Add the rt linux 4.1.3-rt3 as base

[kvmfornfv.git] / kernel / drivers / clocksource / versatile.c

diff --git a/kernel/drivers/clocksource/versatile.c b/kernel/drivers/clocksource/versatile.c
new file mode 100644 (file)
index 0000000..0a26d3d
--- /dev/null
+++ b/kernel/drivers/clocksource/versatile.c
@@ -0,0 +1,42 @@
+/*
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * Copyright (C) 2014 ARM Limited
+ */
+
+#include <linux/clocksource.h>
+#include <linux/io.h>
+#include <linux/of_address.h>
+#include <linux/sched_clock.h>
+
+#define SYS_24MHZ 0x05c
+
+static void __iomem *versatile_sys_24mhz;
+
+static u64 notrace versatile_sys_24mhz_read(void)
+{
+       return readl(versatile_sys_24mhz);
+}
+
+static void __init versatile_sched_clock_init(struct device_node *node)
+{
+       void __iomem *base = of_iomap(node, 0);
+
+       if (!base)
+               return;
+
+       versatile_sys_24mhz = base + SYS_24MHZ;
+
+       sched_clock_register(versatile_sys_24mhz_read, 32, 24000000);
+}
+CLOCKSOURCE_OF_DECLARE(vexpress, "arm,vexpress-sysreg",
+                      versatile_sched_clock_init);
+CLOCKSOURCE_OF_DECLARE(versatile, "arm,versatile-sysreg",
+                      versatile_sched_clock_init);