sun4u/io/pmc.c

	pmc.c revision 6c9bfa0b39999e3f2c9448ede1e4cbd8bfaca728
/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License, Version 1.0 only
 * (the "License").  You may not use this file except in compliance
 * with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
/*
 * Copyright 2005 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

#pragma ident   "%Z%%M% %I% %E% SMI"

/*
 * Driver for the Power Management Controller (logical unit 8) of the
 * PC87317 SuperI/O chip. The PMC contains the hardware watchdog timer.
 */

#include <sys/types.h>
#include <sys/time.h>
#include <sys/cmn_err.h>
#include <sys/param.h>
#include <sys/modctl.h>
#include <sys/conf.h>
#include <sys/stat.h>
#include <sys/clock.h>
#include <sys/reboot.h>
#include <sys/ddi.h>
#include <sys/sunddi.h>
#include <sys/file.h>
#include <sys/note.h>

#ifdef  DEBUG
int pmc_debug_flag = 0;
#define DPRINTF(ARGLIST) if (pmc_debug_flag) printf ARGLIST;
#else
#define DPRINTF(ARGLIST)
#endif /* DEBUG */

/* Driver soft state structure */
typedef struct pmc {
    dev_info_t      *dip;
    ddi_acc_handle_t    pmc_handle;
} pmc_t;

static void *pmc_soft_state;
static int instance = -1;

/* dev_ops and cb_ops entry point function declarations */
static int pmc_attach(dev_info_t *, ddi_attach_cmd_t);
static int pmc_detach(dev_info_t *, ddi_detach_cmd_t);
static int pmc_getinfo(dev_info_t *, ddi_info_cmd_t, void *, void **);

/* hardware watchdog parameters */
static uint_t pmc_set_watchdog_timer(uint_t);
static uint_t pmc_clear_watchdog_timer(void);

extern volatile uint8_t *v_pmc_addr_reg;
extern volatile uint8_t *v_pmc_data_reg;
extern int      watchdog_enable;
extern int      watchdog_available;
extern int      watchdog_activated;
extern int      boothowto;
extern uint_t       watchdog_timeout_seconds;

/*
 * Power Management Registers and values
 */
#define PMC_WDTO    0x05    /* Watchdog Time Out */
#define PMC_CLEAR_WDTO  0x00

struct cb_ops pmc_cb_ops = {
    nodev,
    nodev,
    nodev,
    nodev,
    nodev,          /* dump */
    nodev,
    nodev,
    nodev,
    nodev,          /* devmap */
    nodev,
    nodev,
    nochpoll,
    ddi_prop_op,
    NULL,           /* for STREAMS drivers */
    D_NEW | D_MP,       /* driver compatibility flag */
    CB_REV,
    nodev,
    nodev
};

static struct dev_ops pmc_dev_ops = {
    DEVO_REV,           /* driver build version */
    0,              /* device reference count */
    pmc_getinfo,
    nulldev,
    nulldev,            /* probe */
    pmc_attach,
    pmc_detach,
    nulldev,            /* reset */
    &pmc_cb_ops,
    (struct bus_ops *)NULL,
    nulldev             /* power */
};

/* module configuration stuff */
extern struct mod_ops mod_driverops;
static struct modldrv modldrv = {
    &mod_driverops,
    "pmc driver %I%",
    &pmc_dev_ops
};
static struct modlinkage modlinkage = {
    MODREV_1,
    &modldrv,
    0
};


int
_init(void)
{
    int e;

    e = ddi_soft_state_init(&pmc_soft_state, sizeof (pmc_t), 1);
    if (e != 0) {
        DPRINTF(("_init: ddi_soft_state_init failed\n"));
        return (e);
    }

    e = mod_install(&modlinkage);
    if (e != 0) {
        DPRINTF(("_init: mod_install failed\n"));
        ddi_soft_state_fini(&pmc_soft_state);
        return (e);
    }

    if (v_pmc_addr_reg != NULL) {
        tod_ops.tod_set_watchdog_timer = pmc_set_watchdog_timer;
        tod_ops.tod_clear_watchdog_timer = pmc_clear_watchdog_timer;

        /*
         * See if the user has enabled the watchdog timer, and if
         * it's available.
         */
        if (watchdog_enable) {
            if (!watchdog_available) {
                cmn_err(CE_WARN, "pmc: Hardware watchdog "
                    "unavailable");
            } else if (boothowto & RB_DEBUG) {
                watchdog_available = 0;
                cmn_err(CE_WARN, "pmc: kernel debugger "
                    "detected: hardware watchdog disabled");
            }
        }
    }
    return (e);
}

int
_fini(void)
{
    int e;

    if (v_pmc_addr_reg != NULL)
        return (DDI_FAILURE);
    else {
        e = mod_remove(&modlinkage);
        if (e != 0)
            return (e);

        ddi_soft_state_fini(&pmc_soft_state);
        return (DDI_SUCCESS);
    }
}


int
_info(struct modinfo *modinfop)
{
    return (mod_info(&modlinkage, modinfop));
}

static int
pmc_getinfo(dev_info_t *dip, ddi_info_cmd_t cmd, void *arg, void **result)
{
    _NOTE(ARGUNUSED(dip))

    pmc_t   *pmcp;
    int instance;

    switch (cmd) {
    case DDI_INFO_DEVT2DEVINFO:
        instance = getminor((dev_t)arg);
        pmcp = (pmc_t *)ddi_get_soft_state(pmc_soft_state, instance);
        if (pmcp == NULL) {
            *result = (void *)NULL;
            return (DDI_FAILURE);
        }
        *result = (void *)pmcp->dip;
        return (DDI_SUCCESS);

    case DDI_INFO_DEVT2INSTANCE:
        *result = (void *)(uintptr_t)getminor((dev_t)arg);
        return (DDI_SUCCESS);

    default:
        return (DDI_FAILURE);
    }
}


static int
pmc_attach(dev_info_t *dip, ddi_attach_cmd_t cmd)
{
    pmc_t   *pmcp;
    uint_t  wd_timout;

    switch (cmd) {
    case DDI_ATTACH:
        break;
    case DDI_RESUME:
        if (v_pmc_addr_reg != NULL && watchdog_enable) {
            int ret = 0;
            wd_timout = watchdog_timeout_seconds;
            mutex_enter(&tod_lock);
            ret = tod_ops.tod_set_watchdog_timer(wd_timout);
            mutex_exit(&tod_lock);
            if (ret == 0)
                return (DDI_FAILURE);
        }
        return (DDI_SUCCESS);
    default:
        return (DDI_FAILURE);
    }

    if (instance != -1) {
        DPRINTF(("pmc_attach: Another instance is already attached."));
        return (DDI_FAILURE);
    }

    instance = ddi_get_instance(dip);

    if (ddi_soft_state_zalloc(pmc_soft_state, instance) != DDI_SUCCESS) {
        DPRINTF(("pmc_attach: Failed to allocate soft state."));
        return (DDI_FAILURE);
    }

    pmcp = (pmc_t *)ddi_get_soft_state(pmc_soft_state, instance);
    pmcp->dip = dip;

    return (DDI_SUCCESS);
}

static int
pmc_detach(dev_info_t *dip, ddi_detach_cmd_t cmd)
{
    _NOTE(ARGUNUSED(dip))

    pmc_t   *pmcp;

    switch (cmd) {
    case DDI_DETACH:
        /* allow detach if no hardware watchdog */
        if (v_pmc_addr_reg == NULL || !watchdog_activated) {
            pmcp = (pmc_t *)ddi_get_soft_state(pmc_soft_state,
                instance);
            if (pmcp == NULL)
                return (ENXIO);
            ddi_soft_state_free(pmc_soft_state, instance);
            return (DDI_SUCCESS);
        } else
            return (DDI_FAILURE);
    case DDI_SUSPEND:
        if (v_pmc_addr_reg != NULL && watchdog_activated) {
            mutex_enter(&tod_lock);
            (void) tod_ops.tod_clear_watchdog_timer();
            mutex_exit(&tod_lock);
        }
        return (DDI_SUCCESS);
    default:
        return (DDI_FAILURE);
    }

}

/*
 * Set the hardware watchdog timer; returning what we set it to.
 */
static uint_t
pmc_set_watchdog_timer(uint_t timeoutval)
{
    uint_t timeoutval_minutes;
    ASSERT(MUTEX_HELD(&tod_lock));

    /* sanity checks */
    if (watchdog_enable == 0 || watchdog_available == 0 ||
        timeoutval == 0)
        return (0);

    /*
     * Historically the timer has been counted out in seconds.
     * The PC87317 counts the timeout in minutes. The default
     * timeout is 10 seconds; the least we can do is one minute.
     */
    timeoutval_minutes = (timeoutval + 59) / 60;
    if (timeoutval_minutes > UINT8_MAX)
        return (0);

    *v_pmc_addr_reg = (uint8_t)PMC_WDTO;
    *v_pmc_data_reg = (uint8_t)timeoutval_minutes;
    watchdog_activated = 1;

    /* we'll still return seconds */
    return (timeoutval_minutes * 60);
}

/*
 * Clear the hardware watchdog timer; returning what it was set to.
 */
static uint_t
pmc_clear_watchdog_timer(void)
{
    uint_t  wd_timeout;

    ASSERT(MUTEX_HELD(&tod_lock));
    if (watchdog_activated == 0)
        return (0);

    *v_pmc_addr_reg = (uint8_t)PMC_WDTO;
    wd_timeout = (uint_t)*v_pmc_data_reg;
    *v_pmc_data_reg = (uint8_t)PMC_CLEAR_WDTO;
    watchdog_activated = 0;

    /* return seconds */
    return (wd_timeout * 60);
}