/****************************************************************************** * arch/avr/src/atmega/atmega_lowconsole.c * * Copyright (C) 2011 Gregory Nutt. All rights reserved. * Author: Gregory Nutt * * 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 #include "atmega_config.h" #include #include #include #include #include #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 }