void sound_play_sample(U8 *data, U32 length, U32 freq, int vol)
{
if (data == (U8 *) 0 || length == 0) return;
// Calculate the clock divisor based upon the recorded sample frequency */
if (freq == 0) freq = DEFRATE;
if (freq > MAXRATE) freq = MAXRATE;
if (freq < MINRATE) freq = MINRATE;
U32 cdiv = (OSC/(2*SAMPBITS) + freq/2)/freq;
set_vol(vol);
// Turn off ints while we update shared values
sound_interrupt_disable();
sound_mode = SOUND_MODE_PCM;
sample.count = length;
sample.ptr = data;
sample.len = PDM_BUFFER_LENGTH;
sample.clock_div = cdiv;
// re-enable and wait for the current sample to complete
sound_interrupt_enable(AT91C_SSC_TXBUFE);
*AT91C_SSC_PTCR = AT91C_PDC_TXTEN;
}
int sound_add_sample(U8 *data, U32 length, U32 freq, int vol)
{
// Add a set of samples into the playback queue, if not currently
// playing start the playback process.
// If this is the first sample simply start to play it
if (sound_mode != SOUND_MODE_PCM || sample.ptr != sample.sample_buf)
{
if (sample.sample_buf == NULL)
{
sample.sample_buf = system_allocate(SAMPLEBUFSZ);
if (sample.sample_buf == NULL) return -1;
}
if (length > SAMPLEBUFSZ - 1) length = SAMPLEBUFSZ - 1;
memcpy(sample.sample_buf, data, length);
sound_play_sample(sample.sample_buf, length, freq, vol);
return length;
}
// Otherwise add the data to the buffer
// Turn off ints while we update shared values
sound_interrupt_disable();
// add the data
U8 *sbuf = sample.ptr;
U32 in = sample.in_index;
U32 out = sample.out_index;
int cnt = (int) ((out - in - 1) & (SAMPLEBUFSZ - 1));
if (cnt > length) cnt = length;
length = cnt;
while (cnt-- > 0)
{
sbuf[in] = *data++;
in = (in + 1) & (SAMPLEBUFSZ - 1);
}
sample.in_index = in;
sample.count = (((in - out) & (SAMPLEBUFSZ - 1)) + SAMPPERBUF - 1)/SAMPPERBUF;
// re-enable and wait for the current sample to complete
sound_interrupt_enable(AT91C_SSC_ENDTX);
*AT91C_SSC_PTCR = AT91C_PDC_TXTEN;
return length;
}
void sound_isr_C()
{
//U64 s = systick_get_ns();
if (sample.count > 0)
{
// refill the buffer, and adjust any clocks
*AT91C_SSC_CMR = sample.clock_div;
sound_enable();
if (*AT91C_SSC_TCR == 0)
{
if (sound_mode == SOUND_MODE_PCM)
{
sound_fill_sample_buffer();
*AT91C_SSC_TPR = (unsigned int)sample.buf[sample.buf_id];
}
else
*AT91C_SSC_TPR = (unsigned int)sample.ptr;
*AT91C_SSC_TCR = sample.len;
sample.count--;
}
if (sound_mode == SOUND_MODE_PCM)
{
sound_fill_sample_buffer();
*AT91C_SSC_TNPR = (unsigned int)sample.buf[sample.buf_id];
}
else
*AT91C_SSC_TNPR = (unsigned int)sample.ptr;
*AT91C_SSC_TNCR = sample.len;
sample.count--;
// If this is the last sample wait for it to complete, otherwise wait
// to switch buffers
sound_interrupt_enable(AT91C_SSC_ENDTX);
}
else
{
sound_disable();
sound_interrupt_disable();
}
//ttime += (systick_get_ns() - s);
}
void sound_freq(U32 freq, U32 ms, int vol)
{
// Set things up ready to go, note we avoid using anything that may
// be used by the interupt routine because ints may still be enabled
// at this point
int len;
// we use longer samples for lower frequencies
if (freq > 1000)
len = 16;
else if (freq < 500)
len = 64;
else
len = 32;
sound_mode = SOUND_MODE_TONE;
// Update the volume lookup table if we need to
set_vol(vol);
int buf = sample.buf_id^1;
create_tone(sine, sizeof(sine), sample.buf[buf], len);
// The note gneration takes approx 1ms, to ensure that we do not get gaps
// when playing a series of tones we extend the requested period to cover
// this 1ms cost.
ms += TONE_OVERHEAD;
// Turn of ints while we update shared values
sound_interrupt_disable();
/* Genrate the pdm wave of the correct amplitude */
sample.clock_div = (OSC/(len*32*2) + freq/2)/freq;
// Calculate actual frequency and use this for length calc
freq = (OSC/(2*sample.clock_div))/(len*32);
if (ms <= TONE_OVERHEAD)
sample.count = 0;
else
sample.count = (freq*ms + 1000-1)/1000;
sample.len = len;
sample.ptr = (U8 *)sample.buf[buf];
sample.buf_id = buf;
*AT91C_SSC_PTCR = AT91C_PDC_TXTEN;
sound_mode = SOUND_MODE_TONE;
sample.in_index = sample.out_index;
sound_interrupt_enable(AT91C_SSC_TXBUFE);
}
