Annotation of sys/dev/pci/wdt.c, Revision 1.1
1.1 ! nbrk 1: /* $OpenBSD: wdt.c,v 1.16 2007/08/14 07:16:26 mk 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/proc.h>
! 35: #include <sys/systm.h>
! 36:
! 37: #include <machine/bus.h>
! 38:
! 39: #include <dev/pci/pcivar.h>
! 40: #include <dev/pci/pcireg.h>
! 41: #include <dev/pci/pcidevs.h>
! 42:
! 43: #include <dev/pci/wdt50x.h>
! 44:
! 45: struct wdt_softc {
! 46: /* wdt_dev must be the first item in the struct */
! 47: struct device wdt_dev;
! 48:
! 49: /* feature set: 0 = none 1 = temp, buzzer, etc. */
! 50: int features;
! 51:
! 52: /* device access through bus space */
! 53: bus_space_tag_t iot;
! 54: bus_space_handle_t ioh;
! 55: };
! 56:
! 57: int wdtprobe(struct device *, void *, void *);
! 58: void wdtattach(struct device *, struct device *, void *);
! 59:
! 60: int wdt_is501(struct wdt_softc *);
! 61: void wdt_8254_count(struct wdt_softc *, int, u_int16_t);
! 62: void wdt_8254_mode(struct wdt_softc *, int, int);
! 63: int wdt_set_timeout(void *, int);
! 64: void wdt_init_timer(struct wdt_softc *);
! 65: void wdt_buzzer_off(struct wdt_softc *);
! 66: void wdt_timer_disable(struct wdt_softc *);
! 67: void wdt_buzzer_enable(struct wdt_softc *);
! 68:
! 69: struct cfattach wdt_ca = {
! 70: sizeof(struct wdt_softc), wdtprobe, wdtattach
! 71: };
! 72:
! 73: struct cfdriver wdt_cd = {
! 74: NULL, "wdt", DV_DULL
! 75: };
! 76:
! 77: const struct pci_matchid wdt_devices[] = {
! 78: { PCI_VENDOR_INDCOMPSRC, PCI_PRODUCT_INDCOMPSRC_WDT50x }
! 79: };
! 80:
! 81: /*
! 82: * 8254 counter mappings
! 83: */
! 84: #define WDT_8254_TC_LO 0 /* low 16 bits of timeout counter */
! 85: #define WDT_8254_TC_HI 1 /* high 16 bits of timeout counter */
! 86: #define WDT_8254_BUZZER 2
! 87:
! 88: /*
! 89: * WDT500/501 ports
! 90: */
! 91: #define WDT_8254_BASE 0
! 92: #define WDT_8254_CTL (WDT_8254_BASE + 3)
! 93: #define WDT_DISABLE_TIMER 7
! 94: #define WDT_ENABLE_TIMER 7
! 95:
! 96: /*
! 97: * WDT501 specific ports
! 98: */
! 99: #define WDT_STATUS_REG 4
! 100: #define WDT_START_BUZZER 4
! 101: #define WDT_TEMPERATURE 5
! 102: #define WDT_STOP_BUZZER 5
! 103:
! 104: int
! 105: wdtprobe(struct device *parent, void *match, void *aux)
! 106: {
! 107: return (pci_matchbyid((struct pci_attach_args *)aux, wdt_devices,
! 108: sizeof(wdt_devices)/sizeof(wdt_devices[0])));
! 109: }
! 110:
! 111: void
! 112: wdtattach(struct device *parent, struct device *self, void *aux)
! 113: {
! 114: struct wdt_softc *wdt = (struct wdt_softc *)self;
! 115: struct pci_attach_args *const pa = (struct pci_attach_args *)aux;
! 116: bus_size_t iosize;
! 117:
! 118: /* retrieve the I/O region (BAR2) */
! 119: if (pci_mapreg_map(pa, 0x18, PCI_MAPREG_TYPE_IO, 0,
! 120: &wdt->iot, &wdt->ioh, NULL, &iosize, 0) != 0) {
! 121: printf("%s: couldn't find PCI I/O region\n",
! 122: wdt->wdt_dev.dv_xname);
! 123: return;
! 124: }
! 125:
! 126: /* sanity check I/O size */
! 127: if (iosize != (bus_size_t)16) {
! 128: printf("%s: invalid I/O region size\n",
! 129: wdt->wdt_dev.dv_xname);
! 130: return;
! 131: }
! 132:
! 133: /* initialize the watchdog timer structure */
! 134:
! 135: /* check the feature set available */
! 136: if (wdt_is501(wdt))
! 137: wdt->features = 1;
! 138: else
! 139: wdt->features = 0;
! 140:
! 141: if (wdt->features) {
! 142: /*
! 143: * turn off the buzzer, it may have been activated
! 144: * by a previous timeout
! 145: */
! 146: wdt_buzzer_off(wdt);
! 147:
! 148: wdt_buzzer_enable(wdt);
! 149: }
! 150:
! 151: /* initialize the timer modes and the lower 16-bit counter */
! 152: wdt_init_timer(wdt);
! 153:
! 154: /*
! 155: * ensure that the watchdog is disabled
! 156: */
! 157: wdt_timer_disable(wdt);
! 158:
! 159: /*
! 160: * register with the watchdog framework
! 161: */
! 162: wdog_register(wdt, wdt_set_timeout);
! 163: }
! 164:
! 165: /*
! 166: * wdt_is501
! 167: *
! 168: * Returns non-zero if the card is a 501 model.
! 169: */
! 170: int
! 171: wdt_is501(struct wdt_softc *wdt)
! 172: {
! 173: /*
! 174: * It makes too much sense to detect the card type
! 175: * by the device ID, so we have to resort to testing
! 176: * the presence of a register to determine the type.
! 177: */
! 178: int v = bus_space_read_1(wdt->iot, wdt->ioh, WDT_TEMPERATURE);
! 179:
! 180: /* XXX may not be reliable */
! 181: if (v == 0 || v == 0xFF)
! 182: return(0);
! 183:
! 184: return(1);
! 185: }
! 186:
! 187: /*
! 188: * wdt_8254_count
! 189: *
! 190: * Loads the specified counter with the 16-bit value 'v'.
! 191: */
! 192: void
! 193: wdt_8254_count(struct wdt_softc *wdt, int counter, u_int16_t v)
! 194: {
! 195: bus_space_write_1(wdt->iot, wdt->ioh,
! 196: WDT_8254_BASE + counter, v & 0xFF);
! 197: bus_space_write_1(wdt->iot, wdt->ioh, WDT_8254_BASE + counter, v >> 8);
! 198: }
! 199:
! 200: /*
! 201: * wdt_8254_mode
! 202: *
! 203: * Sets the mode of the specified counter.
! 204: */
! 205: void
! 206: wdt_8254_mode(struct wdt_softc *wdt, int counter, int mode)
! 207: {
! 208: bus_space_write_1(wdt->iot, wdt->ioh, WDT_8254_CTL,
! 209: (counter << 6) | 0x30 | (mode << 1));
! 210: }
! 211:
! 212: /*
! 213: * wdt_set_timeout
! 214: *
! 215: * Load the watchdog timer with the specified number of seconds.
! 216: * Clamp seconds to be in the interval [2; 1800].
! 217: */
! 218: int
! 219: wdt_set_timeout(void *self, int seconds)
! 220: {
! 221: struct wdt_softc *wdt = (struct wdt_softc *)self;
! 222:
! 223: u_int16_t v;
! 224: int s;
! 225:
! 226: s = splclock();
! 227:
! 228: wdt_timer_disable(wdt);
! 229:
! 230: if (seconds == 0) {
! 231: splx(s);
! 232: return (0);
! 233: } else if (seconds < 2)
! 234: seconds = 2;
! 235: else if (seconds > 1800)
! 236: seconds = 1800;
! 237:
! 238: /* 8254 has been programmed with a 2ms period */
! 239: v = (u_int16_t)seconds * 50;
! 240:
! 241: /* load the new timeout count */
! 242: wdt_8254_count(wdt, WDT_8254_TC_HI, v);
! 243:
! 244: /* enable the timer */
! 245: bus_space_write_1(wdt->iot, wdt->ioh, WDT_ENABLE_TIMER, 0);
! 246:
! 247: splx(s);
! 248:
! 249: return (seconds);
! 250: }
! 251:
! 252: /*
! 253: * wdt_timer_disable
! 254: *
! 255: * Disables the watchdog timer and cancels the scheduled (if any)
! 256: * kernel timeout.
! 257: */
! 258: void
! 259: wdt_timer_disable(struct wdt_softc *wdt)
! 260: {
! 261: (void)bus_space_read_1(wdt->iot, wdt->ioh, WDT_DISABLE_TIMER);
! 262: }
! 263:
! 264: /*
! 265: * wdt_init_timer
! 266: *
! 267: * Configure the modes for the watchdog counters and initialize
! 268: * the low 16-bits of the watchdog counter to have a period of
! 269: * approximately 1/50th of a second.
! 270: */
! 271: void
! 272: wdt_init_timer(struct wdt_softc *wdt)
! 273: {
! 274: wdt_8254_mode(wdt, WDT_8254_TC_LO, 3);
! 275: wdt_8254_mode(wdt, WDT_8254_TC_HI, 2);
! 276: wdt_8254_count(wdt, WDT_8254_TC_LO, 41666);
! 277: }
! 278:
! 279: /*******************************************************************
! 280: * WDT501 specific functions
! 281: *******************************************************************/
! 282:
! 283: /*
! 284: * wdt_buzzer_off
! 285: *
! 286: * Turns the buzzer off.
! 287: */
! 288: void
! 289: wdt_buzzer_off(struct wdt_softc *wdt)
! 290: {
! 291: bus_space_write_1(wdt->iot, wdt->ioh, WDT_STOP_BUZZER, 0);
! 292: }
! 293:
! 294: #ifndef WDT_DISABLE_BUZZER
! 295: /*
! 296: * wdt_buzzer_enable
! 297: *
! 298: * Enables the buzzer when the watchdog counter expires.
! 299: */
! 300: void
! 301: wdt_buzzer_enable(struct wdt_softc *wdt)
! 302: {
! 303: bus_space_write_1(wdt->iot, wdt->ioh, WDT_8254_BUZZER, 1);
! 304: wdt_8254_mode(wdt, WDT_8254_BUZZER, 1);
! 305: }
! 306: #else
! 307: /*
! 308: * wdt_buzzer_disable
! 309: *
! 310: * Disables the buzzer from sounding when the watchdog counter
! 311: * expires.
! 312: */
! 313: void
! 314: wdt_buzzer_disable(struct wdt_softc *wdt)
! 315: {
! 316: wdt_8254_mode(wdt, WDT_8254_BUZZER, 0);
! 317: }
! 318: #endif
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