// SPDX-License-Identifier: GPL-2.0-only
/*
 * Au12x0/Au1550 PSC ALSA ASoC audio support.
 *
 * (c) 2007-2008 MSC Vertriebsges.m.b.H.,
 *      Manuel Lauss <manuel.lauss@gmail.com>
 *
 * Au1xxx-PSC I2S glue.
 *
 * NOTE: so far only PSC slave mode (bit- and frameclock) is supported.
 */

#include <linux/init.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/suspend.h>
#include <sound/core.h>
#include <sound/pcm.h>
#include <sound/initval.h>
#include <sound/soc.h>
#include <asm/mach-au1x00/au1000.h>
#include <asm/mach-au1x00/au1xxx_psc.h>

#include "psc.h"

/* supported I2S DAI hardware formats */
#define AU1XPSC_I2S_DAIFMT \
        (SND_SOC_DAIFMT_I2S | SND_SOC_DAIFMT_LEFT_J |   \
         SND_SOC_DAIFMT_NB_NF)

/* supported I2S direction */
#define AU1XPSC_I2S_DIR \
        (SND_SOC_DAIDIR_PLAYBACK | SND_SOC_DAIDIR_CAPTURE)

#define AU1XPSC_I2S_RATES \
        SNDRV_PCM_RATE_8000_192000

#define AU1XPSC_I2S_FMTS \
        (SNDRV_PCM_FMTBIT_S16_LE | SNDRV_PCM_FMTBIT_S24_LE)

#define I2SSTAT_BUSY(stype)     \
        ((stype) == SNDRV_PCM_STREAM_PLAYBACK ? PSC_I2SSTAT_TB : PSC_I2SSTAT_RB)
#define I2SPCR_START(stype)     \
        ((stype) == SNDRV_PCM_STREAM_PLAYBACK ? PSC_I2SPCR_TS : PSC_I2SPCR_RS)
#define I2SPCR_STOP(stype)      \
        ((stype) == SNDRV_PCM_STREAM_PLAYBACK ? PSC_I2SPCR_TP : PSC_I2SPCR_RP)
#define I2SPCR_CLRFIFO(stype)   \
        ((stype) == SNDRV_PCM_STREAM_PLAYBACK ? PSC_I2SPCR_TC : PSC_I2SPCR_RC)


static int au1xpsc_i2s_set_fmt(struct snd_soc_dai *cpu_dai,
                               unsigned int fmt)
{
        struct au1xpsc_audio_data *pscdata = snd_soc_dai_get_drvdata(cpu_dai);
        unsigned long ct;
        int ret;

        ret = -EINVAL;

        ct = pscdata->cfg;

        ct &= ~(PSC_I2SCFG_XM | PSC_I2SCFG_MLJ);        /* left-justified */
        switch (fmt & SND_SOC_DAIFMT_FORMAT_MASK) {
        case SND_SOC_DAIFMT_I2S:
                ct |= PSC_I2SCFG_XM;    /* enable I2S mode */
                break;
        case SND_SOC_DAIFMT_MSB:
                break;
        case SND_SOC_DAIFMT_LSB:
                ct |= PSC_I2SCFG_MLJ;   /* LSB (right-) justified */
                break;
        default:
                goto out;
        }

        ct &= ~(PSC_I2SCFG_BI | PSC_I2SCFG_WI);         /* IB-IF */
        switch (fmt & SND_SOC_DAIFMT_INV_MASK) {
        case SND_SOC_DAIFMT_NB_NF:
                ct |= PSC_I2SCFG_BI | PSC_I2SCFG_WI;
                break;
        case SND_SOC_DAIFMT_NB_IF:
                ct |= PSC_I2SCFG_BI;
                break;
        case SND_SOC_DAIFMT_IB_NF:
                ct |= PSC_I2SCFG_WI;
                break;
        case SND_SOC_DAIFMT_IB_IF:
                break;
        default:
                goto out;
        }

        switch (fmt & SND_SOC_DAIFMT_CLOCK_PROVIDER_MASK) {
        case SND_SOC_DAIFMT_BC_FC:      /* CODEC provider */
                ct |= PSC_I2SCFG_MS;    /* PSC I2S consumer mode */
                break;
        case SND_SOC_DAIFMT_BP_FP:      /* CODEC consumer */
                ct &= ~PSC_I2SCFG_MS;   /* PSC I2S provider mode */
                break;
        default:
                goto out;
        }

        pscdata->cfg = ct;
        ret = 0;
out:
        return ret;
}

static int au1xpsc_i2s_hw_params(struct snd_pcm_substream *substream,
                                 struct snd_pcm_hw_params *params,
                                 struct snd_soc_dai *dai)
{
        struct au1xpsc_audio_data *pscdata = snd_soc_dai_get_drvdata(dai);

        int cfgbits;
        unsigned long stat;

        /* check if the PSC is already streaming data */
        stat = __raw_readl(I2S_STAT(pscdata));
        if (stat & (PSC_I2SSTAT_TB | PSC_I2SSTAT_RB)) {
                /* reject parameters not currently set up in hardware */
                cfgbits = __raw_readl(I2S_CFG(pscdata));
                if ((PSC_I2SCFG_GET_LEN(cfgbits) != params->msbits) ||
                    (params_rate(params) != pscdata->rate))
                        return -EINVAL;
        } else {
                /* set sample bitdepth */
                pscdata->cfg &= ~(0x1f << 4);
                pscdata->cfg |= PSC_I2SCFG_SET_LEN(params->msbits);
                /* remember current rate for other stream */
                pscdata->rate = params_rate(params);
        }
        return 0;
}

/* Configure PSC late:  on my devel systems the codec  is I2S master and
 * supplies the i2sbitclock __AND__ i2sMclk (!) to the PSC unit.  ASoC
 * uses aggressive PM and  switches the codec off  when it is not in use
 * which also means the PSC unit doesn't get any clocks and is therefore
 * dead. That's why this chunk here gets called from the trigger callback
 * because I can be reasonably certain the codec is driving the clocks.
 */
static int au1xpsc_i2s_configure(struct au1xpsc_audio_data *pscdata)
{
        unsigned long tmo;

        /* bring PSC out of sleep, and configure I2S unit */
        __raw_writel(PSC_CTRL_ENABLE, PSC_CTRL(pscdata));
        wmb(); /* drain writebuffer */

        tmo = 1000000;
        while (!(__raw_readl(I2S_STAT(pscdata)) & PSC_I2SSTAT_SR) && tmo)
                tmo--;

        if (!tmo)
                goto psc_err;

        __raw_writel(0, I2S_CFG(pscdata));
        wmb(); /* drain writebuffer */
        __raw_writel(pscdata->cfg | PSC_I2SCFG_DE_ENABLE, I2S_CFG(pscdata));
        wmb(); /* drain writebuffer */

        /* wait for I2S controller to become ready */
        tmo = 1000000;
        while (!(__raw_readl(I2S_STAT(pscdata)) & PSC_I2SSTAT_DR) && tmo)
                tmo--;

        if (tmo)
                return 0;

psc_err:
        __raw_writel(0, I2S_CFG(pscdata));
        __raw_writel(PSC_CTRL_SUSPEND, PSC_CTRL(pscdata));
        wmb(); /* drain writebuffer */
        return -ETIMEDOUT;
}

static int au1xpsc_i2s_start(struct au1xpsc_audio_data *pscdata, int stype)
{
        unsigned long tmo, stat;
        int ret;

        ret = 0;

        /* if both TX and RX are idle, configure the PSC  */
        stat = __raw_readl(I2S_STAT(pscdata));
        if (!(stat & (PSC_I2SSTAT_TB | PSC_I2SSTAT_RB))) {
                ret = au1xpsc_i2s_configure(pscdata);
                if (ret)
                        goto out;
        }

        __raw_writel(I2SPCR_CLRFIFO(stype), I2S_PCR(pscdata));
        wmb(); /* drain writebuffer */
        __raw_writel(I2SPCR_START(stype), I2S_PCR(pscdata));
        wmb(); /* drain writebuffer */

        /* wait for start confirmation */
        tmo = 1000000;
        while (!(__raw_readl(I2S_STAT(pscdata)) & I2SSTAT_BUSY(stype)) && tmo)
                tmo--;

        if (!tmo) {
                __raw_writel(I2SPCR_STOP(stype), I2S_PCR(pscdata));
                wmb(); /* drain writebuffer */
                ret = -ETIMEDOUT;
        }
out:
        return ret;
}

static int au1xpsc_i2s_stop(struct au1xpsc_audio_data *pscdata, int stype)
{
        unsigned long tmo, stat;

        __raw_writel(I2SPCR_STOP(stype), I2S_PCR(pscdata));
        wmb(); /* drain writebuffer */

        /* wait for stop confirmation */
        tmo = 1000000;
        while ((__raw_readl(I2S_STAT(pscdata)) & I2SSTAT_BUSY(stype)) && tmo)
                tmo--;

        /* if both TX and RX are idle, disable PSC */
        stat = __raw_readl(I2S_STAT(pscdata));
        if (!(stat & (PSC_I2SSTAT_TB | PSC_I2SSTAT_RB))) {
                __raw_writel(0, I2S_CFG(pscdata));
                wmb(); /* drain writebuffer */
                __raw_writel(PSC_CTRL_SUSPEND, PSC_CTRL(pscdata));
                wmb(); /* drain writebuffer */
        }
        return 0;
}

static int au1xpsc_i2s_trigger(struct snd_pcm_substream *substream, int cmd,
                               struct snd_soc_dai *dai)
{
        struct au1xpsc_audio_data *pscdata = snd_soc_dai_get_drvdata(dai);
        int ret, stype = substream->stream;

        switch (cmd) {
        case SNDRV_PCM_TRIGGER_START:
        case SNDRV_PCM_TRIGGER_RESUME:
                ret = au1xpsc_i2s_start(pscdata, stype);
                break;
        case SNDRV_PCM_TRIGGER_STOP:
        case SNDRV_PCM_TRIGGER_SUSPEND:
                ret = au1xpsc_i2s_stop(pscdata, stype);
                break;
        default:
                ret = -EINVAL;
        }
        return ret;
}

static int au1xpsc_i2s_startup(struct snd_pcm_substream *substream,
                               struct snd_soc_dai *dai)
{
        struct au1xpsc_audio_data *pscdata = snd_soc_dai_get_drvdata(dai);
        snd_soc_dai_set_dma_data(dai, substream, &pscdata->dmaids[0]);
        return 0;
}

static const struct snd_soc_dai_ops au1xpsc_i2s_dai_ops = {
        .startup        = au1xpsc_i2s_startup,
        .trigger        = au1xpsc_i2s_trigger,
        .hw_params      = au1xpsc_i2s_hw_params,
        .set_fmt        = au1xpsc_i2s_set_fmt,
};

static const struct snd_soc_dai_driver au1xpsc_i2s_dai_template = {
        .playback = {
                .rates          = AU1XPSC_I2S_RATES,
                .formats        = AU1XPSC_I2S_FMTS,
                .channels_min   = 2,
                .channels_max   = 8,    /* 2 without external help */
        },
        .capture = {
                .rates          = AU1XPSC_I2S_RATES,
                .formats        = AU1XPSC_I2S_FMTS,
                .channels_min   = 2,
                .channels_max   = 8,    /* 2 without external help */
        },
        .ops = &au1xpsc_i2s_dai_ops,
};

static const struct snd_soc_component_driver au1xpsc_i2s_component = {
        .name                   = "au1xpsc-i2s",
        .legacy_dai_naming      = 1,
};

static int au1xpsc_i2s_drvprobe(struct platform_device *pdev)
{
        struct resource *dmares;
        unsigned long sel;
        struct au1xpsc_audio_data *wd;

        wd = devm_kzalloc(&pdev->dev, sizeof(struct au1xpsc_audio_data),
                          GFP_KERNEL);
        if (!wd)
                return -ENOMEM;

        wd->mmio = devm_platform_ioremap_resource(pdev, 0);
        if (IS_ERR(wd->mmio))
                return PTR_ERR(wd->mmio);

        dmares = platform_get_resource(pdev, IORESOURCE_DMA, 0);
        if (!dmares)
                return -EBUSY;
        wd->dmaids[SNDRV_PCM_STREAM_PLAYBACK] = dmares->start;

        dmares = platform_get_resource(pdev, IORESOURCE_DMA, 1);
        if (!dmares)
                return -EBUSY;
        wd->dmaids[SNDRV_PCM_STREAM_CAPTURE] = dmares->start;

        /* preserve PSC clock source set up by platform (dev.platform_data
         * is already occupied by soc layer)
         */
        sel = __raw_readl(PSC_SEL(wd)) & PSC_SEL_CLK_MASK;
        __raw_writel(PSC_CTRL_DISABLE, PSC_CTRL(wd));
        wmb(); /* drain writebuffer */
        __raw_writel(PSC_SEL_PS_I2SMODE | sel, PSC_SEL(wd));
        __raw_writel(0, I2S_CFG(wd));
        wmb(); /* drain writebuffer */

        /* preconfigure: set max rx/tx fifo depths */
        wd->cfg |= PSC_I2SCFG_RT_FIFO8 | PSC_I2SCFG_TT_FIFO8;

        /* don't wait for I2S core to become ready now; clocks may not
         * be running yet; depending on clock input for PSC a wait might
         * time out.
         */

        /* name the DAI like this device instance ("au1xpsc-i2s.PSCINDEX") */
        memcpy(&wd->dai_drv, &au1xpsc_i2s_dai_template,
               sizeof(struct snd_soc_dai_driver));
        wd->dai_drv.name = dev_name(&pdev->dev);

        platform_set_drvdata(pdev, wd);

        return devm_snd_soc_register_component(&pdev->dev,
                                &au1xpsc_i2s_component, &wd->dai_drv, 1);
}

static void au1xpsc_i2s_drvremove(struct platform_device *pdev)
{
        struct au1xpsc_audio_data *wd = platform_get_drvdata(pdev);

        __raw_writel(0, I2S_CFG(wd));
        wmb(); /* drain writebuffer */
        __raw_writel(PSC_CTRL_DISABLE, PSC_CTRL(wd));
        wmb(); /* drain writebuffer */
}

static int au1xpsc_i2s_drvsuspend(struct device *dev)
{
        struct au1xpsc_audio_data *wd = dev_get_drvdata(dev);

        /* save interesting register and disable PSC */
        wd->pm[0] = __raw_readl(PSC_SEL(wd));

        __raw_writel(0, I2S_CFG(wd));
        wmb(); /* drain writebuffer */
        __raw_writel(PSC_CTRL_DISABLE, PSC_CTRL(wd));
        wmb(); /* drain writebuffer */

        return 0;
}

static int au1xpsc_i2s_drvresume(struct device *dev)
{
        struct au1xpsc_audio_data *wd = dev_get_drvdata(dev);

        /* select I2S mode and PSC clock */
        __raw_writel(PSC_CTRL_DISABLE, PSC_CTRL(wd));
        wmb(); /* drain writebuffer */
        __raw_writel(0, PSC_SEL(wd));
        wmb(); /* drain writebuffer */
        __raw_writel(wd->pm[0], PSC_SEL(wd));
        wmb(); /* drain writebuffer */

        return 0;
}

static DEFINE_SIMPLE_DEV_PM_OPS(au1xpsci2s_pmops, au1xpsc_i2s_drvsuspend,
                                au1xpsc_i2s_drvresume);

static struct platform_driver au1xpsc_i2s_driver = {
        .driver         = {
                .name   = "au1xpsc_i2s",
                .pm     = pm_ptr(&au1xpsci2s_pmops),
        },
        .probe          = au1xpsc_i2s_drvprobe,
        .remove         = au1xpsc_i2s_drvremove,
};

module_platform_driver(au1xpsc_i2s_driver);

MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Au12x0/Au1550 PSC I2S ALSA ASoC audio driver");
MODULE_AUTHOR("Manuel Lauss");