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Diffstat (limited to 'drivers/clocksource/i8253.c')
-rw-r--r--drivers/clocksource/i8253.c13
1 files changed, 12 insertions, 1 deletions
diff --git a/drivers/clocksource/i8253.c b/drivers/clocksource/i8253.c
index 33735ebd2dcc..e594f52eb88e 100644
--- a/drivers/clocksource/i8253.c
+++ b/drivers/clocksource/i8253.c
@@ -6,10 +6,20 @@
#include <linux/io.h>
#include <linux/spinlock.h>
#include <linux/timex.h>
-
+#include <linux/module.h>
#include <linux/i8253.h>
/*
+ * Protects access to I/O ports
+ *
+ * 0040-0043 : timer0, i8253 / i8254
+ * 0061-0061 : NMI Control Register which contains two speaker control bits.
+ */
+DEFINE_RAW_SPINLOCK(i8253_lock);
+EXPORT_SYMBOL(i8253_lock);
+
+#ifdef CONFIG_CLKSRC_I8253
+/*
* Since the PIT overflows every tick, its not very useful
* to just read by itself. So use jiffies to emulate a free
* running counter:
@@ -86,3 +96,4 @@ int __init clocksource_i8253_init(void)
{
return clocksource_register_hz(&i8253_cs, PIT_TICK_RATE);
}
+#endif