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[/] [or1k/] [trunk/] [rc203soc/] [sw/] [uClinux/] [drivers/] [block/] [amiflop.c] - Blame information for rev 1765

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/*
 *  linux/amiga/amiflop.c
 *
 *  Copyright (C) 1993  Greg Harp
 *  Portions of this driver are based on code contributed by Brad Pepers
 *
 *  revised 28.5.95 by Joerg Dorchain
 *  - now no bugs(?) any more for both HD & DD
 *  - added support for 40 Track 5.25" drives, 80-track hopefully behaves
 *    like 3.5" dd (no way to test - are there any 5.25" drives out there
 *    that work on an A4000?)
 *  - wrote formatting routine (maybe dirty, but works)
 *
 *  june/july 1995 added ms-dos support by Joerg Dorchain
 *  (portions based on messydos.device and various contributors)
 *  - currently only 9 and 18 sector disks
 *
 *  - fixed a bug with the internal trackbuffer when using multiple
 *    disks the same time
 *  - made formatting a bit safer
 *  - added command line and machine based default for "silent" df0
 *
 *  december 1995 adapted for 1.2.13pl4 by Joerg Dorchain
 *  - works but I think it's inefficient. (look in redo_fd_request)
 *    But the changes were very efficient. (only three and a half lines)
 *
 *  january 1995 added special ioctl for tracking down read/write problems
 *  - usage ioctl(d, RAW_TRACK, ptr); the raw track buffer (MFM-encoded data
 *    is copied to area. (area should be large enough since no checking is
 *    done - 30K is currently sufficient). return the actual size of the
 *    trackbuffer
 *  - replaced udelays() by a timer (CIAA timer B) for the waits
 *    needed for the disk mechanic.
 *
 *  revised Marts 3rd, 1996 by Jes Sorensen for use in the 1.3.28 kernel.
 *  - Minor changes to accept the kdev_t.
 *  - Replaced some more udelays with ms_delays. Udelay is just a loop,
 *    and so the delay will be different depending on the given
 *    processor :-(
 *  - The driver could use a major cleanup because of the new
 *    major/minor handling that came with kdev_t. It seems to work for
 *    the time being, but I can't guarantee that it will stay like
 *    that when we start using 16 (24?) bit minors.
 */
 
#include <linux/sched.h>
#include <linux/fs.h>
#include <linux/fcntl.h>
#include <linux/kernel.h>
#include <linux/timer.h>
#include <linux/fd.h>
#include <linux/errno.h>
#include <linux/types.h>
#include <linux/delay.h>
#include <linux/string.h>
#include <linux/mm.h>
 
#include <asm/amifdreg.h>
#include <asm/amifd.h>
#include <asm/amigahw.h>
#include <asm/amigaints.h>
#include <asm/irq.h>
#include <asm/bootinfo.h>
#include <asm/amigatypes.h>
 
#define MAJOR_NR FLOPPY_MAJOR
#include <linux/blk.h>
 
#undef DEBUG /* print _LOTS_ of infos */
 
#define RAW_IOCTL
#ifdef RAW_IOCTL
#define IOCTL_RAW_TRACK 0x5254524B  /* 'RTRK' */
#endif
 
/* prototypes */
 
static int amiga_read(int,unsigned char *, unsigned long, int);
static void amiga_write(int, unsigned long, unsigned char *, int);
static int dos_read(int, unsigned char *, unsigned long, int);
static void dos_write(int, unsigned long, unsigned char *,int);
static ushort dos_crc(void *, int, int, int);
static void fd_probe(int);
 
 
/*
 *  Defines
 */
#define MAX_SECTORS     22
 
/*
 *  Error codes
 */
#define FD_OK           0        /* operation succeeded */
#define FD_ERROR        -1      /* general error (seek, read, write, etc) */
#define FD_NOUNIT       1       /* unit does not exist */
#define FD_UNITBUSY     2       /* unit already active */
#define FD_NOTACTIVE    3       /* unit is not active */
#define FD_NOTREADY     4       /* unit is not ready (motor not on/no disk) */
 
/*
 *  Floppy ID values
 */
#define FD_NODRIVE      0x00000000  /* response when no unit is present */
#define FD_DD_3         0xffffffff  /* double-density 3.5" (880K) drive */
#define FD_HD_3         0x55555555  /* high-density 3.5" (1760K) drive */
#define FD_DD_5         0xaaaaaaaa  /* double-density 5.25" (440K) drive */
 
static int fd_def_df0 = 0;     /* default for df0 if it doesn't identify */
 
 
/*
 *  Macros
 */
#define MOTOR_ON        (ciab.prb &= ~DSKMOTOR)
#define MOTOR_OFF       (ciab.prb |= DSKMOTOR)
#define SELECT(mask)    (ciab.prb &= ~mask)
#define DESELECT(mask)  (ciab.prb |= mask)
#define SELMASK(drive)  (1 << (3 + (drive & 3)))
 
#define DRIVE(x) ((x) & 3)
#define PROBE(x) ((x) >> 2) & 1)
#define TYPE(x)  ((x) >> 3) & 2)
#define DATA(x)  ((x) >> 5) & 3)
 
static struct fd_drive_type drive_types[] = {
/*  code        name       tr he   rdsz   wrsz sm pc1 pc2 sd  st st*/
/*  warning: times are now in milliseconds (ms)                    */
 { FD_DD_3,     "DD 3.5", 160, 2, 14716, 13630, 1, 80,161, 3, 18, 1},
 { FD_HD_3,     "HD 3.5", 160, 2, 28344, 27258, 2, 80,161, 3, 18, 1},
 { FD_DD_5,     "DD 5.25", 80, 2, 14716, 13630, 1, 40, 81, 6, 30, 2},
 { FD_NODRIVE, "No Drive", 0, 0,     0,     0, 0,  0,  0,  0,  0, 0}
};
static int num_dr_types = sizeof(drive_types) / sizeof(drive_types[0]);
 
/* defaults for 3 1/2" HD-Disks */
static int floppy_sizes[256]={880,880,880,880,720,720,720,};
static int floppy_blocksizes[256]={0,};
/* hardsector size assumed to be 512 */
 
static struct fd_data_type data_types[] = {
  { "Amiga", 11 , amiga_read, amiga_write},
  { "MS-Dos", 9, dos_read, dos_write}
};
static int num_da_types = sizeof(data_types) / sizeof(data_types[0]);
 
/* current info on each unit */
static struct amiga_floppy_struct unit[FD_MAX_UNITS];
 
static struct timer_list flush_track_timer;
static struct timer_list post_write_timer;
static struct timer_list motor_on_timer;
static struct timer_list motor_off_timer[FD_MAX_UNITS];
static int on_attempts;
 
/* track buffer */
static int lastdrive = -1;
static int savedtrack = -1;
static int writepending = 0;
static int writefromint = 0;
static unsigned char trackdata[MAX_SECTORS * 512];
static char *raw_buf;
 
#define RAW_BUF_SIZE 30000  /* size of raw disk data */
 
/*
 * These are global variables, as that's the easiest way to give
 * information to interrupts. They are the data used for the current
 * request.
 */
static char block_flag = 0;
static int selected = 0;
static struct wait_queue *wait_fd_block = NULL;
 
/* Synchronization of FDC access. */
static volatile int fdc_busy = 0;
static struct wait_queue *fdc_wait = NULL;
static struct wait_queue *motor_wait = NULL;
 
/* MS-Dos MFM Coding tables (should go quick and easy) */
static unsigned char mfmencode[16]={
  0x2a, 0x29, 0x24, 0x25, 0x12, 0x11, 0x14, 0x15,
  0x4a, 0x49, 0x44, 0x45, 0x52, 0x51, 0x54, 0x55
};
static unsigned char mfmdecode[128];
 
/* floppy internal millisecond timer stuff */
static struct semaphore ms_sem = MUTEX;
static struct wait_queue *ms_wait = NULL;
#define MS_TICKS ((amiga_eclock+50)/1000)
 
static void ms_isr(int irq, struct pt_regs *fp, void *dummy)
{
wake_up(&ms_wait);
}
 
/* with the semaphore waits are queued up
   A more generic routine would do a schedule a la timer.device */
static void ms_delay(int ms)
{
  int ticks;
  if (ms > 0) {
    down(&ms_sem);
    ticks=MS_TICKS*ms-1;
    ciaa.tblo=ticks%256;
    ciaa.tbhi=ticks/256;
    ciaa.crb=0x19; /* count clock, force load, one-shot, start */
    sleep_on(&ms_wait);
    up(&ms_sem);
  }
}
 
/*
 * Functions
 */
/*======================================================================
  Turn off the motor of the given drive.  Unit must already be active.
  Returns standard floppy error code.
======================================================================*/
static void fd_motor_off(unsigned long drive)
{
        unsigned long flags;
        unsigned char prb = ~0;
 
        drive&=3;
        save_flags(flags);
        cli();
 
        if (unit[drive].track % 2 != 0)
                prb &= ~DSKSIDE;
        ciab.prb |= (SELMASK(0)|SELMASK(1)|SELMASK(2)|SELMASK(3));
        ciab.prb = prb;
        prb &= ~SELMASK(drive);
        ciab.prb = prb;
        udelay (1);
        prb |= (SELMASK(0)|SELMASK(1)|SELMASK(2)|SELMASK(3));
        ciab.prb = prb;
        selected = -1;
        unit[drive].motor = 0;
 
        restore_flags(flags);
}
 
static void motor_on_callback(unsigned long nr)
{
  nr &= 3;
 
        if (!(ciaa.pra & DSKRDY) || --on_attempts == 0) {
                unit[nr].motor = 1;
                wake_up (&motor_wait);
        } else {
                motor_on_timer.expires = jiffies + HZ/10;
                add_timer(&motor_on_timer);
        }
}
 
static int motor_on(int nr)
{
        unsigned long flags;
        unsigned char prb = ~0;
 
        nr &= 3;
        save_flags (flags);
        cli();
        del_timer(motor_off_timer + nr);
 
        if (!unit[nr].motor) {
                del_timer(&motor_on_timer);
                motor_on_timer.data = nr;
                motor_on_timer.expires = jiffies + HZ/2;
                add_timer(&motor_on_timer);
                on_attempts = 10;
 
 
                prb &= ~DSKMOTOR;
                if (unit[nr].track % 2 != 0)
                        prb &= ~DSKSIDE;
                ciab.prb |= (SELMASK(0)|SELMASK(1)|SELMASK(2)|SELMASK(3));
                ciab.prb = prb;
                prb &= ~SELMASK(nr);
                ciab.prb = prb;
                selected = nr;
 
                while (!unit[nr].motor)
                        sleep_on (&motor_wait);
        }
        restore_flags(flags);
 
        if (on_attempts == 0) {
                printk ("motor_on failed, turning motor off\n");
                fd_motor_off (nr);
                return 0;
        }
 
        return 1;
}
 
static void floppy_off (unsigned int nr)
{
        nr&=3;
        del_timer(motor_off_timer+nr);
        motor_off_timer[nr].expires = jiffies + 3*HZ;
        add_timer(motor_off_timer+nr);
}
 
static void fd_select (int drive)
{
        unsigned char prb = ~0;
 
        drive&=3;
        if (drive == selected)
                return;
        selected = drive;
 
        if (unit[drive].track % 2 != 0)
                prb &= ~DSKSIDE;
        if (unit[drive].motor == 1)
                prb &= ~DSKMOTOR;
        ciab.prb |= (SELMASK(0)|SELMASK(1)|SELMASK(2)|SELMASK(3));
        ciab.prb = prb;
        prb &= ~SELMASK(drive);
        ciab.prb = prb;
}
 
static void fd_deselect (int drive)
{
        unsigned char prb;
        unsigned long flags;
 
        drive&=3;
        if (drive != selected)
                return;
 
        save_flags (flags);
        sti();
 
        selected = -1;
 
        prb = ciab.prb;
        prb |= (SELMASK(0)|SELMASK(1)|SELMASK(2)|SELMASK(3));
        ciab.prb = prb;
 
        restore_flags (flags);
 
}
 
/*======================================================================
  Seek the drive to track 0.
  The drive must be active and the motor must be running.
  Returns standard floppy error code.
======================================================================*/
static int fd_calibrate(int drive)
{
        unsigned char prb;
        int n;
 
        drive &= 3;
        if (!motor_on (drive))
                return 0;
        fd_select (drive);
        prb = ciab.prb;
        prb |= DSKSIDE;
        prb &= ~DSKDIREC;
        ciab.prb = prb;
        for (n = unit[drive].type->tracks/4; n != 0; --n) {
                if (ciaa.pra & DSKTRACK0)
                        break;
                prb &= ~DSKSTEP;
                ciab.prb = prb;
                prb |= DSKSTEP;
                ms_delay (2);
                ciab.prb = prb;
                ms_delay(unit[drive].type->step_delay);
        }
        ms_delay (unit[drive].type->settle_time);
        prb |= DSKDIREC;
        n = unit[drive].type->tracks/2 + 20;
        for (;;) {
                prb &= ~DSKSTEP;
                ciab.prb = prb;
                prb |= DSKSTEP;
                ms_delay (2);
                ciab.prb = prb;
                ms_delay(unit[drive].type->step_delay + 1);
                if ((ciaa.pra & DSKTRACK0) == 0)
                        break;
                if (--n == 0) {
                        printk ("calibrate failed, turning motor off\n");
                        fd_motor_off (drive);
                        unit[drive].track = -1;
                        return 0;
                }
        }
        unit[drive].track = 0;
        ms_delay(unit[drive].type->settle_time);
 
        return 1;
}
 
/*======================================================================
  Seek the drive to the requested cylinder.
  The drive must have been calibrated at some point before this.
  The drive must also be active and the motor must be running.
======================================================================*/
static int fd_seek(int drive, int track)
{
        unsigned char prb;
        int cnt;
 
        drive &= 3;
        if (unit[drive].track == track)
                return 1;
        if (!motor_on(drive))
                return 0;
        fd_select (drive);
        if (unit[drive].track < 0 && !fd_calibrate(drive))
                return 0;
 
        cnt = unit[drive].track/2 - track/2;
        prb = ciab.prb;
        prb |= DSKSIDE | DSKDIREC;
        if (track % 2 != 0)
                prb &= ~DSKSIDE;
        if (cnt < 0) {
                cnt = - cnt;
                prb &= ~DSKDIREC;
        }
        ciab.prb = prb;
        if (track % 2 != unit[drive].track % 2)
                ms_delay (unit[drive].type->side_time);
        unit[drive].track = track;
        if (cnt == 0)
                return 1;
        do {
                prb &= ~DSKSTEP;
                ciab.prb = prb;
                prb |= DSKSTEP;
                ms_delay (1);
                ciab.prb = prb;
                ms_delay (unit[drive].type->step_delay);
        } while (--cnt != 0);
        ms_delay (unit[drive].type->settle_time);
 
        return 1;
}
 
static void encode(unsigned long data, unsigned long *dest)
{
  unsigned long data2;
 
  data &= 0x55555555;
  data2 = data ^ 0x55555555;
  data |= ((data2 >> 1) | 0x80000000) & (data2 << 1);
 
  if (*(dest - 1) & 0x00000001)
    data &= 0x7FFFFFFF;
 
  *dest = data;
}
 
static void encode_block(unsigned long *dest, unsigned long *src, int len)
{
  int cnt, to_cnt = 0;
  unsigned long data;
 
  /* odd bits */
  for (cnt = 0; cnt < len / 4; cnt++) {
    data = src[cnt] >> 1;
    encode(data, dest + to_cnt++);
  }
 
  /* even bits */
  for (cnt = 0; cnt < len / 4; cnt++) {
    data = src[cnt];
    encode(data, dest + to_cnt++);
  }
}
 
unsigned long checksum(unsigned long *addr, int len)
{
        unsigned long csum = 0;
 
        len /= sizeof(*addr);
        while (len-- > 0)
                csum ^= *addr++;
        csum = ((csum>>1) & 0x55555555)  ^  (csum & 0x55555555);
 
        return csum;
}
 
struct header {
        unsigned char magic;
        unsigned char track;
        unsigned char sect;
        unsigned char ord;
        unsigned char labels[16];
        unsigned long hdrchk;
        unsigned long datachk;
};
 
static unsigned long *putsec(int disk, unsigned long *raw, int track, int cnt,
                             unsigned char *data)
{
        struct header hdr;
        int i;
 
        if (!AMIGAHW_PRESENT(AMI_FLOPPY))
            return 0;
 
        disk&=3;
        *raw = (raw[-1]&1) ? 0x2AAAAAAA : 0xAAAAAAAA;
        raw++;
        *raw++ = 0x44894489;
 
        hdr.magic = 0xFF;
        hdr.track = track;
        hdr.sect = cnt;
        hdr.ord = unit[disk].sects-cnt;
        for (i = 0; i < 16; i++)
                hdr.labels[i] = 0;
        hdr.hdrchk = checksum((ulong *)&hdr,
                              (char *)&hdr.hdrchk-(char *)&hdr);
        hdr.datachk = checksum((ulong *)data, 512);
 
        encode_block(raw, (ulong *)&hdr.magic, 4);
        raw += 2;
        encode_block(raw, (ulong *)&hdr.labels, 16);
        raw += 8;
        encode_block(raw, (ulong *)&hdr.hdrchk, 4);
        raw += 2;
        encode_block(raw, (ulong *)&hdr.datachk, 4);
        raw += 2;
        encode_block(raw, (ulong *)data, 512);
        raw += 256;
 
        return raw;
}
 
 
/*==========================================================================
  amiga_write converts track/labels data to raw track data
==========================================================================*/
static void amiga_write(int disk, unsigned long raw, unsigned char *data,
                        int track)
{
        int cnt;
        unsigned long *ptr = (unsigned long *)raw;
 
        disk&=3;
        /* gap space */
        for (cnt = 0; cnt < 415 * unit[disk].type->sect_mult; cnt++)
                *ptr++ = 0xaaaaaaaa;
 
        /* sectors */
        for (cnt = 0; cnt < unit[disk].sects; cnt++)
                ptr = putsec (disk, ptr, track, cnt, data + cnt*512);
        *(ushort *)ptr = (ptr[-1]&1) ? 0x2AA8 : 0xAAA8;
        raw = (unsigned long)ptr + 2;
}
 
static unsigned long decode (unsigned long *data, unsigned long *raw,
                                   int len)
{
        ulong *odd, *even;
 
        /* convert length from bytes to longwords */
        len >>= 2;
        odd = raw;
        even = odd + len;
 
        /* prepare return pointer */
        raw += len * 2;
 
        do {
                *data++ = ((*odd++ & 0x55555555) << 1) | (*even++ & 0x55555555);
        } while (--len != 0);
 
        return (ulong)raw;
}
 
#define MFM_NOSYNC      1
#define MFM_HEADER      2
#define MFM_DATA        3
#define MFM_TRACK       4
 
/*==========================================================================
 scan_sync - looks for the next start of sector marked by a sync. d3 is the
                sector number (10..0). When d3 = 10, can't be certain of a
                starting sync.
==========================================================================*/
static unsigned long scan_sync(unsigned long raw, unsigned long end)
{
        ushort *ptr = (ushort *)raw, *endp = (ushort *)end;
 
        while (ptr < endp && *ptr++ != 0x4489)
                ;
        if (ptr < endp) {
                while (*ptr == 0x4489 && ptr < endp)
                        ptr++;
                return (ulong)ptr;
        }
        return 0;
}
 
/*==========================================================================
  amiga_read reads a raw track of data into a track buffer
==========================================================================*/
static int amiga_read(int drive, unsigned char *track_data,
                      unsigned long raw, int track)
{
        unsigned long end;
        int scnt;
        unsigned long csum;
        struct header hdr;
 
        drive&=3;
        end = raw + unit[drive].type->read_size;
 
        for (scnt = 0;scnt < unit[drive].sects; scnt++) {
                if (!(raw = scan_sync(raw, end))) {
                        printk ("can't find sync for sector %d\n", scnt);
                        return MFM_NOSYNC;
                }
 
                raw = decode ((ulong *)&hdr.magic, (ulong *)raw, 4);
                raw = decode ((ulong *)&hdr.labels, (ulong *)raw, 16);
                raw = decode ((ulong *)&hdr.hdrchk, (ulong *)raw, 4);
                raw = decode ((ulong *)&hdr.datachk, (ulong *)raw, 4);
                csum = checksum((ulong *)&hdr,
                                (char *)&hdr.hdrchk-(char *)&hdr);
 
#ifdef DEBUG
                printk ("(%x,%d,%d,%d) (%lx,%lx,%lx,%lx) %lx %lx\n",
                        hdr.magic, hdr.track, hdr.sect, hdr.ord,
                        *(ulong *)&hdr.labels[0], *(ulong *)&hdr.labels[4],
                        *(ulong *)&hdr.labels[8], *(ulong *)&hdr.labels[12],
                        hdr.hdrchk, hdr.datachk);
#endif
 
                if (hdr.hdrchk != csum) {
                        printk("MFM_HEADER: %08lx,%08lx\n", hdr.hdrchk, csum);
                        return MFM_HEADER;
                }
 
                /* verify track */
                if (hdr.track != track) {
                        printk("MFM_TRACK: %d, %d\n", hdr.track, track);
                        return MFM_TRACK;
                }
 
                raw = decode ((ulong *)(track_data + hdr.sect*512),
                              (ulong *)raw, 512);
                csum = checksum((ulong *)(track_data + hdr.sect*512), 512);
 
                if (hdr.datachk != csum) {
                        printk("MFM_DATA: (%x:%d:%d:%d) sc=%d %lx, %lx\n",
                               hdr.magic, hdr.track, hdr.sect, hdr.ord, scnt,
                               hdr.datachk, csum);
                        printk ("data=(%lx,%lx,%lx,%lx)\n",
                                ((ulong *)(track_data+hdr.sect*512))[0],
                                ((ulong *)(track_data+hdr.sect*512))[1],
                                ((ulong *)(track_data+hdr.sect*512))[2],
                                ((ulong *)(track_data+hdr.sect*512))[3]);
                        return MFM_DATA;
                }
        }
 
        return 0;
}
 
struct dos_header {
unsigned char track,   /* 0-80 */
              side,    /* 0-1 */
              sec,     /* 0-...*/
              len_desc;/* 2 */
unsigned short crc;     /* on 68000 we got an alignment problem,
                           but this compiler solves it  by adding silently
                           adding a pad byte so data won't fit
                           and this cost about 3h to discover.... */
unsigned char gap1[22];     /* for longword-alignedness (0x4e) */
};
 
/* crc routines are borrowed from the messydos-handler  */
 
static inline ushort dos_hdr_crc (struct dos_header *hdr)
{
return dos_crc(&(hdr->track), 0xb2, 0x30, 3); /* precomputed magic */
}
 
static inline ushort dos_data_crc(unsigned char *data)
{
return dos_crc(data, 0xe2, 0x95 ,511); /* precomputed magic */
}
 
/* excerpt from the messydos-device
; The CRC is computed not only over the actual data, but including
; the SYNC mark (3 * $a1) and the 'ID/DATA - Address Mark' ($fe/$fb).
; As we don't read or encode these fields into our buffers, we have to
; preload the registers containing the CRC with the values they would have
; after stepping over these fields.
;
; How CRCs "really" work:
;
; First, you should regard a bitstring as a series of coefficients of
; polynomials. We calculate with these polynomials in modulo-2
; arithmetic, in which both add and subtract are done the same as
; exclusive-or. Now, we modify our data (a very long polynomial) in
; such a way that it becomes divisible by the CCITT-standard 16-bit
;                16   12   5
; polynomial:   x  + x  + x + 1, represented by $11021. The easiest
; way to do this would be to multiply (using proper arithmetic) our
; datablock with $11021. So we have:
;   data * $11021                =
;   data * ($10000 + $1021)      =
;   data * $10000 + data * $1021
; The left part of this is simple: Just add two 0 bytes. But then
; the right part (data $1021) remains difficult and even could have
; a carry into the left part. The solution is to use a modified
; multiplication, which has a result that is not correct, but with
; a difference of any multiple of $11021. We then only need to keep
; the 16 least significant bits of the result.
;
; The following algorithm does this for us:
;
;   unsigned char *data, c, crclo, crchi;
;   while (not done) {
;       c = *data++ + crchi;
;       crchi = (@ c) >> 8 + crclo;
;       crclo = @ c;
;   }
;
; Remember, + is done with EOR, the @ operator is in two tables (high
; and low byte separately), which is calculated as
;
;      $1021 * (c & $F0)
;  xor $1021 * (c & $0F)
;  xor $1021 * (c >> 4)         (* is regular multiplication)
;
;
; Anyway, the end result is the same as the remainder of the division of
; the data by $11021. I am afraid I need to study theory a bit more...
 
 
my only works was to code this from manx to C....
 
*/
 
static ushort dos_crc(void * data_a3, int data_d0, int data_d1, int data_d3)
{
static unsigned char CRCTable1[] = {
        0x00,0x10,0x20,0x30,0x40,0x50,0x60,0x70,0x81,0x91,0xa1,0xb1,0xc1,0xd1,0xe1,0xf1,
        0x12,0x02,0x32,0x22,0x52,0x42,0x72,0x62,0x93,0x83,0xb3,0xa3,0xd3,0xc3,0xf3,0xe3,
        0x24,0x34,0x04,0x14,0x64,0x74,0x44,0x54,0xa5,0xb5,0x85,0x95,0xe5,0xf5,0xc5,0xd5,
        0x36,0x26,0x16,0x06,0x76,0x66,0x56,0x46,0xb7,0xa7,0x97,0x87,0xf7,0xe7,0xd7,0xc7,
        0x48,0x58,0x68,0x78,0x08,0x18,0x28,0x38,0xc9,0xd9,0xe9,0xf9,0x89,0x99,0xa9,0xb9,
        0x5a,0x4a,0x7a,0x6a,0x1a,0x0a,0x3a,0x2a,0xdb,0xcb,0xfb,0xeb,0x9b,0x8b,0xbb,0xab,
        0x6c,0x7c,0x4c,0x5c,0x2c,0x3c,0x0c,0x1c,0xed,0xfd,0xcd,0xdd,0xad,0xbd,0x8d,0x9d,
        0x7e,0x6e,0x5e,0x4e,0x3e,0x2e,0x1e,0x0e,0xff,0xef,0xdf,0xcf,0xbf,0xaf,0x9f,0x8f,
        0x91,0x81,0xb1,0xa1,0xd1,0xc1,0xf1,0xe1,0x10,0x00,0x30,0x20,0x50,0x40,0x70,0x60,
        0x83,0x93,0xa3,0xb3,0xc3,0xd3,0xe3,0xf3,0x02,0x12,0x22,0x32,0x42,0x52,0x62,0x72,
        0xb5,0xa5,0x95,0x85,0xf5,0xe5,0xd5,0xc5,0x34,0x24,0x14,0x04,0x74,0x64,0x54,0x44,
        0xa7,0xb7,0x87,0x97,0xe7,0xf7,0xc7,0xd7,0x26,0x36,0x06,0x16,0x66,0x76,0x46,0x56,
        0xd9,0xc9,0xf9,0xe9,0x99,0x89,0xb9,0xa9,0x58,0x48,0x78,0x68,0x18,0x08,0x38,0x28,
        0xcb,0xdb,0xeb,0xfb,0x8b,0x9b,0xab,0xbb,0x4a,0x5a,0x6a,0x7a,0x0a,0x1a,0x2a,0x3a,
        0xfd,0xed,0xdd,0xcd,0xbd,0xad,0x9d,0x8d,0x7c,0x6c,0x5c,0x4c,0x3c,0x2c,0x1c,0x0c,
        0xef,0xff,0xcf,0xdf,0xaf,0xbf,0x8f,0x9f,0x6e,0x7e,0x4e,0x5e,0x2e,0x3e,0x0e,0x1e
};
 
static unsigned char CRCTable2[] = {
        0x00,0x21,0x42,0x63,0x84,0xa5,0xc6,0xe7,0x08,0x29,0x4a,0x6b,0x8c,0xad,0xce,0xef,
        0x31,0x10,0x73,0x52,0xb5,0x94,0xf7,0xd6,0x39,0x18,0x7b,0x5a,0xbd,0x9c,0xff,0xde,
        0x62,0x43,0x20,0x01,0xe6,0xc7,0xa4,0x85,0x6a,0x4b,0x28,0x09,0xee,0xcf,0xac,0x8d,
        0x53,0x72,0x11,0x30,0xd7,0xf6,0x95,0xb4,0x5b,0x7a,0x19,0x38,0xdf,0xfe,0x9d,0xbc,
        0xc4,0xe5,0x86,0xa7,0x40,0x61,0x02,0x23,0xcc,0xed,0x8e,0xaf,0x48,0x69,0x0a,0x2b,
        0xf5,0xd4,0xb7,0x96,0x71,0x50,0x33,0x12,0xfd,0xdc,0xbf,0x9e,0x79,0x58,0x3b,0x1a,
        0xa6,0x87,0xe4,0xc5,0x22,0x03,0x60,0x41,0xae,0x8f,0xec,0xcd,0x2a,0x0b,0x68,0x49,
        0x97,0xb6,0xd5,0xf4,0x13,0x32,0x51,0x70,0x9f,0xbe,0xdd,0xfc,0x1b,0x3a,0x59,0x78,
        0x88,0xa9,0xca,0xeb,0x0c,0x2d,0x4e,0x6f,0x80,0xa1,0xc2,0xe3,0x04,0x25,0x46,0x67,
        0xb9,0x98,0xfb,0xda,0x3d,0x1c,0x7f,0x5e,0xb1,0x90,0xf3,0xd2,0x35,0x14,0x77,0x56,
        0xea,0xcb,0xa8,0x89,0x6e,0x4f,0x2c,0x0d,0xe2,0xc3,0xa0,0x81,0x66,0x47,0x24,0x05,
        0xdb,0xfa,0x99,0xb8,0x5f,0x7e,0x1d,0x3c,0xd3,0xf2,0x91,0xb0,0x57,0x76,0x15,0x34,
        0x4c,0x6d,0x0e,0x2f,0xc8,0xe9,0x8a,0xab,0x44,0x65,0x06,0x27,0xc0,0xe1,0x82,0xa3,
        0x7d,0x5c,0x3f,0x1e,0xf9,0xd8,0xbb,0x9a,0x75,0x54,0x37,0x16,0xf1,0xd0,0xb3,0x92,
        0x2e,0x0f,0x6c,0x4d,0xaa,0x8b,0xe8,0xc9,0x26,0x07,0x64,0x45,0xa2,0x83,0xe0,0xc1,
        0x1f,0x3e,0x5d,0x7c,0x9b,0xba,0xd9,0xf8,0x17,0x36,0x55,0x74,0x93,0xb2,0xd1,0xf0
};
 
/* look at the asm-code - what looks in C a bit strange is almost as good as handmade */
register int i;
register unsigned char *CRCT1, *CRCT2, *data, c, crch, crcl;
 
CRCT1=CRCTable1;
CRCT2=CRCTable2;
data=data_a3;
crcl=data_d1;
crch=data_d0;
for (i=data_d3; i>=0; i--) {
  c = (*data++) ^ crch;
  crch = CRCT1[c] ^ crcl;
  crcl = CRCT2[c];
}
return (crch<<8)|crcl;
}
 
static inline unsigned char dos_decode_byte(ushort word)
{
register ushort w2;
register unsigned char byte;
register unsigned char *dec = mfmdecode;
 
w2=word;
w2>>=8;
w2&=127;
byte = dec[w2];
byte <<= 4;
w2 = word & 127;
byte |= dec[w2];
return byte;
}
 
static unsigned long dos_decode(unsigned char *data, unsigned short *raw, int len)
{
int i;
 
for (i = 0; i < len; i++)
  *data++=dos_decode_byte(*raw++);
return ((ulong)raw);
}
 
#ifdef DEBUG
static void dbg(unsigned long ptr)
{
printk("raw data @%08lx: %08lx, %08lx ,%08lx, %08lx\n",ptr,
  ((ulong *)ptr)[0],((ulong *)ptr)[1],((ulong *)ptr)[2],((ulong *)ptr)[3]);
}
#endif
 
/*******************************************************************
   this reads a raw track of data into trackbuffer for ms-disks
*******************************************************************/
static int dos_read(int drive, unsigned char *track_data,
        unsigned long raw, int track)
{
  unsigned long end;
  int scnt;
  unsigned short crc,data_crc[2];
  struct dos_header hdr;
 
  drive&=3;
  end = raw + unit[drive].type->read_size;
 
  for (scnt=0;scnt<unit[drive].sects;scnt++) {
  do { /* search for the right sync of each sec-hdr */
    if (!(raw = scan_sync (raw, end))) {
      printk("dos_read: no hdr sync on track %d, unit %d for sector %d\n",
        track,drive,scnt);
      return MFM_NOSYNC;
    }
#ifdef DEBUG
  dbg(raw);
#endif
  } while (*((ushort *)raw)!=0x5554); /* loop usually only once done */
  raw+=2; /* skip over headermark */
  raw = dos_decode((unsigned char *)&hdr,(ushort *) raw,8);
  crc = dos_hdr_crc(&hdr);
 
#ifdef DEBUG
  printk("(%3d,%d,%2d,%d) %x\n", hdr.track, hdr.side,
     hdr.sec, hdr.len_desc, hdr.crc);
#endif
 
  if (crc != hdr.crc) {
    printk("dos_read: MFM_HEADER %04x,%04x\n", hdr.crc, crc);
    return MFM_HEADER;
  }
  if (hdr.track != track/unit[drive].type->heads) {
    printk("dos_read: MFM_TRACK %d, %d\n", hdr.track,
      track/unit[drive].type->heads);
    return MFM_TRACK;
  }
 
  if (hdr.side != track%unit[drive].type->heads) {
    printk("dos_read: MFM_SIDE %d, %d\n", hdr.side,
      track%unit[drive].type->heads);
    return MFM_TRACK;
  }
 
  if (hdr.len_desc != 2) {
    printk("dos_read: unknown sector len descriptor %d\n", hdr.len_desc);
    return MFM_DATA;
  }
#ifdef DEBUG
  printk("hdr accepted\n");
#endif
  if (!(raw = scan_sync (raw, end))) {
    printk("dos_read: no data sync on track %d, unit %d for sector%d, disk sector %d\n",
      track, drive, scnt, hdr.sec);
    return MFM_NOSYNC;
  }
#ifdef DEBUG
  dbg(raw);
#endif
 
  if (*((ushort *)raw)!=0x5545) {
    printk("dos_read: no data mark after sync (%d,%d,%d,%d) sc=%d\n",
      hdr.track,hdr.side,hdr.sec,hdr.len_desc,scnt);
    return MFM_NOSYNC;
  }
 
  raw+=2;  /* skip data mark (included in checksum) */
  raw = dos_decode((unsigned char *)(track_data + (hdr.sec - 1) * 512), (ushort *) raw, 512);
  raw = dos_decode((unsigned char  *)data_crc,(ushort *) raw,4);
  crc = dos_data_crc(track_data + (hdr.sec - 1) * 512);
 
  if (crc != data_crc[0]) {
    printk("dos_read: MFM_DATA (%d,%d,%d,%d) sc=%d, %x %x\n",
      hdr.track, hdr.side, hdr.sec, hdr.len_desc,
      scnt,data_crc[0], crc);
    printk("data=(%lx,%lx,%lx,%lx,...)\n",
      ((ulong *)(track_data+(hdr.sec-1)*512))[0],
      ((ulong *)(track_data+(hdr.sec-1)*512))[1],
      ((ulong *)(track_data+(hdr.sec-1)*512))[2],
      ((ulong *)(track_data+(hdr.sec-1)*512))[3]);
    return MFM_DATA;
  }
  }
 return 0;
}
 
static inline ushort dos_encode_byte(unsigned char byte)
{
register unsigned char *enc, b2, b1;
register ushort word;
 
enc=mfmencode;
b1=byte;
b2=b1>>4;
b1&=15;
word=enc[b2] <<8 | enc [b1];
return (word|((word&(256|64)) ? 0: 128));
}
 
static void dos_encode_block(ushort *dest, unsigned char *src, int len)
{
int i;
 
for (i = 0; i < len; i++) {
  *dest=dos_encode_byte(*src++);
  *dest|=((dest[-1]&1)||(*dest&0x4000))? 0: 0x8000;
  dest++;
}
}
 
static unsigned long *ms_putsec(int drive, unsigned long *raw, int track, int cnt,
   unsigned char *data)
{
static struct dos_header hdr={0,0,0,2,0,
  {78,78,78,78,78,78,78,78,78,78,78,78,78,78,78,78,78,78,78,78,78,78}};
int i;
static ushort crc[2]={0,0x4e4e};
 
drive&=3;
/* id gap 1 */
/* the MFM word before is always 9254 */
for(i=0;i<6;i++)
  *raw++=0xaaaaaaaa;
/* 3 sync + 1 headermark */
*raw++=0x44894489;
*raw++=0x44895554;
 
/* fill in the variable parts of the header */
hdr.track=track/unit[drive].type->heads;
hdr.side=track%unit[drive].type->heads;
hdr.sec=cnt+1;
hdr.crc=dos_hdr_crc(&hdr);
 
/* header (without "magic") and id gap 2*/
dos_encode_block((ushort *)raw,(unsigned char *) &hdr.track,28);
raw+=14;
 
/*id gap 3 */
for(i=0;i<6;i++)
  *raw++=0xaaaaaaaa;
 
/* 3 syncs and 1 datamark */
*raw++=0x44894489;
*raw++=0x44895545;
 
/* data */
dos_encode_block((ushort *)raw,(unsigned char *)data,512);
raw+=256;
 
/*data crc + jd's special gap (long words :-/) */
crc[0]=dos_data_crc(data);
dos_encode_block((ushort *) raw,(unsigned char *)crc,4);
raw+=2;
 
/* data gap */
for(i=0;i<38;i++)
  *raw++=0x92549254;
 
return raw; /* wrote 652 MFM words */
}
 
 
/**************************************************************
  builds encoded track data from trackbuffer data
**************************************************************/
static void dos_write(int disk, unsigned long raw, unsigned char *data,
    int track)
{
int cnt;
unsigned long *ptr=(unsigned long *)raw;
 
disk&=3;
/* really gap4 + indexgap , but we write it first and round it up */
for (cnt=0;cnt<425;cnt++)
  *ptr++=0x92549254;
 
/* the following is just guessed */
if (unit[disk].type->sect_mult==2)  /* check for HD-Disks */
  for(cnt=0;cnt<473;cnt++)
    *ptr++=0x92549254;
 
/* now the index marks...*/
for (cnt=0;cnt<20;cnt++)
  *ptr++=0x92549254;
for (cnt=0;cnt<6;cnt++)
  *ptr++=0xaaaaaaaa;
*ptr++=0x52245224;
*ptr++=0x52245552;
for (cnt=0;cnt<20;cnt++)
  *ptr++=0x92549254;
 
/* sectors */
for(cnt=0;cnt<unit[disk].sects;cnt++)
  ptr=ms_putsec(disk,ptr,track,cnt,data+cnt*512);
 
*(ushort *)ptr = 0xaaa8; /* MFM word before is always 0x9254 */
}
 
/*
 * Note that MAX_ERRORS=X doesn't imply that we retry every bad read
 * max X times - some types of errors increase the errorcount by 2 or
 * even 3, so we might actually retry only X/2 times before giving up.
 */
#define MAX_ERRORS 12
 
/*
 * The driver is trying to determine the correct media format
 * while probing is set. rw_interrupt() clears it after a
 * successful access.
 */
static int probing = 0;
 
/* Prevent "aliased" accesses. */
static fd_ref[4] = { 0,0,0,0 };
static fd_device[4] = { 0,0,0,0 };
 
/*
 * Current device number. Taken either from the block header or from the
 * format request descriptor.
 */
#define CURRENT_DEVICE (CURRENT->rq_dev)
 
/* Current error count. */
#define CURRENT_ERRORS (CURRENT->errors)
 
static void request_done(int uptodate)
{
  timer_active &= ~(1 << FLOPPY_TIMER);
  end_request(uptodate);
}
 
/*
 * floppy-change is never called from an interrupt, so we can relax a bit
 * here, sleep etc. Note that floppy-on tries to set current_DOR to point
 * to the desired drive, but it will probably not survive the sleep if
 * several floppies are used at the same time: thus the loop.
 */
static int amiga_floppy_change(kdev_t dev)
{
        int drive = dev & 3;
        int changed;
 
        if (MAJOR(dev) != MAJOR_NR) {
                printk("floppy_change: not a floppy\n");
                return 0;
        }
 
        fd_select (drive);
        changed = !(ciaa.pra & DSKCHANGE);
        fd_deselect (drive);
 
        if (changed) {
                fd_probe(dev);
                unit[drive].track = -1;
                selected = -1;
                savedtrack = -1;
                writepending = 0; /* if this was true before, too bad! */
                writefromint = 0;
                return 1;
        }
        return 0;
}
 
static __inline__ void copy_buffer(void *from, void *to)
{
  ulong *p1,*p2;
  int cnt;
 
  p1 = (ulong *)from;
  p2 = (ulong *)to;
 
  for (cnt = 0; cnt < 512/4; cnt++)
    *p2++ = *p1++;
}
 
static void raw_read(int drive, int track, char *ptrack, int len)
{
        drive&=3;
        /* setup adkcon bits correctly */
        custom.adkcon = ADK_MSBSYNC;
        custom.adkcon = ADK_SETCLR|ADK_WORDSYNC|ADK_FAST;
 
        custom.dsksync = MFM_SYNC;
 
        custom.dsklen = 0;
#if 0
        ms_delay (unit[drive].type->side_time);
#endif
        custom.dskptr = (u_char *)ZTWO_PADDR((u_char *)ptrack);
        custom.dsklen = len/sizeof(short) | DSKLEN_DMAEN;
        custom.dsklen = len/sizeof(short) | DSKLEN_DMAEN;
 
        block_flag = 1;
 
        while (block_flag == 1)
                sleep_on (&wait_fd_block);
 
        custom.dsklen = 0;
}
 
static int raw_write(int drive, int track, char *ptrack, int len)
{
        ushort adk;
 
        drive&=3;
        if ((ciaa.pra & DSKPROT) == 0)
                return 0;
 
        /* clear adkcon bits */
        custom.adkcon = ADK_PRECOMP1|ADK_PRECOMP0|ADK_WORDSYNC|ADK_MSBSYNC;
        /* set appropriate adkcon bits */
        adk = ADK_SETCLR|ADK_FAST;
        if ((ulong)track >= unit[drive].type->precomp2)
                adk |= ADK_PRECOMP1;
        else if ((ulong)track >= unit[drive].type->precomp1)
                adk |= ADK_PRECOMP0;
        custom.adkcon = adk;
 
        custom.dsklen = DSKLEN_WRITE;
#if 0
        ms_delay (unit[drive].type->side_time);
#endif
        custom.dskptr = (u_char *)ZTWO_PADDR((u_char *)ptrack);
        custom.dsklen = len/sizeof(short) | DSKLEN_DMAEN|DSKLEN_WRITE;
        custom.dsklen = len/sizeof(short) | DSKLEN_DMAEN|DSKLEN_WRITE;
 
        block_flag = 2;
        return 1;
}
 
static void post_write (unsigned long dummy)
{
  custom.dsklen = 0;
  writepending = 0;
  writefromint = 0;
}
 
static int get_track(int drive, int track)
{
        int error;
 
        drive&=3;
        if ((lastdrive == drive) && (savedtrack == track))
                return 0;
 
        lastdrive = drive;
        raw_read(drive, track, raw_buf, unit[drive].type->read_size);
        savedtrack = -1;
        error = (*unit[drive].dtype->read_fkt)(drive, trackdata, (unsigned long)raw_buf, track);
        switch (error) {
            case 0:
                savedtrack = track;
                return 0;
            case MFM_TRACK:
                unit[drive].track = -1;
                /* fall through */
            default:
                return -1;
        }
}
 
static void flush_track_callback(unsigned long nr)
{
  nr&=3;
  writefromint = 1;
  (*unit[nr].dtype->write_fkt)(nr, (unsigned long)raw_buf, trackdata, savedtrack);
  if (!raw_write(nr, savedtrack, raw_buf, unit[nr].type->write_size)) {
    printk ("floppy disk write protected\n");
    writefromint = 0;
    writepending = 0;
  }
}
 
static int non_int_flush_track (unsigned long nr)
{
unsigned long flags;
 
  nr&=3;
  writefromint = 0;
  del_timer(&post_write_timer);
  save_flags(flags);
  cli();
  if (writepending != 2) {
    restore_flags(flags);
    (*unit[nr].dtype->write_fkt)(nr, (unsigned long)raw_buf, trackdata, savedtrack);
    if (!raw_write(nr, savedtrack, raw_buf, unit[nr].type->write_size)) {
      printk ("floppy disk write protected in write!\n");
      writepending = 0;
      return 0;
    }
    while (block_flag == 2)
      sleep_on (&wait_fd_block);
  }
  else
    restore_flags(flags);
  ms_delay(2); /* 2 ms post_write delay */
  post_write(0);
  return 1;
}
 
static void redo_fd_request(void)
{
        unsigned int block, track, sector;
        int device, drive, cnt;
        struct amiga_floppy_struct *floppy;
        char *data;
        unsigned long flags;
 
        if (CURRENT && CURRENT->rq_status == RQ_INACTIVE){
                return;
        }
 
    repeat:
        if (!CURRENT) {
                if (!fdc_busy)
                        printk("FDC access conflict!");
                fdc_busy = 0;
                wake_up(&fdc_wait);
                CLEAR_INTR;
                return;
        }
 
        if (MAJOR(CURRENT->rq_dev) != MAJOR_NR)
                panic(DEVICE_NAME ": request list destroyed");
 
        if (CURRENT->bh && !buffer_locked(CURRENT->bh))
                panic(DEVICE_NAME ": block not locked");
 
        probing = 0;
        device = MINOR(CURRENT_DEVICE);
        if (device > 3) {
                /* manual selection */
                drive = device & 3;
                floppy = unit + drive;
        } else {
                /* Auto-detection */
                /* printk("redo_fd_request: can't handle auto detect\n");*/
                /* printk("redo_fd_request: default to normal\n");*/
                drive = device & 3;
                floppy = unit + drive;
        }
 
        save_flags (flags);
        cli();
        if (drive != selected && writepending) {
          del_timer (&flush_track_timer);
          restore_flags (flags);
          if (!non_int_flush_track (selected)) {
            end_request(0);
            goto repeat;
          }
        } else
          restore_flags (flags);
 
 /* Here someone could investigate to be more efficient */
        for (cnt = 0; cnt < CURRENT->current_nr_sectors; cnt++) {
#ifdef DEBUG
                printk("fd: sector %d + %d requested\n",CURRENT->sector,cnt);
#endif
                block = CURRENT->sector + cnt;
                if ((int)block > floppy->blocks) {
                        request_done(0);
                        goto repeat;
                }
 
                track = block / floppy->sects;
                sector = block % floppy->sects;
                data = CURRENT->buffer + 512 * cnt;
 
                save_flags (flags);
                cli();
                if (track != savedtrack && writepending) {
                  del_timer (&flush_track_timer);
                  restore_flags (flags);
                  if (!non_int_flush_track (selected)) {
                    end_request(0);
                    goto repeat;
                  }
                } else
                  restore_flags (flags);
 
                switch (CURRENT->cmd) {
                    case READ:
                        if (!motor_on (drive)) {
                                end_request(0);
                                goto repeat;
                        }
                        fd_select (drive);
                        if (!fd_seek(drive, track)) {
                                end_request(0);
                                goto repeat;
                        }
                        if (get_track(drive, track) == -1) {
                                end_request(0);
                                goto repeat;
                        }
                        copy_buffer(trackdata + sector * 512, data);
                        break;
 
                    case WRITE:
                        if (!motor_on (drive)) {
                                end_request(0);
                                goto repeat;
                        }
                        fd_select (drive);
                        if (!fd_seek(drive, track)) {
                                end_request(0);
                                goto repeat;
                        }
                        if (get_track(drive, track) == -1) {
                                end_request(0);
                                goto repeat;
                        }
                        copy_buffer(data, trackdata + sector * 512);
                        /*
                         * setup a callback to write the track buffer
                         * after a short (1 tick) delay.
                         */
                        save_flags (flags);
                        cli();
 
                        if (writepending)
                            /* reset the timer */
                            del_timer (&flush_track_timer);
 
                        writepending = 1;
                        flush_track_timer.data = drive;
                        flush_track_timer.expires = jiffies + 1;
                        add_timer (&flush_track_timer);
                        restore_flags (flags);
                        break;
 
                    default:
                        printk("do_fd_request: unknown command\n");
                        request_done(0);
                        goto repeat;
                }
        }
        CURRENT->nr_sectors -= CURRENT->current_nr_sectors;
        CURRENT->sector += CURRENT->current_nr_sectors;
 
        request_done(1);
        goto repeat;
}
 
static void do_fd_request(void)
{
unsigned long flags;
 
        save_flags(flags);
        cli();
        while (fdc_busy) sleep_on(&fdc_wait);
        fdc_busy = 1;
        restore_flags(flags); /* sti(); */
        redo_fd_request();
}
 
static int fd_ioctl(struct inode *inode, struct file *filp,
                    unsigned int cmd, unsigned long param)
{
        int drive = inode->i_rdev & 3;
        static struct floppy_struct getprm;
        int error;
 
        switch(cmd)
         {
          case FDFMTBEG:
            if (fd_ref[drive] > 1)
              return -EBUSY;
            fsync_dev(inode->i_rdev);
            if (motor_on(drive) == 0)
              return -ENODEV;
            if (fd_calibrate(drive) == 0)
              return -ENXIO;
            floppy_off(drive);
            break;
          case FDFMTTRK:
            if (param < unit[drive].type->tracks)
             {
              fd_select(drive);
              if (fd_seek(drive,param)!=0)
               {
                savedtrack=param;
                memset(trackdata,FD_FILL_BYTE,unit[drive].sects*512);
                non_int_flush_track(drive);
               }
              floppy_off(drive);
             }
            else
              return -EINVAL;
            break;
          case FDFMTEND:
            floppy_off(drive);
            invalidate_inodes(inode->i_rdev);
            invalidate_buffers(inode->i_rdev);
            break;
          case FDGETPRM:
            error = verify_area(VERIFY_WRITE, (void *)param,
                                sizeof(struct floppy_struct));
            if (error)
              return error;
            memset((void *)&getprm, 0, sizeof (getprm));
            getprm.track=unit[drive].type->tracks/unit[drive].type->heads;
            getprm.head=unit[drive].type->heads;
            getprm.sect=unit[drive].sects;
            getprm.size=unit[drive].blocks;
            memcpy_tofs((void *)param,(void *)&getprm,sizeof(struct floppy_struct));
            break;
          case BLKGETSIZE:
            error = verify_area(VERIFY_WRITE, (void *)param,
                                sizeof(long));
            if (error)
              return error;
            put_fs_long(unit[drive].blocks,(long *)param);
            break;
          case FDSETPRM:
          case FDDEFPRM:
            return -EINVAL;
          case FDFLUSH:
            if ((drive == selected) && (writepending)) {
              del_timer (&flush_track_timer);
              non_int_flush_track(selected);
            }
            break;
#ifdef RAW_IOCTL
          case IOCTL_RAW_TRACK:
            error = verify_area(VERIFY_WRITE, (void *)param,
              unit[drive].type->read_size);
            if (error)
              return error;
            memcpy_tofs((void *)param, raw_buf, unit[drive].type->read_size);
            return unit[drive].type->read_size;
#endif
          default:
            printk("fd_ioctl: unknown cmd %d for drive %d.",cmd,drive);
            return -ENOSYS;
         }
        return 0;
}
 
/*======================================================================
  Return unit ID number of given disk
======================================================================*/
static unsigned long get_drive_id(int drive)
{
        int i;
        ulong id = 0;
 
        drive&=3;
        /* set up for ID */
        MOTOR_ON;
        udelay(2);
        SELECT(SELMASK(drive));
        udelay(2);
        DESELECT(SELMASK(drive));
        udelay(2);
        MOTOR_OFF;
        udelay(2);
        SELECT(SELMASK(drive));
        udelay(2);
        DESELECT(SELMASK(drive));
        udelay(2);
 
        /* loop and read disk ID */
        for (i=0; i<32; i++) {
                SELECT(SELMASK(drive));
                udelay(2);
 
                /* read and store value of DSKRDY */
                id <<= 1;
                id |= (ciaa.pra & DSKRDY) ? 0 : 1;       /* cia regs are low-active! */
 
                DESELECT(SELMASK(drive));
        }
 
        selected = -1;
 
        /*
         * RB: At least A500/A2000's df0: don't identify themselves.
         * As every (real) Amiga has at least a 3.5" DD drive as df0:
         * we default to that if df0: doesn't identify as a certain
         * type.
         */
        if(drive == 0 && id == FD_NODRIVE)
         {
                id = fd_def_df0;
                printk("fd: drive 0 didn't identify, setting default %08lx\n",(ulong)fd_def_df0);
         }
        /* return the ID value */
        return (id);
}
 
static void fd_probe(int dev)
{
        unsigned long code;
        int type;
        int drive;
        int system;
 
        drive = dev & 3;
        code = get_drive_id(drive);
 
        /* get drive type */
        unit[drive].type = NULL;
        for (type = 0; type < num_dr_types; type++)
                if (drive_types[type].code == code)
                        break;
 
        if (type >= num_dr_types) {
                printk("fd_probe: unsupported drive type %08lx found\n",
                       code);
                return;
        }
 
        unit[drive].type = &drive_types[type];
        unit[drive].track = -1;
 
        unit[drive].disk = -1;
        unit[drive].motor = 0;
        unit[drive].busy = 0;
        unit[drive].status = -1;
 
 
        system=(dev & 4)>>2;
        unit[drive].dtype=&data_types[system];
        unit[drive].sects=data_types[system].sects*unit[drive].type->sect_mult;
        unit[drive].blocks=unit[drive].type->heads*unit[drive].type->tracks*
            unit[drive].sects;
 
        floppy_sizes[MINOR(dev)] = unit[drive].blocks >> 1;
 
}
 
static void probe_drives(void)
{
        int drive,found;
 
        printk("FD: probing units\nfound ");
        found=0;
        for(drive=0;drive<FD_MAX_UNITS;drive++) {
          fd_probe(drive);
          if (unit[drive].type->code != FD_NODRIVE) {
            printk("fd%d ",drive);
            found=1;
          }
        }
        printk("%s\n",(found==0)?" no drives":"");
}
 
/*
 * floppy_open check for aliasing (/dev/fd0 can be the same as
 * /dev/PS0 etc), and disallows simultaneous access to the same
 * drive with different device numbers.
 */
static int floppy_open(struct inode *inode, struct file *filp)
{
  int drive;
  int old_dev;
  int system;
 
  drive = inode->i_rdev & 3;
  old_dev = fd_device[drive];
 
  if (fd_ref[drive])
    if (old_dev != inode->i_rdev)
      return -EBUSY;
 
  if (unit[drive].type->code == FD_NODRIVE)
    return -ENODEV;
 
  fd_ref[drive]++;
  fd_device[drive] = inode->i_rdev;
 
  if (old_dev && old_dev != inode->i_rdev)
    invalidate_buffers(old_dev);
 
  if (filp && filp->f_mode)
    check_disk_change(inode->i_rdev);
 
  if (filp && (filp->f_flags & (O_WRONLY|O_RDWR))) {
          int wrprot;
 
          fd_select (drive);
          wrprot = !(ciaa.pra & DSKPROT);
          fd_deselect (drive);
 
          if (wrprot)
                  return -EROFS;
  }
 
  system=(inode->i_rdev & 4)>>2;
  unit[drive].dtype=&data_types[system];
  unit[drive].sects=data_types[system].sects*unit[drive].type->sect_mult;
  unit[drive].blocks=unit[drive].type->heads*unit[drive].type->tracks*
        unit[drive].sects;
 
printk("fd%d: accessing %s-disk with %s-layout\n",drive,unit[drive].type->name,
  data_types[system].name);
 
  return 0;
}
 
static void floppy_release(struct inode * inode, struct file * filp)
{
  unsigned long flags;
 
  fsync_dev(inode->i_rdev);
  invalidate_inodes(inode->i_rdev);
  invalidate_buffers(inode->i_rdev);
  save_flags (flags);
  cli();
  if ((inode->i_rdev & 3) == selected && writepending) {
    del_timer (&flush_track_timer);
    restore_flags (flags);
    non_int_flush_track (selected);
  } else
    restore_flags (flags);
 
  if (!fd_ref[inode->i_rdev & 3]--) {
    printk("floppy_release with fd_ref == 0");
    fd_ref[inode->i_rdev & 3] = 0;
  }
}
 
void amiga_floppy_setup (char *str, int *ints)
{
printk ("amiflop: Setting default df0 to %x\n", ints[1]);
fd_def_df0 = ints[1];
}
 
static struct file_operations floppy_fops = {
        NULL,                   /* lseek - default */
        block_read,             /* read - general block-dev read */
        block_write,            /* write - general block-dev write */
        NULL,                   /* readdir - bad */
        NULL,                   /* select */
        fd_ioctl,               /* ioctl */
        NULL,                   /* mmap */
        floppy_open,            /* open */
        floppy_release,         /* release */
        block_fsync,            /* fsync */
        NULL,                   /* fasync */
        amiga_floppy_change,    /* check_media_change */
        NULL,                   /* revalidate */
};
 
static void fd_block_done(int irq, struct pt_regs *fp, void *dummy)
{
  if (block_flag)
    custom.dsklen = 0x4000;
 
  block_flag = 0;
  wake_up (&wait_fd_block);
 
  if (writefromint) {
    /*
     * if it was a write from an interrupt,
     * we will call post_write from here
     */
    writepending = 2;
    post_write_timer.expires = 1; /* at least 2 ms */
    add_timer(&post_write_timer);
  }
 
}
 
int amiga_floppy_init(void)
{
  int i;
 
  if (!AMIGAHW_PRESENT(AMI_FLOPPY))
    return -ENXIO;
 
  if (register_blkdev(MAJOR_NR,"fd",&floppy_fops)) {
    printk("Unable to get major %d for floppy\n",MAJOR_NR);
    return -EBUSY;
  }
 
  /* initialize variables */
  motor_on_timer.next = NULL;
  motor_on_timer.prev = NULL;
  motor_on_timer.expires = 0;
  motor_on_timer.data = 0;
  motor_on_timer.function = motor_on_callback;
  for (i = 0; i < FD_MAX_UNITS; i++) {
          motor_off_timer[i].next = NULL;
          motor_off_timer[i].prev = NULL;
          motor_off_timer[i].expires = 0;
          motor_off_timer[i].data = i;
          motor_off_timer[i].function = fd_motor_off;
 
          unit[i].track = -1;
  }
 
  flush_track_timer.next = NULL;
  flush_track_timer.prev = NULL;
  flush_track_timer.expires = 0;
  flush_track_timer.data = 0;
  flush_track_timer.function = flush_track_callback;
 
  post_write_timer.next = NULL;
  post_write_timer.prev = NULL;
  post_write_timer.expires = 0;
  post_write_timer.data = 0;
  post_write_timer.function = post_write;
 
  blk_dev[MAJOR_NR].request_fn = DEVICE_REQUEST;
  blksize_size[MAJOR_NR] = floppy_blocksizes;
  blk_size[MAJOR_NR] = floppy_sizes;
 
 
  timer_table[FLOPPY_TIMER].fn = NULL;
  timer_active &= ~(1 << FLOPPY_TIMER);
 
  if (fd_def_df0==0) {
    if ((boot_info.bi_amiga.model == AMI_3000) ||
        (boot_info.bi_amiga.model == AMI_4000))
      fd_def_df0=FD_HD_3;
    else
      fd_def_df0=FD_DD_3;
  }
 
  probe_drives();
 
  raw_buf = (char *)amiga_chip_alloc (RAW_BUF_SIZE);
 
  for (i = 0; i < 128; i++)
    mfmdecode[i]=255;
  for (i = 0; i < 16; i++)
    mfmdecode[mfmencode[i]]=i;
 
  /* make sure that disk DMA is enabled */
  custom.dmacon = DMAF_SETCLR | DMAF_DISK;
 
  add_isr(IRQ_FLOPPY, fd_block_done, 0, NULL, "floppy_dma");
  add_isr(IRQ_AMIGA_CIAA_TB, ms_isr, 0, NULL, "floppy_timer");
 
  return 0;
}
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[/] [or1k/] [trunk/] [rc203soc/] [sw/] [uClinux/] [drivers/] [block/] [amiflop.c] - Blame information for rev 1765

Line No.	Rev	Author	Line
1	1626	jcastillo	`/*`
2			`* linux/amiga/amiflop.c`
3			`*`
4			`* Copyright (C) 1993 Greg Harp`
5			`* Portions of this driver are based on code contributed by Brad Pepers`
6			`*`
7			`* revised 28.5.95 by Joerg Dorchain`
8			`* - now no bugs(?) any more for both HD & DD`
9			`* - added support for 40 Track 5.25" drives, 80-track hopefully behaves`
10			`* like 3.5" dd (no way to test - are there any 5.25" drives out there`
11			`* that work on an A4000?)`
12			`* - wrote formatting routine (maybe dirty, but works)`
13			`*`
14			`* june/july 1995 added ms-dos support by Joerg Dorchain`
15			`* (portions based on messydos.device and various contributors)`
16			`* - currently only 9 and 18 sector disks`
17			`*`
18			`* - fixed a bug with the internal trackbuffer when using multiple`
19			`* disks the same time`
20			`* - made formatting a bit safer`
21			`* - added command line and machine based default for "silent" df0`
22			`*`
23			`* december 1995 adapted for 1.2.13pl4 by Joerg Dorchain`
24			`* - works but I think it's inefficient. (look in redo_fd_request)`
25			`* But the changes were very efficient. (only three and a half lines)`
26			`*`
27			`* january 1995 added special ioctl for tracking down read/write problems`
28			`* - usage ioctl(d, RAW_TRACK, ptr); the raw track buffer (MFM-encoded data`
29			`* is copied to area. (area should be large enough since no checking is`
30			`* done - 30K is currently sufficient). return the actual size of the`
31			`* trackbuffer`
32			`* - replaced udelays() by a timer (CIAA timer B) for the waits`
33			`* needed for the disk mechanic.`
34			`*`
35			`* revised Marts 3rd, 1996 by Jes Sorensen for use in the 1.3.28 kernel.`
36			`* - Minor changes to accept the kdev_t.`
37			`* - Replaced some more udelays with ms_delays. Udelay is just a loop,`
38			`* and so the delay will be different depending on the given`
39			`* processor :-(`
40			`* - The driver could use a major cleanup because of the new`