104 lines
2.9 KiB
C

/*
* This file is part of open_agb_firm
* Copyright (C) 2023 derrek, profi200
*
* 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 "types.h"
#include "arm11/drivers/timer.h"
#include "arm11/drivers/interrupt.h"
#include "fb_assert.h"
#include "arm.h"
void TIMER_init(void)
{
// Timer.
Timer *const timer = getTimerRegs();
timer->cnt = 0;
timer->int_stat = 1;
// Watchdog.
timer->wd_cnt = 0;
timer->wd_disable = WD_DISABLE_MAGIC1;
timer->wd_disable = WD_DISABLE_MAGIC2;
timer->wd_int_stat = 1;
IRQ_registerIsr(IRQ_WATCHDOG, 12, 0, NULL);
}
void TIMER_start(const u16 prescaler, const u32 ticks, const u8 params)
{
fb_assert(prescaler > 0 && prescaler <= 256);
Timer *const timer = getTimerRegs();
timer->load = ticks;
timer->cnt = (prescaler - 1)<<TIMER_PRESC_SHIFT |
params | TIMER_EN;
}
u32 TIMER_getTicks(void)
{
return getTimerRegs()->counter;
}
u32 TIMER_stop(void)
{
Timer *const timer = getTimerRegs();
timer->cnt = 0;
timer->int_stat = 1;
return timer->counter;
}
static void sleepTicks(const u32 ticks)
{
Timer *const timer = getTimerRegs();
timer->wd_load = ticks;
timer->wd_cnt = 0u<<TIMER_PRESC_SHIFT | WD_TIMER_MODE | // Prescaler 1.
TIMER_IRQ_EN | TIMER_SINGLE_SHOT | TIMER_EN;
do
{
__wfi();
} while(timer->wd_counter); // Checking the cnt enable bit is broken.
timer->wd_int_stat = 1;
}
void TIMER_sleepMs(const u32 ms)
{
// This fixed point calculation is accurate enough up to 32038.
// For some inputs we get 1 less than expected
// but this calculation alone will eat that single timer cycle.
sleepTicks((UINT64_C(0x20BA7ED916872) * ms)>>32); // ((u64)TIMER_BASE_FREQ / 8) * ms / (1000 / 8).
}
void TIMER_sleepUs(const u32 us)
{
// This fixed point calculation is accurate enough up to 32038622.
// For some inputs we get 1 less than expected
// but this calculation alone will eat that single timer cycle.
sleepTicks((UINT64_C(0x860E514C22) * us)>>32); // ((u64)TIMER_BASE_FREQ / 8) * us / (1000000 / 8).
}
void TIMER_sleepNs(const u64 ns)
{
// This fixed point calculation is accurate enough up to 32038622678.
// For some inputs we get 1 less than expected
// but this calculation alone will eat that single timer cycle.
sleepTicks((UINT64_C(0x22517D42) * ns)>>32); // ((u64)TIMER_BASE_FREQ / 8) * ns / (1000000000 / 8).
}