emu8000_pcm.c

linux-2.6.15.6

		aux = 0xff;
	else
		aux = (-rec->panning[ch]) & 0xff;
	temp = (temp << 8) | (pt << 16) | aux;
	EMU8000_PTRX_WRITE(hw, ch, temp);
	EMU8000_CPF_WRITE(hw, ch, pt << 16);

	/* start timer */
	spin_lock_irqsave(&rec->timer_lock, flags);
	if (! rec->timer_running) {
		rec->timer.expires = jiffies + 1;
		add_timer(&rec->timer);
		rec->timer_running = 1;
	}
	spin_unlock_irqrestore(&rec->timer_lock, flags);
}

/*
 * stop the voice immediately
 */
static void stop_voice(emu8k_pcm_t *rec, int ch)
{
	unsigned long flags;
	emu8000_t *hw = rec->emu;

	EMU8000_DCYSUSV_WRITE(hw, ch, 0x807F);

	/* stop timer */
	spin_lock_irqsave(&rec->timer_lock, flags);
	if (rec->timer_running) {
		del_timer(&rec->timer);
		rec->timer_running = 0;
	}
	spin_unlock_irqrestore(&rec->timer_lock, flags);
}

static int emu8k_pcm_trigger(snd_pcm_substream_t *subs, int cmd)
{
	emu8k_pcm_t *rec = subs->runtime->private_data;
	int ch;

	switch (cmd) {
	case SNDRV_PCM_TRIGGER_START:
		for (ch = 0; ch < rec->voices; ch++)
			start_voice(rec, ch);
		rec->running = 1;
		break;
	case SNDRV_PCM_TRIGGER_STOP:
		rec->running = 0;
		for (ch = 0; ch < rec->voices; ch++)
			stop_voice(rec, ch);
		break;
	default:
		return -EINVAL;
	}
	return 0;
}


/*
 * copy / silence ops
 */

/*
 * this macro should be inserted in the copy/silence loops
 * to reduce the latency.  without this, the system will hang up
 * during the whole loop.
 */
#define CHECK_SCHEDULER() \
do { \
	cond_resched();\
	if (signal_pending(current))\
		return -EAGAIN;\
} while (0)


#ifdef USE_NONINTERLEAVE
/* copy one channel block */
static int emu8k_transfer_block(emu8000_t *emu, int offset, unsigned short *buf, int count)
{
	EMU8000_SMALW_WRITE(emu, offset);
	while (count > 0) {
		unsigned short sval;
		CHECK_SCHEDULER();
		get_user(sval, buf);
		EMU8000_SMLD_WRITE(emu, sval);
		buf++;
		count--;
	}
	return 0;
}

static int emu8k_pcm_copy(snd_pcm_substream_t *subs,
			  int voice,
			  snd_pcm_uframes_t pos,
			  void *src,
			  snd_pcm_uframes_t count)
{
	emu8k_pcm_t *rec = subs->runtime->private_data;
	emu8000_t *emu = rec->emu;

	snd_emu8000_write_wait(emu, 1);
	if (voice == -1) {
		unsigned short *buf = src;
		int i, err;
		count /= rec->voices;
		for (i = 0; i < rec->voices; i++) {
			err = emu8k_transfer_block(emu, pos + rec->loop_start[i], buf, count);
			if (err < 0)
				return err;
			buf += count;
		}
		return 0;
	} else {
		return emu8k_transfer_block(emu, pos + rec->loop_start[voice], src, count);
	}
}

/* make a channel block silence */
static int emu8k_silence_block(emu8000_t *emu, int offset, int count)
{
	EMU8000_SMALW_WRITE(emu, offset);
	while (count > 0) {
		CHECK_SCHEDULER();
		EMU8000_SMLD_WRITE(emu, 0);
		count--;
	}
	return 0;
}

static int emu8k_pcm_silence(snd_pcm_substream_t *subs,
			     int voice,
			     snd_pcm_uframes_t pos,
			     snd_pcm_uframes_t count)
{
	emu8k_pcm_t *rec = subs->runtime->private_data;
	emu8000_t *emu = rec->emu;

	snd_emu8000_write_wait(emu, 1);
	if (voice == -1 && rec->voices == 1)
		voice = 0;
	if (voice == -1) {
		int err;
		err = emu8k_silence_block(emu, pos + rec->loop_start[0], count / 2);
		if (err < 0)
			return err;
		return emu8k_silence_block(emu, pos + rec->loop_start[1], count / 2);
	} else {
		return emu8k_silence_block(emu, pos + rec->loop_start[voice], count);
	}
}

#else /* interleave */

/*
 * copy the interleaved data can be done easily by using
 * DMA "left" and "right" channels on emu8k engine.
 */
static int emu8k_pcm_copy(snd_pcm_substream_t *subs,
			  int voice,
			  snd_pcm_uframes_t pos,
			  void __user *src,
			  snd_pcm_uframes_t count)
{
	emu8k_pcm_t *rec = subs->runtime->private_data;
	emu8000_t *emu = rec->emu;
	unsigned short __user *buf = src;

	snd_emu8000_write_wait(emu, 1);
	EMU8000_SMALW_WRITE(emu, pos + rec->loop_start[0]);
	if (rec->voices > 1)
		EMU8000_SMARW_WRITE(emu, pos + rec->loop_start[1]);

	while (count-- > 0) {
		unsigned short sval;
		CHECK_SCHEDULER();
		get_user(sval, buf);
		EMU8000_SMLD_WRITE(emu, sval);
		buf++;
		if (rec->voices > 1) {
			CHECK_SCHEDULER();
			get_user(sval, buf);
			EMU8000_SMRD_WRITE(emu, sval);
			buf++;
		}
	}
	return 0;
}

static int emu8k_pcm_silence(snd_pcm_substream_t *subs,
			     int voice,
			     snd_pcm_uframes_t pos,
			     snd_pcm_uframes_t count)
{
	emu8k_pcm_t *rec = subs->runtime->private_data;
	emu8000_t *emu = rec->emu;

	snd_emu8000_write_wait(emu, 1);
	EMU8000_SMALW_WRITE(emu, rec->loop_start[0] + pos);
	if (rec->voices > 1)
		EMU8000_SMARW_WRITE(emu, rec->loop_start[1] + pos);
	while (count-- > 0) {
		CHECK_SCHEDULER();
		EMU8000_SMLD_WRITE(emu, 0);
		if (rec->voices > 1) {
			CHECK_SCHEDULER();
			EMU8000_SMRD_WRITE(emu, 0);
		}
	}
	return 0;
}
#endif


/*
 * allocate a memory block
 */
static int emu8k_pcm_hw_params(snd_pcm_substream_t *subs,
			       snd_pcm_hw_params_t *hw_params)
{
	emu8k_pcm_t *rec = subs->runtime->private_data;

	if (rec->block) {
		/* reallocation - release the old block */
		snd_util_mem_free(rec->emu->memhdr, rec->block);
		rec->block = NULL;
	}

	rec->allocated_bytes = params_buffer_bytes(hw_params) + LOOP_BLANK_SIZE * 4;
	rec->block = snd_util_mem_alloc(rec->emu->memhdr, rec->allocated_bytes);
	if (! rec->block)
		return -ENOMEM;
	rec->offset = EMU8000_DRAM_OFFSET + (rec->block->offset >> 1); /* in word */
	/* at least dma_bytes must be set for non-interleaved mode */
	subs->dma_buffer.bytes = params_buffer_bytes(hw_params);

	return 0;
}

/*
 * free the memory block
 */
static int emu8k_pcm_hw_free(snd_pcm_substream_t *subs)
{
	emu8k_pcm_t *rec = subs->runtime->private_data;

	if (rec->block) {
		int ch;
		for (ch = 0; ch < rec->voices; ch++)
			stop_voice(rec, ch); // to be sure
		if (rec->dram_opened)
			emu8k_close_dram(rec->emu);
		snd_util_mem_free(rec->emu->memhdr, rec->block);
		rec->block = NULL;
	}
	return 0;
}

/*
 */
static int emu8k_pcm_prepare(snd_pcm_substream_t *subs)
{
	emu8k_pcm_t *rec = subs->runtime->private_data;

	rec->pitch = 0xe000 + calc_rate_offset(subs->runtime->rate);
	rec->last_ptr = 0;
	rec->period_pos = 0;

	rec->buf_size = subs->runtime->buffer_size;
	rec->period_size = subs->runtime->period_size;
	rec->voices = subs->runtime->channels;
	rec->loop_start[0] = rec->offset + LOOP_BLANK_SIZE;
	if (rec->voices > 1)
		rec->loop_start[1] = rec->loop_start[0] + rec->buf_size + LOOP_BLANK_SIZE;
	if (rec->voices > 1) {
		rec->panning[0] = 0xff;
		rec->panning[1] = 0x00;
	} else
		rec->panning[0] = 0x80;

	if (! rec->dram_opened) {
		int err, i, ch;

		snd_emux_terminate_all(rec->emu->emu);
		if ((err = emu8k_open_dram_for_pcm(rec->emu, rec->voices)) != 0)
			return err;
		rec->dram_opened = 1;

		/* clear loop blanks */
		snd_emu8000_write_wait(rec->emu, 0);
		EMU8000_SMALW_WRITE(rec->emu, rec->offset);
		for (i = 0; i < LOOP_BLANK_SIZE; i++)
			EMU8000_SMLD_WRITE(rec->emu, 0);
		for (ch = 0; ch < rec->voices; ch++) {
			EMU8000_SMALW_WRITE(rec->emu, rec->loop_start[ch] + rec->buf_size);
			for (i = 0; i < LOOP_BLANK_SIZE; i++)
				EMU8000_SMLD_WRITE(rec->emu, 0);
		}
	}

	setup_voice(rec, 0);
	if (rec->voices > 1)
		setup_voice(rec, 1);
	return 0;
}

static snd_pcm_uframes_t emu8k_pcm_pointer(snd_pcm_substream_t *subs)
{
	emu8k_pcm_t *rec = subs->runtime->private_data;
	if (rec->running)
		return emu8k_get_curpos(rec, 0);
	return 0;
}


static snd_pcm_ops_t emu8k_pcm_ops = {
	.open =		emu8k_pcm_open,
	.close =	emu8k_pcm_close,
	.ioctl =	snd_pcm_lib_ioctl,
	.hw_params =	emu8k_pcm_hw_params,
	.hw_free =	emu8k_pcm_hw_free,
	.prepare =	emu8k_pcm_prepare,
	.trigger =	emu8k_pcm_trigger,
	.pointer =	emu8k_pcm_pointer,
	.copy =		emu8k_pcm_copy,
	.silence =	emu8k_pcm_silence,
};


static void snd_emu8000_pcm_free(snd_pcm_t *pcm)
{
	emu8000_t *emu = pcm->private_data;
	emu->pcm = NULL;
}

int snd_emu8000_pcm_new(snd_card_t *card, emu8000_t *emu, int index)
{
	snd_pcm_t *pcm;
	int err;

	if ((err = snd_pcm_new(card, "Emu8000 PCM", index, 1, 0, &pcm)) < 0)
		return err;
	pcm->private_data = emu;
	pcm->private_free = snd_emu8000_pcm_free;
	snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_PLAYBACK, &emu8k_pcm_ops);
	emu->pcm = pcm;

	snd_device_register(card, pcm);

	return 0;
}