1 files changed, 76 insertions, 0 deletions

diff --git a/arch/m68knommu/include/asm/delay.h b/arch/m68knommu/include/asm/delay.h
new file mode 100644
index 000000000000..55cbd6294ab6
--- /dev/null
+++ b/arch/m68knommu/include/asm/delay.h
@@ -0,0 +1,76 @@
+#ifndef _M68KNOMMU_DELAY_H
+#define _M68KNOMMU_DELAY_H
+
+/*
+ * Copyright (C) 1994 Hamish Macdonald
+ * Copyright (C) 2004 Greg Ungerer <gerg@snapgear.com>
+ */
+
+#include <asm/param.h>
+
+static inline void __delay(unsigned long loops)
+{
+#if defined(CONFIG_COLDFIRE)
+        /* The coldfire runs this loop at significantly different speeds
+         * depending upon long word alignment or not.  We'll pad it to
+         * long word alignment which is the faster version.
+         * The 0x4a8e is of course a 'tstl %fp' instruction.  This is better
+         * than using a NOP (0x4e71) instruction because it executes in one
+         * cycle not three and doesn't allow for an arbitary delay waiting
+         * for bus cycles to finish.  Also fp/a6 isn't likely to cause a
+         * stall waiting for the register to become valid if such is added
+         * to the coldfire at some stage.
+         */
+        __asm__ __volatile__ (  ".balignw 4, 0x4a8e\n\t"
+                                "1: subql #1, %0\n\t"
+                                "jcc 1b"
+                : "=d" (loops) : "0" (loops));
+#else
+        __asm__ __volatile__ (  "1: subql #1, %0\n\t"
+                                "jcc 1b"
+                : "=d" (loops) : "0" (loops));
+#endif
+}
+
+/*
+ *      Ideally we use a 32*32->64 multiply to calculate the number of
+ *      loop iterations, but the older standard 68k and ColdFire do not
+ *      have this instruction. So for them we have a clsoe approximation
+ *      loop using 32*32->32 multiplies only. This calculation based on
+ *      the ARM version of delay.
+ *
+ *      We want to implement:
+ *
+ *      loops = (usecs * 0x10c6 * HZ * loops_per_jiffy) / 2^32
+ */
+
+#define HZSCALE         (268435456 / (1000000/HZ))
+
+extern unsigned long loops_per_jiffy;
+
+static inline void _udelay(unsigned long usecs)
+{
+#if defined(CONFIG_M68328) || defined(CONFIG_M68EZ328) || \
+    defined(CONFIG_M68VZ328) || defined(CONFIG_M68360) || \
+    defined(CONFIG_COLDFIRE)
+        __delay((((usecs * HZSCALE) >> 11) * (loops_per_jiffy >> 11)) >> 6);
+#else
+        unsigned long tmp;
+
+        usecs *= 4295;          /* 2**32 / 1000000 */
+        __asm__ ("mulul %2,%0:%1"
+                : "=d" (usecs), "=d" (tmp)
+                : "d" (usecs), "1" (loops_per_jiffy*HZ));
+        __delay(usecs);
+#endif
+}
+
+/*
+ *      Moved the udelay() function into library code, no longer inlined.
+ *      I had to change the algorithm because we are overflowing now on
+ *      the faster ColdFire parts. The code is a little bigger, so it makes
+ *      sense to library it.
+ */
+extern void udelay(unsigned long usecs);
+
+#endif /* defined(_M68KNOMMU_DELAY_H) */