#!/usr/bin/python3

import sys
import os
import struct

PORT_RES = '/dev/port'
NVRAM_RES = '/dev/nvram'
COLD_RESET = 0xE     # Cold Reset
WARM_RESET = 0x6     # Warm Reset
RESET_REG = 0xCF9

def io_reg_write(resource, offset, val):
    fd = os.open(resource, os.O_RDWR)
    if(fd < 0):
        print('file open failed %s" % resource')
        return
    if(os.lseek(fd, offset, os.SEEK_SET) != offset):
        print('lseek failed on %s' % resource)
        return
    ret = os.write(fd, struct.pack('B', val))
    if(ret != 1):
        print('write failed %d' % ret)
        return
    os.close(fd)

def power_reset(val):
    with open('/sys/devices/platform/dell-s6000-cpld.0/power_reset', 'w') as p:
        p.write(str(int(val)) + '\n')
        p.flush()

def gpio_direction(pin, direction):
    kernpath = '/sys/class/gpio/gpio'+str(pin)+'/direction'
    with open(('kernpath'), 'w') as p:
        p.write(str(direction) + '\n')
        p.flush()

def gpio_set(pin, value):
    kernpath = '/sys/class/gpio/gpio'+str(pin)+'/value'
    with open(('kernpath'), 'w') as p:
        p.write(str(int(value)) + '\n')
        p.flush()

def gpio_export(value):
    with open('/sys/class/gpio/export', 'w') as p:
        p.write(str(int(value)) + '\n')
        p.flush()

if __name__ == "__main__":

    retry_count = 0
    io_reg_write(NVRAM_RES, 0x49, COLD_RESET)

    while retry_count < 3:
        if not os.path.isdir("/sys/class/gpio/gpio10"):
            gpio_export(10)
        gpio_direction("10", "out")
        # Toggle GPIO10 pin (to reset MUX)
        gpio_set("10", 1)
        gpio_set("10", 0)
        power_reset(1)
        retry_count += 1
    io_reg_write(PORT_RES, RESET_REG, COLD_RESET)