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Diffstat (limited to 'drivers/mtd/nand/docg4.c')
| -rw-r--r-- | drivers/mtd/nand/docg4.c | 1377 |
1 files changed, 1377 insertions, 0 deletions
diff --git a/drivers/mtd/nand/docg4.c b/drivers/mtd/nand/docg4.c new file mode 100644 index 0000000..b082026 --- /dev/null +++ b/drivers/mtd/nand/docg4.c @@ -0,0 +1,1377 @@ +/* + * Copyright © 2012 Mike Dunn <mikedunn@newsguy.com> + * + * mtd nand driver for M-Systems DiskOnChip G4 + * + * 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 of the License, or + * (at your option) any later version. + * + * Tested on the Palm Treo 680. The G4 is also present on Toshiba Portege, Asus + * P526, some HTC smartphones (Wizard, Prophet, ...), O2 XDA Zinc, maybe others. + * Should work on these as well. Let me know! + * + * TODO: + * + * Mechanism for management of password-protected areas + * + * Hamming ecc when reading oob only + * + * According to the M-Sys documentation, this device is also available in a + * "dual-die" configuration having a 256MB capacity, but no mechanism for + * detecting this variant is documented. Currently this driver assumes 128MB + * capacity. + * + * Support for multiple cascaded devices ("floors"). Not sure which gadgets + * contain multiple G4s in a cascaded configuration, if any. + * + */ + +#include <linux/kernel.h> +#include <linux/slab.h> +#include <linux/init.h> +#include <linux/string.h> +#include <linux/sched.h> +#include <linux/delay.h> +#include <linux/module.h> +#include <linux/export.h> +#include <linux/platform_device.h> +#include <linux/io.h> +#include <linux/bitops.h> +#include <linux/mtd/partitions.h> +#include <linux/mtd/mtd.h> +#include <linux/mtd/nand.h> +#include <linux/bch.h> +#include <linux/bitrev.h> + +/* + * 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). + * This will also skip the check of the "page written" flag. + */ +static bool ignore_badblocks; +module_param(ignore_badblocks, bool, 0); +MODULE_PARM_DESC(ignore_badblocks, "no badblock checking performed"); + +struct docg4_priv { + struct mtd_info *mtd; + struct device *dev; + void __iomem *virtadr; + int status; + struct { + unsigned int command; + int column; + int page; + } last_command; + uint8_t oob_buf[16]; + uint8_t ecc_buf[7]; + int oob_page; + struct bch_control *bch; +}; + +/* + * Defines prefixed with DOCG4 are unique to the diskonchip G4. All others are + * shared with other diskonchip devices (P3, G3 at least). + * + * Functions with names prefixed with docg4_ are mtd / nand interface functions + * (though they may also be called internally). All others are internal. + */ + +#define DOC_IOSPACE_DATA 0x0800 + +/* register offsets */ +#define DOC_CHIPID 0x1000 +#define DOC_DEVICESELECT 0x100a +#define DOC_ASICMODE 0x100c +#define DOC_DATAEND 0x101e +#define DOC_NOP 0x103e + +#define DOC_FLASHSEQUENCE 0x1032 +#define DOC_FLASHCOMMAND 0x1034 +#define DOC_FLASHADDRESS 0x1036 +#define DOC_FLASHCONTROL 0x1038 +#define DOC_ECCCONF0 0x1040 +#define DOC_ECCCONF1 0x1042 +#define DOC_HAMMINGPARITY 0x1046 +#define DOC_BCH_SYNDROM(idx) (0x1048 + idx) + +#define DOC_ASICMODECONFIRM 0x1072 +#define DOC_CHIPID_INV 0x1074 +#define DOC_POWERMODE 0x107c + +#define DOCG4_MYSTERY_REG 0x1050 + +/* apparently used only to write oob bytes 6 and 7 */ +#define DOCG4_OOB_6_7 0x1052 + +/* DOC_FLASHSEQUENCE register commands */ +#define DOC_SEQ_RESET 0x00 +#define DOCG4_SEQ_PAGE_READ 0x03 +#define DOCG4_SEQ_FLUSH 0x29 +#define DOCG4_SEQ_PAGEWRITE 0x16 +#define DOCG4_SEQ_PAGEPROG 0x1e +#define DOCG4_SEQ_BLOCKERASE 0x24 + +/* DOC_FLASHCOMMAND register commands */ +#define DOCG4_CMD_PAGE_READ 0x00 +#define DOC_CMD_ERASECYCLE2 0xd0 +#define DOCG4_CMD_FLUSH 0x70 +#define DOCG4_CMD_READ2 0x30 +#define DOC_CMD_PROG_BLOCK_ADDR 0x60 +#define DOCG4_CMD_PAGEWRITE 0x80 +#define DOC_CMD_PROG_CYCLE2 0x10 +#define DOC_CMD_RESET 0xff + +/* DOC_POWERMODE register bits */ +#define DOC_POWERDOWN_READY 0x80 + +/* DOC_FLASHCONTROL register bits */ +#define DOC_CTRL_CE 0x10 +#define DOC_CTRL_UNKNOWN 0x40 +#define DOC_CTRL_FLASHREADY 0x01 + +/* DOC_ECCCONF0 register bits */ +#define DOC_ECCCONF0_READ_MODE 0x8000 +#define DOC_ECCCONF0_UNKNOWN 0x2000 +#define DOC_ECCCONF0_ECC_ENABLE 0x1000 +#define DOC_ECCCONF0_DATA_BYTES_MASK 0x07ff + +/* DOC_ECCCONF1 register bits */ +#define DOC_ECCCONF1_BCH_SYNDROM_ERR 0x80 +#define DOC_ECCCONF1_ECC_ENABLE 0x07 +#define DOC_ECCCONF1_PAGE_IS_WRITTEN 0x20 + +/* DOC_ASICMODE register bits */ +#define DOC_ASICMODE_RESET 0x00 +#define DOC_ASICMODE_NORMAL 0x01 +#define DOC_ASICMODE_POWERDOWN 0x02 +#define DOC_ASICMODE_MDWREN 0x04 +#define DOC_ASICMODE_BDETCT_RESET 0x08 +#define DOC_ASICMODE_RSTIN_RESET 0x10 +#define DOC_ASICMODE_RAM_WE 0x20 + +/* good status values read after read/write/erase operations */ +#define DOCG4_PROGSTATUS_GOOD 0x51 +#define DOCG4_PROGSTATUS_GOOD_2 0xe0 + +/* + * On read operations (page and oob-only), the first byte read from I/O reg is a + * status. On error, it reads 0x73; otherwise, it reads either 0x71 (first read + * after reset only) or 0x51, so bit 1 is presumed to be an error indicator. + */ +#define DOCG4_READ_ERROR 0x02 /* bit 1 indicates read error */ + +/* anatomy of the device */ +#define DOCG4_CHIP_SIZE 0x8000000 +#define DOCG4_PAGE_SIZE 0x200 +#define DOCG4_PAGES_PER_BLOCK 0x200 +#define DOCG4_BLOCK_SIZE (DOCG4_PAGES_PER_BLOCK * DOCG4_PAGE_SIZE) +#define DOCG4_NUMBLOCKS (DOCG4_CHIP_SIZE / DOCG4_BLOCK_SIZE) +#define DOCG4_OOB_SIZE 0x10 +#define DOCG4_CHIP_SHIFT 27 /* log_2(DOCG4_CHIP_SIZE) */ +#define DOCG4_PAGE_SHIFT 9 /* log_2(DOCG4_PAGE_SIZE) */ +#define DOCG4_ERASE_SHIFT 18 /* log_2(DOCG4_BLOCK_SIZE) */ + +/* all but the last byte is included in ecc calculation */ +#define DOCG4_BCH_SIZE (DOCG4_PAGE_SIZE + DOCG4_OOB_SIZE - 1) + +#define DOCG4_USERDATA_LEN 520 /* 512 byte page plus 8 oob avail to user */ + +/* expected values from the ID registers */ +#define DOCG4_IDREG1_VALUE 0x0400 +#define DOCG4_IDREG2_VALUE 0xfbff + +/* primitive polynomial used to build the Galois field used by hw ecc gen */ +#define DOCG4_PRIMITIVE_POLY 0x4443 + +#define DOCG4_M 14 /* Galois field is of order 2^14 */ +#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 */ + +/* + * 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. + * 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} } +}; + +/* + * The device has a nop register which M-Sys claims is for the purpose of + * inserting precise delays. But beware; at least some operations fail if the + * nop writes are replaced with a generic delay! + */ +static inline void write_nop(void __iomem *docptr) +{ + writew(0, docptr + DOC_NOP); +} + +static void docg4_read_buf(struct mtd_info *mtd, uint8_t *buf, int len) +{ + int i; + struct nand_chip *nand = mtd->priv; + uint16_t *p = (uint16_t *) buf; + len >>= 1; + + for (i = 0; i < len; i++) + p[i] = readw(nand->IO_ADDR_R); +} + +static void docg4_write_buf16(struct mtd_info *mtd, const uint8_t *buf, int len) +{ + int i; + struct nand_chip *nand = mtd->priv; + uint16_t *p = (uint16_t *) buf; + len >>= 1; + + for (i = 0; i < len; i++) + writew(p[i], nand->IO_ADDR_W); +} + +static int poll_status(struct docg4_priv *doc) +{ + /* + * Busy-wait for the FLASHREADY bit to be set in the FLASHCONTROL + * register. Operations known to take a long time (e.g., block erase) + * should sleep for a while before calling this. + */ + + uint16_t flash_status; + unsigned int timeo; + void __iomem *docptr = doc->virtadr; + + dev_dbg(doc->dev, "%s...\n", __func__); + + /* hardware quirk requires reading twice initially */ + flash_status = readw(docptr + DOC_FLASHCONTROL); + + timeo = 1000; + do { + cpu_relax(); + flash_status = readb(docptr + DOC_FLASHCONTROL); + } while (!(flash_status & DOC_CTRL_FLASHREADY) && --timeo); + + + if (!timeo) { + dev_err(doc->dev, "%s: timed out!\n", __func__); + return NAND_STATUS_FAIL; + } + + if (unlikely(timeo < 50)) + dev_warn(doc->dev, "%s: nearly timed out; %d remaining\n", + __func__, timeo); + + return 0; +} + + +static int docg4_wait(struct mtd_info *mtd, struct nand_chip *nand) +{ + + struct docg4_priv *doc = nand->priv; + int status = NAND_STATUS_WP; /* inverse logic?? */ + dev_dbg(doc->dev, "%s...\n", __func__); + + /* report any previously unreported error */ + if (doc->status) { + status |= doc->status; + doc->status = 0; + return status; + } + + status |= poll_status(doc); + return status; +} + +static void docg4_select_chip(struct mtd_info *mtd, int chip) +{ + /* + * Select among multiple cascaded chips ("floors"). Multiple floors are + * not yet supported, so the only valid non-negative value is 0. + */ + struct nand_chip *nand = mtd->priv; + struct docg4_priv *doc = nand->priv; + void __iomem *docptr = doc->virtadr; + + dev_dbg(doc->dev, "%s: chip %d\n", __func__, chip); + + if (chip < 0) + return; /* deselected */ + + if (chip > 0) + dev_warn(doc->dev, "multiple floors currently unsupported\n"); + + writew(0, docptr + DOC_DEVICESELECT); +} + +static void reset(struct mtd_info *mtd) +{ + /* full device reset */ + + struct nand_chip *nand = mtd->priv; + struct docg4_priv *doc = nand->priv; + void __iomem *docptr = doc->virtadr; + + writew(DOC_ASICMODE_RESET | DOC_ASICMODE_MDWREN, + docptr + DOC_ASICMODE); + writew(~(DOC_ASICMODE_RESET | DOC_ASICMODE_MDWREN), + docptr + DOC_ASICMODECONFIRM); + write_nop(docptr); + + writew(DOC_ASICMODE_NORMAL | DOC_ASICMODE_MDWREN, + docptr + DOC_ASICMODE); + writew(~(DOC_ASICMODE_NORMAL | DOC_ASICMODE_MDWREN), + docptr + DOC_ASICMODECONFIRM); + + writew(DOC_ECCCONF1_ECC_ENABLE, docptr + DOC_ECCCONF1); + + poll_status(doc); +} + +static void read_hw_ecc(void __iomem *docptr, uint8_t *ecc_buf) +{ + /* read the 7 hw-generated ecc bytes */ + + int i; + for (i = 0; i < 7; i++) { /* hw quirk; read twice */ + ecc_buf[i] = readb(docptr + DOC_BCH_SYNDROM(i)); + ecc_buf[i] = readb(docptr + DOC_BCH_SYNDROM(i)); + } +} + +static int correct_data(struct mtd_info *mtd, uint8_t *buf, int page) +{ + /* + * Called after a page read when hardware reports bitflips. + * Up to four bitflips can be corrected. + */ + + struct nand_chip *nand = mtd->priv; + struct docg4_priv *doc = nand->priv; + void __iomem *docptr = doc->virtadr; + int i, numerrs, errpos[4]; + const uint8_t blank_read_hwecc[8] = { + 0xcf, 0x72, 0xfc, 0x1b, 0xa9, 0xc7, 0xb9, 0 }; + + read_hw_ecc(docptr, doc->ecc_buf); /* read 7 hw-generated ecc bytes */ + + /* check if read error is due to a blank page */ + if (!memcmp(doc->ecc_buf, blank_read_hwecc, 7)) + return 0; /* yes */ + + /* skip additional check of "written flag" if ignore_badblocks */ + if (ignore_badblocks == false) { + + /* + * If the hw ecc bytes are not those of a blank page, there's + * still a chance that the page is blank, but was read with + * errors. Check the "written flag" in last oob byte, which + * is set to zero when a page is written. If more than half + * the bits are set, assume a blank page. Unfortunately, the + * bit flips(s) are not reported in stats. + */ + + if (doc->oob_buf[15]) { + int bit, numsetbits = 0; + unsigned long written_flag = doc->oob_buf[15]; + for_each_set_bit(bit, &written_flag, 8) + numsetbits++; + if (numsetbits > 4) { /* assume blank */ + dev_warn(doc->dev, + "error(s) in blank page " + "at offset %08x\n", + page * DOCG4_PAGE_SIZE); + return 0; + } + } + } + + /* + * The hardware ecc unit produces oob_ecc ^ calc_ecc. The kernel's bch + * algorithm is used to decode this. However the hw operates on page + * data in a bit order that is the reverse of that of the bch alg, + * requiring that the bits be reversed on the result. Thanks to Ivan + * Djelic for his analysis! + */ + for (i = 0; i < 7; i++) + doc->ecc_buf[i] = bitrev8(doc->ecc_buf[i]); + + numerrs = decode_bch(doc->bch, NULL, DOCG4_USERDATA_LEN, NULL, + doc->ecc_buf, NULL, errpos); + + if (numerrs == -EBADMSG) { + dev_warn(doc->dev, "uncorrectable errors at offset %08x\n", + page * DOCG4_PAGE_SIZE); + return -EBADMSG; + } + + BUG_ON(numerrs < 0); /* -EINVAL, or anything other than -EBADMSG */ + + /* undo last step in BCH alg (modulo mirroring not needed) */ + for (i = 0; i < numerrs; i++) + errpos[i] = (errpos[i] & ~7)|(7-(errpos[i] & 7)); + + /* fix the errors */ + for (i = 0; i < numerrs; i++) { + + /* ignore if error within oob ecc bytes */ + if (errpos[i] > DOCG4_USERDATA_LEN * 8) + continue; + + /* if error within oob area preceeding ecc bytes... */ + if (errpos[i] > DOCG4_PAGE_SIZE * 8) + change_bit(errpos[i] - DOCG4_PAGE_SIZE * 8, + (unsigned long *)doc->oob_buf); + + else /* error in page data */ + change_bit(errpos[i], (unsigned long *)buf); + } + + dev_notice(doc->dev, "%d error(s) corrected at offset %08x\n", + numerrs, page * DOCG4_PAGE_SIZE); + + return numerrs; +} + +static uint8_t docg4_read_byte(struct mtd_info *mtd) +{ + struct nand_chip *nand = mtd->priv; + struct docg4_priv *doc = nand->priv; + + dev_dbg(doc->dev, "%s\n", __func__); + + if (doc->last_command.command == NAND_CMD_STATUS) { + int status; + + /* + * Previous nand command was status request, so nand + * infrastructure code expects to read the status here. If an + * error occurred in a previous operation, report it. + */ + doc->last_command.command = 0; + + if (doc->status) { + status = doc->status; + doc->status = 0; + } + + /* why is NAND_STATUS_WP inverse logic?? */ + else + status = NAND_STATUS_WP | NAND_STATUS_READY; + + return status; + } + + dev_warn(doc->dev, "unexpectd call to read_byte()\n"); + + return 0; +} + +static void write_addr(struct docg4_priv *doc, uint32_t docg4_addr) +{ + /* write the four address bytes packed in docg4_addr to the device */ + + void __iomem *docptr = doc->virtadr; + writeb(docg4_addr & 0xff, docptr + DOC_FLASHADDRESS); + docg4_addr >>= 8; + writeb(docg4_addr & 0xff, docptr + DOC_FLASHADDRESS); + docg4_addr >>= 8; + writeb(docg4_addr & 0xff, docptr + DOC_FLASHADDRESS); + docg4_addr >>= 8; + writeb(docg4_addr & 0xff, docptr + DOC_FLASHADDRESS); +} + +static int read_progstatus(struct docg4_priv *doc) +{ + /* + * This apparently checks the status of programming. Done after an + * erasure, and after page data is written. On error, the status is + * saved, to be later retrieved by the nand infrastructure code. + */ + void __iomem *docptr = doc->virtadr; + + /* status is read from the I/O reg */ + uint16_t status1 = readw(docptr + DOC_IOSPACE_DATA); + uint16_t status2 = readw(docptr + DOC_IOSPACE_DATA); + uint16_t status3 = readw(docptr + DOCG4_MYSTERY_REG); + + dev_dbg(doc->dev, "docg4: %s: %02x %02x %02x\n", + __func__, status1, status2, status3); + + if (status1 != DOCG4_PROGSTATUS_GOOD + || status2 != DOCG4_PROGSTATUS_GOOD_2 + || status3 != DOCG4_PROGSTATUS_GOOD_2) { + doc->status = NAND_STATUS_FAIL; + dev_warn(doc->dev, "read_progstatus failed: " + "%02x, %02x, %02x\n", status1, status2, status3); + return -EIO; + } + return 0; +} + +static int pageprog(struct mtd_info *mtd) +{ + /* + * Final step in writing a page. Writes the contents of its + * internal buffer out to the flash array, or some such. + */ + + struct nand_chip *nand = mtd->priv; + struct docg4_priv *doc = nand->priv; + void __iomem *docptr = doc->virtadr; + int retval = 0; + + dev_dbg(doc->dev, "docg4: %s\n", __func__); + + writew(DOCG4_SEQ_PAGEPROG, docptr + DOC_FLASHSEQUENCE); + writew(DOC_CMD_PROG_CYCLE2, docptr + DOC_FLASHCOMMAND); + write_nop(docptr); + write_nop(docptr); + + /* Just busy-wait; usleep_range() slows things down noticeably. */ + poll_status(doc); + + writew(DOCG4_SEQ_FLUSH, docptr + DOC_FLASHSEQUENCE); + writew(DOCG4_CMD_FLUSH, docptr + DOC_FLASHCOMMAND); + writew(DOC_ECCCONF0_READ_MODE | 4, docptr + DOC_ECCCONF0); + write_nop(docptr); + write_nop(docptr); + write_nop(docptr); + write_nop(docptr); + write_nop(docptr); + + retval = read_progstatus(doc); + writew(0, docptr + DOC_DATAEND); + write_nop(docptr); + poll_status(doc); + write_nop(docptr); + + return retval; +} + +static void sequence_reset(struct mtd_info *mtd) +{ + /* common starting sequence for all operations */ + + struct nand_chip *nand = mtd->priv; + struct docg4_priv *doc = nand->priv; + void __iomem *docptr = doc->virtadr; + + writew(DOC_CTRL_UNKNOWN | DOC_CTRL_CE, docptr + DOC_FLASHCONTROL); + writew(DOC_SEQ_RESET, docptr + DOC_FLASHSEQUENCE); + writew(DOC_CMD_RESET, docptr + DOC_FLASHCOMMAND); + write_nop(docptr); + write_nop(docptr); + poll_status(doc); + write_nop(docptr); +} + +static void read_page_prologue(struct mtd_info *mtd, uint32_t docg4_addr) +{ + /* first step in reading a page */ + + struct nand_chip *nand = mtd->priv; + struct docg4_priv *doc = nand->priv; + void __iomem *docptr = doc->virtadr; + + dev_dbg(doc->dev, + "docg4: %s: g4 page %08x\n", __func__, docg4_addr); + + sequence_reset(mtd); + + writew(DOCG4_SEQ_PAGE_READ, docptr + DOC_FLASHSEQUENCE); + writew(DOCG4_CMD_PAGE_READ, docptr + DOC_FLASHCOMMAND); + write_nop(docptr); + + write_addr(doc, docg4_addr); + + write_nop(docptr); + writew(DOCG4_CMD_READ2, docptr + DOC_FLASHCOMMAND); + write_nop(docptr); + write_nop(docptr); + + poll_status(doc); +} + +static void write_page_prologue(struct mtd_info *mtd, uint32_t docg4_addr) +{ + /* first step in writing a page */ + + struct nand_chip *nand = mtd->priv; + struct docg4_priv *doc = nand->priv; + void __iomem *docptr = doc->virtadr; + + dev_dbg(doc->dev, + "docg4: %s: g4 addr: %x\n", __func__, docg4_addr); + sequence_reset(mtd); + writew(DOCG4_SEQ_PAGEWRITE, docptr + DOC_FLASHSEQUENCE); + writew(DOCG4_CMD_PAGEWRITE, docptr + DOC_FLASHCOMMAND); + write_nop(docptr); + write_addr(doc, docg4_addr); + write_nop(docptr); + write_nop(docptr); + poll_status(doc); +} + +static uint32_t mtd_to_docg4_address(int page, int column) +{ + /* + * Convert mtd address to format used by the device, 32 bit packed. + * + * Some notes on G4 addressing... The M-Sys documentation on this device + * claims that pages are 2K in length, and indeed, the format of the + * address used by the device reflects that. But within each page are + * four 512 byte "sub-pages", each with its own oob data that is + * read/written immediately after the 512 bytes of page data. This oob + * data contains the ecc bytes for the preceeding 512 bytes. + * + * Rather than tell the mtd nand infrastructure that page size is 2k, + * with four sub-pages each, we engage in a little subterfuge and tell + * the infrastructure code that pages are 512 bytes in size. This is + * done because during the course of reverse-engineering the device, I + * never observed an instance where an entire 2K "page" was read or + * written as a unit. Each "sub-page" is always addressed individually, + * its data read/written, and ecc handled before the next "sub-page" is + * addressed. + * + * This requires us to convert addresses passed by the mtd nand + * infrastructure code to those used by the device. + * + * The address that is written to the device consists of four bytes: the + * first two are the 2k page number, and the second is the index into + * the page. The index is in terms of 16-bit half-words and includes + * the preceeding oob data, so e.g., the index into the second + * "sub-page" is 0x108, and the full device address of the start of mtd + * page 0x201 is 0x00800108. + */ + int g4_page = page / 4; /* device's 2K page */ + int g4_index = (page % 4) * 0x108 + column/2; /* offset into page */ + return (g4_page << 16) | g4_index; /* pack */ +} + +static void docg4_command(struct mtd_info *mtd, unsigned command, int column, + int page_addr) +{ + /* handle standard nand commands */ + + struct nand_chip *nand = mtd->priv; + struct docg4_priv *doc = nand->priv; + uint32_t g4_addr = mtd_to_docg4_address(page_addr, column); + + dev_dbg(doc->dev, "%s %x, page_addr=%x, column=%x\n", + __func__, command, page_addr, column); + + /* + * Save the command and its arguments. This enables emulation of + * standard flash devices, and also some optimizations. + */ + doc->last_command.command = command; + doc->last_command.column = column; + doc->last_command.page = page_addr; + + switch (command) { + + case NAND_CMD_RESET: + reset(mtd); + break; + + case NAND_CMD_READ0: + read_page_prologue(mtd, g4_addr); + break; + + case NAND_CMD_STATUS: + /* next call to read_byte() will expect a status */ + break; + + case NAND_CMD_SEQIN: + write_page_prologue(mtd, g4_addr); + + /* hack for deferred write of oob bytes */ + if (doc->oob_page == page_addr) + memcpy(nand->oob_poi, doc->oob_buf, 16); + break; + + case NAND_CMD_PAGEPROG: + pageprog(mtd); + break; + + /* we don't expect these, based on review of nand_base.c */ + case NAND_CMD_READOOB: + case NAND_CMD_READID: + case NAND_CMD_ERASE1: + case NAND_CMD_ERASE2: + dev_warn(doc->dev, "docg4_command: " + "unexpected nand command 0x%x\n", command); + break; + + } +} + +static int read_page(struct mtd_info *mtd, struct nand_chip *nand, + uint8_t *buf, int page, bool use_ecc) +{ + struct docg4_priv *doc = nand->priv; + void __iomem *docptr = doc->virtadr; + uint16_t status, edc_err, *buf16; + + dev_dbg(doc->dev, "%s: page %08x\n", __func__, page); + + writew(DOC_ECCCONF0_READ_MODE | + DOC_ECCCONF0_ECC_ENABLE | + DOC_ECCCONF0_UNKNOWN | + DOCG4_BCH_SIZE, + docptr + DOC_ECCCONF0); + write_nop(docptr); + write_nop(docptr); + write_nop(docptr); + write_nop(docptr); + write_nop(docptr); + + /* the 1st byte from the I/O reg is a status; the rest is page data */ + status = readw(docptr + DOC_IOSPACE_DATA); + if (status & DOCG4_READ_ERROR) { + dev_err(doc->dev, + "docg4_read_page: bad status: 0x%02x\n", status); + writew(0, docptr + DOC_DATAEND); + return -EIO; + } + + dev_dbg(doc->dev, "%s: status = 0x%x\n", __func__, status); + + docg4_read_buf(mtd, buf, DOCG4_PAGE_SIZE); /* read the page data */ + + /* + * Diskonchips read oob immediately after a page read. Mtd + * infrastructure issues a separate command for reading oob after the + * page is read. So we save the oob bytes in a local buffer and just + * copy it if the next command reads oob from the same page. + */ + + /* first 14 oob bytes read from I/O reg */ + docg4_read_buf(mtd, doc->oob_buf, 14); + + /* last 2 read from another reg */ + buf16 = (uint16_t *)(doc->oob_buf + 14); + *buf16 = readw(docptr + DOCG4_MYSTERY_REG); + + write_nop(docptr); + + if (likely(use_ecc == true)) { + + /* read the register that tells us if bitflip(s) detected */ + edc_err = readw(docptr + DOC_ECCCONF1); + edc_err = readw(docptr + DOC_ECCCONF1); + dev_dbg(doc->dev, "%s: edc_err = 0x%02x\n", __func__, edc_err); + + /* If bitflips are reported, attempt to correct with ecc */ + if (edc_err & DOC_ECCCONF1_BCH_SYNDROM_ERR) { + int bits_corrected = correct_data(mtd, buf, page); + if (bits_corrected == -EBADMSG) + mtd->ecc_stats.failed++; + else + mtd->ecc_stats.corrected += bits_corrected; + } + } + + writew(0, docptr + DOC_DATAEND); + return 0; +} + + +static int docg4_read_page_raw(struct mtd_info *mtd, struct nand_chip *nand, + uint8_t *buf, int page) +{ + return read_page(mtd, nand, buf, page, false); +} + +static int docg4_read_page(struct mtd_info *mtd, struct nand_chip *nand, + uint8_t *buf, int page) +{ + return read_page(mtd, nand, buf, page, true); +} + +static int docg4_read_oob(struct mtd_info *mtd, struct nand_chip *nand, + int page, int sndcmd) +{ + struct docg4_priv *doc = nand->priv; + void __iomem *docptr = doc->virtadr; + uint16_t status; + + dev_dbg(doc->dev, "%s: page %x\n", __func__, page); + + /* + * Oob bytes are read as part of a normal page read. If the previous + * nand command was a read of the page whose oob is now being read, just + * copy the oob bytes that we saved in a local buffer and avoid a + * separate oob read. + */ + if (doc->last_command.command == NAND_CMD_READ0 && + doc->last_command.page == page) { + memcpy(nand->oob_poi, doc->oob_buf, 16); + return 0; + } + + /* + * Separate read of oob data only. + */ + docg4_command(mtd, NAND_CMD_READ0, nand->ecc.size, page); + + writew(DOC_ECCCONF0_READ_MODE | DOCG4_OOB_SIZE, docptr + DOC_ECCCONF0); + write_nop(docptr); + write_nop(docptr); + write_nop(docptr); + write_nop(docptr); + write_nop(docptr); + + /* the 1st byte from the I/O reg is a status; the rest is oob data */ + status = readw(docptr + DOC_IOSPACE_DATA); + if (status & DOCG4_READ_ERROR) { + dev_warn(doc->dev, + "docg4_read_oob failed: status = 0x%02x\n", status); + return -EIO; + } + + dev_dbg(doc->dev, "%s: status = 0x%x\n", __func__, status); + + docg4_read_buf(mtd, nand->oob_poi, 16); + + write_nop(docptr); + write_nop(docptr); + write_nop(docptr); + writew(0, docptr + DOC_DATAEND); + write_nop(docptr); + + return 0; +} + +static void docg4_erase_block(struct mtd_info *mtd, int page) +{ + struct nand_chip *nand = mtd->priv; + struct docg4_priv *doc = nand->priv; + void __iomem *docptr = doc->virtadr; + uint16_t g4_page; + + dev_dbg(doc->dev, "%s: page %04x\n", __func__, page); + + sequence_reset(mtd); + + writew(DOCG4_SEQ_BLOCKERASE, docptr + DOC_FLASHSEQUENCE); + writew(DOC_CMD_PROG_BLOCK_ADDR, docptr + DOC_FLASHCOMMAND); + write_nop(docptr); + + /* only 2 bytes of address are written to specify erase block */ + g4_page = (uint16_t)(page / 4); /* to g4's 2k page addressing */ + writeb(g4_page & 0xff, docptr + DOC_FLASHADDRESS); + g4_page >>= 8; + writeb(g4_page & 0xff, docptr + DOC_FLASHADDRESS); + write_nop(docptr); + + /* start the erasure */ + writew(DOC_CMD_ERASECYCLE2, docptr + DOC_FLASHCOMMAND); + write_nop(docptr); + write_nop(docptr); + + usleep_range(500, 1000); /* erasure is long; take a snooze */ + poll_status(doc); + writew(DOCG4_SEQ_FLUSH, docptr + DOC_FLASHSEQUENCE); + writew(DOCG4_CMD_FLUSH, docptr + DOC_FLASHCOMMAND); + writew(DOC_ECCCONF0_READ_MODE | 4, docptr + DOC_ECCCONF0); + write_nop(docptr); + write_nop(docptr); + write_nop(docptr); + write_nop(docptr); + write_nop(docptr); + + read_progstatus(doc); + + writew(0, docptr + DOC_DATAEND); + write_nop(docptr); + poll_status(doc); + write_nop(docptr); +} + +static void write_page(struct mtd_info *mtd, struct nand_chip *nand, + const uint8_t *buf, bool use_ecc) +{ + struct docg4_priv *doc = nand->priv; + void __iomem *docptr = doc->virtadr; + uint8_t ecc_buf[8]; + + dev_dbg(doc->dev, "%s...\n", __func__); + + writew(DOC_ECCCONF0_ECC_ENABLE | + DOC_ECCCONF0_UNKNOWN | + DOCG4_BCH_SIZE, + docptr + DOC_ECCCONF0); + write_nop(docptr); + + /* write the page data */ + docg4_write_buf16(mtd, buf, DOCG4_PAGE_SIZE); + + /* oob bytes 0 through 5 are written to I/O reg */ + docg4_write_buf16(mtd, nand->oob_poi, 6); + + /* oob byte 6 written to a separate reg */ + writew(nand->oob_poi[6], docptr + DOCG4_OOB_6_7); + + write_nop(docptr); + write_nop(docptr); + + /* write hw-generated ecc bytes to oob */ + if (likely(use_ecc == true)) { + /* oob byte 7 is hamming code */ + uint8_t hamming = readb(docptr + DOC_HAMMINGPARITY); + hamming = readb(docptr + DOC_HAMMINGPARITY); /* 2nd read */ + writew(hamming, docptr + DOCG4_OOB_6_7); + write_nop(docptr); + + /* read the 7 bch bytes from ecc regs */ + read_hw_ecc(docptr, ecc_buf); + ecc_buf[7] = 0; /* clear the "page written" flag */ + } + + /* write user-supplied bytes to oob */ + else { + writew(nand->oob_poi[7], docptr + DOCG4_OOB_6_7); + write_nop(docptr); + memcpy(ecc_buf, &nand->oob_poi[8], 8); + } + + docg4_write_buf16(mtd, ecc_buf, 8); + write_nop(docptr); + write_nop(docptr); + writew(0, docptr + DOC_DATAEND); + write_nop(docptr); +} + +static void docg4_write_page_raw(struct mtd_info *mtd, struct nand_chip *nand, + const uint8_t *buf) +{ + return write_page(mtd, nand, buf, false); +} + +static void docg4_write_page(struct mtd_info *mtd, struct nand_chip *nand, + const uint8_t *buf) +{ + return write_page(mtd, nand, buf, true); +} + +static int docg4_write_oob(struct mtd_info *mtd, struct nand_chip *nand, + int page) +{ + /* + * Writing oob-only is not really supported, because MLC nand must write + * oob bytes at the same time as page data. Nonetheless, we save the + * oob buffer contents here, and then write it along with the page data + * if the same page is subsequently written. This allows user space + * utilities that write the oob data prior to the page data to work + * (e.g., nandwrite). The disdvantage is that, if the intention was to + * write oob only, the operation is quietly ignored. Also, oob can get + * corrupted if two concurrent processes are running nandwrite. + */ + + /* note that bytes 7..14 are hw generated hamming/ecc and overwritten */ + struct docg4_priv *doc = nand->priv; + doc->oob_page = page; + memcpy(doc->oob_buf, nand->oob_poi, 16); + return 0; +} + +static int __init read_factory_bbt(struct mtd_info *mtd) +{ + /* + * The device contains a read-only factory bad block table. Read it and + * update the memory-based bbt accordingly. + */ + + struct nand_chip *nand = mtd->priv; + 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; + + 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, DOCG4_FACTORY_BBT_PAGE); + if (status) + goto exit; + + /* + * If no memory-based bbt was created, exit. This will happen if module + * parameter ignore_badblocks is set. Then why even call this function? + * For an unknown reason, block erase always fails if it's the first + * operation after device power-up. The above read ensures it never is. + * Ugly, I know. + */ + if (nand->bbt == NULL) /* no memory-based bbt */ + 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 + * to lsb). Bit clear means bad block. + */ + for (i = block = 0; block < DOCG4_NUMBLOCKS; block += 8, i++) { + int bitnum; + unsigned long bits = ~buf[i]; + for_each_set_bit(bitnum, &bits, 8) { + int badblock = block + 7 - bitnum; + nand->bbt[badblock / 4] |= + 0x03 << ((badblock % 4) * 2); + mtd->ecc_stats.badblocks++; + dev_notice(doc->dev, "factory-marked bad block: %d\n", + badblock); + } + } + exit: + kfree(buf); + return status; +} + +static int docg4_block_markbad(struct mtd_info *mtd, loff_t ofs) +{ + /* + * Mark a block as bad. Bad blocks are marked in the oob area of the + * first page of the block. The default scan_bbt() in the nand + * infrastructure code works fine for building the memory-based bbt + * during initialization, as does the nand infrastructure function that + * checks if a block is bad by reading the bbt. This function replaces + * the nand default because writes to oob-only are not supported. + */ + + int ret, i; + uint8_t *buf; + struct nand_chip *nand = mtd->priv; + struct docg4_priv *doc = nand->priv; + struct nand_bbt_descr *bbtd = nand->badblock_pattern; + int block = (int)(ofs >> nand->bbt_erase_shift); + int page = (int)(ofs >> nand->page_shift); + uint32_t g4_addr = mtd_to_docg4_address(page, 0); + + dev_dbg(doc->dev, "%s: %08llx\n", __func__, ofs); + + if (unlikely(ofs & (DOCG4_BLOCK_SIZE - 1))) + dev_warn(doc->dev, "%s: ofs %llx not start of block!\n", + __func__, ofs); + + /* allocate blank buffer for page data */ + buf = kzalloc(DOCG4_PAGE_SIZE, GFP_KERNEL); + if (buf == NULL) + return -ENOMEM; + + /* update bbt in memory */ + nand->bbt[block / 4] |= 0x01 << ((block & 0x03) * 2); + + /* write bit-wise negation of pattern to oob buffer */ + memset(nand->oob_poi, 0xff, mtd->oobsize); + for (i = 0; i < bbtd->len; i++) + nand->oob_poi[bbtd->offs + i] = ~bbtd->pattern[i]; + + /* write first page of block */ + write_page_prologue(mtd, g4_addr); + docg4_write_page(mtd, nand, buf); + ret = pageprog(mtd); + if (!ret) + mtd->ecc_stats.badblocks++; + + kfree(buf); + + return ret; +} + +static int docg4_block_neverbad(struct mtd_info *mtd, loff_t ofs, int getchip) +{ + /* only called when module_param ignore_badblocks is set */ + return 0; +} + +static int docg4_suspend(struct platform_device *pdev, pm_message_t state) +{ + /* + * Put the device into "deep power-down" mode. Note that CE# must be + * deasserted for this to take effect. The xscale, e.g., can be + * configured to float this signal when the processor enters power-down, + * and a suitable pull-up ensures its deassertion. + */ + + int i; + uint8_t pwr_down; + struct docg4_priv *doc = platform_get_drvdata(pdev); + void __iomem *docptr = doc->virtadr; + + dev_dbg(doc->dev, "%s...\n", __func__); + + /* poll the register that tells us we're ready to go to sleep */ + for (i = 0; i < 10; i++) { + pwr_down = readb(docptr + DOC_POWERMODE); + if (pwr_down & DOC_POWERDOWN_READY) + break; + usleep_range(1000, 4000); + } + + if (pwr_down & DOC_POWERDOWN_READY) { + dev_err(doc->dev, "suspend failed; " + "timeout polling DOC_POWERDOWN_READY\n"); + return -EIO; + } + + writew(DOC_ASICMODE_POWERDOWN | DOC_ASICMODE_MDWREN, + docptr + DOC_ASICMODE); + writew(~(DOC_ASICMODE_POWERDOWN | DOC_ASICMODE_MDWREN), + docptr + DOC_ASICMODECONFIRM); + + write_nop(docptr); + + return 0; +} + +static int docg4_resume(struct platform_device *pdev) +{ + + /* + * Exit power-down. Twelve consecutive reads of the address below + * accomplishes this, assuming CE# has been asserted. + */ + + struct docg4_priv *doc = platform_get_drvdata(pdev); + void __iomem *docptr = doc->virtadr; + int i; + + dev_dbg(doc->dev, "%s...\n", __func__); + + for (i = 0; i < 12; i++) + readb(docptr + 0x1fff); + + return 0; +} + +static void __init init_mtd_structs(struct mtd_info *mtd) +{ + /* initialize mtd and nand data structures */ + + /* + * Note that some of the following initializations are not usually + * required within a nand driver because they are performed by the nand + * infrastructure code as part of nand_scan(). In this case they need + * to be initialized here because we skip call to nand_scan_ident() (the + * first half of nand_scan()). The call to nand_scan_ident() is skipped + * because for this device the chip id is not read in the manner of a + * standard nand device. Unfortunately, nand_scan_ident() does other + * things as well, such as call nand_set_defaults(). + */ + + struct nand_chip *nand = mtd->priv; + struct docg4_priv *doc = nand->priv; + + mtd->size = DOCG4_CHIP_SIZE; + mtd->name = "Msys_Diskonchip_G4"; + mtd->writesize = DOCG4_PAGE_SIZE; + mtd->erasesize = DOCG4_BLOCK_SIZE; + mtd->oobsize = DOCG4_OOB_SIZE; + nand->chipsize = DOCG4_CHIP_SIZE; + nand->chip_shift = DOCG4_CHIP_SHIFT; + nand->bbt_erase_shift = nand->phys_erase_shift = DOCG4_ERASE_SHIFT; + nand->chip_delay = 20; + nand->page_shift = DOCG4_PAGE_SHIFT; + nand->pagemask = 0x3ffff; + nand->badblockpos = NAND_LARGE_BADBLOCK_POS; + nand->badblockbits = 8; + nand->ecc.layout = &docg4_oobinfo; + nand->ecc.mode = NAND_ECC_HW_SYNDROME; + nand->ecc.size = DOCG4_PAGE_SIZE; + nand->ecc.prepad = 8; + nand->ecc.bytes = 8; + nand->ecc.strength = DOCG4_T; + nand->options = + NAND_BUSWIDTH_16 | NAND_NO_SUBPAGE_WRITE | NAND_NO_AUTOINCR; + nand->IO_ADDR_R = nand->IO_ADDR_W = doc->virtadr + DOC_IOSPACE_DATA; + nand->controller = &nand->hwcontrol; + spin_lock_init(&nand->controller->lock); + init_waitqueue_head(&nand->controller->wq); + + /* methods */ + nand->cmdfunc = docg4_command; + nand->waitfunc = docg4_wait; + nand->select_chip = docg4_select_chip; + nand->read_byte = docg4_read_byte; + nand->block_markbad = docg4_block_markbad; + nand->read_buf = docg4_read_buf; + nand->write_buf = docg4_write_buf16; + nand->scan_bbt = nand_default_bbt; + nand->erase_cmd = docg4_erase_block; + nand->ecc.read_page = docg4_read_page; + nand->ecc.write_page = docg4_write_page; + nand->ecc.read_page_raw = docg4_read_page_raw; + nand->ecc.write_page_raw = docg4_write_page_raw; + nand->ecc.read_oob = docg4_read_oob; + nand->ecc.write_oob = docg4_write_oob; + + /* + * The way the nand infrastructure code is written, a memory-based bbt + * is not created if NAND_SKIP_BBTSCAN is set. With no memory bbt, + * nand->block_bad() is used. So when ignoring bad blocks, we skip the + * scan and define a dummy block_bad() which always returns 0. + */ + if (ignore_badblocks) { + nand->options |= NAND_SKIP_BBTSCAN; + nand->block_bad = docg4_block_neverbad; + } + +} + +static int __init read_id_reg(struct mtd_info *mtd) +{ + struct nand_chip *nand = mtd->priv; + struct docg4_priv *doc = nand->priv; + void __iomem *docptr = doc->virtadr; + uint16_t id1, id2; + + /* check for presence of g4 chip by reading id registers */ + id1 = readw(docptr + DOC_CHIPID); + id1 = readw(docptr + DOCG4_MYSTERY_REG); + id2 = readw(docptr + DOC_CHIPID_INV); + id2 = readw(docptr + DOCG4_MYSTERY_REG); + + if (id1 == DOCG4_IDREG1_VALUE && id2 == DOCG4_IDREG2_VALUE) { + dev_info(doc->dev, + "NAND device: 128MiB Diskonchip G4 detected\n"); + return 0; + } + + return -ENODEV; +} + +static char const *part_probes[] = { "cmdlinepart", "saftlpart", NULL }; + +static int __init probe_docg4(struct platform_device *pdev) +{ + struct mtd_info *mtd; + struct nand_chip *nand; + void __iomem *virtadr; + struct docg4_priv *doc; + int len, retval; + struct resource *r; + struct device *dev = &pdev->dev; + + r = platform_get_resource(pdev, IORESOURCE_MEM, 0); + if (r == NULL) { + dev_err(dev, "no io memory resource defined!\n"); + return -ENODEV; + } + + virtadr = ioremap(r->start, resource_size(r)); + if (!virtadr) { + dev_err(dev, "Diskonchip ioremap failed: %pR\n", r); + return -EIO; + } + + len = sizeof(struct mtd_info) + sizeof(struct nand_chip) + + sizeof(struct docg4_priv); + mtd = kzalloc(len, GFP_KERNEL); + if (mtd == NULL) { + retval = -ENOMEM; + goto fail; + } + nand = (struct nand_chip *) (mtd + 1); + doc = (struct docg4_priv *) (nand + 1); + mtd->priv = nand; + nand->priv = doc; + mtd->owner = THIS_MODULE; + doc->virtadr = virtadr; + doc->dev = dev; + + init_mtd_structs(mtd); + + /* initialize kernel bch algorithm */ + doc->bch = init_bch(DOCG4_M, DOCG4_T, DOCG4_PRIMITIVE_POLY); + if (doc->bch == NULL) { + retval = -EINVAL; + goto fail; + } + + platform_set_drvdata(pdev, doc); + + reset(mtd); + retval = read_id_reg(mtd); + if (retval == -ENODEV) { + dev_warn(dev, "No diskonchip G4 device found.\n"); + goto fail; + } + + retval = nand_scan_tail(mtd); + if (retval) + goto fail; + + retval = read_factory_bbt(mtd); + if (retval) + goto fail; + + retval = mtd_device_parse_register(mtd, part_probes, NULL, NULL, 0); + if (retval) + goto fail; + + doc->mtd = mtd; + return 0; + + fail: + iounmap(virtadr); + if (mtd) { + /* re-declarations avoid compiler warning */ + struct nand_chip *nand = mtd->priv; + struct docg4_priv *doc = nand->priv; + nand_release(mtd); /* deletes partitions and mtd devices */ + platform_set_drvdata(pdev, NULL); + free_bch(doc->bch); + kfree(mtd); + } + + return retval; +} + +static int __exit cleanup_docg4(struct platform_device *pdev) +{ + struct docg4_priv *doc = platform_get_drvdata(pdev); + nand_release(doc->mtd); + platform_set_drvdata(pdev, NULL); + free_bch(doc->bch); + kfree(doc->mtd); + iounmap(doc->virtadr); + return 0; +} + +static struct platform_driver docg4_driver = { + .driver = { + .name = "docg4", + .owner = THIS_MODULE, + }, + .suspend = docg4_suspend, + .resume = docg4_resume, + .remove = __exit_p(cleanup_docg4), +}; + +static int __init docg4_init(void) +{ + return platform_driver_probe(&docg4_driver, probe_docg4); +} + +static void __exit docg4_exit(void) +{ + platform_driver_unregister(&docg4_driver); +} + +module_init(docg4_init); +module_exit(docg4_exit); + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Mike Dunn"); +MODULE_DESCRIPTION("M-Systems DiskOnChip G4 device driver"); |
