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> 29 __FBSDID("$FreeBSD$"); 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 #include <machine/machdep.h> 45 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 52 #define BCM2835_NUM_TIMERS 4 53 54 #define DEFAULT_TIMER 3 55 #define DEFAULT_TIMER_NAME "BCM2835-3" 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 67 struct systimer { 68 int index; 69 bool enabled; 70 struct eventtimer et; 71 }; 72 73 struct 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 83 static 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 91 static 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) 101 102 static unsigned bcm_systimer_tc_get_timecount(struct timecounter *); 103 104 static delay_func bcm_systimer_delay; 105 106 static struct timecounter bcm_systimer_tc = { 107 .tc_name = DEFAULT_TIMER_NAME, 108 .tc_get_timecount = bcm_systimer_tc_get_timecount, 109 .tc_poll_pps = NULL, 110 .tc_counter_mask = ~0u, 111 .tc_frequency = 0, 112 .tc_quality = 1000, 113 }; 114 115 static unsigned 116 bcm_systimer_tc_get_timecount(struct timecounter *tc) 117 { 118 if (bcm_systimer_sc == NULL) 119 return (0); 120 121 return bcm_systimer_tc_read_4(SYSTIMER_CLO); 122 } 123 124 static int 125 bcm_systimer_start(struct eventtimer *et, sbintime_t first, sbintime_t period) 126 { 127 struct systimer *st = et->et_priv; 128 uint32_t clo, clo1; 129 uint32_t count; 130 register_t s; 131 132 if (first != 0) { 133 134 count = ((uint32_t)et->et_frequency * first) >> 32; 135 136 s = intr_disable(); 137 clo = bcm_systimer_tc_read_4(SYSTIMER_CLO); 138 restart: 139 clo += count; 140 /* 141 * Clear pending interrupts 142 */ 143 bcm_systimer_tc_write_4(SYSTIMER_CS, (1 << st->index)); 144 bcm_systimer_tc_write_4(SYSTIMER_C0 + st->index*4, clo); 145 clo1 = bcm_systimer_tc_read_4(SYSTIMER_CLO); 146 if ((int32_t)(clo1 - clo) >= 0) { 147 count *= 2; 148 clo = clo1; 149 goto restart; 150 } 151 st->enabled = 1; 152 intr_restore(s); 153 154 return (0); 155 } 156 157 return (EINVAL); 158 } 159 160 static int 161 bcm_systimer_stop(struct eventtimer *et) 162 { 163 struct systimer *st = et->et_priv; 164 st->enabled = 0; 165 166 return (0); 167 } 168 169 static int 170 bcm_systimer_intr(void *arg) 171 { 172 struct systimer *st = (struct systimer *)arg; 173 uint32_t cs; 174 175 cs = bcm_systimer_tc_read_4(SYSTIMER_CS); 176 if ((cs & (1 << st->index)) == 0) 177 return (FILTER_STRAY); 178 179 /* ACK interrupt */ 180 bcm_systimer_tc_write_4(SYSTIMER_CS, (1 << st->index)); 181 if (st->enabled) { 182 if (st->et.et_active) { 183 st->et.et_event_cb(&st->et, st->et.et_arg); 184 } 185 } 186 187 return (FILTER_HANDLED); 188 } 189 190 static int 191 bcm_systimer_probe(device_t dev) 192 { 193 194 if (!ofw_bus_status_okay(dev)) 195 return (ENXIO); 196 197 if (ofw_bus_is_compatible(dev, "broadcom,bcm2835-system-timer")) { 198 device_set_desc(dev, "BCM2835 System Timer"); 199 return (BUS_PROBE_DEFAULT); 200 } 201 202 return (ENXIO); 203 } 204 205 static int 206 bcm_systimer_attach(device_t dev) 207 { 208 struct bcm_systimer_softc *sc = device_get_softc(dev); 209 int err; 210 int rid = 0; 211 212 if (bcm_systimer_sc != NULL) 213 return (EINVAL); 214 215 sc->mem_res = bus_alloc_resource_any(dev, SYS_RES_MEMORY, &rid, RF_ACTIVE); 216 if (sc->mem_res == NULL) { 217 device_printf(dev, "could not allocate memory resource\n"); 218 return (ENXIO); 219 } 220 221 sc->bst = rman_get_bustag(sc->mem_res); 222 sc->bsh = rman_get_bushandle(sc->mem_res); 223 224 /* Request the IRQ resources */ 225 err = bus_alloc_resources(dev, bcm_systimer_irq_spec, 226 sc->irq_res); 227 if (err) { 228 device_printf(dev, "Error: could not allocate irq resources\n"); 229 return (ENXIO); 230 } 231 232 /* TODO: get frequency from FDT */ 233 sc->sysclk_freq = DEFAULT_FREQUENCY; 234 235 /* Setup and enable the timer */ 236 if (bus_setup_intr(dev, sc->irq_res[DEFAULT_TIMER], INTR_TYPE_CLK, 237 bcm_systimer_intr, NULL, &sc->st[DEFAULT_TIMER], 238 &sc->intr_hl[DEFAULT_TIMER]) != 0) { 239 bus_release_resources(dev, bcm_systimer_irq_spec, 240 sc->irq_res); 241 device_printf(dev, "Unable to setup the clock irq handler.\n"); 242 return (ENXIO); 243 } 244 245 sc->st[DEFAULT_TIMER].index = DEFAULT_TIMER; 246 sc->st[DEFAULT_TIMER].enabled = 0; 247 sc->st[DEFAULT_TIMER].et.et_name = DEFAULT_TIMER_NAME; 248 sc->st[DEFAULT_TIMER].et.et_flags = ET_FLAGS_ONESHOT; 249 sc->st[DEFAULT_TIMER].et.et_quality = 1000; 250 sc->st[DEFAULT_TIMER].et.et_frequency = sc->sysclk_freq; 251 sc->st[DEFAULT_TIMER].et.et_min_period = 252 (MIN_PERIOD << 32) / sc->st[DEFAULT_TIMER].et.et_frequency + 1; 253 sc->st[DEFAULT_TIMER].et.et_max_period = 254 (0x7ffffffeLLU << 32) / sc->st[DEFAULT_TIMER].et.et_frequency; 255 sc->st[DEFAULT_TIMER].et.et_start = bcm_systimer_start; 256 sc->st[DEFAULT_TIMER].et.et_stop = bcm_systimer_stop; 257 sc->st[DEFAULT_TIMER].et.et_priv = &sc->st[DEFAULT_TIMER]; 258 et_register(&sc->st[DEFAULT_TIMER].et); 259 260 bcm_systimer_sc = sc; 261 262 if (device_get_unit(dev) == 0) 263 arm_set_delay(bcm_systimer_delay, sc); 264 265 bcm_systimer_tc.tc_frequency = DEFAULT_FREQUENCY; 266 tc_init(&bcm_systimer_tc); 267 268 return (0); 269 } 270 271 static device_method_t bcm_systimer_methods[] = { 272 DEVMETHOD(device_probe, bcm_systimer_probe), 273 DEVMETHOD(device_attach, bcm_systimer_attach), 274 { 0, 0 } 275 }; 276 277 static driver_t bcm_systimer_driver = { 278 "systimer", 279 bcm_systimer_methods, 280 sizeof(struct bcm_systimer_softc), 281 }; 282 283 static devclass_t bcm_systimer_devclass; 284 285 DRIVER_MODULE(bcm_systimer, simplebus, bcm_systimer_driver, bcm_systimer_devclass, 0, 0); 286 287 static void 288 bcm_systimer_delay(int usec, void *arg) 289 { 290 struct bcm_systimer_softc *sc; 291 int32_t counts; 292 uint32_t first, last; 293 294 sc = (struct bcm_systimer_softc *) arg; 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