diff options
Diffstat (limited to 'drivers/mtd/nand/docg4.c')
| -rw-r--r-- | drivers/mtd/nand/docg4.c | 73 |
1 files changed, 64 insertions, 9 deletions
diff --git a/drivers/mtd/nand/docg4.c b/drivers/mtd/nand/docg4.c index 799da5d1c857..18fa4489e52e 100644 --- a/drivers/mtd/nand/docg4.c +++ b/drivers/mtd/nand/docg4.c @@ -46,6 +46,25 @@ #include <linux/bitrev.h> /* + * In "reliable mode" consecutive 2k pages are used in parallel (in some + * fashion) to store the same data. The data can be read back from the + * even-numbered pages in the normal manner; odd-numbered pages will appear to + * contain junk. Systems that boot from the docg4 typically write the secondary + * program loader (SPL) code in this mode. The SPL is loaded by the initial + * program loader (IPL, stored in the docg4's 2k NOR-like region that is mapped + * to the reset vector address). This module parameter enables you to use this + * driver to write the SPL. When in this mode, no more than 2k of data can be + * written at a time, because the addresses do not increment in the normal + * manner, and the starting offset must be within an even-numbered 2k region; + * i.e., invalid starting offsets are 0x800, 0xa00, 0xc00, 0xe00, 0x1800, + * 0x1a00, ... Reliable mode is a special case and should not be used unless + * you know what you're doing. + */ +static bool reliable_mode; +module_param(reliable_mode, bool, 0); +MODULE_PARM_DESC(reliable_mode, "pages are programmed in reliable mode"); + +/* * You'll want to ignore badblocks if you're reading a partition that contains * data written by the TrueFFS library (i.e., by PalmOS, Windows, etc), since * it does not use mtd nand's method for marking bad blocks (using oob area). @@ -113,6 +132,7 @@ struct docg4_priv { #define DOCG4_SEQ_PAGEWRITE 0x16 #define DOCG4_SEQ_PAGEPROG 0x1e #define DOCG4_SEQ_BLOCKERASE 0x24 +#define DOCG4_SEQ_SETMODE 0x45 /* DOC_FLASHCOMMAND register commands */ #define DOCG4_CMD_PAGE_READ 0x00 @@ -122,6 +142,8 @@ struct docg4_priv { #define DOC_CMD_PROG_BLOCK_ADDR 0x60 #define DOCG4_CMD_PAGEWRITE 0x80 #define DOC_CMD_PROG_CYCLE2 0x10 +#define DOCG4_CMD_FAST_MODE 0xa3 /* functionality guessed */ +#define DOC_CMD_RELIABLE_MODE 0x22 #define DOC_CMD_RESET 0xff /* DOC_POWERMODE register bits */ @@ -190,17 +212,20 @@ struct docg4_priv { #define DOCG4_T 4 /* BCH alg corrects up to 4 bit errors */ #define DOCG4_FACTORY_BBT_PAGE 16 /* page where read-only factory bbt lives */ +#define DOCG4_REDUNDANT_BBT_PAGE 24 /* page where redundant factory bbt lives */ /* - * Oob bytes 0 - 6 are available to the user. - * Byte 7 is hamming ecc for first 7 bytes. Bytes 8 - 14 are hw-generated ecc. + * Bytes 0, 1 are used as badblock marker. + * Bytes 2 - 6 are available to the user. + * Byte 7 is hamming ecc for first 7 oob bytes only. + * Bytes 8 - 14 are hw-generated ecc covering entire page + oob bytes 0 - 14. * Byte 15 (the last) is used by the driver as a "page written" flag. */ static struct nand_ecclayout docg4_oobinfo = { .eccbytes = 9, .eccpos = {7, 8, 9, 10, 11, 12, 13, 14, 15}, - .oobavail = 7, - .oobfree = { {0, 7} } + .oobavail = 5, + .oobfree = { {.offset = 2, .length = 5} } }; /* @@ -611,6 +636,14 @@ static void write_page_prologue(struct mtd_info *mtd, uint32_t docg4_addr) dev_dbg(doc->dev, "docg4: %s: g4 addr: %x\n", __func__, docg4_addr); sequence_reset(mtd); + + if (unlikely(reliable_mode)) { + writew(DOCG4_SEQ_SETMODE, docptr + DOC_FLASHSEQUENCE); + writew(DOCG4_CMD_FAST_MODE, docptr + DOC_FLASHCOMMAND); + writew(DOC_CMD_RELIABLE_MODE, docptr + DOC_FLASHCOMMAND); + write_nop(docptr); + } + writew(DOCG4_SEQ_PAGEWRITE, docptr + DOC_FLASHSEQUENCE); writew(DOCG4_CMD_PAGEWRITE, docptr + DOC_FLASHCOMMAND); write_nop(docptr); @@ -691,6 +724,15 @@ static void docg4_command(struct mtd_info *mtd, unsigned command, int column, break; case NAND_CMD_SEQIN: + if (unlikely(reliable_mode)) { + uint16_t g4_page = g4_addr >> 16; + + /* writes to odd-numbered 2k pages are invalid */ + if (g4_page & 0x01) + dev_warn(doc->dev, + "invalid reliable mode address\n"); + } + write_page_prologue(mtd, g4_addr); /* hack for deferred write of oob bytes */ @@ -979,16 +1021,15 @@ static int __init read_factory_bbt(struct mtd_info *mtd) struct docg4_priv *doc = nand->priv; uint32_t g4_addr = mtd_to_docg4_address(DOCG4_FACTORY_BBT_PAGE, 0); uint8_t *buf; - int i, block, status; + int i, block; + __u32 eccfailed_stats = mtd->ecc_stats.failed; buf = kzalloc(DOCG4_PAGE_SIZE, GFP_KERNEL); if (buf == NULL) return -ENOMEM; read_page_prologue(mtd, g4_addr); - status = docg4_read_page(mtd, nand, buf, 0, DOCG4_FACTORY_BBT_PAGE); - if (status) - goto exit; + docg4_read_page(mtd, nand, buf, 0, DOCG4_FACTORY_BBT_PAGE); /* * If no memory-based bbt was created, exit. This will happen if module @@ -1000,6 +1041,20 @@ static int __init read_factory_bbt(struct mtd_info *mtd) if (nand->bbt == NULL) /* no memory-based bbt */ goto exit; + if (mtd->ecc_stats.failed > eccfailed_stats) { + /* + * Whoops, an ecc failure ocurred reading the factory bbt. + * It is stored redundantly, so we get another chance. + */ + eccfailed_stats = mtd->ecc_stats.failed; + docg4_read_page(mtd, nand, buf, 0, DOCG4_REDUNDANT_BBT_PAGE); + if (mtd->ecc_stats.failed > eccfailed_stats) { + dev_warn(doc->dev, + "The factory bbt could not be read!\n"); + goto exit; + } + } + /* * Parse factory bbt and update memory-based bbt. Factory bbt format is * simple: one bit per block, block numbers increase left to right (msb @@ -1019,7 +1074,7 @@ static int __init read_factory_bbt(struct mtd_info *mtd) } exit: kfree(buf); - return status; + return 0; } static int docg4_block_markbad(struct mtd_info *mtd, loff_t ofs) |