OpenRISC: Library routines

[pandora-kernel.git] / arch / openrisc / lib / delay.c

diff --git a/arch/openrisc/lib/delay.c b/arch/openrisc/lib/delay.c
new file mode 100644 (file)
index 0000000..01d9740
--- /dev/null
+++ b/arch/openrisc/lib/delay.c
@@ -0,0 +1,60 @@
+/*
+ * OpenRISC Linux
+ *
+ * Linux architectural port borrowing liberally from similar works of
+ * others.  All original copyrights apply as per the original source
+ * declaration.
+ *
+ * Modifications for the OpenRISC architecture:
+ * Copyright (C) 2010-2011 Jonas Bonn <jonas@southpole.se>
+ *
+ *      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
+ *
+ * Precise Delay Loops
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <asm/delay.h>
+#include <asm/timex.h>
+#include <asm/processor.h>
+
+int __devinit read_current_timer(unsigned long *timer_value)
+{
+       *timer_value = mfspr(SPR_TTCR);
+       return 0;
+}
+
+void __delay(unsigned long cycles)
+{
+       cycles_t target = get_cycles() + cycles;
+
+       while (get_cycles() < target)
+               cpu_relax();
+}
+EXPORT_SYMBOL(__delay);
+
+inline void __const_udelay(unsigned long xloops)
+{
+       unsigned long long loops;
+
+       loops = xloops * loops_per_jiffy * HZ;
+
+       __delay(loops >> 32);
+}
+EXPORT_SYMBOL(__const_udelay);
+
+void __udelay(unsigned long usecs)
+{
+       __const_udelay(usecs * 0x10C7UL); /* 2**32 / 1000000 (rounded up) */
+}
+EXPORT_SYMBOL(__udelay);
+
+void __ndelay(unsigned long nsecs)
+{
+       __const_udelay(nsecs * 0x5UL); /* 2**32 / 1000000000 (rounded up) */
+}
+EXPORT_SYMBOL(__ndelay);