1 /* $NetBSD: apple_wdog.c,v 1.3 2022/04/05 05:04:04 skrll Exp $ */ 2 3 /*- 4 * Copyright (c) 2021 Jared McNeill <jmcneill@invisible.ca> 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 17 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 18 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 19 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, 21 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 22 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED 23 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 24 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26 * SUCH DAMAGE. 27 */ 28 29 #include <sys/cdefs.h> 30 __KERNEL_RCSID(0, "$NetBSD: apple_wdog.c,v 1.3 2022/04/05 05:04:04 skrll Exp $"); 31 32 #include <sys/param.h> 33 #include <sys/bus.h> 34 #include <sys/device.h> 35 #include <sys/intr.h> 36 #include <sys/kernel.h> 37 #include <sys/lwp.h> 38 #include <sys/systm.h> 39 40 #include <dev/fdt/fdtvar.h> 41 42 #define WDOG_CHIP_CTL 0x000c 43 #define WDOG_SYS_TMR 0x0010 44 #define WDOG_SYS_RST 0x0014 45 #define WDOG_SYS_CTL 0x001c 46 #define WDOG_SYS_CTL_ENABLE __BIT(2) 47 48 static const struct device_compatible_entry compat_data[] = { 49 { .compat = "apple,wdt" }, 50 { .compat = "apple,reboot-v0" }, 51 DEVICE_COMPAT_EOL 52 }; 53 54 struct apple_wdog_softc { 55 device_t sc_dev; 56 bus_space_tag_t sc_bst; 57 bus_space_handle_t sc_bsh; 58 }; 59 60 #define WDOG_READ(sc, reg) \ 61 bus_space_read_4((sc)->sc_bst, (sc)->sc_bsh, (reg)) 62 #define WDOG_WRITE(sc, reg, val) \ 63 bus_space_write_4((sc)->sc_bst, (sc)->sc_bsh, (reg), (val)) 64 65 static void 66 apple_wdog_reset(device_t dev) 67 { 68 struct apple_wdog_softc * const sc = device_private(dev); 69 70 WDOG_WRITE(sc, WDOG_SYS_RST, 1); 71 WDOG_WRITE(sc, WDOG_SYS_CTL, WDOG_SYS_CTL_ENABLE); 72 WDOG_WRITE(sc, WDOG_SYS_TMR, 0); 73 } 74 75 static struct fdtbus_power_controller_func apple_wdog_power_funcs = { 76 .reset = apple_wdog_reset, 77 }; 78 79 static int 80 apple_wdog_match(device_t parent, cfdata_t cf, void *aux) 81 { 82 struct fdt_attach_args * const faa = aux; 83 84 return of_compatible_match(faa->faa_phandle, compat_data); 85 } 86 87 static void 88 apple_wdog_attach(device_t parent, device_t self, void *aux) 89 { 90 struct apple_wdog_softc * const sc = device_private(self); 91 struct fdt_attach_args * const faa = aux; 92 const int phandle = faa->faa_phandle; 93 bus_addr_t addr; 94 bus_size_t size; 95 96 if (fdtbus_get_reg(phandle, 0, &addr, &size) != 0) { 97 aprint_error(": couldn't get registers\n"); 98 return; 99 } 100 101 sc->sc_dev = self; 102 sc->sc_bst = faa->faa_bst; 103 if (bus_space_map(sc->sc_bst, addr, size, 0, &sc->sc_bsh) != 0) { 104 aprint_error(": couldn't map registers\n"); 105 return; 106 } 107 108 aprint_naive("\n"); 109 aprint_normal(": Apple Watchdog\n"); 110 111 WDOG_WRITE(sc, WDOG_CHIP_CTL, 0); 112 WDOG_WRITE(sc, WDOG_SYS_CTL, 0); 113 114 fdtbus_register_power_controller(self, phandle, 115 &apple_wdog_power_funcs); 116 } 117 118 CFATTACH_DECL_NEW(apple_wdog, sizeof(struct apple_wdog_softc), 119 apple_wdog_match, apple_wdog_attach, NULL, NULL); 120