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nuttx/drivers/mtd/mtd_config.c

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/****************************************************************************
* drivers/mtd/mtd_config.c
*
* Copyright (C) 2013 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.
*
****************************************************************************/
/****************************************************************************
* dev_config provides an interface for saving and retrieving
* application configuration data to a standard MTD partition.
* It accepts an MTD pointer (presumable a partition) and
* publishes a /dev/config device file for accessing via
* defined ioctl calls to set and get config data.
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <sys/types.h>
#include <stdbool.h>
#include <string.h>
#include <poll.h>
#include <errno.h>
#include <debug.h>
#include <nuttx/fs/fs.h>
#include <nuttx/kmalloc.h>
#include <nuttx/fs/ioctl.h>
#include <nuttx/mtd/mtd.h>
#include <nuttx/configdata.h>
#ifdef CONFIG_MTD_CONFIG
/************************************************************************************
* Pre-processor Definitions
************************************************************************************/
/* Define the current format version */
#define CONFIGDATA_FORMAT_VERSION 1
#define CONFIGDATA_BLOCK_HDR_SIZE 3
/* Define the erased state of the MTD device, if not already defined */
#ifndef CONFIG_MTD_CONFIG_ERASEDVALUE
# define CONFIG_MTD_CONFIG_ERASEDVALUE 0xff
#endif
#define MTD_ERASED_ID ((CONFIG_MTD_CONFIG_ERASEDVALUE << 8) | \
CONFIG_MTD_CONFIG_ERASEDVALUE)
#define MTD_ERASED_FLAGS CONFIG_MTD_CONFIG_ERASEDVALUE
/****************************************************************************
* Private Types
****************************************************************************/
struct mtdconfig_struct_s
{
FAR struct mtd_dev_s *mtd; /* Contained MTD interface */
sem_t exclsem; /* Supports mutual exclusion */
uint16_t blocksize; /* Size of blocks in contained MTD */
uint16_t erasesize; /* Size of erase block in contained MTD */
size_t nblocks; /* Number of blocks available */
size_t neraseblocks; /* Number of erase blocks available */
off_t readoff; /* Read offset (for hexdump) */
FAR uint8_t *buffer; /* Temp block read buffer */
};
struct mtdconfig_header_s
{
uint8_t flags; /* Entry control flags */
uint8_t instance; /* Instance of the item */
uint16_t id; /* ID of the config data item */
uint16_t len; /* Length of the data block */
} packed_struct;
/****************************************************************************
* Private Function Prototypes
****************************************************************************/
static int mtdconfig_open(FAR struct file *filep);
static int mtdconfig_close(FAR struct file *filep);
static ssize_t mtdconfig_read(FAR struct file *, FAR char *, size_t);
static ssize_t mtdconfig_ioctl(FAR struct file *, int, unsigned long);
#ifndef CONFIG_DISABLE_POLL
static int mtdconfig_poll(FAR struct file *filep, FAR struct pollfd *fds,
bool setup);
#endif
/****************************************************************************
* Private Data
****************************************************************************/
static const struct file_operations mtdconfig_fops =
{
mtdconfig_open, /* open */
mtdconfig_close, /* close */
mtdconfig_read, /* read */
0, /* write */
0, /* seek */
mtdconfig_ioctl /* ioctl */
#ifndef CONFIG_DISABLE_POLL
, mtdconfig_poll /* poll */
#endif
};
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Name: mtdconfig_readbytes
*
* Reads bytes from the contained MTD device. This will either usee
* the read function or if that is not available, the bread with a copy.
*
****************************************************************************/
static int mtdconfig_readbytes(FAR struct mtdconfig_struct_s *dev, int offset,
FAR uint8_t *pdata, int readlen)
{
off_t bytestoread = readlen;
off_t bytesthisblock, firstbyte;
off_t block, index;
int ret = OK;
size_t bytes;
/* Test if read interface supported. If it is, use it directly */
if ((dev->mtd->read == NULL) && (readlen < dev->blocksize))
{
/* Read interface available. Read directly to buffer */
bytes = MTD_READ(dev->mtd, offset, readlen, pdata);
if (bytes != readlen)
{
/* Error reading data! */
ret = -EIO;
}
}
else
{
/* Read interface not available, do a block read into our buffer */
block = offset / dev->blocksize;
firstbyte = offset - (block * dev->blocksize);
bytesthisblock = dev->blocksize - firstbyte;
if (bytesthisblock > readlen)
{
bytesthisblock = readlen;
}
index = 0;
while (bytestoread > 0)
{
if (bytesthisblock < dev->blocksize || bytestoread < dev->blocksize)
{
/* Copy to temp buffer first...don't need the whole block */
bytes = MTD_BREAD(dev->mtd, block, 1, dev->buffer);
if (bytes != 1)
{
/* Error reading data! */
ret = -EIO;
goto errout;
}
/* Copy data to the output buffer */
memcpy(&pdata[index], &dev->buffer[firstbyte], bytesthisblock);
}
else
{
/* We are reading a whole block. Read directly to buffer */
bytes = MTD_BREAD(dev->mtd, block, 1, &pdata[index]);
if (bytes != 1)
{
/* Error reading data! */
ret = -EIO;
goto errout;
}
}
/* Update values for next block read */
bytestoread -= bytesthisblock;
index += bytesthisblock;
bytesthisblock = dev->blocksize;
if (bytesthisblock > bytestoread)
{
bytesthisblock = bytestoread;
}
firstbyte = 0;
block++;
}
}
errout:
return ret;
}
/****************************************************************************
* Name: mtdconfig_writebytes
*
* Writes bytes to the contained MTD device. This will either usee
* the byte write function or if that is not available, the bwrite.
*
****************************************************************************/
static int mtdconfig_writebytes(FAR struct mtdconfig_struct_s *dev, int offset,
FAR const uint8_t *pdata, int writelen)
{
int ret = OK;
#ifdef CONFIG_MTD_BYTE_WRITE
/* Test if this MTD device supports byte write */
if (dev->mtd->write != NULL)
{
ret = MTD_WRITE(dev->mtd, offset, writelen, pdata);
}
else
#endif
/* Perform the write using the block write method of the MTD */
{
uint16_t block;
uint16_t index;
off_t bytes_this_block;
off_t bytes_written = 0;
while (writelen)
{
/* Read existing data from the the block into the buffer */
block = offset / dev->blocksize;
ret = MTD_BREAD(dev->mtd, block, 1, dev->buffer);
if (ret != 1)
{
ret = -EIO;
goto errout;
}
index = offset - block * dev->blocksize;
bytes_this_block = dev->blocksize - index;
if (bytes_this_block > writelen)
{
bytes_this_block = writelen;
}
/* Now write data to the block */
memcpy(&dev->buffer[index], pdata, bytes_this_block);
ret = MTD_BWRITE(dev->mtd, block, 1, dev->buffer);
if (ret != 1)
{
ret = -EIO;
goto errout;
}
/* Update writelen, etc. */
writelen -= bytes_this_block;
pdata += bytes_this_block;
offset += bytes_this_block;
bytes_written += bytes_this_block;
}
/* Return the number of bytes written */
ret = bytes_written;
}
errout:
return ret;
}
/****************************************************************************
* Name: mtdconfig_findfirstentry
*
* Locates the first config entry, even if it is empty.
*
* Returns:
* offset to the start of the entry.
*
****************************************************************************/
static int mtdconfig_findfirstentry(FAR struct mtdconfig_struct_s *dev,
FAR struct mtdconfig_header_s *phdr)
{
off_t offset = CONFIGDATA_BLOCK_HDR_SIZE;
uint8_t sig[CONFIGDATA_BLOCK_HDR_SIZE];
bool found = false;
int ret;
uint16_t block;
off_t bytes_left_in_block;
uint16_t endblock;
mtdconfig_readbytes(dev, 0, sig, sizeof(sig)); /* Read the signature bytes */
if (sig[0] != 'C' || sig[1] != 'D' || sig[2] != CONFIGDATA_FORMAT_VERSION)
{
/* Config Data partition not formatted. */
return 0;
}
#ifdef CONFIG_MTD_CONFIG_RAM_CONSOLIDATE
endblock = dev->neraseblocks;
#else
if (dev->neraseblocks == 1)
{
endblock = 1;
}
else
{
endblock = dev->neraseblocks - 1;
}
#endif
/* Config is formatted. Now loop until we find the first entry */
while (!found)
{
/* Read headers until we find one that hasn't been released.
*/
ret = mtdconfig_readbytes(dev, offset, (uint8_t *) phdr,
sizeof(struct mtdconfig_header_s));
if (ret != OK)
{
return 0;
}
/* Test if this header has been released */
if (phdr->flags != MTD_ERASED_FLAGS)
{
/* This entry has been released. Advance to next entry */
offset += sizeof(struct mtdconfig_header_s) + phdr->len;
block = offset / dev->erasesize;
bytes_left_in_block = (block + 1) * dev->erasesize - offset;
if (bytes_left_in_block <= sizeof(*phdr))
{
offset = (block + 1) * dev->erasesize + CONFIGDATA_BLOCK_HDR_SIZE;
if (block + 1 >= endblock)
return 0;
}
if (bytes_left_in_block == dev->erasesize)
{
/* Skip block hearder */
offset += CONFIGDATA_BLOCK_HDR_SIZE;
}
}
else
{
/* We found the first entry! */
found = true;
}
}
/* Return the offset of the first entry */
return offset;
}
/****************************************************************************
* Name: mtdconfig_findnextentry
*
* Locates the next config entry starting at offset, even if it is empty.
*
* Returns:
* offset to the start of the next entry.
*
****************************************************************************/
static int mtdconfig_findnextentry(FAR struct mtdconfig_struct_s *dev,
off_t offset,
FAR struct mtdconfig_header_s *phdr,
uint16_t size)
{
bool found = false;
int ret;
uint16_t block, bytes_left_in_block;
uint16_t endblock;
#ifdef CONFIG_MTD_CONFIG_RAM_CONSOLIDATE
endblock = dev->neraseblocks;
#else
if (dev->neraseblocks == 1)
{
endblock = 1;
}
else
{
endblock = dev->neraseblocks - 1;
}
#endif
/* Loop until next entry found */
while (!found)
{
/* Calculate offset of the next entry */
offset += sizeof(struct mtdconfig_header_s) + phdr->len;
if (offset % dev->erasesize == 0)
{
offset += CONFIGDATA_BLOCK_HDR_SIZE;
}
if (offset >= endblock * dev->erasesize)
{
return 0;
}
/* Test if too close to the end of the erase block */
block = offset / dev->erasesize;
bytes_left_in_block = (block + 1) * dev->erasesize - offset;
if (bytes_left_in_block <= sizeof(*phdr))
{
offset = (block + 1) * dev->erasesize + CONFIGDATA_BLOCK_HDR_SIZE;
if (block + 1 >= endblock)
{
return 0;
}
}
/* Read next header */
read_next:
ret = mtdconfig_readbytes(dev, offset, (uint8_t *) phdr, sizeof(*phdr));
if (ret != OK)
{
return 0;
}
/* Test if this header has is still active */
if (phdr->flags == MTD_ERASED_FLAGS)
{
if (phdr->id == MTD_ERASED_ID)
{
/* If we are searching for free space, then check
* if this space is large enough. If it is, then
* we are done.
*/
block = offset / dev->erasesize;
bytes_left_in_block = (block + 1) * dev->erasesize - offset;
if (size > 0 && bytes_left_in_block >= size + sizeof(*phdr))
{
/* Free entry of large enough size found */
found = true;
break;
}
/* Advance to next erase block and continue search */
offset = (block + 1) * dev->erasesize + CONFIGDATA_BLOCK_HDR_SIZE;
if (block + 1 >= endblock)
{
return 0;
}
/* Don't return to top of loop since we manually adjusted
* the offset, and don't want to go to the next entry.
*/
goto read_next;
}
else
{
/* If we are searching for existing, active entries
* only, then we are done ... we found one.
*/
if (size == 0)
{
found = true;
}
}
}
}
return offset;
}
/****************************************************************************
* Name: mtdconfig_ramconsolidate
*
* Attempts to perform a RAM based consolidation of released
* items. This requires a large enough free RAM block. This
* method of consolidation is used when only a single erase
* block is available in the partition.
*
* Returns:
* offset to the next available entry (after consolidation)..
*
****************************************************************************/
static off_t mtdconfig_ramconsolidate(FAR struct mtdconfig_struct_s *dev)
{
FAR uint8_t *pBuf;
FAR struct mtdconfig_header_s *phdr;
struct mtdconfig_header_s hdr;
uint16_t src_block = 0, dst_block = 0, blkper;
off_t dst_offset = CONFIGDATA_BLOCK_HDR_SIZE;
off_t src_offset = CONFIGDATA_BLOCK_HDR_SIZE;
off_t bytes_left_in_block;
uint8_t sig[CONFIGDATA_BLOCK_HDR_SIZE];
int ret;
/* Allocate a consolidation buffer */
pBuf = (uint8_t *)kmalloc(dev->erasesize);
if (pBuf == NULL)
{
/* Unable to allocate buffer, can't consolidate! */
return 0;
}
/* Loop for all blocks and consolidate them */
blkper = dev->erasesize / dev->blocksize;
while (src_block < dev->neraseblocks)
{
/* Point to beginning of pBuf and read the next erase block */
ret = MTD_BREAD(dev->mtd, src_block * blkper, blkper, pBuf);
if (ret < 0)
{
/* Error doing block read */
dst_offset = 0;
goto errout;
}
/* Now erase the block */
ret = MTD_ERASE(dev->mtd, src_block, 1);
if (ret < 0)
{
/* Error erasing the block */
dst_offset = 0;
goto errout;
}
/* If this is block zero, then write a format signature */
if (src_block == 0)
{
sig[0] = 'C';
sig[1] = 'D';
sig[2] = CONFIGDATA_FORMAT_VERSION;
mtdconfig_writebytes(dev, 0, sig, sizeof(sig));
}
/* Copy active items back to the MTD device */
while (src_offset < dev->erasesize)
{
phdr = (FAR struct mtdconfig_header_s *) &pBuf[src_offset];
if (phdr->id == MTD_ERASED_ID)
{
/* No more data in this erase block */
src_offset = dev->erasesize;
continue;
}
if (phdr->flags == MTD_ERASED_FLAGS)
{
/* This is an active entry. Copy it. Check if it
* fits in the current destination block.
*/
bytes_left_in_block = (dst_block + 1) * dev->erasesize -
dst_offset;
if (bytes_left_in_block < sizeof(*phdr) + phdr->len)
{
/* Item won't fit in the destination block. Move to
* the next block
*/
dst_block++;
dst_offset = dst_block * dev->erasesize + CONFIGDATA_BLOCK_HDR_SIZE;
/* Test for program bug. We shouldn't ever overflow
* even if no entries were inactive.
*/
DEBUGASSERT(dst_block != dev->neraseblocks);
}
/* Now Write the item to the current dst_offset location */
//printf("REL HDR: ID=%04X,%02X Len=%4d Off=%5d Src off=%4d\n",
// phdr->id, phdr->instance, phdr->len, dst_offset, src_offset);
ret = mtdconfig_writebytes(dev, dst_offset, (uint8_t *) phdr,
sizeof(hdr));
if (ret < 0)
{
dst_offset = 0;
goto errout;
}
dst_offset += sizeof(hdr);
ret = mtdconfig_writebytes(dev, dst_offset, &pBuf[src_offset
+ sizeof(hdr)], phdr->len);
dst_offset += phdr->len;
/* Test if enough space in dst block for another header */
if (dst_offset + sizeof(hdr) >= (dst_block + 1) * dev->erasesize ||
dst_offset == (dst_block + 1) * dev->erasesize)
{
dst_block++;
dst_offset = dst_block * dev->erasesize + CONFIGDATA_BLOCK_HDR_SIZE;
}
}
/* Increment past the current source item */
src_offset += sizeof(hdr) + phdr->len;
if (src_offset + sizeof(hdr) > dev->erasesize)
{
src_offset = dev->erasesize;
}
DEBUGASSERT(src_offset <= dev->erasesize);
}
/* Increment to next source block */
src_block++;
src_offset = CONFIGDATA_BLOCK_HDR_SIZE;
}
errout:
kfree(pBuf);
return dst_offset;
}
/****************************************************************************
* Name: mtdconfig_consolidate
*
* Performs consolidation by writing erase block zero to the
* reserved block at the end, erasing block zero, then
* walking through each item and copying them to the newly
* erased block. It erases all blocks to the end of the
* partition as it goes.
*
* Returns:
* offset to the next available entry (after consolidation)..
*
****************************************************************************/
#ifndef CONFIG_MTD_CONFIG_RAM_CONSOLIDATE
static off_t mtdconfig_consolidate(FAR struct mtdconfig_struct_s *dev)
{
off_t src_block, dst_block;
off_t src_offset, dst_offset;
uint16_t blkper, x, bytes, bytes_left_in_block;
struct mtdconfig_header_s hdr;
int ret;
uint8_t sig[CONFIGDATA_BLOCK_HDR_SIZE];
uint8_t *pBuf;
/* Prepare to copy block 0 to the last block (erase blocks) */
src_block = 0;
dst_block = dev->neraseblocks - 1;
/* Ensure the last block is erased */
MTD_ERASE(dev->mtd, dst_block, 1);
blkper = dev->erasesize / dev->blocksize;
dst_block *= blkper; /* Convert to read/write blocks */
/* Allocate a small buffer for moving data */
pBuf = (uint8_t *)kmalloc(dev->blocksize);
if (pBuf == NULL)
{
return 0;
}
/* Now copy block zero to last block */
for (x = 0; x < blkper; x++)
{
ret = MTD_BREAD(dev->mtd, src_block++, 1, dev->buffer);
if (ret < 0)
{
/* I/O Error! */
goto errout;
}
ret = MTD_BWRITE(dev->mtd, dst_block++, 1, dev->buffer);
if (ret < 0)
{
/* I/O Error! */
goto errout;
}
}
/* Erase block zero and write a format signature. */
MTD_ERASE(dev->mtd, 0, 1);
sig[0] = 'C';
sig[1] = 'D';
sig[2] = CONFIGDATA_FORMAT_VERSION;
mtdconfig_writebytes(dev, 0, sig, sizeof(sig));
/* Now consolidate entries */
src_block = 1;
dst_block = 0;
src_offset = src_block * dev->erasesize + CONFIGDATA_BLOCK_HDR_SIZE;
dst_offset = CONFIGDATA_BLOCK_HDR_SIZE;
while (src_block < dev->neraseblocks)
{
/* Scan all headers and move them to the src_offset */
retry_relocate:
MTD_READ(dev->mtd, src_offset, sizeof(hdr), (uint8_t *) &hdr);
if (hdr.flags == MTD_ERASED_FLAGS)
{
/* Test if the source entry is active or if we are at the end
* of data for this erase block.
*/
if (hdr.id == MTD_ERASED_ID)
{
/* No more data in this erase block. Advance to the
* next one.
*/
src_offset = (src_block + 1) * dev->erasesize + CONFIGDATA_BLOCK_HDR_SIZE;
}
else
{
/* Test if this entry will fit in the current destination block */
bytes_left_in_block = (dst_block + 1) * dev->erasesize - dst_offset;
if (hdr.len + sizeof(hdr) > bytes_left_in_block)
{
/* Item doesn't fit in the block. Advance to the next one */
/* Update control variables */
dst_block++;
dst_offset = dst_block * dev->erasesize + CONFIGDATA_BLOCK_HDR_SIZE;
DEBUGASSERT(dst_block != src_block);
/* Retry the relocate */
goto retry_relocate;
}
/* Copy this entry to the destination */
//printf("REL HDR: ID=%04X,%02X Len=%4d Off=%5d Src off=%4d\n",
// hdr.id, hdr.instance, hdr.len, dst_offset, src_offset);
mtdconfig_writebytes(dev, dst_offset, (uint8_t *) &hdr, sizeof(hdr));
src_offset += sizeof(hdr);
dst_offset += sizeof(hdr);
/* Now copy the data */
while (hdr.len)
{
bytes = hdr.len;
if (bytes > dev->blocksize)
{
bytes = dev->blocksize;
}
/* Move the data. */
mtdconfig_readbytes(dev, src_offset, pBuf, bytes);
mtdconfig_writebytes(dev, dst_offset, pBuf, bytes);
/* Update control variables */
hdr.len -= bytes;
src_offset += bytes;
dst_offset += bytes;
}
}
}
else
{
/* This item has been released. Skip it! */
src_offset += sizeof(hdr) + hdr.len;
if (src_offset + sizeof(hdr) >= (src_block + 1) * dev->erasesize ||
src_offset == (src_block +1 ) * dev->erasesize)
{
/* No room left at end of source block */
src_offset = (src_block + 1) * dev->erasesize + CONFIGDATA_BLOCK_HDR_SIZE;
}
}
/* Test if we are out of space in the src block */
if (src_offset + sizeof(hdr) >= (src_block + 1) * dev->erasesize)
{
/* No room at end of src block for another header. Go to next
* source block.
*/
src_offset = (src_block + 1) * dev->erasesize + CONFIGDATA_BLOCK_HDR_SIZE;
}
/* Test if we advanced to the next block. If we did, then erase the
* old block.
*/
if (src_block != src_offset / dev->erasesize)
{
/* Erase the block ... we have emptied it */
MTD_ERASE(dev->mtd, src_block, 1);
src_block++;
}
/* Test if we are out of space in the dst block */
if (dst_offset + sizeof(hdr) >= (dst_block + 1) * dev->erasesize)
{
/* No room at end of dst block for another header. Go to next block. */
dst_block++;
dst_offset = dst_block * dev->erasesize + CONFIGDATA_BLOCK_HDR_SIZE;
DEBUGASSERT(dst_block != src_block);
}
}
errout:
kfree(pBuf);
return 0;
}
#endif /* CONFIG_MTD_CONFIG_RAM_CONSOLIDATE */
/****************************************************************************
* Name: mtdconfig_open
****************************************************************************/
static int mtdconfig_open(FAR struct file *filep)
{
FAR struct inode *inode = filep->f_inode;
FAR struct mtdconfig_struct_s *dev = inode->i_private;
int ret = OK;
/* Get exclusive access to the device */
ret = sem_wait(&dev->exclsem);
if (ret < 0)
{
ret = -errno;
goto errout;
}
dev->readoff = 0;
errout:
return ret;
}
/****************************************************************************
* Name: mtdconfig_close
****************************************************************************/
static int mtdconfig_close(FAR struct file *filep)
{
FAR struct inode *inode = filep->f_inode;
FAR struct mtdconfig_struct_s *dev = inode->i_private;
/* Release exclusive access to the device */
sem_post(&dev->exclsem);
return OK;
}
/****************************************************************************
* Name: mtdconfig_read
****************************************************************************/
static ssize_t mtdconfig_read(FAR struct file *filep, FAR char *buffer,
size_t len)
{
FAR struct inode *inode = filep->f_inode;
FAR struct mtdconfig_struct_s *dev = inode->i_private;
size_t bytes;
if (dev->readoff >= dev->neraseblocks * dev->erasesize)
{
return 0;
}
/* Read data from the file */
bytes = MTD_READ(dev->mtd, dev->readoff, len, (uint8_t *) buffer);
dev->readoff += bytes;
return bytes;
}
/****************************************************************************
* Name: mtdconfig_findentry
****************************************************************************/
static int mtdconfig_findentry(FAR struct mtdconfig_struct_s *dev,
off_t offset,
FAR struct config_data_s *pdata,
FAR struct mtdconfig_header_s *phdr)
{
uint16_t endblock;
#ifdef CONFIG_MTD_CONFIG_RAM_CONSOLIDATE
endblock = dev->neraseblocks;
#else
if (dev->neraseblocks == 1)
{
endblock = 1;
}
else
{
endblock = dev->neraseblocks - 1;
}
#endif
while (offset > 0 && (pdata->id != phdr->id || pdata->instance != phdr->instance))
{
if (phdr->id == MTD_ERASED_ID)
{
/* Advance to the next block and continue the search */
offset = (offset + dev->erasesize) / dev->erasesize;
offset = offset * dev->erasesize + CONFIGDATA_BLOCK_HDR_SIZE;
if (offset >= endblock * dev->erasesize)
{
/* Entry doesn't exist on the device */
offset = 0;
break;
}
/* Read the 1st header from the next block */
mtdconfig_readbytes(dev, offset, (uint8_t *) phdr, sizeof(*phdr));
if (phdr->flags == MTD_ERASED_FLAGS)
{
continue;
}
}
/* Nope, not the last header. Get the next one */
offset = mtdconfig_findnextentry(dev, offset, phdr, 0);
}
return offset;
}
/****************************************************************************
* Name: mtdconfig_setconfig
****************************************************************************/
static int mtdconfig_setconfig(FAR struct mtdconfig_struct_s *dev,
FAR struct config_data_s *pdata)
{
uint8_t sig[CONFIGDATA_BLOCK_HDR_SIZE]; /* Format signature bytes ("CD") */
char retrycount = 0;
int ret = -ENOSYS;
off_t offset, bytes_left_in_block, bytes;
uint16_t block;
struct mtdconfig_header_s hdr;
uint8_t ram_consolidate;
/* Allocate a temp block buffer */
dev->buffer = (FAR uint8_t *) kmalloc(dev->blocksize);
/* Read and vaidate the signature bytes */
retry:
offset = mtdconfig_findfirstentry(dev, &hdr);
if (offset == 0)
{
/* Config Data partition not formatted. */
if (retrycount)
{
ret = -ENOSYS;
goto errout;
}
/* Try to format the config partition */
ret = MTD_IOCTL(dev->mtd, MTDIOC_BULKERASE, 0);
if (ret < 0)
{
goto errout;
}
/* Write a format signature */
sig[0] = 'C';
sig[1] = 'D';
sig[2] = CONFIGDATA_FORMAT_VERSION;
mtdconfig_writebytes(dev, 0, sig, sizeof(sig));
/* Now go try to read the signature again (as verification) */
retrycount++;
goto retry;
}
/* Okay, the Config Data partition is formatted. Check if the
* config item being written is already in the database. If it
* is, we must mark it as obsolete before creating a new entry.
*/
offset = mtdconfig_findentry(dev, offset, pdata, &hdr);
/* Test if the header was found. */
if (offset > 0 && pdata->id == hdr.id && pdata->instance ==
hdr.instance)
{
/* Mark this entry as released */
hdr.flags = (uint8_t)~MTD_ERASED_FLAGS;
mtdconfig_writebytes(dev, offset, &hdr.flags, sizeof(hdr.flags));
}
/* Test if the new length is zero. If it is, then we are
* deleting the entry.
*/
if (pdata->len == 0)
{
ret = OK;
goto errout;
}
/* Now find a new entry for this config data */
retrycount = 0;
retry_find:
offset = mtdconfig_findfirstentry(dev, &hdr);
if (offset > 0 && hdr.id == MTD_ERASED_ID)
{
block = offset / dev->erasesize;
bytes_left_in_block = (block + 1) * dev->erasesize - offset;
if (bytes_left_in_block < sizeof(hdr) + pdata->len)
{
/* Simulate an active block to search for the next one
* in the code below.
*/
hdr.id = 1;
}
}
if (hdr.id != MTD_ERASED_ID)
{
/* Read the next entry */
offset = mtdconfig_findnextentry(dev, offset, &hdr, pdata->len);
if (offset == 0)
{
/* No free entries left on device! */
#ifdef CONFIG_MTD_CONFIG_RAM_CONSOLIDATE
ram_consolidate = 1;
#else
ram_consolidate = dev->neraseblocks == 1;
#endif
if (ram_consolidate)
{
/* If we only have 1 erase block, then we must do a RAM
* assisted consolidation of released entries.
*/
if (retrycount)
{
/* Out of space! */
ret = -ENOMEM;
goto errout;
}
mtdconfig_ramconsolidate(dev);
retrycount++;
goto retry_find;
}
#ifndef CONFIG_MTD_CONFIG_RAM_CONSOLIDATE
else
{
if (retrycount)
{
/* Out of space! */
ret = -ENOMEM;
goto errout;
}
mtdconfig_consolidate(dev);
retrycount++;
goto retry_find;
}
#endif
}
}
/* Test if a new entry was found */
if (offset > 0)
{
/* Save the data at this entry */
hdr.id = pdata->id;
hdr.instance = pdata->instance;
hdr.len = pdata->len;
hdr.flags = MTD_ERASED_FLAGS;
//printf("SAV HDR: ID=%04X,%02X Len=%4d Off=%5d\n",
// hdr.id, hdr.instance, hdr.len, offset);
mtdconfig_writebytes(dev, offset, (uint8_t *)&hdr, sizeof(hdr));
bytes = mtdconfig_writebytes(dev, offset + sizeof(hdr), pdata->configdata,
pdata->len);
if (bytes != pdata->len)
{
/* Error writing data! */
hdr.flags = MTD_ERASED_FLAGS;
mtdconfig_writebytes(dev, offset, (uint8_t *)&hdr, sizeof(hdr.flags));
ret = -EIO;
goto errout;
}
ret = OK;
}
errout:
/* Free the buffer */
kfree(dev->buffer);
return ret;
}
/****************************************************************************
* Name: mtdconfig_getconfig
****************************************************************************/
static int mtdconfig_getconfig(FAR struct mtdconfig_struct_s *dev,
FAR struct config_data_s *pdata)
{
int ret = -ENOSYS;
off_t offset, bytes_to_read;
struct mtdconfig_header_s hdr;
/* Allocate a temp block buffer */
dev->buffer = (FAR uint8_t *)kmalloc(dev->blocksize);
if (dev->buffer == NULL)
{
return -ENOMEM;
}
/* Get the offset of the first entry. This will also check
* the format signature bytes.
*/
offset = mtdconfig_findfirstentry(dev, &hdr);
offset = mtdconfig_findentry(dev, offset, pdata, &hdr);
/* Test if the header was found. */
if (offset > 0 && (pdata->id == hdr.id && pdata->instance == hdr.instance))
{
/* Entry found. Read the data */
bytes_to_read = hdr.len;
if (bytes_to_read > pdata->len)
{
bytes_to_read = pdata->len;
}
/* Perform the read */
ret = mtdconfig_readbytes(dev, offset + sizeof(hdr), pdata->configdata,
bytes_to_read);
if (ret != OK)
{
/* Error reading the data */
ret = -EIO;
goto errout;
}
ret = OK;
}
errout:
/* Free the buffer */
kfree(dev->buffer);
return ret;
}
/****************************************************************************
* Name: mtdconfig_ioctl
****************************************************************************/
static int mtdconfig_ioctl(FAR struct file *filep, int cmd, unsigned long arg)
{
FAR struct inode *inode = filep->f_inode;
FAR struct mtdconfig_struct_s *dev = inode->i_private;
FAR struct config_data_s *pdata;
int ret = -ENOSYS;
switch (cmd)
{
case CFGDIOC_SETCONFIG:
/* Set the config item */
pdata = (FAR struct config_data_s *)arg;
ret = mtdconfig_setconfig(dev, pdata);
break;
case CFGDIOC_GETCONFIG:
/* Get the config item */
pdata = (FAR struct config_data_s *)arg;
ret = mtdconfig_getconfig(dev, pdata);
break;
}
return ret;
}
/****************************************************************************
* Name: mtdconfig_poll
****************************************************************************/
#ifndef CONFIG_DISABLE_POLL
static int mtdconfig_poll(FAR struct file *filep, FAR struct pollfd *fds,
bool setup)
{
if (setup)
{
fds->revents |= (fds->events & (POLLIN|POLLOUT));
if (fds->revents != 0)
{
sem_post(fds->sem);
}
}
return OK;
}
#endif
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: mtdconfig_register
*
* Description:
* Register a /dev/config device backed by an MTD
*
****************************************************************************/
int mtdconfig_register(FAR struct mtd_dev_s *mtd)
{
int ret = OK;
struct mtdconfig_struct_s *dev;
struct mtd_geometry_s geo; /* Device geometry */
dev = (struct mtdconfig_struct_s *)kmalloc(sizeof(struct mtdconfig_struct_s));
if (dev)
{
/* Initialize the mtdconfig device structure */
dev->mtd = mtd;
sem_init(&dev->exclsem, 0, 1);
/* Get the device geometry. (casting to uintptr_t first eliminates
* complaints on some architectures where the sizeof long is different
* from the size of a pointer).
*/
ret = MTD_IOCTL(mtd, MTDIOC_GEOMETRY, (unsigned long)((uintptr_t)&geo));
if (ret < 0)
{
fdbg("MTD ioctl(MTDIOC_GEOMETRY) failed: %d\n", ret);
kfree(dev);
goto errout;
}
dev->blocksize = geo.blocksize;
dev->neraseblocks = geo.neraseblocks;
dev->erasesize = geo.erasesize;
dev->nblocks = geo.neraseblocks * geo.erasesize / geo.blocksize;
(void)register_driver("/dev/config", &mtdconfig_fops, 0666, dev);
}
errout:
return ret;
}
#endif /* CONFIG_MTD_CONFIG */
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