1 /*- 2 * Copyright (c) 2015 Ian lepore <ian@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 /* 28 * AM335x PPS driver using DMTimer capture. 29 * 30 * Note that this PPS driver does not use an interrupt. Instead it uses the 31 * hardware's ability to latch the timer's count register in response to a 32 * signal on an IO pin. Each of timers 4-7 have an associated pin, and this 33 * code allows any one of those to be used. 34 * 35 * The timecounter routines in kern_tc.c call the pps poll routine periodically 36 * to see if a new counter value has been latched. When a new value has been 37 * latched, the only processing done in the poll routine is to capture the 38 * current set of timecounter timehands (done with pps_capture()) and the 39 * latched value from the timer. The remaining work (done by pps_event() while 40 * holding a mutex) is scheduled to be done later in a non-interrupt context. 41 */ 42 43 #include <sys/cdefs.h> 44 __FBSDID("$FreeBSD$"); 45 46 #include "opt_platform.h" 47 48 #include <sys/param.h> 49 #include <sys/systm.h> 50 #include <sys/bus.h> 51 #include <sys/conf.h> 52 #include <sys/kernel.h> 53 #include <sys/lock.h> 54 #include <sys/module.h> 55 #include <sys/malloc.h> 56 #include <sys/mutex.h> 57 #include <sys/rman.h> 58 #include <sys/timepps.h> 59 #include <sys/timetc.h> 60 #include <machine/bus.h> 61 62 #include <dev/ofw/openfirm.h> 63 #include <dev/ofw/ofw_bus.h> 64 #include <dev/ofw/ofw_bus_subr.h> 65 #include <dev/extres/clk/clk.h> 66 67 #include <arm/ti/ti_sysc.h> 68 #include <arm/ti/ti_pinmux.h> 69 #include <arm/ti/am335x/am335x_scm_padconf.h> 70 71 #include "am335x_dmtreg.h" 72 73 #define PPS_CDEV_NAME "dmtpps" 74 75 struct dmtpps_softc { 76 device_t dev; 77 int mem_rid; 78 struct resource * mem_res; 79 int tmr_num; /* N from hwmod str "timerN" */ 80 char tmr_name[12]; /* "DMTimerN" */ 81 uint32_t tclr; /* Cached TCLR register. */ 82 struct timecounter tc; 83 int pps_curmode; /* Edge mode now set in hw. */ 84 struct cdev * pps_cdev; 85 struct pps_state pps_state; 86 struct mtx pps_mtx; 87 clk_t clk_fck; 88 uint64_t sysclk_freq; 89 }; 90 91 static int dmtpps_tmr_num; /* Set by probe() */ 92 93 /* List of compatible strings for FDT tree */ 94 static struct ofw_compat_data compat_data[] = { 95 {"ti,am335x-timer", 1}, 96 {"ti,am335x-timer-1ms", 1}, 97 {NULL, 0}, 98 }; 99 SIMPLEBUS_PNP_INFO(compat_data); 100 101 /* 102 * A table relating pad names to the hardware timer number they can be mux'd to. 103 */ 104 struct padinfo { 105 char * ballname; 106 int tmr_num; 107 }; 108 static struct padinfo dmtpps_padinfo[] = { 109 {"GPMC_ADVn_ALE", 4}, 110 {"I2C0_SDA", 4}, 111 {"MII1_TX_EN", 4}, 112 {"XDMA_EVENT_INTR0", 4}, 113 {"GPMC_BEn0_CLE", 5}, 114 {"MDC", 5}, 115 {"MMC0_DAT3", 5}, 116 {"UART1_RTSn", 5}, 117 {"GPMC_WEn", 6}, 118 {"MDIO", 6}, 119 {"MMC0_DAT2", 6}, 120 {"UART1_CTSn", 6}, 121 {"GPMC_OEn_REn", 7}, 122 {"I2C0_SCL", 7}, 123 {"UART0_CTSn", 7}, 124 {"XDMA_EVENT_INTR1", 7}, 125 {NULL, 0} 126 }; 127 128 /* 129 * This is either brilliantly user-friendly, or utterly lame... 130 * 131 * The am335x chip is used on the popular Beaglebone boards. Those boards have 132 * pins for all four capture-capable timers available on the P8 header. Allow 133 * users to configure the input pin by giving the name of the header pin. 134 */ 135 struct nicknames { 136 const char * nick; 137 const char * name; 138 }; 139 static struct nicknames dmtpps_pin_nicks[] = { 140 {"P8-7", "GPMC_ADVn_ALE"}, 141 {"P8-9", "GPMC_BEn0_CLE"}, 142 {"P8-10", "GPMC_WEn"}, 143 {"P8-8", "GPMC_OEn_REn",}, 144 {NULL, NULL} 145 }; 146 147 #define DMTIMER_READ4(sc, reg) bus_read_4((sc)->mem_res, (reg)) 148 #define DMTIMER_WRITE4(sc, reg, val) bus_write_4((sc)->mem_res, (reg), (val)) 149 150 /* 151 * Translate a short friendly case-insensitive name to its canonical name. 152 */ 153 static const char * 154 dmtpps_translate_nickname(const char *nick) 155 { 156 struct nicknames *nn; 157 158 for (nn = dmtpps_pin_nicks; nn->nick != NULL; nn++) 159 if (strcasecmp(nick, nn->nick) == 0) 160 return nn->name; 161 return (nick); 162 } 163 164 /* 165 * See if our tunable is set to the name of the input pin. If not, that's NOT 166 * an error, return 0. If so, try to configure that pin as a timer capture 167 * input pin, and if that works, then we have our timer unit number and if it 168 * fails that IS an error, return -1. 169 */ 170 static int 171 dmtpps_find_tmr_num_by_tunable(void) 172 { 173 struct padinfo *pi; 174 char iname[20]; 175 char muxmode[12]; 176 const char * ballname; 177 int err; 178 179 if (!TUNABLE_STR_FETCH("hw.am335x_dmtpps.input", iname, sizeof(iname))) 180 return (0); 181 ballname = dmtpps_translate_nickname(iname); 182 for (pi = dmtpps_padinfo; pi->ballname != NULL; pi++) { 183 if (strcmp(ballname, pi->ballname) != 0) 184 continue; 185 snprintf(muxmode, sizeof(muxmode), "timer%d", pi->tmr_num); 186 err = ti_pinmux_padconf_set(pi->ballname, muxmode, 187 PADCONF_INPUT); 188 if (err != 0) { 189 printf("am335x_dmtpps: unable to configure capture pin " 190 "for %s to input mode\n", muxmode); 191 return (-1); 192 } else if (bootverbose) { 193 printf("am335x_dmtpps: configured pin %s as input " 194 "for %s\n", iname, muxmode); 195 } 196 return (pi->tmr_num); 197 } 198 199 /* Invalid name in the tunable, that's an error. */ 200 printf("am335x_dmtpps: unknown pin name '%s'\n", iname); 201 return (-1); 202 } 203 204 /* 205 * Ask the pinmux driver whether any pin has been configured as a TIMER4..TIMER7 206 * input pin. If so, return the timer number, if not return 0. 207 */ 208 static int 209 dmtpps_find_tmr_num_by_padconf(void) 210 { 211 int err; 212 unsigned int padstate; 213 const char * padmux; 214 struct padinfo *pi; 215 char muxmode[12]; 216 217 for (pi = dmtpps_padinfo; pi->ballname != NULL; pi++) { 218 err = ti_pinmux_padconf_get(pi->ballname, &padmux, &padstate); 219 snprintf(muxmode, sizeof(muxmode), "timer%d", pi->tmr_num); 220 if (err == 0 && (padstate & RXACTIVE) != 0 && 221 strcmp(muxmode, padmux) == 0) 222 return (pi->tmr_num); 223 } 224 /* Nothing found, not an error. */ 225 return (0); 226 } 227 228 /* 229 * Figure out which hardware timer number to use based on input pin 230 * configuration. This is done just once, the first time probe() runs. 231 */ 232 static int 233 dmtpps_find_tmr_num(void) 234 { 235 int tmr_num; 236 237 if ((tmr_num = dmtpps_find_tmr_num_by_tunable()) == 0) 238 tmr_num = dmtpps_find_tmr_num_by_padconf(); 239 240 if (tmr_num <= 0) { 241 printf("am335x_dmtpps: PPS driver not enabled: unable to find " 242 "or configure a capture input pin\n"); 243 tmr_num = -1; /* Must return non-zero to prevent re-probing. */ 244 } 245 return (tmr_num); 246 } 247 248 static void 249 dmtpps_set_hw_capture(struct dmtpps_softc *sc, bool force_off) 250 { 251 int newmode; 252 253 if (force_off) 254 newmode = 0; 255 else 256 newmode = sc->pps_state.ppsparam.mode & PPS_CAPTUREASSERT; 257 258 if (newmode == sc->pps_curmode) 259 return; 260 sc->pps_curmode = newmode; 261 262 if (newmode == PPS_CAPTUREASSERT) 263 sc->tclr |= DMT_TCLR_CAPTRAN_LOHI; 264 else 265 sc->tclr &= ~DMT_TCLR_CAPTRAN_MASK; 266 DMTIMER_WRITE4(sc, DMT_TCLR, sc->tclr); 267 } 268 269 static unsigned 270 dmtpps_get_timecount(struct timecounter *tc) 271 { 272 struct dmtpps_softc *sc; 273 274 sc = tc->tc_priv; 275 276 return (DMTIMER_READ4(sc, DMT_TCRR)); 277 } 278 279 static void 280 dmtpps_poll(struct timecounter *tc) 281 { 282 struct dmtpps_softc *sc; 283 284 sc = tc->tc_priv; 285 286 /* 287 * If a new value has been latched we've got a PPS event. Capture the 288 * timecounter data, then override the capcount field (pps_capture() 289 * populates it from the current DMT_TCRR register) with the latched 290 * value from the TCAR1 register. 291 * 292 * Note that we don't have the TCAR interrupt enabled, but the hardware 293 * still provides the status bits in the "RAW" status register even when 294 * they're masked from generating an irq. However, when clearing the 295 * TCAR status to re-arm the capture for the next second, we have to 296 * write to the IRQ status register, not the RAW register. Quirky. 297 * 298 * We do not need to hold a lock while capturing the pps data, because 299 * it is captured into an area of the pps_state struct which is read 300 * only by pps_event(). We do need to hold a lock while calling 301 * pps_event(), because it manipulates data which is also accessed from 302 * the ioctl(2) context by userland processes. 303 */ 304 if (DMTIMER_READ4(sc, DMT_IRQSTATUS_RAW) & DMT_IRQ_TCAR) { 305 pps_capture(&sc->pps_state); 306 sc->pps_state.capcount = DMTIMER_READ4(sc, DMT_TCAR1); 307 DMTIMER_WRITE4(sc, DMT_IRQSTATUS, DMT_IRQ_TCAR); 308 309 mtx_lock_spin(&sc->pps_mtx); 310 pps_event(&sc->pps_state, PPS_CAPTUREASSERT); 311 mtx_unlock_spin(&sc->pps_mtx); 312 } 313 } 314 315 static int 316 dmtpps_open(struct cdev *dev, int flags, int fmt, 317 struct thread *td) 318 { 319 struct dmtpps_softc *sc; 320 321 sc = dev->si_drv1; 322 323 /* 324 * Begin polling for pps and enable capture in the hardware whenever the 325 * device is open. Doing this stuff again is harmless if this isn't the 326 * first open. 327 */ 328 sc->tc.tc_poll_pps = dmtpps_poll; 329 dmtpps_set_hw_capture(sc, false); 330 331 return 0; 332 } 333 334 static int 335 dmtpps_close(struct cdev *dev, int flags, int fmt, 336 struct thread *td) 337 { 338 struct dmtpps_softc *sc; 339 340 sc = dev->si_drv1; 341 342 /* 343 * Stop polling and disable capture on last close. Use the force-off 344 * flag to override the configured mode and turn off the hardware. 345 */ 346 sc->tc.tc_poll_pps = NULL; 347 dmtpps_set_hw_capture(sc, true); 348 349 return 0; 350 } 351 352 static int 353 dmtpps_ioctl(struct cdev *dev, u_long cmd, caddr_t data, 354 int flags, struct thread *td) 355 { 356 struct dmtpps_softc *sc; 357 int err; 358 359 sc = dev->si_drv1; 360 361 /* Let the kernel do the heavy lifting for ioctl. */ 362 mtx_lock_spin(&sc->pps_mtx); 363 err = pps_ioctl(cmd, data, &sc->pps_state); 364 mtx_unlock_spin(&sc->pps_mtx); 365 if (err != 0) 366 return (err); 367 368 /* 369 * The capture mode could have changed, set the hardware to whatever 370 * mode is now current. Effectively a no-op if nothing changed. 371 */ 372 dmtpps_set_hw_capture(sc, false); 373 374 return (err); 375 } 376 377 static struct cdevsw dmtpps_cdevsw = { 378 .d_version = D_VERSION, 379 .d_open = dmtpps_open, 380 .d_close = dmtpps_close, 381 .d_ioctl = dmtpps_ioctl, 382 .d_name = PPS_CDEV_NAME, 383 }; 384 385 static int 386 dmtpps_probe(device_t dev) 387 { 388 char strbuf[64]; 389 int tmr_num; 390 uint64_t rev_address; 391 392 if (!ofw_bus_status_okay(dev)) 393 return (ENXIO); 394 395 if (ofw_bus_search_compatible(dev, compat_data)->ocd_data == 0) 396 return (ENXIO); 397 398 /* 399 * If we haven't chosen which hardware timer to use yet, go do that now. 400 * We need to know that to decide whether to return success for this 401 * hardware timer instance or not. 402 */ 403 if (dmtpps_tmr_num == 0) 404 dmtpps_tmr_num = dmtpps_find_tmr_num(); 405 406 /* 407 * Figure out which hardware timer is being probed and see if it matches 408 * the configured timer number determined earlier. 409 */ 410 rev_address = ti_sysc_get_rev_address(device_get_parent(dev)); 411 switch (rev_address) { 412 case DMTIMER1_1MS_REV: 413 tmr_num = 1; 414 break; 415 case DMTIMER2_REV: 416 tmr_num = 2; 417 break; 418 case DMTIMER3_REV: 419 tmr_num = 3; 420 break; 421 case DMTIMER4_REV: 422 tmr_num = 4; 423 break; 424 case DMTIMER5_REV: 425 tmr_num = 5; 426 break; 427 case DMTIMER6_REV: 428 tmr_num = 6; 429 break; 430 case DMTIMER7_REV: 431 tmr_num = 7; 432 break; 433 default: 434 return (ENXIO); 435 } 436 437 if (dmtpps_tmr_num != tmr_num) 438 return (ENXIO); 439 440 snprintf(strbuf, sizeof(strbuf), "AM335x PPS-Capture DMTimer%d", 441 tmr_num); 442 device_set_desc_copy(dev, strbuf); 443 444 return(BUS_PROBE_DEFAULT); 445 } 446 447 static int 448 dmtpps_attach(device_t dev) 449 { 450 struct dmtpps_softc *sc; 451 struct make_dev_args mda; 452 int err; 453 clk_t sys_clkin; 454 uint64_t rev_address; 455 456 sc = device_get_softc(dev); 457 sc->dev = dev; 458 459 /* Figure out which hardware timer this is and set the name string. */ 460 rev_address = ti_sysc_get_rev_address(device_get_parent(dev)); 461 switch (rev_address) { 462 case DMTIMER1_1MS_REV: 463 sc->tmr_num = 1; 464 break; 465 case DMTIMER2_REV: 466 sc->tmr_num = 2; 467 break; 468 case DMTIMER3_REV: 469 sc->tmr_num = 3; 470 break; 471 case DMTIMER4_REV: 472 sc->tmr_num = 4; 473 break; 474 case DMTIMER5_REV: 475 sc->tmr_num = 5; 476 break; 477 case DMTIMER6_REV: 478 sc->tmr_num = 6; 479 break; 480 case DMTIMER7_REV: 481 sc->tmr_num = 7; 482 break; 483 } 484 snprintf(sc->tmr_name, sizeof(sc->tmr_name), "DMTimer%d", sc->tmr_num); 485 486 /* expect one clock */ 487 err = clk_get_by_ofw_index(dev, 0, 0, &sc->clk_fck); 488 if (err != 0) { 489 device_printf(dev, "Cant find clock index 0. err: %d\n", err); 490 return (ENXIO); 491 } 492 493 err = clk_get_by_name(dev, "sys_clkin_ck@40", &sys_clkin); 494 if (err != 0) { 495 device_printf(dev, "Cant find sys_clkin_ck@40 err: %d\n", err); 496 return (ENXIO); 497 } 498 499 /* Select M_OSC as DPLL parent */ 500 err = clk_set_parent_by_clk(sc->clk_fck, sys_clkin); 501 if (err != 0) { 502 device_printf(dev, "Cant set mux to CLK_M_OSC\n"); 503 return (ENXIO); 504 } 505 506 /* Enable clocks and power on the device. */ 507 err = ti_sysc_clock_enable(device_get_parent(dev)); 508 if (err != 0) { 509 device_printf(dev, "Cant enable sysc clkctrl, err %d\n", err); 510 return (ENXIO); 511 } 512 513 /* Get the base clock frequency. */ 514 err = clk_get_freq(sc->clk_fck, &sc->sysclk_freq); 515 if (err != 0) { 516 device_printf(dev, "Cant get sysclk frequency, err %d\n", err); 517 return (ENXIO); 518 } 519 /* Request the memory resources. */ 520 sc->mem_res = bus_alloc_resource_any(dev, SYS_RES_MEMORY, 521 &sc->mem_rid, RF_ACTIVE); 522 if (sc->mem_res == NULL) { 523 return (ENXIO); 524 } 525 526 /* 527 * Configure the timer pulse/capture pin to input/capture mode. This is 528 * required in addition to configuring the pin as input with the pinmux 529 * controller (which was done via fdt data or tunable at probe time). 530 */ 531 sc->tclr = DMT_TCLR_GPO_CFG; 532 DMTIMER_WRITE4(sc, DMT_TCLR, sc->tclr); 533 534 /* Set up timecounter hardware, start it. */ 535 DMTIMER_WRITE4(sc, DMT_TSICR, DMT_TSICR_RESET); 536 while (DMTIMER_READ4(sc, DMT_TIOCP_CFG) & DMT_TIOCP_RESET) 537 continue; 538 539 sc->tclr |= DMT_TCLR_START | DMT_TCLR_AUTOLOAD; 540 DMTIMER_WRITE4(sc, DMT_TLDR, 0); 541 DMTIMER_WRITE4(sc, DMT_TCRR, 0); 542 DMTIMER_WRITE4(sc, DMT_TCLR, sc->tclr); 543 544 /* Register the timecounter. */ 545 sc->tc.tc_name = sc->tmr_name; 546 sc->tc.tc_get_timecount = dmtpps_get_timecount; 547 sc->tc.tc_counter_mask = ~0u; 548 sc->tc.tc_frequency = sc->sysclk_freq; 549 sc->tc.tc_quality = 1000; 550 sc->tc.tc_priv = sc; 551 552 tc_init(&sc->tc); 553 554 /* 555 * Indicate our PPS capabilities. Have the kernel init its part of the 556 * pps_state struct and add its capabilities. 557 * 558 * While the hardware has a mode to capture each edge, it's not clear we 559 * can use it that way, because there's only a single interrupt/status 560 * bit to say something was captured, but not which edge it was. For 561 * now, just say we can only capture assert events (the positive-going 562 * edge of the pulse). 563 */ 564 mtx_init(&sc->pps_mtx, "dmtpps", NULL, MTX_SPIN); 565 sc->pps_state.flags = PPSFLAG_MTX_SPIN; 566 sc->pps_state.ppscap = PPS_CAPTUREASSERT; 567 sc->pps_state.driver_abi = PPS_ABI_VERSION; 568 sc->pps_state.driver_mtx = &sc->pps_mtx; 569 pps_init_abi(&sc->pps_state); 570 571 /* Create the PPS cdev. */ 572 make_dev_args_init(&mda); 573 mda.mda_flags = MAKEDEV_WAITOK; 574 mda.mda_devsw = &dmtpps_cdevsw; 575 mda.mda_cr = NULL; 576 mda.mda_uid = UID_ROOT; 577 mda.mda_gid = GID_WHEEL; 578 mda.mda_mode = 0600; 579 mda.mda_unit = device_get_unit(dev); 580 mda.mda_si_drv1 = sc; 581 if ((err = make_dev_s(&mda, &sc->pps_cdev, PPS_CDEV_NAME)) != 0) { 582 device_printf(dev, "Failed to create cdev %s\n", PPS_CDEV_NAME); 583 return (err); 584 } 585 586 if (bootverbose) 587 device_printf(sc->dev, "Using %s for PPS device /dev/%s\n", 588 sc->tmr_name, PPS_CDEV_NAME); 589 590 return (0); 591 } 592 593 static int 594 dmtpps_detach(device_t dev) 595 { 596 597 /* 598 * There is no way to remove a timecounter once it has been registered, 599 * even if it's not in use, so we can never detach. If we were 600 * dynamically loaded as a module this will prevent unloading. 601 */ 602 return (EBUSY); 603 } 604 605 static device_method_t dmtpps_methods[] = { 606 DEVMETHOD(device_probe, dmtpps_probe), 607 DEVMETHOD(device_attach, dmtpps_attach), 608 DEVMETHOD(device_detach, dmtpps_detach), 609 { 0, 0 } 610 }; 611 612 static driver_t dmtpps_driver = { 613 "am335x_dmtpps", 614 dmtpps_methods, 615 sizeof(struct dmtpps_softc), 616 }; 617 618 DRIVER_MODULE(am335x_dmtpps, simplebus, dmtpps_driver, 0, 0); 619 MODULE_DEPEND(am335x_dmtpps, ti_sysc, 1, 1, 1); 620