The default QEMU config is to have the RTC in UTC. However, if run with
-rtc base=localtime (and wall_cmos_clock is set to match), the driver
fails to account for adjkerntz due to the use of CLOCKF_SETTIME_NO_ADJ.
Copy the same code used by other CLOCKF_SETTIME_NO_ADJ-using drivers
to fix this, namely manually subtracting utc_offset().
Fixes: d63a631e72
("Add Goldfish RTC device driver for RISC-V")
MFC after: 1 week
186 lines
4.9 KiB
C
186 lines
4.9 KiB
C
/*-
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* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
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*
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* Copyright (c) 2020 Jessica Clarke <jrtc27@FreeBSD.org>
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*/
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/*
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* RTC for the goldfish virtual hardware platform implemented in QEMU,
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* initially for Android but now also used for RISC-V's virt machine.
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*
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* https://android.googlesource.com/platform/external/qemu/+/master/docs/GOLDFISH-VIRTUAL-HARDWARE.TXT
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*/
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#include <sys/cdefs.h>
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__FBSDID("$FreeBSD$");
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#include <sys/param.h>
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#include <sys/systm.h>
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#include <sys/bus.h>
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#include <sys/clock.h>
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#include <sys/kernel.h>
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#include <sys/lock.h>
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#include <sys/module.h>
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#include <sys/mutex.h>
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#include <sys/types.h>
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#include <dev/ofw/ofw_bus.h>
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#include <dev/ofw/ofw_bus_subr.h>
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#include <machine/bus.h>
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#include <machine/resource.h>
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#include <sys/rman.h>
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#include "clock_if.h"
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#define GOLDFISH_RTC_TIME_LOW 0x00
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#define GOLDFISH_RTC_TIME_HIGH 0x04
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struct goldfish_rtc_softc {
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struct resource *res;
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int rid;
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struct mtx mtx;
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};
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static int
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goldfish_rtc_probe(device_t dev)
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{
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if (!ofw_bus_status_okay(dev))
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return (ENXIO);
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if (ofw_bus_is_compatible(dev, "google,goldfish-rtc")) {
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device_set_desc(dev, "Goldfish RTC");
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return (BUS_PROBE_DEFAULT);
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}
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return (ENXIO);
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}
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static int
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goldfish_rtc_attach(device_t dev)
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{
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struct goldfish_rtc_softc *sc;
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sc = device_get_softc(dev);
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sc->rid = 0;
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sc->res = bus_alloc_resource_any(dev, SYS_RES_MEMORY, &sc->rid,
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RF_ACTIVE);
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if (sc->res == NULL) {
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device_printf(dev, "could not allocate resource\n");
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return (ENXIO);
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}
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mtx_init(&sc->mtx, device_get_nameunit(dev), NULL, MTX_DEF);
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/*
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* Register as a system realtime clock with 1 second resolution.
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*/
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clock_register_flags(dev, 1000000, CLOCKF_SETTIME_NO_ADJ);
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clock_schedule(dev, 1);
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return (0);
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}
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static int
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goldfish_rtc_detach(device_t dev)
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{
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struct goldfish_rtc_softc *sc;
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sc = device_get_softc(dev);
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clock_unregister(dev);
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mtx_destroy(&sc->mtx);
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bus_release_resource(dev, SYS_RES_MEMORY, sc->rid, sc->res);
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return (0);
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}
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static int
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goldfish_rtc_gettime(device_t dev, struct timespec *ts)
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{
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struct goldfish_rtc_softc *sc;
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uint64_t low, high, nsec;
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sc = device_get_softc(dev);
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/*
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* Reading TIME_HIGH is defined in the documentation to give the high
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* 32 bits corresponding to the last TIME_LOW read, so must be done in
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* that order, but means we have atomicity guaranteed.
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*/
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mtx_lock(&sc->mtx);
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low = bus_read_4(sc->res, GOLDFISH_RTC_TIME_LOW);
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high = bus_read_4(sc->res, GOLDFISH_RTC_TIME_HIGH);
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mtx_unlock(&sc->mtx);
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nsec = (high << 32) | low;
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ts->tv_sec = nsec / 1000000000;
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ts->tv_nsec = nsec % 1000000000;
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return (0);
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}
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static int
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goldfish_rtc_settime(device_t dev, struct timespec *ts)
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{
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struct goldfish_rtc_softc *sc;
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uint64_t nsec;
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sc = device_get_softc(dev);
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/*
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* We request a timespec with no resolution-adjustment. That also
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* disables utc adjustment, so apply that ourselves.
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*/
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ts->tv_sec -= utc_offset();
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nsec = (uint64_t)ts->tv_sec * 1000000000 + ts->tv_nsec;
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mtx_lock(&sc->mtx);
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bus_write_4(sc->res, GOLDFISH_RTC_TIME_HIGH, nsec >> 32);
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bus_write_4(sc->res, GOLDFISH_RTC_TIME_LOW, nsec);
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mtx_unlock(&sc->mtx);
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return (0);
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}
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static device_method_t goldfish_rtc_methods[] = {
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/* Device interface */
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DEVMETHOD(device_probe, goldfish_rtc_probe),
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DEVMETHOD(device_attach, goldfish_rtc_attach),
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DEVMETHOD(device_detach, goldfish_rtc_detach),
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/* Clock interface */
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DEVMETHOD(clock_gettime, goldfish_rtc_gettime),
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DEVMETHOD(clock_settime, goldfish_rtc_settime),
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DEVMETHOD_END,
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};
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DEFINE_CLASS_0(goldfish_rtc, goldfish_rtc_driver, goldfish_rtc_methods,
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sizeof(struct goldfish_rtc_softc));
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DRIVER_MODULE(goldfish_rtc, simplebus, goldfish_rtc_driver, NULL, NULL);
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