i2sbus-pcm.c

linux 内核源代码

}
#endif

static int i2sbus_pcm_trigger(struct i2sbus_dev *i2sdev, int in, int cmd)
{
	struct codec_info_item *cii;
	struct pcm_info *pi;
	int result = 0;
	unsigned long flags;

	spin_lock_irqsave(&i2sdev->low_lock, flags);

	get_pcm_info(i2sdev, in, &pi, NULL);

	switch (cmd) {
	case SNDRV_PCM_TRIGGER_START:
	case SNDRV_PCM_TRIGGER_RESUME:
		if (pi->dbdma_ring.running) {
			result = -EALREADY;
			goto out_unlock;
		}
		list_for_each_entry(cii, &i2sdev->sound.codec_list, list)
			if (cii->codec->start)
				cii->codec->start(cii, pi->substream);
		pi->dbdma_ring.running = 1;

		if (pi->dbdma_ring.stopping) {
			/* Clear the S0 bit, then see if we stopped yet */
			out_le32(&pi->dbdma->control, 1 << 16);
			if (in_le32(&pi->dbdma->status) & ACTIVE) {
				/* possible race here? */
				udelay(10);
				if (in_le32(&pi->dbdma->status) & ACTIVE) {
					pi->dbdma_ring.stopping = 0;
					goto out_unlock; /* keep running */
				}
			}
		}

		/* make sure RUN, PAUSE and S0 bits are cleared */
		out_le32(&pi->dbdma->control, (RUN | PAUSE | 1) << 16);

		/* set branch condition select register */
		out_le32(&pi->dbdma->br_sel, (1 << 16) | 1);

		/* write dma command buffer address to the dbdma chip */
		out_le32(&pi->dbdma->cmdptr, pi->dbdma_ring.bus_cmd_start);

		/* initialize the frame count and current period */
		pi->current_period = 0;
		pi->frame_count = in_le32(&i2sdev->intfregs->frame_count);

		/* set the DMA controller running */
		out_le32(&pi->dbdma->control, (RUN << 16) | RUN);

		/* off you go! */
		break;

	case SNDRV_PCM_TRIGGER_STOP:
	case SNDRV_PCM_TRIGGER_SUSPEND:
		if (!pi->dbdma_ring.running) {
			result = -EALREADY;
			goto out_unlock;
		}
		pi->dbdma_ring.running = 0;

		/* Set the S0 bit to make the DMA branch to the stop cmd */
		out_le32(&pi->dbdma->control, (1 << 16) | 1);
		pi->dbdma_ring.stopping = 1;

		list_for_each_entry(cii, &i2sdev->sound.codec_list, list)
			if (cii->codec->stop)
				cii->codec->stop(cii, pi->substream);
		break;
	default:
		result = -EINVAL;
		goto out_unlock;
	}

 out_unlock:
	spin_unlock_irqrestore(&i2sdev->low_lock, flags);
	return result;
}

static snd_pcm_uframes_t i2sbus_pcm_pointer(struct i2sbus_dev *i2sdev, int in)
{
	struct pcm_info *pi;
	u32 fc;

	get_pcm_info(i2sdev, in, &pi, NULL);

	fc = in_le32(&i2sdev->intfregs->frame_count);
	fc = fc - pi->frame_count;

	if (fc >= pi->substream->runtime->buffer_size)
		fc %= pi->substream->runtime->buffer_size;
	return fc;
}

static inline void handle_interrupt(struct i2sbus_dev *i2sdev, int in)
{
	struct pcm_info *pi;
	u32 fc, nframes;
	u32 status;
	int timeout, i;
	int dma_stopped = 0;
	struct snd_pcm_runtime *runtime;

	spin_lock(&i2sdev->low_lock);
	get_pcm_info(i2sdev, in, &pi, NULL);
	if (!pi->dbdma_ring.running && !pi->dbdma_ring.stopping)
		goto out_unlock;

	i = pi->current_period;
	runtime = pi->substream->runtime;
	while (pi->dbdma_ring.cmds[i].xfer_status) {
		if (le16_to_cpu(pi->dbdma_ring.cmds[i].xfer_status) & BT)
			/*
			 * BT is the branch taken bit.  If it took a branch
			 * it is because we set the S0 bit to make it
			 * branch to the stop command.
			 */
			dma_stopped = 1;
		pi->dbdma_ring.cmds[i].xfer_status = 0;

		if (++i >= runtime->periods) {
			i = 0;
			pi->frame_count += runtime->buffer_size;
		}
		pi->current_period = i;

		/*
		 * Check the frame count.  The DMA tends to get a bit
		 * ahead of the frame counter, which confuses the core.
		 */
		fc = in_le32(&i2sdev->intfregs->frame_count);
		nframes = i * runtime->period_size;
		if (fc < pi->frame_count + nframes)
			pi->frame_count = fc - nframes;
	}

	if (dma_stopped) {
		timeout = 1000;
		for (;;) {
			status = in_le32(&pi->dbdma->status);
			if (!(status & ACTIVE) && (!in || (status & 0x80)))
				break;
			if (--timeout <= 0) {
				printk(KERN_ERR "i2sbus: timed out "
				       "waiting for DMA to stop!\n");
				break;
			}
			udelay(1);
		}

		/* Turn off DMA controller, clear S0 bit */
		out_le32(&pi->dbdma->control, (RUN | PAUSE | 1) << 16);

		pi->dbdma_ring.stopping = 0;
		if (pi->stop_completion)
			complete(pi->stop_completion);
	}

	if (!pi->dbdma_ring.running)
		goto out_unlock;
	spin_unlock(&i2sdev->low_lock);
	/* may call _trigger again, hence needs to be unlocked */
	snd_pcm_period_elapsed(pi->substream);
	return;

 out_unlock:
	spin_unlock(&i2sdev->low_lock);
}

irqreturn_t i2sbus_tx_intr(int irq, void *devid)
{
	handle_interrupt((struct i2sbus_dev *)devid, 0);
	return IRQ_HANDLED;
}

irqreturn_t i2sbus_rx_intr(int irq, void *devid)
{
	handle_interrupt((struct i2sbus_dev *)devid, 1);
	return IRQ_HANDLED;
}

static int i2sbus_playback_open(struct snd_pcm_substream *substream)
{
	struct i2sbus_dev *i2sdev = snd_pcm_substream_chip(substream);

	if (!i2sdev)
		return -EINVAL;
	i2sdev->out.substream = substream;
	return i2sbus_pcm_open(i2sdev, 0);
}

static int i2sbus_playback_close(struct snd_pcm_substream *substream)
{
	struct i2sbus_dev *i2sdev = snd_pcm_substream_chip(substream);
	int err;

	if (!i2sdev)
		return -EINVAL;
	if (i2sdev->out.substream != substream)
		return -EINVAL;
	err = i2sbus_pcm_close(i2sdev, 0);
	if (!err)
		i2sdev->out.substream = NULL;
	return err;
}

static int i2sbus_playback_prepare(struct snd_pcm_substream *substream)
{
	struct i2sbus_dev *i2sdev = snd_pcm_substream_chip(substream);

	if (!i2sdev)
		return -EINVAL;
	if (i2sdev->out.substream != substream)
		return -EINVAL;
	return i2sbus_pcm_prepare(i2sdev, 0);
}

static int i2sbus_playback_trigger(struct snd_pcm_substream *substream, int cmd)
{
	struct i2sbus_dev *i2sdev = snd_pcm_substream_chip(substream);

	if (!i2sdev)
		return -EINVAL;
	if (i2sdev->out.substream != substream)
		return -EINVAL;
	return i2sbus_pcm_trigger(i2sdev, 0, cmd);
}

static snd_pcm_uframes_t i2sbus_playback_pointer(struct snd_pcm_substream
						 *substream)
{
	struct i2sbus_dev *i2sdev = snd_pcm_substream_chip(substream);

	if (!i2sdev)
		return -EINVAL;
	if (i2sdev->out.substream != substream)
		return 0;
	return i2sbus_pcm_pointer(i2sdev, 0);
}

static struct snd_pcm_ops i2sbus_playback_ops = {
	.open =		i2sbus_playback_open,
	.close =	i2sbus_playback_close,
	.ioctl =	snd_pcm_lib_ioctl,
	.hw_params =	i2sbus_hw_params,
	.hw_free =	i2sbus_playback_hw_free,
	.prepare =	i2sbus_playback_prepare,
	.trigger =	i2sbus_playback_trigger,
	.pointer =	i2sbus_playback_pointer,
};

static int i2sbus_record_open(struct snd_pcm_substream *substream)
{
	struct i2sbus_dev *i2sdev = snd_pcm_substream_chip(substream);

	if (!i2sdev)
		return -EINVAL;
	i2sdev->in.substream = substream;
	return i2sbus_pcm_open(i2sdev, 1);
}

static int i2sbus_record_close(struct snd_pcm_substream *substream)
{
	struct i2sbus_dev *i2sdev = snd_pcm_substream_chip(substream);
	int err;

	if (!i2sdev)
		return -EINVAL;
	if (i2sdev->in.substream != substream)
		return -EINVAL;
	err = i2sbus_pcm_close(i2sdev, 1);
	if (!err)
		i2sdev->in.substream = NULL;
	return err;
}

static int i2sbus_record_prepare(struct snd_pcm_substream *substream)
{
	struct i2sbus_dev *i2sdev = snd_pcm_substream_chip(substream);

	if (!i2sdev)
		return -EINVAL;
	if (i2sdev->in.substream != substream)
		return -EINVAL;
	return i2sbus_pcm_prepare(i2sdev, 1);
}

static int i2sbus_record_trigger(struct snd_pcm_substream *substream, int cmd)
{
	struct i2sbus_dev *i2sdev = snd_pcm_substream_chip(substream);

	if (!i2sdev)
		return -EINVAL;
	if (i2sdev->in.substream != substream)
		return -EINVAL;
	return i2sbus_pcm_trigger(i2sdev, 1, cmd);
}

static snd_pcm_uframes_t i2sbus_record_pointer(struct snd_pcm_substream
					       *substream)
{
	struct i2sbus_dev *i2sdev = snd_pcm_substream_chip(substream);

	if (!i2sdev)
		return -EINVAL;
	if (i2sdev->in.substream != substream)
		return 0;
	return i2sbus_pcm_pointer(i2sdev, 1);
}

static struct snd_pcm_ops i2sbus_record_ops = {
	.open =		i2sbus_record_open,
	.close =	i2sbus_record_close,
	.ioctl =	snd_pcm_lib_ioctl,
	.hw_params =	i2sbus_hw_params,
	.hw_free =	i2sbus_record_hw_free,
	.prepare =	i2sbus_record_prepare,
	.trigger =	i2sbus_record_trigger,
	.pointer =	i2sbus_record_pointer,
};

static void i2sbus_private_free(struct snd_pcm *pcm)
{
	struct i2sbus_dev *i2sdev = snd_pcm_chip(pcm);
	struct codec_info_item *p, *tmp;

	i2sdev->sound.pcm = NULL;
	i2sdev->out.created = 0;
	i2sdev->in.created = 0;
	list_for_each_entry_safe(p, tmp, &i2sdev->sound.codec_list, list) {
		printk(KERN_ERR "i2sbus: a codec didn't unregister!\n");
		list_del(&p->list);
		module_put(p->codec->owner);
		kfree(p);
	}
	soundbus_dev_put(&i2sdev->sound);
	module_put(THIS_MODULE);
}

int
i2sbus_attach_codec(struct soundbus_dev *dev, struct snd_card *card,
		    struct codec_info *ci, void *data)
{
	int err, in = 0, out = 0;
	struct transfer_info *tmp;
	struct i2sbus_dev *i2sdev = soundbus_dev_to_i2sbus_dev(dev);
	struct codec_info_item *cii;

	if (!dev->pcmname || dev->pcmid == -1) {
		printk(KERN_ERR "i2sbus: pcm name and id must be set!\n");
		return -EINVAL;
	}

	list_for_each_entry(cii, &dev->codec_list, list) {
		if (cii->codec_data == data)
			return -EALREADY;
	}

	if (!ci->transfers || !ci->transfers->formats
	    || !ci->transfers->rates || !ci->usable)
		return -EINVAL;

	/* we currently code the i2s transfer on the clock, and support only
	 * 32 and 64 */
	if (ci->bus_factor != 32 && ci->bus_factor != 64)
		return -EINVAL;

	/* If you want to fix this, you need to keep track of what transport infos
	 * are to be used, which codecs they belong to, and then fix all the
	 * sysclock/busclock stuff above to depend on which is usable */
	list_for_each_entry(cii, &dev->codec_list, list) {
		if (cii->codec->sysclock_factor != ci->sysclock_factor) {
			printk(KERN_DEBUG
			       "cannot yet handle multiple different sysclocks!\n");
			return -EINVAL;
		}
		if (cii->codec->bus_factor != ci->bus_factor) {
			printk(KERN_DEBUG
			       "cannot yet handle multiple different bus clocks!\n");
			return -EINVAL;
		}
	}

	tmp = ci->transfers;
	while (tmp->formats && tmp->rates) {
		if (tmp->transfer_in)
			in = 1;
		else
			out = 1;
		tmp++;
	}

	cii = kzalloc(sizeof(struct codec_info_item), GFP_KERNEL);
	if (!cii) {
		printk(KERN_DEBUG "i2sbus: failed to allocate cii\n");
		return -ENOMEM;
	}

	/* use the private data to point to the codec info */
	cii->sdev = soundbus_dev_get(dev);
	cii->codec = ci;
	cii->codec_data = data;

	if (!cii->sdev) {
		printk(KERN_DEBUG
		       "i2sbus: failed to get soundbus dev reference\n");
		err = -ENODEV;
		goto out_free_cii;
	}

	if (!try_module_get(THIS_MODULE)) {
		printk(KERN_DEBUG "i2sbus: failed to get module reference!\n");
		err = -EBUSY;
		goto out_put_sdev;
	}

	if (!try_module_get(ci->owner)) {
		printk(KERN_DEBUG
		       "i2sbus: failed to get module reference to codec owner!\n");
		err = -EBUSY;
		goto out_put_this_module;
	}

	if (!dev->pcm) {
		err = snd_pcm_new(card, dev->pcmname, dev->pcmid, 0, 0,
				  &dev->pcm);
		if (err) {
			printk(KERN_DEBUG "i2sbus: failed to create pcm\n");
			goto out_put_ci_module;
		}
		dev->pcm->dev = &dev->ofdev.dev;
	}

	/* ALSA yet again sucks.
	 * If it is ever fixed, remove this line. See below. */
	out = in = 1;

	if (!i2sdev->out.created && out) {
		if (dev->pcm->card != card) {
			/* eh? */
			printk(KERN_ERR
			       "Can't attach same bus to different cards!\n");
			err = -EINVAL;
			goto out_put_ci_module;
		}
		err = snd_pcm_new_stream(dev->pcm, SNDRV_PCM_STREAM_PLAYBACK, 1);
		if (err)
			goto out_put_ci_module;
		snd_pcm_set_ops(dev->pcm, SNDRV_PCM_STREAM_PLAYBACK,
				&i2sbus_playback_ops);
		i2sdev->out.created = 1;
	}

	if (!i2sdev->in.created && in) {
		if (dev->pcm->card != card) {
			printk(KERN_ERR
			       "Can't attach same bus to different cards!\n");
			goto out_put_ci_module;
		}
		err = snd_pcm_new_stream(dev->pcm, SNDRV_PCM_STREAM_CAPTURE, 1);
		if (err)
			goto out_put_ci_module;
		snd_pcm_set_ops(dev->pcm, SNDRV_PCM_STREAM_CAPTURE,
				&i2sbus_record_ops);
		i2sdev->in.created = 1;
	}

	/* so we have to register the pcm after adding any substream
	 * to it because alsa doesn't create the devices for the
	 * substreams when we add them later.
	 * Therefore, force in and out on both busses (above) and
	 * register the pcm now instead of just after creating it.
	 */
	err = snd_device_register(card, dev->pcm);
	if (err) {
		printk(KERN_ERR "i2sbus: error registering new pcm\n");
		goto out_put_ci_module;
	}
	/* no errors any more, so let's add this to our list */
	list_add(&cii->list, &dev->codec_list);

	dev->pcm->private_data = i2sdev;
	dev->pcm->private_free = i2sbus_private_free;

	/* well, we really should support scatter/gather DMA */
	snd_pcm_lib_preallocate_pages_for_all(
		dev->pcm, SNDRV_DMA_TYPE_DEV,
		snd_dma_pci_data(macio_get_pci_dev(i2sdev->macio)),
		64 * 1024, 64 * 1024);

	return 0;
 out_put_ci_module:
	module_put(ci->owner);
 out_put_this_module:
	module_put(THIS_MODULE);
 out_put_sdev:
	soundbus_dev_put(dev);
 out_free_cii:
	kfree(cii);
	return err;
}

void i2sbus_detach_codec(struct soundbus_dev *dev, void *data)
{
	struct codec_info_item *cii = NULL, *i;

	list_for_each_entry(i, &dev->codec_list, list) {
		if (i->codec_data == data) {
			cii = i;
			break;
		}
	}
	if (cii) {
		list_del(&cii->list);
		module_put(cii->codec->owner);
		kfree(cii);
	}
	/* no more codecs, but still a pcm? */
	if (list_empty(&dev->codec_list) && dev->pcm) {
		/* the actual cleanup is done by the callback above! */
		snd_device_free(dev->pcm->card, dev->pcm);
	}
}