/*
 * Driver for Blackfin on-chip ATAPI controller.
 *
 * Enter bugs at http://blackfin.uclinux.org/
 *
 * Copyright (c) 2008 Analog Devices Inc.
 *
 * Licensed under the GPL-2 or later.
 */

#include <common.h>
#include <command.h>
#include <config.h>
#include <asm/byteorder.h>
#include <asm/io.h>
#include <asm/errno.h>
#include <asm/mach-common/bits/pata.h>
#include <ata.h>
#include <libata.h>
#include "pata_bfin.h"

static struct ata_port port[CONFIG_SYS_SATA_MAX_DEVICE];

/**
 * PIO Mode - Frequency compatibility
 */
/* mode: 0         1         2         3         4 */
static const u32 pio_fsclk[] =
{ 33333333, 33333333, 33333333, 33333333, 33333333 };

/**
 * MDMA Mode - Frequency compatibility
 */
/*               mode:      0         1         2        */
static const u32 mdma_fsclk[] = { 33333333, 33333333, 33333333 };

/**
 * UDMA Mode - Frequency compatibility
 *
 * UDMA5 - 100 MB/s   - SCLK  = 133 MHz
 * UDMA4 - 66 MB/s    - SCLK >=  80 MHz
 * UDMA3 - 44.4 MB/s  - SCLK >=  50 MHz
 * UDMA2 - 33 MB/s    - SCLK >=  40 MHz
 */
/* mode: 0         1         2         3         4          5 */
static const u32 udma_fsclk[] =
{ 33333333, 33333333, 40000000, 50000000, 80000000, 133333333 };

/**
 * Register transfer timing table
 */
/*               mode:       0    1    2    3    4    */
/* Cycle Time                     */
static const u32 reg_t0min[]   = { 600, 383, 330, 180, 120 };
/* DIOR/DIOW to end cycle         */
static const u32 reg_t2min[]   = { 290, 290, 290, 70,  25  };
/* DIOR/DIOW asserted pulse width */
static const u32 reg_teocmin[] = { 290, 290, 290, 80,  70  };

/**
 * PIO timing table
 */
/*               mode:       0    1    2    3    4    */
/* Cycle Time                     */
static const u32 pio_t0min[]   = { 600, 383, 240, 180, 120 };
/* Address valid to DIOR/DIORW    */
static const u32 pio_t1min[]   = { 70,  50,  30,  30,  25  };
/* DIOR/DIOW to end cycle         */
static const u32 pio_t2min[]   = { 165, 125, 100, 80,  70  };
/* DIOR/DIOW asserted pulse width */
static const u32 pio_teocmin[] = { 165, 125, 100, 70,  25  };
/* DIOW data hold                 */
static const u32 pio_t4min[]   = { 30,  20,  15,  10,  10  };

/* ******************************************************************
 * Multiword DMA timing table
 * ******************************************************************
 */
/*               mode:       0   1    2        */
/* Cycle Time                     */
static const u32 mdma_t0min[]  = { 480, 150, 120 };
/* DIOR/DIOW asserted pulse width */
static const u32 mdma_tdmin[]  = { 215, 80,  70  };
/* DMACK to read data released    */
static const u32 mdma_thmin[]  = { 20,  15,  10  };
/* DIOR/DIOW to DMACK hold        */
static const u32 mdma_tjmin[]  = { 20,  5,   5   };
/* DIOR negated pulse width       */
static const u32 mdma_tkrmin[] = { 50,  50,  25  };
/* DIOR negated pulse width       */
static const u32 mdma_tkwmin[] = { 215, 50,  25  };
/* CS[1:0] valid to DIOR/DIOW     */
static const u32 mdma_tmmin[]  = { 50,  30,  25  };
/* DMACK to read data released    */
static const u32 mdma_tzmax[]  = { 20,  25,  25  };

/**
 * Ultra DMA timing table
 */
/*               mode:         0    1    2    3    4    5       */
static const u32 udma_tcycmin[]  = { 112, 73,  54,  39,  25,  17 };
static const u32 udma_tdvsmin[]  = { 70,  48,  31,  20,  7,   5  };
static const u32 udma_tenvmax[]  = { 70,  70,  70,  55,  55,  50 };
static const u32 udma_trpmin[]   = { 160, 125, 100, 100, 100, 85 };
static const u32 udma_tmin[]     = { 5,   5,   5,   5,   3,   3  };


static const u32 udma_tmlimin = 20;
static const u32 udma_tzahmin = 20;
static const u32 udma_tenvmin = 20;
static const u32 udma_tackmin = 20;
static const u32 udma_tssmin = 50;

static void msleep(int count)
{
        int i;

        for (i = 0; i < count; i++)
                udelay(1000);
}

/**
 *
 *      Function:       num_clocks_min
 *
 *      Description:
 *      calculate number of SCLK cycles to meet minimum timing
 */
static unsigned short num_clocks_min(unsigned long tmin,
                                unsigned long fsclk)
{
        unsigned long tmp ;
        unsigned short result;

        tmp = tmin * (fsclk/1000/1000) / 1000;
        result = (unsigned short)tmp;
        if ((tmp*1000*1000) < (tmin*(fsclk/1000)))
                result++;

        return result;
}

/**
 *      bfin_set_piomode - Initialize host controller PATA PIO timings
 *      @ap: Port whose timings we are configuring
 *      @pio_mode: mode
 *
 *      Set PIO mode for device.
 *
 *      LOCKING:
 *      None (inherited from caller).
 */

static void bfin_set_piomode(struct ata_port *ap, int pio_mode)
{
        int mode = pio_mode - XFER_PIO_0;
        void __iomem *base = (void __iomem *)ap->ioaddr.ctl_addr;
        unsigned int fsclk = get_sclk();
        unsigned short teoc_reg, t2_reg, teoc_pio;
        unsigned short t4_reg, t2_pio, t1_reg;
        unsigned short n0, n6, t6min = 5;

        /* the most restrictive timing value is t6 and tc, the DIOW - data hold
        * If one SCLK pulse is longer than this minimum value then register
        * transfers cannot be supported at this frequency.
        */
        n6 = num_clocks_min(t6min, fsclk);
        if (mode >= 0 && mode <= 4 && n6 >= 1) {
                debug("set piomode: mode=%d, fsclk=%ud\n", mode, fsclk);
                /* calculate the timing values for register transfers. */
                while (mode > 0 && pio_fsclk[mode] > fsclk)
                        mode--;

                /* DIOR/DIOW to end cycle time */
                t2_reg = num_clocks_min(reg_t2min[mode], fsclk);
                /* DIOR/DIOW asserted pulse width */
                teoc_reg = num_clocks_min(reg_teocmin[mode], fsclk);
                /* Cycle Time */
                n0  = num_clocks_min(reg_t0min[mode], fsclk);

                /* increase t2 until we meed the minimum cycle length */
                if (t2_reg + teoc_reg < n0)
                        t2_reg = n0 - teoc_reg;

                /* calculate the timing values for pio transfers. */

                /* DIOR/DIOW to end cycle time */
                t2_pio = num_clocks_min(pio_t2min[mode], fsclk);
                /* DIOR/DIOW asserted pulse width */
                teoc_pio = num_clocks_min(pio_teocmin[mode], fsclk);
                /* Cycle Time */
                n0  = num_clocks_min(pio_t0min[mode], fsclk);

                /* increase t2 until we meed the minimum cycle length */
                if (t2_pio + teoc_pio < n0)
                        t2_pio = n0 - teoc_pio;

                /* Address valid to DIOR/DIORW */
                t1_reg = num_clocks_min(pio_t1min[mode], fsclk);

                /* DIOW data hold */
                t4_reg = num_clocks_min(pio_t4min[mode], fsclk);

                ATAPI_SET_REG_TIM_0(base, (teoc_reg<<8 | t2_reg));
                ATAPI_SET_PIO_TIM_0(base, (t4_reg<<12 | t2_pio<<4 | t1_reg));
                ATAPI_SET_PIO_TIM_1(base, teoc_pio);
                if (mode > 2) {
                        ATAPI_SET_CONTROL(base,
                                ATAPI_GET_CONTROL(base) | IORDY_EN);
                } else {
                        ATAPI_SET_CONTROL(base,
                                ATAPI_GET_CONTROL(base) & ~IORDY_EN);
                }

                /* Disable host ATAPI PIO interrupts */
                ATAPI_SET_INT_MASK(base, ATAPI_GET_INT_MASK(base)
                        & ~(PIO_DONE_MASK | HOST_TERM_XFER_MASK));
                SSYNC();
        }
}

/**
 *
 *    Function:       wait_complete
 *
 *    Description:    Waits the interrupt from device
 *
 */
static inline void wait_complete(void __iomem *base, unsigned short mask)
{
        unsigned short status;
        unsigned int i = 0;

        for (i = 0; i < PATA_BFIN_WAIT_TIMEOUT; i++) {
                status = ATAPI_GET_INT_STATUS(base) & mask;
                if (status)
                        break;
        }

        ATAPI_SET_INT_STATUS(base, mask);
}

/**
 *
 *    Function:       write_atapi_register
 *
 *    Description:    Writes to ATA Device Resgister
 *
 */

static void write_atapi_register(void __iomem *base,
                unsigned long ata_reg, unsigned short value)
{
        /* Program the ATA_DEV_TXBUF register with write data (to be
         * written into the device).
         */
        ATAPI_SET_DEV_TXBUF(base, value);

        /* Program the ATA_DEV_ADDR register with address of the
         * device register (0x01 to 0x0F).
         */
        ATAPI_SET_DEV_ADDR(base, ata_reg);

        /* Program the ATA_CTRL register with dir set to write (1)
         */
        ATAPI_SET_CONTROL(base, (ATAPI_GET_CONTROL(base) | XFER_DIR));

        /* ensure PIO DMA is not set */
        ATAPI_SET_CONTROL(base, (ATAPI_GET_CONTROL(base) & ~PIO_USE_DMA));

        /* and start the transfer */
        ATAPI_SET_CONTROL(base, (ATAPI_GET_CONTROL(base) | PIO_START));

        /* Wait for the interrupt to indicate the end of the transfer.
         * (We need to wait on and clear rhe ATA_DEV_INT interrupt status)
         */
        wait_complete(base, PIO_DONE_INT);
}

/**
 *
 *      Function:       read_atapi_register
 *
 *Description:    Reads from ATA Device Resgister
 *
 */

static unsigned short read_atapi_register(void __iomem *base,
                unsigned long ata_reg)
{
        /* Program the ATA_DEV_ADDR register with address of the
         * device register (0x01 to 0x0F).
         */
        ATAPI_SET_DEV_ADDR(base, ata_reg);

        /* Program the ATA_CTRL register with dir set to read (0) and
         */
        ATAPI_SET_CONTROL(base, (ATAPI_GET_CONTROL(base) & ~XFER_DIR));

        /* ensure PIO DMA is not set */
        ATAPI_SET_CONTROL(base, (ATAPI_GET_CONTROL(base) & ~PIO_USE_DMA));

        /* and start the transfer */
        ATAPI_SET_CONTROL(base, (ATAPI_GET_CONTROL(base) | PIO_START));

        /* Wait for the interrupt to indicate the end of the transfer.
         * (PIO_DONE interrupt is set and it doesn't seem to matter
         * that we don't clear it)
         */
        wait_complete(base, PIO_DONE_INT);

        /* Read the ATA_DEV_RXBUF register with write data (to be
         * written into the device).
         */
        return ATAPI_GET_DEV_RXBUF(base);
}

/**
 *
 *    Function:       write_atapi_register_data
 *
 *    Description:    Writes to ATA Device Resgister
 *
 */

static void write_atapi_data(void __iomem *base,
                int len, unsigned short *buf)
{
        int i;

        /* Set transfer length to 1 */
        ATAPI_SET_XFER_LEN(base, 1);

        /* Program the ATA_DEV_ADDR register with address of the
         * ATA_REG_DATA
         */
        ATAPI_SET_DEV_ADDR(base, ATA_REG_DATA);

        /* Program the ATA_CTRL register with dir set to write (1)
         */
        ATAPI_SET_CONTROL(base, (ATAPI_GET_CONTROL(base) | XFER_DIR));

        /* ensure PIO DMA is not set */
        ATAPI_SET_CONTROL(base, (ATAPI_GET_CONTROL(base) & ~PIO_USE_DMA));

        for (i = 0; i < len; i++) {
                /* Program the ATA_DEV_TXBUF register with write data (to be
                 * written into the device).
                 */
                ATAPI_SET_DEV_TXBUF(base, buf[i]);

                /* and start the transfer */
                ATAPI_SET_CONTROL(base, (ATAPI_GET_CONTROL(base) | PIO_START));

                /* Wait for the interrupt to indicate the end of the transfer.
                 * (We need to wait on and clear rhe ATA_DEV_INT
                 * interrupt status)
                 */
                wait_complete(base, PIO_DONE_INT);
        }
}

/**
 *
 *      Function:       read_atapi_register_data
 *
 *      Description:    Reads from ATA Device Resgister
 *
 */

static void read_atapi_data(void __iomem *base,
                int len, unsigned short *buf)
{
        int i;

        /* Set transfer length to 1 */
        ATAPI_SET_XFER_LEN(base, 1);

        /* Program the ATA_DEV_ADDR register with address of the
         * ATA_REG_DATA
         */
        ATAPI_SET_DEV_ADDR(base, ATA_REG_DATA);

        /* Program the ATA_CTRL register with dir set to read (0) and
         */
        ATAPI_SET_CONTROL(base, (ATAPI_GET_CONTROL(base) & ~XFER_DIR));

        /* ensure PIO DMA is not set */
        ATAPI_SET_CONTROL(base, (ATAPI_GET_CONTROL(base) & ~PIO_USE_DMA));

        for (i = 0; i < len; i++) {
                /* and start the transfer */
                ATAPI_SET_CONTROL(base, (ATAPI_GET_CONTROL(base) | PIO_START));

                /* Wait for the interrupt to indicate the end of the transfer.
                 * (PIO_DONE interrupt is set and it doesn't seem to matter
                 * that we don't clear it)
                 */
                wait_complete(base, PIO_DONE_INT);

                /* Read the ATA_DEV_RXBUF register with write data (to be
                 * written into the device).
                 */
                buf[i] = ATAPI_GET_DEV_RXBUF(base);
        }
}

/**
 *      bfin_check_status - Read device status reg & clear interrupt
 *      @ap: port where the device is
 *
 *      Note: Original code is ata_check_status().
 */

static u8 bfin_check_status(struct ata_port *ap)
{
        void __iomem *base = (void __iomem *)ap->ioaddr.ctl_addr;
        return read_atapi_register(base, ATA_REG_STATUS);
}

/**
 *      bfin_check_altstatus - Read device alternate status reg
 *      @ap: port where the device is
 */

static u8 bfin_check_altstatus(struct ata_port *ap)
{
        void __iomem *base = (void __iomem *)ap->ioaddr.ctl_addr;
        return read_atapi_register(base, ATA_REG_ALTSTATUS);
}

/**
 *      bfin_ata_busy_wait - Wait for a port status register
 *      @ap: Port to wait for.
 *      @bits: bits that must be clear
 *      @max: number of 10uS waits to perform
 *
 *      Waits up to max*10 microseconds for the selected bits in the port's
 *      status register to be cleared.
 *      Returns final value of status register.
 *
 *      LOCKING:
 *      Inherited from caller.
 */
static inline u8 bfin_ata_busy_wait(struct ata_port *ap, unsigned int bits,
                                unsigned int max, u8 usealtstatus)
{
        u8 status;

        do {
                udelay(10);
                if (usealtstatus)
                        status = bfin_check_altstatus(ap);
                else
                        status = bfin_check_status(ap);
                max--;
        } while (status != 0xff && (status & bits) && (max > 0));

        return status;
}

/**
 *      bfin_ata_busy_sleep - sleep until BSY clears, or timeout
 *      @ap: port containing status register to be polled
 *      @tmout_pat: impatience timeout in msecs
 *      @tmout: overall timeout in msecs
 *
 *      Sleep until ATA Status register bit BSY clears,
 *      or a timeout occurs.
 *
 *      RETURNS:
 *      0 on success, -errno otherwise.
 */
static int bfin_ata_busy_sleep(struct ata_port *ap,
                       long tmout_pat, unsigned long tmout)
{
        u8 status;

        status = bfin_ata_busy_wait(ap, ATA_BUSY, 300, 0);
        while (status != 0xff && (status & ATA_BUSY) && tmout_pat > 0) {
                msleep(50);
                tmout_pat -= 50;
                status = bfin_ata_busy_wait(ap, ATA_BUSY, 3, 0);
        }

        if (status != 0xff && (status & ATA_BUSY))
                printf("port is slow to respond, please be patient "
                                "(Status 0x%x)\n", status);

        while (status != 0xff && (status & ATA_BUSY) && tmout_pat > 0) {
                msleep(50);
                tmout_pat -= 50;
                status = bfin_check_status(ap);
        }

        if (status == 0xff)
                return -ENODEV;

        if (status & ATA_BUSY) {
                printf("port failed to respond "
                                "(%lu secs, Status 0x%x)\n",
                                DIV_ROUND_UP(tmout, 1000), status);
                return -EBUSY;
        }

        return 0;
}

/**
 *      bfin_dev_select - Select device 0/1 on ATA bus
 *      @ap: ATA channel to manipulate
 *      @device: ATA device (numbered from zero) to select
 *
 *      Note: Original code is ata_sff_dev_select().
 */

static void bfin_dev_select(struct ata_port *ap, unsigned int device)
{
        void __iomem *base = (void __iomem *)ap->ioaddr.ctl_addr;
        u8 tmp;


        if (device == 0)
                tmp = ATA_DEVICE_OBS;
        else
                tmp = ATA_DEVICE_OBS | ATA_DEV1;

        write_atapi_register(base, ATA_REG_DEVICE, tmp);
        udelay(1);
}

/**
 *      bfin_devchk - PATA device presence detection
 *      @ap: ATA channel to examine
 *      @device: Device to examine (starting at zero)
 *
 *      Note: Original code is ata_devchk().
 */

static unsigned int bfin_devchk(struct ata_port *ap,
                                unsigned int device)
{
        void __iomem *base = (void __iomem *)ap->ioaddr.ctl_addr;
        u8 nsect, lbal;

        bfin_dev_select(ap, device);

        write_atapi_register(base, ATA_REG_NSECT, 0x55);
        write_atapi_register(base, ATA_REG_LBAL, 0xaa);

        write_atapi_register(base, ATA_REG_NSECT, 0xaa);
        write_atapi_register(base, ATA_REG_LBAL, 0x55);

        write_atapi_register(base, ATA_REG_NSECT, 0x55);
        write_atapi_register(base, ATA_REG_LBAL, 0xaa);

        nsect = read_atapi_register(base, ATA_REG_NSECT);
        lbal = read_atapi_register(base, ATA_REG_LBAL);

        if ((nsect == 0x55) && (lbal == 0xaa))
                return 1;       /* we found a device */

        return 0;               /* nothing found */
}

/**
 *      bfin_bus_post_reset - PATA device post reset
 *
 *      Note: Original code is ata_bus_post_reset().
 */

static void bfin_bus_post_reset(struct ata_port *ap, unsigned int devmask)
{
        void __iomem *base = (void __iomem *)ap->ioaddr.ctl_addr;
        unsigned int dev0 = devmask & (1 << 0);
        unsigned int dev1 = devmask & (1 << 1);
        long deadline;

        /* if device 0 was found in ata_devchk, wait for its
         * BSY bit to clear
         */
        if (dev0)
                bfin_ata_busy_sleep(ap, ATA_TMOUT_BOOT_QUICK, ATA_TMOUT_BOOT);

        /* if device 1 was found in ata_devchk, wait for
         * register access, then wait for BSY to clear
         */
        deadline = ATA_TMOUT_BOOT;
        while (dev1) {
                u8 nsect, lbal;

                bfin_dev_select(ap, 1);
                nsect = read_atapi_register(base, ATA_REG_NSECT);
                lbal = read_atapi_register(base, ATA_REG_LBAL);
                if ((nsect == 1) && (lbal == 1))
                        break;
                if (deadline <= 0) {
                        dev1 = 0;
                        break;
                }
                msleep(50);     /* give drive a breather */
                deadline -= 50;
        }
        if (dev1)
                bfin_ata_busy_sleep(ap, ATA_TMOUT_BOOT_QUICK, ATA_TMOUT_BOOT);

        /* is all this really necessary? */
        bfin_dev_select(ap, 0);
        if (dev1)
                bfin_dev_select(ap, 1);
        if (dev0)
                bfin_dev_select(ap, 0);
}

/**
 *      bfin_bus_softreset - PATA device software reset
 *
 *      Note: Original code is ata_bus_softreset().
 */

static unsigned int bfin_bus_softreset(struct ata_port *ap,
                                       unsigned int devmask)
{
        void __iomem *base = (void __iomem *)ap->ioaddr.ctl_addr;

        /* software reset.  causes dev0 to be selected */
        write_atapi_register(base, ATA_REG_CTRL, ap->ctl_reg);
        udelay(20);
        write_atapi_register(base, ATA_REG_CTRL, ap->ctl_reg | ATA_SRST);
        udelay(20);
        write_atapi_register(base, ATA_REG_CTRL, ap->ctl_reg);

        /* spec mandates ">= 2ms" before checking status.
         * We wait 150ms, because that was the magic delay used for
         * ATAPI devices in Hale Landis's ATADRVR, for the period of time
         * between when the ATA command register is written, and then
         * status is checked.  Because waiting for "a while" before
         * checking status is fine, post SRST, we perform this magic
         * delay here as well.
         *
         * Old drivers/ide uses the 2mS rule and then waits for ready
         */
        msleep(150);

        /* Before we perform post reset processing we want to see if
         * the bus shows 0xFF because the odd clown forgets the D7
         * pulldown resistor.
         */
        if (bfin_check_status(ap) == 0xFF)
                return 0;

        bfin_bus_post_reset(ap, devmask);

        return 0;
}

/**
 *      bfin_softreset - reset host port via ATA SRST
 *      @ap: port to reset
 *
 *      Note: Original code is ata_sff_softreset().
 */

static int bfin_softreset(struct ata_port *ap)
{
        unsigned int err_mask;

        ap->dev_mask = 0;

        /* determine if device 0/1 are present.
         * only one device is supported on one port by now.
        */
        if (bfin_devchk(ap, 0))
                ap->dev_mask |= (1 << 0);
        else if (bfin_devchk(ap, 1))
                ap->dev_mask |= (1 << 1);
        else
                return -ENODEV;

        /* select device 0 again */
        bfin_dev_select(ap, 0);

        /* issue bus reset */
        err_mask = bfin_bus_softreset(ap, ap->dev_mask);
        if (err_mask) {
                printf("SRST failed (err_mask=0x%x)\n",
                                err_mask);
                ap->dev_mask = 0;
                return -EIO;
        }

        return 0;
}

/**
 *      bfin_irq_clear - Clear ATAPI interrupt.
 *      @ap: Port associated with this ATA transaction.
 *
 *      Note: Original code is ata_sff_irq_clear().
 */

static void bfin_irq_clear(struct ata_port *ap)
{
        void __iomem *base = (void __iomem *)ap->ioaddr.ctl_addr;

        ATAPI_SET_INT_STATUS(base, ATAPI_GET_INT_STATUS(base)|ATAPI_DEV_INT
                | MULTI_DONE_INT | UDMAIN_DONE_INT | UDMAOUT_DONE_INT
                | MULTI_TERM_INT | UDMAIN_TERM_INT | UDMAOUT_TERM_INT);
}

static u8 bfin_wait_for_irq(struct ata_port *ap, unsigned int max)
{
        void __iomem *base = (void __iomem *)ap->ioaddr.ctl_addr;

        do {
                if (ATAPI_GET_INT_STATUS(base) & (ATAPI_DEV_INT
                | MULTI_DONE_INT | UDMAIN_DONE_INT | UDMAOUT_DONE_INT
                | MULTI_TERM_INT | UDMAIN_TERM_INT | UDMAOUT_TERM_INT)) {
                        break;
                }
                udelay(1000);
                max--;
        } while ((max > 0));

        return max == 0;
}

/**
 *      bfin_ata_reset_port - initialize BFIN ATAPI port.
 */

static int bfin_ata_reset_port(struct ata_port *ap)
{
        void __iomem *base = (void __iomem *)ap->ioaddr.ctl_addr;
        int count;
        unsigned short status;

        /* Disable all ATAPI interrupts */
        ATAPI_SET_INT_MASK(base, 0);
        SSYNC();

        /* Assert the RESET signal 25us*/
        ATAPI_SET_CONTROL(base, ATAPI_GET_CONTROL(base) | DEV_RST);
        udelay(30);

        /* Negate the RESET signal for 2ms*/
        ATAPI_SET_CONTROL(base, ATAPI_GET_CONTROL(base) & ~DEV_RST);
        msleep(2);

        /* Wait on Busy flag to clear */
        count = 10000000;
        do {
                status = read_atapi_register(base, ATA_REG_STATUS);
        } while (--count && (status & ATA_BUSY));

        /* Enable only ATAPI Device interrupt */
        ATAPI_SET_INT_MASK(base, 1);
        SSYNC();

        return !count;
}

/**
 *
 *      Function:       bfin_config_atapi_gpio
 *
 *      Description:    Configures the ATAPI pins for use
 *
 */
static int bfin_config_atapi_gpio(struct ata_port *ap)
{
        bfin_write_PORTH_FER(bfin_read_PORTH_FER() | 0x4);
        bfin_write_PORTH_MUX(bfin_read_PORTH_MUX() & ~0x30);
        bfin_write_PORTH_DIR_SET(0x4);

        bfin_write_PORTJ_FER(0x7f8);
        bfin_write_PORTJ_MUX(bfin_read_PORTI_MUX() & ~0x3fffc0);
        bfin_write_PORTJ_DIR_SET(0x5f8);
        bfin_write_PORTJ_DIR_CLEAR(0x200);
        bfin_write_PORTJ_INEN(0x200);

        bfin_write_PINT2_ASSIGN(0x0707);
        bfin_write_PINT2_MASK_SET(0x200);
        SSYNC();

        return 0;
}

/**
 *      bfin_atapi_probe        -       attach a bfin atapi interface
 *      @pdev: platform device
 *
 *      Register a bfin atapi interface.
 *
 *
 *      Platform devices are expected to contain 2 resources per port:
 *
 *              - I/O Base (IORESOURCE_IO)
 *              - IRQ      (IORESOURCE_IRQ)
 *
 */
static int bfin_ata_probe_port(struct ata_port *ap)
{
        if (bfin_config_atapi_gpio(ap)) {
                printf("Requesting Peripherals faild\n");
                return -EFAULT;
        }

        if (bfin_ata_reset_port(ap)) {
                printf("Fail to reset ATAPI device\n");
                return -EFAULT;
        }

        if (ap->ata_mode >= XFER_PIO_0 && ap->ata_mode <= XFER_PIO_4)
                bfin_set_piomode(ap, ap->ata_mode);
        else {
                printf("Given ATA data transfer mode is not supported.\n");
                return -EFAULT;
        }

        return 0;
}

#define ATA_SECTOR_WORDS (ATA_SECT_SIZE/2)

static void bfin_ata_identify(struct ata_port *ap, int dev)
{
        void __iomem *base = (void __iomem *)ap->ioaddr.ctl_addr;
        u8 status = 0;
        static u16 iobuf[ATA_SECTOR_WORDS];
        u64 n_sectors = 0;
        hd_driveid_t *iop = (hd_driveid_t *)iobuf;

        memset(iobuf, 0, sizeof(iobuf));

        if (!(ap->dev_mask & (1 << dev)))
                return;

        debug("port=%d dev=%d\n", ap->port_no, dev);

        bfin_dev_select(ap, dev);

        status = 0;
        /* Device Identify Command */
        write_atapi_register(base, ATA_REG_CMD, ATA_CMD_ID_ATA);
        bfin_check_altstatus(ap);
        udelay(10);

        status = bfin_ata_busy_wait(ap, ATA_BUSY, 1000, 0);
        if (status & ATA_ERR) {
                printf("\ndevice not responding\n");
                ap->dev_mask &= ~(1 << dev);
                return;
        }

        read_atapi_data(base, ATA_SECTOR_WORDS, iobuf);

        ata_swap_buf_le16(iobuf, ATA_SECTOR_WORDS);

        /* we require LBA and DMA support (bits 8 & 9 of word 49) */
        if (!ata_id_has_dma(iobuf) || !ata_id_has_lba(iobuf))
                printf("ata%u: no dma/lba\n", ap->port_no);

#ifdef DEBUG
        ata_dump_id(iobuf);
#endif

        n_sectors = ata_id_n_sectors(iobuf);

        if (n_sectors == 0) {
                ap->dev_mask &= ~(1 << dev);
                return;
        }

        ata_id_c_string(iobuf, (unsigned char *)sata_dev_desc[ap->port_no].revision,
                         ATA_ID_FW_REV, sizeof(sata_dev_desc[ap->port_no].revision));
        ata_id_c_string(iobuf, (unsigned char *)sata_dev_desc[ap->port_no].vendor,
                         ATA_ID_PROD, sizeof(sata_dev_desc[ap->port_no].vendor));
        ata_id_c_string(iobuf, (unsigned char *)sata_dev_desc[ap->port_no].product,
                         ATA_ID_SERNO, sizeof(sata_dev_desc[ap->port_no].product));

        if ((iop->config & 0x0080) == 0x0080)
                sata_dev_desc[ap->port_no].removable = 1;
        else
                sata_dev_desc[ap->port_no].removable = 0;

        sata_dev_desc[ap->port_no].lba = (u32) n_sectors;
        debug("lba=0x%x\n", sata_dev_desc[ap->port_no].lba);

#ifdef CONFIG_LBA48
        if (iop->command_set_2 & 0x0400)
                sata_dev_desc[ap->port_no].lba48 = 1;
        else
                sata_dev_desc[ap->port_no].lba48 = 0;
#endif

        /* assuming HD */
        sata_dev_desc[ap->port_no].type = DEV_TYPE_HARDDISK;
        sata_dev_desc[ap->port_no].blksz = ATA_SECT_SIZE;
        sata_dev_desc[ap->port_no].lun = 0;     /* just to fill something in... */

        printf("PATA device#%d %s is found on ata port#%d.\n",
                ap->port_no%PATA_DEV_NUM_PER_PORT,
                sata_dev_desc[ap->port_no].vendor,
                ap->port_no/PATA_DEV_NUM_PER_PORT);
}

static void bfin_ata_set_Feature_cmd(struct ata_port *ap, int dev)
{
        void __iomem *base = (void __iomem *)ap->ioaddr.ctl_addr;
        u8 status = 0;

        if (!(ap->dev_mask & (1 << dev)))
                return;

        bfin_dev_select(ap, dev);

        write_atapi_register(base, ATA_REG_FEATURE, SETFEATURES_XFER);
        write_atapi_register(base, ATA_REG_NSECT, ap->ata_mode);
        write_atapi_register(base, ATA_REG_LBAL, 0);
        write_atapi_register(base, ATA_REG_LBAM, 0);
        write_atapi_register(base, ATA_REG_LBAH, 0);

        write_atapi_register(base, ATA_REG_DEVICE, ATA_DEVICE_OBS);
        write_atapi_register(base, ATA_REG_CMD, ATA_CMD_SET_FEATURES);

        udelay(50);
        msleep(150);

        status = bfin_ata_busy_wait(ap, ATA_BUSY, 5000, 0);
        if ((status & (ATA_BUSY | ATA_ERR))) {
                printf("Error  : status 0x%02x\n", status);
                ap->dev_mask &= ~(1 << dev);
        }
}

int scan_sata(int dev)
{
        /* dev is the index of each ata device in the system. one PATA port
         * contains 2 devices. one element in scan_done array indicates one
         * PATA port. device connected to one PATA port is selected by
         * bfin_dev_select() before access.
         */
        struct ata_port *ap = &port[dev];
        static int scan_done[(CONFIG_SYS_SATA_MAX_DEVICE+1)/PATA_DEV_NUM_PER_PORT];

        if (scan_done[dev/PATA_DEV_NUM_PER_PORT])
                return 0;

        /* Check for attached device */
        if (!bfin_ata_probe_port(ap)) {
                if (bfin_softreset(ap)) {
                        /* soft reset failed, try a hard one */
                        bfin_ata_reset_port(ap);
                        if (bfin_softreset(ap))
                                scan_done[dev/PATA_DEV_NUM_PER_PORT] = 1;
                } else {
                        scan_done[dev/PATA_DEV_NUM_PER_PORT] = 1;
                }
        }
        if (scan_done[dev/PATA_DEV_NUM_PER_PORT]) {
                /* Probe device and set xfer mode */
                bfin_ata_identify(ap, dev%PATA_DEV_NUM_PER_PORT);
                bfin_ata_set_Feature_cmd(ap, dev%PATA_DEV_NUM_PER_PORT);
                init_part(&sata_dev_desc[dev]);
                return 0;
        }

        printf("PATA device#%d is not present on ATA port#%d.\n",
                ap->port_no%PATA_DEV_NUM_PER_PORT,
                ap->port_no/PATA_DEV_NUM_PER_PORT);

        return -1;
}

int init_sata(int dev)
{
        struct ata_port *ap = &port[dev];
        static u8 init_done;
        int res = 1;

        if (init_done)
                return res;

        init_done = 1;

        switch (dev/PATA_DEV_NUM_PER_PORT) {
        case 0:
                ap->ioaddr.ctl_addr = ATAPI_CONTROL;
                ap->ata_mode = CONFIG_BFIN_ATA_MODE;
                break;
        default:
                printf("Tried to scan unknown port %d.\n", dev);
                return res;
        }

        if (ap->ata_mode < XFER_PIO_0 || ap->ata_mode > XFER_PIO_4) {
                ap->ata_mode = XFER_PIO_4;
                printf("DMA mode is not supported. Set to PIO mode 4.\n");
        }

        ap->port_no = dev;
        ap->ctl_reg = 0x8;      /*Default value of control reg */

        res = 0;
        return res;
}

/* Read up to 255 sectors
 *
 * Returns sectors read
*/
static u8 do_one_read(struct ata_port *ap, u64 blknr, u8 blkcnt, u16 *buffer,
                        uchar lba48)
{
        void __iomem *base = (void __iomem *)ap->ioaddr.ctl_addr;
        u8 sr = 0;
        u8 status;
        u16 err = 0;

        if (!(bfin_check_status(ap) & ATA_DRDY)) {
                printf("Device ata%d not ready\n", ap->port_no);
                return 0;
        }

        /* Set up transfer */
#ifdef CONFIG_LBA48
        if (lba48) {
                /* write high bits */
                write_atapi_register(base, ATA_REG_NSECT, 0);
                write_atapi_register(base, ATA_REG_LBAL, (blknr >> 24) & 0xFF);
                write_atapi_register(base, ATA_REG_LBAM, (blknr >> 32) & 0xFF);
                write_atapi_register(base, ATA_REG_LBAH, (blknr >> 40) & 0xFF);
        }
#endif
        write_atapi_register(base, ATA_REG_NSECT, blkcnt);
        write_atapi_register(base, ATA_REG_LBAL, (blknr >> 0) & 0xFF);
        write_atapi_register(base, ATA_REG_LBAM, (blknr >> 8) & 0xFF);
        write_atapi_register(base, ATA_REG_LBAH, (blknr >> 16) & 0xFF);

#ifdef CONFIG_LBA48
        if (lba48) {
                write_atapi_register(base, ATA_REG_DEVICE, ATA_LBA);
                write_atapi_register(base, ATA_REG_CMD, ATA_CMD_PIO_READ_EXT);
        } else
#endif
        {
                write_atapi_register(base, ATA_REG_DEVICE, ATA_LBA | ((blknr >> 24) & 0xF));
                write_atapi_register(base, ATA_REG_CMD, ATA_CMD_PIO_READ);
        }
        status = bfin_ata_busy_wait(ap, ATA_BUSY, 500000, 1);

        if (status & (ATA_BUSY | ATA_ERR)) {
                printf("Device %d not responding status 0x%x.\n", ap->port_no, status);
                err = read_atapi_register(base, ATA_REG_ERR);
                printf("Error reg = 0x%x\n", err);
                return sr;
        }

        while (blkcnt--) {
                if (bfin_wait_for_irq(ap, 500)) {
                        printf("ata%u irq failed\n", ap->port_no);
                        return sr;
                }

                status = bfin_check_status(ap);
                if (status & ATA_ERR) {
                        err = read_atapi_register(base, ATA_REG_ERR);
                        printf("ata%u error %d\n", ap->port_no, err);
                        return sr;
                }
                bfin_irq_clear(ap);

                /* Read one sector */
                read_atapi_data(base, ATA_SECTOR_WORDS, buffer);
                buffer += ATA_SECTOR_WORDS;
                sr++;
        }

        return sr;
}

ulong sata_read(int dev, ulong block, ulong blkcnt, void *buff)
{
        struct ata_port *ap = &port[dev];
        ulong n = 0, sread;
        u16 *buffer = (u16 *) buff;
        u8 status = 0;
        u64 blknr = (u64) block;
        unsigned char lba48 = 0;

#ifdef CONFIG_LBA48
        if (blknr > 0xfffffff) {
                if (!sata_dev_desc[dev].lba48) {
                        printf("Drive doesn't support 48-bit addressing\n");
                        return 0;
                }
                /* more than 28 bits used, use 48bit mode */
                lba48 = 1;
        }
#endif
        bfin_dev_select(ap, dev%PATA_DEV_NUM_PER_PORT);

        while (blkcnt > 0) {

                if (blkcnt > 255)
                        sread = 255;
                else
                        sread = blkcnt;

                status = do_one_read(ap, blknr, sread, buffer, lba48);
                if (status != sread) {
                        printf("Read failed\n");
                        return n;
                }

                blkcnt -= sread;
                blknr += sread;
                n += sread;
                buffer += sread * ATA_SECTOR_WORDS;
        }
        return n;
}

ulong sata_write(int dev, ulong block, ulong blkcnt, const void *buff)
{
        struct ata_port *ap = &port[dev];
        void __iomem *base = (void __iomem *)ap->ioaddr.ctl_addr;
        ulong n = 0;
        u16 *buffer = (u16 *) buff;
        unsigned char status = 0;
        u64 blknr = (u64) block;
#ifdef CONFIG_LBA48
        unsigned char lba48 = 0;

        if (blknr > 0xfffffff) {
                if (!sata_dev_desc[dev].lba48) {
                        printf("Drive doesn't support 48-bit addressing\n");
                        return 0;
                }
                /* more than 28 bits used, use 48bit mode */
                lba48 = 1;
        }
#endif

        bfin_dev_select(ap, dev%PATA_DEV_NUM_PER_PORT);

        while (blkcnt-- > 0) {
                status = bfin_ata_busy_wait(ap, ATA_BUSY, 50000, 0);
                if (status & ATA_BUSY) {
                        printf("ata%u failed to respond\n", ap->port_no);
                        return n;
                }
#ifdef CONFIG_LBA48
                if (lba48) {
                        /* write high bits */
                        write_atapi_register(base, ATA_REG_NSECT, 0);
                        write_atapi_register(base, ATA_REG_LBAL,
                                (blknr >> 24) & 0xFF);
                        write_atapi_register(base, ATA_REG_LBAM,
                                (blknr >> 32) & 0xFF);
                        write_atapi_register(base, ATA_REG_LBAH,
                                (blknr >> 40) & 0xFF);
                }
#endif
                write_atapi_register(base, ATA_REG_NSECT, 1);
                write_atapi_register(base, ATA_REG_LBAL, (blknr >> 0) & 0xFF);
                write_atapi_register(base, ATA_REG_LBAM, (blknr >> 8) & 0xFF);
                write_atapi_register(base, ATA_REG_LBAH, (blknr >> 16) & 0xFF);
#ifdef CONFIG_LBA48
                if (lba48) {
                        write_atapi_register(base, ATA_REG_DEVICE, ATA_LBA);
                        write_atapi_register(base, ATA_REG_CMD,
                                ATA_CMD_PIO_WRITE_EXT);
                } else
#endif
                {
                        write_atapi_register(base, ATA_REG_DEVICE,
                                ATA_LBA | ((blknr >> 24) & 0xF));
                        write_atapi_register(base, ATA_REG_CMD,
                                ATA_CMD_PIO_WRITE);
                }

                /*may take up to 5 sec */
                status = bfin_ata_busy_wait(ap, ATA_BUSY, 50000, 0);
                if ((status & (ATA_DRQ | ATA_BUSY | ATA_ERR)) != ATA_DRQ) {
                        printf("Error no DRQ dev %d blk %ld: sts 0x%02x\n",
                                ap->port_no, (ulong) blknr, status);
                        return n;
                }

                write_atapi_data(base, ATA_SECTOR_WORDS, buffer);
                bfin_check_altstatus(ap);
                udelay(1);

                ++n;
                ++blknr;
                buffer += ATA_SECTOR_WORDS;
        }
        return n;
}