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- // 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;
- }
- }
- }
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