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");
62 uart_add_sysdev(struct uart_devinfo *di)
64 SLIST_INSERT_HEAD(&uart_sysdevs, di, next);
68 uart_getname(struct uart_class *uc)
70 return ((uc != NULL) ? uc->name : NULL);
74 uart_getops(struct uart_class *uc)
76 return ((uc != NULL) ? uc->uc_ops : NULL);
80 uart_getrange(struct uart_class *uc)
82 return ((uc != NULL) ? uc->uc_range : 0);
86 * Schedule a soft interrupt. We do this on the 0 to !0 transition
87 * of the TTY pending interrupt status.
90 uart_sched_softih(struct uart_softc *sc, uint32_t ipend)
97 } while (!atomic_cmpset_32(&sc->sc_ttypend, old, new));
99 if ((old & SER_INT_MASK) == 0)
100 swi_sched(sc->sc_softih, 0);
104 * A break condition has been detected. We treat the break condition as
105 * a special case that should not happen during normal operation. When
106 * the break condition is to be passed to higher levels in the form of
107 * a NUL character, we really want the break to be in the right place in
108 * the input stream. The overhead to achieve that is not in relation to
109 * the exceptional nature of the break condition, so we permit ourselves
113 uart_intr_break(void *arg)
115 struct uart_softc *sc = arg;
118 if (sc->sc_sysdev != NULL && sc->sc_sysdev->type == UART_DEV_CONSOLE) {
124 uart_sched_softih(sc, SER_INT_BREAK);
129 * Handle a receiver overrun situation. We lost at least 1 byte in the
130 * input stream and it's our job to contain the situation. We grab as
131 * much of the data we can, but otherwise flush the receiver FIFO to
132 * create some breathing room. The net effect is that we avoid the
133 * overrun condition to happen for the next X characters, where X is
134 * related to the FIFO size at the cost of loosing data right away.
135 * So, instead of having multiple overrun interrupts in close proximity
136 * to each other and possibly pessimizing UART interrupt latency for
137 * other UARTs in a multiport configuration, we create a longer segment
138 * of missing characters by freeing up the FIFO.
139 * Each overrun condition is marked in the input buffer by a token. The
140 * token represents the loss of at least one, but possible more bytes in
144 uart_intr_overrun(void *arg)
146 struct uart_softc *sc = arg;
150 if (uart_rx_put(sc, UART_STAT_OVERRUN))
151 sc->sc_rxbuf[sc->sc_rxput] = UART_STAT_OVERRUN;
152 uart_sched_softih(sc, SER_INT_RXREADY);
154 UART_FLUSH(sc, UART_FLUSH_RECEIVER);
159 * Received data ready.
162 uart_intr_rxready(void *arg)
164 struct uart_softc *sc = arg;
170 if (sc->sc_sysdev != NULL && sc->sc_sysdev->type == UART_DEV_CONSOLE) {
171 while (rxp != sc->sc_rxput) {
172 kdb_alt_break(sc->sc_rxbuf[rxp++], &sc->sc_altbrk);
173 if (rxp == sc->sc_rxbufsz)
179 uart_sched_softih(sc, SER_INT_RXREADY);
181 sc->sc_rxput = sc->sc_rxget; /* Ignore received data. */
186 * Line or modem status change (OOB signalling).
187 * We pass the signals to the software interrupt handler for further
188 * processing. Note that we merge the delta bits, but set the state
189 * bits. This is to avoid loosing state transitions due to having more
190 * than 1 hardware interrupt between software interrupts.
193 uart_intr_sigchg(void *arg)
195 struct uart_softc *sc = arg;
198 sig = UART_GETSIG(sc);
200 if (sc->sc_pps.ppsparam.mode & PPS_CAPTUREBOTH) {
201 if (sig & UART_SIG_DPPS) {
202 pps_capture(&sc->sc_pps);
203 pps_event(&sc->sc_pps, (sig & UART_SIG_PPS) ?
204 PPS_CAPTUREASSERT : PPS_CAPTURECLEAR);
209 * Keep track of signal changes, even when the device is not
210 * opened. This allows us to inform upper layers about a
211 * possible loss of DCD and thus the existence of a (possibly)
212 * different connection when we have DCD back, during the time
213 * that the device was closed.
216 old = sc->sc_ttypend;
217 new = old & ~SER_MASK_STATE;
218 new |= sig & SER_INT_SIGMASK;
219 } while (!atomic_cmpset_32(&sc->sc_ttypend, old, new));
222 uart_sched_softih(sc, SER_INT_SIGCHG);
227 * The transmitter can accept more data.
230 uart_intr_txidle(void *arg)
232 struct uart_softc *sc = arg;
236 uart_sched_softih(sc, SER_INT_TXIDLE);
244 struct uart_softc *sc = arg;
247 while (!sc->sc_leaving && (ipend = UART_IPEND(sc)) != 0) {
249 if (ipend & SER_INT_OVERRUN)
250 uart_intr_overrun(sc);
251 if (ipend & SER_INT_BREAK)
253 if (ipend & SER_INT_RXREADY)
254 uart_intr_rxready(sc);
255 if (ipend & SER_INT_SIGCHG)
256 uart_intr_sigchg(sc);
257 if (ipend & SER_INT_TXIDLE)
258 uart_intr_txidle(sc);
260 return((flag)?FILTER_HANDLED:FILTER_STRAY);
264 uart_bus_ihand(device_t dev, int ipend)
269 return (uart_intr_break);
270 case SER_INT_OVERRUN:
271 return (uart_intr_overrun);
272 case SER_INT_RXREADY:
273 return (uart_intr_rxready);
275 return (uart_intr_sigchg);
277 return (uart_intr_txidle);
283 uart_bus_ipend(device_t dev)
285 struct uart_softc *sc;
287 sc = device_get_softc(dev);
288 return (UART_IPEND(sc));
292 uart_bus_sysdev(device_t dev)
294 struct uart_softc *sc;
296 sc = device_get_softc(dev);
297 return ((sc->sc_sysdev != NULL) ? 1 : 0);
301 uart_bus_probe(device_t dev, int regshft, int rclk, int rid, int chan)
303 struct uart_softc *sc;
304 struct uart_devinfo *sysdev;
307 sc = device_get_softc(dev);
310 * All uart_class references are weak. Check that the needed
311 * class has been compiled-in. Fail if not.
313 if (sc->sc_class == NULL)
317 * Initialize the instance. Note that the instance (=softc) does
318 * not necessarily match the hardware specific softc. We can't do
319 * anything about it now, because we may not attach to the device.
320 * Hardware drivers cannot use any of the class specific fields
323 kobj_init((kobj_t)sc, (kobj_class_t)sc->sc_class);
325 if (device_get_desc(dev) == NULL)
326 device_set_desc(dev, uart_getname(sc->sc_class));
329 * Allocate the register resource. We assume that all UARTs have
330 * a single register window in either I/O port space or memory
331 * mapped I/O space. Any UART that needs multiple windows will
332 * consequently not be supported by this driver as-is. We try I/O
333 * port space first because that's the common case.
336 sc->sc_rtype = SYS_RES_IOPORT;
337 sc->sc_rres = bus_alloc_resource(dev, sc->sc_rtype, &sc->sc_rrid,
338 0, ~0, uart_getrange(sc->sc_class), RF_ACTIVE);
339 if (sc->sc_rres == NULL) {
341 sc->sc_rtype = SYS_RES_MEMORY;
342 sc->sc_rres = bus_alloc_resource(dev, sc->sc_rtype,
343 &sc->sc_rrid, 0, ~0, uart_getrange(sc->sc_class),
345 if (sc->sc_rres == NULL)
350 * Fill in the bus access structure and compare this device with
351 * a possible console device and/or a debug port. We set the flags
352 * in the softc so that the hardware dependent probe can adjust
353 * accordingly. In general, you don't want to permanently disrupt
356 sc->sc_bas.bsh = rman_get_bushandle(sc->sc_rres);
357 sc->sc_bas.bst = rman_get_bustag(sc->sc_rres);
358 sc->sc_bas.chan = chan;
359 sc->sc_bas.regshft = regshft;
360 sc->sc_bas.rclk = (rclk == 0) ? sc->sc_class->uc_rclk : rclk;
362 SLIST_FOREACH(sysdev, &uart_sysdevs, next) {
363 if (chan == sysdev->bas.chan &&
364 uart_cpu_eqres(&sc->sc_bas, &sysdev->bas)) {
365 /* XXX check if ops matches class. */
366 sc->sc_sysdev = sysdev;
367 sysdev->bas.rclk = sc->sc_bas.rclk;
371 error = UART_PROBE(sc);
372 bus_release_resource(dev, sc->sc_rtype, sc->sc_rrid, sc->sc_rres);
373 return ((error) ? error : BUS_PROBE_DEFAULT);
377 uart_bus_attach(device_t dev)
379 struct uart_softc *sc, *sc0;
384 * The sc_class field defines the type of UART we're going to work
385 * with and thus the size of the softc. Replace the generic softc
386 * with one that matches the UART now that we're certain we handle
389 sc0 = device_get_softc(dev);
390 if (sc0->sc_class->size > sizeof(*sc)) {
391 sc = malloc(sc0->sc_class->size, M_UART, M_WAITOK|M_ZERO);
392 bcopy(sc0, sc, sizeof(*sc));
393 device_set_softc(dev, sc);
398 * Protect ourselves against interrupts while we're not completely
399 * finished attaching and initializing. We don't expect interrupts
400 * until after UART_ATTACH() though.
404 mtx_init(&sc->sc_hwmtx_s, "uart_hwmtx", NULL, MTX_SPIN);
405 if (sc->sc_hwmtx == NULL)
406 sc->sc_hwmtx = &sc->sc_hwmtx_s;
409 * Re-allocate. We expect that the softc contains the information
410 * collected by uart_bus_probe() intact.
412 sc->sc_rres = bus_alloc_resource(dev, sc->sc_rtype, &sc->sc_rrid,
413 0, ~0, uart_getrange(sc->sc_class), RF_ACTIVE);
414 if (sc->sc_rres == NULL) {
415 mtx_destroy(&sc->sc_hwmtx_s);
418 sc->sc_bas.bsh = rman_get_bushandle(sc->sc_rres);
419 sc->sc_bas.bst = rman_get_bustag(sc->sc_rres);
422 sc->sc_ires = bus_alloc_resource_any(dev, SYS_RES_IRQ, &sc->sc_irid,
423 RF_ACTIVE | RF_SHAREABLE);
424 if (sc->sc_ires != NULL) {
425 error = bus_setup_intr(dev,
426 sc->sc_ires, INTR_TYPE_TTY,
427 uart_intr, NULL, sc, &sc->sc_icookie);
429 error = bus_setup_intr(dev,
430 sc->sc_ires, INTR_TYPE_TTY | INTR_MPSAFE,
431 NULL, (driver_intr_t *)uart_intr, sc, &sc->sc_icookie);
436 device_printf(dev, "could not activate interrupt\n");
437 bus_release_resource(dev, SYS_RES_IRQ, sc->sc_irid,
442 if (sc->sc_ires == NULL) {
443 /* XXX no interrupt resource. Force polled mode. */
447 sc->sc_rxbufsz = 384;
448 sc->sc_rxbuf = malloc(sc->sc_rxbufsz * sizeof(*sc->sc_rxbuf),
450 sc->sc_txbuf = malloc(sc->sc_txfifosz * sizeof(*sc->sc_txbuf),
453 error = UART_ATTACH(sc);
457 if (sc->sc_hwiflow || sc->sc_hwoflow) {
459 device_print_prettyname(dev);
460 if (sc->sc_hwiflow) {
461 printf("%sRTS iflow", sep);
464 if (sc->sc_hwoflow) {
465 printf("%sCTS oflow", sep);
471 if (bootverbose && (sc->sc_fastintr || sc->sc_polled)) {
473 device_print_prettyname(dev);
474 if (sc->sc_fastintr) {
475 printf("%sfast interrupt", sep);
479 printf("%spolled mode", sep);
485 if (sc->sc_sysdev != NULL) {
486 if (sc->sc_sysdev->baudrate == 0) {
487 if (UART_IOCTL(sc, UART_IOCTL_BAUD,
488 (intptr_t)&sc->sc_sysdev->baudrate) != 0)
489 sc->sc_sysdev->baudrate = -1;
491 switch (sc->sc_sysdev->type) {
492 case UART_DEV_CONSOLE:
493 device_printf(dev, "console");
495 case UART_DEV_DBGPORT:
496 device_printf(dev, "debug port");
498 case UART_DEV_KEYBOARD:
499 device_printf(dev, "keyboard");
502 device_printf(dev, "unknown system device");
505 printf(" (%d,%c,%d,%d)\n", sc->sc_sysdev->baudrate,
506 "noems"[sc->sc_sysdev->parity], sc->sc_sysdev->databits,
507 sc->sc_sysdev->stopbits);
510 sc->sc_pps.ppscap = PPS_CAPTUREBOTH;
511 pps_init(&sc->sc_pps);
513 error = (sc->sc_sysdev != NULL && sc->sc_sysdev->attach != NULL)
514 ? (*sc->sc_sysdev->attach)(sc) : uart_tty_attach(sc);
518 if (sc->sc_sysdev != NULL)
519 sc->sc_sysdev->hwmtx = sc->sc_hwmtx;
526 free(sc->sc_txbuf, M_UART);
527 free(sc->sc_rxbuf, M_UART);
529 if (sc->sc_ires != NULL) {
530 bus_teardown_intr(dev, sc->sc_ires, sc->sc_icookie);
531 bus_release_resource(dev, SYS_RES_IRQ, sc->sc_irid,
534 bus_release_resource(dev, sc->sc_rtype, sc->sc_rrid, sc->sc_rres);
536 mtx_destroy(&sc->sc_hwmtx_s);
542 uart_bus_detach(device_t dev)
544 struct uart_softc *sc;
546 sc = device_get_softc(dev);
550 if (sc->sc_sysdev != NULL)
551 sc->sc_sysdev->hwmtx = NULL;
555 if (sc->sc_sysdev != NULL && sc->sc_sysdev->detach != NULL)
556 (*sc->sc_sysdev->detach)(sc);
560 free(sc->sc_txbuf, M_UART);
561 free(sc->sc_rxbuf, M_UART);
563 if (sc->sc_ires != NULL) {
564 bus_teardown_intr(dev, sc->sc_ires, sc->sc_icookie);
565 bus_release_resource(dev, SYS_RES_IRQ, sc->sc_irid,
568 bus_release_resource(dev, sc->sc_rtype, sc->sc_rrid, sc->sc_rres);
570 mtx_destroy(&sc->sc_hwmtx_s);
572 if (sc->sc_class->size > sizeof(*sc)) {
573 device_set_softc(dev, NULL);
576 device_set_softc(dev, NULL);