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/cdefs.h>
37 #include <sys/param.h>
38 #include <sys/systm.h>
39 #include <sys/bus.h>
40 #include <sys/kernel.h>
41 #include <sys/lock.h>
42 #include <sys/module.h>
43 #include <sys/mutex.h>
44 #include <sys/rman.h>
45
46 #include <machine/bus.h>
47
48 #include <dev/ofw/ofw_bus.h>
49 #include <dev/ofw/ofw_bus_subr.h>
50
51 #include "syscon_if.h"
52 #include "syscon.h"
53 #include "syscon_generic.h"
54
55 MALLOC_DECLARE(M_SYSCON);
56
57 static uint32_t syscon_generic_unlocked_read_4(struct syscon *syscon,
58 bus_size_t offset);
59 static int syscon_generic_unlocked_write_4(struct syscon *syscon,
60 bus_size_t offset, uint32_t val);
61 static int syscon_generic_unlocked_modify_4(struct syscon *syscon,
62 bus_size_t offset, uint32_t clear_bits, uint32_t set_bits);
63 static int syscon_generic_detach(device_t dev);
64 /*
65 * Generic syscon driver (FDT)
66 */
67 static struct ofw_compat_data compat_data[] = {
68 {"syscon", 1},
69 {NULL, 0}
70 };
71
72 #define SYSCON_LOCK(_sc) mtx_lock_spin(&(_sc)->mtx)
73 #define SYSCON_UNLOCK(_sc) mtx_unlock_spin(&(_sc)->mtx)
74 #define SYSCON_LOCK_INIT(_sc) mtx_init(&(_sc)->mtx, \
75 device_get_nameunit((_sc)->dev), "syscon", MTX_SPIN)
76 #define SYSCON_LOCK_DESTROY(_sc) mtx_destroy(&(_sc)->mtx);
77 #define SYSCON_ASSERT_LOCKED(_sc) mtx_assert(&(_sc)->mtx, MA_OWNED);
78 #define SYSCON_ASSERT_UNLOCKED(_sc) mtx_assert(&(_sc)->mtx, MA_NOTOWNED);
79
80 static syscon_method_t syscon_generic_methods[] = {
81 SYSCONMETHOD(syscon_unlocked_read_4, syscon_generic_unlocked_read_4),
82 SYSCONMETHOD(syscon_unlocked_write_4, syscon_generic_unlocked_write_4),
83 SYSCONMETHOD(syscon_unlocked_modify_4, syscon_generic_unlocked_modify_4),
84
85 SYSCONMETHOD_END
86 };
87 DEFINE_CLASS_1(syscon_generic, syscon_generic_class, syscon_generic_methods,
88 0, syscon_class);
89
90 static uint32_t
syscon_generic_unlocked_read_4(struct syscon * syscon,bus_size_t offset)91 syscon_generic_unlocked_read_4(struct syscon *syscon, bus_size_t offset)
92 {
93 struct syscon_generic_softc *sc;
94 uint32_t val;
95
96 sc = device_get_softc(syscon->pdev);
97 SYSCON_ASSERT_LOCKED(sc);
98 val = bus_read_4(sc->mem_res, offset);
99 return (val);
100 }
101
102 static int
syscon_generic_unlocked_write_4(struct syscon * syscon,bus_size_t offset,uint32_t val)103 syscon_generic_unlocked_write_4(struct syscon *syscon, bus_size_t offset, uint32_t val)
104 {
105 struct syscon_generic_softc *sc;
106
107 sc = device_get_softc(syscon->pdev);
108 SYSCON_ASSERT_LOCKED(sc);
109 bus_write_4(sc->mem_res, offset, val);
110 return (0);
111 }
112
113 static int
syscon_generic_unlocked_modify_4(struct syscon * syscon,bus_size_t offset,uint32_t clear_bits,uint32_t set_bits)114 syscon_generic_unlocked_modify_4(struct syscon *syscon, bus_size_t offset,
115 uint32_t clear_bits, uint32_t set_bits)
116 {
117 struct syscon_generic_softc *sc;
118 uint32_t val;
119
120 sc = device_get_softc(syscon->pdev);
121 SYSCON_ASSERT_LOCKED(sc);
122 val = bus_read_4(sc->mem_res, offset);
123 val &= ~clear_bits;
124 val |= set_bits;
125 bus_write_4(sc->mem_res, offset, val);
126 return (0);
127 }
128
129 static void
syscon_generic_lock(device_t dev)130 syscon_generic_lock(device_t dev)
131 {
132 struct syscon_generic_softc *sc;
133
134 sc = device_get_softc(dev);
135 SYSCON_LOCK(sc);
136 }
137
138 static void
syscon_generic_unlock(device_t dev)139 syscon_generic_unlock(device_t dev)
140 {
141 struct syscon_generic_softc *sc;
142
143 sc = device_get_softc(dev);
144 SYSCON_UNLOCK(sc);
145 }
146
147 static int
syscon_generic_probe(device_t dev)148 syscon_generic_probe(device_t dev)
149 {
150
151 if (!ofw_bus_status_okay(dev))
152 return (ENXIO);
153 if (ofw_bus_search_compatible(dev, compat_data)->ocd_data == 0)
154 return (ENXIO);
155
156 device_set_desc(dev, "syscon");
157 if (!bootverbose)
158 device_quiet(dev);
159
160 return (BUS_PROBE_GENERIC);
161 }
162
163 static int
syscon_generic_attach(device_t dev)164 syscon_generic_attach(device_t dev)
165 {
166 struct syscon_generic_softc *sc;
167 int rid, rv;
168
169 sc = device_get_softc(dev);
170 sc->dev = dev;
171 rid = 0;
172
173 sc->mem_res = bus_alloc_resource_any(dev, SYS_RES_MEMORY, &rid,
174 RF_ACTIVE);
175 if (sc->mem_res == NULL) {
176 device_printf(dev, "Cannot allocate memory resource\n");
177 return (ENXIO);
178 }
179
180 SYSCON_LOCK_INIT(sc);
181 sc->syscon = syscon_create_ofw_node(dev, &syscon_generic_class,
182 ofw_bus_get_node(dev));
183 if (sc->syscon == NULL) {
184 device_printf(dev, "Failed to create/register syscon\n");
185 syscon_generic_detach(dev);
186 return (ENXIO);
187 }
188 if (ofw_bus_is_compatible(dev, "simple-bus")) {
189 rv = simplebus_attach_impl(sc->dev);
190 if (rv != 0) {
191 device_printf(dev, "Failed to create simplebus\n");
192 syscon_generic_detach(dev);
193 return (ENXIO);
194 }
195 sc->simplebus_attached = true;
196 }
197
198 return (bus_generic_attach(dev));
199 }
200
201 static int
syscon_generic_detach(device_t dev)202 syscon_generic_detach(device_t dev)
203 {
204 struct syscon_generic_softc *sc;
205
206 sc = device_get_softc(dev);
207 if (sc->syscon != NULL) {
208 syscon_unregister(sc->syscon);
209 free(sc->syscon, M_SYSCON);
210 }
211 if (sc->simplebus_attached)
212 simplebus_detach(dev);
213 SYSCON_LOCK_DESTROY(sc);
214
215 if (sc->mem_res != NULL)
216 bus_release_resource(dev, SYS_RES_MEMORY, 0, sc->mem_res);
217 return (0);
218 }
219
220 static device_method_t syscon_generic_dmethods[] = {
221 /* Device interface */
222 DEVMETHOD(device_probe, syscon_generic_probe),
223 DEVMETHOD(device_attach, syscon_generic_attach),
224 DEVMETHOD(device_detach, syscon_generic_detach),
225
226 DEVMETHOD(syscon_device_lock, syscon_generic_lock),
227 DEVMETHOD(syscon_device_unlock, syscon_generic_unlock),
228
229 DEVMETHOD_END
230 };
231
232 DEFINE_CLASS_1(syscon_generic_dev, syscon_generic_driver, syscon_generic_dmethods,
233 sizeof(struct syscon_generic_softc), simplebus_driver);
234
235 EARLY_DRIVER_MODULE(syscon_generic, simplebus, syscon_generic_driver, 0, 0,
236 BUS_PASS_DEFAULT);
237 MODULE_VERSION(syscon_generic, 1);
238