Initial file dump from open source releaseHEADmaster

1 files changed, 58 insertions, 0 deletions

diff --git a/arch/arm/kernel/arch_timer.c b/arch/arm/kernel/arch_timer.c
new file mode 100644
index 00000000..59dcdced
--- /dev/null
+++ b/arch/arm/kernel/arch_timer.c
@@ -0,0 +1,58 @@
+/*
+ *  linux/arch/arm/kernel/arch_timer.c
+ *
+ *  Copyright (C) 2011 ARM Ltd.
+ *  All Rights Reserved
+ *
+ * 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.
+ */
+#include <linux/init.h>
+#include <linux/types.h>
+#include <linux/errno.h>
+
+#include <asm/delay.h>
+#include <asm/sched_clock.h>
+
+#include <clocksource/arm_arch_timer.h>
+
+static unsigned long arch_timer_read_counter_long(void)
+{
+	return arch_timer_read_counter();
+}
+
+static u32 sched_clock_mult __read_mostly;
+
+static unsigned long long notrace arch_timer_sched_clock(void)
+{
+	return arch_timer_read_counter() * sched_clock_mult;
+}
+
+static struct delay_timer arch_delay_timer;
+
+static void __init arch_timer_delay_timer_register(void)
+{
+	/* Use the architected timer for the delay loop. */
+	arch_delay_timer.read_current_timer = arch_timer_read_counter_long;
+	arch_delay_timer.freq = arch_timer_get_rate();
+	register_current_timer_delay(&arch_delay_timer);
+}
+
+int __init arch_timer_arch_init(void)
+{
+        u32 arch_timer_rate = arch_timer_get_rate();
+
+	if (arch_timer_rate == 0)
+		return -ENXIO;
+
+	arch_timer_delay_timer_register();
+
+	/* Cache the sched_clock multiplier to save a divide in the hot path. */
+	sched_clock_mult = NSEC_PER_SEC / arch_timer_rate;
+	sched_clock_func = arch_timer_sched_clock;
+	pr_info("sched_clock: ARM arch timer >56 bits at %ukHz, resolution %uns\n",
+		arch_timer_rate / 1000, sched_clock_mult);
+
+	return 0;
+}