cardwo.c

linux-2.6.15.6

	if (woinst->state & WAVE_STATE_STARTED)
		return -1;

	query_format(wave_dev, format);

	if (woinst->format.samplingrate != format->samplingrate ||
	    woinst->format.channels != format->channels ||
	    woinst->format.bitsperchannel != format->bitsperchannel) {

		woinst->format = *format;

		if (woinst->state == WAVE_STATE_CLOSED)
			return 0;

		emu10k1_timer_uninstall(card, &woinst->timer);

		for (voicenum = 0; voicenum < woinst->num_voices; voicenum++) {
			emu10k1_voice_free(&woinst->voice[voicenum]);

			if (get_voice(card, woinst, voicenum) < 0) {
				ERROR();
				emu10k1_waveout_close(wave_dev);
				return -1;
			}
		}

		delay = (48000 * woinst->buffer.fragment_size) /
			 (woinst->format.samplingrate * woinst->format.bytespervoicesample);

		emu10k1_timer_install(card, &woinst->timer, delay);
	}

	return 0;
}

void emu10k1_waveout_stop(struct emu10k1_wavedevice *wave_dev)
{
	struct emu10k1_card *card = wave_dev->card;
	struct woinst *woinst = wave_dev->woinst;

	DPF(2, "emu10k1_waveout_stop()\n");

	if (!(woinst->state & WAVE_STATE_STARTED))
		return;

	emu10k1_timer_disable(card, &woinst->timer);

	/* Stop actual voices */
	emu10k1_voices_stop(woinst->voice, woinst->num_voices);

	emu10k1_waveout_update(woinst);

	woinst->state &= ~WAVE_STATE_STARTED;
}

/**
 * emu10k1_waveout_getxfersize -
 *
 * gives the total free bytes on the voice buffer, including silence bytes
 * (basically: total_free_bytes = free_bytes + silence_bytes).
 *
 */
void emu10k1_waveout_getxfersize(struct woinst *woinst, u32 *total_free_bytes)
{
	struct waveout_buffer *buffer = &woinst->buffer;
	int pending_bytes;

	if (woinst->mmapped) {
		*total_free_bytes = buffer->free_bytes;
		return;
	}

	pending_bytes = buffer->size - buffer->free_bytes;

	buffer->fill_silence = (pending_bytes < (signed) buffer->fragment_size * 2) ? 1 : 0;

	if (pending_bytes > (signed) buffer->silence_bytes) {
		*total_free_bytes = (buffer->free_bytes + buffer->silence_bytes);
	} else {
		*total_free_bytes = buffer->size;
		buffer->silence_bytes = pending_bytes;
		if (pending_bytes < 0) {
			buffer->silence_pos = buffer->hw_pos;
			buffer->silence_bytes = 0;
			buffer->free_bytes = buffer->size;
			DPF(1, "buffer underrun\n");
		}
	}
}

/**
 * copy_block -
 *
 * copies a block of pcm data to a voice buffer.
 * Notice that the voice buffer is actually a set of disjointed memory pages.
 *
 */
static void copy_block(void **dst, u32 str, u8 __user *src, u32 len)
{
	unsigned int pg;
	unsigned int pgoff;
	unsigned int k;

	pg = str / PAGE_SIZE;
	pgoff = str % PAGE_SIZE;

	if (len > PAGE_SIZE - pgoff) {
		k = PAGE_SIZE - pgoff;
		if (__copy_from_user((u8 *)dst[pg] + pgoff, src, k))
			return;
		len -= k;
		while (len > PAGE_SIZE) {
			if (__copy_from_user(dst[++pg], src + k, PAGE_SIZE))
				return;
			k += PAGE_SIZE;
			len -= PAGE_SIZE;
		}
		if (__copy_from_user(dst[++pg], src + k, len))
			return;

	} else
		__copy_from_user((u8 *)dst[pg] + pgoff, src, len);
}

/**
 * copy_ilv_block -
 *
 * copies a block of pcm data containing n interleaved channels to n mono voice buffers.
 * Notice that the voice buffer is actually a set of disjointed memory pages.
 *
 */
static void copy_ilv_block(struct woinst *woinst, u32 str, u8 __user *src, u32 len) 
{
        unsigned int pg;
	unsigned int pgoff;
	unsigned int voice_num;
	struct emu_voice *voice = woinst->voice;

	pg = str / PAGE_SIZE;
	pgoff = str % PAGE_SIZE;

	while (len) { 
		for (voice_num = 0; voice_num < woinst->num_voices; voice_num++) {
			if (__copy_from_user((u8 *)(voice[voice_num].mem.addr[pg]) + pgoff, src, woinst->format.bytespervoicesample))
				return;
			src += woinst->format.bytespervoicesample;
		}

		len -= woinst->format.bytespervoicesample;

		pgoff += woinst->format.bytespervoicesample;
		if (pgoff >= PAGE_SIZE) {
			pgoff = 0;
			pg++;
		}
	}
}

/**
 * fill_block -
 *
 * fills a set voice buffers with a block of a given sample.
 *
 */
static void fill_block(struct woinst *woinst, u32 str, u8 data, u32 len)
{
	unsigned int pg;
	unsigned int pgoff;
	unsigned int voice_num;
        struct emu_voice *voice = woinst->voice;
	unsigned int  k;

	pg = str / PAGE_SIZE;
	pgoff = str % PAGE_SIZE;

	if (len > PAGE_SIZE - pgoff) {
		k = PAGE_SIZE - pgoff;
		for (voice_num = 0; voice_num < woinst->num_voices; voice_num++)
			memset((u8 *)voice[voice_num].mem.addr[pg] + pgoff, data, k);
		len -= k;
		while (len > PAGE_SIZE) {
			pg++;
			for (voice_num = 0; voice_num < woinst->num_voices; voice_num++)
				memset(voice[voice_num].mem.addr[pg], data, PAGE_SIZE);

			len -= PAGE_SIZE;
		}
		pg++;
		for (voice_num = 0; voice_num < woinst->num_voices; voice_num++)
			memset(voice[voice_num].mem.addr[pg], data, len);

	} else {
		for (voice_num = 0; voice_num < woinst->num_voices; voice_num++)
			memset((u8 *)voice[voice_num].mem.addr[pg] + pgoff, data, len);
	}
}

/**
 * emu10k1_waveout_xferdata -
 *
 * copies pcm data to the voice buffer. Silence samples
 * previously added to the buffer are overwritten.
 *
 */
void emu10k1_waveout_xferdata(struct woinst *woinst, u8 __user *data, u32 *size)
{
	struct waveout_buffer *buffer = &woinst->buffer;
	struct voice_mem *mem = &woinst->voice[0].mem;
	u32 sizetocopy, sizetocopy_now, start;
	unsigned long flags;

	sizetocopy = min_t(u32, buffer->size, *size);
	*size = sizetocopy;

	if (!sizetocopy)
		return;
	
	spin_lock_irqsave(&woinst->lock, flags);
	start = (buffer->size + buffer->silence_pos - buffer->silence_bytes) % buffer->size;

	if (sizetocopy > buffer->silence_bytes) {
		buffer->silence_pos += sizetocopy - buffer->silence_bytes;
		buffer->free_bytes -= sizetocopy - buffer->silence_bytes;
		buffer->silence_bytes = 0;
	} else
		buffer->silence_bytes -= sizetocopy;

	spin_unlock_irqrestore(&woinst->lock, flags);

	sizetocopy_now = buffer->size - start;
	if (sizetocopy > sizetocopy_now) {
		sizetocopy -= sizetocopy_now;
		if (woinst->num_voices > 1) {
			copy_ilv_block(woinst, start, data, sizetocopy_now);
			copy_ilv_block(woinst, 0, data + sizetocopy_now * woinst->num_voices, sizetocopy);
		} else {
			copy_block(mem->addr, start, data, sizetocopy_now);
			copy_block(mem->addr, 0, data + sizetocopy_now, sizetocopy);
		}
	} else {
		if (woinst->num_voices > 1)
			copy_ilv_block(woinst, start, data, sizetocopy);
		else
			copy_block(mem->addr, start, data, sizetocopy);
	}
}

/**
 * emu10k1_waveout_fillsilence -
 *
 * adds samples of silence to the voice buffer so that we
 * don't loop over stale pcm data.
 *
 */
void emu10k1_waveout_fillsilence(struct woinst *woinst)
{
	struct waveout_buffer *buffer = &woinst->buffer;
	u32 sizetocopy, sizetocopy_now, start;
	u8 filldata;
	unsigned long flags;

	sizetocopy = buffer->fragment_size;

	if (woinst->format.bitsperchannel == 16)
		filldata = 0x00;
	else
		filldata = 0x80;

	spin_lock_irqsave(&woinst->lock, flags);
	buffer->silence_bytes += sizetocopy;
	buffer->free_bytes -= sizetocopy;
	buffer->silence_pos %= buffer->size;
	start = buffer->silence_pos;
	buffer->silence_pos += sizetocopy;
	spin_unlock_irqrestore(&woinst->lock, flags);

	sizetocopy_now = buffer->size - start;

	if (sizetocopy > sizetocopy_now) {
		sizetocopy -= sizetocopy_now;
		fill_block(woinst, start, filldata, sizetocopy_now);
		fill_block(woinst, 0, filldata, sizetocopy);
	} else {
		fill_block(woinst, start, filldata, sizetocopy);
	}
}

/**
 * emu10k1_waveout_update -
 *
 * updates the position of the voice buffer hardware pointer (hw_pos)
 * and the number of free bytes on the buffer (free_bytes).
 * The free bytes _don't_ include silence bytes that may have been
 * added to the buffer.
 *
 */
void emu10k1_waveout_update(struct woinst *woinst)
{
	u32 hw_pos;
	u32 diff;

	/* There is no actual start yet */
	if (!(woinst->state & WAVE_STATE_STARTED)) {
		hw_pos = woinst->buffer.hw_pos;
	} else {
		/* hw_pos in sample units */
		hw_pos = sblive_readptr(woinst->voice[0].card, CCCA_CURRADDR, woinst->voice[0].num);

		if(hw_pos < woinst->voice[0].start)
			hw_pos += woinst->buffer.size / woinst->format.bytespervoicesample - woinst->voice[0].start;
		else
			hw_pos -= woinst->voice[0].start;

		hw_pos *= woinst->format.bytespervoicesample;
	}

	diff = (woinst->buffer.size + hw_pos - woinst->buffer.hw_pos) % woinst->buffer.size;
	woinst->total_played += diff;
	woinst->buffer.free_bytes += diff;
	woinst->buffer.hw_pos = hw_pos;
}