2 * Copyright (c) 2003 Marcel Moolenaar
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
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.
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.
27 #include <sys/cdefs.h>
28 __FBSDID("$FreeBSD$");
30 #include <sys/param.h>
31 #include <sys/systm.h>
35 #include <sys/fcntl.h>
36 #include <sys/interrupt.h>
38 #include <sys/kernel.h>
39 #include <sys/malloc.h>
40 #include <sys/queue.h>
41 #include <sys/reboot.h>
42 #include <machine/bus.h>
44 #include <machine/resource.h>
45 #include <machine/stdarg.h>
47 #include <dev/uart/uart.h>
48 #include <dev/uart/uart_bus.h>
49 #include <dev/uart/uart_cpu.h>
53 devclass_t uart_devclass;
54 char uart_driver_name[] = "uart";
56 SLIST_HEAD(uart_devinfo_list, uart_devinfo) uart_sysdevs =
57 SLIST_HEAD_INITIALIZER(uart_sysdevs);
59 static MALLOC_DEFINE(M_UART, "UART", "UART driver");
61 #ifndef UART_POLL_FREQ
62 #define UART_POLL_FREQ 50
64 static int uart_poll_freq = UART_POLL_FREQ;
65 TUNABLE_INT("debug.uart_poll_freq", &uart_poll_freq);
68 uart_add_sysdev(struct uart_devinfo *di)
70 SLIST_INSERT_HEAD(&uart_sysdevs, di, next);
74 uart_getname(struct uart_class *uc)
76 return ((uc != NULL) ? uc->name : NULL);
80 uart_getops(struct uart_class *uc)
82 return ((uc != NULL) ? uc->uc_ops : NULL);
86 uart_getrange(struct uart_class *uc)
88 return ((uc != NULL) ? uc->uc_range : 0);
92 uart_getregshift(struct uart_class *uc)
94 return ((uc != NULL) ? uc->uc_rshift : 0);
98 * Schedule a soft interrupt. We do this on the 0 to !0 transition
99 * of the TTY pending interrupt status.
102 uart_sched_softih(struct uart_softc *sc, uint32_t ipend)
107 old = sc->sc_ttypend;
109 } while (!atomic_cmpset_32(&sc->sc_ttypend, old, new));
111 if ((old & SER_INT_MASK) == 0)
112 swi_sched(sc->sc_softih, 0);
116 * A break condition has been detected. We treat the break condition as
117 * a special case that should not happen during normal operation. When
118 * the break condition is to be passed to higher levels in the form of
119 * a NUL character, we really want the break to be in the right place in
120 * the input stream. The overhead to achieve that is not in relation to
121 * the exceptional nature of the break condition, so we permit ourselves
125 uart_intr_break(void *arg)
127 struct uart_softc *sc = arg;
130 if (sc->sc_sysdev != NULL && sc->sc_sysdev->type == UART_DEV_CONSOLE) {
136 uart_sched_softih(sc, SER_INT_BREAK);
141 * Handle a receiver overrun situation. We lost at least 1 byte in the
142 * input stream and it's our job to contain the situation. We grab as
143 * much of the data we can, but otherwise flush the receiver FIFO to
144 * create some breathing room. The net effect is that we avoid the
145 * overrun condition to happen for the next X characters, where X is
146 * related to the FIFO size at the cost of losing data right away.
147 * So, instead of having multiple overrun interrupts in close proximity
148 * to each other and possibly pessimizing UART interrupt latency for
149 * other UARTs in a multiport configuration, we create a longer segment
150 * of missing characters by freeing up the FIFO.
151 * Each overrun condition is marked in the input buffer by a token. The
152 * token represents the loss of at least one, but possible more bytes in
156 uart_intr_overrun(void *arg)
158 struct uart_softc *sc = arg;
162 if (uart_rx_put(sc, UART_STAT_OVERRUN))
163 sc->sc_rxbuf[sc->sc_rxput] = UART_STAT_OVERRUN;
164 uart_sched_softih(sc, SER_INT_RXREADY);
166 UART_FLUSH(sc, UART_FLUSH_RECEIVER);
171 * Received data ready.
174 uart_intr_rxready(void *arg)
176 struct uart_softc *sc = arg;
182 if (sc->sc_sysdev != NULL && sc->sc_sysdev->type == UART_DEV_CONSOLE) {
183 while (rxp != sc->sc_rxput) {
184 kdb_alt_break(sc->sc_rxbuf[rxp++], &sc->sc_altbrk);
185 if (rxp == sc->sc_rxbufsz)
191 uart_sched_softih(sc, SER_INT_RXREADY);
193 sc->sc_rxput = sc->sc_rxget; /* Ignore received data. */
198 * Line or modem status change (OOB signalling).
199 * We pass the signals to the software interrupt handler for further
200 * processing. Note that we merge the delta bits, but set the state
201 * bits. This is to avoid losing state transitions due to having more
202 * than 1 hardware interrupt between software interrupts.
205 uart_intr_sigchg(void *arg)
207 struct uart_softc *sc = arg;
210 sig = UART_GETSIG(sc);
212 if (sc->sc_pps.ppsparam.mode & PPS_CAPTUREBOTH) {
213 if (sig & UART_SIG_DPPS) {
214 pps_capture(&sc->sc_pps);
215 pps_event(&sc->sc_pps, (sig & UART_SIG_PPS) ?
216 PPS_CAPTUREASSERT : PPS_CAPTURECLEAR);
221 * Keep track of signal changes, even when the device is not
222 * opened. This allows us to inform upper layers about a
223 * possible loss of DCD and thus the existence of a (possibly)
224 * different connection when we have DCD back, during the time
225 * that the device was closed.
228 old = sc->sc_ttypend;
229 new = old & ~SER_MASK_STATE;
230 new |= sig & SER_INT_SIGMASK;
231 } while (!atomic_cmpset_32(&sc->sc_ttypend, old, new));
234 uart_sched_softih(sc, SER_INT_SIGCHG);
239 * The transmitter can accept more data.
242 uart_intr_txidle(void *arg)
244 struct uart_softc *sc = arg;
248 uart_sched_softih(sc, SER_INT_TXIDLE);
256 struct uart_softc *sc = arg;
260 return (FILTER_STRAY);
263 while (cnt < 20 && (ipend = UART_IPEND(sc)) != 0) {
265 if (ipend & SER_INT_OVERRUN)
266 uart_intr_overrun(sc);
267 if (ipend & SER_INT_BREAK)
269 if (ipend & SER_INT_RXREADY)
270 uart_intr_rxready(sc);
271 if (ipend & SER_INT_SIGCHG)
272 uart_intr_sigchg(sc);
273 if (ipend & SER_INT_TXIDLE)
274 uart_intr_txidle(sc);
278 callout_reset(&sc->sc_timer, hz / uart_poll_freq,
279 (timeout_t *)uart_intr, sc);
282 return ((cnt == 0) ? FILTER_STRAY :
283 ((cnt == 20) ? FILTER_SCHEDULE_THREAD : FILTER_HANDLED));
287 uart_bus_ihand(device_t dev, int ipend)
292 return (uart_intr_break);
293 case SER_INT_OVERRUN:
294 return (uart_intr_overrun);
295 case SER_INT_RXREADY:
296 return (uart_intr_rxready);
298 return (uart_intr_sigchg);
300 return (uart_intr_txidle);
306 uart_bus_ipend(device_t dev)
308 struct uart_softc *sc;
310 sc = device_get_softc(dev);
311 return (UART_IPEND(sc));
315 uart_bus_sysdev(device_t dev)
317 struct uart_softc *sc;
319 sc = device_get_softc(dev);
320 return ((sc->sc_sysdev != NULL) ? 1 : 0);
324 uart_bus_probe(device_t dev, int regshft, int rclk, int rid, int chan)
326 struct uart_softc *sc;
327 struct uart_devinfo *sysdev;
330 sc = device_get_softc(dev);
333 * All uart_class references are weak. Check that the needed
334 * class has been compiled-in. Fail if not.
336 if (sc->sc_class == NULL)
340 * Initialize the instance. Note that the instance (=softc) does
341 * not necessarily match the hardware specific softc. We can't do
342 * anything about it now, because we may not attach to the device.
343 * Hardware drivers cannot use any of the class specific fields
346 kobj_init((kobj_t)sc, (kobj_class_t)sc->sc_class);
348 if (device_get_desc(dev) == NULL)
349 device_set_desc(dev, uart_getname(sc->sc_class));
352 * Allocate the register resource. We assume that all UARTs have
353 * a single register window in either I/O port space or memory
354 * mapped I/O space. Any UART that needs multiple windows will
355 * consequently not be supported by this driver as-is. We try I/O
356 * port space first because that's the common case.
359 sc->sc_rtype = SYS_RES_IOPORT;
360 sc->sc_rres = bus_alloc_resource(dev, sc->sc_rtype, &sc->sc_rrid,
361 0, ~0, uart_getrange(sc->sc_class), RF_ACTIVE);
362 if (sc->sc_rres == NULL) {
364 sc->sc_rtype = SYS_RES_MEMORY;
365 sc->sc_rres = bus_alloc_resource(dev, sc->sc_rtype,
366 &sc->sc_rrid, 0, ~0, uart_getrange(sc->sc_class),
368 if (sc->sc_rres == NULL)
373 * Fill in the bus access structure and compare this device with
374 * a possible console device and/or a debug port. We set the flags
375 * in the softc so that the hardware dependent probe can adjust
376 * accordingly. In general, you don't want to permanently disrupt
379 sc->sc_bas.bsh = rman_get_bushandle(sc->sc_rres);
380 sc->sc_bas.bst = rman_get_bustag(sc->sc_rres);
381 sc->sc_bas.chan = chan;
382 sc->sc_bas.regshft = regshft;
383 sc->sc_bas.rclk = (rclk == 0) ? sc->sc_class->uc_rclk : rclk;
385 SLIST_FOREACH(sysdev, &uart_sysdevs, next) {
386 if (chan == sysdev->bas.chan &&
387 uart_cpu_eqres(&sc->sc_bas, &sysdev->bas)) {
388 /* XXX check if ops matches class. */
389 sc->sc_sysdev = sysdev;
390 sysdev->bas.rclk = sc->sc_bas.rclk;
394 error = UART_PROBE(sc);
395 bus_release_resource(dev, sc->sc_rtype, sc->sc_rrid, sc->sc_rres);
396 return ((error) ? error : BUS_PROBE_DEFAULT);
400 uart_bus_attach(device_t dev)
402 struct uart_softc *sc, *sc0;
407 * The sc_class field defines the type of UART we're going to work
408 * with and thus the size of the softc. Replace the generic softc
409 * with one that matches the UART now that we're certain we handle
412 sc0 = device_get_softc(dev);
413 if (sc0->sc_class->size > sizeof(*sc)) {
414 sc = malloc(sc0->sc_class->size, M_UART, M_WAITOK|M_ZERO);
415 bcopy(sc0, sc, sizeof(*sc));
416 device_set_softc(dev, sc);
421 * Now that we know the softc for this device, connect the back
422 * pointer from the sysdev for this device, if any
424 if (sc->sc_sysdev != NULL)
425 sc->sc_sysdev->sc = sc;
428 * Protect ourselves against interrupts while we're not completely
429 * finished attaching and initializing. We don't expect interrupts
430 * until after UART_ATTACH() though.
434 mtx_init(&sc->sc_hwmtx_s, "uart_hwmtx", NULL, MTX_SPIN);
435 if (sc->sc_hwmtx == NULL)
436 sc->sc_hwmtx = &sc->sc_hwmtx_s;
439 * Re-allocate. We expect that the softc contains the information
440 * collected by uart_bus_probe() intact.
442 sc->sc_rres = bus_alloc_resource(dev, sc->sc_rtype, &sc->sc_rrid,
443 0, ~0, uart_getrange(sc->sc_class), RF_ACTIVE);
444 if (sc->sc_rres == NULL) {
445 mtx_destroy(&sc->sc_hwmtx_s);
448 sc->sc_bas.bsh = rman_get_bushandle(sc->sc_rres);
449 sc->sc_bas.bst = rman_get_bustag(sc->sc_rres);
452 * Ensure there is room for at least three full FIFOs of data in the
453 * receive buffer (handles the case of low-level drivers with huge
454 * FIFOs), and also ensure that there is no less than the historical
455 * size of 384 bytes (handles the typical small-FIFO case).
457 sc->sc_rxbufsz = MAX(384, sc->sc_rxfifosz * 3);
458 sc->sc_rxbuf = malloc(sc->sc_rxbufsz * sizeof(*sc->sc_rxbuf),
460 sc->sc_txbuf = malloc(sc->sc_txfifosz * sizeof(*sc->sc_txbuf),
463 error = UART_ATTACH(sc);
467 if (sc->sc_hwiflow || sc->sc_hwoflow) {
469 device_print_prettyname(dev);
470 if (sc->sc_hwiflow) {
471 printf("%sRTS iflow", sep);
474 if (sc->sc_hwoflow) {
475 printf("%sCTS oflow", sep);
481 if (sc->sc_sysdev != NULL) {
482 if (sc->sc_sysdev->baudrate == 0) {
483 if (UART_IOCTL(sc, UART_IOCTL_BAUD,
484 (intptr_t)&sc->sc_sysdev->baudrate) != 0)
485 sc->sc_sysdev->baudrate = -1;
487 switch (sc->sc_sysdev->type) {
488 case UART_DEV_CONSOLE:
489 device_printf(dev, "console");
491 case UART_DEV_DBGPORT:
492 device_printf(dev, "debug port");
494 case UART_DEV_KEYBOARD:
495 device_printf(dev, "keyboard");
498 device_printf(dev, "unknown system device");
501 printf(" (%d,%c,%d,%d)\n", sc->sc_sysdev->baudrate,
502 "noems"[sc->sc_sysdev->parity], sc->sc_sysdev->databits,
503 sc->sc_sysdev->stopbits);
506 sc->sc_pps.ppscap = PPS_CAPTUREBOTH;
507 pps_init(&sc->sc_pps);
510 filt = uart_intr(sc);
513 * Don't use interrupts if we couldn't clear any pending interrupt
514 * conditions. We may have broken H/W and polling is probably the
515 * safest thing to do.
517 if (filt != FILTER_SCHEDULE_THREAD) {
519 sc->sc_ires = bus_alloc_resource_any(dev, SYS_RES_IRQ,
520 &sc->sc_irid, RF_ACTIVE | RF_SHAREABLE);
522 if (sc->sc_ires != NULL) {
523 error = bus_setup_intr(dev, sc->sc_ires, INTR_TYPE_TTY,
524 uart_intr, NULL, sc, &sc->sc_icookie);
525 sc->sc_fastintr = (error == 0) ? 1 : 0;
527 if (!sc->sc_fastintr)
528 error = bus_setup_intr(dev, sc->sc_ires,
529 INTR_TYPE_TTY | INTR_MPSAFE, NULL,
530 (driver_intr_t *)uart_intr, sc, &sc->sc_icookie);
533 device_printf(dev, "could not activate interrupt\n");
534 bus_release_resource(dev, SYS_RES_IRQ, sc->sc_irid,
539 if (sc->sc_ires == NULL) {
540 /* No interrupt resource. Force polled mode. */
542 callout_init(&sc->sc_timer, 1);
545 if (bootverbose && (sc->sc_fastintr || sc->sc_polled)) {
547 device_print_prettyname(dev);
548 if (sc->sc_fastintr) {
549 printf("%sfast interrupt", sep);
553 printf("%spolled mode (%dHz)", sep, uart_poll_freq);
559 error = (sc->sc_sysdev != NULL && sc->sc_sysdev->attach != NULL)
560 ? (*sc->sc_sysdev->attach)(sc) : uart_tty_attach(sc);
564 if (sc->sc_sysdev != NULL)
565 sc->sc_sysdev->hwmtx = sc->sc_hwmtx;
570 free(sc->sc_txbuf, M_UART);
571 free(sc->sc_rxbuf, M_UART);
573 if (sc->sc_ires != NULL) {
574 bus_teardown_intr(dev, sc->sc_ires, sc->sc_icookie);
575 bus_release_resource(dev, SYS_RES_IRQ, sc->sc_irid,
578 bus_release_resource(dev, sc->sc_rtype, sc->sc_rrid, sc->sc_rres);
580 mtx_destroy(&sc->sc_hwmtx_s);
586 uart_bus_detach(device_t dev)
588 struct uart_softc *sc;
590 sc = device_get_softc(dev);
594 if (sc->sc_sysdev != NULL)
595 sc->sc_sysdev->hwmtx = NULL;
599 if (sc->sc_sysdev != NULL && sc->sc_sysdev->detach != NULL)
600 (*sc->sc_sysdev->detach)(sc);
604 free(sc->sc_txbuf, M_UART);
605 free(sc->sc_rxbuf, M_UART);
607 if (sc->sc_ires != NULL) {
608 bus_teardown_intr(dev, sc->sc_ires, sc->sc_icookie);
609 bus_release_resource(dev, SYS_RES_IRQ, sc->sc_irid,
612 bus_release_resource(dev, sc->sc_rtype, sc->sc_rrid, sc->sc_rres);
614 mtx_destroy(&sc->sc_hwmtx_s);
616 if (sc->sc_class->size > sizeof(*sc)) {
617 device_set_softc(dev, NULL);
620 device_set_softc(dev, NULL);
626 uart_bus_resume(device_t dev)
628 struct uart_softc *sc;
630 sc = device_get_softc(dev);
631 return (UART_ATTACH(sc));
635 uart_grab(struct uart_devinfo *di)
643 uart_ungrab(struct uart_devinfo *di)