1 /*- 2 * Copyright (c) 2015 Michal Meloun 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24 * SUCH DAMAGE. 25 */ 26 27 /* 28 * This is a generic syscon driver, whose purpose is to provide access to 29 * various unrelated bits packed in a single register space. It is usually used 30 * as a fallback to more specific driver, but works well enough for simple 31 * access. 32 */ 33 34 #include <sys/cdefs.h> 35 __FBSDID("$FreeBSD$"); 36 #include <sys/param.h> 37 #include <sys/systm.h> 38 #include <sys/bus.h> 39 #include <sys/kernel.h> 40 #include <sys/module.h> 41 #include <sys/rman.h> 42 43 #include <machine/bus.h> 44 45 #include <dev/ofw/ofw_bus.h> 46 #include <dev/ofw/ofw_bus_subr.h> 47 48 #include "syscon_if.h" 49 50 #define SYSCON_LOCK(_sc) mtx_lock(&(_sc)->mtx) 51 #define SYSCON_UNLOCK(_sc) mtx_unlock(&(_sc)->mtx) 52 #define SYSCON_LOCK_INIT(_sc) mtx_init(&(_sc)->mtx, \ 53 device_get_nameunit((_sc)->dev), "syscon", MTX_DEF) 54 #define SYSCON_LOCK_DESTROY(_sc) mtx_destroy(&(_sc)->mtx); 55 #define SYSCON_ASSERT_LOCKED(_sc) mtx_assert(&(_sc)->mtx, MA_OWNED); 56 #define SYSCON_ASSERT_UNLOCKED(_sc) mtx_assert(&(_sc)->mtx, MA_NOTOWNED); 57 58 struct syscon_softc { 59 device_t dev; 60 struct resource *mem_res; 61 struct mtx mtx; 62 }; 63 64 static struct ofw_compat_data compat_data[] = { 65 {"syscon", 1}, 66 {NULL, 0} 67 }; 68 69 static uint32_t 70 syscon_read_4(device_t dev, device_t consumer, bus_size_t offset) 71 { 72 struct syscon_softc *sc; 73 uint32_t val; 74 75 sc = device_get_softc(dev); 76 77 SYSCON_LOCK(sc); 78 val = bus_read_4(sc->mem_res, offset); 79 SYSCON_UNLOCK(sc); 80 return (val); 81 } 82 83 static void 84 syscon_write_4(device_t dev, device_t consumer, bus_size_t offset, uint32_t val) 85 { 86 struct syscon_softc *sc; 87 88 sc = device_get_softc(dev); 89 90 SYSCON_LOCK(sc); 91 bus_write_4(sc->mem_res, offset, val); 92 SYSCON_UNLOCK(sc); 93 } 94 95 static void 96 syscon_modify_4(device_t dev, device_t consumer, bus_size_t offset, 97 uint32_t clear_bits, uint32_t set_bits) 98 { 99 struct syscon_softc *sc; 100 uint32_t val; 101 102 sc = device_get_softc(dev); 103 104 SYSCON_LOCK(sc); 105 val = bus_read_4(sc->mem_res, offset); 106 val &= ~clear_bits; 107 val |= set_bits; 108 bus_write_4(sc->mem_res, offset, val); 109 SYSCON_UNLOCK(sc); 110 } 111 112 static int 113 syscon_probe(device_t dev) 114 { 115 116 if (!ofw_bus_status_okay(dev)) 117 return (ENXIO); 118 if (ofw_bus_search_compatible(dev, compat_data)->ocd_data == 0) 119 return (ENXIO); 120 121 device_set_desc(dev, "syscon"); 122 return (BUS_PROBE_GENERIC); 123 } 124 125 static int 126 syscon_attach(device_t dev) 127 { 128 struct syscon_softc *sc; 129 int rid; 130 phandle_t node; 131 132 sc = device_get_softc(dev); 133 sc->dev = dev; 134 node = ofw_bus_get_node(sc->dev); 135 136 SYSCON_LOCK_INIT(sc); 137 138 rid = 0; 139 sc->mem_res = bus_alloc_resource_any(dev, SYS_RES_MEMORY, &rid, 140 RF_ACTIVE); 141 if (sc->mem_res == NULL) { 142 device_printf(dev, "Cannot allocate memory resource\n"); 143 return (ENXIO); 144 } 145 146 OF_device_register_xref(OF_xref_from_node(node), dev); 147 148 return (0); 149 } 150 151 static int 152 syscon_detach(device_t dev) 153 { 154 struct syscon_softc *sc; 155 156 sc = device_get_softc(dev); 157 158 OF_device_register_xref(OF_xref_from_device(dev), NULL); 159 160 SYSCON_LOCK_DESTROY(sc); 161 if (sc->mem_res != NULL) 162 bus_release_resource(dev, SYS_RES_MEMORY, 0, sc->mem_res); 163 return (0); 164 } 165 166 static device_method_t syscon_methods[] = { 167 /* Device interface */ 168 DEVMETHOD(device_probe, syscon_probe), 169 DEVMETHOD(device_attach, syscon_attach), 170 DEVMETHOD(device_detach, syscon_detach), 171 172 /* Syscon interface */ 173 DEVMETHOD(syscon_read_4, syscon_read_4), 174 DEVMETHOD(syscon_write_4, syscon_write_4), 175 DEVMETHOD(syscon_modify_4, syscon_modify_4), 176 177 DEVMETHOD_END 178 }; 179 180 DEFINE_CLASS_0(syscon, syscon_driver, syscon_methods, 181 sizeof(struct syscon_softc)); 182 static devclass_t syscon_devclass; 183 EARLY_DRIVER_MODULE(syscon, simplebus, syscon_driver, syscon_devclass, 0, 0, 184 BUS_PASS_BUS + BUS_PASS_ORDER_LATE); 185 MODULE_VERSION(syscon, 1); 186