1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3 *
4 * Copyright (c) 2017 Kyle Evans <[email protected]>
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25 * SUCH DAMAGE.
26 */
27
28 /*
29 * This is a generic syscon driver, whose purpose is to provide access to
30 * various unrelated bits packed in a single register space. It is usually used
31 * as a fallback to more specific driver, but works well enough for simple
32 * access.
33 */
34
35 #include <sys/cdefs.h>
36 __FBSDID("$FreeBSD$");
37 #include "opt_platform.h"
38
39 #include <sys/param.h>
40 #include <sys/systm.h>
41 #include <sys/bus.h>
42 #include <sys/kernel.h>
43 #include <sys/kobj.h>
44 #include <sys/lock.h>
45 #include <sys/module.h>
46 #include <sys/rman.h>
47 #include <sys/sx.h>
48 #include <sys/queue.h>
49
50 #include <machine/bus.h>
51
52 #ifdef FDT
53 #include <dev/ofw/ofw_bus.h>
54 #include <dev/ofw/ofw_bus_subr.h>
55 #endif
56
57 #include "syscon_if.h"
58 #include "syscon.h"
59
60 /*
61 * Syscon interface details
62 */
63 typedef TAILQ_HEAD(syscon_list, syscon) syscon_list_t;
64
65 /*
66 * Declarations
67 */
68 static int syscon_method_init(struct syscon *syscon);
69 static int syscon_method_uninit(struct syscon *syscon);
70
71 MALLOC_DEFINE(M_SYSCON, "syscon", "Syscon driver");
72
73 static syscon_list_t syscon_list = TAILQ_HEAD_INITIALIZER(syscon_list);
74 static struct sx syscon_topo_lock;
75 SX_SYSINIT(syscon_topology, &syscon_topo_lock, "Syscon topology lock");
76
77 /*
78 * Syscon methods.
79 */
80 static syscon_method_t syscon_methods[] = {
81 SYSCONMETHOD(syscon_init, syscon_method_init),
82 SYSCONMETHOD(syscon_uninit, syscon_method_uninit),
83
84 SYSCONMETHOD_END
85 };
86 DEFINE_CLASS_0(syscon, syscon_class, syscon_methods, 0);
87
88 #define SYSCON_TOPO_SLOCK() sx_slock(&syscon_topo_lock)
89 #define SYSCON_TOPO_XLOCK() sx_xlock(&syscon_topo_lock)
90 #define SYSCON_TOPO_UNLOCK() sx_unlock(&syscon_topo_lock)
91 #define SYSCON_TOPO_ASSERT() sx_assert(&syscon_topo_lock, SA_LOCKED)
92 #define SYSCON_TOPO_XASSERT() sx_assert(&syscon_topo_lock, SA_XLOCKED)
93
94 /*
95 * Default syscon methods for base class.
96 */
97 static int
syscon_method_init(struct syscon * syscon)98 syscon_method_init(struct syscon *syscon)
99 {
100
101 return (0);
102 };
103
104 static int
syscon_method_uninit(struct syscon * syscon)105 syscon_method_uninit(struct syscon *syscon)
106 {
107
108 return (0);
109 };
110
111 void *
syscon_get_softc(struct syscon * syscon)112 syscon_get_softc(struct syscon *syscon)
113 {
114
115 return (syscon->softc);
116 };
117
118 /*
119 * Create and initialize syscon object, but do not register it.
120 */
121 struct syscon *
syscon_create(device_t pdev,syscon_class_t syscon_class)122 syscon_create(device_t pdev, syscon_class_t syscon_class)
123 {
124 struct syscon *syscon;
125
126 /* Create object and initialize it. */
127 syscon = malloc(sizeof(struct syscon), M_SYSCON,
128 M_WAITOK | M_ZERO);
129 kobj_init((kobj_t)syscon, (kobj_class_t)syscon_class);
130
131 /* Allocate softc if required. */
132 if (syscon_class->size > 0)
133 syscon->softc = malloc(syscon_class->size, M_SYSCON,
134 M_WAITOK | M_ZERO);
135
136 /* Rest of init. */
137 syscon->pdev = pdev;
138 return (syscon);
139 }
140
141 /* Register syscon object. */
142 struct syscon *
syscon_register(struct syscon * syscon)143 syscon_register(struct syscon *syscon)
144 {
145 int rv;
146
147 #ifdef FDT
148 if (syscon->ofw_node <= 0)
149 syscon->ofw_node = ofw_bus_get_node(syscon->pdev);
150 if (syscon->ofw_node <= 0)
151 return (NULL);
152 #endif
153
154 rv = SYSCON_INIT(syscon);
155 if (rv != 0) {
156 printf("SYSCON_INIT failed: %d\n", rv);
157 return (NULL);
158 }
159
160 #ifdef FDT
161 OF_device_register_xref(OF_xref_from_node(syscon->ofw_node),
162 syscon->pdev);
163 #endif
164 SYSCON_TOPO_XLOCK();
165 TAILQ_INSERT_TAIL(&syscon_list, syscon, syscon_link);
166 SYSCON_TOPO_UNLOCK();
167 return (syscon);
168 }
169
170 int
syscon_unregister(struct syscon * syscon)171 syscon_unregister(struct syscon *syscon)
172 {
173
174 SYSCON_TOPO_XLOCK();
175 TAILQ_REMOVE(&syscon_list, syscon, syscon_link);
176 SYSCON_TOPO_UNLOCK();
177 #ifdef FDT
178 OF_device_register_xref(OF_xref_from_node(syscon->ofw_node), NULL);
179 #endif
180 return (SYSCON_UNINIT(syscon));
181 }
182
183 /**
184 * Provider methods
185 */
186 #ifdef FDT
187 static struct syscon *
syscon_find_by_ofw_node(phandle_t node)188 syscon_find_by_ofw_node(phandle_t node)
189 {
190 struct syscon *entry;
191
192 SYSCON_TOPO_ASSERT();
193
194 TAILQ_FOREACH(entry, &syscon_list, syscon_link) {
195 if (entry->ofw_node == node)
196 return (entry);
197 }
198
199 return (NULL);
200 }
201
202 struct syscon *
syscon_create_ofw_node(device_t pdev,syscon_class_t syscon_class,phandle_t node)203 syscon_create_ofw_node(device_t pdev, syscon_class_t syscon_class,
204 phandle_t node)
205 {
206 struct syscon *syscon;
207
208 syscon = syscon_create(pdev, syscon_class);
209 if (syscon == NULL)
210 return (NULL);
211 syscon->ofw_node = node;
212 if (syscon_register(syscon) == NULL)
213 return (NULL);
214 return (syscon);
215 }
216
217 phandle_t
syscon_get_ofw_node(struct syscon * syscon)218 syscon_get_ofw_node(struct syscon *syscon)
219 {
220
221 return (syscon->ofw_node);
222 }
223
224 int
syscon_get_by_ofw_property(device_t cdev,phandle_t cnode,char * name,struct syscon ** syscon)225 syscon_get_by_ofw_property(device_t cdev, phandle_t cnode, char *name,
226 struct syscon **syscon)
227 {
228 pcell_t *cells;
229 int ncells;
230
231 if (cnode <= 0)
232 cnode = ofw_bus_get_node(cdev);
233 if (cnode <= 0) {
234 device_printf(cdev,
235 "%s called on not ofw based device\n", __func__);
236 return (ENXIO);
237 }
238 ncells = OF_getencprop_alloc_multi(cnode, name, sizeof(pcell_t),
239 (void **)&cells);
240 if (ncells < 1)
241 return (ENOENT);
242
243 /* Translate to syscon node. */
244 SYSCON_TOPO_SLOCK();
245 *syscon = syscon_find_by_ofw_node(OF_node_from_xref(cells[0]));
246 if (*syscon == NULL) {
247 SYSCON_TOPO_UNLOCK();
248 device_printf(cdev, "Failed to find syscon node\n");
249 OF_prop_free(cells);
250 return (ENODEV);
251 }
252 SYSCON_TOPO_UNLOCK();
253 OF_prop_free(cells);
254 return (0);
255 }
256 #endif
257
258 int
syscon_get_handle_default(device_t dev,struct syscon ** syscon)259 syscon_get_handle_default(device_t dev, struct syscon **syscon)
260 {
261 device_t parent;
262
263 parent = device_get_parent(dev);
264 if (parent == NULL)
265 return (ENODEV);
266 return (SYSCON_GET_HANDLE(parent, syscon));
267 }
268