1 /* $NetBSD: imxwdog.c,v 1.3 2014/09/25 05:05:28 ryo Exp $ */ 2 3 /* 4 * Copyright (c) 2010 Genetec Corporation. All rights reserved. 5 * Written by Hiroyuki Bessho for Genetec Corporation. 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 GENETEC CORPORATION ``AS IS'' AND 17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 18 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 19 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL GENETEC CORPORATION 20 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 21 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 22 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 23 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 24 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 25 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 26 * POSSIBILITY OF SUCH DAMAGE. 27 */ 28 29 #include <sys/cdefs.h> 30 __KERNEL_RCSID(0, "$NetBSD: imxwdog.c,v 1.3 2014/09/25 05:05:28 ryo Exp $"); 31 32 #include "opt_imx.h" 33 34 #include <sys/param.h> 35 #include <sys/bus.h> 36 #include <sys/cpu.h> 37 #include <sys/device.h> 38 #include <sys/wdog.h> 39 40 #include <prop/proplib.h> 41 42 #include <dev/sysmon/sysmonvar.h> 43 44 #include <arm/imx/imxwdogreg.h> 45 #include <arm/imx/imxwdogvar.h> 46 47 struct wdog_softc { 48 struct sysmon_wdog sc_smw; 49 device_t sc_dev; 50 bus_space_tag_t sc_iot; 51 bus_space_handle_t sc_ioh; 52 53 u_int sc_wdog_max_period; 54 u_int sc_wdog_period; 55 bool sc_wdog_armed; 56 }; 57 58 #ifndef IMXWDOG_PERIOD_DEFAULT 59 #define IMXWDOG_PERIOD_DEFAULT 10 60 #endif 61 62 CFATTACH_DECL_NEW(imxwdog, sizeof(struct wdog_softc), 63 wdog_match, wdog_attach, NULL, NULL); 64 65 static inline uint16_t 66 wdog_read(struct wdog_softc *sc, bus_size_t o) 67 { 68 return bus_space_read_2(sc->sc_iot, sc->sc_ioh, o); 69 } 70 71 static inline void 72 wdog_write(struct wdog_softc *sc, bus_size_t o, uint16_t v) 73 { 74 bus_space_write_2(sc->sc_iot, sc->sc_ioh, o, v); 75 } 76 77 static int 78 wdog_tickle(struct sysmon_wdog *smw) 79 { 80 struct wdog_softc * const sc = smw->smw_cookie; 81 82 wdog_write(sc, IMX_WDOG_WSR, WSR_MAGIC1); 83 wdog_write(sc, IMX_WDOG_WSR, WSR_MAGIC2); 84 85 return 0; 86 } 87 88 static int 89 wdog_setmode(struct sysmon_wdog *smw) 90 { 91 struct wdog_softc * const sc = smw->smw_cookie; 92 uint16_t reg; 93 94 if ((smw->smw_mode & WDOG_MODE_MASK) == WDOG_MODE_DISARMED) { 95 /* this chip do not support wdt disable */ 96 aprint_debug_dev(sc->sc_dev, "setmode disable\n"); 97 return sc->sc_wdog_armed ? EBUSY : 0; 98 } 99 100 /* 101 * If no changes, just tickle it and return. 102 */ 103 if (sc->sc_wdog_armed && smw->smw_period == sc->sc_wdog_period) { 104 wdog_tickle(smw); 105 aprint_debug_dev(sc->sc_dev, "setmode refresh\n"); 106 return 0; 107 } 108 109 /* set default */ 110 if (smw->smw_period == WDOG_PERIOD_DEFAULT) { 111 sc->sc_wdog_period = IMXWDOG_PERIOD_DEFAULT; 112 smw->smw_period = IMXWDOG_PERIOD_DEFAULT; 113 } 114 115 /* 116 * Make sure we don't overflow the counter. 117 */ 118 if (smw->smw_period >= sc->sc_wdog_max_period) 119 return EINVAL; 120 121 sc->sc_wdog_period = smw->smw_period; 122 sc->sc_wdog_armed = true; 123 124 reg = wdog_read(sc, IMX_WDOG_WCR); 125 reg &= ~WCR_WT; 126 reg |= __SHIFTIN(sc->sc_wdog_period * 2 - 1, WCR_WT); 127 reg |= WCR_WDE; 128 wdog_write(sc, IMX_WDOG_WCR, reg); 129 130 return 0; 131 } 132 133 void 134 wdog_attach_common(device_t parent, device_t self, 135 bus_space_tag_t iot, paddr_t addr, size_t size, int irq) 136 { 137 struct wdog_softc *sc = device_private(self); 138 uint16_t reg; 139 140 sc->sc_dev = self; 141 sc->sc_iot = iot; 142 if (bus_space_map(iot, addr, size, 0, &sc->sc_ioh)) { 143 aprint_error_dev(self, "can't map\n"); 144 return; 145 } 146 147 sc->sc_wdog_armed = __SHIFTOUT(wdog_read(sc, IMX_WDOG_WCR), WCR_WDE); 148 /* 149 * Does the config file tell us to turn on the watchdog? 150 */ 151 if (device_cfdata(self)->cf_flags & 1) 152 sc->sc_wdog_armed = true; 153 154 sc->sc_wdog_max_period = 0xff / 2; 155 sc->sc_wdog_period = IMXWDOG_PERIOD_DEFAULT; 156 157 reg = wdog_read(sc, IMX_WDOG_WCR); 158 reg &= ~WCR_WT; 159 reg |= __SHIFTIN(sc->sc_wdog_period * 2 - 1, WCR_WT); 160 wdog_write(sc, IMX_WDOG_WCR, reg); 161 162 aprint_naive("\n"); 163 aprint_normal(": i.MX Watchdog Timer, default period is %u seconds%s\n", 164 sc->sc_wdog_period, 165 sc->sc_wdog_armed ? " (armed)" : ""); 166 167 sc->sc_smw.smw_name = device_xname(self); 168 sc->sc_smw.smw_cookie = sc; 169 sc->sc_smw.smw_setmode = wdog_setmode; 170 sc->sc_smw.smw_tickle = wdog_tickle; 171 sc->sc_smw.smw_period = sc->sc_wdog_period; 172 173 if (sysmon_wdog_register(&sc->sc_smw) != 0) 174 aprint_error_dev(self, "unable to register with sysmon\n"); 175 176 if (sc->sc_wdog_armed) { 177 int error = sysmon_wdog_setmode(&sc->sc_smw, WDOG_MODE_KTICKLE, 178 sc->sc_wdog_period); 179 if (error) 180 aprint_error_dev(self, 181 "failed to start kernel tickler: %d\n", error); 182 else { 183 reg = wdog_read(sc, IMX_WDOG_WCR); 184 reg |= WCR_WDE; 185 wdog_write(sc, IMX_WDOG_WCR, reg); 186 } 187 } 188 } 189