rambo.c revision 1.12
1 /* $NetBSD: rambo.c,v 1.12 2009/03/14 21:04:12 dsl 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 * 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: rambo.c,v 1.12 2009/03/14 21:04:12 dsl Exp $"); 34 35 #include <sys/param.h> 36 #include <sys/kernel.h> 37 #include <sys/device.h> 38 #include <sys/systm.h> 39 #include <sys/timetc.h> 40 41 #include <machine/cpu.h> 42 #include <machine/mainboard.h> 43 #include <machine/autoconf.h> 44 #include <machine/sysconf.h> 45 #include <machine/bus.h> 46 47 #include <mipsco/obio/rambo.h> 48 49 /* 50 * Timer & Interrupt manipulation routines for the Rambo Custom ASIC 51 */ 52 53 static int rambo_match(struct device *, struct cfdata *, void *); 54 static void rambo_attach(struct device *, struct device *, void *); 55 static unsigned rambo_get_timecount(struct timecounter *); 56 void rambo_clkintr(struct clockframe *); 57 static void rambo_tc_init(void); 58 59 struct rambo_softc { 60 struct device dev; 61 struct evcnt sc_intrcnt; 62 bus_space_tag_t sc_bst; 63 bus_space_handle_t sc_bsh; 64 u_int32_t sc_tclast; 65 u_int32_t sc_hzticks; 66 }; 67 68 static struct rambo_softc *rambo; 69 70 CFATTACH_DECL(rambo, sizeof(struct rambo_softc), 71 rambo_match, rambo_attach, NULL, NULL); 72 73 static int 74 rambo_match(struct device *parent, struct cfdata *cf, void *aux) 75 { 76 return 1; 77 } 78 79 static void 80 rambo_attach(struct device *parent, struct device *self, void *aux) 81 { 82 struct confargs *ca = aux; 83 struct rambo_softc *sc = (void *)self; 84 85 sc->sc_bst = ca->ca_bustag; 86 87 if (bus_space_map(ca->ca_bustag, ca->ca_addr, 256, 88 BUS_SPACE_MAP_LINEAR, 89 &sc->sc_bsh) != 0) { 90 printf(": cannot map registers\n"); 91 return; 92 } 93 evcnt_attach_dynamic(&sc->sc_intrcnt, EVCNT_TYPE_INTR, NULL, 94 "timer", "intr"); 95 96 /* Setup RAMBO Timer to generate timer interrupts */ 97 sc->sc_hzticks = HZ_TO_TICKS(hz); 98 99 sc->sc_tclast = 0; 100 bus_space_write_4(sc->sc_bst, sc->sc_bsh, RB_TCOUNT, 0); 101 bus_space_write_4(sc->sc_bst, sc->sc_bsh, RB_TBREAK, sc->sc_hzticks); 102 103 bus_space_write_4(sc->sc_bst, sc->sc_bsh, RB_CTLREG, 104 RB_PARITY_EN | RB_BUZZOFF | RB_CLR_IOERR); 105 106 printf(": parity enabled\n"); 107 rambo = sc; 108 platform.clkinit = rambo_tc_init; 109 } 110 111 void 112 rambo_clkintr(struct clockframe *cf) 113 { 114 register u_int32_t tbreak, tcount; 115 register int delta; 116 117 rambo->sc_intrcnt.ev_count++; 118 tbreak = bus_space_read_4(rambo->sc_bst, rambo->sc_bsh, RB_TBREAK); 119 tcount = bus_space_read_4(rambo->sc_bst, rambo->sc_bsh, RB_TCOUNT); 120 delta = tcount - tbreak; 121 122 if (delta > (rambo->sc_hzticks>>1)) { 123 /* 124 * Either tcount may overtake the updated tbreak value 125 * or we have missed several interrupt's 126 */ 127 int cycles = 10 * hz; 128 while (cycles && tbreak < tcount) { 129 hardclock(cf); 130 rambo->sc_tclast = tbreak; 131 tbreak += rambo->sc_hzticks; 132 cycles--; 133 } 134 if (cycles == 0) { /* catchup failed - assume we are in sync */ 135 tcount = bus_space_read_4(rambo->sc_bst, 136 rambo->sc_bsh, RB_TCOUNT); 137 rambo->sc_tclast = tbreak = tcount; 138 } 139 } else { 140 hardclock(cf); 141 rambo->sc_tclast = tbreak; 142 } 143 144 tbreak += rambo->sc_hzticks; 145 146 bus_space_write_4(rambo->sc_bst, rambo->sc_bsh, RB_TBREAK, tbreak); 147 } 148 149 /* 150 * Calculate the number of microseconds since the last clock tick 151 */ 152 static unsigned 153 rambo_get_timecount(struct timecounter *tc) 154 { 155 156 return (bus_space_read_4(rambo->sc_bst, rambo->sc_bsh, RB_TCOUNT)); 157 } 158 159 static void 160 rambo_tc_init(void) 161 { 162 static struct timecounter tc = { 163 .tc_get_timecount = rambo_get_timecount, 164 .tc_frequency = RB_FREQUENCY, 165 .tc_quality = 100, 166 .tc_name = "rambo_tcount", 167 .tc_counter_mask = ~0 168 }; 169 170 tc_init(&tc); 171 } 172
Indexes created Sat Oct 18 08:10:09 GMT 2025