/*
 * (C) Copyright 2009 SAMSUNG Electronics
 * Minkyu Kang <mk7.kang@samsung.com>
 * Jaehoon Chung <jh80.chung@samsung.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

#include <common.h>
#include <mmc.h>
#include <asm/io.h>
#include <asm/arch/mmc.h>

/* support 4 mmc hosts */
struct mmc mmc_dev[4];
struct mmc_host mmc_host[4];

static inline struct s5p_mmc *s5p_get_base_mmc(int dev_index)
{
        unsigned long offset = dev_index * sizeof(struct s5p_mmc);
        return (struct s5p_mmc *)(samsung_get_base_mmc() + offset);
}

static void mmc_prepare_data(struct mmc_host *host, struct mmc_data *data)
{
        unsigned char ctrl;

        debug("data->dest: %08x\n", (u32)data->dest);
        writel((u32)data->dest, &host->reg->sysad);
        /*
         * DMASEL[4:3]
         * 00 = Selects SDMA
         * 01 = Reserved
         * 10 = Selects 32-bit Address ADMA2
         * 11 = Selects 64-bit Address ADMA2
         */
        ctrl = readb(&host->reg->hostctl);
        ctrl &= ~(3 << 3);
        writeb(ctrl, &host->reg->hostctl);

        /* We do not handle DMA boundaries, so set it to max (512 KiB) */
        writew((7 << 12) | (512 << 0), &host->reg->blksize);
        writew(data->blocks, &host->reg->blkcnt);
}

static void mmc_set_transfer_mode(struct mmc_host *host, struct mmc_data *data)
{
        unsigned short mode;

        /*
         * TRNMOD
         * MUL1SIN0[5]  : Multi/Single Block Select
         * RD1WT0[4]    : Data Transfer Direction Select
         *      1 = read
         *      0 = write
         * ENACMD12[2]  : Auto CMD12 Enable
         * ENBLKCNT[1]  : Block Count Enable
         * ENDMA[0]     : DMA Enable
         */
        mode = (1 << 1) | (1 << 0);
        if (data->blocks > 1)
                mode |= (1 << 5);
        if (data->flags & MMC_DATA_READ)
                mode |= (1 << 4);

        writew(mode, &host->reg->trnmod);
}

static int mmc_send_cmd(struct mmc *mmc, struct mmc_cmd *cmd,
                        struct mmc_data *data)
{
        struct mmc_host *host = (struct mmc_host *)mmc->priv;
        int flags, i;
        unsigned int timeout;
        unsigned int mask;
        unsigned int retry = 0x100000;

        /* Wait max 10 ms */
        timeout = 10;

        /*
         * PRNSTS
         * CMDINHDAT[1] : Command Inhibit (DAT)
         * CMDINHCMD[0] : Command Inhibit (CMD)
         */
        mask = (1 << 0);
        if ((data != NULL) || (cmd->resp_type & MMC_RSP_BUSY))
                mask |= (1 << 1);

        /*
         * We shouldn't wait for data inihibit for stop commands, even
         * though they might use busy signaling
         */
        if (data)
                mask &= ~(1 << 1);

        while (readl(&host->reg->prnsts) & mask) {
                if (timeout == 0) {
                        printf("%s: timeout error\n", __func__);
                        return -1;
                }
                timeout--;
                udelay(1000);
        }

        if (data)
                mmc_prepare_data(host, data);

        debug("cmd->arg: %08x\n", cmd->cmdarg);
        writel(cmd->cmdarg, &host->reg->argument);

        if (data)
                mmc_set_transfer_mode(host, data);

        if ((cmd->resp_type & MMC_RSP_136) && (cmd->resp_type & MMC_RSP_BUSY))
                return -1;

        /*
         * CMDREG
         * CMDIDX[13:8] : Command index
         * DATAPRNT[5]  : Data Present Select
         * ENCMDIDX[4]  : Command Index Check Enable
         * ENCMDCRC[3]  : Command CRC Check Enable
         * RSPTYP[1:0]
         *      00 = No Response
         *      01 = Length 136
         *      10 = Length 48
         *      11 = Length 48 Check busy after response
         */
        if (!(cmd->resp_type & MMC_RSP_PRESENT))
                flags = 0;
        else if (cmd->resp_type & MMC_RSP_136)
                flags = (1 << 0);
        else if (cmd->resp_type & MMC_RSP_BUSY)
                flags = (3 << 0);
        else
                flags = (2 << 0);

        if (cmd->resp_type & MMC_RSP_CRC)
                flags |= (1 << 3);
        if (cmd->resp_type & MMC_RSP_OPCODE)
                flags |= (1 << 4);
        if (data)
                flags |= (1 << 5);

        debug("cmd: %d\n", cmd->cmdidx);

        writew((cmd->cmdidx << 8) | flags, &host->reg->cmdreg);

        for (i = 0; i < retry; i++) {
                mask = readl(&host->reg->norintsts);
                /* Command Complete */
                if (mask & (1 << 0)) {
                        if (!data)
                                writel(mask, &host->reg->norintsts);
                        break;
                }
        }

        if (i == retry) {
                printf("%s: waiting for status update\n", __func__);
                return TIMEOUT;
        }

        if (mask & (1 << 16)) {
                /* Timeout Error */
                debug("timeout: %08x cmd %d\n", mask, cmd->cmdidx);
                return TIMEOUT;
        } else if (mask & (1 << 15)) {
                /* Error Interrupt */
                debug("error: %08x cmd %d\n", mask, cmd->cmdidx);
                return -1;
        }

        if (cmd->resp_type & MMC_RSP_PRESENT) {
                if (cmd->resp_type & MMC_RSP_136) {
                        /* CRC is stripped so we need to do some shifting. */
                        for (i = 0; i < 4; i++) {
                                unsigned int offset =
                                        (unsigned int)(&host->reg->rspreg3 - i);
                                cmd->response[i] = readl(offset) << 8;

                                if (i != 3) {
                                        cmd->response[i] |=
                                                readb(offset - 1);
                                }
                                debug("cmd->resp[%d]: %08x\n",
                                                i, cmd->response[i]);
                        }
                } else if (cmd->resp_type & MMC_RSP_BUSY) {
                        for (i = 0; i < retry; i++) {
                                /* PRNTDATA[23:20] : DAT[3:0] Line Signal */
                                if (readl(&host->reg->prnsts)
                                        & (1 << 20))    /* DAT[0] */
                                        break;
                        }

                        if (i == retry) {
                                printf("%s: card is still busy\n", __func__);
                                return TIMEOUT;
                        }

                        cmd->response[0] = readl(&host->reg->rspreg0);
                        debug("cmd->resp[0]: %08x\n", cmd->response[0]);
                } else {
                        cmd->response[0] = readl(&host->reg->rspreg0);
                        debug("cmd->resp[0]: %08x\n", cmd->response[0]);
                }
        }

        if (data) {
                while (1) {
                        mask = readl(&host->reg->norintsts);

                        if (mask & (1 << 15)) {
                                /* Error Interrupt */
                                writel(mask, &host->reg->norintsts);
                                printf("%s: error during transfer: 0x%08x\n",
                                                __func__, mask);
                                return -1;
                        } else if (mask & (1 << 3)) {
                                /* DMA Interrupt */
                                debug("DMA end\n");
                                break;
                        } else if (mask & (1 << 1)) {
                                /* Transfer Complete */
                                debug("r/w is done\n");
                                break;
                        }
                }
                writel(mask, &host->reg->norintsts);
        }

        udelay(1000);
        return 0;
}

static void mmc_change_clock(struct mmc_host *host, uint clock)
{
        int div;
        unsigned short clk;
        unsigned long timeout;
        unsigned long ctrl2;

        /*
         * SELBASECLK[5:4]
         * 00/01 = HCLK
         * 10 = EPLL
         * 11 = XTI or XEXTCLK
         */
        ctrl2 = readl(&host->reg->control2);
        ctrl2 &= ~(3 << 4);
        ctrl2 |= (2 << 4);
        writel(ctrl2, &host->reg->control2);

        writew(0, &host->reg->clkcon);

        /* XXX: we assume that clock is between 40MHz and 50MHz */
        if (clock == 0)
                goto out;
        else if (clock <= 400000)
                div = 0x100;
        else if (clock <= 20000000)
                div = 4;
        else if (clock <= 26000000)
                div = 2;
        else
                div = 1;
        debug("div: %d\n", div);

        div >>= 1;
        /*
         * CLKCON
         * SELFREQ[15:8]        : base clock divied by value
         * ENSDCLK[2]           : SD Clock Enable
         * STBLINTCLK[1]        : Internal Clock Stable
         * ENINTCLK[0]          : Internal Clock Enable
         */
        clk = (div << 8) | (1 << 0);
        writew(clk, &host->reg->clkcon);

        /* Wait max 10 ms */
        timeout = 10;
        while (!(readw(&host->reg->clkcon) & (1 << 1))) {
                if (timeout == 0) {
                        printf("%s: timeout error\n", __func__);
                        return;
                }
                timeout--;
                udelay(1000);
        }

        clk |= (1 << 2);
        writew(clk, &host->reg->clkcon);

out:
        host->clock = clock;
}

static void mmc_set_ios(struct mmc *mmc)
{
        struct mmc_host *host = mmc->priv;
        unsigned char ctrl;
        unsigned long val;

        debug("bus_width: %x, clock: %d\n", mmc->bus_width, mmc->clock);

        /*
         * SELCLKPADDS[17:16]
         * 00 = 2mA
         * 01 = 4mA
         * 10 = 7mA
         * 11 = 9mA
         */
        writel(0x3 << 16, &host->reg->control4);

        val = readl(&host->reg->control2);
        val &= (0x3 << 4);

        val |=  (1 << 31) |     /* write status clear async mode enable */
                (1 << 30) |     /* command conflict mask enable */
                (1 << 14) |     /* Feedback Clock Enable for Rx Clock */
                (1 << 8);       /* SDCLK hold enable */

        writel(val, &host->reg->control2);

        /*
         * FCSEL1[15] FCSEL0[7]
         * FCSel[1:0] : Rx Feedback Clock Delay Control
         *      Inverter delay means10ns delay if SDCLK 50MHz setting
         *      01 = Delay1 (basic delay)
         *      11 = Delay2 (basic delay + 2ns)
         *      00 = Delay3 (inverter delay)
         *      10 = Delay4 (inverter delay + 2ns)
         */
        writel(0x8080, &host->reg->control3);

        mmc_change_clock(host, mmc->clock);

        ctrl = readb(&host->reg->hostctl);

        /*
         * WIDE8[5]
         * 0 = Depend on WIDE4
         * 1 = 8-bit mode
         * WIDE4[1]
         * 1 = 4-bit mode
         * 0 = 1-bit mode
         */
        if (mmc->bus_width == 8)
                ctrl |= (1 << 5);
        else if (mmc->bus_width == 4)
                ctrl |= (1 << 1);
        else
                ctrl &= ~(1 << 1);

        /*
         * OUTEDGEINV[2]
         * 1 = Riging edge output
         * 0 = Falling edge output
         */
        ctrl &= ~(1 << 2);

        writeb(ctrl, &host->reg->hostctl);
}

static void mmc_reset(struct mmc_host *host)
{
        unsigned int timeout;

        /*
         * RSTALL[0] : Software reset for all
         * 1 = reset
         * 0 = work
         */
        writeb((1 << 0), &host->reg->swrst);

        host->clock = 0;

        /* Wait max 100 ms */
        timeout = 100;

        /* hw clears the bit when it's done */
        while (readb(&host->reg->swrst) & (1 << 0)) {
                if (timeout == 0) {
                        printf("%s: timeout error\n", __func__);
                        return;
                }
                timeout--;
                udelay(1000);
        }
}

static int mmc_core_init(struct mmc *mmc)
{
        struct mmc_host *host = (struct mmc_host *)mmc->priv;
        unsigned int mask;

        mmc_reset(host);

        host->version = readw(&host->reg->hcver);

        /* mask all */
        writel(0xffffffff, &host->reg->norintstsen);
        writel(0xffffffff, &host->reg->norintsigen);

        writeb(0xe, &host->reg->timeoutcon);    /* TMCLK * 2^27 */

        /*
         * NORMAL Interrupt Status Enable Register init
         * [5] ENSTABUFRDRDY : Buffer Read Ready Status Enable
         * [4] ENSTABUFWTRDY : Buffer write Ready Status Enable
         * [1] ENSTASTANSCMPLT : Transfre Complete Status Enable
         * [0] ENSTACMDCMPLT : Command Complete Status Enable
        */
        mask = readl(&host->reg->norintstsen);
        mask &= ~(0xffff);
        mask |= (1 << 5) | (1 << 4) | (1 << 1) | (1 << 0);
        writel(mask, &host->reg->norintstsen);

        /*
         * NORMAL Interrupt Signal Enable Register init
         * [1] ENSTACMDCMPLT : Transfer Complete Signal Enable
         */
        mask = readl(&host->reg->norintsigen);
        mask &= ~(0xffff);
        mask |= (1 << 1);
        writel(mask, &host->reg->norintsigen);

        return 0;
}

static int s5p_mmc_initialize(int dev_index, int bus_width)
{
        struct mmc *mmc;

        mmc = &mmc_dev[dev_index];

        sprintf(mmc->name, "SAMSUNG SD/MMC");
        mmc->priv = &mmc_host[dev_index];
        mmc->send_cmd = mmc_send_cmd;
        mmc->set_ios = mmc_set_ios;
        mmc->init = mmc_core_init;

        mmc->voltages = MMC_VDD_32_33 | MMC_VDD_33_34 | MMC_VDD_165_195;
        if (bus_width == 8)
                mmc->host_caps = MMC_MODE_8BIT;
        else
                mmc->host_caps = MMC_MODE_4BIT;
        mmc->host_caps |= MMC_MODE_HS_52MHz | MMC_MODE_HS;

        mmc->f_min = 400000;
        mmc->f_max = 52000000;

        mmc_host[dev_index].clock = 0;
        mmc_host[dev_index].reg = s5p_get_base_mmc(dev_index);
        mmc_register(mmc);

        return 0;
}

int s5p_mmc_init(int dev_index, int bus_width)
{
        return s5p_mmc_initialize(dev_index, bus_width);
}