sound/soc/qcom/storm.c

Source file repositories/reference/linux-study-clean/sound/soc/qcom/storm.c

File Facts

System
Linux kernel
Corpus path
sound/soc/qcom/storm.c
Extension
.c
Size
3621 bytes
Lines
144
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
/*
 * Copyright (c) 2010-2011,2013-2015 The Linux Foundation. All rights reserved.
 *
 * storm.c -- ALSA SoC machine driver for QTi ipq806x-based Storm board
 */

#include <linux/device.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/mod_devicetable.h>
#include <linux/platform_device.h>
#include <sound/pcm.h>
#include <sound/pcm_params.h>
#include <sound/soc.h>

#define STORM_SYSCLK_MULT			4

static int storm_ops_hw_params(struct snd_pcm_substream *substream,
		struct snd_pcm_hw_params *params)
{
	struct snd_soc_pcm_runtime *soc_runtime = snd_soc_substream_to_rtd(substream);
	struct snd_soc_card *card = soc_runtime->card;
	snd_pcm_format_t format = params_format(params);
	unsigned int rate = params_rate(params);
	unsigned int sysclk_freq;
	int bitwidth, ret;

	bitwidth = snd_pcm_format_width(format);
	if (bitwidth < 0) {
		dev_err(card->dev, "invalid bit width given: %d\n", bitwidth);
		return bitwidth;
	}

	/*
	 * as the CPU DAI is the I2S bus master and no system clock is needed by
	 * the MAX98357a DAC, simply set the system clock to be a constant
	 * multiple of the bit clock for the clock divider
	 */
	sysclk_freq = rate * bitwidth * 2 * STORM_SYSCLK_MULT;

	ret = snd_soc_dai_set_sysclk(snd_soc_rtd_to_cpu(soc_runtime, 0), 0, sysclk_freq, 0);
	if (ret) {
		dev_err(card->dev, "error setting sysclk to %u: %d\n",
			sysclk_freq, ret);
		return ret;
	}

	return 0;
}

static const struct snd_soc_ops storm_soc_ops = {
	.hw_params	= storm_ops_hw_params,
};

SND_SOC_DAILINK_DEFS(hifi,
	DAILINK_COMP_ARRAY(COMP_EMPTY()),
	DAILINK_COMP_ARRAY(COMP_CODEC(NULL, "HiFi")),
	DAILINK_COMP_ARRAY(COMP_EMPTY()));

static struct snd_soc_dai_link storm_dai_link = {
	.name		= "Primary",
	.stream_name	= "Primary",
	.ops		= &storm_soc_ops,
	SND_SOC_DAILINK_REG(hifi),
};

static int storm_parse_of(struct snd_soc_card *card)
{
	struct snd_soc_dai_link *dai_link = card->dai_link;
	struct device_node *np = card->dev->of_node;

	dai_link->cpus->of_node = of_parse_phandle(np, "cpu", 0);
	if (!dai_link->cpus->of_node) {
		dev_err(card->dev, "error getting cpu phandle\n");
		return -EINVAL;
	}
	dai_link->platforms->of_node = dai_link->cpus->of_node;

	dai_link->codecs->of_node = of_parse_phandle(np, "codec", 0);
	if (!dai_link->codecs->of_node) {
		dev_err(card->dev, "error getting codec phandle\n");
		return -EINVAL;
	}

	return 0;
}

static int storm_platform_probe(struct platform_device *pdev)
{

Annotation

Implementation Notes