mac80211: fix race in TX aggregation

[linux-2.6/mini2440.git] / drivers / ata / pata_bf54x.c

/*
 * File:         drivers/ata/pata_bf54x.c
 * Author:       Sonic Zhang <sonic.zhang@analog.com>
 *
 * Created:
 * Description:  PATA Driver for blackfin 54x
 *
 * Modified:
 *               Copyright 2007 Analog Devices Inc.
 *
 * Bugs:         Enter bugs at http://blackfin.uclinux.org/
 *
 * 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, see the file COPYING, or write
 * to the Free Software Foundation, Inc.,
 * 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/pci.h>
#include <linux/init.h>
#include <linux/blkdev.h>
#include <linux/delay.h>
#include <linux/device.h>
#include <scsi/scsi_host.h>
#include <linux/libata.h>
#include <linux/platform_device.h>
#include <asm/dma.h>
#include <asm/gpio.h>
#include <asm/portmux.h>

#define DRV_NAME                "pata-bf54x"
#define DRV_VERSION             "0.9"

#define ATA_REG_CTRL            0x0E
#define ATA_REG_ALTSTATUS       ATA_REG_CTRL

/* These are the offset of the controller's registers */
#define ATAPI_OFFSET_CONTROL            0x00
#define ATAPI_OFFSET_STATUS             0x04
#define ATAPI_OFFSET_DEV_ADDR           0x08
#define ATAPI_OFFSET_DEV_TXBUF          0x0c
#define ATAPI_OFFSET_DEV_RXBUF          0x10
#define ATAPI_OFFSET_INT_MASK           0x14
#define ATAPI_OFFSET_INT_STATUS         0x18
#define ATAPI_OFFSET_XFER_LEN           0x1c
#define ATAPI_OFFSET_LINE_STATUS        0x20
#define ATAPI_OFFSET_SM_STATE           0x24
#define ATAPI_OFFSET_TERMINATE          0x28
#define ATAPI_OFFSET_PIO_TFRCNT         0x2c
#define ATAPI_OFFSET_DMA_TFRCNT         0x30
#define ATAPI_OFFSET_UMAIN_TFRCNT       0x34
#define ATAPI_OFFSET_UDMAOUT_TFRCNT     0x38
#define ATAPI_OFFSET_REG_TIM_0          0x40
#define ATAPI_OFFSET_PIO_TIM_0          0x44
#define ATAPI_OFFSET_PIO_TIM_1          0x48
#define ATAPI_OFFSET_MULTI_TIM_0        0x50
#define ATAPI_OFFSET_MULTI_TIM_1        0x54
#define ATAPI_OFFSET_MULTI_TIM_2        0x58
#define ATAPI_OFFSET_ULTRA_TIM_0        0x60
#define ATAPI_OFFSET_ULTRA_TIM_1        0x64
#define ATAPI_OFFSET_ULTRA_TIM_2        0x68
#define ATAPI_OFFSET_ULTRA_TIM_3        0x6c


#define ATAPI_GET_CONTROL(base)\
        bfin_read16(base + ATAPI_OFFSET_CONTROL)
#define ATAPI_SET_CONTROL(base, val)\
        bfin_write16(base + ATAPI_OFFSET_CONTROL, val)
#define ATAPI_GET_STATUS(base)\
        bfin_read16(base + ATAPI_OFFSET_STATUS)
#define ATAPI_GET_DEV_ADDR(base)\
        bfin_read16(base + ATAPI_OFFSET_DEV_ADDR)
#define ATAPI_SET_DEV_ADDR(base, val)\
        bfin_write16(base + ATAPI_OFFSET_DEV_ADDR, val)
#define ATAPI_GET_DEV_TXBUF(base)\
        bfin_read16(base + ATAPI_OFFSET_DEV_TXBUF)
#define ATAPI_SET_DEV_TXBUF(base, val)\
        bfin_write16(base + ATAPI_OFFSET_DEV_TXBUF, val)
#define ATAPI_GET_DEV_RXBUF(base)\
        bfin_read16(base + ATAPI_OFFSET_DEV_RXBUF)
#define ATAPI_SET_DEV_RXBUF(base, val)\
        bfin_write16(base + ATAPI_OFFSET_DEV_RXBUF, val)
#define ATAPI_GET_INT_MASK(base)\
        bfin_read16(base + ATAPI_OFFSET_INT_MASK)
#define ATAPI_SET_INT_MASK(base, val)\
        bfin_write16(base + ATAPI_OFFSET_INT_MASK, val)
#define ATAPI_GET_INT_STATUS(base)\
        bfin_read16(base + ATAPI_OFFSET_INT_STATUS)
#define ATAPI_SET_INT_STATUS(base, val)\
        bfin_write16(base + ATAPI_OFFSET_INT_STATUS, val)
#define ATAPI_GET_XFER_LEN(base)\
        bfin_read16(base + ATAPI_OFFSET_XFER_LEN)
#define ATAPI_SET_XFER_LEN(base, val)\
        bfin_write16(base + ATAPI_OFFSET_XFER_LEN, val)
#define ATAPI_GET_LINE_STATUS(base)\
        bfin_read16(base + ATAPI_OFFSET_LINE_STATUS)
#define ATAPI_GET_SM_STATE(base)\
        bfin_read16(base + ATAPI_OFFSET_SM_STATE)
#define ATAPI_GET_TERMINATE(base)\
        bfin_read16(base + ATAPI_OFFSET_TERMINATE)
#define ATAPI_SET_TERMINATE(base, val)\
        bfin_write16(base + ATAPI_OFFSET_TERMINATE, val)
#define ATAPI_GET_PIO_TFRCNT(base)\
        bfin_read16(base + ATAPI_OFFSET_PIO_TFRCNT)
#define ATAPI_GET_DMA_TFRCNT(base)\
        bfin_read16(base + ATAPI_OFFSET_DMA_TFRCNT)
#define ATAPI_GET_UMAIN_TFRCNT(base)\
        bfin_read16(base + ATAPI_OFFSET_UMAIN_TFRCNT)
#define ATAPI_GET_UDMAOUT_TFRCNT(base)\
        bfin_read16(base + ATAPI_OFFSET_UDMAOUT_TFRCNT)
#define ATAPI_GET_REG_TIM_0(base)\
        bfin_read16(base + ATAPI_OFFSET_REG_TIM_0)
#define ATAPI_SET_REG_TIM_0(base, val)\
        bfin_write16(base + ATAPI_OFFSET_REG_TIM_0, val)
#define ATAPI_GET_PIO_TIM_0(base)\
        bfin_read16(base + ATAPI_OFFSET_PIO_TIM_0)
#define ATAPI_SET_PIO_TIM_0(base, val)\
        bfin_write16(base + ATAPI_OFFSET_PIO_TIM_0, val)
#define ATAPI_GET_PIO_TIM_1(base)\
        bfin_read16(base + ATAPI_OFFSET_PIO_TIM_1)
#define ATAPI_SET_PIO_TIM_1(base, val)\
        bfin_write16(base + ATAPI_OFFSET_PIO_TIM_1, val)
#define ATAPI_GET_MULTI_TIM_0(base)\
        bfin_read16(base + ATAPI_OFFSET_MULTI_TIM_0)
#define ATAPI_SET_MULTI_TIM_0(base, val)\
        bfin_write16(base + ATAPI_OFFSET_MULTI_TIM_0, val)
#define ATAPI_GET_MULTI_TIM_1(base)\
        bfin_read16(base + ATAPI_OFFSET_MULTI_TIM_1)
#define ATAPI_SET_MULTI_TIM_1(base, val)\
        bfin_write16(base + ATAPI_OFFSET_MULTI_TIM_1, val)
#define ATAPI_GET_MULTI_TIM_2(base)\
        bfin_read16(base + ATAPI_OFFSET_MULTI_TIM_2)
#define ATAPI_SET_MULTI_TIM_2(base, val)\
        bfin_write16(base + ATAPI_OFFSET_MULTI_TIM_2, val)
#define ATAPI_GET_ULTRA_TIM_0(base)\
        bfin_read16(base + ATAPI_OFFSET_ULTRA_TIM_0)
#define ATAPI_SET_ULTRA_TIM_0(base, val)\
        bfin_write16(base + ATAPI_OFFSET_ULTRA_TIM_0, val)
#define ATAPI_GET_ULTRA_TIM_1(base)\
        bfin_read16(base + ATAPI_OFFSET_ULTRA_TIM_1)
#define ATAPI_SET_ULTRA_TIM_1(base, val)\
        bfin_write16(base + ATAPI_OFFSET_ULTRA_TIM_1, val)
#define ATAPI_GET_ULTRA_TIM_2(base)\
        bfin_read16(base + ATAPI_OFFSET_ULTRA_TIM_2)
#define ATAPI_SET_ULTRA_TIM_2(base, val)\
        bfin_write16(base + ATAPI_OFFSET_ULTRA_TIM_2, val)
#define ATAPI_GET_ULTRA_TIM_3(base)\
        bfin_read16(base + ATAPI_OFFSET_ULTRA_TIM_3)
#define ATAPI_SET_ULTRA_TIM_3(base, val)\
        bfin_write16(base + ATAPI_OFFSET_ULTRA_TIM_3, val)

/**
 * 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;

/**
 *
 *      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
 *      @adev: um
 *
 *      Set PIO mode for device.
 *
 *      LOCKING:
 *      None (inherited from caller).
 */

static void bfin_set_piomode(struct ata_port *ap, struct ata_device *adev)
{
        int mode = adev->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) {
                dev_dbg(adev->link->ap->dev, "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();
        }
}

/**
 *      bfin_set_dmamode - Initialize host controller PATA DMA timings
 *      @ap: Port whose timings we are configuring
 *      @adev: um
 *
 *      Set UDMA mode for device.
 *
 *      LOCKING:
 *      None (inherited from caller).
 */

static void bfin_set_dmamode(struct ata_port *ap, struct ata_device *adev)
{
        int mode;
        void __iomem *base = (void __iomem *)ap->ioaddr.ctl_addr;
        unsigned long fsclk = get_sclk();
        unsigned short tenv, tack, tcyc_tdvs, tdvs, tmli, tss, trp, tzah;
        unsigned short tm, td, tkr, tkw, teoc, th;
        unsigned short n0, nf, tfmin = 5;
        unsigned short nmin, tcyc;

        mode = adev->dma_mode - XFER_UDMA_0;
        if (mode >= 0 && mode <= 5) {
                dev_dbg(adev->link->ap->dev, "set udmamode: mode=%d\n", mode);
                /* 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.
                 */
                while (mode > 0 && udma_fsclk[mode] > fsclk)
                        mode--;

                nmin = num_clocks_min(udma_tmin[mode], fsclk);
                if (nmin >= 1) {
                        /* calculate the timing values for Ultra DMA. */
                        tdvs = num_clocks_min(udma_tdvsmin[mode], fsclk);
                        tcyc = num_clocks_min(udma_tcycmin[mode], fsclk);
                        tcyc_tdvs = 2;

                        /* increase tcyc - tdvs (tcyc_tdvs) until we meed
                         * the minimum cycle length
                         */
                        if (tdvs + tcyc_tdvs < tcyc)
                                tcyc_tdvs = tcyc - tdvs;

                        /* Mow assign the values required for the timing
                         * registers
                         */
                        if (tcyc_tdvs < 2)
                                tcyc_tdvs = 2;

                        if (tdvs < 2)
                                tdvs = 2;

                        tack = num_clocks_min(udma_tackmin, fsclk);
                        tss = num_clocks_min(udma_tssmin, fsclk);
                        tmli = num_clocks_min(udma_tmlimin, fsclk);
                        tzah = num_clocks_min(udma_tzahmin, fsclk);
                        trp = num_clocks_min(udma_trpmin[mode], fsclk);
                        tenv = num_clocks_min(udma_tenvmin, fsclk);
                        if (tenv <= udma_tenvmax[mode]) {
                                ATAPI_SET_ULTRA_TIM_0(base, (tenv<<8 | tack));
                                ATAPI_SET_ULTRA_TIM_1(base,
                                        (tcyc_tdvs<<8 | tdvs));
                                ATAPI_SET_ULTRA_TIM_2(base, (tmli<<8 | tss));
                                ATAPI_SET_ULTRA_TIM_3(base, (trp<<8 | tzah));

                                /* Enable host ATAPI Untra DMA interrupts */
                                ATAPI_SET_INT_MASK(base,
                                        ATAPI_GET_INT_MASK(base)
                                        | UDMAIN_DONE_MASK
                                        | UDMAOUT_DONE_MASK
                                        | UDMAIN_TERM_MASK
                                        | UDMAOUT_TERM_MASK);
                        }
                }
        }

        mode = adev->dma_mode - XFER_MW_DMA_0;
        if (mode >= 0 && mode <= 2) {
                dev_dbg(adev->link->ap->dev, "set mdmamode: mode=%d\n", mode);
                /* the most restrictive timing value is tf, the DMACK to
                 * read data released. If one SCLK pulse is longer than
                 * this maximum value then the MDMA mode
                 * cannot be supported at this frequency.
                 */
                while (mode > 0 && mdma_fsclk[mode] > fsclk)
                        mode--;

                nf = num_clocks_min(tfmin, fsclk);
                if (nf >= 1) {
                        /* calculate the timing values for Multi-word DMA. */

                        /* DIOR/DIOW asserted pulse width */
                        td = num_clocks_min(mdma_tdmin[mode], fsclk);

                        /* DIOR negated pulse width */
                        tkw = num_clocks_min(mdma_tkwmin[mode], fsclk);

                        /* Cycle Time */
                        n0  = num_clocks_min(mdma_t0min[mode], fsclk);

                        /* increase tk until we meed the minimum cycle length */
                        if (tkw + td < n0)
                                tkw = n0 - td;

                        /* DIOR negated pulse width - read */
                        tkr = num_clocks_min(mdma_tkrmin[mode], fsclk);
                        /* CS{1:0] valid to DIOR/DIOW */
                        tm = num_clocks_min(mdma_tmmin[mode], fsclk);
                        /* DIOR/DIOW to DMACK hold */
                        teoc = num_clocks_min(mdma_tjmin[mode], fsclk);
                        /* DIOW Data hold */
                        th = num_clocks_min(mdma_thmin[mode], fsclk);

                        ATAPI_SET_MULTI_TIM_0(base, (tm<<8 | td));
                        ATAPI_SET_MULTI_TIM_1(base, (tkr<<8 | tkw));
                        ATAPI_SET_MULTI_TIM_2(base, (teoc<<8 | th));

                        /* Enable host ATAPI Multi DMA interrupts */
                        ATAPI_SET_INT_MASK(base, ATAPI_GET_INT_MASK(base)
                                | MULTI_DONE_MASK | MULTI_TERM_MASK);
                        SSYNC();
                }
        }
        return;
}

/**
 *
 *    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;

#define PATA_BF54X_WAIT_TIMEOUT         10000

        for (i = 0; i < PATA_BF54X_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_tf_load - send taskfile registers to host controller
 *      @ap: Port to which output is sent
 *      @tf: ATA taskfile register set
 *
 *      Note: Original code is ata_sff_tf_load().
 */

static void bfin_tf_load(struct ata_port *ap, const struct ata_taskfile *tf)
{
        void __iomem *base = (void __iomem *)ap->ioaddr.ctl_addr;
        unsigned int is_addr = tf->flags & ATA_TFLAG_ISADDR;

        if (tf->ctl != ap->last_ctl) {
                write_atapi_register(base, ATA_REG_CTRL, tf->ctl);
                ap->last_ctl = tf->ctl;
                ata_wait_idle(ap);
        }

        if (is_addr) {
                if (tf->flags & ATA_TFLAG_LBA48) {
                        write_atapi_register(base, ATA_REG_FEATURE,
                                                tf->hob_feature);
                        write_atapi_register(base, ATA_REG_NSECT,
                                                tf->hob_nsect);
                        write_atapi_register(base, ATA_REG_LBAL, tf->hob_lbal);
                        write_atapi_register(base, ATA_REG_LBAM, tf->hob_lbam);
                        write_atapi_register(base, ATA_REG_LBAH, tf->hob_lbah);
                        dev_dbg(ap->dev, "hob: feat 0x%X nsect 0x%X, lba 0x%X "
                                 "0x%X 0x%X\n",
                                tf->hob_feature,
                                tf->hob_nsect,
                                tf->hob_lbal,
                                tf->hob_lbam,
                                tf->hob_lbah);
                }

                write_atapi_register(base, ATA_REG_FEATURE, tf->feature);
                write_atapi_register(base, ATA_REG_NSECT, tf->nsect);
                write_atapi_register(base, ATA_REG_LBAL, tf->lbal);
                write_atapi_register(base, ATA_REG_LBAM, tf->lbam);
                write_atapi_register(base, ATA_REG_LBAH, tf->lbah);
                dev_dbg(ap->dev, "feat 0x%X nsect 0x%X lba 0x%X 0x%X 0x%X\n",
                        tf->feature,
                        tf->nsect,
                        tf->lbal,
                        tf->lbam,
                        tf->lbah);
        }

        if (tf->flags & ATA_TFLAG_DEVICE) {
                write_atapi_register(base, ATA_REG_DEVICE, tf->device);
                dev_dbg(ap->dev, "device 0x%X\n", tf->device);
        }

        ata_wait_idle(ap);
}

/**
 *      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_tf_read - input device's ATA taskfile shadow registers
 *      @ap: Port from which input is read
 *      @tf: ATA taskfile register set for storing input
 *
 *      Note: Original code is ata_sff_tf_read().
 */

static void bfin_tf_read(struct ata_port *ap, struct ata_taskfile *tf)
{
        void __iomem *base = (void __iomem *)ap->ioaddr.ctl_addr;

        tf->command = bfin_check_status(ap);
        tf->feature = read_atapi_register(base, ATA_REG_ERR);
        tf->nsect = read_atapi_register(base, ATA_REG_NSECT);
        tf->lbal = read_atapi_register(base, ATA_REG_LBAL);
        tf->lbam = read_atapi_register(base, ATA_REG_LBAM);
        tf->lbah = read_atapi_register(base, ATA_REG_LBAH);
        tf->device = read_atapi_register(base, ATA_REG_DEVICE);

        if (tf->flags & ATA_TFLAG_LBA48) {
                write_atapi_register(base, ATA_REG_CTRL, tf->ctl | ATA_HOB);
                tf->hob_feature = read_atapi_register(base, ATA_REG_ERR);
                tf->hob_nsect = read_atapi_register(base, ATA_REG_NSECT);
                tf->hob_lbal = read_atapi_register(base, ATA_REG_LBAL);
                tf->hob_lbam = read_atapi_register(base, ATA_REG_LBAM);
                tf->hob_lbah = read_atapi_register(base, ATA_REG_LBAH);
        }
}

/**
 *      bfin_exec_command - issue ATA command to host controller
 *      @ap: port to which command is being issued
 *      @tf: ATA taskfile register set
 *
 *      Note: Original code is ata_sff_exec_command().
 */

static void bfin_exec_command(struct ata_port *ap,
                              const struct ata_taskfile *tf)
{
        void __iomem *base = (void __iomem *)ap->ioaddr.ctl_addr;
        dev_dbg(ap->dev, "ata%u: cmd 0x%X\n", ap->print_id, tf->command);

        write_atapi_register(base, ATA_REG_CMD, tf->command);
        ata_sff_pause(ap);
}

/**
 *      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_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);
        ata_sff_pause(ap);
}

/**
 *      bfin_bmdma_setup - Set up IDE DMA transaction
 *      @qc: Info associated with this ATA transaction.
 *
 *      Note: Original code is ata_bmdma_setup().
 */

static void bfin_bmdma_setup(struct ata_queued_cmd *qc)
{
        unsigned short config = WDSIZE_16;
        struct scatterlist *sg;
        unsigned int si;

        dev_dbg(qc->ap->dev, "in atapi dma setup\n");
        /* Program the ATA_CTRL register with dir */
        if (qc->tf.flags & ATA_TFLAG_WRITE) {
                /* fill the ATAPI DMA controller */
                set_dma_config(CH_ATAPI_TX, config);
                set_dma_x_modify(CH_ATAPI_TX, 2);
                for_each_sg(qc->sg, sg, qc->n_elem, si) {
                        set_dma_start_addr(CH_ATAPI_TX, sg_dma_address(sg));
                        set_dma_x_count(CH_ATAPI_TX, sg_dma_len(sg) >> 1);
                }
        } else {
                config |= WNR;
                /* fill the ATAPI DMA controller */
                set_dma_config(CH_ATAPI_RX, config);
                set_dma_x_modify(CH_ATAPI_RX, 2);
                for_each_sg(qc->sg, sg, qc->n_elem, si) {
                        set_dma_start_addr(CH_ATAPI_RX, sg_dma_address(sg));
                        set_dma_x_count(CH_ATAPI_RX, sg_dma_len(sg) >> 1);
                }
        }
}

/**
 *      bfin_bmdma_start - Start an IDE DMA transaction
 *      @qc: Info associated with this ATA transaction.
 *
 *      Note: Original code is ata_bmdma_start().
 */

static void bfin_bmdma_start(struct ata_queued_cmd *qc)
{
        struct ata_port *ap = qc->ap;
        void __iomem *base = (void __iomem *)ap->ioaddr.ctl_addr;
        struct scatterlist *sg;
        unsigned int si;

        dev_dbg(qc->ap->dev, "in atapi dma start\n");
        if (!(ap->udma_mask || ap->mwdma_mask))
                return;

        /* start ATAPI DMA controller*/
        if (qc->tf.flags & ATA_TFLAG_WRITE) {
                /*
                 * On blackfin arch, uncacheable memory is not
                 * allocated with flag GFP_DMA. DMA buffer from
                 * common kenel code should be flushed if WB
                 * data cache is enabled. Otherwise, this loop
                 * is an empty loop and optimized out.
                 */
                for_each_sg(qc->sg, sg, qc->n_elem, si) {
                        flush_dcache_range(sg_dma_address(sg),
                                sg_dma_address(sg) + sg_dma_len(sg));
                }
                enable_dma(CH_ATAPI_TX);
                dev_dbg(qc->ap->dev, "enable udma write\n");

                /* Send ATA DMA write command */
                bfin_exec_command(ap, &qc->tf);

                /* set ATA DMA write direction */
                ATAPI_SET_CONTROL(base, (ATAPI_GET_CONTROL(base)
                        | XFER_DIR));
        } else {
                enable_dma(CH_ATAPI_RX);
                dev_dbg(qc->ap->dev, "enable udma read\n");

                /* Send ATA DMA read command */
                bfin_exec_command(ap, &qc->tf);

                /* set ATA DMA read direction */
                ATAPI_SET_CONTROL(base, (ATAPI_GET_CONTROL(base)
                        & ~XFER_DIR));
        }

        /* Reset all transfer count */
        ATAPI_SET_CONTROL(base, ATAPI_GET_CONTROL(base) | TFRCNT_RST);

        /* Set ATAPI state machine contorl in terminate sequence */
        ATAPI_SET_CONTROL(base, ATAPI_GET_CONTROL(base) | END_ON_TERM);

        /* Set transfer length to buffer len */
        for_each_sg(qc->sg, sg, qc->n_elem, si) {
                ATAPI_SET_XFER_LEN(base, (sg_dma_len(sg) >> 1));
        }

        /* Enable ATA DMA operation*/
        if (ap->udma_mask)
                ATAPI_SET_CONTROL(base, ATAPI_GET_CONTROL(base)
                        | ULTRA_START);
        else
                ATAPI_SET_CONTROL(base, ATAPI_GET_CONTROL(base)
                        | MULTI_START);
}

/**
 *      bfin_bmdma_stop - Stop IDE DMA transfer
 *      @qc: Command we are ending DMA for
 */

static void bfin_bmdma_stop(struct ata_queued_cmd *qc)
{
        struct ata_port *ap = qc->ap;
        struct scatterlist *sg;
        unsigned int si;

        dev_dbg(qc->ap->dev, "in atapi dma stop\n");
        if (!(ap->udma_mask || ap->mwdma_mask))
                return;

        /* stop ATAPI DMA controller*/
        if (qc->tf.flags & ATA_TFLAG_WRITE)
                disable_dma(CH_ATAPI_TX);
        else {
                disable_dma(CH_ATAPI_RX);
                if (ap->hsm_task_state & HSM_ST_LAST) {
                        /*
                         * On blackfin arch, uncacheable memory is not
                         * allocated with flag GFP_DMA. DMA buffer from
                         * common kenel code should be invalidated if
                         * data cache is enabled. Otherwise, this loop
                         * is an empty loop and optimized out.
                         */
                        for_each_sg(qc->sg, sg, qc->n_elem, si) {
                                invalidate_dcache_range(
                                        sg_dma_address(sg),
                                        sg_dma_address(sg)
                                        + sg_dma_len(sg));
                        }
                }
        }
}

/**
 *      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);
        unsigned long deadline;

        /* if device 0 was found in ata_devchk, wait for its
         * BSY bit to clear
         */
        if (dev0)
                ata_sff_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_deadline(jiffies, 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 (time_after(jiffies, deadline)) {
                        dev1 = 0;
                        break;
                }
                msleep(50);     /* give drive a breather */
        }
        if (dev1)
                ata_sff_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);
        udelay(20);
        write_atapi_register(base, ATA_REG_CTRL, ap->ctl | ATA_SRST);
        udelay(20);
        write_atapi_register(base, ATA_REG_CTRL, ap->ctl);

        /* 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
 *      @classes: resulting classes of attached devices
 *
 *      Note: Original code is ata_sff_softreset().
 */

static int bfin_softreset(struct ata_link *link, unsigned int *classes,
                          unsigned long deadline)
{
        struct ata_port *ap = link->ap;
        unsigned int slave_possible = ap->flags & ATA_FLAG_SLAVE_POSS;
        unsigned int devmask = 0, err_mask;
        u8 err;

        /* determine if device 0/1 are present */
        if (bfin_devchk(ap, 0))
                devmask |= (1 << 0);
        if (slave_possible && bfin_devchk(ap, 1))
                devmask |= (1 << 1);

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

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

        /* determine by signature whether we have ATA or ATAPI devices */
        classes[0] = ata_sff_dev_classify(&ap->link.device[0],
                                devmask & (1 << 0), &err);
        if (slave_possible && err != 0x81)
                classes[1] = ata_sff_dev_classify(&ap->link.device[1],
                                        devmask & (1 << 1), &err);

        return 0;
}

/**
 *      bfin_bmdma_status - Read IDE DMA status
 *      @ap: Port associated with this ATA transaction.
 */

static unsigned char bfin_bmdma_status(struct ata_port *ap)
{
        unsigned char host_stat = 0;
        void __iomem *base = (void __iomem *)ap->ioaddr.ctl_addr;
        unsigned short int_status = ATAPI_GET_INT_STATUS(base);

        if (ATAPI_GET_STATUS(base) & (MULTI_XFER_ON|ULTRA_XFER_ON))
                host_stat |= ATA_DMA_ACTIVE;
        if (int_status & (MULTI_DONE_INT|UDMAIN_DONE_INT|UDMAOUT_DONE_INT|
                ATAPI_DEV_INT))
                host_stat |= ATA_DMA_INTR;
        if (int_status & (MULTI_TERM_INT|UDMAIN_TERM_INT|UDMAOUT_TERM_INT))
                host_stat |= ATA_DMA_ERR|ATA_DMA_INTR;

        dev_dbg(ap->dev, "ATAPI: host_stat=0x%x\n", host_stat);

        return host_stat;
}

/**
 *      bfin_data_xfer - Transfer data by PIO
 *      @adev: device for this I/O
 *      @buf: data buffer
 *      @buflen: buffer length
 *      @write_data: read/write
 *
 *      Note: Original code is ata_sff_data_xfer().
 */

static unsigned int bfin_data_xfer(struct ata_device *dev, unsigned char *buf,
                                   unsigned int buflen, int rw)
{
        struct ata_port *ap = dev->link->ap;
        void __iomem *base = (void __iomem *)ap->ioaddr.ctl_addr;
        unsigned int words = buflen >> 1;
        unsigned short *buf16 = (u16 *)buf;

        /* Transfer multiple of 2 bytes */
        if (rw == READ)
                read_atapi_data(base, words, buf16);
        else
                write_atapi_data(base, words, buf16);

        /* Transfer trailing 1 byte, if any. */
        if (unlikely(buflen & 0x01)) {
                unsigned short align_buf[1] = { 0 };
                unsigned char *trailing_buf = buf + buflen - 1;

                if (rw == READ) {
                        read_atapi_data(base, 1, align_buf);
                        memcpy(trailing_buf, align_buf, 1);
                } else {
                        memcpy(align_buf, trailing_buf, 1);
                        write_atapi_data(base, 1, align_buf);
                }
                words++;
        }

        return words << 1;
}

/**
 *      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;

        dev_dbg(ap->dev, "in atapi irq clear\n");
        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);
}

/**
 *      bfin_irq_on - Enable interrupts on a port.
 *      @ap: Port on which interrupts are enabled.
 *
 *      Note: Original code is ata_sff_irq_on().
 */

static unsigned char bfin_irq_on(struct ata_port *ap)
{
        void __iomem *base = (void __iomem *)ap->ioaddr.ctl_addr;
        u8 tmp;

        dev_dbg(ap->dev, "in atapi irq on\n");
        ap->ctl &= ~ATA_NIEN;
        ap->last_ctl = ap->ctl;

        write_atapi_register(base, ATA_REG_CTRL, ap->ctl);
        tmp = ata_wait_idle(ap);

        bfin_irq_clear(ap);

        return tmp;
}

/**
 *      bfin_freeze - Freeze DMA controller port
 *      @ap: port to freeze
 *
 *      Note: Original code is ata_sff_freeze().
 */

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

        dev_dbg(ap->dev, "in atapi dma freeze\n");
        ap->ctl |= ATA_NIEN;
        ap->last_ctl = ap->ctl;

        write_atapi_register(base, ATA_REG_CTRL, ap->ctl);

        /* Under certain circumstances, some controllers raise IRQ on
         * ATA_NIEN manipulation.  Also, many controllers fail to mask
         * previously pending IRQ on ATA_NIEN assertion.  Clear it.
         */
        ap->ops->sff_check_status(ap);

        bfin_irq_clear(ap);
}

/**
 *      bfin_thaw - Thaw DMA controller port
 *      @ap: port to thaw
 *
 *      Note: Original code is ata_sff_thaw().
 */

void bfin_thaw(struct ata_port *ap)
{
        dev_dbg(ap->dev, "in atapi dma thaw\n");
        bfin_check_status(ap);
        bfin_irq_on(ap);
}

/**
 *      bfin_postreset - standard postreset callback
 *      @ap: the target ata_port
 *      @classes: classes of attached devices
 *
 *      Note: Original code is ata_sff_postreset().
 */

static void bfin_postreset(struct ata_link *link, unsigned int *classes)
{
        struct ata_port *ap = link->ap;
        void __iomem *base = (void __iomem *)ap->ioaddr.ctl_addr;

        /* re-enable interrupts */
        bfin_irq_on(ap);

        /* is double-select really necessary? */
        if (classes[0] != ATA_DEV_NONE)
                bfin_dev_select(ap, 1);
        if (classes[1] != ATA_DEV_NONE)
                bfin_dev_select(ap, 0);

        /* bail out if no device is present */
        if (classes[0] == ATA_DEV_NONE && classes[1] == ATA_DEV_NONE) {
                return;
        }

        /* set up device control */
        write_atapi_register(base, ATA_REG_CTRL, ap->ctl);
}

static void bfin_port_stop(struct ata_port *ap)
{
        dev_dbg(ap->dev, "in atapi port stop\n");
        if (ap->udma_mask != 0 || ap->mwdma_mask != 0) {
                free_dma(CH_ATAPI_RX);
                free_dma(CH_ATAPI_TX);
        }
}

static int bfin_port_start(struct ata_port *ap)
{
        dev_dbg(ap->dev, "in atapi port start\n");
        if (!(ap->udma_mask || ap->mwdma_mask))
                return 0;

        if (request_dma(CH_ATAPI_RX, "BFIN ATAPI RX DMA") >= 0) {
                if (request_dma(CH_ATAPI_TX,
                        "BFIN ATAPI TX DMA") >= 0)
                        return 0;

                free_dma(CH_ATAPI_RX);
        }

        ap->udma_mask = 0;
        ap->mwdma_mask = 0;
        dev_err(ap->dev, "Unable to request ATAPI DMA!"
                " Continue in PIO mode.\n");

        return 0;
}

static unsigned int bfin_ata_host_intr(struct ata_port *ap,
                                   struct ata_queued_cmd *qc)
{
        struct ata_eh_info *ehi = &ap->link.eh_info;
        u8 status, host_stat = 0;

        VPRINTK("ata%u: protocol %d task_state %d\n",
                ap->print_id, qc->tf.protocol, ap->hsm_task_state);

        /* Check whether we are expecting interrupt in this state */
        switch (ap->hsm_task_state) {
        case HSM_ST_FIRST:
                /* Some pre-ATAPI-4 devices assert INTRQ
                 * at this state when ready to receive CDB.
                 */

                /* Check the ATA_DFLAG_CDB_INTR flag is enough here.
                 * The flag was turned on only for atapi devices.
                 * No need to check is_atapi_taskfile(&qc->tf) again.
                 */
                if (!(qc->dev->flags & ATA_DFLAG_CDB_INTR))
                        goto idle_irq;
                break;
        case HSM_ST_LAST:
                if (qc->tf.protocol == ATA_PROT_DMA ||
                    qc->tf.protocol == ATAPI_PROT_DMA) {
                        /* check status of DMA engine */
                        host_stat = ap->ops->bmdma_status(ap);
                        VPRINTK("ata%u: host_stat 0x%X\n",
                                ap->print_id, host_stat);

                        /* if it's not our irq... */
                        if (!(host_stat & ATA_DMA_INTR))
                                goto idle_irq;

                        /* before we do anything else, clear DMA-Start bit */
                        ap->ops->bmdma_stop(qc);

                        if (unlikely(host_stat & ATA_DMA_ERR)) {
                                /* error when transfering data to/from memory */
                                qc->err_mask |= AC_ERR_HOST_BUS;
                                ap->hsm_task_state = HSM_ST_ERR;
                        }
                }
                break;
        case HSM_ST:
                break;
        default:
                goto idle_irq;
        }

        /* check altstatus */
        status = ap->ops->sff_check_altstatus(ap);
        if (status & ATA_BUSY)
                goto busy_ata;

        /* check main status, clearing INTRQ */
        status = ap->ops->sff_check_status(ap);
        if (unlikely(status & ATA_BUSY))
                goto busy_ata;

        /* ack bmdma irq events */
        ap->ops->sff_irq_clear(ap);

        ata_sff_hsm_move(ap, qc, status, 0);

        if (unlikely(qc->err_mask) && (qc->tf.protocol == ATA_PROT_DMA ||
                                       qc->tf.protocol == ATAPI_PROT_DMA))
                ata_ehi_push_desc(ehi, "BMDMA stat 0x%x", host_stat);

busy_ata:
        return 1;       /* irq handled */

idle_irq:
        ap->stats.idle_irq++;

#ifdef ATA_IRQ_TRAP
        if ((ap->stats.idle_irq % 1000) == 0) {
                ap->ops->irq_ack(ap, 0); /* debug trap */
                ata_port_printk(ap, KERN_WARNING, "irq trap\n");
                return 1;
        }
#endif
        return 0;       /* irq not handled */
}

static irqreturn_t bfin_ata_interrupt(int irq, void *dev_instance)
{
        struct ata_host *host = dev_instance;
        unsigned int i;
        unsigned int handled = 0;
        unsigned long flags;

        /* TODO: make _irqsave conditional on x86 PCI IDE legacy mode */
        spin_lock_irqsave(&host->lock, flags);

        for (i = 0; i < host->n_ports; i++) {
                struct ata_port *ap;

                ap = host->ports[i];
                if (ap &&
                    !(ap->flags & ATA_FLAG_DISABLED)) {
                        struct ata_queued_cmd *qc;

                        qc = ata_qc_from_tag(ap, ap->link.active_tag);
                        if (qc && (!(qc->tf.flags & ATA_TFLAG_POLLING)) &&
                            (qc->flags & ATA_QCFLAG_ACTIVE))
                                handled |= bfin_ata_host_intr(ap, qc);
                }
        }

        spin_unlock_irqrestore(&host->lock, flags);

        return IRQ_RETVAL(handled);
}


static struct scsi_host_template bfin_sht = {
        ATA_BASE_SHT(DRV_NAME),
        .sg_tablesize           = SG_NONE,
        .dma_boundary           = ATA_DMA_BOUNDARY,
};

static struct ata_port_operations bfin_pata_ops = {
        .inherits               = &ata_sff_port_ops,

        .set_piomode            = bfin_set_piomode,
        .set_dmamode            = bfin_set_dmamode,

        .sff_tf_load            = bfin_tf_load,
        .sff_tf_read            = bfin_tf_read,
        .sff_exec_command       = bfin_exec_command,
        .sff_check_status       = bfin_check_status,
        .sff_check_altstatus    = bfin_check_altstatus,
        .sff_dev_select         = bfin_dev_select,

        .bmdma_setup            = bfin_bmdma_setup,
        .bmdma_start            = bfin_bmdma_start,
        .bmdma_stop             = bfin_bmdma_stop,
        .bmdma_status           = bfin_bmdma_status,
        .sff_data_xfer          = bfin_data_xfer,

        .qc_prep                = ata_noop_qc_prep,

        .freeze                 = bfin_freeze,
        .thaw                   = bfin_thaw,
        .softreset              = bfin_softreset,
        .postreset              = bfin_postreset,

        .sff_irq_clear          = bfin_irq_clear,
        .sff_irq_on             = bfin_irq_on,

        .port_start             = bfin_port_start,
        .port_stop              = bfin_port_stop,
};

static struct ata_port_info bfin_port_info[] = {
        {
                .flags          = ATA_FLAG_SLAVE_POSS
                                | ATA_FLAG_MMIO
                                | ATA_FLAG_NO_LEGACY,
                .pio_mask       = 0x1f, /* pio0-4 */
                .mwdma_mask     = 0,
                .udma_mask      = 0,
                .port_ops       = &bfin_pata_ops,
        },
};

/**
 *      bfin_reset_controller - initialize BF54x ATAPI controller.
 */

static int bfin_reset_controller(struct ata_host *host)
{
        void __iomem *base = (void __iomem *)host->ports[0]->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);
}

/**
 *      atapi_io_port - define atapi peripheral port pins.
 */
static unsigned short atapi_io_port[] = {
        P_ATAPI_RESET,
        P_ATAPI_DIOR,
        P_ATAPI_DIOW,
        P_ATAPI_CS0,
        P_ATAPI_CS1,
        P_ATAPI_DMACK,
        P_ATAPI_DMARQ,
        P_ATAPI_INTRQ,
        P_ATAPI_IORDY,
        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 __devinit bfin_atapi_probe(struct platform_device *pdev)
{
        int board_idx = 0;
        struct resource *res;
        struct ata_host *host;
        unsigned int fsclk = get_sclk();
        int udma_mode = 5;
        const struct ata_port_info *ppi[] =
                { &bfin_port_info[board_idx], NULL };

        /*
         * Simple resource validation ..
         */
        if (unlikely(pdev->num_resources != 2)) {
                dev_err(&pdev->dev, "invalid number of resources\n");
                return -EINVAL;
        }

        /*
         * Get the register base first
         */
        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
        if (res == NULL)
                return -EINVAL;

        while (bfin_port_info[board_idx].udma_mask > 0 &&
                        udma_fsclk[udma_mode] > fsclk) {
                udma_mode--;
                bfin_port_info[board_idx].udma_mask >>= 1;
        }

        /*
         * Now that that's out of the way, wire up the port..
         */
        host = ata_host_alloc_pinfo(&pdev->dev, ppi, 1);
        if (!host)
                return -ENOMEM;

        host->ports[0]->ioaddr.ctl_addr = (void *)res->start;

        if (peripheral_request_list(atapi_io_port, "atapi-io-port")) {
                dev_err(&pdev->dev, "Requesting Peripherals faild\n");
                return -EFAULT;
        }

        if (bfin_reset_controller(host)) {
                peripheral_free_list(atapi_io_port);
                dev_err(&pdev->dev, "Fail to reset ATAPI device\n");
                return -EFAULT;
        }

        if (ata_host_activate(host, platform_get_irq(pdev, 0),
                bfin_ata_interrupt, IRQF_SHARED, &bfin_sht) != 0) {
                peripheral_free_list(atapi_io_port);
                dev_err(&pdev->dev, "Fail to attach ATAPI device\n");
                return -ENODEV;
        }

        dev_set_drvdata(&pdev->dev, host);

        return 0;
}

/**
 *      bfin_atapi_remove       -       unplug a bfin atapi interface
 *      @pdev: platform device
 *
 *      A bfin atapi device has been unplugged. Perform the needed
 *      cleanup. Also called on module unload for any active devices.
 */
static int __devexit bfin_atapi_remove(struct platform_device *pdev)
{
        struct device *dev = &pdev->dev;
        struct ata_host *host = dev_get_drvdata(dev);

        ata_host_detach(host);
        dev_set_drvdata(&pdev->dev, NULL);

        peripheral_free_list(atapi_io_port);

        return 0;
}

#ifdef CONFIG_PM
static int bfin_atapi_suspend(struct platform_device *pdev, pm_message_t state)
{
        struct ata_host *host = dev_get_drvdata(&pdev->dev);
        if (host)
                return ata_host_suspend(host, state);
        else
                return 0;
}

static int bfin_atapi_resume(struct platform_device *pdev)
{
        struct ata_host *host = dev_get_drvdata(&pdev->dev);
        int ret;

        if (host) {
                ret = bfin_reset_controller(host);
                if (ret) {
                        printk(KERN_ERR DRV_NAME ": Error during HW init\n");
                        return ret;
                }
                ata_host_resume(host);
        }

        return 0;
}
#else
#define bfin_atapi_suspend NULL
#define bfin_atapi_resume NULL
#endif

static struct platform_driver bfin_atapi_driver = {
        .probe                  = bfin_atapi_probe,
        .remove                 = __devexit_p(bfin_atapi_remove),
        .suspend                = bfin_atapi_suspend,
        .resume                 = bfin_atapi_resume,
        .driver = {
                .name           = DRV_NAME,
                .owner          = THIS_MODULE,
        },
};

#define ATAPI_MODE_SIZE         10
static char bfin_atapi_mode[ATAPI_MODE_SIZE];

static int __init bfin_atapi_init(void)
{
        pr_info("register bfin atapi driver\n");

        switch(bfin_atapi_mode[0]) {
        case 'p':
        case 'P':
                break;
        case 'm':
        case 'M':
                bfin_port_info[0].mwdma_mask = ATA_MWDMA2;
                break;
        default:
                bfin_port_info[0].udma_mask = ATA_UDMA5;
        };

        return platform_driver_register(&bfin_atapi_driver);
}

static void __exit bfin_atapi_exit(void)
{
        platform_driver_unregister(&bfin_atapi_driver);
}

module_init(bfin_atapi_init);
module_exit(bfin_atapi_exit);
/*
 * ATAPI mode:
 * pio/PIO
 * udma/UDMA (default)
 * mwdma/MWDMA
 */
module_param_string(bfin_atapi_mode, bfin_atapi_mode, ATAPI_MODE_SIZE, 0);

MODULE_AUTHOR("Sonic Zhang <sonic.zhang@analog.com>");
MODULE_DESCRIPTION("PATA driver for blackfin 54x ATAPI controller");
MODULE_LICENSE("GPL");
MODULE_VERSION(DRV_VERSION);
MODULE_ALIAS("platform:" DRV_NAME);