/*
 * Copyright (C) 2015 Linaro
 *
 * Author: Jun Nie <jun.nie@linaro.org>
 *
 * License terms: GNU General Public License (GPL) version 2
 */

#include <linux/clk.h>
#include <linux/device.h>
#include <linux/dmaengine.h>
#include <linux/init.h>
#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/of_address.h>
#include <sound/asoundef.h>
#include <sound/core.h>
#include <sound/dmaengine_pcm.h>
#include <sound/initval.h>
#include <sound/pcm.h>
#include <sound/pcm_params.h>
#include <sound/soc.h>
#include <sound/soc-dai.h>

#define ZX_CTRL				0x04
#define ZX_FIFOCTRL			0x08
#define ZX_INT_STATUS			0x10
#define ZX_INT_MASK			0x14
#define ZX_DATA				0x18
#define ZX_VALID_BIT			0x1c
#define ZX_CH_STA_1			0x20
#define ZX_CH_STA_2			0x24
#define ZX_CH_STA_3			0x28
#define ZX_CH_STA_4			0x2c
#define ZX_CH_STA_5			0x30
#define ZX_CH_STA_6			0x34

#define ZX_CTRL_MODA_16			(0 << 6)
#define ZX_CTRL_MODA_18			BIT(6)
#define ZX_CTRL_MODA_20			(2 << 6)
#define ZX_CTRL_MODA_24			(3 << 6)
#define ZX_CTRL_MODA_MASK		(3 << 6)

#define ZX_CTRL_ENB			BIT(4)
#define ZX_CTRL_DNB			(0 << 4)
#define ZX_CTRL_ENB_MASK		BIT(4)

#define ZX_CTRL_TX_OPEN			BIT(0)
#define ZX_CTRL_TX_CLOSE		(0 << 0)
#define ZX_CTRL_TX_MASK			BIT(0)

#define ZX_CTRL_OPEN			(ZX_CTRL_TX_OPEN | ZX_CTRL_ENB)
#define ZX_CTRL_CLOSE			(ZX_CTRL_TX_CLOSE | ZX_CTRL_DNB)

#define ZX_CTRL_DOUBLE_TRACK		(0 << 8)
#define ZX_CTRL_LEFT_TRACK		BIT(8)
#define ZX_CTRL_RIGHT_TRACK		(2 << 8)
#define ZX_CTRL_TRACK_MASK		(3 << 8)

#define ZX_FIFOCTRL_TXTH_MASK		(0x1f << 8)
#define ZX_FIFOCTRL_TXTH(x)		(x << 8)
#define ZX_FIFOCTRL_TX_DMA_EN		BIT(2)
#define ZX_FIFOCTRL_TX_DMA_DIS		(0 << 2)
#define ZX_FIFOCTRL_TX_DMA_EN_MASK	BIT(2)
#define ZX_FIFOCTRL_TX_FIFO_RST		BIT(0)
#define ZX_FIFOCTRL_TX_FIFO_RST_MASK	BIT(0)

#define ZX_VALID_DOUBLE_TRACK		(0 << 0)
#define ZX_VALID_LEFT_TRACK		BIT(1)
#define ZX_VALID_RIGHT_TRACK		(2 << 0)
#define ZX_VALID_TRACK_MASK		(3 << 0)

#define ZX_SPDIF_CLK_RAT		(4 * 32)

struct zx_spdif_info {
	struct snd_dmaengine_dai_dma_data	dma_data;
	struct clk				*dai_clk;
	void __iomem				*reg_base;
	resource_size_t				mapbase;
};

static int zx_spdif_dai_probe(struct snd_soc_dai *dai)
{
	struct zx_spdif_info *zx_spdif = dev_get_drvdata(dai->dev);

	snd_soc_dai_set_drvdata(dai, zx_spdif);
	zx_spdif->dma_data.addr = zx_spdif->mapbase + ZX_DATA;
	zx_spdif->dma_data.maxburst = 8;
	snd_soc_dai_init_dma_data(dai, &zx_spdif->dma_data, NULL);
	return 0;
}

static int zx_spdif_chanstats(void __iomem *base, unsigned int rate)
{
	u32 cstas1;

	switch (rate) {
	case 22050:
		cstas1 = IEC958_AES3_CON_FS_22050;
		break;
	case 24000:
		cstas1 = IEC958_AES3_CON_FS_24000;
		break;
	case 32000:
		cstas1 = IEC958_AES3_CON_FS_32000;
		break;
	case 44100:
		cstas1 = IEC958_AES3_CON_FS_44100;
		break;
	case 48000:
		cstas1 = IEC958_AES3_CON_FS_48000;
		break;
	case 88200:
		cstas1 = IEC958_AES3_CON_FS_88200;
		break;
	case 96000:
		cstas1 = IEC958_AES3_CON_FS_96000;
		break;
	case 176400:
		cstas1 = IEC958_AES3_CON_FS_176400;
		break;
	case 192000:
		cstas1 = IEC958_AES3_CON_FS_192000;
		break;
	default:
		return -EINVAL;
	}
	cstas1 = cstas1 << 24;
	cstas1 |= IEC958_AES0_CON_NOT_COPYRIGHT;

	writel_relaxed(cstas1, base + ZX_CH_STA_1);
	return 0;
}

static int zx_spdif_hw_params(struct snd_pcm_substream *substream,
			      struct snd_pcm_hw_params *params,
			      struct snd_soc_dai *socdai)
{
	struct zx_spdif_info *zx_spdif = dev_get_drvdata(socdai->dev);
	struct zx_spdif_info *spdif = snd_soc_dai_get_drvdata(socdai);
	struct snd_dmaengine_dai_dma_data *dma_data = &zx_spdif->dma_data;
	u32 val, ch_num, rate;
	int ret;

	dma_data = snd_soc_dai_get_dma_data(socdai, substream);
	dma_data->addr_width = params_width(params) >> 3;

	val = readl_relaxed(zx_spdif->reg_base + ZX_CTRL);
	val &= ~ZX_CTRL_MODA_MASK;
	switch (params_format(params)) {
	case SNDRV_PCM_FORMAT_S16_LE:
		val |= ZX_CTRL_MODA_16;
		break;

	case SNDRV_PCM_FORMAT_S18_3LE:
		val |= ZX_CTRL_MODA_18;
		break;

	case SNDRV_PCM_FORMAT_S20_3LE:
		val |= ZX_CTRL_MODA_20;
		break;

	case SNDRV_PCM_FORMAT_S24_LE:
		val |= ZX_CTRL_MODA_24;
		break;
	default:
		dev_err(socdai->dev, "Format not support!\n");
		return -EINVAL;
	}

	ch_num = params_channels(params);
	if (ch_num == 2)
		val |= ZX_CTRL_DOUBLE_TRACK;
	else
		val |= ZX_CTRL_LEFT_TRACK;
	writel_relaxed(val, zx_spdif->reg_base + ZX_CTRL);

	val = readl_relaxed(zx_spdif->reg_base + ZX_VALID_BIT);
	val &= ~ZX_VALID_TRACK_MASK;
	if (ch_num == 2)
		val |= ZX_VALID_DOUBLE_TRACK;
	else
		val |= ZX_VALID_RIGHT_TRACK;
	writel_relaxed(val, zx_spdif->reg_base + ZX_VALID_BIT);

	rate = params_rate(params);
	ret = zx_spdif_chanstats(zx_spdif->reg_base, rate);
	if (ret)
		return ret;
	return clk_set_rate(spdif->dai_clk, rate * ch_num * ZX_SPDIF_CLK_RAT);
}

static void zx_spdif_cfg_tx(void __iomem *base, int on)
{
	u32 val;

	val = readl_relaxed(base + ZX_CTRL);
	val &= ~(ZX_CTRL_ENB_MASK | ZX_CTRL_TX_MASK);
	val |= on ? ZX_CTRL_OPEN : ZX_CTRL_CLOSE;
	writel_relaxed(val, base + ZX_CTRL);

	val = readl_relaxed(base + ZX_FIFOCTRL);
	val &= ~ZX_FIFOCTRL_TX_DMA_EN_MASK;
	if (on)
		val |= ZX_FIFOCTRL_TX_DMA_EN;
	writel_relaxed(val, base + ZX_FIFOCTRL);
}

static int zx_spdif_trigger(struct snd_pcm_substream *substream, int cmd,
			    struct snd_soc_dai *dai)
{
	u32 val;
	struct zx_spdif_info *zx_spdif = dev_get_drvdata(dai->dev);
	int  ret = 0;

	switch (cmd) {
	case SNDRV_PCM_TRIGGER_START:
		val = readl_relaxed(zx_spdif->reg_base + ZX_FIFOCTRL);
		val |= ZX_FIFOCTRL_TX_FIFO_RST;
		writel_relaxed(val, zx_spdif->reg_base + ZX_FIFOCTRL);
	/* fall thru */
	case SNDRV_PCM_TRIGGER_RESUME:
	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
		zx_spdif_cfg_tx(zx_spdif->reg_base, true);
		break;

	case SNDRV_PCM_TRIGGER_STOP:
	case SNDRV_PCM_TRIGGER_SUSPEND:
	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
		zx_spdif_cfg_tx(zx_spdif->reg_base, false);
		break;

	default:
		ret = -EINVAL;
		break;
	}

	return ret;
}

static int zx_spdif_startup(struct snd_pcm_substream *substream,
			    struct snd_soc_dai *dai)
{
	struct zx_spdif_info *zx_spdif = dev_get_drvdata(dai->dev);

	return clk_prepare_enable(zx_spdif->dai_clk);
}

static void zx_spdif_shutdown(struct snd_pcm_substream *substream,
			      struct snd_soc_dai *dai)
{
	struct zx_spdif_info *zx_spdif = dev_get_drvdata(dai->dev);

	clk_disable_unprepare(zx_spdif->dai_clk);
}

#define ZX_RATES \
	(SNDRV_PCM_RATE_22050 | 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)

#define ZX_FORMAT \
	(SNDRV_PCM_FMTBIT_S16_LE | SNDRV_PCM_FMTBIT_S18_3LE \
	| SNDRV_PCM_FMTBIT_S20_3LE | SNDRV_PCM_FMTBIT_S24_LE)

static struct snd_soc_dai_ops zx_spdif_dai_ops = {
	.trigger	= zx_spdif_trigger,
	.startup	= zx_spdif_startup,
	.shutdown	= zx_spdif_shutdown,
	.hw_params	= zx_spdif_hw_params,
};

static struct snd_soc_dai_driver zx_spdif_dai = {
	.name = "spdif",
	.id = 0,
	.probe = zx_spdif_dai_probe,
	.playback = {
		.channels_min = 1,
		.channels_max = 2,
		.rates = ZX_RATES,
		.formats = ZX_FORMAT,
	},
	.ops = &zx_spdif_dai_ops,
};

static const struct snd_soc_component_driver zx_spdif_component = {
	.name	= "spdif",
};

static void zx_spdif_dev_init(void __iomem *base)
{
	u32 val;

	writel_relaxed(0, base + ZX_CTRL);
	writel_relaxed(0, base + ZX_INT_MASK);
	writel_relaxed(0xf, base + ZX_INT_STATUS);
	writel_relaxed(0x1, base + ZX_FIFOCTRL);

	val = readl_relaxed(base + ZX_FIFOCTRL);
	val &= ~(ZX_FIFOCTRL_TXTH_MASK | ZX_FIFOCTRL_TX_FIFO_RST_MASK);
	val |= ZX_FIFOCTRL_TXTH(8);
	writel_relaxed(val, base + ZX_FIFOCTRL);
}

static int zx_spdif_probe(struct platform_device *pdev)
{
	struct resource *res;
	struct zx_spdif_info *zx_spdif;
	int ret;

	zx_spdif = devm_kzalloc(&pdev->dev, sizeof(*zx_spdif), GFP_KERNEL);
	if (!zx_spdif)
		return -ENOMEM;

	zx_spdif->dai_clk = devm_clk_get(&pdev->dev, "tx");
	if (IS_ERR(zx_spdif->dai_clk)) {
		dev_err(&pdev->dev, "Fail to get clk\n");
		return PTR_ERR(zx_spdif->dai_clk);
	}

	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	zx_spdif->mapbase = res->start;
	zx_spdif->reg_base = devm_ioremap_resource(&pdev->dev, res);
	if (!zx_spdif->reg_base) {
		dev_err(&pdev->dev, "ioremap failed!\n");
		return -EIO;
	}

	zx_spdif_dev_init(zx_spdif->reg_base);
	platform_set_drvdata(pdev, zx_spdif);

	ret = devm_snd_soc_register_component(&pdev->dev, &zx_spdif_component,
					 &zx_spdif_dai, 1);
	if (ret) {
		dev_err(&pdev->dev, "Register DAI failed: %d\n", ret);
		return ret;
	}

	ret = devm_snd_dmaengine_pcm_register(&pdev->dev, NULL, 0);
	if (ret)
		dev_err(&pdev->dev, "Register platform PCM failed: %d\n", ret);

	return ret;
}

static const struct of_device_id zx_spdif_dt_ids[] = {
	{ .compatible = "zte,zx296702-spdif", },
	{}
};
MODULE_DEVICE_TABLE(of, zx_spdif_dt_ids);

static struct platform_driver spdif_driver = {
	.probe = zx_spdif_probe,
	.driver = {
		.name = "zx-spdif",
		.of_match_table = zx_spdif_dt_ids,
	},
};

module_platform_driver(spdif_driver);

MODULE_AUTHOR("Jun Nie <jun.nie@linaro.org>");
MODULE_DESCRIPTION("ZTE SPDIF SoC DAI");
MODULE_LICENSE("GPL");