bcm2835_tmr.c revision 1.1.2.4
1 1.1.2.4 riz /* $NetBSD: bcm2835_tmr.c,v 1.1.2.4 2013/02/13 01:36:14 riz Exp $ */ 2 1.1.2.2 jdc 3 1.1.2.2 jdc /*- 4 1.1.2.2 jdc * Copyright (c) 2012 The NetBSD Foundation, Inc. 5 1.1.2.2 jdc * All rights reserved. 6 1.1.2.2 jdc * 7 1.1.2.2 jdc * This code is derived from software contributed to The NetBSD Foundation 8 1.1.2.2 jdc * by Nick Hudson 9 1.1.2.2 jdc * 10 1.1.2.2 jdc * Redistribution and use in source and binary forms, with or without 11 1.1.2.2 jdc * modification, are permitted provided that the following conditions 12 1.1.2.2 jdc * are met: 13 1.1.2.2 jdc * 1. Redistributions of source code must retain the above copyright 14 1.1.2.2 jdc * notice, this list of conditions and the following disclaimer. 15 1.1.2.2 jdc * 2. Redistributions in binary form must reproduce the above copyright 16 1.1.2.2 jdc * notice, this list of conditions and the following disclaimer in the 17 1.1.2.2 jdc * documentation and/or other materials provided with the distribution. 18 1.1.2.2 jdc * 19 1.1.2.2 jdc * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 20 1.1.2.2 jdc * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 21 1.1.2.2 jdc * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 22 1.1.2.2 jdc * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 23 1.1.2.2 jdc * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 24 1.1.2.2 jdc * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 25 1.1.2.2 jdc * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 26 1.1.2.2 jdc * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 27 1.1.2.2 jdc * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 28 1.1.2.2 jdc * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 29 1.1.2.2 jdc * POSSIBILITY OF SUCH DAMAGE. 30 1.1.2.2 jdc */ 31 1.1.2.2 jdc 32 1.1.2.2 jdc #include <sys/cdefs.h> 33 1.1.2.4 riz __KERNEL_RCSID(0, "$NetBSD: bcm2835_tmr.c,v 1.1.2.4 2013/02/13 01:36:14 riz Exp $"); 34 1.1.2.2 jdc 35 1.1.2.2 jdc #include <sys/param.h> 36 1.1.2.2 jdc #include <sys/systm.h> 37 1.1.2.2 jdc #include <sys/device.h> 38 1.1.2.2 jdc #include <sys/kernel.h> 39 1.1.2.2 jdc #include <sys/timetc.h> 40 1.1.2.2 jdc #include <sys/bus.h> 41 1.1.2.2 jdc 42 1.1.2.2 jdc #include <arm/broadcom/bcm_amba.h> 43 1.1.2.2 jdc #include <arm/broadcom/bcm2835_intr.h> 44 1.1.2.2 jdc #include <arm/broadcom/bcm2835reg.h> 45 1.1.2.2 jdc 46 1.1.2.2 jdc #define BCM2835_STIMER_CS 0x00 47 1.1.2.2 jdc #define BCM2835_STIMER_M0 __BIT(0) 48 1.1.2.2 jdc #define BCM2835_STIMER_M1 __BIT(1) 49 1.1.2.2 jdc #define BCM2835_STIMER_M2 __BIT(2) 50 1.1.2.2 jdc #define BCM2835_STIMER_M3 __BIT(3) 51 1.1.2.2 jdc #define BCM2835_STIMER_CLO 0x04 52 1.1.2.2 jdc #define BCM2835_STIMER_CHI 0x08 53 1.1.2.2 jdc #define BCM2835_STIMER_C0 0x0c 54 1.1.2.2 jdc #define BCM2835_STIMER_C1 0x10 55 1.1.2.2 jdc #define BCM2835_STIMER_C2 0x14 56 1.1.2.2 jdc #define BCM2835_STIMER_C3 0x18 57 1.1.2.2 jdc 58 1.1.2.2 jdc #define BCM2835_STIMER_HZ 1000000 59 1.1.2.2 jdc 60 1.1.2.2 jdc static const uint32_t counts_per_usec = (BCM2835_STIMER_HZ / 1000000); 61 1.1.2.2 jdc static uint32_t counts_per_hz = ~0; 62 1.1.2.4 riz 63 1.1.2.2 jdc struct bcm2835tmr_softc { 64 1.1.2.2 jdc device_t sc_dev; 65 1.1.2.2 jdc 66 1.1.2.2 jdc bus_space_tag_t sc_iot; 67 1.1.2.2 jdc bus_space_handle_t sc_ioh; 68 1.1.2.2 jdc }; 69 1.1.2.2 jdc 70 1.1.2.2 jdc static int bcmtmr_match(device_t, cfdata_t, void *); 71 1.1.2.2 jdc static void bcmtmr_attach(device_t, device_t, void *); 72 1.1.2.2 jdc 73 1.1.2.2 jdc static int clockhandler(void *); 74 1.1.2.2 jdc 75 1.1.2.2 jdc static u_int bcm2835tmr_get_timecount(struct timecounter *); 76 1.1.2.2 jdc 77 1.1.2.2 jdc static struct bcm2835tmr_softc *bcm2835tmr_sc; 78 1.1.2.2 jdc 79 1.1.2.2 jdc static struct timecounter bcm2835tmr_timecounter = { 80 1.1.2.2 jdc .tc_get_timecount = bcm2835tmr_get_timecount, 81 1.1.2.2 jdc .tc_poll_pps = 0, 82 1.1.2.2 jdc .tc_counter_mask = ~0u, 83 1.1.2.2 jdc .tc_frequency = BCM2835_STIMER_HZ, 84 1.1.2.2 jdc .tc_name = NULL, /* set by attach */ 85 1.1.2.2 jdc .tc_quality = 100, 86 1.1.2.2 jdc .tc_priv = NULL, 87 1.1.2.2 jdc .tc_next = NULL, 88 1.1.2.2 jdc }; 89 1.1.2.2 jdc 90 1.1.2.2 jdc CFATTACH_DECL_NEW(bcmtmr_amba, sizeof(struct bcm2835tmr_softc), 91 1.1.2.2 jdc bcmtmr_match, bcmtmr_attach, NULL, NULL); 92 1.1.2.2 jdc 93 1.1.2.2 jdc /* ARGSUSED */ 94 1.1.2.2 jdc static int 95 1.1.2.2 jdc bcmtmr_match(device_t parent, cfdata_t match, void *aux) 96 1.1.2.2 jdc { 97 1.1.2.2 jdc struct amba_attach_args *aaa = aux; 98 1.1.2.2 jdc 99 1.1.2.2 jdc if (strcmp(aaa->aaa_name, "bcmtmr") != 0) 100 1.1.2.2 jdc return 0; 101 1.1.2.2 jdc 102 1.1.2.2 jdc return 1; 103 1.1.2.2 jdc } 104 1.1.2.2 jdc 105 1.1.2.2 jdc static void 106 1.1.2.2 jdc bcmtmr_attach(device_t parent, device_t self, void *aux) 107 1.1.2.2 jdc { 108 1.1.2.2 jdc struct bcm2835tmr_softc *sc = device_private(self); 109 1.1.2.2 jdc struct amba_attach_args *aaa = aux; 110 1.1.2.2 jdc 111 1.1.2.2 jdc aprint_naive("\n"); 112 1.1.2.2 jdc aprint_normal(": VC System Timer\n"); 113 1.1.2.2 jdc 114 1.1.2.2 jdc if (bcm2835tmr_sc == NULL) 115 1.1.2.2 jdc bcm2835tmr_sc = sc; 116 1.1.2.4 riz 117 1.1.2.2 jdc sc->sc_dev = self; 118 1.1.2.2 jdc sc->sc_iot = aaa->aaa_iot; 119 1.1.2.2 jdc 120 1.1.2.2 jdc if (bus_space_map(aaa->aaa_iot, aaa->aaa_addr, BCM2835_STIMER_SIZE, 0, 121 1.1.2.2 jdc &sc->sc_ioh)) { 122 1.1.2.2 jdc aprint_error_dev(sc->sc_dev, "unable to map device\n"); 123 1.1.2.2 jdc return; 124 1.1.2.2 jdc } 125 1.1.2.4 riz 126 1.1.2.2 jdc bcm2835tmr_timecounter.tc_name = device_xname(self); 127 1.1.2.2 jdc } 128 1.1.2.2 jdc 129 1.1.2.2 jdc void 130 1.1.2.2 jdc cpu_initclocks(void) 131 1.1.2.2 jdc { 132 1.1.2.2 jdc struct bcm2835tmr_softc *sc = bcm2835tmr_sc; 133 1.1.2.2 jdc void *clock_ih; 134 1.1.2.2 jdc uint32_t stcl; 135 1.1.2.4 riz 136 1.1.2.2 jdc KASSERT(sc != NULL); 137 1.1.2.2 jdc 138 1.1.2.2 jdc bcm2835tmr_timecounter.tc_priv = sc; 139 1.1.2.2 jdc 140 1.1.2.2 jdc counts_per_hz = BCM2835_STIMER_HZ / hz; 141 1.1.2.2 jdc 142 1.1.2.2 jdc stcl = bus_space_read_4(sc->sc_iot, sc->sc_ioh, BCM2835_STIMER_CLO); 143 1.1.2.2 jdc stcl += counts_per_hz; 144 1.1.2.2 jdc 145 1.1.2.2 jdc bus_space_write_4(sc->sc_iot, sc->sc_ioh, BCM2835_STIMER_C3, stcl); 146 1.1.2.2 jdc clock_ih = bcm2835_intr_establish(BCM2835_INT_TIMER3, IPL_CLOCK, 147 1.1.2.2 jdc clockhandler, NULL); 148 1.1.2.2 jdc if (clock_ih == NULL) 149 1.1.2.2 jdc panic("%s: unable to register timer interrupt", __func__); 150 1.1.2.2 jdc 151 1.1.2.2 jdc tc_init(&bcm2835tmr_timecounter); 152 1.1.2.2 jdc } 153 1.1.2.2 jdc 154 1.1.2.2 jdc void 155 1.1.2.2 jdc delay(unsigned int n) 156 1.1.2.2 jdc { 157 1.1.2.2 jdc struct bcm2835tmr_softc *sc = bcm2835tmr_sc; 158 1.1.2.2 jdc uint32_t last, curr; 159 1.1.2.2 jdc uint32_t delta, usecs; 160 1.1.2.2 jdc 161 1.1.2.2 jdc KASSERT(sc != NULL); 162 1.1.2.2 jdc 163 1.1.2.2 jdc last = bus_space_read_4(sc->sc_iot, sc->sc_ioh, BCM2835_STIMER_CLO); 164 1.1.2.2 jdc 165 1.1.2.2 jdc delta = usecs = 0; 166 1.1.2.2 jdc while (n > usecs) { 167 1.1.2.2 jdc curr = bus_space_read_4(sc->sc_iot, sc->sc_ioh, 168 1.1.2.2 jdc BCM2835_STIMER_CLO); 169 1.1.2.2 jdc 170 1.1.2.2 jdc /* Check to see if the timer has wrapped around. */ 171 1.1.2.2 jdc if (curr < last) 172 1.1.2.3 jdc delta += curr + (UINT32_MAX - last); 173 1.1.2.2 jdc else 174 1.1.2.3 jdc delta += curr - last; 175 1.1.2.2 jdc 176 1.1.2.2 jdc last = curr; 177 1.1.2.2 jdc 178 1.1.2.2 jdc if (delta >= counts_per_usec) { 179 1.1.2.2 jdc usecs += delta / counts_per_usec; 180 1.1.2.2 jdc delta %= counts_per_usec; 181 1.1.2.2 jdc } 182 1.1.2.4 riz } 183 1.1.2.2 jdc 184 1.1.2.2 jdc } 185 1.1.2.2 jdc 186 1.1.2.2 jdc /* 187 1.1.2.2 jdc * clockhandler: 188 1.1.2.2 jdc * 189 1.1.2.2 jdc * Handle the hardclock interrupt. 190 1.1.2.2 jdc */ 191 1.1.2.2 jdc static int 192 1.1.2.2 jdc clockhandler(void *arg) 193 1.1.2.2 jdc { 194 1.1.2.2 jdc struct bcm2835tmr_softc *sc = bcm2835tmr_sc; 195 1.1.2.2 jdc struct clockframe *frame = arg; 196 1.1.2.2 jdc uint32_t curr, status; 197 1.1.2.4 riz 198 1.1.2.2 jdc status = bus_space_read_4(sc->sc_iot, sc->sc_ioh, 199 1.1.2.2 jdc BCM2835_STIMER_CS); 200 1.1.2.2 jdc 201 1.1.2.2 jdc if (!(status & BCM2835_STIMER_M3)) 202 1.1.2.2 jdc return 0; 203 1.1.2.2 jdc 204 1.1.2.2 jdc bus_space_write_4(sc->sc_iot, sc->sc_ioh, BCM2835_STIMER_CS, status); 205 1.1.2.2 jdc 206 1.1.2.2 jdc hardclock(frame); 207 1.1.2.2 jdc 208 1.1.2.2 jdc curr = bus_space_read_4(sc->sc_iot, sc->sc_ioh, BCM2835_STIMER_CLO); 209 1.1.2.2 jdc 210 1.1.2.2 jdc curr += counts_per_hz; 211 1.1.2.2 jdc bus_space_write_4(sc->sc_iot, sc->sc_ioh, BCM2835_STIMER_C3, curr); 212 1.1.2.2 jdc 213 1.1.2.2 jdc return 1; 214 1.1.2.2 jdc } 215 1.1.2.2 jdc 216 1.1.2.2 jdc void 217 1.1.2.2 jdc setstatclockrate(int newhz) 218 1.1.2.2 jdc { 219 1.1.2.2 jdc } 220 1.1.2.2 jdc 221 1.1.2.2 jdc static u_int 222 1.1.2.2 jdc bcm2835tmr_get_timecount(struct timecounter *tc) 223 1.1.2.2 jdc { 224 1.1.2.2 jdc struct bcm2835tmr_softc *sc = tc->tc_priv; 225 1.1.2.2 jdc 226 1.1.2.2 jdc return bus_space_read_4(sc->sc_iot, sc->sc_ioh, BCM2835_STIMER_CLO); 227 1.1.2.2 jdc } 228 1.1.2.2 jdc 229
Indexes created Tue Oct 21 16:10:11 GMT 2025