/*
 *  Copyright (C) 2000-2002     Andre Hedrick <andre@linux-ide.org>
 *  Copyright (C) 2003          Red Hat
 *
 */

#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/ide.h>
#include <linux/bitops.h>
#include <linux/nmi.h>

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

void SELECT_MASK(ide_drive_t *drive, int mask)
{
        const struct ide_port_ops *port_ops = drive->hwif->port_ops;

        if (port_ops && port_ops->maskproc)
                port_ops->maskproc(drive, mask);
}

u8 ide_read_error(ide_drive_t *drive)
{
        struct ide_taskfile tf;

        drive->hwif->tp_ops->tf_read(drive, &tf, IDE_VALID_ERROR);

        return tf.error;
}
EXPORT_SYMBOL_GPL(ide_read_error);

void ide_fix_driveid(u16 *id)
{
#ifndef __LITTLE_ENDIAN
# ifdef __BIG_ENDIAN
        int i;

        for (i = 0; i < 256; i++)
                id[i] = __le16_to_cpu(id[i]);
# else
#  error "Please fix <asm/byteorder.h>"
# endif
#endif
}

/*
 * ide_fixstring() cleans up and (optionally) byte-swaps a text string,
 * removing leading/trailing blanks and compressing internal blanks.
 * It is primarily used to tidy up the model name/number fields as
 * returned by the ATA_CMD_ID_ATA[PI] commands.
 */

void ide_fixstring(u8 *s, const int bytecount, const int byteswap)
{
        u8 *p, *end = &s[bytecount & ~1]; /* bytecount must be even */

        if (byteswap) {
                /* convert from big-endian to host byte order */
                for (p = s ; p != end ; p += 2)
                        be16_to_cpus((u16 *) p);
        }

        /* strip leading blanks */
        p = s;
        while (s != end && *s == ' ')
                ++s;
        /* compress internal blanks and strip trailing blanks */
        while (s != end && *s) {
                if (*s++ != ' ' || (s != end && *s && *s != ' '))
                        *p++ = *(s-1);
        }
        /* wipe out trailing garbage */
        while (p != end)
                *p++ = '\0';
}
EXPORT_SYMBOL(ide_fixstring);

/*
 * This routine busy-waits for the drive status to be not "busy".
 * It then checks the status for all of the "good" bits and none
 * of the "bad" bits, and if all is okay it returns 0.  All other
 * cases return error -- caller may then invoke ide_error().
 *
 * This routine should get fixed to not hog the cpu during extra long waits..
 * That could be done by busy-waiting for the first jiffy or two, and then
 * setting a timer to wake up at half second intervals thereafter,
 * until timeout is achieved, before timing out.
 */
int __ide_wait_stat(ide_drive_t *drive, u8 good, u8 bad,
                    unsigned long timeout, u8 *rstat)
{
        ide_hwif_t *hwif = drive->hwif;
        const struct ide_tp_ops *tp_ops = hwif->tp_ops;
        unsigned long flags;
        int i;
        u8 stat;

        udelay(1);      /* spec allows drive 400ns to assert "BUSY" */
        stat = tp_ops->read_status(hwif);

        if (stat & ATA_BUSY) {
                local_save_flags(flags);
                local_irq_enable_in_hardirq();
                timeout += jiffies;
                while ((stat = tp_ops->read_status(hwif)) & ATA_BUSY) {
                        if (time_after(jiffies, timeout)) {
                                /*
                                 * One last read after the timeout in case
                                 * heavy interrupt load made us not make any
                                 * progress during the timeout..
                                 */
                                stat = tp_ops->read_status(hwif);
                                if ((stat & ATA_BUSY) == 0)
                                        break;

                                local_irq_restore(flags);
                                *rstat = stat;
                                return -EBUSY;
                        }
                }
                local_irq_restore(flags);
        }
        /*
         * Allow status to settle, then read it again.
         * A few rare drives vastly violate the 400ns spec here,
         * so we'll wait up to 10usec for a "good" status
         * rather than expensively fail things immediately.
         * This fix courtesy of Matthew Faupel & Niccolo Rigacci.
         */
        for (i = 0; i < 10; i++) {
                udelay(1);
                stat = tp_ops->read_status(hwif);

                if (OK_STAT(stat, good, bad)) {
                        *rstat = stat;
                        return 0;
                }
        }
        *rstat = stat;
        return -EFAULT;
}

/*
 * In case of error returns error value after doing "*startstop = ide_error()".
 * The caller should return the updated value of "startstop" in this case,
 * "startstop" is unchanged when the function returns 0.
 */
int ide_wait_stat(ide_startstop_t *startstop, ide_drive_t *drive, u8 good,
                  u8 bad, unsigned long timeout)
{
        int err;
        u8 stat;

        /* bail early if we've exceeded max_failures */
        if (drive->max_failures && (drive->failures > drive->max_failures)) {
                *startstop = ide_stopped;
                return 1;
        }

        err = __ide_wait_stat(drive, good, bad, timeout, &stat);

        if (err) {
                char *s = (err == -EBUSY) ? "status timeout" : "status error";
                *startstop = ide_error(drive, s, stat);
        }

        return err;
}
EXPORT_SYMBOL(ide_wait_stat);

/**
 *      ide_in_drive_list       -       look for drive in black/white list
 *      @id: drive identifier
 *      @table: list to inspect
 *
 *      Look for a drive in the blacklist and the whitelist tables
 *      Returns 1 if the drive is found in the table.
 */

int ide_in_drive_list(u16 *id, const struct drive_list_entry *table)
{
        for ( ; table->id_model; table++)
                if ((!strcmp(table->id_model, (char *)&id[ATA_ID_PROD])) &&
                    (!table->id_firmware ||
                     strstr((char *)&id[ATA_ID_FW_REV], table->id_firmware)))
                        return 1;
        return 0;
}
EXPORT_SYMBOL_GPL(ide_in_drive_list);

/*
 * Early UDMA66 devices don't set bit14 to 1, only bit13 is valid.
 * Some optical devices with the buggy firmwares have the same problem.
 */
static const struct drive_list_entry ivb_list[] = {
        { "QUANTUM FIREBALLlct10 05"    , "A03.0900"    },
        { "QUANTUM FIREBALLlct20 30"    , "APL.0900"    },
        { "TSSTcorp CDDVDW SH-S202J"    , "SB00"        },
        { "TSSTcorp CDDVDW SH-S202J"    , "SB01"        },
        { "TSSTcorp CDDVDW SH-S202N"    , "SB00"        },
        { "TSSTcorp CDDVDW SH-S202N"    , "SB01"        },
        { "TSSTcorp CDDVDW SH-S202H"    , "SB00"        },
        { "TSSTcorp CDDVDW SH-S202H"    , "SB01"        },
        { "SAMSUNG SP0822N"             , "WA100-10"    },
        { NULL                          , NULL          }
};

/*
 *  All hosts that use the 80c ribbon must use!
 *  The name is derived from upper byte of word 93 and the 80c ribbon.
 */
u8 eighty_ninty_three(ide_drive_t *drive)
{
        ide_hwif_t *hwif = drive->hwif;
        u16 *id = drive->id;
        int ivb = ide_in_drive_list(id, ivb_list);

        if (hwif->cbl == ATA_CBL_SATA || hwif->cbl == ATA_CBL_PATA40_SHORT)
                return 1;

        if (ivb)
                printk(KERN_DEBUG "%s: skipping word 93 validity check\n",
                                  drive->name);

        if (ata_id_is_sata(id) && !ivb)
                return 1;

        if (hwif->cbl != ATA_CBL_PATA80 && !ivb)
                goto no_80w;

        /*
         * FIXME:
         * - change master/slave IDENTIFY order
         * - force bit13 (80c cable present) check also for !ivb devices
         *   (unless the slave device is pre-ATA3)
         */
        if (id[ATA_ID_HW_CONFIG] & 0x4000)
                return 1;

        if (ivb) {
                const char *model = (char *)&id[ATA_ID_PROD];

                if (strstr(model, "TSSTcorp CDDVDW SH-S202")) {
                        /*
                         * These ATAPI devices always report 80c cable
                         * so we have to depend on the host in this case.
                         */
                        if (hwif->cbl == ATA_CBL_PATA80)
                                return 1;
                } else {
                        /* Depend on the device side cable detection. */
                        if (id[ATA_ID_HW_CONFIG] & 0x2000)
                                return 1;
                }
        }
no_80w:
        if (drive->dev_flags & IDE_DFLAG_UDMA33_WARNED)
                return 0;

        printk(KERN_WARNING "%s: %s side 80-wire cable detection failed, "
                            "limiting max speed to UDMA33\n",
                            drive->name,
                            hwif->cbl == ATA_CBL_PATA80 ? "drive" : "host");

        drive->dev_flags |= IDE_DFLAG_UDMA33_WARNED;

        return 0;
}

static const char *nien_quirk_list[] = {
        "QUANTUM FIREBALLlct08 08",
        "QUANTUM FIREBALLP KA6.4",
        "QUANTUM FIREBALLP KA9.1",
        "QUANTUM FIREBALLP KX13.6",
        "QUANTUM FIREBALLP KX20.5",
        "QUANTUM FIREBALLP KX27.3",
        "QUANTUM FIREBALLP LM20.4",
        "QUANTUM FIREBALLP LM20.5",
        "FUJITSU MHZ2160BH G2",
        NULL
};

void ide_check_nien_quirk_list(ide_drive_t *drive)
{
        const char **list, *m = (char *)&drive->id[ATA_ID_PROD];

        for (list = nien_quirk_list; *list != NULL; list++)
                if (strstr(m, *list) != NULL) {
                        drive->dev_flags |= IDE_DFLAG_NIEN_QUIRK;
                        return;
                }
}

int ide_driveid_update(ide_drive_t *drive)
{
        u16 *id;
        int rc;

        id = kmalloc(SECTOR_SIZE, GFP_ATOMIC);
        if (id == NULL)
                return 0;

        SELECT_MASK(drive, 1);
        rc = ide_dev_read_id(drive, ATA_CMD_ID_ATA, id, 1);
        SELECT_MASK(drive, 0);

        if (rc)
                goto out_err;

        drive->id[ATA_ID_UDMA_MODES]  = id[ATA_ID_UDMA_MODES];
        drive->id[ATA_ID_MWDMA_MODES] = id[ATA_ID_MWDMA_MODES];
        drive->id[ATA_ID_SWDMA_MODES] = id[ATA_ID_SWDMA_MODES];
        drive->id[ATA_ID_CFA_MODES]   = id[ATA_ID_CFA_MODES];
        /* anything more ? */

        kfree(id);

        return 1;
out_err:
        if (rc == 2)
                printk(KERN_ERR "%s: %s: bad status\n", drive->name, __func__);
        kfree(id);
        return 0;
}

int ide_config_drive_speed(ide_drive_t *drive, u8 speed)
{
        ide_hwif_t *hwif = drive->hwif;
        const struct ide_tp_ops *tp_ops = hwif->tp_ops;
        struct ide_taskfile tf;
        u16 *id = drive->id, i;
        int error = 0;
        u8 stat;

#ifdef CONFIG_BLK_DEV_IDEDMA
        if (hwif->dma_ops)      /* check if host supports DMA */
                hwif->dma_ops->dma_host_set(drive, 0);
#endif

        /* Skip setting PIO flow-control modes on pre-EIDE drives */
        if ((speed & 0xf8) == XFER_PIO_0 && ata_id_has_iordy(drive->id) == 0)
                goto skip;

        /*
         * Don't use ide_wait_cmd here - it will
         * attempt to set_geometry and recalibrate,
         * but for some reason these don't work at
         * this point (lost interrupt).
         */

        udelay(1);
        tp_ops->dev_select(drive);
        SELECT_MASK(drive, 1);
        udelay(1);
        tp_ops->write_devctl(hwif, ATA_NIEN | ATA_DEVCTL_OBS);

        memset(&tf, 0, sizeof(tf));
        tf.feature = SETFEATURES_XFER;
        tf.nsect   = speed;

        tp_ops->tf_load(drive, &tf, IDE_VALID_FEATURE | IDE_VALID_NSECT);

        tp_ops->exec_command(hwif, ATA_CMD_SET_FEATURES);

        if (drive->dev_flags & IDE_DFLAG_NIEN_QUIRK)
                tp_ops->write_devctl(hwif, ATA_DEVCTL_OBS);

        error = __ide_wait_stat(drive, drive->ready_stat,
                                ATA_BUSY | ATA_DRQ | ATA_ERR,
                                WAIT_CMD, &stat);

        SELECT_MASK(drive, 0);

        if (error) {
                (void) ide_dump_status(drive, "set_drive_speed_status", stat);
                return error;
        }

        if (speed >= XFER_SW_DMA_0) {
                id[ATA_ID_UDMA_MODES]  &= ~0xFF00;
                id[ATA_ID_MWDMA_MODES] &= ~0x0700;
                id[ATA_ID_SWDMA_MODES] &= ~0x0700;
                if (ata_id_is_cfa(id))
                        id[ATA_ID_CFA_MODES] &= ~0x0E00;
        } else  if (ata_id_is_cfa(id))
                id[ATA_ID_CFA_MODES] &= ~0x01C0;

 skip:
#ifdef CONFIG_BLK_DEV_IDEDMA
        if (speed >= XFER_SW_DMA_0 && (drive->dev_flags & IDE_DFLAG_USING_DMA))
                hwif->dma_ops->dma_host_set(drive, 1);
        else if (hwif->dma_ops) /* check if host supports DMA */
                ide_dma_off_quietly(drive);
#endif

        if (speed >= XFER_UDMA_0) {
                i = 1 << (speed - XFER_UDMA_0);
                id[ATA_ID_UDMA_MODES] |= (i << 8 | i);
        } else if (ata_id_is_cfa(id) && speed >= XFER_MW_DMA_3) {
                i = speed - XFER_MW_DMA_2;
                id[ATA_ID_CFA_MODES] |= i << 9;
        } else if (speed >= XFER_MW_DMA_0) {
                i = 1 << (speed - XFER_MW_DMA_0);
                id[ATA_ID_MWDMA_MODES] |= (i << 8 | i);
        } else if (speed >= XFER_SW_DMA_0) {
                i = 1 << (speed - XFER_SW_DMA_0);
                id[ATA_ID_SWDMA_MODES] |= (i << 8 | i);
        } else if (ata_id_is_cfa(id) && speed >= XFER_PIO_5) {
                i = speed - XFER_PIO_4;
                id[ATA_ID_CFA_MODES] |= i << 6;
        }

        if (!drive->init_speed)
                drive->init_speed = speed;
        drive->current_speed = speed;
        return error;
}

/*
 * This should get invoked any time we exit the driver to
 * wait for an interrupt response from a drive.  handler() points
 * at the appropriate code to handle the next interrupt, and a
 * timer is started to prevent us from waiting forever in case
 * something goes wrong (see the ide_timer_expiry() handler later on).
 *
 * See also ide_execute_command
 */
void __ide_set_handler(ide_drive_t *drive, ide_handler_t *handler,
                       unsigned int timeout)
{
        ide_hwif_t *hwif = drive->hwif;

        BUG_ON(hwif->handler);
        hwif->handler           = handler;
        hwif->timer.expires     = jiffies + timeout;
        hwif->req_gen_timer     = hwif->req_gen;
        add_timer(&hwif->timer);
}

void ide_set_handler(ide_drive_t *drive, ide_handler_t *handler,
                     unsigned int timeout)
{
        ide_hwif_t *hwif = drive->hwif;
        unsigned long flags;

        spin_lock_irqsave(&hwif->lock, flags);
        __ide_set_handler(drive, handler, timeout);
        spin_unlock_irqrestore(&hwif->lock, flags);
}
EXPORT_SYMBOL(ide_set_handler);

/**
 *      ide_execute_command     -       execute an IDE command
 *      @drive: IDE drive to issue the command against
 *      @cmd: command
 *      @handler: handler for next phase
 *      @timeout: timeout for command
 *
 *      Helper function to issue an IDE command. This handles the
 *      atomicity requirements, command timing and ensures that the
 *      handler and IRQ setup do not race. All IDE command kick off
 *      should go via this function or do equivalent locking.
 */

void ide_execute_command(ide_drive_t *drive, struct ide_cmd *cmd,
                         ide_handler_t *handler, unsigned timeout)
{
        ide_hwif_t *hwif = drive->hwif;
        unsigned long flags;

        spin_lock_irqsave(&hwif->lock, flags);
        if ((cmd->protocol != ATAPI_PROT_DMA &&
             cmd->protocol != ATAPI_PROT_PIO) ||
            (drive->atapi_flags & IDE_AFLAG_DRQ_INTERRUPT))
                __ide_set_handler(drive, handler, timeout);
        hwif->tp_ops->exec_command(hwif, cmd->tf.command);
        /*
         * Drive takes 400nS to respond, we must avoid the IRQ being
         * serviced before that.
         *
         * FIXME: we could skip this delay with care on non shared devices
         */
        ndelay(400);
        spin_unlock_irqrestore(&hwif->lock, flags);
}

/*
 * ide_wait_not_busy() waits for the currently selected device on the hwif
 * to report a non-busy status, see comments in ide_probe_port().
 */
int ide_wait_not_busy(ide_hwif_t *hwif, unsigned long timeout)
{
        u8 stat = 0;

        while (timeout--) {
                /*
                 * Turn this into a schedule() sleep once I'm sure
                 * about locking issues (2.5 work ?).
                 */
                mdelay(1);
                stat = hwif->tp_ops->read_status(hwif);
                if ((stat & ATA_BUSY) == 0)
                        return 0;
                /*
                 * Assume a value of 0xff means nothing is connected to
                 * the interface and it doesn't implement the pull-down
                 * resistor on D7.
                 */
                if (stat == 0xff)
                        return -ENODEV;
                touch_softlockup_watchdog();
                touch_nmi_watchdog();
        }
        return -EBUSY;
}