/*
* 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>
#include <linux/jiffies.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).
* 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
#define DOCG4_SEQ_SETMODE 0x45
/* 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 DOCG4_CMD_FAST_MODE 0xa3 /* functionality guessed */
#define DOC_CMD_RELIABLE_MODE 0x22
#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 */
#define DOCG4_REDUNDANT_BBT_PAGE 24 /* page where redundant factory bbt lives */
/*
* 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 int docg4_ooblayout_ecc(struct mtd_info *mtd, int section,
struct mtd_oob_region *oobregion)
{
if (section)
return -ERANGE;
oobregion->offset = 7;
oobregion->length = 9;
return 0;
}
static int docg4_ooblayout_free(struct mtd_info *mtd, int section,
struct mtd_oob_region *oobregion)
{
if (section)
return -ERANGE;
oobregion->offset = 2;
oobregion->length = 5;
return 0;
}
static const struct mtd_ooblayout_ops docg4_ooblayout_ops = {
.ecc = docg4_ooblayout_ecc,
.free = docg4_ooblayout_free,
};
/*
* 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_to_nand(mtd);
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_to_nand(mtd);
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 long 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 = jiffies + msecs_to_jiffies(200); /* generous timeout */
do {
cpu_relax();
flash_status = readb(docptr + DOC_FLASHCONTROL);
} while (!(flash_status & DOC_CTRL_FLASHREADY) &&
time_before(jiffies, timeo));
if (unlikely(!(flash_status & DOC_CTRL_FLASHREADY))) {
dev_err(doc->dev, "%s: timed out!\n", __func__);
return NAND_STATUS_FAIL;
}
return 0;
}
static int docg4_wait(struct mtd_info *mtd, struct nand_chip *nand)
{
struct docg4_priv *doc = nand_get_controller_data(nand);
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_to_nand(mtd);
struct docg4_priv *doc = nand_get_controller_data(nand);
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_to_nand(mtd);
struct docg4_priv *doc = nand_get_controller_data(nand);
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_to_nand(mtd);
struct docg4_priv *doc = nand_get_controller_data(nand);
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 (nand->oob_poi[15]) {
int bit, numsetbits = 0;
unsigned long written_flag = nand->oob_poi[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 *)nand->oob_poi);
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_to_nand(mtd);
struct docg4_priv *doc = nand_get_controller_data(nand);
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, "unexpected 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_to_nand(mtd);
struct docg4_priv *doc = nand_get_controller_data(nand);
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_to_nand(mtd);
struct docg4_priv *doc = nand_get_controller_data(nand);
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_to_nand(mtd);
struct docg4_priv *doc = nand_get_controller_data(nand);
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_to_nand(mtd);
struct docg4_priv *doc = nand_get_controller_data(nand);
void __iomem *docptr = doc->virtadr;
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);
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_to_nand(mtd);
struct docg4_priv *doc = nand_get_controller_data(nand);
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:
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 */
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_get_controller_data(nand);
void __iomem *docptr = doc->virtadr;
uint16_t status, edc_err, *buf16;
int bits_corrected = 0;
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 */
/* this device always reads oob after page data */
/* first 14 oob bytes read from I/O reg */
docg4_read_buf(mtd, nand->oob_poi, 14);
/* last 2 read from another reg */
buf16 = (uint16_t *)(nand->oob_poi + 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) {
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);
if (bits_corrected == -EBADMSG) /* uncorrectable errors */
return 0;
return bits_corrected;
}
static int docg4_read_page_raw(struct mtd_info *mtd, struct nand_chip *nand,
uint8_t *buf, int oob_required, 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 oob_required, 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)
{
struct docg4_priv *doc = nand_get_controller_data(nand);
void __iomem *docptr = doc->virtadr;
uint16_t status;
dev_dbg(doc->dev, "%s: page %x\n", __func__, page);
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 int docg4_erase_block(struct mtd_info *mtd, int page)
{
struct nand_chip *nand = mtd_to_nand(mtd);
struct docg4_priv *doc = nand_get_controller_data(nand);
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);
return nand->waitfunc(mtd, nand);
}
static int write_page(struct mtd_info *mtd, struct nand_chip *nand,
const uint8_t *buf, bool use_ecc)
{
struct docg4_priv *doc = nand_get_controller_data(nand);
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);
return 0;
}
static int docg4_write_page_raw(struct mtd_info *mtd, struct nand_chip *nand,
const uint8_t *buf, int oob_required, int page)
{
return write_page(mtd, nand, buf, false);
}
static int docg4_write_page(struct mtd_info *mtd, struct nand_chip *nand,
const uint8_t *buf, int oob_required, int page)
{
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_get_controller_data(nand);
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_to_nand(mtd);
struct docg4_priv *doc = nand_get_controller_data(nand);
uint32_t g4_addr = mtd_to_docg4_address(DOCG4_FACTORY_BBT_PAGE, 0);
uint8_t *buf;
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);
docg4_read_page(mtd, nand, buf, 0, DOCG4_FACTORY_BBT_PAGE);
/*
* 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;
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
* 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 0;
}
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_to_nand(mtd);
struct docg4_priv *doc = nand_get_controller_data(nand);
struct nand_bbt_descr *bbtd = nand->badblock_pattern;
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;
/* 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, 1, page);
ret = pageprog(mtd);
kfree(buf);
return ret;
}
static int docg4_block_neverbad(struct mtd_info *mtd, loff_t ofs)
{
/* 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_to_nand(mtd);
struct docg4_priv *doc = nand_get_controller_data(nand);
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;
mtd_set_ooblayout(mtd, &docg4_ooblayout_ops);
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.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->IO_ADDR_R = nand->IO_ADDR_W = doc->virtadr + DOC_IOSPACE_DATA;
nand->controller = &nand->hwcontrol;
nand_hw_control_init(nand->controller);
/* 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->erase = 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_to_nand(mtd);
struct docg4_priv *doc = nand_get_controller_data(nand);
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 nand_chip) + sizeof(struct docg4_priv);
nand = kzalloc(len, GFP_KERNEL);
if (nand == NULL) {
retval = -ENOMEM;
goto fail_unmap;
}
mtd = nand_to_mtd(nand);
doc = (struct docg4_priv *) (nand + 1);
nand_set_controller_data(nand, doc);
mtd->dev.parent = &pdev->dev;
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:
nand_release(mtd); /* deletes partitions and mtd devices */
free_bch(doc->bch);
kfree(nand);
fail_unmap:
iounmap(virtadr);
return retval;
}
static int __exit cleanup_docg4(struct platform_device *pdev)
{
struct docg4_priv *doc = platform_get_drvdata(pdev);
nand_release(doc->mtd);
free_bch(doc->bch);
kfree(mtd_to_nand(doc->mtd));
iounmap(doc->virtadr);
return 0;
}
static struct platform_driver docg4_driver = {
.driver = {
.name = "docg4",
},
.suspend = docg4_suspend,
.resume = docg4_resume,
.remove = __exit_p(cleanup_docg4),
};
module_platform_driver_probe(docg4_driver, probe_docg4);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Mike Dunn");
MODULE_DESCRIPTION("M-Systems DiskOnChip G4 device driver");