xref: /freebsd/sys/arm/freescale/imx/imx_gpio.c (revision 1f4bcc459a76b7aa664f3fd557684cd0ba6da352)
1 /*-
2  * Copyright (c) 2012, 2013 The FreeBSD Foundation
3  * All rights reserved.
4  *
5  * This software was developed by Oleksandr Rybalko under sponsorship
6  * from the FreeBSD Foundation.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1.	Redistributions of source code must retain the above copyright
12  *	notice, this list of conditions and the following disclaimer.
13  * 2.	Redistributions in binary form must reproduce the above copyright
14  *	notice, this list of conditions and the following disclaimer in the
15  *	documentation and/or other materials provided with the distribution.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  */
29 
30 /*
31  * Freescale i.MX515 GPIO driver.
32  */
33 
34 #include <sys/cdefs.h>
35 __FBSDID("$FreeBSD$");
36 
37 #include "opt_platform.h"
38 
39 #include <sys/param.h>
40 #include <sys/systm.h>
41 #include <sys/bus.h>
42 
43 #include <sys/kernel.h>
44 #include <sys/module.h>
45 #include <sys/rman.h>
46 #include <sys/lock.h>
47 #include <sys/mutex.h>
48 #include <sys/gpio.h>
49 #include <sys/proc.h>
50 
51 #include <machine/bus.h>
52 #include <machine/intr.h>
53 #include <machine/resource.h>
54 
55 #include <dev/fdt/fdt_common.h>
56 #include <dev/gpio/gpiobusvar.h>
57 #include <dev/ofw/openfirm.h>
58 #include <dev/ofw/ofw_bus.h>
59 #include <dev/ofw/ofw_bus_subr.h>
60 
61 #include "gpio_if.h"
62 
63 #ifdef ARM_INTRNG
64 #include "pic_if.h"
65 #endif
66 
67 #define	WRITE4(_sc, _r, _v)						\
68 	    bus_space_write_4((_sc)->sc_iot, (_sc)->sc_ioh, (_r), (_v))
69 #define	READ4(_sc, _r)							\
70 	    bus_space_read_4((_sc)->sc_iot, (_sc)->sc_ioh, (_r))
71 #define	SET4(_sc, _r, _m)						\
72 	    WRITE4((_sc), (_r), READ4((_sc), (_r)) | (_m))
73 #define	CLEAR4(_sc, _r, _m)						\
74 	    WRITE4((_sc), (_r), READ4((_sc), (_r)) & ~(_m))
75 
76 /* Registers definition for Freescale i.MX515 GPIO controller */
77 
78 #define	IMX_GPIO_DR_REG		0x000 /* Pin Data */
79 #define	IMX_GPIO_OE_REG		0x004 /* Set Pin Output */
80 #define	IMX_GPIO_PSR_REG	0x008 /* Pad Status */
81 #define	IMX_GPIO_ICR1_REG	0x00C /* Interrupt Configuration */
82 #define	IMX_GPIO_ICR2_REG	0x010 /* Interrupt Configuration */
83 #define		GPIO_ICR_COND_LOW	0
84 #define		GPIO_ICR_COND_HIGH	1
85 #define		GPIO_ICR_COND_RISE	2
86 #define		GPIO_ICR_COND_FALL	3
87 #define	IMX_GPIO_IMR_REG	0x014 /* Interrupt Mask Register */
88 #define	IMX_GPIO_ISR_REG	0x018 /* Interrupt Status Register */
89 #define	IMX_GPIO_EDGE_REG	0x01C /* Edge Detect Register */
90 
91 #define	DEFAULT_CAPS	(GPIO_PIN_INPUT | GPIO_PIN_OUTPUT)
92 #define	NGPIO		32
93 
94 struct imx51_gpio_softc {
95 	device_t		dev;
96 	device_t		sc_busdev;
97 	struct mtx		sc_mtx;
98 	struct resource		*sc_res[3]; /* 1 x mem, 2 x IRQ */
99 	void			*gpio_ih[2];
100 	bus_space_tag_t		sc_iot;
101 	bus_space_handle_t	sc_ioh;
102 	int			gpio_npins;
103 	struct gpio_pin		gpio_pins[NGPIO];
104 	struct intr_irqsrc 	*gpio_pic_irqsrc[NGPIO];
105 };
106 
107 static struct ofw_compat_data compat_data[] = {
108 	{"fsl,imx6q-gpio",  1},
109 	{"fsl,imx53-gpio",  1},
110 	{"fsl,imx51-gpio",  1},
111 	{NULL,	            0}
112 };
113 
114 static struct resource_spec imx_gpio_spec[] = {
115 	{ SYS_RES_MEMORY,	0,	RF_ACTIVE },
116 	{ SYS_RES_IRQ,		0,	RF_ACTIVE },
117 	{ SYS_RES_IRQ,		1,	RF_ACTIVE },
118 	{ -1, 0 }
119 };
120 
121 /*
122  * Helpers
123  */
124 static void imx51_gpio_pin_configure(struct imx51_gpio_softc *,
125     struct gpio_pin *, uint32_t);
126 
127 /*
128  * Driver stuff
129  */
130 static int imx51_gpio_probe(device_t);
131 static int imx51_gpio_attach(device_t);
132 static int imx51_gpio_detach(device_t);
133 
134 /*
135  * GPIO interface
136  */
137 static device_t imx51_gpio_get_bus(device_t);
138 static int imx51_gpio_pin_max(device_t, int *);
139 static int imx51_gpio_pin_getcaps(device_t, uint32_t, uint32_t *);
140 static int imx51_gpio_pin_getflags(device_t, uint32_t, uint32_t *);
141 static int imx51_gpio_pin_getname(device_t, uint32_t, char *);
142 static int imx51_gpio_pin_setflags(device_t, uint32_t, uint32_t);
143 static int imx51_gpio_pin_set(device_t, uint32_t, unsigned int);
144 static int imx51_gpio_pin_get(device_t, uint32_t, unsigned int *);
145 static int imx51_gpio_pin_toggle(device_t, uint32_t pin);
146 
147 #ifdef ARM_INTRNG
148 /*
149  * this is teardown_intr
150  */
151 static void
152 gpio_pic_disable_intr(device_t dev, struct intr_irqsrc *isrc)
153 {
154 	struct imx51_gpio_softc *sc;
155 	u_int irq;
156 
157 	sc = device_get_softc(dev);
158 	irq = isrc->isrc_data;
159 
160 	// XXX Not sure this is necessary
161 	mtx_lock_spin(&sc->sc_mtx);
162 	CLEAR4(sc, IMX_GPIO_IMR_REG, (1U << irq));
163 	WRITE4(sc, IMX_GPIO_ISR_REG, (1U << irq));
164 	mtx_unlock_spin(&sc->sc_mtx);
165 }
166 
167 /*
168  * this is mask_intr
169  */
170 static void
171 gpio_pic_disable_source(device_t dev, struct intr_irqsrc *isrc)
172 {
173 	struct imx51_gpio_softc *sc;
174 
175 	sc = device_get_softc(dev);
176 
177 	mtx_lock_spin(&sc->sc_mtx);
178 	CLEAR4(sc, IMX_GPIO_IMR_REG, (1U << isrc->isrc_data));
179 	mtx_unlock_spin(&sc->sc_mtx);
180 }
181 
182 /*
183  * this is setup_intr
184  */
185 static void
186 gpio_pic_enable_intr(device_t dev, struct intr_irqsrc *isrc)
187 {
188 	struct imx51_gpio_softc *sc;
189 	int icfg;
190 	u_int irq, reg, shift, wrk;
191 
192 	sc = device_get_softc(dev);
193 
194 	if (isrc->isrc_trig == INTR_TRIGGER_LEVEL) {
195 		if (isrc->isrc_pol == INTR_POLARITY_LOW)
196 			icfg = GPIO_ICR_COND_LOW;
197 		else
198 			icfg = GPIO_ICR_COND_HIGH;
199 	} else {
200 		if (isrc->isrc_pol == INTR_POLARITY_HIGH)
201 			icfg = GPIO_ICR_COND_FALL;
202 		else
203 			icfg = GPIO_ICR_COND_RISE;
204 	}
205 
206 	irq = isrc->isrc_data;
207 	if (irq < 16) {
208 		reg = IMX_GPIO_ICR1_REG;
209 		shift = 2 * irq;
210 	} else {
211 		reg = IMX_GPIO_ICR2_REG;
212 		shift = 2 * (irq - 16);
213 	}
214 
215 	mtx_lock_spin(&sc->sc_mtx);
216 	CLEAR4(sc, IMX_GPIO_IMR_REG, (1U << irq));
217 	WRITE4(sc, IMX_GPIO_ISR_REG, (1U << irq));
218 	wrk = READ4(sc, reg);
219 	wrk &= ~(0x03 << shift);
220 	wrk |= icfg << shift;
221 	WRITE4(sc, reg, wrk);
222 	mtx_unlock_spin(&sc->sc_mtx);
223 }
224 
225 /*
226  * this is unmask_intr
227  */
228 static void
229 gpio_pic_enable_source(device_t dev, struct intr_irqsrc *isrc)
230 {
231 	struct imx51_gpio_softc *sc;
232 
233 	sc = device_get_softc(dev);
234 
235 	mtx_lock_spin(&sc->sc_mtx);
236 	SET4(sc, IMX_GPIO_IMR_REG, (1U << isrc->isrc_data));
237 	mtx_unlock_spin(&sc->sc_mtx);
238 }
239 
240 static void
241 gpio_pic_post_filter(device_t dev, struct intr_irqsrc *isrc)
242 {
243 	struct imx51_gpio_softc *sc;
244 
245 	sc = device_get_softc(dev);
246 
247 	arm_irq_memory_barrier(0);
248         /* EOI.  W1C reg so no r-m-w, no locking needed. */
249 	WRITE4(sc, IMX_GPIO_ISR_REG, (1U << isrc->isrc_data));
250 }
251 
252 static void
253 gpio_pic_post_ithread(device_t dev, struct intr_irqsrc *isrc)
254 {
255 
256 	arm_irq_memory_barrier(0);
257 	gpio_pic_enable_source(dev, isrc);
258 }
259 
260 static void
261 gpio_pic_pre_ithread(device_t dev, struct intr_irqsrc *isrc)
262 {
263 
264 	gpio_pic_disable_source(dev, isrc);
265 }
266 
267 /*
268  * intrng calls this to make a new isrc known to us.
269  */
270 static int
271 gpio_pic_register(device_t dev, struct intr_irqsrc *isrc, boolean_t *is_percpu)
272 {
273 	struct imx51_gpio_softc *sc;
274 	u_int irq, tripol;
275 
276 	sc = device_get_softc(dev);
277 
278 	/*
279 	 * From devicetree/bindings/gpio/fsl-imx-gpio.txt:
280 	 *  #interrupt-cells:  2. The first cell is the GPIO number. The second
281 	 *  cell bits[3:0] is used to specify trigger type and level flags:
282 	 *    1 = low-to-high edge triggered.
283 	 *    2 = high-to-low edge triggered.
284 	 *    4 = active high level-sensitive.
285 	 *    8 = active low level-sensitive.
286          * We can do any single one of these modes, but nothing in combo.
287 	 */
288 
289 	if (isrc->isrc_ncells != 2) {
290 		device_printf(sc->dev, "Invalid #interrupt-cells");
291 		return (EINVAL);
292 	}
293 
294 	irq = isrc->isrc_cells[0];
295 	tripol = isrc->isrc_cells[1];
296 	if (irq >= sc->gpio_npins) {
297 		device_printf(sc->dev, "Invalid interrupt number %d", irq);
298 		return (EINVAL);
299 	}
300 	switch (tripol)
301 	{
302 	case 1:
303 		isrc->isrc_trig = INTR_TRIGGER_EDGE;
304 		isrc->isrc_pol  = INTR_POLARITY_HIGH;
305 		break;
306 	case 2:
307 		isrc->isrc_trig = INTR_TRIGGER_EDGE;
308 		isrc->isrc_pol  = INTR_POLARITY_LOW;
309 		break;
310 	case 4:
311 		isrc->isrc_trig = INTR_TRIGGER_LEVEL;
312 		isrc->isrc_pol  = INTR_POLARITY_HIGH;
313 		break;
314 	case 8:
315 		isrc->isrc_trig = INTR_TRIGGER_LEVEL;
316 		isrc->isrc_pol  = INTR_POLARITY_LOW;
317 		break;
318 	default:
319 		device_printf(sc->dev, "unsupported trigger/polarity 0x%2x\n",
320 		    tripol);
321 		return (ENOTSUP);
322 	}
323 	isrc->isrc_nspc_type = INTR_IRQ_NSPC_PLAIN;
324 	isrc->isrc_nspc_num = irq;
325 
326 	/*
327 	 * 1. The link between ISRC and controller must be set atomically.
328 	 * 2. Just do things only once in rare case when consumers
329 	 *    of shared interrupt came here at the same moment.
330 	 */
331 	mtx_lock_spin(&sc->sc_mtx);
332 	if (sc->gpio_pic_irqsrc[irq] != NULL) {
333 		mtx_unlock_spin(&sc->sc_mtx);
334 		return (sc->gpio_pic_irqsrc[irq] == isrc ? 0 : EEXIST);
335 	}
336 	sc->gpio_pic_irqsrc[irq] = isrc;
337 	isrc->isrc_data = irq;
338 	mtx_unlock_spin(&sc->sc_mtx);
339 
340 	intr_irq_set_name(isrc, "%s,%u", device_get_nameunit(sc->dev), irq);
341 	return (0);
342 }
343 
344 static int
345 gpio_pic_unregister(device_t dev, struct intr_irqsrc *isrc)
346 {
347 	struct imx51_gpio_softc *sc;
348 	u_int irq;
349 
350 	sc = device_get_softc(dev);
351 
352 	mtx_lock_spin(&sc->sc_mtx);
353 	irq = isrc->isrc_data;
354 	if (sc->gpio_pic_irqsrc[irq] != isrc) {
355 		mtx_unlock_spin(&sc->sc_mtx);
356 		return (sc->gpio_pic_irqsrc[irq] == NULL ? 0 : EINVAL);
357 	}
358 	sc->gpio_pic_irqsrc[irq] = NULL;
359 	isrc->isrc_data = 0;
360 	mtx_unlock_spin(&sc->sc_mtx);
361 
362 	intr_irq_set_name(isrc, "");
363 	return (0);
364 }
365 
366 static int
367 gpio_pic_filter(void *arg)
368 {
369 	struct imx51_gpio_softc *sc;
370 	uint32_t i, interrupts;
371 
372 	sc = arg;
373 	mtx_lock_spin(&sc->sc_mtx);
374 	interrupts = READ4(sc, IMX_GPIO_ISR_REG) & READ4(sc, IMX_GPIO_IMR_REG);
375 	mtx_unlock_spin(&sc->sc_mtx);
376 
377 	for (i = 0; interrupts != 0; i++, interrupts >>= 1) {
378 		if ((interrupts & 0x1) == 0)
379 			continue;
380 		if (sc->gpio_pic_irqsrc[i])
381 			intr_irq_dispatch(sc->gpio_pic_irqsrc[i], curthread->td_intr_frame);
382 		else
383 			device_printf(sc->dev, "spurious interrupt %d\n", i);
384 	}
385 
386 	return (FILTER_HANDLED);
387 }
388 #endif
389 
390 /*
391  *
392  */
393 static void
394 imx51_gpio_pin_configure(struct imx51_gpio_softc *sc, struct gpio_pin *pin,
395     unsigned int flags)
396 {
397 
398 	mtx_lock_spin(&sc->sc_mtx);
399 
400 	/*
401 	 * Manage input/output
402 	 */
403 	if (flags & (GPIO_PIN_INPUT|GPIO_PIN_OUTPUT)) {
404 		pin->gp_flags &= ~(GPIO_PIN_INPUT|GPIO_PIN_OUTPUT);
405 		if (flags & GPIO_PIN_OUTPUT) {
406 			pin->gp_flags |= GPIO_PIN_OUTPUT;
407 			SET4(sc, IMX_GPIO_OE_REG, (1U << pin->gp_pin));
408 		}
409 		else {
410 			pin->gp_flags |= GPIO_PIN_INPUT;
411 			CLEAR4(sc, IMX_GPIO_OE_REG, (1U << pin->gp_pin));
412 		}
413 	}
414 
415 	mtx_unlock_spin(&sc->sc_mtx);
416 }
417 
418 static device_t
419 imx51_gpio_get_bus(device_t dev)
420 {
421 	struct imx51_gpio_softc *sc;
422 
423 	sc = device_get_softc(dev);
424 
425 	return (sc->sc_busdev);
426 }
427 
428 static int
429 imx51_gpio_pin_max(device_t dev, int *maxpin)
430 {
431 	struct imx51_gpio_softc *sc;
432 
433 	sc = device_get_softc(dev);
434 	*maxpin = sc->gpio_npins - 1;
435 
436 	return (0);
437 }
438 
439 static int
440 imx51_gpio_pin_getcaps(device_t dev, uint32_t pin, uint32_t *caps)
441 {
442 	struct imx51_gpio_softc *sc;
443 	int i;
444 
445 	sc = device_get_softc(dev);
446 	for (i = 0; i < sc->gpio_npins; i++) {
447 		if (sc->gpio_pins[i].gp_pin == pin)
448 			break;
449 	}
450 
451 	if (i >= sc->gpio_npins)
452 		return (EINVAL);
453 
454 	mtx_lock_spin(&sc->sc_mtx);
455 	*caps = sc->gpio_pins[i].gp_caps;
456 	mtx_unlock_spin(&sc->sc_mtx);
457 
458 	return (0);
459 }
460 
461 static int
462 imx51_gpio_pin_getflags(device_t dev, uint32_t pin, uint32_t *flags)
463 {
464 	struct imx51_gpio_softc *sc;
465 	int i;
466 
467 	sc = device_get_softc(dev);
468 	for (i = 0; i < sc->gpio_npins; i++) {
469 		if (sc->gpio_pins[i].gp_pin == pin)
470 			break;
471 	}
472 
473 	if (i >= sc->gpio_npins)
474 		return (EINVAL);
475 
476 	mtx_lock_spin(&sc->sc_mtx);
477 	*flags = sc->gpio_pins[i].gp_flags;
478 	mtx_unlock_spin(&sc->sc_mtx);
479 
480 	return (0);
481 }
482 
483 static int
484 imx51_gpio_pin_getname(device_t dev, uint32_t pin, char *name)
485 {
486 	struct imx51_gpio_softc *sc;
487 	int i;
488 
489 	sc = device_get_softc(dev);
490 	for (i = 0; i < sc->gpio_npins; i++) {
491 		if (sc->gpio_pins[i].gp_pin == pin)
492 			break;
493 	}
494 
495 	if (i >= sc->gpio_npins)
496 		return (EINVAL);
497 
498 	mtx_lock_spin(&sc->sc_mtx);
499 	memcpy(name, sc->gpio_pins[i].gp_name, GPIOMAXNAME);
500 	mtx_unlock_spin(&sc->sc_mtx);
501 
502 	return (0);
503 }
504 
505 static int
506 imx51_gpio_pin_setflags(device_t dev, uint32_t pin, uint32_t flags)
507 {
508 	struct imx51_gpio_softc *sc;
509 	int i;
510 
511 	sc = device_get_softc(dev);
512 	for (i = 0; i < sc->gpio_npins; i++) {
513 		if (sc->gpio_pins[i].gp_pin == pin)
514 			break;
515 	}
516 
517 	if (i >= sc->gpio_npins)
518 		return (EINVAL);
519 
520 	imx51_gpio_pin_configure(sc, &sc->gpio_pins[i], flags);
521 
522 	return (0);
523 }
524 
525 static int
526 imx51_gpio_pin_set(device_t dev, uint32_t pin, unsigned int value)
527 {
528 	struct imx51_gpio_softc *sc;
529 	int i;
530 
531 	sc = device_get_softc(dev);
532 	for (i = 0; i < sc->gpio_npins; i++) {
533 		if (sc->gpio_pins[i].gp_pin == pin)
534 			break;
535 	}
536 
537 	if (i >= sc->gpio_npins)
538 		return (EINVAL);
539 
540 	mtx_lock_spin(&sc->sc_mtx);
541 	if (value)
542 		SET4(sc, IMX_GPIO_DR_REG, (1U << i));
543 	else
544 		CLEAR4(sc, IMX_GPIO_DR_REG, (1U << i));
545 	mtx_unlock_spin(&sc->sc_mtx);
546 
547 	return (0);
548 }
549 
550 static int
551 imx51_gpio_pin_get(device_t dev, uint32_t pin, unsigned int *val)
552 {
553 	struct imx51_gpio_softc *sc;
554 	int i;
555 
556 	sc = device_get_softc(dev);
557 	for (i = 0; i < sc->gpio_npins; i++) {
558 		if (sc->gpio_pins[i].gp_pin == pin)
559 			break;
560 	}
561 
562 	if (i >= sc->gpio_npins)
563 		return (EINVAL);
564 
565 	mtx_lock_spin(&sc->sc_mtx);
566 	*val = (READ4(sc, IMX_GPIO_DR_REG) >> i) & 1;
567 	mtx_unlock_spin(&sc->sc_mtx);
568 
569 	return (0);
570 }
571 
572 static int
573 imx51_gpio_pin_toggle(device_t dev, uint32_t pin)
574 {
575 	struct imx51_gpio_softc *sc;
576 	int i;
577 
578 	sc = device_get_softc(dev);
579 	for (i = 0; i < sc->gpio_npins; i++) {
580 		if (sc->gpio_pins[i].gp_pin == pin)
581 			break;
582 	}
583 
584 	if (i >= sc->gpio_npins)
585 		return (EINVAL);
586 
587 	mtx_lock_spin(&sc->sc_mtx);
588 	WRITE4(sc, IMX_GPIO_DR_REG,
589 	    (READ4(sc, IMX_GPIO_DR_REG) ^ (1U << i)));
590 	mtx_unlock_spin(&sc->sc_mtx);
591 
592 	return (0);
593 }
594 
595 static int
596 imx51_gpio_probe(device_t dev)
597 {
598 
599 	if (!ofw_bus_status_okay(dev))
600 		return (ENXIO);
601 
602 	if (ofw_bus_search_compatible(dev, compat_data)->ocd_data != 0) {
603 		device_set_desc(dev, "Freescale i.MX GPIO Controller");
604 		return (BUS_PROBE_DEFAULT);
605 	}
606 
607 	return (ENXIO);
608 }
609 
610 static int
611 imx51_gpio_attach(device_t dev)
612 {
613 	struct imx51_gpio_softc *sc;
614 	int i, irq, unit;
615 
616 	sc = device_get_softc(dev);
617 	sc->dev = dev;
618 	sc->gpio_npins = NGPIO;
619 
620 	mtx_init(&sc->sc_mtx, device_get_nameunit(sc->dev), NULL, MTX_SPIN);
621 
622 	if (bus_alloc_resources(dev, imx_gpio_spec, sc->sc_res)) {
623 		device_printf(dev, "could not allocate resources\n");
624 		bus_release_resources(dev, imx_gpio_spec, sc->sc_res);
625 		mtx_destroy(&sc->sc_mtx);
626 		return (ENXIO);
627 	}
628 
629 	sc->sc_iot = rman_get_bustag(sc->sc_res[0]);
630 	sc->sc_ioh = rman_get_bushandle(sc->sc_res[0]);
631 	/*
632 	 * Mask off all interrupts in hardware, then set up interrupt handling.
633 	 */
634 	WRITE4(sc, IMX_GPIO_IMR_REG, 0);
635 	for (irq = 0; irq < 2; irq++) {
636 #ifdef ARM_INTRNG
637 		if ((bus_setup_intr(dev, sc->sc_res[1 + irq], INTR_TYPE_CLK,
638 		    gpio_pic_filter, NULL, sc, &sc->gpio_ih[irq]))) {
639 			device_printf(dev,
640 			    "WARNING: unable to register interrupt handler\n");
641 			imx51_gpio_detach(dev);
642 			return (ENXIO);
643 		}
644 #endif
645 	}
646 
647 	unit = device_get_unit(dev);
648 	for (i = 0; i < sc->gpio_npins; i++) {
649  		sc->gpio_pins[i].gp_pin = i;
650  		sc->gpio_pins[i].gp_caps = DEFAULT_CAPS;
651  		sc->gpio_pins[i].gp_flags =
652  		    (READ4(sc, IMX_GPIO_OE_REG) & (1U << i)) ? GPIO_PIN_OUTPUT :
653  		    GPIO_PIN_INPUT;
654  		snprintf(sc->gpio_pins[i].gp_name, GPIOMAXNAME,
655  		    "imx_gpio%d.%d", unit, i);
656 	}
657 
658 #ifdef ARM_INTRNG
659 	intr_pic_register(dev, OF_xref_from_node(ofw_bus_get_node(dev)));
660 #endif
661 	sc->sc_busdev = gpiobus_attach_bus(dev);
662 
663 	if (sc->sc_busdev == NULL) {
664 		imx51_gpio_detach(dev);
665 		return (ENXIO);
666 	}
667 
668 	return (0);
669 }
670 
671 static int
672 imx51_gpio_detach(device_t dev)
673 {
674 	int irq;
675 	struct imx51_gpio_softc *sc;
676 
677 	sc = device_get_softc(dev);
678 
679 	gpiobus_detach_bus(dev);
680 	for (irq = 1; irq <= 2; irq++) {
681 		if (sc->gpio_ih[irq])
682 			bus_teardown_intr(dev, sc->sc_res[irq], sc->gpio_ih[irq]);
683 	}
684 	bus_release_resources(dev, imx_gpio_spec, sc->sc_res);
685 	mtx_destroy(&sc->sc_mtx);
686 
687 	return(0);
688 }
689 
690 static device_method_t imx51_gpio_methods[] = {
691 	DEVMETHOD(device_probe,		imx51_gpio_probe),
692 	DEVMETHOD(device_attach,	imx51_gpio_attach),
693 	DEVMETHOD(device_detach,	imx51_gpio_detach),
694 
695 #ifdef ARM_INTRNG
696 	/* Interrupt controller interface */
697 	DEVMETHOD(pic_disable_intr,	gpio_pic_disable_intr),
698 	DEVMETHOD(pic_disable_source,	gpio_pic_disable_source),
699 	DEVMETHOD(pic_enable_intr,	gpio_pic_enable_intr),
700 	DEVMETHOD(pic_enable_source,	gpio_pic_enable_source),
701 	DEVMETHOD(pic_post_filter,	gpio_pic_post_filter),
702 	DEVMETHOD(pic_post_ithread,	gpio_pic_post_ithread),
703 	DEVMETHOD(pic_pre_ithread,	gpio_pic_pre_ithread),
704 	DEVMETHOD(pic_register,		gpio_pic_register),
705 	DEVMETHOD(pic_unregister,	gpio_pic_unregister),
706 #endif
707 
708 	/* GPIO protocol */
709 	DEVMETHOD(gpio_get_bus,		imx51_gpio_get_bus),
710 	DEVMETHOD(gpio_pin_max,		imx51_gpio_pin_max),
711 	DEVMETHOD(gpio_pin_getname,	imx51_gpio_pin_getname),
712 	DEVMETHOD(gpio_pin_getflags,	imx51_gpio_pin_getflags),
713 	DEVMETHOD(gpio_pin_getcaps,	imx51_gpio_pin_getcaps),
714 	DEVMETHOD(gpio_pin_setflags,	imx51_gpio_pin_setflags),
715 	DEVMETHOD(gpio_pin_get,		imx51_gpio_pin_get),
716 	DEVMETHOD(gpio_pin_set,		imx51_gpio_pin_set),
717 	DEVMETHOD(gpio_pin_toggle,	imx51_gpio_pin_toggle),
718 	{0, 0},
719 };
720 
721 static driver_t imx51_gpio_driver = {
722 	"gpio",
723 	imx51_gpio_methods,
724 	sizeof(struct imx51_gpio_softc),
725 };
726 static devclass_t imx51_gpio_devclass;
727 
728 DRIVER_MODULE(imx51_gpio, simplebus, imx51_gpio_driver, imx51_gpio_devclass,
729     0, 0);
730