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authorAurelien Jacquiot <a-jacquiot@ti.com>2011-10-04 11:05:33 -0400
committerMark Salter <msalter@redhat.com>2011-10-06 19:47:51 -0400
commit546a39546c64ad7e73796c5508ef5487af42cae2 (patch)
tree9ab7fb5512ac1a99ab29267482469dcd8a8252ff /arch/c6x/kernel
parent03a347558749caaab482f34410ae5d27e893db89 (diff)
downloadvexpress-lsk-546a39546c64ad7e73796c5508ef5487af42cae2.tar.gz
C6X: time management
Original port to early 2.6 kernel using TI COFF toolchain. Brought up to date by Mark Salter <msalter@redhat.com> Signed-off-by: Aurelien Jacquiot <a-jacquiot@ti.com> Signed-off-by: Mark Salter <msalter@redhat.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Arnd Bergmann <arnd@arndb.de>
Diffstat (limited to 'arch/c6x/kernel')
-rw-r--r--arch/c6x/kernel/time.c65
1 files changed, 65 insertions, 0 deletions
diff --git a/arch/c6x/kernel/time.c b/arch/c6x/kernel/time.c
new file mode 100644
index 00000000000..4c9f136165f
--- /dev/null
+++ b/arch/c6x/kernel/time.c
@@ -0,0 +1,65 @@
+/*
+ * Port on Texas Instruments TMS320C6x architecture
+ *
+ * Copyright (C) 2004, 2009, 2010, 2011 Texas Instruments Incorporated
+ * Author: Aurelien Jacquiot (aurelien.jacquiot@jaluna.com)
+ *
+ * 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/kernel.h>
+#include <linux/clocksource.h>
+#include <linux/errno.h>
+#include <linux/sched.h>
+#include <linux/param.h>
+#include <linux/string.h>
+#include <linux/mm.h>
+#include <linux/interrupt.h>
+#include <linux/timex.h>
+#include <linux/profile.h>
+
+#include <asm/timer64.h>
+
+static u32 sched_clock_multiplier;
+#define SCHED_CLOCK_SHIFT 16
+
+static cycle_t tsc_read(struct clocksource *cs)
+{
+ return get_cycles();
+}
+
+static struct clocksource clocksource_tsc = {
+ .name = "timestamp",
+ .rating = 300,
+ .read = tsc_read,
+ .mask = CLOCKSOURCE_MASK(64),
+ .flags = CLOCK_SOURCE_IS_CONTINUOUS,
+};
+
+/*
+ * scheduler clock - returns current time in nanoseconds.
+ */
+u64 sched_clock(void)
+{
+ u64 tsc = get_cycles();
+
+ return (tsc * sched_clock_multiplier) >> SCHED_CLOCK_SHIFT;
+}
+
+void time_init(void)
+{
+ u64 tmp = (u64)NSEC_PER_SEC << SCHED_CLOCK_SHIFT;
+
+ do_div(tmp, c6x_core_freq);
+ sched_clock_multiplier = tmp;
+
+ clocksource_register_hz(&clocksource_tsc, c6x_core_freq);
+
+ /* write anything into TSCL to enable counting */
+ set_creg(TSCL, 0);
+
+ /* probe for timer64 event timer */
+ timer64_init();
+}