bcm2835_gpio.c revision 278786 
1/*-
2 * Copyright (c) 2012 Oleksandr Tymoshenko <gonzo@freebsd.org>
3 * Copyright (c) 2012 Luiz Otavio O Souza.
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 *    notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 *    notice, this list of conditions and the following disclaimer in the
13 *    documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25 * SUCH DAMAGE.
26 *
27 */
28#include <sys/cdefs.h>
29__FBSDID("$FreeBSD: stable/10/sys/arm/broadcom/bcm2835/bcm2835_gpio.c 278786 2015-02-14 21:16:19Z loos $");
30
31#include <sys/param.h>
32#include <sys/systm.h>
33#include <sys/bus.h>
34
35#include <sys/kernel.h>
36#include <sys/module.h>
37#include <sys/rman.h>
38#include <sys/lock.h>
39#include <sys/mutex.h>
40#include <sys/gpio.h>
41#include <sys/sysctl.h>
42
43#include <machine/bus.h>
44#include <machine/cpu.h>
45#include <machine/cpufunc.h>
46#include <machine/resource.h>
47#include <machine/fdt.h>
48#include <machine/intr.h>
49
50#include <dev/fdt/fdt_common.h>
51#include <dev/ofw/ofw_bus.h>
52#include <dev/ofw/ofw_bus_subr.h>
53
54#include <arm/broadcom/bcm2835/bcm2835_gpio.h>
55
56#include "gpio_if.h"
57
58#ifdef DEBUG
59#define dprintf(fmt, args...) do { printf("%s(): ", __func__);   \
60    printf(fmt,##args); } while (0)
61#else
62#define dprintf(fmt, args...)
63#endif
64
65#define	BCM_GPIO_PINS		54
66#define	BCM_GPIO_DEFAULT_CAPS	(GPIO_PIN_INPUT | GPIO_PIN_OUTPUT |	\
67    GPIO_PIN_PULLUP | GPIO_PIN_PULLDOWN)
68
69struct bcm_gpio_sysctl {
70	struct bcm_gpio_softc	*sc;
71	uint32_t		pin;
72};
73
74struct bcm_gpio_softc {
75	device_t		sc_dev;
76	struct mtx		sc_mtx;
77	struct resource *	sc_mem_res;
78	struct resource *	sc_irq_res;
79	bus_space_tag_t		sc_bst;
80	bus_space_handle_t	sc_bsh;
81	void *			sc_intrhand;
82	int			sc_gpio_npins;
83	int			sc_ro_npins;
84	int			sc_ro_pins[BCM_GPIO_PINS];
85	struct gpio_pin		sc_gpio_pins[BCM_GPIO_PINS];
86	struct bcm_gpio_sysctl	sc_sysctl[BCM_GPIO_PINS];
87};
88
89enum bcm_gpio_pud {
90	BCM_GPIO_NONE,
91	BCM_GPIO_PULLDOWN,
92	BCM_GPIO_PULLUP,
93};
94
95#define	BCM_GPIO_LOCK(_sc)	mtx_lock(&_sc->sc_mtx)
96#define	BCM_GPIO_UNLOCK(_sc)	mtx_unlock(&_sc->sc_mtx)
97#define	BCM_GPIO_LOCK_ASSERT(_sc)	mtx_assert(&_sc->sc_mtx, MA_OWNED)
98
99#define	BCM_GPIO_GPFSEL(_bank)	0x00 + _bank * 4
100#define	BCM_GPIO_GPSET(_bank)	0x1c + _bank * 4
101#define	BCM_GPIO_GPCLR(_bank)	0x28 + _bank * 4
102#define	BCM_GPIO_GPLEV(_bank)	0x34 + _bank * 4
103#define	BCM_GPIO_GPPUD(_bank)	0x94
104#define	BCM_GPIO_GPPUDCLK(_bank)	0x98 + _bank * 4
105
106#define	BCM_GPIO_WRITE(_sc, _off, _val)		\
107    bus_space_write_4(_sc->sc_bst, _sc->sc_bsh, _off, _val)
108#define	BCM_GPIO_READ(_sc, _off)		\
109    bus_space_read_4(_sc->sc_bst, _sc->sc_bsh, _off)
110
111static int
112bcm_gpio_pin_is_ro(struct bcm_gpio_softc *sc, int pin)
113{
114	int i;
115
116	for (i = 0; i < sc->sc_ro_npins; i++)
117		if (pin == sc->sc_ro_pins[i])
118			return (1);
119	return (0);
120}
121
122static uint32_t
123bcm_gpio_get_function(struct bcm_gpio_softc *sc, uint32_t pin)
124{
125	uint32_t bank, func, offset;
126
127	/* Five banks, 10 pins per bank, 3 bits per pin. */
128	bank = pin / 10;
129	offset = (pin - bank * 10) * 3;
130
131	BCM_GPIO_LOCK(sc);
132	func = (BCM_GPIO_READ(sc, BCM_GPIO_GPFSEL(bank)) >> offset) & 7;
133	BCM_GPIO_UNLOCK(sc);
134
135	return (func);
136}
137
138static void
139bcm_gpio_func_str(uint32_t nfunc, char *buf, int bufsize)
140{
141
142	switch (nfunc) {
143	case BCM_GPIO_INPUT:
144		strncpy(buf, "input", bufsize);
145		break;
146	case BCM_GPIO_OUTPUT:
147		strncpy(buf, "output", bufsize);
148		break;
149	case BCM_GPIO_ALT0:
150		strncpy(buf, "alt0", bufsize);
151		break;
152	case BCM_GPIO_ALT1:
153		strncpy(buf, "alt1", bufsize);
154		break;
155	case BCM_GPIO_ALT2:
156		strncpy(buf, "alt2", bufsize);
157		break;
158	case BCM_GPIO_ALT3:
159		strncpy(buf, "alt3", bufsize);
160		break;
161	case BCM_GPIO_ALT4:
162		strncpy(buf, "alt4", bufsize);
163		break;
164	case BCM_GPIO_ALT5:
165		strncpy(buf, "alt5", bufsize);
166		break;
167	default:
168		strncpy(buf, "invalid", bufsize);
169	}
170}
171
172static int
173bcm_gpio_str_func(char *func, uint32_t *nfunc)
174{
175
176	if (strcasecmp(func, "input") == 0)
177		*nfunc = BCM_GPIO_INPUT;
178	else if (strcasecmp(func, "output") == 0)
179		*nfunc = BCM_GPIO_OUTPUT;
180	else if (strcasecmp(func, "alt0") == 0)
181		*nfunc = BCM_GPIO_ALT0;
182	else if (strcasecmp(func, "alt1") == 0)
183		*nfunc = BCM_GPIO_ALT1;
184	else if (strcasecmp(func, "alt2") == 0)
185		*nfunc = BCM_GPIO_ALT2;
186	else if (strcasecmp(func, "alt3") == 0)
187		*nfunc = BCM_GPIO_ALT3;
188	else if (strcasecmp(func, "alt4") == 0)
189		*nfunc = BCM_GPIO_ALT4;
190	else if (strcasecmp(func, "alt5") == 0)
191		*nfunc = BCM_GPIO_ALT5;
192	else
193		return (-1);
194
195	return (0);
196}
197
198static uint32_t
199bcm_gpio_func_flag(uint32_t nfunc)
200{
201
202	switch (nfunc) {
203	case BCM_GPIO_INPUT:
204		return (GPIO_PIN_INPUT);
205	case BCM_GPIO_OUTPUT:
206		return (GPIO_PIN_OUTPUT);
207	}
208	return (0);
209}
210
211static void
212bcm_gpio_set_function(struct bcm_gpio_softc *sc, uint32_t pin, uint32_t f)
213{
214	uint32_t bank, data, offset;
215
216	/* Must be called with lock held. */
217	BCM_GPIO_LOCK_ASSERT(sc);
218
219	/* Five banks, 10 pins per bank, 3 bits per pin. */
220	bank = pin / 10;
221	offset = (pin - bank * 10) * 3;
222
223	data = BCM_GPIO_READ(sc, BCM_GPIO_GPFSEL(bank));
224	data &= ~(7 << offset);
225	data |= (f << offset);
226	BCM_GPIO_WRITE(sc, BCM_GPIO_GPFSEL(bank), data);
227}
228
229static void
230bcm_gpio_set_pud(struct bcm_gpio_softc *sc, uint32_t pin, uint32_t state)
231{
232	uint32_t bank, offset;
233
234	/* Must be called with lock held. */
235	BCM_GPIO_LOCK_ASSERT(sc);
236
237	bank = pin / 32;
238	offset = pin - 32 * bank;
239
240	BCM_GPIO_WRITE(sc, BCM_GPIO_GPPUD(0), state);
241	DELAY(10);
242	BCM_GPIO_WRITE(sc, BCM_GPIO_GPPUDCLK(bank), (1 << offset));
243	DELAY(10);
244	BCM_GPIO_WRITE(sc, BCM_GPIO_GPPUD(0), 0);
245	BCM_GPIO_WRITE(sc, BCM_GPIO_GPPUDCLK(bank), 0);
246}
247
248void
249bcm_gpio_set_alternate(device_t dev, uint32_t pin, uint32_t nfunc)
250{
251	struct bcm_gpio_softc *sc;
252	int i;
253
254	sc = device_get_softc(dev);
255	BCM_GPIO_LOCK(sc);
256
257	/* Disable pull-up or pull-down on pin. */
258	bcm_gpio_set_pud(sc, pin, BCM_GPIO_NONE);
259
260	/* And now set the pin function. */
261	bcm_gpio_set_function(sc, pin, nfunc);
262
263	/* Update the pin flags. */
264	for (i = 0; i < sc->sc_gpio_npins; i++) {
265		if (sc->sc_gpio_pins[i].gp_pin == pin)
266			break;
267	}
268	if (i < sc->sc_gpio_npins)
269		sc->sc_gpio_pins[i].gp_flags = bcm_gpio_func_flag(nfunc);
270
271        BCM_GPIO_UNLOCK(sc);
272}
273
274static void
275bcm_gpio_pin_configure(struct bcm_gpio_softc *sc, struct gpio_pin *pin,
276    unsigned int flags)
277{
278
279	BCM_GPIO_LOCK(sc);
280
281	/*
282	 * Manage input/output.
283	 */
284	if (flags & (GPIO_PIN_INPUT|GPIO_PIN_OUTPUT)) {
285		pin->gp_flags &= ~(GPIO_PIN_INPUT|GPIO_PIN_OUTPUT);
286		if (flags & GPIO_PIN_OUTPUT) {
287			pin->gp_flags |= GPIO_PIN_OUTPUT;
288			bcm_gpio_set_function(sc, pin->gp_pin,
289			    BCM_GPIO_OUTPUT);
290		} else {
291			pin->gp_flags |= GPIO_PIN_INPUT;
292			bcm_gpio_set_function(sc, pin->gp_pin,
293			    BCM_GPIO_INPUT);
294		}
295	}
296
297	/* Manage Pull-up/pull-down. */
298	pin->gp_flags &= ~(GPIO_PIN_PULLUP|GPIO_PIN_PULLDOWN);
299	if (flags & (GPIO_PIN_PULLUP|GPIO_PIN_PULLDOWN)) {
300		if (flags & GPIO_PIN_PULLUP) {
301			pin->gp_flags |= GPIO_PIN_PULLUP;
302			bcm_gpio_set_pud(sc, pin->gp_pin, BCM_GPIO_PULLUP);
303		} else {
304			pin->gp_flags |= GPIO_PIN_PULLDOWN;
305			bcm_gpio_set_pud(sc, pin->gp_pin, BCM_GPIO_PULLDOWN);
306		}
307	} else
308		bcm_gpio_set_pud(sc, pin->gp_pin, BCM_GPIO_NONE);
309
310	BCM_GPIO_UNLOCK(sc);
311}
312
313static int
314bcm_gpio_pin_max(device_t dev, int *maxpin)
315{
316
317	*maxpin = BCM_GPIO_PINS - 1;
318	return (0);
319}
320
321static int
322bcm_gpio_pin_getcaps(device_t dev, uint32_t pin, uint32_t *caps)
323{
324	struct bcm_gpio_softc *sc = device_get_softc(dev);
325	int i;
326
327	for (i = 0; i < sc->sc_gpio_npins; i++) {
328		if (sc->sc_gpio_pins[i].gp_pin == pin)
329			break;
330	}
331
332	if (i >= sc->sc_gpio_npins)
333		return (EINVAL);
334
335	BCM_GPIO_LOCK(sc);
336	*caps = sc->sc_gpio_pins[i].gp_caps;
337	BCM_GPIO_UNLOCK(sc);
338
339	return (0);
340}
341
342static int
343bcm_gpio_pin_getflags(device_t dev, uint32_t pin, uint32_t *flags)
344{
345	struct bcm_gpio_softc *sc = device_get_softc(dev);
346	int i;
347
348	for (i = 0; i < sc->sc_gpio_npins; i++) {
349		if (sc->sc_gpio_pins[i].gp_pin == pin)
350			break;
351	}
352
353	if (i >= sc->sc_gpio_npins)
354		return (EINVAL);
355
356	BCM_GPIO_LOCK(sc);
357	*flags = sc->sc_gpio_pins[i].gp_flags;
358	BCM_GPIO_UNLOCK(sc);
359
360	return (0);
361}
362
363static int
364bcm_gpio_pin_getname(device_t dev, uint32_t pin, char *name)
365{
366	struct bcm_gpio_softc *sc = device_get_softc(dev);
367	int i;
368
369	for (i = 0; i < sc->sc_gpio_npins; i++) {
370		if (sc->sc_gpio_pins[i].gp_pin == pin)
371			break;
372	}
373
374	if (i >= sc->sc_gpio_npins)
375		return (EINVAL);
376
377	BCM_GPIO_LOCK(sc);
378	memcpy(name, sc->sc_gpio_pins[i].gp_name, GPIOMAXNAME);
379	BCM_GPIO_UNLOCK(sc);
380
381	return (0);
382}
383
384static int
385bcm_gpio_pin_setflags(device_t dev, uint32_t pin, uint32_t flags)
386{
387	struct bcm_gpio_softc *sc = device_get_softc(dev);
388	int i;
389
390	for (i = 0; i < sc->sc_gpio_npins; i++) {
391		if (sc->sc_gpio_pins[i].gp_pin == pin)
392			break;
393	}
394
395	if (i >= sc->sc_gpio_npins)
396		return (EINVAL);
397
398	/* We never touch on read-only/reserved pins. */
399	if (bcm_gpio_pin_is_ro(sc, pin))
400		return (EINVAL);
401
402	bcm_gpio_pin_configure(sc, &sc->sc_gpio_pins[i], flags);
403
404	return (0);
405}
406
407static int
408bcm_gpio_pin_set(device_t dev, uint32_t pin, unsigned int value)
409{
410	struct bcm_gpio_softc *sc = device_get_softc(dev);
411	uint32_t bank, offset;
412	int i;
413
414	for (i = 0; i < sc->sc_gpio_npins; i++) {
415		if (sc->sc_gpio_pins[i].gp_pin == pin)
416			break;
417	}
418
419	if (i >= sc->sc_gpio_npins)
420		return (EINVAL);
421
422	/* We never write to read-only/reserved pins. */
423	if (bcm_gpio_pin_is_ro(sc, pin))
424		return (EINVAL);
425
426	bank = pin / 32;
427	offset = pin - 32 * bank;
428
429	BCM_GPIO_LOCK(sc);
430	if (value)
431		BCM_GPIO_WRITE(sc, BCM_GPIO_GPSET(bank), (1 << offset));
432	else
433		BCM_GPIO_WRITE(sc, BCM_GPIO_GPCLR(bank), (1 << offset));
434	BCM_GPIO_UNLOCK(sc);
435
436	return (0);
437}
438
439static int
440bcm_gpio_pin_get(device_t dev, uint32_t pin, unsigned int *val)
441{
442	struct bcm_gpio_softc *sc = device_get_softc(dev);
443	uint32_t bank, offset, reg_data;
444	int i;
445
446	for (i = 0; i < sc->sc_gpio_npins; i++) {
447		if (sc->sc_gpio_pins[i].gp_pin == pin)
448			break;
449	}
450
451	if (i >= sc->sc_gpio_npins)
452		return (EINVAL);
453
454	bank = pin / 32;
455	offset = pin - 32 * bank;
456
457	BCM_GPIO_LOCK(sc);
458	reg_data = BCM_GPIO_READ(sc, BCM_GPIO_GPLEV(bank));
459	BCM_GPIO_UNLOCK(sc);
460	*val = (reg_data & (1 << offset)) ? 1 : 0;
461
462	return (0);
463}
464
465static int
466bcm_gpio_pin_toggle(device_t dev, uint32_t pin)
467{
468	struct bcm_gpio_softc *sc = device_get_softc(dev);
469	uint32_t bank, data, offset;
470	int i;
471
472	for (i = 0; i < sc->sc_gpio_npins; i++) {
473		if (sc->sc_gpio_pins[i].gp_pin == pin)
474			break;
475	}
476
477	if (i >= sc->sc_gpio_npins)
478		return (EINVAL);
479
480	/* We never write to read-only/reserved pins. */
481	if (bcm_gpio_pin_is_ro(sc, pin))
482		return (EINVAL);
483
484	bank = pin / 32;
485	offset = pin - 32 * bank;
486
487	BCM_GPIO_LOCK(sc);
488	data = BCM_GPIO_READ(sc, BCM_GPIO_GPLEV(bank));
489	if (data & (1 << offset))
490		BCM_GPIO_WRITE(sc, BCM_GPIO_GPCLR(bank), (1 << offset));
491	else
492		BCM_GPIO_WRITE(sc, BCM_GPIO_GPSET(bank), (1 << offset));
493	BCM_GPIO_UNLOCK(sc);
494
495	return (0);
496}
497
498static int
499bcm_gpio_get_ro_pins(struct bcm_gpio_softc *sc)
500{
501	int i, len;
502	pcell_t pins[BCM_GPIO_PINS];
503	phandle_t gpio;
504
505	/* Find the gpio node to start. */
506	gpio = ofw_bus_get_node(sc->sc_dev);
507
508	len = OF_getproplen(gpio, "broadcom,read-only");
509	if (len < 0 || len > sizeof(pins))
510		return (-1);
511
512	if (OF_getprop(gpio, "broadcom,read-only", &pins, len) < 0)
513		return (-1);
514
515	sc->sc_ro_npins = len / sizeof(pcell_t);
516
517	device_printf(sc->sc_dev, "read-only pins: ");
518	for (i = 0; i < sc->sc_ro_npins; i++) {
519		sc->sc_ro_pins[i] = fdt32_to_cpu(pins[i]);
520		if (i > 0)
521			printf(",");
522		printf("%d", sc->sc_ro_pins[i]);
523	}
524	if (i > 0)
525		printf(".");
526	printf("\n");
527
528	return (0);
529}
530
531static int
532bcm_gpio_func_proc(SYSCTL_HANDLER_ARGS)
533{
534	char buf[16];
535	struct bcm_gpio_softc *sc;
536	struct bcm_gpio_sysctl *sc_sysctl;
537	uint32_t nfunc;
538	int error;
539
540	sc_sysctl = arg1;
541	sc = sc_sysctl->sc;
542
543	/* Get the current pin function. */
544	nfunc = bcm_gpio_get_function(sc, sc_sysctl->pin);
545	bcm_gpio_func_str(nfunc, buf, sizeof(buf));
546
547	error = sysctl_handle_string(oidp, buf, sizeof(buf), req);
548	if (error != 0 || req->newptr == NULL)
549		return (error);
550
551	/* Parse the user supplied string and check for a valid pin function. */
552	if (bcm_gpio_str_func(buf, &nfunc) != 0)
553		return (EINVAL);
554
555	/* Update the pin alternate function. */
556	bcm_gpio_set_alternate(sc->sc_dev, sc_sysctl->pin, nfunc);
557
558	return (0);
559}
560
561static void
562bcm_gpio_sysctl_init(struct bcm_gpio_softc *sc)
563{
564	char pinbuf[3];
565	struct bcm_gpio_sysctl *sc_sysctl;
566	struct sysctl_ctx_list *ctx;
567	struct sysctl_oid *tree_node, *pin_node, *pinN_node;
568	struct sysctl_oid_list *tree, *pin_tree, *pinN_tree;
569	int i;
570
571	/*
572	 * Add per-pin sysctl tree/handlers.
573	 */
574	ctx = device_get_sysctl_ctx(sc->sc_dev);
575 	tree_node = device_get_sysctl_tree(sc->sc_dev);
576 	tree = SYSCTL_CHILDREN(tree_node);
577	pin_node = SYSCTL_ADD_NODE(ctx, tree, OID_AUTO, "pin",
578	    CTLFLAG_RD, NULL, "GPIO Pins");
579	pin_tree = SYSCTL_CHILDREN(pin_node);
580
581	for (i = 0; i < sc->sc_gpio_npins; i++) {
582
583		snprintf(pinbuf, sizeof(pinbuf), "%d", i);
584		pinN_node = SYSCTL_ADD_NODE(ctx, pin_tree, OID_AUTO, pinbuf,
585		    CTLFLAG_RD, NULL, "GPIO Pin");
586		pinN_tree = SYSCTL_CHILDREN(pinN_node);
587
588		sc->sc_sysctl[i].sc = sc;
589		sc_sysctl = &sc->sc_sysctl[i];
590		sc_sysctl->sc = sc;
591		sc_sysctl->pin = sc->sc_gpio_pins[i].gp_pin;
592		SYSCTL_ADD_PROC(ctx, pinN_tree, OID_AUTO, "function",
593		    CTLFLAG_RW | CTLTYPE_STRING, sc_sysctl,
594		    sizeof(struct bcm_gpio_sysctl), bcm_gpio_func_proc,
595		    "A", "Pin Function");
596	}
597}
598
599static int
600bcm_gpio_get_reserved_pins(struct bcm_gpio_softc *sc)
601{
602	int i, j, len, npins;
603	pcell_t pins[BCM_GPIO_PINS];
604	phandle_t gpio, node, reserved;
605	char name[32];
606
607	/* Get read-only pins. */
608	if (bcm_gpio_get_ro_pins(sc) != 0)
609		return (-1);
610
611	/* Find the gpio/reserved pins node to start. */
612	gpio = ofw_bus_get_node(sc->sc_dev);
613	node = OF_child(gpio);
614
615	/*
616	 * Find reserved node
617	 */
618	reserved = 0;
619	while ((node != 0) && (reserved == 0)) {
620		len = OF_getprop(node, "name", name,
621		    sizeof(name) - 1);
622		name[len] = 0;
623		if (strcmp(name, "reserved") == 0)
624			reserved = node;
625		node = OF_peer(node);
626	}
627
628	if (reserved == 0)
629		return (-1);
630
631	/* Get the reserved pins. */
632	len = OF_getproplen(reserved, "broadcom,pins");
633	if (len < 0 || len > sizeof(pins))
634		return (-1);
635
636	if (OF_getprop(reserved, "broadcom,pins", &pins, len) < 0)
637		return (-1);
638
639	npins = len / sizeof(pcell_t);
640
641	j = 0;
642	device_printf(sc->sc_dev, "reserved pins: ");
643	for (i = 0; i < npins; i++) {
644		if (i > 0)
645			printf(",");
646		printf("%d", fdt32_to_cpu(pins[i]));
647		/* Some pins maybe already on the list of read-only pins. */
648		if (bcm_gpio_pin_is_ro(sc, fdt32_to_cpu(pins[i])))
649			continue;
650		sc->sc_ro_pins[j++ + sc->sc_ro_npins] = fdt32_to_cpu(pins[i]);
651	}
652	sc->sc_ro_npins += j;
653	if (i > 0)
654		printf(".");
655	printf("\n");
656
657	return (0);
658}
659
660static int
661bcm_gpio_probe(device_t dev)
662{
663
664	if (!ofw_bus_status_okay(dev))
665		return (ENXIO);
666
667	if (!ofw_bus_is_compatible(dev, "broadcom,bcm2835-gpio"))
668		return (ENXIO);
669
670	device_set_desc(dev, "BCM2708/2835 GPIO controller");
671	return (BUS_PROBE_DEFAULT);
672}
673
674static int
675bcm_gpio_attach(device_t dev)
676{
677	struct bcm_gpio_softc *sc = device_get_softc(dev);
678	uint32_t func;
679	int i, j, rid;
680	phandle_t gpio;
681
682	sc->sc_dev = dev;
683
684	mtx_init(&sc->sc_mtx, "bcm gpio", "gpio", MTX_DEF);
685
686	rid = 0;
687	sc->sc_mem_res = bus_alloc_resource_any(dev, SYS_RES_MEMORY, &rid,
688	    RF_ACTIVE);
689	if (!sc->sc_mem_res) {
690		device_printf(dev, "cannot allocate memory window\n");
691		return (ENXIO);
692	}
693
694	sc->sc_bst = rman_get_bustag(sc->sc_mem_res);
695	sc->sc_bsh = rman_get_bushandle(sc->sc_mem_res);
696
697	rid = 0;
698	sc->sc_irq_res = bus_alloc_resource_any(dev, SYS_RES_IRQ, &rid,
699	    RF_ACTIVE);
700	if (!sc->sc_irq_res) {
701		bus_release_resource(dev, SYS_RES_MEMORY, 0, sc->sc_mem_res);
702		device_printf(dev, "cannot allocate interrupt\n");
703		return (ENXIO);
704	}
705
706	/* Find our node. */
707	gpio = ofw_bus_get_node(sc->sc_dev);
708
709	if (!OF_hasprop(gpio, "gpio-controller"))
710		/* Node is not a GPIO controller. */
711		goto fail;
712
713	/*
714	 * Find the read-only pins.  These are pins we never touch or bad
715	 * things could happen.
716	 */
717	if (bcm_gpio_get_reserved_pins(sc) == -1)
718		goto fail;
719
720	/* Initialize the software controlled pins. */
721	for (i = 0, j = 0; j < BCM_GPIO_PINS; j++) {
722		if (bcm_gpio_pin_is_ro(sc, j))
723			continue;
724		snprintf(sc->sc_gpio_pins[i].gp_name, GPIOMAXNAME,
725		    "pin %d", j);
726		func = bcm_gpio_get_function(sc, j);
727		sc->sc_gpio_pins[i].gp_pin = j;
728		sc->sc_gpio_pins[i].gp_caps = BCM_GPIO_DEFAULT_CAPS;
729		sc->sc_gpio_pins[i].gp_flags = bcm_gpio_func_flag(func);
730		i++;
731	}
732	sc->sc_gpio_npins = i;
733
734	bcm_gpio_sysctl_init(sc);
735
736	device_add_child(dev, "gpioc", -1);
737	device_add_child(dev, "gpiobus", -1);
738
739	return (bus_generic_attach(dev));
740
741fail:
742	if (sc->sc_irq_res)
743		bus_release_resource(dev, SYS_RES_IRQ, 0, sc->sc_irq_res);
744	if (sc->sc_mem_res)
745		bus_release_resource(dev, SYS_RES_MEMORY, 0, sc->sc_mem_res);
746	return (ENXIO);
747}
748
749static int
750bcm_gpio_detach(device_t dev)
751{
752
753	return (EBUSY);
754}
755
756static phandle_t
757bcm_gpio_get_node(device_t bus, device_t dev)
758{
759
760	/* We only have one child, the GPIO bus, which needs our own node. */
761	return (ofw_bus_get_node(bus));
762}
763
764static device_method_t bcm_gpio_methods[] = {
765	/* Device interface */
766	DEVMETHOD(device_probe,		bcm_gpio_probe),
767	DEVMETHOD(device_attach,	bcm_gpio_attach),
768	DEVMETHOD(device_detach,	bcm_gpio_detach),
769
770	/* GPIO protocol */
771	DEVMETHOD(gpio_pin_max,		bcm_gpio_pin_max),
772	DEVMETHOD(gpio_pin_getname,	bcm_gpio_pin_getname),
773	DEVMETHOD(gpio_pin_getflags,	bcm_gpio_pin_getflags),
774	DEVMETHOD(gpio_pin_getcaps,	bcm_gpio_pin_getcaps),
775	DEVMETHOD(gpio_pin_setflags,	bcm_gpio_pin_setflags),
776	DEVMETHOD(gpio_pin_get,		bcm_gpio_pin_get),
777	DEVMETHOD(gpio_pin_set,		bcm_gpio_pin_set),
778	DEVMETHOD(gpio_pin_toggle,	bcm_gpio_pin_toggle),
779
780	/* ofw_bus interface */
781	DEVMETHOD(ofw_bus_get_node,	bcm_gpio_get_node),
782
783	DEVMETHOD_END
784};
785
786static devclass_t bcm_gpio_devclass;
787
788static driver_t bcm_gpio_driver = {
789	"gpio",
790	bcm_gpio_methods,
791	sizeof(struct bcm_gpio_softc),
792};
793
794DRIVER_MODULE(bcm_gpio, simplebus, bcm_gpio_driver, bcm_gpio_devclass, 0, 0);
795