1 /* 2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD 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/cdefs.h> 31 __FBSDID("$FreeBSD$"); 32 33 #include <sys/param.h> 34 #include <sys/systm.h> 35 #include <sys/bus.h> 36 #include <sys/kernel.h> 37 #include <sys/module.h> 38 #include <sys/malloc.h> 39 #include <sys/rman.h> 40 #include <sys/timeet.h> 41 #include <sys/timetc.h> 42 #include <sys/watchdog.h> 43 #include <machine/bus.h> 44 #include <machine/cpu.h> 45 #include <machine/intr.h> 46 #include <machine/machdep.h> 47 48 #include <dev/ofw/openfirm.h> 49 #include <dev/ofw/ofw_bus.h> 50 #include <dev/ofw/ofw_bus_subr.h> 51 52 #include <machine/bus.h> 53 54 #define BCM2835_NUM_TIMERS 4 55 56 #define DEFAULT_TIMER 3 57 #define DEFAULT_TIMER_NAME "BCM2835-3" 58 #define DEFAULT_FREQUENCY 1000000 59 #define MIN_PERIOD 5LLU 60 61 #define SYSTIMER_CS 0x00 62 #define SYSTIMER_CLO 0x04 63 #define SYSTIMER_CHI 0x08 64 #define SYSTIMER_C0 0x0C 65 #define SYSTIMER_C1 0x10 66 #define SYSTIMER_C2 0x14 67 #define SYSTIMER_C3 0x18 68 69 struct systimer { 70 int index; 71 bool enabled; 72 struct eventtimer et; 73 }; 74 75 struct bcm_systimer_softc { 76 struct resource* mem_res; 77 struct resource* irq_res[BCM2835_NUM_TIMERS]; 78 void* intr_hl[BCM2835_NUM_TIMERS]; 79 uint32_t sysclk_freq; 80 bus_space_tag_t bst; 81 bus_space_handle_t bsh; 82 struct systimer st[BCM2835_NUM_TIMERS]; 83 }; 84 85 static struct resource_spec bcm_systimer_irq_spec[] = { 86 { SYS_RES_IRQ, 0, RF_ACTIVE }, 87 { SYS_RES_IRQ, 1, RF_ACTIVE }, 88 { SYS_RES_IRQ, 2, RF_ACTIVE }, 89 { SYS_RES_IRQ, 3, RF_ACTIVE }, 90 { -1, 0, 0 } 91 }; 92 93 static struct ofw_compat_data compat_data[] = { 94 {"broadcom,bcm2835-system-timer", 1}, 95 {"brcm,bcm2835-system-timer", 1}, 96 {NULL, 0} 97 }; 98 99 static struct bcm_systimer_softc *bcm_systimer_sc = NULL; 100 101 /* Read/Write macros for Timer used as timecounter */ 102 #define bcm_systimer_tc_read_4(reg) \ 103 bus_space_read_4(bcm_systimer_sc->bst, \ 104 bcm_systimer_sc->bsh, reg) 105 106 #define bcm_systimer_tc_write_4(reg, val) \ 107 bus_space_write_4(bcm_systimer_sc->bst, \ 108 bcm_systimer_sc->bsh, reg, val) 109 110 static unsigned bcm_systimer_tc_get_timecount(struct timecounter *); 111 112 static delay_func bcm_systimer_delay; 113 114 static struct timecounter bcm_systimer_tc = { 115 .tc_name = DEFAULT_TIMER_NAME, 116 .tc_get_timecount = bcm_systimer_tc_get_timecount, 117 .tc_poll_pps = NULL, 118 .tc_counter_mask = ~0u, 119 .tc_frequency = 0, 120 .tc_quality = 1000, 121 }; 122 123 static unsigned 124 bcm_systimer_tc_get_timecount(struct timecounter *tc) 125 { 126 if (bcm_systimer_sc == NULL) 127 return (0); 128 129 return bcm_systimer_tc_read_4(SYSTIMER_CLO); 130 } 131 132 static int 133 bcm_systimer_start(struct eventtimer *et, sbintime_t first, sbintime_t period) 134 { 135 struct systimer *st = et->et_priv; 136 uint32_t clo, clo1; 137 uint32_t count; 138 register_t s; 139 140 if (first != 0) { 141 142 count = ((uint32_t)et->et_frequency * first) >> 32; 143 144 s = intr_disable(); 145 clo = bcm_systimer_tc_read_4(SYSTIMER_CLO); 146 restart: 147 clo += count; 148 /* 149 * Clear pending interrupts 150 */ 151 bcm_systimer_tc_write_4(SYSTIMER_CS, (1 << st->index)); 152 bcm_systimer_tc_write_4(SYSTIMER_C0 + st->index*4, clo); 153 clo1 = bcm_systimer_tc_read_4(SYSTIMER_CLO); 154 if ((int32_t)(clo1 - clo) >= 0) { 155 count *= 2; 156 clo = clo1; 157 goto restart; 158 } 159 st->enabled = 1; 160 intr_restore(s); 161 162 return (0); 163 } 164 165 return (EINVAL); 166 } 167 168 static int 169 bcm_systimer_stop(struct eventtimer *et) 170 { 171 struct systimer *st = et->et_priv; 172 st->enabled = 0; 173 174 return (0); 175 } 176 177 static int 178 bcm_systimer_intr(void *arg) 179 { 180 struct systimer *st = (struct systimer *)arg; 181 uint32_t cs; 182 183 cs = bcm_systimer_tc_read_4(SYSTIMER_CS); 184 if ((cs & (1 << st->index)) == 0) 185 return (FILTER_STRAY); 186 187 /* ACK interrupt */ 188 bcm_systimer_tc_write_4(SYSTIMER_CS, (1 << st->index)); 189 if (st->enabled) { 190 if (st->et.et_active) { 191 st->et.et_event_cb(&st->et, st->et.et_arg); 192 } 193 } 194 195 return (FILTER_HANDLED); 196 } 197 198 static int 199 bcm_systimer_probe(device_t dev) 200 { 201 202 if (!ofw_bus_status_okay(dev)) 203 return (ENXIO); 204 205 if (ofw_bus_search_compatible(dev, compat_data)->ocd_data == 0) 206 return (ENXIO); 207 208 return (BUS_PROBE_DEFAULT); 209 } 210 211 static int 212 bcm_systimer_attach(device_t dev) 213 { 214 struct bcm_systimer_softc *sc = device_get_softc(dev); 215 int err; 216 int rid = 0; 217 218 if (bcm_systimer_sc != NULL) 219 return (EINVAL); 220 221 sc->mem_res = bus_alloc_resource_any(dev, SYS_RES_MEMORY, &rid, RF_ACTIVE); 222 if (sc->mem_res == NULL) { 223 device_printf(dev, "could not allocate memory resource\n"); 224 return (ENXIO); 225 } 226 227 sc->bst = rman_get_bustag(sc->mem_res); 228 sc->bsh = rman_get_bushandle(sc->mem_res); 229 230 /* Request the IRQ resources */ 231 err = bus_alloc_resources(dev, bcm_systimer_irq_spec, 232 sc->irq_res); 233 if (err) { 234 device_printf(dev, "Error: could not allocate irq resources\n"); 235 return (ENXIO); 236 } 237 238 /* TODO: get frequency from FDT */ 239 sc->sysclk_freq = DEFAULT_FREQUENCY; 240 241 /* Setup and enable the timer */ 242 if (bus_setup_intr(dev, sc->irq_res[DEFAULT_TIMER], INTR_TYPE_CLK, 243 bcm_systimer_intr, NULL, &sc->st[DEFAULT_TIMER], 244 &sc->intr_hl[DEFAULT_TIMER]) != 0) { 245 bus_release_resources(dev, bcm_systimer_irq_spec, 246 sc->irq_res); 247 device_printf(dev, "Unable to setup the clock irq handler.\n"); 248 return (ENXIO); 249 } 250 251 sc->st[DEFAULT_TIMER].index = DEFAULT_TIMER; 252 sc->st[DEFAULT_TIMER].enabled = 0; 253 sc->st[DEFAULT_TIMER].et.et_name = DEFAULT_TIMER_NAME; 254 sc->st[DEFAULT_TIMER].et.et_flags = ET_FLAGS_ONESHOT; 255 sc->st[DEFAULT_TIMER].et.et_quality = 1000; 256 sc->st[DEFAULT_TIMER].et.et_frequency = sc->sysclk_freq; 257 sc->st[DEFAULT_TIMER].et.et_min_period = 258 (MIN_PERIOD << 32) / sc->st[DEFAULT_TIMER].et.et_frequency + 1; 259 sc->st[DEFAULT_TIMER].et.et_max_period = 260 (0x7ffffffeLLU << 32) / sc->st[DEFAULT_TIMER].et.et_frequency; 261 sc->st[DEFAULT_TIMER].et.et_start = bcm_systimer_start; 262 sc->st[DEFAULT_TIMER].et.et_stop = bcm_systimer_stop; 263 sc->st[DEFAULT_TIMER].et.et_priv = &sc->st[DEFAULT_TIMER]; 264 et_register(&sc->st[DEFAULT_TIMER].et); 265 266 bcm_systimer_sc = sc; 267 268 if (device_get_unit(dev) == 0) 269 arm_set_delay(bcm_systimer_delay, sc); 270 271 bcm_systimer_tc.tc_frequency = DEFAULT_FREQUENCY; 272 tc_init(&bcm_systimer_tc); 273 274 return (0); 275 } 276 277 static device_method_t bcm_systimer_methods[] = { 278 DEVMETHOD(device_probe, bcm_systimer_probe), 279 DEVMETHOD(device_attach, bcm_systimer_attach), 280 { 0, 0 } 281 }; 282 283 static driver_t bcm_systimer_driver = { 284 "systimer", 285 bcm_systimer_methods, 286 sizeof(struct bcm_systimer_softc), 287 }; 288 289 static devclass_t bcm_systimer_devclass; 290 291 DRIVER_MODULE(bcm_systimer, simplebus, bcm_systimer_driver, bcm_systimer_devclass, 0, 0); 292 293 static void 294 bcm_systimer_delay(int usec, void *arg) 295 { 296 struct bcm_systimer_softc *sc; 297 int32_t counts; 298 uint32_t first, last; 299 300 sc = (struct bcm_systimer_softc *) arg; 301 302 /* Get the number of times to count */ 303 counts = usec * (bcm_systimer_tc.tc_frequency / 1000000) + 1; 304 305 first = bcm_systimer_tc_read_4(SYSTIMER_CLO); 306 307 while (counts > 0) { 308 last = bcm_systimer_tc_read_4(SYSTIMER_CLO); 309 if (last == first) 310 continue; 311 if (last>first) { 312 counts -= (int32_t)(last - first); 313 } else { 314 counts -= (int32_t)((0xFFFFFFFF - first) + last); 315 } 316 first = last; 317 } 318 } 319