nes-proj/platform/avr-ravenlcd/sleep.c

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/*
* Copyright (c) 2008 Swedish Institute of Computer Science
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * 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.
* * Neither the name of the copyright holders nor the names of
* 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.
*/
/**
* \file
*
* \brief
* This controls the sleep operation for the LCD.
*
* \author
* Mike Vidales mavida404@gmail.com
*
*/
#include <avr/interrupt.h>
#include <avr/sleep.h>
#include <avr/wdt.h>
#include <stdbool.h>
#include "sleep.h"
#include "uart.h"
/**
* \addtogroup lcd
* \{
*/
/*---------------------------------------------------------------------------*/
/**
* \brief Prepares for and executes sleep. This function sets up the
* processor to enter sleep mode, and to wake up when the joystick
* button (PE2/PCINT2) is pressed.
*/
void
sleep_now(void)
{
/* Disable watchdog */
wdt_disable();
/* Setup sleep mode */
set_sleep_mode(SLEEP_MODE_PWR_DOWN);
/* Enable wakeup interrupt */
EIMSK |= (1 << PCIE0);
/* Enable PCINT2 as interrupt */
PCMSK0 |= (1 << PCINT2);
/* Go to sleep now */
sleep_mode();
/* Disable the interrupt for the enter button */
EIMSK &= ~(1 << PCIE0);
}
/*---------------------------------------------------------------------------*/
/**
* \brief This will send a single character forever to the ATmega1284p to cause a wakeup.
*
* The 1284p polls the USART for new data during each sleep cycle. Upon receiving a
* character from the user LCD, it will wake up and send an acknowledgement frame.
*/
void
sleep_wakeup(void)
{
/* First, clear the input buffer and get any chars waiting */
while(rx_char_ready()){
uart_get_char_rx();
}
/* Flood 1284p with serial chars until it responds. */
for(;;){
uart_send_byte('x');
if (rx_char_ready())
break;
}
/* Get a frame back */
uart_serial_rcv_frame(true);
}
/*---------------------------------------------------------------------------*/
/**
* \brief This is the wake up button interrupt. When this interrupt fires,
* nothing is done. The program will simply continue from the end of the sleep
* command.
*/
ISR
(PCINT0_vect)
{
}
/** \} */