1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause 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 #include <sys/param.h> 38 #include <sys/bus.h> 39 #include <sys/types.h> 40 #include <sys/eventhandler.h> 41 #include <sys/kernel.h> 42 #include <sys/module.h> 43 #include <sys/reboot.h> 44 45 #include <machine/bus.h> 46 47 #include <dev/ofw/ofw_bus.h> 48 #include <dev/ofw/ofw_bus_subr.h> 49 #include <dev/ofw/openfirm.h> 50 51 #include "syscon_if.h" 52 #include "syscon.h" 53 54 struct syscon_power_softc { 55 struct syscon *regmap; 56 uint32_t offset; 57 uint32_t value; 58 uint32_t mask; 59 bool reboot; 60 eventhandler_tag shutdown_tag; 61 }; 62 63 static void 64 syscon_power_shutdown_final(device_t dev, int howto) 65 { 66 struct syscon_power_softc *sc; 67 bool write; 68 69 sc = device_get_softc(dev); 70 if (sc->reboot) 71 write = (howto & RB_HALT) == 0; 72 else 73 write = (howto & RB_POWEROFF) != 0; 74 75 if (write) 76 SYSCON_MODIFY_4(sc->regmap, sc->offset, sc->mask, 77 sc->value & sc->mask); 78 } 79 80 static int 81 syscon_power_probe(device_t dev) 82 { 83 84 if (!ofw_bus_status_okay(dev)) 85 return (ENXIO); 86 87 if (ofw_bus_is_compatible(dev, "syscon-poweroff")) { 88 device_set_desc(dev, "Syscon poweroff"); 89 return (BUS_PROBE_DEFAULT); 90 } else if (ofw_bus_is_compatible(dev, "syscon-reboot")) { 91 device_set_desc(dev, "Syscon reboot"); 92 return (BUS_PROBE_DEFAULT); 93 } 94 95 return (ENXIO); 96 } 97 98 static int 99 syscon_power_attach(device_t dev) 100 { 101 struct syscon_power_softc *sc; 102 phandle_t node; 103 int error, len; 104 bool has_mask; 105 106 sc = device_get_softc(dev); 107 node = ofw_bus_get_node(dev); 108 109 if (!OF_hasprop(node, "regmap")) { 110 device_printf(dev, "could not find regmap\n"); 111 return (ENXIO); 112 } 113 114 error = syscon_get_by_ofw_property(dev, node, "regmap", &sc->regmap); 115 if (error != 0) { 116 device_printf(dev, "could not get syscon\n"); 117 return (ENXIO); 118 } 119 120 len = OF_getproplen(node, "offset"); 121 if (len != 4) { 122 device_printf(dev, "could not get offset\n"); 123 return (ENXIO); 124 } 125 126 OF_getencprop(node, "offset", &sc->offset, sizeof(sc->offset)); 127 128 /* Optional mask */ 129 has_mask = OF_hasprop(node, "mask"); 130 if (has_mask) { 131 len = OF_getproplen(node, "mask"); 132 if (len != 4) { 133 device_printf(dev, "cannot handle mask\n"); 134 return (ENXIO); 135 } 136 137 OF_getencprop(node, "mask", &sc->mask, sizeof(sc->mask)); 138 } else { 139 sc->mask = 0xffffffff; 140 } 141 142 /* 143 * From the device tree specification: 144 * 145 * Legacy usage: If a node doesn't contain a value property but 146 * contains a mask property, the mask property is used as the value. 147 */ 148 if (!OF_hasprop(node, "value")) { 149 if (!has_mask) { 150 device_printf(dev, "must have a value or a mask\n"); 151 return (ENXIO); 152 } 153 154 sc->value = sc->mask; 155 } else { 156 len = OF_getproplen(node, "value"); 157 if (len != 4) { 158 device_printf(dev, "cannot handle value\n"); 159 return (ENXIO); 160 } 161 162 OF_getencprop(node, "value", &sc->value, sizeof(sc->value)); 163 } 164 165 /* Handle reboot after shutdown_panic. */ 166 sc->reboot = ofw_bus_is_compatible(dev, "syscon-reboot"); 167 sc->shutdown_tag = EVENTHANDLER_REGISTER(shutdown_final, 168 syscon_power_shutdown_final, dev, 169 sc->reboot ? SHUTDOWN_PRI_LAST + 150 : SHUTDOWN_PRI_LAST); 170 171 return (0); 172 } 173 174 static int 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)); 195 196 DRIVER_MODULE(syscon_power, simplebus, syscon_power_driver, NULL, NULL); 197