1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3 *
4 * Copyright (c) 2020 Jessica Clarke <[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 * Driver for simple syscon poweroff and reset devices. The device tree
30 * specifications are fully described at:
31 *
32 * https://www.kernel.org/doc/Documentation/devicetree/bindings/power/reset/syscon-poweroff.txt
33 * https://www.kernel.org/doc/Documentation/devicetree/bindings/power/reset/syscon-reboot.txt
34 */
35
36 #include <sys/cdefs.h>
37 __FBSDID("$FreeBSD$");
38
39 #include <sys/param.h>
40 #include <sys/bus.h>
41 #include <sys/types.h>
42 #include <sys/eventhandler.h>
43 #include <sys/kernel.h>
44 #include <sys/module.h>
45 #include <sys/reboot.h>
46
47 #include <machine/bus.h>
48
49 #include <dev/ofw/ofw_bus.h>
50 #include <dev/ofw/ofw_bus_subr.h>
51 #include <dev/ofw/openfirm.h>
52
53 #include "syscon_if.h"
54 #include "syscon.h"
55
56 struct syscon_power_softc {
57 struct syscon *regmap;
58 uint32_t offset;
59 uint32_t value;
60 uint32_t mask;
61 bool reboot;
62 eventhandler_tag shutdown_tag;
63 };
64
65 static void
syscon_power_shutdown_final(device_t dev,int howto)66 syscon_power_shutdown_final(device_t dev, int howto)
67 {
68 struct syscon_power_softc *sc;
69 bool write;
70
71 sc = device_get_softc(dev);
72 if (sc->reboot)
73 write = (howto & RB_HALT) == 0;
74 else
75 write = (howto & RB_POWEROFF) != 0;
76
77 if (write)
78 SYSCON_MODIFY_4(sc->regmap, sc->offset, sc->mask,
79 sc->value & sc->mask);
80 }
81
82 static int
syscon_power_probe(device_t dev)83 syscon_power_probe(device_t dev)
84 {
85
86 if (!ofw_bus_status_okay(dev))
87 return (ENXIO);
88
89 if (ofw_bus_is_compatible(dev, "syscon-poweroff")) {
90 device_set_desc(dev, "Syscon poweroff");
91 return (BUS_PROBE_DEFAULT);
92 } else if (ofw_bus_is_compatible(dev, "syscon-reboot")) {
93 device_set_desc(dev, "Syscon reboot");
94 return (BUS_PROBE_DEFAULT);
95 }
96
97 return (ENXIO);
98 }
99
100 static int
syscon_power_attach(device_t dev)101 syscon_power_attach(device_t dev)
102 {
103 struct syscon_power_softc *sc;
104 phandle_t node;
105 int error, len;
106 bool has_mask;
107
108 sc = device_get_softc(dev);
109 node = ofw_bus_get_node(dev);
110
111 if (!OF_hasprop(node, "regmap")) {
112 device_printf(dev, "could not find regmap\n");
113 return (ENXIO);
114 }
115
116 error = syscon_get_by_ofw_property(dev, node, "regmap", &sc->regmap);
117 if (error != 0) {
118 device_printf(dev, "could not get syscon\n");
119 return (ENXIO);
120 }
121
122 len = OF_getproplen(node, "offset");
123 if (len != 4) {
124 device_printf(dev, "could not get offset\n");
125 return (ENXIO);
126 }
127
128 OF_getencprop(node, "offset", &sc->offset, sizeof(sc->offset));
129
130 /* Optional mask */
131 has_mask = OF_hasprop(node, "mask");
132 if (has_mask) {
133 len = OF_getproplen(node, "mask");
134 if (len != 4) {
135 device_printf(dev, "cannot handle mask\n");
136 return (ENXIO);
137 }
138
139 OF_getencprop(node, "mask", &sc->mask, sizeof(sc->mask));
140 } else {
141 sc->mask = 0xffffffff;
142 }
143
144 /*
145 * From the device tree specification:
146 *
147 * Legacy usage: If a node doesn't contain a value property but
148 * contains a mask property, the mask property is used as the value.
149 */
150 if (!OF_hasprop(node, "value")) {
151 if (!has_mask) {
152 device_printf(dev, "must have a value or a mask\n");
153 return (ENXIO);
154 }
155
156 sc->value = sc->mask;
157 } else {
158 len = OF_getproplen(node, "value");
159 if (len != 4) {
160 device_printf(dev, "cannot handle value\n");
161 return (ENXIO);
162 }
163
164 OF_getencprop(node, "value", &sc->value, sizeof(sc->value));
165 }
166
167 sc->reboot = ofw_bus_is_compatible(dev, "syscon-reboot");
168 sc->shutdown_tag = EVENTHANDLER_REGISTER(shutdown_final,
169 syscon_power_shutdown_final, dev, SHUTDOWN_PRI_LAST);
170
171 return (0);
172 }
173
174 static int
syscon_power_detach(device_t dev)175 syscon_power_detach(device_t dev)
176 {
177 struct syscon_power_softc *sc;
178
179 sc = device_get_softc(dev);
180 EVENTHANDLER_DEREGISTER(shutdown_final, sc->shutdown_tag);
181
182 return (0);
183 }
184
185 static device_method_t syscon_power_methods[] = {
186 DEVMETHOD(device_probe, syscon_power_probe),
187 DEVMETHOD(device_attach, syscon_power_attach),
188 DEVMETHOD(device_detach, syscon_power_detach),
189
190 DEVMETHOD_END
191 };
192
193 DEFINE_CLASS_0(syscon_power, syscon_power_driver, syscon_power_methods,
194 sizeof(struct syscon_power_softc));
195 static devclass_t syscon_power_devclass;
196
197 DRIVER_MODULE(syscon_power, simplebus, syscon_power_driver,
198 syscon_power_devclass, NULL, NULL);
199