sun4u/io/todblade.c

/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (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 2010 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

#include <sys/types.h>
#include <sys/conf.h>
#include <sys/kmem.h>
#include <sys/open.h>
#include <sys/ddi.h>
#include <sys/sunddi.h>

#include <sys/todm5819.h>
#include <sys/modctl.h>
#include <sys/stat.h>
#include <sys/clock.h>
#include <sys/reboot.h>
#include <sys/machsystm.h>
#include <sys/poll.h>
#include <sys/pbio.h>
#include <sys/lom_priv.h>

#define WDOG_ON 1
#define WDOG_OFF 0

static timestruc_t  todbl_get(void);
static void     todbl_set(timestruc_t);
static uint_t       todbl_set_watchdog_timer(uint_t);
static uint_t       todbl_clear_watchdog_timer(void);
static void     todbl_set_power_alarm(timestruc_t);
static void     todbl_clear_power_alarm(void);
static uint64_t     todbl_get_cpufrequency(void);

static todinfo_t    rtc_to_tod(struct rtc_t *);
static uint_t       read_rtc(struct rtc_t *);
static void     write_rtc_time(struct rtc_t *);
static uint_t       configure_wdog(uint8_t new_state);

extern uint64_t     find_cpufrequency(volatile uint8_t *);

/*
 * External variables
 */
extern int  watchdog_enable;
extern int  watchdog_available;
extern int  watchdog_activated;
extern uint_t   watchdog_timeout_seconds;
extern int  boothowto;
extern void (*bsc_drv_func_ptr)(struct bscv_idi_info *);

/*
 * Global variables
 */
int m5819_debug_flags;
uint8_t wdog_reset_on_timeout = 1;
static clock_t last_pat_lbt;


static struct modlmisc modlmisc = {
    &mod_miscops, "todblade module",
};

static struct modlinkage modlinkage = {
    MODREV_1, &modlmisc, NULL
};


int
_init(void)
{
    if (strcmp(tod_module_name, "todblade") == 0) {
        RTC_PUT8(RTC_B, (RTC_DM | RTC_HM));

        tod_ops.tod_get = todbl_get;
        tod_ops.tod_set = todbl_set;
        tod_ops.tod_set_watchdog_timer = todbl_set_watchdog_timer;
        tod_ops.tod_clear_watchdog_timer = todbl_clear_watchdog_timer;
        tod_ops.tod_set_power_alarm = todbl_set_power_alarm;
        tod_ops.tod_clear_power_alarm = todbl_clear_power_alarm;
        tod_ops.tod_get_cpufrequency = todbl_get_cpufrequency;

        if (watchdog_enable && (boothowto & RB_DEBUG)) {
                watchdog_available = 0;
                cmn_err(CE_WARN, "todblade: kernel debugger "
                    "detected: hardware watchdog disabled");
        }
    }
    return (mod_install(&modlinkage));
}

int
_fini(void)
{
    if (strcmp(tod_module_name, "todblade") == 0) {
        return (EBUSY);
    } else {
        return (mod_remove(&modlinkage));
    }
}

/*
 * The loadable-module _info(9E) entry point
 */
int
_info(struct modinfo *modinfop)
{
    return (mod_info(&modlinkage, modinfop));
}


/*
 * Read the current time from the clock chip and convert to UNIX form.
 * Assumes that the year in the clock chip is valid.
 * Must be called with tod_lock held.
 */
static timestruc_t
todbl_get(void)
{
    int i;
    timestruc_t ts;
    struct rtc_t rtc;
    struct bscv_idi_info bscv_info;

    ASSERT(MUTEX_HELD(&tod_lock));

    /*
     * We must check that the value of watchdog enable hasnt changed
     * as its a user knob for turning it on and off
     */
    if (watchdog_available) {
        if (watchdog_activated && !watchdog_enable) {
            (void) configure_wdog(WDOG_OFF);
        } else if (!watchdog_activated && watchdog_enable) {
            (void) configure_wdog(WDOG_ON);
        } else if (watchdog_activated &&
            (ddi_get_lbolt() - last_pat_lbt) >= SEC_TO_TICK(1)) {
            /*
             * PAT THE WATCHDOG!!
             * We dont want to accelerate the pat frequency
             * when userland calls to the TOD_GET_DATE ioctl
             * pass through here.
             */
            bscv_info.type = BSCV_IDI_WDOG_PAT;
            bscv_info.data = NULL;
            bscv_info.size = 0;
            if (bsc_drv_func_ptr != NULL) {
                (*bsc_drv_func_ptr)(&bscv_info);
                last_pat_lbt = ddi_get_lbolt();
            }
        }
    }

    /*
     * Read from the tod, and if it isnt accessible wait
     * before retrying.
     */
    for (i = 0; i < TODM5819_UIP_RETRY_THRESH; i++) {
        if (read_rtc(&rtc))
            break;
        drv_usecwait(TODM5819_UIP_WAIT_USEC);
    }
    if (i == TODM5819_UIP_RETRY_THRESH) {
        /*
         * We couldn't read from the TOD.
         */
        tod_status_set(TOD_GET_FAILED);
        return (hrestime);
    }

    DPRINTF("todbl_get: century=%d year=%d dom=%d hrs=%d\n",
        rtc.rtc_century, rtc.rtc_year, rtc.rtc_dom, rtc.rtc_hrs);

    /* read was successful so ensure failure flag is clear */
    tod_status_clear(TOD_GET_FAILED);

    ts.tv_sec = tod_to_utc(rtc_to_tod(&rtc));
    ts.tv_nsec = 0;
    return (ts);
}

static todinfo_t
rtc_to_tod(struct rtc_t *rtc)
{
    todinfo_t tod;

    /*
     * tod_year is base 1900 so this code needs to adjust the true
     * year retrieved from the rtc's century and year fields.
     */
    tod.tod_year    = rtc->rtc_year + (rtc->rtc_century * 100) - 1900;
    tod.tod_month   = rtc->rtc_mon;
    tod.tod_day = rtc->rtc_dom;
    tod.tod_dow = rtc->rtc_dow;
    tod.tod_hour    = rtc->rtc_hrs;
    tod.tod_min = rtc->rtc_min;
    tod.tod_sec = rtc->rtc_sec;

    return (tod);
}


static uint_t
read_rtc(struct rtc_t *rtc)
{
    int s;
    uint_t rtc_readable = 0;

    s = splhi();
    /*
     * If UIP bit is not set we have at least 274us
     * to read the values.
     */
    if (!(RTC_GET8(RTC_A) & RTC_UIP)) {
        rtc_readable = 1;

        rtc->rtc_sec = RTC_GET8(RTC_SEC);
        rtc->rtc_asec = RTC_GET8(RTC_ASEC);
        rtc->rtc_min = RTC_GET8(RTC_MIN);
        rtc->rtc_amin = RTC_GET8(RTC_AMIN);

        rtc->rtc_hrs = RTC_GET8(RTC_HRS);
        rtc->rtc_ahrs = RTC_GET8(RTC_AHRS);
        rtc->rtc_dow = RTC_GET8(RTC_DOW);
        rtc->rtc_dom = RTC_GET8(RTC_DOM);
        rtc->rtc_adom = RTC_GET8(RTC_D) & 0x3f;

        rtc->rtc_mon = RTC_GET8(RTC_MON);
        rtc->rtc_year = RTC_GET8(RTC_YEAR);
        rtc->rtc_century = RTC_GET8(RTC_CENTURY);
        rtc->rtc_amon = 0;

        /* Clear wakeup data */
        rtc->apc_wdwr = 0;
        rtc->apc_wdmr = 0;
        rtc->apc_wmr = 0;
        rtc->apc_wyr = 0;
        rtc->apc_wcr = 0;
    }

    splx(s);
    return (rtc_readable);
}

/*
 * Write the specified time into the clock chip.
 * Must be called with tod_lock held.
 */
static void
todbl_set(timestruc_t ts)
{
    struct rtc_t    rtc;
    todinfo_t tod = utc_to_tod(ts.tv_sec);
    struct bscv_idi_info bscv_info;
    int year;

    ASSERT(MUTEX_HELD(&tod_lock));

    /* tod_year is base 1900 so this code needs to adjust */
    year = 1900 + tod.tod_year;
    rtc.rtc_year    = year % 100;
    rtc.rtc_century = year / 100;
    rtc.rtc_mon = (uint8_t)tod.tod_month;
    rtc.rtc_dom = (uint8_t)tod.tod_day;
    rtc.rtc_dow = (uint8_t)tod.tod_dow;
    rtc.rtc_hrs = (uint8_t)tod.tod_hour;
    rtc.rtc_min = (uint8_t)tod.tod_min;
    rtc.rtc_sec = (uint8_t)tod.tod_sec;
    DPRINTF("todbl_set: century=%d year=%d dom=%d hrs=%d\n",
        rtc.rtc_century, rtc.rtc_year, rtc.rtc_dom, rtc.rtc_hrs);

    write_rtc_time(&rtc);

    /*
     * Because of a generic solaris problem where calls to stime()
     * starve calls to tod_get(), we need to check to see when the
     * watchdog was last patted and pat it if necessary.
     */
    if (watchdog_activated &&
        (ddi_get_lbolt() - last_pat_lbt) >= SEC_TO_TICK(1)) {
        /*
         * Pat the watchdog!
         */
        bscv_info.type = BSCV_IDI_WDOG_PAT;
        bscv_info.data = NULL;
        bscv_info.size = 0;
        if (bsc_drv_func_ptr != NULL) {
            (*bsc_drv_func_ptr)(&bscv_info);
            last_pat_lbt = ddi_get_lbolt();
        }
    }
}

static void
write_rtc_time(struct rtc_t *rtc)
{
    uint8_t regb;
    int i;

    /*
     * Freeze
     */
    regb = RTC_GET8(RTC_B);
    RTC_PUT8(RTC_B, (regb | RTC_SET));

    /*
     * If an update is in progress wait for the UIP flag to clear.
     * If we write whilst UIP is still set there is a slight but real
     * possibility of corrupting the RTC date and time registers.
     *
     * The expected wait is one internal cycle of the chip.  We could
     * simply spin but this may hang a CPU if we were to have a broken
     * RTC chip where UIP is stuck, so we use a retry loop instead.
     * No critical section is needed here as the UIP flag will not be
     * re-asserted until we clear RTC_SET.
     */
    for (i = 0; i < TODM5819_UIP_RETRY_THRESH; i++) {
        if (!(RTC_GET8(RTC_A) & RTC_UIP)) {
            break;
        }
        drv_usecwait(TODM5819_UIP_WAIT_USEC);
    }
    if (i < TODM5819_UIP_RETRY_THRESH) {
        RTC_PUT8(RTC_SEC, (rtc->rtc_sec));
        RTC_PUT8(RTC_ASEC, (rtc->rtc_asec));
        RTC_PUT8(RTC_MIN, (rtc->rtc_min));
        RTC_PUT8(RTC_AMIN, (rtc->rtc_amin));

        RTC_PUT8(RTC_HRS, (rtc->rtc_hrs));
        RTC_PUT8(RTC_AHRS, (rtc->rtc_ahrs));
        RTC_PUT8(RTC_DOW, (rtc->rtc_dow));
        RTC_PUT8(RTC_DOM, (rtc->rtc_dom));

        RTC_PUT8(RTC_MON, (rtc->rtc_mon));
        RTC_PUT8(RTC_YEAR, (rtc->rtc_year));
        RTC_PUT8(RTC_CENTURY, (rtc->rtc_century));
    } else {
        cmn_err(CE_WARN, "todblade: Could not write the RTC\n");
    }

    /*
     * Unfreeze
     */
    RTC_PUT8(RTC_B, regb);
}


/*
 * The TOD alarm functionality is not supported on our platform
 * as the interrupt is not wired, so do nothing.
 */
/*ARGSUSED*/
static void
todbl_set_power_alarm(timestruc_t ts)
{
    ASSERT(MUTEX_HELD(&tod_lock));
}

/*
 * clear alarm interrupt
 */
static void
todbl_clear_power_alarm(void)
{
    ASSERT(MUTEX_HELD(&tod_lock));
}

/*
 * Determine the cpu frequency by watching the TOD chip rollover twice.
 * Cpu clock rate is determined by computing the ticks added (in tick register)
 * during one second interval on TOD.
 */
uint64_t
todbl_get_cpufrequency(void)
{
    ASSERT(MUTEX_HELD(&tod_lock));
    M5819_ADDR_REG = RTC_SEC;
    return (find_cpufrequency(v_rtc_data_reg));
}


static uint_t
todbl_set_watchdog_timer(uint_t timeoutval)
{
    /*
     * We get started during kernel intilaisation only
     * if watchdog_enable is set.
     */
    ASSERT(MUTEX_HELD(&tod_lock));

    if (watchdog_available && (!watchdog_activated ||
        (watchdog_activated && (timeoutval != watchdog_timeout_seconds)))) {
        watchdog_timeout_seconds = timeoutval;
        if (configure_wdog(WDOG_ON))
            return (watchdog_timeout_seconds);
    }
    return (0);
}

static uint_t
todbl_clear_watchdog_timer(void)
{
    /*
     * The core kernel will call us here to disable the wdog when:
     * 1. we're panicing
     * 2. we're entering debug
     * 3. we're rebooting
     */
    ASSERT(MUTEX_HELD(&tod_lock));

    if (watchdog_available && watchdog_activated) {
        watchdog_enable = 0;
        if (!configure_wdog(WDOG_OFF))
            return (0);
    }
    return (watchdog_timeout_seconds);
}

static uint_t
configure_wdog(uint8_t new_state)
{
    bscv_wdog_t wdog_cmd;
    struct bscv_idi_info bscv_info;

    if (new_state == WDOG_ON || new_state == WDOG_OFF) {

        wdog_cmd.enable_wdog = new_state;
        wdog_cmd.wdog_timeout_s = watchdog_timeout_seconds;
        wdog_cmd.reset_system_on_timeout = wdog_reset_on_timeout;
        bscv_info.type = BSCV_IDI_WDOG_CFG;
        bscv_info.data = &wdog_cmd;
        bscv_info.size = sizeof (wdog_cmd);

        if (bsc_drv_func_ptr != NULL) {
            watchdog_activated = new_state;
            (*bsc_drv_func_ptr)(&bscv_info);
            return (1);
        }
    }
    return (0);

}