i2s.c

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/* sound/soc/samsung/i2s.c
 *
 * ALSA SoC Audio Layer - Samsung I2S Controller driver
 *
 * Copyright (c) 2010 Samsung Electronics Co. Ltd.
 *  Jaswinder Singh <[email protected]>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#include <linux/delay.h>
#include <linux/slab.h>
#include <linux/clk.h>
#include <linux/io.h>
#include <linux/module.h>
#include <linux/pm_runtime.h>

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

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

#include "dma.h"
#include "idma.h"
#include "i2s.h"
#include "i2s-regs.h"

#define msecs_to_loops(t) (loops_per_jiffy / 1000 * HZ * t)

struct i2s_dai {
    /* Platform device for this DAI */
    struct platform_device *pdev;
    /* IOREMAP'd SFRs */
    void __iomem    *addr;
    /* Physical base address of SFRs */
    u32 base;
    /* Rate of RCLK source clock */
    unsigned long rclk_srcrate;
    /* Frame Clock */
    unsigned frmclk;
    /*
     * Specifically requested RCLK,BCLK by MACHINE Driver.
     * 0 indicates CPU driver is free to choose any value.
     */
    unsigned rfs, bfs;
    /* I2S Controller's core clock */
    struct clk *clk;
    /* Clock for generating I2S signals */
    struct clk *op_clk;
    /* Array of clock names for op_clk */
    const char **src_clk;
    /* Pointer to the Primary_Fifo if this is Sec_Fifo, NULL otherwise */
    struct i2s_dai *pri_dai;
    /* Pointer to the Secondary_Fifo if it has one, NULL otherwise */
    struct i2s_dai *sec_dai;
#define DAI_OPENED  (1 << 0) /* Dai is opened */
#define DAI_MANAGER (1 << 1) /* Dai is the manager */
    unsigned mode;
    /* Driver for this DAI */
    struct snd_soc_dai_driver i2s_dai_drv;
    /* DMA parameters */
    struct s3c_dma_params dma_playback;
    struct s3c_dma_params dma_capture;
    struct s3c_dma_params idma_playback;
    u32 quirks;
    u32 suspend_i2smod;
    u32 suspend_i2scon;
    u32 suspend_i2spsr;
};

/* Lock for cross i/f checks */
static DEFINE_SPINLOCK(lock);

/* If this is the 'overlay' stereo DAI */
static inline bool is_secondary(struct i2s_dai *i2s)
{
    return i2s->pri_dai ? true : false;
}

/* If operating in SoC-Slave mode */
static inline bool is_slave(struct i2s_dai *i2s)
{
    return (readl(i2s->addr + I2SMOD) & MOD_SLAVE) ? true : false;
}

/* If this interface of the controller is transmitting data */
static inline bool tx_active(struct i2s_dai *i2s)
{
    u32 active;

    if (!i2s)
        return false;

    active = readl(i2s->addr + I2SCON);

    if (is_secondary(i2s))
        active &= CON_TXSDMA_ACTIVE;
    else
        active &= CON_TXDMA_ACTIVE;

    return active ? true : false;
}

/* If the other interface of the controller is transmitting data */
static inline bool other_tx_active(struct i2s_dai *i2s)
{
    struct i2s_dai *other = i2s->pri_dai ? : i2s->sec_dai;

    return tx_active(other);
}

/* If any interface of the controller is transmitting data */
static inline bool any_tx_active(struct i2s_dai *i2s)
{
    return tx_active(i2s) || other_tx_active(i2s);
}

/* If this interface of the controller is receiving data */
static inline bool rx_active(struct i2s_dai *i2s)
{
    u32 active;

    if (!i2s)
        return false;

    active = readl(i2s->addr + I2SCON) & CON_RXDMA_ACTIVE;

    return active ? true : false;
}

/* If the other interface of the controller is receiving data */
static inline bool other_rx_active(struct i2s_dai *i2s)
{
    struct i2s_dai *other = i2s->pri_dai ? : i2s->sec_dai;

    return rx_active(other);
}

/* If any interface of the controller is receiving data */
static inline bool any_rx_active(struct i2s_dai *i2s)
{
    return rx_active(i2s) || other_rx_active(i2s);
}

/* If the other DAI is transmitting or receiving data */
static inline bool other_active(struct i2s_dai *i2s)
{
    return other_rx_active(i2s) || other_tx_active(i2s);
}

/* If this DAI is transmitting or receiving data */
static inline bool this_active(struct i2s_dai *i2s)
{
    return tx_active(i2s) || rx_active(i2s);
}

/* If the controller is active anyway */
static inline bool any_active(struct i2s_dai *i2s)
{
    return this_active(i2s) || other_active(i2s);
}

static inline struct i2s_dai *to_info(struct snd_soc_dai *dai)
{
    return snd_soc_dai_get_drvdata(dai);
}

static inline bool is_opened(struct i2s_dai *i2s)
{
    if (i2s && (i2s->mode & DAI_OPENED))
        return true;
    else
        return false;
}

static inline bool is_manager(struct i2s_dai *i2s)
{
    if (is_opened(i2s) && (i2s->mode & DAI_MANAGER))
        return true;
    else
        return false;
}

/* Read RCLK of I2S (in multiples of LRCLK) */
static inline unsigned get_rfs(struct i2s_dai *i2s)
{
    u32 rfs = (readl(i2s->addr + I2SMOD) >> 3) & 0x3;

    switch (rfs) {
    case 3: return 768;
    case 2: return 384;
    case 1: return 512;
    default: return 256;
    }
}

/* Write RCLK of I2S (in multiples of LRCLK) */
static inline void set_rfs(struct i2s_dai *i2s, unsigned rfs)
{
    u32 mod = readl(i2s->addr + I2SMOD);

    mod &= ~MOD_RCLK_MASK;

    switch (rfs) {
    case 768:
        mod |= MOD_RCLK_768FS;
        break;
    case 512:
        mod |= MOD_RCLK_512FS;
        break;
    case 384:
        mod |= MOD_RCLK_384FS;
        break;
    default:
        mod |= MOD_RCLK_256FS;
        break;
    }

    writel(mod, i2s->addr + I2SMOD);
}

/* Read Bit-Clock of I2S (in multiples of LRCLK) */
static inline unsigned get_bfs(struct i2s_dai *i2s)
{
    u32 bfs = (readl(i2s->addr + I2SMOD) >> 1) & 0x3;

    switch (bfs) {
    case 3: return 24;
    case 2: return 16;
    case 1: return 48;
    default: return 32;
    }
}

/* Write Bit-Clock of I2S (in multiples of LRCLK) */
static inline void set_bfs(struct i2s_dai *i2s, unsigned bfs)
{
    u32 mod = readl(i2s->addr + I2SMOD);

    mod &= ~MOD_BCLK_MASK;

    switch (bfs) {
    case 48:
        mod |= MOD_BCLK_48FS;
        break;
    case 32:
        mod |= MOD_BCLK_32FS;
        break;
    case 24:
        mod |= MOD_BCLK_24FS;
        break;
    case 16:
        mod |= MOD_BCLK_16FS;
        break;
    default:
        dev_err(&i2s->pdev->dev, "Wrong BCLK Divider!\n");
        return;
    }

    writel(mod, i2s->addr + I2SMOD);
}

/* Sample-Size */
static inline int get_blc(struct i2s_dai *i2s)
{
    int blc = readl(i2s->addr + I2SMOD);

    blc = (blc >> 13) & 0x3;

    switch (blc) {
    case 2: return 24;
    case 1: return 8;
    default: return 16;
    }
}

/* TX Channel Control */
static void i2s_txctrl(struct i2s_dai *i2s, int on)
{
    void __iomem *addr = i2s->addr;
    u32 con = readl(addr + I2SCON);
    u32 mod = readl(addr + I2SMOD) & ~MOD_MASK;

    if (on) {
        con |= CON_ACTIVE;
        con &= ~CON_TXCH_PAUSE;

        if (is_secondary(i2s)) {
            con |= CON_TXSDMA_ACTIVE;
            con &= ~CON_TXSDMA_PAUSE;
        } else {
            con |= CON_TXDMA_ACTIVE;
            con &= ~CON_TXDMA_PAUSE;
        }

        if (any_rx_active(i2s))
            mod |= MOD_TXRX;
        else
            mod |= MOD_TXONLY;
    } else {
        if (is_secondary(i2s)) {
            con |=  CON_TXSDMA_PAUSE;
            con &= ~CON_TXSDMA_ACTIVE;
        } else {
            con |=  CON_TXDMA_PAUSE;
            con &= ~CON_TXDMA_ACTIVE;
        }

        if (other_tx_active(i2s)) {
            writel(con, addr + I2SCON);
            return;
        }

        con |=  CON_TXCH_PAUSE;

        if (any_rx_active(i2s))
            mod |= MOD_RXONLY;
        else
            con &= ~CON_ACTIVE;
    }

    writel(mod, addr + I2SMOD);
    writel(con, addr + I2SCON);
}

/* RX Channel Control */
static void i2s_rxctrl(struct i2s_dai *i2s, int on)
{
    void __iomem *addr = i2s->addr;
    u32 con = readl(addr + I2SCON);
    u32 mod = readl(addr + I2SMOD) & ~MOD_MASK;

    if (on) {
        con |= CON_RXDMA_ACTIVE | CON_ACTIVE;
        con &= ~(CON_RXDMA_PAUSE | CON_RXCH_PAUSE);

        if (any_tx_active(i2s))
            mod |= MOD_TXRX;
        else
            mod |= MOD_RXONLY;
    } else {
        con |=  CON_RXDMA_PAUSE | CON_RXCH_PAUSE;
        con &= ~CON_RXDMA_ACTIVE;

        if (any_tx_active(i2s))
            mod |= MOD_TXONLY;
        else
            con &= ~CON_ACTIVE;
    }

    writel(mod, addr + I2SMOD);
    writel(con, addr + I2SCON);
}

/* Flush FIFO of an interface */
static inline void i2s_fifo(struct i2s_dai *i2s, u32 flush)
{
    void __iomem *fic;
    u32 val;

    if (!i2s)
        return;

    if (is_secondary(i2s))
        fic = i2s->addr + I2SFICS;
    else
        fic = i2s->addr + I2SFIC;

    /* Flush the FIFO */
    writel(readl(fic) | flush, fic);

    /* Be patient */
    val = msecs_to_loops(1) / 1000; /* 1 usec */
    while (--val)
        cpu_relax();

    writel(readl(fic) & ~flush, fic);
}

static int i2s_set_sysclk(struct snd_soc_dai *dai,
      int clk_id, unsigned int rfs, int dir)
{
    struct i2s_dai *i2s = to_info(dai);
    struct i2s_dai *other = i2s->pri_dai ? : i2s->sec_dai;
    u32 mod = readl(i2s->addr + I2SMOD);

    switch (clk_id) {
    case SAMSUNG_I2S_CDCLK:
        /* Shouldn't matter in GATING(CLOCK_IN) mode */
        if (dir == SND_SOC_CLOCK_IN)
            rfs = 0;

        if ((rfs && other->rfs && (other->rfs != rfs)) ||
                (any_active(i2s) &&
                (((dir == SND_SOC_CLOCK_IN)
                    && !(mod & MOD_CDCLKCON)) ||
                ((dir == SND_SOC_CLOCK_OUT)
                    && (mod & MOD_CDCLKCON))))) {
            dev_err(&i2s->pdev->dev,
                "%s:%d Other DAI busy\n", __func__, __LINE__);
            return -EAGAIN;
        }

        if (dir == SND_SOC_CLOCK_IN)
            mod |= MOD_CDCLKCON;
        else
            mod &= ~MOD_CDCLKCON;

        i2s->rfs = rfs;
        break;

    case SAMSUNG_I2S_RCLKSRC_0: /* clock corrsponding to IISMOD[10] := 0 */
    case SAMSUNG_I2S_RCLKSRC_1: /* clock corrsponding to IISMOD[10] := 1 */
        if ((i2s->quirks & QUIRK_NO_MUXPSR)
                || (clk_id == SAMSUNG_I2S_RCLKSRC_0))
            clk_id = 0;
        else
            clk_id = 1;

        if (!any_active(i2s)) {
            if (i2s->op_clk) {
                if ((clk_id && !(mod & MOD_IMS_SYSMUX)) ||
                    (!clk_id && (mod & MOD_IMS_SYSMUX))) {
                    clk_disable(i2s->op_clk);
                    clk_put(i2s->op_clk);
                } else {
                    i2s->rclk_srcrate =
                        clk_get_rate(i2s->op_clk);
                    return 0;
                }
            }

            i2s->op_clk = clk_get(&i2s->pdev->dev,
                        i2s->src_clk[clk_id]);
            clk_enable(i2s->op_clk);
            i2s->rclk_srcrate = clk_get_rate(i2s->op_clk);

            /* Over-ride the other's */
            if (other) {
                other->op_clk = i2s->op_clk;
                other->rclk_srcrate = i2s->rclk_srcrate;
            }
        } else if ((!clk_id && (mod & MOD_IMS_SYSMUX))
                || (clk_id && !(mod & MOD_IMS_SYSMUX))) {
            dev_err(&i2s->pdev->dev,
                "%s:%d Other DAI busy\n", __func__, __LINE__);
            return -EAGAIN;
        } else {
            /* Call can't be on the active DAI */
            i2s->op_clk = other->op_clk;
            i2s->rclk_srcrate = other->rclk_srcrate;
            return 0;
        }

        if (clk_id == 0)
            mod &= ~MOD_IMS_SYSMUX;
        else
            mod |= MOD_IMS_SYSMUX;
        break;

    default:
        dev_err(&i2s->pdev->dev, "We don't serve that!\n");
        return -EINVAL;
    }

    writel(mod, i2s->addr + I2SMOD);

    return 0;
}

static int i2s_set_fmt(struct snd_soc_dai *dai,
    unsigned int fmt)
{
    struct i2s_dai *i2s = to_info(dai);
    u32 mod = readl(i2s->addr + I2SMOD);
    u32 tmp = 0;

    /* Format is priority */
    switch (fmt & SND_SOC_DAIFMT_FORMAT_MASK) {
    case SND_SOC_DAIFMT_RIGHT_J:
        tmp |= MOD_LR_RLOW;
        tmp |= MOD_SDF_MSB;
        break;
    case SND_SOC_DAIFMT_LEFT_J:
        tmp |= MOD_LR_RLOW;
        tmp |= MOD_SDF_LSB;
        break;
    case SND_SOC_DAIFMT_I2S:
        tmp |= MOD_SDF_IIS;
        break;
    default:
        dev_err(&i2s->pdev->dev, "Format not supported\n");
        return -EINVAL;
    }

    /*
     * INV flag is relative to the FORMAT flag - if set it simply
     * flips the polarity specified by the Standard
     */
    switch (fmt & SND_SOC_DAIFMT_INV_MASK) {
    case SND_SOC_DAIFMT_NB_NF:
        break;
    case SND_SOC_DAIFMT_NB_IF:
        if (tmp & MOD_LR_RLOW)
            tmp &= ~MOD_LR_RLOW;
        else
            tmp |= MOD_LR_RLOW;
        break;
    default:
        dev_err(&i2s->pdev->dev, "Polarity not supported\n");
        return -EINVAL;
    }

    switch (fmt & SND_SOC_DAIFMT_MASTER_MASK) {
    case SND_SOC_DAIFMT_CBM_CFM:
        tmp |= MOD_SLAVE;
        break;
    case SND_SOC_DAIFMT_CBS_CFS:
        /* Set default source clock in Master mode */
        if (i2s->rclk_srcrate == 0)
            i2s_set_sysclk(dai, SAMSUNG_I2S_RCLKSRC_0,
                            0, SND_SOC_CLOCK_IN);
        break;
    default:
        dev_err(&i2s->pdev->dev, "master/slave format not supported\n");
        return -EINVAL;
    }

    if (any_active(i2s) &&
            ((mod & (MOD_SDF_MASK | MOD_LR_RLOW
                | MOD_SLAVE)) != tmp)) {
        dev_err(&i2s->pdev->dev,
                "%s:%d Other DAI busy\n", __func__, __LINE__);
        return -EAGAIN;
    }

    mod &= ~(MOD_SDF_MASK | MOD_LR_RLOW | MOD_SLAVE);
    mod |= tmp;
    writel(mod, i2s->addr + I2SMOD);

    return 0;
}

static int i2s_hw_params(struct snd_pcm_substream *substream,
    struct snd_pcm_hw_params *params, struct snd_soc_dai *dai)
{
    struct i2s_dai *i2s = to_info(dai);
    u32 mod = readl(i2s->addr + I2SMOD);

    if (!is_secondary(i2s))
        mod &= ~(MOD_DC2_EN | MOD_DC1_EN);

    switch (params_channels(params)) {
    case 6:
        mod |= MOD_DC2_EN;
    case 4:
        mod |= MOD_DC1_EN;
        break;
    case 2:
        if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
            i2s->dma_playback.dma_size = 4;
        else
            i2s->dma_capture.dma_size = 4;
        break;
    case 1:
        if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
            i2s->dma_playback.dma_size = 2;
        else
            i2s->dma_capture.dma_size = 2;

        break;
    default:
        dev_err(&i2s->pdev->dev, "%d channels not supported\n",
                params_channels(params));
        return -EINVAL;
    }

    if (is_secondary(i2s))
        mod &= ~MOD_BLCS_MASK;
    else
        mod &= ~MOD_BLCP_MASK;

    if (is_manager(i2s))
        mod &= ~MOD_BLC_MASK;

    switch (params_format(params)) {
    case SNDRV_PCM_FORMAT_S8:
        if (is_secondary(i2s))
            mod |= MOD_BLCS_8BIT;
        else
            mod |= MOD_BLCP_8BIT;
        if (is_manager(i2s))
            mod |= MOD_BLC_8BIT;
        break;
    case SNDRV_PCM_FORMAT_S16_LE:
        if (is_secondary(i2s))
            mod |= MOD_BLCS_16BIT;
        else
            mod |= MOD_BLCP_16BIT;
        if (is_manager(i2s))
            mod |= MOD_BLC_16BIT;
        break;
    case SNDRV_PCM_FORMAT_S24_LE:
        if (is_secondary(i2s))
            mod |= MOD_BLCS_24BIT;
        else
            mod |= MOD_BLCP_24BIT;
        if (is_manager(i2s))
            mod |= MOD_BLC_24BIT;
        break;
    default:
        dev_err(&i2s->pdev->dev, "Format(%d) not supported\n",
                params_format(params));
        return -EINVAL;
    }
    writel(mod, i2s->addr + I2SMOD);

    if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
        snd_soc_dai_set_dma_data(dai, substream,
            (void *)&i2s->dma_playback);
    else
        snd_soc_dai_set_dma_data(dai, substream,
            (void *)&i2s->dma_capture);

    i2s->frmclk = params_rate(params);

    return 0;
}

/* We set constraints on the substream acc to the version of I2S */
static int i2s_startup(struct snd_pcm_substream *substream,
      struct snd_soc_dai *dai)
{
    struct i2s_dai *i2s = to_info(dai);
    struct i2s_dai *other = i2s->pri_dai ? : i2s->sec_dai;
    unsigned long flags;

    spin_lock_irqsave(&lock, flags);

    i2s->mode |= DAI_OPENED;

    if (is_manager(other))
        i2s->mode &= ~DAI_MANAGER;
    else
        i2s->mode |= DAI_MANAGER;

    /* Enforce set_sysclk in Master mode */
    i2s->rclk_srcrate = 0;

    spin_unlock_irqrestore(&lock, flags);

    return 0;
}

static void i2s_shutdown(struct snd_pcm_substream *substream,
    struct snd_soc_dai *dai)
{
    struct i2s_dai *i2s = to_info(dai);
    struct i2s_dai *other = i2s->pri_dai ? : i2s->sec_dai;
    unsigned long flags;

    spin_lock_irqsave(&lock, flags);

    i2s->mode &= ~DAI_OPENED;
    i2s->mode &= ~DAI_MANAGER;

    if (is_opened(other))
        other->mode |= DAI_MANAGER;

    /* Reset any constraint on RFS and BFS */
    i2s->rfs = 0;
    i2s->bfs = 0;

    spin_unlock_irqrestore(&lock, flags);

    /* Gate CDCLK by default */
    if (!is_opened(other))
        i2s_set_sysclk(dai, SAMSUNG_I2S_CDCLK,
                0, SND_SOC_CLOCK_IN);
}

static int config_setup(struct i2s_dai *i2s)
{
    struct i2s_dai *other = i2s->pri_dai ? : i2s->sec_dai;
    unsigned rfs, bfs, blc;
    u32 psr;

    blc = get_blc(i2s);

    bfs = i2s->bfs;

    if (!bfs && other)
        bfs = other->bfs;

    /* Select least possible multiple(2) if no constraint set */
    if (!bfs)
        bfs = blc * 2;

    rfs = i2s->rfs;

    if (!rfs && other)
        rfs = other->rfs;

    if ((rfs == 256 || rfs == 512) && (blc == 24)) {
        dev_err(&i2s->pdev->dev,
            "%d-RFS not supported for 24-blc\n", rfs);
        return -EINVAL;
    }

    if (!rfs) {
        if (bfs == 16 || bfs == 32)
            rfs = 256;
        else
            rfs = 384;
    }

    /* If already setup and running */
    if (any_active(i2s) && (get_rfs(i2s) != rfs || get_bfs(i2s) != bfs)) {
        dev_err(&i2s->pdev->dev,
                "%s:%d Other DAI busy\n", __func__, __LINE__);
        return -EAGAIN;
    }

    /* Don't bother RFS, BFS & PSR in Slave mode */
    if (is_slave(i2s))
        return 0;

    set_bfs(i2s, bfs);
    set_rfs(i2s, rfs);

    if (!(i2s->quirks & QUIRK_NO_MUXPSR)) {
        psr = i2s->rclk_srcrate / i2s->frmclk / rfs;
        writel(((psr - 1) << 8) | PSR_PSREN, i2s->addr + I2SPSR);
        dev_dbg(&i2s->pdev->dev,
            "RCLK_SRC=%luHz PSR=%u, RCLK=%dfs, BCLK=%dfs\n",
                i2s->rclk_srcrate, psr, rfs, bfs);
    }

    return 0;
}

static int i2s_trigger(struct snd_pcm_substream *substream,
    int cmd, struct snd_soc_dai *dai)
{
    int capture = (substream->stream == SNDRV_PCM_STREAM_CAPTURE);
    struct snd_soc_pcm_runtime *rtd = substream->private_data;
    struct i2s_dai *i2s = to_info(rtd->cpu_dai);
    unsigned long flags;

    switch (cmd) {
    case SNDRV_PCM_TRIGGER_START:
    case SNDRV_PCM_TRIGGER_RESUME:
    case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
        local_irq_save(flags);

        if (config_setup(i2s)) {
            local_irq_restore(flags);
            return -EINVAL;
        }

        if (capture)
            i2s_rxctrl(i2s, 1);
        else
            i2s_txctrl(i2s, 1);

        local_irq_restore(flags);
        break;
    case SNDRV_PCM_TRIGGER_STOP:
    case SNDRV_PCM_TRIGGER_SUSPEND:
    case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
        local_irq_save(flags);

        if (capture) {
            i2s_rxctrl(i2s, 0);
            i2s_fifo(i2s, FIC_RXFLUSH);
        } else {
            i2s_txctrl(i2s, 0);
            i2s_fifo(i2s, FIC_TXFLUSH);
        }

        local_irq_restore(flags);
        break;
    }

    return 0;
}

static int i2s_set_clkdiv(struct snd_soc_dai *dai,
    int div_id, int div)
{
    struct i2s_dai *i2s = to_info(dai);
    struct i2s_dai *other = i2s->pri_dai ? : i2s->sec_dai;

    switch (div_id) {
    case SAMSUNG_I2S_DIV_BCLK:
        if ((any_active(i2s) && div && (get_bfs(i2s) != div))
            || (other && other->bfs && (other->bfs != div))) {
            dev_err(&i2s->pdev->dev,
                "%s:%d Other DAI busy\n", __func__, __LINE__);
            return -EAGAIN;
        }
        i2s->bfs = div;
        break;
    default:
        dev_err(&i2s->pdev->dev,
            "Invalid clock divider(%d)\n", div_id);
        return -EINVAL;
    }

    return 0;
}

static snd_pcm_sframes_t
i2s_delay(struct snd_pcm_substream *substream, struct snd_soc_dai *dai)
{
    struct i2s_dai *i2s = to_info(dai);
    u32 reg = readl(i2s->addr + I2SFIC);
    snd_pcm_sframes_t delay;

    if (substream->stream == SNDRV_PCM_STREAM_CAPTURE)
        delay = FIC_RXCOUNT(reg);
    else if (is_secondary(i2s))
        delay = FICS_TXCOUNT(readl(i2s->addr + I2SFICS));
    else
        delay = FIC_TXCOUNT(reg);

    return delay;
}

#ifdef CONFIG_PM
static int i2s_suspend(struct snd_soc_dai *dai)
{
    struct i2s_dai *i2s = to_info(dai);

    if (dai->active) {
        i2s->suspend_i2smod = readl(i2s->addr + I2SMOD);
        i2s->suspend_i2scon = readl(i2s->addr + I2SCON);
        i2s->suspend_i2spsr = readl(i2s->addr + I2SPSR);
    }

    return 0;
}

static int i2s_resume(struct snd_soc_dai *dai)
{
    struct i2s_dai *i2s = to_info(dai);

    if (dai->active) {
        writel(i2s->suspend_i2scon, i2s->addr + I2SCON);
        writel(i2s->suspend_i2smod, i2s->addr + I2SMOD);
        writel(i2s->suspend_i2spsr, i2s->addr + I2SPSR);
    }

    return 0;
}
#else
#define i2s_suspend NULL
#define i2s_resume  NULL
#endif

static int samsung_i2s_dai_probe(struct snd_soc_dai *dai)
{
    struct i2s_dai *i2s = to_info(dai);
    struct i2s_dai *other = i2s->pri_dai ? : i2s->sec_dai;

    if (other && other->clk) /* If this is probe on secondary */
        goto probe_exit;

    i2s->addr = ioremap(i2s->base, 0x100);
    if (i2s->addr == NULL) {
        dev_err(&i2s->pdev->dev, "cannot ioremap registers\n");
        return -ENXIO;
    }

    i2s->clk = clk_get(&i2s->pdev->dev, "iis");
    if (IS_ERR(i2s->clk)) {
        dev_err(&i2s->pdev->dev, "failed to get i2s_clock\n");
        iounmap(i2s->addr);
        return -ENOENT;
    }
    clk_enable(i2s->clk);

    if (other) {
        other->addr = i2s->addr;
        other->clk = i2s->clk;
    }

    if (i2s->quirks & QUIRK_NEED_RSTCLR)
        writel(CON_RSTCLR, i2s->addr + I2SCON);

    if (i2s->quirks & QUIRK_SEC_DAI)
        idma_reg_addr_init(i2s->addr,
                    i2s->sec_dai->idma_playback.dma_addr);

probe_exit:
    /* Reset any constraint on RFS and BFS */
    i2s->rfs = 0;
    i2s->bfs = 0;
    i2s_txctrl(i2s, 0);
    i2s_rxctrl(i2s, 0);
    i2s_fifo(i2s, FIC_TXFLUSH);
    i2s_fifo(other, FIC_TXFLUSH);
    i2s_fifo(i2s, FIC_RXFLUSH);

    /* Gate CDCLK by default */
    if (!is_opened(other))
        i2s_set_sysclk(dai, SAMSUNG_I2S_CDCLK,
                0, SND_SOC_CLOCK_IN);

    return 0;
}

static int samsung_i2s_dai_remove(struct snd_soc_dai *dai)
{
    struct i2s_dai *i2s = snd_soc_dai_get_drvdata(dai);
    struct i2s_dai *other = i2s->pri_dai ? : i2s->sec_dai;

    if (!other || !other->clk) {

        if (i2s->quirks & QUIRK_NEED_RSTCLR)
            writel(0, i2s->addr + I2SCON);

        clk_disable(i2s->clk);
        clk_put(i2s->clk);

        iounmap(i2s->addr);
    }

    i2s->clk = NULL;

    return 0;
}

static const struct snd_soc_dai_ops samsung_i2s_dai_ops = {
    .trigger = i2s_trigger,
    .hw_params = i2s_hw_params,
    .set_fmt = i2s_set_fmt,
    .set_clkdiv = i2s_set_clkdiv,
    .set_sysclk = i2s_set_sysclk,
    .startup = i2s_startup,
    .shutdown = i2s_shutdown,
    .delay = i2s_delay,
};

#define SAMSUNG_I2S_RATES   SNDRV_PCM_RATE_8000_96000

#define SAMSUNG_I2S_FMTS    (SNDRV_PCM_FMTBIT_S8 | \
                    SNDRV_PCM_FMTBIT_S16_LE | \
                    SNDRV_PCM_FMTBIT_S24_LE)

static __devinit
struct i2s_dai *i2s_alloc_dai(struct platform_device *pdev, bool sec)
{
    struct i2s_dai *i2s;

    i2s = devm_kzalloc(&pdev->dev, sizeof(struct i2s_dai), GFP_KERNEL);
    if (i2s == NULL)
        return NULL;

    i2s->pdev = pdev;
    i2s->pri_dai = NULL;
    i2s->sec_dai = NULL;
    i2s->i2s_dai_drv.symmetric_rates = 1;
    i2s->i2s_dai_drv.probe = samsung_i2s_dai_probe;
    i2s->i2s_dai_drv.remove = samsung_i2s_dai_remove;
    i2s->i2s_dai_drv.ops = &samsung_i2s_dai_ops;
    i2s->i2s_dai_drv.suspend = i2s_suspend;
    i2s->i2s_dai_drv.resume = i2s_resume;
    i2s->i2s_dai_drv.playback.channels_min = 2;
    i2s->i2s_dai_drv.playback.channels_max = 2;
    i2s->i2s_dai_drv.playback.rates = SAMSUNG_I2S_RATES;
    i2s->i2s_dai_drv.playback.formats = SAMSUNG_I2S_FMTS;

    if (!sec) {
        i2s->i2s_dai_drv.capture.channels_min = 1;
        i2s->i2s_dai_drv.capture.channels_max = 2;
        i2s->i2s_dai_drv.capture.rates = SAMSUNG_I2S_RATES;
        i2s->i2s_dai_drv.capture.formats = SAMSUNG_I2S_FMTS;
    } else {    /* Create a new platform_device for Secondary */
        i2s->pdev = platform_device_register_resndata(NULL,
                pdev->name, pdev->id + SAMSUNG_I2S_SECOFF,
                NULL, 0, NULL, 0);
        if (IS_ERR(i2s->pdev))
            return NULL;
    }

    /* Pre-assign snd_soc_dai_set_drvdata */
    dev_set_drvdata(&i2s->pdev->dev, i2s);

    return i2s;
}

static __devinit int samsung_i2s_probe(struct platform_device *pdev)
{
    u32 dma_pl_chan, dma_cp_chan, dma_pl_sec_chan;
    struct i2s_dai *pri_dai, *sec_dai = NULL;
    struct s3c_audio_pdata *i2s_pdata;
    struct samsung_i2s *i2s_cfg;
    struct resource *res;
    u32 regs_base, quirks;
    int ret = 0;

    /* Call during Seconday interface registration */
    if (pdev->id >= SAMSUNG_I2S_SECOFF) {
        sec_dai = dev_get_drvdata(&pdev->dev);
        snd_soc_register_dai(&sec_dai->pdev->dev,
            &sec_dai->i2s_dai_drv);
        return 0;
    }

    i2s_pdata = pdev->dev.platform_data;
    if (i2s_pdata == NULL) {
        dev_err(&pdev->dev, "Can't work without s3c_audio_pdata\n");
        return -EINVAL;
    }

    res = platform_get_resource(pdev, IORESOURCE_DMA, 0);
    if (!res) {
        dev_err(&pdev->dev, "Unable to get I2S-TX dma resource\n");
        return -ENXIO;
    }
    dma_pl_chan = res->start;

    res = platform_get_resource(pdev, IORESOURCE_DMA, 1);
    if (!res) {
        dev_err(&pdev->dev, "Unable to get I2S-RX dma resource\n");
        return -ENXIO;
    }
    dma_cp_chan = res->start;

    res = platform_get_resource(pdev, IORESOURCE_DMA, 2);
    if (res)
        dma_pl_sec_chan = res->start;
    else
        dma_pl_sec_chan = 0;

    res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
    if (!res) {
        dev_err(&pdev->dev, "Unable to get I2S SFR address\n");
        return -ENXIO;
    }

    if (!request_mem_region(res->start, resource_size(res),
                            "samsung-i2s")) {
        dev_err(&pdev->dev, "Unable to request SFR region\n");
        return -EBUSY;
    }
    regs_base = res->start;

    i2s_cfg = &i2s_pdata->type.i2s;
    quirks = i2s_cfg->quirks;

    pri_dai = i2s_alloc_dai(pdev, false);
    if (!pri_dai) {
        dev_err(&pdev->dev, "Unable to alloc I2S_pri\n");
        ret = -ENOMEM;
        goto err;
    }

    pri_dai->dma_playback.dma_addr = regs_base + I2STXD;
    pri_dai->dma_capture.dma_addr = regs_base + I2SRXD;
    pri_dai->dma_playback.client =
        (struct s3c2410_dma_client *)&pri_dai->dma_playback;
    pri_dai->dma_capture.client =
        (struct s3c2410_dma_client *)&pri_dai->dma_capture;
    pri_dai->dma_playback.channel = dma_pl_chan;
    pri_dai->dma_capture.channel = dma_cp_chan;
    pri_dai->src_clk = i2s_cfg->src_clk;
    pri_dai->dma_playback.dma_size = 4;
    pri_dai->dma_capture.dma_size = 4;
    pri_dai->base = regs_base;
    pri_dai->quirks = quirks;

    if (quirks & QUIRK_PRI_6CHAN)
        pri_dai->i2s_dai_drv.playback.channels_max = 6;

    if (quirks & QUIRK_SEC_DAI) {
        sec_dai = i2s_alloc_dai(pdev, true);
        if (!sec_dai) {
            dev_err(&pdev->dev, "Unable to alloc I2S_sec\n");
            ret = -ENOMEM;
            goto err;
        }
        sec_dai->dma_playback.dma_addr = regs_base + I2STXDS;
        sec_dai->dma_playback.client =
            (struct s3c2410_dma_client *)&sec_dai->dma_playback;
        /* Use iDMA always if SysDMA not provided */
        sec_dai->dma_playback.channel = dma_pl_sec_chan ? : -1;
        sec_dai->src_clk = i2s_cfg->src_clk;
        sec_dai->dma_playback.dma_size = 4;
        sec_dai->base = regs_base;
        sec_dai->quirks = quirks;
        sec_dai->idma_playback.dma_addr = i2s_cfg->idma_addr;
        sec_dai->pri_dai = pri_dai;
        pri_dai->sec_dai = sec_dai;
    }

    if (i2s_pdata->cfg_gpio && i2s_pdata->cfg_gpio(pdev)) {
        dev_err(&pdev->dev, "Unable to configure gpio\n");
        ret = -EINVAL;
        goto err;
    }

    snd_soc_register_dai(&pri_dai->pdev->dev, &pri_dai->i2s_dai_drv);

    pm_runtime_enable(&pdev->dev);

    return 0;
err:
    release_mem_region(regs_base, resource_size(res));

    return ret;
}

static __devexit int samsung_i2s_remove(struct platform_device *pdev)
{
    struct i2s_dai *i2s, *other;
    struct resource *res;

    i2s = dev_get_drvdata(&pdev->dev);
    other = i2s->pri_dai ? : i2s->sec_dai;

    if (other) {
        other->pri_dai = NULL;
        other->sec_dai = NULL;
    } else {
        pm_runtime_disable(&pdev->dev);
        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
        if (res)
            release_mem_region(res->start, resource_size(res));
    }

    i2s->pri_dai = NULL;
    i2s->sec_dai = NULL;

    snd_soc_unregister_dai(&pdev->dev);

    return 0;
}

static struct platform_driver samsung_i2s_driver = {
    .probe  = samsung_i2s_probe,
    .remove = __devexit_p(samsung_i2s_remove),
    .driver = {
        .name = "samsung-i2s",
        .owner = THIS_MODULE,
    },
};

module_platform_driver(samsung_i2s_driver);

/* Module information */
MODULE_AUTHOR("Jaswinder Singh, <[email protected]>");
MODULE_DESCRIPTION("Samsung I2S Interface");
MODULE_ALIAS("platform:samsung-i2s");
MODULE_LICENSE("GPL");