xref: /freebsd/sys/dev/gpio/gpiobus.c (revision 4ba91e076ee84101112d8296785098ae31dac35e)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
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/param.h>
30 #include <sys/systm.h>
31 #include <sys/bus.h>
32 #include <sys/gpio.h>
33 #ifdef INTRNG
34 #include <sys/intr.h>
35 #endif
36 #include <sys/kernel.h>
37 #include <sys/malloc.h>
38 #include <sys/module.h>
39 #include <sys/sbuf.h>
40 
41 #include <dev/gpio/gpiobusvar.h>
42 #include <dev/gpio/gpiobus_internal.h>
43 
44 #include "gpiobus_if.h"
45 
46 #undef GPIOBUS_DEBUG
47 #ifdef GPIOBUS_DEBUG
48 #define	dprintf printf
49 #else
50 #define	dprintf(x, arg...)
51 #endif
52 
53 static void gpiobus_print_pins(struct gpiobus_ivar *, struct sbuf *);
54 static int gpiobus_parse_pins(struct gpiobus_softc *, device_t, int);
55 static int gpiobus_probe(device_t);
56 static int gpiobus_suspend(device_t);
57 static int gpiobus_resume(device_t);
58 static void gpiobus_probe_nomatch(device_t, device_t);
59 static int gpiobus_print_child(device_t, device_t);
60 static device_t gpiobus_add_child(device_t, u_int, const char *, int);
61 static void gpiobus_hinted_child(device_t, const char *, int);
62 
63 /*
64  * GPIOBUS interface
65  */
66 static int gpiobus_acquire_bus(device_t, device_t, int);
67 static void gpiobus_release_bus(device_t, device_t);
68 static int gpiobus_pin_setflags(device_t, device_t, uint32_t, uint32_t);
69 static int gpiobus_pin_getflags(device_t, device_t, uint32_t, uint32_t*);
70 static int gpiobus_pin_getcaps(device_t, device_t, uint32_t, uint32_t*);
71 static int gpiobus_pin_set(device_t, device_t, uint32_t, unsigned int);
72 static int gpiobus_pin_get(device_t, device_t, uint32_t, unsigned int*);
73 static int gpiobus_pin_toggle(device_t, device_t, uint32_t);
74 
75 /*
76  * gpiobus_pin flags
77  *  The flags in struct gpiobus_pin are not related to the flags used by the
78  *  low-level controller driver in struct gpio_pin.  Currently, only pins
79  *  acquired via FDT data have gpiobus_pin.flags set, sourced from the flags in
80  *  the FDT properties.  In theory, these flags are defined per-platform.  In
81  *  practice they are always the flags from the dt-bindings/gpio/gpio.h file.
82  *  The only one of those flags we currently support is for handling active-low
83  *  pins, so we just define that flag here instead of including a GPL'd header.
84  */
85 #define	GPIO_ACTIVE_LOW 1
86 
87 /*
88  * XXX -> Move me to better place - gpio_subr.c?
89  * Also, this function must be changed when interrupt configuration
90  * data will be moved into struct resource.
91  */
92 #ifdef INTRNG
93 
94 struct resource *
95 gpio_alloc_intr_resource(device_t consumer_dev, int *rid, u_int alloc_flags,
96     gpio_pin_t pin, uint32_t intr_mode)
97 {
98 	u_int irq;
99 	struct intr_map_data_gpio *gpio_data;
100 	struct resource *res;
101 
102 	gpio_data = (struct intr_map_data_gpio *)intr_alloc_map_data(
103 	    INTR_MAP_DATA_GPIO, sizeof(*gpio_data), M_WAITOK | M_ZERO);
104 	gpio_data->gpio_pin_num = pin->pin;
105 	gpio_data->gpio_pin_flags = pin->flags;
106 	gpio_data->gpio_intr_mode = intr_mode;
107 
108 	irq = intr_map_irq(pin->dev, 0, (struct intr_map_data *)gpio_data);
109 	res = bus_alloc_resource(consumer_dev, SYS_RES_IRQ, rid, irq, irq, 1,
110 	    alloc_flags);
111 	if (res == NULL) {
112 		intr_unmap_irq(irq);
113 		return (NULL);
114 	}
115 	return (res);
116 }
117 #else
118 struct resource *
119 gpio_alloc_intr_resource(device_t consumer_dev, int *rid, u_int alloc_flags,
120     gpio_pin_t pin, uint32_t intr_mode)
121 {
122 
123 	return (NULL);
124 }
125 #endif
126 
127 int
128 gpio_check_flags(uint32_t caps, uint32_t flags)
129 {
130 
131 	/* Filter unwanted flags. */
132 	flags &= caps;
133 
134 	/* Cannot mix input/output together. */
135 	if (flags & GPIO_PIN_INPUT && flags & GPIO_PIN_OUTPUT)
136 		return (EINVAL);
137 	/* Cannot mix pull-up/pull-down together. */
138 	if (flags & GPIO_PIN_PULLUP && flags & GPIO_PIN_PULLDOWN)
139 		return (EINVAL);
140 	/* Cannot mix output and interrupt flags together */
141 	if (flags & GPIO_PIN_OUTPUT && flags & GPIO_INTR_MASK)
142 		return (EINVAL);
143 	/* Only one interrupt flag can be defined at once */
144 	if ((flags & GPIO_INTR_MASK) & ((flags & GPIO_INTR_MASK) - 1))
145 		return (EINVAL);
146 	/* The interrupt attached flag cannot be set */
147 	if (flags & GPIO_INTR_ATTACHED)
148 		return (EINVAL);
149 
150 	return (0);
151 }
152 
153 int
154 gpio_pin_get_by_bus_pinnum(device_t busdev, uint32_t pinnum, gpio_pin_t *ppin)
155 {
156 	gpio_pin_t pin;
157 	int err;
158 
159 	err = gpiobus_acquire_pin(busdev, pinnum);
160 	if (err != 0)
161 		return (EBUSY);
162 
163 	pin = malloc(sizeof(*pin), M_DEVBUF, M_WAITOK | M_ZERO);
164 
165 	pin->dev = device_get_parent(busdev);
166 	pin->pin = pinnum;
167 	pin->flags = 0;
168 
169 	*ppin = pin;
170 	return (0);
171 }
172 
173 int
174 gpio_pin_get_by_child_index(device_t childdev, uint32_t idx, gpio_pin_t *ppin)
175 {
176 	struct gpiobus_ivar *devi;
177 
178 	devi = GPIOBUS_IVAR(childdev);
179 	if (idx >= devi->npins)
180 		return (EINVAL);
181 
182 	return (gpio_pin_get_by_bus_pinnum(device_get_parent(childdev),
183 	    devi->pins[idx], ppin));
184 }
185 
186 int
187 gpio_pin_getcaps(gpio_pin_t pin, uint32_t *caps)
188 {
189 
190 	KASSERT(pin != NULL, ("GPIO pin is NULL."));
191 	KASSERT(pin->dev != NULL, ("GPIO pin device is NULL."));
192 	return (GPIO_PIN_GETCAPS(pin->dev, pin->pin, caps));
193 }
194 
195 int
196 gpio_pin_is_active(gpio_pin_t pin, bool *active)
197 {
198 	int rv;
199 	uint32_t tmp;
200 
201 	KASSERT(pin != NULL, ("GPIO pin is NULL."));
202 	KASSERT(pin->dev != NULL, ("GPIO pin device is NULL."));
203 	rv = GPIO_PIN_GET(pin->dev, pin->pin, &tmp);
204 	if (rv  != 0) {
205 		return (rv);
206 	}
207 
208 	if (pin->flags & GPIO_ACTIVE_LOW)
209 		*active = tmp == 0;
210 	else
211 		*active = tmp != 0;
212 	return (0);
213 }
214 
215 /*
216  * Note that this function should only
217  * be used in cases where a pre-existing
218  * gpiobus_pin structure exists. In most
219  * cases, the gpio_pin_get_by_* functions
220  * suffice.
221  */
222 int
223 gpio_pin_acquire(gpio_pin_t gpio)
224 {
225 	device_t busdev;
226 
227 	KASSERT(gpio != NULL, ("GPIO pin is NULL."));
228 	KASSERT(gpio->dev != NULL, ("GPIO pin device is NULL."));
229 
230 	busdev = GPIO_GET_BUS(gpio->dev);
231 	if (busdev == NULL)
232 		return (ENXIO);
233 
234 	return (gpiobus_acquire_pin(busdev, gpio->pin));
235 }
236 
237 void
238 gpio_pin_release(gpio_pin_t gpio)
239 {
240 	device_t busdev;
241 
242 	KASSERT(gpio != NULL, ("GPIO pin is NULL."));
243 	KASSERT(gpio->dev != NULL, ("GPIO pin device is NULL."));
244 
245 	busdev = GPIO_GET_BUS(gpio->dev);
246 	KASSERT(busdev != NULL, ("gpiobus dev is NULL."));
247 
248 	gpiobus_release_pin(busdev, gpio->pin);
249 	free(gpio, M_DEVBUF);
250 }
251 
252 int
253 gpio_pin_set_active(gpio_pin_t pin, bool active)
254 {
255 	int rv;
256 	uint32_t tmp;
257 
258 	if (pin->flags & GPIO_ACTIVE_LOW)
259 		tmp = active ? 0 : 1;
260 	else
261 		tmp = active ? 1 : 0;
262 
263 	KASSERT(pin != NULL, ("GPIO pin is NULL."));
264 	KASSERT(pin->dev != NULL, ("GPIO pin device is NULL."));
265 	rv = GPIO_PIN_SET(pin->dev, pin->pin, tmp);
266 	return (rv);
267 }
268 
269 int
270 gpio_pin_setflags(gpio_pin_t pin, uint32_t flags)
271 {
272 	int rv;
273 
274 	KASSERT(pin != NULL, ("GPIO pin is NULL."));
275 	KASSERT(pin->dev != NULL, ("GPIO pin device is NULL."));
276 
277 	rv = GPIO_PIN_SETFLAGS(pin->dev, pin->pin, flags);
278 	return (rv);
279 }
280 
281 static void
282 gpiobus_print_pins(struct gpiobus_ivar *devi, struct sbuf *sb)
283 {
284 	int i, range_start, range_stop, need_coma;
285 
286 	if (devi->npins == 0)
287 		return;
288 
289 	need_coma = 0;
290 	range_start = range_stop = devi->pins[0];
291 	for (i = 1; i < devi->npins; i++) {
292 		if (devi->pins[i] != (range_stop + 1)) {
293 			if (need_coma)
294 				sbuf_cat(sb, ",");
295 			if (range_start != range_stop)
296 				sbuf_printf(sb, "%d-%d", range_start, range_stop);
297 			else
298 				sbuf_printf(sb, "%d", range_start);
299 			range_start = range_stop = devi->pins[i];
300 			need_coma = 1;
301 		}
302 		else
303 			range_stop++;
304 	}
305 
306 	if (need_coma)
307 		sbuf_cat(sb, ",");
308 	if (range_start != range_stop)
309 		sbuf_printf(sb, "%d-%d", range_start, range_stop);
310 	else
311 		sbuf_printf(sb, "%d", range_start);
312 }
313 
314 device_t
315 gpiobus_add_bus(device_t dev)
316 {
317 	device_t busdev;
318 
319 	busdev = device_add_child(dev, "gpiobus", DEVICE_UNIT_ANY);
320 	if (busdev == NULL)
321 		return (NULL);
322 	if (device_add_child(dev, "gpioc", DEVICE_UNIT_ANY) == NULL) {
323 		device_delete_child(dev, busdev);
324 		return (NULL);
325 	}
326 #ifdef FDT
327 	ofw_gpiobus_register_provider(dev);
328 #endif
329 	return (busdev);
330 }
331 
332 int
333 gpiobus_detach_bus(device_t dev)
334 {
335 #ifdef FDT
336 	ofw_gpiobus_unregister_provider(dev);
337 #endif
338 	return (bus_generic_detach(dev));
339 }
340 
341 int
342 gpiobus_init_softc(device_t dev)
343 {
344 	struct gpiobus_softc *sc;
345 
346 	sc = GPIOBUS_SOFTC(dev);
347 	sc->sc_busdev = dev;
348 	sc->sc_dev = device_get_parent(dev);
349 	sc->sc_intr_rman.rm_type = RMAN_ARRAY;
350 	sc->sc_intr_rman.rm_descr = "GPIO Interrupts";
351 	if (rman_init(&sc->sc_intr_rman) != 0 ||
352 	    rman_manage_region(&sc->sc_intr_rman, 0, ~0) != 0)
353 		panic("%s: failed to set up rman.", __func__);
354 
355 	if (GPIO_PIN_MAX(sc->sc_dev, &sc->sc_npins) != 0)
356 		return (ENXIO);
357 
358 	KASSERT(sc->sc_npins >= 0, ("GPIO device with no pins"));
359 
360 	/* Pins = GPIO_PIN_MAX() + 1 */
361 	sc->sc_npins++;
362 
363 	sc->sc_pins = malloc(sizeof(*sc->sc_pins) * sc->sc_npins, M_DEVBUF,
364 	    M_NOWAIT | M_ZERO);
365 	if (sc->sc_pins == NULL)
366 		return (ENOMEM);
367 
368 	/* Initialize the bus lock. */
369 	GPIOBUS_LOCK_INIT(sc);
370 
371 	return (0);
372 }
373 
374 int
375 gpiobus_alloc_ivars(struct gpiobus_ivar *devi)
376 {
377 
378 	/* Allocate pins and flags memory. */
379 	devi->pins = malloc(sizeof(uint32_t) * devi->npins, M_DEVBUF,
380 	    M_NOWAIT | M_ZERO);
381 	if (devi->pins == NULL)
382 		return (ENOMEM);
383 	return (0);
384 }
385 
386 void
387 gpiobus_free_ivars(struct gpiobus_ivar *devi)
388 {
389 
390 	if (devi->pins) {
391 		free(devi->pins, M_DEVBUF);
392 		devi->pins = NULL;
393 	}
394 	devi->npins = 0;
395 }
396 
397 int
398 gpiobus_acquire_pin(device_t bus, uint32_t pin)
399 {
400 	struct gpiobus_softc *sc;
401 
402 	sc = device_get_softc(bus);
403 	/* Consistency check. */
404 	if (pin >= sc->sc_npins) {
405 		panic("%s: invalid pin %d, max: %d",
406 		    device_get_nameunit(bus), pin, sc->sc_npins - 1);
407 	}
408 	/* Mark pin as mapped and give warning if it's already mapped. */
409 	if (sc->sc_pins[pin].mapped) {
410 		device_printf(bus, "warning: pin %d is already mapped\n", pin);
411 		return (EBUSY);
412 	}
413 	sc->sc_pins[pin].mapped = 1;
414 
415 	return (0);
416 }
417 
418 /* Release mapped pin */
419 void
420 gpiobus_release_pin(device_t bus, uint32_t pin)
421 {
422 	struct gpiobus_softc *sc;
423 
424 	sc = device_get_softc(bus);
425 	/* Consistency check. */
426 	if (pin >= sc->sc_npins) {
427 		panic("%s: invalid pin %d, max: %d",
428 		    device_get_nameunit(bus), pin, sc->sc_npins - 1);
429 	}
430 
431 	if (!sc->sc_pins[pin].mapped)
432 		panic("%s: pin %d is not mapped", device_get_nameunit(bus),
433 		    pin);
434 
435 	sc->sc_pins[pin].mapped = 0;
436 }
437 
438 static int
439 gpiobus_acquire_child_pins(device_t dev, device_t child)
440 {
441 	struct gpiobus_ivar *devi = GPIOBUS_IVAR(child);
442 	int i;
443 
444 	for (i = 0; i < devi->npins; i++) {
445 		/* Reserve the GPIO pin. */
446 		if (gpiobus_acquire_pin(dev, devi->pins[i]) != 0) {
447 			device_printf(child, "cannot acquire pin %d\n",
448 			    devi->pins[i]);
449 			while (--i >= 0) {
450 				gpiobus_release_pin(dev, devi->pins[i]);
451 			}
452 			gpiobus_free_ivars(devi);
453 			return (EBUSY);
454 		}
455 	}
456 	for (i = 0; i < devi->npins; i++) {
457 		/* Use the child name as pin name. */
458 		GPIOBUS_PIN_SETNAME(dev, devi->pins[i],
459 		    device_get_nameunit(child));
460 
461 	}
462 	return (0);
463 }
464 
465 static int
466 gpiobus_parse_pins(struct gpiobus_softc *sc, device_t child, int mask)
467 {
468 	struct gpiobus_ivar *devi = GPIOBUS_IVAR(child);
469 	int i, npins;
470 
471 	npins = 0;
472 	for (i = 0; i < 32; i++) {
473 		if (mask & (1 << i))
474 			npins++;
475 	}
476 	if (npins == 0) {
477 		device_printf(child, "empty pin mask\n");
478 		return (EINVAL);
479 	}
480 	devi->npins = npins;
481 	if (gpiobus_alloc_ivars(devi) != 0) {
482 		device_printf(child, "cannot allocate device ivars\n");
483 		return (EINVAL);
484 	}
485 	npins = 0;
486 	for (i = 0; i < 32; i++) {
487 		if ((mask & (1 << i)) == 0)
488 			continue;
489 		devi->pins[npins++] = i;
490 	}
491 
492 	return (0);
493 }
494 
495 static int
496 gpiobus_parse_pin_list(struct gpiobus_softc *sc, device_t child,
497     const char *pins)
498 {
499 	struct gpiobus_ivar *devi = GPIOBUS_IVAR(child);
500 	const char *p;
501 	char *endp;
502 	unsigned long pin;
503 	int i, npins;
504 
505 	npins = 0;
506 	p = pins;
507 	for (;;) {
508 		pin = strtoul(p, &endp, 0);
509 		if (endp == p)
510 			break;
511 		npins++;
512 		if (*endp == '\0')
513 			break;
514 		p = endp + 1;
515 	}
516 
517 	if (*endp != '\0') {
518 		device_printf(child, "garbage in the pin list: %s\n", endp);
519 		return (EINVAL);
520 	}
521 	if (npins == 0) {
522 		device_printf(child, "empty pin list\n");
523 		return (EINVAL);
524 	}
525 
526 	devi->npins = npins;
527 	if (gpiobus_alloc_ivars(devi) != 0) {
528 		device_printf(child, "cannot allocate device ivars\n");
529 		return (EINVAL);
530 	}
531 
532 	i = 0;
533 	p = pins;
534 	for (;;) {
535 		pin = strtoul(p, &endp, 0);
536 
537 		devi->pins[i] = pin;
538 
539 		if (*endp == '\0')
540 			break;
541 		i++;
542 		p = endp + 1;
543 	}
544 
545 	return (0);
546 }
547 
548 static int
549 gpiobus_probe(device_t dev)
550 {
551 	device_set_desc(dev, "GPIO bus");
552 
553 	return (BUS_PROBE_GENERIC);
554 }
555 
556 int
557 gpiobus_attach(device_t dev)
558 {
559 	int err;
560 
561 	err = gpiobus_init_softc(dev);
562 	if (err != 0)
563 		return (err);
564 
565 	/*
566 	 * Get parent's pins and mark them as unmapped
567 	 */
568 	bus_identify_children(dev);
569 	bus_enumerate_hinted_children(dev);
570 
571 	bus_attach_children(dev);
572 	return (0);
573 }
574 
575 /*
576  * Since this is not a self-enumerating bus, and since we always add
577  * children in attach, we have to always delete children here.
578  */
579 int
580 gpiobus_detach(device_t dev)
581 {
582 	struct gpiobus_softc *sc;
583 	int i, err;
584 
585 	sc = GPIOBUS_SOFTC(dev);
586 	KASSERT(mtx_initialized(&sc->sc_mtx),
587 	    ("gpiobus mutex not initialized"));
588 	GPIOBUS_LOCK_DESTROY(sc);
589 
590 	if ((err = bus_detach_children(dev)) != 0)
591 		return (err);
592 
593 	rman_fini(&sc->sc_intr_rman);
594 	if (sc->sc_pins) {
595 		for (i = 0; i < sc->sc_npins; i++) {
596 			if (sc->sc_pins[i].name != NULL)
597 				free(sc->sc_pins[i].name, M_DEVBUF);
598 			sc->sc_pins[i].name = NULL;
599 		}
600 		free(sc->sc_pins, M_DEVBUF);
601 		sc->sc_pins = NULL;
602 	}
603 
604 	return (0);
605 }
606 
607 static int
608 gpiobus_suspend(device_t dev)
609 {
610 
611 	return (bus_generic_suspend(dev));
612 }
613 
614 static int
615 gpiobus_resume(device_t dev)
616 {
617 
618 	return (bus_generic_resume(dev));
619 }
620 
621 static void
622 gpiobus_probe_nomatch(device_t dev, device_t child)
623 {
624 	char pins[128];
625 	struct sbuf sb;
626 	struct gpiobus_ivar *devi;
627 
628 	devi = GPIOBUS_IVAR(child);
629 	sbuf_new(&sb, pins, sizeof(pins), SBUF_FIXEDLEN);
630 	gpiobus_print_pins(devi, &sb);
631 	sbuf_finish(&sb);
632 	device_printf(dev, "<unknown device> at pin%s %s",
633 	    devi->npins > 1 ? "s" : "", sbuf_data(&sb));
634 	resource_list_print_type(&devi->rl, "irq", SYS_RES_IRQ, "%jd");
635 	printf("\n");
636 }
637 
638 static int
639 gpiobus_print_child(device_t dev, device_t child)
640 {
641 	char pins[128];
642 	struct sbuf sb;
643 	int retval = 0;
644 	struct gpiobus_ivar *devi;
645 
646 	devi = GPIOBUS_IVAR(child);
647 	retval += bus_print_child_header(dev, child);
648 	if (devi->npins > 0) {
649 		if (devi->npins > 1)
650 			retval += printf(" at pins ");
651 		else
652 			retval += printf(" at pin ");
653 		sbuf_new(&sb, pins, sizeof(pins), SBUF_FIXEDLEN);
654 		gpiobus_print_pins(devi, &sb);
655 		sbuf_finish(&sb);
656 		retval += printf("%s", sbuf_data(&sb));
657 	}
658 	resource_list_print_type(&devi->rl, "irq", SYS_RES_IRQ, "%jd");
659 	retval += bus_print_child_footer(dev, child);
660 
661 	return (retval);
662 }
663 
664 int
665 gpiobus_child_location(device_t bus, device_t child, struct sbuf *sb)
666 {
667 	struct gpiobus_ivar *devi;
668 
669 	devi = GPIOBUS_IVAR(child);
670 	sbuf_printf(sb, "pins=");
671 	gpiobus_print_pins(devi, sb);
672 
673 	return (0);
674 }
675 
676 device_t
677 gpiobus_add_child_common(device_t dev, u_int order, const char *name, int unit,
678     size_t ivars_size)
679 {
680 	device_t child;
681 	struct gpiobus_ivar *devi;
682 
683 	KASSERT(ivars_size >= sizeof(struct gpiobus_ivar),
684 	    ("child ivars must include gpiobus_ivar as their first member"));
685 	child = device_add_child_ordered(dev, order, name, unit);
686 	if (child == NULL)
687 		return (child);
688 	devi = malloc(ivars_size, M_DEVBUF, M_NOWAIT | M_ZERO);
689 	if (devi == NULL) {
690 		device_delete_child(dev, child);
691 		return (NULL);
692 	}
693 	resource_list_init(&devi->rl);
694 	device_set_ivars(child, devi);
695 
696 	return (child);
697 }
698 
699 static device_t
700 gpiobus_add_child(device_t dev, u_int order, const char *name, int unit)
701 {
702 	return (gpiobus_add_child_common(dev, order, name, unit,
703 	    sizeof(struct gpiobus_ivar)));
704 }
705 
706 static void
707 gpiobus_child_deleted(device_t dev, device_t child)
708 {
709 	struct gpiobus_ivar *devi;
710 
711 	devi = GPIOBUS_IVAR(child);
712 	if (devi == NULL)
713 		return;
714 	gpiobus_free_ivars(devi);
715 	resource_list_free(&devi->rl);
716 	free(devi, M_DEVBUF);
717 }
718 
719 static int
720 gpiobus_rescan(device_t dev)
721 {
722 
723 	/*
724 	 * Re-scan is supposed to remove and add children, but if someone has
725 	 * deleted the hints for a child we attached earlier, we have no easy
726 	 * way to handle that.  So this just attaches new children for whom new
727 	 * hints or drivers have arrived since we last tried.
728 	 */
729 	bus_enumerate_hinted_children(dev);
730 	bus_attach_children(dev);
731 	return (0);
732 }
733 
734 static void
735 gpiobus_hinted_child(device_t bus, const char *dname, int dunit)
736 {
737 	struct gpiobus_softc *sc = GPIOBUS_SOFTC(bus);
738 	device_t child;
739 	const char *pins;
740 	int irq, pinmask;
741 
742 	if (device_find_child(bus, dname, dunit) != NULL) {
743 		return;
744 	}
745 
746 	child = BUS_ADD_CHILD(bus, 0, dname, dunit);
747 	if (resource_int_value(dname, dunit, "pins", &pinmask) == 0) {
748 		if (gpiobus_parse_pins(sc, child, pinmask)) {
749 			device_delete_child(bus, child);
750 			return;
751 		}
752 	}
753 	else if (resource_string_value(dname, dunit, "pin_list", &pins) == 0) {
754 		if (gpiobus_parse_pin_list(sc, child, pins)) {
755 			device_delete_child(bus, child);
756 			return;
757 		}
758 	}
759 	if (resource_int_value(dname, dunit, "irq", &irq) == 0) {
760 		if (bus_set_resource(child, SYS_RES_IRQ, 0, irq, 1) != 0)
761 			device_printf(bus,
762 			    "warning: bus_set_resource() failed\n");
763 	}
764 }
765 
766 int
767 gpiobus_read_ivar(device_t dev, device_t child, int which, uintptr_t *result)
768 {
769 	struct gpiobus_ivar *devi;
770 
771 	devi = GPIOBUS_IVAR(child);
772         switch (which) {
773 	case GPIOBUS_IVAR_NPINS:
774 		*result = devi->npins;
775 		break;
776 	case GPIOBUS_IVAR_PINS:
777 		/* Children do not ever need to directly examine this. */
778 		return (ENOTSUP);
779         default:
780                 return (ENOENT);
781         }
782 
783 	return (0);
784 }
785 
786 static int
787 gpiobus_write_ivar(device_t dev, device_t child, int which, uintptr_t value)
788 {
789 	struct gpiobus_ivar *devi;
790 	const uint32_t *ptr;
791 	int i;
792 
793 	devi = GPIOBUS_IVAR(child);
794         switch (which) {
795 	case GPIOBUS_IVAR_NPINS:
796 		/* GPIO ivars are set once. */
797 		if (devi->npins != 0) {
798 			return (EBUSY);
799 		}
800 		devi->npins = value;
801 		if (gpiobus_alloc_ivars(devi) != 0) {
802 			device_printf(child, "cannot allocate device ivars\n");
803 			devi->npins = 0;
804 			return (ENOMEM);
805 		}
806 		break;
807 	case GPIOBUS_IVAR_PINS:
808 		ptr = (const uint32_t *)value;
809 		for (i = 0; i < devi->npins; i++)
810 			devi->pins[i] = ptr[i];
811 		if (gpiobus_acquire_child_pins(dev, child) != 0)
812 			return (EBUSY);
813 		break;
814         default:
815                 return (ENOENT);
816         }
817 
818         return (0);
819 }
820 
821 static struct rman *
822 gpiobus_get_rman(device_t bus, int type, u_int flags)
823 {
824 	struct gpiobus_softc *sc;
825 
826 	sc = device_get_softc(bus);
827 	switch (type) {
828 	case SYS_RES_IRQ:
829 		return (&sc->sc_intr_rman);
830 	default:
831 		return (NULL);
832 	}
833 }
834 
835 static struct resource *
836 gpiobus_alloc_resource(device_t bus, device_t child, int type, int *rid,
837     rman_res_t start, rman_res_t end, rman_res_t count, u_int flags)
838 {
839 	struct resource_list *rl;
840 	struct resource_list_entry *rle;
841 	int isdefault;
842 
843 	isdefault = (RMAN_IS_DEFAULT_RANGE(start, end) && count == 1);
844 	if (isdefault) {
845 		rl = BUS_GET_RESOURCE_LIST(bus, child);
846 		if (rl == NULL)
847 			return (NULL);
848 		rle = resource_list_find(rl, type, *rid);
849 		if (rle == NULL)
850 			return (NULL);
851 		start = rle->start;
852 		count = rle->count;
853 		end = rle->end;
854 	}
855 	return (bus_generic_rman_alloc_resource(bus, child, type, rid, start,
856 	    end, count, flags));
857 }
858 
859 static int
860 gpiobus_release_resource(device_t dev, device_t child, struct resource *r)
861 {
862 	int err;
863 #ifdef INTRNG
864 	u_int irq;
865 
866 	irq = rman_get_start(r);
867 	MPASS(irq == rman_get_end(r));
868 #endif
869 	err = bus_generic_rman_release_resource(dev, child, r);
870 	if (err != 0)
871 		return (err);
872 #ifdef INTRNG
873 	intr_unmap_irq(irq);
874 #endif
875 	return (0);
876 }
877 
878 static struct resource_list *
879 gpiobus_get_resource_list(device_t bus __unused, device_t child)
880 {
881 	struct gpiobus_ivar *ivar;
882 
883 	ivar = GPIOBUS_IVAR(child);
884 
885 	return (&ivar->rl);
886 }
887 
888 static int
889 gpiobus_acquire_bus(device_t busdev, device_t child, int how)
890 {
891 	struct gpiobus_softc *sc;
892 
893 	sc = device_get_softc(busdev);
894 	GPIOBUS_ASSERT_UNLOCKED(sc);
895 	GPIOBUS_LOCK(sc);
896 	if (sc->sc_owner != NULL) {
897 		if (sc->sc_owner == child)
898 			panic("%s: %s still owns the bus.",
899 			    device_get_nameunit(busdev),
900 			    device_get_nameunit(child));
901 		if (how == GPIOBUS_DONTWAIT) {
902 			GPIOBUS_UNLOCK(sc);
903 			return (EWOULDBLOCK);
904 		}
905 		while (sc->sc_owner != NULL)
906 			mtx_sleep(sc, &sc->sc_mtx, 0, "gpiobuswait", 0);
907 	}
908 	sc->sc_owner = child;
909 	GPIOBUS_UNLOCK(sc);
910 
911 	return (0);
912 }
913 
914 static void
915 gpiobus_release_bus(device_t busdev, device_t child)
916 {
917 	struct gpiobus_softc *sc;
918 
919 	sc = device_get_softc(busdev);
920 	GPIOBUS_ASSERT_UNLOCKED(sc);
921 	GPIOBUS_LOCK(sc);
922 	if (sc->sc_owner == NULL)
923 		panic("%s: %s releasing unowned bus.",
924 		    device_get_nameunit(busdev),
925 		    device_get_nameunit(child));
926 	if (sc->sc_owner != child)
927 		panic("%s: %s trying to release bus owned by %s",
928 		    device_get_nameunit(busdev),
929 		    device_get_nameunit(child),
930 		    device_get_nameunit(sc->sc_owner));
931 	sc->sc_owner = NULL;
932 	wakeup(sc);
933 	GPIOBUS_UNLOCK(sc);
934 }
935 
936 static int
937 gpiobus_pin_setflags(device_t dev, device_t child, uint32_t pin,
938     uint32_t flags)
939 {
940 	struct gpiobus_softc *sc = GPIOBUS_SOFTC(dev);
941 	struct gpiobus_ivar *devi = GPIOBUS_IVAR(child);
942 	uint32_t caps;
943 
944 	if (pin >= devi->npins)
945 		return (EINVAL);
946 	if (GPIO_PIN_GETCAPS(sc->sc_dev, devi->pins[pin], &caps) != 0)
947 		return (EINVAL);
948 	if (gpio_check_flags(caps, flags) != 0)
949 		return (EINVAL);
950 
951 	return (GPIO_PIN_SETFLAGS(sc->sc_dev, devi->pins[pin], flags));
952 }
953 
954 static int
955 gpiobus_pin_getflags(device_t dev, device_t child, uint32_t pin,
956     uint32_t *flags)
957 {
958 	struct gpiobus_softc *sc = GPIOBUS_SOFTC(dev);
959 	struct gpiobus_ivar *devi = GPIOBUS_IVAR(child);
960 
961 	if (pin >= devi->npins)
962 		return (EINVAL);
963 
964 	return GPIO_PIN_GETFLAGS(sc->sc_dev, devi->pins[pin], flags);
965 }
966 
967 static int
968 gpiobus_pin_getcaps(device_t dev, device_t child, uint32_t pin,
969     uint32_t *caps)
970 {
971 	struct gpiobus_softc *sc = GPIOBUS_SOFTC(dev);
972 	struct gpiobus_ivar *devi = GPIOBUS_IVAR(child);
973 
974 	if (pin >= devi->npins)
975 		return (EINVAL);
976 
977 	return GPIO_PIN_GETCAPS(sc->sc_dev, devi->pins[pin], caps);
978 }
979 
980 static int
981 gpiobus_pin_set(device_t dev, device_t child, uint32_t pin,
982     unsigned int value)
983 {
984 	struct gpiobus_softc *sc = GPIOBUS_SOFTC(dev);
985 	struct gpiobus_ivar *devi = GPIOBUS_IVAR(child);
986 
987 	if (pin >= devi->npins)
988 		return (EINVAL);
989 
990 	return GPIO_PIN_SET(sc->sc_dev, devi->pins[pin], value);
991 }
992 
993 static int
994 gpiobus_pin_get(device_t dev, device_t child, uint32_t pin,
995     unsigned int *value)
996 {
997 	struct gpiobus_softc *sc = GPIOBUS_SOFTC(dev);
998 	struct gpiobus_ivar *devi = GPIOBUS_IVAR(child);
999 
1000 	if (pin >= devi->npins)
1001 		return (EINVAL);
1002 
1003 	return GPIO_PIN_GET(sc->sc_dev, devi->pins[pin], value);
1004 }
1005 
1006 static int
1007 gpiobus_pin_toggle(device_t dev, device_t child, uint32_t pin)
1008 {
1009 	struct gpiobus_softc *sc = GPIOBUS_SOFTC(dev);
1010 	struct gpiobus_ivar *devi = GPIOBUS_IVAR(child);
1011 
1012 	if (pin >= devi->npins)
1013 		return (EINVAL);
1014 
1015 	return GPIO_PIN_TOGGLE(sc->sc_dev, devi->pins[pin]);
1016 }
1017 
1018 static int
1019 gpiobus_pin_getname(device_t dev, uint32_t pin, char *name)
1020 {
1021 	struct gpiobus_softc *sc;
1022 
1023 	sc = GPIOBUS_SOFTC(dev);
1024 	if (pin > sc->sc_npins)
1025 		return (EINVAL);
1026 	/* Did we have a name for this pin ? */
1027 	if (sc->sc_pins[pin].name != NULL) {
1028 		memcpy(name, sc->sc_pins[pin].name, GPIOMAXNAME);
1029 		return (0);
1030 	}
1031 
1032 	/* Return the default pin name. */
1033 	return (GPIO_PIN_GETNAME(device_get_parent(dev), pin, name));
1034 }
1035 
1036 static int
1037 gpiobus_pin_setname(device_t dev, uint32_t pin, const char *name)
1038 {
1039 	struct gpiobus_softc *sc;
1040 
1041 	sc = GPIOBUS_SOFTC(dev);
1042 	if (pin > sc->sc_npins)
1043 		return (EINVAL);
1044 	if (name == NULL)
1045 		return (EINVAL);
1046 	/* Save the pin name. */
1047 	if (sc->sc_pins[pin].name == NULL)
1048 		sc->sc_pins[pin].name = malloc(GPIOMAXNAME, M_DEVBUF,
1049 		    M_WAITOK | M_ZERO);
1050 	strlcpy(sc->sc_pins[pin].name, name, GPIOMAXNAME);
1051 
1052 	return (0);
1053 }
1054 
1055 static device_method_t gpiobus_methods[] = {
1056 	/* Device interface */
1057 	DEVMETHOD(device_probe,		gpiobus_probe),
1058 	DEVMETHOD(device_attach,	gpiobus_attach),
1059 	DEVMETHOD(device_detach,	gpiobus_detach),
1060 	DEVMETHOD(device_shutdown,	bus_generic_shutdown),
1061 	DEVMETHOD(device_suspend,	gpiobus_suspend),
1062 	DEVMETHOD(device_resume,	gpiobus_resume),
1063 
1064 	/* Bus interface */
1065 	DEVMETHOD(bus_setup_intr,	bus_generic_setup_intr),
1066 	DEVMETHOD(bus_config_intr,	bus_generic_config_intr),
1067 	DEVMETHOD(bus_teardown_intr,	bus_generic_teardown_intr),
1068 	DEVMETHOD(bus_delete_resource,	bus_generic_rl_delete_resource),
1069 	DEVMETHOD(bus_get_resource,	bus_generic_rl_get_resource),
1070 	DEVMETHOD(bus_set_resource,	bus_generic_rl_set_resource),
1071 	DEVMETHOD(bus_alloc_resource,	gpiobus_alloc_resource),
1072 	DEVMETHOD(bus_release_resource,	gpiobus_release_resource),
1073 	DEVMETHOD(bus_activate_resource,	bus_generic_rman_activate_resource),
1074 	DEVMETHOD(bus_deactivate_resource,	bus_generic_rman_deactivate_resource),
1075 	DEVMETHOD(bus_get_resource_list,	gpiobus_get_resource_list),
1076 	DEVMETHOD(bus_get_rman,		gpiobus_get_rman),
1077 	DEVMETHOD(bus_add_child,	gpiobus_add_child),
1078 	DEVMETHOD(bus_child_deleted,	gpiobus_child_deleted),
1079 	DEVMETHOD(bus_rescan,		gpiobus_rescan),
1080 	DEVMETHOD(bus_probe_nomatch,	gpiobus_probe_nomatch),
1081 	DEVMETHOD(bus_print_child,	gpiobus_print_child),
1082 	DEVMETHOD(bus_child_location,	gpiobus_child_location),
1083 	DEVMETHOD(bus_hinted_child,	gpiobus_hinted_child),
1084 	DEVMETHOD(bus_read_ivar,        gpiobus_read_ivar),
1085 	DEVMETHOD(bus_write_ivar,       gpiobus_write_ivar),
1086 
1087 	/* GPIO protocol */
1088 	DEVMETHOD(gpiobus_acquire_bus,	gpiobus_acquire_bus),
1089 	DEVMETHOD(gpiobus_release_bus,	gpiobus_release_bus),
1090 	DEVMETHOD(gpiobus_pin_getflags,	gpiobus_pin_getflags),
1091 	DEVMETHOD(gpiobus_pin_getcaps,	gpiobus_pin_getcaps),
1092 	DEVMETHOD(gpiobus_pin_setflags,	gpiobus_pin_setflags),
1093 	DEVMETHOD(gpiobus_pin_get,	gpiobus_pin_get),
1094 	DEVMETHOD(gpiobus_pin_set,	gpiobus_pin_set),
1095 	DEVMETHOD(gpiobus_pin_toggle,	gpiobus_pin_toggle),
1096 	DEVMETHOD(gpiobus_pin_getname,	gpiobus_pin_getname),
1097 	DEVMETHOD(gpiobus_pin_setname,	gpiobus_pin_setname),
1098 
1099 	DEVMETHOD_END
1100 };
1101 
1102 driver_t gpiobus_driver = {
1103 	"gpiobus",
1104 	gpiobus_methods,
1105 	sizeof(struct gpiobus_softc)
1106 };
1107 
1108 EARLY_DRIVER_MODULE(gpiobus, gpio, gpiobus_driver, 0, 0,
1109     BUS_PASS_BUS + BUS_PASS_ORDER_MIDDLE);
1110 MODULE_VERSION(gpiobus, 1);
1111