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