docg3.c

Go to the documentation of this file.

/*
 * Handles the M-Systems DiskOnChip G3 chip
 *
 * Copyright (C) 2011 Robert Jarzmik
 *
 * 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.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/errno.h>
#include <linux/platform_device.h>
#include <linux/string.h>
#include <linux/slab.h>
#include <linux/io.h>
#include <linux/delay.h>
#include <linux/mtd/mtd.h>
#include <linux/mtd/partitions.h>
#include <linux/bitmap.h>
#include <linux/bitrev.h>
#include <linux/bch.h>

#include <linux/debugfs.h>
#include <linux/seq_file.h>

#define CREATE_TRACE_POINTS
#include "docg3.h"

/*
 * This driver handles the DiskOnChip G3 flash memory.
 *
 * As no specification is available from M-Systems/Sandisk, this drivers lacks
 * several functions available on the chip, as :
 *  - IPL write
 *
 * The bus data width (8bits versus 16bits) is not handled (if_cfg flag), and
 * the driver assumes a 16bits data bus.
 *
 * DocG3 relies on 2 ECC algorithms, which are handled in hardware :
 *  - a 1 byte Hamming code stored in the OOB for each page
 *  - a 7 bytes BCH code stored in the OOB for each page
 * The BCH ECC is :
 *  - BCH is in GF(2^14)
 *  - BCH is over data of 520 bytes (512 page + 7 page_info bytes
 *                                   + 1 hamming byte)
 *  - BCH can correct up to 4 bits (t = 4)
 *  - BCH syndroms are calculated in hardware, and checked in hardware as well
 *
 */

static unsigned int reliable_mode;
module_param(reliable_mode, uint, 0);
MODULE_PARM_DESC(reliable_mode, "Set the docg3 mode (0=normal MLC, 1=fast, "
         "2=reliable) : MLC normal operations are in normal mode");

static struct nand_ecclayout docg3_oobinfo = {
    .eccbytes = 8,
    .eccpos = {7, 8, 9, 10, 11, 12, 13, 14},
    .oobfree = {{0, 7}, {15, 1} },
    .oobavail = 8,
};

static inline u8 doc_readb(struct docg3 *docg3, u16 reg)
{
    u8 val = readb(docg3->cascade->base + reg);

    trace_docg3_io(0, 8, reg, (int)val);
    return val;
}

static inline u16 doc_readw(struct docg3 *docg3, u16 reg)
{
    u16 val = readw(docg3->cascade->base + reg);

    trace_docg3_io(0, 16, reg, (int)val);
    return val;
}

static inline void doc_writeb(struct docg3 *docg3, u8 val, u16 reg)
{
    writeb(val, docg3->cascade->base + reg);
    trace_docg3_io(1, 8, reg, val);
}

static inline void doc_writew(struct docg3 *docg3, u16 val, u16 reg)
{
    writew(val, docg3->cascade->base + reg);
    trace_docg3_io(1, 16, reg, val);
}

static inline void doc_flash_command(struct docg3 *docg3, u8 cmd)
{
    doc_writeb(docg3, cmd, DOC_FLASHCOMMAND);
}

static inline void doc_flash_sequence(struct docg3 *docg3, u8 seq)
{
    doc_writeb(docg3, seq, DOC_FLASHSEQUENCE);
}

static inline void doc_flash_address(struct docg3 *docg3, u8 addr)
{
    doc_writeb(docg3, addr, DOC_FLASHADDRESS);
}

static char const *part_probes[] = { "cmdlinepart", "saftlpart", NULL };

static int doc_register_readb(struct docg3 *docg3, int reg)
{
    u8 val;

    doc_writew(docg3, reg, DOC_READADDRESS);
    val = doc_readb(docg3, reg);
    doc_vdbg("Read register %04x : %02x\n", reg, val);
    return val;
}

static int doc_register_readw(struct docg3 *docg3, int reg)
{
    u16 val;

    doc_writew(docg3, reg, DOC_READADDRESS);
    val = doc_readw(docg3, reg);
    doc_vdbg("Read register %04x : %04x\n", reg, val);
    return val;
}

static void doc_delay(struct docg3 *docg3, int nbNOPs)
{
    int i;

    doc_vdbg("NOP x %d\n", nbNOPs);
    for (i = 0; i < nbNOPs; i++)
        doc_writeb(docg3, 0, DOC_NOP);
}

static int is_prot_seq_error(struct docg3 *docg3)
{
    int ctrl;

    ctrl = doc_register_readb(docg3, DOC_FLASHCONTROL);
    return ctrl & (DOC_CTRL_PROTECTION_ERROR | DOC_CTRL_SEQUENCE_ERROR);
}

static int doc_is_ready(struct docg3 *docg3)
{
    int ctrl;

    ctrl = doc_register_readb(docg3, DOC_FLASHCONTROL);
    return ctrl & DOC_CTRL_FLASHREADY;
}

static int doc_wait_ready(struct docg3 *docg3)
{
    int maxWaitCycles = 100;

    do {
        doc_delay(docg3, 4);
        cpu_relax();
    } while (!doc_is_ready(docg3) && maxWaitCycles--);
    doc_delay(docg3, 2);
    if (maxWaitCycles > 0)
        return 0;
    else
        return -EIO;
}

static int doc_reset_seq(struct docg3 *docg3)
{
    int ret;

    doc_writeb(docg3, 0x10, DOC_FLASHCONTROL);
    doc_flash_sequence(docg3, DOC_SEQ_RESET);
    doc_flash_command(docg3, DOC_CMD_RESET);
    doc_delay(docg3, 2);
    ret = doc_wait_ready(docg3);

    doc_dbg("doc_reset_seq() -> isReady=%s\n", ret ? "false" : "true");
    return ret;
}

static void doc_read_data_area(struct docg3 *docg3, void *buf, int len,
                   int first)
{
    int i, cdr, len4;
    u16 data16, *dst16;
    u8 data8, *dst8;

    doc_dbg("doc_read_data_area(buf=%p, len=%d)\n", buf, len);
    cdr = len & 0x1;
    len4 = len - cdr;

    if (first)
        doc_writew(docg3, DOC_IOSPACE_DATA, DOC_READADDRESS);
    dst16 = buf;
    for (i = 0; i < len4; i += 2) {
        data16 = doc_readw(docg3, DOC_IOSPACE_DATA);
        if (dst16) {
            *dst16 = data16;
            dst16++;
        }
    }

    if (cdr) {
        doc_writew(docg3, DOC_IOSPACE_DATA | DOC_READADDR_ONE_BYTE,
               DOC_READADDRESS);
        doc_delay(docg3, 1);
        dst8 = (u8 *)dst16;
        for (i = 0; i < cdr; i++) {
            data8 = doc_readb(docg3, DOC_IOSPACE_DATA);
            if (dst8) {
                *dst8 = data8;
                dst8++;
            }
        }
    }
}

static void doc_write_data_area(struct docg3 *docg3, const void *buf, int len)
{
    int i, cdr, len4;
    u16 *src16;
    u8 *src8;

    doc_dbg("doc_write_data_area(buf=%p, len=%d)\n", buf, len);
    cdr = len & 0x3;
    len4 = len - cdr;

    doc_writew(docg3, DOC_IOSPACE_DATA, DOC_READADDRESS);
    src16 = (u16 *)buf;
    for (i = 0; i < len4; i += 2) {
        doc_writew(docg3, *src16, DOC_IOSPACE_DATA);
        src16++;
    }

    src8 = (u8 *)src16;
    for (i = 0; i < cdr; i++) {
        doc_writew(docg3, DOC_IOSPACE_DATA | DOC_READADDR_ONE_BYTE,
               DOC_READADDRESS);
        doc_writeb(docg3, *src8, DOC_IOSPACE_DATA);
        src8++;
    }
}

static void doc_set_reliable_mode(struct docg3 *docg3)
{
    static char *strmode[] = { "normal", "fast", "reliable", "invalid" };

    doc_dbg("doc_set_reliable_mode(%s)\n", strmode[docg3->reliable]);
    switch (docg3->reliable) {
    case 0:
        break;
    case 1:
        doc_flash_sequence(docg3, DOC_SEQ_SET_FASTMODE);
        doc_flash_command(docg3, DOC_CMD_FAST_MODE);
        break;
    case 2:
        doc_flash_sequence(docg3, DOC_SEQ_SET_RELIABLEMODE);
        doc_flash_command(docg3, DOC_CMD_FAST_MODE);
        doc_flash_command(docg3, DOC_CMD_RELIABLE_MODE);
        break;
    default:
        doc_err("doc_set_reliable_mode(): invalid mode\n");
        break;
    }
    doc_delay(docg3, 2);
}

static void doc_set_asic_mode(struct docg3 *docg3, u8 mode)
{
    int i;

    for (i = 0; i < 12; i++)
        doc_readb(docg3, DOC_IOSPACE_IPL);

    mode |= DOC_ASICMODE_MDWREN;
    doc_dbg("doc_set_asic_mode(%02x)\n", mode);
    doc_writeb(docg3, mode, DOC_ASICMODE);
    doc_writeb(docg3, ~mode, DOC_ASICMODECONFIRM);
    doc_delay(docg3, 1);
}

static void doc_set_device_id(struct docg3 *docg3, int id)
{
    u8 ctrl;

    doc_dbg("doc_set_device_id(%d)\n", id);
    doc_writeb(docg3, id, DOC_DEVICESELECT);
    ctrl = doc_register_readb(docg3, DOC_FLASHCONTROL);

    ctrl &= ~DOC_CTRL_VIOLATION;
    ctrl |= DOC_CTRL_CE;
    doc_writeb(docg3, ctrl, DOC_FLASHCONTROL);
}

static int doc_set_extra_page_mode(struct docg3 *docg3)
{
    int fctrl;

    doc_dbg("doc_set_extra_page_mode()\n");
    doc_flash_sequence(docg3, DOC_SEQ_PAGE_SIZE_532);
    doc_flash_command(docg3, DOC_CMD_PAGE_SIZE_532);
    doc_delay(docg3, 2);

    fctrl = doc_register_readb(docg3, DOC_FLASHCONTROL);
    if (fctrl & (DOC_CTRL_PROTECTION_ERROR | DOC_CTRL_SEQUENCE_ERROR))
        return -EIO;
    else
        return 0;
}

static void doc_setup_addr_sector(struct docg3 *docg3, int sector)
{
    doc_delay(docg3, 1);
    doc_flash_address(docg3, sector & 0xff);
    doc_flash_address(docg3, (sector >> 8) & 0xff);
    doc_flash_address(docg3, (sector >> 16) & 0xff);
    doc_delay(docg3, 1);
}

static void doc_setup_writeaddr_sector(struct docg3 *docg3, int sector, int ofs)
{
    ofs = ofs >> 2;
    doc_delay(docg3, 1);
    doc_flash_address(docg3, ofs & 0xff);
    doc_flash_address(docg3, sector & 0xff);
    doc_flash_address(docg3, (sector >> 8) & 0xff);
    doc_flash_address(docg3, (sector >> 16) & 0xff);
    doc_delay(docg3, 1);
}

static int doc_read_seek(struct docg3 *docg3, int block0, int block1, int page,
             int wear, int ofs)
{
    int sector, ret = 0;

    doc_dbg("doc_seek(blocks=(%d,%d), page=%d, ofs=%d, wear=%d)\n",
        block0, block1, page, ofs, wear);

    if (!wear && (ofs < 2 * DOC_LAYOUT_PAGE_SIZE)) {
        doc_flash_sequence(docg3, DOC_SEQ_SET_PLANE1);
        doc_flash_command(docg3, DOC_CMD_READ_PLANE1);
        doc_delay(docg3, 2);
    } else {
        doc_flash_sequence(docg3, DOC_SEQ_SET_PLANE2);
        doc_flash_command(docg3, DOC_CMD_READ_PLANE2);
        doc_delay(docg3, 2);
    }

    doc_set_reliable_mode(docg3);
    if (wear)
        ret = doc_set_extra_page_mode(docg3);
    if (ret)
        goto out;

    doc_flash_sequence(docg3, DOC_SEQ_READ);
    sector = (block0 << DOC_ADDR_BLOCK_SHIFT) + (page & DOC_ADDR_PAGE_MASK);
    doc_flash_command(docg3, DOC_CMD_PROG_BLOCK_ADDR);
    doc_setup_addr_sector(docg3, sector);

    sector = (block1 << DOC_ADDR_BLOCK_SHIFT) + (page & DOC_ADDR_PAGE_MASK);
    doc_flash_command(docg3, DOC_CMD_PROG_BLOCK_ADDR);
    doc_setup_addr_sector(docg3, sector);
    doc_delay(docg3, 1);

out:
    return ret;
}

static int doc_write_seek(struct docg3 *docg3, int block0, int block1, int page,
             int ofs)
{
    int ret = 0, sector;

    doc_dbg("doc_write_seek(blocks=(%d,%d), page=%d, ofs=%d)\n",
        block0, block1, page, ofs);

    doc_set_reliable_mode(docg3);

    if (ofs < 2 * DOC_LAYOUT_PAGE_SIZE) {
        doc_flash_sequence(docg3, DOC_SEQ_SET_PLANE1);
        doc_flash_command(docg3, DOC_CMD_READ_PLANE1);
        doc_delay(docg3, 2);
    } else {
        doc_flash_sequence(docg3, DOC_SEQ_SET_PLANE2);
        doc_flash_command(docg3, DOC_CMD_READ_PLANE2);
        doc_delay(docg3, 2);
    }

    doc_flash_sequence(docg3, DOC_SEQ_PAGE_SETUP);
    doc_flash_command(docg3, DOC_CMD_PROG_CYCLE1);

    sector = (block0 << DOC_ADDR_BLOCK_SHIFT) + (page & DOC_ADDR_PAGE_MASK);
    doc_setup_writeaddr_sector(docg3, sector, ofs);

    doc_flash_command(docg3, DOC_CMD_PROG_CYCLE3);
    doc_delay(docg3, 2);
    ret = doc_wait_ready(docg3);
    if (ret)
        goto out;

    doc_flash_command(docg3, DOC_CMD_PROG_CYCLE1);
    sector = (block1 << DOC_ADDR_BLOCK_SHIFT) + (page & DOC_ADDR_PAGE_MASK);
    doc_setup_writeaddr_sector(docg3, sector, ofs);
    doc_delay(docg3, 1);

out:
    return ret;
}


static int doc_read_page_ecc_init(struct docg3 *docg3, int len)
{
    doc_writew(docg3, DOC_ECCCONF0_READ_MODE
           | DOC_ECCCONF0_BCH_ENABLE | DOC_ECCCONF0_HAMMING_ENABLE
           | (len & DOC_ECCCONF0_DATA_BYTES_MASK),
           DOC_ECCCONF0);
    doc_delay(docg3, 4);
    doc_register_readb(docg3, DOC_FLASHCONTROL);
    return doc_wait_ready(docg3);
}

static int doc_write_page_ecc_init(struct docg3 *docg3, int len)
{
    doc_writew(docg3, DOC_ECCCONF0_WRITE_MODE
           | DOC_ECCCONF0_BCH_ENABLE | DOC_ECCCONF0_HAMMING_ENABLE
           | (len & DOC_ECCCONF0_DATA_BYTES_MASK),
           DOC_ECCCONF0);
    doc_delay(docg3, 4);
    doc_register_readb(docg3, DOC_FLASHCONTROL);
    return doc_wait_ready(docg3);
}

static void doc_ecc_disable(struct docg3 *docg3)
{
    doc_writew(docg3, DOC_ECCCONF0_READ_MODE, DOC_ECCCONF0);
    doc_delay(docg3, 4);
}

static void doc_hamming_ecc_init(struct docg3 *docg3, int nb_bytes)
{
    u8 ecc_conf1;

    ecc_conf1 = doc_register_readb(docg3, DOC_ECCCONF1);
    ecc_conf1 &= ~DOC_ECCCONF1_HAMMING_BITS_MASK;
    ecc_conf1 |= (nb_bytes & DOC_ECCCONF1_HAMMING_BITS_MASK);
    doc_writeb(docg3, ecc_conf1, DOC_ECCCONF1);
}

static int doc_ecc_bch_fix_data(struct docg3 *docg3, void *buf, u8 *hwecc)
{
    u8 ecc[DOC_ECC_BCH_SIZE];
    int errorpos[DOC_ECC_BCH_T], i, numerrs;

    for (i = 0; i < DOC_ECC_BCH_SIZE; i++)
        ecc[i] = bitrev8(hwecc[i]);
    numerrs = decode_bch(docg3->cascade->bch, NULL,
                 DOC_ECC_BCH_COVERED_BYTES,
                 NULL, ecc, NULL, errorpos);
    BUG_ON(numerrs == -EINVAL);
    if (numerrs < 0)
        goto out;

    for (i = 0; i < numerrs; i++)
        errorpos[i] = (errorpos[i] & ~7) | (7 - (errorpos[i] & 7));
    for (i = 0; i < numerrs; i++)
        if (errorpos[i] < DOC_ECC_BCH_COVERED_BYTES*8)
            /* error is located in data, correct it */
            change_bit(errorpos[i], buf);
out:
    doc_dbg("doc_ecc_bch_fix_data: flipped %d bits\n", numerrs);
    return numerrs;
}


static int doc_read_page_prepare(struct docg3 *docg3, int block0, int block1,
                 int page, int offset)
{
    int wear_area = 0, ret = 0;

    doc_dbg("doc_read_page_prepare(blocks=(%d,%d), page=%d, ofsInPage=%d)\n",
        block0, block1, page, offset);
    if (offset >= DOC_LAYOUT_WEAR_OFFSET)
        wear_area = 1;
    if (!wear_area && offset > (DOC_LAYOUT_PAGE_OOB_SIZE * 2))
        return -EINVAL;

    doc_set_device_id(docg3, docg3->device_id);
    ret = doc_reset_seq(docg3);
    if (ret)
        goto err;

    /* Program the flash address block and page */
    ret = doc_read_seek(docg3, block0, block1, page, wear_area, offset);
    if (ret)
        goto err;

    doc_flash_command(docg3, DOC_CMD_READ_ALL_PLANES);
    doc_delay(docg3, 2);
    doc_wait_ready(docg3);

    doc_flash_command(docg3, DOC_CMD_SET_ADDR_READ);
    doc_delay(docg3, 1);
    if (offset >= DOC_LAYOUT_PAGE_SIZE * 2)
        offset -= 2 * DOC_LAYOUT_PAGE_SIZE;
    doc_flash_address(docg3, offset >> 2);
    doc_delay(docg3, 1);
    doc_wait_ready(docg3);

    doc_flash_command(docg3, DOC_CMD_READ_FLASH);

    return 0;
err:
    doc_writeb(docg3, 0, DOC_DATAEND);
    doc_delay(docg3, 2);
    return -EIO;
}

static int doc_read_page_getbytes(struct docg3 *docg3, int len, u_char *buf,
                  int first, int last_odd)
{
    if (last_odd && len > 0) {
        doc_read_data_area(docg3, buf, 1, first);
        doc_read_data_area(docg3, buf ? buf + 1 : buf, len - 1, 0);
    } else {
        doc_read_data_area(docg3, buf, len, first);
    }
    doc_delay(docg3, 2);
    return len;
}

static void doc_write_page_putbytes(struct docg3 *docg3, int len,
                    const u_char *buf)
{
    doc_write_data_area(docg3, buf, len);
    doc_delay(docg3, 2);
}

static void doc_get_bch_hw_ecc(struct docg3 *docg3, u8 *hwecc)
{
    int i;

    for (i = 0; i < DOC_ECC_BCH_SIZE; i++)
        hwecc[i] = doc_register_readb(docg3, DOC_BCH_HW_ECC(i));
}

static void doc_page_finish(struct docg3 *docg3)
{
    doc_writeb(docg3, 0, DOC_DATAEND);
    doc_delay(docg3, 2);
}

static void doc_read_page_finish(struct docg3 *docg3)
{
    doc_page_finish(docg3);
    doc_set_device_id(docg3, 0);
}

static void calc_block_sector(loff_t from, int *block0, int *block1, int *page,
                  int *ofs, int reliable)
{
    uint sector, pages_biblock;

    pages_biblock = DOC_LAYOUT_PAGES_PER_BLOCK * DOC_LAYOUT_NBPLANES;
    if (reliable == 1 || reliable == 2)
        pages_biblock /= 2;

    sector = from / DOC_LAYOUT_PAGE_SIZE;
    *block0 = sector / pages_biblock * DOC_LAYOUT_NBPLANES;
    *block1 = *block0 + 1;
    *page = sector % pages_biblock;
    *page /= DOC_LAYOUT_NBPLANES;
    if (reliable == 1 || reliable == 2)
        *page *= 2;
    if (sector % 2)
        *ofs = DOC_LAYOUT_PAGE_OOB_SIZE;
    else
        *ofs = 0;
}

static int doc_read_oob(struct mtd_info *mtd, loff_t from,
            struct mtd_oob_ops *ops)
{
    struct docg3 *docg3 = mtd->priv;
    int block0, block1, page, ret, skip, ofs = 0;
    u8 *oobbuf = ops->oobbuf;
    u8 *buf = ops->datbuf;
    size_t len, ooblen, nbdata, nboob;
    u8 hwecc[DOC_ECC_BCH_SIZE], eccconf1;
    int max_bitflips = 0;

    if (buf)
        len = ops->len;
    else
        len = 0;
    if (oobbuf)
        ooblen = ops->ooblen;
    else
        ooblen = 0;

    if (oobbuf && ops->mode == MTD_OPS_PLACE_OOB)
        oobbuf += ops->ooboffs;

    doc_dbg("doc_read_oob(from=%lld, mode=%d, data=(%p:%zu), oob=(%p:%zu))\n",
        from, ops->mode, buf, len, oobbuf, ooblen);
    if (ooblen % DOC_LAYOUT_OOB_SIZE)
        return -EINVAL;

    if (from + len > mtd->size)
        return -EINVAL;

    ops->oobretlen = 0;
    ops->retlen = 0;
    ret = 0;
    skip = from % DOC_LAYOUT_PAGE_SIZE;
    mutex_lock(&docg3->cascade->lock);
    while (ret >= 0 && (len > 0 || ooblen > 0)) {
        calc_block_sector(from - skip, &block0, &block1, &page, &ofs,
            docg3->reliable);
        nbdata = min_t(size_t, len, DOC_LAYOUT_PAGE_SIZE - skip);
        nboob = min_t(size_t, ooblen, (size_t)DOC_LAYOUT_OOB_SIZE);
        ret = doc_read_page_prepare(docg3, block0, block1, page, ofs);
        if (ret < 0)
            goto out;
        ret = doc_read_page_ecc_init(docg3, DOC_ECC_BCH_TOTAL_BYTES);
        if (ret < 0)
            goto err_in_read;
        ret = doc_read_page_getbytes(docg3, skip, NULL, 1, 0);
        if (ret < skip)
            goto err_in_read;
        ret = doc_read_page_getbytes(docg3, nbdata, buf, 0, skip % 2);
        if (ret < nbdata)
            goto err_in_read;
        doc_read_page_getbytes(docg3,
                       DOC_LAYOUT_PAGE_SIZE - nbdata - skip,
                       NULL, 0, (skip + nbdata) % 2);
        ret = doc_read_page_getbytes(docg3, nboob, oobbuf, 0, 0);
        if (ret < nboob)
            goto err_in_read;
        doc_read_page_getbytes(docg3, DOC_LAYOUT_OOB_SIZE - nboob,
                       NULL, 0, nboob % 2);

        doc_get_bch_hw_ecc(docg3, hwecc);
        eccconf1 = doc_register_readb(docg3, DOC_ECCCONF1);

        if (nboob >= DOC_LAYOUT_OOB_SIZE) {
            doc_dbg("OOB - INFO: %*phC\n", 7, oobbuf);
            doc_dbg("OOB - HAMMING: %02x\n", oobbuf[7]);
            doc_dbg("OOB - BCH_ECC: %*phC\n", 7, oobbuf + 8);
            doc_dbg("OOB - UNUSED: %02x\n", oobbuf[15]);
        }
        doc_dbg("ECC checks: ECCConf1=%x\n", eccconf1);
        doc_dbg("ECC HW_ECC: %*phC\n", 7, hwecc);

        ret = -EIO;
        if (is_prot_seq_error(docg3))
            goto err_in_read;
        ret = 0;
        if ((block0 >= DOC_LAYOUT_BLOCK_FIRST_DATA) &&
            (eccconf1 & DOC_ECCCONF1_BCH_SYNDROM_ERR) &&
            (eccconf1 & DOC_ECCCONF1_PAGE_IS_WRITTEN) &&
            (ops->mode != MTD_OPS_RAW) &&
            (nbdata == DOC_LAYOUT_PAGE_SIZE)) {
            ret = doc_ecc_bch_fix_data(docg3, buf, hwecc);
            if (ret < 0) {
                mtd->ecc_stats.failed++;
                ret = -EBADMSG;
            }
            if (ret > 0) {
                mtd->ecc_stats.corrected += ret;
                max_bitflips = max(max_bitflips, ret);
                ret = max_bitflips;
            }
        }

        doc_read_page_finish(docg3);
        ops->retlen += nbdata;
        ops->oobretlen += nboob;
        buf += nbdata;
        oobbuf += nboob;
        len -= nbdata;
        ooblen -= nboob;
        from += DOC_LAYOUT_PAGE_SIZE;
        skip = 0;
    }

out:
    mutex_unlock(&docg3->cascade->lock);
    return ret;
err_in_read:
    doc_read_page_finish(docg3);
    goto out;
}

static int doc_read(struct mtd_info *mtd, loff_t from, size_t len,
         size_t *retlen, u_char *buf)
{
    struct mtd_oob_ops ops;
    size_t ret;

    memset(&ops, 0, sizeof(ops));
    ops.datbuf = buf;
    ops.len = len;
    ops.mode = MTD_OPS_AUTO_OOB;

    ret = doc_read_oob(mtd, from, &ops);
    *retlen = ops.retlen;
    return ret;
}

static int doc_reload_bbt(struct docg3 *docg3)
{
    int block = DOC_LAYOUT_BLOCK_BBT;
    int ret = 0, nbpages, page;
    u_char *buf = docg3->bbt;

    nbpages = DIV_ROUND_UP(docg3->max_block + 1, 8 * DOC_LAYOUT_PAGE_SIZE);
    for (page = 0; !ret && (page < nbpages); page++) {
        ret = doc_read_page_prepare(docg3, block, block + 1,
                        page + DOC_LAYOUT_PAGE_BBT, 0);
        if (!ret)
            ret = doc_read_page_ecc_init(docg3,
                             DOC_LAYOUT_PAGE_SIZE);
        if (!ret)
            doc_read_page_getbytes(docg3, DOC_LAYOUT_PAGE_SIZE,
                           buf, 1, 0);
        buf += DOC_LAYOUT_PAGE_SIZE;
    }
    doc_read_page_finish(docg3);
    return ret;
}

static int doc_block_isbad(struct mtd_info *mtd, loff_t from)
{
    struct docg3 *docg3 = mtd->priv;
    int block0, block1, page, ofs, is_good;

    calc_block_sector(from, &block0, &block1, &page, &ofs,
        docg3->reliable);
    doc_dbg("doc_block_isbad(from=%lld) => block=(%d,%d), page=%d, ofs=%d\n",
        from, block0, block1, page, ofs);

    if (block0 < DOC_LAYOUT_BLOCK_FIRST_DATA)
        return 0;
    if (block1 > docg3->max_block)
        return -EINVAL;

    is_good = docg3->bbt[block0 >> 3] & (1 << (block0 & 0x7));
    return !is_good;
}

#if 0

static int doc_get_erase_count(struct docg3 *docg3, loff_t from)
{
    u8 buf[DOC_LAYOUT_WEAR_SIZE];
    int ret, plane1_erase_count, plane2_erase_count;
    int block0, block1, page, ofs;

    doc_dbg("doc_get_erase_count(from=%lld, buf=%p)\n", from, buf);
    if (from % DOC_LAYOUT_PAGE_SIZE)
        return -EINVAL;
    calc_block_sector(from, &block0, &block1, &page, &ofs, docg3->reliable);
    if (block1 > docg3->max_block)
        return -EINVAL;

    ret = doc_reset_seq(docg3);
    if (!ret)
        ret = doc_read_page_prepare(docg3, block0, block1, page,
                        ofs + DOC_LAYOUT_WEAR_OFFSET, 0);
    if (!ret)
        ret = doc_read_page_getbytes(docg3, DOC_LAYOUT_WEAR_SIZE,
                         buf, 1, 0);
    doc_read_page_finish(docg3);

    if (ret || (buf[0] != DOC_ERASE_MARK) || (buf[2] != DOC_ERASE_MARK))
        return -EIO;
    plane1_erase_count = (u8)(~buf[1]) | ((u8)(~buf[4]) << 8)
        | ((u8)(~buf[5]) << 16);
    plane2_erase_count = (u8)(~buf[3]) | ((u8)(~buf[6]) << 8)
        | ((u8)(~buf[7]) << 16);

    return max(plane1_erase_count, plane2_erase_count);
}
#endif

static int doc_get_op_status(struct docg3 *docg3)
{
    u8 status;

    doc_flash_sequence(docg3, DOC_SEQ_PLANES_STATUS);
    doc_flash_command(docg3, DOC_CMD_PLANES_STATUS);
    doc_delay(docg3, 5);

    doc_ecc_disable(docg3);
    doc_read_data_area(docg3, &status, 1, 1);
    return status;
}

static int doc_write_erase_wait_status(struct docg3 *docg3)
{
    int i, status, ret = 0;

    for (i = 0; !doc_is_ready(docg3) && i < 5; i++)
        msleep(20);
    if (!doc_is_ready(docg3)) {
        doc_dbg("Timeout reached and the chip is still not ready\n");
        ret = -EAGAIN;
        goto out;
    }

    status = doc_get_op_status(docg3);
    if (status & DOC_PLANES_STATUS_FAIL) {
        doc_dbg("Erase/Write failed on (a) plane(s), status = %x\n",
            status);
        ret = -EIO;
    }

out:
    doc_page_finish(docg3);
    return ret;
}

static int doc_erase_block(struct docg3 *docg3, int block0, int block1)
{
    int ret, sector;

    doc_dbg("doc_erase_block(blocks=(%d,%d))\n", block0, block1);
    ret = doc_reset_seq(docg3);
    if (ret)
        return -EIO;

    doc_set_reliable_mode(docg3);
    doc_flash_sequence(docg3, DOC_SEQ_ERASE);

    sector = block0 << DOC_ADDR_BLOCK_SHIFT;
    doc_flash_command(docg3, DOC_CMD_PROG_BLOCK_ADDR);
    doc_setup_addr_sector(docg3, sector);
    sector = block1 << DOC_ADDR_BLOCK_SHIFT;
    doc_flash_command(docg3, DOC_CMD_PROG_BLOCK_ADDR);
    doc_setup_addr_sector(docg3, sector);
    doc_delay(docg3, 1);

    doc_flash_command(docg3, DOC_CMD_ERASECYCLE2);
    doc_delay(docg3, 2);

    if (is_prot_seq_error(docg3)) {
        doc_err("Erase blocks %d,%d error\n", block0, block1);
        return -EIO;
    }

    return doc_write_erase_wait_status(docg3);
}

static int doc_erase(struct mtd_info *mtd, struct erase_info *info)
{
    struct docg3 *docg3 = mtd->priv;
    uint64_t len;
    int block0, block1, page, ret, ofs = 0;

    doc_dbg("doc_erase(from=%lld, len=%lld\n", info->addr, info->len);

    info->state = MTD_ERASE_PENDING;
    calc_block_sector(info->addr + info->len, &block0, &block1, &page,
              &ofs, docg3->reliable);
    ret = -EINVAL;
    if (info->addr + info->len > mtd->size || page || ofs)
        goto reset_err;

    ret = 0;
    calc_block_sector(info->addr, &block0, &block1, &page, &ofs,
              docg3->reliable);
    mutex_lock(&docg3->cascade->lock);
    doc_set_device_id(docg3, docg3->device_id);
    doc_set_reliable_mode(docg3);
    for (len = info->len; !ret && len > 0; len -= mtd->erasesize) {
        info->state = MTD_ERASING;
        ret = doc_erase_block(docg3, block0, block1);
        block0 += 2;
        block1 += 2;
    }
    mutex_unlock(&docg3->cascade->lock);

    if (ret)
        goto reset_err;

    info->state = MTD_ERASE_DONE;
    return 0;

reset_err:
    info->state = MTD_ERASE_FAILED;
    return ret;
}

static int doc_write_page(struct docg3 *docg3, loff_t to, const u_char *buf,
              const u_char *oob, int autoecc)
{
    int block0, block1, page, ret, ofs = 0;
    u8 hwecc[DOC_ECC_BCH_SIZE], hamming;

    doc_dbg("doc_write_page(to=%lld)\n", to);
    calc_block_sector(to, &block0, &block1, &page, &ofs, docg3->reliable);

    doc_set_device_id(docg3, docg3->device_id);
    ret = doc_reset_seq(docg3);
    if (ret)
        goto err;

    /* Program the flash address block and page */
    ret = doc_write_seek(docg3, block0, block1, page, ofs);
    if (ret)
        goto err;

    doc_write_page_ecc_init(docg3, DOC_ECC_BCH_TOTAL_BYTES);
    doc_delay(docg3, 2);
    doc_write_page_putbytes(docg3, DOC_LAYOUT_PAGE_SIZE, buf);

    if (oob && autoecc) {
        doc_write_page_putbytes(docg3, DOC_LAYOUT_OOB_PAGEINFO_SZ, oob);
        doc_delay(docg3, 2);
        oob += DOC_LAYOUT_OOB_UNUSED_OFS;

        hamming = doc_register_readb(docg3, DOC_HAMMINGPARITY);
        doc_delay(docg3, 2);
        doc_write_page_putbytes(docg3, DOC_LAYOUT_OOB_HAMMING_SZ,
                    &hamming);
        doc_delay(docg3, 2);

        doc_get_bch_hw_ecc(docg3, hwecc);
        doc_write_page_putbytes(docg3, DOC_LAYOUT_OOB_BCH_SZ, hwecc);
        doc_delay(docg3, 2);

        doc_write_page_putbytes(docg3, DOC_LAYOUT_OOB_UNUSED_SZ, oob);
    }
    if (oob && !autoecc)
        doc_write_page_putbytes(docg3, DOC_LAYOUT_OOB_SIZE, oob);

    doc_delay(docg3, 2);
    doc_page_finish(docg3);
    doc_delay(docg3, 2);
    doc_flash_command(docg3, DOC_CMD_PROG_CYCLE2);
    doc_delay(docg3, 2);

    /*
     * The wait status will perform another doc_page_finish() call, but that
     * seems to please the docg3, so leave it.
     */
    ret = doc_write_erase_wait_status(docg3);
    return ret;
err:
    doc_read_page_finish(docg3);
    return ret;
}

static int doc_guess_autoecc(struct mtd_oob_ops *ops)
{
    int autoecc;

    switch (ops->mode) {
    case MTD_OPS_PLACE_OOB:
    case MTD_OPS_AUTO_OOB:
        autoecc = 1;
        break;
    case MTD_OPS_RAW:
        autoecc = 0;
        break;
    default:
        autoecc = -EINVAL;
    }
    return autoecc;
}

static void doc_fill_autooob(u8 *dst, u8 *oobsrc)
{
    memcpy(dst, oobsrc, DOC_LAYOUT_OOB_PAGEINFO_SZ);
    dst[DOC_LAYOUT_OOB_UNUSED_OFS] = oobsrc[DOC_LAYOUT_OOB_PAGEINFO_SZ];
}

static int doc_backup_oob(struct docg3 *docg3, loff_t to,
              struct mtd_oob_ops *ops)
{
    int ooblen = ops->ooblen, autoecc;

    if (ooblen != DOC_LAYOUT_OOB_SIZE)
        return -EINVAL;
    autoecc = doc_guess_autoecc(ops);
    if (autoecc < 0)
        return autoecc;

    docg3->oob_write_ofs = to;
    docg3->oob_autoecc = autoecc;
    if (ops->mode == MTD_OPS_AUTO_OOB) {
        doc_fill_autooob(docg3->oob_write_buf, ops->oobbuf);
        ops->oobretlen = 8;
    } else {
        memcpy(docg3->oob_write_buf, ops->oobbuf, DOC_LAYOUT_OOB_SIZE);
        ops->oobretlen = DOC_LAYOUT_OOB_SIZE;
    }
    return 0;
}

static int doc_write_oob(struct mtd_info *mtd, loff_t ofs,
             struct mtd_oob_ops *ops)
{
    struct docg3 *docg3 = mtd->priv;
    int ret, autoecc, oobdelta;
    u8 *oobbuf = ops->oobbuf;
    u8 *buf = ops->datbuf;
    size_t len, ooblen;
    u8 oob[DOC_LAYOUT_OOB_SIZE];

    if (buf)
        len = ops->len;
    else
        len = 0;
    if (oobbuf)
        ooblen = ops->ooblen;
    else
        ooblen = 0;

    if (oobbuf && ops->mode == MTD_OPS_PLACE_OOB)
        oobbuf += ops->ooboffs;

    doc_dbg("doc_write_oob(from=%lld, mode=%d, data=(%p:%zu), oob=(%p:%zu))\n",
        ofs, ops->mode, buf, len, oobbuf, ooblen);
    switch (ops->mode) {
    case MTD_OPS_PLACE_OOB:
    case MTD_OPS_RAW:
        oobdelta = mtd->oobsize;
        break;
    case MTD_OPS_AUTO_OOB:
        oobdelta = mtd->ecclayout->oobavail;
        break;
    default:
        oobdelta = 0;
    }
    if ((len % DOC_LAYOUT_PAGE_SIZE) || (ooblen % oobdelta) ||
        (ofs % DOC_LAYOUT_PAGE_SIZE))
        return -EINVAL;
    if (len && ooblen &&
        (len / DOC_LAYOUT_PAGE_SIZE) != (ooblen / oobdelta))
        return -EINVAL;
    if (ofs + len > mtd->size)
        return -EINVAL;

    ops->oobretlen = 0;
    ops->retlen = 0;
    ret = 0;
    if (len == 0 && ooblen == 0)
        return -EINVAL;
    if (len == 0 && ooblen > 0)
        return doc_backup_oob(docg3, ofs, ops);

    autoecc = doc_guess_autoecc(ops);
    if (autoecc < 0)
        return autoecc;

    mutex_lock(&docg3->cascade->lock);
    while (!ret && len > 0) {
        memset(oob, 0, sizeof(oob));
        if (ofs == docg3->oob_write_ofs)
            memcpy(oob, docg3->oob_write_buf, DOC_LAYOUT_OOB_SIZE);
        else if (ooblen > 0 && ops->mode == MTD_OPS_AUTO_OOB)
            doc_fill_autooob(oob, oobbuf);
        else if (ooblen > 0)
            memcpy(oob, oobbuf, DOC_LAYOUT_OOB_SIZE);
        ret = doc_write_page(docg3, ofs, buf, oob, autoecc);

        ofs += DOC_LAYOUT_PAGE_SIZE;
        len -= DOC_LAYOUT_PAGE_SIZE;
        buf += DOC_LAYOUT_PAGE_SIZE;
        if (ooblen) {
            oobbuf += oobdelta;
            ooblen -= oobdelta;
            ops->oobretlen += oobdelta;
        }
        ops->retlen += DOC_LAYOUT_PAGE_SIZE;
    }

    doc_set_device_id(docg3, 0);
    mutex_unlock(&docg3->cascade->lock);
    return ret;
}

static int doc_write(struct mtd_info *mtd, loff_t to, size_t len,
             size_t *retlen, const u_char *buf)
{
    struct docg3 *docg3 = mtd->priv;
    int ret;
    struct mtd_oob_ops ops;

    doc_dbg("doc_write(to=%lld, len=%zu)\n", to, len);
    ops.datbuf = (char *)buf;
    ops.len = len;
    ops.mode = MTD_OPS_PLACE_OOB;
    ops.oobbuf = NULL;
    ops.ooblen = 0;
    ops.ooboffs = 0;

    ret = doc_write_oob(mtd, to, &ops);
    *retlen = ops.retlen;
    return ret;
}

static struct docg3 *sysfs_dev2docg3(struct device *dev,
                     struct device_attribute *attr)
{
    int floor;
    struct platform_device *pdev = to_platform_device(dev);
    struct mtd_info **docg3_floors = platform_get_drvdata(pdev);

    floor = attr->attr.name[1] - '0';
    if (floor < 0 || floor >= DOC_MAX_NBFLOORS)
        return NULL;
    else
        return docg3_floors[floor]->priv;
}

static ssize_t dps0_is_key_locked(struct device *dev,
                  struct device_attribute *attr, char *buf)
{
    struct docg3 *docg3 = sysfs_dev2docg3(dev, attr);
    int dps0;

    mutex_lock(&docg3->cascade->lock);
    doc_set_device_id(docg3, docg3->device_id);
    dps0 = doc_register_readb(docg3, DOC_DPS0_STATUS);
    doc_set_device_id(docg3, 0);
    mutex_unlock(&docg3->cascade->lock);

    return sprintf(buf, "%d\n", !(dps0 & DOC_DPS_KEY_OK));
}

static ssize_t dps1_is_key_locked(struct device *dev,
                  struct device_attribute *attr, char *buf)
{
    struct docg3 *docg3 = sysfs_dev2docg3(dev, attr);
    int dps1;

    mutex_lock(&docg3->cascade->lock);
    doc_set_device_id(docg3, docg3->device_id);
    dps1 = doc_register_readb(docg3, DOC_DPS1_STATUS);
    doc_set_device_id(docg3, 0);
    mutex_unlock(&docg3->cascade->lock);

    return sprintf(buf, "%d\n", !(dps1 & DOC_DPS_KEY_OK));
}

static ssize_t dps0_insert_key(struct device *dev,
                   struct device_attribute *attr,
                   const char *buf, size_t count)
{
    struct docg3 *docg3 = sysfs_dev2docg3(dev, attr);
    int i;

    if (count != DOC_LAYOUT_DPS_KEY_LENGTH)
        return -EINVAL;

    mutex_lock(&docg3->cascade->lock);
    doc_set_device_id(docg3, docg3->device_id);
    for (i = 0; i < DOC_LAYOUT_DPS_KEY_LENGTH; i++)
        doc_writeb(docg3, buf[i], DOC_DPS0_KEY);
    doc_set_device_id(docg3, 0);
    mutex_unlock(&docg3->cascade->lock);
    return count;
}

static ssize_t dps1_insert_key(struct device *dev,
                   struct device_attribute *attr,
                   const char *buf, size_t count)
{
    struct docg3 *docg3 = sysfs_dev2docg3(dev, attr);
    int i;

    if (count != DOC_LAYOUT_DPS_KEY_LENGTH)
        return -EINVAL;

    mutex_lock(&docg3->cascade->lock);
    doc_set_device_id(docg3, docg3->device_id);
    for (i = 0; i < DOC_LAYOUT_DPS_KEY_LENGTH; i++)
        doc_writeb(docg3, buf[i], DOC_DPS1_KEY);
    doc_set_device_id(docg3, 0);
    mutex_unlock(&docg3->cascade->lock);
    return count;
}

#define FLOOR_SYSFS(id) { \
    __ATTR(f##id##_dps0_is_keylocked, S_IRUGO, dps0_is_key_locked, NULL), \
    __ATTR(f##id##_dps1_is_keylocked, S_IRUGO, dps1_is_key_locked, NULL), \
    __ATTR(f##id##_dps0_protection_key, S_IWUGO, NULL, dps0_insert_key), \
    __ATTR(f##id##_dps1_protection_key, S_IWUGO, NULL, dps1_insert_key), \
}

static struct device_attribute doc_sys_attrs[DOC_MAX_NBFLOORS][4] = {
    FLOOR_SYSFS(0), FLOOR_SYSFS(1), FLOOR_SYSFS(2), FLOOR_SYSFS(3)
};

static int doc_register_sysfs(struct platform_device *pdev,
                  struct docg3_cascade *cascade)
{
    int ret = 0, floor, i = 0;
    struct device *dev = &pdev->dev;

    for (floor = 0; !ret && floor < DOC_MAX_NBFLOORS &&
             cascade->floors[floor]; floor++)
        for (i = 0; !ret && i < 4; i++)
            ret = device_create_file(dev, &doc_sys_attrs[floor][i]);
    if (!ret)
        return 0;
    do {
        while (--i >= 0)
            device_remove_file(dev, &doc_sys_attrs[floor][i]);
        i = 4;
    } while (--floor >= 0);
    return ret;
}

static void doc_unregister_sysfs(struct platform_device *pdev,
                 struct docg3_cascade *cascade)
{
    struct device *dev = &pdev->dev;
    int floor, i;

    for (floor = 0; floor < DOC_MAX_NBFLOORS && cascade->floors[floor];
         floor++)
        for (i = 0; i < 4; i++)
            device_remove_file(dev, &doc_sys_attrs[floor][i]);
}

/*
 * Debug sysfs entries
 */
static int dbg_flashctrl_show(struct seq_file *s, void *p)
{
    struct docg3 *docg3 = (struct docg3 *)s->private;

    int pos = 0;
    u8 fctrl;

    mutex_lock(&docg3->cascade->lock);
    fctrl = doc_register_readb(docg3, DOC_FLASHCONTROL);
    mutex_unlock(&docg3->cascade->lock);

    pos += seq_printf(s,
         "FlashControl : 0x%02x (%s,CE# %s,%s,%s,flash %s)\n",
         fctrl,
         fctrl & DOC_CTRL_VIOLATION ? "protocol violation" : "-",
         fctrl & DOC_CTRL_CE ? "active" : "inactive",
         fctrl & DOC_CTRL_PROTECTION_ERROR ? "protection error" : "-",
         fctrl & DOC_CTRL_SEQUENCE_ERROR ? "sequence error" : "-",
         fctrl & DOC_CTRL_FLASHREADY ? "ready" : "not ready");
    return pos;
}
DEBUGFS_RO_ATTR(flashcontrol, dbg_flashctrl_show);

static int dbg_asicmode_show(struct seq_file *s, void *p)
{
    struct docg3 *docg3 = (struct docg3 *)s->private;

    int pos = 0, pctrl, mode;

    mutex_lock(&docg3->cascade->lock);
    pctrl = doc_register_readb(docg3, DOC_ASICMODE);
    mode = pctrl & 0x03;
    mutex_unlock(&docg3->cascade->lock);

    pos += seq_printf(s,
             "%04x : RAM_WE=%d,RSTIN_RESET=%d,BDETCT_RESET=%d,WRITE_ENABLE=%d,POWERDOWN=%d,MODE=%d%d (",
             pctrl,
             pctrl & DOC_ASICMODE_RAM_WE ? 1 : 0,
             pctrl & DOC_ASICMODE_RSTIN_RESET ? 1 : 0,
             pctrl & DOC_ASICMODE_BDETCT_RESET ? 1 : 0,
             pctrl & DOC_ASICMODE_MDWREN ? 1 : 0,
             pctrl & DOC_ASICMODE_POWERDOWN ? 1 : 0,
             mode >> 1, mode & 0x1);

    switch (mode) {
    case DOC_ASICMODE_RESET:
        pos += seq_printf(s, "reset");
        break;
    case DOC_ASICMODE_NORMAL:
        pos += seq_printf(s, "normal");
        break;
    case DOC_ASICMODE_POWERDOWN:
        pos += seq_printf(s, "powerdown");
        break;
    }
    pos += seq_printf(s, ")\n");
    return pos;
}
DEBUGFS_RO_ATTR(asic_mode, dbg_asicmode_show);

static int dbg_device_id_show(struct seq_file *s, void *p)
{
    struct docg3 *docg3 = (struct docg3 *)s->private;
    int pos = 0;
    int id;

    mutex_lock(&docg3->cascade->lock);
    id = doc_register_readb(docg3, DOC_DEVICESELECT);
    mutex_unlock(&docg3->cascade->lock);

    pos += seq_printf(s, "DeviceId = %d\n", id);
    return pos;
}
DEBUGFS_RO_ATTR(device_id, dbg_device_id_show);

static int dbg_protection_show(struct seq_file *s, void *p)
{
    struct docg3 *docg3 = (struct docg3 *)s->private;
    int pos = 0;
    int protect, dps0, dps0_low, dps0_high, dps1, dps1_low, dps1_high;

    mutex_lock(&docg3->cascade->lock);
    protect = doc_register_readb(docg3, DOC_PROTECTION);
    dps0 = doc_register_readb(docg3, DOC_DPS0_STATUS);
    dps0_low = doc_register_readw(docg3, DOC_DPS0_ADDRLOW);
    dps0_high = doc_register_readw(docg3, DOC_DPS0_ADDRHIGH);
    dps1 = doc_register_readb(docg3, DOC_DPS1_STATUS);
    dps1_low = doc_register_readw(docg3, DOC_DPS1_ADDRLOW);
    dps1_high = doc_register_readw(docg3, DOC_DPS1_ADDRHIGH);
    mutex_unlock(&docg3->cascade->lock);

    pos += seq_printf(s, "Protection = 0x%02x (",
             protect);
    if (protect & DOC_PROTECT_FOUNDRY_OTP_LOCK)
        pos += seq_printf(s, "FOUNDRY_OTP_LOCK,");
    if (protect & DOC_PROTECT_CUSTOMER_OTP_LOCK)
        pos += seq_printf(s, "CUSTOMER_OTP_LOCK,");
    if (protect & DOC_PROTECT_LOCK_INPUT)
        pos += seq_printf(s, "LOCK_INPUT,");
    if (protect & DOC_PROTECT_STICKY_LOCK)
        pos += seq_printf(s, "STICKY_LOCK,");
    if (protect & DOC_PROTECT_PROTECTION_ENABLED)
        pos += seq_printf(s, "PROTECTION ON,");
    if (protect & DOC_PROTECT_IPL_DOWNLOAD_LOCK)
        pos += seq_printf(s, "IPL_DOWNLOAD_LOCK,");
    if (protect & DOC_PROTECT_PROTECTION_ERROR)
        pos += seq_printf(s, "PROTECT_ERR,");
    else
        pos += seq_printf(s, "NO_PROTECT_ERR");
    pos += seq_printf(s, ")\n");

    pos += seq_printf(s, "DPS0 = 0x%02x : "
             "Protected area [0x%x - 0x%x] : OTP=%d, READ=%d, "
             "WRITE=%d, HW_LOCK=%d, KEY_OK=%d\n",
             dps0, dps0_low, dps0_high,
             !!(dps0 & DOC_DPS_OTP_PROTECTED),
             !!(dps0 & DOC_DPS_READ_PROTECTED),
             !!(dps0 & DOC_DPS_WRITE_PROTECTED),
             !!(dps0 & DOC_DPS_HW_LOCK_ENABLED),
             !!(dps0 & DOC_DPS_KEY_OK));
    pos += seq_printf(s, "DPS1 = 0x%02x : "
             "Protected area [0x%x - 0x%x] : OTP=%d, READ=%d, "
             "WRITE=%d, HW_LOCK=%d, KEY_OK=%d\n",
             dps1, dps1_low, dps1_high,
             !!(dps1 & DOC_DPS_OTP_PROTECTED),
             !!(dps1 & DOC_DPS_READ_PROTECTED),
             !!(dps1 & DOC_DPS_WRITE_PROTECTED),
             !!(dps1 & DOC_DPS_HW_LOCK_ENABLED),
             !!(dps1 & DOC_DPS_KEY_OK));
    return pos;
}
DEBUGFS_RO_ATTR(protection, dbg_protection_show);

static int __init doc_dbg_register(struct docg3 *docg3)
{
    struct dentry *root, *entry;

    root = debugfs_create_dir("docg3", NULL);
    if (!root)
        return -ENOMEM;

    entry = debugfs_create_file("flashcontrol", S_IRUSR, root, docg3,
                  &flashcontrol_fops);
    if (entry)
        entry = debugfs_create_file("asic_mode", S_IRUSR, root,
                        docg3, &asic_mode_fops);
    if (entry)
        entry = debugfs_create_file("device_id", S_IRUSR, root,
                        docg3, &device_id_fops);
    if (entry)
        entry = debugfs_create_file("protection", S_IRUSR, root,
                        docg3, &protection_fops);
    if (entry) {
        docg3->debugfs_root = root;
        return 0;
    } else {
        debugfs_remove_recursive(root);
        return -ENOMEM;
    }
}

static void __exit doc_dbg_unregister(struct docg3 *docg3)
{
    debugfs_remove_recursive(docg3->debugfs_root);
}

static void __init doc_set_driver_info(int chip_id, struct mtd_info *mtd)
{
    struct docg3 *docg3 = mtd->priv;
    int cfg;

    cfg = doc_register_readb(docg3, DOC_CONFIGURATION);
    docg3->if_cfg = (cfg & DOC_CONF_IF_CFG ? 1 : 0);
    docg3->reliable = reliable_mode;

    switch (chip_id) {
    case DOC_CHIPID_G3:
        mtd->name = kasprintf(GFP_KERNEL, "docg3.%d",
                      docg3->device_id);
        docg3->max_block = 2047;
        break;
    }
    mtd->type = MTD_NANDFLASH;
    mtd->flags = MTD_CAP_NANDFLASH;
    mtd->size = (docg3->max_block + 1) * DOC_LAYOUT_BLOCK_SIZE;
    if (docg3->reliable == 2)
        mtd->size /= 2;
    mtd->erasesize = DOC_LAYOUT_BLOCK_SIZE * DOC_LAYOUT_NBPLANES;
    if (docg3->reliable == 2)
        mtd->erasesize /= 2;
    mtd->writebufsize = mtd->writesize = DOC_LAYOUT_PAGE_SIZE;
    mtd->oobsize = DOC_LAYOUT_OOB_SIZE;
    mtd->owner = THIS_MODULE;
    mtd->_erase = doc_erase;
    mtd->_read = doc_read;
    mtd->_write = doc_write;
    mtd->_read_oob = doc_read_oob;
    mtd->_write_oob = doc_write_oob;
    mtd->_block_isbad = doc_block_isbad;
    mtd->ecclayout = &docg3_oobinfo;
    mtd->ecc_strength = DOC_ECC_BCH_T;
}

static struct mtd_info * __init
doc_probe_device(struct docg3_cascade *cascade, int floor, struct device *dev)
{
    int ret, bbt_nbpages;
    u16 chip_id, chip_id_inv;
    struct docg3 *docg3;
    struct mtd_info *mtd;

    ret = -ENOMEM;
    docg3 = kzalloc(sizeof(struct docg3), GFP_KERNEL);
    if (!docg3)
        goto nomem1;
    mtd = kzalloc(sizeof(struct mtd_info), GFP_KERNEL);
    if (!mtd)
        goto nomem2;
    mtd->priv = docg3;
    bbt_nbpages = DIV_ROUND_UP(docg3->max_block + 1,
                   8 * DOC_LAYOUT_PAGE_SIZE);
    docg3->bbt = kzalloc(bbt_nbpages * DOC_LAYOUT_PAGE_SIZE, GFP_KERNEL);
    if (!docg3->bbt)
        goto nomem3;

    docg3->dev = dev;
    docg3->device_id = floor;
    docg3->cascade = cascade;
    doc_set_device_id(docg3, docg3->device_id);
    if (!floor)
        doc_set_asic_mode(docg3, DOC_ASICMODE_RESET);
    doc_set_asic_mode(docg3, DOC_ASICMODE_NORMAL);

    chip_id = doc_register_readw(docg3, DOC_CHIPID);
    chip_id_inv = doc_register_readw(docg3, DOC_CHIPID_INV);

    ret = 0;
    if (chip_id != (u16)(~chip_id_inv)) {
        goto nomem3;
    }

    switch (chip_id) {
    case DOC_CHIPID_G3:
        doc_info("Found a G3 DiskOnChip at addr %p, floor %d\n",
             docg3->cascade->base, floor);
        break;
    default:
        doc_err("Chip id %04x is not a DiskOnChip G3 chip\n", chip_id);
        goto nomem3;
    }

    doc_set_driver_info(chip_id, mtd);

    doc_hamming_ecc_init(docg3, DOC_LAYOUT_OOB_PAGEINFO_SZ);
    doc_reload_bbt(docg3);
    return mtd;

nomem3:
    kfree(mtd);
nomem2:
    kfree(docg3);
nomem1:
    return ERR_PTR(ret);
}

static void doc_release_device(struct mtd_info *mtd)
{
    struct docg3 *docg3 = mtd->priv;

    mtd_device_unregister(mtd);
    kfree(docg3->bbt);
    kfree(docg3);
    kfree(mtd->name);
    kfree(mtd);
}

static int docg3_resume(struct platform_device *pdev)
{
    int i;
    struct docg3_cascade *cascade;
    struct mtd_info **docg3_floors, *mtd;
    struct docg3 *docg3;

    cascade = platform_get_drvdata(pdev);
    docg3_floors = cascade->floors;
    mtd = docg3_floors[0];
    docg3 = mtd->priv;

    doc_dbg("docg3_resume()\n");
    for (i = 0; i < 12; i++)
        doc_readb(docg3, DOC_IOSPACE_IPL);
    return 0;
}

static int docg3_suspend(struct platform_device *pdev, pm_message_t state)
{
    int floor, i;
    struct docg3_cascade *cascade;
    struct mtd_info **docg3_floors, *mtd;
    struct docg3 *docg3;
    u8 ctrl, pwr_down;

    cascade = platform_get_drvdata(pdev);
    docg3_floors = cascade->floors;
    for (floor = 0; floor < DOC_MAX_NBFLOORS; floor++) {
        mtd = docg3_floors[floor];
        if (!mtd)
            continue;
        docg3 = mtd->priv;

        doc_writeb(docg3, floor, DOC_DEVICESELECT);
        ctrl = doc_register_readb(docg3, DOC_FLASHCONTROL);
        ctrl &= ~DOC_CTRL_VIOLATION & ~DOC_CTRL_CE;
        doc_writeb(docg3, ctrl, DOC_FLASHCONTROL);

        for (i = 0; i < 10; i++) {
            usleep_range(3000, 4000);
            pwr_down = doc_register_readb(docg3, DOC_POWERMODE);
            if (pwr_down & DOC_POWERDOWN_READY)
                break;
        }
        if (pwr_down & DOC_POWERDOWN_READY) {
            doc_dbg("docg3_suspend(): floor %d powerdown ok\n",
                floor);
        } else {
            doc_err("docg3_suspend(): floor %d powerdown failed\n",
                floor);
            return -EIO;
        }
    }

    mtd = docg3_floors[0];
    docg3 = mtd->priv;
    doc_set_asic_mode(docg3, DOC_ASICMODE_POWERDOWN);
    return 0;
}

static int __init docg3_probe(struct platform_device *pdev)
{
    struct device *dev = &pdev->dev;
    struct mtd_info *mtd;
    struct resource *ress;
    void __iomem *base;
    int ret, floor, found = 0;
    struct docg3_cascade *cascade;

    ret = -ENXIO;
    ress = platform_get_resource(pdev, IORESOURCE_MEM, 0);
    if (!ress) {
        dev_err(dev, "No I/O memory resource defined\n");
        goto noress;
    }
    base = ioremap(ress->start, DOC_IOSPACE_SIZE);

    ret = -ENOMEM;
    cascade = kzalloc(sizeof(*cascade) * DOC_MAX_NBFLOORS,
              GFP_KERNEL);
    if (!cascade)
        goto nomem1;
    cascade->base = base;
    mutex_init(&cascade->lock);
    cascade->bch = init_bch(DOC_ECC_BCH_M, DOC_ECC_BCH_T,
                 DOC_ECC_BCH_PRIMPOLY);
    if (!cascade->bch)
        goto nomem2;

    for (floor = 0; floor < DOC_MAX_NBFLOORS; floor++) {
        mtd = doc_probe_device(cascade, floor, dev);
        if (IS_ERR(mtd)) {
            ret = PTR_ERR(mtd);
            goto err_probe;
        }
        if (!mtd) {
            if (floor == 0)
                goto notfound;
            else
                continue;
        }
        cascade->floors[floor] = mtd;
        ret = mtd_device_parse_register(mtd, part_probes, NULL, NULL,
                        0);
        if (ret)
            goto err_probe;
        found++;
    }

    ret = doc_register_sysfs(pdev, cascade);
    if (ret)
        goto err_probe;
    if (!found)
        goto notfound;

    platform_set_drvdata(pdev, cascade);
    doc_dbg_register(cascade->floors[0]->priv);
    return 0;

notfound:
    ret = -ENODEV;
    dev_info(dev, "No supported DiskOnChip found\n");
err_probe:
    kfree(cascade->bch);
    for (floor = 0; floor < DOC_MAX_NBFLOORS; floor++)
        if (cascade->floors[floor])
            doc_release_device(cascade->floors[floor]);
nomem2:
    kfree(cascade);
nomem1:
    iounmap(base);
noress:
    return ret;
}

static int __exit docg3_release(struct platform_device *pdev)
{
    struct docg3_cascade *cascade = platform_get_drvdata(pdev);
    struct docg3 *docg3 = cascade->floors[0]->priv;
    void __iomem *base = cascade->base;
    int floor;

    doc_unregister_sysfs(pdev, cascade);
    doc_dbg_unregister(docg3);
    for (floor = 0; floor < DOC_MAX_NBFLOORS; floor++)
        if (cascade->floors[floor])
            doc_release_device(cascade->floors[floor]);

    free_bch(docg3->cascade->bch);
    kfree(cascade);
    iounmap(base);
    return 0;
}

static struct platform_driver g3_driver = {
    .driver     = {
        .name   = "docg3",
        .owner  = THIS_MODULE,
    },
    .suspend    = docg3_suspend,
    .resume     = docg3_resume,
    .remove     = __exit_p(docg3_release),
};

static int __init docg3_init(void)
{
    return platform_driver_probe(&g3_driver, docg3_probe);
}
module_init(docg3_init);


static void __exit docg3_exit(void)
{
    platform_driver_unregister(&g3_driver);
}
module_exit(docg3_exit);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Robert Jarzmik <[email protected]>");
MODULE_DESCRIPTION("MTD driver for DiskOnChip G3");