/* $NetBSD: gfrtc.c,v 1.5 2024/03/05 11:19:30 isaki Exp $ */
/*-
* Copyright (c) 2023 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Nick Hudson and by Jason R. Thorpe.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: gfrtc.c,v 1.5 2024/03/05 11:19:30 isaki Exp $");
#include <sys/param.h>
#include <sys/bus.h>
#include <sys/device.h>
#include <dev/goldfish/gfrtcvar.h>
#define GOLDFISH_RTC_TIME_LOW 0x00
#define GOLDFISH_RTC_TIME_HIGH 0x04
#define GOLDFISH_RTC_ALARM_LOW 0x08
#define GOLDFISH_RTC_ALARM_HIGH 0x0c
#define GOLDFISH_RTC_IRQ_ENABLED 0x10
#define GOLDFISH_RTC_CLEAR_ALARM 0x14
#define GOLDFISH_RTC_ALARM_STATUS 0x18
#define GOLDFISH_RTC_CLEAR_INTERRUPT 0x1c
/*
*
https://android.googlesource.com/platform/external/qemu/+/master/docs/GOLDFISH-VIRTUAL-HARDWARE.TXT
*
* (Despite what the Google docs say, the Qemu goldfish-rtc implements
* the timer functionality.)
*/
#define GOLDFISH_RTC_READ(sc, reg) \
bus_space_read_4((sc)->sc_bst, (sc)->sc_bsh, (reg))
#define GOLDFISH_RTC_WRITE(sc, reg, val) \
bus_space_write_4((sc)->sc_bst, (sc)->sc_bsh, (reg), (val))
static int
gfrtc_gettime(struct todr_chip_handle *ch, struct timeval *tv)
{
struct gfrtc_softc *sc = ch->cookie;
const uint64_t nsec = gfrtc_get_time(sc);
tv->tv_sec = nsec / 1000000000;
tv->tv_usec = (nsec - tv->tv_sec * 1000000000) / 1000;
return 0;
}
static int
gfrtc_settime(struct todr_chip_handle *ch, struct timeval *tv)
{
struct gfrtc_softc *sc = ch->cookie;
const uint64_t nsec = (tv->tv_sec * 1000000 + tv->tv_usec) * 1000;
const uint32_t hi = (uint32_t)(nsec >> 32);
const uint32_t lo = (uint32_t)nsec;
GOLDFISH_RTC_WRITE(sc, GOLDFISH_RTC_TIME_HIGH, hi);
GOLDFISH_RTC_WRITE(sc, GOLDFISH_RTC_TIME_LOW, lo);
return 0;
}
void
gfrtc_attach(struct gfrtc_softc * const sc, bool todr)
{
aprint_naive("\n");
aprint_normal(": Google Goldfish RTC + timer\n");
/* Cancel any alarms, make sure interrupt is disabled. */
GOLDFISH_RTC_WRITE(sc, GOLDFISH_RTC_IRQ_ENABLED, 0);
GOLDFISH_RTC_WRITE(sc, GOLDFISH_RTC_CLEAR_ALARM, 0);
GOLDFISH_RTC_WRITE(sc, GOLDFISH_RTC_CLEAR_INTERRUPT, 0);
if (todr) {
aprint_normal_dev(sc->sc_dev,
"using as Time of Day Register.\n");
sc->sc_todr.cookie = sc;
sc->sc_todr.todr_gettime = gfrtc_gettime;
sc->sc_todr.todr_settime = gfrtc_settime;
sc->sc_todr.todr_setwen = NULL;
todr_attach(&sc->sc_todr);
}
}
void
gfrtc_delay(device_t dev, unsigned int usec)
{
struct gfrtc_softc *sc = device_private(dev);
uint64_t start_ns, end_ns, min_ns;
/* Get the start time now while we do the setup work. */
start_ns = gfrtc_get_time(sc);
/* Delay for this many nsec. */
min_ns = (uint64_t)usec * 1000;
do {
end_ns = gfrtc_get_time(sc);
} while ((end_ns - start_ns) < min_ns);
}
uint64_t
gfrtc_get_time(struct gfrtc_softc * const sc)
{
const uint64_t lo = GOLDFISH_RTC_READ(sc, GOLDFISH_RTC_TIME_LOW);
const uint64_t hi = GOLDFISH_RTC_READ(sc, GOLDFISH_RTC_TIME_HIGH);
return (hi << 32) | lo;
}
void
gfrtc_set_alarm(struct gfrtc_softc * const sc, const uint64_t next)
{
GOLDFISH_RTC_WRITE(sc, GOLDFISH_RTC_ALARM_HIGH, (uint32_t)(next >> 32));
GOLDFISH_RTC_WRITE(sc, GOLDFISH_RTC_ALARM_LOW, (uint32_t)next);
}
void
gfrtc_clear_alarm(struct gfrtc_softc * const sc)
{
GOLDFISH_RTC_WRITE(sc, GOLDFISH_RTC_CLEAR_ALARM, 0);
}
void
gfrtc_enable_interrupt(struct gfrtc_softc * const sc)
{
GOLDFISH_RTC_WRITE(sc, GOLDFISH_RTC_IRQ_ENABLED, 1);
}
void
gfrtc_disable_interrupt(struct gfrtc_softc * const sc)
{
GOLDFISH_RTC_WRITE(sc, GOLDFISH_RTC_IRQ_ENABLED, 0);
}
void
gfrtc_clear_interrupt(struct gfrtc_softc * const sc)
{
GOLDFISH_RTC_WRITE(sc, GOLDFISH_RTC_CLEAR_INTERRUPT, 0);
}
