More serial driver stuff for AVR

git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@3694 42af7a65-404d-4744-a932-0658087f49c3

2 files changed, 244 insertions, 50 deletions

diff --git a/nuttx/arch/avr/src/atmega/atmega_lowconsole.c b/nuttx/arch/avr/src/atmega/atmega_lowconsole.c
index f841c9d78..b318dd608 100644
--- a/nuttx/arch/avr/src/atmega/atmega_lowconsole.c
+++ b/nuttx/arch/avr/src/atmega/atmega_lowconsole.c
@@ -45,6 +45,7 @@
 
 #include <arch/irq.h>
 #include <arch/board/board.h>
+#include <avr/io.h>
 
 #include "up_arch.h"
 #include "up_internal.h"
@@ -54,22 +55,110 @@
  * Private Definitions
  ******************************************************************************/
 
-/* Select USART parameters for the selected console */
-
-#if defined(CONFIG_USART0_SERIAL_CONSOLE)
-#  define AVR__CONSOLE_BASE     AVR__USART0_BASE
-#  define AVR__CONSOLE_BAUD     CONFIG_USART0_BAUD
-#  define AVR__CONSOLE_BITS     CONFIG_USART0_BITS
-#  define AVR__CONSOLE_PARITY   CONFIG_USART0_PARITY
-#  define AVR__CONSOLE_2STOP    CONFIG_USART0_2STOP
-#elif defined(CONFIG_USART1_SERIAL_CONSOLE)
-#  define AVR__CONSOLE_BASE     AVR__USART1_BASE
-#  define AVR__CONSOLE_BAUD     CONFIG_USART1_BAUD
-#  define AVR__CONSOLE_BITS     CONFIG_USART1_BITS
-#  define AVR__CONSOLE_PARITY   CONFIG_USART1_PARITY
-#  define AVR__CONSOLE_2STOP    CONFIG_USART1_2STOP
+/* USART0 Baud rate settings for normal and double speed settings  */
+
+#define AVR_NORMAL_UBRR0 \
+  ((((BOARD_CPU_CLOCK / 16) + (CONFIG_USART0_BAUD / 2)) / (CONFIG_USART0_BAUD)) - 1)
+
+#define AVR_DBLSPEED_UBRR0 \
+  ((((BOARD_CPU_CLOCK / 8) + (CONFIG_USART0_BAUD / 2)) / (CONFIG_USART0_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 UART0_DOUBLE_SPEED
+#if BOARD_CPU_CLOCK <= 4000000
+#  if CONFIG_USART0_BAUD <= 9600
+#    define AVR_UBRR0 AVR_NORMAL_UBRR0
+#  else
+#    define AVR_UBRR0 AVR_DBLSPEED_UBRR0
+#    define UART0_DOUBLE_SPEED 1
+#  endif
+#elif BOARD_CPU_CLOCK <= 8000000
+#  if CONFIG_USART0_BAUD <= 19200
+#    define AVR_UBRR0 AVR_NORMAL_UBRR0
+#  else
+#    define AVR_UBRR0 AVR_DBLSPEED_UBRR0
+#    define UART0_DOUBLE_SPEED 1
+#  endif
+#elif BOARD_CPU_CLOCK <= 12000000
+#  if CONFIG_USART0_BAUD <= 28800
+#    define AVR_UBRR0 AVR_NORMAL_UBRR0
+#  else
+#    define AVR_UBRR0 AVR_DBLSPEED_UBRR0
+#    define UART0_DOUBLE_SPEED 1
+#  endif
 #else
-#  error "No CONFIG_USARTn_SERIAL_CONSOLE Setting"
+#  if CONFIG_USART0_BAUD <= 38400
+#    define AVR_UBRR0 AVR_NORMAL_UBRR0
+#  else
+#    define AVR_UBRR0 AVR_DBLSPEED_UBRR0
+#    define UART0_DOUBLE_SPEED 1
+#  endif
+#endif
+
+/* USART1 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 UART1_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 UART1_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 UART1_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 UART1_DOUBLE_SPEED 1
+#  endif
+#else
+#  if CONFIG_USART1_BAUD <= 38400
+#    define AVR_UBRR1 AVR_NORMAL_UBRR1
+#  else
+#    define AVR_UBRR1 AVR_DBLSPEED_UBRR1
+#    define UART1_DOUBLE_SPEED 1
+#  endif
 #endif
 
 /******************************************************************************
@@ -107,14 +196,27 @@
 #ifdef CONFIG_ATMEGA_USART0
 void usart0_reset(void)
 {
+  UCSR0A = 0;
+  UCSR0B = 0;
+  UCSR0C = 0;
+
 # warning "Missing logic"
+
+  UBRR0  = 0;
 }
 #endif
 
 #ifdef CONFIG_ATMEGA_USART1
 void usart1_reset(void)
 {
-# warning "Missing logic"
+  UCSR1A = 0;
+  UCSR1B = 0;
+  UCSR1C = 0;
+
+  DDRD  &= ~(1 << 3);  
+  PORTD &= ~(1 << 2);
+        
+  UBRR1  = 0;
 }
 #endif
 
@@ -129,14 +231,123 @@ void usart1_reset(void)
 #ifdef CONFIG_AVR_USART0
 void usart0_configure(void)
 {
-# warning "Missing logic"
+  uint8_t ucsr0b;
+  uint8_t ucsr0c;
+
+  /* Select normal or double speed. */
+
+#ifdef UART0_DOUBLE_SPEED
+  UCSR0A = (1 << U2X0);
+#else
+  UCSR0A = 0;
+#endif
+
+  /* Select baud, parity, nubmer of bits, stop bits, etc. */
+
+  ucsr0b = ((1 << TXEN0)  | (1 << RXEN0));
+  ucsr0c = 0;
+ 
+  /* Select parity */
+
+#if CONFIG_USART0_PARITY == 1
+  ucsr0c |= (UPM01 | UPM00); /* Odd parity */
+#else
+  ucsr0c |= UPM00;           /* Even parity */
+#endif
+
+  /* 1 or 2 stop bits */
+
+#if defined(CONFIG_USART0_2STOP) && CONFIG_USART0_2STOP > 0
+  ucsr0c |= USBS0;           /* Two stop bits */
+#endif
+
+  /* Word size */
+
+#if CONFIG_USART0_BITS == 5
+#elif CONFIG_USART0_BITS == 6
+  ucsr0c |= UCSZ00;
+#elif CONFIG_USART0_BITS == 7
+  ucsr0c |= UCSZ01;
+#elif CONFIG_USART0_BITS == 8
+  ucsr0c |= (UCSZ00 | UCSZ01);
+#elif CONFIG_USART0_BITS == 9
+  ucsr0c |= (UCSZ00 | UCSZ01);
+  ucsr0b |= UCSZ02;
+#else
+#  error "Unsupported word size"
+#endif
+  UCSR0B = ucsr0b;
+  UCSR0C = ucsr0c;
+
+  /* Configure pin */
+
+#warning "Missing logic"
+
+  /* Set the baud rate divisor */
+
+  UBRR0  = AVR_UBRR0;
 }
 #endif
 
 #ifdef CONFIG_AVR_USART1
 void usart1_configure(void)
 {
-# warning "Missing logic"
+  uint8_t ucsr1b;
+  uint8_t ucsr1c;
+
+  /* Select normal or double speed. */
+
+#ifdef UART1_DOUBLE_SPEED
+  UCSR1A = (1 << U2X1);
+#else
+  UCSR1A = 0;
+#endif
+
+  /* Select baud, parity, nubmer of bits, stop bits, etc. */
+
+  ucsr1b = ((1 << TXEN1)  | (1 << RXEN1));
+  ucsr1c = 0;
+ 
+  /* Select parity */
+
+#if CONFIG_USART1_PARITY == 1
+  ucsr1c |= (UPM11 | UPM10); /* Odd parity */
+#else
+  ucsr1c |= UPM11;           /* Even parity */
+#endif
+
+  /* 1 or 2 stop bits */
+
+#if defined(CONFIG_USART1_2STOP) && CONFIG_USART1_2STOP > 0
+  ucsr1c |= USBS1;           /* Two stop bits */
+#endif
+
+  /* Word size */
+
+#if CONFIG_USART1_BITS == 5
+#elif CONFIG_USART1_BITS == 6
+  ucsr1c |= UCSZ10;
+#elif CONFIG_USART1_BITS == 7
+  ucsr1c |= UCSZ11;
+#elif CONFIG_USART1_BITS == 8
+  ucsr1c |= (UCSZ10 | UCSZ11);
+#elif CONFIG_USART1_BITS == 9
+  ucsr1c |= (UCSZ10 | UCSZ11);
+  ucsr1b |= UCSZ12;
+#else
+#  error "Unsupported word size"
+#endif
+  UCSR1B = ucsr1b;
+  UCSR1C = ucsr1c;
+
+  /* Configure pin */
+
+  DDRD  |= (1 << 3);  
+  PORTD |= (1 << 2);
+
+  /* Set the baud rate divisor */
+
+  UBRR1  = AVR_UBRR1;
 }
 #endif
 
@@ -173,9 +384,11 @@ void up_lowputc(char ch)
 {
 #ifdef HAVE_SERIAL_CONSOLE
 #  if defined(CONFIG_USART0_SERIAL_CONSOLE)
-#    warning "Missing logic"
+  while ((UCSR0A & (1 << UDRE0)) == 0);
+  UDR0 = ch;
 #  elif defined(CONFIG_USART1_SERIAL_CONSOLE)
-#    warning "Missing logic"
+  while ((UCSR1A & (1 << UDRE1)) == 0);
+  UDR1 = ch;
 #  endif
 #endif
 }
diff --git a/nuttx/arch/avr/src/atmega/atmega_serial.c b/nuttx/arch/avr/src/atmega/atmega_serial.c
index 4d3b5a23c..f55d22ec2 100644
--- a/nuttx/arch/avr/src/atmega/atmega_serial.c
+++ b/nuttx/arch/avr/src/atmega/atmega_serial.c
@@ -52,6 +52,7 @@
 #include <nuttx/irq.h>
 #include <nuttx/arch.h>
 #include <nuttx/serial.h>
+#include <avr/io.h>
 
 #include <arch/board/board.h>
 
@@ -562,46 +563,32 @@ static int usart1_ioctl(struct file *filep, int cmd, unsigned long arg)
 #ifdef CONFIG_AVR_USART0
 static int usart0_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.
-   */
-
-# warning "Missing logic"
-
   /* Return status information */
 
   if (status)
     {
-# warning "Missing logic"
+	  *status = (uint32_t)UCSR0A;
     }
 
   /* Then return the actual received byte */
 
-# warning "Missing logic"
-  return 0;
+  return UDR0;
 }
 #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.
-   */
-
-# warning "Missing logic"
-
   /* Return status information */
 
   if (status)
     {
-# warning "Missing logic"
+	  *status = (uint32_t)UCSR1A;
     }
 
   /* Then return the actual received byte */
 
-# warning "Missing logic"
-  return 0;
+  return UDR1;
 }
 #endif
 
@@ -664,16 +651,14 @@ static void usart1_rxint(struct uart_dev_s *dev, bool enable)
 #ifdef CONFIG_AVR_USART0
 static bool usart0_rxavailable(struct uart_dev_s *dev)
 {
-# warning "Missing logic"
-  return 0;
+  return (UCSR0A & (1 << RXC0)) != 0;
 }
 #endif
 
 #ifdef CONFIG_AVR_USART1
 static bool usart1_rxavailable(struct uart_dev_s *dev)
 {
-# warning "Missing logic"
-  return 0;
+  return (UCSR1A & (1 << RXC1)) != 0;
 }
 #endif
 
@@ -688,16 +673,14 @@ static bool usart1_rxavailable(struct uart_dev_s *dev)
 #ifdef CONFIG_AVR_USART0
 static void usart0_send(struct uart_dev_s *dev, int ch)
 {
-# warning "Missing logic"
-  return 0;
+  UDR0 = ch;
 }
 #endif
 
 #ifdef CONFIG_AVR_USART0
 static void usart0_send(struct uart_dev_s *dev, int ch)
 {
-# warning "Missing logic"
-  return 0;
+  UDR1 = ch;
 }
 #endif
 
@@ -780,16 +763,14 @@ static void usart1_txint(struct uart_dev_s *dev, bool enable)
 #ifdef CONFIG_AVR_USART0
 static bool usart0_txready(struct uart_dev_s *dev)
 {
-# warning "Missing logic"
-  return 0;
+  return (UCSR0A & (1 << UDRE0)) != 0;
 }
 #endif
 
 #ifdef CONFIG_AVR_USART1
 static bool usart1_txready(struct uart_dev_s *dev)
 {
-# warning "Missing logic"
-  return 0;
+  return (UCSR1A & (1 << UDRE1)) != 0;
 }
 #endif