1 /* $NetBSD: gfrtc_fdt.c,v 1.1 2023/05/08 07:51:44 skrll 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_fdt.c,v 1.1 2023/05/08 07:51:44 skrll Exp $"); 34 35 #include <sys/param.h> 36 37 #include <sys/bus.h> 38 #include <sys/device.h> 39 40 #include <dev/fdt/fdtvar.h> 41 42 /* 43 * https://android.googlesource.com/platform/external/qemu/+/master/docs/GOLDFISH-VIRTUAL-HARDWARE.TXT 44 */ 45 46 static const struct device_compatible_entry compat_data[] = { 47 { .compat = "google,goldfish-rtc" }, 48 DEVICE_COMPAT_EOL 49 }; 50 51 struct gfrtc_fdt_softc { 52 device_t sc_dev; 53 bus_space_tag_t sc_bst; 54 bus_space_handle_t sc_bsh; 55 56 struct todr_chip_handle sc_todr; 57 }; 58 59 #define GOLDFISH_RTC_READ(sc, reg) \ 60 bus_space_read_4((sc)->sc_bst, (sc)->sc_bsh, (reg)) 61 #define GOLDFISH_RTC_WRITE(sc, reg, val) \ 62 bus_space_write_4((sc)->sc_bst, (sc)->sc_bsh, (reg), (val)) 63 64 65 #define GOLDFISH_RTC_TIME_LOW 0x00 66 #define GOLDFISH_RTC_TIME_HIGH 0x04 67 68 69 static int 70 gfrtc_gettime(struct todr_chip_handle *ch, struct timeval *tv) 71 { 72 struct gfrtc_fdt_softc *sc = ch->cookie; 73 const uint64_t lo = GOLDFISH_RTC_READ(sc, GOLDFISH_RTC_TIME_LOW); 74 const uint64_t hi = GOLDFISH_RTC_READ(sc, GOLDFISH_RTC_TIME_HIGH); 75 76 uint64_t nsec = (hi << 32) | lo; 77 78 tv->tv_sec = nsec / 1000000000; 79 tv->tv_usec = (nsec - tv->tv_sec) / 1000; // Always 0? 80 81 return 0; 82 } 83 84 static int 85 gfrtc_settime(struct todr_chip_handle *ch, struct timeval *tv) 86 { 87 struct gfrtc_fdt_softc *sc = ch->cookie; 88 89 uint64_t nsec = (tv->tv_sec * 1000000 + tv->tv_usec) * 1000; 90 uint32_t hi = nsec >> 32; 91 uint32_t lo = nsec; 92 93 GOLDFISH_RTC_WRITE(sc, GOLDFISH_RTC_TIME_HIGH, hi); 94 GOLDFISH_RTC_WRITE(sc, GOLDFISH_RTC_TIME_HIGH, lo); 95 96 return 0; 97 } 98 99 100 static int 101 gfrtc_fdt_match(device_t parent, cfdata_t cf, void *aux) 102 { 103 struct fdt_attach_args * const faa = aux; 104 105 return of_compatible_match(faa->faa_phandle, compat_data); 106 } 107 108 static void 109 gfrtc_fdt_attach(device_t parent, device_t self, void *aux) 110 { 111 struct gfrtc_fdt_softc * const sc = device_private(self); 112 struct fdt_attach_args * const faa = aux; 113 const int phandle = faa->faa_phandle; 114 bus_addr_t addr; 115 bus_size_t size; 116 117 if (fdtbus_get_reg(phandle, 0, &addr, &size) != 0) { 118 aprint_error(": couldn't get registers\n"); 119 return; 120 } 121 122 sc->sc_dev = self; 123 sc->sc_bst = faa->faa_bst; 124 if (bus_space_map(sc->sc_bst, addr, size, 0, &sc->sc_bsh) != 0) { 125 aprint_error(": couldn't map registers\n"); 126 return; 127 } 128 129 aprint_naive("\n"); 130 aprint_normal(": Google Goldfish RTC\n"); 131 132 sc->sc_todr.cookie = sc; 133 sc->sc_todr.todr_gettime = gfrtc_gettime; 134 sc->sc_todr.todr_settime = gfrtc_settime; 135 sc->sc_todr.todr_setwen = NULL; 136 137 todr_attach(&sc->sc_todr); 138 } 139 140 CFATTACH_DECL_NEW(gfrtc_fdt, sizeof(struct gfrtc_fdt_softc), 141 gfrtc_fdt_match, gfrtc_fdt_attach, NULL, NULL); 142