1 /* $OpenBSD: gfrtc.c,v 1.3 2022/10/17 19:09:46 kettenis Exp $ */ 2 3 /* 4 * Copyright (c) 2021 Jonathan Gray <jsg@openbsd.org> 5 * 6 * Permission to use, copy, modify, and distribute this software for any 7 * purpose with or without fee is hereby granted, provided that the above 8 * copyright notice and this permission notice appear in all copies. 9 * 10 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES 11 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 12 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR 13 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 14 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 15 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF 16 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 17 */ 18 19 /* 20 * Google Goldfish virtual real-time clock described in 21 * https://android.googlesource.com/platform/external/qemu/+/master/docs/GOLDFISH-VIRTUAL-HARDWARE.TXT 22 */ 23 24 #include <sys/param.h> 25 #include <sys/device.h> 26 #include <sys/malloc.h> 27 #include <sys/systm.h> 28 29 #include <machine/bus.h> 30 #include <machine/fdt.h> 31 #include <dev/clock_subr.h> 32 33 #include <dev/ofw/openfirm.h> 34 #include <dev/ofw/fdt.h> 35 36 #define TIME_LOW 0x00 37 #define TIME_HIGH 0x04 38 #define ALARM_LOW 0x0c 39 #define CLEAR_INTERRUPT 0x10 40 41 struct gfrtc_softc { 42 struct device sc_dev; 43 bus_space_tag_t sc_iot; 44 bus_space_handle_t sc_ioh; 45 struct todr_chip_handle sc_todr; 46 }; 47 48 int gfrtc_match(struct device *, void *, void *); 49 void gfrtc_attach(struct device *, struct device *, void *); 50 int gfrtc_gettime(struct todr_chip_handle *, struct timeval *); 51 int gfrtc_settime(struct todr_chip_handle *, struct timeval *); 52 53 const struct cfattach gfrtc_ca = { 54 sizeof(struct gfrtc_softc), gfrtc_match, gfrtc_attach 55 }; 56 57 struct cfdriver gfrtc_cd = { 58 NULL, "gfrtc", DV_DULL 59 }; 60 61 int 62 gfrtc_gettime(todr_chip_handle_t handle, struct timeval *tv) 63 { 64 struct gfrtc_softc *sc = handle->cookie; 65 uint64_t tl, th; 66 67 tl = bus_space_read_4(sc->sc_iot, sc->sc_ioh, TIME_LOW); 68 th = bus_space_read_4(sc->sc_iot, sc->sc_ioh, TIME_HIGH); 69 70 NSEC_TO_TIMEVAL((th << 32) | tl, tv); 71 72 return 0; 73 } 74 75 int 76 gfrtc_settime(todr_chip_handle_t handle, struct timeval *tv) 77 { 78 struct gfrtc_softc *sc = handle->cookie; 79 uint64_t ns; 80 81 ns = TIMEVAL_TO_NSEC(tv); 82 83 bus_space_write_4(sc->sc_iot, sc->sc_ioh, TIME_HIGH, ns >> 32); 84 bus_space_write_4(sc->sc_iot, sc->sc_ioh, TIME_LOW, ns); 85 86 return 0; 87 } 88 89 int 90 gfrtc_match(struct device *parent, void *match, void *aux) 91 { 92 struct fdt_attach_args *faa = aux; 93 94 return OF_is_compatible(faa->fa_node, "google,goldfish-rtc"); 95 } 96 97 void 98 gfrtc_attach(struct device *parent, struct device *self, void *aux) 99 { 100 struct fdt_attach_args *faa = aux; 101 struct gfrtc_softc *sc = (struct gfrtc_softc *) self; 102 103 sc->sc_iot = faa->fa_iot; 104 105 if (bus_space_map(sc->sc_iot, faa->fa_reg[0].addr, 106 faa->fa_reg[0].size, 0, &sc->sc_ioh)) { 107 printf(": failed to map mem space\n"); 108 return; 109 } 110 111 sc->sc_todr.cookie = sc; 112 sc->sc_todr.todr_gettime = gfrtc_gettime; 113 sc->sc_todr.todr_settime = gfrtc_settime; 114 sc->sc_todr.todr_quality = 1000; 115 todr_attach(&sc->sc_todr); 116 117 printf("\n"); 118 } 119