Im a newbie in kernel development.

I'm developing software for a piece of hardware which runs linux kernel on it. The hardware board has a PowerPC mpc8313 processor. It also has a FLASH memory connected to the localbus, using CS0 powerpc pin. Everything works fine.

The problem is, we had to connect another chipset to the localbus. This new chip is using CS2 powerpc chipselect.

Now, how do I tell PowerPC to select the new device's chipselect pin? How PowerPC will know how to read/write data from/to the device when I write data to a device driver memory address?

The device driver that the chip manufacturer provided does the initialization with an ioctl(fd, DEV_INIT, DEVICE_ADDRESS). So, i have to inform the driver where the device memory is mapped, so it could perform a io_remap(). But the hardware designer didnt mention any memory address. Only the chipselect index.
How can I link the device memory to the physical powerpc memory? I though it was done by changing the DTS file.