Message-Id: <20180829150051.18190-5-jbrunet@baylibre.com>
Date:   Wed, 29 Aug 2018 17:00:51 +0200
From:   Jerome Brunet <jbrunet@...libre.com>
To:     Mark Brown <broonie@...nel.org>,
        Liam Girdwood <lgirdwood@...il.com>,
        Kevin Hilman <khilman@...libre.com>,
        Carlo Caione <carlo@...one.org>
Cc:     Jerome Brunet <jbrunet@...libre.com>, alsa-devel@...a-project.org,
        linux-amlogic@...ts.infradead.org, linux-kernel@...r.kernel.org
Subject: [PATCH 4/4] ASoC: meson: add axg pdm input

Add pdm input driver for the device found on the amlogic AXG SoC family

Signed-off-by: Jerome Brunet <jbrunet@...libre.com>
---
 sound/soc/meson/Kconfig   |   9 +
 sound/soc/meson/Makefile  |   2 +
 sound/soc/meson/axg-pdm.c | 654 ++++++++++++++++++++++++++++++++++++++
 3 files changed, 665 insertions(+)
 create mode 100644 sound/soc/meson/axg-pdm.c

diff --git a/sound/soc/meson/Kconfig b/sound/soc/meson/Kconfig
index 2ccbadc387de..8b8426ed2363 100644
--- a/sound/soc/meson/Kconfig
+++ b/sound/soc/meson/Kconfig
@@ -54,6 +54,7 @@ config SND_MESON_AXG_SOUND_CARD
 	imply SND_MESON_AXG_TDMIN
 	imply SND_MESON_AXG_TDMOUT
 	imply SND_MESON_AXG_SPDIFOUT
+	imply SND_MESON_AXG_PDM
 	help
 	  Select Y or M to add support for the AXG SoC sound card
 
@@ -66,4 +67,12 @@ config SND_MESON_AXG_SPDIFOUT
 	  Select Y or M to add support for SPDIF output serializer embedded
 	  in the Amlogic AXG SoC family
 
+config SND_MESON_AXG_PDM
+	tristate "Amlogic AXG PDM Input Support"
+	imply SND_SOC_DMIC
+	imply COMMON_CLK_AXG_AUDIO
+	help
+	  Select Y or M to add support for PDM input embedded
+	  in the Amlogic AXG SoC family
+
 endmenu
diff --git a/sound/soc/meson/Makefile b/sound/soc/meson/Makefile
index c5e003b093db..4cd25104029d 100644
--- a/sound/soc/meson/Makefile
+++ b/sound/soc/meson/Makefile
@@ -9,6 +9,7 @@ snd-soc-meson-axg-tdmin-objs := axg-tdmin.o
 snd-soc-meson-axg-tdmout-objs := axg-tdmout.o
 snd-soc-meson-axg-sound-card-objs := axg-card.o
 snd-soc-meson-axg-spdifout-objs := axg-spdifout.o
+snd-soc-meson-axg-pdm-objs := axg-pdm.o
 
 obj-$(CONFIG_SND_MESON_AXG_FIFO) += snd-soc-meson-axg-fifo.o
 obj-$(CONFIG_SND_MESON_AXG_FRDDR) += snd-soc-meson-axg-frddr.o
@@ -19,3 +20,4 @@ obj-$(CONFIG_SND_MESON_AXG_TDMIN) += snd-soc-meson-axg-tdmin.o
 obj-$(CONFIG_SND_MESON_AXG_TDMOUT) += snd-soc-meson-axg-tdmout.o
 obj-$(CONFIG_SND_MESON_AXG_SOUND_CARD) += snd-soc-meson-axg-sound-card.o
 obj-$(CONFIG_SND_MESON_AXG_SPDIFOUT) += snd-soc-meson-axg-spdifout.o
+obj-$(CONFIG_SND_MESON_AXG_PDM) += snd-soc-meson-axg-pdm.o
diff --git a/sound/soc/meson/axg-pdm.c b/sound/soc/meson/axg-pdm.c
new file mode 100644
index 000000000000..9d5684493ffc
--- /dev/null
+++ b/sound/soc/meson/axg-pdm.c
@@ -0,0 +1,654 @@
+// SPDX-License-Identifier: (GPL-2.0 OR MIT)
+//
+// Copyright (c) 2018 BayLibre, SAS.
+// Author: Jerome Brunet <jbrunet@...libre.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;
+	struct resource *res;
+	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;
+	}
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	regs = devm_ioremap_resource(dev, res);
+	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@...libre.com>");
+MODULE_LICENSE("GPL v2");
-- 
2.17.1

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