rme9652.c

底层驱动开发

	/* Tell the card where it is */

	rme9652_write(rme9652, RME9652_rec_buffer, cb_bus);
	rme9652_write(rme9652, RME9652_play_buffer, pb_bus);

	rme9652->capture_buffer = rme9652->capture_dma_buf.area + (cb_bus - rme9652->capture_dma_buf.addr);
	rme9652->playback_buffer = rme9652->playback_dma_buf.area + (pb_bus - rme9652->playback_dma_buf.addr);

	return 0;
}

static void snd_rme9652_set_defaults(rme9652_t *rme9652)
{
	unsigned int k;

	/* ASSUMPTION: rme9652->lock is either held, or
	   there is no need to hold it (e.g. during module
	   initalization).
	 */

	/* set defaults:

	   SPDIF Input via Coax 
	   autosync clock mode
	   maximum latency (7 = 8192 samples, 64Kbyte buffer,
	   which implies 2 4096 sample, 32Kbyte periods).
	   
	   if rev 1.5, initialize the S/PDIF receiver.

	 */

	rme9652->control_register =
	    RME9652_inp_0 | rme9652_encode_latency(7);

	rme9652_write(rme9652, RME9652_control_register, rme9652->control_register);

	rme9652_reset_hw_pointer(rme9652);
	rme9652_compute_period_size(rme9652);

	/* default: thru off for all channels */

	for (k = 0; k < RME9652_NCHANNELS; ++k)
		rme9652_write(rme9652, RME9652_thru_base + k * 4, 0);

	rme9652->thru_bits = 0;
	rme9652->passthru = 0;

	/* set a default rate so that the channel map is set up */

	rme9652_set_rate(rme9652, 48000);
}

static irqreturn_t snd_rme9652_interrupt(int irq, void *dev_id, struct pt_regs *regs)
{
	rme9652_t *rme9652 = (rme9652_t *) dev_id;

	if (!(rme9652_read(rme9652, RME9652_status_register) & RME9652_IRQ)) {
		return IRQ_NONE;
	}

	rme9652_write(rme9652, RME9652_irq_clear, 0);

	if (rme9652->capture_substream) {
		snd_pcm_period_elapsed(rme9652->pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream);
	}

	if (rme9652->playback_substream) {
		snd_pcm_period_elapsed(rme9652->pcm->streams[SNDRV_PCM_STREAM_PLAYBACK].substream);
	}
	return IRQ_HANDLED;
}

static snd_pcm_uframes_t snd_rme9652_hw_pointer(snd_pcm_substream_t *substream)
{
	rme9652_t *rme9652 = snd_pcm_substream_chip(substream);
	return rme9652_hw_pointer(rme9652);
}

static char *rme9652_channel_buffer_location(rme9652_t *rme9652,
					     int stream,
					     int channel)

{
	int mapped_channel;

        snd_assert(channel >= 0 || channel < RME9652_NCHANNELS, return NULL);
        
	if ((mapped_channel = rme9652->channel_map[channel]) < 0) {
		return NULL;
	}
	
	if (stream == SNDRV_PCM_STREAM_CAPTURE) {
		return rme9652->capture_buffer +
			(mapped_channel * RME9652_CHANNEL_BUFFER_BYTES);
	} else {
		return rme9652->playback_buffer +
			(mapped_channel * RME9652_CHANNEL_BUFFER_BYTES);
	}
}

static int snd_rme9652_playback_copy(snd_pcm_substream_t *substream, int channel,
				     snd_pcm_uframes_t pos, void __user *src, snd_pcm_uframes_t count)
{
	rme9652_t *rme9652 = snd_pcm_substream_chip(substream);
	char *channel_buf;

	snd_assert(pos + count <= RME9652_CHANNEL_BUFFER_BYTES / 4, return -EINVAL);

	channel_buf = rme9652_channel_buffer_location (rme9652,
						       substream->pstr->stream,
						       channel);
	snd_assert(channel_buf != NULL, return -EIO);
	if (copy_from_user(channel_buf + pos * 4, src, count * 4))
		return -EFAULT;
	return count;
}

static int snd_rme9652_capture_copy(snd_pcm_substream_t *substream, int channel,
				    snd_pcm_uframes_t pos, void __user *dst, snd_pcm_uframes_t count)
{
	rme9652_t *rme9652 = snd_pcm_substream_chip(substream);
	char *channel_buf;

	snd_assert(pos + count <= RME9652_CHANNEL_BUFFER_BYTES / 4, return -EINVAL);

	channel_buf = rme9652_channel_buffer_location (rme9652,
						       substream->pstr->stream,
						       channel);
	snd_assert(channel_buf != NULL, return -EIO);
	if (copy_to_user(dst, channel_buf + pos * 4, count * 4))
		return -EFAULT;
	return count;
}

static int snd_rme9652_hw_silence(snd_pcm_substream_t *substream, int channel,
				  snd_pcm_uframes_t pos, snd_pcm_uframes_t count)
{
	rme9652_t *rme9652 = snd_pcm_substream_chip(substream);
	char *channel_buf;

	channel_buf = rme9652_channel_buffer_location (rme9652,
						       substream->pstr->stream,
						       channel);
	snd_assert(channel_buf != NULL, return -EIO);
	memset(channel_buf + pos * 4, 0, count * 4);
	return count;
}

static int snd_rme9652_reset(snd_pcm_substream_t *substream)
{
	snd_pcm_runtime_t *runtime = substream->runtime;
	rme9652_t *rme9652 = snd_pcm_substream_chip(substream);
	snd_pcm_substream_t *other;
	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
		other = rme9652->capture_substream;
	else
		other = rme9652->playback_substream;
	if (rme9652->running)
		runtime->status->hw_ptr = rme9652_hw_pointer(rme9652);
	else
		runtime->status->hw_ptr = 0;
	if (other) {
		struct list_head *pos;
		snd_pcm_substream_t *s;
		snd_pcm_runtime_t *oruntime = other->runtime;
		snd_pcm_group_for_each(pos, substream) {
			s = snd_pcm_group_substream_entry(pos);
			if (s == other) {
				oruntime->status->hw_ptr = runtime->status->hw_ptr;
				break;
			}
		}
	}
	return 0;
}

static int snd_rme9652_hw_params(snd_pcm_substream_t *substream,
				 snd_pcm_hw_params_t *params)
{
	rme9652_t *rme9652 = snd_pcm_substream_chip(substream);
	int err;
	pid_t this_pid;
	pid_t other_pid;

	spin_lock_irq(&rme9652->lock);

	if (substream->pstr->stream == SNDRV_PCM_STREAM_PLAYBACK) {
		rme9652->control_register &= ~(RME9652_PRO | RME9652_Dolby | RME9652_EMP);
		rme9652_write(rme9652, RME9652_control_register, rme9652->control_register |= rme9652->creg_spdif_stream);
		this_pid = rme9652->playback_pid;
		other_pid = rme9652->capture_pid;
	} else {
		this_pid = rme9652->capture_pid;
		other_pid = rme9652->playback_pid;
	}

	if ((other_pid > 0) && (this_pid != other_pid)) {

		/* The other stream is open, and not by the same
		   task as this one. Make sure that the parameters
		   that matter are the same.
		 */

		if ((int)params_rate(params) !=
		    rme9652_adat_sample_rate(rme9652)) {
			spin_unlock_irq(&rme9652->lock);
			_snd_pcm_hw_param_setempty(params, SNDRV_PCM_HW_PARAM_RATE);
			return -EBUSY;
		}

		if (params_period_size(params) != rme9652->period_bytes / 4) {
			spin_unlock_irq(&rme9652->lock);
			_snd_pcm_hw_param_setempty(params, SNDRV_PCM_HW_PARAM_PERIOD_SIZE);
			return -EBUSY;
		}

		/* We're fine. */

		spin_unlock_irq(&rme9652->lock);
 		return 0;

	} else {
		spin_unlock_irq(&rme9652->lock);
	}

	/* how to make sure that the rate matches an externally-set one ?
	 */

	if ((err = rme9652_set_rate(rme9652, params_rate(params))) < 0) {
		_snd_pcm_hw_param_setempty(params, SNDRV_PCM_HW_PARAM_RATE);
		return err;
	}

	if ((err = rme9652_set_interrupt_interval(rme9652, params_period_size(params))) < 0) {
		_snd_pcm_hw_param_setempty(params, SNDRV_PCM_HW_PARAM_PERIOD_SIZE);
		return err;
	}

	return 0;
}

static int snd_rme9652_channel_info(snd_pcm_substream_t *substream,
				    snd_pcm_channel_info_t *info)
{
	rme9652_t *rme9652 = snd_pcm_substream_chip(substream);
	int chn;

	snd_assert(info->channel < RME9652_NCHANNELS, return -EINVAL);

	if ((chn = rme9652->channel_map[info->channel]) < 0) {
		return -EINVAL;
	}

	info->offset = chn * RME9652_CHANNEL_BUFFER_BYTES;
	info->first = 0;
	info->step = 32;
	return 0;
}

static int snd_rme9652_ioctl(snd_pcm_substream_t *substream,
			     unsigned int cmd, void *arg)
{
	switch (cmd) {
	case SNDRV_PCM_IOCTL1_RESET:
	{
		return snd_rme9652_reset(substream);
	}
	case SNDRV_PCM_IOCTL1_CHANNEL_INFO:
	{
		snd_pcm_channel_info_t *info = arg;
		return snd_rme9652_channel_info(substream, info);
	}
	default:
		break;
	}

	return snd_pcm_lib_ioctl(substream, cmd, arg);
}

static void rme9652_silence_playback(rme9652_t *rme9652)
{
	memset(rme9652->playback_buffer, 0, RME9652_DMA_AREA_BYTES);
}

static int snd_rme9652_trigger(snd_pcm_substream_t *substream,
			       int cmd)
{
	rme9652_t *rme9652 = snd_pcm_substream_chip(substream);
	snd_pcm_substream_t *other;
	int running;
	spin_lock(&rme9652->lock);
	running = rme9652->running;
	switch (cmd) {
	case SNDRV_PCM_TRIGGER_START:
		running |= 1 << substream->stream;
		break;
	case SNDRV_PCM_TRIGGER_STOP:
		running &= ~(1 << substream->stream);
		break;
	default:
		snd_BUG();
		spin_unlock(&rme9652->lock);
		return -EINVAL;
	}
	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
		other = rme9652->capture_substream;
	else
		other = rme9652->playback_substream;

	if (other) {
		struct list_head *pos;
		snd_pcm_substream_t *s;
		snd_pcm_group_for_each(pos, substream) {
			s = snd_pcm_group_substream_entry(pos);
			if (s == other) {
				snd_pcm_trigger_done(s, substream);
				if (cmd == SNDRV_PCM_TRIGGER_START)
					running |= 1 << s->stream;
				else
					running &= ~(1 << s->stream);
				goto _ok;
			}
		}
		if (cmd == SNDRV_PCM_TRIGGER_START) {
			if (!(running & (1 << SNDRV_PCM_STREAM_PLAYBACK)) &&
			    substream->stream == SNDRV_PCM_STREAM_CAPTURE)
				rme9652_silence_playback(rme9652);
		} else {
			if (running &&
			    substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
				rme9652_silence_playback(rme9652);
		}
	} else {
		if (substream->stream == SNDRV_PCM_STREAM_CAPTURE) 
			rme9652_silence_playback(rme9652);
	}
 _ok:
	snd_pcm_trigger_done(substream, substream);
	if (!rme9652->running && running)
		rme9652_start(rme9652);
	else if (rme9652->running && !running)
		rme9652_stop(rme9652);
	rme9652->running = running;
	spin_unlock(&rme9652->lock);

	return 0;
}

static int snd_rme9652_prepare(snd_pcm_substream_t *substream)
{
	rme9652_t *rme9652 = snd_pcm_substream_chip(substream);
	unsigned long flags;
	int result = 0;

	spin_lock_irqsave(&rme9652->lock, flags);
	if (!rme9652->running)
		rme9652_reset_hw_pointer(rme9652);
	spin_unlock_irqrestore(&rme9652->lock, flags);
	return result;
}

static snd_pcm_hardware_t snd_rme9652_playback_subinfo =
{
	.info =			(SNDRV_PCM_INFO_MMAP |
				 SNDRV_PCM_INFO_MMAP_VALID |
				 SNDRV_PCM_INFO_NONINTERLEAVED |
				 SNDRV_PCM_INFO_SYNC_START |
				 SNDRV_PCM_INFO_DOUBLE),
	.formats =		SNDRV_PCM_FMTBIT_S32_LE,
	.rates =		(SNDRV_PCM_RATE_44100 | 
				 SNDRV_PCM_RATE_48000 | 
				 SNDRV_PCM_RATE_88200 | 
				 SNDRV_PCM_RATE_96000),
	.rate_min =		44100,
	.rate_max =		96000,
	.channels_min =		10,
	.channels_max =		26,
	.buffer_bytes_max =	RME9652_CHANNEL_BUFFER_BYTES * 26,
	.period_bytes_min =	(64 * 4) * 10,
	.period_bytes_max =	(8192 * 4) * 26,
	.periods_min =		2,
	.periods_max =		2,
	.fifo_size =		0,
};

static snd_pcm_hardware_t snd_rme9652_capture_subinfo =
{
	.info =			(SNDRV_PCM_INFO_MMAP |
				 SNDRV_PCM_INFO_MMAP_VALID |
				 SNDRV_PCM_INFO_NONINTERLEAVED |
				 SNDRV_PCM_INFO_SYNC_START),
	.formats =		SNDRV_PCM_FMTBIT_S32_LE,
	.rates =		(SNDRV_PCM_RATE_44100 | 
				 SNDRV_PCM_RATE_48000 | 
				 SNDRV_PCM_RATE_88200 | 
				 SNDRV_PCM_RATE_96000),
	.rate_min =		44100,
	.rate_max =		96000,
	.channels_min =		10,
	.channels_max =		26,
	.buffer_bytes_max =	RME9652_CHANNEL_BUFFER_BYTES *26,
	.period_bytes_min =	(64 * 4) * 10,
	.period_bytes_max =	(8192 * 4) * 26,
	.periods_min =		2,
	.periods_max =		2,
	.fifo_size =		0,
};

static unsigned int period_sizes[] = { 64, 128, 256, 512, 1024, 2048, 4096, 8192 };

static snd_pcm_hw_constraint_list_t hw_constraints_period_sizes = {
	.count = ARRAY_SIZE(period_sizes),
	.list = period_sizes,
	.mask = 0
};

static int snd_rme9652_hw_rule_channels(snd_pcm_hw_params_t *params,
					snd_pcm_hw_rule_t *rule)
{
	rme9652_t *rme9652 = rule->private;
	snd_interval_t *c = hw_param_interval(params, SNDRV_PCM_HW_PARAM_CHANNELS);
	unsigned int list[2] = { rme9652->ds_channels, rme9652->ss_channels };
	return snd_interval_list(c, 2, list, 0);
}

static int snd_rme9652_hw_rule_channels_rate(snd_pcm_hw_params_t *params,
					     snd_pcm_hw_rule_t *rule)
{
	rme9652_t *rme9652 = rule->private;
	snd_interval_t *c = hw_param_interval(params, SNDRV_PCM_HW_PARAM_CHANNELS);
	snd_interval_t *r = hw_param_interval(params, SNDRV_PCM_HW_PARAM_RATE);
	if (r->min > 48000) {
		snd_interval_t t = {
			.min = rme9652->ds_channels,
			.max = rme9652->ds_channels,
			.integer = 1,
		};
		return snd_interval_refine(c, &t);
	} else if (r->max < 88200) {
		snd_interval_t t = {
			.min = rme9652->ss_channels,
			.max = rme9652->ss_channels,
			.integer = 1,
		};
		return snd_interval_refine(c, &t);
	}
	return 0;
}

static int snd_rme9652_hw_rule_rate_channels(snd_pcm_hw_params_t *params,
					     snd_pcm_hw_rule_t *rule)
{
	rme9652_t *rme9652 = rule->private;
	snd_interval_t *c = hw_param_interval(params, SNDRV_PCM_HW_PARAM_CHANNELS);
	snd_interval_t *r = hw_param_interval(params, SNDRV_PCM_HW_PARAM_RATE);
	if (c->min >= rme9652->ss_channels) {
		snd