MLK-16929-2: sound: soc: fsl: imx pdm mic driver over SAI

i.MX Sound SoC Audio support for PDM mics on SAI
Set audio recording hardware constrains, support
Sample rates: 8000, 16000, 32000, 48000, 64000
PDM decimation factor property fixed to 64
Number of channels: 1

Signed-off-by: Adrian Alonso <adrian.alonso@nxp.com>
Reviewed-by: Shengjiu Wang <shengjiu.wang@nxp.com>
[ Aisheng: clean for a new base ]
Signed-off-by: Dong Aisheng <aisheng.dong@nxp.com>

1 files changed, 197 insertions, 0 deletions

diff --git a/sound/soc/fsl/imx-pdm.c b/sound/soc/fsl/imx-pdm.c
new file mode 100644
index 000000000000..eea08300a1be
--- /dev/null
+++ b/sound/soc/fsl/imx-pdm.c
@@ -0,0 +1,197 @@
+/*
+ * Copyright 2017 NXP.
+ *
+ * The code contained herein is licensed under the GNU General Public
+ * License. You may obtain a copy of the GNU General Public License
+ * Version 2 or later at the following locations:
+ *
+ * http://www.opensource.org/licenses/gpl-license.html
+ * http://www.gnu.org/copyleft/gpl.html
+ */
+
+#include <linux/module.h>
+#include <linux/of_platform.h>
+#include <linux/slab.h>
+#include <linux/clk.h>
+#include <sound/soc.h>
+
+#include "fsl_sai.h"
+
+struct imx_pdm_data {
+	struct snd_soc_dai_link dai;
+	struct snd_soc_card card;
+	unsigned int decimation;
+};
+
+static u32 imx_pdm_mic_rates[] = { 8000, 16000, 32000, 48000, 64000 };
+static struct snd_pcm_hw_constraint_list imx_pdm_mic_rate_constrains = {
+	.count = ARRAY_SIZE(imx_pdm_mic_rates),
+	.list = imx_pdm_mic_rates,
+};
+static u32 imx_pdm_mic_channels[] = { 1 };
+static struct snd_pcm_hw_constraint_list imx_pdm_mic_channels_constrains = {
+	.count = ARRAY_SIZE(imx_pdm_mic_channels),
+	.list = imx_pdm_mic_channels,
+};
+
+static int imx_pdm_mic_startup(struct snd_pcm_substream *substream)
+{
+	struct snd_soc_pcm_runtime *rtd = substream->private_data;
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	struct snd_soc_card *card = rtd->card;
+	int ret;
+
+	ret = snd_pcm_hw_constraint_list(runtime, 0, SNDRV_PCM_HW_PARAM_RATE,
+			&imx_pdm_mic_rate_constrains);
+	if (ret) {
+		dev_err(card->dev,
+			"fail to set pcm hw rate constrains: %d\n", ret);
+		return ret;
+	}
+
+	ret = snd_pcm_hw_constraint_list(runtime, 0,
+		SNDRV_PCM_HW_PARAM_CHANNELS, &imx_pdm_mic_channels_constrains);
+	if (ret) {
+		dev_err(card->dev,
+			"fail to set pcm hw channels constrains: %d", ret);
+		return ret;
+	}
+
+	return 0;
+}
+
+static int imx_pdm_mic_hw_params(struct snd_pcm_substream *substream,
+		struct snd_pcm_hw_params *params)
+{
+	struct snd_soc_pcm_runtime *rtd = substream->private_data;
+	struct snd_soc_dai *cpu_dai = rtd->cpu_dai;
+	struct snd_soc_card *card = rtd->card;
+	struct imx_pdm_data *data = snd_soc_card_get_drvdata(card);
+	unsigned int bitclk = params_rate(params) * data->decimation;
+	int ret;
+
+	/* set cpu dai format configuration */
+	ret = snd_soc_dai_set_fmt(cpu_dai, SND_SOC_DAIFMT_DSP_A |
+			SND_SOC_DAIFMT_NB_NF | SND_SOC_DAIFMT_CBS_CFS);
+	if (ret) {
+		dev_err(card->dev, "fail to set cpu dai fmt: %d\n", ret);
+		return ret;
+	}
+	/* set tdm slots only one for now */
+	snd_soc_dai_set_tdm_slot(cpu_dai, 0, 0, 1, 32);
+	/* Set clock out */
+	ret = snd_soc_dai_set_sysclk(cpu_dai, FSL_SAI_CLK_MAST1,
+			bitclk, SND_SOC_CLOCK_OUT);
+	if (ret) {
+		dev_err(card->dev, "fail to set cpu sysclk: %d\n", ret);
+		return ret;
+	}
+
+	return 0;
+}
+
+static const struct snd_soc_ops imx_pdm_mic_ops = {
+	.startup = imx_pdm_mic_startup,
+	.hw_params = imx_pdm_mic_hw_params,
+};
+
+static int imx_pdm_mic_probe(struct platform_device *pdev)
+{
+	struct device_node *cpu_np = NULL;
+	struct device_node *np = pdev->dev.of_node;
+	struct platform_device *cpu_pdev;
+	struct imx_pdm_data *data;
+	int ret;
+
+	cpu_np = of_parse_phandle(np, "audio-cpu", 0);
+	if (!cpu_np) {
+		dev_err(&pdev->dev, "cpu dai phandle missing or invalid\n");
+		ret = -EINVAL;
+		goto fail;
+	}
+
+	cpu_pdev = of_find_device_by_node(cpu_np);
+	if (!cpu_pdev) {
+		dev_err(&pdev->dev, "fail to find SAI platform device\n");
+		ret = -EINVAL;
+		goto fail;
+	}
+
+	data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
+	if (!data) {
+		ret = -ENOMEM;
+		goto fail;
+	}
+
+	ret = of_property_read_u32(np, "decimation", &data->decimation);
+	if (ret < 0) {
+		ret = -EINVAL;
+		goto fail;
+	}
+
+	data->dai.name = "pdm hifi";
+	data->dai.stream_name = "pdm hifi";
+	data->dai.codec_dai_name = "snd-soc-dummy-dai";
+	data->dai.codec_name = "snd-soc-dummy";
+	data->dai.cpu_dai_name = dev_name(&cpu_pdev->dev);
+	data->dai.platform_of_node = cpu_np;
+	data->dai.capture_only = "true";
+	data->dai.ops = &imx_pdm_mic_ops;
+
+	data->card.dev = &pdev->dev;
+	data->card.owner = THIS_MODULE;
+
+	ret = snd_soc_of_parse_card_name(&data->card, "model");
+	if (ret) {
+		dev_err(&pdev->dev, "fail to find card model name\n");
+		goto fail;
+	}
+
+	data->card.num_links = 1;
+	data->card.dai_link = &data->dai;
+
+	platform_set_drvdata(pdev, &data->card);
+	snd_soc_card_set_drvdata(&data->card, data);
+
+	ret = devm_snd_soc_register_card(&pdev->dev, &data->card);
+	if (ret) {
+		dev_err(&pdev->dev, "snd soc register card failed: %d\n", ret);
+		goto fail;
+	}
+
+	ret = 0;
+fail:
+	if (cpu_np)
+		of_node_put(cpu_np);
+
+	return ret;
+}
+
+static int imx_pdm_mic_remove(struct platform_device *pdev)
+{
+	struct imx_pdm_data *data = platform_get_drvdata(pdev);
+	/* unregister card */
+	snd_soc_unregister_card(&data->card);
+	return 0;
+}
+
+static const struct of_device_id imx_pdm_mic_dt_ids[] = {
+	{ .compatible = "fsl,imx-pdm-mic", },
+	{ /* sentinel*/ }
+};
+MODULE_DEVICE_TABLE(of, imx_pdm_mic_dt_ids);
+
+static struct platform_driver imx_pdm_mic_driver = {
+	.driver = {
+		.name = "imx-pdm-mic",
+		.pm = &snd_soc_pm_ops,
+		.of_match_table = imx_pdm_mic_dt_ids,
+	},
+	.probe = imx_pdm_mic_probe,
+	.remove = imx_pdm_mic_remove,
+};
+module_platform_driver(imx_pdm_mic_driver);
+
+MODULE_DESCRIPTION("NXP i.MX PDM mic ASoC machine driver");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:imx-pdm-mic");