[PATCH 10/21] ARM: MM: Add DT binding for Feroceon L2 cache

[andrew@lunn.ch (Andrew Lunn)]

Instantiate the L2 cache from DT. Indicate in DT where the cache
control register is and if write through should be made.

Signed-off-by: Andrew Lunn <andrew@lunn.ch>
---
 .../devicetree/bindings/arm/mrvl/foroceon.txt      | 19 +++++++++
 arch/arm/boot/dts/kirkwood.dtsi                    |  5 +++
 arch/arm/include/asm/hardware/cache-feroceon-l2.h  |  2 +
 arch/arm/mach-kirkwood/board-dt.c                  | 15 +------
 arch/arm/mm/cache-feroceon-l2.c                    | 46 ++++++++++++++++++++++
 5 files changed, 73 insertions(+), 14 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/arm/mrvl/foroceon.txt

diff --git a/Documentation/devicetree/bindings/arm/mrvl/foroceon.txt b/Documentation/devicetree/bindings/arm/mrvl/foroceon.txt
new file mode 100644
index 000000000000..8058676d1476
--- /dev/null
+++ b/Documentation/devicetree/bindings/arm/mrvl/foroceon.txt
@@ -0,0 +1,19 @@
+* Marvell Feroceon Cache
+
+Required properties:
+- compatible : Should be "marvell,feroceon-kirkwood".
+- reg        : Address of the L2 cache control register
+
+Optional properties:
+- writethrough : only if present, the cache will be used in write through mode.
+
+Example:
+		l2: l2-cache at 20128 {
+			compatible = "marvell,marvell,feroceon-kirkwood";
+			reg = <0x20128 0x4>;
+		};
+
+There are at least two variants of the Feroceon, differing in how
+write through is enabled or not. If mv78xx0 support is added, it is
+expected to have a different compatibility string.
+
diff --git a/arch/arm/boot/dts/kirkwood.dtsi b/arch/arm/boot/dts/kirkwood.dtsi
index 6abf44d257df..1d8129ac2672 100644
--- a/arch/arm/boot/dts/kirkwood.dtsi
+++ b/arch/arm/boot/dts/kirkwood.dtsi
@@ -161,6 +161,11 @@
 			#clock-cells = <1>;
 		};
 
+		l2: l2-cache at 20128 {
+			compatible = "marvell,feroceon-kirkwood";
+			reg = <0x20128 0x4>;
+		};
+
 		intc: main-interrupt-ctrl at 20200 {
 			compatible = "marvell,orion-intc";
 			interrupt-controller;
diff --git a/arch/arm/include/asm/hardware/cache-feroceon-l2.h b/arch/arm/include/asm/hardware/cache-feroceon-l2.h
index 8edd330aabf6..12e1588dc4f1 100644
--- a/arch/arm/include/asm/hardware/cache-feroceon-l2.h
+++ b/arch/arm/include/asm/hardware/cache-feroceon-l2.h
@@ -9,3 +9,5 @@
  */
 
 extern void __init feroceon_l2_init(int l2_wt_override);
+extern int __init feroceon_of_init(void);
+
diff --git a/arch/arm/mach-kirkwood/board-dt.c b/arch/arm/mach-kirkwood/board-dt.c
index 34c35510fd17..2ef59ee2182d 100644
--- a/arch/arm/mach-kirkwood/board-dt.c
+++ b/arch/arm/mach-kirkwood/board-dt.c
@@ -42,19 +42,6 @@ static void __init kirkwood_map_io(void)
 	iotable_init(kirkwood_io_desc, ARRAY_SIZE(kirkwood_io_desc));
 }
 
-static void __init kirkwood_l2_init(void)
-{
-#ifdef CONFIG_CACHE_FEROCEON_L2
-#ifdef CONFIG_CACHE_FEROCEON_L2_WRITETHROUGH
-	writel(readl(L2_CONFIG_REG) | L2_WRITETHROUGH, L2_CONFIG_REG);
-	feroceon_l2_init(1);
-#else
-	writel(readl(L2_CONFIG_REG) & ~L2_WRITETHROUGH, L2_CONFIG_REG);
-	feroceon_l2_init(0);
-#endif
-#endif
-}
-
 static struct resource kirkwood_cpufreq_resources[] = {
 	[0] = {
 		.start  = CPU_CONTROL_PHYS,
@@ -211,7 +198,7 @@ static void __init kirkwood_dt_init(void)
 
 	BUG_ON(mvebu_mbus_dt_init());
 
-	kirkwood_l2_init();
+	feroceon_of_init();
 
 	kirkwood_cpufreq_init();
 	kirkwood_cpuidle_init();
diff --git a/arch/arm/mm/cache-feroceon-l2.c b/arch/arm/mm/cache-feroceon-l2.c
index 898362e7972b..193fe7dbdb12 100644
--- a/arch/arm/mm/cache-feroceon-l2.c
+++ b/arch/arm/mm/cache-feroceon-l2.c
@@ -13,11 +13,17 @@
  */
 
 #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	0x00000010
+
+
 /*
  * Low-level cache maintenance operations.
  *
@@ -350,3 +356,43 @@ 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,feroceon-kirkwood"},
+	{}
+};
+
+int __init feroceon_of_init(void)
+{
+	struct device_node *node;
+	void __iomem *base;
+	bool writethrough = false;
+	struct resource res;
+
+	node = of_find_matching_node(NULL, feroceon_ids);
+	if (!node) {
+		pr_info("Didn't find marvell,feroceon-*, not enabling it\n");
+		return -ENODEV;
+	}
+
+	if (of_property_read_bool(node, "writethrough"))
+		writethrough = true;
+
+	if (of_address_to_resource(node, 0, &res))
+		return -ENODEV;
+
+	base = ioremap(res.start, resource_size(&res));
+	if (!base)
+		return -ENOMEM;
+
+	if (writethrough) {
+		writel(readl(base) | L2_WRITETHROUGH_KIRKWOOD, base);
+		feroceon_l2_init(1);
+	} else {
+		writel(readl(base) & ~L2_WRITETHROUGH_KIRKWOOD, base);
+	feroceon_l2_init(0);
+	}
+
+	return 0;
+}
+#endif
-- 
1.8.5.3