1 /* $OpenBSD: wdt.c,v 1.21 2012/10/17 22:32:01 deraadt Exp $ */ 2 3 /*- 4 * Copyright (c) 1998,1999 Alex Nash 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 AND CONTRIBUTORS ``AS IS'' AND 17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24 * LIABILITY, 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 30 #include <sys/types.h> 31 #include <sys/param.h> 32 #include <sys/device.h> 33 #include <sys/kernel.h> 34 #include <sys/systm.h> 35 36 #include <machine/bus.h> 37 38 #include <dev/pci/pcivar.h> 39 #include <dev/pci/pcireg.h> 40 #include <dev/pci/pcidevs.h> 41 42 struct wdt_softc { 43 /* wdt_dev must be the first item in the struct */ 44 struct device sc_dev; 45 46 /* feature set: 0 = none 1 = temp, buzzer, etc. */ 47 int sc_features; 48 49 /* device access through bus space */ 50 bus_space_tag_t sc_iot; 51 bus_space_handle_t sc_ioh; 52 }; 53 54 int wdt_probe(struct device *, void *, void *); 55 void wdt_attach(struct device *, struct device *, void *); 56 57 int wdt_is501(struct wdt_softc *); 58 void wdt_8254_count(struct wdt_softc *, int, u_int16_t); 59 void wdt_8254_mode(struct wdt_softc *, int, int); 60 int wdt_set_timeout(void *, int); 61 void wdt_init_timer(struct wdt_softc *); 62 void wdt_buzzer_off(struct wdt_softc *); 63 void wdt_timer_disable(struct wdt_softc *); 64 void wdt_buzzer_enable(struct wdt_softc *); 65 66 struct cfattach wdt_ca = { 67 sizeof(struct wdt_softc), wdt_probe, wdt_attach 68 }; 69 70 struct cfdriver wdt_cd = { 71 NULL, "wdt", DV_DULL 72 }; 73 74 const struct pci_matchid wdt_devices[] = { 75 { PCI_VENDOR_INDCOMPSRC, PCI_PRODUCT_INDCOMPSRC_WDT50x } 76 }; 77 78 /* 79 * 8254 counter mappings 80 */ 81 #define WDT_8254_TC_LO 0 /* low 16 bits of timeout counter */ 82 #define WDT_8254_TC_HI 1 /* high 16 bits of timeout counter */ 83 #define WDT_8254_BUZZER 2 84 85 /* 86 * WDT500/501 ports 87 */ 88 #define WDT_8254_BASE 0 89 #define WDT_8254_CTL (WDT_8254_BASE + 3) 90 #define WDT_DISABLE_TIMER 7 91 #define WDT_ENABLE_TIMER 7 92 93 /* 94 * WDT501 specific ports 95 */ 96 #define WDT_STATUS_REG 4 97 #define WDT_START_BUZZER 4 98 #define WDT_TEMPERATURE 5 99 #define WDT_STOP_BUZZER 5 100 101 int 102 wdt_probe(struct device *parent, void *match, void *aux) 103 { 104 return (pci_matchbyid((struct pci_attach_args *)aux, wdt_devices, 105 nitems(wdt_devices))); 106 } 107 108 void 109 wdt_attach(struct device *parent, struct device *self, void *aux) 110 { 111 struct wdt_softc *wdt = (struct wdt_softc *)self; 112 struct pci_attach_args *const pa = (struct pci_attach_args *)aux; 113 bus_size_t iosize; 114 115 /* retrieve the I/O region (BAR2) */ 116 if (pci_mapreg_map(pa, 0x18, PCI_MAPREG_TYPE_IO, 0, 117 &wdt->sc_iot, &wdt->sc_ioh, NULL, &iosize, 0) != 0) { 118 printf("%s: couldn't find PCI I/O region\n", 119 wdt->sc_dev.dv_xname); 120 return; 121 } 122 123 /* sanity check I/O size */ 124 if (iosize != (bus_size_t)16) { 125 printf("%s: invalid I/O region size\n", 126 wdt->sc_dev.dv_xname); 127 return; 128 } 129 130 /* initialize the watchdog timer structure */ 131 132 /* check the feature set available */ 133 if (wdt_is501(wdt)) 134 wdt->sc_features = 1; 135 else 136 wdt->sc_features = 0; 137 138 if (wdt->sc_features) { 139 /* 140 * turn off the buzzer, it may have been activated 141 * by a previous timeout 142 */ 143 wdt_buzzer_off(wdt); 144 145 wdt_buzzer_enable(wdt); 146 } 147 148 /* initialize the timer modes and the lower 16-bit counter */ 149 wdt_init_timer(wdt); 150 151 /* 152 * ensure that the watchdog is disabled 153 */ 154 wdt_timer_disable(wdt); 155 156 /* 157 * register with the watchdog framework 158 */ 159 wdog_register(wdt_set_timeout, wdt); 160 } 161 162 /* 163 * wdt_is501 164 * 165 * Returns non-zero if the card is a 501 model. 166 */ 167 int 168 wdt_is501(struct wdt_softc *wdt) 169 { 170 /* 171 * It makes too much sense to detect the card type 172 * by the device ID, so we have to resort to testing 173 * the presence of a register to determine the type. 174 */ 175 int v = bus_space_read_1(wdt->sc_iot, wdt->sc_ioh, WDT_TEMPERATURE); 176 177 /* XXX may not be reliable */ 178 if (v == 0 || v == 0xFF) 179 return(0); 180 181 return(1); 182 } 183 184 /* 185 * wdt_8254_count 186 * 187 * Loads the specified counter with the 16-bit value 'v'. 188 */ 189 void 190 wdt_8254_count(struct wdt_softc *wdt, int counter, u_int16_t v) 191 { 192 bus_space_write_1(wdt->sc_iot, wdt->sc_ioh, 193 WDT_8254_BASE + counter, v & 0xFF); 194 bus_space_write_1(wdt->sc_iot, wdt->sc_ioh, WDT_8254_BASE + counter, v >> 8); 195 } 196 197 /* 198 * wdt_8254_mode 199 * 200 * Sets the mode of the specified counter. 201 */ 202 void 203 wdt_8254_mode(struct wdt_softc *wdt, int counter, int mode) 204 { 205 bus_space_write_1(wdt->sc_iot, wdt->sc_ioh, WDT_8254_CTL, 206 (counter << 6) | 0x30 | (mode << 1)); 207 } 208 209 /* 210 * wdt_set_timeout 211 * 212 * Load the watchdog timer with the specified number of seconds. 213 * Clamp seconds to be in the interval [2; 1800]. 214 */ 215 int 216 wdt_set_timeout(void *self, int seconds) 217 { 218 struct wdt_softc *wdt = (struct wdt_softc *)self; 219 220 u_int16_t v; 221 int s; 222 223 s = splclock(); 224 225 wdt_timer_disable(wdt); 226 227 if (seconds == 0) { 228 splx(s); 229 return (0); 230 } else if (seconds < 2) 231 seconds = 2; 232 else if (seconds > 1800) 233 seconds = 1800; 234 235 /* 8254 has been programmed with a 2ms period */ 236 v = (u_int16_t)seconds * 50; 237 238 /* load the new timeout count */ 239 wdt_8254_count(wdt, WDT_8254_TC_HI, v); 240 241 /* enable the timer */ 242 bus_space_write_1(wdt->sc_iot, wdt->sc_ioh, WDT_ENABLE_TIMER, 0); 243 244 splx(s); 245 246 return (seconds); 247 } 248 249 /* 250 * wdt_timer_disable 251 * 252 * Disables the watchdog timer and cancels the scheduled (if any) 253 * kernel timeout. 254 */ 255 void 256 wdt_timer_disable(struct wdt_softc *wdt) 257 { 258 (void)bus_space_read_1(wdt->sc_iot, wdt->sc_ioh, WDT_DISABLE_TIMER); 259 } 260 261 /* 262 * wdt_init_timer 263 * 264 * Configure the modes for the watchdog counters and initialize 265 * the low 16-bits of the watchdog counter to have a period of 266 * approximately 1/50th of a second. 267 */ 268 void 269 wdt_init_timer(struct wdt_softc *wdt) 270 { 271 wdt_8254_mode(wdt, WDT_8254_TC_LO, 3); 272 wdt_8254_mode(wdt, WDT_8254_TC_HI, 2); 273 wdt_8254_count(wdt, WDT_8254_TC_LO, 41666); 274 } 275 276 /******************************************************************* 277 * WDT501 specific functions 278 *******************************************************************/ 279 280 /* 281 * wdt_buzzer_off 282 * 283 * Turns the buzzer off. 284 */ 285 void 286 wdt_buzzer_off(struct wdt_softc *wdt) 287 { 288 bus_space_write_1(wdt->sc_iot, wdt->sc_ioh, WDT_STOP_BUZZER, 0); 289 } 290 291 #ifndef WDT_DISABLE_BUZZER 292 /* 293 * wdt_buzzer_enable 294 * 295 * Enables the buzzer when the watchdog counter expires. 296 */ 297 void 298 wdt_buzzer_enable(struct wdt_softc *wdt) 299 { 300 bus_space_write_1(wdt->sc_iot, wdt->sc_ioh, WDT_8254_BUZZER, 1); 301 wdt_8254_mode(wdt, WDT_8254_BUZZER, 1); 302 } 303 #else 304 /* 305 * wdt_buzzer_disable 306 * 307 * Disables the buzzer from sounding when the watchdog counter 308 * expires. 309 */ 310 void 311 wdt_buzzer_disable(struct wdt_softc *wdt) 312 { 313 wdt_8254_mode(wdt, WDT_8254_BUZZER, 0); 314 } 315 #endif 316