/************************************************************************************ * drivers/mtd/sector512.c * MTD driver that contains another MTD driver and converts a larger sector size * to a standard 512 byte sector size. * * Copyright (C) 2014 Gregory Nutt. All rights reserved. * Author: Gregory Nutt * * 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 #include #include #include #include #include #include #include #include #include #include #include #include /************************************************************************************ * Pre-processor Definitions ************************************************************************************/ /* Configuration */ #ifndef CONFIG_MTD_SECT512_ERASED_STATE # define CONFIG_MTD_SECT512_ERASED_STATE 0xff #endif /* 512-byte sector constants */ #define SECTOR_512 512 #define SHIFT_512 9 #define MASK_512 511 /* Cache flags */ #define SST25_CACHE_VALID (1 << 0) /* 1=Cache has valid data */ #define SST25_CACHE_DIRTY (1 << 1) /* 1=Cache is dirty */ #define SST25_CACHE_ERASED (1 << 2) /* 1=Backing FLASH is erased */ #define IS_VALID(p) ((((p)->flags) & SST25_CACHE_VALID) != 0) #define IS_DIRTY(p) ((((p)->flags) & SST25_CACHE_DIRTY) != 0) #define IS_ERASED(p) ((((p)->flags) & SST25_CACHE_DIRTY) != 0) #define SET_VALID(p) do { (p)->flags |= SST25_CACHE_VALID; } while (0) #define SET_DIRTY(p) do { (p)->flags |= SST25_CACHE_DIRTY; } while (0) #define SET_ERASED(p) do { (p)->flags |= SST25_CACHE_DIRTY; } while (0) #define CLR_VALID(p) do { (p)->flags &= ~SST25_CACHE_VALID; } while (0) #define CLR_DIRTY(p) do { (p)->flags &= ~SST25_CACHE_DIRTY; } while (0) #define CLR_ERASED(p) do { (p)->flags &= ~SST25_CACHE_DIRTY; } while (0) /************************************************************************************ * 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 s512_dev_s. */ struct s512_dev_s { struct mtd_dev_s mtd; /* MTD interface */ FAR struct mtd_dev_s *dev; /* Saved lower level MTD interface instance */ uint32_t eblocksize; /* Size of one erase block */ size_t neblocks; /* Number of erase blocks */ size_t sectperblock; /* Number of read/write sectors per erase block */ uint16_t stdperblock; /* Number of 512 byte sectors in one erase block */ uint8_t flags; /* Buffered sector flags */ uint32_t eblockno; /* Erase sector number in the cache */ FAR uint8_t *eblock; /* Allocated erase block */ }; /************************************************************************************ * Private Function Prototypes ************************************************************************************/ /* Helpers */ static FAR uint8_t *s512_cacheread(struct s512_dev_s *priv, off_t sector); #ifndef CONFIG_MTD_SECT512_READONLY static void s512_cacheflush(struct s512_dev_s *priv); #endif /* MTD driver methods */ static int s512_erase(FAR struct mtd_dev_s *dev, off_t sector512, size_t nsectors); static ssize_t s512_bread(FAR struct mtd_dev_s *dev, off_t sector512, size_t nsectors, FAR uint8_t *buf); static ssize_t s512_bwrite(FAR struct mtd_dev_s *dev, off_t sector512, size_t nsectors, FAR const uint8_t *buf); static ssize_t s512_read(FAR struct mtd_dev_s *dev, off_t offset, size_t nbytes, FAR uint8_t *buffer); static int s512_ioctl(FAR struct mtd_dev_s *dev, int cmd, unsigned long arg); /************************************************************************************ * Private Data ************************************************************************************/ /************************************************************************************ * Private Functions ************************************************************************************/ /************************************************************************************ * Name: s512_cacheread ************************************************************************************/ static FAR uint8_t *s512_cacheread(struct s512_dev_s *priv, off_t sector512) { off_t eblockno; off_t sector; ssize_t result; int index; /* Get the erase block containing this sector */ eblockno = sector512 / priv->stdperblock; finfo("sector512: %lu eblockno: %lu\n", (unsigned long)sector512, (unsigned long)eblockno); /* Check if the requested erase block is already in the cache */ if (!IS_VALID(priv) || eblockno != priv->eblockno) { /* No.. Flush any dirty erase block currently in the cache */ s512_cacheflush(priv); /* Read the erase block into the cache */ sector = eblockno * priv->sectperblock; result = priv->dev->bread(priv->dev, sector, priv->sectperblock, priv->eblock); if (result < 0) { ferr("ERROR: bread(%lu, %lu) returned %ld\n", (unsigned long)sector, (unsigned long)priv->eblocksize, (long)result); return NULL; } /* Mark the sector as cached */ priv->eblockno = eblockno; SET_VALID(priv); /* The data in the cache is valid */ CLR_DIRTY(priv); /* It should match the FLASH contents */ CLR_ERASED(priv); /* The underlying FLASH has not been erased */ } /* Get the index to the 512 sector in the erase block that holds the argument */ index = sector512 % priv->stdperblock; /* Return the address in the cache that holds this sector */ return &priv->eblock[index << SHIFT_512]; } /************************************************************************************ * Name: s512_cacheflush ************************************************************************************/ #if !defined(CONFIG_MTD_SECT512_READONLY) static void s512_cacheflush(struct s512_dev_s *priv) { off_t sector; ssize_t result; /* If the cached is dirty (meaning that it no longer matches the old FLASH contents) * or was erased (with the cache containing the correct FLASH contents), then write * the cached erase block to FLASH. */ if (IS_DIRTY(priv) || IS_ERASED(priv)) { /* Write entire erase block to FLASH */ sector = priv->eblockno * priv->sectperblock; result = priv->dev->bwrite(priv->dev, sector, priv->sectperblock, priv->eblock); if (result < 0) { ferr("ERROR: bwrite(%lu, %lu) returned %ld\n", (unsigned long)sector, (unsigned long)priv->eblocksize, (long)result); return; } /* The cache is no long dirty and the FLASH is no longer erased */ CLR_DIRTY(priv); CLR_ERASED(priv); } } #endif /************************************************************************************ * Name: s512_erase ************************************************************************************/ static int s512_erase(FAR struct mtd_dev_s *dev, off_t sector512, size_t nsectors) { #ifdef CONFIG_MTD_SECT512_READONLY return -EACESS #else FAR struct s512_dev_s *priv = (FAR struct s512_dev_s *)dev; FAR uint8_t *dest; size_t sectorsleft = nsectors; size_t eblockno; int ret; finfo("sector512: %08lx nsectors: %lu\n", (unsigned long)sector512, (unsigned int)nsectors); while (sectorsleft-- > 0) { /* Erase each sector. First, make sure that the erase block containing the * 512 byte sector is in the cache. */ dest = s512_cacheread(priv, sector512); if (!dest) { ferr("ERROR: s512_cacheread(%ul) failed\n", (unsigned long)sector512); DEBUGPANIC(); return -EIO; } /* Erase the block containing this sector if it is not already erased. * The erased indicator will be cleared when the data from the erase sector * is read into the cache and set here when we erase the block. */ if (!IS_ERASED(priv)) { eblockno = sector512 / priv->stdperblock; finfo("sector512: %lu eblockno: %lu\n", (unsigned long)sector512, (unsigned long)eblockno); ret = priv->dev->erase(priv->dev, eblockno, 1); if (ret < 0) { ferr("ERROR: Failed to erase block %lu: %d\n", (unsigned long)eblockno, ret); return ret; } SET_ERASED(priv); } /* Put the cached sector data into the erase state and mark the cache * as dirty (but don't update the FLASH yet. The caller will do that * at a more optimal time). */ memset(dest, CONFIG_MTD_SECT512_ERASED_STATE, SECTOR_512); SET_DIRTY(priv); sector512++; } /* Flush the last erase block left in the cache */ s512_cacheflush(priv); return (int)nsectors; #endif } /************************************************************************************ * Name: s512_bread ************************************************************************************/ static ssize_t s512_bread(FAR struct mtd_dev_s *dev, off_t sector512, size_t nsectors, FAR uint8_t *buffer) { FAR struct s512_dev_s *priv = (FAR struct s512_dev_s *)dev; FAR uint8_t *src; ssize_t remaining; ssize_t result = nsectors; finfo("sector512: %08lx nsectors: %d\n", (long)sector512, (int)nsectors); /* Read each 512 byte sector from the block via the erase block cache */ for (remaining = nsectors; remaining; remaining--) { /* Make sure that the next sector is in the erase block cache */ src = s512_cacheread(priv, sector512); if (!src) { ferr("ERROR: s512_cacheread(%ul) failed\n", (unsigned long)sector512); DEBUGPANIC(); result = (ssize_t)nsectors - remaining; if (result <= 0) { result = -EIO; } break; } /* Copy the sector data from the erase block cache into the user buffer */ memcpy(buffer, src, SECTOR_512); buffer += SECTOR_512; sector512++; } return result; } /************************************************************************************ * Name: s512_bwrite ************************************************************************************/ static ssize_t s512_bwrite(FAR struct mtd_dev_s *dev, off_t sector512, size_t nsectors, FAR const uint8_t *buffer) { #ifdef CONFIG_MTD_SECT512_READONLY return -EACCESS; #else FAR struct s512_dev_s *priv = (FAR struct s512_dev_s *)dev; ssize_t remaining; ssize_t result; off_t eblockno; finfo("sector512: %08lx nsectors: %d\n", (long)sector512, (int)nsectors); FAR uint8_t *dest; for (remaining = nsectors; remaining > 0; remaining--) { /* First, make sure that the erase block containing 512 byte sector is in * memory. */ dest = s512_cacheread(priv, sector512); if (!dest) { result = (ssize_t)nsectors - remaining; if (result <= 0) { result = -EIO; } return result; } /* Erase the block containing this sector if it is not already erased. * The erased indicated will be cleared when the data from the erase sector * is read into the cache and set here when we erase the sector. */ if (!IS_ERASED(priv)) { eblockno = sector512 / priv->stdperblock; finfo("sector512: %lu eblockno: %lu\n", (unsigned long)sector512, (unsigned long)eblockno); result = priv->dev->erase(priv->dev, eblockno, 1); if (result < 0) { ferr("ERROR: Failed to erase block %lu: %ld\n", (unsigned long)eblockno, (long)result); return result; } SET_ERASED(priv); } /* Copy the new sector data into cached erase block */ memcpy(dest, buffer, SECTOR_512); SET_DIRTY(priv); /* Set up for the next 512 byte sector */ buffer += SECTOR_512; sector512++; } /* Flush the last erase block left in the cache */ s512_cacheflush(priv); return nsectors; #endif } /************************************************************************************ * Name: s512_read ************************************************************************************/ static ssize_t s512_read(FAR struct mtd_dev_s *dev, off_t offset, size_t nbytes, FAR uint8_t *buffer) { FAR struct s512_dev_s *priv = (FAR struct s512_dev_s *)dev; FAR uint8_t *src; ssize_t remaining; ssize_t xfrsize; off_t sectoffset; off_t sector; finfo("offset: %08lx nbytes: %lu\n", (unsigned long)offset, (unsigned long)nbytes); /* Convert the offset into 512 byte sector address and a byte offset */ sectoffset = offset & MASK_512; sector = offset >> SHIFT_512; for (remaining = nbytes; remaining > 0; remaining -= xfrsize) { /* Read the erase block into the cache and get the address of the * beginning of the 512 byte block in the cached erase block. */ src = s512_cacheread(priv, sector); if (!src) { int result; ferr("ERROR: s512_cacheread(%ul) failed\n", (unsigned long)sector); DEBUGPANIC(); result = (ssize_t)nbytes - remaining; if (result <= 0) { result = -EIO; } return result; } /* Then copy the requested bytes from the cached erase block */ xfrsize = remaining; if (sectoffset + xfrsize > SECTOR_512) { xfrsize = SECTOR_512 - sectoffset; } memcpy(buffer, src + sectoffset, xfrsize); buffer += xfrsize; } finfo("return nbytes: %d\n", (int)nbytes); return nbytes; } /************************************************************************************ * Name: s512_ioctl ************************************************************************************/ static int s512_ioctl(FAR struct mtd_dev_s *dev, int cmd, unsigned long arg) { FAR struct s512_dev_s *priv = (FAR struct s512_dev_s *)dev; int ret = -EINVAL; /* Assume good command with bad parameters */ finfo("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 = SECTOR_512; geo->erasesize = SECTOR_512; geo->neraseblocks = priv->neblocks * priv->stdperblock; ret = OK; finfo("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) { priv->flags = 0; /* Buffered sector flags */ priv->eblockno = 0; /* Erase sector number in the cache */ priv->eblock = NULL; /* Allocated erase block */ } } break; case MTDIOC_XIPBASE: default: ret = -ENOTTY; /* Bad command */ break; } finfo("return %d\n", ret); return ret; } /************************************************************************************ * Public Functions ************************************************************************************/ /************************************************************************************ * Name: s512_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 *s512_initialize(FAR struct mtd_dev_s *mtd) { FAR struct s512_dev_s *priv; FAR struct mtd_geometry_s geo; int ret; finfo("mtd: %p\n", mtd); /* Get the device geometry */ DEBUGASSERT(mtd && mtd->ioctl); ret = mtd->ioctl(mtd, MTDIOC_GEOMETRY, (unsigned long)((uintptr_t)&geo)); /* We expect that the block size will be >512 and an even multiple of 512 */ if (ret < 0 || geo.erasesize <= SECTOR_512 || (geo.erasesize & ~MASK_512) != geo.erasesize) { ferr("ERROR: MTDIOC_GEOMETRY ioctl returned %d, eraseize=%d\n", ret, geo.erasesize); DEBUGPANIC(); 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 s512_dev_s *)kmm_zalloc(sizeof(struct s512_dev_s)); if (priv) { /* Initialize the allocated structure. (unsupported methods/fields * were already nullified by kmm_zalloc). */ priv->mtd.erase = s512_erase; priv->mtd.bread = s512_bread; priv->mtd.bwrite = s512_bwrite; priv->mtd.read = s512_read; priv->mtd.ioctl = s512_ioctl; priv->dev = mtd; priv->eblocksize = geo.erasesize; priv->neblocks = geo.neraseblocks; priv->sectperblock = geo.erasesize / geo.blocksize; priv->stdperblock = geo.erasesize >> 9; /* Allocate a buffer for the erase block cache */ priv->eblock = (FAR uint8_t *)kmm_malloc(priv->eblocksize); if (!priv->eblock) { /* Allocation failed! Discard all of that work we just did and return NULL */ ferr("ERROR: Allocation failed\n"); kmm_free(priv); priv = NULL; } } /* Register the MTD with the procfs system if enabled */ #ifdef CONFIG_MTD_REGISTRATION mtd_register(&priv->mtd, "sector512"); #endif /* Return the implementation-specific state structure as the MTD device */ finfo("Return %p\n", priv); return &priv->mtd; }