1 /* $NetBSD: g2rtc.c,v 1.1 2006/09/05 11:09:36 uwe Exp $ */ 2 3 /*- 4 * Copyright (c) 2002 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. All advertising materials mentioning features or use of this software 16 * must display the following acknowledgement: 17 * This product includes software developed by the NetBSD 18 * Foundation, Inc. and its contributors. 19 * 4. Neither the name of The NetBSD Foundation nor the names of its 20 * contributors may be used to endorse or promote products derived 21 * from this software without specific prior written permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 24 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 25 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 26 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 27 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 28 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 29 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 30 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 31 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 32 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 33 * POSSIBILITY OF SUCH DAMAGE. 34 */ 35 36 #include <sys/cdefs.h> 37 __KERNEL_RCSID(0, "$NetBSD: g2rtc.c,v 1.1 2006/09/05 11:09:36 uwe Exp $"); 38 39 #include <sys/param.h> 40 #include <sys/systm.h> 41 42 #include <dev/clock_subr.h> 43 44 #include <machine/bus.h> 45 #include <dreamcast/dev/g2/g2busvar.h> 46 47 48 #define G2RTC_REG_BASE 0x00710000 49 #define G2RTC_REG_SIZE 12 50 51 /* Offset by 20 years, 5 of them are leap */ 52 #define G2RTC_OFFSET (20 * SECYR + 5 * SECDAY) 53 54 struct g2rtc_softc { 55 struct device sc_dev; 56 57 bus_space_tag_t sc_bt; 58 bus_space_handle_t sc_bh; 59 }; 60 61 /* autoconf glue */ 62 static int g2rtc_match(struct device *, struct cfdata *, void *); 63 static void g2rtc_attach(struct device *, struct device *, void *); 64 65 CFATTACH_DECL(g2rtc, sizeof(struct g2rtc_softc), 66 g2rtc_match, g2rtc_attach, NULL, NULL); 67 68 69 /* todr(9) methods */ 70 static int g2rtc_todr_gettime(todr_chip_handle_t, volatile struct timeval *); 71 static int g2rtc_todr_settime(todr_chip_handle_t, volatile struct timeval *); 72 73 static struct todr_chip_handle g2rtc_todr_handle = { 74 .cookie = NULL, /* set on attach */ 75 .todr_gettime = g2rtc_todr_gettime, 76 .todr_settime = g2rtc_todr_settime, 77 }; 78 79 80 static inline uint32_t g2rtc_read(bus_space_tag_t, bus_space_handle_t); 81 82 83 static int 84 g2rtc_match(struct device *parent, struct cfdata *cf, void *aux) 85 { 86 static int g2rtc_matched = 0; 87 88 if (g2rtc_matched) 89 return 0; 90 91 g2rtc_matched = 1; 92 return 1; 93 } 94 95 96 static void 97 g2rtc_attach(struct device *parent, struct device *self, void *aux) 98 { 99 struct g2rtc_softc *sc = (void *)self; 100 struct g2bus_attach_args *ga = aux; 101 102 sc->sc_bt = ga->ga_memt; 103 if (bus_space_map(sc->sc_bt, G2RTC_REG_BASE, G2RTC_REG_SIZE, 0, 104 &sc->sc_bh) != 0) 105 { 106 printf(": unable to map registers\n"); 107 return; 108 } 109 printf(": time-of-day clock\n"); 110 111 g2rtc_todr_handle.cookie = sc; 112 todr_attach(&g2rtc_todr_handle); 113 } 114 115 116 static inline uint32_t 117 g2rtc_read(bus_space_tag_t bt, bus_space_handle_t bh) 118 { 119 120 return ((bus_space_read_4(bt, bh, 0) & 0xffff) << 16) 121 | (bus_space_read_4(bt, bh, 4) & 0xffff); 122 } 123 124 125 /* 126 * Get time-of-day and convert to `struct timeval'. 127 * Return 0 on success; an error number otherwise. 128 */ 129 static int 130 g2rtc_todr_gettime(todr_chip_handle_t handle, volatile struct timeval *tv) 131 { 132 struct g2rtc_softc *sc = handle->cookie; 133 uint32_t new, old; 134 int i; 135 136 for (old = 0;;) { 137 for (i = 0; i < 3; i++) { 138 new = g2rtc_read(sc->sc_bt, sc->sc_bh); 139 if (new != old) 140 break; 141 } 142 if (i < 3) 143 old = new; 144 else 145 break; 146 } 147 148 tv->tv_sec = new - G2RTC_OFFSET; 149 tv->tv_usec = 0; 150 151 return 0; 152 } 153 154 155 /* 156 * Set the time-of-day clock based on the value of the `struct timeval' arg. 157 * Return 0 on success; an error number otherwise. 158 */ 159 static int 160 g2rtc_todr_settime(todr_chip_handle_t handle, volatile struct timeval *tv) 161 { 162 struct g2rtc_softc *sc = handle->cookie; 163 uint32_t secs; 164 int i, retry; 165 166 secs = (uint32_t)tv->tv_sec + G2RTC_OFFSET; 167 168 for (retry = 0; retry < 5; retry++) { 169 170 /* Don't change the order */ 171 bus_space_write_4(sc->sc_bt, sc->sc_bh, 8, 1); 172 bus_space_write_4(sc->sc_bt, sc->sc_bh, 4, secs & 0xffff); 173 bus_space_write_4(sc->sc_bt, sc->sc_bh, 0, secs >> 16); 174 175 /* verify */ 176 for (i = 0; i < 3; i++) 177 if (g2rtc_read(sc->sc_bt, sc->sc_bh) == secs) 178 return 0; /* ok */ 179 } 180 181 return EIO; 182 183 } 184