// SPDX-License-Identifier: GPL-2.0+ /* * Copyright (C) 2012 Samsung Electronics * R. Chandrasekar */ #include #include #include 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; if (!half) { memset(data, 0, size); return; } /* Make sure we don't overflow our buffer */ if (size % 2) size--; while (size) { int i, j; for (i = 0; size && i < half; i++) { for (j = 0; size && j < channels; j++, size -= 2) *data++ = amplitude; } for (i = 0; size && i < period - half; i++) { for (j = 0; size && j < channels; j++, size -= 2) *data++ = -amplitude; } } }