ide-floppy.c

ep9315平台下硬盘驱动的源码

	unsigned	ansi_version	:3;	/* ANSI Version */
	unsigned	ecma_version	:3;	/* ECMA Version */
	unsigned	iso_version	:2;	/* ISO Version */
	unsigned	response_format :4;	/* Response Data Format */
	unsigned	reserved3_45	:2;	/* Reserved */
	unsigned	reserved3_6	:1;	/* TrmIOP - Reserved */
	unsigned	reserved3_7	:1;	/* AENC - Reserved */
#elif defined(__BIG_ENDIAN_BITFIELD)
	unsigned	reserved0_765	:3;	/* Peripheral Qualifier - Reserved */
	unsigned	device_type	:5;	/* Peripheral Device Type */
	unsigned	rmb		:1;	/* Removable Medium Bit */
	unsigned	reserved1_6t0	:7;	/* Reserved */
	unsigned	iso_version	:2;	/* ISO Version */
	unsigned	ecma_version	:3;	/* ECMA Version */
	unsigned	ansi_version	:3;	/* ANSI Version */
	unsigned	reserved3_7	:1;	/* AENC - Reserved */
	unsigned	reserved3_6	:1;	/* TrmIOP - Reserved */
	unsigned	reserved3_45	:2;	/* Reserved */
	unsigned	response_format :4;	/* Response Data Format */
#else
#error "Bitfield endianness not defined! Check your byteorder.h"
#endif
	u8		additional_length;	/* Additional Length (total_length-4) */
	u8		rsv5, rsv6, rsv7;	/* Reserved */
	u8		vendor_id[8];		/* Vendor Identification */
	u8		product_id[16];		/* Product Identification */
	u8		revision_level[4];	/* Revision Level */
	u8		vendor_specific[20];	/* Vendor Specific - Optional */
	u8		reserved56t95[40];	/* Reserved - Optional */
						/* Additional information may be returned */
} idefloppy_inquiry_result_t;

/*
 *	REQUEST SENSE packet command result - Data Format.
 */
typedef struct {
#if defined(__LITTLE_ENDIAN_BITFIELD)
	unsigned	error_code	:7;	/* Current error (0x70) */
	unsigned	valid		:1;	/* The information field conforms to SFF-8070i */
	u8		reserved1	:8;	/* Reserved */
	unsigned	sense_key	:4;	/* Sense Key */
	unsigned	reserved2_4	:1;	/* Reserved */
	unsigned	ili		:1;	/* Incorrect Length Indicator */
	unsigned	reserved2_67	:2;
#elif defined(__BIG_ENDIAN_BITFIELD)
	unsigned	valid		:1;	/* The information field conforms to SFF-8070i */
	unsigned	error_code	:7;	/* Current error (0x70) */
	u8		reserved1	:8;	/* Reserved */
	unsigned	reserved2_67	:2;
	unsigned	ili		:1;	/* Incorrect Length Indicator */
	unsigned	reserved2_4	:1;	/* Reserved */
	unsigned	sense_key	:4;	/* Sense Key */
#else
#error "Bitfield endianness not defined! Check your byteorder.h"
#endif
	u32		information __attribute__ ((packed));
	u8		asl;			/* Additional sense length (n-7) */
	u32		command_specific;	/* Additional command specific information */
	u8		asc;			/* Additional Sense Code */
	u8		ascq;			/* Additional Sense Code Qualifier */
	u8		replaceable_unit_code;	/* Field Replaceable Unit Code */
	u8		sksv[3];
	u8		pad[2];			/* Padding to 20 bytes */
} idefloppy_request_sense_result_t;

/*
 *	Pages of the SELECT SENSE / MODE SENSE packet commands.
 */
#define	IDEFLOPPY_CAPABILITIES_PAGE	0x1b
#define IDEFLOPPY_FLEXIBLE_DISK_PAGE	0x05

/*
 *	Mode Parameter Header for the MODE SENSE packet command
 */
typedef struct {
	u16		mode_data_length;	/* Length of the following data transfer */
	u8		medium_type;		/* Medium Type */
#if defined(__LITTLE_ENDIAN_BITFIELD)
	unsigned	reserved3	:7;
	unsigned	wp		:1;	/* Write protect */
#elif defined(__BIG_ENDIAN_BITFIELD)
	unsigned	wp		:1;	/* Write protect */
	unsigned	reserved3	:7;
#else
#error "Bitfield endianness not defined! Check your byteorder.h"
#endif
	u8		reserved[4];
} idefloppy_mode_parameter_header_t;

#define IDEFLOPPY_MIN(a,b)	((a)<(b) ? (a):(b))
#define	IDEFLOPPY_MAX(a,b)	((a)>(b) ? (a):(b))

/*
 *	Too bad. The drive wants to send us data which we are not ready to accept.
 *	Just throw it away.
 */
static void idefloppy_discard_data (ide_drive_t *drive, unsigned int bcount)
{
	while (bcount--)
		(void) HWIF(drive)->INB(IDE_DATA_REG);
}

#if IDEFLOPPY_DEBUG_BUGS
static void idefloppy_write_zeros (ide_drive_t *drive, unsigned int bcount)
{
	while (bcount--)
		HWIF(drive)->OUTB(0, IDE_DATA_REG);
}
#endif /* IDEFLOPPY_DEBUG_BUGS */


static int idefloppy_end_request (ide_drive_t *drive, int uptodate)
{
	struct request *rq;
	unsigned long flags;
	int ret = 1;

	spin_lock_irqsave(&io_request_lock, flags);
	rq = HWGROUP(drive)->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(drive)->hwif->ide_dma_on(drive);
	}

	if (!end_that_request_first(rq, uptodate, drive->name)) {
		add_blkdev_randomness(MAJOR(rq->rq_dev));
		blkdev_dequeue_request(rq);
		HWGROUP(drive)->rq = NULL;
		end_that_request_last(rq);
		ret = 0;
	}
	spin_unlock_irqrestore(&io_request_lock, flags);
	return ret;
}

/*
 *	idefloppy_do_end_request is used to finish servicing a request.
 *
 *	For read/write requests, we will call ide_end_request to pass to the
 *	next buffer.
 */
static int idefloppy_do_end_request (ide_drive_t *drive, int uptodate)
{
	idefloppy_floppy_t *floppy = drive->driver_data;
	struct request *rq = HWGROUP(drive)->rq;
	int error;

#if IDEFLOPPY_DEBUG_LOG
	printk(KERN_INFO "Reached idefloppy_end_request\n");
#endif /* IDEFLOPPY_DEBUG_LOG */

	switch (uptodate) {
		case 0: error = IDEFLOPPY_ERROR_GENERAL; break;
		case 1: error = 0; break;
		default: error = uptodate;
	}
	if (error)
		floppy->failed_pc = NULL;
	/* Why does this happen? */
	if (!rq)
		return 0;
	if (!IDEFLOPPY_RQ_CMD(rq->cmd)) {
		/* our real local end request function */
		idefloppy_end_request(drive, uptodate);
		return 0;
	}
	rq->errors = error;
	/* fixme: need to move this local also */
	ide_end_drive_cmd(drive, 0, 0);
	return 0;
}

static void idefloppy_input_buffers (ide_drive_t *drive, idefloppy_pc_t *pc, unsigned int bcount)
{
	struct request *rq = pc->rq;
	struct buffer_head *bh = rq->bh;
	int count;

	while (bcount) {
		if (pc->b_count == bh->b_size) {
			rq->sector += rq->current_nr_sectors;
			rq->nr_sectors -= rq->current_nr_sectors;
			idefloppy_do_end_request(drive, 1);
			if ((bh = rq->bh) != NULL)
				pc->b_count = 0;
		}
		if (bh == NULL) {
			printk(KERN_ERR "%s: bh == NULL in "
				"idefloppy_input_buffers, bcount == %d\n",
				drive->name, bcount);
			idefloppy_discard_data(drive, bcount);
			return;
		}
		count = IDEFLOPPY_MIN(bh->b_size - pc->b_count, bcount);
		HWIF(drive)->atapi_input_bytes(drive, bh->b_data + pc->b_count, count);
		bcount -= count;
		pc->b_count += count;
	}
}

static void idefloppy_output_buffers (ide_drive_t *drive, idefloppy_pc_t *pc, unsigned int bcount)
{
	struct request *rq = pc->rq;
	struct buffer_head *bh = rq->bh;
	int count;
	
	while (bcount) {
		if (!pc->b_count) {
			rq->sector += rq->current_nr_sectors;
			rq->nr_sectors -= rq->current_nr_sectors;
			idefloppy_do_end_request(drive, 1);
			if ((bh = rq->bh) != NULL) {
				pc->b_data = bh->b_data;
				pc->b_count = bh->b_size;
			}
		}
		if (bh == NULL) {
			printk(KERN_ERR "%s: bh == NULL in "
				"idefloppy_output_buffers, bcount == %d\n",
				drive->name, bcount);
			idefloppy_write_zeros (drive, bcount);
			return;
		}
		count = IDEFLOPPY_MIN(pc->b_count, bcount);
		HWIF(drive)->atapi_output_bytes(drive, pc->b_data, count);
		bcount -= count;
		pc->b_data += count;
		pc->b_count -= count;
	}
}

#ifdef CONFIG_BLK_DEV_IDEDMA
static void idefloppy_update_buffers (ide_drive_t *drive, idefloppy_pc_t *pc)
{
	struct request *rq = pc->rq;
	struct buffer_head *bh = rq->bh;

	while ((bh = rq->bh) != NULL)
		idefloppy_do_end_request(drive, 1);
}
#endif /* CONFIG_BLK_DEV_IDEDMA */

/*
 *	idefloppy_queue_pc_head generates a new packet command request in front
 *	of the request queue, before the current request, so that it will be
 *	processed immediately, on the next pass through the driver.
 */
static void idefloppy_queue_pc_head (ide_drive_t *drive,idefloppy_pc_t *pc,struct request *rq)
{
	ide_init_drive_cmd(rq);
	rq->buffer = (char *)pc;
	rq->cmd = IDEFLOPPY_PC_RQ;
	(void) ide_do_drive_cmd(drive, rq, ide_preempt);
}

static idefloppy_pc_t *idefloppy_next_pc_storage (ide_drive_t *drive)
{
	idefloppy_floppy_t *floppy = drive->driver_data;

	if (floppy->pc_stack_index == IDEFLOPPY_PC_STACK)
		floppy->pc_stack_index=0;
	return (&floppy->pc_stack[floppy->pc_stack_index++]);
}

static struct request *idefloppy_next_rq_storage (ide_drive_t *drive)
{
	idefloppy_floppy_t *floppy = drive->driver_data;

	if (floppy->rq_stack_index == IDEFLOPPY_PC_STACK)
		floppy->rq_stack_index = 0;
	return (&floppy->rq_stack[floppy->rq_stack_index++]);
}

/*
 *	idefloppy_analyze_error is called on each failed packet command retry
 *	to analyze the request sense.
 */
static void idefloppy_analyze_error (ide_drive_t *drive,idefloppy_request_sense_result_t *result)
{
	idefloppy_floppy_t *floppy = drive->driver_data;

	floppy->sense_key = result->sense_key;
	floppy->asc = result->asc;
	floppy->ascq = result->ascq;
	floppy->progress_indication = result->sksv[0] & 0x80 ?
		(u16)get_unaligned((u16 *)(result->sksv+1)):0x10000;
#if IDEFLOPPY_DEBUG_LOG
	if (floppy->failed_pc)
		printk(KERN_INFO "ide-floppy: pc = %x, sense key = %x, "
			"asc = %x, ascq = %x\n", floppy->failed_pc->c[0],
			result->sense_key, result->asc, result->ascq);
	else
		printk(KERN_INFO "ide-floppy: sense key = %x, asc = %x, "
			"ascq = %x\n", result->sense_key,
			result->asc, result->ascq);
#endif /* IDEFLOPPY_DEBUG_LOG */
}

static void idefloppy_request_sense_callback (ide_drive_t *drive)
{
	idefloppy_floppy_t *floppy = drive->driver_data;

#if IDEFLOPPY_DEBUG_LOG
	printk(KERN_INFO "ide-floppy: Reached %s\n", __FUNCTION__);
#endif /* IDEFLOPPY_DEBUG_LOG */
	if (!floppy->pc->error) {
		idefloppy_analyze_error(drive,(idefloppy_request_sense_result_t *) floppy->pc->buffer);
		idefloppy_do_end_request(drive, 1);
	} else {
		printk(KERN_ERR "Error in REQUEST SENSE itself - Aborting request!\n");
		idefloppy_do_end_request(drive, 0);
	}
}

/*
 *	General packet command callback function.
 */
static void idefloppy_pc_callback (ide_drive_t *drive)
{
	idefloppy_floppy_t *floppy = drive->driver_data;
	
#if IDEFLOPPY_DEBUG_LOG
	printk (KERN_INFO "ide-floppy: Reached %s\n", __FUNCTION__);
#endif /* IDEFLOPPY_DEBUG_LOG */

	idefloppy_do_end_request(drive, floppy->pc->error ? 0 : 1);
}

/*
 *	idefloppy_init_pc initializes a packet command.
 */
static void idefloppy_init_pc (idefloppy_pc_t *pc)
{
	memset(pc->c, 0, 12);
	pc->retries = 0;
	pc->flags = 0;
	pc->request_transfer = 0;
	pc->buffer = pc->pc_buffer;
	pc->buffer_size = IDEFLOPPY_PC_BUFFER_SIZE;
	pc->b_data = NULL;
	pc->callback = &idefloppy_pc_callback;
}

static void idefloppy_create_request_sense_cmd (idefloppy_pc_t *pc)
{
	idefloppy_init_pc(pc);	
	pc->c[0] = IDEFLOPPY_REQUEST_SENSE_CMD;
	pc->c[4] = 255;
	pc->request_transfer = 18;
	pc->callback = &idefloppy_request_sense_callback;
}

/*
 *	idefloppy_retry_pc is called when an error was detected during the
 *	last packet command. We queue a request sense packet command in
 *	the head of the request list.
 */
static void idefloppy_retry_pc (ide_drive_t *drive)
{
	idefloppy_pc_t *pc;
	struct request *rq;
	atapi_error_t error;

	error.all = HWIF(drive)->INB(IDE_ERROR_REG);
	pc = idefloppy_next_pc_storage(drive);
	rq = idefloppy_next_rq_storage(drive);
	idefloppy_create_request_sense_cmd(pc);
	idefloppy_queue_pc_head(drive, pc, rq);
}

/*
 *	idefloppy_pc_intr is the usual interrupt handler which will be called
 *	during a packet command.
 */
static ide_startstop_t idefloppy_pc_intr (ide_drive_t *drive)
{
	idefloppy_floppy_t *floppy = drive->driver_data;
	atapi_status_t status;
	atapi_bcount_t bcount;
	atapi_ireason_t ireason;
	idefloppy_pc_t *pc = floppy->pc;
	struct request *rq = pc->rq;
	unsigned int temp;

#if IDEFLOPPY_DEBUG_LOG
	printk(KERN_INFO "ide-floppy: Reached %s interrupt handler\n",
		__FUNCTION__);
#endif /* IDEFLOPPY_DEBUG_LOG */	

#ifdef CONFIG_BLK_DEV_IDEDMA
	if (test_bit(PC_DMA_IN_PROGRESS, &pc->flags)) {
		if (HWIF(drive)->ide_dma_end(drive)) {
			set_bit(PC_DMA_ERROR, &pc->flags);
		} else {
			pc->actually_transferred = pc->request_transfer;
			idefloppy_update_buffers(drive, pc);
		}
#if IDEFLOPPY_DEBUG_LOG
		printk (KERN_INFO "ide-floppy: DMA finished\n");
#endif /* IDEFLOPPY_DEBUG_LOG */
	}
#endif /* CONFIG_BLK_DEV_IDEDMA */

	/* Clear the interrupt */
	status.all = HWIF(drive)->INB(IDE_STATUS_REG);

	if (!status.b.drq) {			/* No more interrupts */
#if IDEFLOPPY_DEBUG_LOG
		printk(KERN_INFO "Packet command completed, %d bytes "
			"transferred\n", pc->actually_transferred);
#endif /* IDEFLOPPY_DEBUG_LOG */
		clear_bit(PC_DMA_IN_PROGRESS, &pc->flags);

		local_irq_enable();