gfrtc.c revision 1.1
1/* $NetBSD: gfrtc.c,v 1.1 2023/12/29 23:31:44 thorpej Exp $ */ 2 3/*- 4 * Copyright (c) 2023 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to The NetBSD Foundation 8 * by Nick Hudson. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 29 * POSSIBILITY OF SUCH DAMAGE. 30 */ 31 32#include <sys/cdefs.h> 33__KERNEL_RCSID(0, "$NetBSD: gfrtc.c,v 1.1 2023/12/29 23:31:44 thorpej Exp $"); 34 35#include <sys/param.h> 36 37#include <sys/bus.h> 38#include <sys/device.h> 39 40#include <dev/goldfish/gfrtcvar.h> 41 42/* 43 * https://android.googlesource.com/platform/external/qemu/+/master/docs/GOLDFISH-VIRTUAL-HARDWARE.TXT 44 */ 45 46#define GOLDFISH_RTC_READ(sc, reg) \ 47 bus_space_read_4((sc)->sc_bst, (sc)->sc_bsh, (reg)) 48#define GOLDFISH_RTC_WRITE(sc, reg, val) \ 49 bus_space_write_4((sc)->sc_bst, (sc)->sc_bsh, (reg), (val)) 50 51 52#define GOLDFISH_RTC_TIME_LOW 0x00 53#define GOLDFISH_RTC_TIME_HIGH 0x04 54 55 56static int 57gfrtc_gettime(struct todr_chip_handle *ch, struct timeval *tv) 58{ 59 struct gfrtc_softc *sc = ch->cookie; 60 const uint64_t lo = GOLDFISH_RTC_READ(sc, GOLDFISH_RTC_TIME_LOW); 61 const uint64_t hi = GOLDFISH_RTC_READ(sc, GOLDFISH_RTC_TIME_HIGH); 62 63 uint64_t nsec = (hi << 32) | lo; 64 65 tv->tv_sec = nsec / 1000000000; 66 tv->tv_usec = (nsec - tv->tv_sec) / 1000; // Always 0? 67 68 return 0; 69} 70 71static int 72gfrtc_settime(struct todr_chip_handle *ch, struct timeval *tv) 73{ 74 struct gfrtc_softc *sc = ch->cookie; 75 76 uint64_t nsec = (tv->tv_sec * 1000000 + tv->tv_usec) * 1000; 77 uint32_t hi = nsec >> 32; 78 uint32_t lo = nsec; 79 80 GOLDFISH_RTC_WRITE(sc, GOLDFISH_RTC_TIME_HIGH, hi); 81 GOLDFISH_RTC_WRITE(sc, GOLDFISH_RTC_TIME_HIGH, lo); 82 83 return 0; 84} 85 86 87void 88gfrtc_attach(struct gfrtc_softc * const sc) 89{ 90 sc->sc_todr.cookie = sc; 91 sc->sc_todr.todr_gettime = gfrtc_gettime; 92 sc->sc_todr.todr_settime = gfrtc_settime; 93 sc->sc_todr.todr_setwen = NULL; 94 95 todr_attach(&sc->sc_todr); 96} 97