108 lines
2.6 KiB
C
108 lines
2.6 KiB
C
/* Copyright 2013-2014 IBM Corp.
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
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* implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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#include <skiboot.h>
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#include <opal.h>
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#include <mem_region.h>
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#include <device.h>
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#include <timebase.h>
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#include <time-utils.h>
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#include <lock.h>
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/* timebase when tm_offset was assigned */
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static unsigned long tb_synctime;
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/*
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* Absolute time that was last assigned.
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* Current rtc value is calculated from this.
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*/
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static struct tm tm_offset;
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/* protects tm_offset & tb_synctime */
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static struct lock emulation_lock;
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static int64_t fake_rtc_write(uint32_t ymd, uint64_t hmsm)
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{
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lock(&emulation_lock);
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datetime_to_tm(ymd, hmsm, &tm_offset);
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tb_synctime = mftb();
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unlock(&emulation_lock);
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return OPAL_SUCCESS;
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}
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static int64_t fake_rtc_read(uint32_t *ymd, uint64_t *hmsm)
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{
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time_t sec;
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struct tm tm_calculated;
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if (!ymd || !hmsm)
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return OPAL_PARAMETER;
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/* Compute the emulated clock value */
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lock(&emulation_lock);
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sec = tb_to_secs(mftb() - tb_synctime) + mktime(&tm_offset);
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gmtime_r(&sec, &tm_calculated);
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tm_to_datetime(&tm_calculated, ymd, hmsm);
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unlock(&emulation_lock);
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return OPAL_SUCCESS;
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}
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void fake_rtc_init(void)
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{
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struct mem_region *rtc_region = NULL;
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uint32_t *rtc = NULL, *fake_ymd;
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uint64_t *fake_hmsm;
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struct dt_node *np;
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/* Read initial values from reserved memory */
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rtc_region = find_mem_region("ibm,fake-rtc");
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/* Should we register anyway? */
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if (!rtc_region) {
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prlog(PR_TRACE, "No initial RTC value found\n");
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return;
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}
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init_lock(&emulation_lock);
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/* Fetch the initial rtc values */
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rtc = (uint32_t *) rtc_region->start;
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fake_ymd = rtc;
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fake_hmsm = ((uint64_t *) &rtc[1]);
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fake_rtc_write(*fake_ymd, *fake_hmsm);
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/* Register opal calls */
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opal_register(OPAL_RTC_READ, fake_rtc_read, 2);
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opal_register(OPAL_RTC_WRITE, fake_rtc_write, 2);
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/* add the fake rtc dt node */
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np = dt_new(opal_node, "rtc");
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dt_add_property_strings(np, "compatible", "ibm,opal-rtc");
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prlog(PR_TRACE, "Init fake RTC to Date:%d-%d-%d Time:%d-%d-%d\n",
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tm_offset.tm_mon, tm_offset.tm_mday, tm_offset.tm_year,
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tm_offset.tm_hour, tm_offset.tm_min, tm_offset.tm_sec);
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}
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