100 lines
2.2 KiB
C
100 lines
2.2 KiB
C
// SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later
|
|
/* Copyright 2013-2017 IBM Corp. */
|
|
|
|
#include <skiboot.h>
|
|
#include <opal.h>
|
|
#include <mem_region.h>
|
|
#include <device.h>
|
|
#include <timebase.h>
|
|
#include <time-utils.h>
|
|
#include <lock.h>
|
|
|
|
/* timebase when tm_offset was assigned */
|
|
static unsigned long tb_synctime;
|
|
|
|
/*
|
|
* Absolute time that was last assigned.
|
|
* Current rtc value is calculated from this.
|
|
*/
|
|
static struct tm tm_offset;
|
|
|
|
/* protects tm_offset & tb_synctime */
|
|
static struct lock emulation_lock;
|
|
|
|
static int64_t fake_rtc_write(uint32_t ymd, uint64_t hmsm)
|
|
{
|
|
|
|
lock(&emulation_lock);
|
|
|
|
datetime_to_tm(ymd, hmsm, &tm_offset);
|
|
tb_synctime = mftb();
|
|
|
|
unlock(&emulation_lock);
|
|
|
|
return OPAL_SUCCESS;
|
|
}
|
|
|
|
static int64_t fake_rtc_read(__be32 *__ymd, __be64 *__hmsm)
|
|
{
|
|
|
|
time_t sec;
|
|
struct tm tm_calculated;
|
|
uint32_t ymd;
|
|
uint64_t hmsm;
|
|
|
|
if (!__ymd || !__hmsm)
|
|
return OPAL_PARAMETER;
|
|
|
|
/* Compute the emulated clock value */
|
|
lock(&emulation_lock);
|
|
|
|
sec = tb_to_secs(mftb() - tb_synctime) + mktime(&tm_offset);
|
|
gmtime_r(&sec, &tm_calculated);
|
|
tm_to_datetime(&tm_calculated, &ymd, &hmsm);
|
|
|
|
unlock(&emulation_lock);
|
|
|
|
*__ymd = cpu_to_be32(ymd);
|
|
*__hmsm = cpu_to_be64(hmsm);
|
|
|
|
return OPAL_SUCCESS;
|
|
}
|
|
|
|
void fake_rtc_init(void)
|
|
{
|
|
struct mem_region *rtc_region = NULL;
|
|
uint32_t *rtc = NULL, *fake_ymd;
|
|
uint64_t *fake_hmsm;
|
|
struct dt_node *np;
|
|
|
|
/* Read initial values from reserved memory */
|
|
rtc_region = find_mem_region("ibm,fake-rtc");
|
|
|
|
/* Should we register anyway? */
|
|
if (!rtc_region) {
|
|
prlog(PR_TRACE, "No initial RTC value found\n");
|
|
return;
|
|
}
|
|
|
|
init_lock(&emulation_lock);
|
|
|
|
/* Fetch the initial rtc values */
|
|
rtc = (uint32_t *) rtc_region->start;
|
|
|
|
fake_ymd = rtc;
|
|
fake_hmsm = ((uint64_t *) &rtc[1]);
|
|
|
|
fake_rtc_write(*fake_ymd, *fake_hmsm);
|
|
|
|
/* Register opal calls */
|
|
opal_register(OPAL_RTC_READ, fake_rtc_read, 2);
|
|
opal_register(OPAL_RTC_WRITE, fake_rtc_write, 2);
|
|
|
|
/* add the fake rtc dt node */
|
|
np = dt_new(opal_node, "rtc");
|
|
dt_add_property_strings(np, "compatible", "ibm,opal-rtc");
|
|
|
|
prlog(PR_TRACE, "Init fake RTC to Date:%d-%d-%d Time:%d-%d-%d\n",
|
|
tm_offset.tm_mon, tm_offset.tm_mday, tm_offset.tm_year,
|
|
tm_offset.tm_hour, tm_offset.tm_min, tm_offset.tm_sec);
|
|
}
|