sddr55.c

LINUX下USB驱动程序的开发

/* Driver for SanDisk SDDR-55 SmartMedia reader
 *
 * $Id:$
 *
 * SDDR55 driver v0.1:
 *
 * First release
 *
 * Current development and maintenance by:
 *   (c) 2002 Simon Munton
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the
 * Free Software Foundation; either version 2, or (at your option) any
 * later version.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 675 Mass Ave, Cambridge, MA 02139, USA.
 */

#include "transport.h"
#include "protocol.h"
#include "usb.h"
#include "debug.h"
#include "sddr55.h"

#include <linux/sched.h>
#include <linux/errno.h>
#include <linux/slab.h>

#define short_pack(lsb,msb) ( ((u16)(lsb)) | ( ((u16)(msb))<<8 ) )
#define LSB_of(s) ((s)&0xFF)
#define MSB_of(s) ((s)>>8)
#define PAGESIZE  512

#define set_sense_info(sk, asc, ascq)	\
    do {				\
	info->sense_data[2] = sk;	\
	info->sense_data[12] = asc;	\
	info->sense_data[13] = ascq;	\
	} while (0)


struct sddr55_card_info {
	unsigned long	capacity;	/* Size of card in bytes */
	int		max_log_blks;	/* maximum number of logical blocks */
	int		pageshift;	/* log2 of pagesize */
	int		smallpageshift;	/* 1 if pagesize == 256 */
	int		blocksize;	/* Size of block in pages */
	int		blockshift;	/* log2 of blocksize */
	int		blockmask;	/* 2^blockshift - 1 */
	int		read_only;	/* non zero if card is write protected */
	int		force_read_only;	/* non zero if we find a map error*/
	int		*lba_to_pba;	/* logical to physical map */
	int		*pba_to_lba;	/* physical to logical map */
	int		fatal_error;	/* set if we detect something nasty */
	unsigned long 	last_access;	/* number of jiffies since we last talked to device */
	unsigned char   sense_data[18];
};


#define NOT_ALLOCATED		0xffffffff
#define BAD_BLOCK		0xffff
#define CIS_BLOCK		0x400
#define UNUSED_BLOCK		0x3ff



static int sddr55_raw_bulk(struct us_data *us, 
		int direction,
		unsigned char *data,
		unsigned int len) {

	int result;
	int act_len;
	int pipe;

	if (direction == SCSI_DATA_READ)
		pipe = usb_rcvbulkpipe(us->pusb_dev, us->ep_in);
	else
		pipe = usb_sndbulkpipe(us->pusb_dev, us->ep_out);

	result = usb_stor_bulk_msg(us, data, pipe, len, &act_len);

	/* if we stall, we need to clear it before we go on */
	if (result == -EPIPE) {
		US_DEBUGP("EPIPE: clearing endpoint halt for"
			" pipe 0x%x, stalled at %d bytes\n",
			pipe, act_len);
		usb_clear_halt(us->pusb_dev, pipe);
	}

	if (result) {

		/* NAK - that means we've retried a few times already */
		if (result == -ETIMEDOUT) {
			US_DEBUGP("usbat_raw_bulk():"
				" device NAKed\n");

			return US_BULK_TRANSFER_FAILED;
		}

		/* -ECONNRESET -- we canceled this transfer */
		if (result == -ECONNRESET) {
			US_DEBUGP("usbat_raw_bulk():"
				" transfer aborted\n");
			return US_BULK_TRANSFER_ABORTED;
		}

		if (result == -EPIPE) {
			US_DEBUGP("usbat_raw_bulk():"
				" output pipe stalled\n");
			return US_BULK_TRANSFER_FAILED;
		}

		/* the catch-all case */
		US_DEBUGP("us_transfer_partial(): unknown error\n");
		return US_BULK_TRANSFER_FAILED;
	}

	if (act_len != len) {
		US_DEBUGP("Warning: Transferred only %d bytes\n",
			act_len);
		return US_BULK_TRANSFER_SHORT;
	}

	US_DEBUGP("Transferred %d of %d bytes\n", act_len, len);

	return US_BULK_TRANSFER_GOOD;
}

/*
 * Note: direction must be set if command_len == 0.
 */

static int sddr55_bulk_transport(struct us_data *us,
			  int direction,
			  unsigned char *data,
			  unsigned int len) {

	int result = USB_STOR_TRANSPORT_GOOD;
	struct sddr55_card_info *info = (struct sddr55_card_info *)us->extra;

	if (len==0)
		return USB_STOR_TRANSPORT_GOOD;

	info->last_access = jiffies;

#ifdef CONFIG_USB_STORAGE_DEBUG
	if (direction == SCSI_DATA_WRITE) {
		int i;
		char string[64];

		/* Debug-print the first 48 bytes of the write transfer */

		strcpy(string, "wr: ");
		for (i=0; i<len && i<48; i++) {
			sprintf(string+strlen(string), "%02X ",
			  data[i]);
			if ((i%16)==15) {
				US_DEBUGP("%s\n", string);
				strcpy(string, "wr: ");
			}
		}
		if ((i%16)!=0)
			US_DEBUGP("%s\n", string);
	}
#endif

	/* transfer the data */

	US_DEBUGP("SCM data %s transfer %d\n",
		  ( direction==SCSI_DATA_READ ? "in" : "out"),
		  len);

	result = sddr55_raw_bulk(us, direction, data, len);

#ifdef CONFIG_USB_STORAGE_DEBUG
	if (direction == SCSI_DATA_READ) {
		int i;
		char string[64];

		/* Debug-print the first 48 bytes of the read transfer */

		strcpy(string, "rd: ");
		for (i=0; i<len && i<48; i++) {
			sprintf(string+strlen(string), "%02X ",
			  data[i]);
			if ((i%16)==15) {
				US_DEBUGP("%s\n", string);
				strcpy(string, "rd: ");
			}
		}
		if ((i%16)!=0)
			US_DEBUGP("%s\n", string);
	}
#endif

	return result;
}


/* check if card inserted, if there is, update read_only status
 * return non zero if no card
 */

static int sddr55_status(struct us_data *us)
{
	int result;
	unsigned char command[8] = {
		0, 0, 0, 0, 0, 0xb0, 0, 0x80
	};
	unsigned char status[8];
	struct sddr55_card_info *info = (struct sddr55_card_info *)us->extra;

	/* send command */
	result = sddr55_bulk_transport(us,
		SCSI_DATA_WRITE, command, 8);

	US_DEBUGP("Result for send_command in status %d\n",
		result);

	if (result != US_BULK_TRANSFER_GOOD) {
		set_sense_info (4, 0, 0);	/* hardware error */
		return result;
	}

	result = sddr55_bulk_transport(us,
		SCSI_DATA_READ, status,	4);

	/* expect to get short transfer if no card fitted */
	if (result == US_BULK_TRANSFER_SHORT) {
		/* had a short transfer, no card inserted, free map memory */
		if (info->lba_to_pba)
			kfree(info->lba_to_pba);
		if (info->pba_to_lba)
			kfree(info->pba_to_lba);
		info->lba_to_pba = NULL;
		info->pba_to_lba = NULL;

		info->fatal_error = 0;
		info->force_read_only = 0;

		set_sense_info (2, 0x3a, 0);	/* not ready, medium not present */
		return result;
	}

	if (result != US_BULK_TRANSFER_GOOD) {
		set_sense_info (4, 0, 0);	/* hardware error */
		return result;
	}
	
	/* check write protect status */
	info->read_only = (status[0] & 0x20);

	/* now read status */
	result = sddr55_bulk_transport(us,
		SCSI_DATA_READ, status,	2);

	if (result != US_BULK_TRANSFER_GOOD) {
		set_sense_info (4, 0, 0);	/* hardware error */
	}

	return result;
}


static int sddr55_read_data(struct us_data *us,
		unsigned int lba,
		unsigned int page,
		unsigned short sectors,
		unsigned char *content,
		int use_sg) {

	int result;
	unsigned char command[8] = {
		0, 0, 0, 0, 0, 0xb0, 0, 0x85
	};
	unsigned char status[8];
	struct sddr55_card_info *info = (struct sddr55_card_info *)us->extra;

	unsigned int pba;
	unsigned long address;

	unsigned short pages;
	unsigned char *buffer = NULL;
	unsigned char *ptr;
	struct scatterlist *sg = NULL;
	int i;
	int len;
	int transferred;

	// If we're using scatter-gather, we have to create a new
	// buffer to read all of the data in first, since a
	// scatter-gather buffer could in theory start in the middle
	// of a page, which would be bad. A developer who wants a
	// challenge might want to write a limited-buffer
	// version of this code.

	len = sectors * PAGESIZE;

	if (use_sg) {
		sg = (struct scatterlist *)content;
		buffer = kmalloc(len, GFP_NOIO);
		if (buffer == NULL)
			return USB_STOR_TRANSPORT_ERROR;
		ptr = buffer;
	} else
		ptr = content;

	// This could be made much more efficient by checking for
	// contiguous LBA's. Another exercise left to the student.

	while (sectors>0) {

		/* have we got to end? */
		if (lba >= info->max_log_blks)
			break;

		pba = info->lba_to_pba[lba];

		// Read as many sectors as possible in this block

		pages = info->blocksize - page;
		if (pages > (sectors << info->smallpageshift))
			pages = (sectors << info->smallpageshift);

		US_DEBUGP("Read %02X pages, from PBA %04X"
			" (LBA %04X) page %02X\n",
			pages, pba, lba, page);

		if (pba == NOT_ALLOCATED) {
			/* no pba for this lba, fill with zeroes */
			memset (ptr, 0, pages << info->pageshift);
		} else {

			address = (pba << info->blockshift) + page;

			command[1] = LSB_of(address>>16);
			command[2] = LSB_of(address>>8);
			command[3] = LSB_of(address);

			command[6] = LSB_of(pages << (1 - info->smallpageshift));

			/* send command */
			result = sddr55_bulk_transport(us,
				SCSI_DATA_WRITE, command, 8);

			US_DEBUGP("Result for send_command in read_data %d\n",
				result);

			if (result != US_BULK_TRANSFER_GOOD) {
				if (use_sg)
					kfree(buffer);
				return result;
			}

			/* read data */
			result = sddr55_bulk_transport(us,
				SCSI_DATA_READ, ptr,
				pages<<info->pageshift);

			if (result != US_BULK_TRANSFER_GOOD) {
				if (use_sg)
					kfree(buffer);
				return result;
			}

			/* now read status */
			result = sddr55_bulk_transport(us,
				SCSI_DATA_READ, status, 2);

			if (result != US_BULK_TRANSFER_GOOD) {
				if (use_sg)
					kfree(buffer);
				return result;
			}

			/* check status for error */
			if (status[0] == 0xff && status[1] == 0x4) {
				set_sense_info (3, 0x11, 0);
				if (use_sg)
					kfree(buffer);

				return USB_STOR_TRANSPORT_FAILED;
			}

		}

		page = 0;
		lba++;
		sectors -= pages >> info->smallpageshift;
		ptr += (pages << info->pageshift);
	}

	if (use_sg) {
		transferred = 0;
		for (i=0; i<use_sg && transferred<len; i++) {
			memcpy(sg[i].address, buffer+transferred,
				len-transferred > sg[i].length ?
					sg[i].length : len-transferred);
			transferred += sg[i].length;
		}
		kfree(buffer);
	}

	return USB_STOR_TRANSPORT_GOOD;
}

static int sddr55_write_data(struct us_data *us,
		unsigned int lba,
		unsigned int page,
		unsigned short sectors,
		unsigned char *content,
		int use_sg) {

	int result;
	unsigned char command[8] = {
		0, 0, 0, 0, 0, 0xb0, 0, 0x86
	};
	unsigned char status[8];
	struct sddr55_card_info *info = (struct sddr55_card_info *)us->extra;

	unsigned int pba;
	unsigned int new_pba;
	unsigned long address;

	unsigned short pages;
	unsigned char *buffer = NULL;
	unsigned char *ptr;
	struct scatterlist *sg = NULL;
	int i;
	int len;
	int transferred;

	/* check if we are allowed to write */
	if (info->read_only || info->force_read_only) {
		set_sense_info (7, 0x27, 0);	/* read only */
		return USB_STOR_TRANSPORT_FAILED;
	}

	// If we're using scatter-gather, we have to create a new
	// buffer to write all of the data in first, since a
	// scatter-gather buffer could in theory start in the middle
	// of a page, which would be bad. A developer who wants a
	// challenge might want to write a limited-buffer
	// version of this code.

	len = sectors * PAGESIZE;

	if (use_sg) {
		sg = (struct scatterlist *)content;
		buffer = kmalloc(len, GFP_NOIO);
		if (buffer == NULL)
			return USB_STOR_TRANSPORT_ERROR;

		transferred = 0;
		for (i=0; i<use_sg && transferred<len; i++) {
			memcpy(buffer+transferred, sg[i].address,
				len-transferred > sg[i].length ?
					sg[i].length : len-transferred);
			transferred += sg[i].length;
		}

		ptr = buffer;
	} else
		ptr = content;

	while (sectors > 0) {

		/* have we got to end? */
		if (lba >= info->max_log_blks)
			break;

		pba = info->lba_to_pba[lba];

		// Write as many sectors as possible in this block

		pages = info->blocksize - page;
		if (pages > (sectors << info->smallpageshift))
			pages = (sectors << info->smallpageshift);

		US_DEBUGP("Write %02X pages, to PBA %04X"
			" (LBA %04X) page %02X\n",
			pages, pba, lba, page);
			
		command[4] = 0;

		if (pba == NOT_ALLOCATED) {
			/* no pba allocated for this lba, find a free pba to use */

			int max_pba = (info->max_log_blks / 250 ) * 256;
			int found_count = 0;
			int found_pba = -1;

			/* set pba to first block in zone lba is in */
			pba = (lba / 1000) * 1024;

			US_DEBUGP("No PBA for LBA %04X\n",lba);

			if (max_pba > 1024)
				max_pba = 1024;

			/* scan through the map lookiong for an unused block
			 * leave 16 unused blocks at start (or as many as possible)
			 * since the sddr55 seems to reuse a used block when it shouldn't
			 * if we don't leave space */
			for (i = 0; i < max_pba; i++, pba++) {
				if (info->pba_to_lba[pba] == UNUSED_BLOCK) {
					found_pba = pba;
					if (found_count++ > 16)
						break;
				}
			}

			pba = found_pba;

			if (pba == -1) {
				/* oh dear, couldn't find an unallocated block */
				US_DEBUGP("Couldn't find unallocated block\n");

				set_sense_info (3, 0x31, 0);	/* medium error */

				if (use_sg)
					kfree(buffer);

				return USB_STOR_TRANSPORT_FAILED;
			}

			US_DEBUGP("Allocating PBA %04X for LBA %04X\n", pba, lba);

			/* set writing to unallocated block flag */
			command[4] = 0x40;
		}

		address = (pba << info->blockshift) + page;

		command[1] = LSB_of(address>>16);
		command[2] = LSB_of(address>>8); 
		command[3] = LSB_of(address);

		/* set the lba into the command, modulo 1000 */
		command[0] = LSB_of(lba % 1000);
		command[6] = MSB_of(lba % 1000);

		command[4] |= LSB_of(pages >> info->smallpageshift);

		/* send command */
		result = sddr55_bulk_transport(us,
			SCSI_DATA_WRITE, command, 8);

		if (result != US_BULK_TRANSFER_GOOD) {
			US_DEBUGP("Result for send_command in write_data %d\n",
			result);

			set_sense_info (3, 0x3, 0);	/* peripheral write error */
			
			if (use_sg)
				kfree(buffer);
			return result;
		}