xref: /freebsd/sys/arm/broadcom/bcm2835/bcm2835_gpio.c (revision b740c88bfb6453416926271c089262e7164dace3)
1 /*-
2  * Copyright (c) 2012 Oleksandr Tymoshenko <gonzo@FreeBSD.org>
3  * Copyright (c) 2012-2015 Luiz Otavio O Souza <loos@FreeBSD.org>
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("$FreeBSD$");
30 
31 #include <sys/param.h>
32 #include <sys/systm.h>
33 #include <sys/bus.h>
34 #include <sys/gpio.h>
35 #include <sys/interrupt.h>
36 #include <sys/kernel.h>
37 #include <sys/lock.h>
38 #include <sys/module.h>
39 #include <sys/mutex.h>
40 #include <sys/rman.h>
41 #include <sys/sysctl.h>
42 
43 #include <machine/bus.h>
44 
45 #include <dev/gpio/gpiobusvar.h>
46 #include <dev/ofw/ofw_bus.h>
47 
48 #include <arm/broadcom/bcm2835/bcm2835_gpio.h>
49 
50 #include "gpio_if.h"
51 
52 #ifdef DEBUG
53 #define dprintf(fmt, args...) do { printf("%s(): ", __func__);   \
54     printf(fmt,##args); } while (0)
55 #else
56 #define dprintf(fmt, args...)
57 #endif
58 
59 #define	BCM_GPIO_IRQS		4
60 #define	BCM_GPIO_PINS		54
61 #define	BCM_GPIO_PINS_PER_BANK	32
62 #define	BCM_GPIO_DEFAULT_CAPS	(GPIO_PIN_INPUT | GPIO_PIN_OUTPUT |	\
63     GPIO_PIN_PULLUP | GPIO_PIN_PULLDOWN)
64 
65 static struct resource_spec bcm_gpio_res_spec[] = {
66 	{ SYS_RES_MEMORY, 0, RF_ACTIVE },
67 	{ SYS_RES_IRQ, 0, RF_ACTIVE },
68 	{ SYS_RES_IRQ, 1, RF_ACTIVE },
69 	{ SYS_RES_IRQ, 2, RF_ACTIVE },
70 	{ SYS_RES_IRQ, 3, RF_ACTIVE },
71 	{ -1, 0, 0 }
72 };
73 
74 struct bcm_gpio_sysctl {
75 	struct bcm_gpio_softc	*sc;
76 	uint32_t		pin;
77 };
78 
79 struct bcm_gpio_softc {
80 	device_t		sc_dev;
81 	device_t		sc_busdev;
82 	struct mtx		sc_mtx;
83 	struct resource *	sc_res[BCM_GPIO_IRQS + 1];
84 	bus_space_tag_t		sc_bst;
85 	bus_space_handle_t	sc_bsh;
86 	void *			sc_intrhand[BCM_GPIO_IRQS];
87 	int			sc_gpio_npins;
88 	int			sc_ro_npins;
89 	int			sc_ro_pins[BCM_GPIO_PINS];
90 	struct gpio_pin		sc_gpio_pins[BCM_GPIO_PINS];
91 	struct intr_event *	sc_events[BCM_GPIO_PINS];
92 	struct bcm_gpio_sysctl	sc_sysctl[BCM_GPIO_PINS];
93 	enum intr_trigger	sc_irq_trigger[BCM_GPIO_PINS];
94 	enum intr_polarity	sc_irq_polarity[BCM_GPIO_PINS];
95 };
96 
97 enum bcm_gpio_pud {
98 	BCM_GPIO_NONE,
99 	BCM_GPIO_PULLDOWN,
100 	BCM_GPIO_PULLUP,
101 };
102 
103 #define	BCM_GPIO_LOCK(_sc)	mtx_lock_spin(&(_sc)->sc_mtx)
104 #define	BCM_GPIO_UNLOCK(_sc)	mtx_unlock_spin(&(_sc)->sc_mtx)
105 #define	BCM_GPIO_LOCK_ASSERT(_sc)	mtx_assert(&(_sc)->sc_mtx, MA_OWNED)
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 #define	BCM_GPIO_CLEAR_BITS(_sc, _off, _bits)	\
111     BCM_GPIO_WRITE(_sc, _off, BCM_GPIO_READ(_sc, _off) & ~(_bits))
112 #define	BCM_GPIO_SET_BITS(_sc, _off, _bits)	\
113     BCM_GPIO_WRITE(_sc, _off, BCM_GPIO_READ(_sc, _off) | _bits)
114 #define	BCM_GPIO_BANK(a)	(a / BCM_GPIO_PINS_PER_BANK)
115 #define	BCM_GPIO_MASK(a)	(1U << (a % BCM_GPIO_PINS_PER_BANK))
116 
117 #define	BCM_GPIO_GPFSEL(_bank)	(0x00 + _bank * 4)	/* Function Select */
118 #define	BCM_GPIO_GPSET(_bank)	(0x1c + _bank * 4)	/* Pin Out Set */
119 #define	BCM_GPIO_GPCLR(_bank)	(0x28 + _bank * 4)	/* Pin Out Clear */
120 #define	BCM_GPIO_GPLEV(_bank)	(0x34 + _bank * 4)	/* Pin Level */
121 #define	BCM_GPIO_GPEDS(_bank)	(0x40 + _bank * 4)	/* Event Status */
122 #define	BCM_GPIO_GPREN(_bank)	(0x4c + _bank * 4)	/* Rising Edge irq */
123 #define	BCM_GPIO_GPFEN(_bank)	(0x58 + _bank * 4)	/* Falling Edge irq */
124 #define	BCM_GPIO_GPHEN(_bank)	(0x64 + _bank * 4)	/* High Level irq */
125 #define	BCM_GPIO_GPLEN(_bank)	(0x70 + _bank * 4)	/* Low Level irq */
126 #define	BCM_GPIO_GPAREN(_bank)	(0x7c + _bank * 4)	/* Async Rising Edge */
127 #define	BCM_GPIO_GPAFEN(_bank)	(0x88 + _bank * 4)	/* Async Falling Egde */
128 #define	BCM_GPIO_GPPUD(_bank)	(0x94)			/* Pin Pull up/down */
129 #define	BCM_GPIO_GPPUDCLK(_bank) (0x98 + _bank * 4)	/* Pin Pull up clock */
130 
131 static struct bcm_gpio_softc *bcm_gpio_sc = NULL;
132 
133 static int
134 bcm_gpio_pin_is_ro(struct bcm_gpio_softc *sc, int pin)
135 {
136 	int i;
137 
138 	for (i = 0; i < sc->sc_ro_npins; i++)
139 		if (pin == sc->sc_ro_pins[i])
140 			return (1);
141 	return (0);
142 }
143 
144 static uint32_t
145 bcm_gpio_get_function(struct bcm_gpio_softc *sc, uint32_t pin)
146 {
147 	uint32_t bank, func, offset;
148 
149 	/* Five banks, 10 pins per bank, 3 bits per pin. */
150 	bank = pin / 10;
151 	offset = (pin - bank * 10) * 3;
152 
153 	BCM_GPIO_LOCK(sc);
154 	func = (BCM_GPIO_READ(sc, BCM_GPIO_GPFSEL(bank)) >> offset) & 7;
155 	BCM_GPIO_UNLOCK(sc);
156 
157 	return (func);
158 }
159 
160 static void
161 bcm_gpio_func_str(uint32_t nfunc, char *buf, int bufsize)
162 {
163 
164 	switch (nfunc) {
165 	case BCM_GPIO_INPUT:
166 		strncpy(buf, "input", bufsize);
167 		break;
168 	case BCM_GPIO_OUTPUT:
169 		strncpy(buf, "output", bufsize);
170 		break;
171 	case BCM_GPIO_ALT0:
172 		strncpy(buf, "alt0", bufsize);
173 		break;
174 	case BCM_GPIO_ALT1:
175 		strncpy(buf, "alt1", bufsize);
176 		break;
177 	case BCM_GPIO_ALT2:
178 		strncpy(buf, "alt2", bufsize);
179 		break;
180 	case BCM_GPIO_ALT3:
181 		strncpy(buf, "alt3", bufsize);
182 		break;
183 	case BCM_GPIO_ALT4:
184 		strncpy(buf, "alt4", bufsize);
185 		break;
186 	case BCM_GPIO_ALT5:
187 		strncpy(buf, "alt5", bufsize);
188 		break;
189 	default:
190 		strncpy(buf, "invalid", bufsize);
191 	}
192 }
193 
194 static int
195 bcm_gpio_str_func(char *func, uint32_t *nfunc)
196 {
197 
198 	if (strcasecmp(func, "input") == 0)
199 		*nfunc = BCM_GPIO_INPUT;
200 	else if (strcasecmp(func, "output") == 0)
201 		*nfunc = BCM_GPIO_OUTPUT;
202 	else if (strcasecmp(func, "alt0") == 0)
203 		*nfunc = BCM_GPIO_ALT0;
204 	else if (strcasecmp(func, "alt1") == 0)
205 		*nfunc = BCM_GPIO_ALT1;
206 	else if (strcasecmp(func, "alt2") == 0)
207 		*nfunc = BCM_GPIO_ALT2;
208 	else if (strcasecmp(func, "alt3") == 0)
209 		*nfunc = BCM_GPIO_ALT3;
210 	else if (strcasecmp(func, "alt4") == 0)
211 		*nfunc = BCM_GPIO_ALT4;
212 	else if (strcasecmp(func, "alt5") == 0)
213 		*nfunc = BCM_GPIO_ALT5;
214 	else
215 		return (-1);
216 
217 	return (0);
218 }
219 
220 static uint32_t
221 bcm_gpio_func_flag(uint32_t nfunc)
222 {
223 
224 	switch (nfunc) {
225 	case BCM_GPIO_INPUT:
226 		return (GPIO_PIN_INPUT);
227 	case BCM_GPIO_OUTPUT:
228 		return (GPIO_PIN_OUTPUT);
229 	}
230 	return (0);
231 }
232 
233 static void
234 bcm_gpio_set_function(struct bcm_gpio_softc *sc, uint32_t pin, uint32_t f)
235 {
236 	uint32_t bank, data, offset;
237 
238 	/* Must be called with lock held. */
239 	BCM_GPIO_LOCK_ASSERT(sc);
240 
241 	/* Five banks, 10 pins per bank, 3 bits per pin. */
242 	bank = pin / 10;
243 	offset = (pin - bank * 10) * 3;
244 
245 	data = BCM_GPIO_READ(sc, BCM_GPIO_GPFSEL(bank));
246 	data &= ~(7 << offset);
247 	data |= (f << offset);
248 	BCM_GPIO_WRITE(sc, BCM_GPIO_GPFSEL(bank), data);
249 }
250 
251 static void
252 bcm_gpio_set_pud(struct bcm_gpio_softc *sc, uint32_t pin, uint32_t state)
253 {
254 	uint32_t bank;
255 
256 	/* Must be called with lock held. */
257 	BCM_GPIO_LOCK_ASSERT(sc);
258 
259 	bank = BCM_GPIO_BANK(pin);
260 	BCM_GPIO_WRITE(sc, BCM_GPIO_GPPUD(0), state);
261 	BCM_GPIO_WRITE(sc, BCM_GPIO_GPPUDCLK(bank), BCM_GPIO_MASK(pin));
262 	BCM_GPIO_WRITE(sc, BCM_GPIO_GPPUD(0), 0);
263 	BCM_GPIO_WRITE(sc, BCM_GPIO_GPPUDCLK(bank), 0);
264 }
265 
266 void
267 bcm_gpio_set_alternate(device_t dev, uint32_t pin, uint32_t nfunc)
268 {
269 	struct bcm_gpio_softc *sc;
270 	int i;
271 
272 	sc = device_get_softc(dev);
273 	BCM_GPIO_LOCK(sc);
274 
275 	/* Disable pull-up or pull-down on pin. */
276 	bcm_gpio_set_pud(sc, pin, BCM_GPIO_NONE);
277 
278 	/* And now set the pin function. */
279 	bcm_gpio_set_function(sc, pin, nfunc);
280 
281 	/* Update the pin flags. */
282 	for (i = 0; i < sc->sc_gpio_npins; i++) {
283 		if (sc->sc_gpio_pins[i].gp_pin == pin)
284 			break;
285 	}
286 	if (i < sc->sc_gpio_npins)
287 		sc->sc_gpio_pins[i].gp_flags = bcm_gpio_func_flag(nfunc);
288 
289         BCM_GPIO_UNLOCK(sc);
290 }
291 
292 static void
293 bcm_gpio_pin_configure(struct bcm_gpio_softc *sc, struct gpio_pin *pin,
294     unsigned int flags)
295 {
296 
297 	BCM_GPIO_LOCK(sc);
298 
299 	/*
300 	 * Manage input/output.
301 	 */
302 	if (flags & (GPIO_PIN_INPUT|GPIO_PIN_OUTPUT)) {
303 		pin->gp_flags &= ~(GPIO_PIN_INPUT|GPIO_PIN_OUTPUT);
304 		if (flags & GPIO_PIN_OUTPUT) {
305 			pin->gp_flags |= GPIO_PIN_OUTPUT;
306 			bcm_gpio_set_function(sc, pin->gp_pin,
307 			    BCM_GPIO_OUTPUT);
308 		} else {
309 			pin->gp_flags |= GPIO_PIN_INPUT;
310 			bcm_gpio_set_function(sc, pin->gp_pin,
311 			    BCM_GPIO_INPUT);
312 		}
313 	}
314 
315 	/* Manage Pull-up/pull-down. */
316 	pin->gp_flags &= ~(GPIO_PIN_PULLUP|GPIO_PIN_PULLDOWN);
317 	if (flags & (GPIO_PIN_PULLUP|GPIO_PIN_PULLDOWN)) {
318 		if (flags & GPIO_PIN_PULLUP) {
319 			pin->gp_flags |= GPIO_PIN_PULLUP;
320 			bcm_gpio_set_pud(sc, pin->gp_pin, BCM_GPIO_PULLUP);
321 		} else {
322 			pin->gp_flags |= GPIO_PIN_PULLDOWN;
323 			bcm_gpio_set_pud(sc, pin->gp_pin, BCM_GPIO_PULLDOWN);
324 		}
325 	} else
326 		bcm_gpio_set_pud(sc, pin->gp_pin, BCM_GPIO_NONE);
327 
328 	BCM_GPIO_UNLOCK(sc);
329 }
330 
331 static device_t
332 bcm_gpio_get_bus(device_t dev)
333 {
334 	struct bcm_gpio_softc *sc;
335 
336 	sc = device_get_softc(dev);
337 
338 	return (sc->sc_busdev);
339 }
340 
341 static int
342 bcm_gpio_pin_max(device_t dev, int *maxpin)
343 {
344 
345 	*maxpin = BCM_GPIO_PINS - 1;
346 	return (0);
347 }
348 
349 static int
350 bcm_gpio_pin_getcaps(device_t dev, uint32_t pin, uint32_t *caps)
351 {
352 	struct bcm_gpio_softc *sc = device_get_softc(dev);
353 	int i;
354 
355 	for (i = 0; i < sc->sc_gpio_npins; i++) {
356 		if (sc->sc_gpio_pins[i].gp_pin == pin)
357 			break;
358 	}
359 
360 	if (i >= sc->sc_gpio_npins)
361 		return (EINVAL);
362 
363 	BCM_GPIO_LOCK(sc);
364 	*caps = sc->sc_gpio_pins[i].gp_caps;
365 	BCM_GPIO_UNLOCK(sc);
366 
367 	return (0);
368 }
369 
370 static int
371 bcm_gpio_pin_getflags(device_t dev, uint32_t pin, uint32_t *flags)
372 {
373 	struct bcm_gpio_softc *sc = device_get_softc(dev);
374 	int i;
375 
376 	for (i = 0; i < sc->sc_gpio_npins; i++) {
377 		if (sc->sc_gpio_pins[i].gp_pin == pin)
378 			break;
379 	}
380 
381 	if (i >= sc->sc_gpio_npins)
382 		return (EINVAL);
383 
384 	BCM_GPIO_LOCK(sc);
385 	*flags = sc->sc_gpio_pins[i].gp_flags;
386 	BCM_GPIO_UNLOCK(sc);
387 
388 	return (0);
389 }
390 
391 static int
392 bcm_gpio_pin_getname(device_t dev, uint32_t pin, char *name)
393 {
394 	struct bcm_gpio_softc *sc = device_get_softc(dev);
395 	int i;
396 
397 	for (i = 0; i < sc->sc_gpio_npins; i++) {
398 		if (sc->sc_gpio_pins[i].gp_pin == pin)
399 			break;
400 	}
401 
402 	if (i >= sc->sc_gpio_npins)
403 		return (EINVAL);
404 
405 	BCM_GPIO_LOCK(sc);
406 	memcpy(name, sc->sc_gpio_pins[i].gp_name, GPIOMAXNAME);
407 	BCM_GPIO_UNLOCK(sc);
408 
409 	return (0);
410 }
411 
412 static int
413 bcm_gpio_pin_setflags(device_t dev, uint32_t pin, uint32_t flags)
414 {
415 	struct bcm_gpio_softc *sc = device_get_softc(dev);
416 	int i;
417 
418 	for (i = 0; i < sc->sc_gpio_npins; i++) {
419 		if (sc->sc_gpio_pins[i].gp_pin == pin)
420 			break;
421 	}
422 
423 	if (i >= sc->sc_gpio_npins)
424 		return (EINVAL);
425 
426 	/* We never touch on read-only/reserved pins. */
427 	if (bcm_gpio_pin_is_ro(sc, pin))
428 		return (EINVAL);
429 
430 	bcm_gpio_pin_configure(sc, &sc->sc_gpio_pins[i], flags);
431 
432 	return (0);
433 }
434 
435 static int
436 bcm_gpio_pin_set(device_t dev, uint32_t pin, unsigned int value)
437 {
438 	struct bcm_gpio_softc *sc = device_get_softc(dev);
439 	uint32_t bank, reg;
440 	int i;
441 
442 	for (i = 0; i < sc->sc_gpio_npins; i++) {
443 		if (sc->sc_gpio_pins[i].gp_pin == pin)
444 			break;
445 	}
446 	if (i >= sc->sc_gpio_npins)
447 		return (EINVAL);
448 	/* We never write to read-only/reserved pins. */
449 	if (bcm_gpio_pin_is_ro(sc, pin))
450 		return (EINVAL);
451 	BCM_GPIO_LOCK(sc);
452 	bank = BCM_GPIO_BANK(pin);
453 	if (value)
454 		reg = BCM_GPIO_GPSET(bank);
455 	else
456 		reg = BCM_GPIO_GPCLR(bank);
457 	BCM_GPIO_WRITE(sc, reg, BCM_GPIO_MASK(pin));
458 	BCM_GPIO_UNLOCK(sc);
459 
460 	return (0);
461 }
462 
463 static int
464 bcm_gpio_pin_get(device_t dev, uint32_t pin, unsigned int *val)
465 {
466 	struct bcm_gpio_softc *sc = device_get_softc(dev);
467 	uint32_t bank, reg_data;
468 	int i;
469 
470 	for (i = 0; i < sc->sc_gpio_npins; i++) {
471 		if (sc->sc_gpio_pins[i].gp_pin == pin)
472 			break;
473 	}
474 	if (i >= sc->sc_gpio_npins)
475 		return (EINVAL);
476 	bank = BCM_GPIO_BANK(pin);
477 	BCM_GPIO_LOCK(sc);
478 	reg_data = BCM_GPIO_READ(sc, BCM_GPIO_GPLEV(bank));
479 	BCM_GPIO_UNLOCK(sc);
480 	*val = (reg_data & BCM_GPIO_MASK(pin)) ? 1 : 0;
481 
482 	return (0);
483 }
484 
485 static int
486 bcm_gpio_pin_toggle(device_t dev, uint32_t pin)
487 {
488 	struct bcm_gpio_softc *sc = device_get_softc(dev);
489 	uint32_t bank, data, reg;
490 	int i;
491 
492 	for (i = 0; i < sc->sc_gpio_npins; i++) {
493 		if (sc->sc_gpio_pins[i].gp_pin == pin)
494 			break;
495 	}
496 	if (i >= sc->sc_gpio_npins)
497 		return (EINVAL);
498 	/* We never write to read-only/reserved pins. */
499 	if (bcm_gpio_pin_is_ro(sc, pin))
500 		return (EINVAL);
501 	BCM_GPIO_LOCK(sc);
502 	bank = BCM_GPIO_BANK(pin);
503 	data = BCM_GPIO_READ(sc, BCM_GPIO_GPLEV(bank));
504 	if (data & BCM_GPIO_MASK(pin))
505 		reg = BCM_GPIO_GPCLR(bank);
506 	else
507 		reg = BCM_GPIO_GPSET(bank);
508 	BCM_GPIO_WRITE(sc, reg, BCM_GPIO_MASK(pin));
509 	BCM_GPIO_UNLOCK(sc);
510 
511 	return (0);
512 }
513 
514 static int
515 bcm_gpio_func_proc(SYSCTL_HANDLER_ARGS)
516 {
517 	char buf[16];
518 	struct bcm_gpio_softc *sc;
519 	struct bcm_gpio_sysctl *sc_sysctl;
520 	uint32_t nfunc;
521 	int error;
522 
523 	sc_sysctl = arg1;
524 	sc = sc_sysctl->sc;
525 
526 	/* Get the current pin function. */
527 	nfunc = bcm_gpio_get_function(sc, sc_sysctl->pin);
528 	bcm_gpio_func_str(nfunc, buf, sizeof(buf));
529 
530 	error = sysctl_handle_string(oidp, buf, sizeof(buf), req);
531 	if (error != 0 || req->newptr == NULL)
532 		return (error);
533 	/* Ignore changes on read-only pins. */
534 	if (bcm_gpio_pin_is_ro(sc, sc_sysctl->pin))
535 		return (0);
536 	/* Parse the user supplied string and check for a valid pin function. */
537 	if (bcm_gpio_str_func(buf, &nfunc) != 0)
538 		return (EINVAL);
539 
540 	/* Update the pin alternate function. */
541 	bcm_gpio_set_alternate(sc->sc_dev, sc_sysctl->pin, nfunc);
542 
543 	return (0);
544 }
545 
546 static void
547 bcm_gpio_sysctl_init(struct bcm_gpio_softc *sc)
548 {
549 	char pinbuf[3];
550 	struct bcm_gpio_sysctl *sc_sysctl;
551 	struct sysctl_ctx_list *ctx;
552 	struct sysctl_oid *tree_node, *pin_node, *pinN_node;
553 	struct sysctl_oid_list *tree, *pin_tree, *pinN_tree;
554 	int i;
555 
556 	/*
557 	 * Add per-pin sysctl tree/handlers.
558 	 */
559 	ctx = device_get_sysctl_ctx(sc->sc_dev);
560  	tree_node = device_get_sysctl_tree(sc->sc_dev);
561  	tree = SYSCTL_CHILDREN(tree_node);
562 	pin_node = SYSCTL_ADD_NODE(ctx, tree, OID_AUTO, "pin",
563 	    CTLFLAG_RD, NULL, "GPIO Pins");
564 	pin_tree = SYSCTL_CHILDREN(pin_node);
565 
566 	for (i = 0; i < sc->sc_gpio_npins; i++) {
567 
568 		snprintf(pinbuf, sizeof(pinbuf), "%d", i);
569 		pinN_node = SYSCTL_ADD_NODE(ctx, pin_tree, OID_AUTO, pinbuf,
570 		    CTLFLAG_RD, NULL, "GPIO Pin");
571 		pinN_tree = SYSCTL_CHILDREN(pinN_node);
572 
573 		sc->sc_sysctl[i].sc = sc;
574 		sc_sysctl = &sc->sc_sysctl[i];
575 		sc_sysctl->sc = sc;
576 		sc_sysctl->pin = sc->sc_gpio_pins[i].gp_pin;
577 		SYSCTL_ADD_PROC(ctx, pinN_tree, OID_AUTO, "function",
578 		    CTLFLAG_RW | CTLTYPE_STRING, sc_sysctl,
579 		    sizeof(struct bcm_gpio_sysctl), bcm_gpio_func_proc,
580 		    "A", "Pin Function");
581 	}
582 }
583 
584 static int
585 bcm_gpio_get_ro_pins(struct bcm_gpio_softc *sc, phandle_t node,
586 	const char *propname, const char *label)
587 {
588 	int i, need_comma, npins, range_start, range_stop;
589 	pcell_t *pins;
590 
591 	/* Get the property data. */
592 	npins = OF_getencprop_alloc(node, propname, sizeof(*pins),
593 	    (void **)&pins);
594 	if (npins < 0)
595 		return (-1);
596 	if (npins == 0) {
597 		free(pins, M_OFWPROP);
598 		return (0);
599 	}
600 	for (i = 0; i < npins; i++)
601 		sc->sc_ro_pins[i + sc->sc_ro_npins] = pins[i];
602 	sc->sc_ro_npins += npins;
603 	need_comma = 0;
604 	device_printf(sc->sc_dev, "%s pins: ", label);
605 	range_start = range_stop = pins[0];
606 	for (i = 1; i < npins; i++) {
607 		if (pins[i] != range_stop + 1) {
608 			if (need_comma)
609 				printf(",");
610 			if (range_start != range_stop)
611 				printf("%d-%d", range_start, range_stop);
612 			else
613 				printf("%d", range_start);
614 			range_start = range_stop = pins[i];
615 			need_comma = 1;
616 		} else
617 			range_stop++;
618 	}
619 	if (need_comma)
620 		printf(",");
621 	if (range_start != range_stop)
622 		printf("%d-%d.\n", range_start, range_stop);
623 	else
624 		printf("%d.\n", range_start);
625 	free(pins, M_OFWPROP);
626 
627 	return (0);
628 }
629 
630 static int
631 bcm_gpio_get_reserved_pins(struct bcm_gpio_softc *sc)
632 {
633 	char *name;
634 	phandle_t gpio, node, reserved;
635 	ssize_t len;
636 
637 	/* Get read-only pins. */
638 	gpio = ofw_bus_get_node(sc->sc_dev);
639 	if (bcm_gpio_get_ro_pins(sc, gpio, "broadcom,read-only",
640 	    "read-only") != 0)
641 		return (-1);
642 	/* Traverse the GPIO subnodes to find the reserved pins node. */
643 	reserved = 0;
644 	node = OF_child(gpio);
645 	while ((node != 0) && (reserved == 0)) {
646 		len = OF_getprop_alloc(node, "name", 1, (void **)&name);
647 		if (len == -1)
648 			return (-1);
649 		if (strcmp(name, "reserved") == 0)
650 			reserved = node;
651 		free(name, M_OFWPROP);
652 		node = OF_peer(node);
653 	}
654 	if (reserved == 0)
655 		return (-1);
656 	/* Get the reserved pins. */
657 	if (bcm_gpio_get_ro_pins(sc, reserved, "broadcom,pins",
658 	    "reserved") != 0)
659 		return (-1);
660 
661 	return (0);
662 }
663 
664 static int
665 bcm_gpio_intr(void *arg)
666 {
667 	int bank_last, irq;
668 	struct bcm_gpio_softc *sc;
669 	struct intr_event *event;
670 	uint32_t bank, mask, reg;
671 
672 	sc = (struct bcm_gpio_softc *)arg;
673 	reg = 0;
674 	bank_last = -1;
675 	for (irq = 0; irq < BCM_GPIO_PINS; irq++) {
676 		bank = BCM_GPIO_BANK(irq);
677 		mask = BCM_GPIO_MASK(irq);
678 		if (bank != bank_last) {
679 			reg = BCM_GPIO_READ(sc, BCM_GPIO_GPEDS(bank));
680 			bank_last = bank;
681 		}
682 		if (reg & mask) {
683 			event = sc->sc_events[irq];
684 			if (event != NULL && !TAILQ_EMPTY(&event->ie_handlers))
685 				intr_event_handle(event, NULL);
686 			else {
687 				device_printf(sc->sc_dev, "Stray IRQ %d\n",
688 				    irq);
689 			}
690 			/* Clear the Status bit by writing '1' to it. */
691 			BCM_GPIO_WRITE(sc, BCM_GPIO_GPEDS(bank), mask);
692 		}
693 	}
694 
695 	return (FILTER_HANDLED);
696 }
697 
698 static int
699 bcm_gpio_probe(device_t dev)
700 {
701 
702 	if (!ofw_bus_status_okay(dev))
703 		return (ENXIO);
704 
705 	if (!ofw_bus_is_compatible(dev, "broadcom,bcm2835-gpio"))
706 		return (ENXIO);
707 
708 	device_set_desc(dev, "BCM2708/2835 GPIO controller");
709 	return (BUS_PROBE_DEFAULT);
710 }
711 
712 static int
713 bcm_gpio_intr_attach(device_t dev)
714 {
715 	struct bcm_gpio_softc *sc;
716 	int i;
717 
718 	sc = device_get_softc(dev);
719 	for (i = 0; i < BCM_GPIO_IRQS; i++) {
720 		if (bus_setup_intr(dev, sc->sc_res[i + 1],
721 		    INTR_TYPE_MISC | INTR_MPSAFE, bcm_gpio_intr,
722 		    NULL, sc, &sc->sc_intrhand[i]) != 0) {
723 			return (-1);
724 		}
725 	}
726 
727 	return (0);
728 }
729 
730 static void
731 bcm_gpio_intr_detach(device_t dev)
732 {
733 	struct bcm_gpio_softc *sc;
734 	int i;
735 
736 	sc = device_get_softc(dev);
737 	for (i = 0; i < BCM_GPIO_IRQS; i++) {
738 		if (sc->sc_intrhand[i]) {
739 			bus_teardown_intr(dev, sc->sc_res[i + 1],
740 			    sc->sc_intrhand[i]);
741 		}
742 	}
743 }
744 
745 static int
746 bcm_gpio_attach(device_t dev)
747 {
748 	int i, j;
749 	phandle_t gpio;
750 	struct bcm_gpio_softc *sc;
751 	uint32_t func;
752 
753 	if (bcm_gpio_sc != NULL)
754 		return (ENXIO);
755 
756 	bcm_gpio_sc = sc = device_get_softc(dev);
757  	sc->sc_dev = dev;
758 	mtx_init(&sc->sc_mtx, "bcm gpio", "gpio", MTX_SPIN);
759 	if (bus_alloc_resources(dev, bcm_gpio_res_spec, sc->sc_res) != 0) {
760 		device_printf(dev, "cannot allocate resources\n");
761 		goto fail;
762 	}
763 	sc->sc_bst = rman_get_bustag(sc->sc_res[0]);
764 	sc->sc_bsh = rman_get_bushandle(sc->sc_res[0]);
765 	/* Setup the GPIO interrupt handler. */
766 	if (bcm_gpio_intr_attach(dev)) {
767 		device_printf(dev, "unable to setup the gpio irq handler\n");
768 		goto fail;
769 	}
770 	/* Find our node. */
771 	gpio = ofw_bus_get_node(sc->sc_dev);
772 	if (!OF_hasprop(gpio, "gpio-controller"))
773 		/* Node is not a GPIO controller. */
774 		goto fail;
775 	/*
776 	 * Find the read-only pins.  These are pins we never touch or bad
777 	 * things could happen.
778 	 */
779 	if (bcm_gpio_get_reserved_pins(sc) == -1)
780 		goto fail;
781 	/* Initialize the software controlled pins. */
782 	for (i = 0, j = 0; j < BCM_GPIO_PINS; j++) {
783 		snprintf(sc->sc_gpio_pins[i].gp_name, GPIOMAXNAME,
784 		    "pin %d", j);
785 		func = bcm_gpio_get_function(sc, j);
786 		sc->sc_gpio_pins[i].gp_pin = j;
787 		sc->sc_gpio_pins[i].gp_caps = BCM_GPIO_DEFAULT_CAPS;
788 		sc->sc_gpio_pins[i].gp_flags = bcm_gpio_func_flag(func);
789 		/* The default is active-low interrupts. */
790 		sc->sc_irq_trigger[i] = INTR_TRIGGER_LEVEL;
791 		sc->sc_irq_polarity[i] = INTR_POLARITY_LOW;
792 		i++;
793 	}
794 	sc->sc_gpio_npins = i;
795 	bcm_gpio_sysctl_init(sc);
796 	sc->sc_busdev = gpiobus_attach_bus(dev);
797 	if (sc->sc_busdev == NULL)
798 		goto fail;
799 
800 	return (0);
801 
802 fail:
803 	bcm_gpio_intr_detach(dev);
804 	bus_release_resources(dev, bcm_gpio_res_spec, sc->sc_res);
805 	mtx_destroy(&sc->sc_mtx);
806 
807 	return (ENXIO);
808 }
809 
810 static int
811 bcm_gpio_detach(device_t dev)
812 {
813 
814 	return (EBUSY);
815 }
816 
817 static uint32_t
818 bcm_gpio_intr_reg(struct bcm_gpio_softc *sc, unsigned int irq, uint32_t bank)
819 {
820 
821 	if (irq > BCM_GPIO_PINS)
822 		return (0);
823 	if (sc->sc_irq_trigger[irq] == INTR_TRIGGER_LEVEL) {
824 		if (sc->sc_irq_polarity[irq] == INTR_POLARITY_LOW)
825 			return (BCM_GPIO_GPLEN(bank));
826 		else if (sc->sc_irq_polarity[irq] == INTR_POLARITY_HIGH)
827 			return (BCM_GPIO_GPHEN(bank));
828 	} else if (sc->sc_irq_trigger[irq] == INTR_TRIGGER_EDGE) {
829 		if (sc->sc_irq_polarity[irq] == INTR_POLARITY_LOW)
830 			return (BCM_GPIO_GPFEN(bank));
831 		else if (sc->sc_irq_polarity[irq] == INTR_POLARITY_HIGH)
832 			return (BCM_GPIO_GPREN(bank));
833 	}
834 
835 	return (0);
836 }
837 
838 static void
839 bcm_gpio_mask_irq(void *source)
840 {
841 	uint32_t bank, mask, reg;
842 	unsigned int irq;
843 
844 	irq = (unsigned int)source;
845 	if (irq > BCM_GPIO_PINS)
846 		return;
847 	if (bcm_gpio_pin_is_ro(bcm_gpio_sc, irq))
848 		return;
849 	bank = BCM_GPIO_BANK(irq);
850 	mask = BCM_GPIO_MASK(irq);
851 	BCM_GPIO_LOCK(bcm_gpio_sc);
852 	reg = bcm_gpio_intr_reg(bcm_gpio_sc, irq, bank);
853 	if (reg != 0)
854 		BCM_GPIO_CLEAR_BITS(bcm_gpio_sc, reg, mask);
855 	BCM_GPIO_UNLOCK(bcm_gpio_sc);
856 }
857 
858 static void
859 bcm_gpio_unmask_irq(void *source)
860 {
861 	uint32_t bank, mask, reg;
862 	unsigned int irq;
863 
864 	irq = (unsigned int)source;
865 	if (irq > BCM_GPIO_PINS)
866 		return;
867 	if (bcm_gpio_pin_is_ro(bcm_gpio_sc, irq))
868 		return;
869 	bank = BCM_GPIO_BANK(irq);
870 	mask = BCM_GPIO_MASK(irq);
871 	BCM_GPIO_LOCK(bcm_gpio_sc);
872 	reg = bcm_gpio_intr_reg(bcm_gpio_sc, irq, bank);
873 	if (reg != 0)
874 		BCM_GPIO_SET_BITS(bcm_gpio_sc, reg, mask);
875 	BCM_GPIO_UNLOCK(bcm_gpio_sc);
876 }
877 
878 static int
879 bcm_gpio_activate_resource(device_t bus, device_t child, int type, int rid,
880 	struct resource *res)
881 {
882 	int pin;
883 
884 	if (type != SYS_RES_IRQ)
885 		return (ENXIO);
886 	/* Unmask the interrupt. */
887 	pin = rman_get_start(res);
888 	bcm_gpio_unmask_irq((void *)pin);
889 
890 	return (0);
891 }
892 
893 static int
894 bcm_gpio_deactivate_resource(device_t bus, device_t child, int type, int rid,
895 	struct resource *res)
896 {
897 	int pin;
898 
899 	if (type != SYS_RES_IRQ)
900 		return (ENXIO);
901 	/* Mask the interrupt. */
902 	pin = rman_get_start(res);
903 	bcm_gpio_mask_irq((void *)pin);
904 
905 	return (0);
906 }
907 
908 static int
909 bcm_gpio_config_intr(device_t dev, int irq, enum intr_trigger trig,
910 	enum intr_polarity pol)
911 {
912 	int bank;
913 	struct bcm_gpio_softc *sc;
914 	uint32_t mask, oldreg, reg;
915 
916 	if (irq > BCM_GPIO_PINS)
917 		return (EINVAL);
918 	/* There is no standard trigger or polarity. */
919 	if (trig == INTR_TRIGGER_CONFORM || pol == INTR_POLARITY_CONFORM)
920 		return (EINVAL);
921 	sc = device_get_softc(dev);
922 	if (bcm_gpio_pin_is_ro(sc, irq))
923 		return (EINVAL);
924 	bank = BCM_GPIO_BANK(irq);
925 	mask = BCM_GPIO_MASK(irq);
926 	BCM_GPIO_LOCK(sc);
927 	oldreg = bcm_gpio_intr_reg(sc, irq, bank);
928 	sc->sc_irq_trigger[irq] = trig;
929 	sc->sc_irq_polarity[irq] = pol;
930 	reg = bcm_gpio_intr_reg(sc, irq, bank);
931 	if (reg != 0)
932 		BCM_GPIO_SET_BITS(sc, reg, mask);
933 	if (reg != oldreg && oldreg != 0)
934 		BCM_GPIO_CLEAR_BITS(sc, oldreg, mask);
935 	BCM_GPIO_UNLOCK(sc);
936 
937 	return (0);
938 }
939 
940 static int
941 bcm_gpio_setup_intr(device_t bus, device_t child, struct resource *ires,
942 	int flags, driver_filter_t *filt, driver_intr_t *handler,
943 	void *arg, void **cookiep)
944 {
945 	struct bcm_gpio_softc *sc;
946 	struct intr_event *event;
947 	int pin, error;
948 
949 	sc = device_get_softc(bus);
950 	pin = rman_get_start(ires);
951 	if (pin > BCM_GPIO_PINS)
952 		panic("%s: bad pin %d", __func__, pin);
953 	event = sc->sc_events[pin];
954 	if (event == NULL) {
955 		error = intr_event_create(&event, (void *)pin, 0, pin,
956 		    bcm_gpio_mask_irq, bcm_gpio_unmask_irq, NULL, NULL,
957 		    "gpio%d pin%d:", device_get_unit(bus), pin);
958 		if (error != 0)
959 			return (error);
960 		sc->sc_events[pin] = event;
961 	}
962 	intr_event_add_handler(event, device_get_nameunit(child), filt,
963 	    handler, arg, intr_priority(flags), flags, cookiep);
964 
965 	return (0);
966 }
967 
968 static int
969 bcm_gpio_teardown_intr(device_t dev, device_t child, struct resource *ires,
970 	void *cookie)
971 {
972 	struct bcm_gpio_softc *sc;
973 	int pin, err;
974 
975 	sc = device_get_softc(dev);
976 	pin = rman_get_start(ires);
977 	if (pin > BCM_GPIO_PINS)
978 		panic("%s: bad pin %d", __func__, pin);
979 	if (sc->sc_events[pin] == NULL)
980 		panic("Trying to teardown unoccupied IRQ");
981 	err = intr_event_remove_handler(cookie);
982 	if (!err)
983 		sc->sc_events[pin] = NULL;
984 
985 	return (err);
986 }
987 
988 static phandle_t
989 bcm_gpio_get_node(device_t bus, device_t dev)
990 {
991 
992 	/* We only have one child, the GPIO bus, which needs our own node. */
993 	return (ofw_bus_get_node(bus));
994 }
995 
996 static device_method_t bcm_gpio_methods[] = {
997 	/* Device interface */
998 	DEVMETHOD(device_probe,		bcm_gpio_probe),
999 	DEVMETHOD(device_attach,	bcm_gpio_attach),
1000 	DEVMETHOD(device_detach,	bcm_gpio_detach),
1001 
1002 	/* GPIO protocol */
1003 	DEVMETHOD(gpio_get_bus,		bcm_gpio_get_bus),
1004 	DEVMETHOD(gpio_pin_max,		bcm_gpio_pin_max),
1005 	DEVMETHOD(gpio_pin_getname,	bcm_gpio_pin_getname),
1006 	DEVMETHOD(gpio_pin_getflags,	bcm_gpio_pin_getflags),
1007 	DEVMETHOD(gpio_pin_getcaps,	bcm_gpio_pin_getcaps),
1008 	DEVMETHOD(gpio_pin_setflags,	bcm_gpio_pin_setflags),
1009 	DEVMETHOD(gpio_pin_get,		bcm_gpio_pin_get),
1010 	DEVMETHOD(gpio_pin_set,		bcm_gpio_pin_set),
1011 	DEVMETHOD(gpio_pin_toggle,	bcm_gpio_pin_toggle),
1012 
1013 	/* Bus interface */
1014 	DEVMETHOD(bus_activate_resource,	bcm_gpio_activate_resource),
1015 	DEVMETHOD(bus_deactivate_resource,	bcm_gpio_deactivate_resource),
1016 	DEVMETHOD(bus_config_intr,	bcm_gpio_config_intr),
1017 	DEVMETHOD(bus_setup_intr,	bcm_gpio_setup_intr),
1018 	DEVMETHOD(bus_teardown_intr,	bcm_gpio_teardown_intr),
1019 
1020 	/* ofw_bus interface */
1021 	DEVMETHOD(ofw_bus_get_node,	bcm_gpio_get_node),
1022 
1023 	DEVMETHOD_END
1024 };
1025 
1026 static devclass_t bcm_gpio_devclass;
1027 
1028 static driver_t bcm_gpio_driver = {
1029 	"gpio",
1030 	bcm_gpio_methods,
1031 	sizeof(struct bcm_gpio_softc),
1032 };
1033 
1034 DRIVER_MODULE(bcm_gpio, simplebus, bcm_gpio_driver, bcm_gpio_devclass, 0, 0);
1035