asm-generic: delay.h fix udelay and ndelay for 8 bit args

[pandora-kernel.git] / include / asm-generic / delay.h

diff --git a/include/asm-generic/delay.h b/include/asm-generic/delay.h
index 4586fec..0f79054 100644 (file)
--- a/include/asm-generic/delay.h
+++ b/include/asm-generic/delay.h
@@ -1,9 +1,44 @@
 #ifndef __ASM_GENERIC_DELAY_H
 #define __ASM_GENERIC_DELAY_H
 
+/* Undefined functions to get compile-time errors */
+extern void __bad_udelay(void);
+extern void __bad_ndelay(void);
+
 extern void __udelay(unsigned long usecs);
+extern void __ndelay(unsigned long nsecs);
+extern void __const_udelay(unsigned long xloops);
 extern void __delay(unsigned long loops);
 
-#define udelay(n) __udelay(n)
+/*
+ * The weird n/20000 thing suppresses a "comparison is always false due to
+ * limited range of data type" warning with non-const 8-bit arguments.
+ */
+
+/* 0x10c7 is 2**32 / 1000000 (rounded up) */
+#define udelay(n)                                                      \
+       ({                                                              \
+               if (__builtin_constant_p(n)) {                          \
+                       if ((n) / 20000 >= 1)                           \
+                                __bad_udelay();                        \
+                       else                                            \
+                               __const_udelay((n) * 0x10c7ul);         \
+               } else {                                                \
+                       __udelay(n);                                    \
+               }                                                       \
+       })
+
+/* 0x5 is 2**32 / 1000000000 (rounded up) */
+#define ndelay(n)                                                      \
+       ({                                                              \
+               if (__builtin_constant_p(n)) {                          \
+                       if ((n) / 20000 >= 1)                           \
+                               __bad_ndelay();                         \
+                       else                                            \
+                               __const_udelay((n) * 5ul);              \
+               } else {                                                \
+                       __ndelay(n);                                    \
+               }                                                       \
+       })
 
 #endif /* __ASM_GENERIC_DELAY_H */