39 lines
815 B
C
39 lines
815 B
C
// SPDX-License-Identifier: GPL-2.0+
|
|
/*
|
|
* Copyright (C) 2012 Samsung Electronics
|
|
* R. Chandrasekar <rcsekar@samsung.com>
|
|
*/
|
|
|
|
#include <common.h>
|
|
#include <log.h>
|
|
#include <sound.h>
|
|
|
|
void sound_create_square_wave(uint sample_rate, unsigned short *data, int size,
|
|
uint freq, uint channels)
|
|
{
|
|
const unsigned short amplitude = 16000; /* between 1 and 32767 */
|
|
const int period = freq ? sample_rate / freq : 0;
|
|
const int half = period / 2;
|
|
|
|
assert(freq);
|
|
|
|
/* Make sure we don't overflow our buffer */
|
|
if (size % 2)
|
|
size--;
|
|
|
|
while (size) {
|
|
int i, j;
|
|
|
|
for (i = 0; size && i < half; i++) {
|
|
size -= 2;
|
|
for (j = 0; j < channels; j++)
|
|
*data++ = amplitude;
|
|
}
|
|
for (i = 0; size && i < period - half; i++) {
|
|
size -= 2;
|
|
for (j = 0; j < channels; j++)
|
|
*data++ = -amplitude;
|
|
}
|
|
}
|
|
}
|