#include "clint.h"


volatile const uint32_t * const mtime_high  = (volatile const uint32_t*)(CLINT_BASE + CLINT_MTIME_HIGH);
volatile const uint32_t * const mtime_low   = (volatile const uint32_t*)(CLINT_BASE + CLINT_MTIME_LOW);
volatile uint32_t * const mtimecmp_high     = (volatile const uint32_t*)(CLINT_BASE + CLINT_MTIMECMP_HIGH);
volatile uint32_t * const mtimecmp_low      = (volatile const uint32_t*)(CLINT_BASE + CLINT_MTIMECMP_LOW);
volatile uint32_t mtimer_int_flag = 0;

void set_mtimecmp(uint64_t value)
{
    *mtimecmp_high = 0xFFFFFFFF; // 先写入高 32 位为全 1（禁用中断）
    *mtimecmp_low  = (uint32_t)value; // 写入低 32 位
    *mtimecmp_high = (uint32_t)(value >> 32); // 写入高 32 位
}


uint64_t read_mtimer()
{
    uint32_t hi, lo;
    do {
        hi = *mtime_high;  // 读取高 32 位
        lo = *mtime_low;   // 读取低 32 位
    } while (hi != *mtime_high); // 检查高 32 位是否变化（避免进位）
    return (((uint64_t)hi << 32) | lo);
}

void enable_mtimer_int() 
{
    __asm__ volatile ("csrs mie, %0" :: "r"(0x80));    // mie.MTIE = 1
    __asm__ volatile ("csrs mstatus, %0" :: "r"(0x8)); // mstatus.MIE = 1
}

void disable_mtimer_int()
{
    __asm__ volatile ("csrc mie, %0" :: "r"(0x80));    // mie.MTIE = 0
    __asm__ volatile ("csrc mstatus, %0" :: "r"(0x8)); // mstatus.MIE = 0
}

void set_mtimer(uint32_t delta_t)
{
    uint64_t t;

    t = read_mtimer();
    t += delta_t;
    set_mtimecmp(t);
    #if 0
    uint64_t t;

    t = *(volatile uint64_t *)(CLINT_BASE + CLINT_MTIME_LOW);
    t += delta_t;
    *(volatile uint64_t *)(CLINT_BASE + CLINT_MTIMECMP_LOW) = t;
    #endif
}