// SPDX-License-Identifier: GPL-2.0
//
// ALSA SoC Audio Layer - Samsung S/PDIF Controller driver
//
// Copyright (c) 2010 Samsung Electronics Co. Ltd
//              http://www.samsung.com/

#include <linux/clk.h>
#include <linux/io.h>
#include <linux/module.h>

#include <sound/soc.h>
#include <sound/pcm_params.h>

#include <linux/platform_data/asoc-s3c.h>

#include "dma.h"
#include "spdif.h"

/* Registers */
#define CLKCON                          0x00
#define CON                             0x04
#define BSTAS                           0x08
#define CSTAS                           0x0C
#define DATA_OUTBUF                     0x10
#define DCNT                            0x14
#define BSTAS_S                         0x18
#define DCNT_S                          0x1C

#define CLKCTL_MASK                     0x7
#define CLKCTL_MCLK_EXT                 (0x1 << 2)
#define CLKCTL_PWR_ON                   (0x1 << 0)

#define CON_MASK                        0x3ffffff
#define CON_FIFO_TH_SHIFT               19
#define CON_FIFO_TH_MASK                (0x7 << 19)
#define CON_USERDATA_23RDBIT            (0x1 << 12)

#define CON_SW_RESET                    (0x1 << 5)

#define CON_MCLKDIV_MASK                (0x3 << 3)
#define CON_MCLKDIV_256FS               (0x0 << 3)
#define CON_MCLKDIV_384FS               (0x1 << 3)
#define CON_MCLKDIV_512FS               (0x2 << 3)

#define CON_PCM_MASK                    (0x3 << 1)
#define CON_PCM_16BIT                   (0x0 << 1)
#define CON_PCM_20BIT                   (0x1 << 1)
#define CON_PCM_24BIT                   (0x2 << 1)

#define CON_PCM_DATA                    (0x1 << 0)

#define CSTAS_MASK                      0x3fffffff
#define CSTAS_SAMP_FREQ_MASK            (0xF << 24)
#define CSTAS_SAMP_FREQ_44              (0x0 << 24)
#define CSTAS_SAMP_FREQ_48              (0x2 << 24)
#define CSTAS_SAMP_FREQ_32              (0x3 << 24)
#define CSTAS_SAMP_FREQ_96              (0xA << 24)

#define CSTAS_CATEGORY_MASK             (0xFF << 8)
#define CSTAS_CATEGORY_CODE_CDP         (0x01 << 8)

#define CSTAS_NO_COPYRIGHT              (0x1 << 2)

/**
 * struct samsung_spdif_info - Samsung S/PDIF Controller information
 * @lock: Spin lock for S/PDIF.
 * @dev: The parent device passed to use from the probe.
 * @regs: The pointer to the device register block.
 * @clk_rate: Current clock rate for calcurate ratio.
 * @pclk: The peri-clock pointer for spdif master operation.
 * @sclk: The source clock pointer for making sync signals.
 * @saved_clkcon: Backup clkcon reg. in suspend.
 * @saved_con: Backup con reg. in suspend.
 * @saved_cstas: Backup cstas reg. in suspend.
 * @dma_playback: DMA information for playback channel.
 */
struct samsung_spdif_info {
        spinlock_t      lock;
        struct device   *dev;
        void __iomem    *regs;
        unsigned long   clk_rate;
        struct clk      *pclk;
        struct clk      *sclk;
        u32             saved_clkcon;
        u32             saved_con;
        u32             saved_cstas;
        struct snd_dmaengine_dai_dma_data *dma_playback;
};

static struct snd_dmaengine_dai_dma_data spdif_stereo_out;
static struct samsung_spdif_info spdif_info;

static inline struct samsung_spdif_info
*component_to_info(struct snd_soc_component *component)
{
        return snd_soc_component_get_drvdata(component);
}

static inline struct samsung_spdif_info *to_info(struct snd_soc_dai *cpu_dai)
{
        return snd_soc_dai_get_drvdata(cpu_dai);
}

static void spdif_snd_txctrl(struct samsung_spdif_info *spdif, int on)
{
        void __iomem *regs = spdif->regs;
        u32 clkcon;

        dev_dbg(spdif->dev, "Entered %s\n", __func__);

        clkcon = readl(regs + CLKCON) & CLKCTL_MASK;
        if (on)
                writel(clkcon | CLKCTL_PWR_ON, regs + CLKCON);
        else
                writel(clkcon & ~CLKCTL_PWR_ON, regs + CLKCON);
}

static int spdif_set_sysclk(struct snd_soc_dai *cpu_dai,
                                int clk_id, unsigned int freq, int dir)
{
        struct samsung_spdif_info *spdif = to_info(cpu_dai);
        u32 clkcon;

        dev_dbg(spdif->dev, "Entered %s\n", __func__);

        clkcon = readl(spdif->regs + CLKCON);

        if (clk_id == SND_SOC_SPDIF_INT_MCLK)
                clkcon &= ~CLKCTL_MCLK_EXT;
        else
                clkcon |= CLKCTL_MCLK_EXT;

        writel(clkcon, spdif->regs + CLKCON);

        spdif->clk_rate = freq;

        return 0;
}

static int spdif_trigger(struct snd_pcm_substream *substream, int cmd,
                                struct snd_soc_dai *dai)
{
        struct snd_soc_pcm_runtime *rtd = snd_soc_substream_to_rtd(substream);
        struct samsung_spdif_info *spdif = to_info(snd_soc_rtd_to_cpu(rtd, 0));
        unsigned long flags;

        dev_dbg(spdif->dev, "Entered %s\n", __func__);

        switch (cmd) {
        case SNDRV_PCM_TRIGGER_START:
        case SNDRV_PCM_TRIGGER_RESUME:
        case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
                spin_lock_irqsave(&spdif->lock, flags);
                spdif_snd_txctrl(spdif, 1);
                spin_unlock_irqrestore(&spdif->lock, flags);
                break;
        case SNDRV_PCM_TRIGGER_STOP:
        case SNDRV_PCM_TRIGGER_SUSPEND:
        case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
                spin_lock_irqsave(&spdif->lock, flags);
                spdif_snd_txctrl(spdif, 0);
                spin_unlock_irqrestore(&spdif->lock, flags);
                break;
        default:
                return -EINVAL;
        }

        return 0;
}

static int spdif_sysclk_ratios[] = {
        512, 384, 256,
};

static int spdif_hw_params(struct snd_pcm_substream *substream,
                                struct snd_pcm_hw_params *params,
                                struct snd_soc_dai *socdai)
{
        struct snd_soc_pcm_runtime *rtd = snd_soc_substream_to_rtd(substream);
        struct samsung_spdif_info *spdif = to_info(snd_soc_rtd_to_cpu(rtd, 0));
        void __iomem *regs = spdif->regs;
        struct snd_dmaengine_dai_dma_data *dma_data;
        u32 con, clkcon, cstas;
        unsigned long flags;
        int i, ratio;

        dev_dbg(spdif->dev, "Entered %s\n", __func__);

        if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
                dma_data = spdif->dma_playback;
        else {
                dev_err(spdif->dev, "Capture is not supported\n");
                return -EINVAL;
        }

        snd_soc_dai_set_dma_data(snd_soc_rtd_to_cpu(rtd, 0), substream, dma_data);

        spin_lock_irqsave(&spdif->lock, flags);

        con = readl(regs + CON) & CON_MASK;
        cstas = readl(regs + CSTAS) & CSTAS_MASK;
        clkcon = readl(regs + CLKCON) & CLKCTL_MASK;

        con &= ~CON_FIFO_TH_MASK;
        con |= (0x7 << CON_FIFO_TH_SHIFT);
        con |= CON_USERDATA_23RDBIT;
        con |= CON_PCM_DATA;

        con &= ~CON_PCM_MASK;
        switch (params_width(params)) {
        case 16:
                con |= CON_PCM_16BIT;
                break;
        default:
                dev_err(spdif->dev, "Unsupported data size.\n");
                goto err;
        }

        ratio = spdif->clk_rate / params_rate(params);
        for (i = 0; i < ARRAY_SIZE(spdif_sysclk_ratios); i++)
                if (ratio == spdif_sysclk_ratios[i])
                        break;
        if (i == ARRAY_SIZE(spdif_sysclk_ratios)) {
                dev_err(spdif->dev, "Invalid clock ratio %ld/%d\n",
                                spdif->clk_rate, params_rate(params));
                goto err;
        }

        con &= ~CON_MCLKDIV_MASK;
        switch (ratio) {
        case 256:
                con |= CON_MCLKDIV_256FS;
                break;
        case 384:
                con |= CON_MCLKDIV_384FS;
                break;
        case 512:
                con |= CON_MCLKDIV_512FS;
                break;
        }

        cstas &= ~CSTAS_SAMP_FREQ_MASK;
        switch (params_rate(params)) {
        case 44100:
                cstas |= CSTAS_SAMP_FREQ_44;
                break;
        case 48000:
                cstas |= CSTAS_SAMP_FREQ_48;
                break;
        case 32000:
                cstas |= CSTAS_SAMP_FREQ_32;
                break;
        case 96000:
                cstas |= CSTAS_SAMP_FREQ_96;
                break;
        default:
                dev_err(spdif->dev, "Invalid sampling rate %d\n",
                                params_rate(params));
                goto err;
        }

        cstas &= ~CSTAS_CATEGORY_MASK;
        cstas |= CSTAS_CATEGORY_CODE_CDP;
        cstas |= CSTAS_NO_COPYRIGHT;

        writel(con, regs + CON);
        writel(cstas, regs + CSTAS);
        writel(clkcon, regs + CLKCON);

        spin_unlock_irqrestore(&spdif->lock, flags);

        return 0;
err:
        spin_unlock_irqrestore(&spdif->lock, flags);
        return -EINVAL;
}

static void spdif_shutdown(struct snd_pcm_substream *substream,
                                struct snd_soc_dai *dai)
{
        struct snd_soc_pcm_runtime *rtd = snd_soc_substream_to_rtd(substream);
        struct samsung_spdif_info *spdif = to_info(snd_soc_rtd_to_cpu(rtd, 0));
        void __iomem *regs = spdif->regs;
        u32 con, clkcon;

        dev_dbg(spdif->dev, "Entered %s\n", __func__);

        con = readl(regs + CON) & CON_MASK;
        clkcon = readl(regs + CLKCON) & CLKCTL_MASK;

        writel(con | CON_SW_RESET, regs + CON);
        cpu_relax();

        writel(clkcon & ~CLKCTL_PWR_ON, regs + CLKCON);
}

#ifdef CONFIG_PM
static int spdif_suspend(struct snd_soc_component *component)
{
        struct samsung_spdif_info *spdif = component_to_info(component);
        u32 con = spdif->saved_con;

        dev_dbg(spdif->dev, "Entered %s\n", __func__);

        spdif->saved_clkcon = readl(spdif->regs + CLKCON) & CLKCTL_MASK;
        spdif->saved_con = readl(spdif->regs + CON) & CON_MASK;
        spdif->saved_cstas = readl(spdif->regs + CSTAS) & CSTAS_MASK;

        writel(con | CON_SW_RESET, spdif->regs + CON);
        cpu_relax();

        return 0;
}

static int spdif_resume(struct snd_soc_component *component)
{
        struct samsung_spdif_info *spdif = component_to_info(component);

        dev_dbg(spdif->dev, "Entered %s\n", __func__);

        writel(spdif->saved_clkcon, spdif->regs + CLKCON);
        writel(spdif->saved_con, spdif->regs + CON);
        writel(spdif->saved_cstas, spdif->regs + CSTAS);

        return 0;
}
#else
#define spdif_suspend NULL
#define spdif_resume NULL
#endif

static const struct snd_soc_dai_ops spdif_dai_ops = {
        .set_sysclk     = spdif_set_sysclk,
        .trigger        = spdif_trigger,
        .hw_params      = spdif_hw_params,
        .shutdown       = spdif_shutdown,
};

static struct snd_soc_dai_driver samsung_spdif_dai = {
        .name = "samsung-spdif",
        .playback = {
                .stream_name = "S/PDIF Playback",
                .channels_min = 2,
                .channels_max = 2,
                .rates = (SNDRV_PCM_RATE_32000 |
                                SNDRV_PCM_RATE_44100 |
                                SNDRV_PCM_RATE_48000 |
                                SNDRV_PCM_RATE_96000),
                .formats = SNDRV_PCM_FMTBIT_S16_LE, },
        .ops = &spdif_dai_ops,
};

static const struct snd_soc_component_driver samsung_spdif_component = {
        .name                   = "samsung-spdif",
        .suspend                = spdif_suspend,
        .resume                 = spdif_resume,
        .legacy_dai_naming      = 1,
};

static int spdif_probe(struct platform_device *pdev)
{
        struct s3c_audio_pdata *spdif_pdata;
        struct resource *mem_res;
        struct samsung_spdif_info *spdif;
        dma_filter_fn filter;
        int ret;

        spdif_pdata = pdev->dev.platform_data;

        dev_dbg(&pdev->dev, "Entered %s\n", __func__);

        mem_res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
        if (!mem_res) {
                dev_err(&pdev->dev, "Unable to get register resource.\n");
                return -ENXIO;
        }

        if (spdif_pdata && spdif_pdata->cfg_gpio
                        && spdif_pdata->cfg_gpio(pdev)) {
                dev_err(&pdev->dev, "Unable to configure GPIO pins\n");
                return -EINVAL;
        }

        spdif = &spdif_info;
        spdif->dev = &pdev->dev;

        spin_lock_init(&spdif->lock);

        spdif->pclk = devm_clk_get(&pdev->dev, "spdif");
        if (IS_ERR(spdif->pclk)) {
                dev_err(&pdev->dev, "failed to get peri-clock\n");
                ret = -ENOENT;
                goto err0;
        }
        ret = clk_prepare_enable(spdif->pclk);
        if (ret)
                goto err0;

        spdif->sclk = devm_clk_get(&pdev->dev, "sclk_spdif");
        if (IS_ERR(spdif->sclk)) {
                dev_err(&pdev->dev, "failed to get internal source clock\n");
                ret = -ENOENT;
                goto err1;
        }
        ret = clk_prepare_enable(spdif->sclk);
        if (ret)
                goto err1;

        /* Request S/PDIF Register's memory region */
        if (!request_mem_region(mem_res->start,
                                resource_size(mem_res), "samsung-spdif")) {
                dev_err(&pdev->dev, "Unable to request register region\n");
                ret = -EBUSY;
                goto err2;
        }

        spdif->regs = ioremap(mem_res->start, 0x100);
        if (spdif->regs == NULL) {
                dev_err(&pdev->dev, "Cannot ioremap registers\n");
                ret = -ENXIO;
                goto err3;
        }

        spdif_stereo_out.addr_width = 2;
        spdif_stereo_out.addr = mem_res->start + DATA_OUTBUF;
        filter = NULL;
        if (spdif_pdata) {
                spdif_stereo_out.filter_data = spdif_pdata->dma_playback;
                filter = spdif_pdata->dma_filter;
        }
        spdif->dma_playback = &spdif_stereo_out;

        ret = samsung_asoc_dma_platform_register(&pdev->dev, filter,
                                                 NULL, NULL, NULL);
        if (ret) {
                dev_err(&pdev->dev, "failed to register DMA: %d\n", ret);
                goto err4;
        }

        dev_set_drvdata(&pdev->dev, spdif);

        ret = devm_snd_soc_register_component(&pdev->dev,
                        &samsung_spdif_component, &samsung_spdif_dai, 1);
        if (ret != 0) {
                dev_err(&pdev->dev, "fail to register dai\n");
                goto err4;
        }

        return 0;
err4:
        iounmap(spdif->regs);
err3:
        release_mem_region(mem_res->start, resource_size(mem_res));
err2:
        clk_disable_unprepare(spdif->sclk);
err1:
        clk_disable_unprepare(spdif->pclk);
err0:
        return ret;
}

static void spdif_remove(struct platform_device *pdev)
{
        struct samsung_spdif_info *spdif = &spdif_info;
        struct resource *mem_res;

        iounmap(spdif->regs);

        mem_res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
        release_mem_region(mem_res->start, resource_size(mem_res));

        clk_disable_unprepare(spdif->sclk);
        clk_disable_unprepare(spdif->pclk);
}

static struct platform_driver samsung_spdif_driver = {
        .probe  = spdif_probe,
        .remove = spdif_remove,
        .driver = {
                .name   = "samsung-spdif",
        },
};

module_platform_driver(samsung_spdif_driver);

MODULE_AUTHOR("Seungwhan Youn, <sw.youn@samsung.com>");
MODULE_DESCRIPTION("Samsung S/PDIF Controller Driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:samsung-spdif");