sound/soc/atmel/sam9x5_wm8731.c

Source file repositories/reference/linux-study-clean/sound/soc/atmel/sam9x5_wm8731.c

File Facts

System
Linux kernel
Corpus path
sound/soc/atmel/sam9x5_wm8731.c
Extension
.c
Size
5318 bytes
Lines
209
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

struct sam9x5_drvdata {
	int ssc_id;
};

/*
 * Logic for a wm8731 as connected on a at91sam9x5ek based board.
 */
static int sam9x5_wm8731_init(struct snd_soc_pcm_runtime *rtd)
{
	struct snd_soc_dai *codec_dai = snd_soc_rtd_to_codec(rtd, 0);
	struct device *dev = rtd->dev;
	int ret;

	dev_dbg(dev, "%s called\n", __func__);

	/* set the codec system clock for DAC and ADC */
	ret = snd_soc_dai_set_sysclk(codec_dai, WM8731_SYSCLK_XTAL,
				     MCLK_RATE, SND_SOC_CLOCK_IN);
	if (ret < 0) {
		dev_err(dev, "Failed to set WM8731 SYSCLK: %d\n", ret);
		return ret;
	}

	return 0;
}

/*
 * Audio paths on at91sam9x5ek board:
 *
 *  |A| ------------> |      | ---R----> Headphone Jack
 *  |T| <----\        |  WM  | ---L--/
 *  |9| ---> CLK <--> | 8731 | <--R----- Line In Jack
 *  |1| <------------ |      | <--L--/
 */
static const struct snd_soc_dapm_widget sam9x5_dapm_widgets[] = {
	SND_SOC_DAPM_HP("Headphone Jack", NULL),
	SND_SOC_DAPM_LINE("Line In Jack", NULL),
};

static int sam9x5_wm8731_driver_probe(struct platform_device *pdev)
{
	struct device_node *np = pdev->dev.of_node;
	struct device_node *codec_np, *cpu_np;
	struct snd_soc_card *card;
	struct snd_soc_dai_link *dai;
	struct sam9x5_drvdata *priv;
	struct snd_soc_dai_link_component *comp;
	int ret;

	if (!np) {
		dev_err(&pdev->dev, "No device node supplied\n");
		return -EINVAL;
	}

	card = devm_kzalloc(&pdev->dev, sizeof(*card), GFP_KERNEL);
	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
	dai = devm_kzalloc(&pdev->dev, sizeof(*dai), GFP_KERNEL);
	comp = devm_kzalloc(&pdev->dev, 3 * sizeof(*comp), GFP_KERNEL);
	if (!dai || !card || !priv || !comp) {
		ret = -ENOMEM;
		goto out;
	}

	snd_soc_card_set_drvdata(card, priv);

	card->dev = &pdev->dev;
	card->owner = THIS_MODULE;
	card->dai_link = dai;
	card->num_links = 1;
	card->dapm_widgets = sam9x5_dapm_widgets;
	card->num_dapm_widgets = ARRAY_SIZE(sam9x5_dapm_widgets);

	dai->cpus = &comp[0];
	dai->num_cpus = 1;
	dai->codecs = &comp[1];
	dai->num_codecs = 1;
	dai->platforms = &comp[2];
	dai->num_platforms = 1;

	dai->name = "WM8731";
	dai->stream_name = "WM8731 PCM";
	dai->codecs->dai_name = "wm8731-hifi";
	dai->init = sam9x5_wm8731_init;
	dai->dai_fmt = SND_SOC_DAIFMT_DSP_A | SND_SOC_DAIFMT_NB_NF
		| SND_SOC_DAIFMT_CBP_CFP;

	ret = snd_soc_of_parse_card_name(card, "atmel,model");
	if (ret) {
		dev_err(&pdev->dev, "atmel,model node missing\n");
		goto out;

Annotation

Implementation Notes