mirror of
https://github.com/DragonOS-Community/DragonOS.git
synced 2025-06-12 10:06:47 +00:00
65 lines
1.9 KiB
C
65 lines
1.9 KiB
C
#include "rtc.h"
|
||
#include <common/kprint.h>
|
||
|
||
/*置位0x70的第7位，禁止不可屏蔽中断*/
|
||
/*
|
||
#define read_cmos(addr) ({ \
|
||
io_out8(0x70, 0x80 | addr); \
|
||
io_in8(0x71); \
|
||
})
|
||
*/
|
||
enum CMOSTimeSelector
|
||
{
|
||
T_SECOND = 0x0,
|
||
T_MINUTE = 0x2,
|
||
T_HOUR = 0x4,
|
||
T_DAY = 0x7,
|
||
T_MONTH = 0x8,
|
||
T_YEAR = 0x9,
|
||
};
|
||
|
||
int read_cmos(uint8_t addr)
|
||
{
|
||
io_out8(0x70, 0x80 | addr);
|
||
io_mfence();
|
||
return (uint8_t)(io_in8(0x71) & 0xff);
|
||
}
|
||
|
||
int rtc_get_cmos_time(struct time *t)
|
||
{
|
||
// 为防止中断请求打断该过程，需要先关中断
|
||
cli();
|
||
|
||
uint8_t status_register_B = read_cmos(0x0B); // 读取状态寄存器B
|
||
bool is_24h = ((status_register_B & 0x02) ? true : false); // 判断是否启用24小时模式
|
||
bool is_binary = ((status_register_B & 0x04) ? true : false); // 判断是否为二进制码
|
||
|
||
do
|
||
{
|
||
t->year = read_cmos(0x09);
|
||
t->month = read_cmos(0x08);
|
||
t->day = read_cmos(0x07);
|
||
t->hour = read_cmos(0x04);
|
||
t->minute = read_cmos(0x02);
|
||
t->second = read_cmos(0x00);
|
||
} while (t->second != read_cmos(0x00)); // 若读取时间过程中时间发生跳变则重新读取
|
||
// 使能NMI中断
|
||
io_out8(0x70, 0x00);
|
||
|
||
if (!is_binary) // 把BCD转为二进制
|
||
{
|
||
t->second = (t->second & 0xf) + (t->second >> 4) * 10;
|
||
t->minute = (t->minute & 0xf) + (t->minute >> 4) * 10;
|
||
t->hour = ((t->hour & 0xf) + ((t->hour & 0x70) >> 4) * 10) | (t->hour & 0x80);
|
||
|
||
t->month = (t->month & 0xf) + (t->month >> 4) * 10;
|
||
t->year = (t->year & 0xf) + (t->year >> 4) * 10;
|
||
}
|
||
t->year += 2000;
|
||
|
||
if ((!is_24h) && t->hour & 0x80) // 将十二小时制转为24小时
|
||
t->hour = ((t->hour & 0x7f) + 12) % 24;
|
||
sti();
|
||
return 0;
|
||
}
|