Device Accessing Problem in 440GP

Device Accessing Problem in 440GP

[Vishwanath]

Hi All,

I am working on IBM 440GP based proprietry board using MVL 2.1 linux. I have
a device siiting on the EBC at 0x100100000 and I want to access it from the
user space. I use mmap call of my driver to do that. I have not initialized
the device. I have set the access parameters and controller registers of EBC
appropriately to access the device.

But when I make ioremap() call using,

 ioremap64(0x100100000, 0x2000),

the function returns a  valid pointer. But when I do a sample write and
read, I am not getting correct values. While I was debigging, I couldn't
find the TLB entry for the real address.

When I try to access the returned mmap() pointer, kernel says ,
do_wp_page: bogus page at address xxxx (page yyyy)

VM: killing process xxx

Does anyone know what could be the reason?

1. Do I  have to initialize the device in setup_arch function ?
2. Do I have to explicitly create a TLB entry for the device ?

Hoping to get a response. I am stuck in the middle.

Thanks and regards,
Vishwa

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