xref: /freebsd/sys/dev/gpio/gpiobus.c (revision 40a8ac8f62b535d30349faf28cf47106b7041b83)
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/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 
41 static int gpiobus_parse_pins(struct gpiobus_softc *, device_t, int);
42 static int gpiobus_probe(device_t);
43 static int gpiobus_attach(device_t);
44 static int gpiobus_detach(device_t);
45 static int gpiobus_suspend(device_t);
46 static int gpiobus_resume(device_t);
47 static int gpiobus_print_child(device_t, device_t);
48 static int gpiobus_child_location_str(device_t, device_t, char *, size_t);
49 static int gpiobus_child_pnpinfo_str(device_t, device_t, char *, size_t);
50 static device_t gpiobus_add_child(device_t, u_int, const char *, int);
51 static void gpiobus_hinted_child(device_t, const char *, int);
52 
53 /*
54  * GPIOBUS interface
55  */
56 static void gpiobus_lock_bus(device_t);
57 static void gpiobus_unlock_bus(device_t);
58 static void gpiobus_acquire_bus(device_t, device_t);
59 static void gpiobus_release_bus(device_t, device_t);
60 static int gpiobus_pin_setflags(device_t, device_t, uint32_t, uint32_t);
61 static int gpiobus_pin_getflags(device_t, device_t, uint32_t, uint32_t*);
62 static int gpiobus_pin_getcaps(device_t, device_t, uint32_t, uint32_t*);
63 static int gpiobus_pin_set(device_t, device_t, uint32_t, unsigned int);
64 static int gpiobus_pin_get(device_t, device_t, uint32_t, unsigned int*);
65 static int gpiobus_pin_toggle(device_t, device_t, uint32_t);
66 
67 void
68 gpiobus_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 
102 static int
103 gpiobus_parse_pins(struct gpiobus_softc *sc, device_t child, int mask)
104 {
105 	struct gpiobus_ivar *devi = GPIOBUS_IVAR(child);
106 	int i, npins;
107 
108 	npins = 0;
109 	for (i = 0; i < 32; i++) {
110 		if (mask & (1 << i))
111 			npins++;
112 	}
113 
114 	if (npins == 0) {
115 		device_printf(child, "empty pin mask\n");
116 		return (EINVAL);
117 	}
118 
119 	devi->npins = npins;
120 	devi->pins = malloc(sizeof(uint32_t) * devi->npins, M_DEVBUF,
121 	    M_NOWAIT | M_ZERO);
122 
123 	if (!devi->pins)
124 		return (ENOMEM);
125 
126 	npins = 0;
127 	for (i = 0; i < 32; i++) {
128 
129 		if ((mask & (1 << i)) == 0)
130 			continue;
131 
132 		if (i >= sc->sc_npins) {
133 			device_printf(child,
134 			    "invalid pin %d, max: %d\n", i, sc->sc_npins - 1);
135 			free(devi->pins, M_DEVBUF);
136 			return (EINVAL);
137 		}
138 
139 		devi->pins[npins++] = i;
140 		/*
141 		 * Mark pin as mapped and give warning if it's already mapped
142 		 */
143 		if (sc->sc_pins_mapped[i]) {
144 			device_printf(child,
145 			    "warning: pin %d is already mapped\n", i);
146 			free(devi->pins, M_DEVBUF);
147 			return (EINVAL);
148 		}
149 		sc->sc_pins_mapped[i] = 1;
150 	}
151 
152 	return (0);
153 }
154 
155 static int
156 gpiobus_probe(device_t dev)
157 {
158 	device_set_desc(dev, "GPIO bus");
159 
160 	return (BUS_PROBE_GENERIC);
161 }
162 
163 static int
164 gpiobus_attach(device_t dev)
165 {
166 	struct gpiobus_softc *sc = GPIOBUS_SOFTC(dev);
167 	int res;
168 
169 	sc->sc_busdev = dev;
170 	sc->sc_dev = device_get_parent(dev);
171 	res = GPIO_PIN_MAX(sc->sc_dev, &sc->sc_npins);
172 	if (res)
173 		return (ENXIO);
174 
175 	KASSERT(sc->sc_npins != 0, ("GPIO device with no pins"));
176 
177 	/*
178 	 * Increase to get number of pins
179 	 */
180 	sc->sc_npins++;
181 
182 	sc->sc_pins_mapped = malloc(sizeof(int) * sc->sc_npins, M_DEVBUF,
183 	    M_NOWAIT | M_ZERO);
184 
185 	if (!sc->sc_pins_mapped)
186 		return (ENOMEM);
187 
188 	/* init bus lock */
189 	GPIOBUS_LOCK_INIT(sc);
190 
191 	/*
192 	 * Get parent's pins and mark them as unmapped
193 	 */
194 	bus_generic_probe(dev);
195 	bus_enumerate_hinted_children(dev);
196 
197 	return (bus_generic_attach(dev));
198 }
199 
200 /*
201  * Since this is not a self-enumerating bus, and since we always add
202  * children in attach, we have to always delete children here.
203  */
204 static int
205 gpiobus_detach(device_t dev)
206 {
207 	struct gpiobus_softc *sc;
208 	struct gpiobus_ivar *devi;
209 	device_t *devlist;
210 	int i, err, ndevs;
211 
212 	sc = GPIOBUS_SOFTC(dev);
213 	KASSERT(mtx_initialized(&sc->sc_mtx),
214 	    ("gpiobus mutex not initialized"));
215 	GPIOBUS_LOCK_DESTROY(sc);
216 
217 	if ((err = bus_generic_detach(dev)) != 0)
218 		return (err);
219 
220 	if ((err = device_get_children(dev, &devlist, &ndevs)) != 0)
221 		return (err);
222 	for (i = 0; i < ndevs; i++) {
223 		device_delete_child(dev, devlist[i]);
224 		devi = GPIOBUS_IVAR(devlist[i]);
225 		if (devi->pins) {
226 			free(devi->pins, M_DEVBUF);
227 			devi->pins = NULL;
228 		}
229 	}
230 	free(devlist, M_TEMP);
231 
232 	if (sc->sc_pins_mapped) {
233 		free(sc->sc_pins_mapped, M_DEVBUF);
234 		sc->sc_pins_mapped = NULL;
235 	}
236 
237 	return (0);
238 }
239 
240 static int
241 gpiobus_suspend(device_t dev)
242 {
243 
244 	return (bus_generic_suspend(dev));
245 }
246 
247 static int
248 gpiobus_resume(device_t dev)
249 {
250 
251 	return (bus_generic_resume(dev));
252 }
253 
254 static int
255 gpiobus_print_child(device_t dev, device_t child)
256 {
257 	struct gpiobus_ivar *devi = GPIOBUS_IVAR(child);
258 	int retval = 0;
259 
260 	retval += bus_print_child_header(dev, child);
261 	retval += printf(" at pin(s) ");
262 	gpiobus_print_pins(devi);
263 	retval += bus_print_child_footer(dev, child);
264 
265 	return (retval);
266 }
267 
268 static int
269 gpiobus_child_location_str(device_t bus, device_t child, char *buf,
270     size_t buflen)
271 {
272 
273 	snprintf(buf, buflen, "pins=?");
274 	return (0);
275 }
276 
277 static int
278 gpiobus_child_pnpinfo_str(device_t bus, device_t child, char *buf,
279     size_t buflen)
280 {
281 
282 	*buf = '\0';
283 	return (0);
284 }
285 
286 static device_t
287 gpiobus_add_child(device_t dev, u_int order, const char *name, int unit)
288 {
289 	device_t child;
290 	struct gpiobus_ivar *devi;
291 
292 	child = device_add_child_ordered(dev, order, name, unit);
293 	if (child == NULL)
294 		return (child);
295 	devi = malloc(sizeof(struct gpiobus_ivar), M_DEVBUF, M_NOWAIT | M_ZERO);
296 	if (devi == NULL) {
297 		device_delete_child(dev, child);
298 		return (0);
299 	}
300 	device_set_ivars(child, devi);
301 	return (child);
302 }
303 
304 static void
305 gpiobus_hinted_child(device_t bus, const char *dname, int dunit)
306 {
307 	struct gpiobus_softc *sc = GPIOBUS_SOFTC(bus);
308 	struct gpiobus_ivar *devi;
309 	device_t child;
310 	int pins;
311 
312 
313 	child = BUS_ADD_CHILD(bus, 0, dname, dunit);
314 	devi = GPIOBUS_IVAR(child);
315 	resource_int_value(dname, dunit, "pins", &pins);
316 	if (gpiobus_parse_pins(sc, child, pins))
317 		device_delete_child(bus, child);
318 }
319 
320 static void
321 gpiobus_lock_bus(device_t busdev)
322 {
323 	struct gpiobus_softc *sc;
324 
325 	sc = device_get_softc(busdev);
326 	GPIOBUS_ASSERT_UNLOCKED(sc);
327 	GPIOBUS_LOCK(sc);
328 }
329 
330 static void
331 gpiobus_unlock_bus(device_t busdev)
332 {
333 	struct gpiobus_softc *sc;
334 
335 	sc = device_get_softc(busdev);
336 	GPIOBUS_ASSERT_LOCKED(sc);
337 	GPIOBUS_UNLOCK(sc);
338 }
339 
340 static void
341 gpiobus_acquire_bus(device_t busdev, device_t child)
342 {
343 	struct gpiobus_softc *sc;
344 
345 	sc = device_get_softc(busdev);
346 	GPIOBUS_ASSERT_LOCKED(sc);
347 
348 	if (sc->sc_owner)
349 		panic("gpiobus: cannot serialize the access to device.");
350 	sc->sc_owner = child;
351 }
352 
353 static void
354 gpiobus_release_bus(device_t busdev, device_t child)
355 {
356 	struct gpiobus_softc *sc;
357 
358 	sc = device_get_softc(busdev);
359 	GPIOBUS_ASSERT_LOCKED(sc);
360 
361 	if (!sc->sc_owner)
362 		panic("gpiobus: releasing unowned bus.");
363 	if (sc->sc_owner != child)
364 		panic("gpiobus: you don't own the bus. game over.");
365 
366 	sc->sc_owner = NULL;
367 }
368 
369 static int
370 gpiobus_pin_setflags(device_t dev, device_t child, uint32_t pin,
371     uint32_t flags)
372 {
373 	struct gpiobus_softc *sc = GPIOBUS_SOFTC(dev);
374 	struct gpiobus_ivar *devi = GPIOBUS_IVAR(child);
375 
376 	if (pin >= devi->npins)
377 		return (EINVAL);
378 
379 	return GPIO_PIN_SETFLAGS(sc->sc_dev, devi->pins[pin], flags);
380 }
381 
382 static int
383 gpiobus_pin_getflags(device_t dev, device_t child, uint32_t pin,
384     uint32_t *flags)
385 {
386 	struct gpiobus_softc *sc = GPIOBUS_SOFTC(dev);
387 	struct gpiobus_ivar *devi = GPIOBUS_IVAR(child);
388 
389 	if (pin >= devi->npins)
390 		return (EINVAL);
391 
392 	return GPIO_PIN_GETFLAGS(sc->sc_dev, devi->pins[pin], flags);
393 }
394 
395 static int
396 gpiobus_pin_getcaps(device_t dev, device_t child, uint32_t pin,
397     uint32_t *caps)
398 {
399 	struct gpiobus_softc *sc = GPIOBUS_SOFTC(dev);
400 	struct gpiobus_ivar *devi = GPIOBUS_IVAR(child);
401 
402 	if (pin >= devi->npins)
403 		return (EINVAL);
404 
405 	return GPIO_PIN_GETCAPS(sc->sc_dev, devi->pins[pin], caps);
406 }
407 
408 static int
409 gpiobus_pin_set(device_t dev, device_t child, uint32_t pin,
410     unsigned int value)
411 {
412 	struct gpiobus_softc *sc = GPIOBUS_SOFTC(dev);
413 	struct gpiobus_ivar *devi = GPIOBUS_IVAR(child);
414 
415 	if (pin >= devi->npins)
416 		return (EINVAL);
417 
418 	return GPIO_PIN_SET(sc->sc_dev, devi->pins[pin], value);
419 }
420 
421 static int
422 gpiobus_pin_get(device_t dev, device_t child, uint32_t pin,
423     unsigned int *value)
424 {
425 	struct gpiobus_softc *sc = GPIOBUS_SOFTC(dev);
426 	struct gpiobus_ivar *devi = GPIOBUS_IVAR(child);
427 
428 	if (pin >= devi->npins)
429 		return (EINVAL);
430 
431 	return GPIO_PIN_GET(sc->sc_dev, devi->pins[pin], value);
432 }
433 
434 static int
435 gpiobus_pin_toggle(device_t dev, device_t child, uint32_t pin)
436 {
437 	struct gpiobus_softc *sc = GPIOBUS_SOFTC(dev);
438 	struct gpiobus_ivar *devi = GPIOBUS_IVAR(child);
439 
440 	if (pin >= devi->npins)
441 		return (EINVAL);
442 
443 	return GPIO_PIN_TOGGLE(sc->sc_dev, devi->pins[pin]);
444 }
445 
446 static device_method_t gpiobus_methods[] = {
447 	/* Device interface */
448 	DEVMETHOD(device_probe,		gpiobus_probe),
449 	DEVMETHOD(device_attach,	gpiobus_attach),
450 	DEVMETHOD(device_detach,	gpiobus_detach),
451 	DEVMETHOD(device_shutdown,	bus_generic_shutdown),
452 	DEVMETHOD(device_suspend,	gpiobus_suspend),
453 	DEVMETHOD(device_resume,	gpiobus_resume),
454 
455 	/* Bus interface */
456 	DEVMETHOD(bus_add_child,	gpiobus_add_child),
457 	DEVMETHOD(bus_print_child,	gpiobus_print_child),
458 	DEVMETHOD(bus_child_pnpinfo_str, gpiobus_child_pnpinfo_str),
459 	DEVMETHOD(bus_child_location_str, gpiobus_child_location_str),
460 	DEVMETHOD(bus_hinted_child,	gpiobus_hinted_child),
461 
462 	/* GPIO protocol */
463 	DEVMETHOD(gpiobus_lock_bus,	gpiobus_lock_bus),
464 	DEVMETHOD(gpiobus_unlock_bus,	gpiobus_unlock_bus),
465 	DEVMETHOD(gpiobus_acquire_bus,	gpiobus_acquire_bus),
466 	DEVMETHOD(gpiobus_release_bus,	gpiobus_release_bus),
467 	DEVMETHOD(gpiobus_pin_getflags,	gpiobus_pin_getflags),
468 	DEVMETHOD(gpiobus_pin_getcaps,	gpiobus_pin_getcaps),
469 	DEVMETHOD(gpiobus_pin_setflags,	gpiobus_pin_setflags),
470 	DEVMETHOD(gpiobus_pin_get,	gpiobus_pin_get),
471 	DEVMETHOD(gpiobus_pin_set,	gpiobus_pin_set),
472 	DEVMETHOD(gpiobus_pin_toggle,	gpiobus_pin_toggle),
473 
474 	DEVMETHOD_END
475 };
476 
477 driver_t gpiobus_driver = {
478 	"gpiobus",
479 	gpiobus_methods,
480 	sizeof(struct gpiobus_softc)
481 };
482 
483 devclass_t	gpiobus_devclass;
484 
485 DRIVER_MODULE(gpiobus, gpio, gpiobus_driver, gpiobus_devclass, 0, 0);
486 MODULE_VERSION(gpiobus, 1);
487