// 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_platform.h>
#include <linux/regmap.h>
#include <sound/soc.h>
#include <sound/soc-dai.h>
#include <sound/pcm_params.h>
#include <sound/pcm_iec958.h>

/*
 * NOTE:
 * The meaning of bits SPDIFOUT_CTRL0_XXX_SEL is actually the opposite
 * of what the documentation says. Manual control on V, U and C bits is
 * applied when the related sel bits are cleared
 */

#define SPDIFOUT_STAT			0x00
#define SPDIFOUT_GAIN0			0x04
#define SPDIFOUT_GAIN1			0x08
#define SPDIFOUT_CTRL0			0x0c
#define  SPDIFOUT_CTRL0_EN		BIT(31)
#define  SPDIFOUT_CTRL0_RST_OUT		BIT(29)
#define  SPDIFOUT_CTRL0_RST_IN		BIT(28)
#define  SPDIFOUT_CTRL0_USEL		BIT(26)
#define  SPDIFOUT_CTRL0_USET		BIT(25)
#define  SPDIFOUT_CTRL0_CHSTS_SEL	BIT(24)
#define  SPDIFOUT_CTRL0_DATA_SEL	BIT(20)
#define  SPDIFOUT_CTRL0_MSB_FIRST	BIT(19)
#define  SPDIFOUT_CTRL0_VSEL		BIT(18)
#define  SPDIFOUT_CTRL0_VSET		BIT(17)
#define  SPDIFOUT_CTRL0_MASK_MASK	GENMASK(11, 4)
#define  SPDIFOUT_CTRL0_MASK(x)		((x) << 4)
#define SPDIFOUT_CTRL1			0x10
#define  SPDIFOUT_CTRL1_MSB_POS_MASK	GENMASK(12, 8)
#define  SPDIFOUT_CTRL1_MSB_POS(x)	((x) << 8)
#define  SPDIFOUT_CTRL1_TYPE_MASK	GENMASK(6, 4)
#define  SPDIFOUT_CTRL1_TYPE(x)		((x) << 4)
#define SPDIFOUT_PREAMB			0x14
#define SPDIFOUT_SWAP			0x18
#define SPDIFOUT_CHSTS0			0x1c
#define SPDIFOUT_CHSTS1			0x20
#define SPDIFOUT_CHSTS2			0x24
#define SPDIFOUT_CHSTS3			0x28
#define SPDIFOUT_CHSTS4			0x2c
#define SPDIFOUT_CHSTS5			0x30
#define SPDIFOUT_CHSTS6			0x34
#define SPDIFOUT_CHSTS7			0x38
#define SPDIFOUT_CHSTS8			0x3c
#define SPDIFOUT_CHSTS9			0x40
#define SPDIFOUT_CHSTSA			0x44
#define SPDIFOUT_CHSTSB			0x48
#define SPDIFOUT_MUTE_VAL		0x4c

struct axg_spdifout {
	struct regmap *map;
	struct clk *mclk;
	struct clk *pclk;
};

static void axg_spdifout_enable(struct regmap *map)
{
	/* Apply both reset */
	regmap_update_bits(map, SPDIFOUT_CTRL0,
			   SPDIFOUT_CTRL0_RST_OUT | SPDIFOUT_CTRL0_RST_IN,
			   0);

	/* Clear out reset before in reset */
	regmap_update_bits(map, SPDIFOUT_CTRL0,
			   SPDIFOUT_CTRL0_RST_OUT, SPDIFOUT_CTRL0_RST_OUT);
	regmap_update_bits(map, SPDIFOUT_CTRL0,
			   SPDIFOUT_CTRL0_RST_IN,  SPDIFOUT_CTRL0_RST_IN);

	/* Enable spdifout */
	regmap_update_bits(map, SPDIFOUT_CTRL0, SPDIFOUT_CTRL0_EN,
			   SPDIFOUT_CTRL0_EN);
}

static void axg_spdifout_disable(struct regmap *map)
{
	regmap_update_bits(map, SPDIFOUT_CTRL0, SPDIFOUT_CTRL0_EN, 0);
}

static int axg_spdifout_trigger(struct snd_pcm_substream *substream, int cmd,
				struct snd_soc_dai *dai)
{
	struct axg_spdifout *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_spdifout_enable(priv->map);
		return 0;

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

	default:
		return -EINVAL;
	}
}

static int axg_spdifout_digital_mute(struct snd_soc_dai *dai, int mute)
{
	struct axg_spdifout *priv = snd_soc_dai_get_drvdata(dai);

	/* Use spdif valid bit to perform digital mute */
	regmap_update_bits(priv->map, SPDIFOUT_CTRL0, SPDIFOUT_CTRL0_VSET,
			   mute ? SPDIFOUT_CTRL0_VSET : 0);

	return 0;
}

static int axg_spdifout_sample_fmt(struct snd_pcm_hw_params *params,
				   struct snd_soc_dai *dai)
{
	struct axg_spdifout *priv = snd_soc_dai_get_drvdata(dai);
	unsigned int val;

	/* Set the samples spdifout will pull from the FIFO */
	switch (params_channels(params)) {
	case 1:
		val = SPDIFOUT_CTRL0_MASK(0x1);
		break;
	case 2:
		val = SPDIFOUT_CTRL0_MASK(0x3);
		break;
	default:
		dev_err(dai->dev, "too many channels for spdif dai: %u\n",
			params_channels(params));
		return -EINVAL;
	}

	regmap_update_bits(priv->map, SPDIFOUT_CTRL0,
			   SPDIFOUT_CTRL0_MASK_MASK, val);

	/* FIFO data are arranged in chunks of 64bits */
	switch (params_physical_width(params)) {
	case 8:
		/* 8 samples of 8 bits */
		val = SPDIFOUT_CTRL1_TYPE(0);
		break;
	case 16:
		/* 4 samples of 16 bits - right justified */
		val = SPDIFOUT_CTRL1_TYPE(2);
		break;
	case 32:
		/* 2 samples of 32 bits - right justified */
		val = SPDIFOUT_CTRL1_TYPE(4);
		break;
	default:
		dev_err(dai->dev, "Unsupported physical width: %u\n",
			params_physical_width(params));
		return -EINVAL;
	}

	/* Position of the MSB in FIFO samples */
	val |= SPDIFOUT_CTRL1_MSB_POS(params_width(params) - 1);

	regmap_update_bits(priv->map, SPDIFOUT_CTRL1,
			   SPDIFOUT_CTRL1_MSB_POS_MASK |
			   SPDIFOUT_CTRL1_TYPE_MASK, val);

	regmap_update_bits(priv->map, SPDIFOUT_CTRL0,
			   SPDIFOUT_CTRL0_MSB_FIRST | SPDIFOUT_CTRL0_DATA_SEL,
			   0);

	return 0;
}

static int axg_spdifout_set_chsts(struct snd_pcm_hw_params *params,
				  struct snd_soc_dai *dai)
{
	struct axg_spdifout *priv = snd_soc_dai_get_drvdata(dai);
	unsigned int offset;
	int ret;
	u8 cs[4];
	u32 val;

	ret = snd_pcm_create_iec958_consumer_hw_params(params, cs, 4);
	if (ret < 0) {
		dev_err(dai->dev, "Creating IEC958 channel status failed %d\n",
			ret);
		return ret;
	}
	val = cs[0] | cs[1] << 8 | cs[2] << 16 | cs[3] << 24;

	/* Setup channel status A bits [31 - 0]*/
	regmap_write(priv->map, SPDIFOUT_CHSTS0, val);

	/* Clear channel status A bits [191 - 32] */
	for (offset = SPDIFOUT_CHSTS1; offset <= SPDIFOUT_CHSTS5;
	     offset += regmap_get_reg_stride(priv->map))
		regmap_write(priv->map, offset, 0);

	/* Setup channel status B bits [31 - 0]*/
	regmap_write(priv->map, SPDIFOUT_CHSTS6, val);

	/* Clear channel status B bits [191 - 32] */
	for (offset = SPDIFOUT_CHSTS7; offset <= SPDIFOUT_CHSTSB;
	     offset += regmap_get_reg_stride(priv->map))
		regmap_write(priv->map, offset, 0);

	return 0;
}

static int axg_spdifout_hw_params(struct snd_pcm_substream *substream,
				  struct snd_pcm_hw_params *params,
				  struct snd_soc_dai *dai)
{
	struct axg_spdifout *priv = snd_soc_dai_get_drvdata(dai);
	unsigned int rate = params_rate(params);
	int ret;

	/* 2 * 32bits per subframe * 2 channels = 128 */
	ret = clk_set_rate(priv->mclk, rate * 128);
	if (ret) {
		dev_err(dai->dev, "failed to set spdif clock\n");
		return ret;
	}

	ret = axg_spdifout_sample_fmt(params, dai);
	if (ret) {
		dev_err(dai->dev, "failed to setup sample format\n");
		return ret;
	}

	ret = axg_spdifout_set_chsts(params, dai);
	if (ret) {
		dev_err(dai->dev, "failed to setup channel status words\n");
		return ret;
	}

	return 0;
}

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

	/* Clock the spdif output block */
	ret = clk_prepare_enable(priv->pclk);
	if (ret) {
		dev_err(dai->dev, "failed to enable pclk\n");
		return ret;
	}

	/* Make sure the block is initially stopped */
	axg_spdifout_disable(priv->map);

	/* Insert data from bit 27 lsb first */
	regmap_update_bits(priv->map, SPDIFOUT_CTRL0,
			   SPDIFOUT_CTRL0_MSB_FIRST | SPDIFOUT_CTRL0_DATA_SEL,
			   0);

	/* Manual control of V, C and U, U = 0 */
	regmap_update_bits(priv->map, SPDIFOUT_CTRL0,
			   SPDIFOUT_CTRL0_CHSTS_SEL | SPDIFOUT_CTRL0_VSEL |
			   SPDIFOUT_CTRL0_USEL | SPDIFOUT_CTRL0_USET,
			   0);

	/* Static SWAP configuration ATM */
	regmap_write(priv->map, SPDIFOUT_SWAP, 0x10);

	return 0;
}

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

	clk_disable_unprepare(priv->pclk);
}

static const struct snd_soc_dai_ops axg_spdifout_ops = {
	.trigger	= axg_spdifout_trigger,
	.digital_mute	= axg_spdifout_digital_mute,
	.hw_params	= axg_spdifout_hw_params,
	.startup	= axg_spdifout_startup,
	.shutdown	= axg_spdifout_shutdown,
};

static struct snd_soc_dai_driver axg_spdifout_dai_drv[] = {
	{
		.name = "SPDIF Output",
		.playback = {
			.stream_name	= "Playback",
			.channels_min	= 1,
			.channels_max	= 2,
			.rates		= (SNDRV_PCM_RATE_32000  |
					   SNDRV_PCM_RATE_44100  |
					   SNDRV_PCM_RATE_48000  |
					   SNDRV_PCM_RATE_88200  |
					   SNDRV_PCM_RATE_96000  |
					   SNDRV_PCM_RATE_176400 |
					   SNDRV_PCM_RATE_192000),
			.formats	= (SNDRV_PCM_FMTBIT_S8     |
					   SNDRV_PCM_FMTBIT_S16_LE |
					   SNDRV_PCM_FMTBIT_S20_LE |
					   SNDRV_PCM_FMTBIT_S24_LE),
		},
		.ops = &axg_spdifout_ops,
	},
};

static const char * const spdifout_sel_texts[] = {
	"IN 0", "IN 1", "IN 2",
};

static SOC_ENUM_SINGLE_DECL(axg_spdifout_sel_enum, SPDIFOUT_CTRL1, 24,
			    spdifout_sel_texts);

static const struct snd_kcontrol_new axg_spdifout_in_mux =
	SOC_DAPM_ENUM("Input Source", axg_spdifout_sel_enum);

static const struct snd_soc_dapm_widget axg_spdifout_dapm_widgets[] = {
	SND_SOC_DAPM_AIF_IN("IN 0", NULL, 0, SND_SOC_NOPM, 0, 0),
	SND_SOC_DAPM_AIF_IN("IN 1", NULL, 0, SND_SOC_NOPM, 0, 0),
	SND_SOC_DAPM_AIF_IN("IN 2", NULL, 0, SND_SOC_NOPM, 0, 0),
	SND_SOC_DAPM_MUX("SRC SEL", SND_SOC_NOPM, 0, 0, &axg_spdifout_in_mux),
};

static const struct snd_soc_dapm_route axg_spdifout_dapm_routes[] = {
	{ "SRC SEL", "IN 0", "IN 0" },
	{ "SRC SEL", "IN 1", "IN 1" },
	{ "SRC SEL", "IN 2", "IN 2" },
	{ "Playback", NULL, "SRC SEL" },
};

static const struct snd_kcontrol_new axg_spdifout_controls[] = {
	SOC_DOUBLE("Playback Volume", SPDIFOUT_GAIN0,  0,  8, 255, 0),
	SOC_DOUBLE("Playback Switch", SPDIFOUT_CTRL0, 22, 21, 1, 1),
	SOC_SINGLE("Playback Gain Enable Switch",
		   SPDIFOUT_CTRL1, 26, 1, 0),
	SOC_SINGLE("Playback Channels Mix Switch",
		   SPDIFOUT_CTRL0, 23, 1, 0),
};

static int axg_spdifout_set_bias_level(struct snd_soc_component *component,
				       enum snd_soc_bias_level level)
{
	struct axg_spdifout *priv = snd_soc_component_get_drvdata(component);
	enum snd_soc_bias_level now =
		snd_soc_component_get_bias_level(component);
	int ret = 0;

	switch (level) {
	case SND_SOC_BIAS_PREPARE:
		if (now == SND_SOC_BIAS_STANDBY)
			ret = clk_prepare_enable(priv->mclk);
		break;

	case SND_SOC_BIAS_STANDBY:
		if (now == SND_SOC_BIAS_PREPARE)
			clk_disable_unprepare(priv->mclk);
		break;

	case SND_SOC_BIAS_OFF:
	case SND_SOC_BIAS_ON:
		break;
	}

	return ret;
}

static const struct snd_soc_component_driver axg_spdifout_component_drv = {
	.controls		= axg_spdifout_controls,
	.num_controls		= ARRAY_SIZE(axg_spdifout_controls),
	.dapm_widgets		= axg_spdifout_dapm_widgets,
	.num_dapm_widgets	= ARRAY_SIZE(axg_spdifout_dapm_widgets),
	.dapm_routes		= axg_spdifout_dapm_routes,
	.num_dapm_routes	= ARRAY_SIZE(axg_spdifout_dapm_routes),
	.set_bias_level		= axg_spdifout_set_bias_level,
};

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

static const struct of_device_id axg_spdifout_of_match[] = {
	{ .compatible = "amlogic,axg-spdifout", },
	{}
};
MODULE_DEVICE_TABLE(of, axg_spdifout_of_match);

static int axg_spdifout_probe(struct platform_device *pdev)
{
	struct device *dev = &pdev->dev;
	struct axg_spdifout *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);

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

	return devm_snd_soc_register_component(dev, &axg_spdifout_component_drv,
			axg_spdifout_dai_drv, ARRAY_SIZE(axg_spdifout_dai_drv));
}

static struct platform_driver axg_spdifout_pdrv = {
	.probe = axg_spdifout_probe,
	.driver = {
		.name = "axg-spdifout",
		.of_match_table = axg_spdifout_of_match,
	},
};
module_platform_driver(axg_spdifout_pdrv);

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