cs46xx.c

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		SGarray[4] = *(ptmp+2);                                             
		SGarray[5] = 0x80000010;                                            
		SGarray[6] = *ptmp;                                                 
		SGarray[7] = *(ptmp+2);                                             
		SGarray[8] = (virt_to_bus(dmabuf->pbuf) & 0xffff000) | 0x10;        

		if (dmabuf->SGok) {                                                 
			dmabuf->numfrag = nSGpages;                                 
			dmabuf->fragsize = 4096;                                    
			dmabuf->fragsamples = 4096 >> sample_shift[dmabuf->fmt];    
			dmabuf->fragshift = 12;                                     
			dmabuf->dmasize = dmabuf->numfrag*4096;                     
		}                                                                   
		else {                                                              
			SGarray[0] = 0xf2c0000f;                                    
			SGarray[1] = 0x00000200;                                    
			SGarray[2] = 0;                                             
			SGarray[3] = 0x00010600;                                    
			SGarray[4]=SGarray[5]=SGarray[6]=SGarray[7]=SGarray[8] = 0; 
			dmabuf->numfrag = 2;                                        
			dmabuf->fragsize = 2048;                                    
			dmabuf->fragsamples = 2048 >> sample_shift[dmabuf->fmt];    
			dmabuf->dmasize = 4096;                                     
			dmabuf->fragshift = 11;                                     
		}
		for(tmp1 = 0; tmp1 < sizeof(SGarray)/4; tmp1++)                     
			cs461x_poke( state->card, BA1_PDTC+tmp1*4, SGarray[tmp1]);  

		memset(dmabuf->rawbuf, (dmabuf->fmt & CS_FMT_16BIT) ? 0 : 0x80,
		       dmabuf->dmasize);

		/*
		 *      Now set up the ring
		 */

		spin_lock_irqsave(&state->card->lock, flags);
		cs_play_setup(state);
		spin_unlock_irqrestore(&state->card->lock, flags);

		/* set the ready flag for the dma buffer */
		dmabuf->ready = 1;

		CS_DBGOUT(CS_PARMS, 4, printk(
			"cs461x: prog_dmabuf(): PLAYBACK rate=%d fmt=0x%x numfrag=%d "
			"fragsize=%d dmasize=%d\n",
			    dmabuf->rate, dmabuf->fmt, dmabuf->numfrag,
			    dmabuf->fragsize, dmabuf->dmasize) );

		CS_DBGOUT(CS_FUNCTION, 4, printk("cs46xx: prog_dmabuf()- \n"));
		return 0;
	}
	else
	{
		CS_DBGOUT(CS_FUNCTION, 4, printk("cs46xx: prog_dmabuf()- Invalid Type %d\n",
			dmabuf->type));
	}
	return 1;
}

static void cs_clear_tail(struct cs_state *state)
{
}

static int drain_dac(struct cs_state *state, int nonblock)
{
	DECLARE_WAITQUEUE(wait, current);
	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;
		}

		tmo = (dmabuf->dmasize * HZ) / dmabuf->rate;
		tmo >>= sample_shift[dmabuf->fmt];
		tmo += (2048*HZ)/dmabuf->rate;
		
		if (!schedule_timeout(tmo ? tmo : 1) && tmo){
			printk(KERN_ERR "cs461x: drain_dac, dma timeout? %d\n", count);
			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 cs_update_ptr(void)
{
	struct cs_card *card=devs;
	struct cs_state *state;
	struct dmabuf *dmabuf;
	unsigned hwptr;
	int diff;

	/* error handling and process wake up for ADC */
	state = card->states[0];
	if(state)
	{
		dmabuf = &state->dmabuf;
		if (dmabuf->enable & ADC_RUNNING) {
			/* update hardware pointer */
			hwptr = cs_get_dma_addr(state);

			diff = (dmabuf->dmasize + hwptr - dmabuf->hwptr) % dmabuf->dmasize;
			CS_DBGOUT(CS_PARMS, 9, printk(
				"cs46xx: cs_update_ptr()+ ADC hwptr=%d diff=%d\n", 
				hwptr,diff) );
			dmabuf->hwptr = hwptr;
			dmabuf->total_bytes += diff;
			dmabuf->count += diff;
			if (dmabuf->count > dmabuf->dmasize)
				dmabuf->count = dmabuf->dmasize;

			if(dmabuf->mapped)
			{
				if (dmabuf->count >= (signed)dmabuf->fragsize)
					wake_up(&dmabuf->wait);
			} else 
			{
				if (dmabuf->count > 0)
					wake_up(&dmabuf->wait);
			}
		}
	}

/*
 * Now the DAC
 */
	state = card->states[1];
	if(state)
	{
		dmabuf = &state->dmabuf;
		/* error handling and process wake up for DAC */
		if (dmabuf->enable & DAC_RUNNING) {
			/* update hardware pointer */
			hwptr = cs_get_dma_addr(state);

			diff = (dmabuf->dmasize + hwptr - dmabuf->hwptr) % dmabuf->dmasize;
			CS_DBGOUT(CS_PARMS, 9, printk(
				"cs46xx: cs_update_ptr()+ DAC hwptr=%d diff=%d\n", 
				hwptr,diff) );
			dmabuf->hwptr = hwptr;
			dmabuf->total_bytes += diff;
			if (dmabuf->mapped) {
				dmabuf->count += diff;
				if (dmabuf->count >= (signed)dmabuf->fragsize)
					wake_up(&dmabuf->wait);
				/*
				 * other drivers use fragsize, but don't see any sense
				 * in that, since dmasize is the buffer asked for
				 * via mmap.
				 */
				if( dmabuf->count > dmabuf->dmasize)
					dmabuf->count &= dmabuf->dmasize-1;
			} else {
				dmabuf->count -= diff;
				/*
				 * backfill with silence and clear out the last 
				 * "diff" number of bytes.
				 */
				if(hwptr >= diff)
				{
					memset(dmabuf->rawbuf + hwptr - diff, 
						(dmabuf->fmt & CS_FMT_16BIT) ? 0 : 0x80, diff);
				}
				else
				{
					memset(dmabuf->rawbuf, 
						(dmabuf->fmt & CS_FMT_16BIT) ? 0 : 0x80,
						(unsigned)hwptr);
					memset((void *)((unsigned)dmabuf->rawbuf + 
							dmabuf->dmasize + hwptr - diff),
						(dmabuf->fmt & CS_FMT_16BIT) ? 0 : 0x80, 
						diff - hwptr); 
				}

				if (dmabuf->count < 0 || dmabuf->count > dmabuf->dmasize) {
					CS_DBGOUT(CS_ERROR, 2, printk(
					  "cs46xx: ERROR DAC count<0 or count > dmasize (%d)\n",
					  	dmabuf->count));
					/* 
					* buffer underrun or buffer overrun, reset the
					* count of bytes written back to 0.
					*/
					if(dmabuf->count < 0)
						dmabuf->underrun=1;
					dmabuf->count = 0;
					dmabuf->error++;
				}
				if (dmabuf->count < (signed)dmabuf->dmasize/2)
					wake_up(&dmabuf->wait);
			}
		}
	}
}


/* hold spinlock for the following! */
static void cs_handle_midi(struct cs_card *card)
{
        unsigned char ch;
        int wake;
        unsigned temp1;

        wake = 0;
        while (!(cs461x_peekBA0(card,  BA0_MIDSR) & MIDSR_RBE)) {
                ch = cs461x_peekBA0(card, BA0_MIDRP);
                if (card->midi.icnt < CS_MIDIINBUF) {
                        card->midi.ibuf[card->midi.iwr] = ch;
                        card->midi.iwr = (card->midi.iwr + 1) % CS_MIDIINBUF;
                        card->midi.icnt++;
                }
                wake = 1;
        }
        if (wake)
                wake_up(&card->midi.iwait);
        wake = 0;
        while (!(cs461x_peekBA0(card,  BA0_MIDSR) & MIDSR_TBF) && card->midi.ocnt > 0) {
                temp1 = ( card->midi.obuf[card->midi.ord] ) & 0x000000ff;
                cs461x_pokeBA0(card, BA0_MIDWP,temp1);
                card->midi.ord = (card->midi.ord + 1) % CS_MIDIOUTBUF;
                card->midi.ocnt--;
                if (card->midi.ocnt < CS_MIDIOUTBUF-16)
                        wake = 1;
        }
        if (wake)
                wake_up(&card->midi.owait);
}

static void cs_interrupt(int irq, void *dev_id, struct pt_regs *regs)
{
	struct cs_card *card = (struct cs_card *)dev_id;
	/* Single channel card */
	struct cs_state *recstate = card->channel[0].state;
	struct cs_state *playstate = card->channel[1].state;
	u32 status;

	CS_DBGOUT(CS_INTERRUPT, 4, printk("cs46xx: cs_interrupt()+ \n"));

	spin_lock(&card->lock);

	status = cs461x_peekBA0(card, BA0_HISR);
	
	if ((status & 0x7fffffff) == 0)
	{
		cs461x_pokeBA0(card, BA0_HICR, HICR_CHGM|HICR_IEV);
		spin_unlock(&card->lock);
		return;
	}
	
	/*
	 * check for playback or capture interrupt only
	 */
	if( ((status & HISR_VC0) && playstate && playstate->dmabuf.ready) || 
	    (((status & HISR_VC1) && recstate && recstate->dmabuf.ready)) )
	{
		CS_DBGOUT(CS_INTERRUPT, 8, printk(
			"cs46xx: cs_interrupt() interrupt bit(s) set (0x%x)\n",status));
		cs_update_ptr();
	}

        if( status & HISR_MIDI )
                cs_handle_midi(card);
	
 	/* clear 'em */
	cs461x_pokeBA0(card, BA0_HICR, HICR_CHGM|HICR_IEV);
	spin_unlock(&card->lock);
	CS_DBGOUT(CS_INTERRUPT, 4, printk("cs46xx: cs_interrupt()- \n"));
}


/**********************************************************************/

static ssize_t cs_midi_read(struct file *file, char *buffer, size_t count, loff_t *ppos)
{
        struct cs_card *card = (struct cs_card *)file->private_data;
        ssize_t ret;
        unsigned long flags;
        unsigned ptr;
        int cnt;

        if (ppos != &file->f_pos)
                return -ESPIPE;
        if (!access_ok(VERIFY_WRITE, buffer, count))
                return -EFAULT;
        ret = 0;
        while (count > 0) {
                spin_lock_irqsave(&card->lock, flags);
                ptr = card->midi.ird;
                cnt = CS_MIDIINBUF - ptr;
                if (card->midi.icnt < cnt)
                        cnt = card->midi.icnt;
                spin_unlock_irqrestore(&card->lock, flags);
                if (cnt > count)
                        cnt = count;
                if (cnt <= 0) {
                        if (file->f_flags & O_NONBLOCK)
                                return ret ? ret : -EAGAIN;
                        interruptible_sleep_on(&card->midi.iwait);
                        if (signal_pending(current))
                                return ret ? ret : -ERESTARTSYS;
                        continue;
                }
                if (copy_to_user(buffer, card->midi.ibuf + ptr, cnt))
                        return ret ? ret : -EFAULT;
                ptr = (ptr + cnt) % CS_MIDIINBUF;
                spin_lock_irqsave(&card->lock, flags);
                card->midi.ird = ptr;
                card->midi.icnt -= cnt;
                spin_unlock_irqrestore(&card->lock, flags);
                count -= cnt;
                buffer += cnt;
                ret += cnt;
        }
        return ret;
}


static ssize_t cs_midi_write(struct file *file, const char *buffer, size_t count, loff_t *ppos)
{
        struct cs_card *card = (struct cs_card *)file->private_data;
        ssize_t ret;
        unsigned long flags;
        unsigned ptr;
        int cnt;

        if (ppos != &file->f_pos)
                return -ESPIPE;
        if (!access_ok(VERIFY_READ, buffer, count))
                return -EFAULT;
        ret = 0;
        while (count > 0) {
                spin_lock_irqsave(&card->lock, flags);
                ptr = card->midi.owr;
                cnt = CS_MIDIOUTBUF - ptr;
                if (card->midi.ocnt + cnt > CS_MIDIOUTBUF)
                        cnt = CS_MIDIOUTBUF - card->midi.ocnt;
                if (cnt <= 0)
                        cs_handle_midi(card);
                spin_unlock_irqrestore(&card->lock, flags);
                if (cnt > count)
                        cnt = count;
                if (cnt <= 0) {
                        if (file->f_flags & O_NONBLOCK)
                                return ret ? ret : -EAGAIN;
                        interruptible_sleep_on(&card->midi.owait);
                        if (signal_pending(current))
                                return ret ? ret : -ERESTARTSYS;
                        continue;
                }
                if (copy_from_user(card->midi.obuf + ptr, buffer, cnt))
                        return ret ? ret : -EFAULT;
                ptr = (ptr + cnt) % CS_MIDIOUTBUF;
                spin_lock_irqsave(&card->lock, flags);
                card->midi.owr = ptr;
                card->midi.ocnt += cnt;
                spin_unlock_irqrestore(&card->lock, flags);
                count -= cnt;
                buffer += cnt;
                ret += cnt;
                spin_lock_irqsave(&card->lock, flags);
                cs_handle_midi(card);
                spin_unlock_irqrestore(&card->lock, flags);
        }
        return ret;
}


static unsigned int cs_midi_poll(struct file *file, struct poll_table_struct *wait)
{
        struct cs_card *card = (struct cs_card *)file->private_data;
        unsigned long flags;
        unsigned int mask = 0;

        if (file->f_flags & FMODE_WRITE)
                poll_wait(file, &card->midi.owait, wait);
        if (file->f_flags & FMODE_READ)
                poll_wait(file, &card->midi.iwait, wait);
        spin_lock_irqsave(&card->lock, flags);
        if (file->f_flags & FMODE_READ) {
                if (card->midi.icnt > 0)
                        mask |= POLLIN | POLLRDNORM;
        }
        if (file->f_flags & FMODE_WRITE) {
                if (card->midi.ocnt < CS_MIDIOUTBUF)
                        mask |= POLLOUT | POLLWRNORM;
        }
        spin_unlock_irqrestore(&card->lock, flags);
        return mask;
}