable */
+	printk(KERN_ERR "trident: no more channels available on Bank B.\n");
+	return NULL;
+}
+
+static struct trident_channel *ali_alloc_rec_pcm_channel(struct trident_card *card)
+{
+	struct trident_pcm_bank *bank;
+	int idx = ALI_PCM_IN_CHANNEL;
+
+	bank = &card->banks[BANK_A];
+	
+	if (!(bank->bitmap & (1 << idx))) {
+		struct trident_channel *channel = &bank->channels[idx];
+		bank->bitmap |= 1 << idx;
+		channel->num = idx;
+		return channel;
+	}
+	return NULL;
+}
+
+
+static void trident_free_pcm_channel(struct trident_card *card, int channel)
+{
+	int bank;
+
+	if (channel < 31 || channel > 63)
+		return;
+
+	bank = channel >> 5;
+	channel = channel & 0x1f;
+
+	card->banks[bank].bitmap &= ~(1 << (channel));
+}
+
+static void ali_free_pcm_channel(struct trident_card *card, int channel)
+{
+	int bank;
+
+	if (channel > 31)
+		return;
+
+	bank = channel >> 5;
+	channel = channel & 0x1f;
+
+	card->banks[bank].bitmap &= ~(1 << (channel));
+}
+
+
+/* called with spin lock held */
+
+static int trident_load_channel_registers(struct trident_card *card, u32 *data, unsigned int channel)
+{
+	int i;
+
+	if (channel > 63)
+		return FALSE;
+
+	/* select hardware channel to write */
+	outb(channel, TRID_REG(card, T4D_LFO_GC_CIR));
+
+	/* Output the channel registers, but don't write register
+	   three to an ALI chip. */
+	for (i = 0; i < CHANNEL_REGS; i++) {
+		if (i == 3 && card->pci_id == PCI_DEVICE_ID_ALI_5451)
+			continue;
+		outl(data[i], TRID_REG(card, CHANNEL_START + 4*i));
+	}
+	return TRUE;
+}
+
+/* called with spin lock held */
+static int trident_write_voice_regs(struct trident_state *state)
+{
+	unsigned int data[CHANNEL_REGS + 1];
+	struct trident_channel *channel;
+
+	channel = state->dmabuf.channel;
+
+	data[1] = channel->lba;
+	data[4] = channel->control;
+
+	switch (state->card->pci_id)
+	{
+	case PCI_DEVICE_ID_ALI_5451:
+		data[0] = 0; /* Current Sample Offset */
+		data[2] = (channel->eso << 16) | (channel->delta & 0xffff);
+		data[3] = 0;
+		break;	
+	case PCI_DEVICE_ID_SI_7018:
+		data[0] = 0; /* Current Sample Offset */
+		data[2] = (channel->eso << 16) | (channel->delta & 0xffff);
+		data[3] = (channel->attribute << 16) | (channel->fm_vol & 0xffff);
+		break;
+	case PCI_DEVICE_ID_TRIDENT_4DWAVE_DX:
+		data[0] = 0; /* Current Sample Offset */
+		data[2] = (channel->eso << 16) | (channel->delta & 0xffff);
+		data[3] = channel->fm_vol & 0xffff;
+		break;
+	case PCI_DEVICE_ID_TRIDENT_4DWAVE_NX:
+		data[0] = (channel->delta << 24);
+		data[2] = ((channel->delta << 16) & 0xff000000) | (channel->eso & 0x00ffffff);
+		data[3] = channel->fm_vol & 0xffff;
+		break;
+	default:
+		return FALSE;
+	}
+
+	return trident_load_channel_registers(state->card, data, channel->num);
+}
+
+static int compute_rate_play(u32 rate)
+{
+	int delta;
+	/* We special case 44100 and 8000 since rounding with the equation
+	   does not give us an accurate enough value. For 11025 and 22050
+	   the equation gives us the best answer. All other frequencies will
+	   also use the equation. JDW */
+	if (rate == 44100)
+		delta = 0xeb3;
+	else if (rate == 8000)
+		delta = 0x2ab;
+	else if (rate == 48000)
+		delta = 0x1000;
+	else
+		delta = (((rate << 12) + rate) / 48000) & 0x0000ffff;
+	return delta;
+}
+
+static int compute_rate_rec(u32 rate)
+{
+	int delta;
+
+	if (rate == 44100)
+		delta = 0x116a;
+	else if (rate == 8000)
+		delta = 0x6000;
+	else if (rate == 48000)
+		delta = 0x1000;
+	else
+		delta = ((48000 << 12) / rate) & 0x0000ffff;
+
+	return delta;
+}
+/* set playback sample rate */
+static unsigned int trident_set_dac_rate(struct trident_state * state, unsigned int rate)
+{	
+	struct dmabuf *dmabuf = &state->dmabuf;
+
+	if (rate > 48000)
+		rate = 48000;
+	if (rate < 4000)
+		rate = 4000;
+
+	dmabuf->rate = rate;
+	dmabuf->channel->delta = compute_rate_play(rate);
+
+	trident_write_voice_regs(state);
+
+#ifdef DEBUG
+	printk("trident: called trident_set_dac_rate : rate = %d\n", rate);
+#endif
+
+	return rate;
+}
+
+/* set recording sample rate */
+static unsigned int trident_set_adc_rate(struct trident_state * state, unsigned int rate)
+{
+	struct dmabuf *dmabuf = &state->dmabuf;
+
+	if (rate > 48000)
+		rate = 48000;
+	if (rate < 4000)
+		rate = 4000;
+
+	dmabuf->rate = rate;
+	dmabuf->channel->delta = compute_rate_rec(rate);
+
+	trident_write_voice_regs(state);
+
+#ifdef DEBUG
+	printk("trident: called trident_set_adc_rate : rate = %d\n", rate);
+#endif
+	return rate;
+}
+
+/* prepare channel attributes for playback */ 
+static void trident_play_setup(struct trident_state *state)
+{
+	struct dmabuf *dmabuf = &state->dmabuf;
+	struct trident_channel *channel = dmabuf->channel;
+
+	channel->lba = virt_to_bus(dmabuf->rawbuf);
+	channel->delta = compute_rate_play(dmabuf->rate);
+
+	channel->eso = dmabuf->dmasize >> sample_shift[dmabuf->fmt];
+	channel->eso -= 1;
+
+	if (state->card->pci_id != PCI_DEVICE_ID_SI_7018) {
+		channel->attribute = 0;
+	}
+
+	channel->fm_vol = 0x0;
+	
+	channel->control = CHANNEL_LOOP;
+	if (dmabuf->fmt & TRIDENT_FMT_16BIT) {
+		/* 16-bits */
+		channel->control |= CHANNEL_16BITS;
+		/* signed */
+		channel->control |= CHANNEL_SIGNED;
+	}
+	if (dmabuf->fmt & TRIDENT_FMT_STEREO)
+		/* stereo */
+		channel->control |= CHANNEL_STEREO;
+#ifdef DEBUG
+	printk("trident: trident_play_setup, LBA = 0x%08x, "
+	       "Delat = 0x%08x, ESO = 0x%08x, Control = 0x%08x\n",
+	       channel->lba, channel->delta, channel->eso, channel->control);
+#endif
+	trident_write_voice_regs(state);
+}
+
+/* prepare channel attributes for recording */
+static void trident_rec_setup(struct trident_state *state)
+{
+	u16 w;
+	struct trident_card *card = state->card;
+	struct dmabuf *dmabuf = &state->dmabuf;
+	struct trident_channel *channel = dmabuf->channel;
+
+	/* Enable AC-97 ADC (capture) */
+	switch (card->pci_id) 
+	{
+	case PCI_DEVICE_ID_ALI_5451:
+	case PCI_DEVICE_ID_SI_7018:
+		/* for 7018, the ac97 is always in playback/record (duplex) mode */
+		break;
+	case PCI_DEVICE_ID_TRIDENT_4DWAVE_DX:
+		w = inb(TRID_REG(card, DX_ACR2_AC97_COM_STAT));
+		outb(w | 0x48, TRID_REG(card, DX_ACR2_AC97_COM_STAT));
+		/* enable and set record channel */
+		outb(0x80 | channel->num, TRID_REG(card, T4D_REC_CH));
+		break;
+	case PCI_DEVICE_ID_TRIDENT_4DWAVE_NX:
+		w = inw(TRID_REG(card, T4D_MISCINT));
+		outw(w | 0x1000, TRID_REG(card, T4D_MISCINT));
+		/* enable and set record channel */
+		outb(0x80 | channel->num, TRID_REG(card, T4D_REC_CH));
+		break;
+	default:
+		return;
+	}
+
+	channel->lba = virt_to_bus(dmabuf->rawbuf);
+	channel->delta = compute_rate_rec(dmabuf->rate);
+
+	channel->eso = dmabuf->dmasize >> sample_shift[dmabuf->fmt];
+	channel->eso -= 1;
+
+	if (state->card->pci_id != PCI_DEVICE_ID_SI_7018) {
+		channel->attribute = 0;
+	}
+
+	channel->fm_vol = 0x0;
+	
+	channel->control = CHANNEL_LOOP;
+	if (dmabuf->fmt & TRIDENT_FMT_16BIT) {
+		/* 16-bits */
+		channel->control |= CHANNEL_16BITS;
+		/* signed */
+		channel->control |= CHANNEL_SIGNED;
+	}
+	if (dmabuf->fmt & TRIDENT_FMT_STEREO)
+		/* stereo */
+		channel->control |= CHANNEL_STEREO;
+#ifdef DEBUG
+	printk("trident: trident_rec_setup, LBA = 0x%08x, "
+	       "Delat = 0x%08x, ESO = 0x%08x, Control = 0x%08x\n",
+	       channel->lba, channel->delta, channel->eso, channel->control);
+#endif
+	trident_write_voice_regs(state);
+}
+
+/* get current playback/recording dma buffer pointer (byte offset from LBA),
+   called with spinlock held! */
+extern __inline__ unsigned trident_get_dma_addr(struct trident_state *state)
+{
+	struct dmabuf *dmabuf = &state->dmabuf;
+	u32 cso;
+
+	if (!dmabuf->enable)
+		return 0;
+
+	outb(dmabuf->channel->num, TRID_REG(state->card, T4D_LFO_GC_CIR));
+
+	switch (state->card->pci_id) 
+	{
+	case PCI_DEVICE_ID_ALI_5451:
+	case PCI_DEVICE_ID_SI_7018:
+	case PCI_DEVICE_ID_TRIDENT_4DWAVE_DX:
+		/* 16 bits ESO, CSO for 7018 and DX */
+		cso = inw(TRID_REG(state->card, CH_DX_CSO_ALPHA_FMS + 2));
+		break;
+	case PCI_DEVICE_ID_TRIDENT_4DWAVE_NX:
+		/* 24 bits ESO, CSO for NX */
+		cso = inl(TRID_REG(state->card, CH_NX_DELTA_CSO)) & 0x00ffffff;
+		break;
+	default:
+		return 0;
+	}
+
+#ifdef DEBUG
+	printk("trident: trident_get_dma_addr: chip reported channel: %d, "
+	       "cso = 0x%04x\n",
+	       dmabuf->channel->num, cso);
+#endif
+	/* ESO and CSO are in units of Samples, convert to byte offset */
+	cso <<= sample_shift[dmabuf->fmt];
+
+	return (cso % dmabuf->dmasize);
+}
+
+/* Stop recording (lock held) */
+extern __inline__ void __stop_adc(struct trident_state *state)
+{
+	struct dmabuf *dmabuf = &state->dmabuf;
+	unsigned int chan_num = dmabuf->channel->num;
+	struct trident_card *card = state->card;
+
+	dmabuf->enable &= ~ADC_RUNNING;
+	trident_stop_voice(card, chan_num);
+	trident_disable_voice_irq(card, chan_num);
+}
+
+static void stop_adc(struct trident_state *state)
+{
+	struct trident_card *card = state->card;
+	unsigned long flags;
+
+	spin_lock_irqsave(&card->lock, flags);
+	__stop_adc(state);
+	spin_unlock_irqrestore(&card->lock, flags);
+}
+
+static void start_adc(struct trident_state *state)
+{
+	struct dmabuf *dmabuf = &state->dmabuf;
+	unsigned int chan_num = dmabuf->channel->num;
+	struct trident_card *card = state->card;
+	unsigned long flags;
+
+	spin_lock_irqsave(&card->lock, flags);
+	if ((dmabuf->mapped || dmabuf->count < (signed)dmabuf->dmasize) && dmabuf->ready) {
+		dmabuf->enable |= ADC_RUNNING;
+		trident_enable_voice_irq(card, chan_num);
+		trident_start_voice(card, chan_num);
+	}
+	spin_unlock_irqrestore(&card->lock, flags);
+}
+
+/* stop playback (lock held) */
+extern __inline__ void __stop_dac(struct trident_state *state)
+{
+	struct dmabuf *dmabuf = &state->dmabuf;
+	unsigned int chan_num = dmabuf->channel->num;
+	struct trident_card *card = state->card;
+
+	dmabuf->enable &= ~DAC_RUNNING;
+	trident_stop_voice(card, chan_num);
+	trident_disable_voice_irq(card, chan_num);
+}
+
+static void stop_dac(struct trident_state *state)
+{
+	struct trident_card *card = state->card;
+	unsigned long flags;
+
+	spin_lock_irqsave(&card->lock, flags);
+	__stop_dac(state);
+	spin_unlock_irqrestore(&card->lock, flags);
+}	
+
+static void start_dac(struct trident_state *state)
+{
+	struct dmabuf *dmabuf = &state->dmabuf;
+	unsigned int chan_num = dmabuf->channel->num;
+	struct trident_card *card = state->card;
+	unsigned long flags;
+
+	spin_lock_irqsave(&card->lock, flags);
+	if ((dmabuf->mapped || dmabuf->count > 0) && dmabuf->ready) {
+		dmabuf->enable |= DAC_RUNNING;
+		trident_enable_voice_irq(card, chan_num);
+		trident_start_voice(card, chan_num);
+	}
+	spin_unlock_irqrestore(&card->lock, flags);
+}
+
+#define DMABUF_DEFAULTORDER (15-PAGE_SHIFT)
+#define DMABUF_MINORDER 1
+
+/* allocate DMA buffer, playback and recording buffer should be allocated seperately */
+static int alloc_dmabuf(struct trident_state *state)
+{
+	struct dmabuf *dmabuf = &state->dmabuf;
+	void *rawbuf;
+	int order;
+	unsigned long map, mapend;
+
+	/* alloc as big a chunk as we can, FIXME: is this necessary ?? */
+	for (order = DMABUF_DEFAULTORDER; order >= DMABUF_MINORDER; order--)
+		if ((rawbuf = (void *)__get_free_pages(GFP_KERNEL, order)))
+			break;
+	if (!rawbuf)
+		return -ENOMEM;
+
+#ifdef DEBUG
+	printk("trident: allocated %ld (order = %d) bytes at %p\n",
+	       PAGE_SIZE << order, order, rawbuf);
+#endif
+
+	/* for 4DWave and 7018, there are only 30 (31) siginifcan bits for Loop Begin Address
+	   (LBA) which limits the address space to 1 (2) GB, bad T^2 design */
+	if ((virt_to_bus(rawbuf) + (PAGE_SIZE << order) - 1) & ~0x3fffffff) {
+		printk(KERN_ERR "trident: DMA buffer beyond 1 GB; "
+		       "bus address = 0x%lx, size = %ld\n",
+		       virt_to_bus(rawbuf), PAGE_SIZE << order);
+		free_pages((unsigned long)rawbuf, order);
+		return -ENOMEM;
+	}
+	dmabuf->ready  = dmabuf->mapped = 0;
+	dmabuf->rawbuf = rawbuf;
+	dmabuf->buforder = order;
+	
+	/* now mark the pages as reserved; otherwise remap_page_range doesn't do what we want */
+	mapend = MAP_NR(rawbuf + (PAGE_SIZE << order) - 1);
+	for (map = MAP_NR(rawbuf); map <= mapend; map++)
+		set_bit(PG_reserved, &mem_map[map].flags);
+
+	return 0;
+}
+
+/* free DMA buffer */
+static void dealloc_dmabuf(struct trident_state *state)
+{
+	struct dmabuf *dmabuf = &state->dmabuf;
+	unsigned long map, mapend;
+
+	if (dmabuf->rawbuf) {
+		/* undo marking the pages as reserved */
+		mapend = MAP_NR(dmabuf->rawbuf + (PAGE_SIZE << dmabuf->buforder) - 1);
+		for (map = MAP_NR(dmabuf->rawbuf); map <= mapend; map++)
+			clear_bit(PG_reserved, &mem_map[map].flags);
+		free_pages((unsigned long)dmabuf->rawbuf, dmabuf->buforder);
+	}
+	dmabuf->rawbuf = NULL;
+	dmabuf->mapped = dmabuf->ready = 0;
+}
+
+static int prog_dmabuf(struct trident_state *state, unsigned rec)
+{
+	struct dmabuf *dmabuf = &state->dmabuf;
+	unsigned bytepersec;
+	unsigned bufsize;
+	unsigned long flags;
+	int ret;
+
+	spin_lock_irqsave(&state->card->lock, flags);
+	dmabuf->hwptr = dmabuf->swptr = dmabuf->total_bytes = 0;
+	dmabuf->count = dmabuf->error = 0;
+	spin_unlock_irqrestore(&state->card->lock, flags);
+
+	/* allocate DMA buffer if not allocated yet */
+	if (!dmabuf->rawbuf)
+		if ((ret = alloc_dmabuf(state)))
+			return ret;
+
+	/* FIXME: figure out all this OSS fragment stuff */
+	bytepersec = dmabuf->rate << sample_shift[dmabuf->fmt];
+	bufsize = PAGE_SIZE << dmabuf->buforder;
+	if (dmabuf->ossfragshift) {
+		if ((1000 << dmabuf->ossfragshift) < bytepersec)
+			dmabuf->fragshift = ld2(bytepersec/1000);
+		else
+			dmabuf->fragshift = dmabuf->ossfragshift;
+	} else {
+		/* lets hand out reasonable big ass buffers by default */
+		dmabuf->fragshift = (dmabuf->buforder + PAGE_SHIFT -2);
+	}
+	dmabuf->numfrag = bufsize >> dmabuf->fragshift;
+	while (dmabuf->numfrag < 4 && dmabuf->fragshift > 3) {
+		dmabuf->fragshift--;
+		dmabuf->numfrag = bufsize >> dmabuf->fragshift;
+	}
+	dmabuf->fragsize = 1 << dmabuf->fragshift;
+	if (dmabuf->ossmaxfrags >= 4 && dmabuf->ossmaxfrags < dmabuf->numfrag)
+		dmabuf->numfrag = dmabuf->ossmaxfrags;
+	dmabuf->fragsamples = dmabuf->fragsize >> sample_shift[dmabuf->fmt];
+	dmabuf->dmasize = dmabuf->numfrag << dmabuf->fragshift;
+
+	memset(dmabuf->rawbuf, (dmabuf->fmt & TRIDENT_FMT_16BIT) ? 0 : 0x80,
+	       dmabuf->dmasize);
+
+	spin_lock_irqsave(&state->card->lock, flags);
+	if (rec) {
+		trident_rec_setup(state);
+	} else {
+		trident_play_setup(state);
+	}
+	spin_unlock_irqrestore(&state->card->lock, flags);
+
+	/* set the ready flag for the dma buffer */
+	dmabuf->ready = 1;
+
+#ifdef DEBUG
+	printk("trident: prog_dmabuf, sample rate = %d, format = %d, numfrag = %d, "
+	       "fragsize = %d dmasize = %d\n",
+	       dmabuf->rate, dmabuf->fmt, dmabuf->numfrag,
+	       dmabuf->fragsize, dmabuf->dmasize);
+#endif
+
+	return 0;
+}
+
+/* we are doing quantum mechanics here, the buffer can only be empty, half or full filled i.e.
+   |------------|------------|   or   |xxxxxxxxxxxx|------------|   or   |xxxxxxxxxxxx|xxxxxxxxxxxx|
+   but we almost always get this
+   |xxxxxx------|------------|   or   |xxxxxxxxxxxx|xxxxx-------|
+   so we have to clear the tail space to "silence"
+   |xxxxxx000000|------------|   or   |xxxxxxxxxxxx|xxxxxx000000|
+*/
+static void trident_clear_tail(struct trident_state *state)
+{
+	struct dmabuf *dmabuf = &state->dmabuf;
+	unsigned swptr;
+	unsigned char silence = (dmabuf->fmt & TRIDENT_FMT_16BIT) ? 0 : 0x80;
+	unsigned int len;
+	unsigned long flags;
+
+	spin_lock_irqsave(&state->card->lock, flags);
+	swptr = dmabuf->swptr;
+	spin_unlock_irqrestore(&state->card->lock, flags);
+
+	if (swptr == 0 || swptr == dmabuf->dmasize / 2 || swptr == dmabuf->dmasize)
+		return;
+
+	if (swptr < dmabuf->dmasize/2)
+		len = dmabuf->dmasize/2 - swptr;
+	else
+		len = dmabuf->dmasize - swptr;
+
+	memset(dmabuf->rawbuf + swptr, silence, len);
+
+	spin_lock_irqsave(&state->card->lock, flags);
+	dmabuf->swptr += len;
+	dmabuf->count += len;
+	spin_unlock_irqrestore(&state->card->lock, flags);
+
+	/* restart the dma machine in case it is halted */
+	start_dac(state);
+}
+
+static int drain_dac(struct trident_state *state, int nonblock)
+{
+	struct wait_queue wait = {current, NULL};
+	struct dmabuf *dmabuf = &state->dmabuf;
+	unsigned long flags;
+	unsigned long tmo;
+	int count;
+
+	if (dmabuf->mapped || !dmabuf->ready)
+		return 0;
+
+	add_wait_queue(&dmabuf->wait, &wait);
+	for (;;) {
+		/* It seems that we have to set the current state to TASK_INTERRUPTIBLE
+		   every time to make the process really go to sleep */
+		current->state = TASK_INTERRUPTIBLE;
+
+		spin_lock_irqsave(&state->card->lock, flags);
+		count = dmabuf->count;
+		spin_unlock_irqrestore(&state->card->lock, flags);
+
+		if (count <= 0)
+			break;
+
+		if (signal_pending(current))
+			break;
+
+		if (nonblock) {
+			remove_wait_queue(&dmabuf->wait, &wait);
+			current->state = TASK_RUNNING;
+			return -EBUSY;
+		}
+
+		/* No matter how much data left in the buffer, we have to wait untill
+		   CSO == ESO/2 or CSO == ESO when address engine interrupts */
+		tmo = (dmabuf->dmasize * HZ) / dmabuf->rate;
+		tmo >>= sample_shift[dmabuf->fmt];
+		if (!schedule_timeout(tmo ? tmo : 1) && tmo){
+			printk(KERN_ERR "trident: drain_dac, dma timeout?\n");
+			break;
+		}
+	}
+	remove_wait_queue(&dmabuf->wait, &wait);
+	current->state = TASK_RUNNING;
+	if (signal_pending(current))
+		return -ERESTARTSYS;
+
+	return 0;
+}
+
+/* update buffer manangement pointers, especially, dmabuf->count and dmabuf->hwptr */
+static void trident_update_ptr(struct trident_state *state)
+{
+	struct dmabuf *dmabuf = &state->dmabuf;
+	unsigned hwptr, swptr;
+	int clear_cnt = 0;
+	int diff;
+	unsigned char silence;
+	unsigned half_dmasize;
+
+	/* update hardware pointer */
+	hwptr = trident_get_dma_addr(state);
+	diff = (dmabuf->dmasize + hwptr - dmabuf->hwptr) % dmabuf->dmasize;
+	dmabuf->hwptr = hwptr;
+	dmabuf->total_bytes += diff;
+
+	/* error handling and process wake up for ADC */
+	if (dmabuf->enable == ADC_RUNNING) {
+		if (dmabuf->mapped) {
+			dmabuf->count -= diff;
+			if (dmabuf->count >= (signed)dmabuf->fragsize)
+				wake_up(&dmabuf->wait);
+		} else {
+			dmabuf->count += diff;
+
+			if (dmabuf->count < 0 || dmabuf->count > dmabuf->dmasize) {
+				/* buffer underrun or buffer overrun, we have no way to recover
+				   it here, just stop the machine and let the process force hwptr
+				   and swptr to sync */
+				__stop_adc(state);
+				dmabuf->error++;
+			}
+			else if (!dmabuf->endcleared) {
+				swptr = dmabuf->swptr;
+				silence = (dmabuf->fmt & TRIDENT_FMT_16BIT ? 0 : 0x80);
+				if (dmabuf->update_flag & ALI_ADDRESS_INT_UPDATE) {
+					/* We must clear end data of 1/2 dmabuf if needed.
+					   According to 1/2 algorithm of Address Engine Interrupt,
+					   check the validation of the data of half dmasize. */
+					half_dmasize = dmabuf->dmasize / 2;
+					if ((diff = hwptr - half_dmasize) < 0 )
+						diff = hwptr;
+					if ((dmabuf->count + diff) < half_dmasize) {
+						//there is invalid data in the end of half buffer
+						if ((clear_cnt = half_dmasize - swptr) < 0)
+							clear_cnt += half_dmasize;
+						//clear the invalid data
+						memset (dmabuf->rawbuf + swptr,
+							silence, clear_cnt);
+
+						dmabuf->endcleared = 1;
+					}
+				} else if (dmabuf->count < (signed) dmabuf->fragsize) {
+					clear_cnt = dmabuf->fragsize;
+					if ((swptr + clear_cnt) > dmabuf->dmasize)
+						clear_cnt = dmabuf->dmasize - swptr;
+					memset (dmabuf->rawbuf + swptr, silence, clear_cnt);
+					dmabuf->endcleared = 1;
+				}
+			}
+			/* trident_update_ptr is called by interrupt handler or by process via
+			   ioctl/poll, we only wake up the waiting process when we have more
+			   than 1/2 buffer of data to process (always true for interrupt handler) */
+			if (dmabuf->count > (signed)dmabuf->dmasize/2)
+				wake_up(&dmabuf->wait);
+		}
+	}
+
+	/* error handling and process wake up for DAC */
+	if (dmabuf->enable == DAC_RUNNING) {
+		if (dmabuf->mapped) {
+			dmabuf->count += diff;
+			if (dmabuf->count >= (signed)dmabuf->fragsize)
+				wake_up(&dmabuf->wait);
+		} else {
+			dmabuf->count -= diff;
+
+			if (dmabuf->count < 0 || dmabuf->count > dmabuf->dmasize) {
+				/* buffer underrun or buffer overrun, we have no way to recover
+				   it here, just stop the machine and let the process force hwptr
+				   and swptr to sync */
+				__stop_dac(state);
+				dmabuf->error++;
+			}
+			/* trident_update_ptr is called by interrupt handler or by process via
+			   ioctl/poll, we only wake up the waiting process when we have more
+			   than 1/2 buffer free (always true for interrupt handler) */
+			if (dmabuf->count < (signed)dmabuf->dmasize/2)
+				wake_up(&dmabuf->wait);
+		}
+	}
+	dmabuf->update_flag &= ~ALI_ADDRESS_INT_UPDATE;
+}
+
+static void trident_address_interrupt(struct trident_card *card)
+{
+	int i;
+	struct trident_state *state;
+	
+	/* Update the pointers for all channels we are running. */
+	/* FIXME: should read interrupt status only once */
+	for (i = 0; i < NR_HW_CH; i++) {
+		if (trident_check_channel_interrupt(card, 63 - i)) {
+			trident_ack_channel_interrupt(card, 63 - i);
+			if ((state = card->states[i]) != NULL) {
+				trident_update_ptr(state);
+			} else {
+				printk("trident: spurious channel irq %d.\n",
+				       63 - i);
+				trident_stop_voice(card, 63 - i);
+				trident_disable_voice_irq(card, 63 - i);
+			}
+		}
+	}
+}
+
+static void ali_address_interrupt(struct trident_card *card)
+{
+	int i;
+	u32 mask = trident_get_interrupt_mask (card, BANK_A);
+
+#ifdef DEBUG
+	/* Sanity check to make sure that every state has a channel
+	   and vice versa. */
+	u32 done = 0;
+	unsigned ns = 0;
+	unsigned nc = 0;
+	for (i = 0; i < NR_HW_CH; i++) {
+		if (card->banks[BANK_A].bitmap & (1<<i))
+			nc ++;
+
+		if (card->states[i]) {
+			u32 bit = 1 << card->states[i]->dmabuf.channel->num;
+			if (bit & done) 
+				printk (KERN_ERR "trident: channel allocated to two states\n");
+			ns++;
+
+			done |= bit;
+		}
+	}
+	if (ns != nc) 
+		printk (KERN_ERR "trident: number of states != number of channels\n");
+#endif
+
+	for (i = 0; mask && i < NR_HW_CH; i++) {			
+		struct trident_state *state = card->states[i];
+		if (!state)
+			continue;
+
+		trident_ack_channel_interrupt(card, state->dmabuf.channel->num);
+		mask &= ~ (1<<state->dmabuf.channel->num);
+		state->dmabuf.update_flag |= ALI_ADDRESS_INT_UPDATE;
+		trident_update_ptr(state);
+	}
+
+	if (mask) 
+		for (i = 0; i < NR_HW_CH; i++)
+			if (mask & (1<<i)) {
+				printk("ali: spurious channel irq %d.\n", i);
+				trident_stop_voice(card, i);
+				trident_disable_voice_irq(card, i);
+			}
+
+}
+
+static void trident_interrupt(int irq, void *dev_id, struct pt_regs *regs)
+{
+	struct trident_card *card = (struct trident_card *)dev_id;
+	u32 event;
+
+	spin_lock(&card->lock);
+	event = inl(TRID_REG(card, T4D_MISCINT));
+
+#ifdef DEBUG
+	printk("trident: trident_interrupt called, MISCINT = 0x%08x\n", event);
+#endif
+
+	if (event & ADDRESS_IRQ) {
+		card->address_interrupt(card);
+	}
+
+	/* manually clear interrupt status, bad hardware design, blame T^2 */
+	outl((ST_TARGET_REACHED | MIXER_OVERFLOW | MIXER_UNDERFLOW),
+	     TRID_REG(card, T4D_MISCINT));
+	spin_unlock(&card->lock);
+}
+
+static loff_t trident_llseek(struct file *file, loff_t offset, int origin)
+{
+	return -ESPIPE;
+}
+
+/* in this loop, dmabuf.count signifies the amount of data that is waiting to be copied to
+   the user's buffer.  it is filled by the dma machine and drained by this loop. */
+static ssize_t trident_read(struct file *file, char *buffer, size_t count, loff_t *ppos)
+{
+	struct trident_state *state = (struct trident_state *)file->private_data;
+	struct dmabuf *dmabuf = &state->dmabuf;
+	ssize_t ret;
+	unsigned long flags;
+	unsigned swptr;
+	int cnt;
+
+#ifdef DEBUG
+	printk("trident: trident_read called, count = %d\n", count);
+#endif
+
+	VALIDATE_STATE(state);
+	if (ppos != &file->f_pos)
+		return -ESPIPE;
+	if (dmabuf->mapped)
+		return -ENXIO;
+	if (!dmabuf->ready && (ret = prog_dmabuf(state, 1)))
+		return ret;
+	if (!access_ok(VERIFY_WRITE, buffer, count))
+		return -EFAULT;
+	ret = 0;
+
+	if (state->card->pci_id == PCI_DEVICE_ID_ALI_5451)
+		outl(inl(TRID_REG (state->card, ALI_GLOBAL_CONTROL)) | ALI_PCM_IN_ENABLE,
+		     TRID_REG (state->card, ALI_GLOBAL_CONTROL));
+
+	while (count > 0) {
+		spin_lock_irqsave(&state->card->lock, flags);
+		if (dmabuf->count > (signed) dmabuf->dmasize) {
+			/* buffer overrun, we are recovering from sleep_on_timeout,
+			   resync hwptr and swptr, make process flush the buffer */
+			dmabuf->count = dmabuf->dmasize;
+			dmabuf->swptr = dmabuf->hwptr;
+		}
+		swptr = dmabuf->swptr;
+		cnt = dmabuf->dmasize - swptr;
+		if (dmabuf->count < cnt)
+			cnt = dmabuf->count;
+		spin_unlock_irqrestore(&state->card->lock, flags);
+
+		if (cnt > count)
+			cnt = count;
+		if (cnt <= 0) {
+			unsigned long tmo;
+			/* buffer is empty, start the dma machine and wait for data to be
+			   recorded */
+			start_adc(state);
+			if (file->f_flags & O_NONBLOCK) {
+				if (!ret) ret = -EAGAIN;
+				return ret;
+			}
+			/* No matter how much space left in the buffer, we have to wait untill
+			   CSO == ESO/2 or CSO == ESO when address engine interrupts */
+			tmo = (dmabuf->dmasize * HZ) / (dmabuf->rate * 2);
+			tmo >>= sample_shift[dmabuf->fmt];
+			/* There are two situations when sleep_on_timeout returns, one is when
+			   the interrupt is serviced correctly and the process is waked up by
+			   ISR ON TIME. Another is when timeout is expired, which means that
+			   either interrupt is NOT serviced correctly (pending interrupt) or it
+			   is TOO LATE for the process to be scheduled to run (scheduler latency)
+			   which results in a (potential) buffer overrun. And worse, there is
+			   NOTHING we can do to prevent it. */
+			if (!interruptible_sleep_on_timeout(&dmabuf->wait, tmo)) {
+#ifdef DEBUG
+				printk(KERN_ERR "trident: recording schedule timeout, "
+				       "dmasz %u fragsz %u count %i hwptr %u swptr %u\n",
+				       dmabuf->dmasize, dmabuf->fragsize, dmabuf->count,
+				       dmabuf->hwptr, dmabuf->swptr);
+#endif
+				/* a buffer overrun, we delay the recovery untill next time the
+				   while loop begin and we REALLY have space to record */
+			}
+			if (signal_pending(current)) {
+				ret = ret ? ret : -ERESTARTSYS;
+				return ret;
+			}
+			continue;
+		}
+
+		if (copy_to_user(buffer, dmabuf->rawbuf + swptr, cnt)) {
+			if (!ret) ret = -EFAULT;
+			return ret;
+		}
+
+		swptr = (swptr + cnt) % dmabuf->dmasize;
+
+		spin_lock_irqsave(&state->card->lock, flags);
+		dmabuf->swptr = swptr;
+		dmabuf->count -= cnt;
+		spin_unlock_irqrestore(&state->card->lock, flags);
+
+		count -= cnt;
+		buffer += cnt;
+		ret += cnt;
+		start_adc(state);
+	}
+	return ret;
+}
+
+/* in this loop, dmabuf.count signifies the amount of data that is waiting to be dma to
+   the soundcard.  it is drained by the dma machine and filled by this loop. */
+static ssize_t trident_write(struct file *file, const char *buffer, size_t count, loff_t *ppos)
+{
+	struct trident_state *state = (struct trident_state *)file->private_data;
+	struct dmabuf *dmabuf = &state->dmabuf;
+	ssize_t ret;
+	unsigned long flags;
+	unsigned swptr;
+	int cnt;
+
+#ifdef DEBUG
+	printk("trident: trident_write called, count = %d\n", count);
+#endif
+
+	VALIDATE_STATE(state);
+	if (ppos != &file->f_pos)
+		return -ESPIPE;
+	if (dmabuf->mapped)
+		return -ENXIO;
+	if (!dmabuf->ready && (ret = prog_dmabuf(state, 0)))
+		return ret;
+	if (!access_ok(VERIFY_READ, buffer, count))
+		return -EFAULT;
+	ret = 0;
+
+	if (state->card->pci_id == PCI_DEVICE_ID_ALI_5451)
+		if (dmabuf->channel->num == ALI_PCM_IN_CHANNEL)
+			outl ( inl (TRID_REG (state->card, ALI_GLOBAL_CONTROL)) &
+			       ALI_PCM_IN_DISABLE, TRID_REG (state->card, ALI_GLOBAL_CONTROL));
+
+	while (count > 0) {
+		spin_lock_irqsave(&state->card->lock, flags);
+		if (dmabuf->count < 0) {
+			/* buffer underrun, we are recovering from sleep_on_timeout,
+			   resync hwptr and swptr */
+			dmabuf->count = 0;
+			dmabuf->swptr = dmabuf->hwptr;
+		}
+		swptr = dmabuf->swptr;
+		cnt = dmabuf->dmasize - swptr;
+		if (dmabuf->count + cnt > dmabuf->dmasize)
+			cnt = dmabuf->dmasize - dmabuf->count;
+		spin_unlock_irqrestore(&state->card->lock, flags);
+
+		if (cnt > count)
+			cnt = count;
+		if (cnt <= 0) {
+			unsigned long tmo;
+			/* buffer is full, start the dma machine and wait for data to be
+			   played */
+			start_dac(state);
+			if (file->f_flags & O_NONBLOCK) {
+				if (!ret) ret = -EAGAIN;
+				return ret;
+			}
+			/* No matter how much data left in the buffer, we have to wait untill
+			   CSO == ESO/2 or CSO == ESO when address engine interrupts */
+			tmo = (dmabuf->dmasize * HZ) / (dmabuf->rate * 2);
+			tmo >>= sample_shift[dmabuf->fmt];
+			/* There are two situations when sleep_on_timeout returns, one is when
+			   the interrupt is serviced correctly and the process is waked up by
+			   ISR ON TIME. Another is when timeout is expired, which means that
+			   either interrupt is NOT serviced correctly (pending interrupt) or it
+			   is TOO LATE for the process to be scheduled to run (scheduler latency)
+			   which results in a (potential) buffer underrun. And worse, there is
+			   NOTHING we can do to prevent it. */
+			if (!interruptible_sleep_on_timeout(&dmabuf->wait, tmo)) {
+#ifdef DEBUG
+				printk(KERN_ERR "trident: playback schedule timeout, "
+				       "dmasz %u fragsz %u count %i hwptr %u swptr %u\n",
+				       dmabuf->dmasize, dmabuf->fragsize, dmabuf->count,
+				       dmabuf->hwptr, dmabuf->swptr);
+#endif
+				/* a buffer underrun, we delay the recovery untill next time the
+				   while loop begin and we REALLY have data to play */
+			}
+			if (signal_pending(current)) {
+				if (!ret) ret = -ERESTARTSYS;
+				return ret;
+			}
+			continue;
+		}
+		if (copy_from_user(dmabuf->rawbuf + swptr, buffer, cnt)) {
+			if (!ret) ret = -EFAULT;
+			return ret;
+		}
+
+		swptr = (swptr + cnt) % dmabuf->dmasize;
+
+		spin_lock_irqsave(&state->card->lock, flags);
+		dmabuf->swptr = swptr;
+		dmabuf->count += cnt;
+		dmabuf->endcleared = 0;
+		spin_unlock_irqrestore(&state->card->lock, flags);
+
+		count -= cnt;
+		buffer += cnt;
+		ret += cnt;
+		start_dac(state);
+	}
+	return ret;
+}
+
+/* No kernel lock - we have our own spinlock */
+static unsigned int trident_poll(struct file *file, struct poll_table_struct *wait)
+{
+	struct trident_state *state = (struct trident_state *)file->private_data;
+	struct dmabuf *dmabuf = &state->dmabuf;
+	unsigned long flags;
+	unsigned int mask = 0;
+
+	VALIDATE_STATE(state);
+	if (file->f_mode & FMODE_WRITE)
+		poll_wait(file, &dmabuf->wait, wait);
+	if (file->f_mode & FMODE_READ)
+		poll_wait(file, &dmabuf->wait, wait);
+
+	spin_lock_irqsave(&state->card->lock, flags);
+	trident_update_ptr(state);
+	if (file->f_mode & FMODE_READ) {
+		if (dmabuf->count >= (signed)dmabuf->fragsize)
+			mask |= POLLIN | POLLRDNORM;
+	}
+	if (file->f_mode & FMODE_WRITE) {
+		if (dmabuf->mapped) {
+			if (dmabuf->count >= (signed)dmabuf->fragsize)
+				mask |= POLLOUT | POLLWRNORM;
+		} else {
+			if ((signed)dmabuf->dmasize >= dmabuf->count + (signed)dmabuf->fragsize)
+				mask |= POLLOUT | POLLWRNORM;
+		}
+	}
+	spin_unlock_irqrestore(&state->card->lock, flags);
+
+	return mask;
+}
+
+static int trident_mmap(struct file *file, struct vm_area_struct *vma)
+{
+	struct trident_state *state = (struct trident_state *)file->private_data;
+	struct dmabuf *dmabuf = &state->dmabuf;
+	int ret;
+	unsigned long size;
+
+	VALIDATE_STATE(state);
+	if (vma->vm_flags & VM_WRITE) {
+		if ((ret = prog_dmabuf(state, 0)) != 0)
+			return ret;
+	} else if (vma->vm_flags & VM_READ) {
+		if ((ret = prog_dmabuf(state, 1)) != 0)
+			return ret;
+	} else 
+		return -EINVAL;
+
+
+	if (vma->vm_offset != 0)
+		return -EINVAL;
+	size = vma->vm_end - vma->vm_start;
+	if (size > (PAGE_SIZE << dmabuf->buforder))
+		return -EINVAL;
+	if (remap_page_range(vma->vm_start, virt_to_phys(dmabuf->rawbuf),
+			     size, vma->vm_page_prot))
+		return -EAGAIN;
+	dmabuf->mapped = 1;
+
+	return 0;
+}
+
+static int trident_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg)
+{
+	struct trident_state *state = (struct trident_state *)file->private_data;
+	struct dmabuf *dmabuf = &state->dmabuf;
+	unsigned long flags;
+	audio_buf_info abinfo;
+	count_info cinfo;
+	int val, mapped, ret;
+
+	VALIDATE_STATE(state);
+	mapped = ((file->f_mode & FMODE_WRITE) && dmabuf->mapped) ||
+		((file->f_mode & FMODE_READ) && dmabuf->mapped);
+#ifdef DEBUG
+	printk("trident: trident_ioctl, command = %2d, arg = 0x%08x\n",
+	       _IOC_NR(cmd), arg ? *(int *)arg : 0);
+#endif
+
+	switch (cmd) 
+	{
+	case OSS_GETVERSION:
+		return put_user(SOUND_VERSION, (int *)arg);
+
+	case SNDCTL_DSP_RESET:
+		/* FIXME: spin_lock ? */
+		if (file->f_mode & FMODE_WRITE) {
+			stop_dac(state);
+			synchronize_irq();
+			dmabuf->ready = 0;
+			dmabuf->swptr = dmabuf->hwptr = 0;
+			dmabuf->count = dmabuf->total_bytes = 0;
+		}
+		if (file->f_mode & FMODE_READ) {
+			stop_adc(state);
+			synchronize_irq();
+			dmabuf->ready = 0;
+			dmabuf->swptr = dmabuf->hwptr = 0;
+			dmabuf->count = dmabuf->total_bytes = 0;
+		}
+		return 0;
+
+	case SNDCTL_DSP_SYNC:
+		if (file->f_mode & FMODE_WRITE)
+			return drain_dac(state, file->f_flags & O_NONBLOCK);
+		return 0;
+
+	case SNDCTL_DSP_SPEED: /* set smaple rate */
+		get_user_ret(val, (int *)arg, -EFAULT);
+		if (val >= 0) {
+			if (file->f_mode & FMODE_WRITE) {
+				stop_dac(state);
+				dmabuf->ready = 0;
+				spin_lock_irqsave(&state->card->lock, flags);
+				trident_set_dac_rate(state, val);
+				spin_unlock_irqrestore(&state->card->lock, flags);
+			}
+			if (file->f_mode & FMODE_READ) {
+				stop_adc(state);
+				dmabuf->ready = 0;
+				spin_lock_irqsave(&state->card->lock, flags);
+				trident_set_adc_rate(state, val);
+				spin_unlock_irqrestore(&state->card->lock, flags);
+			}
+		}
+		return put_user(dmabuf->rate, (int *)arg);
+
+	case SNDCTL_DSP_STEREO: /* set stereo or mono channel */
+		get_user_ret(val, (int *)arg, -EFAULT);
+		if (file->f_mode & FMODE_WRITE) {
+			stop_dac(state);
+			dmabuf->ready = 0;
+			if (val)
+				dmabuf->fmt |= TRIDENT_FMT_STEREO;
+			else
+				dmabuf->fmt &= ~TRIDENT_FMT_STEREO;
+		}
+		if (file->f_mode & FMODE_READ) {
+			stop_adc(state);
+			dmabuf->ready = 0;
+			if (val)
+				dmabuf->fmt |= TRIDENT_FMT_STEREO;
+			else
+				dmabuf->fmt &= ~TRIDENT_FMT_STEREO;
+		}
+		return 0;
+
+	case SNDCTL_DSP_GETBLKSIZE:
+		if (file->f_mode & FMODE_WRITE) {
+			if ((val = prog_dmabuf(state, 0)))
+				return val;
+			return put_user(dmabuf->fragsize, (int *)arg);
+		}
+		if (file->f_mode & FMODE_READ) {
+			if ((val = prog_dmabuf(state, 1)))
+				return val;
+			return put_user(dmabuf->fragsize, (int *)arg);
+		}
+
+	case SNDCTL_DSP_GETFMTS: /* Returns a mask of supported sample format*/
+		return put_user(AFMT_S16_LE|AFMT_U16_LE|AFMT_S8|AFMT_U8, (int *)arg);
+
+	case SNDCTL_DSP_SETFMT: /* Select sample format */
+		get_user_ret(val, (int *)arg, -EFAULT);
+		if (val != AFMT_QUERY) {
+			if (file->f_mode & FMODE_WRITE) {
+				stop_dac(state);
+				dmabuf->ready = 0;
+				if (val == AFMT_S16_LE)
+					dmabuf->fmt |= TRIDENT_FMT_16BIT;
+				else
+					dmabuf->fmt &= ~TRIDENT_FMT_16BIT;
+			}
+			if (file->f_mode & FMODE_READ) {
+				stop_adc(state);
+				dmabuf->ready = 0;
+				if (val == AFMT_S16_LE)
+					dmabuf->fmt |= TRIDENT_FMT_16BIT;
+				else
+					dmabuf->fmt &= ~TRIDENT_FMT_16BIT;
+			}
+		}
+		return put_user((dmabuf->fmt & TRIDENT_FMT_16BIT) ?
+				AFMT_S16_LE : AFMT_U8, (int *)arg);
+
+	case SNDCTL_DSP_CHANNELS:
+		get_user_ret(val, (int *)arg, -EFAULT);
+		if (val != 0) {
+			if (file->f_mode & FMODE_WRITE) {
+				stop_dac(state);
+				dmabuf->ready = 0;
+				if (val >= 2)
+					dmabuf->fmt |= TRIDENT_FMT_STEREO;
+				else
+					dmabuf->fmt &= ~TRIDENT_FMT_STEREO;
+			}
+			if (file->f_mode & FMODE_READ) {
+				stop_adc(state);
+				dmabuf->ready = 0;
+				if (val >= 2)
+					dmabuf->fmt |= TRIDENT_FMT_STEREO;
+				else
+					dmabuf->fmt &= ~TRIDENT_FMT_STEREO;
+			}
+		}
+		return put_user((dmabuf->fmt & TRIDENT_FMT_STEREO) ? 2 : 1,
+				(int *)arg);
+
+	case SNDCTL_DSP_POST:
+		/* FIXME: the same as RESET ?? */
+		return 0;
+
+	case SNDCTL_DSP_SUBDIVIDE:
+		if (dmabuf->subdivision)
+			return -EINVAL;
+		get_user_ret(val, (int *)arg, -EFAULT);
+		if (val != 1 && val != 2 && val != 4)
+			return -EINVAL;
+		dmabuf->subdivision = val;
+		return 0;
+
+	case SNDCTL_DSP_SETFRAGMENT:
+		get_user_ret(val, (int *)arg, -EFAULT);
+
+		dmabuf->ossfragshift = val & 0xffff;
+		dmabuf->ossmaxfrags = (val >> 16) & 0xffff;
+		if (dmabuf->ossfragshift < 4)
+			dmabuf->ossfragshift = 4;
+		if (dmabuf->ossfragshift > 15)
+			dmabuf->ossfragshift = 15;
+		if (dmabuf->ossmaxfrags < 4)
+			dmabuf->ossmaxfrags = 4;
+
+		return 0;
+
+	case SNDCTL_DSP_GETOSPACE:
+		if (!(file->f_mode & FMODE_WRITE))
+			return -EINVAL;
+		if (!dmabuf->enable && (val = prog_dmabuf(state, 0)) != 0)
+			return val;
+		spin_lock_irqsave(&state->card->lock, flags);
+		trident_update_ptr(state);
+		abinfo.fragsize = dmabuf->fragsize;
+		abinfo.bytes = dmabuf->dmasize - dmabuf->count;
+		abinfo.fragstotal = dmabuf->numfrag;
+		abinfo.fragments = abinfo.bytes >> dmabuf->fragshift;
+		spin_unlock_irqrestore(&state->card->lock, flags);
+		return copy_to_user((void *)arg, &abinfo, sizeof(abinfo)) ? -EFAULT : 0;
+
+	case SNDCTL_DSP_GETISPACE:
+		if (!(file->f_mode & FMODE_READ))
+			return -EINVAL;
+		if (!dmabuf->enable && (val = prog_dmabuf(state, 1)) != 0)
+			return val;
+		spin_lock_irqsave(&state->card->lock, flags);
+		trident_update_ptr(state);
+		abinfo.fragsize = dmabuf->fragsize;
+		abinfo.bytes = dmabuf->count;
+		abinfo.fragstotal = dmabuf->numfrag;
+		abinfo.fragments = abinfo.bytes >> dmabuf->fragshift;
+		spin_unlock_irqrestore(&state->card->lock, flags);
+		return copy_to_user((void *)arg, &abinfo, sizeof(abinfo)) ? -EFAULT : 0;
+
+	case SNDCTL_DSP_NONBLOCK:
+		file->f_flags |= O_NONBLOCK;
+		return 0;
+
+	case SNDCTL_DSP_GETCAPS:
+	    return put_user(DSP_CAP_REALTIME|DSP_CAP_TRIGGER|DSP_CAP_MMAP, 
+			    (int *)arg);
+
+	case SNDCTL_DSP_GETTRIGGER:
+		val = 0;
+		if (file->f_mode & FMODE_READ && dmabuf->enable)
+			val |= PCM_ENABLE_INPUT;
+		if (file->f_mode & FMODE_WRITE && dmabuf->enable)
+			val |= PCM_ENABLE_OUTPUT;
+		return put_user(val, (int *)arg);
+
+	case SNDCTL_DSP_SETTRIGGER:
+		get_user_ret(val, (int *)arg, -EFAULT);
+		if (file->f_mode & FMODE_READ) {
+			if (val & PCM_ENABLE_INPUT) {
+				if (!dmabuf->ready && (ret = prog_dmabuf(state, 1)))
+					return ret;
+				start_adc(state);
+			} else
+				stop_adc(state);
+		}
+		if (file->f_mode & FMODE_WRITE) {
+			if (val & PCM_ENABLE_OUTPUT) {
+				if (!dmabuf->ready && (ret = prog_dmabuf(state, 0)))
+					return ret;
+				start_dac(state);
+			} else
+				stop_dac(state);
+		}
+		return 0;
+
+	case SNDCTL_DSP_GETIPTR:
+		if (!(file->f_mode & FMODE_READ))
+			return -EINVAL;
+		spin_lock_irqsave(&state->card->lock, flags);
+		trident_update_ptr(state);
+		cinfo.bytes = dmabuf->total_bytes;
+		cinfo.blocks = dmabuf->count >> dmabuf->fragshift;
+		cinfo.ptr = dmabuf->hwptr;
+		if (dmabuf->mapped)
+			dmabuf->count &= dmabuf->fragsize-1;
+		spin_unlock_irqrestore(&state->card->lock, flags);
+		return copy_to_user((void *)arg, &cinfo, sizeof(cinfo));
+
+	case SNDCTL_DSP_GETOPTR:
+		if (!(file->f_mode & FMODE_WRITE))
+			return -EINVAL;
+		spin_lock_irqsave(&state->card->lock, flags);
+		trident_update_ptr(state);
+		cinfo.bytes = dmabuf->total_bytes;
+		cinfo.blocks = dmabuf->count >> dmabuf->fragshift;
+		cinfo.ptr = dmabuf->hwptr;
+		if (dmabuf->mapped)
+			dmabuf->count &= dmabuf->fragsize-1;
+		spin_unlock_irqrestore(&state->card->lock, flags);
+		return copy_to_user((void *)arg, &cinfo, sizeof(cinfo));
+
+	case SNDCTL_DSP_SETDUPLEX:
+		return -EINVAL;
+
+	case SNDCTL_DSP_GETODELAY:
+		if (!(file->f_mode & FMODE_WRITE))
+			return -EINVAL;
+		spin_lock_irqsave(&state->card->lock, flags);
+		trident_update_ptr(state);
+		val = dmabuf->count;
+		spin_unlock_irqrestore(&state->card->lock, flags);
+		return put_user(val, (int *)arg);
+
+	case SOUND_PCM_READ_RATE:
+		return put_user(dmabuf->rate, (int *)arg);
+
+	case SOUND_PCM_READ_CHANNELS:
+		return put_user((dmabuf->fmt & TRIDENT_FMT_STEREO) ? 2 : 1,
+				(int *)arg);
+
+	case SOUND_PCM_READ_BITS:
+		return put_user((dmabuf->fmt & TRIDENT_FMT_16BIT) ?
+				AFMT_S16_LE : AFMT_U8, (int *)arg);
+
+	case SNDCTL_DSP_MAPINBUF:
+	case SNDCTL_DSP_MAPOUTBUF:
+	case SNDCTL_DSP_SETSYNCRO:
+	case SOUND_PCM_WRITE_FILTER:
+	case SOUND_PCM_READ_FILTER:
+		return -EINVAL;
+		
+	}
+	return -EINVAL;
+}
+
+static int trident_open(struct inode *inode, struct file *file)
+{
+	int i = 0;
+	int minor = MINOR(inode->i_rdev);
+	struct trident_card *card = devs;
+	struct trident_state *state = NULL;
+	struct dmabuf *dmabuf = NULL;
+
+	MOD_INC_USE_COUNT;
+	/* find an avaiable virtual channel (instance of /dev/dsp) */
+	while (card != NULL) {
+		down(&card->open_sem);
+		for (i = 0; i < NR_HW_CH; i++) {
+			if (card->states[i] == NULL) {
+				state = card->states[i] = (struct trident_state *)
+					kmalloc(sizeof(struct trident_state), GFP_KERNEL);
+				if (state == NULL) {
+					MOD_DEC_USE_COUNT;
+					return -ENOMEM;
+				}
+				memset(state, 0, sizeof(struct trident_state));
+				dmabuf = &state->dmabuf;
+				goto found_virt;
+			}
+		}
+		up(&card->open_sem);
+		card = card->next;
+	}
+	/* no more virtual channel avaiable */
+	if (!state) {
+		MOD_DEC_USE_COUNT;
+		return -ENODEV;
+	}
+ found_virt:
+	/* found a free virtual channel, allocate hardware channels */
+	if(file->f_mode & FMODE_READ)
+		dmabuf->channel = card->alloc_rec_pcm_channel(card);
+	else
+		dmabuf->channel = card->alloc_pcm_channel(card);
+		
+	if (dmabuf->channel == NULL) {
+		kfree (card->states[i]);
+		card->states[i] = NULL;
+		MOD_DEC_USE_COUNT;
+		return -ENODEV;
+	}
+
+	/* initialize the virtual channel */
+	state->virt = i;
+	state->card = card;
+	state->magic = TRIDENT_STATE_MAGIC;
+	init_waitqueue(&dmabuf->wait);
+	file->private_data = state;
+
+	/* set default sample format. According to OSS Programmer's Guide  /dev/dsp
+	   should be default to unsigned 8-bits, mono, with sample rate 8kHz and
+	   /dev/dspW will accept 16-bits sample */
+	if (file->f_mode & FMODE_WRITE) {
+		dmabuf->fmt &= ~TRIDENT_FMT_MASK;
+		if ((minor & 0x0f) == SND_DEV_DSP16)
+			dmabuf->fmt |= TRIDENT_FMT_16BIT;
+		dmabuf->ossfragshift = 0;
+		dmabuf->ossmaxfrags  = 0;
+		dmabuf->subdivision  = 0;
+		if (card->pci_id == PCI_DEVICE_ID_SI_7018) {
+			/* set default channel attribute to normal playback */
+			dmabuf->channel->attribute = CHANNEL_PB;
+		}
+		trident_set_dac_rate(state, 8000);
+	}
+
+	if (file->f_mode & FMODE_READ) {
+		if (card->pci_id == PCI_DEVICE_ID_ALI_5451) {
+			card->states[ALI_PCM_IN_CHANNEL] = state;
+			card->states[i] = NULL;
+			state->virt = ALI_PCM_IN_CHANNEL;
+		}
+		/* FIXME: Trident 4d can only record in signed 16-bits stereo, 48kHz sample,
+		   to be dealed with in trident_set_adc_rate() ?? */
+		dmabuf->fmt &= ~TRIDENT_FMT_MASK;
+		if ((minor & 0x0f) == SND_DEV_DSP16)
+			dmabuf->fmt |= TRIDENT_FMT_16BIT;
+		dmabuf->ossfragshift = 0;
+		dmabuf->ossmaxfrags  = 0;
+		dmabuf->subdivision  = 0;
+		if (card->pci_id == PCI_DEVICE_ID_SI_7018) {
+			/* set default channel attribute to 0x8a80, record from
+			   PCM L/R FIFO and mono = (left + right + 1)/2*/
+			dmabuf->channel->attribute =
+				(CHANNEL_REC|PCM_LR|MONO_MIX);
+		}
+		trident_set_adc_rate(state, 8000);
+	}
+
+	state->open_mode |= file->f_mode & (FMODE_READ | FMODE_WRITE);
+	up(&card->open_sem);
+
+#ifdef DEBUG
+       printk(KERN_ERR "trident: open virtual channel %d, hard channel %d\n", 
+              state->virt, dmabuf->channel->num);
+#endif
+
+	return 0;
+}
+
+static int trident_release(struct inode *inode, struct file *file)
+{
+	struct trident_state *state = (struct trident_state *)file->private_data;
+	struct trident_card *card = state->card;
+	struct dmabuf *dmabuf = &state->dmabuf;
+
+	VALIDATE_STATE(state);
+
+	if (file->f_mode & FMODE_WRITE) {
+		trident_clear_tail(state);
+		drain_dac(state, file->f_flags & O_NONBLOCK);
+	}
+
+	/* stop DMA state machine and free DMA buffers/channels */
+	down(&card->open_sem);
+
+	if (file->f_mode & FMODE_WRITE) {
+		stop_dac(state);
+		dealloc_dmabuf(state);
+		state->card->free_pcm_channel(state->card, dmabuf->channel->num);
+	}
+	if (file->f_mode & FMODE_READ) {
+		stop_adc(state);
+		dealloc_dmabuf(state);
+		state->card->free_pcm_channel(state->card, dmabuf->channel->num);
+	}
+
+	card->states[state->virt] = NULL;
+	kfree(state);
+
+	/* we're covered by the open_sem */
+	up(&card->open_sem);
+
+	MOD_DEC_USE_COUNT;
+	return 0;
+}
+
+static /*const*/ struct file_operations trident_audio_fops = {
+	llseek:		trident_llseek,
+	read:		trident_read,
+	write:		trident_write,
+	poll:		trident_poll,
+	ioctl:		trident_ioctl,
+	mmap:		trident_mmap,
+	open:		trident_open,
+	release:	trident_release,
+};
+
+/* trident specific AC97 functions */
+/* Write AC97 codec registers */
+static void trident_ac97_set(struct ac97_codec *codec, u8 reg, u16 val)
+{
+	struct trident_card *card = (struct trident_card *)codec->private_data;
+	unsigned int address, mask, busy;
+	unsigned short count  = 0xffff;
+	unsigned long flags;
+	u32 data;
+
+	data = ((u32) val) << 16;
+
+	switch (card->pci_id)
+	{
+	default:
+	case PCI_DEVICE_ID_SI_7018:
+		address = SI_AC97_WRITE;
+		mask = SI_AC97_BUSY_WRITE | SI_AC97_AUDIO_BUSY;
+		if (codec->id)
+			mask |= SI_AC97_SECONDARY;
+		busy = SI_AC97_BUSY_WRITE;
+		break;
+	case PCI_DEVICE_ID_TRIDENT_4DWAVE_DX:
+		address = DX_ACR0_AC97_W;
+		mask = busy = DX_AC97_BUSY_WRITE;
+		break;
+	case PCI_DEVICE_ID_TRIDENT_4DWAVE_NX:
+		address = NX_ACR1_AC97_W;
+		mask = NX_AC97_BUSY_WRITE;
+		if (codec->id)
+			mask |= NX_AC97_WRITE_SECONDARY;
+		busy = NX_AC97_BUSY_WRITE;
+		break;
+	}
+
+	spin_lock_irqsave(&card->lock, flags);
+	do {
+		if ((inw(TRID_REG(card, address)) & busy) == 0)
+			break;
+	} while (count--);
+
+
+	data |= (mask | (reg & AC97_REG_ADDR));
+
+	if (count == 0) {
+		printk(KERN_ERR "trident: AC97 CODEC write timed out.\n");
+		spin_unlock_irqrestore(&card->lock, flags);
+		return;
+	}
+
+	outl(data, TRID_REG(card, address));
+	spin_unlock_irqrestore(&card->lock, flags);
+}
+
+/* Read AC97 codec registers */
+static u16 trident_ac97_get(struct ac97_codec *codec, u8 reg)
+{
+	struct trident_card *card = (struct trident_card *)codec->private_data;
+	unsigned int address, mask, busy;
+	unsigned short count = 0xffff;
+	unsigned long flags;
+	u32 data;
+
+	switch (card->pci_id)
+	{
+	default:
+	case PCI_DEVICE_ID_SI_7018:
+		address = SI_AC97_READ;
+		mask = SI_AC97_BUSY_READ | SI_AC97_AUDIO_BUSY;
+		if (codec->id)
+			mask |= SI_AC97_SECONDARY;
+		busy = SI_AC97_BUSY_READ;
+		break;
+	case PCI_DEVICE_ID_TRIDENT_4DWAVE_DX:
+		address = DX_ACR1_AC97_R;
+		mask = busy = DX_AC97_BUSY_READ;
+		break;
+	case PCI_DEVICE_ID_TRIDENT_4DWAVE_NX:
+		if (codec->id)
+			address = NX_ACR3_AC97_R_SECONDARY;
+		else
+			address = NX_ACR2_AC97_R_PRIMARY;
+		mask = NX_AC97_BUSY_READ;
+		busy = NX_AC97_BUSY_READ | NX_AC97_BUSY_DATA;
+		break;
+	}
+
+	data = (mask | (reg & AC97_REG_ADDR));
+
+	spin_lock_irqsave(&card->lock, flags);
+	outl(data, TRID_REG(card, address));
+	do {
+		data = inl(TRID_REG(card, address));
+		if ((data & busy) == 0)
+			break;
+	} while (count--);
+	spin_unlock_irqrestore(&card->lock, flags);
+
+	if (count == 0) {
+		printk(KERN_ERR "trident: AC97 CODEC read timed out.\n");
+		data = 0;
+	}
+	return ((u16) (data >> 16));
+}
+
+/* Write AC97 codec registers for ALi*/
+static void ali_ac97_set(struct ac97_codec *codec, u8 reg, u16 val)
+{
+	struct trident_card *card = (struct trident_card *)codec->private_data;
+	unsigned int address, mask;
+	unsigned int wCount1 = 0xffff;
+	unsigned int wCount2= 0xffff;
+	unsigned long chk1, chk2;
+	unsigned long flags;
+	u32 data;
+
+	data = ((u32) val) << 16;
+
+	address = ALI_AC97_WRITE;
+	mask = ALI_AC97_WRITE_ACTION | ALI_AC97_AUDIO_BUSY;
+	if (codec->id)
+		mask |= ALI_AC97_SECONDARY;
+	if (card->revision == 0x02)
+		mask |= ALI_AC97_WRITE_MIXER_REGISTER;
+		
+	spin_lock_irqsave(&card->lock, flags);
+	while (wCount1--) {
+		if ((inw(TRID_REG(card, address)) & ALI_AC97_BUSY_WRITE) == 0) {
+			data |= (mask | (reg & AC97_REG_ADDR));
+			
+			chk1 = inl(TRID_REG(card,  ALI_STIMER));
+			chk2 = inl(TRID_REG(card,  ALI_STIMER));
+			while (wCount2-- && (chk1 == chk2))
+				chk2 = inl(TRID_REG(card,  ALI_STIMER));
+			if (wCount2 == 0) {
+				spin_unlock_irqrestore(&card->lock, flags);
+				return;
+			}
+			outl(data, TRID_REG(card, address));	//write!
+			spin_unlock_irqrestore(&card->lock, flags);
+			return;	//success
+		}
+		inw(TRID_REG(card, address));	//wait a read cycle
+	}
+
+	printk(KERN_ERR "ali: AC97 CODEC write timed out.\n");
+	spin_unlock_irqrestore(&card->lock, flags);
+	return;
+}
+
+/* Read AC97 codec registers for ALi*/
+static u16 ali_ac97_get(struct ac97_codec *codec, u8 reg)
+{
+	struct trident_card *card = (struct trident_card *)codec->private_data;
+	unsigned int address, mask;
+        unsigned int wCount1 = 0xffff;
+        unsigned int wCount2= 0xffff;
+        unsigned long chk1, chk2;
+	unsigned long flags;
+	u32 data;
+
+	address = ALI_AC97_READ;
+	if (card->revision == 0x02) {
+		address = ALI_AC97_WRITE;
+		mask &= ALI_AC97_READ_MIXER_REGISTER;
+	}
+	mask = ALI_AC97_READ_ACTION | ALI_AC97_AUDIO_BUSY;
+	if (codec->id)
+		mask |= ALI_AC97_SECONDARY;
+
+	spin_lock_irqsave(&card->lock, flags);
+	data = (mask | (reg & AC97_REG_ADDR));
+	while (wCount1--) {
+		if ((inw(TRID_REG(card, address)) & ALI_AC97_BUSY_READ) == 0) {
+			chk1 = inl(TRID_REG(card,  ALI_STIMER));
+			chk2 = inl(TRID_REG(card,  ALI_STIMER));
+			while (wCount2-- && (chk1 == chk2))
+				chk2 = inl(TRID_REG(card,  ALI_STIMER));
+			if (wCount2 == 0) {
+				printk(KERN_ERR "ali: AC97 CODEC read timed out.\n");
+				spin_unlock_irqrestore(&card->lock, flags);
+				return 0;
+			}
+			outl(data, TRID_REG(card, address));	//read!
+			wCount2 = 0xffff;
+			while (wCount2--) {
+				if ((inw(TRID_REG(card, address)) & ALI_AC97_BUSY_READ) == 0) {
+					data = inl(TRID_REG(card, address));
+					spin_unlock_irqrestore(&card->lock, flags);
+					return ((u16) (data >> 16));
+				}
+			}
+		}
+		inw(TRID_REG(card, address));	//wait a read cycle
+	}
+	spin_unlock_irqrestore(&card->lock, flags);
+	printk(KERN_ERR "ali: AC97 CODEC read timed out.\n");
+	return 0;
+}
+
+/* OSS /dev/mixer file operation methods */
+static int trident_open_mixdev(struct inode *inode, struct file *file)
+{
+	int i;
+	int minor = MINOR(inode->i_rdev);
+	struct trident_card *card = devs;
+
+	MOD_INC_USE_COUNT;
+	for (card = devs; card != NULL; card = card->next)
+		for (i = 0; i < NR_AC97; i++)
+			if (card->ac97_codec[i] != NULL &&
+			    card->ac97_codec[i]->dev_mixer == minor)
+				goto match;
+
+	if (!card) {
+		MOD_DEC_USE_COUNT;
+		return -ENODEV;
+	}
+ match:
+	file->private_data = card->ac97_codec[i];
+
+
+	return 0;
+}
+
+static int trident_release_mixdev(struct inode *inode, struct file *file)
+{
+	MOD_DEC_USE_COUNT;
+	return 0;
+}
+
+static int trident_ioctl_mixdev(struct inode *inode, struct file *file, unsigned int cmd,
+				unsigned long arg)
+{
+	struct ac97_codec *codec = (struct ac97_codec *)file->private_data;
+
+	return codec->mixer_ioctl(codec, cmd, arg);
+}
+
+static /*const*/ struct file_operations trident_mixer_fops = {
+	llseek:		trident_llseek,
+	ioctl:		trident_ioctl_mixdev,
+	open:		trident_open_mixdev,
+	release:	trident_release_mixdev,
+};
+
+/* AC97 codec initialisation. */
+static int __init trident_ac97_init(struct trident_card *card)
+{
+	int num_ac97 = 0;
+	int ready_2nd = 0;
+	struct ac97_codec *codec;
+
+	/* initialize controller side of AC link, and find out if secondary codes
+	   really exist */
+	switch (card->pci_id)
+	{
+	case PCI_DEVICE_ID_ALI_5451:
+		outl(PCMOUT|SECONDARY_ID, TRID_REG(card, SI_SERIAL_INTF_CTRL));
+		ready_2nd = inl(TRID_REG(card, SI_SERIAL_INTF_CTRL)); 
+		ready_2nd &= SI_AC97_SECONDARY_READY;
+		break;
+	case PCI_DEVICE_ID_SI_7018:
+		/* disable AC97 GPIO interrupt */
+		outl(0x00, TRID_REG(card, SI_AC97_GPIO));
+		/* when power up the AC link is in cold reset mode so stop it */
+		outl(PCMOUT|SURROUT|CENTEROUT|LFEOUT|SECONDARY_ID,
+		     TRID_REG(card, SI_SERIAL_INTF_CTRL));
+		/* it take a long time to recover from a cold reset (especially when you have
+		   more than one codec) */
+		udelay(2000);
+		ready_2nd = inl(TRID_REG(card, SI_SERIAL_INTF_CTRL));
+		ready_2nd &= SI_AC97_SECONDARY_READY;
+		break;
+	case PCI_DEVICE_ID_TRIDENT_4DWAVE_DX:
+		/* playback on */
+		outl(DX_AC97_PLAYBACK, TRID_REG(card, DX_ACR2_AC97_COM_STAT));
+		break;
+	case PCI_DEVICE_ID_TRIDENT_4DWAVE_NX:
+		/* enable AC97 Output Slot 3,4 (PCM Left/Right Playback) */
+		outl(NX_AC97_PCM_OUTPUT, TRID_REG(card, NX_ACR0_AC97_COM_STAT));
+		ready_2nd = inl(TRID_REG(card, NX_ACR0_AC97_COM_STAT));
+		ready_2nd &= NX_AC97_SECONDARY_READY;
+		break;
+	}
+
+	for (num_ac97 = 0; num_ac97 < NR_AC97; num_ac97++) {
+		if ((codec = kmalloc(sizeof(struct ac97_codec), GFP_KERNEL)) == NULL)
+			return -ENOMEM;
+		memset(codec, 0, sizeof(struct ac97_codec));
+
+		/* initialize some basic codec information, other fields will be filled
+		   in ac97_probe_codec */
+		codec->private_data = card;
+		codec->id = num_ac97;
+
+		if (card->pci_id == PCI_DEVICE_ID_ALI_5451) {
+			codec->codec_read = ali_ac97_get;
+			codec->codec_write = ali_ac97_set;
+		}
+		else {
+			codec->codec_read = trident_ac97_get;
+			codec->codec_write = trident_ac97_set;
+		}
+	
+		if (ac97_probe_codec(codec) == 0)
+			break;
+
+		if ((codec->dev_mixer = register_sound_mixer(&trident_mixer_fops, -1)) < 0) {
+			printk(KERN_ERR "trident: couldn't register mixer!\n");
+			kfree(codec);
+			break;
+		}
+
+		card->ac97_codec[num_ac97] = codec;
+
+		/* if there is no secondary codec at all, don't probe any more */
+		if (!ready_2nd)
+			return num_ac97+1;
+	}
+
+	return num_ac97;
+}
+
+/* install the driver, we do not allocate hardware channel nor DMA buffer now, they are defered 
+   untill "ACCESS" time (in prog_dmabuf called by open/read/write/ioctl/mmap) */
+static int __init trident_install(struct pci_dev *pci_dev, struct pci_audio_info *pci_info)
+{
+	u16 w;
+	unsigned long iobase;
+	struct trident_card *card;
+
+
+	iobase = pci_dev->base_address[0] & PCI_BASE_ADDRESS_IO_MASK;
+	if (check_region(iobase, 256)) {
+		printk(KERN_ERR "trident: can't allocate I/O space at 0x%4.4lx\n",
+		       iobase);
+		return -ENODEV;
+	}
+
+	/* just to be sure that IO space and bus master is on */
+	pci_set_master(pci_dev);
+	pci_read_config_word(pci_dev, PCI_COMMAND, &w);
+	w |= PCI_COMMAND_IO|PCI_COMMAND_MASTER;
+	pci_write_config_word(pci_dev, PCI_COMMAND, w);
+
+	if ((card = kmalloc(sizeof(struct trident_card), GFP_KERNEL)) == NULL) {
+		printk(KERN_ERR "trident: out of memory\n");
+		return -ENOMEM;
+	}
+	memset(card, 0, sizeof(*card));
+
+	card->iobase = iobase;
+	card->pci_info = pci_info;
+	card->pci_id = pci_info->device;
+	card->irq = pci_dev->irq;
+	card->next = devs;
+	card->magic = TRIDENT_CARD_MAGIC;
+	card->banks[BANK_A].addresses = &bank_a_addrs;
+	card->banks[BANK_A].bitmap = 0UL;
+	card->banks[BANK_B].addresses = &bank_b_addrs;
+	card->banks[BANK_B].bitmap = 0UL;
+	card->open_sem = MUTEX;
+	spin_lock_init(&card->lock);
+	devs = card;
+
+	printk(KERN_INFO "trident: %s found at IO 0x%04lx, IRQ %d\n",
+	       card->pci_info->name, card->iobase, card->irq);
+
+	if(card->pci_id == PCI_DEVICE_ID_ALI_5451) {
+		card->alloc_pcm_channel = ali_alloc_pcm_channel;
+		card->alloc_rec_pcm_channel = ali_alloc_rec_pcm_channel;
+		card->free_pcm_channel = ali_free_pcm_channel;
+		card->address_interrupt = ali_address_interrupt;
+	}
+	else {
+		card->alloc_pcm_channel = trident_alloc_pcm_channel;
+		card->alloc_rec_pcm_channel = trident_alloc_pcm_channel;
+		card->free_pcm_channel = trident_free_pcm_channel;
+		card->address_interrupt = trident_address_interrupt;
+	}
+
+	/* claim our iospace and irq */
+	request_region(card->iobase, 256, card->pci_info->name);
+	if (request_irq(card->irq, &trident_interrupt, SA_SHIRQ, card->pci_info->name, card)) {
+		printk(KERN_ERR "trident: unable to allocate irq %d\n", card->irq);
+		release_region(card->iobase, 256);
+		kfree(card);
+		return -ENODEV;
+	}
+	/* register /dev/dsp */
+	if ((card->dev_audio = register_sound_dsp(&trident_audio_fops, -1)) < 0) {
+		printk(KERN_ERR "trident: couldn't register DSP device!\n");
+		release_region(iobase, 256);
+		free_irq(card->irq, card);
+		kfree(card);
+		return -ENODEV;
+	}
+	/* initilize AC97 codec and register /dev/mixer */
+	if (trident_ac97_init(card) <= 0) {
+		unregister_sound_dsp(card->dev_audio);
+		release_region(iobase, 256);
+		free_irq(card->irq, card);
+		kfree(card);
+		return -ENODEV;
+	}
+	outl(0x00, TRID_REG(card, T4D_MUSICVOL_WAVEVOL));
+
+	if (card->pci_id == PCI_DEVICE_ID_ALI_5451) {
+		/* edited by HMSEO for GT sound */
+#ifdef CONFIG_ALPHA_NAUTILUS
+		ac97_data = trident_ac97_get (card->ac97_codec[0], AC97_POWER_CONTROL);
+		trident_ac97_set (card->ac97_codec[0], AC97_POWER_CONTROL,
+				  ac97_data | ALI_EAPD_POWER_DOWN);
+#endif
+		/* edited by HMSEO for GT sound*/
+	}
+
+	/* Enable Address Engine Interrupts */
+	trident_enable_loop_interrupts(card);
+
+	return 1;
+}
+
+#ifdef MODULE
+int init_module(void)
+#else
+int init_trident(void)
+#endif
+ {
+	struct pci_dev *pcidev = NULL;
+	int foundone = 0;
+ 	int i;
+ 
+	if (!pci_present())   /* No PCI bus in this machine! */
+		return -ENODEV;
+ 
+	printk(KERN_INFO "Trident 4DWave/SiS 7018 PCI Audio, version "
+	       DRIVER_VERSION ", " __TIME__ " " __DATE__ "\n");
+ 
+	for (i = 0; i < sizeof (pci_audio_devices); i++) {
+		pcidev = NULL;
+		while ((pcidev = pci_find_device(pci_audio_devices[i].vendor,
+						 pci_audio_devices[i].device,
+						 pcidev)) != NULL) {
+			foundone += trident_install(pcidev, pci_audio_devices + i);
+ 		}
+	}
+ 
+	if (!foundone)
+		return -ENODEV;
+	return 0;
+}
+
+#ifdef MODULE
+MODULE_AUTHOR("Alan Cox, Aaron Holtzman, Ollie Lho, Ching Ling Lee");
+MODULE_DESCRIPTION("Trident 4DWave/SiS 7018/ALi 5451 PCI Audio Driver");
+
+void cleanup_module(void)
+#else
+void cleanup_trident(void)
+#endif
+{
+	while (devs != NULL) {
+		int i;
+		/* Kill interrupts, and SP/DIF */
+		trident_disable_loop_interrupts(devs);
+ 
+		/* free hardware resources */
+		free_irq(devs->irq, devs);
+		release_region(devs->iobase, 256);
+ 
+		/* unregister audio devices */
+		for (i = 0; i < NR_AC97; i++)
+			if (devs->ac97_codec[i] != NULL) {
+				unregister_sound_mixer(devs->ac97_codec[i]->dev_mixer);
+				kfree (devs->ac97_codec[i]);
+			}
+		unregister_sound_dsp(devs->dev_audio);
+ 
+		kfree(devs);
+		devs = devs->next;
+	}
+}
+

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