LPC17xx CAN driver now supports all 3 transmit buffers and loopback mode; LCP1766-STK NSH configuration will support the CAN loopback test

git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@4253 42af7a65-404d-4744-a932-0658087f49c3

1 files changed, 761 insertions, 256 deletions

diff --git a/nuttx/arch/arm/src/lpc17xx/lpc17_can.c b/nuttx/arch/arm/src/lpc17xx/lpc17_can.c
index dfcd1f0e7..41f823459 100755
--- a/nuttx/arch/arm/src/lpc17xx/lpc17_can.c
+++ b/nuttx/arch/arm/src/lpc17xx/lpc17_can.c
@@ -2,9 +2,14 @@
  * arch/arm/src/lpc17xx/lpc17_can.c
  *
  *   Copyright (C) 2011 Li Zhuoyi. All rights reserved.
- *   Author: Li Zhuoyi <lzyy.cn@gmail.com>
- *   History: 0.1 2011-07-12 initial version
- *            0.2 2011-08-03 support CAN1/CAN2
+ *   Copyright (C) 2012 Gregory Nutt. All rights reserved.
+ *   Authors:
+ *     Li Zhuoyi <lzyy.cn@gmail.com>
+ *     Gregory Nutt <gnutt@nuttx.org>
+ *   History: 
+ *     2011-07-12: Initial version (Li Zhuoyi)
+ *     2011-08-03: Support CAN1/CAN2 (Li Zhuoyi)
+ *     2012-01-02: Add support for CAN loopback mode (Gregory Nutt)
  * 
  * This file is a part of NuttX:
  *
@@ -65,17 +70,62 @@
 #if defined(CONFIG_LPC17_CAN1) || defined(CONFIG_LPC17_CAN2)
 
 /****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+/* Debug ********************************************************************/
+/* Non-standard debug that may be enabled just for testing CAN */
+
+#if !defined(CONFIG_DEBUG) || !defined(CONFIG_DEBUG_CAN)
+#  undef CONFIG_CAN_REGDEBUG
+#endif
+
+#ifdef CONFIG_DEBUG_CAN
+#  ifdef CONFIG_CAN_REGDEBUG
+#    define candbg  lldbg
+#    define canvdbg llvdbg
+#  else
+#    define candbg  dbg
+#    define canvdbg vdbg
+#  endif
+#  define canlldbg  lldbg
+#  define canllvdbg llvdbg
+#else
+#  define candbg(x...)
+#  define canvdbg(x...)
+#  define canlldbg(x...)
+#  define canllvdbg(x...)
+#endif
+
+/****************************************************************************
  * Private Types
  ****************************************************************************/
+
 struct up_dev_s
 {
-  int port;
-  int baud;      /* Configured baud */
+  uint8_t  port; /* CAN port number */
+  uint32_t baud; /* Configured baud */
+  uint32_t base; /* CAN register base address */
 };
 
 /****************************************************************************
  * Private Function Prototypes
  ****************************************************************************/
+/* CAN Register access */
+
+#ifdef CONFIG_CAN_REGDEBUG
+static void can_printreg(uint32_t addr, uint32_t value);
+#endif
+
+static uint32_t can_getreg(struct up_dev_s *priv, int offset);
+static void can_putreg(struct up_dev_s *priv, int offset, uint32_t value);
+
+#ifdef CONFIG_CAN_REGDEBUG
+static uint32_t can_getcommon(uint32_t addr);
+static void can_putcommon(uint32_t addr, uint32_t value);
+#else
+#  define can_getcommon(addr)        getreg32(addr)
+#  define can_putcommon(addr, value) putreg32(value, addr)
+#endif
 
 /* CAN methods */
 
@@ -88,7 +138,9 @@ static int  can_ioctl(FAR struct can_dev_s *dev, int cmd, unsigned long arg);
 static int  can_remoterequest(FAR struct can_dev_s *dev, uint16_t id);
 static int  can_send(FAR struct can_dev_s *dev, FAR struct can_msg_s *msg);
 static bool can_txempty(FAR struct can_dev_s *dev);
-static int  can_interrupt(int irq, void *context);
+
+static void can_interrupt(FAR struct can_dev_s *dev);
+static int  can12_interrupt(int irq, void *context);
 
 /****************************************************************************
  * Private Data
@@ -96,263 +148,704 @@ static int  can_interrupt(int irq, void *context);
 
 static const struct can_ops_s g_canops =
 {
-    .co_reset =can_reset,
-    .co_setup = can_setup,
-    .co_shutdown = can_shutdown,
-    .co_rxint = can_rxint,
-    .co_txint = can_txint,
-    .co_ioctl = can_ioctl,
-    .co_remoterequest = can_remoterequest,
-    .co_send = can_send,
-    .co_txempty = can_txempty,
+  .co_reset         = can_reset,
+  .co_setup         = can_setup,
+  .co_shutdown      = can_shutdown,
+  .co_rxint         = can_rxint,
+  .co_txint         = can_txint,
+  .co_ioctl         = can_ioctl,
+  .co_remoterequest = can_remoterequest,
+  .co_send          = can_send,
+  .co_txempty       = can_txempty,
 };
 
 #ifdef CONFIG_LPC17_CAN1
 static struct up_dev_s g_can1priv =
 {
-	.port  = 1,
-	.baud  = CONFIG_CAN1_BAUD,
+  .port    = 1,
+  .baud    = CONFIG_CAN1_BAUD,
+  .base    = LPC17_CAN1_BASE,
 };
 
 static struct can_dev_s g_can1dev =
 {
-    .cd_ops = &g_canops,
-	.cd_priv= &g_can1priv,
+  .cd_ops  = &g_canops,
+  .cd_priv = &g_can1priv,
 };
 #endif
 
 #ifdef CONFIG_LPC17_CAN2
 static struct up_dev_s g_can2priv =
 {
-	.port  = 2,
-	.baud  = CONFIG_CAN2_BAUD,
+  .port    = 2,
+  .baud    = CONFIG_CAN2_BAUD,
+  .base    = LPC17_CAN2_BASE,
 };
 
 static struct can_dev_s g_can2dev =
 {
-    .cd_ops = &g_canops,
-	.cd_priv= &g_can2priv,
+  .cd_ops  = &g_canops,
+  .cd_priv = &g_can2priv,
 };
 #endif
 
 /****************************************************************************
  * Private Functions
  ****************************************************************************/
-/* Reset the CAN device.  Called early to initialize the hardware. This
-* is called, before co_setup() and on error conditions.
-*/
+/****************************************************************************
+ * Name: can_printreg
+ *
+ * Description:
+ *   Print the value read from a register.
+ *
+ * Input Parameters:
+ *   addr - The register address
+ *   value - The register value
+ *
+ * Returned Value:
+ *   None
+ *
+ ****************************************************************************/
+
+#ifdef CONFIG_CAN_REGDEBUG
+static void can_printreg(uint32_t addr, uint32_t value)
+{
+  static uint32_t prevaddr = 0;
+  static uint32_t preval   = 0;
+  static uint32_t count    = 0;
+
+  /* Is this the same value that we read from the same register last time?
+   * Are we polling the register?  If so, suppress some of the output.
+   */
+
+  if (addr == prevaddr && value == preval)
+    {
+      if (count == 0xffffffff || ++count > 3)
+        {
+           if (count == 4)
+             {
+               lldbg("...\n");
+             }
+          return;
+        }
+    }
+
+  /* No this is a new address or value */
+
+  else
+    {
+       /* Did we print "..." for the previous value? */
+
+       if (count > 3)
+         {
+           /* Yes.. then show how many times the value repeated */
+
+           lldbg("[repeats %d more times]\n", count-3);
+         }
+
+       /* Save the new address, value, and count */
+
+       prevaddr = addr;
+       preval   = value;
+       count    = 1;
+    }
+
+  /* Show the register value read */
+
+  lldbg("%08x->%08x\n", addr, value);
+}
+#endif
+
+/****************************************************************************
+ * Name: can_getreg
+ *
+ * Description:
+ *   Read the value of an CAN1/2 register.
+ *
+ * Input Parameters:
+ *   priv - A reference to the CAN block status
+ *   offset - The offset to the register to read
+ *
+ * Returned Value:
+ *
+ ****************************************************************************/
+
+#ifdef CONFIG_CAN_REGDEBUG
+static uint32_t can_getreg(struct up_dev_s *priv, int offset)
+{
+  uint32_t addr;
+  uint32_t value;
+
+  /* Read the value from the register */
+
+  addr  = priv->base + offset;
+  value = getreg32(addr);
+  can_printreg(addr, value);
+  return value;
+}
+#else
+static uint32_t can_getreg(struct up_dev_s *priv, int offset)
+{
+  return getreg32(priv->base + offset);
+}
+#endif
+
+/****************************************************************************
+ * Name: can_putreg
+ *
+ * Description:
+ *   Set the value of an CAN1/2 register.
+ *
+ * Input Parameters:
+ *   priv - A reference to the CAN block status
+ *   offset - The offset to the register to write
+ *   value - The value to write to the register
+ *
+ * Returned Value:
+ *   None
+ *
+ ****************************************************************************/
+
+#ifdef CONFIG_CAN_REGDEBUG
+static void can_putreg(struct up_dev_s *priv, int offset, uint32_t value)
+{
+  uint32_t addr = priv->base + offset;
+
+  /* Show the register value being written */
+
+  lldbg("%08x<-%08x\n", addr, value);
+
+  /* Write the value */
+
+  putreg32(value, addr);
+}
+#else
+static void can_putreg(struct up_dev_s *priv, int offset, uint32_t value)
+{
+  putreg32(value, priv->base + offset);
+}
+#endif
+
+/****************************************************************************
+ * Name: can_getcommon
+ *
+ * Description:
+ *   Get the value of common register.
+ *
+ * Input Parameters:
+ *   addr - The address of the register to read
+ *
+ * Returned Value:
+ *   None
+ *
+ ****************************************************************************/
+
+#ifdef CONFIG_CAN_REGDEBUG
+static uint32_t can_getcommon(uint32_t addr)
+{
+  uint32_t value;
+
+  /* Read the value from the register */
+
+  value = getreg32(addr);
+  can_printreg(addr, value);
+  return value;
+}
+#endif
+
+/****************************************************************************
+ * Name: can_putcommon
+ *
+ * Description:
+ *   Set the value of common register.
+ *
+ * Input Parameters:
+ *   addr - The address of the register to write
+ *   value - The value to write to the register
+ *
+ * Returned Value:
+ *   None
+ *
+ ****************************************************************************/
+
+#ifdef CONFIG_CAN_REGDEBUG
+static void can_putcommon(uint32_t addr, uint32_t value)
+{
+  /* Show the register value being written */
+
+  lldbg("%08x<-%08x\n", addr, value);
+
+  /* Write the value */
+
+  putreg32(value, addr);
+}
+#endif
+
+/****************************************************************************
+ * Name: can_reset
+ *
+ * Description:
+ *   Reset the CAN device.  Called early to initialize the hardware. This
+ *   function is called, before can_setup() and on error conditions.
+ *
+ * Input Parameters:
+ *   dev - An instance of the "upper half" can driver state structure.
+ *
+ * Returned Value:
+ *  None
+ *
+ ****************************************************************************/
+
 static void can_reset(FAR struct can_dev_s *dev)
 {
-    irqstate_t flags;
-    uint32_t regval;
-	struct up_dev_s *priv=dev->cd_priv;
-	int baud = priv->baud;
-	int port = priv->port;
-	
-	baud = 0x25c003;
-    flags = irqsave();
-    
-	if(port==1)
-	{
-		putreg32(0x01,LPC17_CAN1_MOD);
-		putreg32(0x00,LPC17_CAN1_IER);
-		putreg32(0x00,LPC17_CAN1_GSR);
-		putreg32(0x02,LPC17_CAN1_CMR);
-		putreg32(baud,LPC17_CAN1_BTR);
-		putreg32(0x00,LPC17_CAN1_MOD);
-		putreg32(0x01,LPC17_CAN1_IER);
-		putreg32(0x02,LPC17_CANAF_AFMR);
-	}
-	else if(port==2)
-	{
-		putreg32(0x01,LPC17_CAN2_MOD);
-		putreg32(0x00,LPC17_CAN2_IER);
-		putreg32(0x00,LPC17_CAN2_GSR);
-		putreg32(0x02,LPC17_CAN2_CMR);
-		putreg32(baud,LPC17_CAN2_BTR);
-		putreg32(0x00,LPC17_CAN2_MOD);
-		putreg32(0x01,LPC17_CAN2_IER);
-		putreg32(0x02,LPC17_CANAF_AFMR);
-	}
-	else
-	{
-		dbg("Unsupport port %d\n",port);
-	}
-    irqrestore(flags);
+  FAR struct up_dev_s *priv = (FAR struct up_dev_s *)dev->cd_priv;
+  uint32_t baud;
+  irqstate_t flags;
+
+  canvdbg("CAN%d\n", priv->port);
+
+#warning "BTR setting must be calculated from priv->baud"
+  baud  = 0x25c003;
+  flags = irqsave();
+
+  can_putreg(priv, LPC17_CAN_MOD_OFFSET, CAN_MOD_RM);  /* Enter Reset Mode */
+  can_putreg(priv, LPC17_CAN_IER_OFFSET, 0);           /* Disable interrupts */
+  can_putreg(priv, LPC17_CAN_GSR_OFFSET, 0);           /* Clear status bits */
+  can_putreg(priv, LPC17_CAN_CMR_OFFSET, CAN_CMR_AT);  /* Abort transmission */
+  can_putreg(priv, LPC17_CAN_BTR_OFFSET, baud);        /* Set bit timing */
+#ifdef CONFIG_CAN_LOOPBACK
+  can_putreg(priv, LPC17_CAN_MOD_OFFSET, CAN_MOD_STM); /* Leave Reset Mode, enter Test Mode */
+#else
+  can_putreg(priv, LPC17_CAN_MOD_OFFSET, 0);           /* Leave Reset Mode */
+#endif
+  can_putcommon(LPC17_CANAF_AFMR, CANAF_AFMR_ACCBP);   /* All RX messages accepted */
+  irqrestore(flags);
 }
 
-/* Configure the CAN. This method is called the first time that the CAN
-* device is opened.  This will occur when the port is first opened.
-* This setup includes configuring and attaching CAN interrupts.  Interrupts
-* are all disabled upon return.
-*/
-static int  can_setup(FAR struct can_dev_s *dev)
+/****************************************************************************
+ * Name: can_setup
+ *
+ * Description:
+ *   Configure the CAN. This method is called the first time that the CAN
+ *   device is opened.  This will occur when the port is first opened.
+ *   This setup includes configuring and attaching CAN interrupts.
+ *   All CAN interrupts are disabled upon return.
+ *
+ * Input Parameters:
+ *   dev - An instance of the "upper half" can driver state structure.
+ *
+ * Returned Value:
+ *   Zero on success; a negated errno on failure
+ *
+ ****************************************************************************/
+
+static int can_setup(FAR struct can_dev_s *dev)
 {
-    int ret = irq_attach(LPC17_IRQ_CAN, can_interrupt);
-    if (ret == OK)
+#ifdef CONFIG_DEBUG_CAN
+  FAR struct up_dev_s *priv = (FAR struct up_dev_s *)dev->cd_priv;
+#endif
+  int ret;
+
+  canvdbg("CAN%d\n", priv->port);
+
+  ret = irq_attach(LPC17_IRQ_CAN, can12_interrupt);
+  if (ret == OK)
     {
-        up_enable_irq(LPC17_IRQ_CAN);
+      up_enable_irq(LPC17_IRQ_CAN);
     }
-    return ret;
+  return ret;
 }
 
-/* Disable the CAN.  This method is called when the CAN device is closed.
-* This method reverses the operation the setup method.
-*/
+/****************************************************************************
+ * Name: can_shutdown
+ *
+ * Description:
+ *   Disable the CAN.  This method is called when the CAN device is closed.
+ *   This method reverses the operation the setup method.
+ *
+ * Input Parameters:
+ *   dev - An instance of the "upper half" can driver state structure.
+ *
+ * Returned Value:
+ *   None
+ *
+ ****************************************************************************/
+
 static void can_shutdown(FAR struct can_dev_s *dev)
 {
-    up_disable_irq(LPC17_IRQ_CAN);
-    irq_detach(LPC17_IRQ_CAN);
+#ifdef CONFIG_DEBUG_CAN
+  FAR struct up_dev_s *priv = (FAR struct up_dev_s *)dev->cd_priv;
+
+  canvdbg("CAN%d\n", priv->port);
+#endif
+
+  up_disable_irq(LPC17_IRQ_CAN);
+  irq_detach(LPC17_IRQ_CAN);
 }
 
-/* Call to enable or disable RX interrupts */
+/****************************************************************************
+ * Name: can_rxint
+ *
+ * Description:
+ *   Call to enable or disable RX interrupts.
+ *
+ * Input Parameters:
+ *   dev - An instance of the "upper half" can driver state structure.
+ *
+ * Returned Value:
+ *   None
+ *
+ ****************************************************************************/
+
 static void can_rxint(FAR struct can_dev_s *dev, bool enable)
 {
-    uint32_t regval;
-    int port = ((struct up_dev_s *)(dev->cd_priv))->port;
-
-	if(port == 1)
-		regval  = getreg32(LPC17_CAN1_IER);
-    else
-		regval  = getreg32(LPC17_CAN2_IER);
-    
-    if (enable)
-        regval |= CAN_IER_RIE;
-    else
-        regval &= ~CAN_IER_RIE;
-    
-    if(port == 1)    
-		putreg32(regval, LPC17_CAN1_IER);
-    else
-		putreg32(regval, LPC17_CAN2_IER);
+  FAR struct up_dev_s *priv = (FAR struct up_dev_s *)dev->cd_priv;
+  uint32_t regval;
+
+  canvdbg("CAN%d enable: %d\n", priv->port, enable);
+
+  regval = can_getreg(priv, LPC17_CAN_IER_OFFSET);
+  if (enable)
+    {
+      regval |= CAN_IER_RIE;
+    }
+  else
+    {
+      regval &= ~CAN_IER_RIE;
+    }
+  can_putreg(priv, LPC17_CAN_IER_OFFSET, regval);
 }
 
-/* Call to enable or disable TX interrupts */
+/****************************************************************************
+ * Name: can_txint
+ *
+ * Description:
+ *   Call to enable or disable TX interrupts.
+ *
+ * Input Parameters:
+ *   dev - An instance of the "upper half" can driver state structure.
+ *
+ * Returned Value:
+ *   None
+ *
+ ****************************************************************************/
+
 static void can_txint(FAR struct can_dev_s *dev, bool enable)
 {
-    uint32_t regval;
-    int port = ((struct up_dev_s *)(dev->cd_priv))->port;
-
-	if(port == 1)
-		regval  = getreg32(LPC17_CAN1_IER);
-    else
-		regval  = getreg32(LPC17_CAN2_IER);
-
-    if (enable)
-        regval |= CAN_IER_TIE1;
-    else
-        regval &= ~CAN_IER_TIE1;
-
-    if(port == 1)    
-		putreg32(regval, LPC17_CAN1_IER);
-    else
-		putreg32(regval, LPC17_CAN2_IER);
+  FAR struct up_dev_s *priv = (FAR struct up_dev_s *)dev->cd_priv;
+  uint32_t regval;
+
+  canvdbg("CAN%d enable: %d\n", priv->port, enable);
+
+  /* Only disabling of the TX interrupt is supported here.  The TX interrupt
+   * is automatically enabled just before a message is sent in order to avoid
+   * lost TX interrupts.
+   */
+
+  if (!enable)
+    {
+      regval = can_getreg(priv, LPC17_CAN_IER_OFFSET);
+      regval &= ~(CAN_IER_TIE1 | CAN_IER_TIE2 | CAN_IER_TIE3);
+      can_putreg(priv, LPC17_CAN_IER_OFFSET, regval);
+    }
 }
 
-/* All ioctl calls will be routed through this method */
-static int  can_ioctl(FAR struct can_dev_s *dev, int cmd, unsigned long arg)
+/****************************************************************************
+ * Name: can_ioctl
+ *
+ * Description:
+ *   All ioctl calls will be routed through this method
+ *
+ * Input Parameters:
+ *   dev - An instance of the "upper half" can driver state structure.
+ *
+ * Returned Value:
+ *   Zero on success; a negated errno on failure
+ *
+ ****************************************************************************/
+
+static int can_ioctl(FAR struct can_dev_s *dev, int cmd, unsigned long arg)
 {
-    dbg("Fix me:Not Implemented\n");
-    return 0;
+  dbg("Fix me:Not Implemented\n");
+  return 0;
 }
 
-/* Send a remote request */
-static int  can_remoterequest(FAR struct can_dev_s *dev, uint16_t id)
+/****************************************************************************
+ * Name: can_remoterequest
+ *
+ * Description:
+ *   Send a remote request
+ *
+ * Input Parameters:
+ *   dev - An instance of the "upper half" can driver state structure.
+ *
+ * Returned Value:
+ *   Zero on success; a negated errno on failure
+ *
+ ****************************************************************************/
+
+static int can_remoterequest(FAR struct can_dev_s *dev, uint16_t id)
 {
-    dbg("Fix me:Not Implemented\n");
-    return 0;
+  dbg("Fix me:Not Implemented\n");
+  return 0;
 }
 
-static int  can_send(FAR struct can_dev_s *dev, FAR struct can_msg_s *msg)
+/****************************************************************************
+ * Name: can_send
+ *
+ * Description:
+ *    Send one can message.
+ *
+ *    One CAN-message consists of a maximum of 10 bytes.  A message is
+ *    composed of at least the first 2 bytes (when there are no data bytes).
+ *
+ *    Byte 0:      Bits 0-7: Bits 3-10 of the 11-bit CAN identifier
+ *    Byte 1:      Bits 5-7: Bits 0-2 of the 11-bit CAN identifier
+ *                 Bit 4:    Remote Tranmission Request (RTR)
+ *                 Bits 0-3: Data Length Code (DLC)
+ *    Bytes 2-10: CAN data
+ *
+ * Input Parameters:
+ *   dev - An instance of the "upper half" can driver state structure.
+ *
+ * Returned Value:
+ *   Zero on success; a negated errno on failure
+ *
+ ****************************************************************************/
+
+static int can_send(FAR struct can_dev_s *dev, FAR struct can_msg_s *msg)
 {
-    int port = ((struct up_dev_s *)(dev->cd_priv))->port;
-    uint32_t tid=CAN_ID(msg->cm_hdr);
-    uint32_t tfi=CAN_DLC(msg->cm_hdr)<<16;
-    if (CAN_RTR(msg->cm_hdr))
-        tfi|=CAN_TFI_RTR;
-	if( port == 1)
-	{
-		putreg32(tfi,LPC17_CAN1_TFI1);
-		putreg32(tid,LPC17_CAN1_TID1);
-		putreg32(*(uint32_t *)&msg->cm_data[0],LPC17_CAN1_TDA1);
-		putreg32(*(uint32_t *)&msg->cm_data[4],LPC17_CAN1_TDB1);
-		putreg32(0x21,LPC17_CAN1_CMR);
-	}
-	else
-	{
-		putreg32(tfi,LPC17_CAN2_TFI1);
-		putreg32(tid,LPC17_CAN2_TID1);
-		putreg32(*(uint32_t *)&msg->cm_data[0],LPC17_CAN2_TDA1);
-		putreg32(*(uint32_t *)&msg->cm_data[4],LPC17_CAN2_TDB1);
-		putreg32(0x21,LPC17_CAN2_CMR);
-	}
-    return 0;
+  FAR struct up_dev_s *priv = (FAR struct up_dev_s *)dev->cd_priv;
+  uint32_t tid = CAN_ID(msg->cm_hdr);
+  uint32_t tfi = CAN_DLC(msg->cm_hdr) << 16;
+  uint32_t regval;
+  irqstate_t flags;
+  int ret = OK;
+
+  canvdbg("CAN%d ID: %d DLC: %d\n",
+          priv->port, CAN_ID(msg->cm_hdr), CAN_DLC(msg->cm_hdr));
+
+  if (CAN_RTR(msg->cm_hdr))
+    {
+      tfi |= CAN_TFI_RTR;
+    }
+
+  flags = irqsave();
+
+  /* Pick a transmit buffer */
+
+  regval = can_getreg(priv, LPC17_CAN_SR_OFFSET);
+  if ((regval & CAN_SR_TBS1) != 0)
+    {
+      /* Set up the transfer */
+
+      can_putreg(priv, LPC17_CAN_TFI1_OFFSET, tfi);
+      can_putreg(priv, LPC17_CAN_TID1_OFFSET, tid);
+      can_putreg(priv, LPC17_CAN_TDA1_OFFSET, *(uint32_t *)&msg->cm_data[0]);
+      can_putreg(priv, LPC17_CAN_TDB1_OFFSET, *(uint32_t *)&msg->cm_data[4]);
+
+      /* Send the message */
+
+#ifdef CONFIG_CAN_LOOPBACK
+      can_putreg(priv, LPC17_CAN_CMR_OFFSET, CAN_CMR_STB1 | CAN_CMR_SRR);
+#else
+      can_putreg(priv, LPC17_CAN_CMR_OFFSET, CAN_CMR_STB1 | CAN_CMR_TR);
+#endif
+
+      /* Tell the caller that the transfer is done.  It isn't, but we have
+       * more transmit buffers and this can speed things up.
+       */
+
+      can_txdone(dev);
+    }
+  else if ((regval & CAN_SR_TBS2) != 0)
+    {
+      /* Set up the transfer */
+
+      can_putreg(priv, LPC17_CAN_TFI2_OFFSET, tfi);
+      can_putreg(priv, LPC17_CAN_TID2_OFFSET, tid);
+      can_putreg(priv, LPC17_CAN_TDA2_OFFSET, *(uint32_t *)&msg->cm_data[0]);
+      can_putreg(priv, LPC17_CAN_TDB2_OFFSET, *(uint32_t *)&msg->cm_data[4]);
+
+      /* Send the message */
+
+#ifdef CONFIG_CAN_LOOPBACK
+      can_putreg(priv, LPC17_CAN_CMR_OFFSET, CAN_CMR_STB2 | CAN_CMR_SRR);
+#else
+      can_putreg(priv, LPC17_CAN_CMR_OFFSET, CAN_CMR_STB2 | CAN_CMR_TR);
+#endif
+
+      /* Tell the caller that the transfer is done.  It isn't, but we have
+       * more transmit buffers and this can speed things up.
+       */
+
+      can_txdone(dev);
+    }
+  else if ((regval & CAN_SR_TBS3) != 0)
+    {
+      /* We have no more buffers.  We will make the caller wait.  First, make
+       * sure that the buffer 3  TX interrupt is enabled BEFORE sending the
+       * message. The TX interrupt is generated TBS3 bit in CANxSR goes from 0
+       * to 1 when the TIE3 bit in CANxIER is 1.  If we don't enable it now,
+       * we will miss interrupts.
+       *
+       * Hmmm... we could probably do better than this.  Buffer 1 or 2 is much
+       * more likely to complete quicker than buffer 3.
+       */
+
+      regval  = can_getreg(priv, LPC17_CAN_IER_OFFSET);
+      regval |= CAN_IER_TIE3;
+      can_putreg(priv, LPC17_CAN_IER_OFFSET, regval);
+
+      /* Set up the transfer */
+
+      can_putreg(priv, LPC17_CAN_TFI3_OFFSET, tfi);
+      can_putreg(priv, LPC17_CAN_TID3_OFFSET, tid);
+      can_putreg(priv, LPC17_CAN_TDA3_OFFSET, *(uint32_t *)&msg->cm_data[0]);
+      can_putreg(priv, LPC17_CAN_TDB3_OFFSET, *(uint32_t *)&msg->cm_data[4]);
+
+      /* Send the message */
+
+#ifdef CONFIG_CAN_LOOPBACK
+      can_putreg(priv, LPC17_CAN_CMR_OFFSET, CAN_CMR_STB3 | CAN_CMR_SRR);
+#else
+      can_putreg(priv, LPC17_CAN_CMR_OFFSET, CAN_CMR_STB3 | CAN_CMR_TR);
+#endif
+    }
+  else
+    {
+      candbg("No available transmission buffer, SR: %08x\n", regval);
+      ret = -EBUSY;
+    }
+
+  irqrestore(flags);
+  return ret;
 }
 
+/****************************************************************************
+ * Name: can_txempty
+ *
+ * Description:
+ *   Return true if all message have been sent.  If for example, the CAN
+ *   hardware implements FIFOs, then this would mean the transmit FIFO is
+ *   empty.  This method is called when the driver needs to make sure that
+ *   all characters are "drained" from the TX hardware before calling
+ *   co_shutdown().
+ *
+ * Input Parameters:
+ *   dev - An instance of the "upper half" can driver state structure.
+ *
+ * Returned Value:
+ *   Zero on success; a negated errno on failure
+ *
+ ****************************************************************************/
+
 static bool can_txempty(FAR struct can_dev_s *dev)
 {
-    uint32_t regval;
-    int port = ((struct up_dev_s *)(dev->cd_priv))->port;
-	if( port == 1)
-		regval  = getreg32(LPC17_CAN1_GSR);
-	else
-		regval  = getreg32(LPC17_CAN2_GSR);
-    if ( regval & CAN_GSR_TBS)
-        return true;
-    else
-        return false;
+  FAR struct up_dev_s *priv = (FAR struct up_dev_s *)dev->cd_priv;
+  uint32_t regval = can_getreg(priv, LPC17_CAN_GSR_OFFSET);
+  return ((regval & CAN_GSR_TBS) != 0);
 }
 
-static int can_interrupt(int irq, void *context)
+/****************************************************************************
+ * Name: can_interrupt
+ *
+ * Description:
+ *   CAN1/2 RX/TX interrupt handler
+ *
+ * Input Parameters:
+ *   dev - An instance of the "upper half" can driver state structure.
+ *
+ * Returned Value:
+ *   Zero on success; a negated errno on failure
+ *
+ ****************************************************************************/
+
+static void can_interrupt(FAR struct can_dev_s *dev)
 {
-    uint32_t regval;
-
-#ifdef CONFIG_LPC17_CAN1    
-	regval=getreg32(LPC17_CAN1_ICR);
-	if (regval & CAN_ICR_RI )           //Receive interrupt
-	{
-		uint16_t hdr;
-		uint32_t data[2];
-		uint32_t rfs=getreg32(LPC17_CAN1_RFS);
-		uint32_t rid=getreg32(LPC17_CAN1_RID);
-		data[0]=getreg32(LPC17_CAN1_RDA);
-		data[1]=getreg32(LPC17_CAN1_RDB);
-		putreg32(0x04,LPC17_CAN1_CMR);           //release recieve buffer
-		hdr=((rid<<5)&~0x1f)|((rfs>>16)&0x0f);
-		if (rfs&CAN_RFS_RTR)
-			hdr|=0x10;
-		can_receive(&g_can1dev,hdr,(uint8_t *)data);
-	}
-	if ( regval & CAN_ICR_TI1)           //Transmit interrupt 1
-		can_txdone(&g_can1dev);
-#endif
+  FAR struct up_dev_s *priv = (FAR struct up_dev_s *)dev->cd_priv;
+  uint32_t data[2];
+  uint32_t rfs;
+  uint32_t rid;
+  uint32_t regval;
+  uint16_t hdr;
+  uint16_t id;
+  uint16_t dlc;
+  uint16_t rtr;
+
+  /* Read the interrupt and capture register (also clearing most status bits) */
+
+  regval = can_getreg(priv, LPC17_CAN_ICR_OFFSET);
+  canllvdbg("CAN%d ICR: %08x\n",  priv->port, regval);
+
+  /* Check for a receive interrupt */
+
+  if ((regval & CAN_ICR_RI) != 0)
+    {
+      rfs     = can_getreg(priv, LPC17_CAN_RFS_OFFSET);
+      rid     = can_getreg(priv, LPC17_CAN_RID_OFFSET);
+      data[0] = can_getreg(priv, LPC17_CAN_RDA_OFFSET);
+      data[1] = can_getreg(priv, LPC17_CAN_RDB_OFFSET);
+
+      /* Release the receive buffer */
+
+      can_putreg(priv, LPC17_CAN_CMR_OFFSET, CAN_CMR_RRB);
+
+      /* Construct the CAN header */
+
+      id      = rid & CAN_RID_ID11_MASK;
+      dlc     = (rfs & CAN_RFS_DLC_MASK) >> CAN_RFS_DLC_SHIFT;
+      rtr     = ((rfs & CAN_RFS_RTR) != 0);
+      hdr     = CAN_HDR(id, rtr, dlc);
+
+      /* Process the received CAN packet */
+
+      can_receive(dev, hdr, (uint8_t *)data);
+    }
+
+  /* Check for a transmit interrupt from buffer 3 */
+
+  if ((regval & CAN_ICR_TI3) != 0)
+    {
+      can_txdone(&g_can1dev);
+    }
+}
+
+/****************************************************************************
+ * Name: can12_interrupt
+ *
+ * Description:
+ *   CAN interrupt handler.  There is a single interrupt for both CAN1 and
+ *   CAN2.
+ *
+ * Input Parameters:
+ *   irq - The IRQ number of the interrupt.
+ *   context - The register state save array at the time of the interrupt.
+ *
+ * Returned Value:
+ *   Zero on success; a negated errno on failure
+ *
+ ****************************************************************************/
+
+static int can12_interrupt(int irq, void *context)
+{
+  /* Handle CAN1/2 interrupts */
 
+  canllvdbg("irq: %d\n",  irq);
+
+#ifdef CONFIG_LPC17_CAN1
+  can_interrupt(&g_can1dev);
+#endif
 #ifdef CONFIG_LPC17_CAN2
-	regval=getreg32(LPC17_CAN2_ICR);
-	if (regval & CAN_ICR_RI )           //Receive interrupt
-	{
-		uint16_t hdr;
-		uint32_t data[2];
-		uint32_t rfs=getreg32(LPC17_CAN2_RFS);
-		uint32_t rid=getreg32(LPC17_CAN2_RID);
-		data[0]=getreg32(LPC17_CAN2_RDA);
-		data[1]=getreg32(LPC17_CAN2_RDB);
-		putreg32(0x04,LPC17_CAN2_CMR);           //release recieve buffer
-		hdr=((rid<<5)&~0x1f)|((rfs>>16)&0x0f);
-		if (rfs&CAN_RFS_RTR)
-			hdr|=0x10;
-		can_receive(&g_can2dev,hdr,data);
-	}
-	if ( regval & CAN_ICR_TI1)           //Transmit interrupt 1
-		can_txdone(&g_can2dev);
+  can_interrupt(&g_can2dev);
 #endif
-    return OK;
+
+  return OK;
 }
 
 /****************************************************************************
  * Public Functions
  ****************************************************************************/
-
 /****************************************************************************
  * Name: lpc17_caninitialize
  *
@@ -369,67 +862,79 @@ static int can_interrupt(int irq, void *context)
 
 FAR struct can_dev_s *lpc17_caninitialize(int port)
 {
-    uint32_t regval;
-    irqstate_t flags;
-    flags = irqsave();
-	struct can_dev_s *candev=NULL;
-
-#ifdef CONFIG_LPC17_CAN1	
-	if( port == 1 )
-	{
-		regval  = getreg32(LPC17_SYSCON_PCONP);
-		regval |= SYSCON_PCONP_PCCAN1;
-		putreg32(regval, LPC17_SYSCON_PCONP);
-
-		regval  = getreg32(LPC17_SYSCON_PCLKSEL0);
-		regval &= ~SYSCON_PCLKSEL0_CAN1_MASK;
-		regval |= (SYSCON_PCLKSEL_CCLK4 << SYSCON_PCLKSEL0_CAN1_SHIFT);
-		putreg32(regval, LPC17_SYSCON_PCLKSEL0);
-
-		lpc17_configgpio(GPIO_CAN1_RD);
-		lpc17_configgpio(GPIO_CAN1_TD);
-
-		putreg32(0x01,LPC17_CAN1_MOD);
-		putreg32(0x00,LPC17_CAN1_IER);
-		putreg32(0x00,LPC17_CAN1_GSR);
-		putreg32(0x02,LPC17_CAN1_CMR);
-		putreg32(0x49c009,LPC17_CAN1_BTR);
-		putreg32(0x00,LPC17_CAN1_MOD);
-		putreg32(0x01,LPC17_CAN1_IER);
-		putreg32(0x02,LPC17_CANAF_AFMR);
-
-		candev = &g_can1dev;
-	}
-#endif	
-#ifdef CONFIG_LPC17_CAN2	
-	if ( port ==2 )
-	{
-		regval  = getreg32(LPC17_SYSCON_PCONP);
-		regval |= SYSCON_PCONP_PCCAN2;
-		putreg32(regval, LPC17_SYSCON_PCONP);
-
-		regval  = getreg32(LPC17_SYSCON_PCLKSEL0);
-		regval &= ~SYSCON_PCLKSEL0_CAN2_MASK;
-		regval |= (SYSCON_PCLKSEL_CCLK4 << SYSCON_PCLKSEL0_CAN2_SHIFT);
-		putreg32(regval, LPC17_SYSCON_PCLKSEL0);
-
-		lpc17_configgpio(GPIO_CAN2_RD);
-		lpc17_configgpio(GPIO_CAN2_TD);
-
-		putreg32(0x01,LPC17_CAN2_MOD);
-		putreg32(0x00,LPC17_CAN2_IER);
-		putreg32(0x00,LPC17_CAN2_GSR);
-		putreg32(0x02,LPC17_CAN2_CMR);
-		putreg32(0x49c009,LPC17_CAN2_BTR);
-		putreg32(0x00,LPC17_CAN2_MOD);
-		putreg32(0x01,LPC17_CAN2_IER);
-		putreg32(0x02,LPC17_CANAF_AFMR);
-
-		candev = &g_can2dev;
-	}
-#endif	
-	irqrestore(flags);
-	return candev;
+  FAR struct can_dev_s *candev;
+  irqstate_t flags;
+  uint32_t regval;
+
+  canllvdbg("CAN%d\n",  port);
+
+  flags = irqsave();
+
+#ifdef CONFIG_LPC17_CAN1  
+  if (port == 1)
+    {
+      /* Enable power to the CAN module */
+
+      regval  = can_getcommon(LPC17_SYSCON_PCONP);
+      regval |= SYSCON_PCONP_PCCAN1;
+      can_putcommon(LPC17_SYSCON_PCONP, regval);
+
+      /* Enable clocking to the CAN module (not necessary... already done
+       * in low level clock configuration logic.
+       */
+
+      regval  = can_getcommon(LPC17_SYSCON_PCLKSEL0);
+      regval &= ~SYSCON_PCLKSEL0_CAN1_MASK;
+      regval |= (SYSCON_PCLKSEL_CCLK4 << SYSCON_PCLKSEL0_CAN1_SHIFT);
+      can_putcommon(LPC17_SYSCON_PCLKSEL0, regval);
+
+      /* Configure CAN GPIO pins */
+
+      lpc17_configgpio(GPIO_CAN1_RD);
+      lpc17_configgpio(GPIO_CAN1_TD);
+
+      candev = &g_can1dev;
+    }
+  else
+#endif
+#ifdef CONFIG_LPC17_CAN2  
+  if (port == 2)
+    {
+      /* Enable power to the CAN module */
+
+      regval  = can_getcommon(LPC17_SYSCON_PCONP);
+      regval |= SYSCON_PCONP_PCCAN2;
+      can_putcommon(LPC17_SYSCON_PCONP, regval);
+
+      /* Enable clocking to the CAN module (not necessary... already done
+       * in low level clock configuration logic.
+       */
+
+      regval  = can_getcommon(LPC17_SYSCON_PCLKSEL0);
+      regval &= ~SYSCON_PCLKSEL0_CAN2_MASK;
+      regval |= (SYSCON_PCLKSEL_CCLK4 << SYSCON_PCLKSEL0_CAN2_SHIFT);
+      can_putcommon(LPC17_SYSCON_PCLKSEL0, regval);
+
+      /* Configure CAN GPIO pins */
+
+      lpc17_configgpio(GPIO_CAN2_RD);
+      lpc17_configgpio(GPIO_CAN2_TD);
+
+      candev = &g_can2dev;
+   }
+ else
+#endif
+  {
+    candbg("Unsupported port: %d\n", port);
+    irqrestore(flags);
+    return NULL;
+  }
+
+  /* Then just perform a CAN reset operation */
+
+  can_reset(candev);
+  irqrestore(flags);
+  return candev;
 }
 #endif