gpiobus.c revision 265191 
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 265191 2014-05-01 14:09:47Z loos $");
29
30#include <sys/param.h>
31#include <sys/bus.h>
32#include <sys/gpio.h>
33#include <sys/kernel.h>
34#include <sys/malloc.h>
35#include <sys/module.h>
36#include <sys/systm.h>
37#include <sys/types.h>
38
39#include <dev/gpio/gpiobusvar.h>
40
41#include "gpio_if.h"
42#include "gpiobus_if.h"
43
44static int gpiobus_parse_pins(struct gpiobus_softc *, device_t, int);
45static int gpiobus_probe(device_t);
46static int gpiobus_attach(device_t);
47static int gpiobus_detach(device_t);
48static int gpiobus_suspend(device_t);
49static int gpiobus_resume(device_t);
50static int gpiobus_print_child(device_t, device_t);
51static int gpiobus_child_location_str(device_t, device_t, char *, size_t);
52static int gpiobus_child_pnpinfo_str(device_t, device_t, char *, size_t);
53static device_t gpiobus_add_child(device_t, u_int, const char *, int);
54static void gpiobus_hinted_child(device_t, const char *, int);
55
56/*
57 * GPIOBUS interface
58 */
59static void gpiobus_lock_bus(device_t);
60static void gpiobus_unlock_bus(device_t);
61static void gpiobus_acquire_bus(device_t, device_t);
62static void gpiobus_release_bus(device_t, device_t);
63static int gpiobus_pin_setflags(device_t, device_t, uint32_t, uint32_t);
64static int gpiobus_pin_getflags(device_t, device_t, uint32_t, uint32_t*);
65static int gpiobus_pin_getcaps(device_t, device_t, uint32_t, uint32_t*);
66static int gpiobus_pin_set(device_t, device_t, uint32_t, unsigned int);
67static int gpiobus_pin_get(device_t, device_t, uint32_t, unsigned int*);
68static int gpiobus_pin_toggle(device_t, device_t, uint32_t);
69
70void
71gpiobus_print_pins(struct gpiobus_ivar *devi)
72{
73	int range_start, range_stop, need_coma;
74	int i;
75
76	if (devi->npins == 0)
77		return;
78
79	need_coma = 0;
80	range_start = range_stop = devi->pins[0];
81	for (i = 1; i < devi->npins; i++) {
82		if (devi->pins[i] != (range_stop + 1)) {
83			if (need_coma)
84				printf(",");
85			if (range_start != range_stop)
86				printf("%d-%d", range_start, range_stop);
87			else
88				printf("%d", range_start);
89
90			range_start = range_stop = devi->pins[i];
91			need_coma = 1;
92		}
93		else
94			range_stop++;
95	}
96
97	if (need_coma)
98		printf(",");
99	if (range_start != range_stop)
100		printf("%d-%d", range_start, range_stop);
101	else
102		printf("%d", range_start);
103}
104
105static int
106gpiobus_parse_pins(struct gpiobus_softc *sc, device_t child, int mask)
107{
108	struct gpiobus_ivar *devi = GPIOBUS_IVAR(child);
109	int i, npins;
110
111	npins = 0;
112	for (i = 0; i < 32; i++) {
113		if (mask & (1 << i))
114			npins++;
115	}
116
117	if (npins == 0) {
118		device_printf(child, "empty pin mask\n");
119		return (EINVAL);
120	}
121
122	devi->npins = npins;
123	devi->pins = malloc(sizeof(uint32_t) * devi->npins, M_DEVBUF,
124	    M_NOWAIT | M_ZERO);
125
126	if (!devi->pins)
127		return (ENOMEM);
128
129	npins = 0;
130	for (i = 0; i < 32; i++) {
131
132		if ((mask & (1 << i)) == 0)
133			continue;
134
135		if (i >= sc->sc_npins) {
136			device_printf(child,
137			    "invalid pin %d, max: %d\n", i, sc->sc_npins - 1);
138			free(devi->pins, M_DEVBUF);
139			return (EINVAL);
140		}
141
142		devi->pins[npins++] = i;
143		/*
144		 * Mark pin as mapped and give warning if it's already mapped
145		 */
146		if (sc->sc_pins_mapped[i]) {
147			device_printf(child,
148			    "warning: pin %d is already mapped\n", i);
149			free(devi->pins, M_DEVBUF);
150			return (EINVAL);
151		}
152		sc->sc_pins_mapped[i] = 1;
153	}
154
155	return (0);
156}
157
158static int
159gpiobus_probe(device_t dev)
160{
161	device_set_desc(dev, "GPIO bus");
162
163	return (BUS_PROBE_GENERIC);
164}
165
166static int
167gpiobus_attach(device_t dev)
168{
169	struct gpiobus_softc *sc = GPIOBUS_SOFTC(dev);
170	int res;
171
172	sc->sc_busdev = dev;
173	sc->sc_dev = device_get_parent(dev);
174	res = GPIO_PIN_MAX(sc->sc_dev, &sc->sc_npins);
175	if (res)
176		return (ENXIO);
177
178	KASSERT(sc->sc_npins != 0, ("GPIO device with no pins"));
179
180	/*
181	 * Increase to get number of pins
182	 */
183	sc->sc_npins++;
184
185	sc->sc_pins_mapped = malloc(sizeof(int) * sc->sc_npins, M_DEVBUF,
186	    M_NOWAIT | M_ZERO);
187
188	if (!sc->sc_pins_mapped)
189		return (ENOMEM);
190
191	/* init bus lock */
192	GPIOBUS_LOCK_INIT(sc);
193
194	/*
195	 * Get parent's pins and mark them as unmapped
196	 */
197	bus_generic_probe(dev);
198	bus_enumerate_hinted_children(dev);
199
200	return (bus_generic_attach(dev));
201}
202
203/*
204 * Since this is not a self-enumerating bus, and since we always add
205 * children in attach, we have to always delete children here.
206 */
207static int
208gpiobus_detach(device_t dev)
209{
210	struct gpiobus_softc *sc;
211	struct gpiobus_ivar *devi;
212	device_t *devlist;
213	int i, err, ndevs;
214
215	sc = GPIOBUS_SOFTC(dev);
216	KASSERT(mtx_initialized(&sc->sc_mtx),
217	    ("gpiobus mutex not initialized"));
218	GPIOBUS_LOCK_DESTROY(sc);
219
220	if ((err = bus_generic_detach(dev)) != 0)
221		return (err);
222
223	if ((err = device_get_children(dev, &devlist, &ndevs)) != 0)
224		return (err);
225	for (i = 0; i < ndevs; i++) {
226		device_delete_child(dev, devlist[i]);
227		devi = GPIOBUS_IVAR(devlist[i]);
228		if (devi->pins) {
229			free(devi->pins, M_DEVBUF);
230			devi->pins = NULL;
231		}
232	}
233	free(devlist, M_TEMP);
234
235	if (sc->sc_pins_mapped) {
236		free(sc->sc_pins_mapped, M_DEVBUF);
237		sc->sc_pins_mapped = NULL;
238	}
239
240	return (0);
241}
242
243static int
244gpiobus_suspend(device_t dev)
245{
246
247	return (bus_generic_suspend(dev));
248}
249
250static int
251gpiobus_resume(device_t dev)
252{
253
254	return (bus_generic_resume(dev));
255}
256
257static int
258gpiobus_print_child(device_t dev, device_t child)
259{
260	struct gpiobus_ivar *devi = GPIOBUS_IVAR(child);
261	int retval = 0;
262
263	retval += bus_print_child_header(dev, child);
264	retval += printf(" at pin(s) ");
265	gpiobus_print_pins(devi);
266	retval += bus_print_child_footer(dev, child);
267
268	return (retval);
269}
270
271static int
272gpiobus_child_location_str(device_t bus, device_t child, char *buf,
273    size_t buflen)
274{
275
276	snprintf(buf, buflen, "pins=?");
277	return (0);
278}
279
280static int
281gpiobus_child_pnpinfo_str(device_t bus, device_t child, char *buf,
282    size_t buflen)
283{
284
285	*buf = '\0';
286	return (0);
287}
288
289static device_t
290gpiobus_add_child(device_t dev, u_int order, const char *name, int unit)
291{
292	device_t child;
293	struct gpiobus_ivar *devi;
294
295	child = device_add_child_ordered(dev, order, name, unit);
296	if (child == NULL)
297		return (child);
298	devi = malloc(sizeof(struct gpiobus_ivar), M_DEVBUF, M_NOWAIT | M_ZERO);
299	if (devi == NULL) {
300		device_delete_child(dev, child);
301		return (0);
302	}
303	device_set_ivars(child, devi);
304	return (child);
305}
306
307static void
308gpiobus_hinted_child(device_t bus, const char *dname, int dunit)
309{
310	struct gpiobus_softc *sc = GPIOBUS_SOFTC(bus);
311	struct gpiobus_ivar *devi;
312	device_t child;
313	int pins;
314
315
316	child = BUS_ADD_CHILD(bus, 0, dname, dunit);
317	devi = GPIOBUS_IVAR(child);
318	resource_int_value(dname, dunit, "pins", &pins);
319	if (gpiobus_parse_pins(sc, child, pins))
320		device_delete_child(bus, child);
321}
322
323static void
324gpiobus_lock_bus(device_t busdev)
325{
326	struct gpiobus_softc *sc;
327
328	sc = device_get_softc(busdev);
329	GPIOBUS_ASSERT_UNLOCKED(sc);
330	GPIOBUS_LOCK(sc);
331}
332
333static void
334gpiobus_unlock_bus(device_t busdev)
335{
336	struct gpiobus_softc *sc;
337
338	sc = device_get_softc(busdev);
339	GPIOBUS_ASSERT_LOCKED(sc);
340	GPIOBUS_UNLOCK(sc);
341}
342
343static void
344gpiobus_acquire_bus(device_t busdev, device_t child)
345{
346	struct gpiobus_softc *sc;
347
348	sc = device_get_softc(busdev);
349	GPIOBUS_ASSERT_LOCKED(sc);
350
351	if (sc->sc_owner)
352		panic("gpiobus: cannot serialize the access to device.");
353	sc->sc_owner = child;
354}
355
356static void
357gpiobus_release_bus(device_t busdev, device_t child)
358{
359	struct gpiobus_softc *sc;
360
361	sc = device_get_softc(busdev);
362	GPIOBUS_ASSERT_LOCKED(sc);
363
364	if (!sc->sc_owner)
365		panic("gpiobus: releasing unowned bus.");
366	if (sc->sc_owner != child)
367		panic("gpiobus: you don't own the bus. game over.");
368
369	sc->sc_owner = NULL;
370}
371
372static int
373gpiobus_pin_setflags(device_t dev, device_t child, uint32_t pin,
374    uint32_t flags)
375{
376	struct gpiobus_softc *sc = GPIOBUS_SOFTC(dev);
377	struct gpiobus_ivar *devi = GPIOBUS_IVAR(child);
378
379	if (pin >= devi->npins)
380		return (EINVAL);
381
382	return GPIO_PIN_SETFLAGS(sc->sc_dev, devi->pins[pin], flags);
383}
384
385static int
386gpiobus_pin_getflags(device_t dev, device_t child, uint32_t pin,
387    uint32_t *flags)
388{
389	struct gpiobus_softc *sc = GPIOBUS_SOFTC(dev);
390	struct gpiobus_ivar *devi = GPIOBUS_IVAR(child);
391
392	if (pin >= devi->npins)
393		return (EINVAL);
394
395	return GPIO_PIN_GETFLAGS(sc->sc_dev, devi->pins[pin], flags);
396}
397
398static int
399gpiobus_pin_getcaps(device_t dev, device_t child, uint32_t pin,
400    uint32_t *caps)
401{
402	struct gpiobus_softc *sc = GPIOBUS_SOFTC(dev);
403	struct gpiobus_ivar *devi = GPIOBUS_IVAR(child);
404
405	if (pin >= devi->npins)
406		return (EINVAL);
407
408	return GPIO_PIN_GETCAPS(sc->sc_dev, devi->pins[pin], caps);
409}
410
411static int
412gpiobus_pin_set(device_t dev, device_t child, uint32_t pin,
413    unsigned int value)
414{
415	struct gpiobus_softc *sc = GPIOBUS_SOFTC(dev);
416	struct gpiobus_ivar *devi = GPIOBUS_IVAR(child);
417
418	if (pin >= devi->npins)
419		return (EINVAL);
420
421	return GPIO_PIN_SET(sc->sc_dev, devi->pins[pin], value);
422}
423
424static int
425gpiobus_pin_get(device_t dev, device_t child, uint32_t pin,
426    unsigned int *value)
427{
428	struct gpiobus_softc *sc = GPIOBUS_SOFTC(dev);
429	struct gpiobus_ivar *devi = GPIOBUS_IVAR(child);
430
431	if (pin >= devi->npins)
432		return (EINVAL);
433
434	return GPIO_PIN_GET(sc->sc_dev, devi->pins[pin], value);
435}
436
437static int
438gpiobus_pin_toggle(device_t dev, device_t child, uint32_t pin)
439{
440	struct gpiobus_softc *sc = GPIOBUS_SOFTC(dev);
441	struct gpiobus_ivar *devi = GPIOBUS_IVAR(child);
442
443	if (pin >= devi->npins)
444		return (EINVAL);
445
446	return GPIO_PIN_TOGGLE(sc->sc_dev, devi->pins[pin]);
447}
448
449static device_method_t gpiobus_methods[] = {
450	/* Device interface */
451	DEVMETHOD(device_probe,		gpiobus_probe),
452	DEVMETHOD(device_attach,	gpiobus_attach),
453	DEVMETHOD(device_detach,	gpiobus_detach),
454	DEVMETHOD(device_shutdown,	bus_generic_shutdown),
455	DEVMETHOD(device_suspend,	gpiobus_suspend),
456	DEVMETHOD(device_resume,	gpiobus_resume),
457
458	/* Bus interface */
459	DEVMETHOD(bus_add_child,	gpiobus_add_child),
460	DEVMETHOD(bus_print_child,	gpiobus_print_child),
461	DEVMETHOD(bus_child_pnpinfo_str, gpiobus_child_pnpinfo_str),
462	DEVMETHOD(bus_child_location_str, gpiobus_child_location_str),
463	DEVMETHOD(bus_hinted_child,	gpiobus_hinted_child),
464
465	/* GPIO protocol */
466	DEVMETHOD(gpiobus_lock_bus,	gpiobus_lock_bus),
467	DEVMETHOD(gpiobus_unlock_bus,	gpiobus_unlock_bus),
468	DEVMETHOD(gpiobus_acquire_bus,	gpiobus_acquire_bus),
469	DEVMETHOD(gpiobus_release_bus,	gpiobus_release_bus),
470	DEVMETHOD(gpiobus_pin_getflags,	gpiobus_pin_getflags),
471	DEVMETHOD(gpiobus_pin_getcaps,	gpiobus_pin_getcaps),
472	DEVMETHOD(gpiobus_pin_setflags,	gpiobus_pin_setflags),
473	DEVMETHOD(gpiobus_pin_get,	gpiobus_pin_get),
474	DEVMETHOD(gpiobus_pin_set,	gpiobus_pin_set),
475	DEVMETHOD(gpiobus_pin_toggle,	gpiobus_pin_toggle),
476
477	DEVMETHOD_END
478};
479
480driver_t gpiobus_driver = {
481	"gpiobus",
482	gpiobus_methods,
483	sizeof(struct gpiobus_softc)
484};
485
486devclass_t	gpiobus_devclass;
487
488DRIVER_MODULE(gpiobus, gpio, gpiobus_driver, gpiobus_devclass, 0, 0);
489MODULE_VERSION(gpiobus, 1);
490