refactor checkpoint: splitting MCU-specific code into arch/$MCU.[ch]

Phew, that's a lot of changes!  And there's still a lot more to do...

1 files changed, 125 insertions, 0 deletions

diff --git a/arch/attiny1634.c b/arch/attiny1634.c
new file mode 100644
index 0000000..d4b3767
--- /dev/null
+++ b/arch/attiny1634.c
@@ -0,0 +1,125 @@
+// arch/attiny1634.c: attiny85 support functions
+// Copyright (C) 2014-2023 Selene ToyKeeper
+// SPDX-License-Identifier: GPL-3.0-or-later
+#pragma once
+
+#include "arch/attiny1634.h"
+
+////////// clock speed / delay stuff //////////
+
+///// clock dividers
+// make it a NOP for now
+// FIXME
+//#define clock_prescale_set(x) ((void)0)
+//#define clock_prescale_set(n) {cli(); CCP = 0xD8; CLKPR = n; sei();}
+//#define clock_prescale_set(n) {cli(); CCP = 0xD8; CLKPR = n; sei();}
+inline void clock_prescale_set(uint8_t n) {
+    cli();
+    CCP = 0xD8;
+    CLKPR = n;
+    sei();
+}
+
+////////// default hw_setup() //////////
+
+
+////////// ADC voltage / temperature //////////
+
+inline void mcu_set_admux_therm() {
+    ADMUX = ADMUX_THERM;
+}
+
+inline void mcu_set_admux_voltage() {
+    #ifdef USE_VOLTAGE_DIVIDER  // 1.1V / pin7
+        ADMUX = ADMUX_VOLTAGE_DIVIDER;
+    #else  // VCC / 1.1V reference
+        ADMUX = ADMUX_VCC;
+    #endif
+}
+
+inline void mcu_adc_sleep_mode() {
+    set_sleep_mode(SLEEP_MODE_ADC);
+}
+
+inline void mcu_adc_start_measurement() {
+    ADCSRA |= (1 << ADSC) | (1 << ADIE);
+}
+
+inline void mcu_adc_on() {
+    hwdef_set_admux_voltage();
+    #ifdef USE_VOLTAGE_DIVIDER
+        // disable digital input on divider pin to reduce power consumption
+        VOLTAGE_ADC_DIDR |= (1 << VOLTAGE_ADC);
+    #else
+        // disable digital input on VCC pin to reduce power consumption
+        //VOLTAGE_ADC_DIDR |= (1 << VOLTAGE_ADC);  // FIXME: unsure how to handle for VCC pin
+    #endif
+    //ACSRA |= (1 << ACD);  // turn off analog comparator to save power
+    ADCSRB |= (1 << ADLAR);  // left-adjust flag is here instead of ADMUX
+    // enable, start, auto-retrigger, prescale
+    ADCSRA = (1 << ADEN) | (1 << ADSC) | (1 << ADATE) | ADC_PRSCL;
+}
+
+inline void mcu_adc_off() {
+    ADCSRA &= ~(1<<ADEN); //ADC off
+}
+
+inline uint16_t mcu_adc_result() { return ADC; }
+
+inline uint8_t mcu_adc_lsb() { return (ADCL >> 6) + (ADCH << 2); }
+
+
+////////// WDT //////////
+
+inline void mcu_wdt_active() {
+    wdt_reset();                    // Reset the WDT
+    WDTCSR = (1<<WDIE);             // Enable interrupt every 16ms
+}
+
+inline void mcu_wdt_standby() {
+    wdt_reset();                    // Reset the WDT
+    WDTCSR = (1<<WDIE) | STANDBY_TICK_SPEED;
+}
+
+inline void mcu_wdt_stop() {
+    cli();                // needed because CCP, below
+    wdt_reset();          // Reset the WDT
+    MCUSR &= ~(1<<WDRF);  // clear watchdog reset flag
+    CCP = 0xD8;           // enable config changes
+    WDTCSR = 0;           // disable and clear all WDT settings
+    sei();
+}
+
+
+////////// PCINT - pin change interrupt (e-switch) //////////
+
+inline void mcu_pcint_on() {
+    // enable pin change interrupt
+    #ifdef SWITCH2_PCIE
+    GIMSK |= ((1 << SWITCH_PCIE) | (1 << SWITCH2_PCIE));
+    #else
+    GIMSK |= (1 << SWITCH_PCIE);
+    #endif
+}
+
+inline void mcu_pcint_off() {
+    // disable all pin-change interrupts
+    GIMSK &= ~(1 << SWITCH_PCIE);
+}
+
+
+////////// misc //////////
+
+void reboot() {
+    // put the WDT in hard reset mode, then trigger it
+    cli();
+    // allow protected configuration changes for next 4 clock cycles
+    CCP = 0xD8;  // magic number
+    // reset (WDIF + WDE), no WDIE, fastest (16ms) timing (0000)
+    // (DS section 8.5.2 and table 8-4)
+    WDTCSR = 0b10001000;
+    sei();
+    wdt_reset();
+    while (1) {}
+}
+