#!/bin/sh
########################################################################
# Copyright (c) 2020 Mellanox Technologies. All rights reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions are met:
#
# 1. Redistributions of source code must retain the above copyright
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# 2. Redistributions in binary form must reproduce the above copyright
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#    documentation and/or other materials provided with the distribution.
# 3. Neither the names of the copyright holders nor the names of its
#    contributors may be used to endorse or promote products derived from
#    this software without specific prior written permission.
#
# Alternatively, this software may be distributed under the terms of the
# GNU General Public License ("GPL") version 2 as published by the Free
# Software Foundation.
#
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
# AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
# ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
# LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
# CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
# SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
# INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
# CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
# ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
# POSSIBILITY OF SUCH DAMAGE.
#

# Description: hw-management watchdog actions script.
#              It uses direct access to CPLD watchdog mechanism.
#              1. Start watchdog to provided timeout or default timeout.
#              2. Stop watchdog.
#              3. Check if previous reset was caused by watchdog.
#              4. Check watchdog timeleft.

CPLD_LPC_BASE=0x2500
CPLD_LPC_CPBLT_REG=0xf9
CPLD_LPC_RESET_CAUSE_REG=0x1d
CPLD_LPC_WD2_TMR_REG=0xcd
CPLD_LPC_WD2_ACT_REG=0xcf
CPLD_LPC_WD_CPBLT_BIT=6
CPLD_LPC_WD_RESET_CAUSE_BIT=6
CPLD_LPC_WD_RESET=1
WD3_DFLT_TO=600
WD_TYPE3_MAX_TO=65535

wd_max_to=
wd_act_reg=
wd_tmr_reg=
wd_tleft_reg=
wd_tmr_reg_len=
wd_to=

action=$1
param_num=$#

usage()
{
    echo "Usage: $(basename "$0") start [timeout] | stop | tleft | check_reset | help"
        echo "start - start watchdog"
    echo "        timeout is optional. Default value will be used in case if it's omitted"
        echo "        timeout provided in seconds"
        echo "stop - stop watchdog"
        echo "tleft - check watchdog timeout left"
        echo "check_reset - check if previous reset was caused by watchdog"
    echo "        Prints only in case of watchdog reset"
        echo "help -this help"
}

check_watchdog_type()
{
    reg=$((CPLD_LPC_BASE+CPLD_LPC_CPBLT_REG))
    wd_cpblt=$(iorw -r -b $reg -l 1 | awk '{print $5}')
    wd_cpblt=$((wd_cpblt>>=CPLD_LPC_WD_CPBLT_BIT))
    wd_cpblt=$((wd_cpblt&=1))

    if [ $wd_cpblt -eq 0 ]; then
        wd_type=3
        wd_to=$WD3_DFLT_TO
        wd_max_to=$WD_TYPE3_MAX_TO
        wd_act_reg=$CPLD_LPC_WD2_ACT_REG
        wd_tmr_reg=$CPLD_LPC_WD2_TMR_REG
        wd_tleft_reg=$CPLD_LPC_WD2_TMR_REG
        wd_tmr_reg_len=2
    else
        board=$(cat /sys/devices/virtual/dmi/id/board_name)
        case $board in
            VMOD0001|VMOD0003)
                wd_type=1
                ;;
            *)
                wd_type=2
                ;;
        esac
        echo "Watchdog type ${wd_type} isn't supported by this script."
        exit 1
    fi
}

check_watchdog_timeout()
{
    if [ $param_num -ge 2 ]; then
        wd_to=$2
    fi
    if [ $wd_to -gt $wd_max_to ]; then
        echo "Error: Watchdog timeout ${wd_to} exceeds max timeout ${wd_max_to}"
        exit 1
    fi
}

start_watchdog()
{
    reg=$((CPLD_LPC_BASE+wd_tmr_reg))
    iorw -w -b $reg -v $wd_to -l $wd_tmr_reg_len
    reg=$((CPLD_LPC_BASE+wd_act_reg))
    val=$CPLD_LPC_WD_RESET
    iorw -w -b $reg -v $val -l 1
    echo "Watchdog is started, timeout ${wd_to} sec."
}

stop_watchdog()
{
    reg=$((CPLD_LPC_BASE+wd_act_reg))
    iorw -w -b $reg -v 0 -l 1
    reg=$((CPLD_LPC_BASE+wd_tmr_reg))
    iorw -w -b $reg -v 0 -l 1
    reg=$((reg+1))
    iorw -w -b $reg -v 0 -l 1
    echo "Watchdog is stopped"
}

time_left()
{
    reg=$((CPLD_LPC_BASE+wd_tleft_reg))
    val=$(iorw -r -b $reg -l 2 | awk '{print $3 $2}')
    val=$(printf "0x%s" ${val})
    printf "Watchdog timeleft: %d sec.\n" ${val}
}

check_reset()
{
    reg=$((CPLD_LPC_BASE+CPLD_LPC_RESET_CAUSE_REG))
    val=$(iorw -r -b $reg -l 1 | awk '{print $5}')
    val=$((val>>=CPLD_LPC_WD_RESET_CAUSE_BIT))
    val=$((val&=1))
    if [ $val -eq 1 ]; then
        echo "Watchdog was caused reset in previous boot"
    fi
}

check_watchdog_type

case $action in
    start)
        check_watchdog_timeout "$@"
        start_watchdog
        ;;
    stop)
        stop_watchdog
        ;;
    tleft)
        time_left
        ;;
    check_reset)
        check_reset
        ;;
    help)
        usage
        ;;
    *)
        usage
        exit 1
        ;;
esac

exit 0