/************************************************************************************ * drivers/mtd/at24xx.c * Driver for I2C-based at24cxx EEPROM(at24c32,at24c64,at24c128,at24c256,at24c512) * * Copyright (C) 2011 Li Zhuoyi. All rights reserved. * Author: Li Zhuoyi * History: 0.1 2011-08-20 initial version * * 2011-11-1 Added support for larger MTD block sizes: Hal Glenn * * Derived from drivers/mtd/m25px.c * * Copyright (C) 2009-2011, 2013 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 #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 == 2 /* AT24C32: 2Kbits = 256; 16 * 16 = 256 */ # define AT24XX_NPAGES 16 # define AT24XX_PAGESIZE 16 # define AT24XX_ADDRSIZE 1 #elif CONFIG_AT24XX_SIZE == 32 /* AT24C32: 32Kbits = 4KiB; 128 * 32 = 4096 */ # define AT24XX_NPAGES 128 # define AT24XX_PAGESIZE 32 # define AT24XX_ADDRSIZE 2 #elif CONFIG_AT24XX_SIZE == 48 /* AT24C48: 48Kbits = 6KiB; 192 * 32 = 6144 */ # define AT24XX_NPAGES 192 # define AT24XX_PAGESIZE 32 # define AT24XX_ADDRSIZE 2 #elif CONFIG_AT24XX_SIZE == 64 /* AT24C64: 64Kbits = 8KiB; 256 * 32 = 8192 */ # define AT24XX_NPAGES 256 # define AT24XX_PAGESIZE 32 # define AT24XX_ADDRSIZE 2 #elif CONFIG_AT24XX_SIZE == 128 /* AT24C128: 128Kbits = 16KiB; 256 * 64 = 16384 */ # define AT24XX_NPAGES 256 # define AT24XX_PAGESIZE 64 # define AT24XX_ADDRSIZE 2 #elif CONFIG_AT24XX_SIZE == 256 /* AT24C256: 256Kbits = 32KiB; 512 * 64 = 32768 */ # define AT24XX_NPAGES 512 # define AT24XX_PAGESIZE 64 # define AT24XX_ADDRSIZE 2 #elif CONFIG_AT24XX_SIZE == 512 /* AT24C512: 512Kbits = 64KiB; 512 * 128 = 65536 */ # define AT24XX_NPAGES 512 # define AT24XX_PAGESIZE 128 # define AT24XX_ADDRSIZE 2 #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 */ bool initd; /* True: The device has been initialize */ #ifdef CONFIG_AT24XX_EXTENDED bool extended; /* True: use extended memory region */ #endif 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 + AT24XX_ADDRSIZE]; memset(&buf[AT24XX_ADDRSIZE], 0xff, priv->pagesize); I2C_SETADDRESS(priv->dev, priv->addr, 7); I2C_SETFREQUENCY(priv->dev, 100000); for (startblock = 0; startblock < priv->npages; startblock++) { #if AT24XX_ADDRSIZE == 2 uint16_t offset = startblock * priv->pagesize; buf[1] = offset & 0xff; buf[0] = (offset >> 8) & 0xff; #else buf[0] = startblock * priv->pagesize; #endif while (I2C_WRITE(priv->dev, buf, AT24XX_ADDRSIZE) < 0) { usleep(1000); } I2C_WRITE(priv->dev, buf, AT24XX_PAGESIZE + AT24XX_ADDRSIZE); } 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_read_internal ************************************************************************************/ static ssize_t at24c_read_internal(FAR struct at24c_dev_s *priv, off_t offset, size_t nbytes, FAR uint8_t *buffer, uint8_t address) { uint8_t buf[AT24XX_ADDRSIZE]; fvdbg("offset: %lu nbytes: %lu address: %02x\n", (unsigned long)offset, (unsigned long)nbytes, address); I2C_SETADDRESS(priv->dev, address, 7); I2C_SETFREQUENCY(priv->dev, 100000); /* "Random Read: A Random Read requires a dummy byte write sequence to load in the * data word address. Once the device address word and data word address are clocked * in and acknowledged by the EEPROM, the microcontroller must generate another * Start condition. The microcontroller now initiates a current address read * by sending a device address with the read/write select bit high. The EEPROM * acknowledges the device address and serially clocks out the data word. To end the * random read sequence, the microcontroller does not respond with a zero but does * generate a Stop condition in the subsequent clock cycle." * * A repeated START after the address is suggested, however, this simple driver * just performs the write as a sepate transfer with an additional, unnecessary STOP. */ #if AT24XX_ADDRSIZE == 2 buf[1] = offset & 0xff; buf[0] = (offset >> 8) & 0xff; #else buf[0] = (uint8_t)offset; #endif while (I2C_WRITE(priv->dev, buf, AT24XX_ADDRSIZE) < 0) { fvdbg("wait\n"); usleep(1000); } /* Then transfer the following bytes */ I2C_READ(priv->dev, buffer, nbytes); return nbytes; } /************************************************************************************ * 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; off_t offset; ssize_t nread; size_t i; #if CONFIG_AT24XX_MTD_BLOCKSIZE > AT24XX_PAGESIZE startblock *= (CONFIG_AT24XX_MTD_BLOCKSIZE / AT24XX_PAGESIZE); nblocks *= (CONFIG_AT24XX_MTD_BLOCKSIZE / AT24XX_PAGESIZE); #endif fvdbg("startblock: %08lx nblocks: %lu\n", (unsigned long)startblock, (unsigned long)nblocks); if (startblock >= priv->npages) { return 0; } if (startblock + nblocks > priv->npages) { nblocks = priv->npages - startblock; } /* Convert the access from startblock and number of blocks to a byte * offset and number of bytes. */ offset = startblock * priv->pagesize; /* Then perform the byte-oriented read for each block separately */ for (i = 0; i < nblocks; i++) { nread = at24c_read_internal(priv, offset, priv->pagesize, buffer, priv->addr); if (nread < 0) { return nread; } offset += 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 + AT24XX_ADDRSIZE]; #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) { #if AT24XX_ADDRSIZE uint16_t offset = startblock * priv->pagesize; buf[1] = offset & 0xff; buf[0] = (offset >> 8) & 0xff; #else buf[0] = startblock * priv->pagesize; #endif while (I2C_WRITE(priv->dev, buf, AT24XX_ADDRSIZE) < 0) { fvdbg("wait\n"); usleep(1000); } memcpy(&buf[AT24XX_ADDRSIZE], buffer, priv->pagesize); I2C_WRITE(priv->dev, buf, priv->pagesize + AT24XX_ADDRSIZE); 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_read ************************************************************************************/ static ssize_t at24c_read(FAR struct mtd_dev_s *dev, off_t offset, size_t nbytes, FAR uint8_t *buffer) { FAR struct at24c_dev_s *priv = (FAR struct at24c_dev_s *)dev; size_t memsize; uint8_t addr; fvdbg("offset: %lu nbytes: %lu\n", (unsigned long)offset, (unsigned long)nbytes); /* Don't permit reads beyond the end of the memory region */ #ifdef CONFIG_AT24XX_EXTENDED if (priv->extended) { memsize = CONFIG_AT24XX_EXTSIZE; } else #endif { memsize = AT24XX_NPAGES * AT24XX_PAGESIZE; } if (offset + nbytes > memsize) { /* Return 0 meaning end-of-file */ return 0; } /* Get the I2C address, converting it to the extended I2C if needed */ addr = priv->addr; #ifdef CONFIG_AT24XX_EXTENDED if (priv->extended) { addr |= 0x08; } #endif /* Then perform the byte-oriented read using common logic */ return at24c_read_internal(priv, offset, nbytes, buffer, addr); } /************************************************************************************ * 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; #ifdef CONFIG_AT24XX_EXTENDED case MTDIOC_EXTENDED: priv->extended = (arg != 0); ret = OK; break; #endif 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->initd) { /* Initialize the allocated structure */ priv->addr = CONFIG_AT24XX_ADDR; priv->pagesize = AT24XX_PAGESIZE; priv->npages = AT24XX_NPAGES; /* NOTE since the pre-allocated device structure lies in .bss, any * unsupported methods should have been nullified. */ priv->mtd.erase = at24c_erase; priv->mtd.bread = at24c_bread; priv->mtd.bwrite = at24c_bwrite; priv->mtd.read = at24c_read; priv->mtd.ioctl = at24c_ioctl; priv->dev = dev; /* Register the MTD with the procfs system if enabled */ #ifdef CONFIG_MTD_REGISTRATION mtd_register(&priv->mtd, "at24xx"); #endif priv->initd = true; } /* Return the implementation-specific state structure as the MTD device */ fvdbg("Return %p\n", priv); return (FAR struct mtd_dev_s *)priv; } #endif /* CONFIG_MTD_AT24XX */