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/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 count = ((uint32_t)et->et_frequency * first) >> 32; 142 143 s = intr_disable(); 144 clo = bcm_systimer_tc_read_4(SYSTIMER_CLO); 145 restart: 146 clo += count; 147 /* 148 * Clear pending interrupts 149 */ 150 bcm_systimer_tc_write_4(SYSTIMER_CS, (1 << st->index)); 151 bcm_systimer_tc_write_4(SYSTIMER_C0 + st->index*4, clo); 152 clo1 = bcm_systimer_tc_read_4(SYSTIMER_CLO); 153 if ((int32_t)(clo1 - clo) >= 0) { 154 count *= 2; 155 clo = clo1; 156 goto restart; 157 } 158 st->enabled = 1; 159 intr_restore(s); 160 161 return (0); 162 } 163 164 return (EINVAL); 165 } 166 167 static int 168 bcm_systimer_stop(struct eventtimer *et) 169 { 170 struct systimer *st = et->et_priv; 171 st->enabled = 0; 172 173 return (0); 174 } 175 176 static int 177 bcm_systimer_intr(void *arg) 178 { 179 struct systimer *st = (struct systimer *)arg; 180 uint32_t cs; 181 182 cs = bcm_systimer_tc_read_4(SYSTIMER_CS); 183 if ((cs & (1 << st->index)) == 0) 184 return (FILTER_STRAY); 185 186 /* ACK interrupt */ 187 bcm_systimer_tc_write_4(SYSTIMER_CS, (1 << st->index)); 188 if (st->enabled) { 189 if (st->et.et_active) { 190 st->et.et_event_cb(&st->et, st->et.et_arg); 191 } 192 } 193 194 return (FILTER_HANDLED); 195 } 196 197 static int 198 bcm_systimer_probe(device_t dev) 199 { 200 201 if (!ofw_bus_status_okay(dev)) 202 return (ENXIO); 203 204 if (ofw_bus_search_compatible(dev, compat_data)->ocd_data == 0) 205 return (ENXIO); 206 207 return (BUS_PROBE_DEFAULT); 208 } 209 210 static int 211 bcm_systimer_attach(device_t dev) 212 { 213 struct bcm_systimer_softc *sc = device_get_softc(dev); 214 int err; 215 int rid = 0; 216 217 if (bcm_systimer_sc != NULL) 218 return (EINVAL); 219 220 sc->mem_res = bus_alloc_resource_any(dev, SYS_RES_MEMORY, &rid, RF_ACTIVE); 221 if (sc->mem_res == NULL) { 222 device_printf(dev, "could not allocate memory resource\n"); 223 return (ENXIO); 224 } 225 226 sc->bst = rman_get_bustag(sc->mem_res); 227 sc->bsh = rman_get_bushandle(sc->mem_res); 228 229 /* Request the IRQ resources */ 230 err = bus_alloc_resources(dev, bcm_systimer_irq_spec, 231 sc->irq_res); 232 if (err) { 233 device_printf(dev, "Error: could not allocate irq resources\n"); 234 return (ENXIO); 235 } 236 237 /* TODO: get frequency from FDT */ 238 sc->sysclk_freq = DEFAULT_FREQUENCY; 239 240 /* Setup and enable the timer */ 241 if (bus_setup_intr(dev, sc->irq_res[DEFAULT_TIMER], INTR_TYPE_CLK, 242 bcm_systimer_intr, NULL, &sc->st[DEFAULT_TIMER], 243 &sc->intr_hl[DEFAULT_TIMER]) != 0) { 244 bus_release_resources(dev, bcm_systimer_irq_spec, 245 sc->irq_res); 246 device_printf(dev, "Unable to setup the clock irq handler.\n"); 247 return (ENXIO); 248 } 249 250 sc->st[DEFAULT_TIMER].index = DEFAULT_TIMER; 251 sc->st[DEFAULT_TIMER].enabled = 0; 252 sc->st[DEFAULT_TIMER].et.et_name = DEFAULT_TIMER_NAME; 253 sc->st[DEFAULT_TIMER].et.et_flags = ET_FLAGS_ONESHOT; 254 sc->st[DEFAULT_TIMER].et.et_quality = 1000; 255 sc->st[DEFAULT_TIMER].et.et_frequency = sc->sysclk_freq; 256 sc->st[DEFAULT_TIMER].et.et_min_period = 257 (MIN_PERIOD << 32) / sc->st[DEFAULT_TIMER].et.et_frequency + 1; 258 sc->st[DEFAULT_TIMER].et.et_max_period = 259 (0x7ffffffeLLU << 32) / sc->st[DEFAULT_TIMER].et.et_frequency; 260 sc->st[DEFAULT_TIMER].et.et_start = bcm_systimer_start; 261 sc->st[DEFAULT_TIMER].et.et_stop = bcm_systimer_stop; 262 sc->st[DEFAULT_TIMER].et.et_priv = &sc->st[DEFAULT_TIMER]; 263 et_register(&sc->st[DEFAULT_TIMER].et); 264 265 bcm_systimer_sc = sc; 266 267 if (device_get_unit(dev) == 0) 268 arm_set_delay(bcm_systimer_delay, sc); 269 270 bcm_systimer_tc.tc_frequency = DEFAULT_FREQUENCY; 271 tc_init(&bcm_systimer_tc); 272 273 return (0); 274 } 275 276 static device_method_t bcm_systimer_methods[] = { 277 DEVMETHOD(device_probe, bcm_systimer_probe), 278 DEVMETHOD(device_attach, bcm_systimer_attach), 279 { 0, 0 } 280 }; 281 282 static driver_t bcm_systimer_driver = { 283 "systimer", 284 bcm_systimer_methods, 285 sizeof(struct bcm_systimer_softc), 286 }; 287 288 DRIVER_MODULE(bcm_systimer, simplebus, bcm_systimer_driver, 0, 0); 289 290 static void 291 bcm_systimer_delay(int usec, void *arg) 292 { 293 int32_t counts; 294 uint32_t first, last; 295 296 /* Get the number of times to count */ 297 counts = usec * (bcm_systimer_tc.tc_frequency / 1000000) + 1; 298 299 first = bcm_systimer_tc_read_4(SYSTIMER_CLO); 300 301 while (counts > 0) { 302 last = bcm_systimer_tc_read_4(SYSTIMER_CLO); 303 if (last == first) 304 continue; 305 if (last>first) { 306 counts -= (int32_t)(last - first); 307 } else { 308 counts -= (int32_t)((0xFFFFFFFF - first) + last); 309 } 310 first = last; 311 } 312 } 313