patch-1.3.94 linux/drivers/block/amiflop.c
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- Lines: 1783
- Date:
Sat Mar 30 14:11:12 1996
- Orig file:
v1.3.93/linux/drivers/block/amiflop.c
- Orig date:
Thu Jan 1 02:00:00 1970
diff -u --recursive --new-file v1.3.93/linux/drivers/block/amiflop.c linux/drivers/block/amiflop.c
@@ -0,0 +1,1782 @@
+/*
+ * 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 its 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 wont fit
+ and this cost about 3h to discover.... */
+unsigned char gap1[22]; /* for longword-aligndness (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
+; polymomials. 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: accesing %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;
+}
FUNET's LINUX-ADM group, linux-adm@nic.funet.fi
TCL-scripts by Sam Shen, slshen@lbl.gov
with Sam's (original) version of this