/************************************************************************************
* drivers/mtd/mtd_rwbuffer.c
* MTD driver that contains another MTD driver and provides read-ahead and/or write
* buffering.
*
* Copyright (C) 2014 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <gnutt@nuttx.org>
*
* 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 <stdint.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <assert.h>
#include <errno.h>
#include <debug.h>
#include <nuttx/kmalloc.h>
#include <nuttx/rwbuffer.h>
#include <nuttx/fs/ioctl.h>
#include <nuttx/mtd/mtd.h>
#if defined(CONFIG_DRVR_WRITEBUFFER) || defined(CONFIG_DRVR_READAHEAD)
/************************************************************************************
* Pre-processor Definitions
************************************************************************************/
#ifndef CONFIG_DRVR_INVALIDATE
# error This driver requires CONFIG_DRVR_INVALIDATE
#endif
#ifndef CONFIG_DRVR_READBYTES
# error This driver requires CONFIG_DRVR_READBYTES
#endif
#ifndef CONFIG_MTD_NWRBLOCKS
# define CONFIG_MTD_NWRBLOCKS 4
#endif
#ifndef CONFIG_MTD_NRDBLOCKS
# define CONFIG_MTD_NRDBLOCKS 4
#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 mtd_rwbuffer_s.
*/
struct mtd_rwbuffer_s
{
struct mtd_dev_s mtd; /* Our exported MTD interface */
FAR struct mtd_dev_s *dev; /* Saved lower level MTD interface instance */
struct rwbuffer_s rwb; /* The rwbuffer state structure */
uint16_t spb; /* Number of sectors per block */
};
/************************************************************************************
* Private Function Prototypes
************************************************************************************/
/* rwbuffer callouts */
static ssize_t mtd_reload(FAR void *dev, FAR uint8_t *buffer, off_t startblock,
size_t nblocks);
static ssize_t mtd_flush(FAR void *dev, FAR const uint8_t *buffer, off_t startblock,
size_t nblocks);
/* MTD driver methods */
static int mtd_erase(FAR struct mtd_dev_s *dev, off_t block, size_t nsectors);
static ssize_t mtd_bread(FAR struct mtd_dev_s *dev, off_t block,
size_t nsectors, FAR uint8_t *buf);
static ssize_t mtd_bwrite(FAR struct mtd_dev_s *dev, off_t block,
size_t nsectors, FAR const uint8_t *buf);
static ssize_t mtd_read(FAR struct mtd_dev_s *dev, off_t offset, size_t nbytes,
FAR uint8_t *buffer);
static int mtd_ioctl(FAR struct mtd_dev_s *dev, int cmd, unsigned long arg);
/************************************************************************************
* Private Data
************************************************************************************/
/************************************************************************************
* Private Functions
************************************************************************************/
/************************************************************************************
* Name: mtd_reload
*
* Description:
* Reload the read-ahead buffer
*
************************************************************************************/
static ssize_t mtd_reload(FAR void *dev, FAR uint8_t *buffer, off_t startblock,
size_t nblocks)
{
FAR struct mtd_rwbuffer_s *priv = (FAR struct mtd_rwbuffer_s *)dev;
DEBUGASSERT(priv && priv->dev);
/* This is just a pass-through to the contained MTD */
return priv->dev->bread(priv->dev, startblock, nblocks, buffer);
}
/************************************************************************************
* Name: mtd_flush
*
* Description:
* Flush the write buffer to hardware
*
************************************************************************************/
static ssize_t mtd_flush(FAR void *dev, FAR const uint8_t *buffer, off_t startblock,
size_t nblocks)
{
FAR struct mtd_rwbuffer_s *priv = (FAR struct mtd_rwbuffer_s *)dev;
DEBUGASSERT(priv && priv->dev);
/* This is just a pass-through to the contained MTD */
return priv->dev->bwrite(priv->dev, startblock, nblocks, buffer);
}
/************************************************************************************
* Name: mtd_erase
************************************************************************************/
static int mtd_erase(FAR struct mtd_dev_s *dev, off_t block, size_t nblocks)
{
FAR struct mtd_rwbuffer_s *priv = (FAR struct mtd_rwbuffer_s *)dev;
off_t sector;
size_t nsectors;
int ret;
fvdbg("block: %08lx nsectors: %lu\n",
(unsigned long)block, (unsigned int)nsectors);
/* Convert to logical sectors and sector numbers */
sector = block * priv->spb;
nsectors = nblocks * priv->spb;
/* Then invalidate in cached data */
ret = rwb_invalidate(&priv->rwb, sector, nsectors);
if (ret < 0)
{
fdbg("ERROR: rwb_invalidate failed: %d\n", ret);
return ret;
}
/* Then let the lower level MTD driver do the real erase */
return priv->dev->erase(priv->dev, block, nblocks);
}
/************************************************************************************
* Name: mtd_bread
************************************************************************************/
static ssize_t mtd_bread(FAR struct mtd_dev_s *dev, off_t sector,
size_t nsectors, FAR uint8_t *buffer)
{
FAR struct mtd_rwbuffer_s *priv = (FAR struct mtd_rwbuffer_s *)dev;
/* Let the rwbuffer logic do it real work. It will call out to mtd_reload if is
* needs to read any data.
*/
return rwb_read(&priv->rwb, sector, nsectors, buffer);
}
/************************************************************************************
* Name: mtd_bwrite
************************************************************************************/
static ssize_t mtd_bwrite(FAR struct mtd_dev_s *dev, off_t block, size_t nsectors,
FAR const uint8_t *buffer)
{
FAR struct mtd_rwbuffer_s *priv = (FAR struct mtd_rwbuffer_s *)dev;
/* Let the rwbuffer logic do it real work. It will call out to wrb_reload it is
* needs to read any data.
*/
return rwb_write(&priv->rwb, block, nsectors, buffer);
}
/************************************************************************************
* Name: mtd_read
************************************************************************************/
static ssize_t mtd_read(FAR struct mtd_dev_s *dev, off_t offset, size_t nbytes,
FAR uint8_t *buffer)
{
FAR struct mtd_rwbuffer_s *priv = (FAR struct mtd_rwbuffer_s *)dev;
/* Let the rwbuffer logic do it real work. It will call out to mtd_reload it is
* needs to read any data.
*/
return rwb_readbytes(&priv->rwb, offset, nbytes, buffer);
}
/************************************************************************************
* Name: mtd_ioctl
************************************************************************************/
static int mtd_ioctl(FAR struct mtd_dev_s *dev, int cmd, unsigned long arg)
{
FAR struct mtd_rwbuffer_s *priv = (FAR struct mtd_rwbuffer_s *)dev;
int ret = -EINVAL; /* Assume good command with bad parameters */
fvdbg("cmd: %d \n", cmd);
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.
*
* NOTE: that the device is treated as though it where just an array
* of fixed size blocks. That is most likely not true, but the client
* will expect the device logic to do whatever is necessary to make it
* appear so.
*/
geo->blocksize = priv->rwb.blocksize;
geo->erasesize = priv->rwb.blocksize * priv->spb;
geo->neraseblocks = priv->rwb.nblocks / priv->spb;
ret = OK;
fvdbg("blocksize: %d erasesize: %d neraseblocks: %d\n",
geo->blocksize, geo->erasesize, geo->neraseblocks);
}
}
break;
case MTDIOC_BULKERASE:
{
/* Erase the entire device */
ret = priv->dev->ioctl(priv->dev, MTDIOC_BULKERASE, 0);
if (ret >= 0)
{
fdbg("ERROR: Device ioctl failed: %d\n", ret);
break;
}
/* Then invalidate in cached data */
ret = rwb_invalidate(&priv->rwb,0, priv->rwb.nblocks);
if (ret < 0)
{
fdbg("ERROR: rwb_invalidate failed: %d\n", ret);
}
}
break;
case MTDIOC_XIPBASE:
default:
ret = -ENOTTY; /* Bad command */
break;
}
fvdbg("return %d\n", ret);
return ret;
}
/************************************************************************************
* Public Functions
************************************************************************************/
/************************************************************************************
* Name: mtd_rwb_initialize
*
* Description:
* Create an initialized MTD device instance. This MTD driver contains another
* MTD driver and converts a larger sector size to a standard 512 byte sector
* size.
*
* MTD devices are not registered in the file system, but are created as instances
* that can be bound to other functions (such as a block or character driver front
* end).
*
************************************************************************************/
FAR struct mtd_dev_s *mtd_rwb_initialize(FAR struct mtd_dev_s *mtd)
{
FAR struct mtd_rwbuffer_s *priv;
struct mtd_geometry_s geo;
int ret;
fvdbg("mtd: %p\n", mtd);
DEBUGASSERT(mtd && mtd->ioctl);
/* Get the device geometry */
ret = mtd->ioctl(mtd, MTDIOC_GEOMETRY, (unsigned long)((uintptr_t)&geo));
if (ret < 0)
{
fdbg("ERROR: MTDIOC_GEOMETRY ioctl failed: %d\n", ret);
return NULL;
}
/* Allocate a state structure (we allocate the structure instead of using
* a fixed, static allocation so that we can handle multiple FLASH devices.
* The current implementation would handle only one FLASH part per SPI
* device (only because of the SPIDEV_FLASH definition) and so would have
* to be extended to handle multiple FLASH parts on the same SPI bus.
*/
priv = (FAR struct mtd_rwbuffer_s *)kmm_zalloc(sizeof(struct mtd_rwbuffer_s));
if (priv)
{
/* Initialize the allocated structure. (unsupported methods/fields
* were already nullified by kmm_zalloc).
*/
priv->mtd.erase = mtd_erase; /* Our MTD erase method */
priv->mtd.bread = mtd_bread; /* Our MTD bread method */
priv->mtd.bwrite = mtd_bwrite; /* Our MTD bwrite method */
priv->mtd.read = mtd_read; /* Our MTD read method */
priv->mtd.ioctl = mtd_ioctl; /* Our MTD ioctl method */
priv->dev = mtd; /* The contained MTD instance */
/* Sectors per block. The erase block size must be an even multiple
* of the sector size.
*/
priv->spb = geo.erasesize / geo.blocksize;
DEBUGASSERT((size_t)priv->spb * geo.blocksize == geo.erasesize);
/* Values must be provided to rwb_initialize() */
/* Supported geometry */
priv->rwb.blocksize = geo.blocksize;
priv->rwb.nblocks = geo.neraseblocks * priv->spb;
/* Buffer setup */
#ifdef CONFIG_DRVR_WRITEBUFFER
priv->rwb.wrmaxblocks = CONFIG_MTD_NWRBLOCKS;
#endif
#ifdef CONFIG_DRVR_READAHEAD
priv->rwb.rhmaxblocks = CONFIG_MTD_NRDBLOCKS;
#endif
/* Callouts */
priv->rwb.dev = priv; /* Device state passed to callouts */
priv->rwb.wrflush = mtd_flush; /* Callout to flush buffer */
priv->rwb.rhreload = mtd_reload; /* Callout to reload buffer */
/* Initialize read-ahead/write buffering */
ret = rwb_initialize(&priv->rwb);
if (ret < 0)
{
fdbg("ERROR: rwb_initialize failed: %d\n", ret);
kmm_free(priv);
return NULL;
}
}
/* Register the MTD with the procfs system if enabled */
#ifdef CONFIG_MTD_REGISTRATION
mtd_register(&priv->mtd, "rwbuffer");
#endif
/* Return the implementation-specific state structure as the MTD device */
fvdbg("Return %p\n", priv);
return &priv->mtd;
}
#endif /* CONFIG_DRVR_WRITEBUFFER || CONFIG_DRVR_READAHEAD */
