I will propose to use devm_ioremap_resource() instead for removing this hardcoded 0x100, but i cannot find any user of this driver in any dts. (And so cannot check that this 0x100 is given in any DT resource node)

Is this normal ?

I wanted to use devm_ioremap_resource but could not find DT entry
required for this driver in any of the .dts files. So did not change
that. I could not find any dts/dtsi for this platform. So I assume
that the dtb is not present in the kernel, dtb is supplied by the
bootloader. I may be wrong in this. Can anyone confirm this?

Regards,
PrasannaKumar