1 files changed, 62 insertions, 0 deletions
diff --git a/arch/blackfin/include/asm/delay.h b/arch/blackfin/include/asm/delay.h
new file mode 100644
index 0000000..0889c3a
--- /dev/null
+++ b/arch/blackfin/include/asm/delay.h
@@ -0,0 +1,62 @@
+/*
+ * delay.h - delay functions
+ *
+ * Copyright (c) 2004-2007 Analog Devices Inc.
+ *
+ * Licensed under the GPL-2 or later.
+ */
+
+#ifndef __ASM_DELAY_H__
+#define __ASM_DELAY_H__
+
+#include <mach/anomaly.h>
+
+static inline void __delay(unsigned long loops)
+{
+	if (ANOMALY_05000312) {
+		/* Interrupted loads to loop registers -> bad */
+		unsigned long tmp;
+		__asm__ __volatile__(
+			"[--SP] = LC0;"
+			"[--SP] = LT0;"
+			"[--SP] = LB0;"
+			"LSETUP (1f,1f) LC0 = %1;"
+			"1: NOP;"
+			/* We take advantage of the fact that LC0 is 0 at
+			 * the end of the loop.  Otherwise we'd need some
+			 * NOPs after the CLI here.
+			 */
+			"CLI %0;"
+			"LB0 = [SP++];"
+			"LT0 = [SP++];"
+			"LC0 = [SP++];"
+			"STI %0;"
+			: "=d" (tmp)
+			: "a" (loops)
+		);
+	} else
+		__asm__ __volatile__ (
+			"LSETUP(1f, 1f) LC0 = %0;"
+			"1: NOP;"
+			:
+			: "a" (loops)
+			: "LT0", "LB0", "LC0"
+		);
+}
+
+#include <linux/param.h>	/* needed for HZ */
+
+/*
+ * Use only for very small delays ( < 1 msec).  Should probably use a
+ * lookup table, really, as the multiplications take much too long with
+ * short delays.  This is a "reasonable" implementation, though (and the
+ * first constant multiplications gets optimized away if the delay is
+ * a constant)
+ */
+static inline void udelay(unsigned long usecs)
+{
+	extern unsigned long loops_per_jiffy;
+	__delay(usecs * loops_per_jiffy / (1000000 / HZ));
+}
+
+#endif