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authorAaron Durbin <adurbin@chromium.org>2014-09-25 10:05:15 -0500
committerPatrick Georgi <pgeorgi@google.com>2015-04-08 18:35:01 +0200
commite5e36306a9a5bf96ab8cc990d93bbd62030e635f (patch)
tree9ecc2fb162f97fa1e918f0830f2a49b183340280 /src/lib/timer.c
parent23b4e4c4e80c0acd17c088c6bdde8c3bfccce898 (diff)
downloadcoreboot-e5e36306a9a5bf96ab8cc990d93bbd62030e635f.tar.xz
timer: Add generic udelay() implementation
Add GENERIC_UDELAY Kconfig option so that a generic udelay() implementation is provided utilizing the monotonic timer. That way each board/chipset doesn't need to duplicate the same udelay(). Additionally, assume that GENERIC_UDELAY implies init_timer() is not required. BUG=None BRANCH=None TEST=Built nyan, ryu, and rambi. May need help testing. Change-Id: I7f511a2324b5aa5d1b2959f4519be85a6a7360e8 Signed-off-by: Patrick Georgi <pgeorgi@chromium.org> Original-Commit-Id: 1a85fbcad778933d13eaef545135abe7e4de46ed Original-Change-Id: Idd26de19eefc91ee3b0ceddfb1bc2152e19fd8ab Original-Signed-off-by: Aaron Durbin <adurbin@chromium.org> Original-Reviewed-on: https://chromium-review.googlesource.com/219719 Original-Reviewed-by: Julius Werner <jwerner@chromium.org> Original-Reviewed-by: Furquan Shaikh <furquan@chromium.org> Reviewed-on: http://review.coreboot.org/9334 Tested-by: build bot (Jenkins) Reviewed-by: Patrick Georgi <pgeorgi@google.com>
Diffstat (limited to 'src/lib/timer.c')
-rw-r--r--src/lib/timer.c42
1 files changed, 42 insertions, 0 deletions
diff --git a/src/lib/timer.c b/src/lib/timer.c
new file mode 100644
index 0000000000..a2edc5c96d
--- /dev/null
+++ b/src/lib/timer.c
@@ -0,0 +1,42 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright 2014 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 <console/console.h>
+#include <timer.h>
+#include <delay.h>
+#include <thread.h>
+
+void udelay(unsigned usec)
+{
+ struct stopwatch sw;
+
+ /*
+ * As the timer granularity is in microseconds pad the
+ * requested delay by one to get at least >= requested usec delay.
+ */
+ usec += 1;
+
+ if (!thread_yield_microseconds(usec))
+ return;
+
+ stopwatch_init_usecs_expire(&sw, usec);
+
+ while (!stopwatch_expired(&sw))
+ ;
+}