1/* 2 * SPDX-License-Identifier: BSD-2-Clause 3 * 4 * Copyright (c) 2012 Oleksandr Tymoshenko <gonzo@freebsd.org> 5 * Copyright (c) 2012 Damjan Marion <dmarion@freebsd.org> 6 * All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 */ 29 30#include <sys/param.h> 31#include <sys/systm.h> 32#include <sys/bus.h> 33#include <sys/kernel.h> 34#include <sys/module.h> 35#include <sys/malloc.h> 36#include <sys/rman.h> 37#include <sys/timeet.h> 38#include <sys/timetc.h> 39#include <sys/watchdog.h> 40#include <machine/bus.h> 41#include <machine/cpu.h> 42#include <machine/intr.h> 43#include <machine/machdep.h> 44 45#include <dev/ofw/openfirm.h> 46#include <dev/ofw/ofw_bus.h> 47#include <dev/ofw/ofw_bus_subr.h> 48 49#include <machine/bus.h> 50 51#define BCM2835_NUM_TIMERS 4 52 53#define DEFAULT_TIMER 3 54#define DEFAULT_TIMER_NAME "BCM2835-3" 55#define DEFAULT_FREQUENCY 1000000 56#define MIN_PERIOD 5LLU 57 58#define SYSTIMER_CS 0x00 59#define SYSTIMER_CLO 0x04 60#define SYSTIMER_CHI 0x08 61#define SYSTIMER_C0 0x0C 62#define SYSTIMER_C1 0x10 63#define SYSTIMER_C2 0x14 64#define SYSTIMER_C3 0x18 65 66struct systimer { 67 int index; 68 bool enabled; 69 struct eventtimer et; 70}; 71 72struct bcm_systimer_softc { 73 struct resource* mem_res; 74 struct resource* irq_res[BCM2835_NUM_TIMERS]; 75 void* intr_hl[BCM2835_NUM_TIMERS]; 76 uint32_t sysclk_freq; 77 bus_space_tag_t bst; 78 bus_space_handle_t bsh; 79 struct systimer st[BCM2835_NUM_TIMERS]; 80}; 81 82static struct resource_spec bcm_systimer_irq_spec[] = { 83 { SYS_RES_IRQ, 0, RF_ACTIVE }, 84 { SYS_RES_IRQ, 1, RF_ACTIVE }, 85 { SYS_RES_IRQ, 2, RF_ACTIVE }, 86 { SYS_RES_IRQ, 3, RF_ACTIVE }, 87 { -1, 0, 0 } 88}; 89 90static struct ofw_compat_data compat_data[] = { 91 {"broadcom,bcm2835-system-timer", 1}, 92 {"brcm,bcm2835-system-timer", 1}, 93 {NULL, 0} 94}; 95 96static struct bcm_systimer_softc *bcm_systimer_sc = NULL; 97 98/* Read/Write macros for Timer used as timecounter */ 99#define bcm_systimer_tc_read_4(reg) \ 100 bus_space_read_4(bcm_systimer_sc->bst, \ 101 bcm_systimer_sc->bsh, reg) 102 103#define bcm_systimer_tc_write_4(reg, val) \ 104 bus_space_write_4(bcm_systimer_sc->bst, \ 105 bcm_systimer_sc->bsh, reg, val) 106 107static unsigned bcm_systimer_tc_get_timecount(struct timecounter *); 108 109static delay_func bcm_systimer_delay; 110 111static struct timecounter bcm_systimer_tc = { 112 .tc_name = DEFAULT_TIMER_NAME, 113 .tc_get_timecount = bcm_systimer_tc_get_timecount, 114 .tc_poll_pps = NULL, 115 .tc_counter_mask = ~0u, 116 .tc_frequency = 0, 117 .tc_quality = 1000, 118}; 119 120static unsigned 121bcm_systimer_tc_get_timecount(struct timecounter *tc) 122{ 123 if (bcm_systimer_sc == NULL) 124 return (0); 125 126 return bcm_systimer_tc_read_4(SYSTIMER_CLO); 127} 128 129static int 130bcm_systimer_start(struct eventtimer *et, sbintime_t first, sbintime_t period) 131{ 132 struct systimer *st = et->et_priv; 133 uint32_t clo, clo1; 134 uint32_t count; 135 register_t s; 136 137 if (first != 0) { 138 count = ((uint32_t)et->et_frequency * first) >> 32; 139 140 s = intr_disable(); 141 clo = bcm_systimer_tc_read_4(SYSTIMER_CLO); 142restart: 143 clo += count; 144 /* 145 * Clear pending interrupts 146 */ 147 bcm_systimer_tc_write_4(SYSTIMER_CS, (1 << st->index)); 148 bcm_systimer_tc_write_4(SYSTIMER_C0 + st->index*4, clo); 149 clo1 = bcm_systimer_tc_read_4(SYSTIMER_CLO); 150 if ((int32_t)(clo1 - clo) >= 0) { 151 count *= 2; 152 clo = clo1; 153 goto restart; 154 } 155 st->enabled = 1; 156 intr_restore(s); 157 158 return (0); 159 } 160 161 return (EINVAL); 162} 163 164static int 165bcm_systimer_stop(struct eventtimer *et) 166{ 167 struct systimer *st = et->et_priv; 168 st->enabled = 0; 169 170 return (0); 171} 172 173static int 174bcm_systimer_intr(void *arg) 175{ 176 struct systimer *st = (struct systimer *)arg; 177 uint32_t cs; 178 179 cs = bcm_systimer_tc_read_4(SYSTIMER_CS); 180 if ((cs & (1 << st->index)) == 0) 181 return (FILTER_STRAY); 182 183 /* ACK interrupt */ 184 bcm_systimer_tc_write_4(SYSTIMER_CS, (1 << st->index)); 185 if (st->enabled) { 186 if (st->et.et_active) { 187 st->et.et_event_cb(&st->et, st->et.et_arg); 188 } 189 } 190 191 return (FILTER_HANDLED); 192} 193 194static int 195bcm_systimer_probe(device_t dev) 196{ 197 198 if (!ofw_bus_status_okay(dev)) 199 return (ENXIO); 200 201 if (ofw_bus_search_compatible(dev, compat_data)->ocd_data == 0) 202 return (ENXIO); 203 204 return (BUS_PROBE_DEFAULT); 205} 206 207static int 208bcm_systimer_attach(device_t dev) 209{ 210 struct bcm_systimer_softc *sc = device_get_softc(dev); 211 int err; 212 int rid = 0; 213 214 if (bcm_systimer_sc != NULL) 215 return (EINVAL); 216 217 sc->mem_res = bus_alloc_resource_any(dev, SYS_RES_MEMORY, &rid, RF_ACTIVE); 218 if (sc->mem_res == NULL) { 219 device_printf(dev, "could not allocate memory resource\n"); 220 return (ENXIO); 221 } 222 223 sc->bst = rman_get_bustag(sc->mem_res); 224 sc->bsh = rman_get_bushandle(sc->mem_res); 225 226 /* Request the IRQ resources */ 227 err = bus_alloc_resources(dev, bcm_systimer_irq_spec, 228 sc->irq_res); 229 if (err) { 230 device_printf(dev, "Error: could not allocate irq resources\n"); 231 return (ENXIO); 232 } 233 234 /* TODO: get frequency from FDT */ 235 sc->sysclk_freq = DEFAULT_FREQUENCY; 236 237 /* Setup and enable the timer */ 238 if (bus_setup_intr(dev, sc->irq_res[DEFAULT_TIMER], INTR_TYPE_CLK, 239 bcm_systimer_intr, NULL, &sc->st[DEFAULT_TIMER], 240 &sc->intr_hl[DEFAULT_TIMER]) != 0) { 241 bus_release_resources(dev, bcm_systimer_irq_spec, 242 sc->irq_res); 243 device_printf(dev, "Unable to setup the clock irq handler.\n"); 244 return (ENXIO); 245 } 246 247 sc->st[DEFAULT_TIMER].index = DEFAULT_TIMER; 248 sc->st[DEFAULT_TIMER].enabled = 0; 249 sc->st[DEFAULT_TIMER].et.et_name = DEFAULT_TIMER_NAME; 250 sc->st[DEFAULT_TIMER].et.et_flags = ET_FLAGS_ONESHOT; 251 sc->st[DEFAULT_TIMER].et.et_quality = 1000; 252 sc->st[DEFAULT_TIMER].et.et_frequency = sc->sysclk_freq; 253 sc->st[DEFAULT_TIMER].et.et_min_period = 254 (MIN_PERIOD << 32) / sc->st[DEFAULT_TIMER].et.et_frequency + 1; 255 sc->st[DEFAULT_TIMER].et.et_max_period = 256 (0x7ffffffeLLU << 32) / sc->st[DEFAULT_TIMER].et.et_frequency; 257 sc->st[DEFAULT_TIMER].et.et_start = bcm_systimer_start; 258 sc->st[DEFAULT_TIMER].et.et_stop = bcm_systimer_stop; 259 sc->st[DEFAULT_TIMER].et.et_priv = &sc->st[DEFAULT_TIMER]; 260 et_register(&sc->st[DEFAULT_TIMER].et); 261 262 bcm_systimer_sc = sc; 263 264 if (device_get_unit(dev) == 0) 265 arm_set_delay(bcm_systimer_delay, sc); 266 267 bcm_systimer_tc.tc_frequency = DEFAULT_FREQUENCY; 268 tc_init(&bcm_systimer_tc); 269 270 return (0); 271} 272 273static device_method_t bcm_systimer_methods[] = { 274 DEVMETHOD(device_probe, bcm_systimer_probe), 275 DEVMETHOD(device_attach, bcm_systimer_attach), 276 { 0, 0 } 277}; 278 279static driver_t bcm_systimer_driver = { 280 "systimer", 281 bcm_systimer_methods, 282 sizeof(struct bcm_systimer_softc), 283}; 284 285DRIVER_MODULE(bcm_systimer, simplebus, bcm_systimer_driver, 0, 0); 286 287static void 288bcm_systimer_delay(int usec, void *arg) 289{ 290 int32_t counts; 291 uint32_t first, last; 292 293 /* Get the number of times to count */ 294 counts = usec * (bcm_systimer_tc.tc_frequency / 1000000) + 1; 295 296 first = bcm_systimer_tc_read_4(SYSTIMER_CLO); 297 298 while (counts > 0) { 299 last = bcm_systimer_tc_read_4(SYSTIMER_CLO); 300 if (last == first) 301 continue; 302 if (last>first) { 303 counts -= (int32_t)(last - first); 304 } else { 305 counts -= (int32_t)((0xFFFFFFFF - first) + last); 306 } 307 first = last; 308 } 309} 310