xref: /freebsd/sys/dev/gpio/gpiobus.c (revision 197186496661d8f63639b5b27b33851f727d4da7)
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");
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 			return (EINVAL);
155 		}
156 
157 		devi->pins[npins++] = i;
158 		/*
159 		 * Mark pin as mapped and give warning if it's already mapped
160 		 */
161 		if (sc->sc_pins_mapped[i]) {
162 			device_printf(child,
163 			    "warning: pin %d is already mapped\n", i);
164 			return (EINVAL);
165 		}
166 		sc->sc_pins_mapped[i] = 1;
167 	}
168 
169 	return (0);
170 }
171 
172 static int
173 gpiobus_probe(device_t dev)
174 {
175 	device_set_desc(dev, "GPIO bus");
176 	return (0);
177 }
178 
179 static int
180 gpiobus_attach(device_t dev)
181 {
182 	struct gpiobus_softc *sc = GPIOBUS_SOFTC(dev);
183 	int res;
184 
185 	sc->sc_busdev = dev;
186 	sc->sc_dev = device_get_parent(dev);
187 	res = GPIO_PIN_MAX(sc->sc_dev, &sc->sc_npins);
188 	if (res)
189 		return (ENXIO);
190 
191 	/*
192 	 * Increase to get number of pins
193 	 */
194 	sc->sc_npins++;
195 
196 	KASSERT(sc->sc_npins != 0, ("GPIO device with no pins"));
197 
198 	sc->sc_pins_mapped = malloc(sizeof(int) * sc->sc_npins, M_DEVBUF,
199 	    M_NOWAIT | M_ZERO);
200 
201 	if (!sc->sc_pins_mapped)
202 		return (ENOMEM);
203 
204 	/* init bus lock */
205 	GPIOBUS_LOCK_INIT(sc);
206 
207 	/*
208 	 * Get parent's pins and mark them as unmapped
209 	 */
210 	bus_enumerate_hinted_children(dev);
211 	return (bus_generic_attach(dev));
212 }
213 
214 /*
215  * Since this is not a self-enumerating bus, and since we always add
216  * children in attach, we have to always delete children here.
217  */
218 static int
219 gpiobus_detach(device_t dev)
220 {
221 	struct gpiobus_softc *sc = GPIOBUS_SOFTC(dev);
222 	int err;
223 
224 	KASSERT(mtx_initialized(&sc->sc_mtx),
225 	    ("gpiobus mutex not initialized"));
226 	GPIOBUS_LOCK_DESTROY(sc);
227 
228 	if ((err = bus_generic_detach(dev)) != 0)
229 		return (err);
230 
231 	/* detach and delete all children */
232 	device_delete_children(dev);
233 
234 	if (sc->sc_pins_mapped) {
235 		free(sc->sc_pins_mapped, M_DEVBUF);
236 		sc->sc_pins_mapped = NULL;
237 	}
238 
239 	return (0);
240 }
241 
242 static int
243 gpiobus_suspend(device_t dev)
244 {
245 
246 	return (bus_generic_suspend(dev));
247 }
248 
249 static int
250 gpiobus_resume(device_t dev)
251 {
252 
253 	return (bus_generic_resume(dev));
254 }
255 
256 static int
257 gpiobus_print_child(device_t dev, device_t child)
258 {
259 	struct gpiobus_ivar *devi = GPIOBUS_IVAR(child);
260 	int retval = 0;
261 
262 	retval += bus_print_child_header(dev, child);
263 	retval += printf(" at pin(s) ");
264 	gpiobus_print_pins(devi);
265 	retval += bus_print_child_footer(dev, child);
266 
267 	return (retval);
268 }
269 
270 static int
271 gpiobus_child_location_str(device_t bus, device_t child, char *buf,
272     size_t buflen)
273 {
274 
275 	snprintf(buf, buflen, "pins=?");
276 	return (0);
277 }
278 
279 static int
280 gpiobus_child_pnpinfo_str(device_t bus, device_t child, char *buf,
281     size_t buflen)
282 {
283 
284 	*buf = '\0';
285 	return (0);
286 }
287 
288 static device_t
289 gpiobus_add_child(device_t dev, u_int order, const char *name, int unit)
290 {
291 	device_t child;
292 	struct gpiobus_ivar *devi;
293 
294 	child = device_add_child_ordered(dev, order, name, unit);
295 	if (child == NULL)
296 		return (child);
297 	devi = malloc(sizeof(struct gpiobus_ivar), M_DEVBUF, M_NOWAIT | M_ZERO);
298 	if (devi == NULL) {
299 		device_delete_child(dev, child);
300 		return (0);
301 	}
302 	device_set_ivars(child, devi);
303 	return (child);
304 }
305 
306 static void
307 gpiobus_hinted_child(device_t bus, const char *dname, int dunit)
308 {
309 	struct gpiobus_softc *sc = GPIOBUS_SOFTC(bus);
310 	struct gpiobus_ivar *devi;
311 	device_t child;
312 	int pins;
313 
314 
315 	child = BUS_ADD_CHILD(bus, 0, dname, dunit);
316 	devi = GPIOBUS_IVAR(child);
317 	resource_int_value(dname, dunit, "pins", &pins);
318 	if (gpiobus_parse_pins(sc, child, pins))
319 		device_delete_child(bus, child);
320 }
321 
322 static void
323 gpiobus_lock_bus(device_t busdev)
324 {
325 	struct gpiobus_softc *sc;
326 
327 	sc = device_get_softc(busdev);
328 	GPIOBUS_ASSERT_UNLOCKED(sc);
329 	GPIOBUS_LOCK(sc);
330 }
331 
332 static void
333 gpiobus_unlock_bus(device_t busdev)
334 {
335 	struct gpiobus_softc *sc;
336 
337 	sc = device_get_softc(busdev);
338 	GPIOBUS_ASSERT_LOCKED(sc);
339 	GPIOBUS_UNLOCK(sc);
340 }
341 
342 static void
343 gpiobus_acquire_bus(device_t busdev, device_t child)
344 {
345 	struct gpiobus_softc *sc;
346 
347 	sc = device_get_softc(busdev);
348 	GPIOBUS_ASSERT_LOCKED(sc);
349 
350 	if (sc->sc_owner)
351 		panic("gpiobus: cannot serialize the access to device.");
352 	sc->sc_owner = child;
353 }
354 
355 static void
356 gpiobus_release_bus(device_t busdev, device_t child)
357 {
358 	struct gpiobus_softc *sc;
359 
360 	sc = device_get_softc(busdev);
361 	GPIOBUS_ASSERT_LOCKED(sc);
362 
363 	if (!sc->sc_owner)
364 		panic("gpiobus: releasing unowned bus.");
365 	if (sc->sc_owner != child)
366 		panic("gpiobus: you don't own the bus. game over.");
367 
368 	sc->sc_owner = NULL;
369 }
370 
371 static int
372 gpiobus_pin_setflags(device_t dev, device_t child, uint32_t pin,
373     uint32_t flags)
374 {
375 	struct gpiobus_softc *sc = GPIOBUS_SOFTC(dev);
376 	struct gpiobus_ivar *devi = GPIOBUS_IVAR(child);
377 
378 	if (pin >= devi->npins)
379 		return (EINVAL);
380 
381 	return GPIO_PIN_SETFLAGS(sc->sc_dev, devi->pins[pin], flags);
382 }
383 
384 static int
385 gpiobus_pin_getflags(device_t dev, device_t child, uint32_t pin,
386     uint32_t *flags)
387 {
388 	struct gpiobus_softc *sc = GPIOBUS_SOFTC(dev);
389 	struct gpiobus_ivar *devi = GPIOBUS_IVAR(child);
390 
391 	if (pin >= devi->npins)
392 		return (EINVAL);
393 
394 	return GPIO_PIN_GETFLAGS(sc->sc_dev, devi->pins[pin], flags);
395 }
396 
397 static int
398 gpiobus_pin_getcaps(device_t dev, device_t child, uint32_t pin,
399     uint32_t *caps)
400 {
401 	struct gpiobus_softc *sc = GPIOBUS_SOFTC(dev);
402 	struct gpiobus_ivar *devi = GPIOBUS_IVAR(child);
403 
404 	if (pin >= devi->npins)
405 		return (EINVAL);
406 
407 	return GPIO_PIN_GETCAPS(sc->sc_dev, devi->pins[pin], caps);
408 }
409 
410 static int
411 gpiobus_pin_set(device_t dev, device_t child, uint32_t pin,
412     unsigned int value)
413 {
414 	struct gpiobus_softc *sc = GPIOBUS_SOFTC(dev);
415 	struct gpiobus_ivar *devi = GPIOBUS_IVAR(child);
416 
417 	if (pin >= devi->npins)
418 		return (EINVAL);
419 
420 	return GPIO_PIN_SET(sc->sc_dev, devi->pins[pin], value);
421 }
422 
423 static int
424 gpiobus_pin_get(device_t dev, device_t child, uint32_t pin,
425     unsigned int *value)
426 {
427 	struct gpiobus_softc *sc = GPIOBUS_SOFTC(dev);
428 	struct gpiobus_ivar *devi = GPIOBUS_IVAR(child);
429 
430 	if (pin >= devi->npins)
431 		return (EINVAL);
432 
433 	return GPIO_PIN_GET(sc->sc_dev, devi->pins[pin], value);
434 }
435 
436 static int
437 gpiobus_pin_toggle(device_t dev, device_t child, uint32_t pin)
438 {
439 	struct gpiobus_softc *sc = GPIOBUS_SOFTC(dev);
440 	struct gpiobus_ivar *devi = GPIOBUS_IVAR(child);
441 
442 	if (pin >= devi->npins)
443 		return (EINVAL);
444 
445 	return GPIO_PIN_TOGGLE(sc->sc_dev, devi->pins[pin]);
446 }
447 
448 static device_method_t gpiobus_methods[] = {
449 	/* Device interface */
450 	DEVMETHOD(device_probe,		gpiobus_probe),
451 	DEVMETHOD(device_attach,	gpiobus_attach),
452 	DEVMETHOD(device_detach,	gpiobus_detach),
453 	DEVMETHOD(device_shutdown,	bus_generic_shutdown),
454 	DEVMETHOD(device_suspend,	gpiobus_suspend),
455 	DEVMETHOD(device_resume,	gpiobus_resume),
456 
457 	/* Bus interface */
458 	DEVMETHOD(bus_add_child,	gpiobus_add_child),
459 	DEVMETHOD(bus_print_child,	gpiobus_print_child),
460 	DEVMETHOD(bus_child_pnpinfo_str, gpiobus_child_pnpinfo_str),
461 	DEVMETHOD(bus_child_location_str, gpiobus_child_location_str),
462 	DEVMETHOD(bus_hinted_child,	gpiobus_hinted_child),
463 
464 	/* GPIO protocol */
465 	DEVMETHOD(gpiobus_lock_bus,	gpiobus_lock_bus),
466 	DEVMETHOD(gpiobus_unlock_bus,	gpiobus_unlock_bus),
467 	DEVMETHOD(gpiobus_acquire_bus,	gpiobus_acquire_bus),
468 	DEVMETHOD(gpiobus_release_bus,	gpiobus_release_bus),
469 	DEVMETHOD(gpiobus_pin_getflags,	gpiobus_pin_getflags),
470 	DEVMETHOD(gpiobus_pin_getcaps,	gpiobus_pin_getcaps),
471 	DEVMETHOD(gpiobus_pin_setflags,	gpiobus_pin_setflags),
472 	DEVMETHOD(gpiobus_pin_get,	gpiobus_pin_get),
473 	DEVMETHOD(gpiobus_pin_set,	gpiobus_pin_set),
474 	DEVMETHOD(gpiobus_pin_toggle,	gpiobus_pin_toggle),
475 
476 	DEVMETHOD_END
477 };
478 
479 driver_t gpiobus_driver = {
480 	"gpiobus",
481 	gpiobus_methods,
482 	sizeof(struct gpiobus_softc)
483 };
484 
485 devclass_t	gpiobus_devclass;
486 
487 DRIVER_MODULE(gpiobus, gpio, gpiobus_driver, gpiobus_devclass, 0, 0);
488 MODULE_VERSION(gpiobus, 1);
489