On Tue, Dec 18, 2001 at 02:03:44AM -0500, Jim Paris wrote:
> Date: Tue, 18 Dec 2001 02:03:44 -0500
> From: Jim Paris <jim@jtan.com>
> To: Ralf Baechle <ralf@oss.sgi.com>
> Cc: linux-mips@oss.sgi.com
> Subject: Re: [ppopov@mvista.com: Re: [Linux-mips-kernel]ioremap & ISA]
>
> > ISA, the good old stonage PC bus system with all it's limitations that also
> > infected some MIPS systems.
>
> Let me restate my problem differently, and perhaps a bit more clearly
> (as I see it):
>
> My system (Vadem Clio 1000, vr4111) has a VG-469 (i82365) PCMCIA
> controller with IO port space at 0x14000000, and IO memory space
> at 0x10000000.
Therefore:
set_io_port_base(0xb4000000);
isa_slot_offset = 0xb0000000;
> The i82365 driver makes the following (reasonable?) expectations:
>
> 1) it can use check/request/release_region on I/O ports
> - this works fine.
> 2) it can use in[bwl] and out[bwl] with absolute port numbers
> - this also works fine.
> 3) it can use check/request/release_mem_region on I/O memory
> - this fails, because the iomem resource map contains the kernel:
> > -more /proc/iomem
> 00000000-00ffffff : System Ram
> 00002000-001bc6af : Kernel code
> 001cf300-00299fff : Kernel data
> (this seems very wrong to me, since the kernel is most definately
> not in the I/O memory space; real memory, of course, but I/O memory??)
No, this makes perfect sense on a 16mb system.
> 4) it can use ioremap, and then read[bwl] and write[bwl] with the result
> - this fails with the current ioremap; neither ioremap nor read/write[bwl]
> take isa_slot_offset into account
And that's right because isa_slot_offset is used by the isa_{read,write}[bwl]
functions which do not require ioremap having been called before. You're
(fortunately ...) using PCI and PCI drivers are required to use ioremap.
I assume that your PCMCIA bridge is at a physical address < 0x20000000, is
that right? If so, what ioremap returns is trivial, it's just 0x80000000
+ the argument to ioremap(). Verify that. Also note that read[wl] and
write[wl] do byteorder swapping on the data if your system is big endian
and CONFIG_SWAP_IO_SPACE is set.
Ralf
