/*
 * 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.
 */


/*
 * tod driver module for ALI M5819P part
 */

#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/todm5819p.h>
#include <sys/rmc_comm_dp.h>
#include <sys/rmc_comm_drvintf.h>
#include <sys/modctl.h>
#include <sys/stat.h>
#include <sys/clock.h>
#include <sys/reboot.h>
#include <sys/machsystm.h>

static timestruc_t      todm5819p_rmc_get(void);
static void             todm5819p_rmc_set(timestruc_t);
static uint_t           todm5819p_rmc_set_watchdog_timer(uint_t);
static uint_t           todm5819p_rmc_clear_watchdog_timer(void);
static void             todm5819p_rmc_set_power_alarm(timestruc_t);
static void             todm5819p_rmc_clear_power_alarm(void);
static uint64_t         todm5819p_rmc_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 m5819p_debug_flags;

/*
 * Module linkage information for the kernel.
 */
static struct modlmisc modlmisc = {
        &mod_miscops, "tod module for ALI M5819P"
};

static struct modlinkage modlinkage = {
        MODREV_1, (void *)&modlmisc, NULL
};

static todinfo_t rtc_to_tod(struct rtc_t *);
static void read_rtc(struct rtc_t *);
static void write_rtc_time(struct rtc_t *);
static void write_rtc_alarm(struct rtc_t *);


int
_init(void)
{
        if (strcmp(tod_module_name, "todm5819p_rmc") == 0) {
                M5819P_ADDR_REG = RTC_B;
                M5819P_DATA_REG = (RTC_DM | RTC_HM);

                tod_ops.tod_get = todm5819p_rmc_get;
                tod_ops.tod_set = todm5819p_rmc_set;

                tod_ops.tod_set_watchdog_timer =
                    todm5819p_rmc_set_watchdog_timer;
                tod_ops.tod_clear_watchdog_timer =
                    todm5819p_rmc_clear_watchdog_timer;
                tod_ops.tod_set_power_alarm = todm5819p_rmc_set_power_alarm;
                tod_ops.tod_clear_power_alarm = todm5819p_rmc_clear_power_alarm;
                tod_ops.tod_get_cpufrequency = todm5819p_rmc_get_cpufrequency;
                if (boothowto & RB_DEBUG) {
                        cmn_err(CE_WARN, "todm5819p_rmc: kernel debugger "
                            "detected: hardware watchdog disabled");
                }
        }

        return (mod_install(&modlinkage));
}

int
_fini(void)
{
        if (strcmp(tod_module_name, "todm5819p_rmc") == 0)
                return (EBUSY);

        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
todm5819p_rmc_get(void)
{
        int i;
        int s;
        timestruc_t ts;
        struct rtc_t rtc;

        ASSERT(MUTEX_HELD(&tod_lock));

        /* set the hw watchdog timer if it's been activated */
        if (watchdog_activated) {
                int ret = 0;
                ret = tod_ops.tod_set_watchdog_timer(0);
                /*
                 * The empty set_watchdog routine returns a 0. So if a
                 * coded routine fails we will look for a -1 for a failure.
                 */
                if (ret == -1)
                        cmn_err(CE_WARN, "todm5819p: failed to set hardware "
                            "watchdog timer.");
        }

        /*
         * Read current time from the tod. If the tod isn't accessible, wait and
         * retry.
         * Run critical in the time critical section to avoid being interrupted
         */
        for (i = 0; i < TODM5819_UIP_RETRY_THRESH; i++) {
                s = ddi_enter_critical();
                M5819P_ADDR_REG = RTC_A;
                if (!(M5819P_DATA_REG & RTC_UIP)) {
                        read_rtc(&rtc);
                        ddi_exit_critical(s);
                        break;
                }
                ddi_exit_critical(s);
                drv_usecwait(TODM5819_UIP_WAIT_USEC);
        }
        if (i == TODM5819_UIP_RETRY_THRESH) {
                /*
                 * tod is inaccessible: just return current software time
                 */
                tod_status_set(TOD_GET_FAILED);
                return (hrestime);
        }

        /* 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 void
read_rtc(struct rtc_t *rtc)
{
        M5819P_ADDR_REG = RTC_SEC;
        rtc->rtc_sec = M5819P_DATA_REG;
        M5819P_ADDR_REG = RTC_ASEC;
        rtc->rtc_asec = M5819P_DATA_REG;
        M5819P_ADDR_REG = RTC_MIN;
        rtc->rtc_min = M5819P_DATA_REG;
        M5819P_ADDR_REG = RTC_AMIN;
        rtc->rtc_amin = M5819P_DATA_REG;
        M5819P_ADDR_REG = RTC_HRS;
        rtc->rtc_hrs = M5819P_DATA_REG;
        M5819P_ADDR_REG = RTC_AHRS;
        rtc->rtc_ahrs = M5819P_DATA_REG;
        M5819P_ADDR_REG = RTC_DOW;
        rtc->rtc_dow = M5819P_DATA_REG;
        M5819P_ADDR_REG = RTC_DOM;
        rtc->rtc_dom = M5819P_DATA_REG;
        M5819P_ADDR_REG = RTC_MON;
        rtc->rtc_mon = M5819P_DATA_REG;
        M5819P_ADDR_REG = RTC_YEAR;
        rtc->rtc_year = M5819P_DATA_REG;
        M5819P_ADDR_REG = RTC_CENTURY;
        rtc->rtc_century = M5819P_DATA_REG;

        /* Read date alarm */
        M5819P_ADDR_REG = RTC_ADOM_REG;
        rtc->rtc_adom = (M5819P_DATA_REG) & RTC_ADOM;
}

/*
 * Write the specified time into the clock chip.
 * Must be called with tod_lock held.
 */
static void
todm5819p_rmc_set(timestruc_t ts)
{
        struct rtc_t    rtc;
        todinfo_t tod = utc_to_tod(ts.tv_sec);
        int year;
        rmc_comm_msg_t request;
        dp_set_date_time_t set_time_msg;

        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;

        write_rtc_time(&rtc);

        set_time_msg.year       = year - 1900;
        set_time_msg.month      = tod.tod_month - 1;
        set_time_msg.day        = tod.tod_day;
        set_time_msg.hour       = tod.tod_hour;
        set_time_msg.minute     = tod.tod_min;
        set_time_msg.second     = tod.tod_sec;

        request.msg_type = DP_SET_DATE_TIME;
        request.msg_len = sizeof (set_time_msg);
        request.msg_buf = (caddr_t)&set_time_msg;

        (void) rmc_comm_request_nowait(&request, 0);
}

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

        /*
         * Freeze
         */
        M5819P_ADDR_REG = RTC_B;
        regb = M5819P_DATA_REG;
        M5819P_DATA_REG = (regb | RTC_SET);

        /*
         * If an update cycle 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.
         */
        M5819P_ADDR_REG = RTC_A;
        for (i = 0; i < TODM5819_UIP_RETRY_THRESH; i++) {
                if (!(M5819P_DATA_REG & RTC_UIP)) {
                        break;
                }
                drv_usecwait(TODM5819_UIP_WAIT_USEC);
        }
        if (i < TODM5819_UIP_RETRY_THRESH) {
                M5819P_ADDR_REG = RTC_SEC;
                M5819P_DATA_REG = rtc->rtc_sec;
                M5819P_ADDR_REG = RTC_MIN;
                M5819P_DATA_REG = rtc->rtc_min;
                M5819P_ADDR_REG = RTC_HRS;
                M5819P_DATA_REG = rtc->rtc_hrs;
                M5819P_ADDR_REG = RTC_DOW;
                M5819P_DATA_REG = rtc->rtc_dow;
                M5819P_ADDR_REG = RTC_DOM;
                M5819P_DATA_REG = rtc->rtc_dom;
                M5819P_ADDR_REG = RTC_MON;
                M5819P_DATA_REG = rtc->rtc_mon;
                M5819P_ADDR_REG = RTC_YEAR;
                M5819P_DATA_REG = rtc->rtc_year;
                M5819P_ADDR_REG = RTC_CENTURY;
                M5819P_DATA_REG = rtc->rtc_century;
        } else {
                cmn_err(CE_WARN, "todm5819p_rmc: Could not write the RTC\n");
        }

        /*
         * Unfreeze
         */
        M5819P_ADDR_REG = RTC_B;
        M5819P_DATA_REG = regb;
}

void
write_rtc_alarm(struct rtc_t *rtc)
{
        M5819P_ADDR_REG = RTC_ASEC;
        M5819P_DATA_REG = rtc->rtc_asec;
        M5819P_ADDR_REG = RTC_AMIN;
        M5819P_DATA_REG = rtc->rtc_amin;
        M5819P_ADDR_REG = RTC_AHRS;
        M5819P_DATA_REG = rtc->rtc_ahrs;

        M5819P_ADDR_REG = RTC_ADOM_REG;
        M5819P_DATA_REG = rtc->rtc_adom;
}

/*
 * program the rtc registers for alarm to go off at the specified time
 */
static void
todm5819p_rmc_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 and clear AF flag by reading reg C
         */
        M5819P_ADDR_REG = RTC_B;
        regb = M5819P_DATA_REG;
        M5819P_DATA_REG = regb & ~RTC_AIE;
        M5819P_ADDR_REG = RTC_C;
        (void) M5819P_DATA_REG;

        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 alarm values and enable alarm
         */
        write_rtc_alarm(&rtc);

        M5819P_ADDR_REG = RTC_B;
        M5819P_DATA_REG = regb | RTC_AIE;
}

/*
 * clear alarm interrupt
 */
static void
todm5819p_rmc_clear_power_alarm(void)
{
        uint8_t regb;

        ASSERT(MUTEX_HELD(&tod_lock));

        M5819P_ADDR_REG = RTC_B;
        regb = M5819P_DATA_REG;
        M5819P_DATA_REG = 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
todm5819p_rmc_get_cpufrequency(void)
{
        ASSERT(MUTEX_HELD(&tod_lock));
        M5819P_ADDR_REG = RTC_SEC;
        return (find_cpufrequency(v_rtc_data_reg));
}

/*ARGSUSED*/
static uint_t
todm5819p_rmc_set_watchdog_timer(uint_t timeoutval)
{
        ASSERT(MUTEX_HELD(&tod_lock));
        return (0);
}

static uint_t
todm5819p_rmc_clear_watchdog_timer(void)
{
        ASSERT(MUTEX_HELD(&tod_lock));
        return (0);
}