xref: /freebsd/sys/dev/gpio/ofw_gpiobus.c (revision 1a61beb0549e05b33df31380e427d90f6e46ff7e)
1 /*-
2  * Copyright (c) 2009, Nathan Whitehorn <nwhitehorn@FreeBSD.org>
3  * Copyright (c) 2013, Luiz Otavio O Souza <loos@FreeBSD.org>
4  * Copyright (c) 2013 The FreeBSD Foundation
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice unmodified, this list of conditions, and the following
12  *    disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27  */
28 
29 #include <sys/cdefs.h>
30 __FBSDID("$FreeBSD$");
31 
32 #include <sys/param.h>
33 #include <sys/bus.h>
34 #include <sys/gpio.h>
35 #include <sys/kernel.h>
36 #include <sys/libkern.h>
37 #include <sys/lock.h>
38 #include <sys/module.h>
39 #include <sys/mutex.h>
40 
41 #include <dev/fdt/fdt_common.h>
42 #include <dev/gpio/gpiobusvar.h>
43 #include <dev/ofw/ofw_bus.h>
44 #include <dev/ofw/openfirm.h>
45 
46 #include <machine/resource.h>
47 
48 #include "gpio_if.h"
49 #include "gpiobus_if.h"
50 
51 struct ofw_gpiobus_devinfo {
52 	struct gpiobus_ivar	opd_dinfo;
53 	struct ofw_bus_devinfo	opd_obdinfo;
54 };
55 
56 static int ofw_gpiobus_parse_gpios(struct gpiobus_softc *,
57     struct gpiobus_ivar *, phandle_t);
58 static struct ofw_gpiobus_devinfo *ofw_gpiobus_setup_devinfo(device_t,
59     phandle_t);
60 static void ofw_gpiobus_destroy_devinfo(struct ofw_gpiobus_devinfo *);
61 
62 device_t
63 ofw_gpiobus_add_fdt_child(device_t bus, phandle_t child)
64 {
65 	struct ofw_gpiobus_devinfo *dinfo;
66 	device_t childdev;
67 
68 	/*
69 	 * Set up the GPIO child and OFW bus layer devinfo and add it to bus.
70 	 */
71 	dinfo = ofw_gpiobus_setup_devinfo(bus, child);
72 	if (dinfo == NULL)
73 		return (NULL);
74 	childdev = device_add_child(bus, NULL, -1);
75 	if (childdev == NULL) {
76 		device_printf(bus, "could not add child: %s\n",
77 		    dinfo->opd_obdinfo.obd_name);
78 		ofw_gpiobus_destroy_devinfo(dinfo);
79 		return (NULL);
80 	}
81 	device_set_ivars(childdev, dinfo);
82 
83 	return (childdev);
84 }
85 
86 static int
87 ofw_gpiobus_parse_gpios(struct gpiobus_softc *sc, struct gpiobus_ivar *dinfo,
88 	phandle_t child)
89 {
90 	int i, len;
91 	pcell_t *gpios;
92 	phandle_t gpio;
93 
94 	/* Retrieve the gpios property. */
95 	if ((len = OF_getproplen(child, "gpios")) < 0)
96 		return (EINVAL);
97 	gpios = malloc(len, M_DEVBUF, M_NOWAIT | M_ZERO);
98 	if (gpios == NULL)
99 		return (ENOMEM);
100 	if (OF_getencprop(child, "gpios", gpios, len) < 0) {
101 		free(gpios, M_DEVBUF);
102 		return (EINVAL);
103 	}
104 
105 	/*
106 	 * Each 'gpios' entry must contain 4 pcells.
107 	 * The first one is the GPIO controller phandler.
108 	 * Then the last three are the GPIO pin, the GPIO pin direction and
109 	 * the GPIO pin flags.
110 	 */
111 	if ((len / sizeof(pcell_t)) % 4) {
112 		free(gpios, M_DEVBUF);
113 		return (EINVAL);
114 	}
115 	dinfo->npins = len / (sizeof(pcell_t) * 4);
116 	dinfo->pins = malloc(sizeof(uint32_t) * dinfo->npins, M_DEVBUF,
117 	    M_NOWAIT | M_ZERO);
118 	if (dinfo->pins == NULL) {
119 		free(gpios, M_DEVBUF);
120 		return (ENOMEM);
121 	}
122 
123 	for (i = 0; i < dinfo->npins; i++) {
124 
125 		/* Verify if we're attaching to the correct gpio controller. */
126 		gpio = OF_xref_phandle(gpios[i * 4 + 0]);
127 		if (!OF_hasprop(gpio, "gpio-controller") ||
128 		    gpio != ofw_bus_get_node(sc->sc_dev)) {
129 			free(dinfo->pins, M_DEVBUF);
130 			free(gpios, M_DEVBUF);
131 			return (EINVAL);
132 		}
133 
134 		/* Get the GPIO pin number. */
135 		dinfo->pins[i] = gpios[i * 4 + 1];
136 		/* gpios[i * 4 + 2] - GPIO pin direction */
137 		/* gpios[i * 4 + 3] - GPIO pin flags */
138 
139 		if (dinfo->pins[i] > sc->sc_npins) {
140 			device_printf(sc->sc_busdev,
141 			    "invalid pin %d, max: %d\n",
142 			    dinfo->pins[i], sc->sc_npins - 1);
143 			free(dinfo->pins, M_DEVBUF);
144 			free(gpios, M_DEVBUF);
145 			return (EINVAL);
146 		}
147 
148 		/*
149 		 * Mark pin as mapped and give warning if it's already mapped.
150 		 */
151 		if (sc->sc_pins_mapped[dinfo->pins[i]]) {
152 			device_printf(sc->sc_busdev,
153 			    "warning: pin %d is already mapped\n",
154 			    dinfo->pins[i]);
155 			free(dinfo->pins, M_DEVBUF);
156 			free(gpios, M_DEVBUF);
157 			return (EINVAL);
158 		}
159 		sc->sc_pins_mapped[dinfo->pins[i]] = 1;
160 	}
161 
162 	free(gpios, M_DEVBUF);
163 
164 	return (0);
165 }
166 
167 static struct ofw_gpiobus_devinfo *
168 ofw_gpiobus_setup_devinfo(device_t dev, phandle_t node)
169 {
170 	struct gpiobus_softc *sc;
171 	struct ofw_gpiobus_devinfo *dinfo;
172 
173 	sc = device_get_softc(dev);
174 	dinfo = malloc(sizeof(*dinfo), M_DEVBUF, M_NOWAIT | M_ZERO);
175 	if (dinfo == NULL)
176 		return (NULL);
177 	if (ofw_bus_gen_setup_devinfo(&dinfo->opd_obdinfo, node) != 0) {
178 		free(dinfo, M_DEVBUF);
179 		return (NULL);
180 	}
181 
182 	/* Parse the gpios property for the child. */
183 	if (ofw_gpiobus_parse_gpios(sc, &dinfo->opd_dinfo, node) != 0) {
184 		ofw_bus_gen_destroy_devinfo(&dinfo->opd_obdinfo);
185 		free(dinfo, M_DEVBUF);
186 		return (NULL);
187 	}
188 
189 	return (dinfo);
190 }
191 
192 static void
193 ofw_gpiobus_destroy_devinfo(struct ofw_gpiobus_devinfo *dinfo)
194 {
195 
196 	ofw_bus_gen_destroy_devinfo(&dinfo->opd_obdinfo);
197 	free(dinfo, M_DEVBUF);
198 }
199 
200 static int
201 ofw_gpiobus_probe(device_t dev)
202 {
203 
204 	if (ofw_bus_get_node(dev) == -1)
205 		return (ENXIO);
206 	device_set_desc(dev, "OFW GPIO bus");
207 
208 	return (0);
209 }
210 
211 static int
212 ofw_gpiobus_attach(device_t dev)
213 {
214 	struct gpiobus_softc *sc;
215 	phandle_t child;
216 
217 	sc = GPIOBUS_SOFTC(dev);
218 	sc->sc_busdev = dev;
219 	sc->sc_dev = device_get_parent(dev);
220 
221 	/* Read the pin max. value */
222 	if (GPIO_PIN_MAX(sc->sc_dev, &sc->sc_npins) != 0)
223 		return (ENXIO);
224 
225 	KASSERT(sc->sc_npins != 0, ("GPIO device with no pins"));
226 
227 	/*
228 	 * Increase to get number of pins.
229 	 */
230 	sc->sc_npins++;
231 
232 	sc->sc_pins_mapped = malloc(sizeof(int) * sc->sc_npins, M_DEVBUF,
233 	    M_NOWAIT | M_ZERO);
234 
235 	if (!sc->sc_pins_mapped)
236 		return (ENOMEM);
237 
238 	/* Init the bus lock. */
239 	GPIOBUS_LOCK_INIT(sc);
240 
241 	bus_generic_probe(dev);
242 	bus_enumerate_hinted_children(dev);
243 
244 	/*
245 	 * Attach the children represented in the device tree.
246 	 */
247 	for (child = OF_child(ofw_bus_get_node(dev)); child != 0;
248 	    child = OF_peer(child))
249 		if (ofw_gpiobus_add_fdt_child(dev, child) == NULL)
250 			continue;
251 
252 	return (bus_generic_attach(dev));
253 }
254 
255 static device_t
256 ofw_gpiobus_add_child(device_t dev, u_int order, const char *name, int unit)
257 {
258 	device_t child;
259 	struct ofw_gpiobus_devinfo *devi;
260 
261 	child = device_add_child_ordered(dev, order, name, unit);
262 	if (child == NULL)
263 		return (child);
264 	devi = malloc(sizeof(struct ofw_gpiobus_devinfo), M_DEVBUF,
265 	    M_NOWAIT | M_ZERO);
266 	if (devi == NULL) {
267 		device_delete_child(dev, child);
268 		return (0);
269 	}
270 
271 	/*
272 	 * NULL all the OFW-related parts of the ivars for non-OFW
273 	 * children.
274 	 */
275 	devi->opd_obdinfo.obd_node = -1;
276 	devi->opd_obdinfo.obd_name = NULL;
277 	devi->opd_obdinfo.obd_compat = NULL;
278 	devi->opd_obdinfo.obd_type = NULL;
279 	devi->opd_obdinfo.obd_model = NULL;
280 
281 	device_set_ivars(child, devi);
282 
283 	return (child);
284 }
285 
286 static int
287 ofw_gpiobus_print_child(device_t dev, device_t child)
288 {
289 	struct ofw_gpiobus_devinfo *devi;
290 	int retval = 0;
291 
292 	devi = device_get_ivars(child);
293 	retval += bus_print_child_header(dev, child);
294 	retval += printf(" at pin(s) ");
295 	gpiobus_print_pins(&devi->opd_dinfo);
296 	retval += bus_print_child_footer(dev, child);
297 
298 	return (retval);
299 }
300 
301 static const struct ofw_bus_devinfo *
302 ofw_gpiobus_get_devinfo(device_t bus, device_t dev)
303 {
304 	struct ofw_gpiobus_devinfo *dinfo;
305 
306 	dinfo = device_get_ivars(dev);
307 
308 	return (&dinfo->opd_obdinfo);
309 }
310 
311 static device_method_t ofw_gpiobus_methods[] = {
312 	/* Device interface */
313 	DEVMETHOD(device_probe,		ofw_gpiobus_probe),
314 	DEVMETHOD(device_attach,	ofw_gpiobus_attach),
315 
316 	/* Bus interface */
317 	DEVMETHOD(bus_child_pnpinfo_str,	ofw_bus_gen_child_pnpinfo_str),
318 	DEVMETHOD(bus_print_child,	ofw_gpiobus_print_child),
319 	DEVMETHOD(bus_add_child,	ofw_gpiobus_add_child),
320 
321 	/* ofw_bus interface */
322 	DEVMETHOD(ofw_bus_get_devinfo,	ofw_gpiobus_get_devinfo),
323 	DEVMETHOD(ofw_bus_get_compat,	ofw_bus_gen_get_compat),
324 	DEVMETHOD(ofw_bus_get_model,	ofw_bus_gen_get_model),
325 	DEVMETHOD(ofw_bus_get_name,	ofw_bus_gen_get_name),
326 	DEVMETHOD(ofw_bus_get_node,	ofw_bus_gen_get_node),
327 	DEVMETHOD(ofw_bus_get_type,	ofw_bus_gen_get_type),
328 
329 	DEVMETHOD_END
330 };
331 
332 static devclass_t ofwgpiobus_devclass;
333 
334 DEFINE_CLASS_1(gpiobus, ofw_gpiobus_driver, ofw_gpiobus_methods,
335     sizeof(struct gpiobus_softc), gpiobus_driver);
336 DRIVER_MODULE(ofw_gpiobus, gpio, ofw_gpiobus_driver, ofwgpiobus_devclass, 0, 0);
337 MODULE_VERSION(ofw_gpiobus, 1);
338 MODULE_DEPEND(ofw_gpiobus, gpiobus, 1, 1, 1);
339