xref: /freebsd/sys/dev/gpio/gpiobus.c (revision a0409676120c1e558d0ade943019934e0f15118d)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3  *
4  * Copyright (c) 2009 Oleksandr Tymoshenko <gonzo@freebsd.org>
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  */
28 
29 #include <sys/cdefs.h>
30 __FBSDID("$FreeBSD$");
31 
32 #include <sys/param.h>
33 #include <sys/systm.h>
34 #include <sys/bus.h>
35 #include <sys/gpio.h>
36 #ifdef INTRNG
37 #include <sys/intr.h>
38 #endif
39 #include <sys/kernel.h>
40 #include <sys/malloc.h>
41 #include <sys/module.h>
42 
43 #include <dev/gpio/gpiobusvar.h>
44 
45 #include "gpiobus_if.h"
46 
47 #undef GPIOBUS_DEBUG
48 #ifdef GPIOBUS_DEBUG
49 #define	dprintf printf
50 #else
51 #define	dprintf(x, arg...)
52 #endif
53 
54 static void gpiobus_print_pins(struct gpiobus_ivar *, char *, size_t);
55 static int gpiobus_parse_pins(struct gpiobus_softc *, device_t, int);
56 static int gpiobus_probe(device_t);
57 static int gpiobus_attach(device_t);
58 static int gpiobus_detach(device_t);
59 static int gpiobus_suspend(device_t);
60 static int gpiobus_resume(device_t);
61 static void gpiobus_probe_nomatch(device_t, device_t);
62 static int gpiobus_print_child(device_t, device_t);
63 static int gpiobus_child_location_str(device_t, device_t, char *, size_t);
64 static int gpiobus_child_pnpinfo_str(device_t, device_t, char *, size_t);
65 static device_t gpiobus_add_child(device_t, u_int, const char *, int);
66 static void gpiobus_hinted_child(device_t, const char *, int);
67 
68 /*
69  * GPIOBUS interface
70  */
71 static int gpiobus_acquire_bus(device_t, device_t, int);
72 static void gpiobus_release_bus(device_t, device_t);
73 static int gpiobus_pin_setflags(device_t, device_t, uint32_t, uint32_t);
74 static int gpiobus_pin_getflags(device_t, device_t, uint32_t, uint32_t*);
75 static int gpiobus_pin_getcaps(device_t, device_t, uint32_t, uint32_t*);
76 static int gpiobus_pin_set(device_t, device_t, uint32_t, unsigned int);
77 static int gpiobus_pin_get(device_t, device_t, uint32_t, unsigned int*);
78 static int gpiobus_pin_toggle(device_t, device_t, uint32_t);
79 
80 /*
81  * gpiobus_pin flags
82  *  The flags in struct gpiobus_pin are not related to the flags used by the
83  *  low-level controller driver in struct gpio_pin.  Currently, only pins
84  *  acquired via FDT data have gpiobus_pin.flags set, sourced from the flags in
85  *  the FDT properties.  In theory, these flags are defined per-platform.  In
86  *  practice they are always the flags from the dt-bindings/gpio/gpio.h file.
87  *  The only one of those flags we currently support is for handling active-low
88  *  pins, so we just define that flag here instead of including a GPL'd header.
89  */
90 #define	GPIO_ACTIVE_LOW 1
91 
92 /*
93  * XXX -> Move me to better place - gpio_subr.c?
94  * Also, this function must be changed when interrupt configuration
95  * data will be moved into struct resource.
96  */
97 #ifdef INTRNG
98 
99 struct resource *
100 gpio_alloc_intr_resource(device_t consumer_dev, int *rid, u_int alloc_flags,
101     gpio_pin_t pin, uint32_t intr_mode)
102 {
103 	u_int irq;
104 	struct intr_map_data_gpio *gpio_data;
105 	struct resource *res;
106 
107 	gpio_data = (struct intr_map_data_gpio *)intr_alloc_map_data(
108 	    INTR_MAP_DATA_GPIO, sizeof(*gpio_data), M_WAITOK | M_ZERO);
109 	gpio_data->gpio_pin_num = pin->pin;
110 	gpio_data->gpio_pin_flags = pin->flags;
111 	gpio_data->gpio_intr_mode = intr_mode;
112 
113 	irq = intr_map_irq(pin->dev, 0, (struct intr_map_data *)gpio_data);
114 	res = bus_alloc_resource(consumer_dev, SYS_RES_IRQ, rid, irq, irq, 1,
115 	    alloc_flags);
116 	if (res == NULL) {
117 		intr_free_intr_map_data((struct intr_map_data *)gpio_data);
118 		return (NULL);
119 	}
120 	rman_set_virtual(res, gpio_data);
121 	return (res);
122 }
123 #else
124 struct resource *
125 gpio_alloc_intr_resource(device_t consumer_dev, int *rid, u_int alloc_flags,
126     gpio_pin_t pin, uint32_t intr_mode)
127 {
128 
129 	return (NULL);
130 }
131 #endif
132 
133 int
134 gpio_check_flags(uint32_t caps, uint32_t flags)
135 {
136 
137 	/* Filter unwanted flags. */
138 	flags &= caps;
139 
140 	/* Cannot mix input/output together. */
141 	if (flags & GPIO_PIN_INPUT && flags & GPIO_PIN_OUTPUT)
142 		return (EINVAL);
143 	/* Cannot mix pull-up/pull-down together. */
144 	if (flags & GPIO_PIN_PULLUP && flags & GPIO_PIN_PULLDOWN)
145 		return (EINVAL);
146 	/* Cannot mix output and interrupt flags together */
147 	if (flags & GPIO_PIN_OUTPUT && flags & GPIO_INTR_MASK)
148 		return (EINVAL);
149 	/* Only one interrupt flag can be defined at once */
150 	if ((flags & GPIO_INTR_MASK) & ((flags & GPIO_INTR_MASK) - 1))
151 		return (EINVAL);
152 	/* The interrupt attached flag cannot be set */
153 	if (flags & GPIO_INTR_ATTACHED)
154 		return (EINVAL);
155 
156 	return (0);
157 }
158 
159 int
160 gpio_pin_get_by_bus_pinnum(device_t busdev, uint32_t pinnum, gpio_pin_t *ppin)
161 {
162 	gpio_pin_t pin;
163 	int err;
164 
165 	err = gpiobus_acquire_pin(busdev, pinnum);
166 	if (err != 0)
167 		return (EBUSY);
168 
169 	pin = malloc(sizeof(*pin), M_DEVBUF, M_WAITOK | M_ZERO);
170 
171 	pin->dev = device_get_parent(busdev);
172 	pin->pin = pinnum;
173 	pin->flags = 0;
174 
175 	*ppin = pin;
176 	return (0);
177 }
178 
179 int
180 gpio_pin_get_by_child_index(device_t childdev, uint32_t idx, gpio_pin_t *ppin)
181 {
182 	struct gpiobus_ivar *devi;
183 
184 	devi = GPIOBUS_IVAR(childdev);
185 	if (idx >= devi->npins)
186 		return (EINVAL);
187 
188 	return (gpio_pin_get_by_bus_pinnum(device_get_parent(childdev),
189 	    devi->pins[idx], ppin));
190 }
191 
192 int
193 gpio_pin_getcaps(gpio_pin_t pin, uint32_t *caps)
194 {
195 
196 	KASSERT(pin != NULL, ("GPIO pin is NULL."));
197 	KASSERT(pin->dev != NULL, ("GPIO pin device is NULL."));
198 	return (GPIO_PIN_GETCAPS(pin->dev, pin->pin, caps));
199 }
200 
201 int
202 gpio_pin_is_active(gpio_pin_t pin, bool *active)
203 {
204 	int rv;
205 	uint32_t tmp;
206 
207 	KASSERT(pin != NULL, ("GPIO pin is NULL."));
208 	KASSERT(pin->dev != NULL, ("GPIO pin device is NULL."));
209 	rv = GPIO_PIN_GET(pin->dev, pin->pin, &tmp);
210 	if (rv  != 0) {
211 		return (rv);
212 	}
213 
214 	if (pin->flags & GPIO_ACTIVE_LOW)
215 		*active = tmp == 0;
216 	else
217 		*active = tmp != 0;
218 	return (0);
219 }
220 
221 void
222 gpio_pin_release(gpio_pin_t gpio)
223 {
224 	device_t busdev;
225 
226 	if (gpio == NULL)
227 		return;
228 
229 	KASSERT(gpio->dev != NULL, ("GPIO pin device is NULL."));
230 
231 	busdev = GPIO_GET_BUS(gpio->dev);
232 	if (busdev != NULL)
233 		gpiobus_release_pin(busdev, gpio->pin);
234 
235 	free(gpio, M_DEVBUF);
236 }
237 
238 int
239 gpio_pin_set_active(gpio_pin_t pin, bool active)
240 {
241 	int rv;
242 	uint32_t tmp;
243 
244 	if (pin->flags & GPIO_ACTIVE_LOW)
245 		tmp = active ? 0 : 1;
246 	else
247 		tmp = active ? 1 : 0;
248 
249 	KASSERT(pin != NULL, ("GPIO pin is NULL."));
250 	KASSERT(pin->dev != NULL, ("GPIO pin device is NULL."));
251 	rv = GPIO_PIN_SET(pin->dev, pin->pin, tmp);
252 	return (rv);
253 }
254 
255 int
256 gpio_pin_setflags(gpio_pin_t pin, uint32_t flags)
257 {
258 	int rv;
259 
260 	KASSERT(pin != NULL, ("GPIO pin is NULL."));
261 	KASSERT(pin->dev != NULL, ("GPIO pin device is NULL."));
262 
263 	rv = GPIO_PIN_SETFLAGS(pin->dev, pin->pin, flags);
264 	return (rv);
265 }
266 
267 static void
268 gpiobus_print_pins(struct gpiobus_ivar *devi, char *buf, size_t buflen)
269 {
270 	char tmp[128];
271 	int i, range_start, range_stop, need_coma;
272 
273 	if (devi->npins == 0)
274 		return;
275 
276 	need_coma = 0;
277 	range_start = range_stop = devi->pins[0];
278 	for (i = 1; i < devi->npins; i++) {
279 		if (devi->pins[i] != (range_stop + 1)) {
280 			if (need_coma)
281 				strlcat(buf, ",", buflen);
282 			memset(tmp, 0, sizeof(tmp));
283 			if (range_start != range_stop)
284 				snprintf(tmp, sizeof(tmp) - 1, "%d-%d",
285 				    range_start, range_stop);
286 			else
287 				snprintf(tmp, sizeof(tmp) - 1, "%d",
288 				    range_start);
289 			strlcat(buf, tmp, buflen);
290 
291 			range_start = range_stop = devi->pins[i];
292 			need_coma = 1;
293 		}
294 		else
295 			range_stop++;
296 	}
297 
298 	if (need_coma)
299 		strlcat(buf, ",", buflen);
300 	memset(tmp, 0, sizeof(tmp));
301 	if (range_start != range_stop)
302 		snprintf(tmp, sizeof(tmp) - 1, "%d-%d",
303 		    range_start, range_stop);
304 	else
305 		snprintf(tmp, sizeof(tmp) - 1, "%d",
306 		    range_start);
307 	strlcat(buf, tmp, buflen);
308 }
309 
310 device_t
311 gpiobus_attach_bus(device_t dev)
312 {
313 	device_t busdev;
314 
315 	busdev = device_add_child(dev, "gpiobus", -1);
316 	if (busdev == NULL)
317 		return (NULL);
318 	if (device_add_child(dev, "gpioc", -1) == NULL) {
319 		device_delete_child(dev, busdev);
320 		return (NULL);
321 	}
322 #ifdef FDT
323 	ofw_gpiobus_register_provider(dev);
324 #endif
325 	bus_generic_attach(dev);
326 
327 	return (busdev);
328 }
329 
330 int
331 gpiobus_detach_bus(device_t dev)
332 {
333 	int err;
334 
335 #ifdef FDT
336 	ofw_gpiobus_unregister_provider(dev);
337 #endif
338 	err = bus_generic_detach(dev);
339 	if (err != 0)
340 		return (err);
341 
342 	return (device_delete_children(dev));
343 }
344 
345 int
346 gpiobus_init_softc(device_t dev)
347 {
348 	struct gpiobus_softc *sc;
349 
350 	sc = GPIOBUS_SOFTC(dev);
351 	sc->sc_busdev = dev;
352 	sc->sc_dev = device_get_parent(dev);
353 	sc->sc_intr_rman.rm_type = RMAN_ARRAY;
354 	sc->sc_intr_rman.rm_descr = "GPIO Interrupts";
355 	if (rman_init(&sc->sc_intr_rman) != 0 ||
356 	    rman_manage_region(&sc->sc_intr_rman, 0, ~0) != 0)
357 		panic("%s: failed to set up rman.", __func__);
358 
359 	if (GPIO_PIN_MAX(sc->sc_dev, &sc->sc_npins) != 0)
360 		return (ENXIO);
361 
362 	KASSERT(sc->sc_npins >= 0, ("GPIO device with no pins"));
363 
364 	/* Pins = GPIO_PIN_MAX() + 1 */
365 	sc->sc_npins++;
366 
367 	sc->sc_pins = malloc(sizeof(*sc->sc_pins) * sc->sc_npins, M_DEVBUF,
368 	    M_NOWAIT | M_ZERO);
369 	if (sc->sc_pins == NULL)
370 		return (ENOMEM);
371 
372 	/* Initialize the bus lock. */
373 	GPIOBUS_LOCK_INIT(sc);
374 
375 	return (0);
376 }
377 
378 int
379 gpiobus_alloc_ivars(struct gpiobus_ivar *devi)
380 {
381 
382 	/* Allocate pins and flags memory. */
383 	devi->pins = malloc(sizeof(uint32_t) * devi->npins, M_DEVBUF,
384 	    M_NOWAIT | M_ZERO);
385 	if (devi->pins == NULL)
386 		return (ENOMEM);
387 	return (0);
388 }
389 
390 void
391 gpiobus_free_ivars(struct gpiobus_ivar *devi)
392 {
393 
394 	if (devi->pins) {
395 		free(devi->pins, M_DEVBUF);
396 		devi->pins = NULL;
397 	}
398 	devi->npins = 0;
399 }
400 
401 int
402 gpiobus_acquire_pin(device_t bus, uint32_t pin)
403 {
404 	struct gpiobus_softc *sc;
405 
406 	sc = device_get_softc(bus);
407 	/* Consistency check. */
408 	if (pin >= sc->sc_npins) {
409 		device_printf(bus,
410 		    "invalid pin %d, max: %d\n", pin, sc->sc_npins - 1);
411 		return (-1);
412 	}
413 	/* Mark pin as mapped and give warning if it's already mapped. */
414 	if (sc->sc_pins[pin].mapped) {
415 		device_printf(bus, "warning: pin %d is already mapped\n", pin);
416 		return (-1);
417 	}
418 	sc->sc_pins[pin].mapped = 1;
419 
420 	return (0);
421 }
422 
423 /* Release mapped pin */
424 int
425 gpiobus_release_pin(device_t bus, uint32_t pin)
426 {
427 	struct gpiobus_softc *sc;
428 
429 	sc = device_get_softc(bus);
430 	/* Consistency check. */
431 	if (pin >= sc->sc_npins) {
432 		device_printf(bus,
433 		    "invalid pin %d, max=%d\n",
434 		    pin, sc->sc_npins - 1);
435 		return (-1);
436 	}
437 
438 	if (!sc->sc_pins[pin].mapped) {
439 		device_printf(bus, "pin %d is not mapped\n", pin);
440 		return (-1);
441 	}
442 	sc->sc_pins[pin].mapped = 0;
443 
444 	return (0);
445 }
446 
447 static int
448 gpiobus_acquire_child_pins(device_t dev, device_t child)
449 {
450 	struct gpiobus_ivar *devi = GPIOBUS_IVAR(child);
451 	int i;
452 
453 	for (i = 0; i < devi->npins; i++) {
454 		/* Reserve the GPIO pin. */
455 		if (gpiobus_acquire_pin(dev, devi->pins[i]) != 0) {
456 			device_printf(child, "cannot acquire pin %d\n",
457 			    devi->pins[i]);
458 			while (--i >= 0) {
459 				(void)gpiobus_release_pin(dev,
460 				    devi->pins[i]);
461 			}
462 			gpiobus_free_ivars(devi);
463 			return (EBUSY);
464 		}
465 	}
466 	for (i = 0; i < devi->npins; i++) {
467 		/* Use the child name as pin name. */
468 		GPIOBUS_PIN_SETNAME(dev, devi->pins[i],
469 		    device_get_nameunit(child));
470 
471 	}
472 	return (0);
473 }
474 
475 static int
476 gpiobus_parse_pins(struct gpiobus_softc *sc, device_t child, int mask)
477 {
478 	struct gpiobus_ivar *devi = GPIOBUS_IVAR(child);
479 	int i, npins;
480 
481 	npins = 0;
482 	for (i = 0; i < 32; i++) {
483 		if (mask & (1 << i))
484 			npins++;
485 	}
486 	if (npins == 0) {
487 		device_printf(child, "empty pin mask\n");
488 		return (EINVAL);
489 	}
490 	devi->npins = npins;
491 	if (gpiobus_alloc_ivars(devi) != 0) {
492 		device_printf(child, "cannot allocate device ivars\n");
493 		return (EINVAL);
494 	}
495 	npins = 0;
496 	for (i = 0; i < 32; i++) {
497 		if ((mask & (1 << i)) == 0)
498 			continue;
499 		devi->pins[npins++] = i;
500 	}
501 
502 	return (0);
503 }
504 
505 static int
506 gpiobus_parse_pin_list(struct gpiobus_softc *sc, device_t child,
507     const char *pins)
508 {
509 	struct gpiobus_ivar *devi = GPIOBUS_IVAR(child);
510 	const char *p;
511 	char *endp;
512 	unsigned long pin;
513 	int i, npins;
514 
515 	npins = 0;
516 	p = pins;
517 	for (;;) {
518 		pin = strtoul(p, &endp, 0);
519 		if (endp == p)
520 			break;
521 		npins++;
522 		if (*endp == '\0')
523 			break;
524 		p = endp + 1;
525 	}
526 
527 	if (*endp != '\0') {
528 		device_printf(child, "garbage in the pin list: %s\n", endp);
529 		return (EINVAL);
530 	}
531 	if (npins == 0) {
532 		device_printf(child, "empty pin list\n");
533 		return (EINVAL);
534 	}
535 
536 	devi->npins = npins;
537 	if (gpiobus_alloc_ivars(devi) != 0) {
538 		device_printf(child, "cannot allocate device ivars\n");
539 		return (EINVAL);
540 	}
541 
542 	i = 0;
543 	p = pins;
544 	for (;;) {
545 		pin = strtoul(p, &endp, 0);
546 
547 		devi->pins[i] = pin;
548 
549 		if (*endp == '\0')
550 			break;
551 		i++;
552 		p = endp + 1;
553 	}
554 
555 	return (0);
556 }
557 
558 static int
559 gpiobus_probe(device_t dev)
560 {
561 	device_set_desc(dev, "GPIO bus");
562 
563 	return (BUS_PROBE_GENERIC);
564 }
565 
566 static int
567 gpiobus_attach(device_t dev)
568 {
569 	int err;
570 
571 	err = gpiobus_init_softc(dev);
572 	if (err != 0)
573 		return (err);
574 
575 	/*
576 	 * Get parent's pins and mark them as unmapped
577 	 */
578 	bus_generic_probe(dev);
579 	bus_enumerate_hinted_children(dev);
580 
581 	return (bus_generic_attach(dev));
582 }
583 
584 /*
585  * Since this is not a self-enumerating bus, and since we always add
586  * children in attach, we have to always delete children here.
587  */
588 static int
589 gpiobus_detach(device_t dev)
590 {
591 	struct gpiobus_softc *sc;
592 	struct gpiobus_ivar *devi;
593 	device_t *devlist;
594 	int i, err, ndevs;
595 
596 	sc = GPIOBUS_SOFTC(dev);
597 	KASSERT(mtx_initialized(&sc->sc_mtx),
598 	    ("gpiobus mutex not initialized"));
599 	GPIOBUS_LOCK_DESTROY(sc);
600 
601 	if ((err = bus_generic_detach(dev)) != 0)
602 		return (err);
603 
604 	if ((err = device_get_children(dev, &devlist, &ndevs)) != 0)
605 		return (err);
606 	for (i = 0; i < ndevs; i++) {
607 		devi = GPIOBUS_IVAR(devlist[i]);
608 		gpiobus_free_ivars(devi);
609 		resource_list_free(&devi->rl);
610 		free(devi, M_DEVBUF);
611 		device_delete_child(dev, devlist[i]);
612 	}
613 	free(devlist, M_TEMP);
614 	rman_fini(&sc->sc_intr_rman);
615 	if (sc->sc_pins) {
616 		for (i = 0; i < sc->sc_npins; i++) {
617 			if (sc->sc_pins[i].name != NULL)
618 				free(sc->sc_pins[i].name, M_DEVBUF);
619 			sc->sc_pins[i].name = NULL;
620 		}
621 		free(sc->sc_pins, M_DEVBUF);
622 		sc->sc_pins = NULL;
623 	}
624 
625 	return (0);
626 }
627 
628 static int
629 gpiobus_suspend(device_t dev)
630 {
631 
632 	return (bus_generic_suspend(dev));
633 }
634 
635 static int
636 gpiobus_resume(device_t dev)
637 {
638 
639 	return (bus_generic_resume(dev));
640 }
641 
642 static void
643 gpiobus_probe_nomatch(device_t dev, device_t child)
644 {
645 	char pins[128];
646 	struct gpiobus_ivar *devi;
647 
648 	devi = GPIOBUS_IVAR(child);
649 	memset(pins, 0, sizeof(pins));
650 	gpiobus_print_pins(devi, pins, sizeof(pins));
651 	if (devi->npins > 1)
652 		device_printf(dev, "<unknown device> at pins %s", pins);
653 	else
654 		device_printf(dev, "<unknown device> at pin %s", pins);
655 	resource_list_print_type(&devi->rl, "irq", SYS_RES_IRQ, "%jd");
656 	printf("\n");
657 }
658 
659 static int
660 gpiobus_print_child(device_t dev, device_t child)
661 {
662 	char pins[128];
663 	int retval = 0;
664 	struct gpiobus_ivar *devi;
665 
666 	devi = GPIOBUS_IVAR(child);
667 	memset(pins, 0, sizeof(pins));
668 	retval += bus_print_child_header(dev, child);
669 	if (devi->npins > 0) {
670 		if (devi->npins > 1)
671 			retval += printf(" at pins ");
672 		else
673 			retval += printf(" at pin ");
674 		gpiobus_print_pins(devi, pins, sizeof(pins));
675 		retval += printf("%s", pins);
676 	}
677 	resource_list_print_type(&devi->rl, "irq", SYS_RES_IRQ, "%jd");
678 	retval += bus_print_child_footer(dev, child);
679 
680 	return (retval);
681 }
682 
683 static int
684 gpiobus_child_location_str(device_t bus, device_t child, char *buf,
685     size_t buflen)
686 {
687 	struct gpiobus_ivar *devi;
688 
689 	devi = GPIOBUS_IVAR(child);
690 	if (devi->npins > 1)
691 		strlcpy(buf, "pins=", buflen);
692 	else
693 		strlcpy(buf, "pin=", buflen);
694 	gpiobus_print_pins(devi, buf, buflen);
695 
696 	return (0);
697 }
698 
699 static int
700 gpiobus_child_pnpinfo_str(device_t bus, device_t child, char *buf,
701     size_t buflen)
702 {
703 
704 	*buf = '\0';
705 	return (0);
706 }
707 
708 static device_t
709 gpiobus_add_child(device_t dev, u_int order, const char *name, int unit)
710 {
711 	device_t child;
712 	struct gpiobus_ivar *devi;
713 
714 	child = device_add_child_ordered(dev, order, name, unit);
715 	if (child == NULL)
716 		return (child);
717 	devi = malloc(sizeof(struct gpiobus_ivar), M_DEVBUF, M_NOWAIT | M_ZERO);
718 	if (devi == NULL) {
719 		device_delete_child(dev, child);
720 		return (NULL);
721 	}
722 	resource_list_init(&devi->rl);
723 	device_set_ivars(child, devi);
724 
725 	return (child);
726 }
727 
728 static int
729 gpiobus_rescan(device_t dev)
730 {
731 
732 	/*
733 	 * Re-scan is supposed to remove and add children, but if someone has
734 	 * deleted the hints for a child we attached earlier, we have no easy
735 	 * way to handle that.  So this just attaches new children for whom new
736 	 * hints or drivers have arrived since we last tried.
737 	 */
738 	bus_enumerate_hinted_children(dev);
739 	bus_generic_attach(dev);
740 	return (0);
741 }
742 
743 static void
744 gpiobus_hinted_child(device_t bus, const char *dname, int dunit)
745 {
746 	struct gpiobus_softc *sc = GPIOBUS_SOFTC(bus);
747 	struct gpiobus_ivar *devi;
748 	device_t child;
749 	const char *pins;
750 	int irq, pinmask;
751 
752 	if (device_find_child(bus, dname, dunit) != NULL) {
753 		return;
754 	}
755 
756 	child = BUS_ADD_CHILD(bus, 0, dname, dunit);
757 	devi = GPIOBUS_IVAR(child);
758 	if (resource_int_value(dname, dunit, "pins", &pinmask) == 0) {
759 		if (gpiobus_parse_pins(sc, child, pinmask)) {
760 			resource_list_free(&devi->rl);
761 			free(devi, M_DEVBUF);
762 			device_delete_child(bus, child);
763 			return;
764 		}
765 	}
766 	else if (resource_string_value(dname, dunit, "pin_list", &pins) == 0) {
767 		if (gpiobus_parse_pin_list(sc, child, pins)) {
768 			resource_list_free(&devi->rl);
769 			free(devi, M_DEVBUF);
770 			device_delete_child(bus, child);
771 			return;
772 		}
773 	}
774 	if (resource_int_value(dname, dunit, "irq", &irq) == 0) {
775 		if (bus_set_resource(child, SYS_RES_IRQ, 0, irq, 1) != 0)
776 			device_printf(bus,
777 			    "warning: bus_set_resource() failed\n");
778 	}
779 }
780 
781 static int
782 gpiobus_set_resource(device_t dev, device_t child, int type, int rid,
783     rman_res_t start, rman_res_t count)
784 {
785 	struct gpiobus_ivar *devi;
786 	struct resource_list_entry *rle;
787 
788 	dprintf("%s: entry (%p, %p, %d, %d, %p, %ld)\n",
789 	    __func__, dev, child, type, rid, (void *)(intptr_t)start, count);
790 	devi = GPIOBUS_IVAR(child);
791 	rle = resource_list_add(&devi->rl, type, rid, start,
792 	    start + count - 1, count);
793 	if (rle == NULL)
794 		return (ENXIO);
795 
796 	return (0);
797 }
798 
799 static int
800 gpiobus_read_ivar(device_t dev, device_t child, int which, uintptr_t *result)
801 {
802 	struct gpiobus_ivar *devi;
803 
804 	devi = GPIOBUS_IVAR(child);
805         switch (which) {
806 	case GPIOBUS_IVAR_NPINS:
807 		*result = devi->npins;
808 		break;
809 	case GPIOBUS_IVAR_PINS:
810 		/* Children do not ever need to directly examine this. */
811 		return (ENOTSUP);
812         default:
813                 return (ENOENT);
814         }
815 
816 	return (0);
817 }
818 
819 static int
820 gpiobus_write_ivar(device_t dev, device_t child, int which, uintptr_t value)
821 {
822 	struct gpiobus_ivar *devi;
823 	const uint32_t *ptr;
824 	int i;
825 
826 	devi = GPIOBUS_IVAR(child);
827         switch (which) {
828 	case GPIOBUS_IVAR_NPINS:
829 		/* GPIO ivars are set once. */
830 		if (devi->npins != 0) {
831 			return (EBUSY);
832 		}
833 		devi->npins = value;
834 		if (gpiobus_alloc_ivars(devi) != 0) {
835 			device_printf(child, "cannot allocate device ivars\n");
836 			devi->npins = 0;
837 			return (ENOMEM);
838 		}
839 		break;
840 	case GPIOBUS_IVAR_PINS:
841 		ptr = (const uint32_t *)value;
842 		for (i = 0; i < devi->npins; i++)
843 			devi->pins[i] = ptr[i];
844 		if (gpiobus_acquire_child_pins(dev, child) != 0)
845 			return (EBUSY);
846 		break;
847         default:
848                 return (ENOENT);
849         }
850 
851         return (0);
852 }
853 
854 static struct resource *
855 gpiobus_alloc_resource(device_t bus, device_t child, int type, int *rid,
856     rman_res_t start, rman_res_t end, rman_res_t count, u_int flags)
857 {
858 	struct gpiobus_softc *sc;
859 	struct resource *rv;
860 	struct resource_list *rl;
861 	struct resource_list_entry *rle;
862 	int isdefault;
863 
864 	if (type != SYS_RES_IRQ)
865 		return (NULL);
866 	isdefault = (RMAN_IS_DEFAULT_RANGE(start, end) && count == 1);
867 	rle = NULL;
868 	if (isdefault) {
869 		rl = BUS_GET_RESOURCE_LIST(bus, child);
870 		if (rl == NULL)
871 			return (NULL);
872 		rle = resource_list_find(rl, type, *rid);
873 		if (rle == NULL)
874 			return (NULL);
875 		if (rle->res != NULL)
876 			panic("%s: resource entry is busy", __func__);
877 		start = rle->start;
878 		count = rle->count;
879 		end = rle->end;
880 	}
881 	sc = device_get_softc(bus);
882 	rv = rman_reserve_resource(&sc->sc_intr_rman, start, end, count, flags,
883 	    child);
884 	if (rv == NULL)
885 		return (NULL);
886 	rman_set_rid(rv, *rid);
887 	if ((flags & RF_ACTIVE) != 0 &&
888 	    bus_activate_resource(child, type, *rid, rv) != 0) {
889 		rman_release_resource(rv);
890 		return (NULL);
891 	}
892 
893 	return (rv);
894 }
895 
896 static int
897 gpiobus_release_resource(device_t bus __unused, device_t child, int type,
898     int rid, struct resource *r)
899 {
900 	int error;
901 
902 	if (rman_get_flags(r) & RF_ACTIVE) {
903 		error = bus_deactivate_resource(child, type, rid, r);
904 		if (error)
905 			return (error);
906 	}
907 
908 	return (rman_release_resource(r));
909 }
910 
911 static struct resource_list *
912 gpiobus_get_resource_list(device_t bus __unused, device_t child)
913 {
914 	struct gpiobus_ivar *ivar;
915 
916 	ivar = GPIOBUS_IVAR(child);
917 
918 	return (&ivar->rl);
919 }
920 
921 static int
922 gpiobus_acquire_bus(device_t busdev, device_t child, int how)
923 {
924 	struct gpiobus_softc *sc;
925 
926 	sc = device_get_softc(busdev);
927 	GPIOBUS_ASSERT_UNLOCKED(sc);
928 	GPIOBUS_LOCK(sc);
929 	if (sc->sc_owner != NULL) {
930 		if (sc->sc_owner == child)
931 			panic("%s: %s still owns the bus.",
932 			    device_get_nameunit(busdev),
933 			    device_get_nameunit(child));
934 		if (how == GPIOBUS_DONTWAIT) {
935 			GPIOBUS_UNLOCK(sc);
936 			return (EWOULDBLOCK);
937 		}
938 		while (sc->sc_owner != NULL)
939 			mtx_sleep(sc, &sc->sc_mtx, 0, "gpiobuswait", 0);
940 	}
941 	sc->sc_owner = child;
942 	GPIOBUS_UNLOCK(sc);
943 
944 	return (0);
945 }
946 
947 static void
948 gpiobus_release_bus(device_t busdev, device_t child)
949 {
950 	struct gpiobus_softc *sc;
951 
952 	sc = device_get_softc(busdev);
953 	GPIOBUS_ASSERT_UNLOCKED(sc);
954 	GPIOBUS_LOCK(sc);
955 	if (sc->sc_owner == NULL)
956 		panic("%s: %s releasing unowned bus.",
957 		    device_get_nameunit(busdev),
958 		    device_get_nameunit(child));
959 	if (sc->sc_owner != child)
960 		panic("%s: %s trying to release bus owned by %s",
961 		    device_get_nameunit(busdev),
962 		    device_get_nameunit(child),
963 		    device_get_nameunit(sc->sc_owner));
964 	sc->sc_owner = NULL;
965 	wakeup(sc);
966 	GPIOBUS_UNLOCK(sc);
967 }
968 
969 static int
970 gpiobus_pin_setflags(device_t dev, device_t child, uint32_t pin,
971     uint32_t flags)
972 {
973 	struct gpiobus_softc *sc = GPIOBUS_SOFTC(dev);
974 	struct gpiobus_ivar *devi = GPIOBUS_IVAR(child);
975 	uint32_t caps;
976 
977 	if (pin >= devi->npins)
978 		return (EINVAL);
979 	if (GPIO_PIN_GETCAPS(sc->sc_dev, devi->pins[pin], &caps) != 0)
980 		return (EINVAL);
981 	if (gpio_check_flags(caps, flags) != 0)
982 		return (EINVAL);
983 
984 	return (GPIO_PIN_SETFLAGS(sc->sc_dev, devi->pins[pin], flags));
985 }
986 
987 static int
988 gpiobus_pin_getflags(device_t dev, device_t child, uint32_t pin,
989     uint32_t *flags)
990 {
991 	struct gpiobus_softc *sc = GPIOBUS_SOFTC(dev);
992 	struct gpiobus_ivar *devi = GPIOBUS_IVAR(child);
993 
994 	if (pin >= devi->npins)
995 		return (EINVAL);
996 
997 	return GPIO_PIN_GETFLAGS(sc->sc_dev, devi->pins[pin], flags);
998 }
999 
1000 static int
1001 gpiobus_pin_getcaps(device_t dev, device_t child, uint32_t pin,
1002     uint32_t *caps)
1003 {
1004 	struct gpiobus_softc *sc = GPIOBUS_SOFTC(dev);
1005 	struct gpiobus_ivar *devi = GPIOBUS_IVAR(child);
1006 
1007 	if (pin >= devi->npins)
1008 		return (EINVAL);
1009 
1010 	return GPIO_PIN_GETCAPS(sc->sc_dev, devi->pins[pin], caps);
1011 }
1012 
1013 static int
1014 gpiobus_pin_set(device_t dev, device_t child, uint32_t pin,
1015     unsigned int value)
1016 {
1017 	struct gpiobus_softc *sc = GPIOBUS_SOFTC(dev);
1018 	struct gpiobus_ivar *devi = GPIOBUS_IVAR(child);
1019 
1020 	if (pin >= devi->npins)
1021 		return (EINVAL);
1022 
1023 	return GPIO_PIN_SET(sc->sc_dev, devi->pins[pin], value);
1024 }
1025 
1026 static int
1027 gpiobus_pin_get(device_t dev, device_t child, uint32_t pin,
1028     unsigned int *value)
1029 {
1030 	struct gpiobus_softc *sc = GPIOBUS_SOFTC(dev);
1031 	struct gpiobus_ivar *devi = GPIOBUS_IVAR(child);
1032 
1033 	if (pin >= devi->npins)
1034 		return (EINVAL);
1035 
1036 	return GPIO_PIN_GET(sc->sc_dev, devi->pins[pin], value);
1037 }
1038 
1039 static int
1040 gpiobus_pin_toggle(device_t dev, device_t child, uint32_t pin)
1041 {
1042 	struct gpiobus_softc *sc = GPIOBUS_SOFTC(dev);
1043 	struct gpiobus_ivar *devi = GPIOBUS_IVAR(child);
1044 
1045 	if (pin >= devi->npins)
1046 		return (EINVAL);
1047 
1048 	return GPIO_PIN_TOGGLE(sc->sc_dev, devi->pins[pin]);
1049 }
1050 
1051 static int
1052 gpiobus_pin_getname(device_t dev, uint32_t pin, char *name)
1053 {
1054 	struct gpiobus_softc *sc;
1055 
1056 	sc = GPIOBUS_SOFTC(dev);
1057 	if (pin > sc->sc_npins)
1058 		return (EINVAL);
1059 	/* Did we have a name for this pin ? */
1060 	if (sc->sc_pins[pin].name != NULL) {
1061 		memcpy(name, sc->sc_pins[pin].name, GPIOMAXNAME);
1062 		return (0);
1063 	}
1064 
1065 	/* Return the default pin name. */
1066 	return (GPIO_PIN_GETNAME(device_get_parent(dev), pin, name));
1067 }
1068 
1069 static int
1070 gpiobus_pin_setname(device_t dev, uint32_t pin, const char *name)
1071 {
1072 	struct gpiobus_softc *sc;
1073 
1074 	sc = GPIOBUS_SOFTC(dev);
1075 	if (pin > sc->sc_npins)
1076 		return (EINVAL);
1077 	if (name == NULL)
1078 		return (EINVAL);
1079 	/* Save the pin name. */
1080 	if (sc->sc_pins[pin].name == NULL)
1081 		sc->sc_pins[pin].name = malloc(GPIOMAXNAME, M_DEVBUF,
1082 		    M_WAITOK | M_ZERO);
1083 	strlcpy(sc->sc_pins[pin].name, name, GPIOMAXNAME);
1084 
1085 	return (0);
1086 }
1087 
1088 static device_method_t gpiobus_methods[] = {
1089 	/* Device interface */
1090 	DEVMETHOD(device_probe,		gpiobus_probe),
1091 	DEVMETHOD(device_attach,	gpiobus_attach),
1092 	DEVMETHOD(device_detach,	gpiobus_detach),
1093 	DEVMETHOD(device_shutdown,	bus_generic_shutdown),
1094 	DEVMETHOD(device_suspend,	gpiobus_suspend),
1095 	DEVMETHOD(device_resume,	gpiobus_resume),
1096 
1097 	/* Bus interface */
1098 	DEVMETHOD(bus_setup_intr,	bus_generic_setup_intr),
1099 	DEVMETHOD(bus_config_intr,	bus_generic_config_intr),
1100 	DEVMETHOD(bus_teardown_intr,	bus_generic_teardown_intr),
1101 	DEVMETHOD(bus_set_resource,	gpiobus_set_resource),
1102 	DEVMETHOD(bus_alloc_resource,	gpiobus_alloc_resource),
1103 	DEVMETHOD(bus_release_resource,	gpiobus_release_resource),
1104 	DEVMETHOD(bus_activate_resource,	bus_generic_activate_resource),
1105 	DEVMETHOD(bus_deactivate_resource,	bus_generic_deactivate_resource),
1106 	DEVMETHOD(bus_get_resource_list,	gpiobus_get_resource_list),
1107 	DEVMETHOD(bus_add_child,	gpiobus_add_child),
1108 	DEVMETHOD(bus_rescan,		gpiobus_rescan),
1109 	DEVMETHOD(bus_probe_nomatch,	gpiobus_probe_nomatch),
1110 	DEVMETHOD(bus_print_child,	gpiobus_print_child),
1111 	DEVMETHOD(bus_child_pnpinfo_str, gpiobus_child_pnpinfo_str),
1112 	DEVMETHOD(bus_child_location_str, gpiobus_child_location_str),
1113 	DEVMETHOD(bus_hinted_child,	gpiobus_hinted_child),
1114 	DEVMETHOD(bus_read_ivar,        gpiobus_read_ivar),
1115 	DEVMETHOD(bus_write_ivar,       gpiobus_write_ivar),
1116 
1117 	/* GPIO protocol */
1118 	DEVMETHOD(gpiobus_acquire_bus,	gpiobus_acquire_bus),
1119 	DEVMETHOD(gpiobus_release_bus,	gpiobus_release_bus),
1120 	DEVMETHOD(gpiobus_pin_getflags,	gpiobus_pin_getflags),
1121 	DEVMETHOD(gpiobus_pin_getcaps,	gpiobus_pin_getcaps),
1122 	DEVMETHOD(gpiobus_pin_setflags,	gpiobus_pin_setflags),
1123 	DEVMETHOD(gpiobus_pin_get,	gpiobus_pin_get),
1124 	DEVMETHOD(gpiobus_pin_set,	gpiobus_pin_set),
1125 	DEVMETHOD(gpiobus_pin_toggle,	gpiobus_pin_toggle),
1126 	DEVMETHOD(gpiobus_pin_getname,	gpiobus_pin_getname),
1127 	DEVMETHOD(gpiobus_pin_setname,	gpiobus_pin_setname),
1128 
1129 	DEVMETHOD_END
1130 };
1131 
1132 driver_t gpiobus_driver = {
1133 	"gpiobus",
1134 	gpiobus_methods,
1135 	sizeof(struct gpiobus_softc)
1136 };
1137 
1138 devclass_t	gpiobus_devclass;
1139 
1140 EARLY_DRIVER_MODULE(gpiobus, gpio, gpiobus_driver, gpiobus_devclass, 0, 0,
1141     BUS_PASS_BUS + BUS_PASS_ORDER_MIDDLE);
1142 MODULE_VERSION(gpiobus, 1);
1143