/* ps2esdi driver based on assembler code by Arindam Banerji,
   written by Peter De Schrijver */
/* Reassuring note to IBM : This driver was NOT developed by vice-versa
   engineering the PS/2's BIOS */
/* Dedicated to Wannes, Tofke, Ykke, Godot, Killroy and all those 
   other lovely fish out there... */
/* This code was written during the long and boring WINA 
   elections 1994 */
/* Thanks to Arindam Banerij for giving me the source of his driver */
/* This code may be freely distributed and modified in any way, 
   as long as these notes remain intact */

/*  Revised: 05/07/94 by Arindam Banerji (axb@cse.nd.edu) */
/*  Revised: 09/08/94 by Peter De Schrijver (stud11@cc4.kuleuven.ac.be)
   Thanks to Arindam Banerij for sending me the docs of the adapter */

/* BA Modified for ThinkPad 720 by Boris Ashkinazi */
/*                    (bash@vnet.ibm.com) 08/08/95 */

/* Modified further for ThinkPad-720C by Uri Blumenthal */
/*                    (uri@watson.ibm.com) Sep 11, 1995 */

/* TODO : 
   + Timeouts
   + Get disk parameters
   + DMA above 16MB
   + reset after read/write error
 */

#include <linux/config.h>
#include <linux/major.h>

#ifdef  CONFIG_BLK_DEV_PS2

#define MAJOR_NR PS2ESDI_MAJOR

#include <linux/errno.h>
#include <linux/sched.h>
#include <linux/mm.h>
#include <linux/fs.h>
#include <linux/kernel.h>
#include <linux/genhd.h>
#include <linux/ps2esdi.h>
#include <linux/devfs_fs_kernel.h>
#include <linux/blk.h>
#include <linux/blkpg.h>
#include <linux/mca.h>
#include <linux/init.h>
#include <linux/ioport.h>
#include <linux/module.h>

#include <asm/system.h>
#include <asm/io.h>
#include <asm/segment.h>
#include <asm/dma.h>
#include <asm/mca_dma.h>
#include <asm/uaccess.h>

#define PS2ESDI_IRQ 14
#define MAX_HD 2
#define MAX_RETRIES 5
#define MAX_16BIT 65536
#define ESDI_TIMEOUT   0xf000
#define ESDI_STAT_TIMEOUT 4

#define TYPE_0_CMD_BLK_LENGTH 2
#define TYPE_1_CMD_BLK_LENGTH 4


static void reset_ctrl(void);

int ps2esdi_init(void);

static void ps2esdi_geninit(void);

static void do_ps2esdi_request(request_queue_t * q);

static void ps2esdi_readwrite(int cmd, u_char drive, u_int block, u_int count);

static void ps2esdi_fill_cmd_block(u_short * cmd_blk, u_short cmd,
u_short cyl, u_short head, u_short sector, u_short length, u_char drive);

static int ps2esdi_out_cmd_blk(u_short * cmd_blk);

static void ps2esdi_prep_dma(char *buffer, u_short length, u_char dma_xmode);

static void ps2esdi_interrupt_handler(int irq, void *dev_id,
                                      struct pt_regs *regs);
static void (*current_int_handler) (u_int) = NULL;
static void ps2esdi_normal_interrupt_handler(u_int);
static void ps2esdi_initial_reset_int_handler(u_int);
static void ps2esdi_geometry_int_handler(u_int);

static int ps2esdi_open(struct inode *inode, struct file *file);

static int ps2esdi_release(struct inode *inode, struct file *file);

static int ps2esdi_ioctl(struct inode *inode, struct file *file,
                         u_int cmd, u_long arg);

static int ps2esdi_reread_partitions(kdev_t dev);

static int ps2esdi_read_status_words(int num_words, int max_words, u_short * buffer);

static void dump_cmd_complete_status(u_int int_ret_code);

static void ps2esdi_get_device_cfg(void);

static void ps2esdi_reset_timer(unsigned long unused);

static u_int dma_arb_level;             /* DMA arbitration level */

static DECLARE_WAIT_QUEUE_HEAD(ps2esdi_int);
static DECLARE_WAIT_QUEUE_HEAD(ps2esdi_wait_open);

static int no_int_yet;
static int access_count[MAX_HD];
static char ps2esdi_valid[MAX_HD];
static int ps2esdi_sizes[MAX_HD << 6];
static int ps2esdi_blocksizes[MAX_HD << 6];
static int ps2esdi_maxsect[MAX_HD << 6];
static int ps2esdi_drives;
static struct hd_struct ps2esdi[MAX_HD << 6];
static u_short io_base;
static struct timer_list esdi_timer = { function: ps2esdi_reset_timer };
static int reset_status;
static int ps2esdi_slot = -1;
static int tp720esdi = 0;       /* Is it Integrated ESDI of ThinkPad-720? */
static int intg_esdi = 0;       /* If integrated adapter */
struct ps2esdi_i_struct {
        unsigned int head, sect, cyl, wpcom, lzone, ctl;
};

#if 0
#if 0                           /* try both - I don't know which one is better... UB */
static struct ps2esdi_i_struct ps2esdi_info[MAX_HD] =
{
        {4, 48, 1553, 0, 0, 0},
        {0, 0, 0, 0, 0, 0}};
#else
static struct ps2esdi_i_struct ps2esdi_info[MAX_HD] =
{
        {64, 32, 161, 0, 0, 0},
        {0, 0, 0, 0, 0, 0}};
#endif
#endif
static struct ps2esdi_i_struct ps2esdi_info[MAX_HD] =
{
        {0, 0, 0, 0, 0, 0},
        {0, 0, 0, 0, 0, 0}};

static struct block_device_operations ps2esdi_fops =
{
        owner:          THIS_MODULE,
        open:           ps2esdi_open,
        release:        ps2esdi_release,
        ioctl:          ps2esdi_ioctl,
};

static struct gendisk ps2esdi_gendisk =
{
        major:          MAJOR_NR,
        major_name:     "ed",
        minor_shift:    6,
        max_p:          1 << 6,
        part:           ps2esdi,
        sizes:          ps2esdi_sizes,
        real_devices:   (void *)ps2esdi_info,
        fops:           &ps2esdi_fops,
};

/* initialization routine called by ll_rw_blk.c   */
int __init ps2esdi_init(void)
{

        /* register the device - pass the name, major number and operations
           vector .                                                 */
        if (devfs_register_blkdev(MAJOR_NR, "ed", &ps2esdi_fops)) {
                printk("%s: Unable to get major number %d\n", DEVICE_NAME, MAJOR_NR);
                return -1;
        }
        /* set up some global information - indicating device specific info */
        blk_init_queue(BLK_DEFAULT_QUEUE(MAJOR_NR), DEVICE_REQUEST);
        read_ahead[MAJOR_NR] = 8;       /* 8 sector (4kB) read ahead */

        /* some minor housekeeping - setup the global gendisk structure */
        add_gendisk(&ps2esdi_gendisk);
        ps2esdi_geninit();
        return 0;
}                               /* ps2esdi_init */

#ifdef MODULE

static int cyl[MAX_HD] = {-1,-1};
static int head[MAX_HD] = {-1, -1};
static int sect[MAX_HD] = {-1, -1};

MODULE_PARM(tp720esdi, "i");
MODULE_PARM(cyl, "i");
MODULE_PARM(head, "i");
MODULE_PARM(track, "i");
MODULE_LICENSE("GPL");

int init_module(void) {
        int drive;

        for(drive = 0; drive < MAX_HD; drive++) {
                struct ps2_esdi_i_struct *info = &ps2esdi_info[drive];

                if (cyl[drive] != -1) {
                        info->cyl = info->lzone = cyl[drive];
                        info->wpcom = 0;
                }
                if (head[drive] != -1) {
                        info->head = head[drive];
                        info->ctl = (head[drive] > 8 ? 8 : 0);
                }
                if (sect[drive] != -1) info->sect = sect[drive];
        }
        return ps2esdi_init();
}

void
cleanup_module(void)
{
        if(ps2esdi_slot) {
                mca_mark_as_unused(ps2esdi_slot);
                mca_set_adapter_procfn(ps2esdi_slot, NULL, NULL);
        }
        release_region(io_base, 4);
        free_dma(dma_arb_level);
        free_irq(PS2ESDI_IRQ, NULL);
        devfs_unregister_blkdev(MAJOR_NR, "ed");
        del_gendisk(&ps2esdi_gendisk);
        blk_cleanup_queue(BLK_DEFAULT_QUEUE(MAJOR_NR));
}
#endif /* MODULE */

/* handles boot time command line parameters */
void __init tp720_setup(char *str, int *ints)
{
        /* no params, just sets the tp720esdi flag if it exists */

        printk("%s: TP 720 ESDI flag set\n", DEVICE_NAME);
        tp720esdi = 1;
}

void __init ed_setup(char *str, int *ints)
{
        int hdind = 0;

        /* handles 3 parameters only - corresponding to
           1. Number of cylinders
           2. Number of heads
           3. Sectors/track
         */

        if (ints[0] != 3)
                return;

        /* print out the information - seen at boot time */
        printk("%s: ints[0]=%d ints[1]=%d ints[2]=%d ints[3]=%d\n",
               DEVICE_NAME, ints[0], ints[1], ints[2], ints[3]);

        /* set the index into device specific information table */
        if (ps2esdi_info[0].head != 0)
                hdind = 1;

        /* set up all the device information */
        ps2esdi_info[hdind].head = ints[2];
        ps2esdi_info[hdind].sect = ints[3];
        ps2esdi_info[hdind].cyl = ints[1];
        ps2esdi_info[hdind].wpcom = 0;
        ps2esdi_info[hdind].lzone = ints[1];
        ps2esdi_info[hdind].ctl = (ints[2] > 8 ? 8 : 0);
#if 0                           /* this may be needed for PS2/Mod.80, but it hurts ThinkPad! */
        ps2esdi_drives = hdind + 1;     /* increment index for the next time */
#endif
}                               /* ed_setup */

static int ps2esdi_getinfo(char *buf, int slot, void *d)
{
        int len = 0;

        len += sprintf(buf + len, "DMA Arbitration Level: %d\n",
                       dma_arb_level);
        len += sprintf(buf + len, "IO Port: %x\n", io_base);
        len += sprintf(buf + len, "IRQ: 14\n");
        len += sprintf(buf + len, "Drives: %d\n", ps2esdi_drives);

        return len;
}

/* ps2 esdi specific initialization - called thru the gendisk chain */
static void __init ps2esdi_geninit(void)
{
        /*
           The first part contains the initialization code
           for the ESDI disk subsystem.  All we really do
           is search for the POS registers of the controller
           to do some simple setup operations.  First, we
           must ensure that the controller is installed,
           enabled, and configured as PRIMARY.  Then we must
           determine the DMA arbitration level being used by
           the controller so we can handle data transfer
           operations properly.  If all of this works, then
           we will set the INIT_FLAG to a non-zero value.
         */

        int slot = 0, i, reset_start, reset_end;
        u_char status;
        unsigned short adapterID;

        if ((slot = mca_find_adapter(INTG_ESDI_ID, 0)) != MCA_NOTFOUND) {
                adapterID = INTG_ESDI_ID;
                printk("%s: integrated ESDI adapter found in slot %d\n",
                       DEVICE_NAME, slot+1);
#ifndef MODULE
                mca_set_adapter_name(slot, "PS/2 Integrated ESDI");
#endif
        } else if ((slot = mca_find_adapter(NRML_ESDI_ID, 0)) != -1) {
                adapterID = NRML_ESDI_ID;
                printk("%s: normal ESDI adapter found in slot %d\n",
                       DEVICE_NAME, slot+1);
                mca_set_adapter_name(slot, "PS/2 ESDI");
        } else {
                return;
        }

        ps2esdi_slot = slot;
        mca_mark_as_used(slot);
        mca_set_adapter_procfn(slot, (MCA_ProcFn) ps2esdi_getinfo, NULL);

        /* Found the slot - read the POS register 2 to get the necessary
           configuration and status information.  POS register 2 has the
           following information :
           Bit           Function
           7             reserved = 0
           6             arbitration method
           0 - fairness enabled
           1 - fairness disabled, linear priority assignment
           5-2           arbitration level
           1             alternate address
           1              alternate address
           0 - use addresses 0x3510 - 0x3517
           0             adapter enable
         */

        status = mca_read_stored_pos(slot, 2);
        /* is it enabled ? */
        if (!(status & STATUS_ENABLED)) {
                printk("%s: ESDI adapter disabled\n", DEVICE_NAME);
                return;
        }
        /* try to grab IRQ, and try to grab a slow IRQ if it fails, so we can
           share with the SCSI driver */
        if (request_irq(PS2ESDI_IRQ, ps2esdi_interrupt_handler,
                  SA_INTERRUPT | SA_SHIRQ, "PS/2 ESDI", &ps2esdi_gendisk)
            && request_irq(PS2ESDI_IRQ, ps2esdi_interrupt_handler,
                           SA_SHIRQ, "PS/2 ESDI", &ps2esdi_gendisk)
            ) {
                printk("%s: Unable to get IRQ %d\n", DEVICE_NAME, PS2ESDI_IRQ);
                return;
        }
        if (status & STATUS_ALTERNATE)
                io_base = ALT_IO_BASE;
        else
                io_base = PRIMARY_IO_BASE;

        /* get the dma arbitration level */
        dma_arb_level = (status >> 2) & 0xf;

        /* BA */
        printk("%s: DMA arbitration level : %d\n",
               DEVICE_NAME, dma_arb_level);

        LITE_ON;
        current_int_handler = ps2esdi_initial_reset_int_handler;
        reset_ctrl();
        reset_status = 0;
        reset_start = jiffies;
        while (!reset_status) {
                init_timer(&esdi_timer);
                esdi_timer.expires = jiffies + HZ;
                esdi_timer.data = 0;
                add_timer(&esdi_timer);
                sleep_on(&ps2esdi_int);
        }
        reset_end = jiffies;
        LITE_OFF;
        printk("%s: reset interrupt after %d jiffies,  %u.%02u secs\n",
               DEVICE_NAME, reset_end - reset_start, (reset_end - reset_start) / HZ,
               (reset_end - reset_start) % HZ);


        /* Integrated ESDI Disk and Controller has only one drive! */
        if (adapterID == INTG_ESDI_ID) {/* if not "normal" PS2 ESDI adapter */
                ps2esdi_drives = 1;     /* then we have only one physical disk! */              intg_esdi = 1;
        }



        /* finally this part sets up some global data structures etc. */

        ps2esdi_get_device_cfg();

        /* some annoyance in the above routine returns TWO drives?
         Is something else happining in the background?
         Regaurdless we fix the # of drives again. AJK */
        /* Integrated ESDI Disk and Controller has only one drive! */
        if (adapterID == INTG_ESDI_ID)  /* if not "normal" PS2 ESDI adapter */
                ps2esdi_drives = 1;     /* Not three or two, ONE DAMNIT! */

        current_int_handler = ps2esdi_normal_interrupt_handler;

        ps2esdi_gendisk.nr_real = ps2esdi_drives;

        /* 128 was old default, maybe maxsect=255 is ok too? - Paul G. */
        for (i = 0; i < (MAX_HD << 6); i++) {
                ps2esdi_maxsect[i] = 128;
                ps2esdi_blocksizes[i] = 1024;
        }

        request_dma(dma_arb_level, "ed");
        request_region(io_base, 4, "ed");
        blksize_size[MAJOR_NR] = ps2esdi_blocksizes;
        max_sectors[MAJOR_NR] = ps2esdi_maxsect;

        for (i = 0; i < ps2esdi_drives; i++) {
                register_disk(&ps2esdi_gendisk,MKDEV(MAJOR_NR,i<<6),1<<6,
                                &ps2esdi_fops,
                                ps2esdi_info[i].head * ps2esdi_info[i].sect *
                                ps2esdi_info[i].cyl);
                ps2esdi_valid[i] = 1;
        }
}

static void __init ps2esdi_get_device_cfg(void)
{
        u_short cmd_blk[TYPE_0_CMD_BLK_LENGTH];

        /*BA */ printk("%s: Drive 0\n", DEVICE_NAME);
        current_int_handler = ps2esdi_geometry_int_handler;
        cmd_blk[0] = CMD_GET_DEV_CONFIG | 0x600;
        cmd_blk[1] = 0;
        no_int_yet = TRUE;
        ps2esdi_out_cmd_blk(cmd_blk);
        if (no_int_yet)
                sleep_on(&ps2esdi_int);

        if (ps2esdi_drives > 1) {
                printk("%s: Drive 1\n", DEVICE_NAME);   /*BA */
                cmd_blk[0] = CMD_GET_DEV_CONFIG | (1 << 5) | 0x600;
                cmd_blk[1] = 0;
                no_int_yet = TRUE;
                ps2esdi_out_cmd_blk(cmd_blk);
                if (no_int_yet)
                        sleep_on(&ps2esdi_int);
        }                       /* if second physical drive is present */
        return;
}

/* strategy routine that handles most of the IO requests */
static void do_ps2esdi_request(request_queue_t * q)
{
        u_int block, count;
        /* since, this routine is called with interrupts cleared - they 
           must be before it finishes  */

#if 0
        printk("%s:got request. device : %d minor : %d command : %d  sector : %ld count : %ld, buffer: %p\n",
               DEVICE_NAME,
               CURRENT_DEV, MINOR(CURRENT->rq_dev),
               CURRENT->cmd, CURRENT->sector,
               CURRENT->current_nr_sectors, CURRENT->buffer);
#endif

        /* standard macro that ensures that requests are really on the
           list + sanity checks.                     */
        INIT_REQUEST;

        if (virt_to_bus(CURRENT->buffer + CURRENT->current_nr_sectors * 512) > 16 * MB) {
                printk("%s: DMA above 16MB not supported\n", DEVICE_NAME);
                end_request(FAIL);
        }                       /* check for above 16Mb dmas */
        else if ((CURRENT_DEV < ps2esdi_drives) &&
            (CURRENT->sector + CURRENT->current_nr_sectors <=
             ps2esdi[MINOR(CURRENT->rq_dev)].nr_sects)) {
#if 0
                printk("%s:got request. device : %d minor : %d command : %d  sector : %ld count : %ld\n",
                       DEVICE_NAME,
                       CURRENT_DEV, MINOR(CURRENT->rq_dev),
                       CURRENT->cmd, CURRENT->sector,
                       CURRENT->current_nr_sectors);
#endif


                block = CURRENT->sector + ps2esdi[MINOR(CURRENT->rq_dev)].start_sect;

#if 0
                printk("%s: blocknumber : %d\n", DEVICE_NAME, block);
#endif
                count = CURRENT->current_nr_sectors;
                switch (CURRENT->cmd) {
                case READ:
                        ps2esdi_readwrite(READ, CURRENT_DEV, block, count);
                        break;
                case WRITE:
                        ps2esdi_readwrite(WRITE, CURRENT_DEV, block, count);
                        break;
                default:
                        printk("%s: Unknown command\n", DEVICE_NAME);
                        end_request(FAIL);
                        break;
                }               /* handle different commands */
        }
        /* is request is valid */ 
        else {
                printk("Grrr. error. ps2esdi_drives: %d, %lu %lu\n", ps2esdi_drives,
                       CURRENT->sector, ps2esdi[MINOR(CURRENT->rq_dev)].nr_sects);
                end_request(FAIL);
        }

}                               /* main strategy routine */

/* resets the ESDI adapter */
static void reset_ctrl(void)
{

        u_long expire;
        u_short status;

        /* enable interrupts on the controller */
        status = inb(ESDI_INTRPT);
        outb((status & 0xe0) | ATT_EOI, ESDI_ATTN);     /* to be sure we don't have
                                                           any interrupt pending... */
        outb_p(CTRL_ENABLE_INTR, ESDI_CONTROL);

        /* read the ESDI status port - if the controller is not busy,
           simply do a soft reset (fast) - otherwise we'll have to do a
           hard (slow) reset.  */
        if (!(inb_p(ESDI_STATUS) & STATUS_BUSY)) {
                /*BA */ printk("%s: soft reset...\n", DEVICE_NAME);
                outb_p(CTRL_SOFT_RESET, ESDI_ATTN);
        }
        /* soft reset */ 
        else {
                /*BA */
                printk("%s: hard reset...\n", DEVICE_NAME);
                outb_p(CTRL_HARD_RESET, ESDI_CONTROL);
                expire = jiffies + 2*HZ;
                while (time_before(jiffies, expire));
                outb_p(1, ESDI_CONTROL);
        }                       /* hard reset */


}                               /* reset the controller */

/* called by the strategy routine to handle read and write requests */
static void ps2esdi_readwrite(int cmd, u_char drive, u_int block, u_int count)
{

        u_short track, head, cylinder, sector;
        u_short cmd_blk[TYPE_1_CMD_BLK_LENGTH];
        int err;

        /* do some relevant arithmatic */
        track = block / ps2esdi_info[drive].sect;
        head = track % ps2esdi_info[drive].head;
        cylinder = track / ps2esdi_info[drive].head;
        sector = block % ps2esdi_info[drive].sect;

#if 0
        printk("%s: cyl=%d head=%d sect=%d\n", DEVICE_NAME, cylinder, head, sector);
#endif
        /* call the routine that actually fills out a command block */
        ps2esdi_fill_cmd_block
            (cmd_blk,
             (cmd == READ) ? CMD_READ : CMD_WRITE,
             cylinder, head, sector,
             CURRENT->current_nr_sectors, drive);

        spin_unlock_irq(&io_request_lock);
        /* send the command block to the controller */
        err = ps2esdi_out_cmd_blk(cmd_blk);
        spin_lock_irq(&io_request_lock);
        
        if (err) {
                printk(KERN_ERR "%s: Controller failed\n", DEVICE_NAME);
                if ((++CURRENT->errors) >= MAX_RETRIES)
                        end_request(FAIL);
        }
        /* check for failure to put out the command block */ 
        else {
#if 0
                printk("%s: waiting for xfer\n", DEVICE_NAME);
#endif
                /* turn disk lights on */
                LITE_ON;
        }

}                               /* ps2esdi_readwrite */

/* fill out the command block */
static void ps2esdi_fill_cmd_block(u_short * cmd_blk, u_short cmd,
 u_short cyl, u_short head, u_short sector, u_short length, u_char drive)
{

        cmd_blk[0] = (drive << 5) | cmd;
        cmd_blk[1] = length;
        cmd_blk[2] = ((cyl & 0x1f) << 11) | (head << 5) | sector;
        cmd_blk[3] = (cyl & 0x3E0) >> 5;

}                               /* fill out the command block */

/* write a command block to the controller */
static int ps2esdi_out_cmd_blk(u_short * cmd_blk)
{

        int i, j;
        u_char status;

        /* enable interrupts */
        outb(CTRL_ENABLE_INTR, ESDI_CONTROL);

        /* do not write to the controller, if it is busy */
        for (i = jiffies + ESDI_STAT_TIMEOUT; time_after(i, jiffies) && (inb(ESDI_STATUS) &
                                                          STATUS_BUSY););

#if 0
        printk("%s: i(1)=%d\n", DEVICE_NAME, i);
#endif

        /* if device is still busy - then just time out */
        if (inb(ESDI_STATUS) & STATUS_BUSY) {
                printk("%s: ps2esdi_out_cmd timed out (1)\n", DEVICE_NAME);
                return ERROR;
        }                       /* timeout ??? */
        /* Set up the attention register in the controller */
        outb(((*cmd_blk) & 0xE0) | 1, ESDI_ATTN);

#if 0
        printk("%s: sending %d words to controller\n", DEVICE_NAME, (((*cmd_blk) >> 14) + 1) << 1);
#endif

        /* one by one send each word out */
        for (i = (((*cmd_blk) >> 14) + 1) << 1; i; i--) {
                status = inb(ESDI_STATUS);
                for (j = jiffies + ESDI_STAT_TIMEOUT;
                     time_after(j, jiffies) && (status & STATUS_BUSY) &&
                   (status & STATUS_CMD_INF); status = inb(ESDI_STATUS));
                if ((status & (STATUS_BUSY | STATUS_CMD_INF)) == STATUS_BUSY) {
#if 0
                        printk("%s: sending %04X\n", DEVICE_NAME, *cmd_blk);
#endif
                        outw(*cmd_blk++, ESDI_CMD_INT);
                } else {
                        printk("%s: ps2esdi_out_cmd timed out while sending command (status=%02X)\n",
                               DEVICE_NAME, status);
                        return ERROR;
                }
        }                       /* send all words out */
        return OK;
}                               /* send out the commands */


/* prepare for dma - do all the necessary setup */
static void ps2esdi_prep_dma(char *buffer, u_short length, u_char dma_xmode)
{
        unsigned long flags;
#if 0
        printk("ps2esdi: b_wait: %p\n", &CURRENT->bh->b_wait);
#endif
        flags = claim_dma_lock();

        mca_disable_dma(dma_arb_level);

        mca_set_dma_addr(dma_arb_level, virt_to_bus(buffer));

        mca_set_dma_count(dma_arb_level, length * 512 / 2);

        mca_set_dma_mode(dma_arb_level, dma_xmode);

        mca_enable_dma(dma_arb_level);

        release_dma_lock(flags);

}                               /* prepare for dma */



static void ps2esdi_interrupt_handler(int irq, void *dev_id,
                                      struct pt_regs *regs)
{
        u_int int_ret_code;

        if (inb(ESDI_STATUS) & STATUS_INTR) {
                int_ret_code = inb(ESDI_INTRPT);
                if (current_int_handler) {
                        /* Disable adapter interrupts till processing is finished */
                        outb(CTRL_DISABLE_INTR, ESDI_CONTROL);
                        current_int_handler(int_ret_code);
                } else
                        printk("%s: help ! No interrupt handler.\n", DEVICE_NAME);
        } else {
                return;
        }
}

static void ps2esdi_initial_reset_int_handler(u_int int_ret_code)
{

        switch (int_ret_code & 0xf) {
        case INT_RESET:
                /*BA */
                printk("%s: initial reset completed.\n", DEVICE_NAME);
                outb((int_ret_code & 0xe0) | ATT_EOI, ESDI_ATTN);
                wake_up(&ps2esdi_int);
                break;
        case INT_ATTN_ERROR:
                printk("%s: Attention error. interrupt status : %02X\n", DEVICE_NAME,
                       int_ret_code);
                printk("%s: status: %02x\n", DEVICE_NAME, inb(ESDI_STATUS));
                break;
        default:
                printk("%s: initial reset handler received interrupt: %02X\n",
                       DEVICE_NAME, int_ret_code);
                outb((int_ret_code & 0xe0) | ATT_EOI, ESDI_ATTN);
                break;
        }
        outb(CTRL_ENABLE_INTR, ESDI_CONTROL);
}


static void ps2esdi_geometry_int_handler(u_int int_ret_code)
{
        u_int status, drive_num;
        unsigned long rba;
        int i;

        drive_num = int_ret_code >> 5;
        switch (int_ret_code & 0xf) {
        case INT_CMD_COMPLETE:
                for (i = ESDI_TIMEOUT; i & !(inb(ESDI_STATUS) & STATUS_STAT_AVAIL); i--);
                if (!(inb(ESDI_STATUS) & STATUS_STAT_AVAIL)) {
                        printk("%s: timeout reading status word\n", DEVICE_NAME);
                        outb((int_ret_code & 0xe0) | ATT_EOI, ESDI_ATTN);
                        break;
                }
                status = inw(ESDI_STT_INT);
                if ((status & 0x1F) == CMD_GET_DEV_CONFIG) {
#define REPLY_WORDS 5           /* we already read word 0 */
                        u_short reply[REPLY_WORDS];

                        if (ps2esdi_read_status_words((status >> 8) - 1, REPLY_WORDS, reply)) {
                                /*BA */
                                printk("%s: Device Configuration Status for drive %u\n",
                                       DEVICE_NAME, drive_num);

                                printk("%s: Spares/cyls: %u", DEVICE_NAME, reply[0] >> 8);

                                printk
                                    ("Config bits: %s%s%s%s%s\n",
                                     (reply[0] & CONFIG_IS) ? "Invalid Secondary, " : "",
                                     ((reply[0] & CONFIG_ZD) && !(reply[0] & CONFIG_IS))
                                 ? "Zero Defect, " : "Defects Present, ",
                                     (reply[0] & CONFIG_SF) ? "Skewed Format, " : "",
                                     (reply[0] & CONFIG_FR) ? "Removable, " : "Non-Removable, ",
                                     (reply[0] & CONFIG_RT) ? "No Retries" : "Retries");

                                rba = reply[1] | ((unsigned long) reply[2] << 16);
                                printk("%s: Number of RBA's: %lu\n", DEVICE_NAME, rba);

                                printk("%s: Physical number of cylinders: %u, Sectors/Track: %u, Heads: %u\n",
                                       DEVICE_NAME, reply[3], reply[4] >> 8, reply[4] & 0xff);

                                if (!ps2esdi_info[drive_num].head) {
                                        ps2esdi_info[drive_num].head = 64;
                                        ps2esdi_info[drive_num].sect = 32;
                                        ps2esdi_info[drive_num].cyl = rba / (64 * 32);
                                        ps2esdi_info[drive_num].wpcom = 0;
                                        ps2esdi_info[drive_num].lzone = ps2esdi_info[drive_num].cyl;
                                        ps2esdi_info[drive_num].ctl = 8;
                                        if (tp720esdi) {        /* store the retrieved parameters */
                                                ps2esdi_info[0].head = reply[4] & 0Xff;
                                                ps2esdi_info[0].sect = reply[4] >> 8;
                                                ps2esdi_info[0].cyl = reply[3];
                                                ps2esdi_info[0].wpcom = 0;
                                                ps2esdi_info[0].lzone = reply[3];
                                        } else {
                                                if (!intg_esdi)
                                                        ps2esdi_drives++;
                                        }
                                }
#ifdef OBSOLETE
                                if (!ps2esdi_info[drive_num].head) {
                                        ps2esdi_info[drive_num].head = reply[4] & 0Xff;
                                        ps2esdi_info[drive_num].sect = reply[4] >> 8;
                                        ps2esdi_info[drive_num].cyl = reply[3];
                                        ps2esdi_info[drive_num].wpcom = 0;
                                        ps2esdi_info[drive_num].lzone = reply[3];
                                        if (tp720esdi) {        /* store the retrieved parameters */
                                                ps2esdi_info[0].head = reply[4] & 0Xff;
                                                ps2esdi_info[0].sect = reply[4] >> 8;
                                                ps2esdi_info[0].cyl = reply[3];
                                                ps2esdi_info[0].wpcom = 0;
                                                ps2esdi_info[0].lzone = reply[3];
                                        } else {
                                                ps2esdi_drives++;
                                        }
                                }
#endif

                        } else
                                printk("%s: failed while getting device config\n", DEVICE_NAME);
#undef REPLY_WORDS
                } else
                        printk("%s: command %02X unknown by geometry handler\n",
                               DEVICE_NAME, status & 0x1f);

                outb((int_ret_code & 0xe0) | ATT_EOI, ESDI_ATTN);
                break;

        case INT_ATTN_ERROR:
                printk("%s: Attention error. interrupt status : %02X\n", DEVICE_NAME,
                       int_ret_code);
                printk("%s: Device not available\n", DEVICE_NAME);
                break;
        case INT_CMD_ECC:
        case INT_CMD_RETRY:
        case INT_CMD_ECC_RETRY:
        case INT_CMD_WARNING:
        case INT_CMD_ABORT:
        case INT_CMD_FAILED:
        case INT_DMA_ERR:
        case INT_CMD_BLK_ERR:
                /*BA */ printk("%s: Whaa. Error occurred...\n", DEVICE_NAME);
                dump_cmd_complete_status(int_ret_code);
                outb((int_ret_code & 0xe0) | ATT_EOI, ESDI_ATTN);
                break;
        default:
                printk("%s: Unknown interrupt reason: %02X\n",
                       DEVICE_NAME, int_ret_code & 0xf);
                outb((int_ret_code & 0xe0) | ATT_EOI, ESDI_ATTN);
                break;
        }

        wake_up(&ps2esdi_int);
        no_int_yet = FALSE;
        outb(CTRL_ENABLE_INTR, ESDI_CONTROL);

}

static void ps2esdi_normal_interrupt_handler(u_int int_ret_code)
{
        unsigned long flags;
        u_int status;
        u_int ending;
        int i;

        switch (int_ret_code & 0x0f) {
        case INT_TRANSFER_REQ:
                ps2esdi_prep_dma(CURRENT->buffer, CURRENT->current_nr_sectors,
                    (CURRENT->cmd == READ)
                    ? MCA_DMA_MODE_16 | MCA_DMA_MODE_WRITE | MCA_DMA_MODE_XFER
                    : MCA_DMA_MODE_16 | MCA_DMA_MODE_READ);
                outb(CTRL_ENABLE_DMA | CTRL_ENABLE_INTR, ESDI_CONTROL);
                ending = -1;
                break;

        case INT_ATTN_ERROR:
                printk("%s: Attention error. interrupt status : %02X\n", DEVICE_NAME,
                       int_ret_code);
                outb(CTRL_ENABLE_INTR, ESDI_CONTROL);
                ending = FAIL;
                break;

        case INT_CMD_COMPLETE:
                for (i = ESDI_TIMEOUT; i & !(inb(ESDI_STATUS) & STATUS_STAT_AVAIL); i--);
                if (!(inb(ESDI_STATUS) & STATUS_STAT_AVAIL)) {
                        printk("%s: timeout reading status word\n", DEVICE_NAME);
                        outb((int_ret_code & 0xe0) | ATT_EOI, ESDI_ATTN);
                        outb(CTRL_ENABLE_INTR, ESDI_CONTROL);
                        if ((++CURRENT->errors) >= MAX_RETRIES)
                                ending = FAIL;
                        else
                                ending = -1;
                        break;
                }
                status = inw(ESDI_STT_INT);
                switch (status & 0x1F) {
                case (CMD_READ & 0xff):
                case (CMD_WRITE & 0xff):
                        LITE_OFF;
                        outb((int_ret_code & 0xe0) | ATT_EOI, ESDI_ATTN);
                        outb(CTRL_ENABLE_INTR, ESDI_CONTROL);
#if 0
                        printk("ps2esdi: cmd_complete b_wait: %p\n", &CURRENT->bh->b_wait);
#endif
                        ending = SUCCES;
                        break;
                default:
                        printk("%s: interrupt for unknown command %02X\n",
                               DEVICE_NAME, status & 0x1f);
                        outb((int_ret_code & 0xe0) | ATT_EOI, ESDI_ATTN);
                        outb(CTRL_ENABLE_INTR, ESDI_CONTROL);
                        ending = -1;
                        break;
                }
                break;
        case INT_CMD_ECC:
        case INT_CMD_RETRY:
        case INT_CMD_ECC_RETRY:
                LITE_OFF;
                dump_cmd_complete_status(int_ret_code);
                outb((int_ret_code & 0xe0) | ATT_EOI, ESDI_ATTN);
                outb(CTRL_ENABLE_INTR, ESDI_CONTROL);
                ending = SUCCES;
                break;
        case INT_CMD_WARNING:
        case INT_CMD_ABORT:
        case INT_CMD_FAILED:
        case INT_DMA_ERR:
                LITE_OFF;
                dump_cmd_complete_status(int_ret_code);
                outb((int_ret_code & 0xe0) | ATT_EOI, ESDI_ATTN);
                outb(CTRL_ENABLE_INTR, ESDI_CONTROL);
                if ((++CURRENT->errors) >= MAX_RETRIES)
                        ending = FAIL;
                else
                        ending = -1;
                break;

        case INT_CMD_BLK_ERR:
                dump_cmd_complete_status(int_ret_code);
                outb((int_ret_code & 0xe0) | ATT_EOI, ESDI_ATTN);
                outb(CTRL_ENABLE_INTR, ESDI_CONTROL);
                ending = FAIL;
                break;

        case INT_CMD_FORMAT:
                printk("%s: huh ? Who issued this format command ?\n"
                       ,DEVICE_NAME);
                outb((int_ret_code & 0xe0) | ATT_EOI, ESDI_ATTN);
                outb(CTRL_ENABLE_INTR, ESDI_CONTROL);
                ending = -1;
                break;

        case INT_RESET:
                /* BA printk("%s: reset completed.\n", DEVICE_NAME) */ ;
                outb((int_ret_code & 0xe0) | ATT_EOI, ESDI_ATTN);
                outb(CTRL_ENABLE_INTR, ESDI_CONTROL);
                ending = -1;
                break;

        default:
                printk("%s: Unknown interrupt reason: %02X\n",
                       DEVICE_NAME, int_ret_code & 0xf);
                outb((int_ret_code & 0xe0) | ATT_EOI, ESDI_ATTN);
                outb(CTRL_ENABLE_INTR, ESDI_CONTROL);
                ending = -1;
                break;
        }
        if(ending != -1) {
                spin_lock_irqsave(&io_request_lock, flags);
                end_request(ending);
                do_ps2esdi_request(BLK_DEFAULT_QUEUE(MAJOR_NR));
                spin_unlock_irqrestore(&io_request_lock, flags);
        }
}                               /* handle interrupts */



static int ps2esdi_read_status_words(int num_words,
                                     int max_words,
                                     u_short * buffer)
{
        int i;

        for (; max_words && num_words; max_words--, num_words--, buffer++) {
                for (i = ESDI_TIMEOUT; i && !(inb(ESDI_STATUS) & STATUS_STAT_AVAIL); i--);
                if (!(inb(ESDI_STATUS) & STATUS_STAT_AVAIL)) {
                        printk("%s: timeout reading status word\n", DEVICE_NAME);
                        return FAIL;
                }
                *buffer = inw(ESDI_STT_INT);
        }
        return SUCCES;
}




static void dump_cmd_complete_status(u_int int_ret_code)
{
#define WAIT_FOR_STATUS \
  for(i=ESDI_TIMEOUT;i && !(inb(ESDI_STATUS) & STATUS_STAT_AVAIL);i--); \
    if(!(inb(ESDI_STATUS) & STATUS_STAT_AVAIL)) { \
    printk("%s: timeout reading status word\n",DEVICE_NAME); \
    return; \

    }

        int i, word_count;
        u_short stat_word;
        u_long rba;

        printk("%s: Device: %u, interrupt ID: %02X\n",
               DEVICE_NAME, int_ret_code >> 5,
               int_ret_code & 0xf);

        WAIT_FOR_STATUS;
        stat_word = inw(ESDI_STT_INT);
        word_count = (stat_word >> 8) - 1;
        printk("%s: %u status words, command: %02X\n", DEVICE_NAME, word_count,
               stat_word & 0xff);

        if (word_count--) {
                WAIT_FOR_STATUS;
                stat_word = inw(ESDI_STT_INT);
                printk("%s: command status code: %02X, command error code: %02X\n",
                       DEVICE_NAME, stat_word >> 8, stat_word & 0xff);
        }
        if (word_count--) {
                WAIT_FOR_STATUS;
                stat_word = inw(ESDI_STT_INT);
                printk("%s: device error code: %s%s%s%s%s,%02X\n", DEVICE_NAME,
                       (stat_word & 0x1000) ? "Ready, " : "Not Ready, ",
                  (stat_word & 0x0800) ? "Selected, " : "Not Selected, ",
                       (stat_word & 0x0400) ? "Write Fault, " : "",
                       (stat_word & 0x0200) ? "Track 0, " : "",
                (stat_word & 0x0100) ? "Seek or command complete, " : "",
                       stat_word >> 8);
        }
        if (word_count--) {
                WAIT_FOR_STATUS;
                stat_word = inw(ESDI_STT_INT);
                printk("%s: Blocks to do: %u", DEVICE_NAME, stat_word);
        }
        if (word_count -= 2) {
                WAIT_FOR_STATUS;
                rba = inw(ESDI_STT_INT);
                WAIT_FOR_STATUS;
                rba |= inw(ESDI_STT_INT) << 16;
                printk(", Last Cyl: %u Head: %u Sector: %u\n",
                       (u_short) ((rba & 0x1ff80000) >> 11),
                 (u_short) ((rba & 0x7E0) >> 5), (u_short) (rba & 0x1f));
        } else
                printk("\n");

        if (word_count--) {
                WAIT_FOR_STATUS;
                stat_word = inw(ESDI_STT_INT);
                printk("%s: Blocks required ECC: %u", DEVICE_NAME, stat_word);
        }
        printk("\n");

#undef WAIT_FOR_STATUS

}


static int ps2esdi_open(struct inode *inode, struct file *file)
{
        int dev = DEVICE_NR(inode->i_rdev);

        if (dev < ps2esdi_drives) {
                while (!ps2esdi_valid[dev])
                        sleep_on(&ps2esdi_wait_open);

                access_count[dev]++;

                return (0);
        } else
                return (-ENODEV);
}



static int ps2esdi_release(struct inode *inode, struct file *file)
{
        int dev = DEVICE_NR(inode->i_rdev);

        if (dev < ps2esdi_drives) {
                access_count[dev]--;
        }
        return 0;
}



static int ps2esdi_ioctl(struct inode *inode,
                         struct file *file, u_int cmd, u_long arg)
{

        struct ps2esdi_geometry *geometry = (struct ps2esdi_geometry *) arg;
        int dev = DEVICE_NR(inode->i_rdev), err;

        if (inode && (dev < ps2esdi_drives))
                switch (cmd) {
                case HDIO_GETGEO:
                        if (arg) {
                                if ((err = verify_area(VERIFY_WRITE, geometry, sizeof(*geometry))))
                                        return (err);
                                put_user(ps2esdi_info[dev].head, (char *) &geometry->heads);
                                put_user(ps2esdi_info[dev].sect, (char *) &geometry->sectors);
                                put_user(ps2esdi_info[dev].cyl, (short *) &geometry->cylinders);
                                put_user(ps2esdi[MINOR(inode->i_rdev)].start_sect,
                                            (long *) &geometry->start);

                                return (0);
                        }
                        break;

                case BLKRRPART:
                        if (!capable(CAP_SYS_ADMIN)) 
                                return -EACCES;
                        return (ps2esdi_reread_partitions(inode->i_rdev));

                case BLKGETSIZE:
                case BLKGETSIZE64:
                case BLKROSET:
                case BLKROGET:
                case BLKRASET:
                case BLKRAGET:
                case BLKFLSBUF:
                case BLKBSZGET:
                case BLKBSZSET:
                case BLKPG:
                        return blk_ioctl(inode->i_rdev, cmd, arg);
                }
        return (-EINVAL);
}



static int ps2esdi_reread_partitions(kdev_t dev)
{
        int target = DEVICE_NR(dev);
        int start = target << ps2esdi_gendisk.minor_shift;
        int partition;

        ps2esdi_valid[target] = (access_count[target] != 1);
        if (ps2esdi_valid[target])
                return (-EBUSY);

        for (partition = ps2esdi_gendisk.max_p - 1;
             partition >= 0; partition--) {
                int minor = (start | partition);
                invalidate_device(MKDEV(MAJOR_NR, minor), 1);
                ps2esdi_gendisk.part[minor].start_sect = 0;
                ps2esdi_gendisk.part[minor].nr_sects = 0;
        }

        grok_partitions(&ps2esdi_gendisk, target, 1<<6, 
                ps2esdi_info[target].head * ps2esdi_info[target].cyl * ps2esdi_info[target].sect);

        ps2esdi_valid[target] = 1;
        wake_up(&ps2esdi_wait_open);

        return (0);
}

static void ps2esdi_reset_timer(unsigned long unused)
{

        int status;

        status = inb(ESDI_INTRPT);
        if ((status & 0xf) == INT_RESET) {
                outb((status & 0xe0) | ATT_EOI, ESDI_ATTN);
                outb(CTRL_ENABLE_INTR, ESDI_CONTROL);
                reset_status = 1;
        }
        wake_up(&ps2esdi_int);
}

#endif