1 /*- 2 * Copyright (c) 2003 Marcel Moolenaar 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 * 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 ``AS IS'' AND ANY EXPRESS OR 16 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 17 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 18 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 19 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 20 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 21 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 22 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 24 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 25 */ 26 27 #include <sys/cdefs.h> 28 __FBSDID("$FreeBSD$"); 29 30 #ifndef KLD_MODULE 31 #include "opt_comconsole.h" 32 #endif 33 34 #include <sys/param.h> 35 #include <sys/systm.h> 36 #include <sys/bus.h> 37 #include <sys/conf.h> 38 #include <sys/cons.h> 39 #include <sys/fcntl.h> 40 #include <sys/interrupt.h> 41 #include <sys/kdb.h> 42 #include <sys/kernel.h> 43 #include <sys/malloc.h> 44 #include <sys/queue.h> 45 #include <sys/reboot.h> 46 #include <machine/bus.h> 47 #include <sys/rman.h> 48 #include <sys/termios.h> 49 #include <sys/tty.h> 50 #include <machine/resource.h> 51 #include <machine/stdarg.h> 52 53 #include <dev/uart/uart.h> 54 #include <dev/uart/uart_bus.h> 55 #include <dev/uart/uart_cpu.h> 56 57 #include "uart_if.h" 58 59 devclass_t uart_devclass; 60 char uart_driver_name[] = "uart"; 61 62 SLIST_HEAD(uart_devinfo_list, uart_devinfo) uart_sysdevs = 63 SLIST_HEAD_INITIALIZER(uart_sysdevs); 64 65 MALLOC_DEFINE(M_UART, "UART", "UART driver"); 66 67 void 68 uart_add_sysdev(struct uart_devinfo *di) 69 { 70 SLIST_INSERT_HEAD(&uart_sysdevs, di, next); 71 } 72 73 const char * 74 uart_getname(struct uart_class *uc) 75 { 76 return ((uc != NULL) ? uc->name : NULL); 77 } 78 79 struct uart_ops * 80 uart_getops(struct uart_class *uc) 81 { 82 return ((uc != NULL) ? uc->uc_ops : NULL); 83 } 84 85 int 86 uart_getrange(struct uart_class *uc) 87 { 88 return ((uc != NULL) ? uc->uc_range : 0); 89 } 90 91 /* 92 * Schedule a soft interrupt. We do this on the 0 to !0 transition 93 * of the TTY pending interrupt status. 94 */ 95 static void 96 uart_sched_softih(struct uart_softc *sc, uint32_t ipend) 97 { 98 uint32_t new, old; 99 100 do { 101 old = sc->sc_ttypend; 102 new = old | ipend; 103 } while (!atomic_cmpset_32(&sc->sc_ttypend, old, new)); 104 105 if ((old & SER_INT_MASK) == 0) 106 swi_sched(sc->sc_softih, 0); 107 } 108 109 /* 110 * A break condition has been detected. We treat the break condition as 111 * a special case that should not happen during normal operation. When 112 * the break condition is to be passed to higher levels in the form of 113 * a NUL character, we really want the break to be in the right place in 114 * the input stream. The overhead to achieve that is not in relation to 115 * the exceptional nature of the break condition, so we permit ourselves 116 * to be sloppy. 117 */ 118 static __inline int 119 uart_intr_break(void *arg) 120 { 121 struct uart_softc *sc = arg; 122 123 #if defined(KDB) && defined(BREAK_TO_DEBUGGER) 124 if (sc->sc_sysdev != NULL && sc->sc_sysdev->type == UART_DEV_CONSOLE) { 125 kdb_enter(KDB_WHY_BREAK, "Line break on console"); 126 return (0); 127 } 128 #endif 129 if (sc->sc_opened) 130 uart_sched_softih(sc, SER_INT_BREAK); 131 return (0); 132 } 133 134 /* 135 * Handle a receiver overrun situation. We lost at least 1 byte in the 136 * input stream and it's our job to contain the situation. We grab as 137 * much of the data we can, but otherwise flush the receiver FIFO to 138 * create some breathing room. The net effect is that we avoid the 139 * overrun condition to happen for the next X characters, where X is 140 * related to the FIFO size at the cost of loosing data right away. 141 * So, instead of having multiple overrun interrupts in close proximity 142 * to each other and possibly pessimizing UART interrupt latency for 143 * other UARTs in a multiport configuration, we create a longer segment 144 * of missing characters by freeing up the FIFO. 145 * Each overrun condition is marked in the input buffer by a token. The 146 * token represents the loss of at least one, but possible more bytes in 147 * the input stream. 148 */ 149 static __inline int 150 uart_intr_overrun(void *arg) 151 { 152 struct uart_softc *sc = arg; 153 154 if (sc->sc_opened) { 155 UART_RECEIVE(sc); 156 if (uart_rx_put(sc, UART_STAT_OVERRUN)) 157 sc->sc_rxbuf[sc->sc_rxput] = UART_STAT_OVERRUN; 158 uart_sched_softih(sc, SER_INT_RXREADY); 159 } 160 UART_FLUSH(sc, UART_FLUSH_RECEIVER); 161 return (0); 162 } 163 164 /* 165 * Received data ready. 166 */ 167 static __inline int 168 uart_intr_rxready(void *arg) 169 { 170 struct uart_softc *sc = arg; 171 int rxp; 172 173 rxp = sc->sc_rxput; 174 UART_RECEIVE(sc); 175 #if defined(KDB) && defined(ALT_BREAK_TO_DEBUGGER) 176 if (sc->sc_sysdev != NULL && sc->sc_sysdev->type == UART_DEV_CONSOLE) { 177 while (rxp != sc->sc_rxput) { 178 if (kdb_alt_break(sc->sc_rxbuf[rxp++], &sc->sc_altbrk)) 179 kdb_enter(KDB_WHY_BREAK, 180 "Break sequence on console"); 181 if (rxp == sc->sc_rxbufsz) 182 rxp = 0; 183 } 184 } 185 #endif 186 if (sc->sc_opened) 187 uart_sched_softih(sc, SER_INT_RXREADY); 188 else 189 sc->sc_rxput = sc->sc_rxget; /* Ignore received data. */ 190 return (1); 191 } 192 193 /* 194 * Line or modem status change (OOB signalling). 195 * We pass the signals to the software interrupt handler for further 196 * processing. Note that we merge the delta bits, but set the state 197 * bits. This is to avoid loosing state transitions due to having more 198 * than 1 hardware interrupt between software interrupts. 199 */ 200 static __inline int 201 uart_intr_sigchg(void *arg) 202 { 203 struct uart_softc *sc = arg; 204 int new, old, sig; 205 206 sig = UART_GETSIG(sc); 207 208 if (sc->sc_pps.ppsparam.mode & PPS_CAPTUREBOTH) { 209 if (sig & UART_SIG_DPPS) { 210 pps_capture(&sc->sc_pps); 211 pps_event(&sc->sc_pps, (sig & UART_SIG_PPS) ? 212 PPS_CAPTUREASSERT : PPS_CAPTURECLEAR); 213 } 214 } 215 216 /* 217 * Keep track of signal changes, even when the device is not 218 * opened. This allows us to inform upper layers about a 219 * possible loss of DCD and thus the existence of a (possibly) 220 * different connection when we have DCD back, during the time 221 * that the device was closed. 222 */ 223 do { 224 old = sc->sc_ttypend; 225 new = old & ~SER_MASK_STATE; 226 new |= sig & SER_INT_SIGMASK; 227 } while (!atomic_cmpset_32(&sc->sc_ttypend, old, new)); 228 229 if (sc->sc_opened) 230 uart_sched_softih(sc, SER_INT_SIGCHG); 231 return (1); 232 } 233 234 /* 235 * The transmitter can accept more data. 236 */ 237 static __inline int 238 uart_intr_txidle(void *arg) 239 { 240 struct uart_softc *sc = arg; 241 242 if (sc->sc_txbusy) { 243 sc->sc_txbusy = 0; 244 uart_sched_softih(sc, SER_INT_TXIDLE); 245 } 246 return (0); 247 } 248 249 static int 250 uart_intr(void *arg) 251 { 252 struct uart_softc *sc = arg; 253 int flag = 0, ipend; 254 255 while (!sc->sc_leaving && (ipend = UART_IPEND(sc)) != 0) { 256 flag = 1; 257 if (ipend & SER_INT_OVERRUN) 258 uart_intr_overrun(sc); 259 if (ipend & SER_INT_BREAK) 260 uart_intr_break(sc); 261 if (ipend & SER_INT_RXREADY) 262 uart_intr_rxready(sc); 263 if (ipend & SER_INT_SIGCHG) 264 uart_intr_sigchg(sc); 265 if (ipend & SER_INT_TXIDLE) 266 uart_intr_txidle(sc); 267 } 268 return((flag)?FILTER_HANDLED:FILTER_STRAY); 269 } 270 271 serdev_intr_t * 272 uart_bus_ihand(device_t dev, int ipend) 273 { 274 275 switch (ipend) { 276 case SER_INT_BREAK: 277 return (uart_intr_break); 278 case SER_INT_OVERRUN: 279 return (uart_intr_overrun); 280 case SER_INT_RXREADY: 281 return (uart_intr_rxready); 282 case SER_INT_SIGCHG: 283 return (uart_intr_sigchg); 284 case SER_INT_TXIDLE: 285 return (uart_intr_txidle); 286 } 287 return (NULL); 288 } 289 290 int 291 uart_bus_ipend(device_t dev) 292 { 293 struct uart_softc *sc; 294 295 sc = device_get_softc(dev); 296 return (UART_IPEND(sc)); 297 } 298 299 int 300 uart_bus_sysdev(device_t dev) 301 { 302 struct uart_softc *sc; 303 304 sc = device_get_softc(dev); 305 return ((sc->sc_sysdev != NULL) ? 1 : 0); 306 } 307 308 int 309 uart_bus_probe(device_t dev, int regshft, int rclk, int rid, int chan) 310 { 311 struct uart_softc *sc; 312 struct uart_devinfo *sysdev; 313 int error; 314 315 sc = device_get_softc(dev); 316 317 /* 318 * All uart_class references are weak. Check that the needed 319 * class has been compiled-in. Fail if not. 320 */ 321 if (sc->sc_class == NULL) 322 return (ENXIO); 323 324 /* 325 * Initialize the instance. Note that the instance (=softc) does 326 * not necessarily match the hardware specific softc. We can't do 327 * anything about it now, because we may not attach to the device. 328 * Hardware drivers cannot use any of the class specific fields 329 * while probing. 330 */ 331 kobj_init((kobj_t)sc, (kobj_class_t)sc->sc_class); 332 sc->sc_dev = dev; 333 if (device_get_desc(dev) == NULL) 334 device_set_desc(dev, uart_getname(sc->sc_class)); 335 336 /* 337 * Allocate the register resource. We assume that all UARTs have 338 * a single register window in either I/O port space or memory 339 * mapped I/O space. Any UART that needs multiple windows will 340 * consequently not be supported by this driver as-is. We try I/O 341 * port space first because that's the common case. 342 */ 343 sc->sc_rrid = rid; 344 sc->sc_rtype = SYS_RES_IOPORT; 345 sc->sc_rres = bus_alloc_resource(dev, sc->sc_rtype, &sc->sc_rrid, 346 0, ~0, uart_getrange(sc->sc_class), RF_ACTIVE); 347 if (sc->sc_rres == NULL) { 348 sc->sc_rrid = rid; 349 sc->sc_rtype = SYS_RES_MEMORY; 350 sc->sc_rres = bus_alloc_resource(dev, sc->sc_rtype, 351 &sc->sc_rrid, 0, ~0, uart_getrange(sc->sc_class), 352 RF_ACTIVE); 353 if (sc->sc_rres == NULL) 354 return (ENXIO); 355 } 356 357 /* 358 * Fill in the bus access structure and compare this device with 359 * a possible console device and/or a debug port. We set the flags 360 * in the softc so that the hardware dependent probe can adjust 361 * accordingly. In general, you don't want to permanently disrupt 362 * console I/O. 363 */ 364 sc->sc_bas.bsh = rman_get_bushandle(sc->sc_rres); 365 sc->sc_bas.bst = rman_get_bustag(sc->sc_rres); 366 sc->sc_bas.chan = chan; 367 sc->sc_bas.regshft = regshft; 368 sc->sc_bas.rclk = (rclk == 0) ? sc->sc_class->uc_rclk : rclk; 369 370 SLIST_FOREACH(sysdev, &uart_sysdevs, next) { 371 if (chan == sysdev->bas.chan && 372 uart_cpu_eqres(&sc->sc_bas, &sysdev->bas)) { 373 /* XXX check if ops matches class. */ 374 sc->sc_sysdev = sysdev; 375 sysdev->bas.rclk = sc->sc_bas.rclk; 376 } 377 } 378 379 error = UART_PROBE(sc); 380 bus_release_resource(dev, sc->sc_rtype, sc->sc_rrid, sc->sc_rres); 381 return ((error) ? error : BUS_PROBE_DEFAULT); 382 } 383 384 int 385 uart_bus_attach(device_t dev) 386 { 387 struct uart_softc *sc, *sc0; 388 const char *sep; 389 int error; 390 391 /* 392 * The sc_class field defines the type of UART we're going to work 393 * with and thus the size of the softc. Replace the generic softc 394 * with one that matches the UART now that we're certain we handle 395 * the device. 396 */ 397 sc0 = device_get_softc(dev); 398 if (sc0->sc_class->size > sizeof(*sc)) { 399 sc = malloc(sc0->sc_class->size, M_UART, M_WAITOK|M_ZERO); 400 bcopy(sc0, sc, sizeof(*sc)); 401 device_set_softc(dev, sc); 402 } else 403 sc = sc0; 404 405 /* 406 * Protect ourselves against interrupts while we're not completely 407 * finished attaching and initializing. We don't expect interrupts 408 * until after UART_ATTACH() though. 409 */ 410 sc->sc_leaving = 1; 411 412 mtx_init(&sc->sc_hwmtx_s, "uart_hwmtx", NULL, MTX_SPIN); 413 if (sc->sc_hwmtx == NULL) 414 sc->sc_hwmtx = &sc->sc_hwmtx_s; 415 416 /* 417 * Re-allocate. We expect that the softc contains the information 418 * collected by uart_bus_probe() intact. 419 */ 420 sc->sc_rres = bus_alloc_resource(dev, sc->sc_rtype, &sc->sc_rrid, 421 0, ~0, uart_getrange(sc->sc_class), RF_ACTIVE); 422 if (sc->sc_rres == NULL) { 423 mtx_destroy(&sc->sc_hwmtx_s); 424 return (ENXIO); 425 } 426 sc->sc_bas.bsh = rman_get_bushandle(sc->sc_rres); 427 sc->sc_bas.bst = rman_get_bustag(sc->sc_rres); 428 429 sc->sc_irid = 0; 430 sc->sc_ires = bus_alloc_resource_any(dev, SYS_RES_IRQ, &sc->sc_irid, 431 RF_ACTIVE | RF_SHAREABLE); 432 if (sc->sc_ires != NULL) { 433 error = bus_setup_intr(dev, 434 sc->sc_ires, INTR_TYPE_TTY, 435 uart_intr, NULL, sc, &sc->sc_icookie); 436 if (error) 437 error = bus_setup_intr(dev, 438 sc->sc_ires, INTR_TYPE_TTY | INTR_MPSAFE, 439 NULL, (driver_intr_t *)uart_intr, sc, &sc->sc_icookie); 440 else 441 sc->sc_fastintr = 1; 442 443 if (error) { 444 device_printf(dev, "could not activate interrupt\n"); 445 bus_release_resource(dev, SYS_RES_IRQ, sc->sc_irid, 446 sc->sc_ires); 447 sc->sc_ires = NULL; 448 } 449 } 450 if (sc->sc_ires == NULL) { 451 /* XXX no interrupt resource. Force polled mode. */ 452 sc->sc_polled = 1; 453 } 454 455 sc->sc_rxbufsz = IBUFSIZ; 456 sc->sc_rxbuf = malloc(sc->sc_rxbufsz * sizeof(*sc->sc_rxbuf), 457 M_UART, M_WAITOK); 458 sc->sc_txbuf = malloc(sc->sc_txfifosz * sizeof(*sc->sc_txbuf), 459 M_UART, M_WAITOK); 460 461 error = UART_ATTACH(sc); 462 if (error) 463 goto fail; 464 465 if (sc->sc_hwiflow || sc->sc_hwoflow) { 466 sep = ""; 467 device_print_prettyname(dev); 468 if (sc->sc_hwiflow) { 469 printf("%sRTS iflow", sep); 470 sep = ", "; 471 } 472 if (sc->sc_hwoflow) { 473 printf("%sCTS oflow", sep); 474 sep = ", "; 475 } 476 printf("\n"); 477 } 478 479 if (bootverbose && (sc->sc_fastintr || sc->sc_polled)) { 480 sep = ""; 481 device_print_prettyname(dev); 482 if (sc->sc_fastintr) { 483 printf("%sfast interrupt", sep); 484 sep = ", "; 485 } 486 if (sc->sc_polled) { 487 printf("%spolled mode", sep); 488 sep = ", "; 489 } 490 printf("\n"); 491 } 492 493 if (sc->sc_sysdev != NULL) { 494 if (sc->sc_sysdev->baudrate == 0) { 495 if (UART_IOCTL(sc, UART_IOCTL_BAUD, 496 (intptr_t)&sc->sc_sysdev->baudrate) != 0) 497 sc->sc_sysdev->baudrate = -1; 498 } 499 switch (sc->sc_sysdev->type) { 500 case UART_DEV_CONSOLE: 501 device_printf(dev, "console"); 502 break; 503 case UART_DEV_DBGPORT: 504 device_printf(dev, "debug port"); 505 break; 506 case UART_DEV_KEYBOARD: 507 device_printf(dev, "keyboard"); 508 break; 509 default: 510 device_printf(dev, "unknown system device"); 511 break; 512 } 513 printf(" (%d,%c,%d,%d)\n", sc->sc_sysdev->baudrate, 514 "noems"[sc->sc_sysdev->parity], sc->sc_sysdev->databits, 515 sc->sc_sysdev->stopbits); 516 } 517 518 sc->sc_pps.ppscap = PPS_CAPTUREBOTH; 519 pps_init(&sc->sc_pps); 520 521 error = (sc->sc_sysdev != NULL && sc->sc_sysdev->attach != NULL) 522 ? (*sc->sc_sysdev->attach)(sc) : uart_tty_attach(sc); 523 if (error) 524 goto fail; 525 526 if (sc->sc_sysdev != NULL) 527 sc->sc_sysdev->hwmtx = sc->sc_hwmtx; 528 529 sc->sc_leaving = 0; 530 uart_intr(sc); 531 return (0); 532 533 fail: 534 free(sc->sc_txbuf, M_UART); 535 free(sc->sc_rxbuf, M_UART); 536 537 if (sc->sc_ires != NULL) { 538 bus_teardown_intr(dev, sc->sc_ires, sc->sc_icookie); 539 bus_release_resource(dev, SYS_RES_IRQ, sc->sc_irid, 540 sc->sc_ires); 541 } 542 bus_release_resource(dev, sc->sc_rtype, sc->sc_rrid, sc->sc_rres); 543 544 mtx_destroy(&sc->sc_hwmtx_s); 545 546 return (error); 547 } 548 549 int 550 uart_bus_detach(device_t dev) 551 { 552 struct uart_softc *sc; 553 554 sc = device_get_softc(dev); 555 556 sc->sc_leaving = 1; 557 558 if (sc->sc_sysdev != NULL) 559 sc->sc_sysdev->hwmtx = NULL; 560 561 UART_DETACH(sc); 562 563 if (sc->sc_sysdev != NULL && sc->sc_sysdev->detach != NULL) 564 (*sc->sc_sysdev->detach)(sc); 565 else 566 uart_tty_detach(sc); 567 568 free(sc->sc_txbuf, M_UART); 569 free(sc->sc_rxbuf, M_UART); 570 571 if (sc->sc_ires != NULL) { 572 bus_teardown_intr(dev, sc->sc_ires, sc->sc_icookie); 573 bus_release_resource(dev, SYS_RES_IRQ, sc->sc_irid, 574 sc->sc_ires); 575 } 576 bus_release_resource(dev, sc->sc_rtype, sc->sc_rrid, sc->sc_rres); 577 578 mtx_destroy(&sc->sc_hwmtx_s); 579 580 if (sc->sc_class->size > sizeof(*sc)) { 581 device_set_softc(dev, NULL); 582 free(sc, M_UART); 583 } else 584 device_set_softc(dev, NULL); 585 586 return (0); 587 } 588