1 /*- 2 * Copyright (c) 2012 Damjan Marion <dmarion@Freebsd.org> 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24 * SUCH DAMAGE. 25 */ 26 27 #include <sys/cdefs.h> 28 __FBSDID("$FreeBSD$"); 29 30 #include <sys/param.h> 31 #include <sys/systm.h> 32 #include <sys/bus.h> 33 #include <sys/kernel.h> 34 #include <sys/module.h> 35 #include <sys/malloc.h> 36 #include <sys/rman.h> 37 #include <sys/timeet.h> 38 #include <sys/timetc.h> 39 #include <machine/bus.h> 40 41 #include <dev/ofw/openfirm.h> 42 #include <dev/ofw/ofw_bus.h> 43 #include <dev/ofw/ofw_bus_subr.h> 44 45 #include <arm/ti/ti_prcm.h> 46 #include <arm/ti/ti_hwmods.h> 47 48 #include "am335x_dmtreg.h" 49 50 struct am335x_dmtimer_softc { 51 device_t dev; 52 int tmr_mem_rid; 53 struct resource * tmr_mem_res; 54 int tmr_irq_rid; 55 struct resource * tmr_irq_res; 56 void *tmr_irq_handler; 57 uint32_t sysclk_freq; 58 uint32_t tclr; /* Cached TCLR register. */ 59 union { 60 struct timecounter tc; 61 struct eventtimer et; 62 } func; 63 int tmr_num; /* Hardware unit number. */ 64 char tmr_name[12]; /* "DMTimerN", N = tmr_num */ 65 }; 66 67 static struct am335x_dmtimer_softc *am335x_dmtimer_et_sc = NULL; 68 static struct am335x_dmtimer_softc *am335x_dmtimer_tc_sc = NULL; 69 70 /* 71 * We use dmtimer2 for eventtimer and dmtimer3 for timecounter. 72 */ 73 #define ET_TMR_NUM 2 74 #define TC_TMR_NUM 3 75 76 /* List of compatible strings for FDT tree */ 77 static struct ofw_compat_data compat_data[] = { 78 {"ti,am335x-timer", 1}, 79 {"ti,am335x-timer-1ms", 1}, 80 {NULL, 0}, 81 }; 82 83 #define DMTIMER_READ4(sc, reg) bus_read_4((sc)->tmr_mem_res, (reg)) 84 #define DMTIMER_WRITE4(sc, reg, val) bus_write_4((sc)->tmr_mem_res, (reg), (val)) 85 86 static int 87 am335x_dmtimer_et_start(struct eventtimer *et, sbintime_t first, sbintime_t period) 88 { 89 struct am335x_dmtimer_softc *sc; 90 uint32_t initial_count, reload_count; 91 92 sc = et->et_priv; 93 94 /* 95 * Stop the timer before changing it. This routine will often be called 96 * while the timer is still running, to either lengthen or shorten the 97 * current event time. We need to ensure the timer doesn't expire while 98 * we're working with it. 99 * 100 * Also clear any pending interrupt status, because it's at least 101 * theoretically possible that we're running in a primary interrupt 102 * context now, and a timer interrupt could be pending even before we 103 * stopped the timer. The more likely case is that we're being called 104 * from the et_event_cb() routine dispatched from our own handler, but 105 * it's not clear to me that that's the only case possible. 106 */ 107 sc->tclr &= ~(DMT_TCLR_START | DMT_TCLR_AUTOLOAD); 108 DMTIMER_WRITE4(sc, DMT_TCLR, sc->tclr); 109 DMTIMER_WRITE4(sc, DMT_IRQSTATUS, DMT_IRQ_OVF); 110 111 if (period != 0) { 112 reload_count = ((uint32_t)et->et_frequency * period) >> 32; 113 sc->tclr |= DMT_TCLR_AUTOLOAD; 114 } else { 115 reload_count = 0; 116 } 117 118 if (first != 0) 119 initial_count = ((uint32_t)et->et_frequency * first) >> 32; 120 else 121 initial_count = reload_count; 122 123 /* 124 * Set auto-reload and current-count values. This timer hardware counts 125 * up from the initial/reload value and interrupts on the zero rollover. 126 */ 127 DMTIMER_WRITE4(sc, DMT_TLDR, 0xFFFFFFFF - reload_count); 128 DMTIMER_WRITE4(sc, DMT_TCRR, 0xFFFFFFFF - initial_count); 129 130 /* Enable overflow interrupt, and start the timer. */ 131 DMTIMER_WRITE4(sc, DMT_IRQENABLE_SET, DMT_IRQ_OVF); 132 sc->tclr |= DMT_TCLR_START; 133 DMTIMER_WRITE4(sc, DMT_TCLR, sc->tclr); 134 135 return (0); 136 } 137 138 static int 139 am335x_dmtimer_et_stop(struct eventtimer *et) 140 { 141 struct am335x_dmtimer_softc *sc; 142 143 sc = et->et_priv; 144 145 /* Stop timer, disable and clear interrupt. */ 146 sc->tclr &= ~(DMT_TCLR_START | DMT_TCLR_AUTOLOAD); 147 DMTIMER_WRITE4(sc, DMT_TCLR, sc->tclr); 148 DMTIMER_WRITE4(sc, DMT_IRQENABLE_CLR, DMT_IRQ_OVF); 149 DMTIMER_WRITE4(sc, DMT_IRQSTATUS, DMT_IRQ_OVF); 150 return (0); 151 } 152 153 static int 154 am335x_dmtimer_et_intr(void *arg) 155 { 156 struct am335x_dmtimer_softc *sc; 157 158 sc = arg; 159 160 /* Ack the interrupt, and invoke the callback if it's still enabled. */ 161 DMTIMER_WRITE4(sc, DMT_IRQSTATUS, DMT_IRQ_OVF); 162 if (sc->func.et.et_active) 163 sc->func.et.et_event_cb(&sc->func.et, sc->func.et.et_arg); 164 165 return (FILTER_HANDLED); 166 } 167 168 static int 169 am335x_dmtimer_et_init(struct am335x_dmtimer_softc *sc) 170 { 171 KASSERT(am335x_dmtimer_et_sc == NULL, ("already have an eventtimer")); 172 173 /* 174 * Setup eventtimer interrupt handling. Panic if anything goes wrong, 175 * because the system just isn't going to run without an eventtimer. 176 */ 177 sc->tmr_irq_res = bus_alloc_resource_any(sc->dev, SYS_RES_IRQ, 178 &sc->tmr_irq_rid, RF_ACTIVE); 179 if (sc->tmr_irq_res == NULL) 180 panic("am335x_dmtimer: could not allocate irq resources"); 181 if (bus_setup_intr(sc->dev, sc->tmr_irq_res, INTR_TYPE_CLK, 182 am335x_dmtimer_et_intr, NULL, sc, &sc->tmr_irq_handler) != 0) 183 panic("am335x_dmtimer: count not setup irq handler"); 184 185 sc->func.et.et_name = sc->tmr_name; 186 sc->func.et.et_flags = ET_FLAGS_PERIODIC | ET_FLAGS_ONESHOT; 187 sc->func.et.et_quality = 500; 188 sc->func.et.et_frequency = sc->sysclk_freq; 189 sc->func.et.et_min_period = 190 ((0x00000005LLU << 32) / sc->func.et.et_frequency); 191 sc->func.et.et_max_period = 192 (0xfffffffeLLU << 32) / sc->func.et.et_frequency; 193 sc->func.et.et_start = am335x_dmtimer_et_start; 194 sc->func.et.et_stop = am335x_dmtimer_et_stop; 195 sc->func.et.et_priv = sc; 196 197 am335x_dmtimer_et_sc = sc; 198 et_register(&sc->func.et); 199 200 return (0); 201 } 202 203 static unsigned 204 am335x_dmtimer_tc_get_timecount(struct timecounter *tc) 205 { 206 struct am335x_dmtimer_softc *sc; 207 208 sc = tc->tc_priv; 209 210 return (DMTIMER_READ4(sc, DMT_TCRR)); 211 } 212 213 static int 214 am335x_dmtimer_tc_init(struct am335x_dmtimer_softc *sc) 215 { 216 KASSERT(am335x_dmtimer_tc_sc == NULL, ("already have a timecounter")); 217 218 /* Set up timecounter, start it, register it. */ 219 DMTIMER_WRITE4(sc, DMT_TSICR, DMT_TSICR_RESET); 220 while (DMTIMER_READ4(sc, DMT_TIOCP_CFG) & DMT_TIOCP_RESET) 221 continue; 222 223 sc->tclr |= DMT_TCLR_START | DMT_TCLR_AUTOLOAD; 224 DMTIMER_WRITE4(sc, DMT_TLDR, 0); 225 DMTIMER_WRITE4(sc, DMT_TCRR, 0); 226 DMTIMER_WRITE4(sc, DMT_TCLR, sc->tclr); 227 228 sc->func.tc.tc_name = sc->tmr_name; 229 sc->func.tc.tc_get_timecount = am335x_dmtimer_tc_get_timecount; 230 sc->func.tc.tc_counter_mask = ~0u; 231 sc->func.tc.tc_frequency = sc->sysclk_freq; 232 sc->func.tc.tc_quality = 500; 233 sc->func.tc.tc_priv = sc; 234 235 am335x_dmtimer_tc_sc = sc; 236 tc_init(&sc->func.tc); 237 238 return (0); 239 } 240 241 static int 242 am335x_dmtimer_probe(device_t dev) 243 { 244 char strbuf[32]; 245 int tmr_num; 246 247 if (!ofw_bus_status_okay(dev)) 248 return (ENXIO); 249 250 if (ofw_bus_search_compatible(dev, compat_data)->ocd_data == 0) 251 return (ENXIO); 252 253 /* 254 * Get the hardware unit number (the N from ti,hwmods="timerN"). 255 * If this isn't the hardware unit we're going to use for either the 256 * eventtimer or the timecounter, no point in instantiating the device. 257 */ 258 tmr_num = ti_hwmods_get_unit(dev, "timer"); 259 if (tmr_num != ET_TMR_NUM && tmr_num != TC_TMR_NUM) 260 return (ENXIO); 261 262 snprintf(strbuf, sizeof(strbuf), "AM335x DMTimer%d", tmr_num); 263 device_set_desc_copy(dev, strbuf); 264 265 return(BUS_PROBE_DEFAULT); 266 } 267 268 static int 269 am335x_dmtimer_attach(device_t dev) 270 { 271 struct am335x_dmtimer_softc *sc; 272 clk_ident_t timer_id; 273 int err; 274 275 sc = device_get_softc(dev); 276 sc->dev = dev; 277 278 /* Get the base clock frequency. */ 279 if ((err = ti_prcm_clk_get_source_freq(SYS_CLK, &sc->sysclk_freq)) != 0) 280 return (err); 281 282 /* Enable clocks and power on the device. */ 283 if ((timer_id = ti_hwmods_get_clock(dev)) == INVALID_CLK_IDENT) 284 return (ENXIO); 285 if ((err = ti_prcm_clk_set_source(timer_id, SYSCLK_CLK)) != 0) 286 return (err); 287 if ((err = ti_prcm_clk_enable(timer_id)) != 0) 288 return (err); 289 290 /* Request the memory resources. */ 291 sc->tmr_mem_res = bus_alloc_resource_any(dev, SYS_RES_MEMORY, 292 &sc->tmr_mem_rid, RF_ACTIVE); 293 if (sc->tmr_mem_res == NULL) { 294 return (ENXIO); 295 } 296 297 sc->tmr_num = ti_hwmods_get_unit(dev, "timer"); 298 snprintf(sc->tmr_name, sizeof(sc->tmr_name), "DMTimer%d", sc->tmr_num); 299 300 /* 301 * Go set up either a timecounter or eventtimer. We wouldn't have 302 * attached if we weren't one or the other. 303 */ 304 if (sc->tmr_num == ET_TMR_NUM) 305 am335x_dmtimer_et_init(sc); 306 else if (sc->tmr_num == TC_TMR_NUM) 307 am335x_dmtimer_tc_init(sc); 308 else 309 panic("am335x_dmtimer: bad timer number %d", sc->tmr_num); 310 311 return (0); 312 } 313 314 static device_method_t am335x_dmtimer_methods[] = { 315 DEVMETHOD(device_probe, am335x_dmtimer_probe), 316 DEVMETHOD(device_attach, am335x_dmtimer_attach), 317 { 0, 0 } 318 }; 319 320 static driver_t am335x_dmtimer_driver = { 321 "am335x_dmtimer", 322 am335x_dmtimer_methods, 323 sizeof(struct am335x_dmtimer_softc), 324 }; 325 326 static devclass_t am335x_dmtimer_devclass; 327 328 DRIVER_MODULE(am335x_dmtimer, simplebus, am335x_dmtimer_driver, am335x_dmtimer_devclass, 0, 0); 329 MODULE_DEPEND(am335x_dmtimer, am335x_prcm, 1, 1, 1); 330 331 void 332 DELAY(int usec) 333 { 334 struct am335x_dmtimer_softc *sc; 335 int32_t counts; 336 uint32_t first, last; 337 338 sc = am335x_dmtimer_tc_sc; 339 340 if (sc == NULL) { 341 for (; usec > 0; usec--) 342 for (counts = 200; counts > 0; counts--) 343 /* Prevent gcc from optimizing out the loop */ 344 cpufunc_nullop(); 345 return; 346 } 347 348 /* Get the number of times to count */ 349 counts = (usec + 1) * (sc->sysclk_freq / 1000000); 350 351 first = DMTIMER_READ4(sc, DMT_TCRR); 352 353 while (counts > 0) { 354 last = DMTIMER_READ4(sc, DMT_TCRR); 355 if (last > first) { 356 counts -= (int32_t)(last - first); 357 } else { 358 counts -= (int32_t)((0xFFFFFFFF - first) + last); 359 } 360 first = last; 361 } 362 } 363 364