[MTD] LPDDR Command set driver

Driver which handles device command operation.
Details on device operations are available here:
http://www.numonyx.com/Documents/Datasheets/DS-315768_Velocity-Discrete.pdf

Signed-off-by: Alexey Korolev <akorolev@infradead.org>
Acked-by: Jared Hulbert <jaredeh@gmail.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

1 files changed, 796 insertions, 0 deletions

diff --git a/drivers/mtd/lpddr/lpddr_cmds.c b/drivers/mtd/lpddr/lpddr_cmds.c
new file mode 100644
index 000000000000..e22ca49583e7
--- /dev/null
+++ b/drivers/mtd/lpddr/lpddr_cmds.c
@@ -0,0 +1,796 @@
+/*
+ * LPDDR flash memory device operations. This module provides read, write,
+ * erase, lock/unlock support for LPDDR flash memories
+ * (C) 2008 Korolev Alexey <akorolev@infradead.org>
+ * (C) 2008 Vasiliy Leonenko <vasiliy.leonenko@gmail.com>
+ * Many thanks to Roman Borisov for intial enabling
+ *
+ * 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., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301, USA.
+ * TODO:
+ * Implement VPP management
+ * Implement XIP support
+ * Implement OTP support
+ */
+#include <linux/mtd/pfow.h>
+#include <linux/mtd/qinfo.h>
+
+static int lpddr_read(struct mtd_info *mtd, loff_t adr, size_t len,
+                                        size_t *retlen, u_char *buf);
+static int lpddr_write_buffers(struct mtd_info *mtd, loff_t to,
+                                size_t len, size_t *retlen, const u_char *buf);
+static int lpddr_writev(struct mtd_info *mtd, const struct kvec *vecs,
+                                unsigned long count, loff_t to, size_t *retlen);
+static int lpddr_erase(struct mtd_info *mtd, struct erase_info *instr);
+static int lpddr_lock(struct mtd_info *mtd, loff_t ofs, uint64_t len);
+static int lpddr_unlock(struct mtd_info *mtd, loff_t ofs, uint64_t len);
+static int lpddr_point(struct mtd_info *mtd, loff_t adr, size_t len,
+                        size_t *retlen, void **mtdbuf, resource_size_t *phys);
+static void lpddr_unpoint(struct mtd_info *mtd, loff_t adr, size_t len);
+static int get_chip(struct map_info *map, struct flchip *chip, int mode);
+static int chip_ready(struct map_info *map, struct flchip *chip, int mode);
+static void put_chip(struct map_info *map, struct flchip *chip);
+
+struct mtd_info *lpddr_cmdset(struct map_info *map)
+{
+        struct lpddr_private *lpddr = map->fldrv_priv;
+        struct flchip_shared *shared;
+        struct flchip *chip;
+        struct mtd_info *mtd;
+        int numchips;
+        int i, j;
+
+        mtd = kzalloc(sizeof(*mtd), GFP_KERNEL);
+        if (!mtd) {
+                printk(KERN_ERR "Failed to allocate memory for MTD device\n");
+                return NULL;
+        }
+        mtd->priv = map;
+        mtd->type = MTD_NORFLASH;
+
+        /* Fill in the default mtd operations */
+        mtd->read = lpddr_read;
+        mtd->type = MTD_NORFLASH;
+        mtd->flags = MTD_CAP_NORFLASH;
+        mtd->flags &= ~MTD_BIT_WRITEABLE;
+        mtd->erase = lpddr_erase;
+        mtd->write = lpddr_write_buffers;
+        mtd->writev = lpddr_writev;
+        mtd->read_oob = NULL;
+        mtd->write_oob = NULL;
+        mtd->sync = NULL;
+        mtd->lock = lpddr_lock;
+        mtd->unlock = lpddr_unlock;
+        mtd->suspend = NULL;
+        mtd->resume = NULL;
+        if (map_is_linear(map)) {
+                mtd->point = lpddr_point;
+                mtd->unpoint = lpddr_unpoint;
+        }
+        mtd->block_isbad = NULL;
+        mtd->block_markbad = NULL;
+        mtd->size = 1 << lpddr->qinfo->DevSizeShift;
+        mtd->erasesize = 1 << lpddr->qinfo->UniformBlockSizeShift;
+        mtd->writesize = 1 << lpddr->qinfo->BufSizeShift;
+
+        shared = kmalloc(sizeof(struct flchip_shared) * lpddr->numchips,
+                                                GFP_KERNEL);
+        if (!shared) {
+                kfree(lpddr);
+                kfree(mtd);
+                return NULL;
+        }
+
+        chip = &lpddr->chips[0];
+        numchips = lpddr->numchips / lpddr->qinfo->HWPartsNum;
+        for (i = 0; i < numchips; i++) {
+                shared[i].writing = shared[i].erasing = NULL;
+                spin_lock_init(&shared[i].lock);
+                for (j = 0; j < lpddr->qinfo->HWPartsNum; j++) {
+                        *chip = lpddr->chips[i];
+                        chip->start += j << lpddr->chipshift;
+                        chip->oldstate = chip->state = FL_READY;
+                        chip->priv = &shared[i];
+                        /* those should be reset too since
+                           they create memory references. */
+                        init_waitqueue_head(&chip->wq);
+                        spin_lock_init(&chip->_spinlock);
+                        chip->mutex = &chip->_spinlock;
+                        chip++;
+                }
+        }
+
+        return mtd;
+}
+EXPORT_SYMBOL(lpddr_cmdset);
+
+static int wait_for_ready(struct map_info *map, struct flchip *chip,
+                unsigned int chip_op_time)
+{
+        unsigned int timeo, reset_timeo, sleep_time;
+        unsigned int dsr;
+        flstate_t chip_state = chip->state;
+        int ret = 0;
+
+        /* set our timeout to 8 times the expected delay */
+        timeo = chip_op_time * 8;
+        if (!timeo)
+                timeo = 500000;
+        reset_timeo = timeo;
+        sleep_time = chip_op_time / 2;
+
+        for (;;) {
+                dsr = CMDVAL(map_read(map, map->pfow_base + PFOW_DSR));
+                if (dsr & DSR_READY_STATUS)
+                        break;
+                if (!timeo) {
+                        printk(KERN_ERR "%s: Flash timeout error state %d \n",
+                                                        map->name, chip_state);
+                        ret = -ETIME;
+                        break;
+                }
+
+                /* OK Still waiting. Drop the lock, wait a while and retry. */
+                spin_unlock(chip->mutex);
+                if (sleep_time >= 1000000/HZ) {
+                        /*
+                         * Half of the normal delay still remaining
+                         * can be performed with a sleeping delay instead
+                         * of busy waiting.
+                         */
+                        msleep(sleep_time/1000);
+                        timeo -= sleep_time;
+                        sleep_time = 1000000/HZ;
+                } else {
+                        udelay(1);
+                        cond_resched();
+                        timeo--;
+                }
+                spin_lock(chip->mutex);
+
+                while (chip->state != chip_state) {
+                        /* Someone's suspended the operation: sleep */
+                        DECLARE_WAITQUEUE(wait, current);
+                        set_current_state(TASK_UNINTERRUPTIBLE);
+                        add_wait_queue(&chip->wq, &wait);
+                        spin_unlock(chip->mutex);
+                        schedule();
+                        remove_wait_queue(&chip->wq, &wait);
+                        spin_lock(chip->mutex);
+                }
+                if (chip->erase_suspended || chip->write_suspended)  {
+                        /* Suspend has occured while sleep: reset timeout */
+                        timeo = reset_timeo;
+                        chip->erase_suspended = chip->write_suspended = 0;
+                }
+        }
+        /* check status for errors */
+        if (dsr & DSR_ERR) {
+                /* Clear DSR*/
+                map_write(map, CMD(~(DSR_ERR)), map->pfow_base + PFOW_DSR);
+                printk(KERN_WARNING"%s: Bad status on wait: 0x%x \n",
+                                map->name, dsr);
+                print_drs_error(dsr);
+                ret = -EIO;
+        }
+        chip->state = FL_READY;
+        return ret;
+}
+
+static int get_chip(struct map_info *map, struct flchip *chip, int mode)
+{
+        int ret;
+        DECLARE_WAITQUEUE(wait, current);
+
+ retry:
+        if (chip->priv && (mode == FL_WRITING || mode == FL_ERASING)
+                && chip->state != FL_SYNCING) {
+                /*
+                 * OK. We have possibility for contension on the write/erase
+                 * operations which are global to the real chip and not per
+                 * partition.  So let's fight it over in the partition which
+                 * currently has authority on the operation.
+                 *
+                 * The rules are as follows:
+                 *
+                 * - any write operation must own shared->writing.
+                 *
+                 * - any erase operation must own _both_ shared->writing and
+                 *   shared->erasing.
+                 *
+                 * - contension arbitration is handled in the owner's context.
+                 *
+                 * The 'shared' struct can be read and/or written only when
+                 * its lock is taken.
+                 */
+                struct flchip_shared *shared = chip->priv;
+                struct flchip *contender;
+                spin_lock(&shared->lock);
+                contender = shared->writing;
+                if (contender && contender != chip) {
+                        /*
+                         * The engine to perform desired operation on this
+                         * partition is already in use by someone else.
+                         * Let's fight over it in the context of the chip
+                         * currently using it.  If it is possible to suspend,
+                         * that other partition will do just that, otherwise
+                         * it'll happily send us to sleep.  In any case, when
+                         * get_chip returns success we're clear to go ahead.
+                         */
+                        ret = spin_trylock(contender->mutex);
+                        spin_unlock(&shared->lock);
+                        if (!ret)
+                                goto retry;
+                        spin_unlock(chip->mutex);
+                        ret = chip_ready(map, contender, mode);
+                        spin_lock(chip->mutex);
+
+                        if (ret == -EAGAIN) {
+                                spin_unlock(contender->mutex);
+                                goto retry;
+                        }
+                        if (ret) {
+                                spin_unlock(contender->mutex);
+                                return ret;
+                        }
+                        spin_lock(&shared->lock);
+
+                        /* We should not own chip if it is already in FL_SYNCING
+                         * state. Put contender and retry. */
+                        if (chip->state == FL_SYNCING) {
+                                put_chip(map, contender);
+                                spin_unlock(contender->mutex);
+                                goto retry;
+                        }
+                        spin_unlock(contender->mutex);
+                }
+
+                /* Check if we have suspended erase on this chip.
+                   Must sleep in such a case. */
+                if (mode == FL_ERASING && shared->erasing
+                    && shared->erasing->oldstate == FL_ERASING) {
+                        spin_unlock(&shared->lock);
+                        set_current_state(TASK_UNINTERRUPTIBLE);
+                        add_wait_queue(&chip->wq, &wait);
+                        spin_unlock(chip->mutex);
+                        schedule();
+                        remove_wait_queue(&chip->wq, &wait);
+                        spin_lock(chip->mutex);
+                        goto retry;
+                }
+
+                /* We now own it */
+                shared->writing = chip;
+                if (mode == FL_ERASING)
+                        shared->erasing = chip;
+                spin_unlock(&shared->lock);
+        }
+
+        ret = chip_ready(map, chip, mode);
+        if (ret == -EAGAIN)
+                goto retry;
+
+        return ret;
+}
+
+static int chip_ready(struct map_info *map, struct flchip *chip, int mode)
+{
+        struct lpddr_private *lpddr = map->fldrv_priv;
+        int ret = 0;
+        DECLARE_WAITQUEUE(wait, current);
+
+        /* Prevent setting state FL_SYNCING for chip in suspended state. */
+        if (FL_SYNCING == mode && FL_READY != chip->oldstate)
+                goto sleep;
+
+        switch (chip->state) {
+        case FL_READY:
+        case FL_JEDEC_QUERY:
+                return 0;
+
+        case FL_ERASING:
+                if (!lpddr->qinfo->SuspEraseSupp ||
+                        !(mode == FL_READY || mode == FL_POINT))
+                        goto sleep;
+
+                map_write(map, CMD(LPDDR_SUSPEND),
+                        map->pfow_base + PFOW_PROGRAM_ERASE_SUSPEND);
+                chip->oldstate = FL_ERASING;
+                chip->state = FL_ERASE_SUSPENDING;
+                ret = wait_for_ready(map, chip, 0);
+                if (ret) {
+                        /* Oops. something got wrong. */
+                        /* Resume and pretend we weren't here.  */
+                        map_write(map, CMD(LPDDR_RESUME),
+                                map->pfow_base + PFOW_COMMAND_CODE);
+                        map_write(map, CMD(LPDDR_START_EXECUTION),
+                                map->pfow_base + PFOW_COMMAND_EXECUTE);
+                        chip->state = FL_ERASING;
+                        chip->oldstate = FL_READY;
+                        printk(KERN_ERR "%s: suspend operation failed."
+                                        "State may be wrong \n", map->name);
+                        return -EIO;
+                }
+                chip->erase_suspended = 1;
+                chip->state = FL_READY;
+                return 0;
+                /* Erase suspend */
+        case FL_POINT:
+                /* Only if there's no operation suspended... */
+                if (mode == FL_READY && chip->oldstate == FL_READY)
+                        return 0;
+
+        default:
+sleep:
+                set_current_state(TASK_UNINTERRUPTIBLE);
+                add_wait_queue(&chip->wq, &wait);
+                spin_unlock(chip->mutex);
+                schedule();
+                remove_wait_queue(&chip->wq, &wait);
+                spin_lock(chip->mutex);
+                return -EAGAIN;
+        }
+}
+
+static void put_chip(struct map_info *map, struct flchip *chip)
+{
+        if (chip->priv) {
+                struct flchip_shared *shared = chip->priv;
+                spin_lock(&shared->lock);
+                if (shared->writing == chip && chip->oldstate == FL_READY) {
+                        /* We own the ability to write, but we're done */
+                        shared->writing = shared->erasing;
+                        if (shared->writing && shared->writing != chip) {
+                                /* give back the ownership */
+                                struct flchip *loaner = shared->writing;
+                                spin_lock(loaner->mutex);
+                                spin_unlock(&shared->lock);
+                                spin_unlock(chip->mutex);
+                                put_chip(map, loaner);
+                                spin_lock(chip->mutex);
+                                spin_unlock(loaner->mutex);
+                                wake_up(&chip->wq);
+                                return;
+                        }
+                        shared->erasing = NULL;
+                        shared->writing = NULL;
+                } else if (shared->erasing == chip && shared->writing != chip) {
+                        /*
+                         * We own the ability to erase without the ability
+                         * to write, which means the erase was suspended
+                         * and some other partition is currently writing.
+                         * Don't let the switch below mess things up since
+                         * we don't have ownership to resume anything.
+                         */
+                        spin_unlock(&shared->lock);
+                        wake_up(&chip->wq);
+                        return;
+                }
+                spin_unlock(&shared->lock);
+        }
+
+        switch (chip->oldstate) {
+        case FL_ERASING:
+                chip->state = chip->oldstate;
+                map_write(map, CMD(LPDDR_RESUME),
+                                map->pfow_base + PFOW_COMMAND_CODE);
+                map_write(map, CMD(LPDDR_START_EXECUTION),
+                                map->pfow_base + PFOW_COMMAND_EXECUTE);
+                chip->oldstate = FL_READY;
+                chip->state = FL_ERASING;
+                break;
+        case FL_READY:
+                break;
+        default:
+                printk(KERN_ERR "%s: put_chip() called with oldstate %d!\n",
+                                map->name, chip->oldstate);
+        }
+        wake_up(&chip->wq);
+}
+
+int do_write_buffer(struct map_info *map, struct flchip *chip,
+                        unsigned long adr, const struct kvec **pvec,
+                        unsigned long *pvec_seek, int len)
+{
+        struct lpddr_private *lpddr = map->fldrv_priv;
+        map_word datum;
+        int ret, wbufsize, word_gap, words;
+        const struct kvec *vec;
+        unsigned long vec_seek;
+        unsigned long prog_buf_ofs;
+
+        wbufsize = 1 << lpddr->qinfo->BufSizeShift;
+
+        spin_lock(chip->mutex);
+        ret = get_chip(map, chip, FL_WRITING);
+        if (ret) {
+                spin_unlock(chip->mutex);
+                return ret;
+        }
+        /* Figure out the number of words to write */
+        word_gap = (-adr & (map_bankwidth(map)-1));
+        words = (len - word_gap + map_bankwidth(map) - 1) / map_bankwidth(map);
+        if (!word_gap) {
+                words--;
+        } else {
+                word_gap = map_bankwidth(map) - word_gap;
+                adr -= word_gap;
+                datum = map_word_ff(map);
+        }
+        /* Write data */
+        /* Get the program buffer offset from PFOW register data first*/
+        prog_buf_ofs = map->pfow_base + CMDVAL(map_read(map,
+                                map->pfow_base + PFOW_PROGRAM_BUFFER_OFFSET));
+        vec = *pvec;
+        vec_seek = *pvec_seek;
+        do {
+                int n = map_bankwidth(map) - word_gap;
+
+                if (n > vec->iov_len - vec_seek)
+                        n = vec->iov_len - vec_seek;
+                if (n > len)
+                        n = len;
+
+                if (!word_gap && (len < map_bankwidth(map)))
+                        datum = map_word_ff(map);
+
+                datum = map_word_load_partial(map, datum,
+                                vec->iov_base + vec_seek, word_gap, n);
+
+                len -= n;
+                word_gap += n;
+                if (!len || word_gap == map_bankwidth(map)) {
+                        map_write(map, datum, prog_buf_ofs);
+                        prog_buf_ofs += map_bankwidth(map);
+                        word_gap = 0;
+                }
+
+                vec_seek += n;
+                if (vec_seek == vec->iov_len) {
+                        vec++;
+                        vec_seek = 0;
+                }
+        } while (len);
+        *pvec = vec;
+        *pvec_seek = vec_seek;
+
+        /* GO GO GO */
+        send_pfow_command(map, LPDDR_BUFF_PROGRAM, adr, wbufsize, NULL);
+        chip->state = FL_WRITING;
+        ret = wait_for_ready(map, chip, (1<<lpddr->qinfo->ProgBufferTime));
+        if (ret)        {
+                printk(KERN_WARNING"%s Buffer program error: %d at %lx; \n",
+                        map->name, ret, adr);
+                goto out;
+        }
+
+ out:   put_chip(map, chip);
+        spin_unlock(chip->mutex);
+        return ret;
+}
+
+int do_erase_oneblock(struct mtd_info *mtd, loff_t adr)
+{
+        struct map_info *map = mtd->priv;
+        struct lpddr_private *lpddr = map->fldrv_priv;
+        int chipnum = adr >> lpddr->chipshift;
+        struct flchip *chip = &lpddr->chips[chipnum];
+        int ret;
+
+        spin_lock(chip->mutex);
+        ret = get_chip(map, chip, FL_ERASING);
+        if (ret) {
+                spin_unlock(chip->mutex);
+                return ret;
+        }
+        send_pfow_command(map, LPDDR_BLOCK_ERASE, adr, 0, NULL);
+        chip->state = FL_ERASING;
+        ret = wait_for_ready(map, chip, (1<<lpddr->qinfo->BlockEraseTime)*1000);
+        if (ret) {
+                printk(KERN_WARNING"%s Erase block error %d at : %llx\n",
+                        map->name, ret, adr);
+                goto out;
+        }
+ out:   put_chip(map, chip);
+        spin_unlock(chip->mutex);
+        return ret;
+}
+
+static int lpddr_read(struct mtd_info *mtd, loff_t adr, size_t len,
+                        size_t *retlen, u_char *buf)
+{
+        struct map_info *map = mtd->priv;
+        struct lpddr_private *lpddr = map->fldrv_priv;
+        int chipnum = adr >> lpddr->chipshift;
+        struct flchip *chip = &lpddr->chips[chipnum];
+        int ret = 0;
+
+        spin_lock(chip->mutex);
+        ret = get_chip(map, chip, FL_READY);
+        if (ret) {
+                spin_unlock(chip->mutex);
+                return ret;
+        }
+
+        map_copy_from(map, buf, adr, len);
+        *retlen = len;
+
+        put_chip(map, chip);
+        spin_unlock(chip->mutex);
+        return ret;
+}
+
+static int lpddr_point(struct mtd_info *mtd, loff_t adr, size_t len,
+                        size_t *retlen, void **mtdbuf, resource_size_t *phys)
+{
+        struct map_info *map = mtd->priv;
+        struct lpddr_private *lpddr = map->fldrv_priv;
+        int chipnum = adr >> lpddr->chipshift;
+        unsigned long ofs, last_end = 0;
+        struct flchip *chip = &lpddr->chips[chipnum];
+        int ret = 0;
+
+        if (!map->virt || (adr + len > mtd->size))
+                return -EINVAL;
+
+        /* ofs: offset within the first chip that the first read should start */
+        ofs = adr - (chipnum << lpddr->chipshift);
+
+        *mtdbuf = (void *)map->virt + chip->start + ofs;
+        *retlen = 0;
+
+        while (len) {
+                unsigned long thislen;
+
+                if (chipnum >= lpddr->numchips)
+                        break;
+
+                /* We cannot point across chips that are virtually disjoint */
+                if (!last_end)
+                        last_end = chip->start;
+                else if (chip->start != last_end)
+                        break;
+
+                if ((len + ofs - 1) >> lpddr->chipshift)
+                        thislen = (1<<lpddr->chipshift) - ofs;
+                else
+                        thislen = len;
+                /* get the chip */
+                spin_lock(chip->mutex);
+                ret = get_chip(map, chip, FL_POINT);
+                spin_unlock(chip->mutex);
+                if (ret)
+                        break;
+
+                chip->state = FL_POINT;
+                chip->ref_point_counter++;
+                *retlen += thislen;
+                len -= thislen;
+
+                ofs = 0;
+                last_end += 1 << lpddr->chipshift;
+                chipnum++;
+                chip = &lpddr->chips[chipnum];
+        }
+        return 0;
+}
+
+static void lpddr_unpoint (struct mtd_info *mtd, loff_t adr, size_t len)
+{
+        struct map_info *map = mtd->priv;
+        struct lpddr_private *lpddr = map->fldrv_priv;
+        int chipnum = adr >> lpddr->chipshift;
+        unsigned long ofs;
+
+        /* ofs: offset within the first chip that the first read should start */
+        ofs = adr - (chipnum << lpddr->chipshift);
+
+        while (len) {
+                unsigned long thislen;
+                struct flchip *chip;
+
+                chip = &lpddr->chips[chipnum];
+                if (chipnum >= lpddr->numchips)
+                        break;
+
+                if ((len + ofs - 1) >> lpddr->chipshift)
+                        thislen = (1<<lpddr->chipshift) - ofs;
+                else
+                        thislen = len;
+
+                spin_lock(chip->mutex);
+                if (chip->state == FL_POINT) {
+                        chip->ref_point_counter--;
+                        if (chip->ref_point_counter == 0)
+                                chip->state = FL_READY;
+                } else
+                        printk(KERN_WARNING "%s: Warning: unpoint called on non"
+                                        "pointed region\n", map->name);
+
+                put_chip(map, chip);
+                spin_unlock(chip->mutex);
+
+                len -= thislen;
+                ofs = 0;
+                chipnum++;
+        }
+}
+
+static int lpddr_write_buffers(struct mtd_info *mtd, loff_t to, size_t len,
+                                size_t *retlen, const u_char *buf)
+{
+        struct kvec vec;
+
+        vec.iov_base = (void *) buf;
+        vec.iov_len = len;
+
+        return lpddr_writev(mtd, &vec, 1, to, retlen);
+}
+
+
+static int lpddr_writev(struct mtd_info *mtd, const struct kvec *vecs,
+                                unsigned long count, loff_t to, size_t *retlen)
+{
+        struct map_info *map = mtd->priv;
+        struct lpddr_private *lpddr = map->fldrv_priv;
+        int ret = 0;
+        int chipnum;
+        unsigned long ofs, vec_seek, i;
+        int wbufsize = 1 << lpddr->qinfo->BufSizeShift;
+
+        size_t len = 0;
+
+        for (i = 0; i < count; i++)
+                len += vecs[i].iov_len;
+
+        *retlen = 0;
+        if (!len)
+                return 0;
+
+        chipnum = to >> lpddr->chipshift;
+
+        ofs = to;
+        vec_seek = 0;
+
+        do {
+                /* We must not cross write block boundaries */
+                int size = wbufsize - (ofs & (wbufsize-1));
+
+                if (size > len)
+                        size = len;
+
+                ret = do_write_buffer(map, &lpddr->chips[chipnum],
+                                          ofs, &vecs, &vec_seek, size);
+                if (ret)
+                        return ret;
+
+                ofs += size;
+                (*retlen) += size;
+                len -= size;
+
+                /* Be nice and reschedule with the chip in a usable
+                 * state for other processes */
+                cond_resched();
+
+        } while (len);
+
+        return 0;
+}
+
+static int lpddr_erase(struct mtd_info *mtd, struct erase_info *instr)
+{
+        unsigned long ofs, len;
+        int ret;
+        struct map_info *map = mtd->priv;
+        struct lpddr_private *lpddr = map->fldrv_priv;
+        int size = 1 << lpddr->qinfo->UniformBlockSizeShift;
+
+        ofs = instr->addr;
+        len = instr->len;
+
+        if (ofs > mtd->size || (len + ofs) > mtd->size)
+                return -EINVAL;
+
+        while (len > 0) {
+                ret = do_erase_oneblock(mtd, ofs);
+                if (ret)
+                        return ret;
+                ofs += size;
+                len -= size;
+        }
+        instr->state = MTD_ERASE_DONE;
+        mtd_erase_callback(instr);
+
+        return 0;
+}
+
+#define DO_XXLOCK_LOCK          1
+#define DO_XXLOCK_UNLOCK        2
+int do_xxlock(struct mtd_info *mtd, loff_t adr, uint32_t len, int thunk)
+{
+        int ret = 0;
+        struct map_info *map = mtd->priv;
+        struct lpddr_private *lpddr = map->fldrv_priv;
+        int chipnum = adr >> lpddr->chipshift;
+        struct flchip *chip = &lpddr->chips[chipnum];
+
+        spin_lock(chip->mutex);
+        ret = get_chip(map, chip, FL_LOCKING);
+        if (ret) {
+                spin_unlock(chip->mutex);
+                return ret;
+        }
+
+        if (thunk == DO_XXLOCK_LOCK) {
+                send_pfow_command(map, LPDDR_LOCK_BLOCK, adr, adr + len, NULL);
+                chip->state = FL_LOCKING;
+        } else if (thunk == DO_XXLOCK_UNLOCK) {
+                send_pfow_command(map, LPDDR_UNLOCK_BLOCK, adr, adr + len, NULL);
+                chip->state = FL_UNLOCKING;
+        } else
+                BUG();
+
+        ret = wait_for_ready(map, chip, 1);
+        if (ret)        {
+                printk(KERN_ERR "%s: block unlock error status %d \n",
+                                map->name, ret);
+                goto out;
+        }
+out:    put_chip(map, chip);
+        spin_unlock(chip->mutex);
+        return ret;
+}
+
+static int lpddr_lock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
+{
+        return do_xxlock(mtd, ofs, len, DO_XXLOCK_LOCK);
+}
+
+static int lpddr_unlock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
+{
+        return do_xxlock(mtd, ofs, len, DO_XXLOCK_UNLOCK);
+}
+
+int word_program(struct map_info *map, loff_t adr, uint32_t curval)
+{
+    int ret;
+        struct lpddr_private *lpddr = map->fldrv_priv;
+        int chipnum = adr >> lpddr->chipshift;
+        struct flchip *chip = &lpddr->chips[chipnum];
+
+        spin_lock(chip->mutex);
+        ret = get_chip(map, chip, FL_WRITING);
+        if (ret) {
+                spin_unlock(chip->mutex);
+                return ret;
+        }
+
+        send_pfow_command(map, LPDDR_WORD_PROGRAM, adr, 0x00, (map_word *)&curval);
+
+        ret = wait_for_ready(map, chip, (1<<lpddr->qinfo->SingleWordProgTime));
+        if (ret)        {
+                printk(KERN_WARNING"%s word_program error at: %llx; val: %x\n",
+                        map->name, adr, curval);
+                goto out;
+        }
+
+out:    put_chip(map, chip);
+        spin_unlock(chip->mutex);
+        return ret;
+}
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Alexey Korolev <akorolev@infradead.org>");
+MODULE_DESCRIPTION("MTD driver for LPDDR flash chips");