1 files changed, 70 insertions, 0 deletions
diff --git a/arch/arm/mach-prima2/rstc.c b/arch/arm/mach-prima2/rstc.c
new file mode 100644
index 00000000000..492cfa8d261
--- /dev/null
+++ b/arch/arm/mach-prima2/rstc.c
@@ -0,0 +1,70 @@
+/*
+ * reset controller for CSR SiRFprimaII
+ *
+ * Copyright (c) 2011 Cambridge Silicon Radio Limited, a CSR plc group company.
+ *
+ * Licensed under GPLv2 or later.
+ */
+
+#include <linux/kernel.h>
+#include <linux/mutex.h>
+#include <linux/io.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+
+void __iomem *sirfsoc_rstc_base;
+static DEFINE_MUTEX(rstc_lock);
+
+static struct of_device_id rstc_ids[]  = {
+	{ .compatible = "sirf,prima2-rstc" },
+	{},
+};
+
+static int __init sirfsoc_of_rstc_init(void)
+{
+	struct device_node *np;
+
+	np = of_find_matching_node(NULL, rstc_ids);
+	if (!np)
+		panic("unable to find compatible rstc node in dtb\n");
+
+	sirfsoc_rstc_base = of_iomap(np, 0);
+	if (!sirfsoc_rstc_base)
+		panic("unable to map rstc cpu registers\n");
+
+	of_node_put(np);
+
+	return 0;
+}
+early_initcall(sirfsoc_of_rstc_init);
+
+int sirfsoc_reset_device(struct device *dev)
+{
+	const unsigned int *prop = of_get_property(dev->of_node, "reset-bit", NULL);
+	unsigned int reset_bit;
+
+	if (!prop)
+		return -ENODEV;
+
+	reset_bit = be32_to_cpup(prop);
+
+	mutex_lock(&rstc_lock);
+
+	/*
+	 * Writing 1 to this bit resets corresponding block. Writing 0 to this
+	 * bit de-asserts reset signal of the corresponding block.
+	 * datasheet doesn't require explicit delay between the set and clear
+	 * of reset bit. it could be shorter if tests pass.
+	 */
+	writel(readl(sirfsoc_rstc_base + (reset_bit / 32) * 4) | reset_bit,
+		sirfsoc_rstc_base + (reset_bit / 32) * 4);
+	msleep(10);
+	writel(readl(sirfsoc_rstc_base + (reset_bit / 32) * 4) & ~reset_bit,
+		sirfsoc_rstc_base + (reset_bit / 32) * 4);
+
+	mutex_unlock(&rstc_lock);
+
+	return 0;
+}