xref: /freebsd/sys/dev/gpio/ofw_gpiobus.c (revision 5b56413d04e608379c9a306373554a8e4d321bc0)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
3  *
4  * Copyright (c) 2009, Nathan Whitehorn <nwhitehorn@FreeBSD.org>
5  * Copyright (c) 2013, Luiz Otavio O Souza <loos@FreeBSD.org>
6  * Copyright (c) 2013 The FreeBSD Foundation
7  * All rights reserved.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice unmodified, this list of conditions, and the following
14  *    disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
20  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
21  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
22  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
23  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
24  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
25  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
26  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
27  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
28  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29  */
30 
31 #include <sys/param.h>
32 #include <sys/systm.h>
33 #include <sys/bus.h>
34 #include <sys/kernel.h>
35 #include <sys/malloc.h>
36 #include <sys/module.h>
37 
38 #include <dev/gpio/gpiobusvar.h>
39 #include <dev/ofw/ofw_bus.h>
40 
41 #include "gpiobus_if.h"
42 
43 static struct ofw_gpiobus_devinfo *ofw_gpiobus_setup_devinfo(device_t,
44 	device_t, phandle_t);
45 static void ofw_gpiobus_destroy_devinfo(device_t, struct ofw_gpiobus_devinfo *);
46 static int ofw_gpiobus_parse_gpios_impl(device_t, phandle_t, char *,
47 	struct gpiobus_softc *, struct gpiobus_pin **);
48 
49 /*
50  * Utility functions for easier handling of OFW GPIO pins.
51  *
52  * !!! BEWARE !!!
53  * GPIOBUS uses children's IVARs, so we cannot use this interface for cross
54  * tree consumers.
55  *
56  */
57 int
58 gpio_pin_get_by_ofw_propidx(device_t consumer, phandle_t cnode,
59     char *prop_name, int idx, gpio_pin_t *out_pin)
60 {
61 	phandle_t xref;
62 	pcell_t *cells;
63 	device_t busdev;
64 	struct gpiobus_pin pin;
65 	int ncells, rv;
66 
67 	KASSERT(consumer != NULL && cnode > 0,
68 	    ("both consumer and cnode required"));
69 
70 	rv = ofw_bus_parse_xref_list_alloc(cnode, prop_name, "#gpio-cells",
71 	    idx, &xref, &ncells, &cells);
72 	if (rv != 0)
73 		return (rv);
74 
75 	/* Translate provider to device. */
76 	pin.dev = OF_device_from_xref(xref);
77 	if (pin.dev == NULL) {
78 		OF_prop_free(cells);
79 		return (ENODEV);
80 	}
81 
82 	/* Test if GPIO bus already exist. */
83 	busdev = GPIO_GET_BUS(pin.dev);
84 	if (busdev == NULL) {
85 		OF_prop_free(cells);
86 		return (ENODEV);
87 	}
88 
89 	/* Map GPIO pin. */
90 	rv = gpio_map_gpios(pin.dev, cnode, OF_node_from_xref(xref), ncells,
91 	    cells, &pin.pin, &pin.flags);
92 	OF_prop_free(cells);
93 	if (rv != 0)
94 		return (ENXIO);
95 
96 	/* Reserve GPIO pin. */
97 	rv = gpiobus_acquire_pin(busdev, pin.pin);
98 	if (rv != 0)
99 		return (EBUSY);
100 
101 	*out_pin = malloc(sizeof(struct gpiobus_pin), M_DEVBUF,
102 	    M_WAITOK | M_ZERO);
103 	**out_pin = pin;
104 	return (0);
105 }
106 
107 int
108 gpio_pin_get_by_ofw_idx(device_t consumer, phandle_t node,
109     int idx, gpio_pin_t *pin)
110 {
111 
112 	return (gpio_pin_get_by_ofw_propidx(consumer, node, "gpios", idx, pin));
113 }
114 
115 int
116 gpio_pin_get_by_ofw_property(device_t consumer, phandle_t node,
117     char *name, gpio_pin_t *pin)
118 {
119 
120 	return (gpio_pin_get_by_ofw_propidx(consumer, node, name, 0, pin));
121 }
122 
123 int
124 gpio_pin_get_by_ofw_name(device_t consumer, phandle_t node,
125     char *name, gpio_pin_t *pin)
126 {
127 	int rv, idx;
128 
129 	KASSERT(consumer != NULL && node > 0,
130 	    ("both consumer and node required"));
131 
132 	rv = ofw_bus_find_string_index(node, "gpio-names", name, &idx);
133 	if (rv != 0)
134 		return (rv);
135 	return (gpio_pin_get_by_ofw_idx(consumer, node, idx, pin));
136 }
137 
138 /*
139  * OFW_GPIOBUS driver.
140  */
141 device_t
142 ofw_gpiobus_add_fdt_child(device_t bus, const char *drvname, phandle_t child)
143 {
144 	device_t childdev;
145 	int i;
146 	struct gpiobus_ivar *devi;
147 	struct ofw_gpiobus_devinfo *dinfo;
148 
149 	/*
150 	 * Check to see if we already have a child for @p child, and if so
151 	 * return it.
152 	 */
153 	childdev = ofw_bus_find_child_device_by_phandle(bus, child);
154 	if (childdev != NULL)
155 		return (childdev);
156 
157 	/*
158 	 * Set up the GPIO child and OFW bus layer devinfo and add it to bus.
159 	 */
160 	childdev = device_add_child(bus, drvname, DEVICE_UNIT_ANY);
161 	if (childdev == NULL)
162 		return (NULL);
163 	dinfo = ofw_gpiobus_setup_devinfo(bus, childdev, child);
164 	if (dinfo == NULL) {
165 		device_delete_child(bus, childdev);
166 		return (NULL);
167 	}
168 	if (device_probe_and_attach(childdev) != 0) {
169 		ofw_gpiobus_destroy_devinfo(bus, dinfo);
170 		device_delete_child(bus, childdev);
171 		return (NULL);
172 	}
173 	/* Use the child name as pin name. */
174 	devi = &dinfo->opd_dinfo;
175 	for (i = 0; i < devi->npins; i++)
176 		GPIOBUS_PIN_SETNAME(bus, devi->pins[i],
177 		    device_get_nameunit(childdev));
178 
179 	return (childdev);
180 }
181 
182 int
183 ofw_gpiobus_parse_gpios(device_t consumer, char *pname,
184 	struct gpiobus_pin **pins)
185 {
186 
187 	return (ofw_gpiobus_parse_gpios_impl(consumer,
188 	    ofw_bus_get_node(consumer), pname, NULL, pins));
189 }
190 
191 void
192 ofw_gpiobus_register_provider(device_t provider)
193 {
194 	phandle_t node;
195 
196 	node = ofw_bus_get_node(provider);
197 	if (node != -1)
198 		OF_device_register_xref(OF_xref_from_node(node), provider);
199 }
200 
201 void
202 ofw_gpiobus_unregister_provider(device_t provider)
203 {
204 	phandle_t node;
205 
206 	node = ofw_bus_get_node(provider);
207 	if (node != -1)
208 		OF_device_register_xref(OF_xref_from_node(node), NULL);
209 }
210 
211 static struct ofw_gpiobus_devinfo *
212 ofw_gpiobus_setup_devinfo(device_t bus, device_t child, phandle_t node)
213 {
214 	int i, npins;
215 	struct gpiobus_ivar *devi;
216 	struct gpiobus_pin *pins;
217 	struct gpiobus_softc *sc;
218 	struct ofw_gpiobus_devinfo *dinfo;
219 
220 	sc = device_get_softc(bus);
221 	dinfo = malloc(sizeof(*dinfo), M_DEVBUF, M_NOWAIT | M_ZERO);
222 	if (dinfo == NULL)
223 		return (NULL);
224 	if (ofw_bus_gen_setup_devinfo(&dinfo->opd_obdinfo, node) != 0) {
225 		free(dinfo, M_DEVBUF);
226 		return (NULL);
227 	}
228 	/* Parse the gpios property for the child. */
229 	npins = ofw_gpiobus_parse_gpios_impl(child, node, "gpios", sc, &pins);
230 	if (npins <= 0) {
231 		ofw_bus_gen_destroy_devinfo(&dinfo->opd_obdinfo);
232 		free(dinfo, M_DEVBUF);
233 		return (NULL);
234 	}
235 	/* Initialize the irq resource list. */
236 	resource_list_init(&dinfo->opd_dinfo.rl);
237 	/* Allocate the child ivars and copy the parsed pin data. */
238 	devi = &dinfo->opd_dinfo;
239 	devi->npins = (uint32_t)npins;
240 	if (gpiobus_alloc_ivars(devi) != 0) {
241 		free(pins, M_DEVBUF);
242 		ofw_gpiobus_destroy_devinfo(bus, dinfo);
243 		return (NULL);
244 	}
245 	for (i = 0; i < devi->npins; i++)
246 		devi->pins[i] = pins[i].pin;
247 	free(pins, M_DEVBUF);
248 	/* Parse the interrupt resources. */
249 	if (ofw_bus_intr_to_rl(bus, node, &dinfo->opd_dinfo.rl, NULL) != 0) {
250 		ofw_gpiobus_destroy_devinfo(bus, dinfo);
251 		return (NULL);
252 	}
253 	device_set_ivars(child, dinfo);
254 
255 	return (dinfo);
256 }
257 
258 static void
259 ofw_gpiobus_destroy_devinfo(device_t bus, struct ofw_gpiobus_devinfo *dinfo)
260 {
261 	int i;
262 	struct gpiobus_ivar *devi;
263 	struct gpiobus_softc *sc;
264 
265 	sc = device_get_softc(bus);
266 	devi = &dinfo->opd_dinfo;
267 	for (i = 0; i < devi->npins; i++) {
268 		if (devi->pins[i] > sc->sc_npins)
269 			continue;
270 		sc->sc_pins[devi->pins[i]].mapped = 0;
271 	}
272 	gpiobus_free_ivars(devi);
273 	resource_list_free(&dinfo->opd_dinfo.rl);
274 	ofw_bus_gen_destroy_devinfo(&dinfo->opd_obdinfo);
275 	free(dinfo, M_DEVBUF);
276 }
277 
278 static int
279 ofw_gpiobus_parse_gpios_impl(device_t consumer, phandle_t cnode, char *pname,
280 	struct gpiobus_softc *bussc, struct gpiobus_pin **pins)
281 {
282 	int gpiocells, i, j, ncells, npins;
283 	pcell_t *gpios;
284 	phandle_t gpio;
285 
286 	ncells = OF_getencprop_alloc_multi(cnode, pname, sizeof(*gpios),
287             (void **)&gpios);
288 	if (ncells == -1) {
289 		device_printf(consumer,
290 		    "Warning: No %s specified in fdt data; "
291 		    "device may not function.\n", pname);
292 		return (-1);
293 	}
294 	/*
295 	 * The gpio-specifier is controller independent, the first pcell has
296 	 * the reference to the GPIO controller phandler.
297 	 * Count the number of encoded gpio-specifiers on the first pass.
298 	 */
299 	i = 0;
300 	npins = 0;
301 	while (i < ncells) {
302 		/* Allow NULL specifiers. */
303 		if (gpios[i] == 0) {
304 			npins++;
305 			i++;
306 			continue;
307 		}
308 		gpio = OF_node_from_xref(gpios[i]);
309 		/* If we have bussc, ignore devices from other gpios. */
310 		if (bussc != NULL)
311 			if (ofw_bus_get_node(bussc->sc_dev) != gpio)
312 				return (0);
313 		/*
314 		 * Check for gpio-controller property and read the #gpio-cells
315 		 * for this GPIO controller.
316 		 */
317 		if (!OF_hasprop(gpio, "gpio-controller") ||
318 		    OF_getencprop(gpio, "#gpio-cells", &gpiocells,
319 		    sizeof(gpiocells)) < 0) {
320 			device_printf(consumer,
321 			    "gpio reference is not a gpio-controller.\n");
322 			OF_prop_free(gpios);
323 			return (-1);
324 		}
325 		if (ncells - i < gpiocells + 1) {
326 			device_printf(consumer,
327 			    "%s cells doesn't match #gpio-cells.\n", pname);
328 			return (-1);
329 		}
330 		npins++;
331 		i += gpiocells + 1;
332 	}
333 	if (npins == 0 || pins == NULL) {
334 		if (npins == 0)
335 			device_printf(consumer, "no pin specified in %s.\n",
336 			    pname);
337 		OF_prop_free(gpios);
338 		return (npins);
339 	}
340 	*pins = malloc(sizeof(struct gpiobus_pin) * npins, M_DEVBUF,
341 	    M_NOWAIT | M_ZERO);
342 	if (*pins == NULL) {
343 		OF_prop_free(gpios);
344 		return (-1);
345 	}
346 	/* Decode the gpio specifier on the second pass. */
347 	i = 0;
348 	j = 0;
349 	while (i < ncells) {
350 		/* Allow NULL specifiers. */
351 		if (gpios[i] == 0) {
352 			j++;
353 			i++;
354 			continue;
355 		}
356 		gpio = OF_node_from_xref(gpios[i]);
357 		/* Read gpio-cells property for this GPIO controller. */
358 		if (OF_getencprop(gpio, "#gpio-cells", &gpiocells,
359 		    sizeof(gpiocells)) < 0) {
360 			device_printf(consumer,
361 			    "gpio does not have the #gpio-cells property.\n");
362 			goto fail;
363 		}
364 		/* Return the device reference for the GPIO controller. */
365 		(*pins)[j].dev = OF_device_from_xref(gpios[i]);
366 		if ((*pins)[j].dev == NULL) {
367 			device_printf(consumer,
368 			    "no device registered for the gpio controller.\n");
369 			goto fail;
370 		}
371 		/*
372 		 * If the gpiobus softc is NULL we use the GPIO_GET_BUS() to
373 		 * retrieve it.  The GPIO_GET_BUS() method is only valid after
374 		 * the child is probed and attached.
375 		 */
376 		if (bussc == NULL) {
377 			if (GPIO_GET_BUS((*pins)[j].dev) == NULL) {
378 				device_printf(consumer,
379 				    "no gpiobus reference for %s.\n",
380 				    device_get_nameunit((*pins)[j].dev));
381 				goto fail;
382 			}
383 			bussc = device_get_softc(GPIO_GET_BUS((*pins)[j].dev));
384 		}
385 		/* Get the GPIO pin number and flags. */
386 		if (gpio_map_gpios((*pins)[j].dev, cnode, gpio, gpiocells,
387 		    &gpios[i + 1], &(*pins)[j].pin, &(*pins)[j].flags) != 0) {
388 			device_printf(consumer,
389 			    "cannot map the gpios specifier.\n");
390 			goto fail;
391 		}
392 		/* Reserve the GPIO pin. */
393 		if (gpiobus_acquire_pin(bussc->sc_busdev, (*pins)[j].pin) != 0)
394 			goto fail;
395 		j++;
396 		i += gpiocells + 1;
397 	}
398 	OF_prop_free(gpios);
399 
400 	return (npins);
401 
402 fail:
403 	OF_prop_free(gpios);
404 	free(*pins, M_DEVBUF);
405 	return (-1);
406 }
407 
408 static int
409 ofw_gpiobus_probe(device_t dev)
410 {
411 
412 	if (ofw_bus_get_node(dev) == -1)
413 		return (ENXIO);
414 	device_set_desc(dev, "OFW GPIO bus");
415 
416 	return (BUS_PROBE_DEFAULT);
417 }
418 
419 static int
420 ofw_gpiobus_attach(device_t dev)
421 {
422 	int err;
423 	phandle_t child;
424 
425 	err = gpiobus_init_softc(dev);
426 	if (err != 0)
427 		return (err);
428 	bus_generic_probe(dev);
429 	bus_enumerate_hinted_children(dev);
430 	/*
431 	 * Attach the children represented in the device tree.
432 	 */
433 	for (child = OF_child(ofw_bus_get_node(dev)); child != 0;
434 	    child = OF_peer(child)) {
435 		if (OF_hasprop(child, "gpio-hog"))
436 			continue;
437 		if (!OF_hasprop(child, "gpios"))
438 			continue;
439 		if (ofw_gpiobus_add_fdt_child(dev, NULL, child) == NULL)
440 			continue;
441 	}
442 
443 	return (bus_generic_attach(dev));
444 }
445 
446 static device_t
447 ofw_gpiobus_add_child(device_t dev, u_int order, const char *name, int unit)
448 {
449 	device_t child;
450 	struct ofw_gpiobus_devinfo *devi;
451 
452 	child = device_add_child_ordered(dev, order, name, unit);
453 	if (child == NULL)
454 		return (child);
455 	devi = malloc(sizeof(struct ofw_gpiobus_devinfo), M_DEVBUF,
456 	    M_NOWAIT | M_ZERO);
457 	if (devi == NULL) {
458 		device_delete_child(dev, child);
459 		return (0);
460 	}
461 
462 	/*
463 	 * NULL all the OFW-related parts of the ivars for non-OFW
464 	 * children.
465 	 */
466 	devi->opd_obdinfo.obd_node = -1;
467 	devi->opd_obdinfo.obd_name = NULL;
468 	devi->opd_obdinfo.obd_compat = NULL;
469 	devi->opd_obdinfo.obd_type = NULL;
470 	devi->opd_obdinfo.obd_model = NULL;
471 
472 	device_set_ivars(child, devi);
473 
474 	return (child);
475 }
476 
477 static const struct ofw_bus_devinfo *
478 ofw_gpiobus_get_devinfo(device_t bus, device_t dev)
479 {
480 	struct ofw_gpiobus_devinfo *dinfo;
481 
482 	dinfo = device_get_ivars(dev);
483 
484 	return (&dinfo->opd_obdinfo);
485 }
486 
487 static device_method_t ofw_gpiobus_methods[] = {
488 	/* Device interface */
489 	DEVMETHOD(device_probe,		ofw_gpiobus_probe),
490 	DEVMETHOD(device_attach,	ofw_gpiobus_attach),
491 
492 	/* Bus interface */
493 	DEVMETHOD(bus_child_pnpinfo,	ofw_bus_gen_child_pnpinfo),
494 	DEVMETHOD(bus_add_child,	ofw_gpiobus_add_child),
495 
496 	/* ofw_bus interface */
497 	DEVMETHOD(ofw_bus_get_devinfo,	ofw_gpiobus_get_devinfo),
498 	DEVMETHOD(ofw_bus_get_compat,	ofw_bus_gen_get_compat),
499 	DEVMETHOD(ofw_bus_get_model,	ofw_bus_gen_get_model),
500 	DEVMETHOD(ofw_bus_get_name,	ofw_bus_gen_get_name),
501 	DEVMETHOD(ofw_bus_get_node,	ofw_bus_gen_get_node),
502 	DEVMETHOD(ofw_bus_get_type,	ofw_bus_gen_get_type),
503 
504 	DEVMETHOD_END
505 };
506 
507 DEFINE_CLASS_1(gpiobus, ofw_gpiobus_driver, ofw_gpiobus_methods,
508     sizeof(struct gpiobus_softc), gpiobus_driver);
509 EARLY_DRIVER_MODULE(ofw_gpiobus, gpio, ofw_gpiobus_driver, 0, 0, BUS_PASS_BUS);
510 MODULE_VERSION(ofw_gpiobus, 1);
511 MODULE_DEPEND(ofw_gpiobus, gpiobus, 1, 1, 1);
512