xref: /netbsd-src/sys/dev/gpio/gpio.c (revision 3816d47b2c42fcd6e549e3407f842a5b1a1d23ad)
1 /* $NetBSD: gpio.c,v 1.30 2010/01/08 19:48:18 dyoung Exp $ */
2 /*	$OpenBSD: gpio.c,v 1.6 2006/01/14 12:33:49 grange Exp $	*/
3 
4 /*
5  * Copyright (c) 2008, 2009 Marc Balmer <marc@msys.ch>
6  * Copyright (c) 2004, 2006 Alexander Yurchenko <grange@openbsd.org>
7  *
8  * Permission to use, copy, modify, and distribute this software for any
9  * purpose with or without fee is hereby granted, provided that the above
10  * copyright notice and this permission notice appear in all copies.
11  *
12  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
13  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
14  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
15  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
16  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
17  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
18  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
19  */
20 
21 #include <sys/cdefs.h>
22 __KERNEL_RCSID(0, "$NetBSD: gpio.c,v 1.30 2010/01/08 19:48:18 dyoung Exp $");
23 
24 /*
25  * General Purpose Input/Output framework.
26  */
27 
28 #include <sys/param.h>
29 #include <sys/systm.h>
30 #include <sys/conf.h>
31 #include <sys/device.h>
32 #include <sys/fcntl.h>
33 #include <sys/ioctl.h>
34 #include <sys/gpio.h>
35 #include <sys/vnode.h>
36 #include <sys/kmem.h>
37 #include <sys/queue.h>
38 #include <sys/kauth.h>
39 
40 #include <dev/gpio/gpiovar.h>
41 
42 #include "locators.h"
43 
44 #ifdef GPIO_DEBUG
45 #define DPRINTFN(n, x)	do { if (gpiodebug > (n)) printf x; } while (0)
46 int gpiodebug = 0;
47 #else
48 #define DPRINTFN(n, x)
49 #endif
50 #define DPRINTF(x)	DPRINTFN(0, x)
51 
52 struct gpio_softc {
53 	device_t		 sc_dev;
54 
55 	gpio_chipset_tag_t	 sc_gc;		/* GPIO controller */
56 	gpio_pin_t		*sc_pins;	/* pins array */
57 	int			 sc_npins;	/* number of pins */
58 
59 	int			 sc_opened;
60 	LIST_HEAD(, gpio_dev)	 sc_devs;	/* devices */
61 	LIST_HEAD(, gpio_name)	 sc_names;	/* named pins */
62 };
63 
64 int	gpio_match(device_t, cfdata_t, void *);
65 int	gpio_submatch(device_t, cfdata_t, const int *, void *);
66 void	gpio_attach(device_t, device_t, void *);
67 int	gpio_rescan(device_t, const char *, const int *);
68 void	gpio_childdetached(device_t, device_t);
69 bool	gpio_resume(device_t, pmf_qual_t);
70 int	gpio_detach(device_t, int);
71 int	gpio_search(device_t, cfdata_t, const int *, void *);
72 int	gpio_print(void *, const char *);
73 int	gpio_pinbyname(struct gpio_softc *, char *);
74 
75 /* Old API */
76 int	gpio_ioctl_oapi(struct gpio_softc *, u_long, void *, int, kauth_cred_t);
77 
78 CFATTACH_DECL3_NEW(gpio, sizeof(struct gpio_softc),
79     gpio_match, gpio_attach, gpio_detach, NULL, gpio_rescan,
80     gpio_childdetached, DVF_DETACH_SHUTDOWN);
81 
82 dev_type_open(gpioopen);
83 dev_type_close(gpioclose);
84 dev_type_ioctl(gpioioctl);
85 
86 const struct cdevsw gpio_cdevsw = {
87 	gpioopen, gpioclose, noread, nowrite, gpioioctl,
88 	nostop, notty, nopoll, nommap, nokqfilter, D_OTHER,
89 };
90 
91 extern struct cfdriver gpio_cd;
92 
93 int
94 gpio_match(device_t parent, cfdata_t cf, void *aux)
95 {
96 	return 1;
97 }
98 
99 int
100 gpio_submatch(device_t parent, cfdata_t cf, const int *ip, void *aux)
101 {
102 	struct gpio_attach_args *ga = aux;
103 
104 	if (ga->ga_offset == -1)
105 		return 0;
106 
107 	return strcmp(ga->ga_dvname, cf->cf_name) == 0;
108 }
109 
110 bool
111 gpio_resume(device_t self, pmf_qual_t qual)
112 {
113 	struct gpio_softc *sc = device_private(self);
114 	int pin;
115 
116 	for (pin = 0; pin < sc->sc_npins; pin++) {
117 		gpiobus_pin_ctl(sc->sc_gc, pin, sc->sc_pins[pin].pin_flags);
118 		gpiobus_pin_write(sc->sc_gc, pin, sc->sc_pins[pin].pin_state);
119 	}
120 	return true;
121 }
122 
123 void
124 gpio_childdetached(device_t self, device_t child)
125 {
126 	/* gpio(4) keeps no references to its children, so do nothing. */
127 }
128 
129 int
130 gpio_rescan(device_t self, const char *ifattr, const int *locators)
131 {
132 	struct gpio_softc *sc = device_private(self);
133 
134 	config_search_loc(gpio_search, self, ifattr, locators, sc);
135 
136 	return 0;
137 }
138 
139 void
140 gpio_attach(device_t parent, device_t self, void *aux)
141 {
142 	struct gpio_softc *sc = device_private(self);
143 	struct gpiobus_attach_args *gba = aux;
144 
145 	sc->sc_dev = self;
146 	sc->sc_gc = gba->gba_gc;
147 	sc->sc_pins = gba->gba_pins;
148 	sc->sc_npins = gba->gba_npins;
149 
150 	printf(": %d pins\n", sc->sc_npins);
151 
152 	if (!pmf_device_register(self, NULL, gpio_resume))
153 		aprint_error_dev(self, "couldn't establish power handler\n");
154 
155 	/*
156 	 * Attach all devices that can be connected to the GPIO pins
157 	 * described in the kernel configuration file.
158 	 */
159 	gpio_rescan(self, "gpio", NULL);
160 }
161 
162 int
163 gpio_detach(device_t self, int flags)
164 {
165 	int rc;
166 
167 	if ((rc = config_detach_children(self, flags)) != 0)
168 		return rc;
169 
170 #if 0
171 	int maj, mn;
172 
173 	/* Locate the major number */
174 	for (maj = 0; maj < nchrdev; maj++)
175 		if (cdevsw[maj].d_open == gpioopen)
176 			break;
177 
178 	/* Nuke the vnodes for any open instances (calls close) */
179 	mn = device_unit(self);
180 	vdevgone(maj, mn, mn, VCHR);
181 #endif
182 	return 0;
183 }
184 
185 int
186 gpio_search(device_t parent, cfdata_t cf,
187     const int *ldesc, void *aux)
188 {
189 	struct gpio_attach_args ga;
190 
191 	ga.ga_gpio = aux;
192 	ga.ga_offset = cf->cf_loc[GPIOCF_OFFSET];
193 	ga.ga_mask = cf->cf_loc[GPIOCF_MASK];
194 
195 	if (config_match(parent, cf, &ga) > 0)
196 		config_attach(parent, cf, &ga, gpio_print);
197 
198 	return 0;
199 }
200 
201 int
202 gpio_print(void *aux, const char *pnp)
203 {
204 	struct gpio_attach_args *ga = aux;
205 	int i;
206 
207 	printf(" pins");
208 	for (i = 0; i < 32; i++)
209 		if (ga->ga_mask & (1 << i))
210 			printf(" %d", ga->ga_offset + i);
211 
212 	return UNCONF;
213 }
214 
215 int
216 gpiobus_print(void *aux, const char *pnp)
217 {
218 #if 0
219 	struct gpiobus_attach_args *gba = aux;
220 #endif
221 	if (pnp != NULL)
222 		printf("gpiobus at %s", pnp);
223 
224 	return UNCONF;
225 }
226 
227 /* return 1 if all pins can be mapped, 0 if not */
228 
229 int
230 gpio_pin_can_map(void *gpio, int offset, u_int32_t mask)
231 {
232 	struct gpio_softc *sc = gpio;
233 	int npins, pin, i;
234 
235 	npins = gpio_npins(mask);
236 	if (npins > sc->sc_npins)
237 		return 0;
238 
239 	for (npins = 0, i = 0; i < 32; i++)
240 		if (mask & (1 << i)) {
241 			pin = offset + i;
242 			if (pin < 0 || pin >= sc->sc_npins)
243 				return 0;
244 			if (sc->sc_pins[pin].pin_mapped)
245 				return 0;
246 		}
247 
248 	return 1;
249 }
250 
251 int
252 gpio_pin_map(void *gpio, int offset, u_int32_t mask, struct gpio_pinmap *map)
253 {
254 	struct gpio_softc *sc = gpio;
255 	int npins, pin, i;
256 
257 	npins = gpio_npins(mask);
258 	if (npins > sc->sc_npins)
259 		return 1;
260 
261 	for (npins = 0, i = 0; i < 32; i++)
262 		if (mask & (1 << i)) {
263 			pin = offset + i;
264 			if (pin < 0 || pin >= sc->sc_npins)
265 				return 1;
266 			if (sc->sc_pins[pin].pin_mapped)
267 				return 1;
268 			sc->sc_pins[pin].pin_mapped = 1;
269 			map->pm_map[npins++] = pin;
270 		}
271 	map->pm_size = npins;
272 
273 	return 0;
274 }
275 
276 void
277 gpio_pin_unmap(void *gpio, struct gpio_pinmap *map)
278 {
279 	struct gpio_softc *sc = gpio;
280 	int pin, i;
281 
282 	for (i = 0; i < map->pm_size; i++) {
283 		pin = map->pm_map[i];
284 		sc->sc_pins[pin].pin_mapped = 0;
285 	}
286 }
287 
288 int
289 gpio_pin_read(void *gpio, struct gpio_pinmap *map, int pin)
290 {
291 	struct gpio_softc *sc = gpio;
292 
293 	return gpiobus_pin_read(sc->sc_gc, map->pm_map[pin]);
294 }
295 
296 void
297 gpio_pin_write(void *gpio, struct gpio_pinmap *map, int pin, int value)
298 {
299 	struct gpio_softc *sc = gpio;
300 
301 	gpiobus_pin_write(sc->sc_gc, map->pm_map[pin], value);
302 	sc->sc_pins[map->pm_map[pin]].pin_state = value;
303 }
304 
305 void
306 gpio_pin_ctl(void *gpio, struct gpio_pinmap *map, int pin, int flags)
307 {
308 	struct gpio_softc *sc = gpio;
309 
310 	return gpiobus_pin_ctl(sc->sc_gc, map->pm_map[pin], flags);
311 }
312 
313 int
314 gpio_pin_caps(void *gpio, struct gpio_pinmap *map, int pin)
315 {
316 	struct gpio_softc *sc = gpio;
317 
318 	return sc->sc_pins[map->pm_map[pin]].pin_caps;
319 }
320 
321 int
322 gpio_npins(u_int32_t mask)
323 {
324 	int npins, i;
325 
326 	for (npins = 0, i = 0; i < 32; i++)
327 		if (mask & (1 << i))
328 			npins++;
329 
330 	return npins;
331 }
332 
333 int
334 gpioopen(dev_t dev, int flag, int mode, struct lwp *l)
335 {
336 	struct gpio_softc *sc;
337 	int ret;
338 
339 	sc = device_lookup_private(&gpio_cd, minor(dev));
340 	if (sc == NULL)
341 		return ENXIO;
342 	DPRINTF(("%s: opening\n", device_xname(sc->sc_dev)));
343 	if (sc->sc_opened) {
344 		DPRINTF(("%s: already opened\n", device_xname(sc->sc_dev)));
345 		return EBUSY;
346 	}
347 
348 	if ((ret = gpiobus_open(sc->sc_gc, sc->sc_dev))) {
349 		DPRINTF(("%s: gpiobus_open returned %d\n",
350 		    device_xname(sc->sc_dev),
351 		    ret));
352 		return ret;
353 	}
354 
355 	sc->sc_opened = 1;
356 
357 	return 0;
358 }
359 
360 int
361 gpioclose(dev_t dev, int flag, int mode, struct lwp *l)
362 {
363 	struct gpio_softc *sc;
364 
365 	sc = device_lookup_private(&gpio_cd, minor(dev));
366 	DPRINTF(("%s: closing\n", device_xname(sc->sc_dev)));
367 	gpiobus_close(sc->sc_gc, sc->sc_dev);
368 	sc->sc_opened = 0;
369 
370 	return 0;
371 }
372 
373 int
374 gpio_pinbyname(struct gpio_softc *sc, char *gp_name)
375 {
376         struct gpio_name *nm;
377 
378         LIST_FOREACH(nm, &sc->sc_names, gp_next)
379                 if (!strcmp(nm->gp_name, gp_name))
380                         return nm->gp_pin;
381         return -1;
382 }
383 
384 int
385 gpioioctl(dev_t dev, u_long cmd, void *data, int flag, struct lwp *l)
386 {
387 	struct gpio_softc *sc;
388 	gpio_chipset_tag_t gc;
389 	struct gpio_info *info;
390 	struct gpio_attach *attach;
391 	struct gpio_attach_args ga;
392 	struct gpio_dev *gdev;
393 	struct gpio_req *req;
394 	struct gpio_name *nm;
395 	struct gpio_set *set;
396 	device_t dv;
397 	cfdata_t cf;
398 	kauth_cred_t cred;
399 	int locs[GPIOCF_NLOCS];
400 	int pin, value, flags, npins;
401 
402 	sc = device_lookup_private(&gpio_cd, minor(dev));
403 	gc = sc->sc_gc;
404 
405 	if (cmd != GPIOINFO && !device_is_active(sc->sc_dev)) {
406 		DPRINTF(("%s: device is not active\n",
407 		    device_xname(sc->sc_dev)));
408 		return EBUSY;
409 	}
410 
411 	cred = kauth_cred_get();
412 
413 	switch (cmd) {
414 	case GPIOINFO:
415 		info = (struct gpio_info *)data;
416 		if (!kauth_authorize_device(cred, KAUTH_DEVICE_GPIO_PINSET,
417 		    NULL, NULL, NULL, NULL))
418 			info->gpio_npins = sc->sc_npins;
419 		else {
420 			for (pin = npins = 0; pin < sc->sc_npins; pin++)
421 				if (sc->sc_pins[pin].pin_flags & GPIO_PIN_SET)
422 					++npins;
423 			info->gpio_npins = npins;
424 		}
425 		break;
426 	case GPIOREAD:
427 		req = (struct gpio_req *)data;
428 
429 		if (req->gp_name[0] != '\0') {
430 			pin = gpio_pinbyname(sc, req->gp_name);
431 			if (pin == -1)
432 				return EINVAL;
433 		} else
434 			pin = req->gp_pin;
435 
436 		if (pin < 0 || pin >= sc->sc_npins)
437 			return EINVAL;
438 
439 		if (!(sc->sc_pins[pin].pin_flags & GPIO_PIN_SET) &&
440 		    kauth_authorize_device(cred, KAUTH_DEVICE_GPIO_PINSET,
441 		    NULL, NULL, NULL, NULL))
442 			return EPERM;
443 
444 		/* return read value */
445 		req->gp_value = gpiobus_pin_read(gc, pin);
446 		break;
447 	case GPIOWRITE:
448 		if ((flag & FWRITE) == 0)
449 			return EBADF;
450 
451 		req = (struct gpio_req *)data;
452 
453 		if (req->gp_name[0] != '\0') {
454 			pin = gpio_pinbyname(sc, req->gp_name);
455 			if (pin == -1)
456 				return EINVAL;
457 		} else
458 			pin = req->gp_pin;
459 
460 		if (pin < 0 || pin >= sc->sc_npins)
461 			return EINVAL;
462 
463 		if (sc->sc_pins[pin].pin_mapped)
464 			return EBUSY;
465 
466 		if (!(sc->sc_pins[pin].pin_flags & GPIO_PIN_SET) &&
467 		    kauth_authorize_device(cred, KAUTH_DEVICE_GPIO_PINSET,
468 		    NULL, NULL, NULL, NULL))
469 			return EPERM;
470 
471 		value = req->gp_value;
472 		if (value != GPIO_PIN_LOW && value != GPIO_PIN_HIGH)
473 			return EINVAL;
474 
475 		gpiobus_pin_write(gc, pin, value);
476 		/* return old value */
477 		req->gp_value = sc->sc_pins[pin].pin_state;
478 		/* update current value */
479 		sc->sc_pins[pin].pin_state = value;
480 		break;
481 	case GPIOTOGGLE:
482 		if ((flag & FWRITE) == 0)
483 			return EBADF;
484 
485 		req = (struct gpio_req *)data;
486 
487 		if (req->gp_name[0] != '\0') {
488 			pin = gpio_pinbyname(sc, req->gp_name);
489 			if (pin == -1)
490 				return EINVAL;
491 		} else
492 			pin = req->gp_pin;
493 
494 		if (pin < 0 || pin >= sc->sc_npins)
495 			return EINVAL;
496 
497 		if (sc->sc_pins[pin].pin_mapped)
498 			return EBUSY;
499 
500 		if (!(sc->sc_pins[pin].pin_flags & GPIO_PIN_SET) &&
501 		    kauth_authorize_device(cred, KAUTH_DEVICE_GPIO_PINSET,
502 		    NULL, NULL, NULL, NULL))
503 			return EPERM;
504 
505 		value = (sc->sc_pins[pin].pin_state == GPIO_PIN_LOW ?
506 		    GPIO_PIN_HIGH : GPIO_PIN_LOW);
507 		gpiobus_pin_write(gc, pin, value);
508 		/* return old value */
509 		req->gp_value = sc->sc_pins[pin].pin_state;
510 		/* update current value */
511 		sc->sc_pins[pin].pin_state = value;
512 		break;
513 	case GPIOATTACH:
514 		if (kauth_authorize_device(cred, KAUTH_DEVICE_GPIO_PINSET,
515 		    NULL, NULL, NULL, NULL))
516 			return EPERM;
517 
518 		attach = (struct gpio_attach *)data;
519 
520 		/* do not try to attach if the pins are already mapped */
521 		if (!gpio_pin_can_map(sc, attach->ga_offset, attach->ga_mask))
522 			return EBUSY;
523 
524 		ga.ga_gpio = sc;
525 		ga.ga_dvname = attach->ga_dvname;
526 		ga.ga_offset = attach->ga_offset;
527 		ga.ga_mask = attach->ga_mask;
528 		DPRINTF(("%s: attach %s with offset %d and mask 0x%02x\n",
529 		    device_xname(sc->sc_dev), ga.ga_dvname, ga.ga_offset,
530 		    ga.ga_mask));
531 
532 		locs[GPIOCF_OFFSET] = ga.ga_offset;
533 		locs[GPIOCF_MASK] = ga.ga_mask;
534 
535 		cf = config_search_loc(NULL, sc->sc_dev, "gpio", locs, &ga);
536 		if (cf != NULL) {
537 			dv = config_attach_loc(sc->sc_dev, cf, locs, &ga,
538 			    gpiobus_print);
539 			if (dv != NULL) {
540 				gdev = kmem_alloc(sizeof(struct gpio_dev),
541 				    KM_SLEEP);
542 				gdev->sc_dev = dv;
543 				LIST_INSERT_HEAD(&sc->sc_devs, gdev, sc_next);
544 			} else
545 				return EINVAL;
546 		} else
547 			return EINVAL;
548 		break;
549 	case GPIODETACH:
550 		if (kauth_authorize_device(cred, KAUTH_DEVICE_GPIO_PINSET,
551 		    NULL, NULL, NULL, NULL))
552 			return EPERM;
553 
554 		attach = (struct gpio_attach *)data;
555 		LIST_FOREACH(gdev, &sc->sc_devs, sc_next) {
556 			if (strcmp(device_xname(gdev->sc_dev),
557 			    attach->ga_dvname) == 0) {
558 				if (config_detach(gdev->sc_dev, 0) == 0) {
559 					LIST_REMOVE(gdev, sc_next);
560 					kmem_free(gdev,
561 					    sizeof(struct gpio_dev));
562 					return 0;
563 				}
564 				break;
565 			}
566 		}
567 		return EINVAL;
568 		break;
569 	case GPIOSET:
570 		if (kauth_authorize_device(cred, KAUTH_DEVICE_GPIO_PINSET,
571 		    NULL, NULL, NULL, NULL))
572 			return EPERM;
573 
574 		set = (struct gpio_set *)data;
575 
576 		if (set->gp_name[0] != '\0') {
577 			pin = gpio_pinbyname(sc, set->gp_name);
578 			if (pin == -1)
579 				return EINVAL;
580 		} else
581 			pin = set->gp_pin;
582 		if (pin < 0 || pin >= sc->sc_npins)
583 			return EINVAL;
584 		flags = set->gp_flags;
585 
586 		/* check that the controller supports all requested flags */
587 		if ((flags & sc->sc_pins[pin].pin_caps) != flags)
588 			return ENODEV;
589 		flags = set->gp_flags | GPIO_PIN_SET;
590 
591 		set->gp_caps = sc->sc_pins[pin].pin_caps;
592 		/* return old value */
593 		set->gp_flags = sc->sc_pins[pin].pin_flags;
594 		if (flags > 0) {
595 			gpiobus_pin_ctl(gc, pin, flags);
596 			/* update current value */
597 			sc->sc_pins[pin].pin_flags = flags;
598 		}
599 
600 		/* rename pin or new pin? */
601 		if (set->gp_name2[0] != '\0') {
602 			struct gpio_name *gnm;
603 
604 			gnm = NULL;
605 			LIST_FOREACH(nm, &sc->sc_names, gp_next) {
606 				if (!strcmp(nm->gp_name, set->gp_name2) &&
607 				    nm->gp_pin != pin)
608 					return EINVAL;	/* duplicate name */
609 				if (nm->gp_pin == pin)
610 					gnm = nm;
611 			}
612 			if (gnm != NULL)
613 				strlcpy(gnm->gp_name, set->gp_name2,
614 				    sizeof(gnm->gp_name));
615 			else  {
616 				nm = kmem_alloc(sizeof(struct gpio_name),
617 				    KM_SLEEP);
618 				strlcpy(nm->gp_name, set->gp_name2,
619 				    sizeof(nm->gp_name));
620 				nm->gp_pin = set->gp_pin;
621 				LIST_INSERT_HEAD(&sc->sc_names, nm, gp_next);
622 			}
623 		}
624 		break;
625 	case GPIOUNSET:
626 		if (kauth_authorize_device(cred, KAUTH_DEVICE_GPIO_PINSET,
627 		    NULL, NULL, NULL, NULL))
628 			return EPERM;
629 
630 		set = (struct gpio_set *)data;
631 		if (set->gp_name[0] != '\0') {
632 			pin = gpio_pinbyname(sc, set->gp_name);
633 			if (pin == -1)
634 				return EINVAL;
635 		} else
636 			pin = set->gp_pin;
637 
638 		if (pin < 0 || pin >= sc->sc_npins)
639 			return EINVAL;
640 		if (sc->sc_pins[pin].pin_mapped)
641 			return EBUSY;
642 		if (!(sc->sc_pins[pin].pin_flags & GPIO_PIN_SET))
643 			return EINVAL;
644 
645 		LIST_FOREACH(nm, &sc->sc_names, gp_next) {
646 			if (nm->gp_pin == pin) {
647 				LIST_REMOVE(nm, gp_next);
648 				kmem_free(nm, sizeof(struct gpio_name));
649 				break;
650 			}
651 		}
652 		sc->sc_pins[pin].pin_flags &= ~GPIO_PIN_SET;
653 		break;
654 	default:
655 		/* Try the old API */
656 		DPRINTF(("%s: trying the old API\n", device_xname(sc->sc_dev)));
657 		return gpio_ioctl_oapi(sc, cmd, data, flag, cred);
658 	}
659 	return 0;
660 }
661 
662 int
663 gpio_ioctl_oapi(struct gpio_softc *sc, u_long cmd, void *data, int flag,
664     kauth_cred_t cred)
665 {
666 	gpio_chipset_tag_t gc;
667 	struct gpio_pin_op *op;
668 	struct gpio_pin_ctl *ctl;
669 	int pin, value, flags;
670 
671 	gc = sc->sc_gc;
672 
673 	switch (cmd) {
674 	case GPIOPINREAD:
675 		op = (struct gpio_pin_op *)data;
676 
677 		pin = op->gp_pin;
678 
679 		if (pin < 0 || pin >= sc->sc_npins)
680 			return EINVAL;
681 
682 		if (!(sc->sc_pins[pin].pin_flags & GPIO_PIN_SET) &&
683 		    kauth_authorize_device(cred, KAUTH_DEVICE_GPIO_PINSET,
684 		    NULL, NULL, NULL, NULL))
685 			return EPERM;
686 
687 		/* return read value */
688 		op->gp_value = gpiobus_pin_read(gc, pin);
689 		break;
690 	case GPIOPINWRITE:
691 		if ((flag & FWRITE) == 0)
692 			return EBADF;
693 
694 		op = (struct gpio_pin_op *)data;
695 
696 		pin = op->gp_pin;
697 
698 		if (pin < 0 || pin >= sc->sc_npins)
699 			return EINVAL;
700 
701 		if (sc->sc_pins[pin].pin_mapped)
702 			return EBUSY;
703 
704 		if (!(sc->sc_pins[pin].pin_flags & GPIO_PIN_SET) &&
705 		    kauth_authorize_device(cred, KAUTH_DEVICE_GPIO_PINSET,
706 		    NULL, NULL, NULL, NULL))
707 			return EPERM;
708 
709 		value = op->gp_value;
710 		if (value != GPIO_PIN_LOW && value != GPIO_PIN_HIGH)
711 			return EINVAL;
712 
713 		gpiobus_pin_write(gc, pin, value);
714 		/* return old value */
715 		op->gp_value = sc->sc_pins[pin].pin_state;
716 		/* update current value */
717 		sc->sc_pins[pin].pin_state = value;
718 		break;
719 	case GPIOPINTOGGLE:
720 		if ((flag & FWRITE) == 0)
721 			return EBADF;
722 
723 		op = (struct gpio_pin_op *)data;
724 
725 		pin = op->gp_pin;
726 
727 		if (pin < 0 || pin >= sc->sc_npins)
728 			return EINVAL;
729 
730 		if (sc->sc_pins[pin].pin_mapped)
731 			return EBUSY;
732 
733 		if (!(sc->sc_pins[pin].pin_flags & GPIO_PIN_SET) &&
734 		    kauth_authorize_device(cred, KAUTH_DEVICE_GPIO_PINSET,
735 		    NULL, NULL, NULL, NULL))
736 			return EPERM;
737 
738 		value = (sc->sc_pins[pin].pin_state == GPIO_PIN_LOW ?
739 		    GPIO_PIN_HIGH : GPIO_PIN_LOW);
740 		gpiobus_pin_write(gc, pin, value);
741 		/* return old value */
742 		op->gp_value = sc->sc_pins[pin].pin_state;
743 		/* update current value */
744 		sc->sc_pins[pin].pin_state = value;
745 		break;
746 	case GPIOPINCTL:
747 		ctl = (struct gpio_pin_ctl *) data;
748 
749 		if (kauth_authorize_device(cred, KAUTH_DEVICE_GPIO_PINSET,
750 		    NULL, NULL, NULL, NULL))
751 			return EPERM;
752 
753 		pin = ctl->gp_pin;
754 
755 		if (pin < 0 || pin >= sc->sc_npins)
756 			return EINVAL;
757 		if (sc->sc_pins[pin].pin_mapped)
758 			return EBUSY;
759 		flags = ctl->gp_flags;
760 
761 		/* check that the controller supports all requested flags */
762 		if ((flags & sc->sc_pins[pin].pin_caps) != flags)
763 			return ENODEV;
764 
765 		ctl->gp_caps = sc->sc_pins[pin].pin_caps;
766 		/* return old value */
767 		ctl->gp_flags = sc->sc_pins[pin].pin_flags;
768 		if (flags > 0) {
769 			gpiobus_pin_ctl(gc, pin, flags);
770 			/* update current value */
771 			sc->sc_pins[pin].pin_flags = flags;
772 		}
773 		break;
774 	default:
775 		return ENOTTY;
776 	}
777 	return 0;
778 }
779