blob: 9b8785a869dd304416c6d75649dbc078ff59cdf4 [file] [log] [blame]
#include "kvm/rtc.h"
#include "kvm/fdt.h"
#include "kvm/ioport.h"
#include "kvm/kvm.h"
#include <time.h>
#if defined(CONFIG_ARM) || defined(CONFIG_ARM64)
#define RTC_BUS_TYPE DEVICE_BUS_MMIO
#define RTC_BASE_ADDRESS ARM_RTC_MMIO_BASE
#else
/* PORT 0070-007F - CMOS RAM/RTC (REAL TIME CLOCK) */
#define RTC_BUS_TYPE DEVICE_BUS_IOPORT
#define RTC_BASE_ADDRESS 0x70
#endif
/*
* MC146818 RTC registers
*/
#define RTC_SECONDS 0x00
#define RTC_SECONDS_ALARM 0x01
#define RTC_MINUTES 0x02
#define RTC_MINUTES_ALARM 0x03
#define RTC_HOURS 0x04
#define RTC_HOURS_ALARM 0x05
#define RTC_DAY_OF_WEEK 0x06
#define RTC_DAY_OF_MONTH 0x07
#define RTC_MONTH 0x08
#define RTC_YEAR 0x09
#define RTC_CENTURY 0x32
#define RTC_REG_A 0x0A
#define RTC_REG_B 0x0B
#define RTC_REG_C 0x0C
#define RTC_REG_D 0x0D
/*
* Register D Bits
*/
#define RTC_REG_D_VRT (1 << 7)
struct rtc_device {
u8 cmos_idx;
u8 cmos_data[128];
};
static struct rtc_device rtc;
static inline unsigned char bin2bcd(unsigned val)
{
return ((val / 10) << 4) + val % 10;
}
static void cmos_ram_io(struct kvm_cpu *vcpu, u64 addr, u8 *data,
u32 len, u8 is_write, void *ptr)
{
struct tm *tm;
time_t ti;
if (is_write) {
if (addr == RTC_BASE_ADDRESS) { /* index register */
u8 value = ioport__read8(data);
vcpu->kvm->nmi_disabled = value & (1UL << 7);
rtc.cmos_idx = value & ~(1UL << 7);
return;
}
switch (rtc.cmos_idx) {
case RTC_REG_C:
case RTC_REG_D:
/* Read-only */
break;
default:
rtc.cmos_data[rtc.cmos_idx] = ioport__read8(data);
break;
}
return;
}
if (addr == RTC_BASE_ADDRESS) /* index register is write-only */
return;
time(&ti);
tm = gmtime(&ti);
switch (rtc.cmos_idx) {
case RTC_SECONDS:
ioport__write8(data, bin2bcd(tm->tm_sec));
break;
case RTC_MINUTES:
ioport__write8(data, bin2bcd(tm->tm_min));
break;
case RTC_HOURS:
ioport__write8(data, bin2bcd(tm->tm_hour));
break;
case RTC_DAY_OF_WEEK:
ioport__write8(data, bin2bcd(tm->tm_wday + 1));
break;
case RTC_DAY_OF_MONTH:
ioport__write8(data, bin2bcd(tm->tm_mday));
break;
case RTC_MONTH:
ioport__write8(data, bin2bcd(tm->tm_mon + 1));
break;
case RTC_YEAR: {
int year;
year = tm->tm_year + 1900;
ioport__write8(data, bin2bcd(year % 100));
break;
}
case RTC_CENTURY: {
int year;
year = tm->tm_year + 1900;
ioport__write8(data, bin2bcd(year / 100));
break;
}
default:
ioport__write8(data, rtc.cmos_data[rtc.cmos_idx]);
break;
}
}
#ifdef CONFIG_HAS_LIBFDT
static void generate_rtc_fdt_node(void *fdt,
struct device_header *dev_hdr,
void (*generate_irq_prop)(void *fdt,
u8 irq,
enum irq_type))
{
u64 reg_prop[2] = { cpu_to_fdt64(RTC_BASE_ADDRESS), cpu_to_fdt64(2) };
_FDT(fdt_begin_node(fdt, "rtc"));
_FDT(fdt_property_string(fdt, "compatible", "motorola,mc146818"));
_FDT(fdt_property(fdt, "reg", reg_prop, sizeof(reg_prop)));
_FDT(fdt_end_node(fdt));
}
#else
#define generate_rtc_fdt_node NULL
#endif
struct device_header rtc_dev_hdr = {
.bus_type = RTC_BUS_TYPE,
.data = generate_rtc_fdt_node,
};
int rtc__init(struct kvm *kvm)
{
int r;
r = device__register(&rtc_dev_hdr);
if (r < 0)
return r;
r = kvm__register_iotrap(kvm, RTC_BASE_ADDRESS, 2, cmos_ram_io, NULL,
RTC_BUS_TYPE);
if (r < 0)
goto out_device;
/* Set the VRT bit in Register D to indicate valid RAM and time */
rtc.cmos_data[RTC_REG_D] = RTC_REG_D_VRT;
return r;
out_device:
device__unregister(&rtc_dev_hdr);
return r;
}
dev_init(rtc__init);
int rtc__exit(struct kvm *kvm)
{
kvm__deregister_iotrap(kvm, RTC_BASE_ADDRESS, RTC_BUS_TYPE);
return 0;
}
dev_exit(rtc__exit);