1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause
3 *
4 * Copyright (c) 2015 Michal Meloun
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, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 */
28
29 /*
30 * This is a generic syscon driver, whose purpose is to provide access to
31 * various unrelated bits packed in a single register space. It is usually used
32 * as a fallback to more specific driver, but works well enough for simple
33 * access.
34 */
35
36 #include <sys/param.h>
37 #include <sys/systm.h>
38 #include <sys/bus.h>
39 #include <sys/kernel.h>
40 #include <sys/lock.h>
41 #include <sys/module.h>
42 #include <sys/mutex.h>
43 #include <sys/rman.h>
44
45 #include <machine/bus.h>
46
47 #include <dev/ofw/ofw_bus.h>
48 #include <dev/ofw/ofw_bus_subr.h>
49
50 #include "syscon_if.h"
51 #include "syscon.h"
52 #include "syscon_generic.h"
53
54 MALLOC_DECLARE(M_SYSCON);
55
56 static uint32_t syscon_generic_unlocked_read_4(struct syscon *syscon,
57 bus_size_t offset);
58 static int syscon_generic_unlocked_write_4(struct syscon *syscon,
59 bus_size_t offset, uint32_t val);
60 static int syscon_generic_unlocked_modify_4(struct syscon *syscon,
61 bus_size_t offset, uint32_t clear_bits, uint32_t set_bits);
62 static int syscon_generic_detach(device_t dev);
63 /*
64 * Generic syscon driver (FDT)
65 */
66 static struct ofw_compat_data compat_data[] = {
67 {"syscon", 1},
68 {NULL, 0}
69 };
70
71 #define SYSCON_LOCK(_sc) mtx_lock_spin(&(_sc)->mtx)
72 #define SYSCON_UNLOCK(_sc) mtx_unlock_spin(&(_sc)->mtx)
73 #define SYSCON_LOCK_INIT(_sc) mtx_init(&(_sc)->mtx, \
74 device_get_nameunit((_sc)->dev), "syscon", MTX_SPIN)
75 #define SYSCON_LOCK_DESTROY(_sc) mtx_destroy(&(_sc)->mtx);
76 #define SYSCON_ASSERT_LOCKED(_sc) mtx_assert(&(_sc)->mtx, MA_OWNED);
77 #define SYSCON_ASSERT_UNLOCKED(_sc) mtx_assert(&(_sc)->mtx, MA_NOTOWNED);
78
79 static syscon_method_t syscon_generic_methods[] = {
80 SYSCONMETHOD(syscon_unlocked_read_4, syscon_generic_unlocked_read_4),
81 SYSCONMETHOD(syscon_unlocked_write_4, syscon_generic_unlocked_write_4),
82 SYSCONMETHOD(syscon_unlocked_modify_4, syscon_generic_unlocked_modify_4),
83
84 SYSCONMETHOD_END
85 };
86 DEFINE_CLASS_1(syscon_generic, syscon_generic_class, syscon_generic_methods,
87 0, syscon_class);
88
89 static uint32_t
syscon_generic_unlocked_read_4(struct syscon * syscon,bus_size_t offset)90 syscon_generic_unlocked_read_4(struct syscon *syscon, bus_size_t offset)
91 {
92 struct syscon_generic_softc *sc;
93 uint32_t val;
94
95 sc = device_get_softc(syscon->pdev);
96 SYSCON_ASSERT_LOCKED(sc);
97 val = bus_read_4(sc->mem_res, offset);
98 return (val);
99 }
100
101 static int
syscon_generic_unlocked_write_4(struct syscon * syscon,bus_size_t offset,uint32_t val)102 syscon_generic_unlocked_write_4(struct syscon *syscon, bus_size_t offset, uint32_t val)
103 {
104 struct syscon_generic_softc *sc;
105
106 sc = device_get_softc(syscon->pdev);
107 SYSCON_ASSERT_LOCKED(sc);
108 bus_write_4(sc->mem_res, offset, val);
109 return (0);
110 }
111
112 static int
syscon_generic_unlocked_modify_4(struct syscon * syscon,bus_size_t offset,uint32_t clear_bits,uint32_t set_bits)113 syscon_generic_unlocked_modify_4(struct syscon *syscon, bus_size_t offset,
114 uint32_t clear_bits, uint32_t set_bits)
115 {
116 struct syscon_generic_softc *sc;
117 uint32_t val;
118
119 sc = device_get_softc(syscon->pdev);
120 SYSCON_ASSERT_LOCKED(sc);
121 val = bus_read_4(sc->mem_res, offset);
122 val &= ~clear_bits;
123 val |= set_bits;
124 bus_write_4(sc->mem_res, offset, val);
125 return (0);
126 }
127
128 static void
syscon_generic_lock(device_t dev)129 syscon_generic_lock(device_t dev)
130 {
131 struct syscon_generic_softc *sc;
132
133 sc = device_get_softc(dev);
134 SYSCON_LOCK(sc);
135 }
136
137 static void
syscon_generic_unlock(device_t dev)138 syscon_generic_unlock(device_t dev)
139 {
140 struct syscon_generic_softc *sc;
141
142 sc = device_get_softc(dev);
143 SYSCON_UNLOCK(sc);
144 }
145
146 static int
syscon_generic_probe(device_t dev)147 syscon_generic_probe(device_t dev)
148 {
149
150 if (!ofw_bus_status_okay(dev))
151 return (ENXIO);
152 if (ofw_bus_search_compatible(dev, compat_data)->ocd_data == 0)
153 return (ENXIO);
154
155 device_set_desc(dev, "syscon");
156 if (!bootverbose)
157 device_quiet(dev);
158
159 return (BUS_PROBE_GENERIC);
160 }
161
162 static int
syscon_generic_attach(device_t dev)163 syscon_generic_attach(device_t dev)
164 {
165 struct syscon_generic_softc *sc;
166 int rid, rv;
167
168 sc = device_get_softc(dev);
169 sc->dev = dev;
170 rid = 0;
171
172 sc->mem_res = bus_alloc_resource_any(dev, SYS_RES_MEMORY, &rid,
173 RF_ACTIVE);
174 if (sc->mem_res == NULL) {
175 device_printf(dev, "Cannot allocate memory resource\n");
176 return (ENXIO);
177 }
178
179 SYSCON_LOCK_INIT(sc);
180 sc->syscon = syscon_create_ofw_node(dev, &syscon_generic_class,
181 ofw_bus_get_node(dev));
182 if (sc->syscon == NULL) {
183 device_printf(dev, "Failed to create/register syscon\n");
184 syscon_generic_detach(dev);
185 return (ENXIO);
186 }
187 if (ofw_bus_is_compatible(dev, "simple-bus")) {
188 rv = simplebus_attach_impl(sc->dev);
189 if (rv != 0) {
190 device_printf(dev, "Failed to create simplebus\n");
191 syscon_generic_detach(dev);
192 return (ENXIO);
193 }
194 sc->simplebus_attached = true;
195 }
196
197 return (bus_generic_attach(dev));
198 }
199
200 static int
syscon_generic_detach(device_t dev)201 syscon_generic_detach(device_t dev)
202 {
203 struct syscon_generic_softc *sc;
204
205 sc = device_get_softc(dev);
206 if (sc->syscon != NULL) {
207 syscon_unregister(sc->syscon);
208 free(sc->syscon, M_SYSCON);
209 }
210 if (sc->simplebus_attached)
211 simplebus_detach(dev);
212 SYSCON_LOCK_DESTROY(sc);
213
214 if (sc->mem_res != NULL)
215 bus_release_resource(dev, SYS_RES_MEMORY, 0, sc->mem_res);
216 return (0);
217 }
218
219 static device_method_t syscon_generic_dmethods[] = {
220 /* Device interface */
221 DEVMETHOD(device_probe, syscon_generic_probe),
222 DEVMETHOD(device_attach, syscon_generic_attach),
223 DEVMETHOD(device_detach, syscon_generic_detach),
224
225 DEVMETHOD(syscon_device_lock, syscon_generic_lock),
226 DEVMETHOD(syscon_device_unlock, syscon_generic_unlock),
227
228 DEVMETHOD_END
229 };
230
231 DEFINE_CLASS_1(syscon_generic_dev, syscon_generic_driver, syscon_generic_dmethods,
232 sizeof(struct syscon_generic_softc), simplebus_driver);
233
234 EARLY_DRIVER_MODULE(syscon_generic, simplebus, syscon_generic_driver, 0, 0,
235 BUS_PASS_DEFAULT);
236 MODULE_VERSION(syscon_generic, 1);
237