ARM: MM: Add DT binding for Feroceon L2 cache

Instantiate the L2 cache from DT. Indicate in DT where the cache
control register is so that it is possible to enable/disable write
through on the CPU.

Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Tested-by: Jason Gunthorpe <jgunthorpe@obsidianresearch.com>
Signed-off-by: Jason Cooper <jason@lakedaemon.net>

arch/arm/mm/cache-feroceon-l2.c

@@ -13,11 +13,16 @@
  */
 
 #include <linux/init.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
 #include <linux/highmem.h>
+#include <linux/io.h>
 #include <asm/cacheflush.h>
 #include <asm/cp15.h>
 #include <asm/hardware/cache-feroceon-l2.h>
 
+#define L2_WRITETHROUGH_KIRKWOOD	BIT(4)
+
 /*
  * Low-level cache maintenance operations.
  *
@@ -350,3 +355,41 @@ void __init feroceon_l2_init(int __l2_wt_override)
 	printk(KERN_INFO "Feroceon L2: Cache support initialised%s.\n",
 			 l2_wt_override ? ", in WT override mode" : "");
 }
+#ifdef CONFIG_OF
+static const struct of_device_id feroceon_ids[] __initconst = {
+	{ .compatible = "marvell,kirkwood-cache"},
+	{ .compatible = "marvell,feroceon-cache"},
+	{}
+};
+
+int __init feroceon_of_init(void)
+{
+	struct device_node *node;
+	void __iomem *base;
+	bool l2_wt_override = false;
+	struct resource res;
+
+#if defined(CONFIG_CACHE_FEROCEON_L2_WRITETHROUGH)
+	l2_wt_override = true;
+#endif
+
+	node = of_find_matching_node(NULL, feroceon_ids);
+	if (node && of_device_is_compatible(node, "marvell,kirkwood-cache")) {
+		if (of_address_to_resource(node, 0, &res))
+			return -ENODEV;
+
+		base = ioremap(res.start, resource_size(&res));
+		if (!base)
+			return -ENOMEM;
+
+		if (l2_wt_override)
+			writel(readl(base) | L2_WRITETHROUGH_KIRKWOOD, base);
+		else
+			writel(readl(base) & ~L2_WRITETHROUGH_KIRKWOOD, base);
+	}
+
+	feroceon_l2_init(l2_wt_override);
+
+	return 0;
+}
+#endif