gpiobus.c revision 273569 
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: head/sys/dev/gpio/gpiobus.c 273569 2014-10-23 23:20:04Z loos $");
29
30#include <sys/param.h>
31#include <sys/systm.h>
32#include <sys/bus.h>
33#include <sys/kernel.h>
34#include <sys/malloc.h>
35#include <sys/module.h>
36
37#include <dev/gpio/gpiobusvar.h>
38
39#include "gpiobus_if.h"
40
41static int gpiobus_parse_pins(struct gpiobus_softc *, device_t, int);
42static int gpiobus_probe(device_t);
43static int gpiobus_attach(device_t);
44static int gpiobus_detach(device_t);
45static int gpiobus_suspend(device_t);
46static int gpiobus_resume(device_t);
47static int gpiobus_print_child(device_t, device_t);
48static int gpiobus_child_location_str(device_t, device_t, char *, size_t);
49static int gpiobus_child_pnpinfo_str(device_t, device_t, char *, size_t);
50static device_t gpiobus_add_child(device_t, u_int, const char *, int);
51static void gpiobus_hinted_child(device_t, const char *, int);
52
53/*
54 * GPIOBUS interface
55 */
56static void gpiobus_lock_bus(device_t);
57static void gpiobus_unlock_bus(device_t);
58static void gpiobus_acquire_bus(device_t, device_t);
59static void gpiobus_release_bus(device_t, device_t);
60static int gpiobus_pin_setflags(device_t, device_t, uint32_t, uint32_t);
61static int gpiobus_pin_getflags(device_t, device_t, uint32_t, uint32_t*);
62static int gpiobus_pin_getcaps(device_t, device_t, uint32_t, uint32_t*);
63static int gpiobus_pin_set(device_t, device_t, uint32_t, unsigned int);
64static int gpiobus_pin_get(device_t, device_t, uint32_t, unsigned int*);
65static int gpiobus_pin_toggle(device_t, device_t, uint32_t);
66
67void
68gpiobus_print_pins(struct gpiobus_ivar *devi)
69{
70	int range_start, range_stop, need_coma;
71	int i;
72
73	if (devi->npins == 0)
74		return;
75
76	need_coma = 0;
77	range_start = range_stop = devi->pins[0];
78	for (i = 1; i < devi->npins; i++) {
79		if (devi->pins[i] != (range_stop + 1)) {
80			if (need_coma)
81				printf(",");
82			if (range_start != range_stop)
83				printf("%d-%d", range_start, range_stop);
84			else
85				printf("%d", range_start);
86
87			range_start = range_stop = devi->pins[i];
88			need_coma = 1;
89		}
90		else
91			range_stop++;
92	}
93
94	if (need_coma)
95		printf(",");
96	if (range_start != range_stop)
97		printf("%d-%d", range_start, range_stop);
98	else
99		printf("%d", range_start);
100}
101
102int
103gpiobus_init_softc(device_t dev)
104{
105	struct gpiobus_softc *sc;
106
107	sc = GPIOBUS_SOFTC(dev);
108	sc->sc_busdev = dev;
109	sc->sc_dev = device_get_parent(dev);
110
111	if (GPIO_PIN_MAX(sc->sc_dev, &sc->sc_npins) != 0)
112		return (ENXIO);
113
114	KASSERT(sc->sc_npins != 0, ("GPIO device with no pins"));
115
116	/* Pins = GPIO_PIN_MAX() + 1 */
117	sc->sc_npins++;
118
119	sc->sc_pins_mapped = malloc(sizeof(int) * sc->sc_npins, M_DEVBUF,
120	    M_NOWAIT | M_ZERO);
121	if (sc->sc_pins_mapped == NULL)
122		return (ENOMEM);
123
124	/* Initialize the bus lock. */
125	GPIOBUS_LOCK_INIT(sc);
126
127	return (0);
128}
129
130static int
131gpiobus_parse_pins(struct gpiobus_softc *sc, device_t child, int mask)
132{
133	struct gpiobus_ivar *devi = GPIOBUS_IVAR(child);
134	int i, npins;
135
136	npins = 0;
137	for (i = 0; i < 32; i++) {
138		if (mask & (1 << i))
139			npins++;
140	}
141
142	if (npins == 0) {
143		device_printf(child, "empty pin mask\n");
144		return (EINVAL);
145	}
146
147	devi->npins = npins;
148	devi->pins = malloc(sizeof(uint32_t) * devi->npins, M_DEVBUF,
149	    M_NOWAIT | M_ZERO);
150
151	if (!devi->pins)
152		return (ENOMEM);
153
154	npins = 0;
155	for (i = 0; i < 32; i++) {
156
157		if ((mask & (1 << i)) == 0)
158			continue;
159
160		if (i >= sc->sc_npins) {
161			device_printf(child,
162			    "invalid pin %d, max: %d\n", i, sc->sc_npins - 1);
163			free(devi->pins, M_DEVBUF);
164			return (EINVAL);
165		}
166
167		devi->pins[npins++] = i;
168		/*
169		 * Mark pin as mapped and give warning if it's already mapped
170		 */
171		if (sc->sc_pins_mapped[i]) {
172			device_printf(child,
173			    "warning: pin %d is already mapped\n", i);
174			free(devi->pins, M_DEVBUF);
175			return (EINVAL);
176		}
177		sc->sc_pins_mapped[i] = 1;
178	}
179
180	return (0);
181}
182
183static int
184gpiobus_probe(device_t dev)
185{
186	device_set_desc(dev, "GPIO bus");
187
188	return (BUS_PROBE_GENERIC);
189}
190
191static int
192gpiobus_attach(device_t dev)
193{
194	int err;
195
196	err = gpiobus_init_softc(dev);
197	if (err != 0)
198		return (err);
199
200	/*
201	 * Get parent's pins and mark them as unmapped
202	 */
203	bus_generic_probe(dev);
204	bus_enumerate_hinted_children(dev);
205
206	return (bus_generic_attach(dev));
207}
208
209/*
210 * Since this is not a self-enumerating bus, and since we always add
211 * children in attach, we have to always delete children here.
212 */
213static int
214gpiobus_detach(device_t dev)
215{
216	struct gpiobus_softc *sc;
217	struct gpiobus_ivar *devi;
218	device_t *devlist;
219	int i, err, ndevs;
220
221	sc = GPIOBUS_SOFTC(dev);
222	KASSERT(mtx_initialized(&sc->sc_mtx),
223	    ("gpiobus mutex not initialized"));
224	GPIOBUS_LOCK_DESTROY(sc);
225
226	if ((err = bus_generic_detach(dev)) != 0)
227		return (err);
228
229	if ((err = device_get_children(dev, &devlist, &ndevs)) != 0)
230		return (err);
231	for (i = 0; i < ndevs; i++) {
232		device_delete_child(dev, devlist[i]);
233		devi = GPIOBUS_IVAR(devlist[i]);
234		if (devi->pins) {
235			free(devi->pins, M_DEVBUF);
236			devi->pins = NULL;
237		}
238	}
239	free(devlist, M_TEMP);
240
241	if (sc->sc_pins_mapped) {
242		free(sc->sc_pins_mapped, M_DEVBUF);
243		sc->sc_pins_mapped = NULL;
244	}
245
246	return (0);
247}
248
249static int
250gpiobus_suspend(device_t dev)
251{
252
253	return (bus_generic_suspend(dev));
254}
255
256static int
257gpiobus_resume(device_t dev)
258{
259
260	return (bus_generic_resume(dev));
261}
262
263static int
264gpiobus_print_child(device_t dev, device_t child)
265{
266	struct gpiobus_ivar *devi = GPIOBUS_IVAR(child);
267	int retval = 0;
268
269	retval += bus_print_child_header(dev, child);
270	retval += printf(" at pin(s) ");
271	gpiobus_print_pins(devi);
272	retval += bus_print_child_footer(dev, child);
273
274	return (retval);
275}
276
277static int
278gpiobus_child_location_str(device_t bus, device_t child, char *buf,
279    size_t buflen)
280{
281
282	snprintf(buf, buflen, "pins=?");
283	return (0);
284}
285
286static int
287gpiobus_child_pnpinfo_str(device_t bus, device_t child, char *buf,
288    size_t buflen)
289{
290
291	*buf = '\0';
292	return (0);
293}
294
295static device_t
296gpiobus_add_child(device_t dev, u_int order, const char *name, int unit)
297{
298	device_t child;
299	struct gpiobus_ivar *devi;
300
301	child = device_add_child_ordered(dev, order, name, unit);
302	if (child == NULL)
303		return (child);
304	devi = malloc(sizeof(struct gpiobus_ivar), M_DEVBUF, M_NOWAIT | M_ZERO);
305	if (devi == NULL) {
306		device_delete_child(dev, child);
307		return (0);
308	}
309	device_set_ivars(child, devi);
310	return (child);
311}
312
313static void
314gpiobus_hinted_child(device_t bus, const char *dname, int dunit)
315{
316	struct gpiobus_softc *sc = GPIOBUS_SOFTC(bus);
317	struct gpiobus_ivar *devi;
318	device_t child;
319	int pins;
320
321
322	child = BUS_ADD_CHILD(bus, 0, dname, dunit);
323	devi = GPIOBUS_IVAR(child);
324	resource_int_value(dname, dunit, "pins", &pins);
325	if (gpiobus_parse_pins(sc, child, pins))
326		device_delete_child(bus, child);
327}
328
329static void
330gpiobus_lock_bus(device_t busdev)
331{
332	struct gpiobus_softc *sc;
333
334	sc = device_get_softc(busdev);
335	GPIOBUS_ASSERT_UNLOCKED(sc);
336	GPIOBUS_LOCK(sc);
337}
338
339static void
340gpiobus_unlock_bus(device_t busdev)
341{
342	struct gpiobus_softc *sc;
343
344	sc = device_get_softc(busdev);
345	GPIOBUS_ASSERT_LOCKED(sc);
346	GPIOBUS_UNLOCK(sc);
347}
348
349static void
350gpiobus_acquire_bus(device_t busdev, device_t child)
351{
352	struct gpiobus_softc *sc;
353
354	sc = device_get_softc(busdev);
355	GPIOBUS_ASSERT_LOCKED(sc);
356
357	if (sc->sc_owner)
358		panic("gpiobus: cannot serialize the access to device.");
359	sc->sc_owner = child;
360}
361
362static void
363gpiobus_release_bus(device_t busdev, device_t child)
364{
365	struct gpiobus_softc *sc;
366
367	sc = device_get_softc(busdev);
368	GPIOBUS_ASSERT_LOCKED(sc);
369
370	if (!sc->sc_owner)
371		panic("gpiobus: releasing unowned bus.");
372	if (sc->sc_owner != child)
373		panic("gpiobus: you don't own the bus. game over.");
374
375	sc->sc_owner = NULL;
376}
377
378static int
379gpiobus_pin_setflags(device_t dev, device_t child, uint32_t pin,
380    uint32_t flags)
381{
382	struct gpiobus_softc *sc = GPIOBUS_SOFTC(dev);
383	struct gpiobus_ivar *devi = GPIOBUS_IVAR(child);
384
385	if (pin >= devi->npins)
386		return (EINVAL);
387
388	return GPIO_PIN_SETFLAGS(sc->sc_dev, devi->pins[pin], flags);
389}
390
391static int
392gpiobus_pin_getflags(device_t dev, device_t child, uint32_t pin,
393    uint32_t *flags)
394{
395	struct gpiobus_softc *sc = GPIOBUS_SOFTC(dev);
396	struct gpiobus_ivar *devi = GPIOBUS_IVAR(child);
397
398	if (pin >= devi->npins)
399		return (EINVAL);
400
401	return GPIO_PIN_GETFLAGS(sc->sc_dev, devi->pins[pin], flags);
402}
403
404static int
405gpiobus_pin_getcaps(device_t dev, device_t child, uint32_t pin,
406    uint32_t *caps)
407{
408	struct gpiobus_softc *sc = GPIOBUS_SOFTC(dev);
409	struct gpiobus_ivar *devi = GPIOBUS_IVAR(child);
410
411	if (pin >= devi->npins)
412		return (EINVAL);
413
414	return GPIO_PIN_GETCAPS(sc->sc_dev, devi->pins[pin], caps);
415}
416
417static int
418gpiobus_pin_set(device_t dev, device_t child, uint32_t pin,
419    unsigned int value)
420{
421	struct gpiobus_softc *sc = GPIOBUS_SOFTC(dev);
422	struct gpiobus_ivar *devi = GPIOBUS_IVAR(child);
423
424	if (pin >= devi->npins)
425		return (EINVAL);
426
427	return GPIO_PIN_SET(sc->sc_dev, devi->pins[pin], value);
428}
429
430static int
431gpiobus_pin_get(device_t dev, device_t child, uint32_t pin,
432    unsigned int *value)
433{
434	struct gpiobus_softc *sc = GPIOBUS_SOFTC(dev);
435	struct gpiobus_ivar *devi = GPIOBUS_IVAR(child);
436
437	if (pin >= devi->npins)
438		return (EINVAL);
439
440	return GPIO_PIN_GET(sc->sc_dev, devi->pins[pin], value);
441}
442
443static int
444gpiobus_pin_toggle(device_t dev, device_t child, uint32_t pin)
445{
446	struct gpiobus_softc *sc = GPIOBUS_SOFTC(dev);
447	struct gpiobus_ivar *devi = GPIOBUS_IVAR(child);
448
449	if (pin >= devi->npins)
450		return (EINVAL);
451
452	return GPIO_PIN_TOGGLE(sc->sc_dev, devi->pins[pin]);
453}
454
455static device_method_t gpiobus_methods[] = {
456	/* Device interface */
457	DEVMETHOD(device_probe,		gpiobus_probe),
458	DEVMETHOD(device_attach,	gpiobus_attach),
459	DEVMETHOD(device_detach,	gpiobus_detach),
460	DEVMETHOD(device_shutdown,	bus_generic_shutdown),
461	DEVMETHOD(device_suspend,	gpiobus_suspend),
462	DEVMETHOD(device_resume,	gpiobus_resume),
463
464	/* Bus interface */
465	DEVMETHOD(bus_add_child,	gpiobus_add_child),
466	DEVMETHOD(bus_print_child,	gpiobus_print_child),
467	DEVMETHOD(bus_child_pnpinfo_str, gpiobus_child_pnpinfo_str),
468	DEVMETHOD(bus_child_location_str, gpiobus_child_location_str),
469	DEVMETHOD(bus_hinted_child,	gpiobus_hinted_child),
470
471	/* GPIO protocol */
472	DEVMETHOD(gpiobus_lock_bus,	gpiobus_lock_bus),
473	DEVMETHOD(gpiobus_unlock_bus,	gpiobus_unlock_bus),
474	DEVMETHOD(gpiobus_acquire_bus,	gpiobus_acquire_bus),
475	DEVMETHOD(gpiobus_release_bus,	gpiobus_release_bus),
476	DEVMETHOD(gpiobus_pin_getflags,	gpiobus_pin_getflags),
477	DEVMETHOD(gpiobus_pin_getcaps,	gpiobus_pin_getcaps),
478	DEVMETHOD(gpiobus_pin_setflags,	gpiobus_pin_setflags),
479	DEVMETHOD(gpiobus_pin_get,	gpiobus_pin_get),
480	DEVMETHOD(gpiobus_pin_set,	gpiobus_pin_set),
481	DEVMETHOD(gpiobus_pin_toggle,	gpiobus_pin_toggle),
482
483	DEVMETHOD_END
484};
485
486driver_t gpiobus_driver = {
487	"gpiobus",
488	gpiobus_methods,
489	sizeof(struct gpiobus_softc)
490};
491
492devclass_t	gpiobus_devclass;
493
494DRIVER_MODULE(gpiobus, gpio, gpiobus_driver, gpiobus_devclass, 0, 0);
495MODULE_VERSION(gpiobus, 1);
496