1 /* $NetBSD: rambo.c,v 1.3 2000/09/06 07:52:47 wdk Exp $ */ 2 3 /* 4 * Copyright (c) 2000 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to The NetBSD Foundation 8 * by Wayne Knowles 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 * 3. All advertising materials mentioning features or use of this software 19 * must display the following acknowledgement: 20 * This product includes software developed by the NetBSD 21 * Foundation, Inc. and its contributors. 22 * 4. Neither the name of The NetBSD Foundation nor the names of its 23 * contributors may be used to endorse or promote products derived 24 * from this software without specific prior written permission. 25 * 26 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 27 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 28 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 29 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 30 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 31 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 32 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 33 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 34 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 35 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 36 * POSSIBILITY OF SUCH DAMAGE. 37 */ 38 39 #include <sys/param.h> 40 #include <sys/kernel.h> 41 #include <sys/device.h> 42 #include <sys/systm.h> 43 44 #include <machine/cpu.h> 45 #include <machine/mainboard.h> 46 #include <machine/autoconf.h> 47 #include <machine/sysconf.h> 48 #include <machine/bus.h> 49 50 #include <mipsco/obio/rambo.h> 51 52 /* 53 * Timer & Interrupt manipulation routines for the Rambo Custom ASIC 54 */ 55 56 static int rambo_match __P((struct device *, struct cfdata *, void *)); 57 static void rambo_attach __P((struct device *, struct device *, void *)); 58 static unsigned rambo_clkread __P((void)); 59 void rambo_clkintr __P((struct clockframe *)); 60 61 struct rambo_softc { 62 struct device dev; 63 struct evcnt sc_intrcnt; 64 bus_space_tag_t sc_bst; 65 bus_space_handle_t sc_bsh; 66 u_int32_t sc_tclast; 67 u_int32_t sc_hzticks; 68 }; 69 70 static struct rambo_softc *rambo; 71 72 struct cfattach rambo_ca = { 73 sizeof(struct rambo_softc), rambo_match, rambo_attach 74 }; 75 76 static int 77 rambo_match(parent, cf, aux) 78 struct device *parent; 79 struct cfdata *cf; 80 void *aux; 81 { 82 return 1; 83 } 84 85 static void 86 rambo_attach(parent, self, aux) 87 struct device *parent, *self; 88 void *aux; 89 { 90 struct confargs *ca = aux; 91 struct rambo_softc *sc = (void *)self; 92 93 sc->sc_bst = ca->ca_bustag; 94 95 if (bus_space_map(ca->ca_bustag, ca->ca_addr, 256, 96 BUS_SPACE_MAP_LINEAR, 97 &sc->sc_bsh) != 0) { 98 printf(": cannot map registers\n"); 99 return; 100 } 101 evcnt_attach_dynamic(&sc->sc_intrcnt, EVCNT_TYPE_INTR, NULL, 102 "timer", "intr"); 103 104 /* Setup RAMBO Timer to generate timer interrupts */ 105 sc->sc_hzticks = HZ_TO_TICKS(hz); 106 107 sc->sc_tclast = 0; 108 bus_space_write_4(sc->sc_bst, sc->sc_bsh, RB_TCOUNT, 0); 109 bus_space_write_4(sc->sc_bst, sc->sc_bsh, RB_TBREAK, sc->sc_hzticks); 110 111 bus_space_write_4(sc->sc_bst, sc->sc_bsh, RB_CTLREG, 112 RB_PARITY_EN | RB_BUZZOFF | RB_CLR_IOERR); 113 114 printf(": parity enabled\n"); 115 rambo = sc; 116 platform.clkread = rambo_clkread; 117 } 118 119 void 120 rambo_clkintr(cf) 121 struct clockframe *cf; 122 { 123 register u_int32_t tbreak, tcount; 124 register int delta; 125 126 rambo->sc_intrcnt.ev_count++; 127 tbreak = bus_space_read_4(rambo->sc_bst, rambo->sc_bsh, RB_TBREAK); 128 tcount = bus_space_read_4(rambo->sc_bst, rambo->sc_bsh, RB_TCOUNT); 129 delta = tcount - tbreak; 130 131 if (delta > (rambo->sc_hzticks>>1)) { 132 /* 133 * Either tcount may overtake the updated tbreak value 134 * or we have missed several interrupt's 135 */ 136 int cycles = 10 * hz; 137 while (cycles && tbreak < tcount) { 138 hardclock(cf); 139 rambo->sc_tclast = tbreak; 140 tbreak += rambo->sc_hzticks; 141 cycles--; 142 } 143 if (cycles == 0) { /* catchup failed - assume we are in sync */ 144 tcount = bus_space_read_4(rambo->sc_bst, 145 rambo->sc_bsh, RB_TCOUNT); 146 rambo->sc_tclast = tbreak = tcount; 147 } 148 } else { 149 hardclock(cf); 150 rambo->sc_tclast = tbreak; 151 } 152 153 tbreak += rambo->sc_hzticks; 154 155 bus_space_write_4(rambo->sc_bst, rambo->sc_bsh, RB_TBREAK, tbreak); 156 } 157 158 /* 159 * Calculate the number of microseconds since the last clock tick 160 */ 161 static unsigned 162 rambo_clkread() 163 { 164 register u_int32_t tcount; 165 166 tcount = bus_space_read_4(rambo->sc_bst, rambo->sc_bsh, RB_TCOUNT); 167 return TICKS_TO_USECS(tcount - rambo->sc_tclast); 168 } 169