floppy.c

Linux块设备驱动源码

				if (!probing) {
					printk("sector not found");
					tell_sector();
				} else
					printk("probe failed...");
			} else if (ST2 & ST2_WC) {	/* seek error */
				printk("wrong cylinder");
			} else if (ST2 & ST2_BC) {	/* cylinder marked as bad */
				printk("bad cylinder");
			} else {
				printk
				    ("unknown error. ST[0..2] are: 0x%x 0x%x 0x%x",
				     ST0, ST1, ST2);
				tell_sector();
			}
			printk("\n");

		}
		if (ST2 & ST2_WC || ST2 & ST2_BC)
			/* wrong cylinder => recal */
			DRS->track = NEED_2_RECAL;
		return bad;
	case 0x80:		/* invalid command given */
		DPRINT("Invalid FDC command given!\n");
		cont->done(0);
		return 2;
	case 0xc0:
		DPRINT("Abnormal termination caused by polling\n");
		cont->error();
		return 2;
	default:		/* (0) Normal command termination */
		return 0;
	}
}

/*
 * This routine is called when everything should be correctly set up
 * for the transfer (i.e. floppy motor is on, the correct floppy is
 * selected, and the head is sitting on the right track).
 */
static void setup_rw_floppy(void)
{
	int i, r, flags, dflags;
	unsigned long ready_date;
	timeout_fn function;

	flags = raw_cmd->flags;
	if (flags & (FD_RAW_READ | FD_RAW_WRITE))
		flags |= FD_RAW_INTR;

	if ((flags & FD_RAW_SPIN) && !(flags & FD_RAW_NO_MOTOR)) {
		ready_date = DRS->spinup_date + DP->spinup;
		/* If spinup will take a long time, rerun scandrives
		 * again just before spinup completion. Beware that
		 * after scandrives, we must again wait for selection.
		 */
		if ((signed)(ready_date - jiffies) > DP->select_delay) {
			ready_date -= DP->select_delay;
			function = (timeout_fn) floppy_start;
		} else
			function = (timeout_fn) setup_rw_floppy;

		/* wait until the floppy is spinning fast enough */
		if (fd_wait_for_completion(ready_date, function))
			return;
	}
	dflags = DRS->flags;

	if ((flags & FD_RAW_READ) || (flags & FD_RAW_WRITE))
		setup_DMA();

	if (flags & FD_RAW_INTR)
		do_floppy = main_command_interrupt;

	r = 0;
	for (i = 0; i < raw_cmd->cmd_count; i++)
		r |= output_byte(raw_cmd->cmd[i]);

	debugt("rw_command: ");

	if (r) {
		cont->error();
		reset_fdc();
		return;
	}

	if (!(flags & FD_RAW_INTR)) {
		inr = result();
		cont->interrupt();
	} else if (flags & FD_RAW_NEED_DISK)
		fd_watchdog();
}

static int blind_seek;

/*
 * This is the routine called after every seek (or recalibrate) interrupt
 * from the floppy controller.
 */
static void seek_interrupt(void)
{
	debugt("seek interrupt:");
	if (inr != 2 || (ST0 & 0xF8) != 0x20) {
		DPRINT("seek failed\n");
		DRS->track = NEED_2_RECAL;
		cont->error();
		cont->redo();
		return;
	}
	if (DRS->track >= 0 && DRS->track != ST1 && !blind_seek) {
#ifdef DCL_DEBUG
		if (DP->flags & FD_DEBUG) {
			DPRINT
			    ("clearing NEWCHANGE flag because of effective seek\n");
			DPRINT("jiffies=%lu\n", jiffies);
		}
#endif
		CLEARF(FD_DISK_NEWCHANGE);	/* effective seek */
		DRS->select_date = jiffies;
	}
	DRS->track = ST1;
	floppy_ready();
}

static void check_wp(void)
{
	if (TESTF(FD_VERIFY)) {
		/* check write protection */
		output_byte(FD_GETSTATUS);
		output_byte(UNIT(current_drive));
		if (result() != 1) {
			FDCS->reset = 1;
			return;
		}
		CLEARF(FD_VERIFY);
		CLEARF(FD_NEED_TWADDLE);
#ifdef DCL_DEBUG
		if (DP->flags & FD_DEBUG) {
			DPRINT("checking whether disk is write protected\n");
			DPRINT("wp=%x\n", ST3 & 0x40);
		}
#endif
		if (!(ST3 & 0x40))
			SETF(FD_DISK_WRITABLE);
		else
			CLEARF(FD_DISK_WRITABLE);
	}
}

static void seek_floppy(void)
{
	int track;

	blind_seek = 0;

#ifdef DCL_DEBUG
	if (DP->flags & FD_DEBUG) {
		DPRINT("calling disk change from seek\n");
	}
#endif

	if (!TESTF(FD_DISK_NEWCHANGE) &&
	    disk_change(current_drive) && (raw_cmd->flags & FD_RAW_NEED_DISK)) {
		/* the media changed flag should be cleared after the seek.
		 * If it isn't, this means that there is really no disk in
		 * the drive.
		 */
		SETF(FD_DISK_CHANGED);
		cont->done(0);
		cont->redo();
		return;
	}
	if (DRS->track <= NEED_1_RECAL) {
		recalibrate_floppy();
		return;
	} else if (TESTF(FD_DISK_NEWCHANGE) &&
		   (raw_cmd->flags & FD_RAW_NEED_DISK) &&
		   (DRS->track <= NO_TRACK || DRS->track == raw_cmd->track)) {
		/* we seek to clear the media-changed condition. Does anybody
		 * know a more elegant way, which works on all drives? */
		if (raw_cmd->track)
			track = raw_cmd->track - 1;
		else {
			if (DP->flags & FD_SILENT_DCL_CLEAR) {
				set_dor(fdc, ~(0x10 << UNIT(current_drive)), 0);
				blind_seek = 1;
				raw_cmd->flags |= FD_RAW_NEED_SEEK;
			}
			track = 1;
		}
	} else {
		check_wp();
		if (raw_cmd->track != DRS->track &&
		    (raw_cmd->flags & FD_RAW_NEED_SEEK))
			track = raw_cmd->track;
		else {
			setup_rw_floppy();
			return;
		}
	}

	do_floppy = seek_interrupt;
	output_byte(FD_SEEK);
	output_byte(UNIT(current_drive));
	LAST_OUT(track);
	debugt("seek command:");
}

static void recal_interrupt(void)
{
	debugt("recal interrupt:");
	if (inr != 2)
		FDCS->reset = 1;
	else if (ST0 & ST0_ECE) {
		switch (DRS->track) {
		case NEED_1_RECAL:
			debugt("recal interrupt need 1 recal:");
			/* after a second recalibrate, we still haven't
			 * reached track 0. Probably no drive. Raise an
			 * error, as failing immediately might upset
			 * computers possessed by the Devil :-) */
			cont->error();
			cont->redo();
			return;
		case NEED_2_RECAL:
			debugt("recal interrupt need 2 recal:");
			/* If we already did a recalibrate,
			 * and we are not at track 0, this
			 * means we have moved. (The only way
			 * not to move at recalibration is to
			 * be already at track 0.) Clear the
			 * new change flag */
#ifdef DCL_DEBUG
			if (DP->flags & FD_DEBUG) {
				DPRINT
				    ("clearing NEWCHANGE flag because of second recalibrate\n");
			}
#endif

			CLEARF(FD_DISK_NEWCHANGE);
			DRS->select_date = jiffies;
			/* fall through */
		default:
			debugt("recal interrupt default:");
			/* Recalibrate moves the head by at
			 * most 80 steps. If after one
			 * recalibrate we don't have reached
			 * track 0, this might mean that we
			 * started beyond track 80.  Try
			 * again.  */
			DRS->track = NEED_1_RECAL;
			break;
		}
	} else
		DRS->track = ST1;
	floppy_ready();
}

static void print_result(char *message, int inr)
{
	int i;

	DPRINT("%s ", message);
	if (inr >= 0)
		for (i = 0; i < inr; i++)
			printk("repl[%d]=%x ", i, reply_buffer[i]);
	printk("\n");
}

/* interrupt handler. Note that this can be called externally on the Sparc */
irqreturn_t floppy_interrupt(int irq, void *dev_id, struct pt_regs *regs)
{
	void (*handler) (void) = do_floppy;
	int do_print;
	unsigned long f;

	lasthandler = handler;
	interruptjiffies = jiffies;

	f = claim_dma_lock();
	fd_disable_dma();
	release_dma_lock(f);

	floppy_enable_hlt();
	do_floppy = NULL;
	if (fdc >= N_FDC || FDCS->address == -1) {
		/* we don't even know which FDC is the culprit */
		printk("DOR0=%x\n", fdc_state[0].dor);
		printk("floppy interrupt on bizarre fdc %d\n", fdc);
		printk("handler=%p\n", handler);
		is_alive("bizarre fdc");
		return IRQ_NONE;
	}

	FDCS->reset = 0;
	/* We have to clear the reset flag here, because apparently on boxes
	 * with level triggered interrupts (PS/2, Sparc, ...), it is needed to
	 * emit SENSEI's to clear the interrupt line. And FDCS->reset blocks the
	 * emission of the SENSEI's.
	 * It is OK to emit floppy commands because we are in an interrupt
	 * handler here, and thus we have to fear no interference of other
	 * activity.
	 */

	do_print = !handler && print_unex && !initialising;

	inr = result();
	if (do_print)
		print_result("unexpected interrupt", inr);
	if (inr == 0) {
		int max_sensei = 4;
		do {
			output_byte(FD_SENSEI);
			inr = result();
			if (do_print)
				print_result("sensei", inr);
			max_sensei--;
		} while ((ST0 & 0x83) != UNIT(current_drive) && inr == 2
			 && max_sensei);
	}
	if (!handler) {
		FDCS->reset = 1;
		return IRQ_NONE;
	}
	schedule_bh(handler);
	is_alive("normal interrupt end");

	/* FIXME! Was it really for us? */
	return IRQ_HANDLED;
}

static void recalibrate_floppy(void)
{
	debugt("recalibrate floppy:");
	do_floppy = recal_interrupt;
	output_byte(FD_RECALIBRATE);
	LAST_OUT(UNIT(current_drive));
}

/*
 * Must do 4 FD_SENSEIs after reset because of ``drive polling''.
 */
static void reset_interrupt(void)
{
	debugt("reset interrupt:");
	result();		/* get the status ready for set_fdc */
	if (FDCS->reset) {
		printk("reset set in interrupt, calling %p\n", cont->error);
		cont->error();	/* a reset just after a reset. BAD! */
	}
	cont->redo();
}

/*
 * reset is done by pulling bit 2 of DOR low for a while (old FDCs),
 * or by setting the self clearing bit 7 of STATUS (newer FDCs)
 */
static void reset_fdc(void)
{
	unsigned long flags;

	do_floppy = reset_interrupt;
	FDCS->reset = 0;
	reset_fdc_info(0);

	/* Pseudo-DMA may intercept 'reset finished' interrupt.  */
	/* Irrelevant for systems with true DMA (i386).          */

	flags = claim_dma_lock();
	fd_disable_dma();
	release_dma_lock(flags);

	if (FDCS->version >= FDC_82072A)
		fd_outb(0x80 | (FDCS->dtr & 3), FD_STATUS);
	else {
		fd_outb(FDCS->dor & ~0x04, FD_DOR);
		udelay(FD_RESET_DELAY);
		fd_outb(FDCS->dor, FD_DOR);
	}
}

static void show_floppy(void)
{
	int i;

	printk("\n");
	printk("floppy driver state\n");
	printk("-------------------\n");
	printk("now=%lu last interrupt=%lu diff=%lu last called handler=%p\n",
	       jiffies, interruptjiffies, jiffies - interruptjiffies,
	       lasthandler);

#ifdef FLOPPY_SANITY_CHECK
	printk("timeout_message=%s\n", timeout_message);
	printk("last output bytes:\n");
	for (i = 0; i < OLOGSIZE; i++)
		printk("%2x %2x %lu\n",
		       output_log[(i + output_log_pos) % OLOGSIZE].data,
		       output_log[(i + output_log_pos) % OLOGSIZE].status,
		       output_log[(i + output_log_pos) % OLOGSIZE].jiffies);
	printk("last result at %lu\n", resultjiffies);
	printk("last redo_fd_request at %lu\n", lastredo);
	for (i = 0; i < resultsize; i++) {
		printk("%2x ", reply_buffer[i]);
	}
	printk("\n");
#endif

	printk("status=%x\n", fd_inb(FD_STATUS));
	printk("fdc_busy=%lu\n", fdc_busy);
	if (do_floppy)
		printk("do_floppy=%p\n", do_floppy);
	if (floppy_work.pending)
		printk("floppy_work.func=%p\n", floppy_work.func);
	if (timer_pending(&fd_timer))
		printk("fd_timer.function=%p\n", fd_timer.function);
	if (timer_pending(&fd_timeout)) {
		printk("timer_function=%p\n", fd_timeout.function);
		printk("expires=%lu\n", fd_timeout.expires - jiffies);
		printk("now=%lu\n", jiffies);
	}
	printk("cont=%p\n", cont);
	printk("current_req=%p\n", current_req);
	printk("command_status=%d\n", command_status);
	printk("\n");
}

static void floppy_shutdown(unsigned long data)
{
	unsigned long flags;

	if (!initialising)
		show_floppy();
	cancel_activity();

	floppy_enable_hlt();

	flags = claim_dma_lock();
	fd_disable_dma();
	release_dma_lock(flags);

	/* avoid dma going to a random drive after shutdown */

	if (!initialising)
		DPRINT("floppy timeout called\n");
	FDCS->reset = 1;
	if (cont) {
		cont->done(0);
		cont->redo();	/* this will recall reset when needed */
	} else {
		printk("no cont in shutdown!\n");
		process_fd_request();
	}
	is_alive("floppy shutdown");
}

/*typedef void (*timeout_fn)(unsigned long);*/

/* start motor, check media-changed condition and write protection */
static int start_motor(void (*function) (void))
{
	int mask, data;

	mask = 0xfc;
	data = UNIT(current_drive);
	if (!(raw_cmd->flags & FD_RAW_NO_MOTOR)) {
		if (!(FDCS->dor & (0x10 << UNIT(current_drive)))) {
			set_debugt();
			/* no read since this drive is running */
			DRS->first_read_date = 0;
			/* note motor start time if motor is not yet running */
			DRS->spinup_date = jiffies;
			data |= (0x10 << UNIT(current_drive));
		}
	} else if (FDCS->dor & (0x10 << UNIT(current_drive)))
		mask &= ~(0x10 << UNIT(current_drive));

	/* starts motor and selects floppy */
	del_timer(motor_off_timer + current_drive);
	set_dor(fdc, mask, data);

	/* wait_for_completion also schedules reset if needed. */
	return (fd_wait_for_completion(DRS->select_date + DP->select_delay,
				       (timeout_fn) function));
}

static void floppy_ready(void)
{
	CHECK_RESET;
	if (start_motor(floppy_ready))