neptune/kern/rtc.c
2025-10-01 03:38:46 +02:00

56 lines
1.5 KiB
C

#include <stdint.h>
#define VIRT_RTC_BASE 0x0101000UL
#define VIRT_RTC_SIZE 0x1000
#define RTC_TIME_LOW 0x00
#define RTC_TIME_HIGH 0x04
#define RTC_ALARM_LOW 0x08
#define RTC_ALARM_HIGH 0x0c
#define RTC_IRQ_ENABLED 0x10
#define RTC_CLEAR_ALARM 0x14
#define RTC_ALARM_STATUS 0x18
#define RTC_CLEAR_INTERRUPT 0x1c
static inline uint32_t mmio_read32(uintptr_t addr) {
return *(volatile uint32_t *)addr;
}
static inline void mmio_write32(uintptr_t addr, uint32_t value) {
*(volatile uint32_t *)addr = value;
}
uint64_t rtc_time_read(void) {
uint32_t low = mmio_read32(VIRT_RTC_BASE + RTC_TIME_LOW);
uint32_t high = mmio_read32(VIRT_RTC_BASE + RTC_TIME_HIGH);
return ((uint64_t)high << 32) | low;
}
void rtc_time_set(uint64_t ns) {
mmio_write32(VIRT_RTC_BASE + RTC_TIME_LOW, ns);
mmio_write32(VIRT_RTC_BASE + RTC_TIME_HIGH, ns);
}
void rtc_alarm_set(uint64_t ns) {
mmio_write32(VIRT_RTC_BASE + RTC_ALARM_HIGH, ns >> 32);
mmio_write32(VIRT_RTC_BASE + RTC_ALARM_LOW, ns & 0xffffffff);
}
uint64_t rtc_alarm_read(void) {
uint32_t low = mmio_read32(VIRT_RTC_BASE + RTC_ALARM_LOW);
uint32_t high = mmio_read32(VIRT_RTC_BASE + RTC_ALARM_HIGH);
return ((uint64_t)high << 32) | low;
}
void rtc_alarm_enable(void) {
mmio_write32(VIRT_RTC_BASE + RTC_IRQ_ENABLED, 1);
}
void rtc_alarm_disable(void) {
mmio_write32(VIRT_RTC_BASE + RTC_IRQ_ENABLED, 0);
}
uint32_t rtc_alarm_status(void) {
return mmio_read32(VIRT_RTC_BASE + RTC_IRQ_ENABLED);
}