ide.c

《嵌入式系统设计与实例开发实验教材II：基于ARM9微处理器与Linux操作系统》IDE—CF卡模块读写实验

	if (io_32bit) {
#if SUPPORT_VLB_SYNC
		if (io_32bit & 2) {
			unsigned long flags;
			__save_flags(flags);	/* local CPU only */
			__cli();		/* local CPU only */
			do_vlb_sync(IDE_NSECTOR_REG);
			insl(IDE_DATA_REG, buffer, wcount);
			__restore_flags(flags);	/* local CPU only */
		} else
#endif /* SUPPORT_VLB_SYNC */
			insl(IDE_DATA_REG, buffer, wcount);
	} else {
#if SUPPORT_SLOW_DATA_PORTS
		if (drive->slow) {
			unsigned short *ptr = (unsigned short *) buffer;
			while (wcount--) {
				*ptr++ = inw_p(IDE_DATA_REG);
				*ptr++ = inw_p(IDE_DATA_REG);
			}
		} else
#endif /* SUPPORT_SLOW_DATA_PORTS */
			insw(IDE_DATA_REG, buffer, wcount<<1);
	}
}

/*
 * This is used for most PIO data transfers *to* the IDE interface
 */
void ide_output_data (ide_drive_t *drive, void *buffer, unsigned int wcount)
{
	byte io_32bit;

	if(HWIF(drive)->ideproc) {
		HWIF(drive)->ideproc(ideproc_ide_output_data,
				     drive, buffer, wcount);
		return;
	}

	io_32bit = drive->io_32bit;

	if (io_32bit) {
#if SUPPORT_VLB_SYNC
		if (io_32bit & 2) {
			unsigned long flags;
			__save_flags(flags);	/* local CPU only */
			__cli();		/* local CPU only */
			do_vlb_sync(IDE_NSECTOR_REG);
			outsl(IDE_DATA_REG, buffer, wcount);
			__restore_flags(flags);	/* local CPU only */
		} else
#endif /* SUPPORT_VLB_SYNC */
			outsl(IDE_DATA_REG, buffer, wcount);
	} else {
#if SUPPORT_SLOW_DATA_PORTS
		if (drive->slow) {
			unsigned short *ptr = (unsigned short *) buffer;
			while (wcount--) {
				outw_p(*ptr++, IDE_DATA_REG);
				outw_p(*ptr++, IDE_DATA_REG);
			}
		} else
#endif /* SUPPORT_SLOW_DATA_PORTS */
			outsw(IDE_DATA_REG, buffer, wcount<<1);
	}
}

/*
 * The following routines are mainly used by the ATAPI drivers.
 *
 * These routines will round up any request for an odd number of bytes,
 * so if an odd bytecount is specified, be sure that there's at least one
 * extra byte allocated for the buffer.
 */
void atapi_input_bytes (ide_drive_t *drive, void *buffer, unsigned int bytecount)
{
	if(HWIF(drive)->ideproc) {
		HWIF(drive)->ideproc(ideproc_atapi_input_bytes,
				     drive, buffer, bytecount);
		return;
	}

	++bytecount;
#if defined(CONFIG_ATARI) || defined(CONFIG_Q40)
	if (MACH_IS_ATARI || MACH_IS_Q40) {
		/* Atari has a byte-swapped IDE interface */
		insw_swapw(IDE_DATA_REG, buffer, bytecount / 2);
		return;
	}
#endif /* CONFIG_ATARI */
	ide_input_data (drive, buffer, bytecount / 4);
	if ((bytecount & 0x03) >= 2)
		insw (IDE_DATA_REG, ((byte *)buffer) + (bytecount & ~0x03), 1);
}

void atapi_output_bytes (ide_drive_t *drive, void *buffer, unsigned int bytecount)
{
	if(HWIF(drive)->ideproc) {
		HWIF(drive)->ideproc(ideproc_atapi_output_bytes,
				     drive, buffer, bytecount);
		return;
	}

	++bytecount;
#if defined(CONFIG_ATARI) || defined(CONFIG_Q40)
	if (MACH_IS_ATARI || MACH_IS_Q40) {
		/* Atari has a byte-swapped IDE interface */
		outsw_swapw(IDE_DATA_REG, buffer, bytecount / 2);
		return;
	}
#endif /* CONFIG_ATARI */
	ide_output_data (drive, buffer, bytecount / 4);
	if ((bytecount & 0x03) >= 2)
		outsw (IDE_DATA_REG, ((byte *)buffer) + (bytecount & ~0x03), 1);
}

/*
 * Needed for PCI irq sharing
 */
static inline int drive_is_ready (ide_drive_t *drive)
{
	byte stat = 0;
	if (drive->waiting_for_dma)
		return HWIF(drive)->dmaproc(ide_dma_test_irq, drive);
#if 0
	udelay(1);	/* need to guarantee 400ns since last command was issued */
#endif

#ifdef CONFIG_IDEPCI_SHARE_IRQ
	/*
	 * We do a passive status test under shared PCI interrupts on
	 * cards that truly share the ATA side interrupt, but may also share
	 * an interrupt with another pci card/device.  We make no assumptions
	 * about possible isa-pnp and pci-pnp issues yet.
	 */
	if (IDE_CONTROL_REG)
		stat = GET_ALTSTAT();
	else
#endif /* CONFIG_IDEPCI_SHARE_IRQ */
	stat = GET_STAT();	/* Note: this may clear a pending IRQ!! */

	if (stat & BUSY_STAT)
		return 0;	/* drive busy:  definitely not interrupting */
	return 1;		/* drive ready: *might* be interrupting */
}

/*
 * This is our end_request replacement function.
 */
void ide_end_request (byte uptodate, ide_hwgroup_t *hwgroup)
{
	struct request *rq;
	unsigned long flags;
	ide_drive_t *drive = hwgroup->drive;

	spin_lock_irqsave(&io_request_lock, flags);
	rq = hwgroup->rq;

	/*
	 * decide whether to reenable DMA -- 3 is a random magic for now,
	 * if we DMA timeout more than 3 times, just stay in PIO
	 */
	if (drive->state == DMA_PIO_RETRY && drive->retry_pio <= 3) {
		drive->state = 0;
		hwgroup->hwif->dmaproc(ide_dma_on, drive);
	}

	if (!end_that_request_first(rq, uptodate, hwgroup->drive->name)) {
		add_blkdev_randomness(MAJOR(rq->rq_dev));
		blkdev_dequeue_request(rq);
        	hwgroup->rq = NULL;
		end_that_request_last(rq);
	}
	spin_unlock_irqrestore(&io_request_lock, flags);
}

/*
 * This should get invoked any time we exit the driver to
 * wait for an interrupt response from a drive.  handler() points
 * at the appropriate code to handle the next interrupt, and a
 * timer is started to prevent us from waiting forever in case
 * something goes wrong (see the ide_timer_expiry() handler later on).
 */
void ide_set_handler (ide_drive_t *drive, ide_handler_t *handler,
		      unsigned int timeout, ide_expiry_t *expiry)
{
	unsigned long flags;
	ide_hwgroup_t *hwgroup = HWGROUP(drive);

	spin_lock_irqsave(&io_request_lock, flags);
	if (hwgroup->handler != NULL) {
		printk("%s: ide_set_handler: handler not null; old=%p, new=%p\n",
			drive->name, hwgroup->handler, handler);
	}
	hwgroup->handler	= handler;
	hwgroup->expiry		= expiry;
	hwgroup->timer.expires	= jiffies + timeout;
	add_timer(&hwgroup->timer);
	spin_unlock_irqrestore(&io_request_lock, flags);
}

/*
 * current_capacity() returns the capacity (in sectors) of a drive
 * according to its current geometry/LBA settings.
 */
unsigned long current_capacity (ide_drive_t *drive)
{
	if (!drive->present)
		return 0;
	if (drive->driver != NULL)
		return DRIVER(drive)->capacity(drive);
	return 0;
}

extern struct block_device_operations ide_fops[];
/*
 * ide_geninit() is called exactly *once* for each interface.
 */
void ide_geninit (ide_hwif_t *hwif)
{
	unsigned int unit;
	struct gendisk *gd = hwif->gd;

	for (unit = 0; unit < MAX_DRIVES; ++unit) {
		ide_drive_t *drive = &hwif->drives[unit];

		if (!drive->present)
			continue;
		if (drive->media!=ide_disk && drive->media!=ide_floppy)
			continue;
		register_disk(gd,MKDEV(hwif->major,unit<<PARTN_BITS),
#ifdef CONFIG_BLK_DEV_ISAPNP
			(drive->forced_geom && drive->noprobe) ? 1 :
#endif /* CONFIG_BLK_DEV_ISAPNP */
			1<<PARTN_BITS, ide_fops,
			current_capacity(drive));
	}
}

static ide_startstop_t do_reset1 (ide_drive_t *, int);		/* needed below */

/*
 * atapi_reset_pollfunc() gets invoked to poll the interface for completion every 50ms
 * during an atapi drive reset operation. If the drive has not yet responded,
 * and we have not yet hit our maximum waiting time, then the timer is restarted
 * for another 50ms.
 */
static ide_startstop_t atapi_reset_pollfunc (ide_drive_t *drive)
{
	ide_hwgroup_t *hwgroup = HWGROUP(drive);
	byte stat;

	SELECT_DRIVE(HWIF(drive),drive);
	udelay (10);

	if (OK_STAT(stat=GET_STAT(), 0, BUSY_STAT)) {
		printk("%s: ATAPI reset complete\n", drive->name);
	} else {
		if (0 < (signed long)(hwgroup->poll_timeout - jiffies)) {
			ide_set_handler (drive, &atapi_reset_pollfunc, HZ/20, NULL);
			return ide_started;	/* continue polling */
		}
		hwgroup->poll_timeout = 0;	/* end of polling */
		printk("%s: ATAPI reset timed-out, status=0x%02x\n", drive->name, stat);
		return do_reset1 (drive, 1);	/* do it the old fashioned way */
	}
	hwgroup->poll_timeout = 0;	/* done polling */
	return ide_stopped;
}

/*
 * reset_pollfunc() gets invoked to poll the interface for completion every 50ms
 * during an ide reset operation. If the drives have not yet responded,
 * and we have not yet hit our maximum waiting time, then the timer is restarted
 * for another 50ms.
 */
static ide_startstop_t reset_pollfunc (ide_drive_t *drive)
{
	ide_hwgroup_t *hwgroup = HWGROUP(drive);
	ide_hwif_t *hwif = HWIF(drive);
	byte tmp;

	if (!OK_STAT(tmp=GET_STAT(), 0, BUSY_STAT)) {
		if (0 < (signed long)(hwgroup->poll_timeout - jiffies)) {
			ide_set_handler (drive, &reset_pollfunc, HZ/20, NULL);
			return ide_started;	/* continue polling */
		}
		printk("%s: reset timed-out, status=0x%02x\n", hwif->name, tmp);
		drive->failures++;
	} else  {
		printk("%s: reset: ", hwif->name);
		if ((tmp = GET_ERR()) == 1) {
			printk("success\n");
			drive->failures = 0;
		} else {
			drive->failures++;
#if FANCY_STATUS_DUMPS
			printk("master: ");
			switch (tmp & 0x7f) {
				case 1: printk("passed");
					break;
				case 2: printk("formatter device error");
					break;
				case 3: printk("sector buffer error");
					break;
				case 4: printk("ECC circuitry error");
					break;
				case 5: printk("controlling MPU error");
					break;
				default:printk("error (0x%02x?)", tmp);
			}
			if (tmp & 0x80)
				printk("; slave: failed");
			printk("\n");
#else
			printk("failed\n");
#endif /* FANCY_STATUS_DUMPS */
		}
	}
	hwgroup->poll_timeout = 0;	/* done polling */
	return ide_stopped;
}

static void check_dma_crc (ide_drive_t *drive)
{
	if (drive->crc_count) {
		(void) HWIF(drive)->dmaproc(ide_dma_off_quietly, drive);
		if ((HWIF(drive)->speedproc) != NULL)
			HWIF(drive)->speedproc(drive, ide_auto_reduce_xfer(drive));
		if (drive->current_speed >= XFER_SW_DMA_0)
			(void) HWIF(drive)->dmaproc(ide_dma_on, drive);
	} else {
		(void) HWIF(drive)->dmaproc(ide_dma_off, drive);
	}
}

static void pre_reset (ide_drive_t *drive)
{
	if (drive->driver != NULL)
		DRIVER(drive)->pre_reset(drive);

	if (!drive->keep_settings) {
		if (drive->using_dma) {
			check_dma_crc(drive);
		} else {
			drive->unmask = 0;
			drive->io_32bit = 0;
		}
		return;
	}
	if (drive->using_dma)
		check_dma_crc(drive);
}

/*
 * do_reset1() attempts to recover a confused drive by resetting it.
 * Unfortunately, resetting a disk drive actually resets all devices on
 * the same interface, so it can really be thought of as resetting the
 * interface rather than resetting the drive.
 *
 * ATAPI devices have their own reset mechanism which allows them to be
 * individually reset without clobbering other devices on the same interface.
 *
 * Unfortunately, the IDE interface does not generate an interrupt to let
 * us know when the reset operation has finished, so we must poll for this.
 * Equally poor, though, is the fact that this may a very long time to complete,
 * (up to 30 seconds worstcase).  So, instead of busy-waiting here for it,
 * we set a timer to poll at 50ms intervals.
 */
static ide_startstop_t do_reset1 (ide_drive_t *drive, int do_not_try_atapi)
{
	unsigned int unit;
	unsigned long flags;
	ide_hwif_t *hwif = HWIF(drive);
	ide_hwgroup_t *hwgroup = HWGROUP(drive);

	__save_flags(flags);	/* local CPU only */
	__cli();		/* local CPU only */

	/* For an ATAPI device, first try an ATAPI SRST. */
	if (drive->media != ide_disk && !do_not_try_atapi) {
		pre_reset(drive);
		SELECT_DRIVE(hwif,drive);
		udelay (20);
		OUT_BYTE (WIN_SRST, IDE_COMMAND_REG);
		hwgroup->poll_timeout = jiffies + WAIT_WORSTCASE;
		ide_set_handler (drive, &atapi_reset_pollfunc, HZ/20, NULL);
		__restore_flags (flags);	/* local CPU only */
		return ide_started;
	}

	/*
	 * First, reset any device state data we were maintaining
	 * for any of the drives on this interface.
	 */
	for (unit = 0; unit < MAX_DRIVES; ++unit)
		pre_reset(&hwif->drives[unit]);

#if OK_TO_RESET_CONTROLLER
	if (!IDE_CONTROL_REG) {
		__restore_flags(flags);
		return ide_stopped;
	}
	/*
	 * Note that we also set nIEN while resetting the device,
	 * to mask unwanted interrupts from the interface during the reset.
	 * However, due to the design of PC hardware, this will cause an
	 * immediate interrupt due to the edge transition it produces.
	 * This single interrupt gives us a "fast poll" for drives that
	 * recover from reset very quickly, saving us the first 50ms wait time.
	 */
	OUT_BYTE(drive->ctl|6,IDE_CONTROL_REG);	/* set SRST and nIEN */
	udelay(10);			/* more than enough time */
	OUT_BYTE(drive->ctl|2,IDE_CONTROL_REG);	/* clear SRST, leave nIEN */
	udelay(10);			/* more than enough time */
	hwgroup->poll_timeout = jiffies + WAIT_WORSTCASE;
	ide_set_handler (drive, &reset_pollfunc, HZ/20, NULL);