vwsnd.c

iis s3c2410-uda1341语音系统的 开发

			     wport->sample_size);
		ad1843_setup_dac(&devc->lith,
				 wport->sw_framerate,
				 wport->sw_samplefmt,
				 wport->sw_channels);
		li_enable_interrupts(&devc->lith, WRITE_INTR_MASK);
	}
	DBGRV();
	return 0;
}

/*
 * pcm_shutdown_port - shut down one port (direction) for PCM I/O.
 * Only called from pcm_shutdown.
 */

static void pcm_shutdown_port(vwsnd_dev_t *devc,
			      vwsnd_port_t *aport,
			      unsigned int mask)
{
	unsigned long flags;
	vwsnd_port_hwstate_t hwstate;
	DECLARE_WAITQUEUE(wait, current);

	aport->swstate = SW_INITIAL;
	add_wait_queue(&aport->queue, &wait);
	while (1) {
		set_current_state(TASK_UNINTERRUPTIBLE);
		spin_lock_irqsave(&aport->lock, flags);
		{
			hwstate = aport->hwstate;
		}		
		spin_unlock_irqrestore(&aport->lock, flags);
		if (hwstate == HW_STOPPED)
			break;
		schedule();
	}
	current->state = TASK_RUNNING;
	remove_wait_queue(&aport->queue, &wait);
	li_disable_interrupts(&devc->lith, mask);
	if (aport == &devc->rport)
		ad1843_shutdown_adc(&devc->lith);
	else /* aport == &devc->wport) */
		ad1843_shutdown_dac(&devc->lith);
	li_shutdown_dma(&aport->chan);
	vfree(aport->swbuf);
	aport->swbuf = NULL;
	aport->byte_count = 0;
}

/*
 * pcm_shutdown undoes what pcm_setup did.
 * Also sets the ports' swstate to newstate.
 */

static void pcm_shutdown(vwsnd_dev_t *devc,
			 vwsnd_port_t *rport,
			 vwsnd_port_t *wport)
{
	DBGEV("(devc=0x%p, rport=0x%p, wport=0x%p)\n", devc, rport, wport);

	if (rport && rport->swbuf) {
		DBGPV("shutting down rport\n");
		pcm_shutdown_port(devc, rport, READ_INTR_MASK);
	}
	if (wport && wport->swbuf) {
		DBGPV("shutting down wport\n");
		pcm_shutdown_port(devc, wport, WRITE_INTR_MASK);
	}
	DBGRV();
}

static void pcm_copy_in(vwsnd_port_t *rport, int swidx, int hwidx, int nb)
{
	char *src = rport->hwbuf + hwidx;
	char *dst = rport->swbuf + swidx;
	int fmt = rport->sw_samplefmt;

	DBGPV("swidx = %d, hwidx = %d\n", swidx, hwidx);
	ASSERT(rport->hwbuf != NULL);
	ASSERT(rport->swbuf != NULL);
	ASSERT(nb > 0 && (nb % 32) == 0);
	ASSERT(swidx % 32 == 0 && hwidx % 32 == 0);
	ASSERT(swidx >= 0 && swidx + nb <= rport->swbuf_size);
	ASSERT(hwidx >= 0 && hwidx + nb <= rport->hwbuf_size);

	if (fmt == AFMT_MU_LAW || fmt == AFMT_A_LAW || fmt == AFMT_S8) {

		/* See Sample Format Notes above. */

		char *end = src + nb;
		while (src < end)
			*dst++ = *src++ ^ 0x80;
	} else
		memcpy(dst, src, nb);
}

static void pcm_copy_out(vwsnd_port_t *wport, int swidx, int hwidx, int nb)
{
	char *src = wport->swbuf + swidx;
	char *dst = wport->hwbuf + hwidx;
	int fmt = wport->sw_samplefmt;

	ASSERT(nb > 0 && (nb % 32) == 0);
	ASSERT(wport->hwbuf != NULL);
	ASSERT(wport->swbuf != NULL);
	ASSERT(swidx % 32 == 0 && hwidx % 32 == 0);
	ASSERT(swidx >= 0 && swidx + nb <= wport->swbuf_size);
	ASSERT(hwidx >= 0 && hwidx + nb <= wport->hwbuf_size);
	if (fmt == AFMT_MU_LAW || fmt == AFMT_A_LAW || fmt == AFMT_S8) {

		/* See Sample Format Notes above. */

		char *end = src + nb;
		while (src < end)
			*dst++ = *src++ ^ 0x80;
	} else
		memcpy(dst, src, nb);
}

/*
 * pcm_output() is called both from baselevel and from interrupt level.
 * This is where audio frames are copied into the hardware-accessible
 * ring buffer.
 *
 * Locking note: The part of this routine that figures out what to do
 * holds wport->lock.  The longer part releases wport->lock, but sets
 * wport->flags & HW_BUSY.  Afterward, it reacquires wport->lock, and
 * checks for more work to do.
 *
 * If another thread calls pcm_output() while HW_BUSY is set, it
 * returns immediately, knowing that the thread that set HW_BUSY will
 * look for more work to do before returning.
 *
 * This has the advantage that port->lock is held for several short
 * periods instead of one long period.  Also, when pcm_output is
 * called from base level, it reenables interrupts.
 */

static void pcm_output(vwsnd_dev_t *devc, int erflown, int nb)
{
	vwsnd_port_t *wport = &devc->wport;
	const int hwmax  = wport->hwbuf_max;
	const int hwsize = wport->hwbuf_size;
	const int swsize = wport->swbuf_size;
	const int fragsize = wport->hw_fragsize;
	unsigned long iflags;

	DBGEV("(devc=0x%p, erflown=%d, nb=%d)\n", devc, erflown, nb);
	spin_lock_irqsave(&wport->lock, iflags);
	if (erflown)
		wport->flags |= ERFLOWN;
	(void) __swb_inc_u(wport, nb);
	if (wport->flags & HW_BUSY) {
		spin_unlock_irqrestore(&wport->lock, iflags);
		DBGPV("returning: HW BUSY\n");
		return;
	}
	if (wport->flags & DISABLED) {
		spin_unlock_irqrestore(&wport->lock, iflags);
		DBGPV("returning: DISABLED\n");
		return;
	}
	wport->flags |= HW_BUSY;
	while (1) {
		int swptr, hwptr, hw_avail, sw_avail, swidx;
		vwsnd_port_hwstate_t hwstate = wport->hwstate;
		vwsnd_port_swstate_t swstate = wport->swstate;
		int hw_unavail;
		ustmsc_t ustmsc;

		hwptr = li_read_hwptr(&wport->chan);
		swptr = li_read_swptr(&wport->chan);
		hw_unavail = (swptr - hwptr + hwsize) % hwsize;
		hw_avail = (hwmax - hw_unavail) & -fragsize;
		sw_avail = wport->swb_i_avail & -fragsize;
		if (sw_avail && swstate == SW_RUN) {
			if (wport->flags & ERFLOWN) {
				wport->flags &= ~ERFLOWN;
			}
		} else if (swstate == SW_INITIAL ||
			 swstate == SW_OFF ||
			 (swstate == SW_DRAIN &&
			  !sw_avail &&
			  (wport->flags & ERFLOWN))) {
			DBGP("stopping.  hwstate = %d\n", hwstate);
			if (hwstate != HW_STOPPED) {
				li_deactivate_dma(&wport->chan);
				wport->hwstate = HW_STOPPED;
			}
			wake_up(&wport->queue);
			break;
		}
		if (!sw_avail || !hw_avail)
			break;
		spin_unlock_irqrestore(&wport->lock, iflags);

		/*
		 * We gave up the port lock, but we have the HW_BUSY flag.
		 * Proceed without accessing any nonlocal state.
		 * Do not exit the loop -- must check for more work.
		 */

		swidx = wport->swb_i_idx;
		nb = hw_avail;
		if (nb > sw_avail)
			nb = sw_avail;
		if (nb > hwsize - swptr)
			nb = hwsize - swptr; /* don't overflow hwbuf */
		if (nb > swsize - swidx)
			nb = swsize - swidx; /* don't overflow swbuf */
		ASSERT(nb > 0);
		if (nb % fragsize) {
			DBGP("nb = %d, fragsize = %d\n", nb, fragsize);
			DBGP("hw_avail = %d\n", hw_avail);
			DBGP("sw_avail = %d\n", sw_avail);
			DBGP("hwsize = %d, swptr = %d\n", hwsize, swptr);
			DBGP("swsize = %d, swidx = %d\n", swsize, swidx);
		}
		ASSERT(!(nb % fragsize));
		DBGPV("copying swb[%d..%d] to hwb[%d..%d]\n",
		      swidx, swidx + nb, swptr, swptr + nb);
		pcm_copy_out(wport, swidx, swptr, nb);
		li_write_swptr(&wport->chan, (swptr + nb) % hwsize);
		spin_lock_irqsave(&wport->lock, iflags);
		if (hwstate == HW_STOPPED) {
			DBGPV("starting\n");
			li_activate_dma(&wport->chan);
			wport->hwstate = HW_RUNNING;
			li_read_USTMSC(&wport->chan, &ustmsc);
			ASSERT(wport->byte_count % wport->frame_size == 0);
			wport->MSC_offset = ustmsc.msc - wport->byte_count / wport->frame_size;
		}
		__swb_inc_i(wport, nb);
		wport->byte_count += nb;
		wport->frag_count += nb / fragsize;
		ASSERT(nb % fragsize == 0);
		wake_up(&wport->queue);
	}
	wport->flags &= ~HW_BUSY;
	spin_unlock_irqrestore(&wport->lock, iflags);
	DBGRV();
}

/*
 * pcm_input() is called both from baselevel and from interrupt level.
 * This is where audio frames are copied out of the hardware-accessible
 * ring buffer.
 *
 * Locking note: The part of this routine that figures out what to do
 * holds rport->lock.  The longer part releases rport->lock, but sets
 * rport->flags & HW_BUSY.  Afterward, it reacquires rport->lock, and
 * checks for more work to do.
 *
 * If another thread calls pcm_input() while HW_BUSY is set, it
 * returns immediately, knowing that the thread that set HW_BUSY will
 * look for more work to do before returning.
 *
 * This has the advantage that port->lock is held for several short
 * periods instead of one long period.  Also, when pcm_input is
 * called from base level, it reenables interrupts.
 */

static void pcm_input(vwsnd_dev_t *devc, int erflown, int nb)
{
	vwsnd_port_t *rport = &devc->rport;
	const int hwmax  = rport->hwbuf_max;
	const int hwsize = rport->hwbuf_size;
	const int swsize = rport->swbuf_size;
	const int fragsize = rport->hw_fragsize;
	unsigned long iflags;

	DBGEV("(devc=0x%p, erflown=%d, nb=%d)\n", devc, erflown, nb);

	spin_lock_irqsave(&rport->lock, iflags);
	if (erflown)
		rport->flags |= ERFLOWN;
	(void) __swb_inc_u(rport, nb);
	if (rport->flags & HW_BUSY || !rport->swbuf) {
		spin_unlock_irqrestore(&rport->lock, iflags);
		DBGPV("returning: HW BUSY or !swbuf\n");
		return;
	}
	if (rport->flags & DISABLED) {
		spin_unlock_irqrestore(&rport->lock, iflags);
		DBGPV("returning: DISABLED\n");
		return;
	}
	rport->flags |= HW_BUSY;
	while (1) {
		int swptr, hwptr, hw_avail, sw_avail, swidx;
		vwsnd_port_hwstate_t hwstate = rport->hwstate;
		vwsnd_port_swstate_t swstate = rport->swstate;

		hwptr = li_read_hwptr(&rport->chan);
		swptr = li_read_swptr(&rport->chan);
		hw_avail = (hwptr - swptr + hwsize) % hwsize & -fragsize;
		if (hw_avail > hwmax)
			hw_avail = hwmax;
		sw_avail = rport->swb_i_avail & -fragsize;
		if (swstate != SW_RUN) {
			DBGP("stopping.  hwstate = %d\n", hwstate);
			if (hwstate != HW_STOPPED) {
				li_deactivate_dma(&rport->chan);
				rport->hwstate = HW_STOPPED;
			}
			wake_up(&rport->queue);
			break;
		}
		if (!sw_avail || !hw_avail)
			break;
		spin_unlock_irqrestore(&rport->lock, iflags);

		/*
		 * We gave up the port lock, but we have the HW_BUSY flag.
		 * Proceed without accessing any nonlocal state.
		 * Do not exit the loop -- must check for more work.
		 */

		swidx = rport->swb_i_idx;
		nb = hw_avail;
		if (nb > sw_avail)
			nb = sw_avail;
		if (nb > hwsize - swptr)
			nb = hwsize - swptr; /* don't overflow hwbuf */
		if (nb > swsize - swidx)
			nb = swsize - swidx; /* don't overflow swbuf */
		ASSERT(nb > 0);
		if (nb % fragsize) {
			DBGP("nb = %d, fragsize = %d\n", nb, fragsize);
			DBGP("hw_avail = %d\n", hw_avail);
			DBGP("sw_avail = %d\n", sw_avail);
			DBGP("hwsize = %d, swptr = %d\n", hwsize, swptr);
			DBGP("swsize = %d, swidx = %d\n", swsize, swidx);
		}
		ASSERT(!(nb % fragsize));
		DBGPV("copying hwb[%d..%d] to swb[%d..%d]\n",
		      swptr, swptr + nb, swidx, swidx + nb);
		pcm_copy_in(rport, swidx, swptr, nb);
		li_write_swptr(&rport->chan, (swptr + nb) % hwsize);
		spin_lock_irqsave(&rport->lock, iflags);
		__swb_inc_i(rport, nb);
		rport->byte_count += nb;
		rport->frag_count += nb / fragsize;
		ASSERT(nb % fragsize == 0);
		wake_up(&rport->queue);
	}
	rport->flags &= ~HW_BUSY;
	spin_unlock_irqrestore(&rport->lock, iflags);
	DBGRV();
}

/*
 * pcm_flush_frag() writes zero samples to fill the current fragment,
 * then flushes it to the hardware.
 *
 * It is only meaningful to flush output, not input.
 */

static void pcm_flush_frag(vwsnd_dev_t *devc)
{
	vwsnd_port_t *wport = &devc->wport;

	DBGPV("swstate = %d\n", wport->swstate);
	if (wport->swstate == SW_RUN) {
		int idx = wport->swb_u_idx;
		int end = (idx + wport->hw_fragsize - 1)
			>> wport->hw_fragshift
			<< wport->hw_fragshift;
		int nb = end - idx;
		DBGPV("clearing %d bytes\n", nb);
		if (nb)
			memset(wport->swbuf + idx,
			       (char) wport->zero_word,
			       nb);
		wport->swstate = SW_DRAIN;
		pcm_output(devc, 0, nb);
	}
	DBGRV();
}

/*
 * Wait for output to drain.  This sleeps uninterruptibly because
 * there is nothing intelligent we can do if interrupted.  This
 * means the process will be delayed in responding to the signal.
 */

static void pcm_write_sync(vwsnd_dev_t *devc)
{
	vwsnd_port_t *wport = &devc->wport;
	DECLARE_WAITQUEUE(wait, current);
	unsigned long flags;
	vwsnd_port_hwstate_t hwstate;

	DBGEV("(devc=0x%p)\n", devc);
	add_wait_queue(&wport->queue, &wait);
	while (1) {
		set_current_state(TASK_UNINTERRUPTIBLE);
		spin_lock_irqsave(&wport->lock, flags);
		{
			hwstate = wport->hwstate;
		}
		spin_unlock_irqrestore(&wport->lock, flags);
		if (hwstate == HW_STOPPED)
			break;
		schedule();
	}
	current->state = TASK_RUNNING;
	remove_wait_queue(&wport->queue, &wait);
	DBGPV("swstate = %d, hwstate = %d\n", wport->swstate, wport->hwstate);
	DBGRV();
}

/*****************************************************************************/
/* audio driver */

/*
 * seek on an audio device always fails.
 */

static void vwsnd_audio_read_intr(vwsnd_dev_t *devc, unsigned int status)
{
	int overflown = status & LI_INTR_COMM1_OVERFLOW;

	if (status & READ_INTR_MASK)
		pcm_input(devc, overflown, 0);
}

static void vwsnd_audio_write_intr(vwsnd_dev_t *devc, unsigned int status)
{
	int underflown = status & LI_INTR_COMM2_UNDERFLOW;

	if (status & WRITE_INTR_MASK)
		pcm_output(devc, underflown, 0);
}

static void vwsnd_audio_intr(int irq, void *dev_id, struct pt_regs *regs)
{
	vwsnd_dev_t *devc = (vwsnd_dev_t *) dev_id;
	unsigned int status;

	DBGEV("(irq=%d, dev_id=0x%p, regs=0x%p)\n", irq, dev_id, regs);

	status = li_get_clear_intr_status(&devc->lith);
	vwsnd_audio_read_intr(devc, status);
	vwsnd_audio_write_intr(devc, status);
}

static ssize_t vwsnd_audio_do_read(struct file *file,
				   char *buffe