xref: /netbsd-src/sys/arch/arm/broadcom/bcm2835_gpio.c (revision bdc22b2e01993381dcefeff2bc9b56ca75a4235c)
1 /*	$NetBSD: bcm2835_gpio.c,v 1.7 2018/05/19 14:02:10 thorpej Exp $	*/
2 
3 /*-
4  * Copyright (c) 2013, 2014, 2017 The NetBSD Foundation, Inc.
5  * All rights reserved.
6  *
7  * This code is derived from software contributed to The NetBSD Foundation
8  * by Jonathan A. Kollasch, Frank Kardel and Nick Hudson
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
20  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT HOLDER OR
23  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
24  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
25  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
26  * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
27  * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
28  * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
29  * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
30  */
31 
32 #include <sys/cdefs.h>
33 __KERNEL_RCSID(0, "$NetBSD: bcm2835_gpio.c,v 1.7 2018/05/19 14:02:10 thorpej Exp $");
34 
35 /*
36  * Driver for BCM2835 GPIO
37  *
38  * see: http://www.raspberrypi.org/wp-content/uploads/2012/02/BCM2835-ARM-Peripherals.pdf
39  */
40 
41 #include <sys/param.h>
42 #include <sys/device.h>
43 #include <sys/systm.h>
44 #include <sys/mutex.h>
45 #include <sys/bus.h>
46 #include <sys/intr.h>
47 #include <sys/kernel.h>
48 #include <sys/kmem.h>
49 #include <sys/proc.h>
50 #include <sys/gpio.h>
51 
52 #include <sys/bitops.h>
53 
54 #include <arm/broadcom/bcm2835reg.h>
55 #include <arm/broadcom/bcm2835_gpioreg.h>
56 
57 #include <dev/gpio/gpiovar.h>
58 #include <dev/fdt/fdtvar.h>
59 
60 /* #define BCM2835_GPIO_DEBUG */
61 #ifdef BCM2835_GPIO_DEBUG
62 int bcm2835gpiodebug = 3;
63 #define DPRINTF(l, x)	do { if (l <= bcm2835gpiodebug) { printf x; } } while (0)
64 #else
65 #define DPRINTF(l, x)
66 #endif
67 
68 #define	BCMGPIO_MAXPINS	54
69 
70 struct bcmgpio_eint {
71 	 int			(*eint_func)(void *);
72 	 void			*eint_arg;
73 	 int			eint_flags;
74 	 int			eint_bank;
75 	 int			eint_num;
76 };
77 
78 #define	BCMGPIO_INTR_POS_EDGE	0x01
79 #define	BCMGPIO_INTR_NEG_EDGE	0x02
80 #define	BCMGPIO_INTR_HIGH_LEVEL	0x04
81 #define	BCMGPIO_INTR_LOW_LEVEL	0x08
82 #define	BCMGPIO_INTR_MPSAFE	0x10
83 
84 struct bcmgpio_softc;
85 struct bcmgpio_bank {
86 	struct bcmgpio_softc	*sc_bcm;
87 	void			*sc_ih;
88 	struct bcmgpio_eint	sc_eint[32];
89 	int			sc_bankno;
90 };
91 #define	BCMGPIO_NBANKS	2
92 
93 struct bcmgpio_softc {
94 	device_t		sc_dev;
95 	bus_space_tag_t		sc_iot;
96 	bus_space_handle_t	sc_ioh;
97 	struct gpio_chipset_tag	sc_gpio_gc;
98 
99 	kmutex_t		sc_lock;
100 	gpio_pin_t		sc_gpio_pins[BCMGPIO_MAXPINS];
101 
102 	/* For interrupt support. */
103 	struct bcmgpio_bank	sc_banks[BCMGPIO_NBANKS];
104 };
105 
106 struct bcmgpio_pin {
107 	int			pin_no;
108 	u_int			pin_flags;
109 	bool			pin_actlo;
110 };
111 
112 
113 static int	bcmgpio_match(device_t, cfdata_t, void *);
114 static void	bcmgpio_attach(device_t, device_t, void *);
115 
116 static int	bcm2835gpio_gpio_pin_read(void *, int);
117 static void	bcm2835gpio_gpio_pin_write(void *, int, int);
118 static void	bcm2835gpio_gpio_pin_ctl(void *, int, int);
119 
120 static void *	bcmgpio_gpio_intr_establish(void *, int, int, int,
121 					    int (*)(void *), void *);
122 static void	bcmgpio_gpio_intr_disestablish(void *, void *);
123 static bool	bcmgpio_gpio_intrstr(void *, int, int, char *, size_t);
124 
125 static int	bcmgpio_intr(void *);
126 
127 u_int		bcm283x_pin_getfunc(const struct bcmgpio_softc * const, u_int);
128 void		bcm283x_pin_setfunc(const struct bcmgpio_softc * const, u_int,
129 		    u_int);
130 void		bcm283x_pin_setpull(const struct bcmgpio_softc * const, u_int,
131 		    u_int);
132 
133 static int 	bcm283x_pinctrl_set_config(device_t, const void *, size_t);
134 
135 static void *	bcmgpio_fdt_acquire(device_t, const void *, size_t, int);
136 static void	bcmgpio_fdt_release(device_t, void *);
137 static int	bcmgpio_fdt_read(device_t, void *, bool);
138 static void	bcmgpio_fdt_write(device_t, void *, int, bool);
139 
140 static struct fdtbus_gpio_controller_func bcmgpio_funcs = {
141 	.acquire = bcmgpio_fdt_acquire,
142 	.release = bcmgpio_fdt_release,
143 	.read = bcmgpio_fdt_read,
144 	.write = bcmgpio_fdt_write
145 };
146 
147 static void *	bcmgpio_fdt_intr_establish(device_t, u_int *, int, int,
148 		    int (*func)(void *), void *);
149 static void	bcmgpio_fdt_intr_disestablish(device_t, void *);
150 static bool	bcmgpio_fdt_intrstr(device_t, u_int *, char *, size_t);
151 
152 static struct fdtbus_interrupt_controller_func bcmgpio_fdt_intrfuncs = {
153 	.establish = bcmgpio_fdt_intr_establish,
154 	.disestablish = bcmgpio_fdt_intr_disestablish,
155 	.intrstr = bcmgpio_fdt_intrstr,
156 };
157 
158 CFATTACH_DECL_NEW(bcmgpio, sizeof(struct bcmgpio_softc),
159     bcmgpio_match, bcmgpio_attach, NULL, NULL);
160 
161 
162 static struct fdtbus_pinctrl_controller_func bcm283x_pinctrl_funcs = {
163 	.set_config = bcm283x_pinctrl_set_config,
164 };
165 
166 static int
167 bcm283x_pinctrl_set_config(device_t dev, const void *data, size_t len)
168 {
169 	struct bcmgpio_softc * const sc = device_private(dev);
170 
171 	if (len != 4)
172 		return -1;
173 
174 	const int phandle = fdtbus_get_phandle_from_native(be32dec(data));
175 
176 	/*
177 	 * Required: brcm,pins
178 	 * Optional: brcm,function, brcm,pull
179 	 */
180 
181 	int pins_len;
182 	const u_int *pins = fdtbus_get_prop(phandle, "brcm,pins", &pins_len);
183 
184 	if (pins == NULL)
185 		return -1;
186 
187 	int pull_len = 0;
188 	const u_int *pull = fdtbus_get_prop(phandle, "brcm,pull", &pull_len);
189 
190 	int func_len = 0;
191 	const u_int *func = fdtbus_get_prop(phandle, "brcm,function", &func_len);
192 
193 	if (!pull && !func) {
194 		aprint_error_dev(dev, "one of brcm,pull or brcm,funcion must "
195 		    "be specified");
196 		return -1;
197 	}
198 
199 	const int npins = pins_len / 4;
200 	const int npull = pull_len / 4;
201 	const int nfunc = func_len / 4;
202 
203 	if (npull > 1 && npull != npins) {
204 		aprint_error_dev(dev, "brcm,pull must have 1 or %d entries",
205 		    npins);
206 		return -1;
207 	}
208 	if (nfunc > 1 && nfunc != npins) {
209 		aprint_error_dev(dev, "brcm,function must have 1 or %d entries",
210 		    npins);
211 		return -1;
212 	}
213 
214 	mutex_enter(&sc->sc_lock);
215 
216 	for (int i = 0; i < npins; i++) {
217 		const u_int pin = be32toh(pins[i]);
218 
219 		if (pin > BCMGPIO_MAXPINS)
220 			continue;
221 		if (pull) {
222 			const int value = be32toh(pull[npull == 1 ? 0 : i]);
223 			bcm283x_pin_setpull(sc, pin, value);
224 		}
225 		if (func) {
226 			const int value = be32toh(func[nfunc == 1 ? 0 : i]);
227 			bcm283x_pin_setfunc(sc, pin, value);
228 		}
229 	}
230 
231 	mutex_exit(&sc->sc_lock);
232 
233 	return 0;
234 }
235 
236 static int
237 bcmgpio_match(device_t parent, cfdata_t cf, void *aux)
238 {
239 	const char * const compatible[] = { "brcm,bcm2835-gpio", NULL };
240 	struct fdt_attach_args * const faa = aux;
241 
242 	return of_match_compatible(faa->faa_phandle, compatible);
243 }
244 
245 static void
246 bcmgpio_attach(device_t parent, device_t self, void *aux)
247 {
248 	struct bcmgpio_softc * const sc = device_private(self);
249 	struct fdt_attach_args * const faa = aux;
250 	struct gpiobus_attach_args gba;
251 	bus_addr_t addr;
252 	bus_size_t size;
253 	u_int func;
254 	int error;
255 	int pin;
256 	int bank;
257 
258 	const int phandle = faa->faa_phandle;
259 	if (fdtbus_get_reg(phandle, 0, &addr, &size) != 0) {
260 		aprint_error(": couldn't get registers\n");
261 		return;
262 	}
263 
264 	sc->sc_dev = self;
265 
266 	aprint_naive("\n");
267 	aprint_normal(": GPIO controller\n");
268 
269 	sc->sc_iot = faa->faa_bst;
270 	error = bus_space_map(sc->sc_iot, addr, size, 0, &sc->sc_ioh);
271 	if (error) {
272 		aprint_error_dev(self, "couldn't map registers\n");
273 		return;
274 	}
275 
276 	mutex_init(&sc->sc_lock, MUTEX_DEFAULT, IPL_VM);
277 
278 	for (pin = 0; pin < BCMGPIO_MAXPINS; pin++) {
279 		sc->sc_gpio_pins[pin].pin_num = pin;
280 		/*
281 		 * find out pins still available for GPIO
282 		 */
283 		func = bcm283x_pin_getfunc(sc, pin);
284 
285 		if (func == BCM2835_GPIO_IN ||
286 		    func == BCM2835_GPIO_OUT) {
287 			/* XXX TRISTATE?  Really? */
288 			sc->sc_gpio_pins[pin].pin_caps = GPIO_PIN_INPUT |
289 				GPIO_PIN_OUTPUT |
290 				GPIO_PIN_PUSHPULL | GPIO_PIN_TRISTATE |
291 				GPIO_PIN_PULLUP | GPIO_PIN_PULLDOWN;
292 			sc->sc_gpio_pins[pin].pin_intrcaps =
293 				GPIO_INTR_POS_EDGE |
294 				GPIO_INTR_NEG_EDGE |
295 				GPIO_INTR_DOUBLE_EDGE |
296 				GPIO_INTR_HIGH_LEVEL |
297 				GPIO_INTR_LOW_LEVEL |
298 				GPIO_INTR_MPSAFE;
299 			/* read initial state */
300 			sc->sc_gpio_pins[pin].pin_state =
301 				bcm2835gpio_gpio_pin_read(sc, pin);
302 			DPRINTF(1, ("%s: attach pin %d\n", device_xname(sc->sc_dev), pin));
303 		} else {
304 			sc->sc_gpio_pins[pin].pin_caps = 0;
305 			sc->sc_gpio_pins[pin].pin_state = 0;
306   			DPRINTF(1, ("%s: skip pin %d - func = 0x%x\n", device_xname(sc->sc_dev), pin, func));
307 		}
308 	}
309 
310 	/* Initialize interrupts. */
311 	for (bank = 0; bank < BCMGPIO_NBANKS; bank++) {
312 		char intrstr[128];
313 
314 		if (!fdtbus_intr_str(phandle, bank, intrstr, sizeof(intrstr))) {
315 			aprint_error_dev(self, "failed to decode interrupt\n");
316 			continue;
317 		}
318 
319 		sc->sc_banks[bank].sc_bankno = bank;
320 		sc->sc_banks[bank].sc_bcm = sc;
321 		sc->sc_banks[bank].sc_ih =
322 		    fdtbus_intr_establish(phandle, bank, IPL_VM,
323 		    			  FDT_INTR_MPSAFE,
324 					  bcmgpio_intr, &sc->sc_banks[bank]);
325 		if (sc->sc_banks[bank].sc_ih) {
326 			aprint_normal_dev(self,
327 			    "pins %d..%d interrupting on %s\n",
328 			    bank * 32,
329 			    MIN((bank * 32) + 31, BCMGPIO_MAXPINS),
330 			    intrstr);
331 		} else {
332 			aprint_normal_dev(self,
333 			    "failed to establish interrupt for pins %d..%d\n",
334 			    bank * 32,
335 			    MIN((bank * 32) + 31, BCMGPIO_MAXPINS));
336 		}
337 	}
338 
339 	fdtbus_register_gpio_controller(self, faa->faa_phandle, &bcmgpio_funcs);
340 
341 	for (int child = OF_child(phandle); child; child = OF_peer(child)) {
342 		if (!of_hasprop(child, "brcm,pins"))
343 			continue;
344 		fdtbus_register_pinctrl_config(self, child,
345 		    &bcm283x_pinctrl_funcs);
346 	}
347 
348 	fdtbus_pinctrl_configure();
349 
350 	fdtbus_register_interrupt_controller(self, phandle,
351 	    &bcmgpio_fdt_intrfuncs);
352 
353 	/* create controller tag */
354 	sc->sc_gpio_gc.gp_cookie = sc;
355 	sc->sc_gpio_gc.gp_pin_read = bcm2835gpio_gpio_pin_read;
356 	sc->sc_gpio_gc.gp_pin_write = bcm2835gpio_gpio_pin_write;
357 	sc->sc_gpio_gc.gp_pin_ctl = bcm2835gpio_gpio_pin_ctl;
358 	sc->sc_gpio_gc.gp_intr_establish = bcmgpio_gpio_intr_establish;
359 	sc->sc_gpio_gc.gp_intr_disestablish = bcmgpio_gpio_intr_disestablish;
360 	sc->sc_gpio_gc.gp_intr_str = bcmgpio_gpio_intrstr;
361 
362 	gba.gba_gc = &sc->sc_gpio_gc;
363 	gba.gba_pins = &sc->sc_gpio_pins[0];
364 	gba.gba_npins = BCMGPIO_MAXPINS;
365 	(void) config_found_ia(self, "gpiobus", &gba, gpiobus_print);
366 }
367 
368 /* GPIO interrupt support functions */
369 
370 static int
371 bcmgpio_intr(void *arg)
372 {
373 	struct bcmgpio_bank * const b = arg;
374 	struct bcmgpio_softc * const sc = b->sc_bcm;
375 	struct bcmgpio_eint *eint;
376 	uint32_t status, pending, bit;
377 	uint32_t clear_level;
378 	int (*func)(void *);
379 	int rv = 0;
380 
381 	for (;;) {
382 		status = pending = bus_space_read_4(sc->sc_iot, sc->sc_ioh,
383 		    BCM2835_GPIO_GPEDS(b->sc_bankno));
384 		if (status == 0)
385 			break;
386 
387 		/*
388 		 * This will clear the indicator for any pending
389 		 * edge-triggered pins, but level-triggered pins
390 		 * will still be indicated until the pin is
391 		 * de-asserted.  We'll have to clear level-triggered
392 		 * indicators below.
393 		 */
394 		bus_space_write_4(sc->sc_iot, sc->sc_ioh,
395 		    BCM2835_GPIO_GPEDS(b->sc_bankno), status);
396 		clear_level = 0;
397 
398 		while ((bit = ffs32(pending)) != 0) {
399 			pending &= ~__BIT(bit - 1);
400 			eint = &b->sc_eint[bit - 1];
401 			if ((func = eint->eint_func) == NULL)
402 				continue;
403 			if (eint->eint_flags & (BCMGPIO_INTR_HIGH_LEVEL |
404 						BCMGPIO_INTR_LOW_LEVEL))
405 				clear_level |= __BIT(bit - 1);
406 			const bool mpsafe =
407 			    (eint->eint_flags & BCMGPIO_INTR_MPSAFE) != 0;
408 			if (!mpsafe)
409 				KERNEL_LOCK(1, curlwp);
410 			rv |= (*func)(eint->eint_arg);
411 			if (!mpsafe)
412 				KERNEL_UNLOCK_ONE(curlwp);
413 		}
414 
415 		/*
416 		 * Now that all of the handlers have been called,
417 		 * we can clear the indicators for any level-triggered
418 		 * pins.
419 		 */
420 		if (clear_level)
421 			bus_space_write_4(sc->sc_iot, sc->sc_ioh,
422 			    BCM2835_GPIO_GPEDS(b->sc_bankno), clear_level);
423 	}
424 
425 	return (rv);
426 }
427 
428 static void *
429 bmcgpio_intr_enable(struct bcmgpio_softc *sc, int (*func)(void *), void *arg,
430 		    int bank, int pin, int flags)
431 {
432 	struct bcmgpio_eint *eint;
433 	uint32_t mask, enabled_ren, enabled_fen, enabled_hen, enabled_len;
434 	int has_edge = flags & (BCMGPIO_INTR_POS_EDGE|BCMGPIO_INTR_NEG_EDGE);
435 	int has_level = flags &
436 	    (BCMGPIO_INTR_HIGH_LEVEL|BCMGPIO_INTR_LOW_LEVEL);
437 
438 	if (bank < 0 || bank >= BCMGPIO_NBANKS)
439 		return NULL;
440 	if (pin < 0 || pin >= 32)
441 		return (NULL);
442 
443 	/* Must specify a mode. */
444 	if (!has_edge && !has_level)
445 		return (NULL);
446 
447 	/* Can't have HIGH and LOW together. */
448 	if (has_level == (BCMGPIO_INTR_HIGH_LEVEL|BCMGPIO_INTR_LOW_LEVEL))
449 		return (NULL);
450 
451 	/* Can't have EDGE and LEVEL together. */
452 	if (has_edge && has_level)
453 		return (NULL);
454 
455 	eint = &sc->sc_banks[bank].sc_eint[pin];
456 
457 	mask = __BIT(pin);
458 
459 	mutex_enter(&sc->sc_lock);
460 
461 	if (eint->eint_func != NULL) {
462 		mutex_exit(&sc->sc_lock);
463 		return (NULL);	/* in use */
464 	}
465 
466 	eint->eint_func = func;
467 	eint->eint_arg = arg;
468 	eint->eint_flags = flags;
469 	eint->eint_bank = bank;
470 	eint->eint_num = pin;
471 
472 	enabled_ren = bus_space_read_4(sc->sc_iot, sc->sc_ioh,
473 				       BCM2835_GPIO_GPREN(bank));
474 	enabled_fen = bus_space_read_4(sc->sc_iot, sc->sc_ioh,
475 				       BCM2835_GPIO_GPFEN(bank));
476 	enabled_hen = bus_space_read_4(sc->sc_iot, sc->sc_ioh,
477 				       BCM2835_GPIO_GPHEN(bank));
478 	enabled_len = bus_space_read_4(sc->sc_iot, sc->sc_ioh,
479 				       BCM2835_GPIO_GPLEN(bank));
480 
481 	enabled_ren &= ~mask;
482 	enabled_fen &= ~mask;
483 	enabled_hen &= ~mask;
484 	enabled_len &= ~mask;
485 
486 	if (flags & BCMGPIO_INTR_POS_EDGE)
487 		enabled_ren |= mask;
488 	if (flags & BCMGPIO_INTR_NEG_EDGE)
489 		enabled_fen |= mask;
490 	if (flags & BCMGPIO_INTR_HIGH_LEVEL)
491 		enabled_hen |= mask;
492 	if (flags & BCMGPIO_INTR_LOW_LEVEL)
493 		enabled_len |= mask;
494 
495 	bus_space_write_4(sc->sc_iot, sc->sc_ioh,
496 			  BCM2835_GPIO_GPREN(bank), enabled_ren);
497 	bus_space_write_4(sc->sc_iot, sc->sc_ioh,
498 			  BCM2835_GPIO_GPFEN(bank), enabled_fen);
499 	bus_space_write_4(sc->sc_iot, sc->sc_ioh,
500 			  BCM2835_GPIO_GPHEN(bank), enabled_hen);
501 	bus_space_write_4(sc->sc_iot, sc->sc_ioh,
502 			  BCM2835_GPIO_GPLEN(bank), enabled_len);
503 
504 	mutex_exit(&sc->sc_lock);
505 	return (eint);
506 }
507 
508 static void
509 bcmgpio_intr_disable(struct bcmgpio_softc *sc, struct bcmgpio_eint *eint)
510 {
511 	uint32_t mask, enabled_ren, enabled_fen, enabled_hen, enabled_len;
512 	int bank = eint->eint_bank;
513 
514 	mask = __BIT(eint->eint_num);
515 
516 	KASSERT(eint->eint_func != NULL);
517 
518 	mutex_enter(&sc->sc_lock);
519 
520 	enabled_ren = bus_space_read_4(sc->sc_iot, sc->sc_ioh,
521 				       BCM2835_GPIO_GPREN(bank));
522 	enabled_fen = bus_space_read_4(sc->sc_iot, sc->sc_ioh,
523 				       BCM2835_GPIO_GPFEN(bank));
524 	enabled_hen = bus_space_read_4(sc->sc_iot, sc->sc_ioh,
525 				       BCM2835_GPIO_GPHEN(bank));
526 	enabled_len = bus_space_read_4(sc->sc_iot, sc->sc_ioh,
527 				       BCM2835_GPIO_GPLEN(bank));
528 
529 	enabled_ren &= ~mask;
530 	enabled_fen &= ~mask;
531 	enabled_hen &= ~mask;
532 	enabled_len &= ~mask;
533 
534 	bus_space_write_4(sc->sc_iot, sc->sc_ioh,
535 			  BCM2835_GPIO_GPREN(bank), enabled_ren);
536 	bus_space_write_4(sc->sc_iot, sc->sc_ioh,
537 			  BCM2835_GPIO_GPFEN(bank), enabled_fen);
538 	bus_space_write_4(sc->sc_iot, sc->sc_ioh,
539 			  BCM2835_GPIO_GPHEN(bank), enabled_hen);
540 	bus_space_write_4(sc->sc_iot, sc->sc_ioh,
541 			  BCM2835_GPIO_GPLEN(bank), enabled_len);
542 
543 	eint->eint_func = NULL;
544 	eint->eint_arg = NULL;
545 	eint->eint_flags = 0;
546 
547 	mutex_exit(&sc->sc_lock);
548 }
549 
550 static void *
551 bcmgpio_fdt_intr_establish(device_t dev, u_int *specifier, int ipl, int flags,
552     int (*func)(void *), void *arg)
553 {
554 	struct bcmgpio_softc * const sc = device_private(dev);
555 	int eint_flags = (flags & FDT_INTR_MPSAFE) ? BCMGPIO_INTR_MPSAFE : 0;
556 
557 	if (ipl != IPL_VM) {
558 		aprint_error_dev(dev, "%s: wrong IPL %d (expected %d)\n",
559 		    __func__, ipl, IPL_VM);
560 		return (NULL);
561 	}
562 
563 	/* 1st cell is the bank */
564 	/* 2nd cell is the pin */
565 	/* 3rd cell is flags */
566 	const u_int bank = be32toh(specifier[0]);
567 	const u_int pin = be32toh(specifier[1]);
568 	const u_int type = be32toh(specifier[2]) & 0xf;
569 
570 	switch (type) {
571 	case 0x1:
572 		eint_flags |= BCMGPIO_INTR_POS_EDGE;
573 		break;
574 	case 0x2:
575 		eint_flags |= BCMGPIO_INTR_NEG_EDGE;
576 		break;
577 	case 0x3:
578 		eint_flags |= BCMGPIO_INTR_POS_EDGE | BCMGPIO_INTR_NEG_EDGE;
579 		break;
580 	case 0x4:
581 		eint_flags |= BCMGPIO_INTR_HIGH_LEVEL;
582 		break;
583 	case 0x8:
584 		eint_flags |= BCMGPIO_INTR_LOW_LEVEL;
585 		break;
586 	default:
587 		aprint_error_dev(dev, "%s: unsupported irq type 0x%x\n",
588 		    __func__, type);
589 		return (NULL);
590 	}
591 
592 	return (bmcgpio_intr_enable(sc, func, arg, bank, pin, eint_flags));
593 }
594 
595 static void
596 bcmgpio_fdt_intr_disestablish(device_t dev, void *ih)
597 {
598 	struct bcmgpio_softc * const sc = device_private(dev);
599 	struct bcmgpio_eint * const eint = ih;
600 
601 	bcmgpio_intr_disable(sc, eint);
602 }
603 
604 static void *
605 bcmgpio_gpio_intr_establish(void *vsc, int pin, int ipl, int irqmode,
606 			    int (*func)(void *), void *arg)
607 {
608 	struct bcmgpio_softc * const sc = vsc;
609 	int eint_flags = (irqmode & GPIO_INTR_MPSAFE) ? BCMGPIO_INTR_MPSAFE : 0;
610 	int bank = pin / 32;
611 	int type = irqmode & GPIO_INTR_MODE_MASK;
612 
613 	pin %= 32;
614 
615 	if (ipl != IPL_VM) {
616 		aprint_error_dev(sc->sc_dev, "%s: wrong IPL %d (expected %d)\n",
617 		    __func__, ipl, IPL_VM);
618 		return (NULL);
619 	}
620 
621 	switch (type) {
622 	case GPIO_INTR_POS_EDGE:
623 		eint_flags |= BCMGPIO_INTR_POS_EDGE;
624 		break;
625 	case GPIO_INTR_NEG_EDGE:
626 		eint_flags |= BCMGPIO_INTR_NEG_EDGE;
627 		break;
628 	case GPIO_INTR_DOUBLE_EDGE:
629 		eint_flags |= BCMGPIO_INTR_POS_EDGE | BCMGPIO_INTR_NEG_EDGE;
630 		break;
631 	case GPIO_INTR_HIGH_LEVEL:
632 		eint_flags |= BCMGPIO_INTR_HIGH_LEVEL;
633 		break;
634 	case GPIO_INTR_LOW_LEVEL:
635 		eint_flags |= BCMGPIO_INTR_LOW_LEVEL;
636 		break;
637 	default:
638 		aprint_error_dev(sc->sc_dev, "%s: unsupported irq type 0x%x\n",
639 		    __func__, type);
640 		return (NULL);
641 	}
642 
643 	return (bmcgpio_intr_enable(sc, func, arg, bank, pin, eint_flags));
644 }
645 
646 static void
647 bcmgpio_gpio_intr_disestablish(void *vsc, void *ih)
648 {
649 	struct bcmgpio_softc * const sc = vsc;
650 	struct bcmgpio_eint * const eint = ih;
651 
652 	bcmgpio_intr_disable(sc, eint);
653 }
654 
655 static bool
656 bcmgpio_gpio_intrstr(void *vsc, int pin, int irqmode, char *buf, size_t buflen)
657 {
658 
659 	if (pin < 0 || pin >= BCMGPIO_MAXPINS)
660 		return (false);
661 
662 	snprintf(buf, buflen, "GPIO %d", pin);
663 
664 	return (true);
665 }
666 
667 static bool
668 bcmgpio_fdt_intrstr(device_t dev, u_int *specifier, char *buf, size_t buflen)
669 {
670 
671 	/* 1st cell is the bank */
672 	/* 2nd cell is the pin */
673 	/* 3rd cell is flags */
674 	if (!specifier)
675 		return (false);
676 	const u_int bank = be32toh(specifier[0]);
677 	const u_int pin = be32toh(specifier[1]);
678 
679 	if (bank >= BCMGPIO_NBANKS)
680 		return (false);
681 	if (pin >= 32)
682 		return (false);
683 
684 	snprintf(buf, buflen, "GPIO %u", (bank * 32) + pin);
685 
686 	return (true);
687 }
688 
689 /* GPIO support functions */
690 static int
691 bcm2835gpio_gpio_pin_read(void *arg, int pin)
692 {
693 	struct bcmgpio_softc *sc = arg;
694 	uint32_t val;
695 	int res;
696 
697 	val = bus_space_read_4(sc->sc_iot, sc->sc_ioh,
698 		BCM2835_GPIO_GPLEV(pin / BCM2835_GPIO_GPLEV_PINS_PER_REGISTER));
699 
700 	res = val & (1 << (pin % BCM2835_GPIO_GPLEV_PINS_PER_REGISTER)) ?
701 		GPIO_PIN_HIGH : GPIO_PIN_LOW;
702 
703 	DPRINTF(2, ("%s: gpio_read pin %d->%d\n", device_xname(sc->sc_dev),
704 	    pin, (res == GPIO_PIN_HIGH)));
705 
706 	return res;
707 }
708 
709 static void
710 bcm2835gpio_gpio_pin_write(void *arg, int pin, int value)
711 {
712 	struct bcmgpio_softc *sc = arg;
713 	bus_size_t reg;
714 
715 	if (value == GPIO_PIN_HIGH) {
716 		reg = BCM2835_GPIO_GPSET(pin / BCM2835_GPIO_GPSET_PINS_PER_REGISTER);
717 	} else {
718 		reg = BCM2835_GPIO_GPCLR(pin / BCM2835_GPIO_GPCLR_PINS_PER_REGISTER);
719 	}
720 
721 	bus_space_write_4(sc->sc_iot, sc->sc_ioh, reg,
722 	    1 << (pin % BCM2835_GPIO_GPSET_PINS_PER_REGISTER));
723 
724 	DPRINTF(2, ("%s: gpio_write pin %d<-%d\n", device_xname(sc->sc_dev),
725 	    pin, (value == GPIO_PIN_HIGH)));
726 }
727 
728 
729 void
730 bcm283x_pin_setfunc(const struct bcmgpio_softc * const sc, u_int pin,
731     u_int func)
732 {
733 	const u_int mask = (1 << BCM2835_GPIO_GPFSEL_BITS_PER_PIN) - 1;
734 	const u_int regid = (pin / BCM2835_GPIO_GPFSEL_PINS_PER_REGISTER);
735 	const u_int shift = (pin % BCM2835_GPIO_GPFSEL_PINS_PER_REGISTER) *
736 	    BCM2835_GPIO_GPFSEL_BITS_PER_PIN;
737 	uint32_t v;
738 
739 	KASSERT(mutex_owned(&sc->sc_lock));
740 	KASSERT(func <= mask);
741 
742 	v = bus_space_read_4(sc->sc_iot, sc->sc_ioh, BCM2835_GPIO_GPFSEL(regid));
743 
744 	if (((v >> shift) & mask) == func) {
745 		return;
746 	}
747 
748 	DPRINTF(2, ("%s: gpio_write pin %d<-%d\n", device_xname(sc->sc_dev),
749 	    pin, func));
750 
751 	v &= ~(mask << shift);
752 	v |=  (func << shift);
753 
754 	bus_space_write_4(sc->sc_iot, sc->sc_ioh, BCM2835_GPIO_GPFSEL(regid), v);
755 }
756 
757 u_int
758 bcm283x_pin_getfunc(const struct bcmgpio_softc * const sc, u_int pin)
759 {
760 	const u_int mask = (1 << BCM2835_GPIO_GPFSEL_BITS_PER_PIN) - 1;
761 	const u_int regid = (pin / BCM2835_GPIO_GPFSEL_PINS_PER_REGISTER);
762 	const u_int shift = (pin % BCM2835_GPIO_GPFSEL_PINS_PER_REGISTER) *
763 	    BCM2835_GPIO_GPFSEL_BITS_PER_PIN;
764 	uint32_t v;
765 
766 	v = bus_space_read_4(sc->sc_iot, sc->sc_ioh, BCM2835_GPIO_GPFSEL(regid));
767 
768 	return ((v >> shift) & mask);
769 }
770 
771 void
772 bcm283x_pin_setpull(const struct bcmgpio_softc * const sc, u_int pin, u_int pud)
773 {
774 
775 	KASSERT(mutex_owned(&sc->sc_lock));
776 
777 	const u_int mask = 1 << (pin % BCM2835_GPIO_GPPUD_PINS_PER_REGISTER);
778 	const u_int regid = (pin / BCM2835_GPIO_GPPUD_PINS_PER_REGISTER);
779 
780 	bus_space_write_4(sc->sc_iot, sc->sc_ioh, BCM2835_GPIO_GPPUD, pud);
781 	delay(1);
782 	bus_space_write_4(sc->sc_iot, sc->sc_ioh, BCM2835_GPIO_GPPUDCLK(regid), mask);
783 	delay(1);
784 	bus_space_write_4(sc->sc_iot, sc->sc_ioh, BCM2835_GPIO_GPPUD, 0);
785 	bus_space_write_4(sc->sc_iot, sc->sc_ioh, BCM2835_GPIO_GPPUDCLK(regid), 0);
786 }
787 
788 
789 static void
790 bcm2835gpio_gpio_pin_ctl(void *arg, int pin, int flags)
791 {
792 	struct bcmgpio_softc *sc = arg;
793 	uint32_t cmd;
794 
795 	DPRINTF(2, ("%s: gpio_ctl pin %d flags 0x%x\n", device_xname(sc->sc_dev), pin, flags));
796 
797 	mutex_enter(&sc->sc_lock);
798 	if (flags & (GPIO_PIN_OUTPUT|GPIO_PIN_INPUT)) {
799 		if ((flags & GPIO_PIN_INPUT) || !(flags & GPIO_PIN_OUTPUT)) {
800 			/* for safety INPUT will overide output */
801 			bcm283x_pin_setfunc(sc, pin, BCM2835_GPIO_IN);
802 		} else {
803 			bcm283x_pin_setfunc(sc, pin, BCM2835_GPIO_OUT);
804 		}
805 	}
806 
807 	if (flags & (GPIO_PIN_PULLUP|GPIO_PIN_PULLDOWN)) {
808 		cmd = (flags & GPIO_PIN_PULLUP) ?
809 			BCM2835_GPIO_GPPUD_PULLUP : BCM2835_GPIO_GPPUD_PULLDOWN;
810 	} else {
811 		cmd = BCM2835_GPIO_GPPUD_PULLOFF;
812 	}
813 
814 	/* set up control signal */
815 	bus_space_write_4(sc->sc_iot, sc->sc_ioh, BCM2835_GPIO_GPPUD, cmd);
816 	delay(1); /* wait 150 cycles */
817 	/* set clock signal */
818 	bus_space_write_4(sc->sc_iot, sc->sc_ioh,
819 	    BCM2835_GPIO_GPPUDCLK(pin / BCM2835_GPIO_GPLEV_PINS_PER_REGISTER),
820 	    1 << (pin % BCM2835_GPIO_GPPUD_PINS_PER_REGISTER));
821 	delay(1); /* wait 150 cycles */
822 	/* reset control signal and clock */
823 	bus_space_write_4(sc->sc_iot, sc->sc_ioh,
824 	    BCM2835_GPIO_GPPUD, BCM2835_GPIO_GPPUD_PULLOFF);
825 	bus_space_write_4(sc->sc_iot, sc->sc_ioh,
826 	    BCM2835_GPIO_GPPUDCLK(pin / BCM2835_GPIO_GPLEV_PINS_PER_REGISTER),
827 	    0);
828 	mutex_exit(&sc->sc_lock);
829 }
830 
831 static void *
832 bcmgpio_fdt_acquire(device_t dev, const void *data, size_t len, int flags)
833 {
834 	struct bcmgpio_softc *sc = device_private(dev);
835 	struct bcmgpio_pin *gpin;
836 	const u_int *gpio = data;
837 
838 	if (len != 12)
839 		return NULL;
840 
841 	const u_int pin = be32toh(gpio[1]);
842 	const bool actlo = be32toh(gpio[2]) & 1;
843 
844 	if (pin >= BCMGPIO_MAXPINS)
845 		return NULL;
846 
847 	gpin = kmem_alloc(sizeof(*gpin), KM_SLEEP);
848 	gpin->pin_no = pin;
849 	gpin->pin_flags = flags;
850 	gpin->pin_actlo = actlo;
851 
852 	bcm2835gpio_gpio_pin_ctl(sc, gpin->pin_no, gpin->pin_flags);
853 
854 	return gpin;
855 }
856 
857 static void
858 bcmgpio_fdt_release(device_t dev, void *priv)
859 {
860 	struct bcmgpio_softc *sc = device_private(dev);
861 	struct bcmgpio_pin *gpin = priv;
862 
863 	bcm2835gpio_gpio_pin_ctl(sc, gpin->pin_no, GPIO_PIN_INPUT);
864 	kmem_free(gpin, sizeof(*gpin));
865 }
866 
867 static int
868 bcmgpio_fdt_read(device_t dev, void *priv, bool raw)
869 {
870 	struct bcmgpio_softc *sc = device_private(dev);
871 	struct bcmgpio_pin *gpin = priv;
872 	int val;
873 
874 	val = bcm2835gpio_gpio_pin_read(sc, gpin->pin_no);
875 
876 	if (!raw && gpin->pin_actlo)
877 		val = !val;
878 
879 	return val;
880 }
881 
882 static void
883 bcmgpio_fdt_write(device_t dev, void *priv, int val, bool raw)
884 {
885 	struct bcmgpio_softc *sc = device_private(dev);
886 	struct bcmgpio_pin *gpin = priv;
887 
888 	if (!raw && gpin->pin_actlo)
889 		val = !val;
890 
891 	bcm2835gpio_gpio_pin_write(sc, gpin->pin_no, val);
892 }
893