summaryrefslogtreecommitdiff
path: root/src/cpu
diff options
context:
space:
mode:
authorDavid Hendricks <dhendrix@chromium.org>2013-05-02 13:23:08 -0700
committerStefan Reinauer <stefan.reinauer@coreboot.org>2013-05-03 06:28:54 +0200
commit5ec69ed884852426e17439263e3678c5dfbc71e7 (patch)
tree35ad1882b197bd5f484e32eabb3eebbf0e38d0eb /src/cpu
parent008616247d4f03b47b2eb996029072a21789f3e0 (diff)
exynos5250: monotonic timer implementation (using MCT)
This implements the new monotonic timer API using the global multi-core timer (MCT). Change-Id: Id56249ff5d3e0f85808f5754954c83c0bc75f1c1 Signed-off-by: David Hendricks <dhendrix@chromium.org> Reviewed-on: http://review.coreboot.org/3175 Reviewed-by: Aaron Durbin <adurbin@google.com> Tested-by: build bot (Jenkins)
Diffstat (limited to 'src/cpu')
-rw-r--r--src/cpu/samsung/exynos5250/clk.h2
-rw-r--r--src/cpu/samsung/exynos5250/mct.c5
-rw-r--r--src/cpu/samsung/exynos5250/monotonic_timer.c58
3 files changed, 62 insertions, 3 deletions
diff --git a/src/cpu/samsung/exynos5250/clk.h b/src/cpu/samsung/exynos5250/clk.h
index 4785894668..1894c006d2 100644
--- a/src/cpu/samsung/exynos5250/clk.h
+++ b/src/cpu/samsung/exynos5250/clk.h
@@ -585,4 +585,6 @@ int clock_get_mem_selection(enum ddr_mode *mem_type,
unsigned *frequency_mhz, unsigned *arm_freq,
enum mem_manuf *mem_manuf);
+uint64_t mct_raw_value(void);
+
#endif
diff --git a/src/cpu/samsung/exynos5250/mct.c b/src/cpu/samsung/exynos5250/mct.c
index ddabbf7957..4216643140 100644
--- a/src/cpu/samsung/exynos5250/mct.c
+++ b/src/cpu/samsung/exynos5250/mct.c
@@ -88,7 +88,7 @@ static int enabled = 0;
static struct mct_regs *const mct =
(struct mct_regs *)MCT_ADDRESS;
-static uint64_t timer_raw_value(void)
+uint64_t mct_raw_value(void)
{
if (!enabled) {
writel(readl(&mct->g_tcon) | (0x1 << 8), &mct->g_tcon);
@@ -109,9 +109,8 @@ void timer_start(void)
u32 timer_us(void)
{
- uint64_t raw = timer_raw_value();
+ uint64_t raw = mct_raw_value();
static uint32_t ticks_per_microsecond = MCT_HZ/1000000;
uint32_t usec = raw / ticks_per_microsecond;
return usec;
}
-
diff --git a/src/cpu/samsung/exynos5250/monotonic_timer.c b/src/cpu/samsung/exynos5250/monotonic_timer.c
new file mode 100644
index 0000000000..85fb2082b3
--- /dev/null
+++ b/src/cpu/samsung/exynos5250/monotonic_timer.c
@@ -0,0 +1,58 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright (C) 2013 Google, Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ *
+ * 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include <stdint.h>
+#include <delay.h>
+#include <timer.h>
+#include <time.h> /* TODO: deprecate in favor of monotonic timer stuff */
+
+#include "clk.h"
+
+static struct monotonic_counter {
+ int initialized;
+ struct mono_time time;
+ uint64_t last_value;
+} mono_counter;
+
+static const uint32_t clocks_per_usec = MCT_HZ/1000000;
+
+void timer_monotonic_get(struct mono_time *mt)
+{
+ uint64_t current_tick;
+ uint64_t usecs_elapsed;
+
+ if (!mono_counter.initialized) {
+ init_timer();
+ mono_counter.last_value = mct_raw_value();
+ mono_counter.initialized = 1;
+ }
+
+ current_tick = mct_raw_value();
+ usecs_elapsed = (current_tick - mono_counter.last_value) /
+ clocks_per_usec;
+
+ /* Update current time and tick values only if a full tick occurred. */
+ if (usecs_elapsed) {
+ mono_time_add_usecs(&mono_counter.time, usecs_elapsed);
+ mono_counter.last_value = current_tick;
+ }
+
+ /* Save result. */
+ *mt = mono_counter.time;
+}