1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD 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 static devclass_t tbgpio_devclass; 65 66 EARLY_DRIVER_MODULE(tbgpio, macgpio, tbgpio_driver, tbgpio_devclass, 0, 0, 67 BUS_PASS_CPU); 68 69 static int 70 tbgpio_probe(device_t dev) 71 { 72 phandle_t node; 73 const char *name; 74 pcell_t pfunc[32]; 75 int res; 76 77 name = ofw_bus_get_name(dev); 78 node = ofw_bus_get_node(dev); 79 80 if (strcmp(name, "timebase-enable") != 0) 81 return (ENXIO); 82 83 res = OF_getencprop(node, "platform-do-cpu-timebase", pfunc, 84 sizeof(pfunc)); 85 if (res == -1) 86 return (ENXIO); 87 88 /* 89 * If this doesn't look like a simple gpio_write pfunc, 90 * complain about it so we can collect the pfunc. 91 */ 92 if (res != 20 || pfunc[2] != 0x01) { 93 printf("\nUnknown platform function detected!\n"); 94 printf("Please send a PR including the following data:\n"); 95 printf("===================\n"); 96 printf("Func: platform-do-cpu-timebase\n"); 97 hexdump(pfunc, res, NULL, HD_OMIT_CHARS); 98 printf("===================\n"); 99 return (ENXIO); 100 } 101 102 device_set_desc(dev, "CPU Timebase Control"); 103 return (BUS_PROBE_SPECIFIC); 104 } 105 106 static int 107 tbgpio_attach(device_t dev) 108 { 109 phandle_t node; 110 struct tbgpio_softc *sc; 111 112 /* 113 * Structure of pfunc: 114 * pfunc[0]: phandle to /cpus 115 * pfunc[1]: flags 116 * pfunc[2]: 0x1 == CMD_WRITE_GPIO 117 * pfunc[3]: value 118 * pfunc[4]: mask 119 */ 120 pcell_t pfunc[5]; 121 122 sc = device_get_softc(dev); 123 node = ofw_bus_get_node(dev); 124 125 OF_getencprop(node, "platform-do-cpu-timebase", pfunc, sizeof(pfunc)); 126 127 sc->sc_value = pfunc[3]; 128 sc->sc_mask = pfunc[4]; 129 130 powermac_register_timebase(dev, tbgpio_freeze_timebase); 131 return (0); 132 } 133 134 static void 135 tbgpio_freeze_timebase(device_t dev, bool freeze) 136 { 137 struct tbgpio_softc *sc; 138 uint32_t val; 139 140 sc = device_get_softc(dev); 141 142 val = sc->sc_value; 143 if (freeze) 144 val = ~val; 145 val &= sc->sc_mask; 146 147 macgpio_write(dev, val); 148 } 149