1 /* $NetBSD: rambo.c,v 1.5 2002/10/02 05:38:11 thorpej 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 CFATTACH_DECL(rambo, sizeof(struct rambo_softc), 73 rambo_match, rambo_attach, NULL, NULL); 74 75 static int 76 rambo_match(parent, cf, aux) 77 struct device *parent; 78 struct cfdata *cf; 79 void *aux; 80 { 81 return 1; 82 } 83 84 static void 85 rambo_attach(parent, self, aux) 86 struct device *parent, *self; 87 void *aux; 88 { 89 struct confargs *ca = aux; 90 struct rambo_softc *sc = (void *)self; 91 92 sc->sc_bst = ca->ca_bustag; 93 94 if (bus_space_map(ca->ca_bustag, ca->ca_addr, 256, 95 BUS_SPACE_MAP_LINEAR, 96 &sc->sc_bsh) != 0) { 97 printf(": cannot map registers\n"); 98 return; 99 } 100 evcnt_attach_dynamic(&sc->sc_intrcnt, EVCNT_TYPE_INTR, NULL, 101 "timer", "intr"); 102 103 /* Setup RAMBO Timer to generate timer interrupts */ 104 sc->sc_hzticks = HZ_TO_TICKS(hz); 105 106 sc->sc_tclast = 0; 107 bus_space_write_4(sc->sc_bst, sc->sc_bsh, RB_TCOUNT, 0); 108 bus_space_write_4(sc->sc_bst, sc->sc_bsh, RB_TBREAK, sc->sc_hzticks); 109 110 bus_space_write_4(sc->sc_bst, sc->sc_bsh, RB_CTLREG, 111 RB_PARITY_EN | RB_BUZZOFF | RB_CLR_IOERR); 112 113 printf(": parity enabled\n"); 114 rambo = sc; 115 platform.clkread = rambo_clkread; 116 } 117 118 void 119 rambo_clkintr(cf) 120 struct clockframe *cf; 121 { 122 register u_int32_t tbreak, tcount; 123 register int delta; 124 125 rambo->sc_intrcnt.ev_count++; 126 tbreak = bus_space_read_4(rambo->sc_bst, rambo->sc_bsh, RB_TBREAK); 127 tcount = bus_space_read_4(rambo->sc_bst, rambo->sc_bsh, RB_TCOUNT); 128 delta = tcount - tbreak; 129 130 if (delta > (rambo->sc_hzticks>>1)) { 131 /* 132 * Either tcount may overtake the updated tbreak value 133 * or we have missed several interrupt's 134 */ 135 int cycles = 10 * hz; 136 while (cycles && tbreak < tcount) { 137 hardclock(cf); 138 rambo->sc_tclast = tbreak; 139 tbreak += rambo->sc_hzticks; 140 cycles--; 141 } 142 if (cycles == 0) { /* catchup failed - assume we are in sync */ 143 tcount = bus_space_read_4(rambo->sc_bst, 144 rambo->sc_bsh, RB_TCOUNT); 145 rambo->sc_tclast = tbreak = tcount; 146 } 147 } else { 148 hardclock(cf); 149 rambo->sc_tclast = tbreak; 150 } 151 152 tbreak += rambo->sc_hzticks; 153 154 bus_space_write_4(rambo->sc_bst, rambo->sc_bsh, RB_TBREAK, tbreak); 155 } 156 157 /* 158 * Calculate the number of microseconds since the last clock tick 159 */ 160 static unsigned 161 rambo_clkread() 162 { 163 register u_int32_t tcount; 164 165 tcount = bus_space_read_4(rambo->sc_bst, rambo->sc_bsh, RB_TCOUNT); 166 return TICKS_TO_USECS(tcount - rambo->sc_tclast); 167 } 168