freebsd-skq/sys/dev/viawd/viawd.c

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/*-
2011-12-22 15:13:32 +00:00
* Copyright (c) 2011 Fabien Thomas <fabient@FreeBSD.org>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/kernel.h>
#include <sys/module.h>
#include <sys/systm.h>
#include <sys/bus.h>
#include <machine/bus.h>
#include <sys/rman.h>
#include <machine/resource.h>
#include <sys/watchdog.h>
#include <isa/isavar.h>
#include <dev/pci/pcivar.h>
#include "viawd.h"
#define viawd_read_4(sc, off) bus_read_4((sc)->wd_res, (off))
#define viawd_write_4(sc, off, val) \
bus_write_4((sc)->wd_res, (off), (val))
static struct viawd_device viawd_devices[] = {
{ DEVICEID_VT8251, "VIA VT8251 watchdog timer" },
{ DEVICEID_CX700, "VIA CX700 watchdog timer" },
{ DEVICEID_VX800, "VIA VX800 watchdog timer" },
{ DEVICEID_VX855, "VIA VX855 watchdog timer" },
{ DEVICEID_VX900, "VIA VX900 watchdog timer" },
{ 0, NULL },
};
static devclass_t viawd_devclass;
static void
viawd_tmr_state(struct viawd_softc *sc, int enable)
{
uint32_t reg;
reg = viawd_read_4(sc, VIAWD_MEM_CTRL);
if (enable)
reg |= VIAWD_MEM_CTRL_TRIGGER | VIAWD_MEM_CTRL_ENABLE;
else
reg &= ~VIAWD_MEM_CTRL_ENABLE;
viawd_write_4(sc, VIAWD_MEM_CTRL, reg);
}
static void
viawd_tmr_set(struct viawd_softc *sc, unsigned int timeout)
{
/* Keep value in range. */
if (timeout < VIAWD_MEM_COUNT_MIN)
timeout = VIAWD_MEM_COUNT_MIN;
else if (timeout > VIAWD_MEM_COUNT_MAX)
timeout = VIAWD_MEM_COUNT_MAX;
viawd_write_4(sc, VIAWD_MEM_COUNT, timeout);
sc->timeout = timeout;
}
/*
* Watchdog event handler - called by the framework to enable or disable
* the watchdog or change the initial timeout value.
*/
static void
viawd_event(void *arg, unsigned int cmd, int *error)
{
struct viawd_softc *sc = arg;
unsigned int timeout;
/* Convert from power-of-two-ns to second. */
cmd &= WD_INTERVAL;
timeout = ((uint64_t)1 << cmd) / 1000000000;
if (cmd) {
if (timeout != sc->timeout)
viawd_tmr_set(sc, timeout);
viawd_tmr_state(sc, 1);
*error = 0;
} else
viawd_tmr_state(sc, 0);
}
/* Look for a supported VIA south bridge. */
static struct viawd_device *
viawd_find(device_t dev)
{
struct viawd_device *id;
if (pci_get_vendor(dev) != VENDORID_VIA)
return (NULL);
for (id = viawd_devices; id->desc != NULL; id++)
if (pci_get_device(dev) == id->device)
return (id);
return (NULL);
}
static void
viawd_identify(driver_t *driver, device_t parent)
{
if (viawd_find(parent) == NULL)
return;
if (device_find_child(parent, driver->name, -1) == NULL)
BUS_ADD_CHILD(parent, 0, driver->name, 0);
}
static int
viawd_probe(device_t dev)
{
struct viawd_device *id;
id = viawd_find(device_get_parent(dev));
KASSERT(id != NULL, ("parent should be a valid VIA SB"));
device_set_desc(dev, id->desc);
return (BUS_PROBE_GENERIC);
}
static int
viawd_attach(device_t dev)
{
device_t sb_dev;
struct viawd_softc *sc;
uint32_t pmbase, reg;
sc = device_get_softc(dev);
sc->dev = dev;
sb_dev = device_get_parent(dev);
if (sb_dev == NULL) {
device_printf(dev, "Can not find watchdog device.\n");
goto fail;
}
sc->sb_dev = sb_dev;
/* Get watchdog memory base. */
pmbase = pci_read_config(sb_dev, VIAWD_CONFIG_BASE, 4);
if (pmbase == 0) {
device_printf(dev,
"Watchdog disabled in BIOS or hardware\n");
goto fail;
}
/* Allocate I/O register space. */
sc->wd_rid = VIAWD_CONFIG_BASE;
sc->wd_res = bus_alloc_resource_any(sb_dev, SYS_RES_MEMORY, &sc->wd_rid,
RF_ACTIVE | RF_SHAREABLE);
if (sc->wd_res == NULL) {
device_printf(dev, "Unable to map watchdog memory\n");
goto fail;
}
if (rman_get_size(sc->wd_res) < VIAWD_MEM_LEN) {
device_printf(dev, "Bad size for watchdog memory: %#x\n",
(unsigned)rman_get_size(sc->wd_res));
goto fail;
}
/* Check if watchdog fired last boot. */
reg = viawd_read_4(sc, VIAWD_MEM_CTRL);
if (reg & VIAWD_MEM_CTRL_FIRED) {
device_printf(dev,
"ERROR: watchdog rebooted the system\n");
/* Reset bit state. */
viawd_write_4(sc, VIAWD_MEM_CTRL, reg);
}
/* Register the watchdog event handler. */
sc->ev_tag = EVENTHANDLER_REGISTER(watchdog_list, viawd_event, sc, 0);
return (0);
fail:
if (sc->wd_res != NULL)
bus_release_resource(sb_dev, SYS_RES_MEMORY,
sc->wd_rid, sc->wd_res);
return (ENXIO);
}
static int
viawd_detach(device_t dev)
{
struct viawd_softc *sc;
uint32_t reg;
sc = device_get_softc(dev);
/* Deregister event handler. */
if (sc->ev_tag != NULL)
EVENTHANDLER_DEREGISTER(watchdog_list, sc->ev_tag);
sc->ev_tag = NULL;
/*
* Do not stop the watchdog on shutdown if active but bump the
* timer to avoid spurious reset.
*/
reg = viawd_read_4(sc, VIAWD_MEM_CTRL);
if (reg & VIAWD_MEM_CTRL_ENABLE) {
viawd_tmr_set(sc, VIAWD_TIMEOUT_SHUTDOWN);
viawd_tmr_state(sc, 1);
device_printf(dev,
"Keeping watchog alive during shutdown for %d seconds\n",
VIAWD_TIMEOUT_SHUTDOWN);
}
if (sc->wd_res != NULL)
bus_release_resource(sc->sb_dev, SYS_RES_MEMORY,
sc->wd_rid, sc->wd_res);
return (0);
}
static device_method_t viawd_methods[] = {
DEVMETHOD(device_identify, viawd_identify),
DEVMETHOD(device_probe, viawd_probe),
DEVMETHOD(device_attach, viawd_attach),
DEVMETHOD(device_detach, viawd_detach),
DEVMETHOD(device_shutdown, viawd_detach),
{0,0}
};
static driver_t viawd_driver = {
"viawd",
viawd_methods,
sizeof(struct viawd_softc),
};
DRIVER_MODULE(viawd, isab, viawd_driver, viawd_devclass, NULL, NULL);