sddr09.c

LINUX下USB驱动程序的开发

	}
	if (status & 0x40)
		US_DEBUGP(" Ready");
	if (status & 0x20)
		US_DEBUGP(" Suspended");
	if (status & 0x1)
		US_DEBUGP(" Error");
	US_DEBUGP("\n");
	return USB_STOR_TRANSPORT_GOOD;
}

#if 0
/*
 * Reset Command: 12 bytes.
 * byte 0: opcode: EB
 */
static int
sddr09_reset(struct us_data *us) {

	unsigned char command[12] = {
		0xeb, 0x20, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
	};

	return sddr09_send_scsi_command(us, command, sizeof(command));
}
#endif

static struct nand_flash_dev *
sddr09_get_cardinfo(struct us_data *us, unsigned char flags) {
	struct nand_flash_dev *cardinfo;
	unsigned char deviceID[4];
	char blurbtxt[256];
	int result;

	US_DEBUGP("Reading capacity...\n");

	result = sddr09_read_deviceID(us, deviceID);

	if (result != USB_STOR_TRANSPORT_GOOD) {
		US_DEBUGP("Result of read_deviceID is %d\n", result);
		printk("sddr09: could not read card info\n");
		return 0;
	}

	sprintf(blurbtxt, "sddr09: Found Flash card, ID = %02X %02X %02X %02X",
		deviceID[0], deviceID[1], deviceID[2], deviceID[3]);

	/* Byte 0 is the manufacturer */
	sprintf(blurbtxt + strlen(blurbtxt),
		": Manuf. %s",
		nand_flash_manufacturer(deviceID[0]));

	/* Byte 1 is the device type */
	cardinfo = nand_find_id(deviceID[1]);
	if (cardinfo) {
		/* MB or MiB? It is neither. A 16 MB card has
		   17301504 raw bytes, of which 16384000 are
		   usable for user data. */
		sprintf(blurbtxt + strlen(blurbtxt),
			", %d MB", 1<<(cardinfo->chipshift - 20));
	} else {
		sprintf(blurbtxt + strlen(blurbtxt),
			", type unrecognized");
	}

	/* Byte 2 is code to signal availability of 128-bit ID */
	if (deviceID[2] == 0xa5) {
		sprintf(blurbtxt + strlen(blurbtxt),
			", 128-bit ID");
	}

	/* Byte 3 announces the availability of another read ID command */
	if (deviceID[3] == 0xc0) {
		sprintf(blurbtxt + strlen(blurbtxt),
			", extra cmd");
	}

	if (flags & SDDR09_WP)
		sprintf(blurbtxt + strlen(blurbtxt),
			", WP");

	printk("%s\n", blurbtxt);

	return cardinfo;
}

static int
sddr09_read_map(struct us_data *us) {

	struct scatterlist *sg;
	struct sddr09_card_info *info = (struct sddr09_card_info *) us->extra;
	int numblocks, alloc_len, alloc_blocks;
	int i, j, result;
	unsigned char *ptr;
	unsigned int lba, lbact;

	if (!info->capacity)
		return -1;

	// read 64 (1<<6) bytes for every block 
	// ( 1 << ( blockshift + pageshift ) bytes)
	//	 of capacity:
	// (1<<6)*capacity/(1<<(b+p)) =
	// ((1<<6)*capacity)>>(b+p) =
	// capacity>>(b+p-6)

	alloc_len = info->capacity >> 
		(info->blockshift + info->pageshift - CONTROL_SHIFT);

	// Allocate a number of scatterlist structures according to
	// the number of 128k blocks in the alloc_len. Adding 128k-1
	// and then dividing by 128k gives the correct number of blocks.
	// 128k = 1<<17

	alloc_blocks = (alloc_len + (1<<17) - 1) >> 17;
	sg = kmalloc(alloc_blocks*sizeof(struct scatterlist),
		     GFP_NOIO);
	if (sg == NULL)
		return 0;

	for (i=0; i<alloc_blocks; i++) {
		if (i<alloc_blocks-1) {
			sg[i].address = kmalloc( (1<<17), GFP_NOIO );
			sg[i].page = NULL;
			sg[i].length = (1<<17);
		} else {
			sg[i].address = kmalloc(alloc_len, GFP_NOIO);
			sg[i].page = NULL;
			sg[i].length = alloc_len;
		}
		alloc_len -= sg[i].length;
	}
	for (i=0; i<alloc_blocks; i++)
		if (sg[i].address == NULL) {
			for (i=0; i<alloc_blocks; i++)
				if (sg[i].address != NULL)
					kfree(sg[i].address);
			kfree(sg);
			return 0;
		}

	numblocks = info->capacity >> (info->blockshift + info->pageshift);

	result = sddr09_read_control(us, 0, numblocks,
				     (unsigned char *)sg, alloc_blocks);
	if (result != USB_STOR_TRANSPORT_GOOD) {
		for (i=0; i<alloc_blocks; i++)
			kfree(sg[i].address);
		kfree(sg);
		return -1;
	}

	kfree(info->lba_to_pba);
	kfree(info->pba_to_lba);
	info->lba_to_pba = kmalloc(numblocks*sizeof(int), GFP_NOIO);
	info->pba_to_lba = kmalloc(numblocks*sizeof(int), GFP_NOIO);

	if (info->lba_to_pba == NULL || info->pba_to_lba == NULL) {
		kfree(info->lba_to_pba);
		kfree(info->pba_to_lba);
		info->lba_to_pba = NULL;
		info->pba_to_lba = NULL;
		for (i=0; i<alloc_blocks; i++)
			kfree(sg[i].address);
		kfree(sg);
		return 0;
	}

	for (i = 0; i < numblocks; i++)
		info->lba_to_pba[i] = info->pba_to_lba[i] = UNDEF;

	ptr = sg[0].address;

	/*
	 * Define lba-pba translation table
	 */
	// Each block is 64 bytes of control data, so block i is located in
	// scatterlist block i*64/128k = i*(2^6)*(2^-17) = i*(2^-11)

#if 0
	/* No translation */
	for (i=0; i<numblocks; i++) {
		lba = i;
		info->pba_to_lba[i] = lba;
		info->lba_to_pba[lba] = i;
	}
	printk("sddr09: no translation today\n");
#else
	for (i=0; i<numblocks; i++) {
		ptr = sg[i>>11].address + ((i&0x7ff)<<6);

		if (i == 0 || i == 1) {
			info->pba_to_lba[i] = UNUSABLE;
			continue;
		}

		/* special PBAs have control field 0^16 */
		for (j = 0; j < 16; j++)
			if (ptr[j] != 0)
				goto nonz;
		info->pba_to_lba[i] = UNUSABLE;
		printk("sddr09: PBA %04X has no logical mapping\n", i);
		continue;

	nonz:
		/* unwritten PBAs have control field FF^16 */
		for (j = 0; j < 16; j++)
			if (ptr[j] != 0xff)
				goto nonff;
		continue;

	nonff:
		/* normal PBAs start with six FFs */
		if (j < 6) {
			printk("sddr09: PBA %04X has no logical mapping: "
			       "reserved area = %02X%02X%02X%02X "
			       "data status %02X block status %02X\n",
			       i, ptr[0], ptr[1], ptr[2], ptr[3],
			       ptr[4], ptr[5]);
			info->pba_to_lba[i] = UNUSABLE;
			continue;
		}

		if ((ptr[6] >> 4) != 0x01) {
			printk("sddr09: PBA %04X has invalid address field "
			       "%02X%02X/%02X%02X\n",
			       i, ptr[6], ptr[7], ptr[11], ptr[12]);
			info->pba_to_lba[i] = UNUSABLE;
			continue;
		}

		/* check even parity */
		if (parity[ptr[6] ^ ptr[7]]) {
			printk("sddr09: Bad parity in LBA for block %04X"
			       " (%02X %02X)\n", i, ptr[6], ptr[7]);
			info->pba_to_lba[i] = UNUSABLE;
			continue;
		}

		lba = short_pack(ptr[7], ptr[6]);
		lba = (lba & 0x07FF) >> 1;

		/*
		 * Every 1024 physical blocks ("zone"), the LBA numbers
		 * go back to zero, but are within a higher block of LBA's.
		 * Also, there is a maximum of 1000 LBA's per zone.
		 * In other words, in PBA 1024-2047 you will find LBA 0-999
		 * which are really LBA 1000-1999. This allows for 24 bad
		 * or special physical blocks per zone.
		 */

		if (lba >= 1000) {
			printk("sddr09: Bad LBA %04X for block %04X\n",
			       lba, i);
			info->pba_to_lba[i] = UNDEF /* UNUSABLE */;
			continue;
		}

		lba += 1000*(i/0x400);

		if (lba<0x10 || (lba >= 0x3E0 && lba < 0x3EF))
			US_DEBUGP("LBA %04X <-> PBA %04X\n", lba, i);

		info->pba_to_lba[i] = lba;
		info->lba_to_pba[lba] = i;
	}
#endif

	/*
	 * Approximate capacity. This is not entirely correct yet,
	 * since a zone with less than 1000 usable pages leads to
	 * missing LBAs. Especially if it is the last zone, some
	 * LBAs can be past capacity.
	 */
	lbact = 0;
	for (i = 0; i < numblocks; i += 1024) {
		int ct = 0;

		for (j = 0; j < 1024 && i+j < numblocks; j++) {
			if (info->pba_to_lba[i+j] != UNUSABLE) {
				if (ct >= 1000)
					info->pba_to_lba[i+j] = SPARE;
				else
					ct++;
			}
		}
		lbact += ct;
	}
	info->lbact = lbact;
	US_DEBUGP("Found %d LBA's\n", lbact);

	for (i=0; i<alloc_blocks; i++)
		kfree(sg[i].address);
	kfree(sg);
	return 0;
}

static void
sddr09_card_info_destructor(void *extra) {
	struct sddr09_card_info *info = (struct sddr09_card_info *)extra;

	if (!info)
		return;

	kfree(info->lba_to_pba);
	kfree(info->pba_to_lba);
}

static void
sddr09_init_card_info(struct us_data *us) {
	if (!us->extra) {
		us->extra = kmalloc(sizeof(struct sddr09_card_info), GFP_NOIO);
		if (us->extra) {
			memset(us->extra, 0, sizeof(struct sddr09_card_info));
			us->extra_destructor = sddr09_card_info_destructor;
		}
	}
}

/*
 * It is unclear whether this does anything.
 * However, the request sense succeeds only after a reboot,
 * not if we do this a second time.
 */
int
sddr09_init(struct us_data *us) {
#if 0
	int result;
	unsigned char data[2];

	printk("sddr09_init\n");

	nand_init_ecc();

	result = sddr09_send_command(us, 0x01, USB_DIR_IN, data, 2);
	if (result != USB_STOR_TRANSPORT_GOOD) {
		US_DEBUGP("sddr09_init: send_command fails\n");
		return result;
	}

	US_DEBUGP("SDDR09init: %02X %02X\n", data[0], data[1]);
	// get 07 02

	result = sddr09_send_command(us, 0x08, USB_DIR_IN, data, 2);
	if (result != USB_STOR_TRANSPORT_GOOD) {
		US_DEBUGP("sddr09_init: 2nd send_command fails\n");
		return result;
	}

	US_DEBUGP("SDDR09init: %02X %02X\n", data[0], data[1]);
	// get 07 00

#if 1
	result = sddr09_request_sense(us, data, sizeof(data));
	if (result == USB_STOR_TRANSPORT_GOOD && data[2] != 0) {
		int j;
		for (j=0; j<sizeof(data); j++)
			printk(" %02X", data[j]);
		printk("\n");
		// get 70 00 00 00 00 00 00 * 00 00 00 00 00 00
		// 70: current command
		// sense key 0, sense code 0, extd sense code 0
		// additional transfer length * = sizeof(data) - 7
	}
#endif
#endif
	return USB_STOR_TRANSPORT_GOOD;		/* not result */
}

/*
 * Transport for the Sandisk SDDR-09
 */
int sddr09_transport(Scsi_Cmnd *srb, struct us_data *us)
{
	static unsigned char sense = 0;
	static unsigned char havefakesense = 0;
	int result, i;
	unsigned char *ptr;
	unsigned long capacity;
	unsigned int page, pages;
	char string[64];

	struct sddr09_card_info *info;

	unsigned char inquiry_response[36] = {
		0x00, 0x80, 0x00, 0x02, 0x1F, 0x00, 0x00, 0x00
	};

	unsigned char mode_page_01[16] = {
		0x0F, 0x00, 0, 0x00,
		0x01, 0x0A,
		0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00
	};

	info = (struct sddr09_card_info *)us->extra;
	if (!info) {
		nand_init_ecc();
		sddr09_init_card_info(us);
		info = (struct sddr09_card_info *)us->extra;
		if (!info)
			return USB_STOR_TRANSPORT_ERROR;
	}

	ptr = (unsigned char *)srb->request_buffer;

	if (srb->cmnd[0] == REQUEST_SENSE && havefakesense) {
		/* for a faked command, we have to follow with a faked sense */
		memset(ptr, 0, srb->request_bufflen);
		if (srb->request_bufflen > 7) {
			ptr[0] = 0x70;
			ptr[2] = sense;
			ptr[7] = srb->request_bufflen - 7;
		}
		sense = havefakesense = 0;
		return USB_STOR_TRANSPORT_GOOD;
	}

	sense = 0;
	havefakesense = 1;

	/* Dummy up a response for INQUIRY since SDDR09 doesn't
	   respond to INQUIRY commands */

	if (srb->cmnd[0] == INQUIRY) {
		memset(inquiry_response+8, 0, 28);
		fill_inquiry_response(us, inquiry_response, 36);
		return USB_STOR_TRANSPORT_GOOD;
	}

	if (srb->cmnd[0] == READ_CAPACITY) {
		struct nand_flash_dev *cardinfo;

		sddr09_get_wp(us, info);	/* read WP bit */

		cardinfo = sddr09_get_cardinfo(us, info->flags);
		if (!cardinfo)
			return USB_STOR_TRANSPORT_FAILED;

		info->capacity = (1 << cardinfo->chipshift);
		info->pageshift = cardinfo->pageshift;
		info->pagesize = (1 << info->pageshift);
		info->blockshift = cardinfo->blockshift;
		info->blocksize = (1 << info->blockshift);
		info->blockmask = info->blocksize - 1;

		// map initialization, must follow get_cardinfo()
		sddr09_read_map(us);

		// Report capacity

		capacity = (info->lbact << info->blockshift) - 1;

		ptr[0] = MSB_of(capacity>>16);
		ptr[1] = LSB_of(capacity>>16);
		ptr[2] = MSB_of(capacity&0xFFFF);
		ptr[3] = LSB_of(capacity&0xFFFF);

		// Report page size

		ptr[4] = MSB_of(info->pagesize>>16);
		ptr[5] = LSB_of(info->pagesize>>16);
		ptr[6] = MSB_of(info->pagesize&0xFFFF);
		ptr[7] = LSB_of(info->pagesize&0xFFFF);

		return USB_STOR_TRANSPORT_GOOD;
	}

	if (srb->cmnd[0] == MODE_SENSE) {

		// Read-write error recovery page: there needs to
		// be a check for write-protect here

		if ( (srb->cmnd[2] & 0x3F) == 0x01 ) {

			US_DEBUGP(
				"SDDR09: Dummy up request for mode page 1\n");

			if (ptr == NULL || 
			    srb->request_bufflen<sizeof(mode_page_01))
				return USB_STOR_TRANSPORT_ERROR;

			mode_page_01[0] = sizeof(mode_page_01) - 1;
			mode_page_01[2] = (info->flags & SDDR09_WP) ? 0x80 : 0;
			memcpy(ptr, mode_page_01, sizeof(mode_page_01));
			return USB_STOR_TRANSPORT_GOOD;

		} else if ( (srb->cmnd[2] & 0x3F) == 0x3F ) {

			US_DEBUGP("SDDR09: Dummy up request for "
				  "all mode pages\n");

			if (ptr == NULL || 
			    srb->request_bufflen<sizeof(mode_page_01))
				return USB_STOR_TRANSPORT_ERROR;

			memcpy(ptr, mode_page_01, sizeof(mode_page_01));
			return USB_STOR_TRANSPORT_GOOD;

		}

		return USB_STOR_TRANSPORT_ERROR;
	}

	if (srb->cmnd[0] == ALLOW_MEDIUM_REMOVAL) {

		US_DEBUGP(
			"SDDR09: %s medium removal. Not that I can do"
			" anything about it...\n",
			(srb->cmnd[4]&0x03) ? "Prevent" : "Allow");

		return USB_STOR_TRANSPORT_GOOD;

	}

	havefakesense = 0;

	if (srb->cmnd[0] == READ_10) {

		page = short_pack(srb->cmnd[3], srb->cmnd[2]);
		page <<= 16;
		page |= short_pack(srb->cmnd[5], srb->cmnd[4]);
		pages = short_pack(srb->cmnd[8], srb->cmnd[7]);

		US_DEBUGP("READ_10: read page %d pagect %d\n",
			  page, pages);

		return sddr09_read_data(us, page, pages, ptr, srb->use_sg);
	}

	if (srb->cmnd[0] == WRITE_10) {

		page = short_pack(srb->cmnd[3], srb->cmnd[2]);
		page <<= 16;
		page |= short_pack(srb->cmnd[5], srb->cmnd[4]);
		pages = short_pack(srb->cmnd[8], srb->cmnd[7]);

		US_DEBUGP("WRITE_10: write page %d pagect %d\n",
			  page, pages);

		return sddr09_write_data(us, page, pages, ptr, srb->use_sg);
	}

	// Pass TEST_UNIT_READY and REQUEST_SENSE through

	if (srb->cmnd[0] != TEST_UNIT_READY &&
	    srb->cmnd[0] != REQUEST_SENSE) {
		havefakesense = 1;
		return USB_STOR_TRANSPORT_ERROR;
	}

	for (; srb->cmd_len<12; srb->cmd_len++)
		srb->cmnd[srb->cmd_len] = 0;

	srb->cmnd[1] = 0x20;

	string[0] = 0;
	for (i=0; i<12; i++)
		sprintf(string+strlen(string), "%02X ", srb->cmnd[i]);

	US_DEBUGP("SDDR09: Send control for command %s\n",
		  string);

	result = sddr09_send_scsi_command(us, srb->cmnd, 12);
	if (result != USB_STOR_TRANSPORT_GOOD) {
		US_DEBUGP("sddr09_transport: sddr09_send_scsi_command "
			  "returns %d\n", result);
		return result;
	}

	if (srb->request_bufflen == 0)
		return USB_STOR_TRANSPORT_GOOD;

	if (srb->sc_data_direction == SCSI_DATA_WRITE ||
	    srb->sc_data_direction == SCSI_DATA_READ) {

		US_DEBUGP("SDDR09: %s %d bytes\n",
			  (srb->sc_data_direction == SCSI_DATA_WRITE) ?
			  "sending" : "receiving",
			  srb->request_bufflen);

		result = sddr09_bulk_transport(us,
					       srb->sc_data_direction,
					       srb->request_buffer, 
					       srb->request_bufflen,
					       srb->use_sg);

		return result;
	} 

	return USB_STOR_TRANSPORT_GOOD;
}