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d0e8777bee
'sound play 1 100000' results in an endless loop on the sandbox.
If the frequency exceeds half the sampling rate, zero out the output
buffer.
Fixes: 511ed5fdd389 ("SOUND: SAMSUNG: Add I2S driver")
Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
40 lines
862 B
C
40 lines
862 B
C
// SPDX-License-Identifier: GPL-2.0+
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/*
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* Copyright (C) 2012 Samsung Electronics
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* R. Chandrasekar <rcsekar@samsung.com>
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*/
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#include <common.h>
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#include <log.h>
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#include <sound.h>
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void sound_create_square_wave(uint sample_rate, unsigned short *data, int size,
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uint freq, uint channels)
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{
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const unsigned short amplitude = 16000; /* between 1 and 32767 */
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const int period = freq ? sample_rate / freq : 0;
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const int half = period / 2;
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if (!half) {
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memset(data, 0, size);
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return;
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}
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/* Make sure we don't overflow our buffer */
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if (size % 2)
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size--;
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while (size) {
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int i, j;
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for (i = 0; size && i < half; i++) {
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for (j = 0; size && j < channels; j++, size -= 2)
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*data++ = amplitude;
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}
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for (i = 0; size && i < period - half; i++) {
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for (j = 0; size && j < channels; j++, size -= 2)
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*data++ = -amplitude;
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}
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}
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}
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