nuttx/drivers/mtd/at24xx.c
patacongo 19e5bfd627 Add AT24xx and LPC17xx I2C drivers (from Lzyy)
git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@3941 42af7a65-404d-4744-a932-0658087f49c3
2011-09-07 13:32:13 +00:00

350 lines
12 KiB
C
Executable File

/************************************************************************************
* 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
*
* Derived from drivers/mtd/m25px.c
*
* Copyright (C) 2009-2011 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <spudmonkey@racsa.co.cr>
*
* 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 <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
************************************************************************************/
#ifndef CONFIG_AT24XX_SIZE
#define CONFIG_AT24XX_SIZE 64
#endif
#ifndef CONFIG_AT24XX_ADDR
#define CONFIG_AT24XX_ADDR 0x50
#endif
#if CONFIG_AT24XX_SIZE == 32
#define AT24XX_NPAGES 128
#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
/************************************************************************************
* 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;
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
************************************************************************************/
static struct at24c_dev_s g_at24c =
{
.addr = CONFIG_AT24XX_ADDR,
.pagesize = AT24XX_PAGESIZE,
.npages = AT24XX_NPAGES,
};
/************************************************************************************
* Private Functions
************************************************************************************/
static int at24c_eraseall(FAR struct at24c_dev_s *priv)
{
int blocksleft = priv->pagesize;
int startblock = 0;
uint8_t buf[66];
memset(&buf[2],0xff,priv->pagesize);
I2C_SETADDRESS(priv->dev,priv->addr,7);
I2C_SETFREQUENCY(priv->dev,100000);
while (blocksleft-- > 0)
{
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);
startblock++;
}
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 = 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);
int tail;
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;
}
return nblocks;
}
/************************************************************************************
* Name: at24c_bwrite
************************************************************************************/
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 = nblocks;
uint8_t buf[66];
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;
}
return nblocks;
}
/************************************************************************************
* 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.
*/
geo->blocksize = priv->pagesize;
geo->erasesize = priv->pagesize;
geo->neraseblocks = priv->npages;
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;
int ret;
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 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 = &g_at24c;
if (priv)
{
/* Initialize the allocated structure */
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