57 lines
1.7 KiB
C
57 lines
1.7 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* Copyright (c) 2019 MediaTek Inc.
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* Author: Kai Chieh Chuang <kaichieh.chuang@mediatek.com>
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*/
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#include <linux/io.h>
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#include <linux/module.h>
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#include "mtk-sp-pcm-ops.h"
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#include "mtk-afe-platform-driver.h"
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#include "mtk-base-afe.h"
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/* clean buffer that have already been play to HW, to minimize pop when xrun */
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#define CLEAR_BUFFER_US 600
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int mtk_sp_clean_written_buffer_ack(struct snd_pcm_substream *substream)
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{
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struct snd_pcm_runtime *runtime = substream->runtime;
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unsigned int size_per_frame = runtime->frame_bits / 8;
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snd_pcm_uframes_t avail = snd_pcm_playback_avail(runtime);
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unsigned int copy_size = word_size_align(avail * size_per_frame);
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snd_pcm_uframes_t appl_ofs = runtime->control->appl_ptr %
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runtime->buffer_size;
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unsigned int write_idx = appl_ofs * size_per_frame;
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unsigned int max_clear_buffer_size;
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max_clear_buffer_size = word_size_align(runtime->rate *
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CLEAR_BUFFER_US *
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size_per_frame / 1000000);
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if (copy_size == 0)
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return 0;
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if (copy_size > max_clear_buffer_size)
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copy_size = max_clear_buffer_size;
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if (write_idx + copy_size < runtime->dma_bytes) {
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memset_io(runtime->dma_area + write_idx, 0, copy_size);
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} else {
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unsigned int size_1 = 0, size_2 = 0;
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size_1 = word_size_align(runtime->dma_bytes - write_idx);
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size_2 = word_size_align(copy_size - size_1);
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memset_io(runtime->dma_area + write_idx, 0, size_1);
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memset_io(runtime->dma_area, 0, size_2);
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}
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return 0;
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}
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EXPORT_SYMBOL_GPL(mtk_sp_clean_written_buffer_ack);
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MODULE_DESCRIPTION("Mediatek Smart Phone PCM Operation");
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MODULE_AUTHOR("Kai Chieh Chuang <kaichieh.chuang@mediatek.com>");
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MODULE_LICENSE("GPL v2");
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