xref: /freebsd/sys/dev/gpio/gpiobus.c (revision 5abd6fdcfa8cd6bdce99672b3a421d9313870472)
1 /*-
2  * Copyright (c) 2009 Oleksandr Tymoshenko <gonzo@freebsd.org>
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24  * SUCH DAMAGE.
25  */
26 
27 #include <sys/cdefs.h>
28 __FBSDID("$FreeBSD$");
29 
30 #include <sys/param.h>
31 #include <sys/systm.h>
32 #include <sys/malloc.h>
33 #include <sys/module.h>
34 #include <sys/kernel.h>
35 #include <sys/queue.h>
36 #include <sys/sysctl.h>
37 #include <sys/types.h>
38 
39 #include <sys/bus.h>
40 #include <machine/bus.h>
41 #include <sys/rman.h>
42 #include <machine/resource.h>
43 
44 #include <sys/gpio.h>
45 #include <dev/gpio/gpiobusvar.h>
46 #include "gpio_if.h"
47 #include "gpiobus_if.h"
48 
49 static void gpiobus_print_pins(struct gpiobus_ivar *);
50 static int gpiobus_parse_pins(struct gpiobus_softc *, device_t, int);
51 static int gpiobus_probe(device_t);
52 static int gpiobus_attach(device_t);
53 static int gpiobus_detach(device_t);
54 static int gpiobus_suspend(device_t);
55 static int gpiobus_resume(device_t);
56 static int gpiobus_print_child(device_t, device_t);
57 static int gpiobus_child_location_str(device_t, device_t, char *, size_t);
58 static int gpiobus_child_pnpinfo_str(device_t, device_t, char *, size_t);
59 static device_t gpiobus_add_child(device_t, u_int, const char *, int);
60 static void gpiobus_hinted_child(device_t, const char *, int);
61 
62 /*
63  * GPIOBUS interface
64  */
65 static void gpiobus_lock_bus(device_t);
66 static void gpiobus_unlock_bus(device_t);
67 static void gpiobus_acquire_bus(device_t, device_t);
68 static void gpiobus_release_bus(device_t, device_t);
69 static int gpiobus_pin_setflags(device_t, device_t, uint32_t, uint32_t);
70 static int gpiobus_pin_getflags(device_t, device_t, uint32_t, uint32_t*);
71 static int gpiobus_pin_getcaps(device_t, device_t, uint32_t, uint32_t*);
72 static int gpiobus_pin_set(device_t, device_t, uint32_t, unsigned int);
73 static int gpiobus_pin_get(device_t, device_t, uint32_t, unsigned int*);
74 static int gpiobus_pin_toggle(device_t, device_t, uint32_t);
75 
76 #define	GPIOBUS_LOCK(_sc) mtx_lock(&(_sc)->sc_mtx)
77 #define	GPIOBUS_UNLOCK(_sc) mtx_unlock(&(_sc)->sc_mtx)
78 #define	GPIOBUS_LOCK_INIT(_sc) \
79 	mtx_init(&_sc->sc_mtx, device_get_nameunit(_sc->sc_dev), \
80 	    "gpiobus", MTX_DEF)
81 #define	GPIOBUS_LOCK_DESTROY(_sc) mtx_destroy(&_sc->sc_mtx);
82 #define	GPIOBUS_ASSERT_LOCKED(_sc) mtx_assert(&_sc->sc_mtx, MA_OWNED);
83 #define	GPIOBUS_ASSERT_UNLOCKED(_sc) mtx_assert(&_sc->sc_mtx, MA_NOTOWNED);
84 
85 
86 static void
87 gpiobus_print_pins(struct gpiobus_ivar *devi)
88 {
89 	int range_start, range_stop, need_coma;
90 	int i;
91 
92 	if (devi->npins == 0)
93 		return;
94 
95 	need_coma = 0;
96 	range_start = range_stop = devi->pins[0];
97 	for (i = 1; i < devi->npins; i++) {
98 		if (devi->pins[i] != (range_stop + 1)) {
99 			if (need_coma)
100 				printf(",");
101 			if (range_start != range_stop)
102 				printf("%d-%d", range_start, range_stop);
103 			else
104 				printf("%d", range_start);
105 
106 			range_start = range_stop = devi->pins[i];
107 			need_coma = 1;
108 		}
109 		else
110 			range_stop++;
111 	}
112 
113 	if (need_coma)
114 		printf(",");
115 	if (range_start != range_stop)
116 		printf("%d-%d", range_start, range_stop);
117 	else
118 		printf("%d", range_start);
119 }
120 
121 static int
122 gpiobus_parse_pins(struct gpiobus_softc *sc, device_t child, int mask)
123 {
124 	struct gpiobus_ivar *devi = GPIOBUS_IVAR(child);
125 	int i, npins;
126 
127 	npins = 0;
128 	for (i = 0; i < 32; i++) {
129 		if (mask & (1 << i))
130 			npins++;
131 	}
132 
133 	if (npins == 0) {
134 		device_printf(child, "empty pin mask\n");
135 		return (EINVAL);
136 	}
137 
138 	devi->npins = npins;
139 	devi->pins = malloc(sizeof(uint32_t) * devi->npins, M_DEVBUF,
140 	    M_NOWAIT | M_ZERO);
141 
142 	if (!devi->pins)
143 		return (ENOMEM);
144 
145 	npins = 0;
146 	for (i = 0; i < 32; i++) {
147 
148 		if ((mask & (1 << i)) == 0)
149 			continue;
150 
151 		if (i >= sc->sc_npins) {
152 			device_printf(child,
153 			    "invalid pin %d, max: %d\n", i, sc->sc_npins - 1);
154 			free(devi->pins, M_DEVBUF);
155 			return (EINVAL);
156 		}
157 
158 		devi->pins[npins++] = i;
159 		/*
160 		 * Mark pin as mapped and give warning if it's already mapped
161 		 */
162 		if (sc->sc_pins_mapped[i]) {
163 			device_printf(child,
164 			    "warning: pin %d is already mapped\n", i);
165 			free(devi->pins, M_DEVBUF);
166 			return (EINVAL);
167 		}
168 		sc->sc_pins_mapped[i] = 1;
169 	}
170 
171 	return (0);
172 }
173 
174 static int
175 gpiobus_probe(device_t dev)
176 {
177 	device_set_desc(dev, "GPIO bus");
178 
179 	return (BUS_PROBE_GENERIC);
180 }
181 
182 static int
183 gpiobus_attach(device_t dev)
184 {
185 	struct gpiobus_softc *sc = GPIOBUS_SOFTC(dev);
186 	int res;
187 
188 	sc->sc_busdev = dev;
189 	sc->sc_dev = device_get_parent(dev);
190 	res = GPIO_PIN_MAX(sc->sc_dev, &sc->sc_npins);
191 	if (res)
192 		return (ENXIO);
193 
194 	KASSERT(sc->sc_npins != 0, ("GPIO device with no pins"));
195 
196 	/*
197 	 * Increase to get number of pins
198 	 */
199 	sc->sc_npins++;
200 
201 	sc->sc_pins_mapped = malloc(sizeof(int) * sc->sc_npins, M_DEVBUF,
202 	    M_NOWAIT | M_ZERO);
203 
204 	if (!sc->sc_pins_mapped)
205 		return (ENOMEM);
206 
207 	/* init bus lock */
208 	GPIOBUS_LOCK_INIT(sc);
209 
210 	/*
211 	 * Get parent's pins and mark them as unmapped
212 	 */
213 	bus_generic_probe(dev);
214 	bus_enumerate_hinted_children(dev);
215 
216 	return (bus_generic_attach(dev));
217 }
218 
219 /*
220  * Since this is not a self-enumerating bus, and since we always add
221  * children in attach, we have to always delete children here.
222  */
223 static int
224 gpiobus_detach(device_t dev)
225 {
226 	struct gpiobus_softc *sc;
227 	struct gpiobus_ivar *devi;
228 	device_t *devlist;
229 	int i, err, ndevs;
230 
231 	sc = GPIOBUS_SOFTC(dev);
232 	KASSERT(mtx_initialized(&sc->sc_mtx),
233 	    ("gpiobus mutex not initialized"));
234 	GPIOBUS_LOCK_DESTROY(sc);
235 
236 	if ((err = bus_generic_detach(dev)) != 0)
237 		return (err);
238 
239 	if ((err = device_get_children(dev, &devlist, &ndevs)) != 0)
240 		return (err);
241 	for (i = 0; i < ndevs; i++) {
242 		device_delete_child(dev, devlist[i]);
243 		devi = GPIOBUS_IVAR(devlist[i]);
244 		if (devi->pins) {
245 			free(devi->pins, M_DEVBUF);
246 			devi->pins = NULL;
247 		}
248 	}
249 	free(devlist, M_TEMP);
250 
251 	if (sc->sc_pins_mapped) {
252 		free(sc->sc_pins_mapped, M_DEVBUF);
253 		sc->sc_pins_mapped = NULL;
254 	}
255 
256 	return (0);
257 }
258 
259 static int
260 gpiobus_suspend(device_t dev)
261 {
262 
263 	return (bus_generic_suspend(dev));
264 }
265 
266 static int
267 gpiobus_resume(device_t dev)
268 {
269 
270 	return (bus_generic_resume(dev));
271 }
272 
273 static int
274 gpiobus_print_child(device_t dev, device_t child)
275 {
276 	struct gpiobus_ivar *devi = GPIOBUS_IVAR(child);
277 	int retval = 0;
278 
279 	retval += bus_print_child_header(dev, child);
280 	retval += printf(" at pin(s) ");
281 	gpiobus_print_pins(devi);
282 	retval += bus_print_child_footer(dev, child);
283 
284 	return (retval);
285 }
286 
287 static int
288 gpiobus_child_location_str(device_t bus, device_t child, char *buf,
289     size_t buflen)
290 {
291 
292 	snprintf(buf, buflen, "pins=?");
293 	return (0);
294 }
295 
296 static int
297 gpiobus_child_pnpinfo_str(device_t bus, device_t child, char *buf,
298     size_t buflen)
299 {
300 
301 	*buf = '\0';
302 	return (0);
303 }
304 
305 static device_t
306 gpiobus_add_child(device_t dev, u_int order, const char *name, int unit)
307 {
308 	device_t child;
309 	struct gpiobus_ivar *devi;
310 
311 	child = device_add_child_ordered(dev, order, name, unit);
312 	if (child == NULL)
313 		return (child);
314 	devi = malloc(sizeof(struct gpiobus_ivar), M_DEVBUF, M_NOWAIT | M_ZERO);
315 	if (devi == NULL) {
316 		device_delete_child(dev, child);
317 		return (0);
318 	}
319 	device_set_ivars(child, devi);
320 	return (child);
321 }
322 
323 static void
324 gpiobus_hinted_child(device_t bus, const char *dname, int dunit)
325 {
326 	struct gpiobus_softc *sc = GPIOBUS_SOFTC(bus);
327 	struct gpiobus_ivar *devi;
328 	device_t child;
329 	int pins;
330 
331 
332 	child = BUS_ADD_CHILD(bus, 0, dname, dunit);
333 	devi = GPIOBUS_IVAR(child);
334 	resource_int_value(dname, dunit, "pins", &pins);
335 	if (gpiobus_parse_pins(sc, child, pins))
336 		device_delete_child(bus, child);
337 }
338 
339 static void
340 gpiobus_lock_bus(device_t busdev)
341 {
342 	struct gpiobus_softc *sc;
343 
344 	sc = device_get_softc(busdev);
345 	GPIOBUS_ASSERT_UNLOCKED(sc);
346 	GPIOBUS_LOCK(sc);
347 }
348 
349 static void
350 gpiobus_unlock_bus(device_t busdev)
351 {
352 	struct gpiobus_softc *sc;
353 
354 	sc = device_get_softc(busdev);
355 	GPIOBUS_ASSERT_LOCKED(sc);
356 	GPIOBUS_UNLOCK(sc);
357 }
358 
359 static void
360 gpiobus_acquire_bus(device_t busdev, device_t child)
361 {
362 	struct gpiobus_softc *sc;
363 
364 	sc = device_get_softc(busdev);
365 	GPIOBUS_ASSERT_LOCKED(sc);
366 
367 	if (sc->sc_owner)
368 		panic("gpiobus: cannot serialize the access to device.");
369 	sc->sc_owner = child;
370 }
371 
372 static void
373 gpiobus_release_bus(device_t busdev, device_t child)
374 {
375 	struct gpiobus_softc *sc;
376 
377 	sc = device_get_softc(busdev);
378 	GPIOBUS_ASSERT_LOCKED(sc);
379 
380 	if (!sc->sc_owner)
381 		panic("gpiobus: releasing unowned bus.");
382 	if (sc->sc_owner != child)
383 		panic("gpiobus: you don't own the bus. game over.");
384 
385 	sc->sc_owner = NULL;
386 }
387 
388 static int
389 gpiobus_pin_setflags(device_t dev, device_t child, uint32_t pin,
390     uint32_t flags)
391 {
392 	struct gpiobus_softc *sc = GPIOBUS_SOFTC(dev);
393 	struct gpiobus_ivar *devi = GPIOBUS_IVAR(child);
394 
395 	if (pin >= devi->npins)
396 		return (EINVAL);
397 
398 	return GPIO_PIN_SETFLAGS(sc->sc_dev, devi->pins[pin], flags);
399 }
400 
401 static int
402 gpiobus_pin_getflags(device_t dev, device_t child, uint32_t pin,
403     uint32_t *flags)
404 {
405 	struct gpiobus_softc *sc = GPIOBUS_SOFTC(dev);
406 	struct gpiobus_ivar *devi = GPIOBUS_IVAR(child);
407 
408 	if (pin >= devi->npins)
409 		return (EINVAL);
410 
411 	return GPIO_PIN_GETFLAGS(sc->sc_dev, devi->pins[pin], flags);
412 }
413 
414 static int
415 gpiobus_pin_getcaps(device_t dev, device_t child, uint32_t pin,
416     uint32_t *caps)
417 {
418 	struct gpiobus_softc *sc = GPIOBUS_SOFTC(dev);
419 	struct gpiobus_ivar *devi = GPIOBUS_IVAR(child);
420 
421 	if (pin >= devi->npins)
422 		return (EINVAL);
423 
424 	return GPIO_PIN_GETCAPS(sc->sc_dev, devi->pins[pin], caps);
425 }
426 
427 static int
428 gpiobus_pin_set(device_t dev, device_t child, uint32_t pin,
429     unsigned int value)
430 {
431 	struct gpiobus_softc *sc = GPIOBUS_SOFTC(dev);
432 	struct gpiobus_ivar *devi = GPIOBUS_IVAR(child);
433 
434 	if (pin >= devi->npins)
435 		return (EINVAL);
436 
437 	return GPIO_PIN_SET(sc->sc_dev, devi->pins[pin], value);
438 }
439 
440 static int
441 gpiobus_pin_get(device_t dev, device_t child, uint32_t pin,
442     unsigned int *value)
443 {
444 	struct gpiobus_softc *sc = GPIOBUS_SOFTC(dev);
445 	struct gpiobus_ivar *devi = GPIOBUS_IVAR(child);
446 
447 	if (pin >= devi->npins)
448 		return (EINVAL);
449 
450 	return GPIO_PIN_GET(sc->sc_dev, devi->pins[pin], value);
451 }
452 
453 static int
454 gpiobus_pin_toggle(device_t dev, device_t child, uint32_t pin)
455 {
456 	struct gpiobus_softc *sc = GPIOBUS_SOFTC(dev);
457 	struct gpiobus_ivar *devi = GPIOBUS_IVAR(child);
458 
459 	if (pin >= devi->npins)
460 		return (EINVAL);
461 
462 	return GPIO_PIN_TOGGLE(sc->sc_dev, devi->pins[pin]);
463 }
464 
465 static device_method_t gpiobus_methods[] = {
466 	/* Device interface */
467 	DEVMETHOD(device_probe,		gpiobus_probe),
468 	DEVMETHOD(device_attach,	gpiobus_attach),
469 	DEVMETHOD(device_detach,	gpiobus_detach),
470 	DEVMETHOD(device_shutdown,	bus_generic_shutdown),
471 	DEVMETHOD(device_suspend,	gpiobus_suspend),
472 	DEVMETHOD(device_resume,	gpiobus_resume),
473 
474 	/* Bus interface */
475 	DEVMETHOD(bus_add_child,	gpiobus_add_child),
476 	DEVMETHOD(bus_print_child,	gpiobus_print_child),
477 	DEVMETHOD(bus_child_pnpinfo_str, gpiobus_child_pnpinfo_str),
478 	DEVMETHOD(bus_child_location_str, gpiobus_child_location_str),
479 	DEVMETHOD(bus_hinted_child,	gpiobus_hinted_child),
480 
481 	/* GPIO protocol */
482 	DEVMETHOD(gpiobus_lock_bus,	gpiobus_lock_bus),
483 	DEVMETHOD(gpiobus_unlock_bus,	gpiobus_unlock_bus),
484 	DEVMETHOD(gpiobus_acquire_bus,	gpiobus_acquire_bus),
485 	DEVMETHOD(gpiobus_release_bus,	gpiobus_release_bus),
486 	DEVMETHOD(gpiobus_pin_getflags,	gpiobus_pin_getflags),
487 	DEVMETHOD(gpiobus_pin_getcaps,	gpiobus_pin_getcaps),
488 	DEVMETHOD(gpiobus_pin_setflags,	gpiobus_pin_setflags),
489 	DEVMETHOD(gpiobus_pin_get,	gpiobus_pin_get),
490 	DEVMETHOD(gpiobus_pin_set,	gpiobus_pin_set),
491 	DEVMETHOD(gpiobus_pin_toggle,	gpiobus_pin_toggle),
492 
493 	DEVMETHOD_END
494 };
495 
496 driver_t gpiobus_driver = {
497 	"gpiobus",
498 	gpiobus_methods,
499 	sizeof(struct gpiobus_softc)
500 };
501 
502 devclass_t	gpiobus_devclass;
503 
504 DRIVER_MODULE(gpiobus, gpio, gpiobus_driver, gpiobus_devclass, 0, 0);
505 MODULE_VERSION(gpiobus, 1);
506