vx_pcm.c

鼎力推荐！本程序是基于嵌入式LUNUX系统开发的源程序代码

	if (chip->chip_status & VX_STAT_IS_STALE)
		return -EBUSY;

	data_mode = (chip->uer_bits & IEC958_AES0_NONAUDIO) != 0;
	if (data_mode != pipe->data_mode && ! pipe->is_capture) {
		/* IEC958 status (raw-mode) was changed */
		/* we reopen the pipe */
		struct vx_rmh rmh;
		snd_printdd(KERN_DEBUG "reopen the pipe with data_mode = %d\n", data_mode);
		vx_init_rmh(&rmh, CMD_FREE_PIPE);
		vx_set_pipe_cmd_params(&rmh, 0, pipe->number, 0);
		if ((err = vx_send_msg(chip, &rmh)) < 0)
			return err;
		vx_init_rmh(&rmh, CMD_RES_PIPE);
		vx_set_pipe_cmd_params(&rmh, 0, pipe->number, pipe->channels);
		if (data_mode)
			rmh.Cmd[0] |= BIT_DATA_MODE;
		if ((err = vx_send_msg(chip, &rmh)) < 0)
			return err;
		pipe->data_mode = data_mode;
	}

	if (chip->pcm_running && chip->freq != runtime->rate) {
		snd_printk(KERN_ERR "vx: cannot set different clock %d from the current %d\n", runtime->rate, chip->freq);
		return -EINVAL;
	}
	vx_set_clock(chip, runtime->rate);

	if ((err = vx_set_format(chip, pipe, runtime)) < 0)
		return err;

	if (vx_is_pcmcia(chip)) {
		pipe->align = 2; /* 16bit word */
	} else {
		pipe->align = 4; /* 32bit word */
	}

	pipe->buffer_bytes = frames_to_bytes(runtime, runtime->buffer_size);
	pipe->period_bytes = frames_to_bytes(runtime, runtime->period_size);
	pipe->hw_ptr = 0;

	/* set the timestamp */
	vx_update_pipe_position(chip, runtime, pipe);
	/* clear again */
	pipe->transferred = 0;
	pipe->position = 0;

	pipe->prepared = 1;

	return 0;
}


/*
 * operators for PCM playback
 */
static snd_pcm_ops_t vx_pcm_playback_ops = {
	.open =		vx_pcm_playback_open,
	.close =	vx_pcm_playback_close,
	.ioctl =	snd_pcm_lib_ioctl,
	.hw_params =	vx_pcm_hw_params,
	.hw_free =	vx_pcm_hw_free,
	.prepare =	vx_pcm_prepare,
	.trigger =	vx_pcm_trigger,
	.pointer =	vx_pcm_playback_pointer,
	.page =		snd_pcm_get_vmalloc_page,
};


/*
 * playback hw information
 */

static snd_pcm_hardware_t vx_pcm_capture_hw = {
	.info =			(SNDRV_PCM_INFO_MMAP | SNDRV_PCM_INFO_INTERLEAVED |
				 SNDRV_PCM_INFO_PAUSE | SNDRV_PCM_INFO_MMAP_VALID |
				 SNDRV_PCM_INFO_RESUME),
	.formats =		/*SNDRV_PCM_FMTBIT_U8 |*/ SNDRV_PCM_FMTBIT_S16_LE | SNDRV_PCM_FMTBIT_S24_3LE,
	.rates =		SNDRV_PCM_RATE_CONTINUOUS | SNDRV_PCM_RATE_8000_48000,
	.rate_min =		5000,
	.rate_max =		48000,
	.channels_min =		1,
	.channels_max =		2,
	.buffer_bytes_max =	(128*1024),
	.period_bytes_min =	126,
	.period_bytes_max =	(128*1024),
	.periods_min =		2,
	.periods_max =		VX_MAX_PERIODS,
	.fifo_size =		126,
};


/*
 * vx_pcm_capture_open - open callback for capture
 */
static int vx_pcm_capture_open(snd_pcm_substream_t *subs)
{
	snd_pcm_runtime_t *runtime = subs->runtime;
	vx_core_t *chip = snd_pcm_substream_chip(subs);
	vx_pipe_t *pipe;
	vx_pipe_t *pipe_out_monitoring = NULL;
	unsigned int audio;
	int err;

	if (chip->chip_status & VX_STAT_IS_STALE)
		return -EBUSY;

	audio = subs->pcm->device * 2;
	snd_assert(audio < chip->audio_ins, return -EINVAL);
	err = vx_alloc_pipe(chip, 1, audio, 2, &pipe);
	if (err < 0)
		return err;
	pipe->substream = subs;
	tasklet_init(&pipe->start_tq, vx_pcm_delayed_start, (unsigned long)subs);
	chip->capture_pipes[audio] = pipe;

	/* check if monitoring is needed */
	if (chip->audio_monitor_active[audio]) {
		pipe_out_monitoring = chip->playback_pipes[audio];
		if (! pipe_out_monitoring) {
			/* allocate a pipe */
			err = vx_alloc_pipe(chip, 0, audio, 2, &pipe_out_monitoring);
			if (err < 0)
				return err;
			chip->playback_pipes[audio] = pipe_out_monitoring;
		}
		pipe_out_monitoring->references++;
		/* 
		   if an output pipe is available, it's audios still may need to be 
		   unmuted. hence we'll have to call a mixer entry point.
		*/
		vx_set_monitor_level(chip, audio, chip->audio_monitor[audio], chip->audio_monitor_active[audio]);
		/* assuming stereo */
		vx_set_monitor_level(chip, audio+1, chip->audio_monitor[audio+1], chip->audio_monitor_active[audio+1]); 
	}

	pipe->monitoring_pipe = pipe_out_monitoring; /* default value NULL */

	runtime->hw = vx_pcm_capture_hw;
	runtime->hw.period_bytes_min = chip->ibl.size;
	runtime->private_data = pipe;

	/* align to 4 bytes (otherwise will be problematic when 24bit is used) */ 
	snd_pcm_hw_constraint_step(runtime, 0, SNDRV_PCM_HW_PARAM_BUFFER_BYTES, 4);
	snd_pcm_hw_constraint_step(runtime, 0, SNDRV_PCM_HW_PARAM_PERIOD_BYTES, 4);

	return 0;
}

/*
 * vx_pcm_capture_close - close callback for capture
 */
static int vx_pcm_capture_close(snd_pcm_substream_t *subs)
{
	vx_core_t *chip = snd_pcm_substream_chip(subs);
	vx_pipe_t *pipe;
	vx_pipe_t *pipe_out_monitoring;
	
	if (! subs->runtime->private_data)
		return -EINVAL;
	pipe = subs->runtime->private_data;
	chip->capture_pipes[pipe->number] = NULL;

	pipe_out_monitoring = pipe->monitoring_pipe;

	/*
	  if an output pipe is attached to this input, 
	  check if it needs to be released.
	*/
	if (pipe_out_monitoring) {
		if (--pipe_out_monitoring->references == 0) {
			vx_free_pipe(chip, pipe_out_monitoring);
			chip->playback_pipes[pipe->number] = NULL;
			pipe->monitoring_pipe = NULL;
		}
	}
	
	vx_free_pipe(chip, pipe);
	return 0;
}



#define DMA_READ_ALIGN	6	/* hardware alignment for read */

/*
 * vx_pcm_capture_update - update the capture buffer
 */
static void vx_pcm_capture_update(vx_core_t *chip, snd_pcm_substream_t *subs, vx_pipe_t *pipe)
{
	int size, space, count;
	snd_pcm_runtime_t *runtime = subs->runtime;

	if (! pipe->prepared || (chip->chip_status & VX_STAT_IS_STALE))
		return;

	size = runtime->buffer_size - snd_pcm_capture_avail(runtime);
	if (! size)
		return;
	size = frames_to_bytes(runtime, size);
	space = vx_query_hbuffer_size(chip, pipe);
	if (space < 0)
		goto _error;
	if (size > space)
		size = space;
	size = (size / 3) * 3; /* align to 3 bytes */
	if (size < DMA_READ_ALIGN)
		goto _error;

	/* keep the last 6 bytes, they will be read after disconnection */
	count = size - DMA_READ_ALIGN;
	/* read bytes until the current pointer reaches to the aligned position
	 * for word-transfer
	 */
	while (count > 0) {
		if ((pipe->hw_ptr % pipe->align) == 0)
			break;
		if (vx_wait_for_rx_full(chip) < 0)
			goto _error;
		vx_pcm_read_per_bytes(chip, runtime, pipe);
		count -= 3;
	}
	if (count > 0) {
		/* ok, let's accelerate! */
		int align = pipe->align * 3;
		space = (count / align) * align;
		vx_pseudo_dma_read(chip, runtime, pipe, space);
		count -= space;
	}
	/* read the rest of bytes */
	while (count > 0) {
		if (vx_wait_for_rx_full(chip) < 0)
			goto _error;
		vx_pcm_read_per_bytes(chip, runtime, pipe);
		count -= 3;
	}
	/* disconnect the host, SIZE_HBUF command always switches to the stream mode */
	vx_send_rih_nolock(chip, IRQ_CONNECT_STREAM_NEXT);
	/* read the last pending 6 bytes */
	count = DMA_READ_ALIGN;
	while (count > 0) {
		vx_pcm_read_per_bytes(chip, runtime, pipe);
		count -= 3;
	}
	/* update the position */
	pipe->transferred += size;
	if (pipe->transferred >= pipe->period_bytes) {
		pipe->transferred %= pipe->period_bytes;
		snd_pcm_period_elapsed(subs);
	}
	return;

 _error:
	/* disconnect the host, SIZE_HBUF command always switches to the stream mode */
	vx_send_rih_nolock(chip, IRQ_CONNECT_STREAM_NEXT);
	return;
}

/*
 * vx_pcm_capture_pointer - pointer callback for capture
 */
static snd_pcm_uframes_t vx_pcm_capture_pointer(snd_pcm_substream_t *subs)
{
	snd_pcm_runtime_t *runtime = subs->runtime;
	vx_pipe_t *pipe = runtime->private_data;
	return bytes_to_frames(runtime, pipe->hw_ptr);
}

/*
 * operators for PCM capture
 */
static snd_pcm_ops_t vx_pcm_capture_ops = {
	.open =		vx_pcm_capture_open,
	.close =	vx_pcm_capture_close,
	.ioctl =	snd_pcm_lib_ioctl,
	.hw_params =	vx_pcm_hw_params,
	.hw_free =	vx_pcm_hw_free,
	.prepare =	vx_pcm_prepare,
	.trigger =	vx_pcm_trigger,
	.pointer =	vx_pcm_capture_pointer,
	.page =		snd_pcm_get_vmalloc_page,
};


/*
 * interrupt handler for pcm streams
 */
void vx_pcm_update_intr(vx_core_t *chip, unsigned int events)
{
	unsigned int i;
	vx_pipe_t *pipe;

#define EVENT_MASK	(END_OF_BUFFER_EVENTS_PENDING|ASYNC_EVENTS_PENDING)

	if (events & EVENT_MASK) {
		vx_init_rmh(&chip->irq_rmh, CMD_ASYNC);
		if (events & ASYNC_EVENTS_PENDING)
			chip->irq_rmh.Cmd[0] |= 0x00000001;	/* SEL_ASYNC_EVENTS */
		if (events & END_OF_BUFFER_EVENTS_PENDING)
			chip->irq_rmh.Cmd[0] |= 0x00000002;	/* SEL_END_OF_BUF_EVENTS */

		if (vx_send_msg(chip, &chip->irq_rmh) < 0) {
			snd_printdd(KERN_ERR "msg send error!!\n");
			return;
		}

		i = 1;
		while (i < chip->irq_rmh.LgStat) {
			int p, buf, capture, eob;
			p = chip->irq_rmh.Stat[i] & MASK_FIRST_FIELD;
			capture = (chip->irq_rmh.Stat[i] & 0x400000) ? 1 : 0;
			eob = (chip->irq_rmh.Stat[i] & 0x800000) ? 1 : 0;
			i++;
			if (events & ASYNC_EVENTS_PENDING)
				i++;
			buf = 1; /* force to transfer */
			if (events & END_OF_BUFFER_EVENTS_PENDING) {
				if (eob)
					buf = chip->irq_rmh.Stat[i];
				i++;
			}
			if (capture)
				continue;
			snd_assert(p >= 0 && (unsigned int)p < chip->audio_outs,);
			pipe = chip->playback_pipes[p];
			if (pipe && pipe->substream) {
				vx_pcm_playback_update(chip, pipe->substream, pipe);
				vx_pcm_playback_transfer(chip, pipe->substream, pipe, buf);
			}
		}
	}

	/* update the capture pcm pointers as frequently as possible */
	for (i = 0; i < chip->audio_ins; i++) {
		pipe = chip->capture_pipes[i];
		if (pipe && pipe->substream)
			vx_pcm_capture_update(chip, pipe->substream, pipe);
	}
}


/*
 * vx_init_audio_io - check the availabe audio i/o and allocate pipe arrays
 */
static int vx_init_audio_io(vx_core_t *chip)
{
	struct vx_rmh rmh;
	int preferred;

	vx_init_rmh(&rmh, CMD_SUPPORTED);
	if (vx_send_msg(chip, &rmh) < 0) {
		snd_printk(KERN_ERR "vx: cannot get the supported audio data\n");
		return -ENXIO;
	}

	chip->audio_outs = rmh.Stat[0] & MASK_FIRST_FIELD;
	chip->audio_ins = (rmh.Stat[0] >> (FIELD_SIZE*2)) & MASK_FIRST_FIELD;
	chip->audio_info = rmh.Stat[1];

	/* allocate pipes */
	chip->playback_pipes = kmalloc(sizeof(vx_pipe_t *) * chip->audio_outs, GFP_KERNEL);
	chip->capture_pipes = kmalloc(sizeof(vx_pipe_t *) * chip->audio_ins, GFP_KERNEL);
	if (! chip->playback_pipes || ! chip->capture_pipes)
		return -ENOMEM;

	memset(chip->playback_pipes, 0, sizeof(vx_pipe_t *) * chip->audio_outs);
	memset(chip->capture_pipes, 0, sizeof(vx_pipe_t *) * chip->audio_ins);

	preferred = chip->ibl.size;
	chip->ibl.size = 0;
	vx_set_ibl(chip, &chip->ibl); /* query the info */
	if (preferred > 0) {
		chip->ibl.size = ((preferred + chip->ibl.granularity - 1) / chip->ibl.granularity) * chip->ibl.granularity;
		if (chip->ibl.size > chip->ibl.max_size)
			chip->ibl.size = chip->ibl.max_size;
	} else
		chip->ibl.size = chip->ibl.min_size; /* set to the minimum */
	vx_set_ibl(chip, &chip->ibl);

	return 0;
}


/*
 * free callback for pcm
 */
static void snd_vx_pcm_free(snd_pcm_t *pcm)
{
	vx_core_t *chip = pcm->private_data;
	chip->pcm[pcm->device] = NULL;
	if (chip->playback_pipes) {
		kfree(chip->playback_pipes);
		chip->playback_pipes = NULL;
	}
	if (chip->capture_pipes) {
		kfree(chip->capture_pipes);
		chip->capture_pipes = NULL;
	}
}

/*
 * snd_vx_pcm_new - create and initialize a pcm
 */
int snd_vx_pcm_new(vx_core_t *chip)
{
	snd_pcm_t *pcm;
	unsigned int i;
	int err;

	if ((err = vx_init_audio_io(chip)) < 0)
		return err;

	for (i = 0; i < chip->hw->num_codecs; i++) {
		unsigned int outs, ins;
		outs = chip->audio_outs > i * 2 ? 1 : 0;
		ins = chip->audio_ins > i * 2 ? 1 : 0;
		if (! outs && ! ins)
			break;
		err = snd_pcm_new(chip->card, "VX PCM", i,
				  outs, ins, &pcm);
		if (err < 0)
			return err;
		if (outs)
			snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_PLAYBACK, &vx_pcm_playback_ops);
		if (ins)
			snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_CAPTURE, &vx_pcm_capture_ops);

		pcm->private_data = chip;
		pcm->private_free = snd_vx_pcm_free;
		pcm->info_flags = 0;
		strcpy(pcm->name, chip->card->shortname);
		chip->pcm[i] = pcm;
	}

	return 0;
}