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/*
* Copyright 2014 Ettus Research LLC
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <avr/interrupt.h>
#include <avr/io.h>
#include <debug.h>
#include <octoclock.h>
#include <clkdist.h>
#include <state.h>
void led(LEDs which, int turn_it_on) {
// selects the proper bit
uint8_t LED = 0x20 << which;
if(turn_it_on)
PORTC |= LED;
else
PORTC &= ~LED;
}
void LEDs_Off(void){
led(Top,false);
led(Middle,false);
led(Bottom,false);
}
void force_internal(void){
led(Top,true);
led(Middle,false);
led(Bottom,true);
setup_TI_CDCE18005(Primary_GPS);
// Set PPS to Primary (1) n.b.: "1" in general means "Internal" for all
// such signals
PORTA |= (1<<PA6);
}
void force_external(void){
led(Top, false);
led(Middle, true);
led(Bottom, true);
setup_TI_CDCE18005(Secondary_Ext);
// Set PPS to External
PORTA &= ~(1<<PA6);
}
void prefer_internal(void){
// if internal is NOT OK, then force external
if(global_gps_present)
force_internal();
else if(global_ext_ref_is_present)
force_external();
else
LEDs_Off();
}
void prefer_external(void){
// if external is NOT OK, then force internal
if(global_ext_ref_is_present)
force_external();
else if(global_gps_present)
force_internal();
else
LEDs_Off();
}
static uint8_t prev_PE7 = 0;
static uint32_t timer0_num_overflows = 0;
ISR(TIMER0_OVF_vect){
global_gps_present = (PIND & (1<<DDD4));
// Every ~1/10 second
if(!(timer0_num_overflows % 610)){
prev_PE7 = (PINE & (1<<DDE7));
if(get_switch_pos() == UP) prefer_internal();
else prefer_external();
global_ext_ref_is_present = false;
}
if(!global_ext_ref_is_present){
global_ext_ref_is_present = (prev_PE7 != (PINE & (1<<DDE7)));
}
timer0_num_overflows++;
}
ref_t which_ref(void){
if(!global_gps_present && !global_ext_ref_is_present) global_which_ref = NO_REF;
else if(global_gps_present && !global_ext_ref_is_present) global_which_ref = INTERNAL;
else if(!global_gps_present && global_ext_ref_is_present) global_which_ref = EXTERNAL;
else global_which_ref = (get_switch_pos() == UP) ? INTERNAL : EXTERNAL;
return global_which_ref;
}
switch_pos_t get_switch_pos(void){
uint8_t portC = PINC;
// UP is prefer internal,
// DOWN is prefer external
return (portC & (1<<DDC1)) ? DOWN : UP;
}
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