patch-2.4.10 linux/Documentation/mips/pci/pci.README

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diff -u --recursive --new-file v2.4.9/linux/Documentation/mips/pci/pci.README linux/Documentation/mips/pci/pci.README
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+
+Pete Popov, ppopov@pacbell.net
+07/11/2001
+
+This README briefly explains how to use the pci and pci_auto
+code in arch/mips/kernel.  The code was ported from PowerPC and
+modified slightly. It has been tested pretty well on PPC on some
+rather complex systems with multiple bridges and devices behind
+each bridge. However, at the time this README was written, the
+mips port was tested only on boards with a single pci bus and
+no P2P bridges.  It's very possible that on boards with P2P
+bridges some modifications have to be made. The code will 
+evolve, no doubt, but currently every single mips board
+is doing its own pcibios thing and it has become a big
+mess.  This generic pci code is meant to clean up the mips
+pci mess and make it easier to add pci support to new boards.
+
+arch/mips/kernel/pci_auto.c has the pci bus enumeration code.
+This code scans the pci bus(es) and assigns all of the resources.
+Thus, you don't need the boot code to that, and many boot codes
+don't do it correctly anyway.  To enable the pci_auto code, add
+
+define_bool CONFIG_PCI_AUTO y 
+
+inside the define for your board in arch/mips/config.in. 
+For example, the Galileo EV96100 board  looks like this:
+
+if [ "$CONFIG_MIPS_EV96100" = "y" ]; then
+	define_bool CONFIG_PCI y
+	define_bool CONFIG_MIPS_GT96100 y
+	define_bool CONFIG_NEW_PCI y
+	define_bool CONFIG_PCI_AUTO y
+	define_bool CONFIG_SWAP_IO_SPACE y
+fi 
+
+
+Next, if you want to use the arch/mips/kernel/pci code, which has the
+pcibios_init() function, add
+
+define_bool CONFIG_NEW_PCI y
+ 
+inside the define for your board. Again, the EV96100 example above
+show NEW_PCI turned on.
+
+Note that you can enable CONFIG_NEW_PCI code without enabling 
+CONFIG_PCI_AUTO. But you can't do the opposite because the pci_auto
+routines are called from pcibios_init(), which is part of the 
+CONFIG_NEW_PCI code.
+
+
+Now you need to add your files to hook in your pci configuration
+cycles.  Usually you'll need only a couple of files named something
+like pci_fixups.c and pci_ops.c.  You can copy the templates
+provided and fill in the code.
+
+The file pci_ops.c should contain the pci configuration cycles routines.
+It also has the mips_pci_channels[] array which contains the descriptors
+of each pci controller.
+
+The file pci_fixups.c contains a few routines to do interrupt fixups,
+resources fixups, and, if needed, pci bios fixups.
+
+Usually you'll put your pci_fixups.c file in your board specific directory, 
+since the functions in that file are board specific.  The functions in
+pci_ops.c, on the other hand, are usually pci controller specific so that
+file could be shared among a few different boards using the same
+pci controller.

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