diff options
Diffstat (limited to 'nuttx/drivers/mtd/at24xx.c')
-rw-r--r-- | nuttx/drivers/mtd/at24xx.c | 429 |
1 files changed, 429 insertions, 0 deletions
diff --git a/nuttx/drivers/mtd/at24xx.c b/nuttx/drivers/mtd/at24xx.c new file mode 100644 index 000000000..67d7f1f52 --- /dev/null +++ b/nuttx/drivers/mtd/at24xx.c @@ -0,0 +1,429 @@ +/************************************************************************************ + * drivers/mtd/at24xx.c + * Driver for I2C-based at24cxx EEPROM(at24c32,at24c64,at24c128,at24c256) + * + * Copyright (C) 2011 Li Zhuoyi. All rights reserved. + * Author: Li Zhuoyi <lzyy.cn@gmail.com> + * History: 0.1 2011-08-20 initial version + * + * 2011-11-1 Added support for larger MTD block sizes: Hal Glenn <hglenn@2g-eng.com> + * + * Derived from drivers/mtd/m25px.c + * + * Copyright (C) 2009-2011 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 <stdbool.h> +#include <stdlib.h> +#include <unistd.h> +#include <string.h> +#include <errno.h> +#include <debug.h> + +#include <nuttx/kmalloc.h> +#include <nuttx/ioctl.h> +#include <nuttx/i2c.h> +#include <nuttx/mtd.h> + +#ifdef CONFIG_MTD_AT24XX + +/************************************************************************************ + * Pre-processor Definitions + ************************************************************************************/ + +/* As a minimum, the size of the AT24 part and its 7-bit I2C address are required. */ + +#ifndef CONFIG_AT24XX_SIZE +# warning "Assuming AT24 size 64" +# define CONFIG_AT24XX_SIZE 64 +#endif +#ifndef CONFIG_AT24XX_ADDR +# warning "Assuming AT24 address of 0x50" +# define CONFIG_AT24XX_ADDR 0x50 +#endif + +/* Get the part configuration based on the size configuration */ + +#if CONFIG_AT24XX_SIZE == 32 +# define AT24XX_NPAGES 128 +# define AT24XX_PAGESIZE 32 +#elif CONFIG_AT24XX_SIZE == 48 +# define AT24XX_NPAGES 192 +# define AT24XX_PAGESIZE 32 +#elif CONFIG_AT24XX_SIZE == 64 +# define AT24XX_NPAGES 256 +# define AT24XX_PAGESIZE 32 +#elif CONFIG_AT24XX_SIZE == 128 +# define AT24XX_NPAGES 256 +# define AT24XX_PAGESIZE 64 +#elif CONFIG_AT24XX_SIZE == 256 +# define AT24XX_NPAGES 512 +# define AT24XX_PAGESIZE 64 +#endif + +/* For applications where a file system is used on the AT24, the tiny page sizes + * will result in very inefficient FLASH usage. In such cases, it is better if + * blocks are comprised of "clusters" of pages so that the file system block + * size is, say, 256 or 512 bytes. In any event, the block size *must* be an + * even multiple of the pages. + */ + +#ifndef CONFIG_AT24XX_MTD_BLOCKSIZE +# warning "Assuming driver block size is the same as the FLASH page size" +# define CONFIG_AT24XX_MTD_BLOCKSIZE AT24XX_PAGESIZE +#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 at24c_dev_s. + */ + +struct at24c_dev_s +{ + struct mtd_dev_s mtd; /* MTD interface */ + FAR struct i2c_dev_s *dev; /* Saved I2C interface instance */ + uint8_t addr; /* I2C address */ + uint16_t pagesize; /* 32, 63 */ + uint16_t npages; /* 128, 256, 512, 1024 */ +}; + +/************************************************************************************ + * Private Function Prototypes + ************************************************************************************/ + +/* MTD driver methods */ + +static int at24c_erase(FAR struct mtd_dev_s *dev, off_t startblock, size_t nblocks); +static ssize_t at24c_bread(FAR struct mtd_dev_s *dev, off_t startblock, + size_t nblocks, FAR uint8_t *buf); +static ssize_t at24c_bwrite(FAR struct mtd_dev_s *dev, off_t startblock, + size_t nblocks, FAR const uint8_t *buf); +static ssize_t at24c_read(FAR struct mtd_dev_s *dev, off_t offset, + size_t nbytes,FAR uint8_t *buffer); +static int at24c_ioctl(FAR struct mtd_dev_s *dev, int cmd, unsigned long arg); + +/************************************************************************************ + * Private Data + ************************************************************************************/ + +/* At present, only a signal AT24 part is supported. In this case, a statically + * allocated state structure may be used. + */ + +static struct at24c_dev_s g_at24c; + +/************************************************************************************ + * Private Functions + ************************************************************************************/ + +static int at24c_eraseall(FAR struct at24c_dev_s *priv) +{ + int startblock = 0; + uint8_t buf[AT24XX_PAGESIZE + 2]; + + memset(&buf[2],0xff,priv->pagesize); + I2C_SETADDRESS(priv->dev,priv->addr,7); + I2C_SETFREQUENCY(priv->dev,100000); + + for (startblock = 0; startblock < priv->npages; startblock++) + { + uint16_t offset = startblock * priv->pagesize; + buf[1] = offset & 0xff; + buf[0] = (offset >> 8) & 0xff; + + while (I2C_WRITE(priv->dev, buf, 2) < 0) + { + usleep(1000); + } + I2C_WRITE(priv->dev, buf, priv->pagesize + 2); + } + + return OK; +} + +/************************************************************************************ + * Name: at24c_erase + ************************************************************************************/ + +static int at24c_erase(FAR struct mtd_dev_s *dev, off_t startblock, size_t nblocks) +{ + /* EEprom need not erase */ + + return (int)nblocks; +} + +/************************************************************************************ + * Name: at24c_bread + ************************************************************************************/ + +static ssize_t at24c_bread(FAR struct mtd_dev_s *dev, off_t startblock, + size_t nblocks, FAR uint8_t *buffer) +{ + FAR struct at24c_dev_s *priv = (FAR struct at24c_dev_s *)dev; + size_t blocksleft; + +#if CONFIG_AT24XX_MTD_BLOCKSIZE > AT24XX_PAGESIZE + startblock *= (CONFIG_AT24XX_MTD_BLOCKSIZE / AT24XX_PAGESIZE); + nblocks *= (CONFIG_AT24XX_MTD_BLOCKSIZE / AT24XX_PAGESIZE); +#endif + blocksleft = nblocks; + + fvdbg("startblock: %08lx nblocks: %d\n", (long)startblock, (int)nblocks); + + if (startblock >= priv->npages) + { + return 0; + } + + if (startblock + nblocks > priv->npages) + { + nblocks = priv->npages - startblock; + } + + I2C_SETADDRESS(priv->dev,priv->addr,7); + I2C_SETFREQUENCY(priv->dev,100000); + + while (blocksleft-- > 0) + { + uint16_t offset = startblock * priv->pagesize; + uint8_t buf[2]; + buf[1] = offset & 0xff; + buf[0] = (offset >> 8) & 0xff; + + while (I2C_WRITE(priv->dev, buf, 2) < 0) + { + fvdbg("wait\n"); + usleep(1000); + } + + I2C_READ(priv->dev, buffer, priv->pagesize); + startblock++; + buffer += priv->pagesize; + } + +#if CONFIG_AT24XX_MTD_BLOCKSIZE > AT24XX_PAGESIZE + return nblocks / (CONFIG_AT24XX_MTD_BLOCKSIZE / AT24XX_PAGESIZE); +#else + return nblocks; +#endif +} + +/************************************************************************************ + * Name: at24c_bwrite + * + * Operates on MTD block's and translates to FLASH pages + * + ************************************************************************************/ + +static ssize_t at24c_bwrite(FAR struct mtd_dev_s *dev, off_t startblock, size_t nblocks, + FAR const uint8_t *buffer) +{ + FAR struct at24c_dev_s *priv = (FAR struct at24c_dev_s *)dev; + size_t blocksleft; + uint8_t buf[AT24XX_PAGESIZE+2]; + +#if CONFIG_AT24XX_MTD_BLOCKSIZE > AT24XX_PAGESIZE + startblock *= (CONFIG_AT24XX_MTD_BLOCKSIZE / AT24XX_PAGESIZE); + nblocks *= (CONFIG_AT24XX_MTD_BLOCKSIZE / AT24XX_PAGESIZE); +#endif + blocksleft = nblocks; + + if (startblock >= priv->npages) + { + return 0; + } + + if (startblock + nblocks > priv->npages) + { + nblocks = priv->npages - startblock; + } + + fvdbg("startblock: %08lx nblocks: %d\n", (long)startblock, (int)nblocks); + I2C_SETADDRESS(priv->dev, priv->addr, 7); + I2C_SETFREQUENCY(priv->dev, 100000); + + while (blocksleft-- > 0) + { + uint16_t offset = startblock * priv->pagesize; + while (I2C_WRITE(priv->dev, (uint8_t *)&offset, 2) < 0) + { + fvdbg("wait\n"); + usleep(1000); + } + + buf[1] = offset & 0xff; + buf[0] = (offset >> 8) & 0xff; + memcpy(&buf[2], buffer, priv->pagesize); + + I2C_WRITE(priv->dev, buf, priv->pagesize + 2); + startblock++; + buffer += priv->pagesize; + } + +#if CONFIG_AT24XX_MTD_BLOCKSIZE > AT24XX_PAGESIZE + return nblocks / (CONFIG_AT24XX_MTD_BLOCKSIZE / AT24XX_PAGESIZE); +#else + return nblocks; +#endif +} + +/************************************************************************************ + * Name: at24c_ioctl + ************************************************************************************/ + +static int at24c_ioctl(FAR struct mtd_dev_s *dev, int cmd, unsigned long arg) +{ + FAR struct at24c_dev_s *priv = (FAR struct at24c_dev_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. + * + * blocksize: + * May be user defined. The block size for the at24XX devices may be + * larger than the page size in order to better support file systems. + * The read and write functions translate BLOCKS to pages for the + * small flash devices + * erasesize: + * It has to be at least as big as the blocksize, bigger serves no + * purpose. + * neraseblocks + * Note that the device size is in kilobits and must be scaled by + * 1024 / 8 + */ + +#if CONFIG_AT24XX_MTD_BLOCKSIZE > AT24XX_PAGESIZE + geo->blocksize = CONFIG_AT24XX_MTD_BLOCKSIZE; + geo->erasesize = CONFIG_AT24XX_MTD_BLOCKSIZE; + geo->neraseblocks = (CONFIG_AT24XX_SIZE * 1024 / 8) / CONFIG_AT24XX_MTD_BLOCKSIZE; +#else + geo->blocksize = priv->pagesize; + geo->erasesize = priv->pagesize; + geo->neraseblocks = priv->npages; +#endif + ret = OK; + + fvdbg("blocksize: %d erasesize: %d neraseblocks: %d\n", + geo->blocksize, geo->erasesize, geo->neraseblocks); + } + } + break; + + case MTDIOC_BULKERASE: + ret=at24c_eraseall(priv); + break; + + case MTDIOC_XIPBASE: + default: + ret = -ENOTTY; /* Bad command */ + break; + } + + return ret; +} + +/************************************************************************************ + * Public Functions + ************************************************************************************/ + +/************************************************************************************ + * Name: at24c_initialize + * + * Description: + * Create an initialize MTD device instance. 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 *at24c_initialize(FAR struct i2c_dev_s *dev) +{ + FAR struct at24c_dev_s *priv; + + fvdbg("dev: %p\n", dev); + + /* 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 I2C + * device (only because of the SPIDEV_FLASH definition) and so would have + * to be extended to handle multiple FLASH parts on the same I2C bus. + */ + + priv = &g_at24c; + if (priv) + { + /* Initialize the allocated structure */ + + priv->addr = CONFIG_AT24XX_ADDR; + priv->pagesize = AT24XX_PAGESIZE; + priv->npages = AT24XX_NPAGES; + + priv->mtd.erase = at24c_erase; + priv->mtd.bread = at24c_bread; + priv->mtd.bwrite = at24c_bwrite; + priv->mtd.ioctl = at24c_ioctl; + priv->dev = dev; + } + + /* Return the implementation-specific state structure as the MTD device */ + + fvdbg("Return %p\n", priv); + return (FAR struct mtd_dev_s *)priv; +} + +#endif |