diff --git a/drivers/mtd/nand/Makefile b/drivers/mtd/nand/Makefile
index c77c0c4..1bcf43c 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-$(CONFIG_SPL_NAND_ECC) += nand_ecc.o
@@ -78,6 +79,7 @@ COBJS-$(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 0000000..7dd9953
--- /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 0000000..95e856c
--- /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;
+}
diff --git a/include/linux/mtd/docg4.h b/include/linux/mtd/docg4.h
new file mode 100644
index 0000000..982f5ad
--- /dev/null
+++ b/include/linux/mtd/docg4.h
@@ -0,0 +1,134 @@
+/*
+ * 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.
+ *
+ */
+
+#ifndef __DOCG4_H__
+#define __DOCG4_H__
+
+#include <common.h>
+#include <linux/mtd/nand.h>
+
+extern int docg4_nand_init(struct mtd_info *mtd,
+			   struct nand_chip *nand, int devnum);
+
+/* SPL-related definitions */
+#define DOCG4_IPL_LOAD_BLOCK_COUNT 2  /* number of blocks that IPL loads */
+#define DOCG4_BLOCK_CAPACITY_SPL 0x10000 /* reliable mode; redundant pages */
+
+#define DOC_IOSPACE_DATA		0x0800
+
+/* register offsets */
+#define DOC_CHIPID			0x1000
+#define DOC_DEVICESELECT		0x100a
+#define DOC_ASICMODE			0x100c
+#define DOC_DATAEND			0x101e
+#define DOC_NOP				0x103e
+
+#define DOC_FLASHSEQUENCE		0x1032
+#define DOC_FLASHCOMMAND		0x1034
+#define DOC_FLASHADDRESS		0x1036
+#define DOC_FLASHCONTROL		0x1038
+#define DOC_ECCCONF0			0x1040
+#define DOC_ECCCONF1			0x1042
+#define DOC_HAMMINGPARITY		0x1046
+#define DOC_BCH_SYNDROM(idx)		(0x1048 + idx)
+
+#define DOC_ASICMODECONFIRM		0x1072
+#define DOC_CHIPID_INV			0x1074
+#define DOC_POWERMODE			0x107c
+
+#define DOCG4_MYSTERY_REG		0x1050
+
+/* apparently used only to write oob bytes 6 and 7 */
+#define DOCG4_OOB_6_7			0x1052
+
+/* DOC_FLASHSEQUENCE register commands */
+#define DOC_SEQ_RESET			0x00
+#define DOCG4_SEQ_PAGE_READ		0x03
+#define DOCG4_SEQ_FLUSH			0x29
+#define DOCG4_SEQ_PAGEWRITE		0x16
+#define DOCG4_SEQ_PAGEPROG		0x1e
+#define DOCG4_SEQ_BLOCKERASE		0x24
+
+/* DOC_FLASHCOMMAND register commands */
+#define DOCG4_CMD_PAGE_READ             0x00
+#define DOC_CMD_ERASECYCLE2		0xd0
+#define DOCG4_CMD_FLUSH                 0x70
+#define DOCG4_CMD_READ2                 0x30
+#define DOC_CMD_PROG_BLOCK_ADDR		0x60
+#define DOCG4_CMD_PAGEWRITE		0x80
+#define DOC_CMD_PROG_CYCLE2		0x10
+#define DOC_CMD_RESET			0xff
+
+/* DOC_POWERMODE register bits */
+#define DOC_POWERDOWN_READY		0x80
+
+/* DOC_FLASHCONTROL register bits */
+#define DOC_CTRL_CE			0x10
+#define DOC_CTRL_UNKNOWN		0x40
+#define DOC_CTRL_FLASHREADY		0x01
+
+/* DOC_ECCCONF0 register bits */
+#define DOC_ECCCONF0_READ_MODE		0x8000
+#define DOC_ECCCONF0_UNKNOWN		0x2000
+#define DOC_ECCCONF0_ECC_ENABLE	        0x1000
+#define DOC_ECCCONF0_DATA_BYTES_MASK	0x07ff
+
+/* DOC_ECCCONF1 register bits */
+#define DOC_ECCCONF1_BCH_SYNDROM_ERR	0x80
+#define DOC_ECCCONF1_ECC_ENABLE         0x07
+#define DOC_ECCCONF1_PAGE_IS_WRITTEN	0x20
+
+/* DOC_ASICMODE register bits */
+#define DOC_ASICMODE_RESET		0x00
+#define DOC_ASICMODE_NORMAL		0x01
+#define DOC_ASICMODE_POWERDOWN		0x02
+#define DOC_ASICMODE_MDWREN		0x04
+#define DOC_ASICMODE_BDETCT_RESET	0x08
+#define DOC_ASICMODE_RSTIN_RESET	0x10
+#define DOC_ASICMODE_RAM_WE		0x20
+
+/* good status values read after read/write/erase operations */
+#define DOCG4_PROGSTATUS_GOOD          0x51
+#define DOCG4_PROGSTATUS_GOOD_2        0xe0
+
+/*
+ * On read operations (page and oob-only), the first byte read from I/O reg is a
+ * status.  On error, it reads 0x73; otherwise, it reads either 0x71 (first read
+ * after reset only) or 0x51, so bit 1 is presumed to be an error indicator.
+ */
+#define DOCG4_READ_ERROR           0x02 /* bit 1 indicates read error */
+
+/* anatomy of the device */
+#define DOCG4_CHIP_SIZE        0x8000000
+#define DOCG4_PAGE_SIZE        0x200
+#define DOCG4_PAGES_PER_BLOCK  0x200
+#define DOCG4_BLOCK_SIZE       (DOCG4_PAGES_PER_BLOCK * DOCG4_PAGE_SIZE)
+#define DOCG4_NUMBLOCKS        (DOCG4_CHIP_SIZE / DOCG4_BLOCK_SIZE)
+#define DOCG4_OOB_SIZE         0x10
+#define DOCG4_CHIP_SHIFT       27    /* log_2(DOCG4_CHIP_SIZE) */
+#define DOCG4_PAGE_SHIFT       9     /* log_2(DOCG4_PAGE_SIZE) */
+#define DOCG4_ERASE_SHIFT      18    /* log_2(DOCG4_BLOCK_SIZE) */
+
+/* all but the last byte is included in ecc calculation */
+#define DOCG4_BCH_SIZE         (DOCG4_PAGE_SIZE + DOCG4_OOB_SIZE - 1)
+
+#define DOCG4_USERDATA_LEN     520 /* 512 byte page plus 8 oob avail to user */
+
+/* expected values from the ID registers */
+#define DOCG4_IDREG1_VALUE     0x0400
+#define DOCG4_IDREG2_VALUE     0xfbff
+
+/* primitive polynomial used to build the Galois field used by hw ecc gen */
+#define DOCG4_PRIMITIVE_POLY   0x4443
+
+#define DOCG4_M                14  /* Galois field is of order 2^14 */
+#define DOCG4_T                4   /* BCH alg corrects up to 4 bit errors */
+
+#define DOCG4_FACTORY_BBT_PAGE 16 /* page where read-only factory bbt lives */
+
+#endif	/* __DOCG4_H__ */
