map iomem in linux_2_4_dev

[Sangmoon Kim]

Hi,
>
> No, that's rubbish.  Use one or the other. ioremap() takes a physical
> address and returns the virtual address at which it mapped it.
>
Sometimes it is needed to use  io_block_mapping and ioremap.
io_block_mapping maps a phiscal address to a virtual address.
And ioremap returns the virtual address.
When I ported linux on an MPC755 based custom board.
My hardware didn't running because it had a serial port at 0x78000000.
Linux uses 0 to 0x7fffffff as a virtual memory for applications.
And the address of 0x78000000 overlaped the serial port.
I had to use io_block_mapping to map it at different location on system initialization,
and ioremap to get the mapped address on serial port driver.
I'm sorry, if it's another rubbish.
-Sangmoon Kim-


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