/******************************************************************************
* arch/avr/src/atmega/atmega_lowconsole.c
*
* 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
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
* 3. Neither the name NuttX nor the names of its contributors may be
* used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
******************************************************************************/
/******************************************************************************
* Included Files
******************************************************************************/
#include <nuttx/config.h>
#include "atmega_config.h"
#include <assert.h>
#include <debug.h>
#include <arch/irq.h>
#include <arch/board/board.h>
#include <avr/io.h>
#include "up_arch.h"
#include "up_internal.h"
#include "atmega_internal.h"
/******************************************************************************
* Private Definitions
******************************************************************************/
/* USART0 Baud rate settings for normal and double speed modes */
#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
#elif BOARD_CPU_CLOCK <= 16000000
# if CONFIG_USART0_BAUD <= 38400
# define AVR_UBRR0 AVR_NORMAL_UBRR0
# else
# define AVR_UBRR0 AVR_DBLSPEED_UBRR0
# define UART0_DOUBLE_SPEED 1
# endif
#else
# if CONFIG_USART0_BAUD <= 57600
# 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 modes */
#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
#elif BOARD_CPU_CLOCK <= 16000000
# if CONFIG_USART1_BAUD <= 38400
# define AVR_UBRR1 AVR_NORMAL_UBRR1
# else
# define AVR_UBRR1 AVR_DBLSPEED_UBRR1
# define UART1_DOUBLE_SPEED 1
# endif
#else
# if CONFIG_USART1_BAUD <= 57600
# define AVR_UBRR1 AVR_NORMAL_UBRR1
# else
# define AVR_UBRR1 AVR_DBLSPEED_UBRR1
# define UART1_DOUBLE_SPEED 1
# endif
#endif
/******************************************************************************
* Private Types
******************************************************************************/
/******************************************************************************
* Private Function Prototypes
******************************************************************************/
/******************************************************************************
* Global Variables
******************************************************************************/
/******************************************************************************
* Private Variables
******************************************************************************/
/******************************************************************************
* Private Functions
******************************************************************************/
/******************************************************************************
* Public Functions
******************************************************************************/
/****************************************************************************
* Name: usart0_reset and usart1_reset
*
* Description:
* Reset USART0 or USART1.
*
****************************************************************************/
#ifdef CONFIG_AVR_USART0
void usart0_reset(void)
{
/* Clear USART configuration */
UCSR0A = 0;
UCSR0B = 0;
UCSR0C = 0;
/* Unconfigure pins (no action needed */
DDRE &= ~(1 << 1);
PORTE &= ~(1 << 0);
/* Unconfigure BAUD divisor */
UBRR0H = 0;
UBRR0L = 0;
}
#endif
#ifdef CONFIG_AVR_USART1
void usart1_reset(void)
{
/* Clear USART configuration */
UCSR1A = 0;
UCSR1B = 0;
UCSR1C = 0;
/* Unconfigure pins */
DDRD &= ~(1 << 3);
PORTD &= ~(1 << 2);
/* Unconfigure BAUD divisor */
UBRR1H = 0;
UBRR1L = 0;
}
#endif
/****************************************************************************
* Name: usart0_configure and usart1_configure
*
* Description:
* Configure USART0 or USART1.
*
****************************************************************************/
#ifdef CONFIG_AVR_USART0
void usart0_configure(void)
{
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 |= ((1 << UPM01) | (1 << UPM00)); /* Odd parity */
#elif CONFIG_USART0_PARITY == 2
ucsr0c |= (1 << UPM00); /* Even parity */
#endif
/* 1 or 2 stop bits */
#if defined(CONFIG_USART0_2STOP) && CONFIG_USART0_2STOP > 0
ucsr0c |= (1 << USBS0); /* Two stop bits */
#endif
/* Word size */
#if CONFIG_USART0_BITS == 5
#elif CONFIG_USART0_BITS == 6
ucsr0c |= (1 << UCSZ00);
#elif CONFIG_USART0_BITS == 7
ucsr0c |= (1 << UCSZ01);
#elif CONFIG_USART0_BITS == 8
ucsr0c |= ((1 << UCSZ00) | (1 << UCSZ01));
#elif CONFIG_USART0_BITS == 9
ucsr0c |= ((1 << UCSZ0) | (1 << UCSZ01));
ucsr0b |= (1 << UCSZ02);
#else
# error "Unsupported word size"
#endif
UCSR0B = ucsr0b;
UCSR0C = ucsr0c;
/* Pin Configuration: None necessary, Port E bits 0&1 are automatically
* configured:
*
* Port E, Bit 0: RXD0, USART0 Receive Pin. Receive Data (Data input pin
* for the USART0). When the USART0 receiver is enabled this pin is
* configured as an input regardless of the value of DDRE0. When the
* USART0 forces this pin to be an input, a logical one in PORTE0 will
* turn on the internal pull-up.
*
* Port E, Bit 1: TXD0, UART0 Transmit pin.
*
* REVISIT: According to table 41, TXD0 is also automatically configured.
* However, this is not explicitly stated in the text.
*/
DDRE |= (1 << 1); /* Force Port E pin 1 to be an input -- might not be necessary */
PORTE |= (1 << 0); /* Set pull-up on Port E pin 0 */
/* Set the baud rate divisor */
UBRR0H = AVR_UBRR0 >> 8;
UBRR0L = AVR_UBRR0 & 0xff;
}
#endif
#ifdef CONFIG_AVR_USART1
void usart1_configure(void)
{
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 |= ((1 << UPM11) | (1 << UPM10)); /* Odd parity */
#elif CONFIG_USART1_PARITY == 2
ucsr1c |= (1 << UPM11); /* Even parity */
#endif
/* 1 or 2 stop bits */
#if defined(CONFIG_USART1_2STOP) && CONFIG_USART1_2STOP > 0
ucsr1c |= (1 << USBS1); /* Two stop bits */
#endif
/* Word size */
#if CONFIG_USART1_BITS == 5
#elif CONFIG_USART1_BITS == 6
ucsr1c |= (1 << UCSZ10);
#elif CONFIG_USART1_BITS == 7
ucsr1c |= (1 << UCSZ11);
#elif CONFIG_USART1_BITS == 8
ucsr1c |= ((1 << UCSZ10) | (1 << UCSZ11));
#elif CONFIG_USART1_BITS == 9
ucsr1c |= (U(1 << CSZ10) | (1 << UCSZ11));
ucsr1b |= (1 << UCSZ12);
#else
# error "Unsupported word size"
#endif
UCSR1B = ucsr1b;
UCSR1C = ucsr1c;
/* Pin Configuration: None necessary, Port D bits 2&3 are automatically
* configured:
*
* Port D, Bit 2: RXD1, Receive Data (Data input pin for the USART1). When
* the USART1 receiver is enabled this pin is configured as an input
* regardless of the value of DDD2. When the USART forces this pin to
* be an input, the pull-up can still be controlled by the PORTD2 bit.
* Port D, Bit 3: TXD1, Transmit Data (Data output pin for the USART1).
* When the USART1 Transmitter is enabled, this pin is configured as
* an output regardless of the value of DDD3.
*/
DDRD |= (1 << 3); /* Force Port D pin 3 to be an output -- should not be necessary */
PORTD |= (1 << 2); /* Set pull-up on port D pin 2 */
/* Set the baud rate divisor */
UBRR1H = AVR_UBRR1 >> 8;
UBRR1L = AVR_UBRR1 & 0xff;
}
#endif
/******************************************************************************
* Name: up_consoleinit
*
* Description:
* Initialize a console for debug output. This function is called very
* early in the intialization sequence to configure the serial console uart
* (only).
*
******************************************************************************/
void up_consoleinit(void)
{
#ifdef HAVE_SERIAL_CONSOLE
# if defined(CONFIG_USART0_SERIAL_CONSOLE)
usart0_configure();
# elif defined(CONFIG_USART1_SERIAL_CONSOLE)
usart1_configure();
# endif
#endif
}
/******************************************************************************
* Name: up_lowputc
*
* Description:
* Output one byte on the serial console
*
******************************************************************************/
void up_lowputc(char ch)
{
#ifdef HAVE_SERIAL_CONSOLE
# if defined(CONFIG_USART0_SERIAL_CONSOLE)
while ((UCSR0A & (1 << UDRE0)) == 0);
UDR0 = ch;
# elif defined(CONFIG_USART1_SERIAL_CONSOLE)
while ((UCSR1A & (1 << UDRE1)) == 0);
UDR1 = ch;
# endif
#endif
}
