usbaudio.c

来自「Linux Kernel 2.6.9 for OMAP1710」· C语言 代码 · 共 2,293 行 · 第 1/5 页

 * the value is referred in prepare_playback_urb().
 */
static int retire_playback_sync_urb(snd_usb_substream_t *subs,
				    snd_pcm_runtime_t *runtime,
				    struct urb *urb)
{
	int i;
	unsigned int f, found;
	unsigned char *cp = urb->transfer_buffer;
	unsigned long flags;

	found = 0;
	for (i = 0; i < urb->number_of_packets; i++, cp += 4) {
		if (urb->iso_frame_desc[i].status ||
		    urb->iso_frame_desc[i].actual_length < 3)
			continue;
		f = combine_triple(cp) << 2;
#if 0
		if (f < subs->freqn - (subs->freqn>>3) || f > subs->freqmax) {
			snd_printd(KERN_WARNING "requested frequency %d (%u,%03uHz) out of range (current nominal %d (%u,%03uHz))\n",
				   f, f >> 14, (f & ((1 << 14) - 1) * 1000) / ((1 << 14) - 1),
				   subs->freqn, subs->freqn >> 14, (subs->freqn & ((1 << 14) - 1) * 1000) / ((1 << 14) - 1));
			continue;
		}
#endif
		found = f;
	}
	if (found) {
		spin_lock_irqsave(&subs->lock, flags);
		subs->freqm = found;
		spin_unlock_irqrestore(&subs->lock, flags);
	}

	return 0;
}

/*
 * process after high speed playback sync complete
 *
 * retrieve the current 12.13 frequency from pipe, and set it.
 * the value is referred in prepare_playback_urb().
 */
static int retire_playback_sync_urb_hs(snd_usb_substream_t *subs,
				       snd_pcm_runtime_t *runtime,
				       struct urb *urb)
{
	int i;
	unsigned int found;
	unsigned char *cp = urb->transfer_buffer;
	unsigned long flags;

	found = 0;
	for (i = 0; i < urb->number_of_packets; i++, cp += 4) {
		if (urb->iso_frame_desc[i].status ||
		    urb->iso_frame_desc[i].actual_length < 4)
			continue;
		found = combine_quad(cp) & 0x0fffffff;
	}
	if (found) {
		spin_lock_irqsave(&subs->lock, flags);
		subs->freqm = found;
		spin_unlock_irqrestore(&subs->lock, flags);
	}

	return 0;
}

/*
 * prepare urb for playback data pipe
 *
 * we copy the data directly from the pcm buffer.
 * the current position to be copied is held in hwptr field.
 * since a urb can handle only a single linear buffer, if the total
 * transferred area overflows the buffer boundary, we cannot send
 * it directly from the buffer.  thus the data is once copied to
 * a temporary buffer and urb points to that.
 */
static int prepare_playback_urb(snd_usb_substream_t *subs,
				snd_pcm_runtime_t *runtime,
				struct urb *urb)
{
	int i, stride, offs;
	unsigned int counts;
	unsigned long flags;
	snd_urb_ctx_t *ctx = (snd_urb_ctx_t *)urb->context;

	stride = runtime->frame_bits >> 3;

	offs = 0;
	urb->dev = ctx->subs->dev; /* we need to set this at each time */
	urb->number_of_packets = 0;
	spin_lock_irqsave(&subs->lock, flags);
	for (i = 0; i < ctx->packets; i++) {
		/* calculate the size of a packet */
		if (subs->fill_max)
			counts = subs->maxframesize; /* fixed */
		else {
			subs->phase = (subs->phase & 0xffff) + subs->freqm;
			counts = subs->phase >> 16;
			if (counts > subs->maxframesize)
				counts = subs->maxframesize;
		}
		/* set up descriptor */
		urb->iso_frame_desc[i].offset = offs * stride;
		urb->iso_frame_desc[i].length = counts * stride;
		offs += counts;
		urb->number_of_packets++;
		subs->transfer_sched += counts;
		if (subs->transfer_sched >= runtime->period_size) {
			subs->transfer_sched -= runtime->period_size;
			if (subs->fmt_type == USB_FORMAT_TYPE_II) {
				if (subs->transfer_sched > 0) {
					/* FIXME: fill-max mode is not supported yet */
					offs -= subs->transfer_sched;
					counts -= subs->transfer_sched;
					urb->iso_frame_desc[i].length = counts * stride;
					subs->transfer_sched = 0;
				}
				i++;
				if (i < ctx->packets) {
					/* add a transfer delimiter */
					urb->iso_frame_desc[i].offset = offs * stride;
					urb->iso_frame_desc[i].length = 0;
					urb->number_of_packets++;
				}
			}
			break;
 		}
	}
	if (subs->hwptr + offs > runtime->buffer_size) {
		/* err, the transferred area goes over buffer boundary.
		 * copy the data to the temp buffer.
		 */
		int len;
		len = runtime->buffer_size - subs->hwptr;
		urb->transfer_buffer = subs->tmpbuf;
		memcpy(subs->tmpbuf, runtime->dma_area + subs->hwptr * stride, len * stride);
		memcpy(subs->tmpbuf + len * stride, runtime->dma_area, (offs - len) * stride);
		subs->hwptr += offs;
		subs->hwptr -= runtime->buffer_size;
	} else {
		/* set the buffer pointer */
		urb->transfer_buffer = runtime->dma_area + subs->hwptr * stride;
		subs->hwptr += offs;
	}
	spin_unlock_irqrestore(&subs->lock, flags);
	urb->transfer_buffer_length = offs * stride;
	ctx->transfer = offs;

	return 0;
}

/*
 * process after playback data complete
 *
 * update the current position and call callback if a period is processed.
 */
static int retire_playback_urb(snd_usb_substream_t *subs,
			       snd_pcm_runtime_t *runtime,
			       struct urb *urb)
{
	unsigned long flags;
	snd_urb_ctx_t *ctx = (snd_urb_ctx_t *)urb->context;

	spin_lock_irqsave(&subs->lock, flags);
	subs->transfer_done += ctx->transfer;
	subs->hwptr_done += ctx->transfer;
	ctx->transfer = 0;
	if (subs->hwptr_done >= runtime->buffer_size)
		subs->hwptr_done -= runtime->buffer_size;
	if (subs->transfer_done >= runtime->period_size) {
		subs->transfer_done -= runtime->period_size;
		spin_unlock_irqrestore(&subs->lock, flags);
		snd_pcm_period_elapsed(subs->pcm_substream);
	} else
		spin_unlock_irqrestore(&subs->lock, flags);
	return 0;
}


/*
 */
static struct snd_urb_ops audio_urb_ops[2] = {
	{
		.prepare =	prepare_playback_urb,
		.retire =	retire_playback_urb,
		.prepare_sync =	prepare_playback_sync_urb,
		.retire_sync =	retire_playback_sync_urb,
	},
	{
		.prepare =	prepare_capture_urb,
		.retire =	retire_capture_urb,
		.prepare_sync =	prepare_capture_sync_urb,
		.retire_sync =	retire_capture_sync_urb,
	},
};

static struct snd_urb_ops audio_urb_ops_high_speed[2] = {
	{
		.prepare =	prepare_playback_urb,
		.retire =	retire_playback_urb,
		.prepare_sync =	prepare_playback_sync_urb_hs,
		.retire_sync =	retire_playback_sync_urb_hs,
	},
	{
		.prepare =	prepare_capture_urb,
		.retire =	retire_capture_urb,
		.prepare_sync =	prepare_capture_sync_urb_hs,
		.retire_sync =	retire_capture_sync_urb,
	},
};

/*
 * complete callback from data urb
 */
static void snd_complete_urb(struct urb *urb, struct pt_regs *regs)
{
	snd_urb_ctx_t *ctx = (snd_urb_ctx_t *)urb->context;
	snd_usb_substream_t *subs = ctx->subs;
	snd_pcm_substream_t *substream = ctx->subs->pcm_substream;
	int err = 0;

	if ((subs->running && subs->ops.retire(subs, substream->runtime, urb)) ||
	    ! subs->running || /* can be stopped during retire callback */
	    (err = subs->ops.prepare(subs, substream->runtime, urb)) < 0 ||
	    (err = usb_submit_urb(urb, GFP_ATOMIC)) < 0) {
		clear_bit(ctx->index, &subs->active_mask);
		if (err < 0) {
			snd_printd(KERN_ERR "cannot submit urb (err = %d)\n", err);
			snd_pcm_stop(substream, SNDRV_PCM_STATE_XRUN);
		}
	}
}


/*
 * complete callback from sync urb
 */
static void snd_complete_sync_urb(struct urb *urb, struct pt_regs *regs)
{
	snd_urb_ctx_t *ctx = (snd_urb_ctx_t *)urb->context;
	snd_usb_substream_t *subs = ctx->subs;
	snd_pcm_substream_t *substream = ctx->subs->pcm_substream;
	int err = 0;

	if ((subs->running && subs->ops.retire_sync(subs, substream->runtime, urb)) ||
	    ! subs->running || /* can be stopped during retire callback */
	    (err = subs->ops.prepare_sync(subs, substream->runtime, urb)) < 0 ||
	    (err = usb_submit_urb(urb, GFP_ATOMIC)) < 0) {
		clear_bit(ctx->index + 16, &subs->active_mask);
		if (err < 0) {
			snd_printd(KERN_ERR "cannot submit sync urb (err = %d)\n", err);
			snd_pcm_stop(substream, SNDRV_PCM_STATE_XRUN);
		}
	}
}


/*
 * unlink active urbs.
 */
static int deactivate_urbs(snd_usb_substream_t *subs, int force, int can_sleep)
{
	unsigned int i;
	int async;

	subs->running = 0;

	if (!force && subs->stream->chip->shutdown) /* to be sure... */
		return 0;

	async = !can_sleep && async_unlink;

	if (! async && in_interrupt())
		return 0;

	for (i = 0; i < subs->nurbs; i++) {
		if (test_bit(i, &subs->active_mask)) {
			if (! test_and_set_bit(i, &subs->unlink_mask)) {
				struct urb *u = subs->dataurb[i].urb;
				if (async)
					u->transfer_flags |= URB_ASYNC_UNLINK;
				else
					u->transfer_flags &= ~URB_ASYNC_UNLINK;
				usb_unlink_urb(u);
			}
		}
	}
	if (subs->syncpipe) {
		for (i = 0; i < SYNC_URBS; i++) {
			if (test_bit(i+16, &subs->active_mask)) {
 				if (! test_and_set_bit(i+16, &subs->unlink_mask)) {
					struct urb *u = subs->syncurb[i].urb;
					if (async)
						u->transfer_flags |= URB_ASYNC_UNLINK;
					else
						u->transfer_flags &= ~URB_ASYNC_UNLINK;
					usb_unlink_urb(u);
				}
			}
		}
	}
	return 0;
}


/*
 * set up and start data/sync urbs
 */
static int start_urbs(snd_usb_substream_t *subs, snd_pcm_runtime_t *runtime)
{
	unsigned int i;
	int err;

	for (i = 0; i < subs->nurbs; i++) {
		snd_assert(subs->dataurb[i].urb, return -EINVAL);
		if (subs->ops.prepare(subs, runtime, subs->dataurb[i].urb) < 0) {
			snd_printk(KERN_ERR "cannot prepare datapipe for urb %d\n", i);
			goto __error;
		}
	}
	if (subs->syncpipe) {
		for (i = 0; i < SYNC_URBS; i++) {
			snd_assert(subs->syncurb[i].urb, return -EINVAL);
			if (subs->ops.prepare_sync(subs, runtime, subs->syncurb[i].urb) < 0) {
				snd_printk(KERN_ERR "cannot prepare syncpipe for urb %d\n", i);
				goto __error;
			}
		}
	}

	subs->active_mask = 0;
	subs->unlink_mask = 0;
	subs->running = 1;
	for (i = 0; i < subs->nurbs; i++) {
		if ((err = usb_submit_urb(subs->dataurb[i].urb, GFP_ATOMIC)) < 0) {
			snd_printk(KERN_ERR "cannot submit datapipe for urb %d, err = %d\n", i, err);
			goto __error;
		}
		set_bit(i, &subs->active_mask);
	}
	if (subs->syncpipe) {
		for (i = 0; i < SYNC_URBS; i++) {
			if ((err = usb_submit_urb(subs->syncurb[i].urb, GFP_ATOMIC)) < 0) {
				snd_printk(KERN_ERR "cannot submit syncpipe for urb %d, err = %d\n", i, err);
				goto __error;
			}
			set_bit(i + 16, &subs->active_mask);
		}
	}
	return 0;

 __error:
	// snd_pcm_stop(subs->pcm_substream, SNDRV_PCM_STATE_XRUN);
	deactivate_urbs(subs, 0, 0);
	return -EPIPE;
}


/*
 *  wait until all urbs are processed.
 */
static int wait_clear_urbs(snd_usb_substream_t *subs)
{
	int timeout = HZ;
	unsigned int i;
	int alive;

	do {
		alive = 0;
		for (i = 0; i < subs->nurbs; i++) {
			if (test_bit(i, &subs->active_mask))
				alive++;
		}
		if (subs->syncpipe) {
			for (i = 0; i < SYNC_URBS; i++) {
				if (test_bit(i + 16, &subs->active_mask))
					alive++;
			}
		}
		if (! alive)
			break;
		set_current_state(TASK_UNINTERRUPTIBLE);
		schedule_timeout(1);
	} while (--timeout > 0);
	if (alive)
		snd_printk(KERN_ERR "timeout: still %d active urbs..\n", alive);
	return 0;
}


/*
 * return the current pcm pointer.  just return the hwptr_done value.
 */
static snd_pcm_uframes_t snd_usb_pcm_pointer(snd_pcm_substream_t *substream)
{
	snd_usb_substream_t *subs = (snd_usb_substream_t *)substream->runtime->private_data;
	return subs->hwptr_done;
}


/*
 * start/stop substream
 */
static int snd_usb_pcm_trigger(snd_pcm_substream_t *substream, int cmd)
{
	snd_usb_substream_t *subs = (snd_usb_substream_t *)substream->runtime->private_data;
	int err;

	switch (cmd) {
	case SNDRV_PCM_TRIGGER_START:
		err = start_urbs(subs, substream->runtime);
		break;
	case SNDRV_PCM_TRIGGER_STOP:
		err = deactivate_urbs(subs, 0, 0);
		break;
	default:
		err = -EINVAL;
		break;
	}
	return err < 0 ? err : 0;
}


/*
 * release a urb data
 */
static void release_urb_ctx(snd_urb_ctx_t *u)
{
	if (u->urb) {
		usb_free_urb(u->urb);
		u->urb = NULL;
	}
	if (u->buf) {
		kfree(u->buf);
		u->buf = NULL;
	}
}

/*
 * release a substream
 */
static void release_substream_urbs(snd_usb_substream_t *subs, int force)
{
	int i;

	/* stop urbs (to be sure) */
	deactivate_urbs(subs, force, 1);
	wait_clear_urbs(subs);

	for (i = 0; i < MAX_URBS; i++)
		release_urb_ctx(&subs->dataurb[i]);
	for (i = 0; i < SYNC_URBS; i++)
		release_urb_ctx(&subs->syncurb[i]);
	if (subs->tmpbuf) {
		kfree(subs->tmpbuf);
		subs->tmpbuf = NULL;
	}
	subs->nurbs = 0;