1 /*-
2 * Copyright 1998 Massachusetts Institute of Technology
3 * Copyright 2001 by Thomas Moestl <[email protected]>.
4 * Copyright 2006 by Marius Strobl <[email protected]>.
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 #include <sys/param.h>
37 #include <sys/systm.h>
38 #include <sys/bus.h>
39 #include <sys/kernel.h>
40 #include <sys/module.h>
41 #include <sys/rman.h>
42
43 #include <dev/ofw/ofw_bus.h>
44 #include <dev/ofw/ofw_bus_subr.h>
45 #include <dev/ofw/openfirm.h>
46 #include <dev/fdt/simplebus.h>
47
48 #include <machine/bus.h>
49 #include <machine/resource.h>
50
51 /*
52 * The ofwbus (which is a pseudo-bus actually) iterates over the nodes that
53 * hang from the Open Firmware root node and adds them as devices to this bus
54 * (except some special nodes which are excluded) so that drivers can be
55 * attached to them. There should be only one ofwbus in the system, added
56 * directly as a child of nexus0.
57 */
58
59 static device_probe_t ofwbus_probe;
60 static device_attach_t ofwbus_attach;
61 static bus_alloc_resource_t ofwbus_alloc_resource;
62 static bus_release_resource_t ofwbus_release_resource;
63
64 static device_method_t ofwbus_methods[] = {
65 /* Device interface */
66 DEVMETHOD(device_probe, ofwbus_probe),
67 DEVMETHOD(device_attach, ofwbus_attach),
68
69 /* Bus interface */
70 DEVMETHOD(bus_alloc_resource, ofwbus_alloc_resource),
71 DEVMETHOD(bus_adjust_resource, bus_generic_adjust_resource),
72 DEVMETHOD(bus_release_resource, ofwbus_release_resource),
73
74 DEVMETHOD_END
75 };
76
77 DEFINE_CLASS_1(ofwbus, ofwbus_driver, ofwbus_methods,
78 sizeof(struct simplebus_softc), simplebus_driver);
79 EARLY_DRIVER_MODULE(ofwbus, nexus, ofwbus_driver, 0, 0,
80 BUS_PASS_BUS + BUS_PASS_ORDER_MIDDLE);
81 MODULE_VERSION(ofwbus, 1);
82
83 static int
ofwbus_probe(device_t dev)84 ofwbus_probe(device_t dev)
85 {
86
87 if (OF_peer(0) == 0)
88 return (ENXIO);
89
90 /* Only one instance of ofwbus. */
91 if (device_get_unit(dev) != 0)
92 panic("ofwbus added with non-zero unit number: %d\n",
93 device_get_unit(dev));
94
95 device_set_desc(dev, "Open Firmware Device Tree");
96 return (BUS_PROBE_NOWILDCARD);
97 }
98
99 static int
ofwbus_attach(device_t dev)100 ofwbus_attach(device_t dev)
101 {
102 phandle_t node;
103
104 node = OF_peer(0);
105
106 /*
107 * If no Open Firmware, bail early
108 */
109 if (node == -1)
110 return (ENXIO);
111
112 /*
113 * ofwbus bus starts on unamed node in FDT, so we cannot make
114 * ofw_bus_devinfo from it. Pass node to simplebus_init directly.
115 */
116 simplebus_init(dev, node);
117
118 /*
119 * Allow devices to identify.
120 */
121 bus_generic_probe(dev);
122
123 /*
124 * Now walk the OFW tree and attach top-level devices.
125 */
126 for (node = OF_child(node); node > 0; node = OF_peer(node))
127 simplebus_add_device(dev, node, 0, NULL, -1, NULL);
128
129 return (bus_generic_attach(dev));
130 }
131
132 static struct resource *
ofwbus_alloc_resource(device_t bus,device_t child,int type,int * rid,rman_res_t start,rman_res_t end,rman_res_t count,u_int flags)133 ofwbus_alloc_resource(device_t bus, device_t child, int type, int *rid,
134 rman_res_t start, rman_res_t end, rman_res_t count, u_int flags)
135 {
136 struct resource *rv;
137 struct resource_list_entry *rle;
138 bool isdefault, passthrough;
139
140 isdefault = RMAN_IS_DEFAULT_RANGE(start, end);
141 passthrough = (device_get_parent(child) != bus);
142 rle = NULL;
143 if (!passthrough && isdefault) {
144 rle = resource_list_find(BUS_GET_RESOURCE_LIST(bus, child),
145 type, *rid);
146 if (rle == NULL) {
147 if (bootverbose)
148 device_printf(bus, "no default resources for "
149 "rid = %d, type = %d\n", *rid, type);
150 return (NULL);
151 }
152 start = rle->start;
153 count = ummax(count, rle->count);
154 end = ummax(rle->end, start + count - 1);
155 }
156
157 /* Let nexus handle the allocation. */
158 rv = bus_generic_alloc_resource(bus, child, type, rid, start, end,
159 count, flags);
160 if (rv == NULL)
161 return (NULL);
162
163 if (!passthrough && rle != NULL) {
164 rle->res = rv;
165 rle->start = rman_get_start(rv);
166 rle->end = rman_get_end(rv);
167 rle->count = rle->end - rle->start + 1;
168 }
169
170 return (rv);
171 }
172
173 static int
ofwbus_release_resource(device_t bus,device_t child,int type,int rid,struct resource * r)174 ofwbus_release_resource(device_t bus, device_t child, int type,
175 int rid, struct resource *r)
176 {
177 struct resource_list_entry *rle;
178 bool passthrough;
179
180 passthrough = (device_get_parent(child) != bus);
181 if (!passthrough) {
182 /* Clean resource list entry */
183 rle = resource_list_find(BUS_GET_RESOURCE_LIST(bus, child),
184 type, rid);
185 if (rle != NULL)
186 rle->res = NULL;
187 }
188
189 /* Let nexus handle the release. */
190 return (bus_generic_release_resource(bus, child, type, rid, r));
191 }
192