summaryrefslogtreecommitdiff
path: root/arch/c6x/kernel/time.c
diff options
context:
space:
mode:
authorLinus Torvalds <torvalds@linux-foundation.org>2012-01-10 17:39:40 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2012-01-10 17:39:40 -0800
commit06792c4dde2ad143928cc95c1ba218c6269c494b (patch)
tree92bdd4631612c9e3d8e5f6f06839f75c5473300a /arch/c6x/kernel/time.c
parent4690dfa8cd66c37fbe99bb8cd5baa86102110776 (diff)
parent166c0eaedfc3157dc1394c27e827add19f05fb27 (diff)
Merge tag 'for-linux-3.3-merge-window' of git://linux-c6x.org/git/projects/linux-c6x-upstreaming
* tag 'for-linux-3.3-merge-window' of git://linux-c6x.org/git/projects/linux-c6x-upstreaming: (29 commits) C6X: replace tick_nohz_stop/restart_sched_tick calls C6X: add register_cpu call C6X: deal with memblock API changes C6X: fix timer64 initialization C6X: fix layout of EMIFA registers C6X: MAINTAINERS C6X: DSCR - Device State Configuration Registers C6X: EMIF - External Memory Interface C6X: general SoC support C6X: library code C6X: headers C6X: ptrace support C6X: loadable module support C6X: cache control C6X: clocks C6X: build infrastructure C6X: syscalls C6X: interrupt handling C6X: time management C6X: signal management ...
Diffstat (limited to 'arch/c6x/kernel/time.c')
-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 000000000000..4c9f136165f7
--- /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();
+}