sound/soc/intel/boards/bytcht_nocodec.c

Source file repositories/reference/linux-study-clean/sound/soc/intel/boards/bytcht_nocodec.c

File Facts

System
Linux kernel
Corpus path
sound/soc/intel/boards/bytcht_nocodec.c
Extension
.c
Size
5111 bytes
Lines
194
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-only
/*
 *  bytcht_nocodec.c - ASoc Machine driver for MinnowBoard Max and Up
 *  to make I2S signals observable on the Low-Speed connector. Audio codec
 *  is not managed by ASoC/DAPM
 *
 *  Copyright (C) 2015-2017 Intel Corp
 *
 *  ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 *
 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 */

#include <linux/module.h>
#include <sound/pcm.h>
#include <sound/pcm_params.h>
#include <sound/soc.h>
#include "../atom/sst-atom-controls.h"

static const struct snd_soc_dapm_widget widgets[] = {
	SND_SOC_DAPM_MIC("Mic", NULL),
	SND_SOC_DAPM_SPK("Speaker", NULL),
};

static const struct snd_kcontrol_new controls[] = {
	SOC_DAPM_PIN_SWITCH("Mic"),
	SOC_DAPM_PIN_SWITCH("Speaker"),
};

static const struct snd_soc_dapm_route audio_map[] = {
	{"ssp2 Tx", NULL, "codec_out0"},
	{"ssp2 Tx", NULL, "codec_out1"},
	{"codec_in0", NULL, "ssp2 Rx"},
	{"codec_in1", NULL, "ssp2 Rx"},

	{"ssp2 Rx", NULL, "Mic"},
	{"Speaker", NULL, "ssp2 Tx"},
};

static int codec_fixup(struct snd_soc_pcm_runtime *rtd,
			    struct snd_pcm_hw_params *params)
{
	struct snd_interval *rate = hw_param_interval(params,
			SNDRV_PCM_HW_PARAM_RATE);
	struct snd_interval *channels = hw_param_interval(params,
						SNDRV_PCM_HW_PARAM_CHANNELS);
	int ret;

	/* The DSP will convert the FE rate to 48k, stereo, 24bits */
	rate->min = rate->max = 48000;
	channels->min = channels->max = 2;

	/* set SSP2 to 24-bit */
	params_set_format(params, SNDRV_PCM_FORMAT_S24_LE);

	/*
	 * Default mode for SSP configuration is TDM 4 slot, override config
	 * with explicit setting to I2S 2ch 24-bit. The word length is set with
	 * dai_set_tdm_slot() since there is no other API exposed
	 */
	ret = snd_soc_dai_set_fmt(snd_soc_rtd_to_cpu(rtd, 0),
				  SND_SOC_DAIFMT_I2S     |
				  SND_SOC_DAIFMT_NB_NF   |
				  SND_SOC_DAIFMT_BP_FP);

	if (ret < 0) {
		dev_err(rtd->dev, "can't set format to I2S, err %d\n", ret);
		return ret;
	}

	ret = snd_soc_dai_set_tdm_slot(snd_soc_rtd_to_cpu(rtd, 0), 0x3, 0x3, 2, 24);
	if (ret < 0) {
		dev_err(rtd->dev, "can't set I2S config, err %d\n", ret);
		return ret;
	}

	return 0;
}

static const unsigned int rates_48000[] = {
	48000,
};

static const struct snd_pcm_hw_constraint_list constraints_48000 = {
	.count = ARRAY_SIZE(rates_48000),
	.list  = rates_48000,
};

static int aif1_startup(struct snd_pcm_substream *substream)
{

Annotation

Implementation Notes