xref: /freebsd/sys/dev/ofw/ofwbus.c (revision d9a42747950146bf03cda7f6e25d219253f8a57a)
1 /*-
2  * Copyright 1998 Massachusetts Institute of Technology
3  * Copyright 2001 by Thomas Moestl <tmm@FreeBSD.org>.
4  * Copyright 2006 by Marius Strobl <marius@FreeBSD.org>.
5  * All rights reserved.
6  *
7  * Permission to use, copy, modify, and distribute this software and
8  * its documentation for any purpose and without fee is hereby
9  * granted, provided that both the above copyright notice and this
10  * permission notice appear in all copies, that both the above
11  * copyright notice and this permission notice appear in all
12  * supporting documentation, and that the name of M.I.T. not be used
13  * in advertising or publicity pertaining to distribution of the
14  * software without specific, written prior permission.  M.I.T. makes
15  * no representations about the suitability of this software for any
16  * purpose.  It is provided "as is" without express or implied
17  * warranty.
18  *
19  * THIS SOFTWARE IS PROVIDED BY M.I.T. ``AS IS''.  M.I.T. DISCLAIMS
20  * ALL EXPRESS OR IMPLIED WARRANTIES WITH REGARD TO THIS SOFTWARE,
21  * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
22  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT
23  * SHALL M.I.T. BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
24  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
25  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
26  * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
27  * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
28  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
29  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30  * SUCH DAMAGE.
31  *
32  * 	from: FreeBSD: src/sys/i386/i386/nexus.c,v 1.43 2001/02/09
33  */
34 
35 #include <sys/cdefs.h>
36 __FBSDID("$FreeBSD$");
37 
38 #include <sys/param.h>
39 #include <sys/systm.h>
40 #include <sys/bus.h>
41 #include <sys/kernel.h>
42 #include <sys/module.h>
43 #include <sys/rman.h>
44 
45 #include <dev/ofw/ofw_bus.h>
46 #include <dev/ofw/ofw_bus_subr.h>
47 #include <dev/ofw/openfirm.h>
48 #include <dev/fdt/simplebus.h>
49 
50 #include <machine/bus.h>
51 #include <machine/resource.h>
52 
53 /*
54  * The ofwbus (which is a pseudo-bus actually) iterates over the nodes that
55  * hang from the Open Firmware root node and adds them as devices to this bus
56  * (except some special nodes which are excluded) so that drivers can be
57  * attached to them. There should be only one ofwbus in the system, added
58  * directly as a child of nexus0.
59  */
60 
61 static device_probe_t ofwbus_probe;
62 static device_attach_t ofwbus_attach;
63 static bus_alloc_resource_t ofwbus_alloc_resource;
64 static bus_release_resource_t ofwbus_release_resource;
65 
66 static device_method_t ofwbus_methods[] = {
67 	/* Device interface */
68 	DEVMETHOD(device_probe,		ofwbus_probe),
69 	DEVMETHOD(device_attach,	ofwbus_attach),
70 
71 	/* Bus interface */
72 	DEVMETHOD(bus_alloc_resource,	ofwbus_alloc_resource),
73 	DEVMETHOD(bus_adjust_resource,	bus_generic_adjust_resource),
74 	DEVMETHOD(bus_release_resource,	ofwbus_release_resource),
75 
76 	DEVMETHOD_END
77 };
78 
79 DEFINE_CLASS_1(ofwbus, ofwbus_driver, ofwbus_methods,
80     sizeof(struct simplebus_softc), simplebus_driver);
81 EARLY_DRIVER_MODULE(ofwbus, nexus, ofwbus_driver, 0, 0,
82     BUS_PASS_BUS + BUS_PASS_ORDER_MIDDLE);
83 MODULE_VERSION(ofwbus, 1);
84 
85 static int
86 ofwbus_probe(device_t dev)
87 {
88 
89 	if (OF_peer(0) == 0)
90 		return (ENXIO);
91 
92 	/* Only one instance of ofwbus. */
93 	if (device_get_unit(dev) != 0)
94 		panic("ofwbus added with non-zero unit number: %d\n",
95 		    device_get_unit(dev));
96 
97 	device_set_desc(dev, "Open Firmware Device Tree");
98 	return (BUS_PROBE_NOWILDCARD);
99 }
100 
101 static int
102 ofwbus_attach(device_t dev)
103 {
104 	phandle_t node;
105 	struct ofw_bus_devinfo obd;
106 
107 	node = OF_peer(0);
108 
109 	/*
110 	 * If no Open Firmware, bail early
111 	 */
112 	if (node == -1)
113 		return (ENXIO);
114 
115 	/*
116 	 * ofwbus bus starts on unamed node in FDT, so we cannot make
117 	 * ofw_bus_devinfo from it. Pass node to simplebus_init directly.
118 	 */
119 	simplebus_init(dev, node);
120 
121 	/*
122 	 * Allow devices to identify.
123 	 */
124 	bus_generic_probe(dev);
125 
126 	/*
127 	 * Now walk the OFW tree and attach top-level devices.
128 	 */
129 	for (node = OF_child(node); node > 0; node = OF_peer(node)) {
130 		if (ofw_bus_gen_setup_devinfo(&obd, node) != 0)
131 			continue;
132 		simplebus_add_device(dev, node, 0, NULL, -1, NULL);
133 		ofw_bus_gen_destroy_devinfo(&obd);
134 	}
135 	return (bus_generic_attach(dev));
136 }
137 
138 static struct resource *
139 ofwbus_alloc_resource(device_t bus, device_t child, int type, int *rid,
140     rman_res_t start, rman_res_t end, rman_res_t count, u_int flags)
141 {
142 	struct resource *rv;
143 	struct resource_list_entry *rle;
144 	bool isdefault, passthrough;
145 
146 	isdefault = RMAN_IS_DEFAULT_RANGE(start, end);
147 	passthrough = (device_get_parent(child) != bus);
148 	rle = NULL;
149 	if (!passthrough && isdefault) {
150 		rle = resource_list_find(BUS_GET_RESOURCE_LIST(bus, child),
151 		    type, *rid);
152 		if (rle == NULL) {
153 			if (bootverbose)
154 				device_printf(bus, "no default resources for "
155 				    "rid = %d, type = %d\n", *rid, type);
156 			return (NULL);
157 		}
158 		start = rle->start;
159 		count = ummax(count, rle->count);
160 		end = ummax(rle->end, start + count - 1);
161 	}
162 
163 	/* Let nexus handle the allocation. */
164 	rv = bus_generic_alloc_resource(bus, child, type, rid, start, end,
165 	    count, flags);
166 	if (rv == NULL)
167 		return (NULL);
168 
169 	if (!passthrough && rle != NULL) {
170 		rle->res = rv;
171 		rle->start = rman_get_start(rv);
172 		rle->end = rman_get_end(rv);
173 		rle->count = rle->end - rle->start + 1;
174 	}
175 
176 	return (rv);
177 }
178 
179 static int
180 ofwbus_release_resource(device_t bus, device_t child, int type,
181     int rid, struct resource *r)
182 {
183 	struct resource_list_entry *rle;
184 	bool passthrough;
185 
186 	passthrough = (device_get_parent(child) != bus);
187 	if (!passthrough) {
188 		/* Clean resource list entry */
189 		rle = resource_list_find(BUS_GET_RESOURCE_LIST(bus, child),
190 		    type, rid);
191 		if (rle != NULL)
192 			rle->res = NULL;
193 	}
194 
195 	/* Let nexus handle the release. */
196 	return (bus_generic_release_resource(bus, child, type, rid, r));
197 }
198