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

7 files changed, 922 insertions, 7 deletions

diff --git a/nuttx/ChangeLog b/nuttx/ChangeLog
index 32522415b..97b90f608 100644
--- a/nuttx/ChangeLog
+++ b/nuttx/ChangeLog
@@ -2056,4 +2056,7 @@
 	  Timeout calculation uses clock_settime() instead of clock_gettime().
 	  Pretty gross error, but actually it works with the side effect of setting
 	  a bad time.
-
+	* drivers/mtd/at24xx.c: Driver for I2C-based at24cxx EEPROM submitted by
+	  Li Zhuoyi (Lzyy).
+	* arch/arm/src/lpc17xx/lpc17_i2c.c: I2C driver for the NXP LPC17xx family
+	  submitted by Li Zhuoyi (Lzyy)
diff --git a/nuttx/Documentation/NuttX.html b/nuttx/Documentation/NuttX.html
index c93b87034..20e81e48f 100644
--- a/nuttx/Documentation/NuttX.html
+++ b/nuttx/Documentation/NuttX.html
@@ -8,7 +8,7 @@
   <tr align="center" bgcolor="#e4e4e4">
     <td>
       <h1><big><font color="#3c34ec"><i>NuttX RTOS</i></font></big></h1>
-      <p>Last Updated: September 4, 2011</p>
+      <p>Last Updated: September 7, 2011</p>
     </td>
   </tr>
 </table>
@@ -1461,7 +1461,8 @@
   <td>
     <p>
       <b>NXP LPC1766 and LPC1768</b>.
-      Configurations are available for three boards:
+      Drivers are available for CAN, DAC, Ethernet, GPIO, GPIO interrupts, I2C, UARTs, SPI, SSP, USB host, and USB device.
+      Verified LPC17xx onfigurations are available for three boards.
       <ul>
         <li>
           The Nucleus 2G board from <a href="http://www.2g-eng.com/">2G Engineering</a> (LPC1768),
@@ -1470,7 +1471,7 @@
           The mbed board from <a href="http://mbed.org">mbed.org</a> (LPC1768, Contributed by Dave Marples), and
         </li>
         <li>
-          The LPC1766-sTK board from <a href="http://www.olimex.com/">Olimex</a> (LPC1766).
+          The LPC1766-STK board from <a href="http://www.olimex.com/">Olimex</a> (LPC1766).
         </li>
         <li>
           The Embedded Artists base board with NXP LPCXpresso LPC1768.
@@ -1478,7 +1479,7 @@
       </ul>
     </p>
     <p>
-      The Nucleus 2G boar, the mbed board, and the LPCXpresso all feature the NXP LPC1768 MCU;
+      The Nucleus 2G board, the mbed board, and the LPCXpresso all feature the NXP LPC1768 MCU;
       the Olimex LPC1766-STK board features an LPC1766.
       All use a GNU arm-elf or arm-eabi toolchain* under either Linux or Cygwin (with native Windows GNU tools or Cygwin-based GNU tools).
     </p>
diff --git a/nuttx/arch/arm/src/lpc17xx/Make.defs b/nuttx/arch/arm/src/lpc17xx/Make.defs
index 1f779f6d4..34591e531 100755
--- a/nuttx/arch/arm/src/lpc17xx/Make.defs
+++ b/nuttx/arch/arm/src/lpc17xx/Make.defs
@@ -58,8 +58,9 @@ endif
 
 CHIP_ASRCS	=
 CHIP_CSRCS	= lpc17_allocateheap.c lpc17_can.c lpc17_clockconfig.c \
-		  lpc17_clrpend.c lpc17_gpio.c lpc17_idle.c lpc17_irq.c lpc17_lowputc.c \
-		  lpc17_serial.c lpc17_spi.c lpc17_ssp.c lpc17_start.c lpc17_timerisr.c
+		  lpc17_clrpend.c lpc17_gpio.c lpc17_i2c.c lpc17_idle.c lpc17_irq.c \
+		  lpc17_lowputc.c lpc17_serial.c lpc17_spi.c lpc17_ssp.c lpc17_start.c \
+		  lpc17_timerisr.c
 
 # Configuration-dependent LPC17xx files
 
diff --git a/nuttx/arch/arm/src/lpc17xx/lpc17_i2c.c b/nuttx/arch/arm/src/lpc17xx/lpc17_i2c.c
new file mode 100755
index 000000000..ccff276e5
--- /dev/null
+++ b/nuttx/arch/arm/src/lpc17xx/lpc17_i2c.c
@@ -0,0 +1,545 @@
+/*******************************************************************************

+ * arch/arm/src/lpc17xx/lpc17_i2c.c

+ *

+ *   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 arch/arm/src/lpc31xx/lpc31_i2c.c

+ *

+ *   Author: David Hewson

+ *

+ *   Copyright (C) 2010-2011 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 <string.h>

+#include <errno.h>

+#include <debug.h>

+

+#include <nuttx/arch.h>

+#include <nuttx/i2c.h>

+

+#include <arch/irq.h>

+#include <arch/board/board.h>

+

+#include "wdog.h"

+#include "chip.h"

+#include "up_arch.h"

+#include "up_internal.h"

+#include "os_internal.h"

+

+

+#include "lpc17_internal.h"

+#include "lpc17_syscon.h"

+#include "lpc17_pinconn.h"

+#include "lpc17_i2c.h"

+

+#if defined(CONFIG_LPC17_I2C0) || defined(CONFIG_LPC17_I2C1) || defined(CONFIG_LPC17_I2C2)

+

+#ifndef GPIO_I2C1_SCL

+ #define GPIO_I2C1_SCL GPIO_I2C1_SCL_1

+ #define GPIO_I2C1_SDA GPIO_I2C1_SDA_1

+#endif

+#ifndef CONFIG_I2C0_FREQ

+ #define CONFIG_I2C0_FREQ 100000

+#endif

+#ifndef CONFIG_I2C1_FREQ

+ #define CONFIG_I2C1_FREQ 100000

+#endif

+#ifndef CONFIG_I2C2_FREQ

+ #define CONFIG_I2C2_FREQ 100000

+#endif

+

+/*******************************************************************************

+ * Definitions

+ *******************************************************************************/

+

+/****************************************************************************

+ * Pre-processor Definitions

+ ****************************************************************************/

+

+#define I2C_TIMEOUT     ((20 * CLK_TCK) / 1000) /* 20 mS */

+

+/****************************************************************************

+ * Private Data

+ ****************************************************************************/

+struct lpc17_i2cdev_s

+{

+    struct i2c_dev_s    dev;        /* Generic I2C device */

+    struct i2c_msg_s    msg;        /* a single message for legacy read/write */

+    unsigned int        base;       /* Base address of registers */

+    uint16_t            irqid;      /* IRQ for this device */

+

+    sem_t               mutex;      /* Only one thread can access at a time */

+    sem_t               wait;       /* Place to wait for state machine completion */

+    volatile uint8_t    state;      /* State of state machine */

+    WDOG_ID             timeout;    /* watchdog to timeout when bus hung */

+

+    uint16_t            wrcnt;      /* number of bytes sent to tx fifo */

+    uint16_t            rdcnt;      /* number of bytes read from rx fifo */

+};

+

+static struct lpc17_i2cdev_s i2cdevices[3];

+

+/****************************************************************************

+ * Private Functions

+ ****************************************************************************/

+static int i2c_start (struct lpc17_i2cdev_s *priv);

+static void i2c_stop (struct lpc17_i2cdev_s *priv);

+static int  i2c_interrupt (int irq, FAR void *context);

+static void i2c_timeout (int argc, uint32_t arg, ...);

+

+/****************************************************************************

+ * I2C device operations

+ ****************************************************************************/

+

+static uint32_t i2c_setfrequency(FAR struct i2c_dev_s *dev, uint32_t frequency);

+static int      i2c_setaddress(FAR struct i2c_dev_s *dev, int addr, int nbits);

+static int      i2c_write(FAR struct i2c_dev_s *dev, const uint8_t *buffer, int buflen);

+static int      i2c_read(FAR struct i2c_dev_s *dev, uint8_t *buffer, int buflen);

+static int      i2c_transfer(FAR struct i2c_dev_s *dev, FAR struct i2c_msg_s *msgs, int count);

+

+struct i2c_ops_s lpc17_i2c_ops =

+{

+    .setfrequency = i2c_setfrequency,

+    .setaddress   = i2c_setaddress,

+    .write        = i2c_write,

+    .read         = i2c_read,

+#ifdef CONFIG_I2C_TRANSFER

+    .transfer     = i2c_transfer

+#endif

+};

+

+/*******************************************************************************

+ * Name: lpc17_i2c_setfrequency

+ *

+ * Description:

+ *   Set the frequence for the next transfer

+ *

+ *******************************************************************************/

+

+static uint32_t i2c_setfrequency(FAR struct i2c_dev_s *dev, uint32_t frequency)

+{

+    struct lpc17_i2cdev_s *priv = (struct lpc17_i2cdev_s *) dev;

+

+    if (frequency > 100000)

+    {

+        /* asymetric per 400Khz I2C spec */

+        putreg32 ( LPC17_CCLK / (83 + 47) * 47 / frequency, priv->base + LPC17_I2C_SCLH_OFFSET);

+        putreg32 ( LPC17_CCLK / (83 + 47) * 83 / frequency, priv->base + LPC17_I2C_SCLL_OFFSET);

+    }

+    else

+    {

+        /* 50/50 mark space ratio */

+        putreg32 (LPC17_CCLK / 100 * 50 / frequency, priv->base + LPC17_I2C_SCLH_OFFSET);

+        putreg32 (LPC17_CCLK / 100 * 50 / frequency, priv->base + LPC17_I2C_SCLL_OFFSET);

+    }

+

+    /* FIXME: This function should return the actual selected frequency */

+    return frequency;

+}

+

+/*******************************************************************************

+ * Name: lpc17_i2c_setaddress

+ *

+ * Description:

+ *   Set the I2C slave address for a subsequent read/write

+ *

+ *******************************************************************************/

+static int i2c_setaddress(FAR struct i2c_dev_s *dev, int addr, int nbits)

+{

+    struct lpc17_i2cdev_s *priv = (struct lpc17_i2cdev_s *) dev;

+

+    DEBUGASSERT(dev != NULL);

+    DEBUGASSERT(nbits == 7 );

+

+    priv->msg.addr  = addr<<1;

+    priv->msg.flags = 0 ;

+

+    return OK;

+}

+

+/*******************************************************************************

+ * Name: lpc17_i2c_write

+ *

+ * Description:

+ *   Send a block of data on I2C using the previously selected I2C

+ *   frequency and slave address.

+ *

+ *******************************************************************************/

+static int i2c_write(FAR struct i2c_dev_s *dev, const uint8_t *buffer, int buflen)

+{

+    struct lpc17_i2cdev_s *priv = (struct lpc17_i2cdev_s *) dev;

+    int ret;

+

+    DEBUGASSERT (dev != NULL);

+

+	priv->wrcnt=0;

+	priv->rdcnt=0;

+    priv->msg.addr &= ~0x01;

+    priv->msg.buffer = (uint8_t*)buffer;

+    priv->msg.length = buflen;

+	

+    ret = i2c_start (priv);

+

+    return ret >0 ? OK : -ETIMEDOUT;

+}

+

+/*******************************************************************************

+ * Name: lpc17_i2c_read

+ *

+ * Description:

+ *   Receive a block of data on I2C using the previously selected I2C

+ *   frequency and slave address.

+ *

+ *******************************************************************************/

+static int i2c_read(FAR struct i2c_dev_s *dev, uint8_t *buffer, int buflen)

+{

+    struct lpc17_i2cdev_s *priv = (struct lpc17_i2cdev_s *) dev;

+    int ret;

+

+    DEBUGASSERT (dev != NULL);

+

+	priv->wrcnt=0;

+	priv->rdcnt=0;

+    priv->msg.addr |= 0x01;

+    priv->msg.buffer = buffer;

+    priv->msg.length = buflen;

+

+    ret = i2c_start (priv);

+

+    return ret >0 ? OK : -ETIMEDOUT;

+}

+

+/*******************************************************************************

+ * Name: i2c_start

+ *

+ * Description:

+ *   Perform a I2C transfer start

+ *

+ *******************************************************************************/

+static int i2c_start (struct lpc17_i2cdev_s *priv)

+{

+	int ret=-1;

+	sem_wait (&priv->mutex);

+

+    putreg32(I2C_CONCLR_STAC|I2C_CONCLR_SIC,priv->base+LPC17_I2C_CONCLR_OFFSET);

+    putreg32(I2C_CONSET_STA,priv->base+LPC17_I2C_CONSET_OFFSET);

+

+	wd_start (priv->timeout, I2C_TIMEOUT, i2c_timeout, 1, (uint32_t)priv);

+	sem_wait(&priv->wait);

+	wd_cancel (priv->timeout);

+	sem_post (&priv->mutex);

+

+	if( priv-> state == 0x18 || priv->state == 0x28)

+		ret=priv->wrcnt;

+	else if( priv-> state == 0x50 || priv->state == 0x58)

+		ret=priv->rdcnt;

+	return ret;

+} 

+

+/*******************************************************************************

+ * Name: i2c_stop

+ *

+ * Description:

+ *   Perform a I2C transfer stop

+ *

+ *******************************************************************************/

+static void i2c_stop (struct lpc17_i2cdev_s *priv)

+{

+	if(priv->state!=0x38)

+		putreg32(I2C_CONSET_STO|I2C_CONSET_AA,priv->base+LPC17_I2C_CONSET_OFFSET);

+	sem_post (&priv->wait);

+}

+

+/*******************************************************************************

+ * Name: i2c_timeout

+ *

+ * Description:

+ *   Watchdog timer for timeout of I2C operation

+ *

+ *******************************************************************************/

+

+static void i2c_timeout (int argc, uint32_t arg, ...)

+{

+    struct lpc17_i2cdev_s *priv = (struct lpc17_i2cdev_s *) arg;

+

+    irqstate_t flags = irqsave();

+    priv->state = 0xff;

+    sem_post (&priv->wait);

+    irqrestore (flags);

+}

+

+/*******************************************************************************

+ * Name: i2c_interrupt

+ *

+ * Description:

+ *   The I2C Interrupt Handler

+ *

+ *******************************************************************************/

+

+static int i2c_interrupt (int irq, FAR void *context)

+{

+	struct lpc17_i2cdev_s *priv;

+#ifdef CONFIG_LPC17_I2C0

+    if (irq == LPC17_IRQ_I2C0)

+    {

+        priv=&i2cdevices[0];

+    }

+    else

+#endif

+#ifdef CONFIG_LPC17_I2C1

+    if (irq == LPC17_IRQ_I2C1)

+    {

+        priv=&i2cdevices[1];

+    }

+    else

+#endif

+#ifdef CONFIG_LPC17_I2C2

+    if (irq == LPC17_IRQ_I2C2)

+    {

+        priv=&i2cdevices[2];

+    }

+  else

+#endif

+    {

+      PANIC(OSERR_INTERNAL);

+    }

+/*

+ * refrence UM10360 19.10.5

+ */    

+	uint32_t state = getreg32(priv->base+LPC17_I2C_STAT_OFFSET);

+	putreg32(I2C_CONCLR_SIC,priv->base+LPC17_I2C_CONCLR_OFFSET);

+	priv->state=state;

+	state &=0xf8;

+	switch (state)

+	{

+		case 0x00:      //Bus Error

+		case 0x20:     

+		case 0x30:

+		case 0x38:

+		case 0x48:

+			i2c_stop(priv);

+			break;

+		case 0x08:     //START 

+		case 0x10:     //Repeat START 

+			putreg32(priv->msg.addr,priv->base+LPC17_I2C_DAT_OFFSET);

+			putreg32(I2C_CONCLR_STAC,priv->base+LPC17_I2C_CONCLR_OFFSET);

+			break;

+		case 0x18:

+			priv->wrcnt=0;

+			putreg32(priv->msg.buffer[0],priv->base+LPC17_I2C_DAT_OFFSET);

+		    break; 

+		case 0x28:

+			priv->wrcnt++;

+			if(priv->wrcnt<priv->msg.length)

+				putreg32(priv->msg.buffer[priv->wrcnt],priv->base+LPC17_I2C_DAT_OFFSET);

+		    else

+				i2c_stop(priv);

+		    break;

+		case 0x40:

+			priv->rdcnt=-1;

+			putreg32(I2C_CONSET_AA,priv->base+LPC17_I2C_CONSET_OFFSET);

+			break;

+		case 0x50:

+			priv->rdcnt++;

+			if(priv->rdcnt<priv->msg.length)

+				priv->msg.buffer[priv->rdcnt]=getreg32(priv->base+LPC17_I2C_BUFR_OFFSET);

+			if(priv->rdcnt>=priv->msg.length-1)

+				putreg32(I2C_CONCLR_AAC|I2C_CONCLR_SIC,priv->base+LPC17_I2C_CONCLR_OFFSET);

+			break;

+		case 0x58:

+			i2c_stop(priv);

+			break;

+		default:

+			i2c_stop(priv);

+			break;

+	}

+    return OK;

+}

+

+/****************************************************************************

+ * Public Functions

+ ****************************************************************************/

+

+

+/*******************************************************************************

+ * Name: up_i2cinitialize

+ *

+ * Description:

+ *   Initialise an I2C device

+ *

+ *******************************************************************************/

+

+struct i2c_dev_s *up_i2cinitialize(int port)

+{

+    struct lpc17_i2cdev_s *priv;

+

+    if (port>2)

+    {

+        dbg("lpc I2C Only support 0,1,2\n");

+        return NULL;

+    }

+

+    irqstate_t flags;

+    uint32_t regval;

+

+    flags = irqsave();

+

+    priv= &i2cdevices[port];

+#ifdef CONFIG_LPC17_I2C0

+    if (port==0)

+    {

+        priv= (FAR struct lpc17_i2cdev_s *)&i2cdevices[0];

+        priv->base  = LPC17_I2C0_BASE;

+        priv->irqid = LPC17_IRQ_I2C0;

+

+        regval  = getreg32(LPC17_SYSCON_PCONP);

+        regval |= SYSCON_PCONP_PCI2C0;

+        putreg32(regval, LPC17_SYSCON_PCONP);

+

+        regval  = getreg32(LPC17_SYSCON_PCLKSEL0);

+        regval &= ~SYSCON_PCLKSEL0_I2C0_MASK;

+        regval |= (SYSCON_PCLKSEL_CCLK << SYSCON_PCLKSEL0_I2C0_SHIFT);

+        putreg32(regval, LPC17_SYSCON_PCLKSEL0);

+        

+        lpc17_configgpio(GPIO_I2C0_SCL);

+        lpc17_configgpio(GPIO_I2C0_SDA);

+        

+        putreg32 (LPC17_CCLK/CONFIG_I2C0_FREQ/2, priv->base + LPC17_I2C_SCLH_OFFSET);

+        putreg32 (LPC17_CCLK/CONFIG_I2C0_FREQ/2, priv->base + LPC17_I2C_SCLL_OFFSET);

+

+    }

+    else

+#endif

+#ifdef CONFIG_LPC17_I2C1

+    if(port==1)

+    {

+        priv= (FAR struct lpc17_i2cdev_s *)&i2cdevices[1];

+        priv->base  = LPC17_I2C1_BASE;

+        priv->irqid = LPC17_IRQ_I2C1;

+

+        regval  = getreg32(LPC17_SYSCON_PCONP);

+        regval |= SYSCON_PCONP_PCI2C1;

+        putreg32(regval, LPC17_SYSCON_PCONP);

+

+        regval  = getreg32(LPC17_SYSCON_PCLKSEL1);

+        regval &= ~SYSCON_PCLKSEL1_I2C1_MASK;

+        regval |= (SYSCON_PCLKSEL_CCLK << SYSCON_PCLKSEL1_I2C1_SHIFT);

+        putreg32(regval, LPC17_SYSCON_PCLKSEL1);

+

+        lpc17_configgpio(GPIO_I2C1_SCL);

+        lpc17_configgpio(GPIO_I2C1_SDA);

+

+        putreg32 (LPC17_CCLK/CONFIG_I2C1_FREQ/2, priv->base + LPC17_I2C_SCLH_OFFSET);

+        putreg32 (LPC17_CCLK/CONFIG_I2C1_FREQ/2, priv->base + LPC17_I2C_SCLL_OFFSET);

+    }

+    else

+#endif

+#ifdef CONFIG_LPC17_I2C2

+    if(port==2)

+    {

+        priv= (FAR struct lpc17_i2cdev_s *)&i2cdevices[2];

+        priv->base  = LPC17_I2C2_BASE;

+        priv->irqid = LPC17_IRQ_I2C2;

+

+        regval  = getreg32(LPC17_SYSCON_PCONP);

+        regval |= SYSCON_PCONP_PCI2C2;

+        putreg32(regval, LPC17_SYSCON_PCONP);

+

+        regval  = getreg32(LPC17_SYSCON_PCLKSEL1);

+        regval &= ~SYSCON_PCLKSEL1_I2C2_MASK;

+        regval |= (SYSCON_PCLKSEL_CCLK << SYSCON_PCLKSEL1_I2C2_SHIFT);

+        putreg32(regval, LPC17_SYSCON_PCLKSEL1);

+        

+        lpc17_configgpio(GPIO_I2C2_SCL);

+        lpc17_configgpio(GPIO_I2C2_SDA);

+        

+        putreg32 (LPC17_CCLK/CONFIG_I2C2_FREQ/2, priv->base + LPC17_I2C_SCLH_OFFSET);

+        putreg32 (LPC17_CCLK/CONFIG_I2C2_FREQ/2, priv->base + LPC17_I2C_SCLL_OFFSET);

+    }

+    else

+#endif

+    {

+        return NULL;

+    }

+    putreg32(I2C_CONSET_I2EN,priv->base+LPC17_I2C_CONSET_OFFSET);

+

+    sem_init (&priv->mutex, 0, 1);

+    sem_init (&priv->wait, 0, 0);

+

+    /* Allocate a watchdog timer */

+    priv->timeout = wd_create();

+

+    DEBUGASSERT(priv->timeout != 0);

+

+    /* Attach Interrupt Handler */

+    irq_attach (priv->irqid, i2c_interrupt);

+

+    /* Enable Interrupt Handler */

+    up_enable_irq(priv->irqid);

+

+    /* Install our operations */

+    priv->dev.ops = &lpc17_i2c_ops;

+

+    return &priv->dev;

+}

+

+/*******************************************************************************

+ * Name: up_i2cuninitalize

+ *

+ * Description:

+ *   Uninitialise an I2C device

+ *

+ *******************************************************************************/

+

+int up_i2cuninitialize(FAR struct i2c_dev_s * dev)

+{

+	struct lpc17_i2cdev_s *priv = (struct lpc17_i2cdev_s *) dev;

+	

+	putreg32(I2C_CONCLRT_I2ENC,priv->base+LPC17_I2C_CONCLR_OFFSET);

+    up_disable_irq(priv->irqid);

+    irq_detach (priv->irqid);

+    return OK;

+}

+

+#endif

diff --git a/nuttx/drivers/mtd/Make.defs b/nuttx/drivers/mtd/Make.defs
index 2a1143158..2f4b9e86d 100644
--- a/nuttx/drivers/mtd/Make.defs
+++ b/nuttx/drivers/mtd/Make.defs
@@ -38,6 +38,10 @@
 
 CSRCS += at45db.c flash_eraseall.c ftl.c m25px.c rammtd.c ramtron.c
 
+ifeq ($(CONFIG_MTD_AT24XX),y)
+CSRCS += at24xx.c
+endif
+
 # Include MTD driver support
 
 DEPPATH += --dep-path mtd
diff --git a/nuttx/drivers/mtd/at24xx.c b/nuttx/drivers/mtd/at24xx.c
new file mode 100755
index 000000000..2aa116d83
--- /dev/null
+++ b/nuttx/drivers/mtd/at24xx.c
@@ -0,0 +1,349 @@
+/************************************************************************************

+ * 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

diff --git a/nuttx/include/nuttx/mtd.h b/nuttx/include/nuttx/mtd.h
index 95286dee5..4dc76e1ef 100644
--- a/nuttx/include/nuttx/mtd.h
+++ b/nuttx/include/nuttx/mtd.h
@@ -196,6 +196,18 @@ EXTERN FAR struct mtd_dev_s *m25p_initialize(FAR struct spi_dev_s *dev);
 
 EXTERN FAR struct mtd_dev_s *at45db_initialize(FAR struct spi_dev_s *dev);
 
+/****************************************************************************
+ * 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).
+ *
+ ****************************************************************************/
+
+EXTERN FAR struct mtd_dev_s *at24c_initialize(FAR struct i2c_dev_s *dev);
+
 #undef EXTERN
 #ifdef __cplusplus
 }