#include <linux/module.h>
#include <linux/types.h>
#include <linux/string.h>
#include <linux/kernel.h>
#include <linux/timer.h>
#include <linux/mm.h>
#include <linux/interrupt.h>
#include <linux/major.h>
#include <linux/errno.h>
#include <linux/genhd.h>
#include <linux/blkpg.h>
#include <linux/slab.h>
#include <linux/pci.h>
#include <linux/delay.h>
#include <linux/hdreg.h>
#include <linux/ide.h>
#include <linux/bitops.h>

#include <asm/byteorder.h>
#include <asm/irq.h>
#include <asm/uaccess.h>
#include <asm/io.h>

/*
 *      IDE library routines. These are plug in code that most 
 *      drivers can use but occasionally may be weird enough
 *      to want to do their own thing with
 *
 *      Add common non I/O op stuff here. Make sure it has proper
 *      kernel-doc function headers or your patch will be rejected
 */

static const char *udma_str[] =
         { "UDMA/16", "UDMA/25",  "UDMA/33",  "UDMA/44",
           "UDMA/66", "UDMA/100", "UDMA/133", "UDMA7" };
static const char *mwdma_str[] =
        { "MWDMA0", "MWDMA1", "MWDMA2" };
static const char *swdma_str[] =
        { "SWDMA0", "SWDMA1", "SWDMA2" };
static const char *pio_str[] =
        { "PIO0", "PIO1", "PIO2", "PIO3", "PIO4", "PIO5" };

/**
 *      ide_xfer_verbose        -       return IDE mode names
 *      @mode: transfer mode
 *
 *      Returns a constant string giving the name of the mode
 *      requested.
 */

const char *ide_xfer_verbose(u8 mode)
{
        const char *s;
        u8 i = mode & 0xf;

        if (mode >= XFER_UDMA_0 && mode <= XFER_UDMA_7)
                s = udma_str[i];
        else if (mode >= XFER_MW_DMA_0 && mode <= XFER_MW_DMA_2)
                s = mwdma_str[i];
        else if (mode >= XFER_SW_DMA_0 && mode <= XFER_SW_DMA_2)
                s = swdma_str[i];
        else if (mode >= XFER_PIO_0 && mode <= XFER_PIO_5)
                s = pio_str[i & 0x7];
        else if (mode == XFER_PIO_SLOW)
                s = "PIO SLOW";
        else
                s = "XFER ERROR";

        return s;
}

EXPORT_SYMBOL(ide_xfer_verbose);

/**
 *      ide_rate_filter         -       filter transfer mode
 *      @drive: IDE device
 *      @speed: desired speed
 *
 *      Given the available transfer modes this function returns
 *      the best available speed at or below the speed requested.
 *
 *      TODO: check device PIO capabilities
 */

static u8 ide_rate_filter(ide_drive_t *drive, u8 speed)
{
        ide_hwif_t *hwif = drive->hwif;
        u8 mode = ide_find_dma_mode(drive, speed);

        if (mode == 0) {
                if (hwif->pio_mask)
                        mode = fls(hwif->pio_mask) - 1 + XFER_PIO_0;
                else
                        mode = XFER_PIO_4;
        }

//      printk("%s: mode 0x%02x, speed 0x%02x\n", __FUNCTION__, mode, speed);

        return min(speed, mode);
}

/*
 * Standard (generic) timings for PIO modes, from ATA2 specification.
 * These timings are for access to the IDE data port register *only*.
 * Some drives may specify a mode, while also specifying a different
 * value for cycle_time (from drive identification data).
 */
const ide_pio_timings_t ide_pio_timings[6] = {
        { 70,   165,    600 },  /* PIO Mode 0 */
        { 50,   125,    383 },  /* PIO Mode 1 */
        { 30,   100,    240 },  /* PIO Mode 2 */
        { 30,   80,     180 },  /* PIO Mode 3 with IORDY */
        { 25,   70,     120 },  /* PIO Mode 4 with IORDY */
        { 20,   50,     100 }   /* PIO Mode 5 with IORDY (nonstandard) */
};

EXPORT_SYMBOL_GPL(ide_pio_timings);

/*
 * Shared data/functions for determining best PIO mode for an IDE drive.
 * Most of this stuff originally lived in cmd640.c, and changes to the
 * ide_pio_blacklist[] table should be made with EXTREME CAUTION to avoid
 * breaking the fragile cmd640.c support.
 */

/*
 * Black list. Some drives incorrectly report their maximal PIO mode,
 * at least in respect to CMD640. Here we keep info on some known drives.
 */
static struct ide_pio_info {
        const char      *name;
        int             pio;
} ide_pio_blacklist [] = {
/*      { "Conner Peripherals 1275MB - CFS1275A", 4 }, */
        { "Conner Peripherals 540MB - CFS540A", 3 },

        { "WDC AC2700",  3 },
        { "WDC AC2540",  3 },
        { "WDC AC2420",  3 },
        { "WDC AC2340",  3 },
        { "WDC AC2250",  0 },
        { "WDC AC2200",  0 },
        { "WDC AC21200", 4 },
        { "WDC AC2120",  0 },
        { "WDC AC2850",  3 },
        { "WDC AC1270",  3 },
        { "WDC AC1170",  1 },
        { "WDC AC1210",  1 },
        { "WDC AC280",   0 },
/*      { "WDC AC21000", 4 }, */
        { "WDC AC31000", 3 },
        { "WDC AC31200", 3 },
/*      { "WDC AC31600", 4 }, */

        { "Maxtor 7131 AT", 1 },
        { "Maxtor 7171 AT", 1 },
        { "Maxtor 7213 AT", 1 },
        { "Maxtor 7245 AT", 1 },
        { "Maxtor 7345 AT", 1 },
        { "Maxtor 7546 AT", 3 },
        { "Maxtor 7540 AV", 3 },

        { "SAMSUNG SHD-3121A", 1 },
        { "SAMSUNG SHD-3122A", 1 },
        { "SAMSUNG SHD-3172A", 1 },

/*      { "ST51080A", 4 },
 *      { "ST51270A", 4 },
 *      { "ST31220A", 4 },
 *      { "ST31640A", 4 },
 *      { "ST32140A", 4 },
 *      { "ST3780A",  4 },
 */
        { "ST5660A",  3 },
        { "ST3660A",  3 },
        { "ST3630A",  3 },
        { "ST3655A",  3 },
        { "ST3391A",  3 },
        { "ST3390A",  1 },
        { "ST3600A",  1 },
        { "ST3290A",  0 },
        { "ST3144A",  0 },
        { "ST3491A",  1 },      /* reports 3, should be 1 or 2 (depending on */ 
                                /* drive) according to Seagates FIND-ATA program */

        { "QUANTUM ELS127A", 0 },
        { "QUANTUM ELS170A", 0 },
        { "QUANTUM LPS240A", 0 },
        { "QUANTUM LPS210A", 3 },
        { "QUANTUM LPS270A", 3 },
        { "QUANTUM LPS365A", 3 },
        { "QUANTUM LPS540A", 3 },
        { "QUANTUM LIGHTNING 540A", 3 },
        { "QUANTUM LIGHTNING 730A", 3 },

        { "QUANTUM FIREBALL_540", 3 }, /* Older Quantum Fireballs don't work */
        { "QUANTUM FIREBALL_640", 3 }, 
        { "QUANTUM FIREBALL_1080", 3 },
        { "QUANTUM FIREBALL_1280", 3 },
        { NULL, 0 }
};

/**
 *      ide_scan_pio_blacklist  -       check for a blacklisted drive
 *      @model: Drive model string
 *
 *      This routine searches the ide_pio_blacklist for an entry
 *      matching the start/whole of the supplied model name.
 *
 *      Returns -1 if no match found.
 *      Otherwise returns the recommended PIO mode from ide_pio_blacklist[].
 */

static int ide_scan_pio_blacklist (char *model)
{
        struct ide_pio_info *p;

        for (p = ide_pio_blacklist; p->name != NULL; p++) {
                if (strncmp(p->name, model, strlen(p->name)) == 0)
                        return p->pio;
        }
        return -1;
}

unsigned int ide_pio_cycle_time(ide_drive_t *drive, u8 pio)
{
        struct hd_driveid *id = drive->id;
        int cycle_time = 0;

        if (id->field_valid & 2) {
                if (id->capability & 8)
                        cycle_time = id->eide_pio_iordy;
                else
                        cycle_time = id->eide_pio;
        }

        /* conservative "downgrade" for all pre-ATA2 drives */
        if (pio < 3) {
                if (cycle_time && cycle_time < ide_pio_timings[pio].cycle_time)
                        cycle_time = 0; /* use standard timing */
        }

        return cycle_time ? cycle_time : ide_pio_timings[pio].cycle_time;
}

EXPORT_SYMBOL_GPL(ide_pio_cycle_time);

/**
 *      ide_get_best_pio_mode   -       get PIO mode from drive
 *      @drive: drive to consider
 *      @mode_wanted: preferred mode
 *      @max_mode: highest allowed mode
 *
 *      This routine returns the recommended PIO settings for a given drive,
 *      based on the drive->id information and the ide_pio_blacklist[].
 *
 *      Drive PIO mode is auto-selected if 255 is passed as mode_wanted.
 *      This is used by most chipset support modules when "auto-tuning".
 */

u8 ide_get_best_pio_mode (ide_drive_t *drive, u8 mode_wanted, u8 max_mode)
{
        int pio_mode;
        struct hd_driveid* id = drive->id;
        int overridden  = 0;

        if (mode_wanted != 255)
                return min_t(u8, mode_wanted, max_mode);

        if ((drive->hwif->host_flags & IDE_HFLAG_PIO_NO_BLACKLIST) == 0 &&
            (pio_mode = ide_scan_pio_blacklist(id->model)) != -1) {
                printk(KERN_INFO "%s: is on PIO blacklist\n", drive->name);
        } else {
                pio_mode = id->tPIO;
                if (pio_mode > 2) {     /* 2 is maximum allowed tPIO value */
                        pio_mode = 2;
                        overridden = 1;
                }
                if (id->field_valid & 2) {        /* drive implements ATA2? */
                        if (id->capability & 8) { /* IORDY supported? */
                                if (id->eide_pio_modes & 7) {
                                        overridden = 0;
                                        if (id->eide_pio_modes & 4)
                                                pio_mode = 5;
                                        else if (id->eide_pio_modes & 2)
                                                pio_mode = 4;
                                        else
                                                pio_mode = 3;
                                }
                        }
                }

                if (overridden)
                        printk(KERN_INFO "%s: tPIO > 2, assuming tPIO = 2\n",
                                         drive->name);

                /*
                 * Conservative "downgrade" for all pre-ATA2 drives
                 */
                if ((drive->hwif->host_flags & IDE_HFLAG_PIO_NO_DOWNGRADE) == 0 &&
                    pio_mode && pio_mode < 4) {
                        pio_mode--;
                        printk(KERN_INFO "%s: applying conservative "
                                         "PIO \"downgrade\"\n", drive->name);
                }
        }

        if (pio_mode > max_mode)
                pio_mode = max_mode;

        return pio_mode;
}

EXPORT_SYMBOL_GPL(ide_get_best_pio_mode);

/* req_pio == "255" for auto-tune */
void ide_set_pio(ide_drive_t *drive, u8 req_pio)
{
        ide_hwif_t *hwif = drive->hwif;
        u8 host_pio, pio;

        if (hwif->set_pio_mode == NULL)
                return;

        BUG_ON(hwif->pio_mask == 0x00);

        host_pio = fls(hwif->pio_mask) - 1;

        pio = ide_get_best_pio_mode(drive, req_pio, host_pio);

        /*
         * TODO:
         * - report device max PIO mode
         * - check req_pio != 255 against device max PIO mode
         */
        printk(KERN_DEBUG "%s: host max PIO%d wanted PIO%d%s selected PIO%d\n",
                          drive->name, host_pio, req_pio,
                          req_pio == 255 ? "(auto-tune)" : "", pio);

        (void)ide_set_pio_mode(drive, XFER_PIO_0 + pio);
}

EXPORT_SYMBOL_GPL(ide_set_pio);

/**
 *      ide_toggle_bounce       -       handle bounce buffering
 *      @drive: drive to update
 *      @on: on/off boolean
 *
 *      Enable or disable bounce buffering for the device. Drives move
 *      between PIO and DMA and that changes the rules we need.
 */
 
void ide_toggle_bounce(ide_drive_t *drive, int on)
{
        u64 addr = BLK_BOUNCE_HIGH;     /* dma64_addr_t */

        if (!PCI_DMA_BUS_IS_PHYS) {
                addr = BLK_BOUNCE_ANY;
        } else if (on && drive->media == ide_disk) {
                if (HWIF(drive)->pci_dev)
                        addr = HWIF(drive)->pci_dev->dma_mask;
        }

        if (drive->queue)
                blk_queue_bounce_limit(drive->queue, addr);
}

int ide_set_pio_mode(ide_drive_t *drive, const u8 mode)
{
        ide_hwif_t *hwif = drive->hwif;

        if (hwif->set_pio_mode == NULL)
                return -1;

        /*
         * TODO: temporary hack for some legacy host drivers that didn't
         * set transfer mode on the device in ->set_pio_mode method...
         */
        if (hwif->set_dma_mode == NULL) {
                hwif->set_pio_mode(drive, mode - XFER_PIO_0);
                return 0;
        }

        if (hwif->host_flags & IDE_HFLAG_POST_SET_MODE) {
                if (ide_config_drive_speed(drive, mode))
                        return -1;
                hwif->set_pio_mode(drive, mode - XFER_PIO_0);
                return 0;
        } else {
                hwif->set_pio_mode(drive, mode - XFER_PIO_0);
                return ide_config_drive_speed(drive, mode);
        }
}

int ide_set_dma_mode(ide_drive_t *drive, const u8 mode)
{
        ide_hwif_t *hwif = drive->hwif;

        if (hwif->set_dma_mode == NULL)
                return -1;

        if (hwif->host_flags & IDE_HFLAG_POST_SET_MODE) {
                if (ide_config_drive_speed(drive, mode))
                        return -1;
                hwif->set_dma_mode(drive, mode);
                return 0;
        } else {
                hwif->set_dma_mode(drive, mode);
                return ide_config_drive_speed(drive, mode);
        }
}

EXPORT_SYMBOL_GPL(ide_set_dma_mode);

/**
 *      ide_set_xfer_rate       -       set transfer rate
 *      @drive: drive to set
 *      @rate: speed to attempt to set
 *      
 *      General helper for setting the speed of an IDE device. This
 *      function knows about user enforced limits from the configuration
 *      which ->set_pio_mode/->set_dma_mode does not.
 */

int ide_set_xfer_rate(ide_drive_t *drive, u8 rate)
{
        ide_hwif_t *hwif = drive->hwif;

        if (hwif->set_dma_mode == NULL)
                return -1;

        rate = ide_rate_filter(drive, rate);

        if (rate >= XFER_PIO_0 && rate <= XFER_PIO_5)
                return ide_set_pio_mode(drive, rate);

        /*
         * TODO: transfer modes 0x00-0x07 passed from the user-space are
         * currently handled here which needs fixing (please note that such
         * case could happen iff the transfer mode has already been set on
         * the device by ide-proc.c::set_xfer_rate()).
         */

        return ide_set_dma_mode(drive, rate);
}

static void ide_dump_opcode(ide_drive_t *drive)
{
        struct request *rq;
        u8 opcode = 0;
        int found = 0;

        spin_lock(&ide_lock);
        rq = NULL;
        if (HWGROUP(drive))
                rq = HWGROUP(drive)->rq;
        spin_unlock(&ide_lock);
        if (!rq)
                return;
        if (rq->cmd_type == REQ_TYPE_ATA_CMD ||
            rq->cmd_type == REQ_TYPE_ATA_TASK) {
                char *args = rq->buffer;
                if (args) {
                        opcode = args[0];
                        found = 1;
                }
        } else if (rq->cmd_type == REQ_TYPE_ATA_TASKFILE) {
                ide_task_t *args = rq->special;
                if (args) {
                        task_struct_t *tf = (task_struct_t *) args->tfRegister;
                        opcode = tf->command;
                        found = 1;
                }
        }

        printk("ide: failed opcode was: ");
        if (!found)
                printk("unknown\n");
        else
                printk("0x%02x\n", opcode);
}

static u8 ide_dump_ata_status(ide_drive_t *drive, const char *msg, u8 stat)
{
        ide_hwif_t *hwif = HWIF(drive);
        unsigned long flags;
        u8 err = 0;

        local_irq_save(flags);
        printk("%s: %s: status=0x%02x { ", drive->name, msg, stat);
        if (stat & BUSY_STAT)
                printk("Busy ");
        else {
                if (stat & READY_STAT)  printk("DriveReady ");
                if (stat & WRERR_STAT)  printk("DeviceFault ");
                if (stat & SEEK_STAT)   printk("SeekComplete ");
                if (stat & DRQ_STAT)    printk("DataRequest ");
                if (stat & ECC_STAT)    printk("CorrectedError ");
                if (stat & INDEX_STAT)  printk("Index ");
                if (stat & ERR_STAT)    printk("Error ");
        }
        printk("}\n");
        if ((stat & (BUSY_STAT|ERR_STAT)) == ERR_STAT) {
                err = hwif->INB(IDE_ERROR_REG);
                printk("%s: %s: error=0x%02x { ", drive->name, msg, err);
                if (err & ABRT_ERR)     printk("DriveStatusError ");
                if (err & ICRC_ERR)
                        printk((err & ABRT_ERR) ? "BadCRC " : "BadSector ");
                if (err & ECC_ERR)      printk("UncorrectableError ");
                if (err & ID_ERR)       printk("SectorIdNotFound ");
                if (err & TRK0_ERR)     printk("TrackZeroNotFound ");
                if (err & MARK_ERR)     printk("AddrMarkNotFound ");
                printk("}");
                if ((err & (BBD_ERR | ABRT_ERR)) == BBD_ERR ||
                    (err & (ECC_ERR|ID_ERR|MARK_ERR))) {
                        if (drive->addressing == 1) {
                                __u64 sectors = 0;
                                u32 low = 0, high = 0;
                                hwif->OUTB(drive->ctl&~0x80, IDE_CONTROL_REG);
                                low = ide_read_24(drive);
                                hwif->OUTB(drive->ctl|0x80, IDE_CONTROL_REG);
                                high = ide_read_24(drive);
                                sectors = ((__u64)high << 24) | low;
                                printk(", LBAsect=%llu, high=%d, low=%d",
                                       (unsigned long long) sectors,
                                       high, low);
                        } else {
                                u8 cur = hwif->INB(IDE_SELECT_REG);
                                if (cur & 0x40) {       /* using LBA? */
                                        printk(", LBAsect=%ld", (unsigned long)
                                         ((cur&0xf)<<24)
                                         |(hwif->INB(IDE_HCYL_REG)<<16)
                                         |(hwif->INB(IDE_LCYL_REG)<<8)
                                         | hwif->INB(IDE_SECTOR_REG));
                                } else {
                                        printk(", CHS=%d/%d/%d",
                                         (hwif->INB(IDE_HCYL_REG)<<8) +
                                          hwif->INB(IDE_LCYL_REG),
                                          cur & 0xf,
                                          hwif->INB(IDE_SECTOR_REG));
                                }
                        }
                        if (HWGROUP(drive) && HWGROUP(drive)->rq)
                                printk(", sector=%llu",
                                        (unsigned long long)HWGROUP(drive)->rq->sector);
                }
                printk("\n");
        }
        ide_dump_opcode(drive);
        local_irq_restore(flags);
        return err;
}

/**
 *      ide_dump_atapi_status       -       print human readable atapi status
 *      @drive: drive that status applies to
 *      @msg: text message to print
 *      @stat: status byte to decode
 *
 *      Error reporting, in human readable form (luxurious, but a memory hog).
 */

static u8 ide_dump_atapi_status(ide_drive_t *drive, const char *msg, u8 stat)
{
        unsigned long flags;

        atapi_status_t status;
        atapi_error_t error;

        status.all = stat;
        error.all = 0;
        local_irq_save(flags);
        printk("%s: %s: status=0x%02x { ", drive->name, msg, stat);
        if (status.b.bsy)
                printk("Busy ");
        else {
                if (status.b.drdy)      printk("DriveReady ");
                if (status.b.df)        printk("DeviceFault ");
                if (status.b.dsc)       printk("SeekComplete ");
                if (status.b.drq)       printk("DataRequest ");
                if (status.b.corr)      printk("CorrectedError ");
                if (status.b.idx)       printk("Index ");
                if (status.b.check)     printk("Error ");
        }
        printk("}\n");
        if (status.b.check && !status.b.bsy) {
                error.all = HWIF(drive)->INB(IDE_ERROR_REG);
                printk("%s: %s: error=0x%02x { ", drive->name, msg, error.all);
                if (error.b.ili)        printk("IllegalLengthIndication ");
                if (error.b.eom)        printk("EndOfMedia ");
                if (error.b.abrt)       printk("AbortedCommand ");
                if (error.b.mcr)        printk("MediaChangeRequested ");
                if (error.b.sense_key)  printk("LastFailedSense=0x%02x ",
                                                error.b.sense_key);
                printk("}\n");
        }
        ide_dump_opcode(drive);
        local_irq_restore(flags);
        return error.all;
}

/**
 *      ide_dump_status         -       translate ATA/ATAPI error
 *      @drive: drive the error occured on
 *      @msg: information string
 *      @stat: status byte
 *
 *      Error reporting, in human readable form (luxurious, but a memory hog).
 *      Combines the drive name, message and status byte to provide a
 *      user understandable explanation of the device error.
 */

u8 ide_dump_status(ide_drive_t *drive, const char *msg, u8 stat)
{
        if (drive->media == ide_disk)
                return ide_dump_ata_status(drive, msg, stat);
        return ide_dump_atapi_status(drive, msg, stat);
}

EXPORT_SYMBOL(ide_dump_status);