When I try to access TTL outputs which are on physical address 0x19800000, I get kernel oops: "imprecise external abort".
I am using kernel v2.6.9 on ARM platform (XScale, PXA255) on ConXS board and the code with which I am accessing this memory is:
#define CS_IO_OUT 0x19800000
ctl_bits = NULL;
if (!request_mem_region(CS_IO_OUT, 2, "Control bits on TTL - J2"))
printk(KERN_ERR "Unable to reserve TTL control bits region\n");
ctl_bits = ioremap(CS_IO_OUT, 2);
printk(KERN_ERR "Unable to map region!\n");
I tried to google for a useful anwser, but have found nothing.
I can't see what is the problem?
Thank you in advance!