datafab.c

usb 子设备程序 支持sd卡 mouse keyboard 的最单单的驱动程序 gcc编译 支持

/* Driver for Datafab USB Compact Flash reader
 *
 * $Id: datafab.c,v 1.1.1.1 2007/06/12 07:27:09 eyryu Exp $
 *
 * datafab driver v0.1:
 *
 * First release
 *
 * Current development and maintenance by:
 *   (c) 2000 Jimmie Mayfield ([e-mail])
 *
 *   Many thanks to Robert Baruch for the SanDisk SmartMedia reader driver
 *   which I used as a template for this driver.
 *
 *   Some bugfixes and scatter-gather code by Gregory P. Smith 
 *   ([e-mail])
 *
 *   Fix for media change by Joerg Schneider ([e-mail])
 *
 * Other contributors:
 *   (c) 2002 Alan Stern <[e-mail]>
 *
 * 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.
 */

/*
 * This driver attempts to support USB CompactFlash reader/writer devices
 * based on Datafab USB-to-ATA chips.  It was specifically developed for the 
 * Datafab MDCFE-B USB CompactFlash reader but has since been found to work 
 * with a variety of Datafab-based devices from a number of manufacturers.
 * I've received a report of this driver working with a Datafab-based
 * SmartMedia device though please be aware that I'm personally unable to
 * test SmartMedia support.
 *
 * This driver supports reading and writing.  If you're truly paranoid,
 * however, you can force the driver into a write-protected state by setting
 * the WP enable bits in datafab_handle_mode_sense().  See the comments
 * in that routine.
 */

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

#include <scsi/scsi.h>
#include <scsi/scsi_cmnd.h>

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

static int datafab_determine_lun(struct us_data *us,
				 struct datafab_info *info);


static inline int
datafab_bulk_read(struct us_data *us, unsigned char *data, unsigned int len) {
	if (len == 0)
		return USB_STOR_XFER_GOOD;

	US_DEBUGP("datafab_bulk_read:  len = %d\n", len);
	return usb_stor_bulk_transfer_buf(us, us->recv_bulk_pipe,
			data, len, NULL);
}


static inline int
datafab_bulk_write(struct us_data *us, unsigned char *data, unsigned int len) {
	if (len == 0)
		return USB_STOR_XFER_GOOD;

	US_DEBUGP("datafab_bulk_write:  len = %d\n", len);
	return usb_stor_bulk_transfer_buf(us, us->send_bulk_pipe,
			data, len, NULL);
}


static int datafab_read_data(struct us_data *us,
			     struct datafab_info *info,
			     u32 sector,
			     u32 sectors)
{
	unsigned char *command = us->iobuf;
	unsigned char *buffer;
	unsigned char  thistime;
	unsigned int totallen, alloclen;
	int len, result;
	unsigned int sg_idx = 0, sg_offset = 0;

	// we're working in LBA mode.  according to the ATA spec, 
	// we can support up to 28-bit addressing.  I don't know if Datafab
	// supports beyond 24-bit addressing.  It's kind of hard to test 
	// since it requires > 8GB CF card.
	//
	if (sectors > 0x0FFFFFFF)
		return USB_STOR_TRANSPORT_ERROR;

	if (info->lun == -1) {
		result = datafab_determine_lun(us, info);
		if (result != USB_STOR_TRANSPORT_GOOD)
			return result;
	}

	totallen = sectors * info->ssize;

	// Since we don't read more than 64 KB at a time, we have to create
	// a bounce buffer and move the data a piece at a time between the
	// bounce buffer and the actual transfer buffer.

	alloclen = min(totallen, 65536u);
	buffer = kmalloc(alloclen, GFP_NOIO);
	if (buffer == NULL)
		return USB_STOR_TRANSPORT_ERROR;

	do {
		// loop, never allocate or transfer more than 64k at once
		// (min(128k, 255*info->ssize) is the real limit)

		len = min(totallen, alloclen);
		thistime = (len / info->ssize) & 0xff;

		command[0] = 0;
		command[1] = thistime;
		command[2] = sector & 0xFF;
		command[3] = (sector >> 8) & 0xFF;
		command[4] = (sector >> 16) & 0xFF;

		command[5] = 0xE0 + (info->lun << 4);
		command[5] |= (sector >> 24) & 0x0F;
		command[6] = 0x20;
		command[7] = 0x01;

		// send the read command
		result = datafab_bulk_write(us, command, 8);
		if (result != USB_STOR_XFER_GOOD)
			goto leave;

		// read the result
		result = datafab_bulk_read(us, buffer, len);
		if (result != USB_STOR_XFER_GOOD)
			goto leave;

		// Store the data in the transfer buffer
		usb_stor_access_xfer_buf(buffer, len, us->srb,
				 &sg_idx, &sg_offset, TO_XFER_BUF);

		sector += thistime;
		totallen -= len;
	} while (totallen > 0);

	kfree(buffer);
	return USB_STOR_TRANSPORT_GOOD;

 leave:
	kfree(buffer);
	return USB_STOR_TRANSPORT_ERROR;
}


static int datafab_write_data(struct us_data *us,
			      struct datafab_info *info,
			      u32 sector,
			      u32 sectors)
{
	unsigned char *command = us->iobuf;
	unsigned char *reply = us->iobuf;
	unsigned char *buffer;
	unsigned char thistime;
	unsigned int totallen, alloclen;
	int len, result;
	unsigned int sg_idx = 0, sg_offset = 0;

	// we're working in LBA mode.  according to the ATA spec, 
	// we can support up to 28-bit addressing.  I don't know if Datafab
	// supports beyond 24-bit addressing.  It's kind of hard to test 
	// since it requires > 8GB CF card.
	//
	if (sectors > 0x0FFFFFFF)
		return USB_STOR_TRANSPORT_ERROR;

	if (info->lun == -1) {
		result = datafab_determine_lun(us, info);
		if (result != USB_STOR_TRANSPORT_GOOD)
			return result;
	}

	totallen = sectors * info->ssize;

	// Since we don't write more than 64 KB at a time, we have to create
	// a bounce buffer and move the data a piece at a time between the
	// bounce buffer and the actual transfer buffer.

	alloclen = min(totallen, 65536u);
	buffer = kmalloc(alloclen, GFP_NOIO);
	if (buffer == NULL)
		return USB_STOR_TRANSPORT_ERROR;

	do {
		// loop, never allocate or transfer more than 64k at once
		// (min(128k, 255*info->ssize) is the real limit)

		len = min(totallen, alloclen);
		thistime = (len / info->ssize) & 0xff;

		// Get the data from the transfer buffer
		usb_stor_access_xfer_buf(buffer, len, us->srb,
				&sg_idx, &sg_offset, FROM_XFER_BUF);

		command[0] = 0;
		command[1] = thistime;
		command[2] = sector & 0xFF;
		command[3] = (sector >> 8) & 0xFF;
		command[4] = (sector >> 16) & 0xFF;

		command[5] = 0xE0 + (info->lun << 4);
		command[5] |= (sector >> 24) & 0x0F;
		command[6] = 0x30;
		command[7] = 0x02;

		// send the command
		result = datafab_bulk_write(us, command, 8);
		if (result != USB_STOR_XFER_GOOD)
			goto leave;

		// send the data
		result = datafab_bulk_write(us, buffer, len);
		if (result != USB_STOR_XFER_GOOD)
			goto leave;

		// read the result
		result = datafab_bulk_read(us, reply, 2);
		if (result != USB_STOR_XFER_GOOD)
			goto leave;

		if (reply[0] != 0x50 && reply[1] != 0) {
			US_DEBUGP("datafab_write_data:  Gah! "
				  "write return code: %02x %02x\n",
				  reply[0], reply[1]);
			result = USB_STOR_TRANSPORT_ERROR;
			goto leave;
		}

		sector += thistime;
		totallen -= len;
	} while (totallen > 0);

	kfree(buffer);
	return USB_STOR_TRANSPORT_GOOD;

 leave:
	kfree(buffer);
	return USB_STOR_TRANSPORT_ERROR;
}


static int datafab_determine_lun(struct us_data *us,
				 struct datafab_info *info)
{
	// Dual-slot readers can be thought of as dual-LUN devices.
	// We need to determine which card slot is being used.
	// We'll send an IDENTIFY DEVICE command and see which LUN responds...
	//
	// There might be a better way of doing this?

	static unsigned char scommand[8] = { 0, 1, 0, 0, 0, 0xa0, 0xec, 1 };
	unsigned char *command = us->iobuf;
	unsigned char *buf;
	int count = 0, rc;

	if (!us || !info)
		return USB_STOR_TRANSPORT_ERROR;

	memcpy(command, scommand, 8);
	buf = kmalloc(512, GFP_NOIO);
	if (!buf)
		return USB_STOR_TRANSPORT_ERROR;

	US_DEBUGP("datafab_determine_lun:  locating...\n");

	// we'll try 3 times before giving up...
	//
	while (count++ < 3) {
		command[5] = 0xa0;

		rc = datafab_bulk_write(us, command, 8);
		if (rc != USB_STOR_XFER_GOOD) {
			rc = USB_STOR_TRANSPORT_ERROR;
			goto leave;
		}

		rc = datafab_bulk_read(us, buf, 512);
		if (rc == USB_STOR_XFER_GOOD) {
			info->lun = 0;
			rc = USB_STOR_TRANSPORT_GOOD;
			goto leave;
		}

		command[5] = 0xb0;

		rc = datafab_bulk_write(us, command, 8);
		if (rc != USB_STOR_XFER_GOOD) {
			rc = USB_STOR_TRANSPORT_ERROR;
			goto leave;
		}

		rc = datafab_bulk_read(us, buf, 512);
		if (rc == USB_STOR_XFER_GOOD) {
			info->lun = 1;
			rc = USB_STOR_TRANSPORT_GOOD;
			goto leave;
		}

		msleep(20);
	}

	rc = USB_STOR_TRANSPORT_ERROR;

 leave:
	kfree(buf);
	return rc;
}