summaryrefslogtreecommitdiff
path: root/drivers
diff options
context:
space:
mode:
Diffstat (limited to 'drivers')
-rw-r--r--drivers/mtd/nand/Makefile2
-rw-r--r--drivers/mtd/nand/docg4.c1028
-rw-r--r--drivers/mtd/nand/docg4_spl.c222
3 files changed, 1252 insertions, 0 deletions
diff --git a/drivers/mtd/nand/Makefile b/drivers/mtd/nand/Makefile
index 35769c5ea3..8821704911 100644
--- a/drivers/mtd/nand/Makefile
+++ b/drivers/mtd/nand/Makefile
@@ -34,6 +34,7 @@ NORMAL_DRIVERS=y
endif
COBJS-$(CONFIG_SPL_NAND_AM33XX_BCH) += am335x_spl_bch.o
+COBJS-$(CONFIG_SPL_NAND_DOCG4) += docg4_spl.o
COBJS-$(CONFIG_SPL_NAND_SIMPLE) += nand_spl_simple.o
COBJS-$(CONFIG_SPL_NAND_LOAD) += nand_spl_load.o
COBJS-$(CONFIG_SPL_NAND_ECC) += nand_ecc.o
@@ -77,6 +78,7 @@ COBJS-$(CONFIG_NAND_SPEAR) += spr_nand.o
COBJS-$(CONFIG_TEGRA_NAND) += tegra_nand.o
COBJS-$(CONFIG_NAND_OMAP_GPMC) += omap_gpmc.o
COBJS-$(CONFIG_NAND_PLAT) += nand_plat.o
+COBJS-$(CONFIG_NAND_DOCG4) += docg4.o
else # minimal SPL drivers
diff --git a/drivers/mtd/nand/docg4.c b/drivers/mtd/nand/docg4.c
new file mode 100644
index 0000000000..7dd9953bed
--- /dev/null
+++ b/drivers/mtd/nand/docg4.c
@@ -0,0 +1,1028 @@
+/*
+ * drivers/mtd/nand/docg4.c
+ *
+ * Copyright (C) 2013 Mike Dunn <mikedunn@newsguy.com>
+ *
+ * This file is released under the terms of GPL v2 and any later version.
+ * See the file COPYING in the root directory of the source tree for details.
+ *
+ * mtd nand driver for M-Systems DiskOnChip G4
+ *
+ * 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 <common.h>
+#include <asm/arch/hardware.h>
+#include <asm/io.h>
+#include <asm/bitops.h>
+#include <asm/errno.h>
+#include <malloc.h>
+#include <nand.h>
+#include <linux/bch.h>
+#include <linux/bitrev.h>
+#include <linux/mtd/docg4.h>
+
+/*
+ * 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 int poll_status(void __iomem *docptr)
+{
+ /*
+ * 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.
+ */
+
+ uint8_t flash_status;
+
+ /* hardware quirk requires reading twice initially */
+ flash_status = readb(docptr + DOC_FLASHCONTROL);
+
+ do {
+ flash_status = readb(docptr + DOC_FLASHCONTROL);
+ } while (!(flash_status & DOC_CTRL_FLASHREADY));
+
+ return 0;
+}
+
+static void write_addr(void __iomem *docptr, uint32_t docg4_addr)
+{
+ /* write the four address bytes packed in docg4_addr to the device */
+
+ 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);
+}
+
+/*
+ * This is a module parameter in the linux kernel version of this driver. It is
+ * hard-coded to 'off' for u-boot. This driver uses oob to mark bad blocks.
+ * This can be problematic when dealing with data not intended for the mtd/nand
+ * subsystem. For example, on boards that boot from the docg4 and use the IPL
+ * to load an spl + u-boot image, the blocks containing the image will be
+ * reported as "bad" because the oob of the first page of each block contains a
+ * magic number that the IPL looks for, which causes the badblock scan to
+ * erroneously add them to the bad block table. To erase such a block, use
+ * u-boot's 'nand scrub'. scrub is safe for the docg4. The device does have a
+ * factory bad block table, but it is read-only, and is used in conjunction with
+ * oob bad block markers that are written by mtd/nand when a block is deemed to
+ * be bad. To read data from "bad" blocks, use 'read.raw'. Unfortunately,
+ * read.raw does not use ecc, which would still work fine on such misidentified
+ * bad blocks. TODO: u-boot nand utilities need the ability to ignore bad
+ * blocks.
+ */
+static const int ignore_badblocks; /* remains false */
+
+struct docg4_priv {
+ 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;
+};
+/*
+ * 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} }
+};
+
+static void reset(void __iomem *docptr)
+{
+ /* full device reset */
+
+ 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(docptr);
+}
+
+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.
+ */
+ void __iomem *docptr = CONFIG_SYS_NAND_BASE;
+
+ if (chip < 0)
+ return; /* deselected */
+
+ if (chip > 0)
+ printf("multiple floors currently unsupported\n");
+
+ writew(0, docptr + DOC_DEVICESELECT);
+}
+
+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 = CONFIG_SYS_NAND_BASE;
+ int i, numerrs;
+ unsigned int 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) {
+ /*
+ * 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 (bit = 0; bit < 8; bit++) {
+ if (written_flag & 0x01)
+ numsetbits++;
+ written_flag >>= 1;
+ }
+ if (numsetbits > 4) { /* assume blank */
+ printf("errors 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) {
+ printf("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);
+ }
+
+ printf("%d error(s) corrected at offset %08x\n",
+ numerrs, page * DOCG4_PAGE_SIZE);
+
+ return numerrs;
+}
+
+static int read_progstatus(struct docg4_priv *doc, void __iomem *docptr)
+{
+ /*
+ * 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.
+ */
+
+ /* 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);
+
+ MTDDEBUG(MTD_DEBUG_LEVEL3, "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;
+ printf("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 = CONFIG_SYS_NAND_BASE;
+ int retval = 0;
+
+ MTDDEBUG(MTD_DEBUG_LEVEL3, "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(docptr);
+
+ 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, docptr);
+ writew(0, docptr + DOC_DATAEND);
+ write_nop(docptr);
+ poll_status(docptr);
+ write_nop(docptr);
+
+ return retval;
+}
+
+static void sequence_reset(void __iomem *docptr)
+{
+ /* common starting sequence for all operations */
+
+ 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(docptr);
+ write_nop(docptr);
+}
+
+static void read_page_prologue(void __iomem *docptr, uint32_t docg4_addr)
+{
+ /* first step in reading a page */
+
+ sequence_reset(docptr);
+
+ writew(DOCG4_SEQ_PAGE_READ, docptr + DOC_FLASHSEQUENCE);
+ writew(DOCG4_CMD_PAGE_READ, docptr + DOC_FLASHCOMMAND);
+ write_nop(docptr);
+
+ write_addr(docptr, docg4_addr);
+
+ write_nop(docptr);
+ writew(DOCG4_CMD_READ2, docptr + DOC_FLASHCOMMAND);
+ write_nop(docptr);
+ write_nop(docptr);
+
+ poll_status(docptr);
+}
+
+static void write_page_prologue(void __iomem *docptr, uint32_t docg4_addr)
+{
+ /* first step in writing a page */
+
+ sequence_reset(docptr);
+ writew(DOCG4_SEQ_PAGEWRITE, docptr + DOC_FLASHSEQUENCE);
+ writew(DOCG4_CMD_PAGEWRITE, docptr + DOC_FLASHCOMMAND);
+ write_nop(docptr);
+ write_addr(docptr, docg4_addr);
+ write_nop(docptr);
+ write_nop(docptr);
+ poll_status(docptr);
+}
+
+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);
+
+ MTDDEBUG(MTD_DEBUG_LEVEL3, "%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(CONFIG_SYS_NAND_BASE);
+ break;
+
+ case NAND_CMD_READ0:
+ read_page_prologue(CONFIG_SYS_NAND_BASE, g4_addr);
+ break;
+
+ case NAND_CMD_STATUS:
+ /* next call to read_byte() will expect a status */
+ break;
+
+ case NAND_CMD_SEQIN:
+ write_page_prologue(CONFIG_SYS_NAND_BASE, 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:
+ printf("docg4_command: unexpected nand command 0x%x\n",
+ command);
+ break;
+ }
+}
+
+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 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 = CONFIG_SYS_NAND_BASE;
+ uint16_t status;
+
+ MTDDEBUG(MTD_DEBUG_LEVEL3, "%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) {
+ printf("docg4_read_oob failed: status = 0x%02x\n", status);
+ return -EIO;
+ }
+
+ MTDDEBUG(MTD_DEBUG_LEVEL3, "%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_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 docg4_block_neverbad(struct mtd_info *mtd, loff_t ofs, int getchip)
+{
+ /* only called when module_param ignore_badblocks is set */
+ return 0;
+}
+
+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 void write_page(struct mtd_info *mtd, struct nand_chip *nand,
+ const uint8_t *buf, int use_ecc)
+{
+ void __iomem *docptr = CONFIG_SYS_NAND_BASE;
+ uint8_t ecc_buf[8];
+
+ 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)) {
+ /* 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, 0);
+}
+
+static void docg4_write_page(struct mtd_info *mtd, struct nand_chip *nand,
+ const uint8_t *buf)
+{
+ return write_page(mtd, nand, buf, 1);
+}
+
+static int read_page(struct mtd_info *mtd, struct nand_chip *nand,
+ uint8_t *buf, int page, int use_ecc)
+{
+ struct docg4_priv *doc = nand->priv;
+ void __iomem *docptr = CONFIG_SYS_NAND_BASE;
+ uint16_t status, edc_err, *buf16;
+
+ 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) {
+ printf("docg4_read_page: bad status: 0x%02x\n", status);
+ writew(0, docptr + DOC_DATAEND);
+ return -EIO;
+ }
+
+ docg4_read_buf(mtd, buf, DOCG4_PAGE_SIZE); /* read the 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);
+
+ /*
+ * 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.
+ */
+ memcpy(doc->oob_buf, nand->oob_poi, 16);
+
+ write_nop(docptr);
+
+ if (likely(use_ecc)) {
+ /* read the register that tells us if bitflip(s) detected */
+ edc_err = readw(docptr + DOC_ECCCONF1);
+ edc_err = readw(docptr + DOC_ECCCONF1);
+
+ /* 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, 0);
+}
+
+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, 1);
+}
+
+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 = CONFIG_SYS_NAND_BASE;
+ uint16_t g4_page;
+
+ MTDDEBUG(MTD_DEBUG_LEVEL3, "%s: page %04x\n", __func__, page);
+
+ sequence_reset(docptr);
+
+ 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);
+
+ poll_status(docptr);
+ 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, docptr);
+
+ writew(0, docptr + DOC_DATAEND);
+ write_nop(docptr);
+ poll_status(docptr);
+ write_nop(docptr);
+}
+
+static int 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;
+ 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(CONFIG_SYS_NAND_BASE, 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;
+ uint8_t mask;
+ for (bitnum = 0, mask = 0x80;
+ bitnum < 8; bitnum++, mask >>= 1) {
+ if (!(buf[i] & mask)) {
+ int badblock = block + bitnum;
+ nand->bbt[badblock / 4] |=
+ 0x03 << ((badblock % 4) * 2);
+ mtd->ecc_stats.badblocks++;
+ printf("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 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);
+
+ MTDDEBUG(MTD_DEBUG_LEVEL3, "%s: %08llx\n", __func__, ofs);
+
+ if (unlikely(ofs & (DOCG4_BLOCK_SIZE - 1)))
+ printf("%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(CONFIG_SYS_NAND_BASE, g4_addr);
+ docg4_write_page(mtd, nand, buf);
+ ret = pageprog(mtd);
+ if (!ret)
+ mtd->ecc_stats.badblocks++;
+
+ kfree(buf);
+
+ return ret;
+}
+
+static uint8_t docg4_read_byte(struct mtd_info *mtd)
+{
+ struct nand_chip *nand = mtd->priv;
+ struct docg4_priv *doc = nand->priv;
+
+ MTDDEBUG(MTD_DEBUG_LEVEL3, "%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;
+ }
+
+ printf("unexpectd call to read_byte()\n");
+
+ 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?? */
+ MTDDEBUG(MTD_DEBUG_LEVEL3, "%s...\n", __func__);
+
+ /* report any previously unreported error */
+ if (doc->status) {
+ status |= doc->status;
+ doc->status = 0;
+ return status;
+ }
+
+ status |= poll_status(CONFIG_SYS_NAND_BASE);
+ return status;
+}
+
+int docg4_nand_init(struct mtd_info *mtd, struct nand_chip *nand, int devnum)
+{
+ uint16_t id1, id2;
+ struct docg4_priv *docg4;
+ int retval;
+
+ docg4 = kzalloc(sizeof(*docg4), GFP_KERNEL);
+ if (!docg4)
+ return -1;
+
+ mtd->priv = nand;
+ nand->priv = docg4;
+
+ /* These must be initialized here because the docg4 is non-standard
+ * and doesn't produce an id that the nand code can use to look up
+ * these values (nand_scan_ident() not called).
+ */
+ 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->IO_ADDR_R =
+ (void __iomem *)CONFIG_SYS_NAND_BASE + DOC_IOSPACE_DATA;
+ nand->IO_ADDR_W = nand->IO_ADDR_R;
+ nand->chipsize = DOCG4_CHIP_SIZE;
+ nand->chip_shift = DOCG4_CHIP_SHIFT;
+ nand->bbt_erase_shift = DOCG4_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->options =
+ NAND_BUSWIDTH_16 | NAND_NO_SUBPAGE_WRITE | NAND_NO_AUTOINCR;
+ nand->controller = &nand->hwcontrol;
+
+ /* 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;
+ }
+
+ reset(CONFIG_SYS_NAND_BASE);
+
+ /* check for presence of g4 chip by reading id registers */
+ id1 = readw(CONFIG_SYS_NAND_BASE + DOC_CHIPID);
+ id1 = readw(CONFIG_SYS_NAND_BASE + DOCG4_MYSTERY_REG);
+ id2 = readw(CONFIG_SYS_NAND_BASE + DOC_CHIPID_INV);
+ id2 = readw(CONFIG_SYS_NAND_BASE + DOCG4_MYSTERY_REG);
+ if (id1 != DOCG4_IDREG1_VALUE || id2 != DOCG4_IDREG2_VALUE)
+ return -1;
+
+ /* initialize bch algorithm */
+ docg4->bch = init_bch(DOCG4_M, DOCG4_T, DOCG4_PRIMITIVE_POLY);
+ if (docg4->bch == NULL)
+ return -1;
+
+ retval = nand_scan_tail(mtd);
+ if (retval)
+ return -1;
+
+ /*
+ * Scan for bad blocks and create bbt here, then add the factory-marked
+ * bad blocks to the bbt.
+ */
+ nand->scan_bbt(mtd);
+ nand->options |= NAND_BBT_SCANNED;
+ retval = read_factory_bbt(mtd);
+ if (retval)
+ return -1;
+
+ retval = nand_register(devnum);
+ if (retval)
+ return -1;
+
+ return 0;
+}
diff --git a/drivers/mtd/nand/docg4_spl.c b/drivers/mtd/nand/docg4_spl.c
new file mode 100644
index 0000000000..95e856c213
--- /dev/null
+++ b/drivers/mtd/nand/docg4_spl.c
@@ -0,0 +1,222 @@
+/*
+ * SPL driver for Diskonchip G4 nand flash
+ *
+ * Copyright (C) 2013 Mike Dunn <mikedunn@newsguy.com>
+ *
+ * This file is released under the terms of GPL v2 and any later version.
+ * See the file COPYING in the root directory of the source tree for details.
+ *
+ *
+ * This driver basically mimics the load functionality of a typical IPL (initial
+ * program loader) resident in the 2k NOR-like region of the docg4 that is
+ * mapped to the reset vector. It allows the u-boot SPL to continue loading if
+ * the IPL loads a fixed number of flash blocks that is insufficient to contain
+ * the entire u-boot image. In this case, a concatenated spl + u-boot image is
+ * written at the flash offset from which the IPL loads an image, and when the
+ * IPL jumps to the SPL, the SPL resumes loading where the IPL left off. See
+ * the palmtreo680 for an example.
+ *
+ * This driver assumes that the data was written to the flash using the device's
+ * "reliable" mode, and also assumes that each 512 byte page is stored
+ * redundantly in the subsequent page. This storage format is likely to be used
+ * by all boards that boot from the docg4. The format compensates for the lack
+ * of ecc in the IPL.
+ *
+ * Reliable mode reduces the capacity of a block by half, and the redundant
+ * pages reduce it by half again. As a result, the normal 256k capacity of a
+ * block is reduced to 64k for the purposes of the IPL/SPL.
+ */
+
+#include <asm/io.h>
+#include <linux/mtd/docg4.h>
+
+/* forward declarations */
+static inline void write_nop(void __iomem *docptr);
+static int poll_status(void __iomem *docptr);
+static void write_addr(void __iomem *docptr, uint32_t docg4_addr);
+static void address_sequence(unsigned int g4_page, unsigned int g4_index,
+ void __iomem *docptr);
+static int docg4_load_block_reliable(uint32_t flash_offset, void *dest_addr);
+
+int nand_spl_load_image(uint32_t offs, unsigned int size, void *dst)
+{
+ void *load_addr = dst;
+ uint32_t flash_offset = offs;
+ const unsigned int block_count =
+ (size + DOCG4_BLOCK_CAPACITY_SPL - 1)
+ / DOCG4_BLOCK_CAPACITY_SPL;
+ int i;
+
+ for (i = 0; i < block_count; i++) {
+ int ret = docg4_load_block_reliable(flash_offset, load_addr);
+ if (ret)
+ return ret;
+ load_addr += DOCG4_BLOCK_CAPACITY_SPL;
+ flash_offset += DOCG4_BLOCK_SIZE;
+ }
+ return 0;
+}
+
+static inline void write_nop(void __iomem *docptr)
+{
+ writew(0, docptr + DOC_NOP);
+}
+
+static int poll_status(void __iomem *docptr)
+{
+ /*
+ * 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.
+ */
+
+ uint8_t flash_status;
+
+ /* hardware quirk requires reading twice initially */
+ flash_status = readb(docptr + DOC_FLASHCONTROL);
+
+ do {
+ flash_status = readb(docptr + DOC_FLASHCONTROL);
+ } while (!(flash_status & DOC_CTRL_FLASHREADY));
+
+ return 0;
+}
+
+static void write_addr(void __iomem *docptr, uint32_t docg4_addr)
+{
+ /* write the four address bytes packed in docg4_addr to the device */
+
+ 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 void address_sequence(unsigned int g4_page, unsigned int g4_index,
+ void __iomem *docptr)
+{
+ writew(DOCG4_SEQ_PAGE_READ, docptr + DOC_FLASHSEQUENCE);
+ writew(DOCG4_CMD_PAGE_READ, docptr + DOC_FLASHCOMMAND);
+ write_nop(docptr);
+ write_addr(docptr, ((uint32_t)g4_page << 16) | g4_index);
+ write_nop(docptr);
+}
+
+static int docg4_load_block_reliable(uint32_t flash_offset, void *dest_addr)
+{
+ void __iomem *docptr = (void *)CONFIG_SYS_NAND_BASE;
+ unsigned int g4_page = flash_offset >> 11; /* 2k page */
+ const unsigned int last_g4_page = g4_page + 0x80; /* last in block */
+ int g4_index = 0;
+ uint16_t flash_status;
+ uint16_t *buf;
+ uint16_t discard, magic_high, magic_low;
+
+ /* flash_offset must be aligned to the start of a block */
+ if (flash_offset & 0x3ffff)
+ return -1;
+
+ writew(DOC_SEQ_RESET, docptr + DOC_FLASHSEQUENCE);
+ writew(DOC_CMD_RESET, docptr + DOC_FLASHCOMMAND);
+ write_nop(docptr);
+ write_nop(docptr);
+ poll_status(docptr);
+ write_nop(docptr);
+ writew(0x45, docptr + DOC_FLASHSEQUENCE);
+ writew(0xa3, docptr + DOC_FLASHCOMMAND);
+ write_nop(docptr);
+ writew(0x22, docptr + DOC_FLASHCOMMAND);
+ write_nop(docptr);
+
+ /* read 1st 4 oob bytes of first subpage of block */
+ address_sequence(g4_page, 0x0100, docptr); /* index at oob */
+ write_nop(docptr);
+ flash_status = readw(docptr + DOC_FLASHCONTROL);
+ flash_status = readw(docptr + DOC_FLASHCONTROL);
+ if (flash_status & 0x06) /* sequence or protection errors */
+ return -1;
+ writew(DOCG4_CMD_READ2, docptr + DOC_FLASHCOMMAND);
+ write_nop(docptr);
+ write_nop(docptr);
+ poll_status(docptr);
+ writew(DOC_ECCCONF0_READ_MODE | 4, docptr + DOC_ECCCONF0);
+ write_nop(docptr);
+ write_nop(docptr);
+ write_nop(docptr);
+ write_nop(docptr);
+ write_nop(docptr);
+
+ /*
+ * Here we read the first four oob bytes of the first page of the block.
+ * The IPL on the palmtreo680 requires that this contain a 32 bit magic
+ * number, or the load aborts. We'll ignore it.
+ */
+ discard = readw(docptr + 0x103c); /* hw quirk; 1st read discarded */
+ magic_low = readw(docptr + 0x103c);
+ magic_high = readw(docptr + DOCG4_MYSTERY_REG);
+ writew(0, docptr + DOC_DATAEND);
+ write_nop(docptr);
+ write_nop(docptr);
+
+ /* load contents of block to memory */
+ buf = (uint16_t *)dest_addr;
+ do {
+ int i;
+
+ address_sequence(g4_page, g4_index, docptr);
+ writew(DOCG4_CMD_READ2,
+ docptr + DOC_FLASHCOMMAND);
+ write_nop(docptr);
+ write_nop(docptr);
+ poll_status(docptr);
+ writew(DOC_ECCCONF0_READ_MODE |
+ DOC_ECCCONF0_ECC_ENABLE |
+ DOCG4_BCH_SIZE,
+ docptr + DOC_ECCCONF0);
+ write_nop(docptr);
+ write_nop(docptr);
+ write_nop(docptr);
+ write_nop(docptr);
+ write_nop(docptr);
+
+ /* read the 512 bytes of page data, 2 bytes at a time */
+ discard = readw(docptr + 0x103c);
+ for (i = 0; i < 256; i++)
+ *buf++ = readw(docptr + 0x103c);
+
+ /* read oob, but discard it */
+ for (i = 0; i < 7; i++)
+ discard = readw(docptr + 0x103c);
+ discard = readw(docptr + DOCG4_OOB_6_7);
+ discard = readw(docptr + DOCG4_OOB_6_7);
+
+ writew(0, docptr + DOC_DATAEND);
+ write_nop(docptr);
+ write_nop(docptr);
+
+ if (!(g4_index & 0x100)) {
+ /* not redundant subpage read; check for ecc error */
+ write_nop(docptr);
+ flash_status = readw(docptr + DOC_ECCCONF1);
+ flash_status = readw(docptr + DOC_ECCCONF1);
+ if (flash_status & 0x80) { /* ecc error */
+ g4_index += 0x108; /* read redundant subpage */
+ buf -= 256; /* back up ram ptr */
+ continue;
+ } else /* no ecc error */
+ g4_index += 0x210; /* skip redundant subpage */
+ } else /* redundant page was just read; skip ecc error check */
+ g4_index += 0x108;
+
+ if (g4_index == 0x420) { /* finished with 2k page */
+ g4_index = 0;
+ g4_page += 2; /* odd-numbered 2k pages skipped */
+ }
+
+ } while (g4_page != last_g4_page); /* while still on same block */
+
+ return 0;
+}
generated by cgit (git 2.34.1) at 2024-12-28 09:18:26 +0000