1 /* $OpenBSD: apldog.c,v 1.2 2021/11/13 23:24:24 kettenis Exp $ */ 2 /* 3 * Copyright (c) 2021 Mark Kettenis <kettenis@openbsd.org> 4 * 5 * Permission to use, copy, modify, and distribute this software for any 6 * purpose with or without fee is hereby granted, provided that the above 7 * copyright notice and this permission notice appear in all copies. 8 * 9 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES 10 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 11 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR 12 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 13 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 14 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF 15 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 16 */ 17 18 #include <sys/param.h> 19 #include <sys/systm.h> 20 #include <sys/device.h> 21 22 #include <machine/bus.h> 23 #include <machine/fdt.h> 24 25 #include <dev/ofw/openfirm.h> 26 #include <dev/ofw/fdt.h> 27 28 extern void (*cpuresetfn)(void); 29 30 /* 31 * This driver is based on preliminary device tree bindings and will 32 * almost certainly need changes once the official bindings land in 33 * mainline Linux. Support for these preliminary bindings will be 34 * dropped as soon as official bindings are available. 35 */ 36 37 #define WDT_CHIP_CTL 0x000c 38 #define WDT_SYS_TMR 0x0010 39 #define WDT_SYS_RST 0x0014 40 #define WDT_SYS_RST_IMMEDIATE (1 << 0) 41 #define WDT_SYS_CTL 0x001c 42 #define WDT_SYS_CTL_ENABLE (1 << 2) 43 44 #define HREAD4(sc, reg) \ 45 (bus_space_read_4((sc)->sc_iot, (sc)->sc_ioh, (reg))) 46 #define HWRITE4(sc, reg, val) \ 47 bus_space_write_4((sc)->sc_iot, (sc)->sc_ioh, (reg), (val)) 48 49 struct apldog_softc { 50 struct device sc_dev; 51 bus_space_tag_t sc_iot; 52 bus_space_handle_t sc_ioh; 53 }; 54 55 struct apldog_softc *apldog_sc; 56 57 int apldog_match(struct device *, void *, void *); 58 void apldog_attach(struct device *, struct device *, void *); 59 60 struct cfattach apldog_ca = { 61 sizeof (struct apldog_softc), apldog_match, apldog_attach 62 }; 63 64 struct cfdriver apldog_cd = { 65 NULL, "apldog", DV_DULL 66 }; 67 68 void apldog_reset(void); 69 70 int 71 apldog_match(struct device *parent, void *match, void *aux) 72 { 73 struct fdt_attach_args *faa = aux; 74 75 return OF_is_compatible(faa->fa_node, "apple,wdt"); 76 } 77 78 void 79 apldog_attach(struct device *parent, struct device *self, void *aux) 80 { 81 struct apldog_softc *sc = (struct apldog_softc *)self; 82 struct fdt_attach_args *faa = aux; 83 84 if (faa->fa_nreg < 1) { 85 printf(": no registers\n"); 86 return; 87 } 88 89 sc->sc_iot = faa->fa_iot; 90 if (bus_space_map(sc->sc_iot, faa->fa_reg[0].addr, 91 faa->fa_reg[0].size, 0, &sc->sc_ioh)) { 92 printf(": can't map registers\n"); 93 return; 94 } 95 96 printf("\n"); 97 98 /* Reset the watchdog timers. */ 99 HWRITE4(sc, WDT_CHIP_CTL, 0); 100 HWRITE4(sc, WDT_SYS_CTL, 0); 101 102 apldog_sc = sc; 103 cpuresetfn = apldog_reset; 104 } 105 106 void 107 apldog_reset(void) 108 { 109 struct apldog_softc *sc = apldog_sc; 110 111 /* Trigger a system reset. */ 112 HWRITE4(sc, WDT_SYS_RST, WDT_SYS_RST_IMMEDIATE); 113 HWRITE4(sc, WDT_SYS_CTL, WDT_SYS_CTL_ENABLE); 114 HWRITE4(sc, WDT_SYS_TMR, 0); 115 116 delay(1000000); 117 } 118