Could not able to read time and date from rtc isl1208

[gauthamikosanam]

I am using raspberry pi 3 B+ board, unable to read time and date from rtc register.....
I have added the dtoverlay in /boot/config.txt
added rtc-isl1208 in /etc/module
if i do sudo modprobe rtc-isl1208 getting like this

[gauthamikosanam]

For this I connect 5v-2A suplly to rpi.It is created nodes when i do modprobe rtc-isl1208.
But for sudo hwclock getting error
hwclock: select() to /dev/rtc0 to wait for clock tick timed out