Blackfin: implement ndelay()

Signed-off-by: Barry Song <barry.song@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>

arch/blackfin/include/asm/delay.h

@@ -30,10 +30,22 @@ __asm__ __volatile__ (
 
 #define	HZSCALE		(268435456 / (1000000/HZ))
 
-static inline void udelay(unsigned long usecs)
+static inline unsigned long __to_delay(unsigned long scale)
 {
 	extern unsigned long loops_per_jiffy;
-	__delay((((usecs * HZSCALE) >> 11) * (loops_per_jiffy >> 11)) >> 6);
+	return (((scale * HZSCALE) >> 11) * (loops_per_jiffy >> 11)) >> 6;
+}
+
+static inline void udelay(unsigned long usecs)
+{
+	__delay(__to_delay(usecs));
 }
 
+static inline void ndelay(unsigned long nsecs)
+{
+	__delay(__to_delay(1) * nsecs / 1000);
+}
+
+#define ndelay ndelay
+
 #endif