i810_audio.c

iis s3c2410-uda1341语音系统的 开发

	 * (assuming one is already allocated, if it isn't, then allocate it).
	 */
	if ((ret = alloc_dmabuf(state)))
		return ret;

	/* FIXME: figure out all this OSS fragment stuff */
	/* I did, it now does what it should according to the OSS API.  DL */
	/* We may not have realloced our dmabuf, but the fragment size to
	 * fragment number ratio may have changed, so go ahead and reprogram
	 * things
	 */
	dmabuf->dmasize = PAGE_SIZE << dmabuf->buforder;
	dmabuf->numfrag = SG_LEN;
	dmabuf->fragsize = dmabuf->dmasize/dmabuf->numfrag;
	dmabuf->fragsamples = dmabuf->fragsize >> 1;
	dmabuf->userfragsize = dmabuf->ossfragsize;
	dmabuf->userfrags = dmabuf->dmasize/dmabuf->ossfragsize;

	memset(dmabuf->rawbuf, 0, dmabuf->dmasize);

	if(dmabuf->ossmaxfrags == 4) {
		fragint = 8;
		dmabuf->fragshift = 2;
	} else if (dmabuf->ossmaxfrags == 8) {
		fragint = 4;
		dmabuf->fragshift = 3;
	} else if (dmabuf->ossmaxfrags == 16) {
		fragint = 2;
		dmabuf->fragshift = 4;
	} else {
		fragint = 1;
		dmabuf->fragshift = 5;
	}
	/*
	 *	Now set up the ring 
	 */
	if(dmabuf->read_channel)
		c = dmabuf->read_channel;
	else
		c = dmabuf->write_channel;
	while(c != NULL) {
		sg=&c->sg[0];
		/*
		 *	Load up 32 sg entries and take an interrupt at half
		 *	way (we might want more interrupts later..) 
		 */
	  
		for(i=0;i<dmabuf->numfrag;i++)
		{
			sg->busaddr=virt_to_bus(dmabuf->rawbuf+dmabuf->fragsize*i);
			// the card will always be doing 16bit stereo
			sg->control=dmabuf->fragsamples;
			if(state->card->pci_id == PCI_DEVICE_ID_SI_7012)
				sg->control <<= 1;
			sg->control|=CON_BUFPAD;
			// set us up to get IOC interrupts as often as needed to
			// satisfy numfrag requirements, no more
			if( ((i+1) % fragint) == 0) {
				sg->control|=CON_IOC;
			}
			sg++;
		}
		spin_lock_irqsave(&state->card->lock, flags);
		outb(2, state->card->iobase+c->port+OFF_CR);   /* reset DMA machine */
		outl(virt_to_bus(&c->sg[0]), state->card->iobase+c->port+OFF_BDBAR);
		outb(0, state->card->iobase+c->port+OFF_CIV);
		outb(0, state->card->iobase+c->port+OFF_LVI);

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

		if(c != dmabuf->write_channel)
			c = dmabuf->write_channel;
		else
			c = NULL;
	}
	
	/* set the ready flag for the dma buffer */
	dmabuf->ready = 1;

#ifdef DEBUG
	printk("i810_audio: prog_dmabuf, sample rate = %d, format = %d,\n\tnumfrag = %d, "
	       "fragsize = %d dmasize = %d\n",
	       dmabuf->rate, dmabuf->fmt, dmabuf->numfrag,
	       dmabuf->fragsize, dmabuf->dmasize);
#endif

	return 0;
}

static void __i810_update_lvi(struct i810_state *state, int rec)
{
	struct dmabuf *dmabuf = &state->dmabuf;
	int x, port;
	
	port = state->card->iobase;
	if(rec)
		port += dmabuf->read_channel->port;
	else
		port += dmabuf->write_channel->port;

	/* if we are currently stopped, then our CIV is actually set to our
	 * *last* sg segment and we are ready to wrap to the next.  However,
	 * if we set our LVI to the last sg segment, then it won't wrap to
	 * the next sg segment, it won't even get a start.  So, instead, when
	 * we are stopped, we set both the LVI value and also we increment
	 * the CIV value to the next sg segment to be played so that when
	 * we call start_{dac,adc}, things will operate properly
	 */
	if (!dmabuf->enable && dmabuf->ready) {
		if(rec && dmabuf->count < dmabuf->dmasize &&
		   (dmabuf->trigger & PCM_ENABLE_INPUT))
		{
			outb((inb(port+OFF_CIV)+1)&31, port+OFF_LVI);
			__start_adc(state);
			while( !(inb(port + OFF_CR) & ((1<<4) | (1<<2))) ) ;
		} else if (!rec && dmabuf->count &&
			   (dmabuf->trigger & PCM_ENABLE_OUTPUT))
		{
			outb((inb(port+OFF_CIV)+1)&31, port+OFF_LVI);
			__start_dac(state);
			while( !(inb(port + OFF_CR) & ((1<<4) | (1<<2))) ) ;
		}
	}

	/* swptr - 1 is the tail of our transfer */
	x = (dmabuf->dmasize + dmabuf->swptr - 1) % dmabuf->dmasize;
	x /= dmabuf->fragsize;
	outb(x, port+OFF_LVI);
}

static void i810_update_lvi(struct i810_state *state, int rec)
{
	struct dmabuf *dmabuf = &state->dmabuf;
	unsigned long flags;

	if(!dmabuf->ready)
		return;
	spin_lock_irqsave(&state->card->lock, flags);
	__i810_update_lvi(state, rec);
	spin_unlock_irqrestore(&state->card->lock, flags);
}

/* update buffer manangement pointers, especially, dmabuf->count and dmabuf->hwptr */
static void i810_update_ptr(struct i810_state *state)
{
	struct dmabuf *dmabuf = &state->dmabuf;
	unsigned hwptr;
	int diff;

	/* error handling and process wake up for DAC */
	if (dmabuf->enable == ADC_RUNNING) {
		/* update hardware pointer */
		hwptr = i810_get_dma_addr(state, 1);
		diff = (dmabuf->dmasize + hwptr - dmabuf->hwptr) % dmabuf->dmasize;
#if defined(DEBUG_INTERRUPTS) || defined(DEBUG_MMAP)
		printk("ADC HWP %d,%d,%d\n", hwptr, dmabuf->hwptr, diff);
#endif
		dmabuf->hwptr = hwptr;
		dmabuf->total_bytes += diff;
		dmabuf->count += diff;
		if (dmabuf->count > dmabuf->dmasize) {
			/* buffer underrun or buffer overrun */
			/* this is normal for the end of a read */
			/* only give an error if we went past the */
			/* last valid sg entry */
			if((inb(state->card->iobase + PI_CIV) & 31) !=
			   (inb(state->card->iobase + PI_LVI) & 31)) {
				printk(KERN_WARNING "i810_audio: DMA overrun on read\n");
				dmabuf->error++;
			}
		}
		if (dmabuf->count > dmabuf->userfragsize)
			wake_up(&dmabuf->wait);
	}
	/* error handling and process wake up for DAC */
	if (dmabuf->enable == DAC_RUNNING) {
		/* update hardware pointer */
		hwptr = i810_get_dma_addr(state, 0);
		diff = (dmabuf->dmasize + hwptr - dmabuf->hwptr) % dmabuf->dmasize;
#if defined(DEBUG_INTERRUPTS) || defined(DEBUG_MMAP)
		printk("DAC HWP %d,%d,%d\n", hwptr, dmabuf->hwptr, diff);
#endif
		dmabuf->hwptr = hwptr;
		dmabuf->total_bytes += diff;
		dmabuf->count -= diff;
		if (dmabuf->count < 0) {
			/* buffer underrun or buffer overrun */
			/* this is normal for the end of a write */
			/* only give an error if we went past the */
			/* last valid sg entry */
			if((inb(state->card->iobase + PO_CIV) & 31) !=
			   (inb(state->card->iobase + PO_LVI) & 31)) {
				printk(KERN_WARNING "i810_audio: DMA overrun on write\n");
				printk("i810_audio: CIV %d, LVI %d, hwptr %x, "
					"count %d\n",
					inb(state->card->iobase + PO_CIV) & 31,
					inb(state->card->iobase + PO_LVI) & 31,
					dmabuf->hwptr, dmabuf->count);
				dmabuf->error++;
			}
		}
		if (dmabuf->count < (dmabuf->dmasize-dmabuf->userfragsize))
			wake_up(&dmabuf->wait);
	}
}

static inline int i810_get_free_write_space(struct i810_state *state)
{
	struct dmabuf *dmabuf = &state->dmabuf;
	int free;

	i810_update_ptr(state);
	// catch underruns during playback
	if (dmabuf->count < 0) {
		dmabuf->count = 0;
		dmabuf->swptr = dmabuf->hwptr;
	}
	free = dmabuf->dmasize - dmabuf->count;
	free -= (dmabuf->hwptr % dmabuf->fragsize);
	if(free < 0)
		return(0);
	return(free);
}

static inline int i810_get_available_read_data(struct i810_state *state)
{
	struct dmabuf *dmabuf = &state->dmabuf;
	int avail;

	i810_update_ptr(state);
	// catch overruns during record
	if (dmabuf->count > dmabuf->dmasize) {
		dmabuf->count = dmabuf->dmasize;
		dmabuf->swptr = dmabuf->hwptr;
	}
	avail = dmabuf->count;
	avail -= (dmabuf->hwptr % dmabuf->fragsize);
	if(avail < 0)
		return(0);
	return(avail);
}

static int drain_dac(struct i810_state *state, int signals_allowed)
{
	DECLARE_WAITQUEUE(wait, current);
	struct dmabuf *dmabuf = &state->dmabuf;
	unsigned long flags;
	unsigned long tmo;
	int count;

	if (!dmabuf->ready)
		return 0;
	if(dmabuf->mapped) {
		stop_dac(state);
		return 0;
	}
	add_wait_queue(&dmabuf->wait, &wait);
	for (;;) {

		spin_lock_irqsave(&state->card->lock, flags);
		i810_update_ptr(state);
		count = dmabuf->count;
		spin_unlock_irqrestore(&state->card->lock, flags);

		if (count <= 0)
			break;

		/* 
		 * This will make sure that our LVI is correct, that our
		 * pointer is updated, and that the DAC is running.  We
		 * have to force the setting of dmabuf->trigger to avoid
		 * any possible deadlocks.
		 */
		if(!dmabuf->enable) {
			dmabuf->trigger = PCM_ENABLE_OUTPUT;
			i810_update_lvi(state,0);
		}
                if (signal_pending(current) && signals_allowed) {
                        break;
                }

		/* It seems that we have to set the current state to
		 * TASK_INTERRUPTIBLE every time to make the process
		 * really go to sleep.  This also has to be *after* the
		 * update_ptr() call because update_ptr is likely to
		 * do a wake_up() which will unset this before we ever
		 * try to sleep, resuling in a tight loop in this code
		 * instead of actually sleeping and waiting for an
		 * interrupt to wake us up!
		 */
		set_current_state(TASK_INTERRUPTIBLE);
		/*
		 * set the timeout to significantly longer than it *should*
		 * take for the DAC to drain the DMA buffer
		 */
		tmo = (count * HZ) / (dmabuf->rate);
		if (!schedule_timeout(tmo >= 2 ? tmo : 2)){
			printk(KERN_ERR "i810_audio: drain_dac, dma timeout?\n");
			count = 0;
			break;
		}
	}
	set_current_state(TASK_RUNNING);
	remove_wait_queue(&dmabuf->wait, &wait);
	if(count > 0 && signal_pending(current) && signals_allowed)
		return -ERESTARTSYS;
	stop_dac(state);
	return 0;
}

static void i810_channel_interrupt(struct i810_card *card)
{
	int i, count;
	
#ifdef DEBUG_INTERRUPTS
	printk("CHANNEL ");
#endif
	for(i=0;i<NR_HW_CH;i++)
	{
		struct i810_state *state = card->states[i];
		struct i810_channel *c;
		struct dmabuf *dmabuf;
		unsigned long port = card->iobase;
		u16 status;
		
		if(!state)
			continue;
		if(!state->dmabuf.ready)
			continue;
		dmabuf = &state->dmabuf;
		if(dmabuf->enable & DAC_RUNNING) {
			c=dmabuf->write_channel;
		} else if(dmabuf->enable & ADC_RUNNING) {
			c=dmabuf->read_channel;
		} else	/* This can occur going from R/W to close */
			continue;
		
		port+=c->port;

		if(card->pci_id == PCI_DEVICE_ID_SI_7012)
			status = inw(port + OFF_PICB);
		else
			status = inw(port + OFF_SR);

#ifdef DEBUG_INTERRUPTS
		printk("NUM %d PORT %X IRQ ( ST%d ", c->num, c->port, status);
#endif
		if(status & DMA_INT_COMPLETE)
		{
			/* only wake_up() waiters if this interrupt signals
			 * us being beyond a userfragsize of data open or
			 * available, and i810_update_ptr() does that for
			 * us
			 */
			i810_update_ptr(state);
#ifdef DEBUG_INTERRUPTS
			printk("COMP %d ", dmabuf->hwptr /
					dmabuf->fragsize);
#endif
		}
		if(status & (DMA_INT_LVI | DMA_INT_DCH))
		{
			/* wake_up() unconditionally on LVI and DCH */
			i810_update_ptr(state);
			wake_up(&dmabuf->wait);
#ifdef DEBUG_INTERRUPTS
			if(status & DMA_INT_LVI)
				printk("LVI ");
			if(status & DMA_INT_DCH)
				printk("DCH -");
#endif
			if(dmabuf->enable & DAC_RUNNING)
				count = dmabuf->count;
			else
				count = dmabuf->dmasize - dmabuf->count;
			if(count > 0) {
				outb(inb(port+OFF_CR) | 1, port+OFF_CR);
#ifdef DEBUG_INTERRUPTS
				printk(" CONTINUE ");
#endif
			} else {
				if (dmabuf->enable & DAC_RUNNING)
					__stop_dac(state);
				if (dmabuf->enable & ADC_RUNNING)
					__stop_adc(state);
				dmabuf->enable = 0;
				wake_up(&dmabuf->wait);
#ifdef DEBUG_INTERRUPTS
				printk(" STOP ");
#endif
			}
		}
		if(card->pci_id == PCI_DEVICE_ID_SI_7012)
			outw(status & DMA_INT_MASK, port + OFF_PICB);
		else
			outw(status & DMA_INT_MASK, port + OFF_SR);
	}
#ifdef DEBUG_INTERRUPTS
	printk(")\n");
#endif
}

static void i810_interrupt(int irq, void *dev_id, struct pt_regs *regs)
{
	struct i810_card *card = (struct i810_card *)dev_id;
	u32 status;

	spin_lock(&card->lock);

	status = inl(card->iobase + GLOB_STA);

	if(!(status & INT_MASK)) 
	{
		spin_unlock(&card->lock);
		return;  /* not for us */
	}

	if(status & (INT_PO|INT_PI|INT_MC))
		i810_channel_interrupt(card);

 	/* clear 'em */
	outl(status & INT_MASK, card->iobase + GLOB_STA);
	spin_unlock(&card->lock);
}

/* 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 i810_read(struct file *file, char *buffer, size_t count, loff_t *ppos)
{
	struct i810_state *state = (struct i810_state *)file->private_data;
	struct i810_card *card=state ? state->card : 0;
	struct dmabuf *dmabuf = &state->dmabuf;
	ssize_t ret;
	unsigned long flags;
	unsigned int swptr;
	int cnt;
        DECLARE_WAITQUEUE(waita, current);

#ifdef DEBUG2
	printk("i810_audio: i810_read called, count = %d\n", count);
#endif

	if (ppos != &file->f_pos)
		return -ESPIPE;