floppy.c

这是一个SIGMA方案的PMP播放器的UCLINUX程序,可播放DVD,VCD,CD MP3...有很好的参考价值.

		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)
		SET_INTR(main_command_interrupt);

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

#ifdef DEBUGT
	debugt("rw_command: ");
#endif
	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)
{
#ifdef DEBUGT
	debugt("seek interrupt:");
#endif
	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;
		}
	}

	SET_INTR(seek_interrupt);
	output_byte(FD_SEEK);
	output_byte(UNIT(current_drive));
	LAST_OUT(track);
#ifdef DEBUGT
	debugt("seek command:");
#endif
}

static void recal_interrupt(void)
{
#ifdef DEBUGT
	debugt("recal interrupt:");
#endif
	if (inr !=2)
		FDCS->reset = 1;
	else if (ST0 & ST0_ECE) {
	       	switch(DRS->track){
			case NEED_1_RECAL:
#ifdef DEBUGT
				debugt("recal interrupt need 1 recal:");
#endif
				/* 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:
#ifdef DEBUGT
				debugt("recal interrupt need 2 recal:");
#endif
				/* 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:
#ifdef DEBUGT
				debugt("recal interrupt default:");
#endif
				/* 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 */
void floppy_interrupt(int irq, void *dev_id, struct pt_regs * regs)
{
	void (*handler)(void) = DEVICE_INTR;
	int do_print;
	unsigned long f;

	lasthandler = handler;
	interruptjiffies = jiffies;

	f=claim_dma_lock();
	fd_disable_dma();
	release_dma_lock(f);
	
	floppy_enable_hlt();
	CLEAR_INTR;
	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;
	}

	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) {
		schedule_bh( (void *)(void *) handler);
	} else
		FDCS->reset = 1;
	is_alive("normal interrupt end");
}

static void recalibrate_floppy(void)
{
#ifdef DEBUGT
	debugt("recalibrate floppy:");
#endif
	SET_INTR(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)
{
#ifdef DEBUGT
	debugt("reset interrupt:");
#endif
	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;
	
	SET_INTR(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 (DEVICE_INTR)
		printk("DEVICE_INTR=%p\n", DEVICE_INTR);
	if (floppy_tq.sync)
		printk("floppy_tq.routine=%p\n", floppy_tq.routine);
	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=%p\n", CURRENT);
	printk("command_status=%d\n", command_status);
	printk("\n");
}

static void floppy_shutdown(void)
{
	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)) return;
	if (fdc_dtr()) return;

#ifdef DCL_DEBUG
	if (DP->flags & FD_DEBUG){
		DPRINT("calling disk change from floppy_ready\n");
	}
#endif
	if (!(raw_cmd->flags & FD_RAW_NO_MOTOR) &&
	   disk_change(current_drive) &&
	   !DP->select_delay)
		twaddle(); /* this clears the dcl on certain drive/controller
			    * combinations */

#ifdef fd_chose_dma_mode
	if ((raw_cmd->flags & FD_RAW_READ) || 
	    (raw_cmd->flags & FD_RAW_WRITE))
	{
		unsigned long flags = claim_dma_lock();
		fd_chose_dma_mode(raw_cmd->kernel_data,
				  raw_cmd->length);
		release_dma_lock(flags);
	}
#endif

	if (raw_cmd->flags & (FD_RAW_NEED_SEEK | FD_RAW_NEED_DISK)){
		perpendicular_mode();
		fdc_specify(); /* must be done here because of hut, hlt ... */
		seek_floppy();
	} else {
		if ((raw_cmd->flags & FD_RAW_READ) || 
		    (raw_cmd->flags & FD_RAW_WRITE))
			fdc_specify();
		setup_rw_floppy();
	}
}

static void floppy_start(void)
{
	reschedule_timeout(CURRENTD, "floppy start", 0);

	scandrives();
#ifdef DCL_DEBUG
	if (DP->flags & FD_DEBUG){
		DPRINT("setting NEWCHANGE in floppy_start\n");
	}
#endif
	SETF(FD_DISK_NEWCHANGE);
	floppy_ready();