linux/drivers/mtd/lpddr/lpddr_cmds.c
Artem Bityutskiy bcb1d23871 mtd: move zero length verification to MTD API functions
In many places in drivers we verify for the zero length, but this is very
inconsistent across drivers. This is obviously the right thing to do, though.
This patch moves the check to the MTD API functions instead and removes a lot
of duplication.

Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Reviewed-by: Shmulik Ladkani <shmulik.ladkani@gmail.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2012-03-27 00:32:19 +01:00

782 lines
20 KiB
C

/*
* 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 initial 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>
#include <linux/slab.h>
#include <linux/module.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 int 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->_lock = lpddr_lock;
mtd->_unlock = lpddr_unlock;
if (map_is_linear(map)) {
mtd->_point = lpddr_point;
mtd->_unpoint = lpddr_unpoint;
}
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;
mutex_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);
mutex_init(&chip->mutex);
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. */
mutex_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--;
}
mutex_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);
mutex_unlock(&chip->mutex);
schedule();
remove_wait_queue(&chip->wq, &wait);
mutex_lock(&chip->mutex);
}
if (chip->erase_suspended || chip->write_suspended) {
/* Suspend has occurred 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;
mutex_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 = mutex_trylock(&contender->mutex);
mutex_unlock(&shared->lock);
if (!ret)
goto retry;
mutex_unlock(&chip->mutex);
ret = chip_ready(map, contender, mode);
mutex_lock(&chip->mutex);
if (ret == -EAGAIN) {
mutex_unlock(&contender->mutex);
goto retry;
}
if (ret) {
mutex_unlock(&contender->mutex);
return ret;
}
mutex_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);
mutex_unlock(&contender->mutex);
goto retry;
}
mutex_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) {
mutex_unlock(&shared->lock);
set_current_state(TASK_UNINTERRUPTIBLE);
add_wait_queue(&chip->wq, &wait);
mutex_unlock(&chip->mutex);
schedule();
remove_wait_queue(&chip->wq, &wait);
mutex_lock(&chip->mutex);
goto retry;
}
/* We now own it */
shared->writing = chip;
if (mode == FL_ERASING)
shared->erasing = chip;
mutex_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. */
put_chip(map, chip);
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);
mutex_unlock(&chip->mutex);
schedule();
remove_wait_queue(&chip->wq, &wait);
mutex_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;
mutex_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;
mutex_lock(&loaner->mutex);
mutex_unlock(&shared->lock);
mutex_unlock(&chip->mutex);
put_chip(map, loaner);
mutex_lock(&chip->mutex);
mutex_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.
*/
mutex_unlock(&shared->lock);
wake_up(&chip->wq);
return;
}
mutex_unlock(&shared->lock);
}
switch (chip->oldstate) {
case FL_ERASING:
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;
mutex_lock(&chip->mutex);
ret = get_chip(map, chip, FL_WRITING);
if (ret) {
mutex_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);
mutex_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;
mutex_lock(&chip->mutex);
ret = get_chip(map, chip, FL_ERASING);
if (ret) {
mutex_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);
mutex_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;
mutex_lock(&chip->mutex);
ret = get_chip(map, chip, FL_READY);
if (ret) {
mutex_unlock(&chip->mutex);
return ret;
}
map_copy_from(map, buf, adr, len);
*retlen = len;
put_chip(map, chip);
mutex_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)
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;
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 */
mutex_lock(&chip->mutex);
ret = get_chip(map, chip, FL_POINT);
mutex_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 int 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, err = 0;
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;
mutex_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);
err = -EINVAL;
}
put_chip(map, chip);
mutex_unlock(&chip->mutex);
len -= thislen;
ofs = 0;
chipnum++;
}
return err;
}
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;
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;
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];
mutex_lock(&chip->mutex);
ret = get_chip(map, chip, FL_LOCKING);
if (ret) {
mutex_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);
mutex_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];
mutex_lock(&chip->mutex);
ret = get_chip(map, chip, FL_WRITING);
if (ret) {
mutex_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);
mutex_unlock(&chip->mutex);
return ret;
}
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Alexey Korolev <akorolev@infradead.org>");
MODULE_DESCRIPTION("MTD driver for LPDDR flash chips");