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