ARM: 7009/1: l2x0: Add OF based initialization

This adds probing for ARM L2x0 cache controllers via device tree. Support
includes the L210, L220, and PL310 controllers. The binding allows setting
up cache RAM latencies and filter addresses (PL310 only).

Signed-off-by: Rob Herring <rob.herring@calxeda.com>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Olof Johansson <olof@lixom.net>
Acked-by: Barry Song <21cnbao@gmail.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

Documentation/devicetree/bindings/arm/l2cc.txt

@@ -0,0 +1,42 @@
+* ARM L2 Cache Controller
+
+ARM cores often have a separate level 2 cache controller. There are various
+implementations of the L2 cache controller with compatible programming models.
+The ARM L2 cache representation in the device tree should be done as follows:
+
+Required properties:
+
+- compatible : should be one of:
+	"arm,pl310-cache"
+	"arm,l220-cache"
+	"arm,l210-cache"
+- cache-unified : Specifies the cache is a unified cache.
+- cache-level : Should be set to 2 for a level 2 cache.
+- reg : Physical base address and size of cache controller's memory mapped
+  registers.
+
+Optional properties:
+
+- arm,data-latency : Cycles of latency for Data RAM accesses. Specifies 3 cells of
+  read, write and setup latencies. Minimum valid values are 1. Controllers
+  without setup latency control should use a value of 0.
+- arm,tag-latency : Cycles of latency for Tag RAM accesses. Specifies 3 cells of
+  read, write and setup latencies. Controllers without setup latency control
+  should use 0. Controllers without separate read and write Tag RAM latency
+  values should only use the first cell.
+- arm,dirty-latency : Cycles of latency for Dirty RAMs. This is a single cell.
+- arm,filter-ranges : <start length> Starting address and length of window to
+  filter. Addresses in the filter window are directed to the M1 port. Other
+  addresses will go to the M0 port.
+
+Example:
+
+L2: cache-controller {
+        compatible = "arm,pl310-cache";
+        reg = <0xfff12000 0x1000>;
+        arm,data-latency = <1 1 1>;
+        arm,tag-latency = <2 2 2>;
+        arm,filter-latency = <0x80000000 0x8000000>;
+        cache-unified;
+        cache-level = <2>;
+};