amiflop.c

linux和2410结合开发 用他可以生成2410所需的zImage文件

/*
 *  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 1996 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.
 *
 *  february 1996 fixed error recovery and multiple disk access
 *  - both got broken the first time I tampered with the driver :-(
 *  - still not safe, but better than before
 *
 *  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.
 *
 * restructured jan 1997 by Joerg Dorchain
 * - Fixed Bug accessing multiple disks
 * - some code cleanup
 * - added trackbuffer for each drive to speed things up
 * - fixed some race conditions (who finds the next may send it to me ;-)
 */

#include <linux/module.h>

#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/hdreg.h>
#include <linux/errno.h>
#include <linux/types.h>
#include <linux/delay.h>
#include <linux/string.h>
#include <linux/slab.h>
#include <linux/init.h>
#include <linux/amifdreg.h>
#include <linux/amifd.h>
#include <linux/ioport.h>

#include <asm/setup.h>
#include <asm/uaccess.h>
#include <asm/amigahw.h>
#include <asm/amigaints.h>
#include <asm/irq.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

/*
 *  Defines
 */

/*
 *  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) */

#define MFM_NOSYNC	1
#define MFM_HEADER	2
#define MFM_DATA	3
#define MFM_TRACK	4

/*
 *  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 long int fd_def_df0 = FD_DD_3;     /* default for df0 if it doesn't identify */

MODULE_PARM(fd_def_df0,"l");
MODULE_LICENSE("GPL");

/*
 *  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)))

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",  80, 2, 14716, 13630, 1, 80,161, 3, 18, 1},
{ FD_HD_3,	"HD 3.5",  80, 2, 28344, 27258, 2, 80,161, 3, 18, 1},
{ FD_DD_5,	"DD 5.25", 40, 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]={880,880,880,880,720,720,720,720,};
static int floppy_blocksizes[256];
/* hardsector size assumed to be 512 */

static int amiga_read(int), dos_read(int);
static void amiga_write(int), dos_write(int);
static struct fd_data_type data_types[] = {
	{ "Amiga", 11 , amiga_read, amiga_write},
	{ "MS-Dos", 9, dos_read, dos_write}
};

/* current info on each unit */
static struct amiga_floppy_struct unit[FD_MAX_UNITS];

static struct timer_list flush_track_timer[FD_MAX_UNITS];
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;

/* Synchronization of FDC access */
/* request loop (trackbuffer) */
static volatile int fdc_busy = -1;
static volatile int fdc_nested;
static DECLARE_WAIT_QUEUE_HEAD(fdc_wait);
 
static DECLARE_WAIT_QUEUE_HEAD(motor_wait);

static volatile int selected = -1;	/* currently selected drive */

static int writepending;
static int writefromint;
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 volatile char block_flag;
static DECLARE_WAIT_QUEUE_HEAD(wait_fd_block);

/* 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 volatile int ms_busy = -1;
static DECLARE_WAIT_QUEUE_HEAD(ms_wait);
#define MS_TICKS ((amiga_eclock+50)/1000)

/*
 * 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

/* Prevent "aliased" accesses. */
static int fd_ref[4] = { 0,0,0,0 };
static int 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)



/*
 * Here come the actual hardware access and helper functions.
 * They are not reentrant and single threaded because all drives
 * share the same hardware and the same trackbuffer.
 */

/* Milliseconds timer */

static void ms_isr(int irq, void *dummy, struct pt_regs *fp)
{
	ms_busy = -1;
	wake_up(&ms_wait);
}

/* all waits are queued up 
   A more generic routine would do a schedule a la timer.device */
static void ms_delay(int ms)
{
	unsigned long flags;
	int ticks;
	if (ms > 0) {
		save_flags(flags);
		cli();
		while (ms_busy == 0)
			sleep_on(&ms_wait);
		ms_busy = 0;
		restore_flags(flags);
		ticks = MS_TICKS*ms-1;
		ciaa.tblo=ticks%256;
		ciaa.tbhi=ticks/256;
		ciaa.crb=0x19; /*count eclock, force load, one-shoot, start */
		sleep_on(&ms_wait);
	}
}

/* Hardware semaphore */

/* returns true when we would get the semaphore */
static inline int try_fdc(int drive)
{
	drive &= 3;
	return ((fdc_busy < 0) || (fdc_busy == drive));
}

static void get_fdc(int drive)
{
	unsigned long flags;

	drive &= 3;
#ifdef DEBUG
	printk("get_fdc: drive %d  fdc_busy %d  fdc_nested %d\n",drive,fdc_busy,fdc_nested);
#endif
	save_flags(flags);
	cli();
	while (!try_fdc(drive))
		sleep_on(&fdc_wait);
	fdc_busy = drive;
	fdc_nested++;
	restore_flags(flags);
}

static inline void rel_fdc(void)
{
#ifdef DEBUG
	if (fdc_nested == 0)
		printk("fd: unmatched rel_fdc\n");
	printk("rel_fdc: fdc_busy %d fdc_nested %d\n",fdc_busy,fdc_nested);
#endif
	fdc_nested--;
	if (fdc_nested == 0) {
		fdc_busy = -1;
		wake_up(&fdc_wait);
	}
}

static void fd_select (int drive)
{
	unsigned char prb = ~0;

	drive&=3;
#ifdef DEBUG
	printk("selecting %d\n",drive);
#endif
	if (drive == selected)
		return;
	get_fdc(drive);
	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;
	rel_fdc();
}

static void fd_deselect (int drive)
{
	unsigned char prb;
	unsigned long flags;

	drive&=3;
#ifdef DEBUG
	printk("deselecting %d\n",drive);
#endif
	if (drive != selected) {
		printk(KERN_WARNING "Deselecting drive %d while %d was selected!\n",drive,selected);
		return;
	}

	get_fdc(drive);
	save_flags (flags);
	sti();

	selected = -1;

	prb = ciab.prb;
	prb |= (SELMASK(0)|SELMASK(1)|SELMASK(2)|SELMASK(3));
	ciab.prb = prb;

	restore_flags (flags);
	rel_fdc();

}

static void motor_on_callback(unsigned long nr)
{
	if (!(ciaa.pra & DSKRDY) || --on_attempts == 0) {
		wake_up (&motor_wait);
	} else {
		motor_on_timer.expires = jiffies + HZ/10;
		add_timer(&motor_on_timer);
	}
}

static int fd_motor_on(int nr)
{
	nr &= 3;

	del_timer(motor_off_timer + nr);

	if (!unit[nr].motor) {
		unit[nr].motor = 1;
		fd_select(nr);

		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;
		sleep_on (&motor_wait);
		fd_deselect(nr);
	}

	if (on_attempts == 0) {
		on_attempts = -1;
#if 0
		printk (KERN_ERR "motor_on failed, turning motor off\n");
		fd_motor_off (nr);
		return 0;
#else
		printk (KERN_WARNING "DSKRDY not set after 1.5 seconds - assuming drive is spinning notwithstanding\n");
#endif
	}

	return 1;
}

static void fd_motor_off(unsigned long drive)
{
	long calledfromint;
#ifdef MODULE
	long decusecount;

	decusecount = drive & 0x40000000;
#endif
	calledfromint = drive & 0x80000000;
	drive&=3;
	if (calledfromint && !try_fdc(drive)) {
		/* We would be blocked in an interrupt, so try again later */
		motor_off_timer[drive].expires = jiffies + 1;
		add_timer(motor_off_timer + drive);
		return;
	}
	unit[drive].motor = 0;
	fd_select(drive);
	udelay (1);
	fd_deselect(drive);

#ifdef MODULE
/*
  this is the last interrupt for any drive access, happens after
  release (from floppy_off). So we have to wait until now to decrease
  the use count.
*/
	if (decusecount)
		MOD_DEC_USE_COUNT;
#endif
}

static void floppy_off (unsigned int nr)
{
	int drive;

	drive = nr & 3;
	del_timer(motor_off_timer + drive);
	motor_off_timer[drive].expires = jiffies + 3*HZ;
	/* called this way it is always from interrupt */
	motor_off_timer[drive].data = nr | 0x80000000;
	add_timer(motor_off_timer + nr);
}

static int fd_calibrate(int drive)
{
	unsigned char prb;
	int n;

	drive &= 3;
	get_fdc(drive);
	if (!fd_motor_on (drive))
		return 0;
	fd_select (drive);
	prb = ciab.prb;
	prb |= DSKSIDE;
	prb &= ~DSKDIREC;
	ciab.prb = prb;
	for (n = unit[drive].type->tracks/2; n != 0; --n) {
		if (ciaa.pra & DSKTRACK0)
			break;
		prb &= ~DSKSTEP;
		ciab.prb = prb;
		prb |= DSKSTEP;
		udelay (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 + 20;
	for (;;) {
		prb &= ~DSKSTEP;
		ciab.prb = prb;
		prb |= DSKSTEP;
		udelay (2);
		ciab.prb = prb;
		ms_delay(unit[drive].type->step_delay + 1);
		if ((ciaa.pra & DSKTRACK0) == 0)
			break;
		if (--n == 0) {
			printk (KERN_ERR "fd%d: calibrate failed, turning motor off\n", drive);
			fd_motor_off (drive);
			unit[drive].track = -1;
			rel_fdc();