/************************************************************************************ * Driver for 24xxxx-style I2C EEPROMs. * * Adapted from: * * 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 * 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 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 #include "systemlib/perf_counter.h" /************************************************************************************ * Pre-processor Definitions ************************************************************************************/ /* * Configuration is as for the AT24 driver, but the CONFIG_MTD_AT24XX define should be * omitted in order to avoid building the AT24XX driver as well. */ /* As a minimum, the size of the AT24 part and its 7-bit I2C address are required. */ #ifndef CONFIG_AT24XX_SIZE /* XXX this is a well vetted special case, * do not issue a warning any more * # warning "Assuming AT24 size 64" */ # define CONFIG_AT24XX_SIZE 64 #endif #ifndef CONFIG_AT24XX_ADDR /* XXX this is a well vetted special case, * do not issue a warning any more * # 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 /* XXX this is a well vetted special case, * do not issue a warning any more * # warning "Assuming driver block size is the same as the FLASH page size" */ # define CONFIG_AT24XX_MTD_BLOCKSIZE AT24XX_PAGESIZE #endif /* The AT24 does not respond on the bus during write cycles, so we depend on a long * timeout to detect problems. The max program time is typically ~5ms. */ #ifndef CONFIG_AT24XX_WRITE_TIMEOUT_MS # define CONFIG_AT24XX_WRITE_TIMEOUT_MS 20 #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 */ perf_counter_t perf_transfers; perf_counter_t perf_resets_retries; perf_counter_t perf_errors; }; /************************************************************************************ * 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 int at24c_ioctl(FAR struct mtd_dev_s *dev, int cmd, unsigned long arg); void at24c_test(void); int at24c_nuke(void); /************************************************************************************ * Private Data ************************************************************************************/ /* At present, only a single 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]; struct i2c_msg_s msgv[1] = { { .addr = priv->addr, .flags = 0, .buffer = &buf[0], .length = sizeof(buf), } }; memset(&buf[2], 0xff, priv->pagesize); for (startblock = 0; startblock < priv->npages; startblock++) { uint16_t offset = startblock * priv->pagesize; buf[1] = offset & 0xff; buf[0] = (offset >> 8) & 0xff; while (I2C_TRANSFER(priv->dev, &msgv[0], 1) < 0) { fvdbg("erase stall\n"); usleep(10000); } } 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_test ************************************************************************************/ void at24c_test(void) { uint8_t buf[CONFIG_AT24XX_MTD_BLOCKSIZE]; unsigned count = 0; unsigned errors = 0; for (count = 0; count < 10000; count++) { ssize_t result = at24c_bread(&g_at24c.mtd, 0, 1, buf); if (result == ERROR) { if (errors++ > 2) { vdbg("too many errors\n"); return; } } else if (result != 1) { vdbg("unexpected %u\n", result); } if ((count % 100) == 0) { vdbg("test %u errors %u\n", count, errors); } } } /************************************************************************************ * 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; uint8_t addr[2]; int ret; struct i2c_msg_s msgv[2] = { { .addr = priv->addr, .flags = 0, .buffer = &addr[0], .length = sizeof(addr), }, { .addr = priv->addr, .flags = I2C_M_READ, .buffer = 0, .length = priv->pagesize, } }; #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; } while (blocksleft-- > 0) { uint16_t offset = startblock * priv->pagesize; unsigned tries = CONFIG_AT24XX_WRITE_TIMEOUT_MS; addr[1] = offset & 0xff; addr[0] = (offset >> 8) & 0xff; msgv[1].buffer = buffer; for (;;) { perf_begin(priv->perf_transfers); ret = I2C_TRANSFER(priv->dev, &msgv[0], 2); perf_end(priv->perf_transfers); if (ret >= 0) break; fvdbg("read stall"); usleep(1000); /* We should normally only be here on the first read after * a write. * * XXX maybe do special first-read handling with optional * bus reset as well? */ perf_count(priv->perf_resets_retries); if (--tries == 0) { perf_count(priv->perf_errors); return ERROR; } } 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]; int ret; struct i2c_msg_s msgv[1] = { { .addr = priv->addr, .flags = 0, .buffer = &buf[0], .length = sizeof(buf), } }; #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); while (blocksleft-- > 0) { uint16_t offset = startblock * priv->pagesize; unsigned tries = CONFIG_AT24XX_WRITE_TIMEOUT_MS; buf[1] = offset & 0xff; buf[0] = (offset >> 8) & 0xff; memcpy(&buf[2], buffer, priv->pagesize); for (;;) { perf_begin(priv->perf_transfers); ret = I2C_TRANSFER(priv->dev, &msgv[0], 1); perf_end(priv->perf_transfers); if (ret >= 0) break; fvdbg("write stall"); usleep(1000); /* We expect to see a number of retries per write cycle as we * poll for write completion. */ if (--tries == 0) { perf_count(priv->perf_errors); return ERROR; } } 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; priv->perf_transfers = perf_alloc(PC_ELAPSED, "eeprom_trans"); priv->perf_resets_retries = perf_alloc(PC_COUNT, "eeprom_rst"); priv->perf_errors = perf_alloc(PC_COUNT, "eeprom_errs"); } /* attempt to read to validate device is present */ unsigned char buf[5]; uint8_t addrbuf[2] = {0, 0}; struct i2c_msg_s msgv[2] = { { .addr = priv->addr, .flags = 0, .buffer = &addrbuf[0], .length = sizeof(addrbuf), }, { .addr = priv->addr, .flags = I2C_M_READ, .buffer = &buf[0], .length = sizeof(buf), } }; perf_begin(priv->perf_transfers); int ret = I2C_TRANSFER(priv->dev, &msgv[0], 2); perf_end(priv->perf_transfers); if (ret < 0) { return NULL; } /* Return the implementation-specific state structure as the MTD device */ fvdbg("Return %p\n", priv); return (FAR struct mtd_dev_s *)priv; } /* * XXX: debug hackery */ int at24c_nuke(void) { return at24c_eraseall(&g_at24c); }