Restructuring AVR serial drivers

git-svn-id: https://nuttx.svn.sourceforge.net/svnroot/nuttx/trunk@3693 7fd9a85b-ad96-42d3-883c-3090e2eb8679

6 files changed, 543 insertions, 401 deletions

diff --git a/nuttx/arch/avr/src/at90usb/at90usb_internal.h b/nuttx/arch/avr/src/at90usb/at90usb_internal.h
index 3d7c4e7dcf..856778c849 100644
--- a/nuttx/arch/avr/src/at90usb/at90usb_internal.h
+++ b/nuttx/arch/avr/src/at90usb/at90usb_internal.h
@@ -94,27 +94,6 @@ extern "C" {
 EXTERN void up_clkinitialize(void);
 
 /****************************************************************************
- * Name: usart_reset
- *
- * Description:
- *   Reset a USART.
- *
- ****************************************************************************/
-
-EXTERN void usart_reset(uintptr_t usart_base);
-
-/****************************************************************************
- * Name: usart_configure
- *
- * Description:
- *   Configure a USART as a RS-232 UART.
- *
- ****************************************************************************/
-
-void usart_configure(uintptr_t usart_base, uint32_t baud, unsigned int parity,
-                     unsigned int nbits, bool stop2);
-
-/****************************************************************************
  * Name: up_consoleinit
  *
  * Description:
diff --git a/nuttx/arch/avr/src/at90usb/at90usb_lowconsole.c b/nuttx/arch/avr/src/at90usb/at90usb_lowconsole.c
index f17d794177..3ec1b93321 100644
--- a/nuttx/arch/avr/src/at90usb/at90usb_lowconsole.c
+++ b/nuttx/arch/avr/src/at90usb/at90usb_lowconsole.c
@@ -1,7 +1,7 @@
 /******************************************************************************
  * arch/avr/src/at90usb/at90usb_lowconsole.c
  *
- *   Copyright (C) 2010 Gregory Nutt. All rights reserved.
+ *   Copyright (C) 2011 Gregory Nutt. All rights reserved.
  *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
  *
  * Redistribution and use in source and binary forms, with or without
@@ -67,6 +67,59 @@
 #  error "No CONFIG_USARTn_SERIAL_CONSOLE Setting"
 #endif
 
+/* Baud rate settings for normal and double speed settings  */
+
+#define AVR_NORMAL_UBRR1 \
+  (((BOARD_CPU_CLOCK / 16) + (CONFIG_USART1_BAUD / 2)) / (CONFIG_USART1_BAUD)) - 1)
+
+#define AVR_DBLSPEED_UBRR1 \
+  (((BOARD_CPU_CLOCK / 8) + (CONFIG_USART1_BAUD / 2)) / (CONFIG_USART1_BAUD)) - 1)
+
+/* Select normal or double speed baud settings.  This is a trade-off between the
+ * sampling rate and the accuracy of the divisor for high baud rates.
+ *
+ * As examples, consider:
+ *
+ *   BOARD_CPU_CLOCK=8MHz and BAUD=115200:
+ *     AVR_NORMAL_UBRR1 = 4 (rounded), actual baud = 125,000
+ *     AVR_DBLSPEED_UBRR1 = 9 (rounded), actual baud = 111,111
+ *
+ *   BOARD_CPU_CLOCK=8MHz and BAUD=9600:
+ *     AVR_NORMAL_UBRR1 = 52 (rounded), actual baud = 9615
+ *     AVR_DBLSPEED_UBRR1 = 104 (rounded), actual baud = 9615
+ */
+ 
+#undef HAVE_DOUBLE_SPEED
+#if BOARD_CPU_CLOCK <= 4000000
+#  if CONFIG_USART1_BAUD <= 9600
+#    define AVR_UBRR1 AVR_NORMAL_UBRR1
+#  else
+#    define AVR_UBRR1 AVR_DBLSPEED_UBRR1
+#    define HAVE_DOUBLE_SPEED 1
+#  endif
+#elif BOARD_CPU_CLOCK <= 8000000
+#  if CONFIG_USART1_BAUD <= 19200
+#    define AVR_UBRR1 AVR_NORMAL_UBRR1
+#  else
+#    define AVR_UBRR1 AVR_DBLSPEED_UBRR1
+#    define HAVE_DOUBLE_SPEED 1
+#  endif
+#elif BOARD_CPU_CLOCK <= 12000000
+#  if CONFIG_USART1_BAUD <= 28800
+#    define AVR_UBRR1 AVR_NORMAL_UBRR1
+#  else
+#    define AVR_UBRR1 AVR_DBLSPEED_UBRR1
+#    define HAVE_DOUBLE_SPEED 1
+#  endif
+#else
+#  if CONFIG_USART1_BAUD <= 38400
+#    define AVR_UBRR1 AVR_NORMAL_UBRR1
+#  else
+#    define AVR_UBRR1 AVR_DBLSPEED_UBRR1
+#    define HAVE_DOUBLE_SPEED 1
+#  endif
+#endif
+
 /******************************************************************************
  * Private Types
  ******************************************************************************/
@@ -88,26 +141,11 @@
  ******************************************************************************/
 
 /******************************************************************************
- * Name: usart_setbaudrate
- *
- * Description:
- *   Configure the USART baud rate.
- *
- ******************************************************************************/
-
-#ifdef HAVE_USART_DEVICE
-static void usart_setbaudrate(uintptr_t usart_base, uint32_t baudrate)
-{
-# warning "Missing logic"
-}
-#endif
-
-/******************************************************************************
  * Public Functions
  ******************************************************************************/
 
 /******************************************************************************
- * Name: usart_reset
+ * Name: usart1_reset
  *
  * Description:
  *   Reset a USART.
@@ -115,23 +153,22 @@ static void usart_setbaudrate(uintptr_t usart_base, uint32_t baudrate)
  ******************************************************************************/
 
 #ifdef HAVE_USART_DEVICE
-void usart_reset(uintptr_t usart_base)
+void usart1_reset(void)
 {
 # warning "Missing Logic"
 }
 #endif
 
 /******************************************************************************
- * Name: usart_configure
+ * Name: usart1_configure
  *
  * Description:
- *   Configure a USART as a RS-232 USART.
+ *   Configure USART1.
  *
  ******************************************************************************/
 
 #ifdef HAVE_USART_DEVICE
-void usart_configure(uintptr_t usart_base, uint32_t baud, unsigned int parity,
-                     unsigned int nbits, bool stop2)
+void usart1_configure(void)
 {
 # warning "Missing Logic"
 }
@@ -149,7 +186,9 @@ void usart_configure(uintptr_t usart_base, uint32_t baud, unsigned int parity,
 
 void up_consoleinit(void)
 {
-# warning "Missing Logic"
+#ifdef HAVE_SERIAL_CONSOLE
+  usart1_configure();
+#endif
 }
 
 /******************************************************************************
diff --git a/nuttx/arch/avr/src/at90usb/at90usb_serial.c b/nuttx/arch/avr/src/at90usb/at90usb_serial.c
index 939c707a78..a774954b4b 100644
--- a/nuttx/arch/avr/src/at90usb/at90usb_serial.c
+++ b/nuttx/arch/avr/src/at90usb/at90usb_serial.c
@@ -78,85 +78,60 @@
 
 #ifdef CONFIG_USE_SERIALDRIVER
 
-/* Which USART with be tty0/console and which tty1? */
-
 #if defined(CONFIG_USART1_SERIAL_CONSOLE)
 #  define CONSOLE_DEV     g_usart1port     /* USART1 is console */
-#  define TTYS0_DEV       g_usart1port     /* USART1 is ttyS0 */
 #endif
+#define TTYS0_DEV         g_usart1port     /* USART1 is ttyS0 */
 
 /****************************************************************************
  * Private Types
  ****************************************************************************/
 
-struct up_dev_s
-{
-  uintptr_t usartbase; /* Base address of USART registers */
-  uint32_t  baud;      /* Configured baud */
-  uint32_t  csr;       /* Saved channel status register contents */
-  uint8_t   irq;       /* IRQ associated with this USART */
-  uint8_t   parity;    /* 0=none, 1=odd, 2=even */
-  uint8_t   bits;      /* Number of bits (5, 6, 7 or 8) */
-  bool      stopbits2; /* true: Configure with 2 stop bits instead of 1 */
-};
-
 /****************************************************************************
  * Private Function Prototypes
  ****************************************************************************/
 
-static int  up_setup(struct uart_dev_s *dev);
-static void up_shutdown(struct uart_dev_s *dev);
-static int  up_attach(struct uart_dev_s *dev);
-static void up_detach(struct uart_dev_s *dev);
-static int  up_interrupt(int irq, void *context);
-static int  up_ioctl(struct file *filep, int cmd, unsigned long arg);
-static int  up_receive(struct uart_dev_s *dev, uint32_t *status);
-static void up_rxint(struct uart_dev_s *dev, bool enable);
-static bool up_rxavailable(struct uart_dev_s *dev);
-static void up_send(struct uart_dev_s *dev, int ch);
-static void up_txint(struct uart_dev_s *dev, bool enable);
-static bool up_txready(struct uart_dev_s *dev);
+static int  usart1_setup(struct uart_dev_s *dev);
+static void usart1_shutdown(struct uart_dev_s *dev);
+static int  usart1_attach(struct uart_dev_s *dev);
+static void usart1_detach(struct uart_dev_s *dev);
+static int  usart1_interrupt(int irq, void *context);
+static int  usart1_ioctl(struct file *filep, int cmd, unsigned long arg);
+static int  usart1_receive(struct uart_dev_s *dev, uint32_t *status);
+static void usart1_rxint(struct uart_dev_s *dev, bool enable);
+static bool usart1_rxavailable(struct uart_dev_s *dev);
+static void usart1_send(struct uart_dev_s *dev, int ch);
+static void usart1_txint(struct uart_dev_s *dev, bool enable);
+static bool usart1_txready(struct uart_dev_s *dev);
 
 /****************************************************************************
  * Private Variables
  ****************************************************************************/
 
-struct uart_ops_s g_uart_ops =
+struct uart_ops_s g_uart1_ops =
 {
-  .setup          = up_setup,
-  .shutdown       = up_shutdown,
-  .attach         = up_attach,
-  .detach         = up_detach,
-  .ioctl          = up_ioctl,
-  .receive        = up_receive,
-  .rxint          = up_rxint,
-  .rxavailable    = up_rxavailable,
-  .send           = up_send,
-  .txint          = up_txint,
-  .txready        = up_txready,
-  .txempty        = up_txready,
+  .setup          = usart1_setup,
+  .shutdown       = usart1_shutdown,
+  .attach         = usart1_attach,
+  .detach         = usart1_detach,
+  .ioctl          = usart1_ioctl,
+  .receive        = usart1_receive,
+  .rxint          = usart1_rxint,
+  .rxavailable    = usart1_rxavailable,
+  .send           = usart1_send,
+  .txint          = usart1_txint,
+  .txready        = usart1_txready,
+  .txempty        = usart1_txready,
 };
 
 /* I/O buffers */
 
-#ifdef CONFIG_AVR_USART1_RS232
 static char g_usart1rxbuffer[CONFIG_USART1_RXBUFSIZE];
 static char g_usart1txbuffer[CONFIG_USART1_TXBUFSIZE];
-#endif
 
-/* This describes the state of the AVR32 USART1 port. */
+/* This describes the state of the AT90USB USART1 port. */
 
 #ifdef CONFIG_AVR_USART1_RS232
-static struct up_dev_s g_usart1priv =
-{
-  .usartbase      = AVR_USART1_BASE,
-  .baud           = CONFIG_USART1_BAUD,
-  .irq            = AVR_IRQ_USART1,
-  .parity         = CONFIG_USART1_PARITY,
-  .bits           = CONFIG_USART1_BITS,
-  .stopbits2      = CONFIG_USART1_2STOP,
-};
-
 static uart_dev_t g_usart1port =
 {
   .recv     =
@@ -169,8 +144,7 @@ static uart_dev_t g_usart1port =
     .size   = CONFIG_USART1_TXBUFSIZE,
     .buffer = g_usart1txbuffer,
    },
-  .ops      = &g_uart_ops,
-  .priv     = &g_usart1priv,
+  .ops      = &g_uart1_ops,
 };
 #endif
 
@@ -179,43 +153,25 @@ static uart_dev_t g_usart1port =
  ****************************************************************************/
 
 /****************************************************************************
- * Name: up_serialin
- ****************************************************************************/
-
-static inline uint32_t up_serialin(struct up_dev_s *priv, int offset)
-{
-# warning "Missing logic"
-}
-
-/****************************************************************************
- * Name: up_serialout
- ****************************************************************************/
-
-static inline void up_serialout(struct up_dev_s *priv, int offset, uint32_t value)
-{
-# warning "Missing logic"
-}
-
-/****************************************************************************
- * Name: up_restoreusartint
+ * Name: usart1_restoreusartint
  ****************************************************************************/
 
-static void up_restoreusartint(struct up_dev_s *priv, uint32_t imr)
+static void usart1_restoreusartint(uint8_t imr)
 {
 # warning "Missing logic"
 }
 
 /****************************************************************************
- * Name: up_disableusartint
+ * Name: usart1_disableusartint
  ****************************************************************************/
 
-static inline void up_disableusartint(struct up_dev_s *priv, uint32_t *imr)
+static inline void usart1_disableusartint(uint8_t *imr)
 {
 # warning "Missing logic"
 }
 
 /****************************************************************************
- * Name: up_setup
+ * Name: usart1_setup
  *
  * Description:
  *   Configure the USART baud, bits, parity, etc. This method is called the
@@ -223,22 +179,20 @@ static inline void up_disableusartint(struct up_dev_s *priv, uint32_t *imr)
  *
  ****************************************************************************/
 
-static int up_setup(struct uart_dev_s *dev)
+static int usart1_setup(struct uart_dev_s *dev)
 {
 #ifndef CONFIG_SUPPRESS_UART_CONFIG
-  struct up_dev_s *priv = (struct up_dev_s*)dev->priv;
 
-  /* Configure the USART as an RS-232 UART */
+  /* Configure the USART1 */
 
-  usart_configure(priv->usartbase, priv->baud, priv->parity,
-                  priv->bits, priv->stopbits2);
+  usart1_configure();
 #endif
 
   return OK;
 }
 
 /****************************************************************************
- * Name: up_shutdown
+ * Name: usart1_shutdown
  *
  * Description:
  *   Disable the USART.  This method is called when the serial
@@ -246,17 +200,15 @@ static int up_setup(struct uart_dev_s *dev)
  *
  ****************************************************************************/
 
-static void up_shutdown(struct uart_dev_s *dev)
+static void usart1_shutdown(struct uart_dev_s *dev)
 {
-  struct up_dev_s *priv = (struct up_dev_s*)dev->priv;
-
   /* Reset, disable interrupts, and disable Rx and Tx */
 
-  usart_reset(priv->usartbase);
+  usart1_reset();
 }
 
 /****************************************************************************
- * Name: up_attach
+ * Name: usart1_attach
  *
  * Description:
  *   Configure the USART to operation in interrupt driven mode.  This method is
@@ -270,17 +222,17 @@ static void up_shutdown(struct uart_dev_s *dev)
  *
  ****************************************************************************/
 
-static int up_attach(struct uart_dev_s *dev)
+static int usart1_attach(struct uart_dev_s *dev)
 {
-  struct up_dev_s *priv = (struct up_dev_s*)dev->priv;
+  /* Attach the USART1 IRQs */
 
-  /* Attach the IRQ */
-
-  return irq_attach(priv->irq, up_interrupt);
+  return irq_attach(AT90USB_IRQ_U1RX, usart1_interrupt);
+  return irq_attach(AT90USB_IRQ_U1DRE, usart1_interrupt);
+  return irq_attach(AT90USB_IRQ_U1TX, usart1_interrupt);
 }
 
 /****************************************************************************
- * Name: up_detach
+ * Name: usart1_detach
  *
  * Description:
  *   Detach USART interrupts.  This method is called when the serial port is
@@ -289,15 +241,21 @@ static int up_attach(struct uart_dev_s *dev)
  *
  ****************************************************************************/
 
-static void up_detach(struct uart_dev_s *dev)
+static void usart1_detach(struct uart_dev_s *dev)
 {
-  struct up_dev_s *priv = (struct up_dev_s*)dev->priv;
+  /* Disable USART1 interrupts */
+
 # warning "Missing logic"
-  irq_detach(priv->irq);
+
+  /* Detach USART1 interrupts */
+
+  return irq_deattach(AT90USB_IRQ_U1RX);
+  return irq_deattach(AT90USB_IRQ_U1DRE);
+  return irq_deattach(AT90USB_IRQ_U1TX);
 }
 
 /****************************************************************************
- * Name: up_interrupt
+ * Name: usart1_interrupt
  *
  * Description:
  *   This is the USART interrupt handler.  It will be invoked when an
@@ -308,27 +266,12 @@ static void up_detach(struct uart_dev_s *dev)
  *
  ****************************************************************************/
 
-static int up_interrupt(int irq, void *context)
+static int usart1_interrupt(int irq, void *context)
 {
-  struct uart_dev_s *dev = NULL;
-  struct up_dev_s   *priv;
-  uint32_t           csr;
+  uint8_t           csr;
   int                passes;
   bool               handled;
 
-#ifdef CONFIG_AVR_USART1_RS232
-  if (g_usart1priv.irq == irq)
-    {
-      dev = &g_usart1port;
-    }
-  else
-#endif
-    {
-      PANIC(OSERR_INTERNAL);
-    }
-  priv = (struct up_dev_s*)dev->priv;
-  DEBUGASSERT(priv);
-
   /* Loop until there are no characters to be transferred or,
    * until we have been looping for a long time.
    */
@@ -363,27 +306,17 @@ static int up_interrupt(int irq, void *context)
 }
 
 /****************************************************************************
- * Name: up_ioctl
+ * Name: usart1_ioctl
  *
  * Description:
  *   All ioctl calls will be routed through this method
  *
  ****************************************************************************/
 
-static int up_ioctl(struct file *filep, int cmd, unsigned long arg)
+static int usart1_ioctl(struct file *filep, int cmd, unsigned long arg)
 {
 #if 0 /* Reserved for future growth */
-  struct inode      *inode;
-  struct uart_dev_s *dev;
-  struct up_dev_s   *priv;
-  int                ret = OK;
-
-  DEBUGASSERT(filep, filep->f_inode);
-  inode = filep->f_inode;
-  dev   = inode->i_private;
-
-  DEBUGASSERT(dev, dev->priv)
-  priv = (struct up_dev_s*)dev->priv;
+  int  ret = OK;
 
   switch (cmd)
     {
@@ -402,7 +335,7 @@ static int up_ioctl(struct file *filep, int cmd, unsigned long arg)
 }
 
 /****************************************************************************
- * Name: up_receive
+ * Name: usart1_receive
  *
  * Description:
  *   Called (usually) from the interrupt level to receive one
@@ -411,10 +344,8 @@ static int up_ioctl(struct file *filep, int cmd, unsigned long arg)
  *
  ****************************************************************************/
 
-static int up_receive(struct uart_dev_s *dev, uint32_t *status)
+static int usart1_receive(struct uart_dev_s *dev, uint32_t *status)
 {
-  struct up_dev_s *priv = (struct up_dev_s*)dev->priv;
-
   /* Get the Rx byte.  The USART Rx interrupt flag is cleared by side effect
    * when reading the received character.
    */
@@ -435,17 +366,15 @@ static int up_receive(struct uart_dev_s *dev, uint32_t *status)
 }
 
 /****************************************************************************
- * Name: up_rxint
+ * Name: usart1_rxint
  *
  * Description:
  *   Call to enable or disable RX interrupts
  *
  ****************************************************************************/
 
-static void up_rxint(struct uart_dev_s *dev, bool enable)
+static void usart1_rxint(struct uart_dev_s *dev, bool enable)
 {
-  struct up_dev_s *priv = (struct up_dev_s*)dev->priv;
-
   if (enable)
     {
       /* Receive an interrupt when their is anything in the Rx data register (or an Rx
@@ -463,46 +392,43 @@ static void up_rxint(struct uart_dev_s *dev, bool enable)
 }
 
 /****************************************************************************
- * Name: up_rxavailable
+ * Name: usart1_rxavailable
  *
  * Description:
  *   Return true if the receive register is not empty
  *
  ****************************************************************************/
 
-static bool up_rxavailable(struct uart_dev_s *dev)
+static bool usart1_rxavailable(struct uart_dev_s *dev)
 {
-  struct up_dev_s *priv = (struct up_dev_s*)dev->priv;
 # warning "Missing logic"
   return 0;
 }
 
 /****************************************************************************
- * Name: up_send
+ * Name: usart1_send
  *
  * Description:
  *   This method will send one byte on the USART.
  *
  ****************************************************************************/
 
-static void up_send(struct uart_dev_s *dev, int ch)
+static void usart1_send(struct uart_dev_s *dev, int ch)
 {
-  struct up_dev_s *priv = (struct up_dev_s*)dev->priv;
 # warning "Missing logic"
   return 0;
 }
 
 /****************************************************************************
- * Name: up_txint
+ * Name: usart1_txint
  *
  * Description:
  *   Call to enable or disable TX interrupts
  *
  ****************************************************************************/
 
-static void up_txint(struct uart_dev_s *dev, bool enable)
+static void usart1_txint(struct uart_dev_s *dev, bool enable)
 {
-  struct up_dev_s *priv = (struct up_dev_s*)dev->priv;
   irqstate_t flags;
 
   flags = irqsave();
@@ -530,16 +456,15 @@ static void up_txint(struct uart_dev_s *dev, bool enable)
 }
 
 /****************************************************************************
- * Name: up_txready
+ * Name: usart1_txready
  *
  * Description:
  *   Return true if the tranmsit data register is empty
  *
  ****************************************************************************/
 
-static bool up_txready(struct uart_dev_s *dev)
+static bool usart1_txready(struct uart_dev_s *dev)
 {
-  struct up_dev_s *priv = (struct up_dev_s*)dev->priv;
 # warning "Missing logic"
   return 0;
 }
@@ -554,9 +479,7 @@ static bool up_txready(struct uart_dev_s *dev)
  * Description:
  *   Performs the low level USART initialization early in debug so that the
  *   serial console will be available during bootup.  This must be called
- *   before up_serialinit.  NOTE:  This function depends on GPIO pin
- *   configuration performed in up_consoleinit() and main clock iniialization
- *   performed in up_clkinitialize().
+ *   before up_serialinit.
  *
  ****************************************************************************/
 
@@ -564,16 +487,13 @@ void up_earlyserialinit(void)
 {
   /* Disable all USARTS */
 
-  up_disableusartint(TTYS0_DEV.priv, NULL);
-#ifdef TTYS1_DEV
-  up_disableusartint(TTYS1_DEV.priv, NULL);
-#endif
+  up_disableusartint(NULL);
 
   /* Configuration whichever one is the console */
 
 #ifdef HAVE_SERIAL_CONSOLE
   CONSOLE_DEV.isconsole = true;
-  up_setup(&CONSOLE_DEV);
+  usart1_setup(&CONSOLE_DEV);
 #endif
 }
 
@@ -613,8 +533,7 @@ void up_serialinit(void)
 int up_putc(int ch)
 {
 #ifdef HAVE_SERIAL_CONSOLE
-  struct up_dev_s *priv = (struct up_dev_s*)CONSOLE_DEV.priv;
-  uint32_t imr;
+  uint8_t imr;
 
   up_disableusartint(priv, &imr);
 
diff --git a/nuttx/arch/avr/src/atmega/atmega_internal.h b/nuttx/arch/avr/src/atmega/atmega_internal.h
index 6a4b2056c6..339db59010 100644
--- a/nuttx/arch/avr/src/atmega/atmega_internal.h
+++ b/nuttx/arch/avr/src/atmega/atmega_internal.h
@@ -94,25 +94,26 @@ extern "C" {
 EXTERN void up_clkinitialize(void);
 
 /****************************************************************************
- * Name: usart_reset
+ * Name: usart0_reset and usart1_reset
  *
  * Description:
- *   Reset a USART.
+ *   Reset USART0 or USART1.
  *
  ****************************************************************************/
 
-EXTERN void usart_reset(uintptr_t usart_base);
+EXTERN void usart0_reset(void);
+EXTERN void usart1_reset(void);
 
 /****************************************************************************
- * Name: usart_configure
+ * Name: usart0_configure and usart1_configure
  *
  * Description:
- *   Configure a USART as a RS-232 UART.
+ *   Configure USART0 or USART1.
  *
  ****************************************************************************/
 
-void usart_configure(uintptr_t usart_base, uint32_t baud, unsigned int parity,
-                     unsigned int nbits, bool stop2);
+EXTERN void usart0_configure(void);
+EXTERN void usart1_configure(void);
 
 /****************************************************************************
  * Name: up_consoleinit
diff --git a/nuttx/arch/avr/src/atmega/atmega_lowconsole.c b/nuttx/arch/avr/src/atmega/atmega_lowconsole.c
index a7ed60c9b8..f841c9d781 100644
--- a/nuttx/arch/avr/src/atmega/atmega_lowconsole.c
+++ b/nuttx/arch/avr/src/atmega/atmega_lowconsole.c
@@ -93,50 +93,48 @@
  ******************************************************************************/
 
 /******************************************************************************
- * Name: usart_setbaudrate
+ * Public Functions
+ ******************************************************************************/
+
+/****************************************************************************
+ * Name: usart0_reset and usart1_reset
  *
  * Description:
- *   Configure the USART baud rate.
+ *   Reset USART0 or USART1.
  *
- ******************************************************************************/
+ ****************************************************************************/
 
-#ifdef HAVE_USART_DEVICE
-static void usart_setbaudrate(uintptr_t usart_base, uint32_t baudrate)
+#ifdef CONFIG_ATMEGA_USART0
+void usart0_reset(void)
 {
 # warning "Missing logic"
 }
 #endif
 
-/******************************************************************************
- * Public Functions
- ******************************************************************************/
+#ifdef CONFIG_ATMEGA_USART1
+void usart1_reset(void)
+{
+# warning "Missing logic"
+}
+#endif
 
-/******************************************************************************
- * Name: usart_reset
+/****************************************************************************
+ * Name: usart0_configure and usart1_configure
  *
  * Description:
- *   Reset a USART.
+ *   Configure USART0 or USART1.
  *
- ******************************************************************************/
+ ****************************************************************************/
 
-#ifdef HAVE_USART_DEVICE
-void usart_reset(uintptr_t usart_base)
+#ifdef CONFIG_AVR_USART0
+void usart0_configure(void)
 {
 # warning "Missing logic"
 }
 #endif
 
-/******************************************************************************
- * Name: usart_configure
- *
- * Description:
- *   Configure a USART as a RS-232 USART.
- *
- ******************************************************************************/
-
-#ifdef HAVE_USART_DEVICE
-void usart_configure(uintptr_t usart_base, uint32_t baud, unsigned int parity,
-                     unsigned int nbits, bool stop2)
+#ifdef CONFIG_AVR_USART1
+void usart1_configure(void)
 {
 # warning "Missing logic"
 }
@@ -154,7 +152,13 @@ void usart_configure(uintptr_t usart_base, uint32_t baud, unsigned int parity,
 
 void up_consoleinit(void)
 {
-# warning "Missing logic"
+#ifdef HAVE_SERIAL_CONSOLE
+#  if defined(CONFIG_USART0_SERIAL_CONSOLE)
+  usart0_configure();
+#  elif defined(CONFIG_USART1_SERIAL_CONSOLE)
+  usart1_configure();
+#  endif
+#endif
 }
 
 /******************************************************************************
@@ -168,7 +172,11 @@ void up_consoleinit(void)
 void up_lowputc(char ch)
 {
 #ifdef HAVE_SERIAL_CONSOLE
-# warning "Missing logic"
+#  if defined(CONFIG_USART0_SERIAL_CONSOLE)
+#    warning "Missing logic"
+#  elif defined(CONFIG_USART1_SERIAL_CONSOLE)
+#    warning "Missing logic"
+#  endif
 #endif
 }
 
diff --git a/nuttx/arch/avr/src/atmega/atmega_serial.c b/nuttx/arch/avr/src/atmega/atmega_serial.c
index 7b5e02bd93..4d3b5a23cb 100644
--- a/nuttx/arch/avr/src/atmega/atmega_serial.c
+++ b/nuttx/arch/avr/src/atmega/atmega_serial.c
@@ -83,7 +83,7 @@
 #if defined(CONFIG_USART0_SERIAL_CONSOLE)
 #  define CONSOLE_DEV     g_usart0port     /* USART0 is console */
 #  define TTYS0_DEV       g_usart0port     /* USART0 is ttyS0 */
-#  ifdef CONFIG_AVR_USART1_RS232
+#  ifdef CONFIG_AVR_USART1
 #    define TTYS1_DEV     g_usart1port     /* USART1 is ttyS1 */
 #  else
 #    undef TTYS1_DEV                       /* No ttyS1 */
@@ -91,7 +91,7 @@
 #elif defined(CONFIG_USART1_SERIAL_CONSOLE)
 #  define CONSOLE_DEV     g_usart1port     /* USART1 is console */
 #  define TTYS0_DEV       g_usart1port     /* USART1 is ttyS0 */
-#  ifdef CONFIG_AVR_USART0_RS232
+#  ifdef CONFIG_AVR_USART0
 #    define TTYS1_DEV     g_usart0port     /* USART0 is ttyS1 */
 #  else
 #    undef TTYS1_DEV                       /* No ttyS1 */
@@ -102,77 +102,69 @@
  * Private Types
  ****************************************************************************/
 
-struct up_dev_s
-{
-  uintptr_t usartbase; /* Base address of USART registers */
-  uint32_t  baud;      /* Configured baud */
-  uint32_t  csr;       /* Saved channel status register contents */
-  uint8_t   irq;       /* IRQ associated with this USART */
-  uint8_t   parity;    /* 0=none, 1=odd, 2=even */
-  uint8_t   bits;      /* Number of bits (5, 6, 7 or 8) */
-  bool      stopbits2; /* true: Configure with 2 stop bits instead of 1 */
-};
-
 /****************************************************************************
  * Private Function Prototypes
  ****************************************************************************/
 
-static int  up_setup(struct uart_dev_s *dev);
-static void up_shutdown(struct uart_dev_s *dev);
-static int  up_attach(struct uart_dev_s *dev);
-static void up_detach(struct uart_dev_s *dev);
-static int  up_interrupt(int irq, void *context);
-static int  up_ioctl(struct file *filep, int cmd, unsigned long arg);
-static int  up_receive(struct uart_dev_s *dev, uint32_t *status);
-static void up_rxint(struct uart_dev_s *dev, bool enable);
-static bool up_rxavailable(struct uart_dev_s *dev);
-static void up_send(struct uart_dev_s *dev, int ch);
-static void up_txint(struct uart_dev_s *dev, bool enable);
-static bool up_txready(struct uart_dev_s *dev);
+#ifdef CONFIG_AVR_USART0
+static int  usart0_setup(struct uart_dev_s *dev);
+static void usart0_shutdown(struct uart_dev_s *dev);
+static int  usart0_attach(struct uart_dev_s *dev);
+static void usart0_detach(struct uart_dev_s *dev);
+static int  usart0_interrupt(int irq, void *context);
+static int  usart0_ioctl(struct file *filep, int cmd, unsigned long arg);
+static int  usart0_receive(struct uart_dev_s *dev, uint32_t *status);
+static void usart0_rxint(struct uart_dev_s *dev, bool enable);
+static bool usart0_rxavailable(struct uart_dev_s *dev);
+static void usart0_send(struct uart_dev_s *dev, int ch);
+static void usart0_txint(struct uart_dev_s *dev, bool enable);
+static bool usart0_txready(struct uart_dev_s *dev);
+#endif
+
+#ifdef CONFIG_AVR_USART1
+static int  usart1_setup(struct uart_dev_s *dev);
+static void usart1_shutdown(struct uart_dev_s *dev);
+static int  usart1_attach(struct uart_dev_s *dev);
+static void usart1_detach(struct uart_dev_s *dev);
+static int  usart1_interrupt(int irq, void *context);
+static int  usart1_ioctl(struct file *filep, int cmd, unsigned long arg);
+static int  usart1_receive(struct uart_dev_s *dev, uint32_t *status);
+static void usart1_rxint(struct uart_dev_s *dev, bool enable);
+static bool usart1_rxavailable(struct uart_dev_s *dev);
+static void usart1_send(struct uart_dev_s *dev, int ch);
+static void usart1_txint(struct uart_dev_s *dev, bool enable);
+static bool usart1_txready(struct uart_dev_s *dev);
+#endif
 
 /****************************************************************************
  * Private Variables
  ****************************************************************************/
 
-struct uart_ops_s g_uart_ops =
-{
-  .setup          = up_setup,
-  .shutdown       = up_shutdown,
-  .attach         = up_attach,
-  .detach         = up_detach,
-  .ioctl          = up_ioctl,
-  .receive        = up_receive,
-  .rxint          = up_rxint,
-  .rxavailable    = up_rxavailable,
-  .send           = up_send,
-  .txint          = up_txint,
-  .txready        = up_txready,
-  .txempty        = up_txready,
+/* USART0 operations */
+
+#ifdef CONFIG_AVR_USART0
+struct uart_ops_s g_usart0_ops =
+{
+  .setup          = usart0_setup,
+  .shutdown       = usart0_shutdown,
+  .attach         = usart0_attach,
+  .detach         = usart0_detach,
+  .ioctl          = usart0_ioctl,
+  .receive        = usart0_receive,
+  .rxint          = usart0_rxint,
+  .rxavailable    = usart0_rxavailable,
+  .send           = usart0_send,
+  .txint          = usart0_txint,
+  .txready        = usart0_txready,
+  .txempty        = usart0_txready,
 };
 
-/* I/O buffers */
+/* USART0 I/O buffers */
 
-#ifdef CONFIG_AVR_USART0_RS232
 static char g_usart0rxbuffer[CONFIG_USART0_RXBUFSIZE];
 static char g_usart0txbuffer[CONFIG_USART0_TXBUFSIZE];
-#endif
-#ifdef CONFIG_AVR_USART1_RS232
-static char g_usart1rxbuffer[CONFIG_USART1_RXBUFSIZE];
-static char g_usart1txbuffer[CONFIG_USART1_TXBUFSIZE];
-#endif
 
-/* This describes the state of the AVR32 USART0 ports. */
-
-#ifdef CONFIG_AVR_USART0_RS232
-static struct up_dev_s g_usart0priv =
-{
-  .usartbase      = AVR_USART0_BASE,
-  .baud           = CONFIG_USART0_BAUD,
-  .irq            = AVR_IRQ_USART0,
-  .parity         = CONFIG_USART0_PARITY,
-  .bits           = CONFIG_USART0_BITS,
-  .stopbits2      = CONFIG_USART0_2STOP,
-};
+/* This describes the state of the ATMega USART0 port. */
 
 static uart_dev_t g_usart0port =
 {
@@ -186,24 +178,36 @@ static uart_dev_t g_usart0port =
     .size   = CONFIG_USART0_TXBUFSIZE,
     .buffer = g_usart0txbuffer,
   },
-  .ops      = &g_uart_ops,
-  .priv     = &g_usart0priv,
+  .ops      = &g_usart0_ops,
 };
 #endif
 
-/* This describes the state of the AVR32 USART1 port. */
+/* USART1 operations */
 
-#ifdef CONFIG_AVR_USART1_RS232
-static struct up_dev_s g_usart1priv =
+#ifdef CONFIG_AVR_USART1
+struct uart_ops_s g_usart1_ops =
 {
-  .usartbase      = AVR_USART1_BASE,
-  .baud           = CONFIG_USART1_BAUD,
-  .irq            = AVR_IRQ_USART1,
-  .parity         = CONFIG_USART1_PARITY,
-  .bits           = CONFIG_USART1_BITS,
-  .stopbits2      = CONFIG_USART1_2STOP,
+  .setup          = usart1_setup,
+  .shutdown       = usart1_shutdown,
+  .attach         = usart1_attach,
+  .detach         = usart1_detach,
+  .ioctl          = usart1_ioctl,
+  .receive        = usart1_receive,
+  .rxint          = usart1_rxint,
+  .rxavailable    = usart1_rxavailable,
+  .send           = usart1_send,
+  .txint          = usart1_txint,
+  .txready        = usart1_txready,
+  .txempty        = usart1_txready,
 };
 
+/* USART 1 I/O buffers */
+
+static char g_usart1rxbuffer[CONFIG_USART1_RXBUFSIZE];
+static char g_usart1txbuffer[CONFIG_USART1_TXBUFSIZE];
+
+/* This describes the state of the ATMega USART1 port. */
+
 static uart_dev_t g_usart1port =
 {
   .recv     =
@@ -216,8 +220,7 @@ static uart_dev_t g_usart1port =
     .size   = CONFIG_USART1_TXBUFSIZE,
     .buffer = g_usart1txbuffer,
    },
-  .ops      = &g_uart_ops,
-  .priv     = &g_usart1priv,
+  .ops      = &g_usart1_ops,
 };
 #endif
 
@@ -226,43 +229,43 @@ static uart_dev_t g_usart1port =
  ****************************************************************************/
 
 /****************************************************************************
- * Name: up_serialin
+ * Name: usart0/1_restoreusartint
  ****************************************************************************/
 
-static inline uint32_t up_serialin(struct up_dev_s *priv, int offset)
+#ifdef CONFIG_AVR_USART0
+static void usart0_restoreusartint(uint8_t imr)
 {
 # warning "Missing logic"
 }
+#endif
 
-/****************************************************************************
- * Name: up_serialout
- ****************************************************************************/
-
-static inline void up_serialout(struct up_dev_s *priv, int offset, uint32_t value)
+#ifdef CONFIG_AVR_USART1
+static void usart1_restoreusartint(uint8_t imr)
 {
 # warning "Missing logic"
 }
+#endif
 
 /****************************************************************************
- * Name: up_restoreusartint
+ * Name: usart0/1_disableusartint
  ****************************************************************************/
 
-static void up_restoreusartint(struct up_dev_s *priv, uint32_t imr)
+#ifdef CONFIG_AVR_USART0
+static inline void usart0_disableusartint(uint8_t *imr)
 {
 # warning "Missing logic"
 }
+#endif
 
-/****************************************************************************
- * Name: up_disableusartint
- ****************************************************************************/
-
-static inline void up_disableusartint(struct up_dev_s *priv, uint32_t *imr)
+#ifdef CONFIG_AVR_USART1
+static inline void usart1_disableusartint(uint8_t *imr)
 {
 # warning "Missing logic"
 }
+#endif
 
 /****************************************************************************
- * Name: up_setup
+ * Name: usart0/1_setup
  *
  * Description:
  *   Configure the USART baud, bits, parity, etc. This method is called the
@@ -270,22 +273,34 @@ static inline void up_disableusartint(struct up_dev_s *priv, uint32_t *imr)
  *
  ****************************************************************************/
 
-static int up_setup(struct uart_dev_s *dev)
+#ifdef CONFIG_AVR_USART0
+static int usart0_setup(struct uart_dev_s *dev)
 {
 #ifndef CONFIG_SUPPRESS_UART_CONFIG
-  struct up_dev_s *priv = (struct up_dev_s*)dev->priv;
+  /* Configure the USART as an RS-232 UART */
 
+  usart0_configure();
+#endif
+
+  return OK;
+}
+#endif
+
+#ifdef CONFIG_AVR_USART1
+static int usart1_setup(struct uart_dev_s *dev)
+{
+#ifndef CONFIG_SUPPRESS_UART_CONFIG
   /* Configure the USART as an RS-232 UART */
 
-  usart_configure(priv->usartbase, priv->baud, priv->parity,
-                  priv->bits, priv->stopbits2);
+  usart1_configure();
 #endif
 
   return OK;
 }
+#endif
 
 /****************************************************************************
- * Name: up_shutdown
+ * Name: usart0/1_shutdown
  *
  * Description:
  *   Disable the USART.  This method is called when the serial
@@ -293,17 +308,26 @@ static int up_setup(struct uart_dev_s *dev)
  *
  ****************************************************************************/
 
-static void up_shutdown(struct uart_dev_s *dev)
+#ifdef CONFIG_AVR_USART0
+static void usart0_shutdown(struct uart_dev_s *dev)
 {
-  struct up_dev_s *priv = (struct up_dev_s*)dev->priv;
+  /* Reset, disable interrupts, and disable Rx and Tx */
+
+  usart0_reset();
+}
+#endif
 
+#ifdef CONFIG_AVR_USART1
+static void usart1_shutdown(struct uart_dev_s *dev)
+{
   /* Reset, disable interrupts, and disable Rx and Tx */
 
-  usart_reset(priv->usartbase);
+  usart1_reset();
 }
+#endif
 
 /****************************************************************************
- * Name: up_attach
+ * Name: usart0/1_attach
  *
  * Description:
  *   Configure the USART to operation in interrupt driven mode.  This method is
@@ -317,17 +341,30 @@ static void up_shutdown(struct uart_dev_s *dev)
  *
  ****************************************************************************/
 
-static int up_attach(struct uart_dev_s *dev)
+#ifdef CONFIG_AVR_USART0
+static int usart0_attach(struct uart_dev_s *dev)
 {
-  struct up_dev_s *priv = (struct up_dev_s*)dev->priv;
+  /* Attach the USART0 IRQs */
 
-  /* Attach the IRQ */
+  return irq_attach(ATMEGA_IRQ_U0RX, usart0_interrupt);
+  return irq_attach(ATMEGA_IRQ_U0DRE, usart0_interrupt);
+  return irq_attach(ATMEGA_IRQ_U0TX, usart0_interrupt);
+}
+#endif
+
+#ifdef CONFIG_AVR_USART0
+static int usart0_attach(struct uart_dev_s *dev)
+{
+  /* Attach the USART0 IRQs */
 
-  return irq_attach(priv->irq, up_interrupt);
+  return irq_attach(ATMEGA_IRQ_U1RX, usart1_interrupt);
+  return irq_attach(ATMEGA_IRQ_U1DRE, usart1_interrupt);
+  return irq_attach(ATMEGA_IRQ_U1TX, usart1_interrupt);
 }
+#endif
 
 /****************************************************************************
- * Name: up_detach
+ * Name: usart0/1_detach
  *
  * Description:
  *   Detach USART interrupts.  This method is called when the serial port is
@@ -336,15 +373,36 @@ static int up_attach(struct uart_dev_s *dev)
  *
  ****************************************************************************/
 
-static void up_detach(struct uart_dev_s *dev)
+#ifdef CONFIG_AVR_USART0
+static void usart0_detach(struct uart_dev_s *dev)
 {
-  struct up_dev_s *priv = (struct up_dev_s*)dev->priv;
+  /* Disable all USART0 interrupts */
 # warning "Missing logic"
-  irq_detach(priv->irq);
+
+  /* Detach the USART0 IRQs */
+
+  return irq_detach(ATMEGA_IRQ_U0RX);
+  return irq_detach(ATMEGA_IRQ_U0DRE);
+  return irq_detach(ATMEGA_IRQ_U0TX);
 }
+#endif
+
+#ifdef CONFIG_AVR_USART1
+static void usart1_detach(struct uart_dev_s *dev)
+{
+  /* Disable all USART0 interrupts */
+# warning "Missing logic"
+
+  /* Detach the USART0 IRQs */
+
+  return irq_deattach(ATMEGA_IRQ_U1RX);
+  return irq_deattach(ATMEGA_IRQ_U1DRE);
+  return irq_deattach(ATMEGA_IRQ_U1TX);
+}
+#endif
 
 /****************************************************************************
- * Name: up_interrupt
+ * Name: usart0/1_interrupt
  *
  * Description:
  *   This is the USART interrupt handler.  It will be invoked when an
@@ -355,33 +413,53 @@ static void up_detach(struct uart_dev_s *dev)
  *
  ****************************************************************************/
 
-static int up_interrupt(int irq, void *context)
+#ifdef CONFIG_AVR_USART0
+static int usart0_interrupt(int irq, void *context)
 {
-  struct uart_dev_s *dev = NULL;
-  struct up_dev_s   *priv;
-  uint32_t           csr;
-  int                passes;
-  bool               handled;
+  uint8_t csr;
+  int     passes;
+  bool    handled;
 
-#ifdef CONFIG_AVR_USART0_RS232
-  if (g_usart0priv.irq == irq)
-    {
-      dev = &g_usart0port;
-    }
-  else
-#endif
-#ifdef CONFIG_AVR_USART1_RS232
-  if (g_usart1priv.irq == irq)
+  /* Loop until there are no characters to be transferred or,
+   * until we have been looping for a long time.
+   */
+
+  handled = true;
+  for (passes = 0; passes < 256 && handled; passes++)
     {
-      dev = &g_usart1port;
+      handled = false;
+
+# warning "Missing logic"
+      /* Handle incoming, receive bytes (with or without timeout) */
+
+# warning "Missing logic"
+        {
+           /* Received data ready... process incoming bytes */
+
+           uart_recvchars(dev);
+           handled = true;
+        }
+
+      /* Handle outgoing, transmit bytes */
+
+# warning "Missing logic"
+        {
+           /* Transmit data regiser empty ... process outgoing bytes */
+
+           uart_xmitchars(dev);
+           handled = true;
+        }
     }
-  else
+    return OK;
+}
 #endif
-    {
-      PANIC(OSERR_INTERNAL);
-    }
-  priv = (struct up_dev_s*)dev->priv;
-  DEBUGASSERT(priv);
+
+#ifdef CONFIG_AVR_USART1
+static int usart1_interrupt(int irq, void *context)
+{
+  uint8_t csr;
+  int     passes;
+  bool    handled;
 
   /* Loop until there are no characters to be transferred or,
    * until we have been looping for a long time.
@@ -415,29 +493,44 @@ static int up_interrupt(int irq, void *context)
     }
     return OK;
 }
+#endif
 
 /****************************************************************************
- * Name: up_ioctl
+ * Name: usart0/1_ioctl
  *
  * Description:
  *   All ioctl calls will be routed through this method
  *
  ****************************************************************************/
 
-static int up_ioctl(struct file *filep, int cmd, unsigned long arg)
+#ifdef CONFIG_AVR_USART0
+static int usart0_ioctl(struct file *filep, int cmd, unsigned long arg)
 {
 #if 0 /* Reserved for future growth */
-  struct inode      *inode;
-  struct uart_dev_s *dev;
-  struct up_dev_s   *priv;
-  int                ret = OK;
+  int ret = OK;
+
+  switch (cmd)
+    {
+    case xxx: /* Add commands here */
+      break;
 
-  DEBUGASSERT(filep, filep->f_inode);
-  inode = filep->f_inode;
-  dev   = inode->i_private;
+    default:
+      ret = -ENOTTY;
+      break;
+    }
+
+  return ret;
+#else
+  return -ENOTTY;
+#endif
+}
+#endif
 
-  DEBUGASSERT(dev, dev->priv)
-  priv = (struct up_dev_s*)dev->priv;
+#ifdef CONFIG_AVR_USART1
+static int usart1_ioctl(struct file *filep, int cmd, unsigned long arg)
+{
+#if 0 /* Reserved for future growth */
+  int ret = OK;
 
   switch (cmd)
     {
@@ -454,9 +547,10 @@ static int up_ioctl(struct file *filep, int cmd, unsigned long arg)
   return -ENOTTY;
 #endif
 }
+#endif
 
 /****************************************************************************
- * Name: up_receive
+ * Name: usart0/1_receive
  *
  * Description:
  *   Called (usually) from the interrupt level to receive one
@@ -465,10 +559,32 @@ static int up_ioctl(struct file *filep, int cmd, unsigned long arg)
  *
  ****************************************************************************/
 
-static int up_receive(struct uart_dev_s *dev, uint32_t *status)
+#ifdef CONFIG_AVR_USART0
+static int usart0_receive(struct uart_dev_s *dev, uint32_t *status)
 {
-  struct up_dev_s *priv = (struct up_dev_s*)dev->priv;
+  /* Get the Rx byte.  The USART Rx interrupt flag is cleared by side effect
+   * when reading the received character.
+   */
+
+# warning "Missing logic"
+
+  /* Return status information */
+
+  if (status)
+    {
+# warning "Missing logic"
+    }
 
+  /* Then return the actual received byte */
+
+# warning "Missing logic"
+  return 0;
+}
+#endif
+
+#ifdef CONFIG_AVR_USART1
+static int usart1_receive(struct uart_dev_s *dev, uint32_t *status)
+{
   /* Get the Rx byte.  The USART Rx interrupt flag is cleared by side effect
    * when reading the received character.
    */
@@ -487,19 +603,39 @@ static int up_receive(struct uart_dev_s *dev, uint32_t *status)
 # warning "Missing logic"
   return 0;
 }
+#endif
 
 /****************************************************************************
- * Name: up_rxint
+ * Name: usart0/1_rxint
  *
  * Description:
  *   Call to enable or disable RX interrupts
  *
  ****************************************************************************/
 
-static void up_rxint(struct uart_dev_s *dev, bool enable)
+#ifdef CONFIG_AVR_USART0
+static void usart0_rxint(struct uart_dev_s *dev, bool enable)
 {
-  struct up_dev_s *priv = (struct up_dev_s*)dev->priv;
+  if (enable)
+    {
+      /* Receive an interrupt when their is anything in the Rx data register (or an Rx
+       * timeout occurs).
+       */
 
+#ifndef CONFIG_SUPPRESS_SERIAL_INTS
+# warning "Missing logic"
+#endif
+    }
+  else
+    {
+# warning "Missing logic"
+    }
+}
+#endif
+
+#ifdef CONFIG_AVR_USART1
+static void usart1_rxint(struct uart_dev_s *dev, bool enable)
+{
   if (enable)
     {
       /* Receive an interrupt when their is anything in the Rx data register (or an Rx
@@ -515,48 +651,97 @@ static void up_rxint(struct uart_dev_s *dev, bool enable)
 # warning "Missing logic"
     }
 }
+#endif
 
 /****************************************************************************
- * Name: up_rxavailable
+ * Name: usart0/1_rxavailable
  *
  * Description:
  *   Return true if the receive register is not empty
  *
  ****************************************************************************/
 
-static bool up_rxavailable(struct uart_dev_s *dev)
+#ifdef CONFIG_AVR_USART0
+static bool usart0_rxavailable(struct uart_dev_s *dev)
 {
-  struct up_dev_s *priv = (struct up_dev_s*)dev->priv;
 # warning "Missing logic"
   return 0;
 }
+#endif
+
+#ifdef CONFIG_AVR_USART1
+static bool usart1_rxavailable(struct uart_dev_s *dev)
+{
+# warning "Missing logic"
+  return 0;
+}
+#endif
 
 /****************************************************************************
- * Name: up_send
+ * Name: usart0/1_send
  *
  * Description:
  *   This method will send one byte on the USART.
  *
  ****************************************************************************/
 
-static void up_send(struct uart_dev_s *dev, int ch)
+#ifdef CONFIG_AVR_USART0
+static void usart0_send(struct uart_dev_s *dev, int ch)
+{
+# warning "Missing logic"
+  return 0;
+}
+#endif
+
+#ifdef CONFIG_AVR_USART0
+static void usart0_send(struct uart_dev_s *dev, int ch)
 {
-  struct up_dev_s *priv = (struct up_dev_s*)dev->priv;
 # warning "Missing logic"
   return 0;
 }
+#endif
 
 /****************************************************************************
- * Name: up_txint
+ * Name: usart0/1_txint
  *
  * Description:
  *   Call to enable or disable TX interrupts
  *
  ****************************************************************************/
 
-static void up_txint(struct uart_dev_s *dev, bool enable)
+#ifdef CONFIG_AVR_USART0
+static void usart0_txint(struct uart_dev_s *dev, bool enable)
+{
+  irqstate_t flags;
+
+  flags = irqsave();
+  if (enable)
+    {
+      /* Set to receive an interrupt when the TX data register is empty */
+
+#ifndef CONFIG_SUPPRESS_SERIAL_INTS
+# warning "Missing logic"
+
+      /* Fake a TX interrupt here by just calling uart_xmitchars() with
+       * interrupts disabled (note this may recurse).
+       */
+
+      uart_xmitchars(dev);
+#endif
+    }
+  else
+    {
+      /* Disable the TX interrupt */
+
+# warning "Missing logic"
+    }
+  irqrestore(flags);
+}
+#endif
+
+#ifdef CONFIG_AVR_USART1
+static void usart1_txint(struct uart_dev_s *dev, bool enable)
 {
-  struct up_dev_s *priv = (struct up_dev_s*)dev->priv;
   irqstate_t flags;
 
   flags = irqsave();
@@ -582,21 +767,31 @@ static void up_txint(struct uart_dev_s *dev, bool enable)
     }
   irqrestore(flags);
 }
+#endif
 
 /****************************************************************************
- * Name: up_txready
+ * Name: usart0/1_txready
  *
  * Description:
  *   Return true if the tranmsit data register is empty
  *
  ****************************************************************************/
 
-static bool up_txready(struct uart_dev_s *dev)
+#ifdef CONFIG_AVR_USART0
+static bool usart0_txready(struct uart_dev_s *dev)
 {
-  struct up_dev_s *priv = (struct up_dev_s*)dev->priv;
 # warning "Missing logic"
   return 0;
 }
+#endif
+
+#ifdef CONFIG_AVR_USART1
+static bool usart1_txready(struct uart_dev_s *dev)
+{
+# warning "Missing logic"
+  return 0;
+}
+#endif
 
 /****************************************************************************
  * Public Functions
@@ -608,9 +803,7 @@ static bool up_txready(struct uart_dev_s *dev)
  * Description:
  *   Performs the low level USART initialization early in debug so that the
  *   serial console will be available during bootup.  This must be called
- *   before up_serialinit.  NOTE:  This function depends on GPIO pin
- *   configuration performed in up_consoleinit() and main clock iniialization
- *   performed in up_clkinitialize().
+ *   before up_serialinit.
  *
  ****************************************************************************/
 
@@ -618,16 +811,20 @@ void up_earlyserialinit(void)
 {
   /* Disable all USARTS */
 
-  up_disableusartint(TTYS0_DEV.priv, NULL);
+  usart0_disableusartint(TTYS0_DEV.priv, NULL);
 #ifdef TTYS1_DEV
-  up_disableusartint(TTYS1_DEV.priv, NULL);
+  usart0_disableusartint(TTYS1_DEV.priv, NULL);
 #endif
 
   /* Configuration whichever one is the console */
 
 #ifdef HAVE_SERIAL_CONSOLE
   CONSOLE_DEV.isconsole = true;
-  up_setup(&CONSOLE_DEV);
+#  if defined(CONFIG_USART0_SERIAL_CONSOLE)
+  usart0_setup(&CONSOLE_DEV);
+#  elif defined(CONFIG_USART1_SERIAL_CONSOLE)
+  usart1_setup(&CONSOLE_DEV);
+#  endif
 #endif
 }
 
@@ -667,10 +864,9 @@ void up_serialinit(void)
 int up_putc(int ch)
 {
 #ifdef HAVE_SERIAL_CONSOLE
-  struct up_dev_s *priv = (struct up_dev_s*)CONSOLE_DEV.priv;
-  uint32_t imr;
+  uint8_t imr;
 
-  up_disableusartint(priv, &imr);
+  up_disableusartint(&imr);
 
   /* Check for LF */
 
@@ -682,7 +878,7 @@ int up_putc(int ch)
     }
 
   up_lowputc(ch);
-  up_restoreusartint(priv, imr);
+  up_restoreusartint(imr);
 #endif
   return ch;
 }