sound/soc/meson/aiu-fifo.c

Source file repositories/reference/linux-study-clean/sound/soc/meson/aiu-fifo.c

File Facts

System
Linux kernel
Corpus path
sound/soc/meson/aiu-fifo.c
Extension
.c
Size
5653 bytes
Lines
216
Domain
Driver Families
Bucket
sound/soc
Inferred role
Driver Families: implementation source
Status
source implementation candidate

Why This File Exists

Repeatable hardware-adapter layer. Deep compatibility for every driver is out of scope; this atlas records patterns, probe lifecycles, bus glue, IRQ/DMA usage, and links back to core abstractions.

Dependency Surface

Detected Declarations

Annotated Snippet

// SPDX-License-Identifier: GPL-2.0
//
// Copyright (c) 2020 BayLibre, SAS.
// Author: Jerome Brunet <jbrunet@baylibre.com>

#include <linux/bitfield.h>
#include <linux/clk.h>
#include <linux/dma-mapping.h>
#include <sound/pcm_params.h>
#include <sound/soc.h>
#include <sound/soc-dai.h>

#include "aiu-fifo.h"

#define AIU_MEM_START	0x00
#define AIU_MEM_RD	0x04
#define AIU_MEM_END	0x08
#define AIU_MEM_MASKS	0x0c
#define  AIU_MEM_MASK_CH_RD GENMASK(7, 0)
#define  AIU_MEM_MASK_CH_MEM GENMASK(15, 8)
#define AIU_MEM_CONTROL	0x10
#define  AIU_MEM_CONTROL_INIT BIT(0)
#define  AIU_MEM_CONTROL_FILL_EN BIT(1)
#define  AIU_MEM_CONTROL_EMPTY_EN BIT(2)

static struct snd_soc_dai *aiu_fifo_dai(struct snd_pcm_substream *ss)
{
	struct snd_soc_pcm_runtime *rtd = snd_soc_substream_to_rtd(ss);

	return snd_soc_rtd_to_cpu(rtd, 0);
}

snd_pcm_uframes_t aiu_fifo_pointer(struct snd_soc_component *component,
				   struct snd_pcm_substream *substream)
{
	struct snd_soc_dai *dai = aiu_fifo_dai(substream);
	struct aiu_fifo *fifo = snd_soc_dai_dma_data_get_playback(dai);
	struct snd_pcm_runtime *runtime = substream->runtime;
	unsigned int addr;

	addr = snd_soc_component_read(component, fifo->mem_offset + AIU_MEM_RD);

	return bytes_to_frames(runtime, addr - (unsigned int)runtime->dma_addr);
}

static void aiu_fifo_enable(struct snd_soc_dai *dai, bool enable)
{
	struct snd_soc_component *component = dai->component;
	struct aiu_fifo *fifo = snd_soc_dai_dma_data_get_playback(dai);
	unsigned int en_mask = (AIU_MEM_CONTROL_FILL_EN |
				AIU_MEM_CONTROL_EMPTY_EN);

	snd_soc_component_update_bits(component,
				      fifo->mem_offset + AIU_MEM_CONTROL,
				      en_mask, enable ? en_mask : 0);
}

int aiu_fifo_trigger(struct snd_pcm_substream *substream, int cmd,
		     struct snd_soc_dai *dai)
{
	switch (cmd) {
	case SNDRV_PCM_TRIGGER_START:
	case SNDRV_PCM_TRIGGER_RESUME:
	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
		aiu_fifo_enable(dai, true);
		break;
	case SNDRV_PCM_TRIGGER_SUSPEND:
	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
	case SNDRV_PCM_TRIGGER_STOP:
		aiu_fifo_enable(dai, false);
		break;
	default:
		return -EINVAL;
	}

	return 0;
}

int aiu_fifo_prepare(struct snd_pcm_substream *substream,
		     struct snd_soc_dai *dai)
{
	struct snd_soc_component *component = dai->component;
	struct aiu_fifo *fifo = snd_soc_dai_dma_data_get_playback(dai);

	snd_soc_component_update_bits(component,
				      fifo->mem_offset + AIU_MEM_CONTROL,
				      AIU_MEM_CONTROL_INIT,
				      AIU_MEM_CONTROL_INIT);
	snd_soc_component_update_bits(component,
				      fifo->mem_offset + AIU_MEM_CONTROL,

Annotation

Implementation Notes