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nuttx/drivers/mtd/filemtd.c

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/****************************************************************************
* drivers/mtd/filemtd.c
*
* Copyright (C) 2015 Ken Pettit. All rights reserved.
* Author: Ken Pettit <pettitkd@gmail.com>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
* 3. Neither the name NuttX nor the names of its contributors may be
* used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <stdint.h>
#include <fcntl.h>
#include <string.h>
#include <assert.h>
#include <errno.h>
#include <debug.h>
#include <nuttx/kmalloc.h>
#include <nuttx/fs/ioctl.h>
#include <nuttx/mtd/mtd.h>
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
/* Configuration ************************************************************/
#ifndef CONFIG_FILEMTD_BLOCKSIZE
# define CONFIG_FILEMTD_BLOCKSIZE 512
#endif
#ifndef CONFIG_FILEMTD_ERASESIZE
# define CONFIG_FILEMTD_ERASESIZE 4096
#endif
#ifndef CONFIG_FILEMTD_ERASESTATE
# define CONFIG_FILEMTD_ERASESTATE 0xff
#endif
#if CONFIG_FILEMTD_ERASESTATE != 0xff && CONFIG_FILEMTD_ERASESTATE != 0x00
# error "Unsupported value for CONFIG_FILEMTD_ERASESTATE"
#endif
#if CONFIG_FILEMTD_BLOCKSIZE > CONFIG_FILEMTD_ERASESIZE
# error "Must have CONFIG_FILEMTD_BLOCKSIZE <= CONFIG_FILEMTD_ERASESIZE"
#endif
#undef FILEMTD_BLKPER
#define FILEMTD_BLKPER (CONFIG_FILEMTD_ERASESIZE/CONFIG_FILEMTD_BLOCKSIZE)
#if FILEMTD_BLKPER*CONFIG_FILEMTD_BLOCKSIZE != CONFIG_FILEMTD_ERASESIZE
# error "CONFIG_FILEMTD_ERASESIZE must be an even multiple of CONFIG_FILEMTD_BLOCKSIZE"
#endif
/****************************************************************************
* Private Types
****************************************************************************/
/* This type represents the state of the MTD device. The struct mtd_dev_s
* must appear at the beginning of the definition so that you can freely
* cast between pointers to struct mtd_dev_s and struct file_dev_s.
*/
struct file_dev_s
{
struct mtd_dev_s mtd; /* MTD device */
int fd; /* File descriptor of underlying file */
size_t nblocks; /* Number of erase blocks */
size_t offset; /* Offset from start of file */
size_t erasesize; /* Offset from start of file */
size_t blocksize; /* Offset from start of file */
};
/****************************************************************************
* Private Function Prototypes
****************************************************************************/
static ssize_t filemtd_read(FAR struct file_dev_s *priv,
FAR unsigned char *buffer, size_t offsetbytes,
unsigned int nbytes);
static ssize_t filemtd_write(FAR struct file_dev_s *priv, size_t offset,
FAR const void *src, size_t len);
/* MTD driver methods */
static int file_erase(FAR struct mtd_dev_s *dev, off_t startblock,
size_t nblocks);
static ssize_t file_bread(FAR struct mtd_dev_s *dev, off_t startblock,
size_t nblocks, FAR uint8_t *buf);
static ssize_t file_bwrite(FAR struct mtd_dev_s *dev, off_t startblock,
size_t nblocks, FAR const uint8_t *buf);
static ssize_t file_byteread(FAR struct mtd_dev_s *dev, off_t offset,
size_t nbytes, FAR uint8_t *buf);
#ifdef CONFIG_MTD_BYTE_WRITE
static ssize_t file_bytewrite(FAR struct mtd_dev_s *dev, off_t offset,
size_t nbytes, FAR const uint8_t *buf);
#endif
static int file_ioctl(FAR struct mtd_dev_s *dev, int cmd,
unsigned long arg);
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Name: filemtd_write
****************************************************************************/
static ssize_t filemtd_write(FAR struct file_dev_s *priv, size_t offset,
FAR const void *src, size_t len)
{
FAR const uint8_t *pin = (FAR const uint8_t *)src;
FAR uint8_t *pout;
char buf[128];
int buflen = 0;
uint8_t oldvalue;
uint8_t srcvalue;
uint8_t newvalue;
size_t seekpos;
/* Set the starting location in the file */
seekpos = priv->offset + offset;
while (len-- > 0)
{
if (buflen == 0)
{
/* Read more data from the file */
lseek(priv->fd, seekpos, SEEK_SET);
buflen = read(priv->fd, buf, sizeof(buf));
pout = (FAR uint8_t *) buf;
}
/* Get the source and destination values */
oldvalue = *pout;
srcvalue = *pin++;
/* Get the new destination value, accounting for bits that cannot be
* changes because they are not in the erased state.
*/
#if CONFIG_FILEMTD_ERASESTATE == 0xff
newvalue = oldvalue & srcvalue; /* We can only clear bits */
#else /* CONFIG_FILEMTD_ERASESTATE == 0x00 */
newvalue = oldvalue | srcvalue; /* We can only set bits */
#endif
/* Report any attempt to change the value of bits that are not in the
* erased state.
*/
#ifdef CONFIG_DEBUG
if (newvalue != srcvalue)
{
dbg("ERROR: Bad write: source=%02x dest=%02x result=%02x\n",
srcvalue, oldvalue, newvalue);
}
#endif
/* Write the modified value to simulated FLASH */
*pout++ = newvalue;
buflen--;
/* If our buffer is full, then seek back to beginning of
* the file and write the buffer contents
*/
if (buflen == 0)
{
lseek(priv->fd, seekpos, SEEK_SET);
write(priv->fd, buf, sizeof(buf));
seekpos += sizeof(buf);
}
}
/* Write remaining bytes */
if (buflen != 0)
{
lseek(priv->fd, seekpos, SEEK_SET);
write(priv->fd, buf, sizeof(buf));
}
return len;
}
/****************************************************************************
* Name: filemtd_read
****************************************************************************/
static ssize_t filemtd_read(FAR struct file_dev_s *priv,
FAR unsigned char *buffer, size_t offsetbytes,
unsigned int nbytes)
{
/* Set the starting location in the file */
lseek(priv->fd, priv->offset + offsetbytes, SEEK_SET);
return read(priv->fd, buffer, nbytes);
}
/****************************************************************************
* Name: file_erase
****************************************************************************/
static int file_erase(FAR struct mtd_dev_s *dev, off_t startblock,
size_t nblocks)
{
FAR struct file_dev_s *priv = (FAR struct file_dev_s *)dev;
size_t nbytes;
size_t offset;
char buffer[128];
DEBUGASSERT(dev);
/* Don't let the erase exceed the original size of the file */
if (startblock >= priv->nblocks)
{
return 0;
}
if (startblock + nblocks > priv->nblocks)
{
nblocks = priv->nblocks - startblock;
}
/* Convert the erase block to a logical block and the number of blocks
* in logical block numbers
*/
startblock *= FILEMTD_BLKPER;
nblocks *= FILEMTD_BLKPER;
/* Get the offset corresponding to the first block and the size
* corresponding to the number of blocks.
*/
offset = startblock * priv->blocksize;
nbytes = nblocks * priv->blocksize;
/* Then erase the data in the file */
lseek(priv->fd, priv->offset + offset, SEEK_SET);
memset(buffer, CONFIG_FILEMTD_ERASESTATE, sizeof(buffer));
while (nbytes)
{
write(priv->fd, buffer, sizeof(buffer));
nbytes -= sizeof(buffer);
}
return OK;
}
/****************************************************************************
* Name: file_bread
****************************************************************************/
static ssize_t file_bread(FAR struct mtd_dev_s *dev, off_t startblock,
size_t nblocks, FAR uint8_t *buf)
{
FAR struct file_dev_s *priv = (FAR struct file_dev_s *)dev;
off_t offset;
off_t maxblock;
size_t nbytes;
DEBUGASSERT(dev && buf);
/* Don't let the read exceed the original size of the file */
maxblock = priv->nblocks * FILEMTD_BLKPER;
if (startblock >= maxblock)
{
return 0;
}
if (startblock + nblocks > maxblock)
{
nblocks = maxblock - startblock;
}
/* Get the offset corresponding to the first block and the size
* corresponding to the number of blocks.
*/
offset = startblock * priv->blocksize;
nbytes = nblocks * priv->blocksize;
/* Then read the data from the file */
filemtd_read(priv, buf, offset, nbytes);
return nblocks;
}
/****************************************************************************
* Name: file_bwrite
****************************************************************************/
static ssize_t file_bwrite(FAR struct mtd_dev_s *dev, off_t startblock,
size_t nblocks, FAR const uint8_t *buf)
{
FAR struct file_dev_s *priv = (FAR struct file_dev_s *)dev;
off_t offset;
off_t maxblock;
size_t nbytes;
DEBUGASSERT(dev && buf);
/* Don't let the write exceed the original size of the file */
maxblock = priv->nblocks * FILEMTD_BLKPER;
if (startblock >= maxblock)
{
return 0;
}
if (startblock + nblocks > maxblock)
{
nblocks = maxblock - startblock;
}
/* Get the offset corresponding to the first block and the size
* corresponding to the number of blocks.
*/
offset = startblock * priv->blocksize;
nbytes = nblocks * priv->blocksize;
/* Then write the data to the file */
filemtd_write(priv, offset, buf, nbytes);
return nblocks;
}
/****************************************************************************
* Name: file_byteread
****************************************************************************/
static ssize_t file_byteread(FAR struct mtd_dev_s *dev, off_t offset,
size_t nbytes, FAR uint8_t *buf)
{
FAR struct file_dev_s *priv = (FAR struct file_dev_s *)dev;
DEBUGASSERT(dev && buf);
/* Don't let read read past end of buffer */
if (offset + nbytes > priv->nblocks * priv->erasesize)
{
return 0;
}
filemtd_read(priv, buf, offset, nbytes);
return nbytes;
}
/****************************************************************************
* Name: file_bytewrite
****************************************************************************/
#ifdef CONFIG_MTD_BYTE_WRITE
static ssize_t file_bytewrite(FAR struct mtd_dev_s *dev, off_t offset,
size_t nbytes, FAR const uint8_t *buf)
{
FAR struct file_dev_s *priv = (FAR struct file_dev_s *)dev;
off_t maxoffset;
DEBUGASSERT(dev && buf);
/* Don't let the write exceed the original size of the file */
maxoffset = priv->nblocks * priv->erasesize;
if (offset + nbytes > maxoffset)
{
return 0;
}
/* Then write the data to the file */
filemtd_write(priv, offset, buf, nbytes);
return nbytes;
}
#endif
/****************************************************************************
* Name: file_ioctl
****************************************************************************/
static int file_ioctl(FAR struct mtd_dev_s *dev, int cmd, unsigned long arg)
{
FAR struct file_dev_s *priv = (FAR struct file_dev_s *)dev;
int ret = -EINVAL; /* Assume good command with bad parameters */
switch (cmd)
{
case MTDIOC_GEOMETRY:
{
FAR struct mtd_geometry_s *geo =
(FAR struct mtd_geometry_s *)((uintptr_t)arg);
if (geo)
{
/* Populate the geometry structure with information need to know
* the capacity and how to access the device.
*/
geo->blocksize = priv->blocksize;
geo->erasesize = priv->erasesize;
geo->neraseblocks = priv->nblocks;
ret = OK;
}
}
break;
case MTDIOC_XIPBASE:
ret = -ENOTTY; /* Bad command */
break;
case MTDIOC_BULKERASE:
{
/* Erase the entire device */
file_erase(dev, 0, priv->nblocks);
ret = OK;
}
break;
default:
ret = -ENOTTY; /* Bad command */
break;
}
return ret;
}
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: filemtd_initialize
*
* Description:
* Create and initialize a FILE MTD device instance.
*
* Input Parameters:
* path - Path name of the file backing the MTD device
*
****************************************************************************/
FAR struct mtd_dev_s *filemtd_initialize(FAR const char *path, size_t offset,
int16_t sectsize, int32_t erasesize)
{
FAR struct file_dev_s *priv;
struct stat sb;
size_t nblocks;
size_t filelen;
int mode, ret;
/* Create an instance of the FILE MTD device state structure */
priv = (FAR struct file_dev_s *)kmm_zalloc(sizeof(struct file_dev_s));
if (!priv)
{
fdbg("Failed to allocate the FILE MTD state structure\n");
return NULL;
}
/* Determine the file open mode */
mode = O_RDOK;
#ifdef CONFIG_FS_WRITABLE
mode |= O_WROK;
#endif
/* Stat the file */
ret = stat(path, &sb);
if (ret < 0)
{
dbg("Failed to stat %s: %d\n", path, get_errno());
return NULL;
}
filelen = sb.st_size;
/* Try to open the file */
priv->fd = open(path, mode);
if (priv->fd == -1)
{
fdbg("Failed to open the FILE MTD file %s\n", path);
kmm_free(priv);
return NULL;
}
/* Set the block size based on the provided sectsize parameter */
if (sectsize <= 0)
{
priv->blocksize = CONFIG_FILEMTD_BLOCKSIZE;
}
else
{
priv->blocksize = sectsize;
}
/* Set the erase size based on the provided erasesize parameter */
if (erasesize <= 0)
{
priv->erasesize = CONFIG_FILEMTD_ERASESIZE;
}
else
{
priv->erasesize = erasesize;
}
/* Force the size to be an even number of the erase block size */
nblocks = (filelen - offset) / priv->erasesize;
if (nblocks < 3)
{
fdbg("Need to provide at least three full erase block\n");
kmm_free(priv);
return NULL;
}
/* Perform initialization as necessary. (unsupported methods were
* nullified by kmm_zalloc).
*/
priv->mtd.erase = file_erase;
priv->mtd.bread = file_bread;
priv->mtd.bwrite = file_bwrite;
priv->mtd.read = file_byteread;
#ifdef CONFIG_MTD_BYTE_WRITE
priv->mtd.write = file_bytewrite;
#endif
priv->mtd.ioctl = file_ioctl;
priv->offset = offset;
priv->nblocks = nblocks;
/* Register the MTD with the procfs system if enabled */
#ifdef CONFIG_MTD_REGISTRATION
mtd_register(&priv->mtd, "filemtd");
#endif
return &priv->mtd;
}
/****************************************************************************
* Name: filemtd_teardown
*
* Description:
* Teardown a previously created filemtd device.
*
* Input Parameters:
* path - Path name of the file backing the MTD device
*
****************************************************************************/
void filemtd_teardown(FAR struct mtd_dev_s *dev)
{
FAR struct file_dev_s *priv;
/* Close the enclosed file */
priv = (FAR struct file_dev_s *) dev;
close(priv->fd);
/* Register the MTD with the procfs system if enabled */
#ifdef CONFIG_MTD_REGISTRATION
mtd_unregister(&priv->mtd);
#endif
/* Free the memory */
kmm_free(priv);
}
/****************************************************************************
* Name: filemtd_isfilemtd
*
* Description:
* Tests if the provided mtd is a filemtd device.
*
* Input Parameters:
* mtd - Pointer to the mtd.
*
****************************************************************************/
bool filemtd_isfilemtd(FAR struct mtd_dev_s *dev)
{
FAR struct file_dev_s *priv = (FAR struct file_dev_s *) dev;
if (priv->mtd.erase == file_erase)
return 1;
return 0;
}
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