xref: /freebsd/sys/dev/gpio/gpiobus.c (revision b79bd43f9ab3bf0dfd4744dee406782f0329134a)
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 
43 #include "gpiobus_if.h"
44 
45 #undef GPIOBUS_DEBUG
46 #ifdef GPIOBUS_DEBUG
47 #define	dprintf printf
48 #else
49 #define	dprintf(x, arg...)
50 #endif
51 
52 static void gpiobus_print_pins(struct gpiobus_ivar *, struct sbuf *);
53 static int gpiobus_parse_pins(struct gpiobus_softc *, device_t, int);
54 static int gpiobus_probe(device_t);
55 static int gpiobus_suspend(device_t);
56 static int gpiobus_resume(device_t);
57 static void gpiobus_probe_nomatch(device_t, device_t);
58 static int gpiobus_print_child(device_t, device_t);
59 static int gpiobus_child_location(device_t, device_t, struct sbuf *);
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_free_intr_map_data((struct intr_map_data *)gpio_data);
113 		return (NULL);
114 	}
115 	rman_set_virtual(res, gpio_data);
116 	return (res);
117 }
118 #else
119 struct resource *
120 gpio_alloc_intr_resource(device_t consumer_dev, int *rid, u_int alloc_flags,
121     gpio_pin_t pin, uint32_t intr_mode)
122 {
123 
124 	return (NULL);
125 }
126 #endif
127 
128 int
129 gpio_check_flags(uint32_t caps, uint32_t flags)
130 {
131 
132 	/* Filter unwanted flags. */
133 	flags &= caps;
134 
135 	/* Cannot mix input/output together. */
136 	if (flags & GPIO_PIN_INPUT && flags & GPIO_PIN_OUTPUT)
137 		return (EINVAL);
138 	/* Cannot mix pull-up/pull-down together. */
139 	if (flags & GPIO_PIN_PULLUP && flags & GPIO_PIN_PULLDOWN)
140 		return (EINVAL);
141 	/* Cannot mix output and interrupt flags together */
142 	if (flags & GPIO_PIN_OUTPUT && flags & GPIO_INTR_MASK)
143 		return (EINVAL);
144 	/* Only one interrupt flag can be defined at once */
145 	if ((flags & GPIO_INTR_MASK) & ((flags & GPIO_INTR_MASK) - 1))
146 		return (EINVAL);
147 	/* The interrupt attached flag cannot be set */
148 	if (flags & GPIO_INTR_ATTACHED)
149 		return (EINVAL);
150 
151 	return (0);
152 }
153 
154 int
155 gpio_pin_get_by_bus_pinnum(device_t busdev, uint32_t pinnum, gpio_pin_t *ppin)
156 {
157 	gpio_pin_t pin;
158 	int err;
159 
160 	err = gpiobus_acquire_pin(busdev, pinnum);
161 	if (err != 0)
162 		return (EBUSY);
163 
164 	pin = malloc(sizeof(*pin), M_DEVBUF, M_WAITOK | M_ZERO);
165 
166 	pin->dev = device_get_parent(busdev);
167 	pin->pin = pinnum;
168 	pin->flags = 0;
169 
170 	*ppin = pin;
171 	return (0);
172 }
173 
174 int
175 gpio_pin_get_by_child_index(device_t childdev, uint32_t idx, gpio_pin_t *ppin)
176 {
177 	struct gpiobus_ivar *devi;
178 
179 	devi = GPIOBUS_IVAR(childdev);
180 	if (idx >= devi->npins)
181 		return (EINVAL);
182 
183 	return (gpio_pin_get_by_bus_pinnum(device_get_parent(childdev),
184 	    devi->pins[idx], ppin));
185 }
186 
187 int
188 gpio_pin_getcaps(gpio_pin_t pin, uint32_t *caps)
189 {
190 
191 	KASSERT(pin != NULL, ("GPIO pin is NULL."));
192 	KASSERT(pin->dev != NULL, ("GPIO pin device is NULL."));
193 	return (GPIO_PIN_GETCAPS(pin->dev, pin->pin, caps));
194 }
195 
196 int
197 gpio_pin_is_active(gpio_pin_t pin, bool *active)
198 {
199 	int rv;
200 	uint32_t tmp;
201 
202 	KASSERT(pin != NULL, ("GPIO pin is NULL."));
203 	KASSERT(pin->dev != NULL, ("GPIO pin device is NULL."));
204 	rv = GPIO_PIN_GET(pin->dev, pin->pin, &tmp);
205 	if (rv  != 0) {
206 		return (rv);
207 	}
208 
209 	if (pin->flags & GPIO_ACTIVE_LOW)
210 		*active = tmp == 0;
211 	else
212 		*active = tmp != 0;
213 	return (0);
214 }
215 
216 void
217 gpio_pin_release(gpio_pin_t gpio)
218 {
219 	device_t busdev;
220 
221 	if (gpio == NULL)
222 		return;
223 
224 	KASSERT(gpio->dev != NULL, ("GPIO pin device is NULL."));
225 
226 	busdev = GPIO_GET_BUS(gpio->dev);
227 	if (busdev != NULL)
228 		gpiobus_release_pin(busdev, gpio->pin);
229 
230 	free(gpio, M_DEVBUF);
231 }
232 
233 int
234 gpio_pin_set_active(gpio_pin_t pin, bool active)
235 {
236 	int rv;
237 	uint32_t tmp;
238 
239 	if (pin->flags & GPIO_ACTIVE_LOW)
240 		tmp = active ? 0 : 1;
241 	else
242 		tmp = active ? 1 : 0;
243 
244 	KASSERT(pin != NULL, ("GPIO pin is NULL."));
245 	KASSERT(pin->dev != NULL, ("GPIO pin device is NULL."));
246 	rv = GPIO_PIN_SET(pin->dev, pin->pin, tmp);
247 	return (rv);
248 }
249 
250 int
251 gpio_pin_setflags(gpio_pin_t pin, uint32_t flags)
252 {
253 	int rv;
254 
255 	KASSERT(pin != NULL, ("GPIO pin is NULL."));
256 	KASSERT(pin->dev != NULL, ("GPIO pin device is NULL."));
257 
258 	rv = GPIO_PIN_SETFLAGS(pin->dev, pin->pin, flags);
259 	return (rv);
260 }
261 
262 static void
263 gpiobus_print_pins(struct gpiobus_ivar *devi, struct sbuf *sb)
264 {
265 	int i, range_start, range_stop, need_coma;
266 
267 	if (devi->npins == 0)
268 		return;
269 
270 	need_coma = 0;
271 	range_start = range_stop = devi->pins[0];
272 	for (i = 1; i < devi->npins; i++) {
273 		if (devi->pins[i] != (range_stop + 1)) {
274 			if (need_coma)
275 				sbuf_cat(sb, ",");
276 			if (range_start != range_stop)
277 				sbuf_printf(sb, "%d-%d", range_start, range_stop);
278 			else
279 				sbuf_printf(sb, "%d", range_start);
280 			range_start = range_stop = devi->pins[i];
281 			need_coma = 1;
282 		}
283 		else
284 			range_stop++;
285 	}
286 
287 	if (need_coma)
288 		sbuf_cat(sb, ",");
289 	if (range_start != range_stop)
290 		sbuf_printf(sb, "%d-%d", range_start, range_stop);
291 	else
292 		sbuf_printf(sb, "%d", range_start);
293 }
294 
295 device_t
296 gpiobus_add_bus(device_t dev)
297 {
298 	device_t busdev;
299 
300 	busdev = device_add_child(dev, "gpiobus", DEVICE_UNIT_ANY);
301 	if (busdev == NULL)
302 		return (NULL);
303 	if (device_add_child(dev, "gpioc", DEVICE_UNIT_ANY) == NULL) {
304 		device_delete_child(dev, busdev);
305 		return (NULL);
306 	}
307 #ifdef FDT
308 	ofw_gpiobus_register_provider(dev);
309 #endif
310 	return (busdev);
311 }
312 
313 /*
314  * Attach a gpiobus child.
315  * Note that the controller is expected
316  * to be fully initialized at this point.
317  */
318 device_t
319 gpiobus_attach_bus(device_t dev)
320 {
321 	device_t busdev;
322 
323 	busdev = gpiobus_add_bus(dev);
324 	if (busdev == NULL)
325 		return (NULL);
326 
327 	bus_attach_children(dev);
328 	return (busdev);
329 }
330 
331 int
332 gpiobus_detach_bus(device_t dev)
333 {
334 #ifdef FDT
335 	ofw_gpiobus_unregister_provider(dev);
336 #endif
337 	return (bus_generic_detach(dev));
338 }
339 
340 int
341 gpiobus_init_softc(device_t dev)
342 {
343 	struct gpiobus_softc *sc;
344 
345 	sc = GPIOBUS_SOFTC(dev);
346 	sc->sc_busdev = dev;
347 	sc->sc_dev = device_get_parent(dev);
348 	sc->sc_intr_rman.rm_type = RMAN_ARRAY;
349 	sc->sc_intr_rman.rm_descr = "GPIO Interrupts";
350 	if (rman_init(&sc->sc_intr_rman) != 0 ||
351 	    rman_manage_region(&sc->sc_intr_rman, 0, ~0) != 0)
352 		panic("%s: failed to set up rman.", __func__);
353 
354 	if (GPIO_PIN_MAX(sc->sc_dev, &sc->sc_npins) != 0)
355 		return (ENXIO);
356 
357 	KASSERT(sc->sc_npins >= 0, ("GPIO device with no pins"));
358 
359 	/* Pins = GPIO_PIN_MAX() + 1 */
360 	sc->sc_npins++;
361 
362 	sc->sc_pins = malloc(sizeof(*sc->sc_pins) * sc->sc_npins, M_DEVBUF,
363 	    M_NOWAIT | M_ZERO);
364 	if (sc->sc_pins == NULL)
365 		return (ENOMEM);
366 
367 	/* Initialize the bus lock. */
368 	GPIOBUS_LOCK_INIT(sc);
369 
370 	return (0);
371 }
372 
373 int
374 gpiobus_alloc_ivars(struct gpiobus_ivar *devi)
375 {
376 
377 	/* Allocate pins and flags memory. */
378 	devi->pins = malloc(sizeof(uint32_t) * devi->npins, M_DEVBUF,
379 	    M_NOWAIT | M_ZERO);
380 	if (devi->pins == NULL)
381 		return (ENOMEM);
382 	return (0);
383 }
384 
385 void
386 gpiobus_free_ivars(struct gpiobus_ivar *devi)
387 {
388 
389 	if (devi->pins) {
390 		free(devi->pins, M_DEVBUF);
391 		devi->pins = NULL;
392 	}
393 	devi->npins = 0;
394 }
395 
396 int
397 gpiobus_acquire_pin(device_t bus, uint32_t pin)
398 {
399 	struct gpiobus_softc *sc;
400 
401 	sc = device_get_softc(bus);
402 	/* Consistency check. */
403 	if (pin >= sc->sc_npins) {
404 		device_printf(bus,
405 		    "invalid pin %d, max: %d\n", pin, sc->sc_npins - 1);
406 		return (-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 (-1);
412 	}
413 	sc->sc_pins[pin].mapped = 1;
414 
415 	return (0);
416 }
417 
418 /* Release mapped pin */
419 int
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 		device_printf(bus,
428 		    "invalid pin %d, max=%d\n",
429 		    pin, sc->sc_npins - 1);
430 		return (-1);
431 	}
432 
433 	if (!sc->sc_pins[pin].mapped) {
434 		device_printf(bus, "pin %d is not mapped\n", pin);
435 		return (-1);
436 	}
437 	sc->sc_pins[pin].mapped = 0;
438 
439 	return (0);
440 }
441 
442 static int
443 gpiobus_acquire_child_pins(device_t dev, device_t child)
444 {
445 	struct gpiobus_ivar *devi = GPIOBUS_IVAR(child);
446 	int i;
447 
448 	for (i = 0; i < devi->npins; i++) {
449 		/* Reserve the GPIO pin. */
450 		if (gpiobus_acquire_pin(dev, devi->pins[i]) != 0) {
451 			device_printf(child, "cannot acquire pin %d\n",
452 			    devi->pins[i]);
453 			while (--i >= 0) {
454 				(void)gpiobus_release_pin(dev,
455 				    devi->pins[i]);
456 			}
457 			gpiobus_free_ivars(devi);
458 			return (EBUSY);
459 		}
460 	}
461 	for (i = 0; i < devi->npins; i++) {
462 		/* Use the child name as pin name. */
463 		GPIOBUS_PIN_SETNAME(dev, devi->pins[i],
464 		    device_get_nameunit(child));
465 
466 	}
467 	return (0);
468 }
469 
470 static int
471 gpiobus_parse_pins(struct gpiobus_softc *sc, device_t child, int mask)
472 {
473 	struct gpiobus_ivar *devi = GPIOBUS_IVAR(child);
474 	int i, npins;
475 
476 	npins = 0;
477 	for (i = 0; i < 32; i++) {
478 		if (mask & (1 << i))
479 			npins++;
480 	}
481 	if (npins == 0) {
482 		device_printf(child, "empty pin mask\n");
483 		return (EINVAL);
484 	}
485 	devi->npins = npins;
486 	if (gpiobus_alloc_ivars(devi) != 0) {
487 		device_printf(child, "cannot allocate device ivars\n");
488 		return (EINVAL);
489 	}
490 	npins = 0;
491 	for (i = 0; i < 32; i++) {
492 		if ((mask & (1 << i)) == 0)
493 			continue;
494 		devi->pins[npins++] = i;
495 	}
496 
497 	return (0);
498 }
499 
500 static int
501 gpiobus_parse_pin_list(struct gpiobus_softc *sc, device_t child,
502     const char *pins)
503 {
504 	struct gpiobus_ivar *devi = GPIOBUS_IVAR(child);
505 	const char *p;
506 	char *endp;
507 	unsigned long pin;
508 	int i, npins;
509 
510 	npins = 0;
511 	p = pins;
512 	for (;;) {
513 		pin = strtoul(p, &endp, 0);
514 		if (endp == p)
515 			break;
516 		npins++;
517 		if (*endp == '\0')
518 			break;
519 		p = endp + 1;
520 	}
521 
522 	if (*endp != '\0') {
523 		device_printf(child, "garbage in the pin list: %s\n", endp);
524 		return (EINVAL);
525 	}
526 	if (npins == 0) {
527 		device_printf(child, "empty pin list\n");
528 		return (EINVAL);
529 	}
530 
531 	devi->npins = npins;
532 	if (gpiobus_alloc_ivars(devi) != 0) {
533 		device_printf(child, "cannot allocate device ivars\n");
534 		return (EINVAL);
535 	}
536 
537 	i = 0;
538 	p = pins;
539 	for (;;) {
540 		pin = strtoul(p, &endp, 0);
541 
542 		devi->pins[i] = pin;
543 
544 		if (*endp == '\0')
545 			break;
546 		i++;
547 		p = endp + 1;
548 	}
549 
550 	return (0);
551 }
552 
553 static int
554 gpiobus_probe(device_t dev)
555 {
556 	device_set_desc(dev, "GPIO bus");
557 
558 	return (BUS_PROBE_GENERIC);
559 }
560 
561 int
562 gpiobus_attach(device_t dev)
563 {
564 	int err;
565 
566 	err = gpiobus_init_softc(dev);
567 	if (err != 0)
568 		return (err);
569 
570 	/*
571 	 * Get parent's pins and mark them as unmapped
572 	 */
573 	bus_identify_children(dev);
574 	bus_enumerate_hinted_children(dev);
575 
576 	bus_attach_children(dev);
577 	return (0);
578 }
579 
580 /*
581  * Since this is not a self-enumerating bus, and since we always add
582  * children in attach, we have to always delete children here.
583  */
584 int
585 gpiobus_detach(device_t dev)
586 {
587 	struct gpiobus_softc *sc;
588 	int i, err;
589 
590 	sc = GPIOBUS_SOFTC(dev);
591 	KASSERT(mtx_initialized(&sc->sc_mtx),
592 	    ("gpiobus mutex not initialized"));
593 	GPIOBUS_LOCK_DESTROY(sc);
594 
595 	if ((err = bus_detach_children(dev)) != 0)
596 		return (err);
597 
598 	rman_fini(&sc->sc_intr_rman);
599 	if (sc->sc_pins) {
600 		for (i = 0; i < sc->sc_npins; i++) {
601 			if (sc->sc_pins[i].name != NULL)
602 				free(sc->sc_pins[i].name, M_DEVBUF);
603 			sc->sc_pins[i].name = NULL;
604 		}
605 		free(sc->sc_pins, M_DEVBUF);
606 		sc->sc_pins = NULL;
607 	}
608 
609 	return (0);
610 }
611 
612 static int
613 gpiobus_suspend(device_t dev)
614 {
615 
616 	return (bus_generic_suspend(dev));
617 }
618 
619 static int
620 gpiobus_resume(device_t dev)
621 {
622 
623 	return (bus_generic_resume(dev));
624 }
625 
626 static void
627 gpiobus_probe_nomatch(device_t dev, device_t child)
628 {
629 	char pins[128];
630 	struct sbuf sb;
631 	struct gpiobus_ivar *devi;
632 
633 	devi = GPIOBUS_IVAR(child);
634 	sbuf_new(&sb, pins, sizeof(pins), SBUF_FIXEDLEN);
635 	gpiobus_print_pins(devi, &sb);
636 	sbuf_finish(&sb);
637 	device_printf(dev, "<unknown device> at pin%s %s",
638 	    devi->npins > 1 ? "s" : "", sbuf_data(&sb));
639 	resource_list_print_type(&devi->rl, "irq", SYS_RES_IRQ, "%jd");
640 	printf("\n");
641 }
642 
643 static int
644 gpiobus_print_child(device_t dev, device_t child)
645 {
646 	char pins[128];
647 	struct sbuf sb;
648 	int retval = 0;
649 	struct gpiobus_ivar *devi;
650 
651 	devi = GPIOBUS_IVAR(child);
652 	retval += bus_print_child_header(dev, child);
653 	if (devi->npins > 0) {
654 		if (devi->npins > 1)
655 			retval += printf(" at pins ");
656 		else
657 			retval += printf(" at pin ");
658 		sbuf_new(&sb, pins, sizeof(pins), SBUF_FIXEDLEN);
659 		gpiobus_print_pins(devi, &sb);
660 		sbuf_finish(&sb);
661 		retval += printf("%s", sbuf_data(&sb));
662 	}
663 	resource_list_print_type(&devi->rl, "irq", SYS_RES_IRQ, "%jd");
664 	retval += bus_print_child_footer(dev, child);
665 
666 	return (retval);
667 }
668 
669 static int
670 gpiobus_child_location(device_t bus, device_t child, struct sbuf *sb)
671 {
672 	struct gpiobus_ivar *devi;
673 
674 	devi = GPIOBUS_IVAR(child);
675 	sbuf_printf(sb, "pins=");
676 	gpiobus_print_pins(devi, sb);
677 
678 	return (0);
679 }
680 
681 static device_t
682 gpiobus_add_child(device_t dev, u_int order, const char *name, int unit)
683 {
684 	device_t child;
685 	struct gpiobus_ivar *devi;
686 
687 	child = device_add_child_ordered(dev, order, name, unit);
688 	if (child == NULL)
689 		return (child);
690 	devi = malloc(sizeof(struct gpiobus_ivar), M_DEVBUF, M_NOWAIT | M_ZERO);
691 	if (devi == NULL) {
692 		device_delete_child(dev, child);
693 		return (NULL);
694 	}
695 	resource_list_init(&devi->rl);
696 	device_set_ivars(child, devi);
697 
698 	return (child);
699 }
700 
701 static void
702 gpiobus_child_deleted(device_t dev, device_t child)
703 {
704 	struct gpiobus_ivar *devi;
705 
706 	devi = GPIOBUS_IVAR(child);
707 	if (devi == NULL)
708 		return;
709 	gpiobus_free_ivars(devi);
710 	resource_list_free(&devi->rl);
711 	free(devi, M_DEVBUF);
712 }
713 
714 static int
715 gpiobus_rescan(device_t dev)
716 {
717 
718 	/*
719 	 * Re-scan is supposed to remove and add children, but if someone has
720 	 * deleted the hints for a child we attached earlier, we have no easy
721 	 * way to handle that.  So this just attaches new children for whom new
722 	 * hints or drivers have arrived since we last tried.
723 	 */
724 	bus_enumerate_hinted_children(dev);
725 	bus_attach_children(dev);
726 	return (0);
727 }
728 
729 static void
730 gpiobus_hinted_child(device_t bus, const char *dname, int dunit)
731 {
732 	struct gpiobus_softc *sc = GPIOBUS_SOFTC(bus);
733 	device_t child;
734 	const char *pins;
735 	int irq, pinmask;
736 
737 	if (device_find_child(bus, dname, dunit) != NULL) {
738 		return;
739 	}
740 
741 	child = BUS_ADD_CHILD(bus, 0, dname, dunit);
742 	if (resource_int_value(dname, dunit, "pins", &pinmask) == 0) {
743 		if (gpiobus_parse_pins(sc, child, pinmask)) {
744 			device_delete_child(bus, child);
745 			return;
746 		}
747 	}
748 	else if (resource_string_value(dname, dunit, "pin_list", &pins) == 0) {
749 		if (gpiobus_parse_pin_list(sc, child, pins)) {
750 			device_delete_child(bus, child);
751 			return;
752 		}
753 	}
754 	if (resource_int_value(dname, dunit, "irq", &irq) == 0) {
755 		if (bus_set_resource(child, SYS_RES_IRQ, 0, irq, 1) != 0)
756 			device_printf(bus,
757 			    "warning: bus_set_resource() failed\n");
758 	}
759 }
760 
761 int
762 gpiobus_read_ivar(device_t dev, device_t child, int which, uintptr_t *result)
763 {
764 	struct gpiobus_ivar *devi;
765 
766 	devi = GPIOBUS_IVAR(child);
767         switch (which) {
768 	case GPIOBUS_IVAR_NPINS:
769 		*result = devi->npins;
770 		break;
771 	case GPIOBUS_IVAR_PINS:
772 		/* Children do not ever need to directly examine this. */
773 		return (ENOTSUP);
774         default:
775                 return (ENOENT);
776         }
777 
778 	return (0);
779 }
780 
781 static int
782 gpiobus_write_ivar(device_t dev, device_t child, int which, uintptr_t value)
783 {
784 	struct gpiobus_ivar *devi;
785 	const uint32_t *ptr;
786 	int i;
787 
788 	devi = GPIOBUS_IVAR(child);
789         switch (which) {
790 	case GPIOBUS_IVAR_NPINS:
791 		/* GPIO ivars are set once. */
792 		if (devi->npins != 0) {
793 			return (EBUSY);
794 		}
795 		devi->npins = value;
796 		if (gpiobus_alloc_ivars(devi) != 0) {
797 			device_printf(child, "cannot allocate device ivars\n");
798 			devi->npins = 0;
799 			return (ENOMEM);
800 		}
801 		break;
802 	case GPIOBUS_IVAR_PINS:
803 		ptr = (const uint32_t *)value;
804 		for (i = 0; i < devi->npins; i++)
805 			devi->pins[i] = ptr[i];
806 		if (gpiobus_acquire_child_pins(dev, child) != 0)
807 			return (EBUSY);
808 		break;
809         default:
810                 return (ENOENT);
811         }
812 
813         return (0);
814 }
815 
816 static struct rman *
817 gpiobus_get_rman(device_t bus, int type, u_int flags)
818 {
819 	struct gpiobus_softc *sc;
820 
821 	sc = device_get_softc(bus);
822 	switch (type) {
823 	case SYS_RES_IRQ:
824 		return (&sc->sc_intr_rman);
825 	default:
826 		return (NULL);
827 	}
828 }
829 
830 static struct resource *
831 gpiobus_alloc_resource(device_t bus, device_t child, int type, int *rid,
832     rman_res_t start, rman_res_t end, rman_res_t count, u_int flags)
833 {
834 	struct resource_list *rl;
835 	struct resource_list_entry *rle;
836 	int isdefault;
837 
838 	isdefault = (RMAN_IS_DEFAULT_RANGE(start, end) && count == 1);
839 	if (isdefault) {
840 		rl = BUS_GET_RESOURCE_LIST(bus, child);
841 		if (rl == NULL)
842 			return (NULL);
843 		rle = resource_list_find(rl, type, *rid);
844 		if (rle == NULL)
845 			return (NULL);
846 		start = rle->start;
847 		count = rle->count;
848 		end = rle->end;
849 	}
850 	return (bus_generic_rman_alloc_resource(bus, child, type, rid, start,
851 	    end, count, flags));
852 }
853 
854 static struct resource_list *
855 gpiobus_get_resource_list(device_t bus __unused, device_t child)
856 {
857 	struct gpiobus_ivar *ivar;
858 
859 	ivar = GPIOBUS_IVAR(child);
860 
861 	return (&ivar->rl);
862 }
863 
864 static int
865 gpiobus_acquire_bus(device_t busdev, device_t child, int how)
866 {
867 	struct gpiobus_softc *sc;
868 
869 	sc = device_get_softc(busdev);
870 	GPIOBUS_ASSERT_UNLOCKED(sc);
871 	GPIOBUS_LOCK(sc);
872 	if (sc->sc_owner != NULL) {
873 		if (sc->sc_owner == child)
874 			panic("%s: %s still owns the bus.",
875 			    device_get_nameunit(busdev),
876 			    device_get_nameunit(child));
877 		if (how == GPIOBUS_DONTWAIT) {
878 			GPIOBUS_UNLOCK(sc);
879 			return (EWOULDBLOCK);
880 		}
881 		while (sc->sc_owner != NULL)
882 			mtx_sleep(sc, &sc->sc_mtx, 0, "gpiobuswait", 0);
883 	}
884 	sc->sc_owner = child;
885 	GPIOBUS_UNLOCK(sc);
886 
887 	return (0);
888 }
889 
890 static void
891 gpiobus_release_bus(device_t busdev, device_t child)
892 {
893 	struct gpiobus_softc *sc;
894 
895 	sc = device_get_softc(busdev);
896 	GPIOBUS_ASSERT_UNLOCKED(sc);
897 	GPIOBUS_LOCK(sc);
898 	if (sc->sc_owner == NULL)
899 		panic("%s: %s releasing unowned bus.",
900 		    device_get_nameunit(busdev),
901 		    device_get_nameunit(child));
902 	if (sc->sc_owner != child)
903 		panic("%s: %s trying to release bus owned by %s",
904 		    device_get_nameunit(busdev),
905 		    device_get_nameunit(child),
906 		    device_get_nameunit(sc->sc_owner));
907 	sc->sc_owner = NULL;
908 	wakeup(sc);
909 	GPIOBUS_UNLOCK(sc);
910 }
911 
912 static int
913 gpiobus_pin_setflags(device_t dev, device_t child, uint32_t pin,
914     uint32_t flags)
915 {
916 	struct gpiobus_softc *sc = GPIOBUS_SOFTC(dev);
917 	struct gpiobus_ivar *devi = GPIOBUS_IVAR(child);
918 	uint32_t caps;
919 
920 	if (pin >= devi->npins)
921 		return (EINVAL);
922 	if (GPIO_PIN_GETCAPS(sc->sc_dev, devi->pins[pin], &caps) != 0)
923 		return (EINVAL);
924 	if (gpio_check_flags(caps, flags) != 0)
925 		return (EINVAL);
926 
927 	return (GPIO_PIN_SETFLAGS(sc->sc_dev, devi->pins[pin], flags));
928 }
929 
930 static int
931 gpiobus_pin_getflags(device_t dev, device_t child, uint32_t pin,
932     uint32_t *flags)
933 {
934 	struct gpiobus_softc *sc = GPIOBUS_SOFTC(dev);
935 	struct gpiobus_ivar *devi = GPIOBUS_IVAR(child);
936 
937 	if (pin >= devi->npins)
938 		return (EINVAL);
939 
940 	return GPIO_PIN_GETFLAGS(sc->sc_dev, devi->pins[pin], flags);
941 }
942 
943 static int
944 gpiobus_pin_getcaps(device_t dev, device_t child, uint32_t pin,
945     uint32_t *caps)
946 {
947 	struct gpiobus_softc *sc = GPIOBUS_SOFTC(dev);
948 	struct gpiobus_ivar *devi = GPIOBUS_IVAR(child);
949 
950 	if (pin >= devi->npins)
951 		return (EINVAL);
952 
953 	return GPIO_PIN_GETCAPS(sc->sc_dev, devi->pins[pin], caps);
954 }
955 
956 static int
957 gpiobus_pin_set(device_t dev, device_t child, uint32_t pin,
958     unsigned int value)
959 {
960 	struct gpiobus_softc *sc = GPIOBUS_SOFTC(dev);
961 	struct gpiobus_ivar *devi = GPIOBUS_IVAR(child);
962 
963 	if (pin >= devi->npins)
964 		return (EINVAL);
965 
966 	return GPIO_PIN_SET(sc->sc_dev, devi->pins[pin], value);
967 }
968 
969 static int
970 gpiobus_pin_get(device_t dev, device_t child, uint32_t pin,
971     unsigned int *value)
972 {
973 	struct gpiobus_softc *sc = GPIOBUS_SOFTC(dev);
974 	struct gpiobus_ivar *devi = GPIOBUS_IVAR(child);
975 
976 	if (pin >= devi->npins)
977 		return (EINVAL);
978 
979 	return GPIO_PIN_GET(sc->sc_dev, devi->pins[pin], value);
980 }
981 
982 static int
983 gpiobus_pin_toggle(device_t dev, device_t child, uint32_t pin)
984 {
985 	struct gpiobus_softc *sc = GPIOBUS_SOFTC(dev);
986 	struct gpiobus_ivar *devi = GPIOBUS_IVAR(child);
987 
988 	if (pin >= devi->npins)
989 		return (EINVAL);
990 
991 	return GPIO_PIN_TOGGLE(sc->sc_dev, devi->pins[pin]);
992 }
993 
994 static int
995 gpiobus_pin_getname(device_t dev, uint32_t pin, char *name)
996 {
997 	struct gpiobus_softc *sc;
998 
999 	sc = GPIOBUS_SOFTC(dev);
1000 	if (pin > sc->sc_npins)
1001 		return (EINVAL);
1002 	/* Did we have a name for this pin ? */
1003 	if (sc->sc_pins[pin].name != NULL) {
1004 		memcpy(name, sc->sc_pins[pin].name, GPIOMAXNAME);
1005 		return (0);
1006 	}
1007 
1008 	/* Return the default pin name. */
1009 	return (GPIO_PIN_GETNAME(device_get_parent(dev), pin, name));
1010 }
1011 
1012 static int
1013 gpiobus_pin_setname(device_t dev, uint32_t pin, const char *name)
1014 {
1015 	struct gpiobus_softc *sc;
1016 
1017 	sc = GPIOBUS_SOFTC(dev);
1018 	if (pin > sc->sc_npins)
1019 		return (EINVAL);
1020 	if (name == NULL)
1021 		return (EINVAL);
1022 	/* Save the pin name. */
1023 	if (sc->sc_pins[pin].name == NULL)
1024 		sc->sc_pins[pin].name = malloc(GPIOMAXNAME, M_DEVBUF,
1025 		    M_WAITOK | M_ZERO);
1026 	strlcpy(sc->sc_pins[pin].name, name, GPIOMAXNAME);
1027 
1028 	return (0);
1029 }
1030 
1031 static device_method_t gpiobus_methods[] = {
1032 	/* Device interface */
1033 	DEVMETHOD(device_probe,		gpiobus_probe),
1034 	DEVMETHOD(device_attach,	gpiobus_attach),
1035 	DEVMETHOD(device_detach,	gpiobus_detach),
1036 	DEVMETHOD(device_shutdown,	bus_generic_shutdown),
1037 	DEVMETHOD(device_suspend,	gpiobus_suspend),
1038 	DEVMETHOD(device_resume,	gpiobus_resume),
1039 
1040 	/* Bus interface */
1041 	DEVMETHOD(bus_setup_intr,	bus_generic_setup_intr),
1042 	DEVMETHOD(bus_config_intr,	bus_generic_config_intr),
1043 	DEVMETHOD(bus_teardown_intr,	bus_generic_teardown_intr),
1044 	DEVMETHOD(bus_delete_resource,	bus_generic_rl_delete_resource),
1045 	DEVMETHOD(bus_get_resource,	bus_generic_rl_get_resource),
1046 	DEVMETHOD(bus_set_resource,	bus_generic_rl_set_resource),
1047 	DEVMETHOD(bus_alloc_resource,	gpiobus_alloc_resource),
1048 	DEVMETHOD(bus_release_resource,	bus_generic_rman_release_resource),
1049 	DEVMETHOD(bus_activate_resource,	bus_generic_rman_activate_resource),
1050 	DEVMETHOD(bus_deactivate_resource,	bus_generic_rman_deactivate_resource),
1051 	DEVMETHOD(bus_get_resource_list,	gpiobus_get_resource_list),
1052 	DEVMETHOD(bus_get_rman,		gpiobus_get_rman),
1053 	DEVMETHOD(bus_add_child,	gpiobus_add_child),
1054 	DEVMETHOD(bus_child_deleted,	gpiobus_child_deleted),
1055 	DEVMETHOD(bus_rescan,		gpiobus_rescan),
1056 	DEVMETHOD(bus_probe_nomatch,	gpiobus_probe_nomatch),
1057 	DEVMETHOD(bus_print_child,	gpiobus_print_child),
1058 	DEVMETHOD(bus_child_location,	gpiobus_child_location),
1059 	DEVMETHOD(bus_hinted_child,	gpiobus_hinted_child),
1060 	DEVMETHOD(bus_read_ivar,        gpiobus_read_ivar),
1061 	DEVMETHOD(bus_write_ivar,       gpiobus_write_ivar),
1062 
1063 	/* GPIO protocol */
1064 	DEVMETHOD(gpiobus_acquire_bus,	gpiobus_acquire_bus),
1065 	DEVMETHOD(gpiobus_release_bus,	gpiobus_release_bus),
1066 	DEVMETHOD(gpiobus_pin_getflags,	gpiobus_pin_getflags),
1067 	DEVMETHOD(gpiobus_pin_getcaps,	gpiobus_pin_getcaps),
1068 	DEVMETHOD(gpiobus_pin_setflags,	gpiobus_pin_setflags),
1069 	DEVMETHOD(gpiobus_pin_get,	gpiobus_pin_get),
1070 	DEVMETHOD(gpiobus_pin_set,	gpiobus_pin_set),
1071 	DEVMETHOD(gpiobus_pin_toggle,	gpiobus_pin_toggle),
1072 	DEVMETHOD(gpiobus_pin_getname,	gpiobus_pin_getname),
1073 	DEVMETHOD(gpiobus_pin_setname,	gpiobus_pin_setname),
1074 
1075 	DEVMETHOD_END
1076 };
1077 
1078 driver_t gpiobus_driver = {
1079 	"gpiobus",
1080 	gpiobus_methods,
1081 	sizeof(struct gpiobus_softc)
1082 };
1083 
1084 EARLY_DRIVER_MODULE(gpiobus, gpio, gpiobus_driver, 0, 0,
1085     BUS_PASS_BUS + BUS_PASS_ORDER_MIDDLE);
1086 MODULE_VERSION(gpiobus, 1);
1087