1 /* $NetBSD: rambo.c,v 1.13 2012/10/27 17:18:03 chs 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 1.13 2012/10/27 17:18:03 chs 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(device_t, cfdata_t, void *); 54 static void rambo_attach(device_t, device_t, 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 evcnt sc_intrcnt; 61 bus_space_tag_t sc_bst; 62 bus_space_handle_t sc_bsh; 63 u_int32_t sc_tclast; 64 u_int32_t sc_hzticks; 65 }; 66 67 static struct rambo_softc *rambo; 68 69 CFATTACH_DECL_NEW(rambo, sizeof(struct rambo_softc), 70 rambo_match, rambo_attach, NULL, NULL); 71 72 static int 73 rambo_match(device_t parent, cfdata_t cf, void *aux) 74 { 75 return 1; 76 } 77 78 static void 79 rambo_attach(device_t parent, device_t self, void *aux) 80 { 81 struct confargs *ca = aux; 82 struct rambo_softc *sc = device_private(self); 83 84 sc->sc_bst = ca->ca_bustag; 85 86 if (bus_space_map(ca->ca_bustag, ca->ca_addr, 256, 87 BUS_SPACE_MAP_LINEAR, 88 &sc->sc_bsh) != 0) { 89 printf(": cannot map registers\n"); 90 return; 91 } 92 evcnt_attach_dynamic(&sc->sc_intrcnt, EVCNT_TYPE_INTR, NULL, 93 "timer", "intr"); 94 95 /* Setup RAMBO Timer to generate timer interrupts */ 96 sc->sc_hzticks = HZ_TO_TICKS(hz); 97 98 sc->sc_tclast = 0; 99 bus_space_write_4(sc->sc_bst, sc->sc_bsh, RB_TCOUNT, 0); 100 bus_space_write_4(sc->sc_bst, sc->sc_bsh, RB_TBREAK, sc->sc_hzticks); 101 102 bus_space_write_4(sc->sc_bst, sc->sc_bsh, RB_CTLREG, 103 RB_PARITY_EN | RB_BUZZOFF | RB_CLR_IOERR); 104 105 printf(": parity enabled\n"); 106 rambo = sc; 107 platform.clkinit = rambo_tc_init; 108 } 109 110 void 111 rambo_clkintr(struct clockframe *cf) 112 { 113 register u_int32_t tbreak, tcount; 114 register int delta; 115 116 rambo->sc_intrcnt.ev_count++; 117 tbreak = bus_space_read_4(rambo->sc_bst, rambo->sc_bsh, RB_TBREAK); 118 tcount = bus_space_read_4(rambo->sc_bst, rambo->sc_bsh, RB_TCOUNT); 119 delta = tcount - tbreak; 120 121 if (delta > (rambo->sc_hzticks>>1)) { 122 /* 123 * Either tcount may overtake the updated tbreak value 124 * or we have missed several interrupt's 125 */ 126 int cycles = 10 * hz; 127 while (cycles && tbreak < tcount) { 128 hardclock(cf); 129 rambo->sc_tclast = tbreak; 130 tbreak += rambo->sc_hzticks; 131 cycles--; 132 } 133 if (cycles == 0) { /* catchup failed - assume we are in sync */ 134 tcount = bus_space_read_4(rambo->sc_bst, 135 rambo->sc_bsh, RB_TCOUNT); 136 rambo->sc_tclast = tbreak = tcount; 137 } 138 } else { 139 hardclock(cf); 140 rambo->sc_tclast = tbreak; 141 } 142 143 tbreak += rambo->sc_hzticks; 144 145 bus_space_write_4(rambo->sc_bst, rambo->sc_bsh, RB_TBREAK, tbreak); 146 } 147 148 /* 149 * Calculate the number of microseconds since the last clock tick 150 */ 151 static unsigned 152 rambo_get_timecount(struct timecounter *tc) 153 { 154 155 return (bus_space_read_4(rambo->sc_bst, rambo->sc_bsh, RB_TCOUNT)); 156 } 157 158 static void 159 rambo_tc_init(void) 160 { 161 static struct timecounter tc = { 162 .tc_get_timecount = rambo_get_timecount, 163 .tc_frequency = RB_FREQUENCY, 164 .tc_quality = 100, 165 .tc_name = "rambo_tcount", 166 .tc_counter_mask = ~0 167 }; 168 169 tc_init(&tc); 170 } 171