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