linux-stable/sound/soc/meson/axg-pdm.c

// SPDX-License-Identifier: (GPL-2.0 OR MIT)
//
// Copyright (c) 2018 BayLibre, SAS.
// Author: Jerome Brunet <jbrunet@baylibre.com>

#include <linux/clk.h>
#include <linux/module.h>
#include <linux/of_irq.h>
#include <linux/of_platform.h>
#include <linux/regmap.h>
#include <sound/soc.h>
#include <sound/soc-dai.h>
#include <sound/pcm_params.h>

#define PDM_CTRL			0x00
#define  PDM_CTRL_EN			BIT(31)
#define  PDM_CTRL_OUT_MODE		BIT(29)
#define  PDM_CTRL_BYPASS_MODE		BIT(28)
#define  PDM_CTRL_RST_FIFO		BIT(16)
#define  PDM_CTRL_CHAN_RSTN_MASK	GENMASK(15, 8)
#define  PDM_CTRL_CHAN_RSTN(x)		((x) << 8)
#define  PDM_CTRL_CHAN_EN_MASK		GENMASK(7, 0)
#define  PDM_CTRL_CHAN_EN(x)		((x) << 0)
#define PDM_HCIC_CTRL1			0x04
#define  PDM_FILTER_EN			BIT(31)
#define  PDM_HCIC_CTRL1_GAIN_SFT_MASK	GENMASK(29, 24)
#define  PDM_HCIC_CTRL1_GAIN_SFT(x)	((x) << 24)
#define  PDM_HCIC_CTRL1_GAIN_MULT_MASK	GENMASK(23, 16)
#define  PDM_HCIC_CTRL1_GAIN_MULT(x)	((x) << 16)
#define  PDM_HCIC_CTRL1_DSR_MASK	GENMASK(8, 4)
#define  PDM_HCIC_CTRL1_DSR(x)		((x) << 4)
#define  PDM_HCIC_CTRL1_STAGE_NUM_MASK	GENMASK(3, 0)
#define  PDM_HCIC_CTRL1_STAGE_NUM(x)	((x) << 0)
#define PDM_HCIC_CTRL2			0x08
#define PDM_F1_CTRL			0x0c
#define  PDM_LPF_ROUND_MODE_MASK	GENMASK(17, 16)
#define  PDM_LPF_ROUND_MODE(x)		((x) << 16)
#define  PDM_LPF_DSR_MASK		GENMASK(15, 12)
#define  PDM_LPF_DSR(x)			((x) << 12)
#define  PDM_LPF_STAGE_NUM_MASK		GENMASK(8, 0)
#define  PDM_LPF_STAGE_NUM(x)		((x) << 0)
#define  PDM_LPF_MAX_STAGE		336
#define  PDM_LPF_NUM			3
#define PDM_F2_CTRL			0x10
#define PDM_F3_CTRL			0x14
#define PDM_HPF_CTRL			0x18
#define  PDM_HPF_SFT_STEPS_MASK		GENMASK(20, 16)
#define  PDM_HPF_SFT_STEPS(x)		((x) << 16)
#define  PDM_HPF_OUT_FACTOR_MASK	GENMASK(15, 0)
#define  PDM_HPF_OUT_FACTOR(x)		((x) << 0)
#define PDM_CHAN_CTRL			0x1c
#define  PDM_CHAN_CTRL_POINTER_WIDTH	8
#define  PDM_CHAN_CTRL_POINTER_MAX	((1 << PDM_CHAN_CTRL_POINTER_WIDTH) - 1)
#define  PDM_CHAN_CTRL_NUM		4
#define PDM_CHAN_CTRL1			0x20
#define PDM_COEFF_ADDR			0x24
#define PDM_COEFF_DATA			0x28
#define PDM_CLKG_CTRL			0x2c
#define PDM_STS				0x30

struct axg_pdm_lpf {
	unsigned int ds;
	unsigned int round_mode;
	const unsigned int *tap;
	unsigned int tap_num;
};

struct axg_pdm_hcic {
	unsigned int shift;
	unsigned int mult;
	unsigned int steps;
	unsigned int ds;
};

struct axg_pdm_hpf {
	unsigned int out_factor;
	unsigned int steps;
};

struct axg_pdm_filters {
	struct axg_pdm_hcic hcic;
	struct axg_pdm_hpf hpf;
	struct axg_pdm_lpf lpf[PDM_LPF_NUM];
};

struct axg_pdm_cfg {
	const struct axg_pdm_filters *filters;
	unsigned int sys_rate;
};

struct axg_pdm {
	const struct axg_pdm_cfg *cfg;
	struct regmap *map;
	struct clk *dclk;
	struct clk *sysclk;
	struct clk *pclk;
};

static void axg_pdm_enable(struct regmap *map)
{
	/* Reset AFIFO */
	regmap_update_bits(map, PDM_CTRL, PDM_CTRL_RST_FIFO, PDM_CTRL_RST_FIFO);
	regmap_update_bits(map, PDM_CTRL, PDM_CTRL_RST_FIFO, 0);

	/* Enable PDM */
	regmap_update_bits(map, PDM_CTRL, PDM_CTRL_EN, PDM_CTRL_EN);
}

static void axg_pdm_disable(struct regmap *map)
{
	regmap_update_bits(map, PDM_CTRL, PDM_CTRL_EN, 0);
}

static void axg_pdm_filters_enable(struct regmap *map, bool enable)
{
	unsigned int val = enable ? PDM_FILTER_EN : 0;

	regmap_update_bits(map, PDM_HCIC_CTRL1, PDM_FILTER_EN, val);
	regmap_update_bits(map, PDM_F1_CTRL, PDM_FILTER_EN, val);
	regmap_update_bits(map, PDM_F2_CTRL, PDM_FILTER_EN, val);
	regmap_update_bits(map, PDM_F3_CTRL, PDM_FILTER_EN, val);
	regmap_update_bits(map, PDM_HPF_CTRL, PDM_FILTER_EN, val);
}

static int axg_pdm_trigger(struct snd_pcm_substream *substream, int cmd,
			   struct snd_soc_dai *dai)
{
	struct axg_pdm *priv = snd_soc_dai_get_drvdata(dai);

	switch (cmd) {
	case SNDRV_PCM_TRIGGER_START:
	case SNDRV_PCM_TRIGGER_RESUME:
	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
		axg_pdm_enable(priv->map);
		return 0;

	case SNDRV_PCM_TRIGGER_STOP:
	case SNDRV_PCM_TRIGGER_SUSPEND:
	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
		axg_pdm_disable(priv->map);
		return 0;

	default:
		return -EINVAL;
	}
}

static unsigned int axg_pdm_get_os(struct axg_pdm *priv)
{
	const struct axg_pdm_filters *filters = priv->cfg->filters;
	unsigned int os = filters->hcic.ds;
	int i;

	/*
	 * The global oversampling factor is defined by the down sampling
	 * factor applied by each filter (HCIC and LPFs)
	 */

	for (i = 0; i < PDM_LPF_NUM; i++)
		os *= filters->lpf[i].ds;

	return os;
}

static int axg_pdm_set_sysclk(struct axg_pdm *priv, unsigned int os,
			      unsigned int rate)
{
	unsigned int sys_rate = os * 2 * rate * PDM_CHAN_CTRL_POINTER_MAX;

	/*
	 * Set the default system clock rate unless it is too fast for
	 * for the requested sample rate. In this case, the sample pointer
	 * counter could overflow so set a lower system clock rate
	 */
	if (sys_rate < priv->cfg->sys_rate)
		return clk_set_rate(priv->sysclk, sys_rate);

	return clk_set_rate(priv->sysclk, priv->cfg->sys_rate);
}

static int axg_pdm_set_sample_pointer(struct axg_pdm *priv)
{
	unsigned int spmax, sp, val;
	int i;

	/* Max sample counter value per half period of dclk */
	spmax = DIV_ROUND_UP_ULL((u64)clk_get_rate(priv->sysclk),
				 clk_get_rate(priv->dclk) * 2);

	/* Check if sysclk is not too fast - should not happen */
	if (WARN_ON(spmax > PDM_CHAN_CTRL_POINTER_MAX))
		return -EINVAL;

	/* Capture the data when we are at 75% of the half period */
	sp = spmax * 3 / 4;

	for (i = 0, val = 0; i < PDM_CHAN_CTRL_NUM; i++)
		val |= sp << (PDM_CHAN_CTRL_POINTER_WIDTH * i);

	regmap_write(priv->map, PDM_CHAN_CTRL, val);
	regmap_write(priv->map, PDM_CHAN_CTRL1, val);

	return 0;
}

static void axg_pdm_set_channel_mask(struct axg_pdm *priv,
				     unsigned int channels)
{
	unsigned int mask = GENMASK(channels - 1, 0);

	/* Put all channel in reset */
	regmap_update_bits(priv->map, PDM_CTRL,
			   PDM_CTRL_CHAN_RSTN_MASK, 0);

	/* Take the necessary channels out of reset and enable them */
	regmap_update_bits(priv->map, PDM_CTRL,
			   PDM_CTRL_CHAN_RSTN_MASK |
			   PDM_CTRL_CHAN_EN_MASK,
			   PDM_CTRL_CHAN_RSTN(mask) |
			   PDM_CTRL_CHAN_EN(mask));
}

static int axg_pdm_hw_params(struct snd_pcm_substream *substream,
			     struct snd_pcm_hw_params *params,
			     struct snd_soc_dai *dai)
{
	struct axg_pdm *priv = snd_soc_dai_get_drvdata(dai);
	unsigned int os = axg_pdm_get_os(priv);
	unsigned int rate = params_rate(params);
	unsigned int val;
	int ret;

	switch (params_width(params)) {
	case 24:
		val = PDM_CTRL_OUT_MODE;
		break;
	case 32:
		val = 0;
		break;
	default:
		dev_err(dai->dev, "unsupported sample width\n");
		return -EINVAL;
	}

	regmap_update_bits(priv->map, PDM_CTRL, PDM_CTRL_OUT_MODE, val);

	ret = axg_pdm_set_sysclk(priv, os, rate);
	if (ret) {
		dev_err(dai->dev, "failed to set system clock\n");
		return ret;
	}

	ret = clk_set_rate(priv->dclk, rate * os);
	if (ret) {
		dev_err(dai->dev, "failed to set dclk\n");
		return ret;
	}

	ret = axg_pdm_set_sample_pointer(priv);
	if (ret) {
		dev_err(dai->dev, "invalid clock setting\n");
		return ret;
	}

	axg_pdm_set_channel_mask(priv, params_channels(params));

	return 0;
}

static int axg_pdm_startup(struct snd_pcm_substream *substream,
			   struct snd_soc_dai *dai)
{
	struct axg_pdm *priv = snd_soc_dai_get_drvdata(dai);
	int ret;

	ret = clk_prepare_enable(priv->dclk);
	if (ret) {
		dev_err(dai->dev, "enabling dclk failed\n");
		return ret;
	}

	/* Enable the filters */
	axg_pdm_filters_enable(priv->map, true);

	return ret;
}

static void axg_pdm_shutdown(struct snd_pcm_substream *substream,
			     struct snd_soc_dai *dai)
{
	struct axg_pdm *priv = snd_soc_dai_get_drvdata(dai);

	axg_pdm_filters_enable(priv->map, false);
	clk_disable_unprepare(priv->dclk);
}

static const struct snd_soc_dai_ops axg_pdm_dai_ops = {
	.trigger	= axg_pdm_trigger,
	.hw_params	= axg_pdm_hw_params,
	.startup	= axg_pdm_startup,
	.shutdown	= axg_pdm_shutdown,
};

static void axg_pdm_set_hcic_ctrl(struct axg_pdm *priv)
{
	const struct axg_pdm_hcic *hcic = &priv->cfg->filters->hcic;
	unsigned int val;

	val = PDM_HCIC_CTRL1_STAGE_NUM(hcic->steps);
	val |= PDM_HCIC_CTRL1_DSR(hcic->ds);
	val |= PDM_HCIC_CTRL1_GAIN_MULT(hcic->mult);
	val |= PDM_HCIC_CTRL1_GAIN_SFT(hcic->shift);

	regmap_update_bits(priv->map, PDM_HCIC_CTRL1,
			   PDM_HCIC_CTRL1_STAGE_NUM_MASK |
			   PDM_HCIC_CTRL1_DSR_MASK |
			   PDM_HCIC_CTRL1_GAIN_MULT_MASK |
			   PDM_HCIC_CTRL1_GAIN_SFT_MASK,
			   val);
}

static void axg_pdm_set_lpf_ctrl(struct axg_pdm *priv, unsigned int index)
{
	const struct axg_pdm_lpf *lpf = &priv->cfg->filters->lpf[index];
	unsigned int offset = index * regmap_get_reg_stride(priv->map)
		+ PDM_F1_CTRL;
	unsigned int val;

	val = PDM_LPF_STAGE_NUM(lpf->tap_num);
	val |= PDM_LPF_DSR(lpf->ds);
	val |= PDM_LPF_ROUND_MODE(lpf->round_mode);

	regmap_update_bits(priv->map, offset,
			   PDM_LPF_STAGE_NUM_MASK |
			   PDM_LPF_DSR_MASK |
			   PDM_LPF_ROUND_MODE_MASK,
			   val);
}

static void axg_pdm_set_hpf_ctrl(struct axg_pdm *priv)
{
	const struct axg_pdm_hpf *hpf = &priv->cfg->filters->hpf;
	unsigned int val;

	val = PDM_HPF_OUT_FACTOR(hpf->out_factor);
	val |= PDM_HPF_SFT_STEPS(hpf->steps);

	regmap_update_bits(priv->map, PDM_HPF_CTRL,
			   PDM_HPF_OUT_FACTOR_MASK |
			   PDM_HPF_SFT_STEPS_MASK,
			   val);
}

static int axg_pdm_set_lpf_filters(struct axg_pdm *priv)
{
	const struct axg_pdm_lpf *lpf = priv->cfg->filters->lpf;
	unsigned int count = 0;
	int i, j;

	for (i = 0; i < PDM_LPF_NUM; i++)
		count += lpf[i].tap_num;

	/* Make sure the coeffs fit in the memory */
	if (count >= PDM_LPF_MAX_STAGE)
		return -EINVAL;

	/* Set the initial APB bus register address */
	regmap_write(priv->map, PDM_COEFF_ADDR, 0);

	/* Set the tap filter values of all 3 filters */
	for (i = 0; i < PDM_LPF_NUM; i++) {
		axg_pdm_set_lpf_ctrl(priv, i);

		for (j = 0; j < lpf[i].tap_num; j++)
			regmap_write(priv->map, PDM_COEFF_DATA, lpf[i].tap[j]);
	}

	return 0;
}

static int axg_pdm_dai_probe(struct snd_soc_dai *dai)
{
	struct axg_pdm *priv = snd_soc_dai_get_drvdata(dai);
	int ret;

	ret = clk_prepare_enable(priv->pclk);
	if (ret) {
		dev_err(dai->dev, "enabling pclk failed\n");
		return ret;
	}

	/*
	 * sysclk must be set and enabled as well to access the pdm registers
	 * Accessing the register w/o it will give a bus error.
	 */
	ret = clk_set_rate(priv->sysclk, priv->cfg->sys_rate);
	if (ret) {
		dev_err(dai->dev, "setting sysclk failed\n");
		goto err_pclk;
	}

	ret = clk_prepare_enable(priv->sysclk);
	if (ret) {
		dev_err(dai->dev, "enabling sysclk failed\n");
		goto err_pclk;
	}

	/* Make sure the device is initially disabled */
	axg_pdm_disable(priv->map);

	/* Make sure filter bypass is disabled */
	regmap_update_bits(priv->map, PDM_CTRL, PDM_CTRL_BYPASS_MODE, 0);

	/* Load filter settings */
	axg_pdm_set_hcic_ctrl(priv);
	axg_pdm_set_hpf_ctrl(priv);

	ret = axg_pdm_set_lpf_filters(priv);
	if (ret) {
		dev_err(dai->dev, "invalid filter configuration\n");
		goto err_sysclk;
	}

	return 0;

err_sysclk:
	clk_disable_unprepare(priv->sysclk);
err_pclk:
	clk_disable_unprepare(priv->pclk);
	return ret;
}

static int axg_pdm_dai_remove(struct snd_soc_dai *dai)
{
	struct axg_pdm *priv = snd_soc_dai_get_drvdata(dai);

	clk_disable_unprepare(priv->sysclk);
	clk_disable_unprepare(priv->pclk);

	return 0;
}

static struct snd_soc_dai_driver axg_pdm_dai_drv = {
	.name = "PDM",
	.capture = {
		.stream_name	= "Capture",
		.channels_min	= 1,
		.channels_max	= 8,
		.rates		= SNDRV_PCM_RATE_CONTINUOUS,
		.rate_min	= 5512,
		.rate_max	= 48000,
		.formats	= (SNDRV_PCM_FMTBIT_S24_LE |
				   SNDRV_PCM_FMTBIT_S32_LE),
	},
	.ops		= &axg_pdm_dai_ops,
	.probe		= axg_pdm_dai_probe,
	.remove		= axg_pdm_dai_remove,
};

static const struct snd_soc_component_driver axg_pdm_component_drv = {};

static const struct regmap_config axg_pdm_regmap_cfg = {
	.reg_bits	= 32,
	.val_bits	= 32,
	.reg_stride	= 4,
	.max_register	= PDM_STS,
};

static const unsigned int lpf1_default_tap[] = {
	0x000014, 0xffffb2, 0xfffed9, 0xfffdce, 0xfffd45,
	0xfffe32, 0x000147, 0x000645, 0x000b86, 0x000e21,
	0x000ae3, 0x000000, 0xffeece, 0xffdca8, 0xffd212,
	0xffd7d1, 0xfff2a7, 0x001f4c, 0x0050c2, 0x0072aa,
	0x006ff1, 0x003c32, 0xffdc4e, 0xff6a18, 0xff0fef,
	0xfefbaf, 0xff4c40, 0x000000, 0x00ebc8, 0x01c077,
	0x02209e, 0x01c1a4, 0x008e60, 0xfebe52, 0xfcd690,
	0xfb8fa5, 0xfba498, 0xfd9812, 0x0181ce, 0x06f5f3,
	0x0d112f, 0x12a958, 0x169686, 0x18000e, 0x169686,
	0x12a958, 0x0d112f, 0x06f5f3, 0x0181ce, 0xfd9812,
	0xfba498, 0xfb8fa5, 0xfcd690, 0xfebe52, 0x008e60,
	0x01c1a4, 0x02209e, 0x01c077, 0x00ebc8, 0x000000,
	0xff4c40, 0xfefbaf, 0xff0fef, 0xff6a18, 0xffdc4e,
	0x003c32, 0x006ff1, 0x0072aa, 0x0050c2, 0x001f4c,
	0xfff2a7, 0xffd7d1, 0xffd212, 0xffdca8, 0xffeece,
	0x000000, 0x000ae3, 0x000e21, 0x000b86, 0x000645,
	0x000147, 0xfffe32, 0xfffd45, 0xfffdce, 0xfffed9,
	0xffffb2, 0x000014,
};

static const unsigned int lpf2_default_tap[] = {
	0x00050a, 0xfff004, 0x0002c1, 0x003c12, 0xffa818,
	0xffc87d, 0x010aef, 0xff5223, 0xfebd93, 0x028f41,
	0xff5c0e, 0xfc63f8, 0x055f81, 0x000000, 0xf478a0,
	0x11c5e3, 0x2ea74d, 0x11c5e3, 0xf478a0, 0x000000,
	0x055f81, 0xfc63f8, 0xff5c0e, 0x028f41, 0xfebd93,
	0xff5223, 0x010aef, 0xffc87d, 0xffa818, 0x003c12,
	0x0002c1, 0xfff004, 0x00050a,
};

static const unsigned int lpf3_default_tap[] = {
	0x000000, 0x000081, 0x000000, 0xfffedb, 0x000000,
	0x00022d, 0x000000, 0xfffc46, 0x000000, 0x0005f7,
	0x000000, 0xfff6eb, 0x000000, 0x000d4e, 0x000000,
	0xffed1e, 0x000000, 0x001a1c, 0x000000, 0xffdcb0,
	0x000000, 0x002ede, 0x000000, 0xffc2d1, 0x000000,
	0x004ebe, 0x000000, 0xff9beb, 0x000000, 0x007dd7,
	0x000000, 0xff633a, 0x000000, 0x00c1d2, 0x000000,
	0xff11d5, 0x000000, 0x012368, 0x000000, 0xfe9c45,
	0x000000, 0x01b252, 0x000000, 0xfdebf6, 0x000000,
	0x0290b8, 0x000000, 0xfcca0d, 0x000000, 0x041d7c,
	0x000000, 0xfa8152, 0x000000, 0x07e9c6, 0x000000,
	0xf28fb5, 0x000000, 0x28b216, 0x3fffde, 0x28b216,
	0x000000, 0xf28fb5, 0x000000, 0x07e9c6, 0x000000,
	0xfa8152, 0x000000, 0x041d7c, 0x000000, 0xfcca0d,
	0x000000, 0x0290b8, 0x000000, 0xfdebf6, 0x000000,
	0x01b252, 0x000000, 0xfe9c45, 0x000000, 0x012368,
	0x000000, 0xff11d5, 0x000000, 0x00c1d2, 0x000000,
	0xff633a, 0x000000, 0x007dd7, 0x000000, 0xff9beb,
	0x000000, 0x004ebe, 0x000000, 0xffc2d1, 0x000000,
	0x002ede, 0x000000, 0xffdcb0, 0x000000, 0x001a1c,
	0x000000, 0xffed1e, 0x000000, 0x000d4e, 0x000000,
	0xfff6eb, 0x000000, 0x0005f7, 0x000000, 0xfffc46,
	0x000000, 0x00022d, 0x000000, 0xfffedb, 0x000000,
	0x000081, 0x000000,
};

/*
 * These values are sane defaults for the axg platform:
 * - OS = 64
 * - Latency = 38700 (?)
 *
 * TODO: There is a lot of different HCIC, LPFs and HPF configurations possible.
 *       the configuration may depend on the dmic used by the platform, the
 *       expected tradeoff between latency and quality, etc ... If/When other
 *       settings are required, we should add a fw interface to this driver to
 *       load new filter settings.
 */
static const struct axg_pdm_filters axg_default_filters = {
	.hcic = {
		.shift = 0x15,
		.mult = 0x80,
		.steps = 7,
		.ds = 8,
	},
	.hpf = {
		.out_factor = 0x8000,
		.steps = 13,
	},
	.lpf = {
		[0] = {
			.ds = 2,
			.round_mode = 1,
			.tap = lpf1_default_tap,
			.tap_num = ARRAY_SIZE(lpf1_default_tap),
		},
		[1] = {
			.ds = 2,
			.round_mode = 0,
			.tap = lpf2_default_tap,
			.tap_num = ARRAY_SIZE(lpf2_default_tap),
		},
		[2] = {
			.ds = 2,
			.round_mode = 1,
			.tap = lpf3_default_tap,
			.tap_num = ARRAY_SIZE(lpf3_default_tap)
		},
	},
};

static const struct axg_pdm_cfg axg_pdm_config = {
	.filters = &axg_default_filters,
	.sys_rate = 250000000,
};

static const struct of_device_id axg_pdm_of_match[] = {
	{
		.compatible = "amlogic,axg-pdm",
		.data = &axg_pdm_config,
	}, {}
};
MODULE_DEVICE_TABLE(of, axg_pdm_of_match);

static int axg_pdm_probe(struct platform_device *pdev)
{
	struct device *dev = &pdev->dev;
	struct axg_pdm *priv;
	void __iomem *regs;
	int ret;

	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
	if (!priv)
		return -ENOMEM;
	platform_set_drvdata(pdev, priv);

	priv->cfg = of_device_get_match_data(dev);
	if (!priv->cfg) {
		dev_err(dev, "failed to match device\n");
		return -ENODEV;
	}

	regs = devm_platform_ioremap_resource(pdev, 0);
	if (IS_ERR(regs))
		return PTR_ERR(regs);

	priv->map = devm_regmap_init_mmio(dev, regs, &axg_pdm_regmap_cfg);
	if (IS_ERR(priv->map)) {
		dev_err(dev, "failed to init regmap: %ld\n",
			PTR_ERR(priv->map));
		return PTR_ERR(priv->map);
	}

	priv->pclk = devm_clk_get(dev, "pclk");
	if (IS_ERR(priv->pclk)) {
		ret = PTR_ERR(priv->pclk);
		if (ret != -EPROBE_DEFER)
			dev_err(dev, "failed to get pclk: %d\n", ret);
		return ret;
	}

	priv->dclk = devm_clk_get(dev, "dclk");
	if (IS_ERR(priv->dclk)) {
		ret = PTR_ERR(priv->dclk);
		if (ret != -EPROBE_DEFER)
			dev_err(dev, "failed to get dclk: %d\n", ret);
		return ret;
	}

	priv->sysclk = devm_clk_get(dev, "sysclk");
	if (IS_ERR(priv->sysclk)) {
		ret = PTR_ERR(priv->sysclk);
		if (ret != -EPROBE_DEFER)
			dev_err(dev, "failed to get dclk: %d\n", ret);
		return ret;
	}

	return devm_snd_soc_register_component(dev, &axg_pdm_component_drv,
					       &axg_pdm_dai_drv, 1);
}

static struct platform_driver axg_pdm_pdrv = {
	.probe = axg_pdm_probe,
	.driver = {
		.name = "axg-pdm",
		.of_match_table = axg_pdm_of_match,
	},
};
module_platform_driver(axg_pdm_pdrv);

MODULE_DESCRIPTION("Amlogic AXG PDM Input driver");
MODULE_AUTHOR("Jerome Brunet <jbrunet@baylibre.com>");
MODULE_LICENSE("GPL v2");