diff options
Diffstat (limited to 'sys/dev/ichwd/i6300esbwd.c')
| -rw-r--r-- | sys/dev/ichwd/i6300esbwd.c | 245 |
1 files changed, 245 insertions, 0 deletions
diff --git a/sys/dev/ichwd/i6300esbwd.c b/sys/dev/ichwd/i6300esbwd.c new file mode 100644 index 000000000000..03d504a350aa --- /dev/null +++ b/sys/dev/ichwd/i6300esbwd.c @@ -0,0 +1,245 @@ +/* + * Copyright (c) 2025 The FreeBSD Foundation + * + * SPDX-License-Identifier: BSD-2-Clause + */ + +/* + * Reference: Intel 6300ESB Controller Hub Datasheet Section 16 + */ + +#include <sys/param.h> +#include <sys/eventhandler.h> +#include <sys/kernel.h> +#include <sys/module.h> +#include <sys/sysctl.h> +#include <sys/errno.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 <dev/pci/pcireg.h> + +#include <dev/ichwd/ichwd.h> +#include <dev/ichwd/i6300esbwd.h> + +#include <x86/pci_cfgreg.h> +#include <dev/pci/pcivar.h> +#include <dev/pci/pci_private.h> + +struct i6300esbwd_softc { + device_t dev; + int res_id; + struct resource *res; + eventhandler_tag ev_tag; + bool locked; +}; + +static const struct i6300esbwd_pci_id { + uint16_t id; + const char *name; +} i6300esbwd_pci_devices[] = { + { DEVICEID_6300ESB_2, "6300ESB Watchdog Timer" }, +}; + +static uint16_t __unused +i6300esbwd_cfg_read(struct i6300esbwd_softc *sc) +{ + return (pci_read_config(sc->dev, WDT_CONFIG_REG, 2)); +} + +static void +i6300esbwd_cfg_write(struct i6300esbwd_softc *sc, uint16_t val) +{ + pci_write_config(sc->dev, WDT_CONFIG_REG, val, 2); +} + +static uint8_t +i6300esbwd_lock_read(struct i6300esbwd_softc *sc) +{ + return (pci_read_config(sc->dev, WDT_LOCK_REG, 1)); +} + +static void +i6300esbwd_lock_write(struct i6300esbwd_softc *sc, uint8_t val) +{ + pci_write_config(sc->dev, WDT_LOCK_REG, val, 1); +} + +/* + * According to Intel 6300ESB I/O Controller Hub Datasheet 16.5.2, + * the resource should be unlocked before modifing any registers. + * The way to unlock is by write 0x80, 0x86 to the reload register. + */ +static void +i6300esbwd_unlock_res(struct i6300esbwd_softc *sc) +{ + bus_write_2(sc->res, WDT_RELOAD_REG, WDT_UNLOCK_SEQ_1_VAL); + bus_write_2(sc->res, WDT_RELOAD_REG, WDT_UNLOCK_SEQ_2_VAL); +} + +static int +i6300esbwd_sysctl_locked(SYSCTL_HANDLER_ARGS) +{ + struct i6300esbwd_softc *sc = (struct i6300esbwd_softc *)arg1; + int error; + int result; + + result = sc->locked; + error = sysctl_handle_int(oidp, &result, 0, req); + + if (error || !req->newptr) + return (error); + + if (result == 1 && !sc->locked) { + i6300esbwd_lock_write(sc, i6300esbwd_lock_read(sc) | WDT_LOCK); + sc->locked = true; + } + + return (0); +} + +static void +i6300esbwd_event(void *arg, unsigned int cmd, int *error) +{ + struct i6300esbwd_softc *sc = arg; + uint32_t timeout; + uint16_t regval; + + cmd &= WD_INTERVAL; + if (cmd != 0 && + (cmd < WD_TO_1MS || (cmd - WD_TO_1MS) >= WDT_PRELOAD_BIT)) { + *error = EINVAL; + return; + } + timeout = 1 << (cmd - WD_TO_1MS); + + /* reset the timer to prevent timeout a timeout is about to occur */ + i6300esbwd_unlock_res(sc); + bus_write_2(sc->res, WDT_RELOAD_REG, WDT_RELOAD); + + if (!cmd) { + /* + * when the lock is enabled, we are unable to overwrite LOCK + * register + */ + if (sc->locked) + *error = EPERM; + else + i6300esbwd_lock_write(sc, + i6300esbwd_lock_read(sc) & ~WDT_ENABLE); + return; + } + + i6300esbwd_unlock_res(sc); + bus_write_4(sc->res, WDT_PRELOAD_1_REG, timeout); + + i6300esbwd_unlock_res(sc); + bus_write_4(sc->res, WDT_PRELOAD_2_REG, timeout); + + i6300esbwd_unlock_res(sc); + bus_write_2(sc->res, WDT_RELOAD_REG, WDT_RELOAD); + + if (!sc->locked) { + i6300esbwd_lock_write(sc, WDT_ENABLE); + regval = i6300esbwd_lock_read(sc); + sc->locked = regval & WDT_LOCK; + } +} + +static int +i6300esbwd_probe(device_t dev) +{ + const struct i6300esbwd_pci_id *pci_id; + uint16_t pci_dev_id; + int err = ENXIO; + + if (pci_get_vendor(dev) != VENDORID_INTEL) + goto end; + + pci_dev_id = pci_get_device(dev); + for (pci_id = i6300esbwd_pci_devices; + pci_id < i6300esbwd_pci_devices + nitems(i6300esbwd_pci_devices); + ++pci_id) { + if (pci_id->id == pci_dev_id) { + device_set_desc(dev, pci_id->name); + err = BUS_PROBE_DEFAULT; + break; + } + } + +end: + return (err); +} + +static int +i6300esbwd_attach(device_t dev) +{ + struct i6300esbwd_softc *sc = device_get_softc(dev); + uint16_t regval; + + sc->dev = dev; + sc->res_id = PCIR_BAR(0); + sc->res = bus_alloc_resource_any(dev, SYS_RES_MEMORY, &sc->res_id, + RF_ACTIVE); + if (sc->res == NULL) { + device_printf(dev, "unable to map memory region\n"); + return (ENXIO); + } + + i6300esbwd_cfg_write(sc, WDT_INT_TYPE_DISABLED_VAL); + regval = i6300esbwd_lock_read(sc); + if (regval & WDT_LOCK) + sc->locked = true; + else { + sc->locked = false; + i6300esbwd_lock_write(sc, WDT_TOUT_CNF_WT_MODE); + } + + i6300esbwd_unlock_res(sc); + bus_write_2(sc->res, WDT_RELOAD_REG, WDT_RELOAD | WDT_TIMEOUT); + + sc->ev_tag = EVENTHANDLER_REGISTER(watchdog_list, i6300esbwd_event, sc, + 0); + + SYSCTL_ADD_PROC(device_get_sysctl_ctx(dev), + SYSCTL_CHILDREN(device_get_sysctl_tree(dev)), OID_AUTO, "locked", + CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_NEEDGIANT, sc, 0, + i6300esbwd_sysctl_locked, "I", + "Lock the timer so that we cannot disable it"); + + return (0); +} + +static int +i6300esbwd_detach(device_t dev) +{ + struct i6300esbwd_softc *sc = device_get_softc(dev); + + if (sc->ev_tag) + EVENTHANDLER_DEREGISTER(watchdog_list, sc->ev_tag); + + if (sc->res) + bus_release_resource(dev, SYS_RES_MEMORY, sc->res_id, sc->res); + + return (0); +} + +static device_method_t i6300esbwd_methods[] = { + DEVMETHOD(device_probe, i6300esbwd_probe), + DEVMETHOD(device_attach, i6300esbwd_attach), + DEVMETHOD(device_detach, i6300esbwd_detach), + DEVMETHOD(device_shutdown, i6300esbwd_detach), + DEVMETHOD_END +}; + +static driver_t i6300esbwd_driver = { + "i6300esbwd", + i6300esbwd_methods, + sizeof(struct i6300esbwd_softc), +}; + +DRIVER_MODULE(i6300esbwd, pci, i6300esbwd_driver, NULL, NULL); |