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>

1 files changed, 103 insertions, 0 deletions

diff --git a/arch/arm/mm/cache-l2x0.c b/arch/arm/mm/cache-l2x0.c
index 9ecfdb5..db4484f 100644
--- a/arch/arm/mm/cache-l2x0.c
+++ b/arch/arm/mm/cache-l2x0.c
@@ -16,9 +16,12 @@
  * along with this program; if not, write to the Free Software
  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  */
+#include <linux/err.h>
 #include <linux/init.h>
 #include <linux/spinlock.h>
 #include <linux/io.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
 
 #include <asm/cacheflush.h>
 #include <asm/hardware/cache-l2x0.h>
@@ -372,3 +375,103 @@ void __init l2x0_init(void __iomem *base, __u32 aux_val, __u32 aux_mask)
 	printk(KERN_INFO "l2x0: %d ways, CACHE_ID 0x%08x, AUX_CTRL 0x%08x, Cache size: %d B\n",
 			ways, cache_id, aux, l2x0_size);
 }
+
+#ifdef CONFIG_OF
+static void __init l2x0_of_setup(const struct device_node *np,
+				 __u32 *aux_val, __u32 *aux_mask)
+{
+	u32 data[2] = { 0, 0 };
+	u32 tag = 0;
+	u32 dirty = 0;
+	u32 val = 0, mask = 0;
+
+	of_property_read_u32(np, "arm,tag-latency", &tag);
+	if (tag) {
+		mask |= L2X0_AUX_CTRL_TAG_LATENCY_MASK;
+		val |= (tag - 1) << L2X0_AUX_CTRL_TAG_LATENCY_SHIFT;
+	}
+
+	of_property_read_u32_array(np, "arm,data-latency",
+				   data, ARRAY_SIZE(data));
+	if (data[0] && data[1]) {
+		mask |= L2X0_AUX_CTRL_DATA_RD_LATENCY_MASK |
+			L2X0_AUX_CTRL_DATA_WR_LATENCY_MASK;
+		val |= ((data[0] - 1) << L2X0_AUX_CTRL_DATA_RD_LATENCY_SHIFT) |
+		       ((data[1] - 1) << L2X0_AUX_CTRL_DATA_WR_LATENCY_SHIFT);
+	}
+
+	of_property_read_u32(np, "arm,dirty-latency", &dirty);
+	if (dirty) {
+		mask |= L2X0_AUX_CTRL_DIRTY_LATENCY_MASK;
+		val |= (dirty - 1) << L2X0_AUX_CTRL_DIRTY_LATENCY_SHIFT;
+	}
+
+	*aux_val &= ~mask;
+	*aux_val |= val;
+	*aux_mask &= ~mask;
+}
+
+static void __init pl310_of_setup(const struct device_node *np,
+				  __u32 *aux_val, __u32 *aux_mask)
+{
+	u32 data[3] = { 0, 0, 0 };
+	u32 tag[3] = { 0, 0, 0 };
+	u32 filter[2] = { 0, 0 };
+
+	of_property_read_u32_array(np, "arm,tag-latency", tag, ARRAY_SIZE(tag));
+	if (tag[0] && tag[1] && tag[2])
+		writel_relaxed(
+			((tag[0] - 1) << L2X0_LATENCY_CTRL_RD_SHIFT) |
+			((tag[1] - 1) << L2X0_LATENCY_CTRL_WR_SHIFT) |
+			((tag[2] - 1) << L2X0_LATENCY_CTRL_SETUP_SHIFT),
+			l2x0_base + L2X0_TAG_LATENCY_CTRL);
+
+	of_property_read_u32_array(np, "arm,data-latency",
+				   data, ARRAY_SIZE(data));
+	if (data[0] && data[1] && data[2])
+		writel_relaxed(
+			((data[0] - 1) << L2X0_LATENCY_CTRL_RD_SHIFT) |
+			((data[1] - 1) << L2X0_LATENCY_CTRL_WR_SHIFT) |
+			((data[2] - 1) << L2X0_LATENCY_CTRL_SETUP_SHIFT),
+			l2x0_base + L2X0_DATA_LATENCY_CTRL);
+
+	of_property_read_u32_array(np, "arm,filter-ranges",
+				   filter, ARRAY_SIZE(filter));
+	if (filter[0] && filter[1]) {
+		writel_relaxed(ALIGN(filter[0] + filter[1], SZ_1M),
+			       l2x0_base + L2X0_ADDR_FILTER_END);
+		writel_relaxed((filter[0] & ~(SZ_1M - 1)) | L2X0_ADDR_FILTER_EN,
+			       l2x0_base + L2X0_ADDR_FILTER_START);
+	}
+}
+
+static const struct of_device_id l2x0_ids[] __initconst = {
+	{ .compatible = "arm,pl310-cache", .data = pl310_of_setup },
+	{ .compatible = "arm,l220-cache", .data = l2x0_of_setup },
+	{ .compatible = "arm,l210-cache", .data = l2x0_of_setup },
+	{}
+};
+
+int __init l2x0_of_init(__u32 aux_val, __u32 aux_mask)
+{
+	struct device_node *np;
+	void (*l2_setup)(const struct device_node *np,
+		__u32 *aux_val, __u32 *aux_mask);
+
+	np = of_find_matching_node(NULL, l2x0_ids);
+	if (!np)
+		return -ENODEV;
+	l2x0_base = of_iomap(np, 0);
+	if (!l2x0_base)
+		return -ENOMEM;
+
+	/* L2 configuration can only be changed if the cache is disabled */
+	if (!(readl_relaxed(l2x0_base + L2X0_CTRL) & 1)) {
+		l2_setup = of_match_node(l2x0_ids, np)->data;
+		if (l2_setup)
+			l2_setup(np, &aux_val, &aux_mask);
+	}
+	l2x0_init(l2x0_base, aux_val, aux_mask);
+	return 0;
+}
+#endif