/*
 * 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>

static timestruc_t      todm5819_get(void);
static void             todm5819_set(timestruc_t);
static uint_t           todm5819_set_watchdog_timer(uint_t);
static uint_t           todm5819_clear_watchdog_timer(void);
static void             todm5819_set_power_alarm(timestruc_t);
static void             todm5819_clear_power_alarm(void);
static uint64_t         todm5819_get_cpufrequency(void);

extern uint64_t         find_cpufrequency(volatile uint8_t *);

/*
 * External variables
 */
extern int              watchdog_enable;
extern int              watchdog_available;
extern int              boothowto;

/*
 * Global variables
 */
int m5819_debug_flags;

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 void             write_rtc_alarm(struct rtc_t *);


static struct modlmisc modlmisc = {
        &mod_miscops, "tod module for ALI M5819",
};

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


int
_init(void)
{
        if (strcmp(tod_module_name, "todm5819") == 0 ||
            strcmp(tod_module_name, "m5819") == 0) {
                RTC_PUT8(RTC_B, (RTC_DM | RTC_HM));

                tod_ops.tod_get = todm5819_get;
                tod_ops.tod_set = todm5819_set;
                tod_ops.tod_set_watchdog_timer = todm5819_set_watchdog_timer;
                tod_ops.tod_clear_watchdog_timer =
                    todm5819_clear_watchdog_timer;
                tod_ops.tod_set_power_alarm = todm5819_set_power_alarm;
                tod_ops.tod_clear_power_alarm = todm5819_clear_power_alarm;
                tod_ops.tod_get_cpufrequency = todm5819_get_cpufrequency;

                /*
                 * check if hardware watchdog timer is available and user
                 * enabled it.
                 */
                if (watchdog_enable) {
                        if (!watchdog_available) {
                                cmn_err(CE_WARN, "m5819: Hardware watchdog "
                                    "unavailable");
                        } else if (boothowto & RB_DEBUG) {
                                cmn_err(CE_WARN, "m5819: Hardware watchdog "
                                    "disabled [debugger]");
                        }
                }
        }

        return (mod_install(&modlinkage));
}

int
_fini(void)
{
        if (strcmp(tod_module_name, "m5819") == 0 ||
            strcmp(tod_module_name, "todm5819") == 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
todm5819_get(void)
{
        int i;
        timestruc_t ts;
        struct rtc_t rtc;

        ASSERT(MUTEX_HELD(&tod_lock));

        /*
         * 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("todm5819_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);
}

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. Otherwise we have up to
         * 336us to wait before we can read it
         */
        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
todm5819_set(timestruc_t ts)
{
        struct rtc_t    rtc;
        todinfo_t tod = utc_to_tod(ts.tv_sec);
        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("todm5819_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);
}

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, "todm5819: Could not write the RTC\n");
        }

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


void
write_rtc_alarm(struct rtc_t *rtc)
{
        RTC_PUT8(RTC_ASEC, (rtc->rtc_asec));
        RTC_PUT8(RTC_AMIN, (rtc->rtc_amin));
        RTC_PUT8(RTC_AHRS, (rtc->rtc_ahrs));
        RTC_PUT8(RTC_D, (rtc->rtc_adom));
}

/*
 * program the rtc registers for alarm to go off at the specified time
 */
static void
todm5819_set_power_alarm(timestruc_t ts)
{
        todinfo_t       tod;
        uint8_t         regb;
        struct rtc_t    rtc;

        ASSERT(MUTEX_HELD(&tod_lock));
        tod = utc_to_tod(ts.tv_sec);

        /*
         * disable alarms
         */
        regb = RTC_GET8(RTC_B);
        RTC_PUT8(RTC_B, (regb & ~RTC_AIE));


        rtc.rtc_asec = (uint8_t)tod.tod_sec;
        rtc.rtc_amin = (uint8_t)tod.tod_min;
        rtc.rtc_ahrs = (uint8_t)tod.tod_hour;
        rtc.rtc_adom = (uint8_t)tod.tod_day;

        write_rtc_alarm(&rtc);
        /*
         * Enable alarm.
         */
        RTC_PUT8(RTC_B, (regb | RTC_AIE));
}

/*
 * clear alarm interrupt
 */
static void
todm5819_clear_power_alarm(void)
{
        uint8_t regb;
        ASSERT(MUTEX_HELD(&tod_lock));

        regb = RTC_GET8(RTC_B);
        RTC_PUT8(RTC_B, (regb & ~RTC_AIE));
}

/*
 * 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
todm5819_get_cpufrequency(void)
{
        ASSERT(MUTEX_HELD(&tod_lock));
        M5819_ADDR_REG = RTC_SEC;
        return (find_cpufrequency(v_rtc_data_reg));
}


/*ARGSUSED*/
static uint_t
todm5819_set_watchdog_timer(uint_t timeoutval)
{
        ASSERT(MUTEX_HELD(&tod_lock));
        return (0);
}

static uint_t
todm5819_clear_watchdog_timer(void)
{
        ASSERT(MUTEX_HELD(&tod_lock));
        return (0);
}