1/* 2 * Copyright (c) 2012 Oleksandr Tymoshenko <gonzo@freebsd.org> 3 * Copyright (c) 2012 Damjan Marion <dmarion@freebsd.org> 4 * All rights reserved. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 18 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 25 * SUCH DAMAGE. 26 */ 27 28#include <sys/cdefs.h>
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30 31#include <sys/param.h> 32#include <sys/systm.h> 33#include <sys/bus.h> 34#include <sys/kernel.h> 35#include <sys/module.h> 36#include <sys/malloc.h> 37#include <sys/rman.h> 38#include <sys/timeet.h> 39#include <sys/timetc.h> 40#include <sys/watchdog.h> 41#include <machine/bus.h> 42#include <machine/cpu.h> 43#include <machine/intr.h> 44 45#include <dev/fdt/fdt_common.h> 46#include <dev/ofw/openfirm.h> 47#include <dev/ofw/ofw_bus.h> 48#include <dev/ofw/ofw_bus_subr.h> 49 50#include <machine/bus.h> 51#include <machine/fdt.h> 52 53#define BCM2835_NUM_TIMERS 4 54 55#define DEFAULT_TIMER 3 56#define DEFAULT_FREQUENCY 1000000 57#define MIN_PERIOD 5LLU 58 59#define SYSTIMER_CS 0x00 60#define SYSTIMER_CLO 0x04 61#define SYSTIMER_CHI 0x08 62#define SYSTIMER_C0 0x0C 63#define SYSTIMER_C1 0x10 64#define SYSTIMER_C2 0x14 65#define SYSTIMER_C3 0x18 66 67struct systimer { 68 int index; 69 bool enabled; 70 struct eventtimer et; 71}; 72 73struct bcm_systimer_softc { 74 struct resource* mem_res; 75 struct resource* irq_res[BCM2835_NUM_TIMERS]; 76 void* intr_hl[BCM2835_NUM_TIMERS]; 77 uint32_t sysclk_freq; 78 bus_space_tag_t bst; 79 bus_space_handle_t bsh; 80 struct systimer st[BCM2835_NUM_TIMERS]; 81}; 82 83static struct resource_spec bcm_systimer_irq_spec[] = { 84 { SYS_RES_IRQ, 0, RF_ACTIVE }, 85 { SYS_RES_IRQ, 1, RF_ACTIVE }, 86 { SYS_RES_IRQ, 2, RF_ACTIVE }, 87 { SYS_RES_IRQ, 3, RF_ACTIVE }, 88 { -1, 0, 0 } 89}; 90 91static struct bcm_systimer_softc *bcm_systimer_sc = NULL; 92 93/* Read/Write macros for Timer used as timecounter */ 94#define bcm_systimer_tc_read_4(reg) \ 95 bus_space_read_4(bcm_systimer_sc->bst, \ 96 bcm_systimer_sc->bsh, reg) 97 98#define bcm_systimer_tc_write_4(reg, val) \ 99 bus_space_write_4(bcm_systimer_sc->bst, \ 100 bcm_systimer_sc->bsh, reg, val) 101 102static unsigned bcm_systimer_tc_get_timecount(struct timecounter *); 103 104static struct timecounter bcm_systimer_tc = { 105 .tc_name = "BCM2835 Timecounter", 106 .tc_get_timecount = bcm_systimer_tc_get_timecount, 107 .tc_poll_pps = NULL, 108 .tc_counter_mask = ~0u, 109 .tc_frequency = 0, 110 .tc_quality = 1000, 111}; 112 113static unsigned 114bcm_systimer_tc_get_timecount(struct timecounter *tc) 115{ 116 return bcm_systimer_tc_read_4(SYSTIMER_CLO); 117} 118 119static int 120bcm_systimer_start(struct eventtimer *et, sbintime_t first, sbintime_t period) 121{ 122 struct systimer *st = et->et_priv; 123 uint32_t clo, clo1; 124 uint32_t count; 125 register_t s; 126 127 if (first != 0) { 128 129 count = ((uint32_t)et->et_frequency * first) >> 32; 130 131 s = intr_disable(); 132 clo = bcm_systimer_tc_read_4(SYSTIMER_CLO); 133restart: 134 clo += count; 135 /* 136 * Clear pending interrupts 137 */ 138 bcm_systimer_tc_write_4(SYSTIMER_CS, (1 << st->index)); 139 bcm_systimer_tc_write_4(SYSTIMER_C0 + st->index*4, clo); 140 clo1 = bcm_systimer_tc_read_4(SYSTIMER_CLO); 141 if ((int32_t)(clo1 - clo) >= 0) { 142 count *= 2; 143 clo = clo1; 144 goto restart; 145 } 146 st->enabled = 1; 147 intr_restore(s); 148 149 return (0); 150 } 151 152 return (EINVAL); 153} 154 155static int 156bcm_systimer_stop(struct eventtimer *et) 157{ 158 struct systimer *st = et->et_priv; 159 st->enabled = 0; 160 161 return (0); 162} 163 164static int 165bcm_systimer_intr(void *arg) 166{ 167 struct systimer *st = (struct systimer *)arg; 168 uint32_t cs; 169 170 cs = bcm_systimer_tc_read_4(SYSTIMER_CS); 171 if ((cs & (1 << st->index)) == 0) 172 return (FILTER_STRAY); 173 174 /* ACK interrupt */ 175 bcm_systimer_tc_write_4(SYSTIMER_CS, (1 << st->index)); 176 if (st->enabled) { 177 if (st->et.et_active) { 178 st->et.et_event_cb(&st->et, st->et.et_arg); 179 } 180 } 181 182 return (FILTER_HANDLED); 183} 184 185static int 186bcm_systimer_probe(device_t dev) 187{ 188 189 if (!ofw_bus_status_okay(dev)) 190 return (ENXIO); 191 192 if (ofw_bus_is_compatible(dev, "broadcom,bcm2835-system-timer")) { 193 device_set_desc(dev, "BCM2835 System Timer"); 194 return (BUS_PROBE_DEFAULT); 195 } 196 197 return (ENXIO); 198} 199 200static int 201bcm_systimer_attach(device_t dev) 202{ 203 struct bcm_systimer_softc *sc = device_get_softc(dev); 204 int err; 205 int rid = 0; 206 207 if (bcm_systimer_sc != NULL) 208 return (EINVAL); 209 210 sc->mem_res = bus_alloc_resource_any(dev, SYS_RES_MEMORY, &rid, RF_ACTIVE); 211 if (sc->mem_res == NULL) { 212 device_printf(dev, "could not allocate memory resource\n"); 213 return (ENXIO); 214 } 215 216 sc->bst = rman_get_bustag(sc->mem_res); 217 sc->bsh = rman_get_bushandle(sc->mem_res); 218 219 /* Request the IRQ resources */ 220 err = bus_alloc_resources(dev, bcm_systimer_irq_spec, 221 sc->irq_res); 222 if (err) { 223 device_printf(dev, "Error: could not allocate irq resources\n"); 224 return (ENXIO); 225 } 226 227 /* TODO: get frequency from FDT */ 228 sc->sysclk_freq = DEFAULT_FREQUENCY; 229 230 /* Setup and enable the timer */ 231 if (bus_setup_intr(dev, sc->irq_res[DEFAULT_TIMER], INTR_TYPE_CLK, 232 bcm_systimer_intr, NULL, &sc->st[DEFAULT_TIMER], 233 &sc->intr_hl[DEFAULT_TIMER]) != 0) { 234 bus_release_resources(dev, bcm_systimer_irq_spec, 235 sc->irq_res); 236 device_printf(dev, "Unable to setup the clock irq handler.\n"); 237 return (ENXIO); 238 } 239 240 sc->st[DEFAULT_TIMER].index = DEFAULT_TIMER; 241 sc->st[DEFAULT_TIMER].enabled = 0; 242 sc->st[DEFAULT_TIMER].et.et_name = malloc(64, M_DEVBUF, M_NOWAIT | M_ZERO); 243 sprintf(sc->st[DEFAULT_TIMER].et.et_name, "BCM2835 Event Timer %d", DEFAULT_TIMER); 244 sc->st[DEFAULT_TIMER].et.et_flags = ET_FLAGS_ONESHOT; 245 sc->st[DEFAULT_TIMER].et.et_quality = 1000; 246 sc->st[DEFAULT_TIMER].et.et_frequency = sc->sysclk_freq; 247 sc->st[DEFAULT_TIMER].et.et_min_period = 248 (MIN_PERIOD << 32) / sc->st[DEFAULT_TIMER].et.et_frequency + 1; 249 sc->st[DEFAULT_TIMER].et.et_max_period = 250 (0x7ffffffeLLU << 32) / sc->st[DEFAULT_TIMER].et.et_frequency; 251 sc->st[DEFAULT_TIMER].et.et_start = bcm_systimer_start; 252 sc->st[DEFAULT_TIMER].et.et_stop = bcm_systimer_stop; 253 sc->st[DEFAULT_TIMER].et.et_priv = &sc->st[DEFAULT_TIMER]; 254 et_register(&sc->st[DEFAULT_TIMER].et); 255 256 bcm_systimer_sc = sc; 257 258 bcm_systimer_tc.tc_frequency = DEFAULT_FREQUENCY; 259 tc_init(&bcm_systimer_tc); 260 261 return (0); 262} 263 264static device_method_t bcm_systimer_methods[] = { 265 DEVMETHOD(device_probe, bcm_systimer_probe), 266 DEVMETHOD(device_attach, bcm_systimer_attach), 267 { 0, 0 } 268}; 269 270static driver_t bcm_systimer_driver = { 271 "systimer", 272 bcm_systimer_methods, 273 sizeof(struct bcm_systimer_softc), 274}; 275 276static devclass_t bcm_systimer_devclass; 277 278DRIVER_MODULE(bcm_systimer, simplebus, bcm_systimer_driver, bcm_systimer_devclass, 0, 0); 279 280void
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