sddr09.c

LINUX下USB驱动程序的开发

/* Driver for SanDisk SDDR-09 SmartMedia reader
 *
 *   (c) 2000, 2001 Robert Baruch ([e-mail])
 *   (c) 2002 Andries Brouwer ([e-mail])
 *
 * The SanDisk SDDR-09 SmartMedia reader uses the Shuttle EUSB-01 chip.
 * This chip is a programmable USB controller. In the SDDR-09, it has
 * been programmed to obey a certain limited set of SCSI commands.
 * This driver translates the "real" SCSI commands to the SDDR-09 SCSI
 * commands.
 *
 * 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 "sddr09.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 US_DEBUGP printk */

/*
 * First some stuff that does not belong here:
 * data on SmartMedia and other cards, completely
 * unrelated to this driver.
 * Similar stuff occurs in <linux/mtd/nand_ids.h>.
 */

struct nand_flash_dev {
	int model_id;
	int chipshift;		/* 1<<cs bytes total capacity */
	char pageshift;		/* 1<<ps bytes in a page */
	char blockshift;	/* 1<<bs pages in an erase block */
	char zoneshift;		/* 1<<zs blocks in a zone */
				/* # of logical blocks is 125/128 of this */
	char pageadrlen;	/* length of an address in bytes - 1 */
};

/*
 * NAND Flash Manufacturer ID Codes
 */
#define NAND_MFR_AMD		0x01
#define NAND_MFR_TOSHIBA	0x98
#define NAND_MFR_SAMSUNG	0xec

static inline char *nand_flash_manufacturer(int manuf_id) {
	switch(manuf_id) {
	case NAND_MFR_AMD:
		return "AMD";
	case NAND_MFR_TOSHIBA:
		return "Toshiba";
	case NAND_MFR_SAMSUNG:
		return "Samsung";
	default:
		return "unknown";
	}
}

/*
 * It looks like it is unnecessary to attach manufacturer to the
 * remaining data: SSFDC prescribes manufacturer-independent id codes.
 */

static struct nand_flash_dev nand_flash_ids[] = {
	/* NAND flash - these I verified */
	{ 0x6e, 20, 8, 4, 8, 2},	/* 1 MB */
	{ 0xe8, 20, 8, 4, 8, 2},	/* 1 MB */
	{ 0xec, 20, 8, 4, 8, 2},	/* 1 MB */
	{ 0x64, 21, 8, 4, 9, 2}, 	/* 2 MB */
	{ 0xea, 21, 8, 4, 9, 2},	/* 2 MB */
	{ 0x6b, 22, 9, 4, 9, 2},	/* 4 MB */
	{ 0xe3, 22, 9, 4, 9, 2},	/* 4 MB */
	{ 0xe5, 22, 9, 4, 9, 2},	/* 4 MB */
	{ 0xe6, 23, 9, 4, 10, 2},	/* 8 MB */
	{ 0x73, 24, 9, 5, 10, 2},	/* 16 MB */
	{ 0x75, 25, 9, 5, 10, 2},	/* 32 MB */
	{ 0x76, 26, 9, 5, 10, 3},	/* 64 MB */
	{ 0x79, 27, 9, 5, 10, 3},	/* 128 MB */
	/* MASK ROM - from unknown source */
	{ 0x5d, 21, 9, 4, 8, 2},	/* 2 MB */
	{ 0xd5, 22, 9, 4, 9, 2},	/* 4 MB */
	{ 0xd6, 23, 9, 4, 10, 2},	/* 8 MB */
	{ 0,}
};

#define SIZE(a)	(sizeof(a)/sizeof((a)[0]))

static struct nand_flash_dev *
nand_find_id(unsigned char id) {
	int i;

	for (i = 0; i < SIZE(nand_flash_ids); i++)
		if (nand_flash_ids[i].model_id == id)
			return &(nand_flash_ids[i]);
	return NULL;
}

/*
 * ECC computation.
 */
static unsigned char parity[256];
static unsigned char ecc2[256];

static void nand_init_ecc(void) {
	int i, j, a;

	parity[0] = 0;
	for (i = 1; i < 256; i++)
		parity[i] = (parity[i&(i-1)] ^ 1);

	for (i = 0; i < 256; i++) {
		a = 0;
		for (j = 0; j < 8; j++) {
			if (i & (1<<j)) {
				if ((j & 1) == 0)
					a ^= 0x04;
				if ((j & 2) == 0)
					a ^= 0x10;
				if ((j & 4) == 0)
					a ^= 0x40;
			}
		}
		ecc2[i] = ~(a ^ (a<<1) ^ (parity[i] ? 0xa8 : 0));
	}
}

/* compute 3-byte ecc on 256 bytes */
static void nand_compute_ecc(unsigned char *data, unsigned char *ecc) {
	int i, j, a;
	unsigned char par, bit, bits[8];

	par = 0;
	for (j = 0; j < 8; j++)
		bits[j] = 0;

	/* collect 16 checksum bits */
	for (i = 0; i < 256; i++) {
		par ^= data[i];
		bit = parity[data[i]];
		for (j = 0; j < 8; j++)
			if ((i & (1<<j)) == 0)
				bits[j] ^= bit;
	}

	/* put 4+4+4 = 12 bits in the ecc */
	a = (bits[3] << 6) + (bits[2] << 4) + (bits[1] << 2) + bits[0];
	ecc[0] = ~(a ^ (a<<1) ^ (parity[par] ? 0xaa : 0));

	a = (bits[7] << 6) + (bits[6] << 4) + (bits[5] << 2) + bits[4];
	ecc[1] = ~(a ^ (a<<1) ^ (parity[par] ? 0xaa : 0));

	ecc[2] = ecc2[par];
}

static int nand_compare_ecc(unsigned char *data, unsigned char *ecc) {
	return (data[0] == ecc[0] && data[1] == ecc[1] && data[2] == ecc[2]);
}

static void nand_store_ecc(unsigned char *data, unsigned char *ecc) {
	memcpy(data, ecc, 3);
}

/*
 * The actual driver starts here.
 */

/*
 * On my 16MB card, control blocks have size 64 (16 real control bytes,
 * and 48 junk bytes). In reality of course the card uses 16 control bytes,
 * so the reader makes up the remaining 48. Don't know whether these numbers
 * depend on the card. For now a constant.
 */
#define CONTROL_SHIFT 6

/*
 * LBA and PBA are unsigned ints. Special values.
 */
#define UNDEF    0xffffffff
#define SPARE    0xfffffffe
#define UNUSABLE 0xfffffffd

/*
 * Send a control message and wait for the response.
 *
 * us - the pointer to the us_data structure for the device to use
 *
 * request - the URB Setup Packet's first 6 bytes. The first byte always
 *  corresponds to the request type, and the second byte always corresponds
 *  to the request.  The other 4 bytes do not correspond to value and index,
 *  since they are used in a custom way by the SCM protocol.
 *
 * xfer_data - a buffer from which to get, or to which to store, any data
 *  that gets send or received, respectively, with the URB. Even though
 *  it looks like we allocate a buffer in this code for the data, xfer_data
 *  must contain enough allocated space.
 *
 * xfer_len - the number of bytes to send or receive with the URB.
 *
 */

static int
sddr09_send_control(struct us_data *us,
		    int pipe,
		    unsigned char request,
		    unsigned char requesttype,
		    unsigned int value,
		    unsigned int index,
		    unsigned char *xfer_data,
		    unsigned int xfer_len) {

	int result;

	// Send the URB to the device and wait for a response.

	/* Why are request and request type reversed in this call? */

	result = usb_stor_control_msg(us, pipe,
			request, requesttype, value, index,
			xfer_data, xfer_len);


	// Check the return code for the command.

	if (result < 0) {
		/* if the command was aborted, indicate that */
		if (result == -ECONNRESET)
			return USB_STOR_TRANSPORT_ABORTED;

		/* a stall is a fatal condition from the device */
		if (result == -EPIPE) {
			US_DEBUGP("-- Stall on control pipe. Clearing\n");
			result = usb_clear_halt(us->pusb_dev, pipe);
			US_DEBUGP("-- usb_clear_halt() returns %d\n", result);
			return USB_STOR_TRANSPORT_FAILED;
		}

		return USB_STOR_TRANSPORT_ERROR;
	}

	return USB_STOR_TRANSPORT_GOOD;
}

/* send vendor interface command (0x41) */
/* called for requests 0, 1, 8 */
static int
sddr09_send_command(struct us_data *us,
		    unsigned char request,
		    unsigned char direction,
		    unsigned char *xfer_data,
		    unsigned int xfer_len) {
	int pipe;
	unsigned char requesttype = (0x41 | direction);

	// Get the receive or send control pipe number

	if (direction == USB_DIR_IN)
		pipe = usb_rcvctrlpipe(us->pusb_dev,0);
	else
		pipe = usb_sndctrlpipe(us->pusb_dev,0);

	return sddr09_send_control(us, pipe, request, requesttype,
				   0, 0, xfer_data, xfer_len);
}

static int
sddr09_send_scsi_command(struct us_data *us,
			 unsigned char *command,
			 unsigned int command_len) {
	return sddr09_send_command(us, 0, USB_DIR_OUT, command, command_len);
}

static int
sddr09_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) {
                /* -ECONNRESET -- we canceled this transfer */
                if (result == -ECONNRESET) {
                        US_DEBUGP("usbat_raw_bulk(): transfer aborted\n");
                        return US_BULK_TRANSFER_ABORTED;
                }

                /* NAK - that means we've retried a few times already */
       	        if (result == -ETIMEDOUT)
                        US_DEBUGP("usbat_raw_bulk(): device NAKed\n");
		else if (result == -EOVERFLOW)
			US_DEBUGP("us_transfer_partial(): babble/overflow\n");
		else if (result != -EPIPE)
			US_DEBUGP("us_transfer_partial(): unknown error %d\n",
				  result);

                return US_BULK_TRANSFER_FAILED;
        }

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

	return US_BULK_TRANSFER_GOOD;
}

static int
sddr09_bulk_transport(struct us_data *us, int direction,
		      unsigned char *data, unsigned int len,
		      int use_sg) {

	int result = USB_STOR_TRANSPORT_GOOD;
	int transferred = 0;
	int i;
	struct scatterlist *sg;
	char string[64];

#define DEBUG_PRCT 12

	if (len == 0)
		return USB_STOR_TRANSPORT_GOOD;

	if (direction == SCSI_DATA_WRITE && !use_sg) {

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

		strcpy(string, "wr: ");
		for (i=0; i<len && i<DEBUG_PRCT; 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);
	}

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

	if (!use_sg)
		result = sddr09_raw_bulk(us, direction, data, len);
	else {
		sg = (struct scatterlist *)data;

		for (i=0; i<use_sg && transferred<len; i++) {
			unsigned char *buf;
			unsigned int length;

			buf = sg[i].address;
			length = len-transferred;
			if (length > sg[i].length)
				length = sg[i].length;

			result = sddr09_raw_bulk(us, direction, buf, length);
			if (result != US_BULK_TRANSFER_GOOD)
				break;
			transferred += sg[i].length;
		}
	}

	if (direction == SCSI_DATA_READ && !use_sg) {

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

		strcpy(string, "rd: ");
		for (i=0; i<len && i<DEBUG_PRCT; 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);
	}

	return result;
}

#if 0
/*
 * Test Unit Ready Command: 12 bytes.
 * byte 0: opcode: 00
 */
static int
sddr09_test_unit_ready(struct us_data *us) {
	unsigned char command[6] = {
		0, 0x20, 0, 0, 0, 0
	};
	int result;

	result = sddr09_send_scsi_command(us, command, sizeof(command));

	US_DEBUGP("sddr09_test_unit_ready returns %d\n", result);

	return result;
}
#endif

/*
 * Request Sense Command: 12 bytes.
 * byte 0: opcode: 03
 * byte 4: data length
 */
#if 0
static int
sddr09_request_sense(struct us_data *us, unsigned char *sensebuf, int buflen) {
	unsigned char command[12] = {
		0x03, 0x20, 0, 0, buflen, 0, 0, 0, 0, 0, 0, 0
	};
	int result;

	result = sddr09_send_scsi_command(us, command, sizeof(command));
	if (result != USB_STOR_TRANSPORT_GOOD) {
		US_DEBUGP("request sense failed\n");
		return result;
	}

	result = sddr09_raw_bulk(us, SCSI_DATA_READ, sensebuf, buflen);
	if (result != USB_STOR_TRANSPORT_GOOD)
		US_DEBUGP("request sense bulk in failed\n");
	else
		US_DEBUGP("request sense worked\n");

	return result;
}
#endif
/*
 * Read Command: 12 bytes.
 * byte 0: opcode: E8
 * byte 1: last two bits: 00: read data, 01: read blockwise control,
 *                        10: read both, 11: read pagewise control.
 *         It turns out we need values 20, 21, 22, 23 here (LUN 1).
 * bytes 2-5: address (interpretation depends on byte 1, see below)
 * bytes 10-11: count (idem)
 *
 * A page has 512 data bytes and 64 control bytes (16 control and 48 junk).
 * A read data command gets data in 512-byte pages.
 * A read control command gets control in 64-byte chunks.
 * A read both command gets data+control in 576-byte chunks.
 *
 * Blocks are groups of 32 pages, and read blockwise control jumps to the
 * next block, while read pagewise control jumps to the next page after
 * reading a group of 64 control bytes.
 * [Here 512 = 1<<pageshift, 32 = 1<<blockshift, 64 is constant?]
 *
 * (1 MB and 2 MB cards are a bit different, but I have only a 16 MB card.)
 */

static int
sddr09_readX(struct us_data *us, int x, unsigned long fromaddress,
	     int nr_of_pages, int bulklen, unsigned char *buf,
	     int use_sg) {

	unsigned char command[12] = {
		0xe8, 0x20 | x, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
	};
	int result;

	command[2] = MSB_of(fromaddress>>16);
	command[3] = LSB_of(fromaddress>>16); 
	command[4] = MSB_of(fromaddress & 0xFFFF);
	command[5] = LSB_of(fromaddress & 0xFFFF); 

	command[10] = MSB_of(nr_of_pages);
	command[11] = LSB_of(nr_of_pages);

	result = sddr09_send_scsi_command(us, command, sizeof(command));

	if (result != USB_STOR_TRANSPORT_GOOD) {
		US_DEBUGP("Result for send_control in sddr09_read2%d %d\n",
			  x, result);
		return result;
	}

	result = sddr09_bulk_transport(us, SCSI_DATA_READ,
				       buf, bulklen, use_sg);

	if (result != USB_STOR_TRANSPORT_GOOD)
		US_DEBUGP("Result for bulk_transport in sddr09_read2%d %d\n",
			  x, result);

	return result;
}

/*
 * Read Data
 *
 * fromaddress counts data shorts:
 * increasing it by 256 shifts the bytestream by 512 bytes;
 * the last 8 bits are ignored.
 *
 * nr_of_pages counts pages of size (1 << pageshift).
 */
static int
sddr09_read20(struct us_data *us, unsigned long fromaddress,
	      int nr_of_pages, int pageshift, unsigned char *buf, int use_sg) {
	int bulklen = nr_of_pages << pageshift;

	/* The last 8 bits of fromaddress are ignored. */
	return sddr09_readX(us, 0, fromaddress, nr_of_pages, bulklen,
			    buf, use_sg);
}

/*
 * Read Blockwise Control
 *
 * fromaddress gives the starting position (as in read data;
 * the last 8 bits are ignored); increasing it by 32*256 shifts
 * the output stream by 64 bytes.
 *
 * count counts control groups of size (1 << controlshift).
 * For me, controlshift = 6. Is this constant?
 *
 * After getting one control group, jump to the next block
 * (fromaddress += 8192).
 */
static int
sddr09_read21(struct us_data *us, unsigned long fromaddress,
	      int count, int controlshift, unsigned char *buf, int use_sg) {

	int bulklen = (count << controlshift);
	return sddr09_readX(us, 1, fromaddress, count, bulklen,
			    buf, use_sg);
}

/*
 * Read both Data and Control
 *
 * fromaddress counts data shorts, ignoring control:
 * increasing it by 256 shifts the bytestream by 576 = 512+64 bytes;
 * the last 8 bits are ignored.
 *
 * nr_of_pages counts pages of size (1 << pageshift) + (1 << controlshift).
 */
static int
sddr09_read22(struct us_data *us, unsigned long fromaddress,
	      int nr_of_pages, int pageshift, unsigned char *buf, int use_sg) {

	int bulklen = (nr_of_pages << pageshift) + (nr_of_pages << CONTROL_SHIFT);
	US_DEBUGP("sddr09_read22: reading %d pages, %d bytes\n",
		  nr_of_pages, bulklen);
	return sddr09_readX(us, 2, fromaddress, nr_of_pages, bulklen,
			    buf, use_sg);
}

#if 0
/*
 * Read Pagewise Control
 *
 * fromaddress gives the starting position (as in read data;
 * the last 8 bits are ignored); increasing it by 256 shifts