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 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 52 #define BCM2835_NUM_TIMERS 4 53 54 #define DEFAULT_TIMER 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 66 struct systimer { 67 int index; 68 bool enabled; 69 struct eventtimer et; 70 }; 71 72 struct 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 82 static 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 90 static struct bcm_systimer_softc *bcm_systimer_sc = NULL; 91 92 /* Read/Write macros for Timer used as timecounter */ 93 #define bcm_systimer_tc_read_4(reg) \ 94 bus_space_read_4(bcm_systimer_sc->bst, \ 95 bcm_systimer_sc->bsh, reg) 96 97 #define bcm_systimer_tc_write_4(reg, val) \ 98 bus_space_write_4(bcm_systimer_sc->bst, \ 99 bcm_systimer_sc->bsh, reg, val) 100 101 static unsigned bcm_systimer_tc_get_timecount(struct timecounter *); 102 103 static struct timecounter bcm_systimer_tc = { 104 .tc_name = "BCM2835 Timecounter", 105 .tc_get_timecount = bcm_systimer_tc_get_timecount, 106 .tc_poll_pps = NULL, 107 .tc_counter_mask = ~0u, 108 .tc_frequency = 0, 109 .tc_quality = 1000, 110 }; 111 112 static unsigned 113 bcm_systimer_tc_get_timecount(struct timecounter *tc) 114 { 115 return bcm_systimer_tc_read_4(SYSTIMER_CLO); 116 } 117 118 static int 119 bcm_systimer_start(struct eventtimer *et, sbintime_t first, sbintime_t period) 120 { 121 struct systimer *st = et->et_priv; 122 uint32_t clo, clo1; 123 uint32_t count; 124 register_t s; 125 126 if (first != 0) { 127 128 count = ((uint32_t)et->et_frequency * first) >> 32; 129 130 s = intr_disable(); 131 clo = bcm_systimer_tc_read_4(SYSTIMER_CLO); 132 restart: 133 clo += count; 134 /* 135 * Clear pending interrupts 136 */ 137 bcm_systimer_tc_write_4(SYSTIMER_CS, (1 << st->index)); 138 bcm_systimer_tc_write_4(SYSTIMER_C0 + st->index*4, clo); 139 clo1 = bcm_systimer_tc_read_4(SYSTIMER_CLO); 140 if ((int32_t)(clo1 - clo) >= 0) { 141 count *= 2; 142 clo = clo1; 143 goto restart; 144 } 145 st->enabled = 1; 146 intr_restore(s); 147 148 return (0); 149 } 150 151 return (EINVAL); 152 } 153 154 static int 155 bcm_systimer_stop(struct eventtimer *et) 156 { 157 struct systimer *st = et->et_priv; 158 st->enabled = 0; 159 160 return (0); 161 } 162 163 static int 164 bcm_systimer_intr(void *arg) 165 { 166 struct systimer *st = (struct systimer *)arg; 167 uint32_t cs; 168 169 cs = bcm_systimer_tc_read_4(SYSTIMER_CS); 170 if ((cs & (1 << st->index)) == 0) 171 return (FILTER_STRAY); 172 173 /* ACK interrupt */ 174 bcm_systimer_tc_write_4(SYSTIMER_CS, (1 << st->index)); 175 if (st->enabled) { 176 if (st->et.et_active) { 177 st->et.et_event_cb(&st->et, st->et.et_arg); 178 } 179 } 180 181 return (FILTER_HANDLED); 182 } 183 184 static int 185 bcm_systimer_probe(device_t dev) 186 { 187 188 if (!ofw_bus_status_okay(dev)) 189 return (ENXIO); 190 191 if (ofw_bus_is_compatible(dev, "broadcom,bcm2835-system-timer")) { 192 device_set_desc(dev, "BCM2835 System Timer"); 193 return (BUS_PROBE_DEFAULT); 194 } 195 196 return (ENXIO); 197 } 198 199 static int 200 bcm_systimer_attach(device_t dev) 201 { 202 struct bcm_systimer_softc *sc = device_get_softc(dev); 203 int err; 204 int rid = 0; 205 206 if (bcm_systimer_sc != NULL) 207 return (EINVAL); 208 209 sc->mem_res = bus_alloc_resource_any(dev, SYS_RES_MEMORY, &rid, RF_ACTIVE); 210 if (sc->mem_res == NULL) { 211 device_printf(dev, "could not allocate memory resource\n"); 212 return (ENXIO); 213 } 214 215 sc->bst = rman_get_bustag(sc->mem_res); 216 sc->bsh = rman_get_bushandle(sc->mem_res); 217 218 /* Request the IRQ resources */ 219 err = bus_alloc_resources(dev, bcm_systimer_irq_spec, 220 sc->irq_res); 221 if (err) { 222 device_printf(dev, "Error: could not allocate irq resources\n"); 223 return (ENXIO); 224 } 225 226 /* TODO: get frequency from FDT */ 227 sc->sysclk_freq = DEFAULT_FREQUENCY; 228 229 /* Setup and enable the timer */ 230 if (bus_setup_intr(dev, sc->irq_res[DEFAULT_TIMER], INTR_TYPE_CLK, 231 bcm_systimer_intr, NULL, &sc->st[DEFAULT_TIMER], 232 &sc->intr_hl[DEFAULT_TIMER]) != 0) { 233 bus_release_resources(dev, bcm_systimer_irq_spec, 234 sc->irq_res); 235 device_printf(dev, "Unable to setup the clock irq handler.\n"); 236 return (ENXIO); 237 } 238 239 sc->st[DEFAULT_TIMER].index = DEFAULT_TIMER; 240 sc->st[DEFAULT_TIMER].enabled = 0; 241 sc->st[DEFAULT_TIMER].et.et_name = malloc(64, M_DEVBUF, M_NOWAIT | M_ZERO); 242 sprintf(sc->st[DEFAULT_TIMER].et.et_name, "BCM2835 Event Timer %d", DEFAULT_TIMER); 243 sc->st[DEFAULT_TIMER].et.et_flags = ET_FLAGS_ONESHOT; 244 sc->st[DEFAULT_TIMER].et.et_quality = 1000; 245 sc->st[DEFAULT_TIMER].et.et_frequency = sc->sysclk_freq; 246 sc->st[DEFAULT_TIMER].et.et_min_period = 247 (MIN_PERIOD << 32) / sc->st[DEFAULT_TIMER].et.et_frequency + 1; 248 sc->st[DEFAULT_TIMER].et.et_max_period = 249 (0x7ffffffeLLU << 32) / sc->st[DEFAULT_TIMER].et.et_frequency; 250 sc->st[DEFAULT_TIMER].et.et_start = bcm_systimer_start; 251 sc->st[DEFAULT_TIMER].et.et_stop = bcm_systimer_stop; 252 sc->st[DEFAULT_TIMER].et.et_priv = &sc->st[DEFAULT_TIMER]; 253 et_register(&sc->st[DEFAULT_TIMER].et); 254 255 bcm_systimer_sc = sc; 256 257 bcm_systimer_tc.tc_frequency = DEFAULT_FREQUENCY; 258 tc_init(&bcm_systimer_tc); 259 260 return (0); 261 } 262 263 static device_method_t bcm_systimer_methods[] = { 264 DEVMETHOD(device_probe, bcm_systimer_probe), 265 DEVMETHOD(device_attach, bcm_systimer_attach), 266 { 0, 0 } 267 }; 268 269 static driver_t bcm_systimer_driver = { 270 "systimer", 271 bcm_systimer_methods, 272 sizeof(struct bcm_systimer_softc), 273 }; 274 275 static devclass_t bcm_systimer_devclass; 276 277 DRIVER_MODULE(bcm_systimer, simplebus, bcm_systimer_driver, bcm_systimer_devclass, 0, 0); 278 279 void 280 DELAY(int usec) 281 { 282 int32_t counts; 283 uint32_t first, last; 284 285 if (bcm_systimer_sc == NULL) { 286 for (; usec > 0; usec--) 287 for (counts = 200; counts > 0; counts--) 288 /* Prevent gcc from optimizing out the loop */ 289 cpufunc_nullop(); 290 return; 291 } 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