1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause 3 * 4 * Copyright (c) 2021 Brandon Bergren <bdragon@FreeBSD.org> 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 #include <sys/cdefs.h> 29 30 #include <sys/param.h> 31 #include <sys/systm.h> 32 #include <sys/kernel.h> 33 #include <sys/module.h> 34 #include <sys/bus.h> 35 36 #include <dev/ofw/ofw_bus.h> 37 #include <dev/ofw/openfirm.h> 38 39 #include <powerpc/powermac/macgpiovar.h> 40 #include <powerpc/powermac/platform_powermac.h> 41 42 static int tbgpio_probe(device_t); 43 static int tbgpio_attach(device_t); 44 static void tbgpio_freeze_timebase(device_t, bool); 45 46 static device_method_t tbgpio_methods[] = { 47 /* Device interface */ 48 DEVMETHOD(device_probe, tbgpio_probe), 49 DEVMETHOD(device_attach, tbgpio_attach), 50 DEVMETHOD_END 51 }; 52 53 struct tbgpio_softc { 54 uint32_t sc_value; 55 uint32_t sc_mask; 56 }; 57 58 static driver_t tbgpio_driver = { 59 "tbgpio", 60 tbgpio_methods, 61 sizeof(struct tbgpio_softc) 62 }; 63 64 EARLY_DRIVER_MODULE(tbgpio, macgpio, tbgpio_driver, 0, 0, BUS_PASS_CPU); 65 66 static int 67 tbgpio_probe(device_t dev) 68 { 69 phandle_t node; 70 const char *name; 71 pcell_t pfunc[32]; 72 int res; 73 74 name = ofw_bus_get_name(dev); 75 node = ofw_bus_get_node(dev); 76 77 if (strcmp(name, "timebase-enable") != 0) 78 return (ENXIO); 79 80 res = OF_getencprop(node, "platform-do-cpu-timebase", pfunc, 81 sizeof(pfunc)); 82 if (res == -1) 83 return (ENXIO); 84 85 /* 86 * If this doesn't look like a simple gpio_write pfunc, 87 * complain about it so we can collect the pfunc. 88 */ 89 if (res != 20 || pfunc[2] != 0x01) { 90 printf("\nUnknown platform function detected!\n"); 91 printf("Please send a PR including the following data:\n"); 92 printf("===================\n"); 93 printf("Func: platform-do-cpu-timebase\n"); 94 hexdump(pfunc, res, NULL, HD_OMIT_CHARS); 95 printf("===================\n"); 96 return (ENXIO); 97 } 98 99 device_set_desc(dev, "CPU Timebase Control"); 100 return (BUS_PROBE_SPECIFIC); 101 } 102 103 static int 104 tbgpio_attach(device_t dev) 105 { 106 phandle_t node; 107 struct tbgpio_softc *sc; 108 109 /* 110 * Structure of pfunc: 111 * pfunc[0]: phandle to /cpus 112 * pfunc[1]: flags 113 * pfunc[2]: 0x1 == CMD_WRITE_GPIO 114 * pfunc[3]: value 115 * pfunc[4]: mask 116 */ 117 pcell_t pfunc[5]; 118 119 sc = device_get_softc(dev); 120 node = ofw_bus_get_node(dev); 121 122 OF_getencprop(node, "platform-do-cpu-timebase", pfunc, sizeof(pfunc)); 123 124 sc->sc_value = pfunc[3]; 125 sc->sc_mask = pfunc[4]; 126 127 powermac_register_timebase(dev, tbgpio_freeze_timebase); 128 return (0); 129 } 130 131 static void 132 tbgpio_freeze_timebase(device_t dev, bool freeze) 133 { 134 struct tbgpio_softc *sc; 135 uint32_t val; 136 137 sc = device_get_softc(dev); 138 139 val = sc->sc_value; 140 if (freeze) 141 val = ~val; 142 val &= sc->sc_mask; 143 144 macgpio_write(dev, val); 145 } 146