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Diffstat (limited to 'nuttx/drivers/mtd/rammtd.c')
| -rw-r--r-- | nuttx/drivers/mtd/rammtd.c | 417 |
1 files changed, 417 insertions, 0 deletions
diff --git a/nuttx/drivers/mtd/rammtd.c b/nuttx/drivers/mtd/rammtd.c new file mode 100644 index 000000000..82a7191ea --- /dev/null +++ b/nuttx/drivers/mtd/rammtd.c @@ -0,0 +1,417 @@ +/**************************************************************************** + * drivers/mtd/rammtd.c + * + * Copyright (C) 2011-2012 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 <string.h> +#include <assert.h> +#include <errno.h> +#include <debug.h> + +#include <nuttx/kmalloc.h> +#include <nuttx/fs/ioctl.h> +#include <nuttx/mtd.h> + +/**************************************************************************** + * Pre-processor Definitions + ****************************************************************************/ +/* Configuration ************************************************************/ + +#ifndef CONFIG_RAMMTD_BLOCKSIZE +# define CONFIG_RAMMTD_BLOCKSIZE 512 +#endif + +#ifndef CONFIG_RAMMTD_ERASESIZE +# define CONFIG_RAMMTD_ERASESIZE 4096 +#endif + +#ifndef CONFIG_RAMMTD_ERASESTATE +# define CONFIG_RAMMTD_ERASESTATE 0xff +#endif + +#if CONFIG_RAMMTD_ERASESTATE != 0xff && CONFIG_RAMMTD_ERASESTATE != 0x00 +# error "Unsupported value for CONFIG_RAMMTD_ERASESTATE" +#endif + +#if CONFIG_RAMMTD_BLOCKSIZE > CONFIG_RAMMTD_ERASESIZE +# error "Must have CONFIG_RAMMTD_BLOCKSIZE <= CONFIG_RAMMTD_ERASESIZE" +#endif + +#undef CONFIG_RAMMTD_BLKPER +#define CONFIG_RAMMTD_BLKPER (CONFIG_RAMMTD_ERASESIZE/CONFIG_RAMMTD_BLOCKSIZE) + +#if CONFIG_RAMMTD_BLKPER*CONFIG_RAMMTD_BLOCKSIZE != CONFIG_RAMMTD_ERASESIZE +# error "CONFIG_RAMMTD_ERASESIZE must be an even multiple of CONFIG_RAMMTD_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 ram_dev_s. + */ + +struct ram_dev_s +{ + struct mtd_dev_s mtd; /* MTD device */ + FAR uint8_t *start; /* Start of RAM */ + size_t nblocks; /* Number of erase blocks */ +}; + +/**************************************************************************** + * Private Function Prototypes + ****************************************************************************/ +/* The RAM MTD driver may be useful just as it is, but another good use of + * the RAM MTD driver is as a FLASH simulation -- to support testing of FLASH + * based logic without having FLASH. CONFIG_RAMMTD_FLASHSIM will add some + * extra logic to improve the level of FLASH simulation. + */ + +#define ram_read(dest, src, len) memcpy(dest, src, len) +#ifdef CONFIG_RAMMTD_FLASHSIM +static void *ram_write(FAR void *dest, FAR const void *src, size_t len); +#else +# define ram_write(dest, src, len) memcpy(dest, src, len) +#endif + +/* MTD driver methods */ + +static int ram_erase(FAR struct mtd_dev_s *dev, off_t startblock, size_t nblocks); +static ssize_t ram_bread(FAR struct mtd_dev_s *dev, off_t startblock, size_t nblocks, + FAR uint8_t *buf); +static ssize_t ram_bwrite(FAR struct mtd_dev_s *dev, off_t startblock, size_t nblocks, + FAR const uint8_t *buf); +static int ram_ioctl(FAR struct mtd_dev_s *dev, int cmd, unsigned long arg); + +/**************************************************************************** + * Private Data + ****************************************************************************/ + +/**************************************************************************** + * Private Functions + ****************************************************************************/ + +/**************************************************************************** + * Name: ram_write + ****************************************************************************/ + +#ifdef CONFIG_RAMMTD_FLASHSIM +static void *ram_write(FAR void *dest, FAR const void *src, size_t len) +{ + FAR uint8_t *pout = (FAR uint8_t *)dest; + FAR const uint8_t *pin = (FAR const uint8_t *)src; + + while (len-- > 0) + { + /* Get the source and destination values */ + + uint8_t oldvalue = *pout; + uint8_t srcvalue = *pin++; + uint8_t newvalue; + + /* Get the new destination value, accounting for bits that cannot be + * changes because they are not in the erased state. + */ + +#if CONFIG_RAMMTD_ERASESTATE == 0xff + newvalue = oldvalue & srcvalue; /* We can only clear bits */ +#else /* CONFIG_RAMMTD_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; + } + + return dest; +} +#endif + +/**************************************************************************** + * Name: ram_erase + ****************************************************************************/ + +static int ram_erase(FAR struct mtd_dev_s *dev, off_t startblock, size_t nblocks) +{ + FAR struct ram_dev_s *priv = (FAR struct ram_dev_s *)dev; + off_t offset; + size_t nbytes; + + DEBUGASSERT(dev); + + /* Don't let the erase exceed the size of the ram buffer */ + + 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 *= CONFIG_RAMMTD_BLKPER; + nblocks *= CONFIG_RAMMTD_BLKPER; + + /* Get the offset corresponding to the first block and the size + * corresponding to the number of blocks. + */ + + offset = startblock * CONFIG_RAMMTD_BLOCKSIZE; + nbytes = nblocks * CONFIG_RAMMTD_BLOCKSIZE; + + /* Then erase the data in RAM */ + + memset(&priv->start[offset], CONFIG_RAMMTD_ERASESTATE, nbytes); + return OK; +} + +/**************************************************************************** + * Name: ram_bread + ****************************************************************************/ + +static ssize_t ram_bread(FAR struct mtd_dev_s *dev, off_t startblock, size_t nblocks, + FAR uint8_t *buf) +{ + FAR struct ram_dev_s *priv = (FAR struct ram_dev_s *)dev; + off_t offset; + off_t maxblock; + size_t nbytes; + + DEBUGASSERT(dev && buf); + + /* Don't let the read exceed the size of the ram buffer */ + + maxblock = priv->nblocks * CONFIG_RAMMTD_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 * CONFIG_RAMMTD_BLOCKSIZE; + nbytes = nblocks * CONFIG_RAMMTD_BLOCKSIZE; + + /* Then read the data frp, RAM */ + + ram_read(buf, &priv->start[offset], nbytes); + return nblocks; +} + +/**************************************************************************** + * Name: ram_bwrite + ****************************************************************************/ + +static ssize_t ram_bwrite(FAR struct mtd_dev_s *dev, off_t startblock, + size_t nblocks, FAR const uint8_t *buf) +{ + FAR struct ram_dev_s *priv = (FAR struct ram_dev_s *)dev; + off_t offset; + off_t maxblock; + size_t nbytes; + + DEBUGASSERT(dev && buf); + + /* Don't let the write exceed the size of the ram buffer */ + + maxblock = priv->nblocks * CONFIG_RAMMTD_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 * CONFIG_RAMMTD_BLOCKSIZE; + nbytes = nblocks * CONFIG_RAMMTD_BLOCKSIZE; + + /* Then write the data to RAM */ + + ram_write(&priv->start[offset], buf, nbytes); + return nblocks; +} + +/**************************************************************************** + * Name: ram_ioctl + ****************************************************************************/ + +static int ram_ioctl(FAR struct mtd_dev_s *dev, int cmd, unsigned long arg) +{ + FAR struct ram_dev_s *priv = (FAR struct ram_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 = CONFIG_RAMMTD_BLOCKSIZE; + geo->erasesize = CONFIG_RAMMTD_ERASESIZE; + geo->neraseblocks = priv->nblocks; + ret = OK; + } + } + break; + + case MTDIOC_XIPBASE: + { + FAR void **ppv = (FAR void**)((uintptr_t)arg); + if (ppv) + { + /* Return (void*) base address of device memory */ + + *ppv = (FAR void*)priv->start; + ret = OK; + } + } + break; + + case MTDIOC_BULKERASE: + { + size_t size = priv->nblocks * CONFIG_RAMMTD_ERASESIZE; + + /* Erase the entire device */ + + memset(priv->start, CONFIG_RAMMTD_ERASESTATE, size); + ret = OK; + } + break; + + default: + ret = -ENOTTY; /* Bad command */ + break; + } + + return ret; +} + +/**************************************************************************** + * Public Functions + ****************************************************************************/ + +/**************************************************************************** + * Name: rammtd_initialize + * + * Description: + * Create and initialize a RAM MTD device instance. + * + * Input Parameters: + * start - Address of the beginning of the allocated RAM regions. + * size - The size in bytes of the allocated RAM region. + * + ****************************************************************************/ + +FAR struct mtd_dev_s *rammtd_initialize(FAR uint8_t *start, size_t size) +{ + FAR struct ram_dev_s *priv; + size_t nblocks; + + /* Create an instance of the RAM MTD device state structure */ + + priv = (FAR struct ram_dev_s *)kmalloc(sizeof(struct ram_dev_s)); + if (!priv) + { + fdbg("Failed to allocate the RAM MTD state structure\n"); + return NULL; + } + + /* Force the size to be an even number of the erase block size */ + + nblocks = size / CONFIG_RAMMTD_ERASESIZE; + if (nblocks <= 0) + { + fdbg("Need to provide at least one full erase block\n"); + return NULL; + } + + /* Perform initialization as necessary */ + + priv->mtd.erase = ram_erase; + priv->mtd.bread = ram_bread; + priv->mtd.bwrite = ram_bwrite; + priv->mtd.ioctl = ram_ioctl; + priv->mtd.erase = ram_erase; + + priv->start = start; + priv->nblocks = nblocks; + return &priv->mtd; +} |