| /* |
| * Linux driver for SSFDC Flash Translation Layer (Read only) |
| * (c) 2005 Eptar srl |
| * Author: Claudio Lanconelli <lanconelli.claudio@eptar.com> |
| * |
| * Based on NTFL and MTDBLOCK_RO drivers |
| * |
| * This program is free software; you can redistribute it and/or modify |
| * it under the terms of the GNU General Public License version 2 as |
| * published by the Free Software Foundation. |
| */ |
| |
| #include <linux/config.h> |
| #include <linux/kernel.h> |
| #include <linux/module.h> |
| #include <linux/init.h> |
| #include <linux/slab.h> |
| #include <linux/hdreg.h> |
| #include <linux/mtd/mtd.h> |
| #include <linux/mtd/nand.h> |
| #include <linux/mtd/blktrans.h> |
| |
| struct ssfdcr_record { |
| struct mtd_blktrans_dev mbd; |
| int usecount; |
| unsigned char heads; |
| unsigned char sectors; |
| unsigned short cylinders; |
| int cis_block; /* block n. containing CIS/IDI */ |
| int erase_size; /* phys_block_size */ |
| unsigned short *logic_block_map; /* all zones (max 8192 phys blocks on |
| the 128MB) */ |
| int map_len; /* n. phys_blocks on the card */ |
| }; |
| |
| #define SSFDCR_MAJOR 257 |
| #define SSFDCR_PARTN_BITS 3 |
| |
| #define SECTOR_SIZE 512 |
| #define SECTOR_SHIFT 9 |
| #define OOB_SIZE 16 |
| |
| #define MAX_LOGIC_BLK_PER_ZONE 1000 |
| #define MAX_PHYS_BLK_PER_ZONE 1024 |
| |
| #define KB(x) ( (x) * 1024L ) |
| #define MB(x) ( KB(x) * 1024L ) |
| |
| /** CHS Table |
| 1MB 2MB 4MB 8MB 16MB 32MB 64MB 128MB |
| NCylinder 125 125 250 250 500 500 500 500 |
| NHead 4 4 4 4 4 8 8 16 |
| NSector 4 8 8 16 16 16 32 32 |
| SumSector 2,000 4,000 8,000 16,000 32,000 64,000 128,000 256,000 |
| SectorSize 512 512 512 512 512 512 512 512 |
| **/ |
| |
| typedef struct { |
| unsigned long size; |
| unsigned short cyl; |
| unsigned char head; |
| unsigned char sec; |
| } chs_entry_t; |
| |
| /* Must be ordered by size */ |
| static const chs_entry_t chs_table[] = { |
| { MB( 1), 125, 4, 4 }, |
| { MB( 2), 125, 4, 8 }, |
| { MB( 4), 250, 4, 8 }, |
| { MB( 8), 250, 4, 16 }, |
| { MB( 16), 500, 4, 16 }, |
| { MB( 32), 500, 8, 16 }, |
| { MB( 64), 500, 8, 32 }, |
| { MB(128), 500, 16, 32 }, |
| { 0 }, |
| }; |
| |
| static int get_chs(unsigned long size, unsigned short *cyl, unsigned char *head, |
| unsigned char *sec) |
| { |
| int k; |
| int found = 0; |
| |
| k = 0; |
| while (chs_table[k].size > 0 && size > chs_table[k].size) |
| k++; |
| |
| if (chs_table[k].size > 0) { |
| if (cyl) |
| *cyl = chs_table[k].cyl; |
| if (head) |
| *head = chs_table[k].head; |
| if (sec) |
| *sec = chs_table[k].sec; |
| found = 1; |
| } |
| |
| return found; |
| } |
| |
| /* These bytes are the signature for the CIS/IDI sector */ |
| static const uint8_t cis_numbers[] = { |
| 0x01, 0x03, 0xD9, 0x01, 0xFF, 0x18, 0x02, 0xDF, 0x01, 0x20 |
| }; |
| |
| /* Read and check for a valid CIS sector */ |
| static int get_valid_cis_sector(struct mtd_info *mtd) |
| { |
| int ret, k, cis_sector; |
| size_t retlen; |
| loff_t offset; |
| uint8_t sect_buf[SECTOR_SIZE]; |
| |
| /* |
| * Look for CIS/IDI sector on the first GOOD block (give up after 4 bad |
| * blocks). If the first good block doesn't contain CIS number the flash |
| * is not SSFDC formatted |
| */ |
| cis_sector = -1; |
| for (k = 0, offset = 0; k < 4; k++, offset += mtd->erasesize) { |
| if (!mtd->block_isbad(mtd, offset)) { |
| ret = mtd->read(mtd, offset, SECTOR_SIZE, &retlen, |
| sect_buf); |
| |
| /* CIS pattern match on the sector buffer */ |
| if ( ret < 0 || retlen != SECTOR_SIZE ) { |
| printk(KERN_WARNING |
| "SSFDC_RO:can't read CIS/IDI sector\n"); |
| } else if ( !memcmp(sect_buf, cis_numbers, |
| sizeof(cis_numbers)) ) { |
| /* Found */ |
| cis_sector = (int)(offset >> SECTOR_SHIFT); |
| } else { |
| DEBUG(MTD_DEBUG_LEVEL1, |
| "SSFDC_RO: CIS/IDI sector not found" |
| " on %s (mtd%d)\n", mtd->name, |
| mtd->index); |
| } |
| break; |
| } |
| } |
| |
| return cis_sector; |
| } |
| |
| /* Read physical sector (wrapper to MTD_READ) */ |
| static int read_physical_sector(struct mtd_info *mtd, uint8_t *sect_buf, |
| int sect_no) |
| { |
| int ret; |
| size_t retlen; |
| loff_t offset = (loff_t)sect_no << SECTOR_SHIFT; |
| |
| ret = mtd->read(mtd, offset, SECTOR_SIZE, &retlen, sect_buf); |
| if (ret < 0 || retlen != SECTOR_SIZE) |
| return -1; |
| |
| return 0; |
| } |
| |
| /* Read redundancy area (wrapper to MTD_READ_OOB */ |
| static int read_raw_oob(struct mtd_info *mtd, loff_t offs, uint8_t *buf) |
| { |
| struct mtd_oob_ops ops; |
| int ret; |
| |
| ops.mode = MTD_OOB_RAW; |
| ops.ooboffs = 0; |
| ops.ooblen = mtd->oobsize; |
| ops.len = OOB_SIZE; |
| ops.oobbuf = buf; |
| ops.datbuf = NULL; |
| |
| ret = mtd->read_oob(mtd, offs, &ops); |
| if (ret < 0 || ops.retlen != OOB_SIZE) |
| return -1; |
| |
| return 0; |
| } |
| |
| /* Parity calculator on a word of n bit size */ |
| static int get_parity(int number, int size) |
| { |
| int k; |
| int parity; |
| |
| parity = 1; |
| for (k = 0; k < size; k++) { |
| parity += (number >> k); |
| parity &= 1; |
| } |
| return parity; |
| } |
| |
| /* Read and validate the logical block address field stored in the OOB */ |
| static int get_logical_address(uint8_t *oob_buf) |
| { |
| int block_address, parity; |
| int offset[2] = {6, 11}; /* offset of the 2 address fields within OOB */ |
| int j; |
| int ok = 0; |
| |
| /* |
| * Look for the first valid logical address |
| * Valid address has fixed pattern on most significant bits and |
| * parity check |
| */ |
| for (j = 0; j < ARRAY_SIZE(offset); j++) { |
| block_address = ((int)oob_buf[offset[j]] << 8) | |
| oob_buf[offset[j]+1]; |
| |
| /* Check for the signature bits in the address field (MSBits) */ |
| if ((block_address & ~0x7FF) == 0x1000) { |
| parity = block_address & 0x01; |
| block_address &= 0x7FF; |
| block_address >>= 1; |
| |
| if (get_parity(block_address, 10) != parity) { |
| DEBUG(MTD_DEBUG_LEVEL0, |
| "SSFDC_RO: logical address field%d" |
| "parity error(0x%04X)\n", j+1, |
| block_address); |
| } else { |
| ok = 1; |
| break; |
| } |
| } |
| } |
| |
| if ( !ok ) |
| block_address = -2; |
| |
| DEBUG(MTD_DEBUG_LEVEL3, "SSFDC_RO: get_logical_address() %d\n", |
| block_address); |
| |
| return block_address; |
| } |
| |
| /* Build the logic block map */ |
| static int build_logical_block_map(struct ssfdcr_record *ssfdc) |
| { |
| unsigned long offset; |
| uint8_t oob_buf[OOB_SIZE]; |
| int ret, block_address, phys_block; |
| struct mtd_info *mtd = ssfdc->mbd.mtd; |
| |
| DEBUG(MTD_DEBUG_LEVEL1, "SSFDC_RO: build_block_map() nblks=%d (%luK)\n", |
| ssfdc->map_len, (unsigned long)ssfdc->map_len * |
| ssfdc->erase_size / 1024 ); |
| |
| /* Scan every physical block, skip CIS block */ |
| for (phys_block = ssfdc->cis_block + 1; phys_block < ssfdc->map_len; |
| phys_block++) { |
| offset = (unsigned long)phys_block * ssfdc->erase_size; |
| if (mtd->block_isbad(mtd, offset)) |
| continue; /* skip bad blocks */ |
| |
| ret = read_raw_oob(mtd, offset, oob_buf); |
| if (ret < 0) { |
| DEBUG(MTD_DEBUG_LEVEL0, |
| "SSFDC_RO: mtd read_oob() failed at %lu\n", |
| offset); |
| return -1; |
| } |
| block_address = get_logical_address(oob_buf); |
| |
| /* Skip invalid addresses */ |
| if (block_address >= 0 && |
| block_address < MAX_LOGIC_BLK_PER_ZONE) { |
| int zone_index; |
| |
| zone_index = phys_block / MAX_PHYS_BLK_PER_ZONE; |
| block_address += zone_index * MAX_LOGIC_BLK_PER_ZONE; |
| ssfdc->logic_block_map[block_address] = |
| (unsigned short)phys_block; |
| |
| DEBUG(MTD_DEBUG_LEVEL2, |
| "SSFDC_RO: build_block_map() phys_block=%d," |
| "logic_block_addr=%d, zone=%d\n", |
| phys_block, block_address, zone_index); |
| } |
| } |
| return 0; |
| } |
| |
| static void ssfdcr_add_mtd(struct mtd_blktrans_ops *tr, struct mtd_info *mtd) |
| { |
| struct ssfdcr_record *ssfdc; |
| int cis_sector; |
| |
| /* Check for small page NAND flash */ |
| if (mtd->type != MTD_NANDFLASH || mtd->oobsize != OOB_SIZE) |
| return; |
| |
| /* Check for SSDFC format by reading CIS/IDI sector */ |
| cis_sector = get_valid_cis_sector(mtd); |
| if (cis_sector == -1) |
| return; |
| |
| ssfdc = kzalloc(sizeof(struct ssfdcr_record), GFP_KERNEL); |
| if (!ssfdc) { |
| printk(KERN_WARNING |
| "SSFDC_RO: out of memory for data structures\n"); |
| return; |
| } |
| |
| ssfdc->mbd.mtd = mtd; |
| ssfdc->mbd.devnum = -1; |
| ssfdc->mbd.blksize = SECTOR_SIZE; |
| ssfdc->mbd.tr = tr; |
| ssfdc->mbd.readonly = 1; |
| |
| ssfdc->cis_block = cis_sector / (mtd->erasesize >> SECTOR_SHIFT); |
| ssfdc->erase_size = mtd->erasesize; |
| ssfdc->map_len = mtd->size / mtd->erasesize; |
| |
| DEBUG(MTD_DEBUG_LEVEL1, |
| "SSFDC_RO: cis_block=%d,erase_size=%d,map_len=%d,n_zones=%d\n", |
| ssfdc->cis_block, ssfdc->erase_size, ssfdc->map_len, |
| (ssfdc->map_len + MAX_PHYS_BLK_PER_ZONE - 1) / |
| MAX_PHYS_BLK_PER_ZONE); |
| |
| /* Set geometry */ |
| ssfdc->heads = 16; |
| ssfdc->sectors = 32; |
| get_chs( mtd->size, NULL, &ssfdc->heads, &ssfdc->sectors); |
| ssfdc->cylinders = (unsigned short)((mtd->size >> SECTOR_SHIFT) / |
| ((long)ssfdc->sectors * (long)ssfdc->heads)); |
| |
| DEBUG(MTD_DEBUG_LEVEL1, "SSFDC_RO: using C:%d H:%d S:%d == %ld sects\n", |
| ssfdc->cylinders, ssfdc->heads , ssfdc->sectors, |
| (long)ssfdc->cylinders * (long)ssfdc->heads * |
| (long)ssfdc->sectors ); |
| |
| ssfdc->mbd.size = (long)ssfdc->heads * (long)ssfdc->cylinders * |
| (long)ssfdc->sectors; |
| |
| /* Allocate logical block map */ |
| ssfdc->logic_block_map = kmalloc( sizeof(ssfdc->logic_block_map[0]) * |
| ssfdc->map_len, GFP_KERNEL); |
| if (!ssfdc->logic_block_map) { |
| printk(KERN_WARNING |
| "SSFDC_RO: out of memory for data structures\n"); |
| goto out_err; |
| } |
| memset(ssfdc->logic_block_map, 0xff, sizeof(ssfdc->logic_block_map[0]) * |
| ssfdc->map_len); |
| |
| /* Build logical block map */ |
| if (build_logical_block_map(ssfdc) < 0) |
| goto out_err; |
| |
| /* Register device + partitions */ |
| if (add_mtd_blktrans_dev(&ssfdc->mbd)) |
| goto out_err; |
| |
| printk(KERN_INFO "SSFDC_RO: Found ssfdc%c on mtd%d (%s)\n", |
| ssfdc->mbd.devnum + 'a', mtd->index, mtd->name); |
| return; |
| |
| out_err: |
| kfree(ssfdc->logic_block_map); |
| kfree(ssfdc); |
| } |
| |
| static void ssfdcr_remove_dev(struct mtd_blktrans_dev *dev) |
| { |
| struct ssfdcr_record *ssfdc = (struct ssfdcr_record *)dev; |
| |
| DEBUG(MTD_DEBUG_LEVEL1, "SSFDC_RO: remove_dev (i=%d)\n", dev->devnum); |
| |
| del_mtd_blktrans_dev(dev); |
| kfree(ssfdc->logic_block_map); |
| kfree(ssfdc); |
| } |
| |
| static int ssfdcr_readsect(struct mtd_blktrans_dev *dev, |
| unsigned long logic_sect_no, char *buf) |
| { |
| struct ssfdcr_record *ssfdc = (struct ssfdcr_record *)dev; |
| int sectors_per_block, offset, block_address; |
| |
| sectors_per_block = ssfdc->erase_size >> SECTOR_SHIFT; |
| offset = (int)(logic_sect_no % sectors_per_block); |
| block_address = (int)(logic_sect_no / sectors_per_block); |
| |
| DEBUG(MTD_DEBUG_LEVEL3, |
| "SSFDC_RO: ssfdcr_readsect(%lu) sec_per_blk=%d, ofst=%d," |
| " block_addr=%d\n", logic_sect_no, sectors_per_block, offset, |
| block_address); |
| |
| if (block_address >= ssfdc->map_len) |
| BUG(); |
| |
| block_address = ssfdc->logic_block_map[block_address]; |
| |
| DEBUG(MTD_DEBUG_LEVEL3, |
| "SSFDC_RO: ssfdcr_readsect() phys_block_addr=%d\n", |
| block_address); |
| |
| if (block_address < 0xffff) { |
| unsigned long sect_no; |
| |
| sect_no = (unsigned long)block_address * sectors_per_block + |
| offset; |
| |
| DEBUG(MTD_DEBUG_LEVEL3, |
| "SSFDC_RO: ssfdcr_readsect() phys_sect_no=%lu\n", |
| sect_no); |
| |
| if (read_physical_sector( ssfdc->mbd.mtd, buf, sect_no ) < 0) |
| return -EIO; |
| } else { |
| memset(buf, 0xff, SECTOR_SIZE); |
| } |
| |
| return 0; |
| } |
| |
| static int ssfdcr_getgeo(struct mtd_blktrans_dev *dev, struct hd_geometry *geo) |
| { |
| struct ssfdcr_record *ssfdc = (struct ssfdcr_record *)dev; |
| |
| DEBUG(MTD_DEBUG_LEVEL1, "SSFDC_RO: ssfdcr_getgeo() C=%d, H=%d, S=%d\n", |
| ssfdc->cylinders, ssfdc->heads, ssfdc->sectors); |
| |
| geo->heads = ssfdc->heads; |
| geo->sectors = ssfdc->sectors; |
| geo->cylinders = ssfdc->cylinders; |
| |
| return 0; |
| } |
| |
| /**************************************************************************** |
| * |
| * Module stuff |
| * |
| ****************************************************************************/ |
| |
| static struct mtd_blktrans_ops ssfdcr_tr = { |
| .name = "ssfdc", |
| .major = SSFDCR_MAJOR, |
| .part_bits = SSFDCR_PARTN_BITS, |
| .getgeo = ssfdcr_getgeo, |
| .readsect = ssfdcr_readsect, |
| .add_mtd = ssfdcr_add_mtd, |
| .remove_dev = ssfdcr_remove_dev, |
| .owner = THIS_MODULE, |
| }; |
| |
| static int __init init_ssfdcr(void) |
| { |
| printk(KERN_INFO "SSFDC read-only Flash Translation layer\n"); |
| |
| return register_mtd_blktrans(&ssfdcr_tr); |
| } |
| |
| static void __exit cleanup_ssfdcr(void) |
| { |
| deregister_mtd_blktrans(&ssfdcr_tr); |
| } |
| |
| module_init(init_ssfdcr); |
| module_exit(cleanup_ssfdcr); |
| |
| MODULE_LICENSE("GPL"); |
| MODULE_AUTHOR("Claudio Lanconelli <lanconelli.claudio@eptar.com>"); |
| MODULE_DESCRIPTION("Flash Translation Layer for read-only SSFDC SmartMedia card"); |