rambo.c revision 1.6
1 /* $NetBSD: rambo.c,v 1.6 2003/07/15 02:43:44 lukem 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/cdefs.h> 40 __KERNEL_RCSID(0, "$NetBSD: rambo.c,v 1.6 2003/07/15 02:43:44 lukem Exp $"); 41 42 #include <sys/param.h> 43 #include <sys/kernel.h> 44 #include <sys/device.h> 45 #include <sys/systm.h> 46 47 #include <machine/cpu.h> 48 #include <machine/mainboard.h> 49 #include <machine/autoconf.h> 50 #include <machine/sysconf.h> 51 #include <machine/bus.h> 52 53 #include <mipsco/obio/rambo.h> 54 55 /* 56 * Timer & Interrupt manipulation routines for the Rambo Custom ASIC 57 */ 58 59 static int rambo_match __P((struct device *, struct cfdata *, void *)); 60 static void rambo_attach __P((struct device *, struct device *, void *)); 61 static unsigned rambo_clkread __P((void)); 62 void rambo_clkintr __P((struct clockframe *)); 63 64 struct rambo_softc { 65 struct device dev; 66 struct evcnt sc_intrcnt; 67 bus_space_tag_t sc_bst; 68 bus_space_handle_t sc_bsh; 69 u_int32_t sc_tclast; 70 u_int32_t sc_hzticks; 71 }; 72 73 static struct rambo_softc *rambo; 74 75 CFATTACH_DECL(rambo, sizeof(struct rambo_softc), 76 rambo_match, rambo_attach, NULL, NULL); 77 78 static int 79 rambo_match(parent, cf, aux) 80 struct device *parent; 81 struct cfdata *cf; 82 void *aux; 83 { 84 return 1; 85 } 86 87 static void 88 rambo_attach(parent, self, aux) 89 struct device *parent, *self; 90 void *aux; 91 { 92 struct confargs *ca = aux; 93 struct rambo_softc *sc = (void *)self; 94 95 sc->sc_bst = ca->ca_bustag; 96 97 if (bus_space_map(ca->ca_bustag, ca->ca_addr, 256, 98 BUS_SPACE_MAP_LINEAR, 99 &sc->sc_bsh) != 0) { 100 printf(": cannot map registers\n"); 101 return; 102 } 103 evcnt_attach_dynamic(&sc->sc_intrcnt, EVCNT_TYPE_INTR, NULL, 104 "timer", "intr"); 105 106 /* Setup RAMBO Timer to generate timer interrupts */ 107 sc->sc_hzticks = HZ_TO_TICKS(hz); 108 109 sc->sc_tclast = 0; 110 bus_space_write_4(sc->sc_bst, sc->sc_bsh, RB_TCOUNT, 0); 111 bus_space_write_4(sc->sc_bst, sc->sc_bsh, RB_TBREAK, sc->sc_hzticks); 112 113 bus_space_write_4(sc->sc_bst, sc->sc_bsh, RB_CTLREG, 114 RB_PARITY_EN | RB_BUZZOFF | RB_CLR_IOERR); 115 116 printf(": parity enabled\n"); 117 rambo = sc; 118 platform.clkread = rambo_clkread; 119 } 120 121 void 122 rambo_clkintr(cf) 123 struct clockframe *cf; 124 { 125 register u_int32_t tbreak, tcount; 126 register int delta; 127 128 rambo->sc_intrcnt.ev_count++; 129 tbreak = bus_space_read_4(rambo->sc_bst, rambo->sc_bsh, RB_TBREAK); 130 tcount = bus_space_read_4(rambo->sc_bst, rambo->sc_bsh, RB_TCOUNT); 131 delta = tcount - tbreak; 132 133 if (delta > (rambo->sc_hzticks>>1)) { 134 /* 135 * Either tcount may overtake the updated tbreak value 136 * or we have missed several interrupt's 137 */ 138 int cycles = 10 * hz; 139 while (cycles && tbreak < tcount) { 140 hardclock(cf); 141 rambo->sc_tclast = tbreak; 142 tbreak += rambo->sc_hzticks; 143 cycles--; 144 } 145 if (cycles == 0) { /* catchup failed - assume we are in sync */ 146 tcount = bus_space_read_4(rambo->sc_bst, 147 rambo->sc_bsh, RB_TCOUNT); 148 rambo->sc_tclast = tbreak = tcount; 149 } 150 } else { 151 hardclock(cf); 152 rambo->sc_tclast = tbreak; 153 } 154 155 tbreak += rambo->sc_hzticks; 156 157 bus_space_write_4(rambo->sc_bst, rambo->sc_bsh, RB_TBREAK, tbreak); 158 } 159 160 /* 161 * Calculate the number of microseconds since the last clock tick 162 */ 163 static unsigned 164 rambo_clkread() 165 { 166 register u_int32_t tcount; 167 168 tcount = bus_space_read_4(rambo->sc_bst, rambo->sc_bsh, RB_TCOUNT); 169 return TICKS_TO_USECS(tcount - rambo->sc_tclast); 170 } 171
Indexes created Tue Sep 30 07:10:03 GMT 2025