ARM: OMAP4: Add L2 Cache Controller in Device Tree

Provide PL310 Level 2 Cache Controller Device Tree
support for OMAP4 based devices.
Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Acked-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Benoit Cousson <b-cousson@ti.com>

arch/arm/boot/dts/omap4.dtsi

@@ -30,12 +30,21 @@ aliases {
 	cpus {
 		cpu@0 {
 			compatible = "arm,cortex-a9";
+			next-level-cache = <&L2>;
 		};
 		cpu@1 {
 			compatible = "arm,cortex-a9";
+			next-level-cache = <&L2>;
 		};
 	};
 
+	L2: l2-cache-controller@48242000 {
+		compatible = "arm,pl310-cache";
+		reg = <0x48242000 0x1000>;
+		cache-unified;
+		cache-level = <2>;
+	};
+
 	/*
 	 * The soc node represents the soc top level view. It is uses for IPs
 	 * that are not memory mapped in the MPU view or for the MPU itself.

arch/arm/mach-omap2/omap4-common.c

@@ -16,6 +16,7 @@
 #include <linux/io.h>
 #include <linux/platform_device.h>
 #include <linux/memblock.h>
+#include <linux/of.h>
 
 #include <asm/hardware/gic.h>
 #include <asm/hardware/cache-l2x0.h>
@@ -171,7 +172,10 @@ static int __init omap_l2_cache_init(void)
 	/* Enable PL310 L2 Cache controller */
 	omap_smc1(0x102, 0x1);
 
-	l2x0_init(l2cache_base, aux_ctrl, L2X0_AUX_CTRL_MASK);
+	if (of_have_populated_dt())
+		l2x0_of_init(aux_ctrl, L2X0_AUX_CTRL_MASK);
+	else
+		l2x0_init(l2cache_base, aux_ctrl, L2X0_AUX_CTRL_MASK);
 
 	/*
 	 * Override default outer_cache.disable with a OMAP4