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 /*
74 * A break condition has been detected. We treat the break condition as
75 * a special case that should not happen during normal operation. When
76 * the break condition is to be passed to higher levels in the form of
77 * a NUL character, we really want the break to be in the right place in
78 * the input stream. The overhead to achieve that is not in relation to
79 * the exceptional nature of the break condition, so we permit ourselves
80 * to be sloppy.
81 */
82 static void
83 uart_intr_break(struct uart_softc *sc)
84 {
85
86 #if defined(KDB) && defined(BREAK_TO_DEBUGGER)
87 if (sc->sc_sysdev != NULL && sc->sc_sysdev->type == UART_DEV_CONSOLE) {
88 kdb_enter("Line break on console");
89 return;
90 }
91 #endif
92 if (sc->sc_opened)
93 atomic_set_32(&sc->sc_ttypend, UART_IPEND_BREAK);
94 }
95
96 /*
97 * Handle a receiver overrun situation. We lost at least 1 byte in the
98 * input stream and it's our job to contain the situation. We grab as
99 * much of the data we can, but otherwise flush the receiver FIFO to
100 * create some breathing room. The net effect is that we avoid the
101 * overrun condition to happen for the next X characters, where X is
102 * related to the FIFO size at the cost of loosing data right away.
103 * So, instead of having multiple overrun interrupts in close proximity
104 * to each other and possibly pessimizing UART interrupt latency for
105 * other UARTs in a multiport configuration, we create a longer segment
106 * of missing characters by freeing up the FIFO.
107 * Each overrun condition is marked in the input buffer by a token. The
108 * token represents the loss of at least one, but possible more bytes in
109 * the input stream.
110 */
111 static void
112 uart_intr_overrun(struct uart_softc *sc)
113 {
114
115 if (sc->sc_opened) {
116 UART_RECEIVE(sc);
117 if (uart_rx_put(sc, UART_STAT_OVERRUN))
118 sc->sc_rxbuf[sc->sc_rxput] = UART_STAT_OVERRUN;
119 atomic_set_32(&sc->sc_ttypend, UART_IPEND_RXREADY);
120 }
121 UART_FLUSH(sc, UART_FLUSH_RECEIVER);
122 }
123
124 /*
125 * Received data ready.
126 */
127 static void
128 uart_intr_rxready(struct uart_softc *sc)
129 {
130 int rxp;
131
132 rxp = sc->sc_rxput;
133 UART_RECEIVE(sc);
134 #if defined(KDB) && defined(ALT_BREAK_TO_DEBUGGER)
135 if (sc->sc_sysdev != NULL && sc->sc_sysdev->type == UART_DEV_CONSOLE) {
136 while (rxp != sc->sc_rxput) {
137 if (kdb_alt_break(sc->sc_rxbuf[rxp++], &sc->sc_altbrk))
138 kdb_enter("Break sequence on console");
139 if (rxp == sc->sc_rxbufsz)
140 rxp = 0;
141 }
142 }
143 #endif
144 if (sc->sc_opened)
145 atomic_set_32(&sc->sc_ttypend, UART_IPEND_RXREADY);
146 else
147 sc->sc_rxput = sc->sc_rxget; /* Ignore received data. */
148 }
149
150 /*
151 * Line or modem status change (OOB signalling).
152 * We pass the signals to the software interrupt handler for further
153 * processing. Note that we merge the delta bits, but set the state
154 * bits. This is to avoid loosing state transitions due to having more
155 * than 1 hardware interrupt between software interrupts.
156 */
157 static void
158 uart_intr_sigchg(struct uart_softc *sc)
159 {
160 int new, old, sig;
161
162 sig = UART_GETSIG(sc);
163
164 if (sc->sc_pps.ppsparam.mode & PPS_CAPTUREBOTH) {
165 if (sig & UART_SIG_DPPS) {
166 pps_capture(&sc->sc_pps);
167 pps_event(&sc->sc_pps, (sig & UART_SIG_PPS) ?
168 PPS_CAPTUREASSERT : PPS_CAPTURECLEAR);
169 }
170 }
171
172 do {
173 old = sc->sc_ttypend;
174 new = old & ~UART_SIGMASK_STATE;
175 new |= sig & UART_IPEND_SIGMASK;
176 new |= UART_IPEND_SIGCHG;
177 } while (!atomic_cmpset_32(&sc->sc_ttypend, old, new));
178 }
179
180 /*
181 * The transmitter can accept more data.
182 */
183 static void
184 uart_intr_txidle(struct uart_softc *sc)
185 {
186 if (sc->sc_txbusy) {
187 sc->sc_txbusy = 0;
188 atomic_set_32(&sc->sc_ttypend, UART_IPEND_TXIDLE);
189 }
190 }
191
192 static void
193 uart_intr(void *arg)
194 {
195 struct uart_softc *sc = arg;
196 int ipend;
197
198 if (sc->sc_leaving)
199 return;
200
201 do {
202 ipend = UART_IPEND(sc);
203 if (ipend == 0)
204 break;
205 if (ipend & UART_IPEND_OVERRUN)
206 uart_intr_overrun(sc);
207 if (ipend & UART_IPEND_BREAK)
208 uart_intr_break(sc);
209 if (ipend & UART_IPEND_RXREADY)
210 uart_intr_rxready(sc);
211 if (ipend & UART_IPEND_SIGCHG)
212 uart_intr_sigchg(sc);
213 if (ipend & UART_IPEND_TXIDLE)
214 uart_intr_txidle(sc);
215 } while (1);
216
217 if (sc->sc_opened && sc->sc_ttypend != 0)
218 swi_sched(sc->sc_softih, 0);
219 }
220
221 int
222 uart_bus_probe(device_t dev, int regshft, int rclk, int rid, int chan)
223 {
224 struct uart_softc *sc;
225 struct uart_devinfo *sysdev;
226 int error;
227
228 /*
229 * Initialize the instance. Note that the instance (=softc) does
230 * not necessarily match the hardware specific softc. We can't do
231 * anything about it now, because we may not attach to the device.
232 * Hardware drivers cannot use any of the class specific fields
233 * while probing.
234 */
235 sc = device_get_softc(dev);
236 kobj_init((kobj_t)sc, (kobj_class_t)sc->sc_class);
237 sc->sc_dev = dev;
238 if (device_get_desc(dev) == NULL)
239 device_set_desc(dev, sc->sc_class->name);
240
241 /*
242 * Allocate the register resource. We assume that all UARTs have
243 * a single register window in either I/O port space or memory
244 * mapped I/O space. Any UART that needs multiple windows will
245 * consequently not be supported by this driver as-is. We try I/O
246 * port space first because that's the common case.
247 */
248 sc->sc_rrid = rid;
249 sc->sc_rtype = SYS_RES_IOPORT;
250 sc->sc_rres = bus_alloc_resource(dev, sc->sc_rtype, &sc->sc_rrid,
251 0, ~0, sc->sc_class->uc_range, RF_ACTIVE);
252 if (sc->sc_rres == NULL) {
253 sc->sc_rrid = rid;
254 sc->sc_rtype = SYS_RES_MEMORY;
255 sc->sc_rres = bus_alloc_resource(dev, sc->sc_rtype,
256 &sc->sc_rrid, 0, ~0, sc->sc_class->uc_range, RF_ACTIVE);
257 if (sc->sc_rres == NULL)
258 return (ENXIO);
259 }
260
261 /*
262 * Fill in the bus access structure and compare this device with
263 * a possible console device and/or a debug port. We set the flags
264 * in the softc so that the hardware dependent probe can adjust
265 * accordingly. In general, you don't want to permanently disrupt
266 * console I/O.
267 */
268 sc->sc_bas.bsh = rman_get_bushandle(sc->sc_rres);
269 sc->sc_bas.bst = rman_get_bustag(sc->sc_rres);
270 sc->sc_bas.chan = chan;
271 sc->sc_bas.regshft = regshft;
272 sc->sc_bas.rclk = (rclk == 0) ? sc->sc_class->uc_rclk : rclk;
273
274 SLIST_FOREACH(sysdev, &uart_sysdevs, next) {
275 if (chan == sysdev->bas.chan &&
276 uart_cpu_eqres(&sc->sc_bas, &sysdev->bas)) {
277 /* XXX check if ops matches class. */
278 sc->sc_sysdev = sysdev;
279 break;
280 }
281 }
282
283 error = UART_PROBE(sc);
284 bus_release_resource(dev, sc->sc_rtype, sc->sc_rrid, sc->sc_rres);
285 return (error);
286 }
287
288 int
289 uart_bus_attach(device_t dev)
290 {
291 struct uart_softc *sc, *sc0;
292 const char *sep;
293 int error;
294
295 /*
296 * The sc_class field defines the type of UART we're going to work
297 * with and thus the size of the softc. Replace the generic softc
298 * with one that matches the UART now that we're certain we handle
299 * the device.
300 */
301 sc0 = device_get_softc(dev);
302 if (sc0->sc_class->size > sizeof(*sc)) {
303 sc = malloc(sc0->sc_class->size, M_UART, M_WAITOK|M_ZERO);
304 bcopy(sc0, sc, sizeof(*sc));
305 device_set_softc(dev, sc);
306 } else
307 sc = sc0;
308
309 /*
310 * Protect ourselves against interrupts while we're not completely
311 * finished attaching and initializing. We don't expect interrupts
312 * until after UART_ATTACH() though.
313 */
314 sc->sc_leaving = 1;
315
316 mtx_init(&sc->sc_hwmtx, "uart_hwmtx", NULL, MTX_SPIN);
317
318 /*
319 * Re-allocate. We expect that the softc contains the information
320 * collected by uart_bus_probe() intact.
321 */
322 sc->sc_rres = bus_alloc_resource(dev, sc->sc_rtype, &sc->sc_rrid,
323 0, ~0, sc->sc_class->uc_range, RF_ACTIVE);
324 if (sc->sc_rres == NULL) {
325 mtx_destroy(&sc->sc_hwmtx);
326 return (ENXIO);
327 }
328 sc->sc_bas.bsh = rman_get_bushandle(sc->sc_rres);
329 sc->sc_bas.bst = rman_get_bustag(sc->sc_rres);
330
331 sc->sc_irid = 0;
332 sc->sc_ires = bus_alloc_resource_any(dev, SYS_RES_IRQ, &sc->sc_irid,
333 RF_ACTIVE | RF_SHAREABLE);
334 if (sc->sc_ires != NULL) {
335 error = BUS_SETUP_INTR(device_get_parent(dev), dev,
336 sc->sc_ires, INTR_TYPE_TTY | INTR_FAST, uart_intr,
337 sc, &sc->sc_icookie);
338 if (error)
339 error = BUS_SETUP_INTR(device_get_parent(dev), dev,
340 sc->sc_ires, INTR_TYPE_TTY | INTR_MPSAFE,
341 uart_intr, sc, &sc->sc_icookie);
342 else
343 sc->sc_fastintr = 1;
344
345 if (error) {
346 device_printf(dev, "could not activate interrupt\n");
347 bus_release_resource(dev, SYS_RES_IRQ, sc->sc_irid,
348 sc->sc_ires);
349 sc->sc_ires = NULL;
350 }
351 }
352 if (sc->sc_ires == NULL) {
353 /* XXX no interrupt resource. Force polled mode. */
354 sc->sc_polled = 1;
355 }
356
357 sc->sc_rxbufsz = IBUFSIZ;
358 sc->sc_rxbuf = malloc(sc->sc_rxbufsz * sizeof(*sc->sc_rxbuf),
359 M_UART, M_WAITOK);
360 sc->sc_txbuf = malloc(sc->sc_txfifosz * sizeof(*sc->sc_txbuf),
361 M_UART, M_WAITOK);
362
363 error = UART_ATTACH(sc);
364 if (error)
365 goto fail;
366
367 if (sc->sc_hwiflow || sc->sc_hwoflow) {
368 sep = "";
369 device_print_prettyname(dev);
370 if (sc->sc_hwiflow) {
371 printf("%sRTS iflow", sep);
372 sep = ", ";
373 }
374 if (sc->sc_hwoflow) {
375 printf("%sCTS oflow", sep);
376 sep = ", ";
377 }
378 printf("\n");
379 }
380
381 if (bootverbose && (sc->sc_fastintr || sc->sc_polled)) {
382 sep = "";
383 device_print_prettyname(dev);
384 if (sc->sc_fastintr) {
385 printf("%sfast interrupt", sep);
386 sep = ", ";
387 }
388 if (sc->sc_polled) {
389 printf("%spolled mode", sep);
390 sep = ", ";
391 }
392 printf("\n");
393 }
394
395 if (sc->sc_sysdev != NULL) {
396 if (sc->sc_sysdev->baudrate == 0) {
397 if (UART_IOCTL(sc, UART_IOCTL_BAUD,
398 (intptr_t)&sc->sc_sysdev->baudrate) != 0)
399 sc->sc_sysdev->baudrate = -1;
400 }
401 switch (sc->sc_sysdev->type) {
402 case UART_DEV_CONSOLE:
403 device_printf(dev, "console");
404 break;
405 case UART_DEV_DBGPORT:
406 device_printf(dev, "debug port");
407 break;
408 case UART_DEV_KEYBOARD:
409 device_printf(dev, "keyboard");
410 break;
411 default:
412 device_printf(dev, "unknown system device");
413 break;
414 }
415 printf(" (%d,%c,%d,%d)\n", sc->sc_sysdev->baudrate,
416 "noems"[sc->sc_sysdev->parity], sc->sc_sysdev->databits,
417 sc->sc_sysdev->stopbits);
418 }
419
420 sc->sc_pps.ppscap = PPS_CAPTUREBOTH;
421 pps_init(&sc->sc_pps);
422
423 error = (sc->sc_sysdev != NULL && sc->sc_sysdev->attach != NULL)
424 ? (*sc->sc_sysdev->attach)(sc) : uart_tty_attach(sc);
425 if (error)
426 goto fail;
427
428 sc->sc_leaving = 0;
429 uart_intr(sc);
430 return (0);
431
432 fail:
433 free(sc->sc_txbuf, M_UART);
434 free(sc->sc_rxbuf, M_UART);
435
436 if (sc->sc_ires != NULL) {
437 bus_teardown_intr(dev, sc->sc_ires, sc->sc_icookie);
438 bus_release_resource(dev, SYS_RES_IRQ, sc->sc_irid,
439 sc->sc_ires);
440 }
441 bus_release_resource(dev, sc->sc_rtype, sc->sc_rrid, sc->sc_rres);
442
443 mtx_destroy(&sc->sc_hwmtx);
444
445 return (error);
446 }
447
448 int
449 uart_bus_detach(device_t dev)
450 {
451 struct uart_softc *sc;
452
453 sc = device_get_softc(dev);
454
455 sc->sc_leaving = 1;
456
457 UART_DETACH(sc);
458
459 if (sc->sc_sysdev != NULL && sc->sc_sysdev->detach != NULL)
460 (*sc->sc_sysdev->detach)(sc);
461 else
462 uart_tty_detach(sc);
463
464 free(sc->sc_txbuf, M_UART);
465 free(sc->sc_rxbuf, M_UART);
466
467 if (sc->sc_ires != NULL) {
468 bus_teardown_intr(dev, sc->sc_ires, sc->sc_icookie);
469 bus_release_resource(dev, SYS_RES_IRQ, sc->sc_irid,
470 sc->sc_ires);
471 }
472 bus_release_resource(dev, sc->sc_rtype, sc->sc_rrid, sc->sc_rres);
473
474 mtx_destroy(&sc->sc_hwmtx);
475
476 if (sc->sc_class->size > sizeof(*sc)) {
477 device_set_softc(dev, NULL);
478 free(sc, M_UART);
479 } else
480 device_set_softc(dev, NULL);
481
482 return (0);
483 }
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