Files
android/sound/soc/mediatek/common/mtk-sp-pcm-ops.c
threeeye bc1d038eac REVVL 6 Pro kernel bring-up: full working tree snapshot (2026-09-12)
Squashed backup commit (no shallow-clone history issues) of
xiaomi-mt6833-dev/kernel_xiaomi_mt6833 (lineage-23.2 branch, upstream
commit 9eece662e) plus all fixes applied to get everpal_defconfig building
clean against a modern (GCC 15.2.0) toolchain -- see the previous commit
message on the lineage-23.2 branch (also in this repo history is not
available here since this is a squashed snapshot; full incremental history
lives in the local DL380 checkout and the upstream GitHub remote).

Upstream: https://github.com/xiaomi-mt6833-dev/kernel_xiaomi_mt6833 (lineage-23.2)
2026-09-12 13:36:46 +00:00

57 lines
1.7 KiB
C

// SPDX-License-Identifier: GPL-2.0
//
// mtk-sp-pcm-ops.c -- Mediatek Smart Phone PCM Operation
//
// Copyright (c) 2017 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;
}
MODULE_DESCRIPTION("Mediatek Smart Phone PCM Operation");
MODULE_AUTHOR("Kai Chieh Chuang <kaichieh.chuang@mediatek.com>");
MODULE_LICENSE("GPL v2");