MIPS: Add support for the IMG Pistachio SoC

Add initial support for boards based on the Imagination Pistachio SoC.
Pistachio is based on a dual-core MIPS interAptiv CPU and will boot
using device-tree.

Signed-off-by: James Hartley <james.hartley@imgtec.com>
Signed-off-by: Andrew Bresticker <abrestic@chromium.org>
Cc: devicetree@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-mips@linux-mips.org
Cc: Ezequiel Garcia <ezequiel.garcia@imgtec.com>
Cc: James Hogan <james.hogan@imgtec.com>
Patchwork: https://patchwork.linux-mips.org/patch/9569/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
diff --git a/arch/mips/pistachio/time.c b/arch/mips/pistachio/time.c
new file mode 100644
index 0000000..67889fc
--- /dev/null
+++ b/arch/mips/pistachio/time.c
@@ -0,0 +1,52 @@
+/*
+ * Pistachio clocksource/timer setup
+ *
+ * Copyright (C) 2014 Google, Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ */
+
+#include <linux/clk.h>
+#include <linux/clk-provider.h>
+#include <linux/clocksource.h>
+#include <linux/init.h>
+#include <linux/irqchip/mips-gic.h>
+#include <linux/of.h>
+
+#include <asm/time.h>
+
+unsigned int get_c0_compare_int(void)
+{
+	return gic_get_c0_compare_int();
+}
+
+int get_c0_perfcount_int(void)
+{
+	return gic_get_c0_perfcount_int();
+}
+
+void __init plat_time_init(void)
+{
+	struct device_node *np;
+	struct clk *clk;
+
+	of_clk_init(NULL);
+	clocksource_of_init();
+
+	np = of_get_cpu_node(0, NULL);
+	if (!np) {
+		pr_err("Failed to get CPU node\n");
+		return;
+	}
+
+	clk = of_clk_get(np, 0);
+	if (IS_ERR(clk)) {
+		pr_err("Failed to get CPU clock: %ld\n", PTR_ERR(clk));
+		return;
+	}
+
+	mips_hpt_frequency = clk_get_rate(clk) / 2;
+	clk_put(clk);
+}