--- /dev/null
+/*
+ * 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 struct nand_ecclayout docg4_oobinfo = {
+ .eccbytes = 9,
+ .eccpos = {7, 8, 9, 10, 11, 12, 13, 14, 15},
+ .oobavail = 5,
+ .oobfree = { {.offset = 2, .length = 5} }
+};
+
+/*
+ * 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 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->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 (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->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, "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->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);
+
+ 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->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:
+ 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->priv;
+ 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->priv;
+ 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->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);
+
+ 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->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);
+
+ return 0;
+}
+
+static int docg4_write_page_raw(struct mtd_info *mtd, struct nand_chip *nand,
+ const uint8_t *buf, int oob_required)
+{
+ 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)
+{
+ 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;
+ __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->priv;
+ struct docg4_priv *doc = nand->priv;
+ 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);
+ ret = pageprog(mtd);
+
+ 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->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->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->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 */
+ 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);
+ free_bch(doc->bch);
+ kfree(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");
Code Review / kvmfornfv.git / blobdiff