register_pci_controller() can fail, but presently is a void function.
Change this over to an int so that we can bail early before continuing on
with post-registration initialization (such as throwing the controller in
to 66MHz mode in the case of the SH7780 host controller).
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
This adds initial support for the PCI-Express module in the SH7786,
particularly as it relates to the urquell platform. Presently it is
only supported in root complex mode, with endpoint mode still requiring
more debugging. 29/32-bit mode and lane configurations are selectable via
board mode pins, and are otherwise fixed.
Only 4x and 1x PCI channels are presently handled, the PCI bridge still
requires additional debugging and stabilization in hardware.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>