power: tps80031: battery-charger: register as mfd sub device
[linux-2.6.git] / include / linux / average.h
1 #ifndef _LINUX_AVERAGE_H
2 #define _LINUX_AVERAGE_H
3
4 /* Exponentially weighted moving average (EWMA) */
5
6 /* For more documentation see lib/average.c */
7
8 struct ewma {
9         unsigned long internal;
10         unsigned long factor;
11         unsigned long weight;
12 };
13
14 extern void ewma_init(struct ewma *avg, unsigned long factor,
15                       unsigned long weight);
16
17 extern struct ewma *ewma_add(struct ewma *avg, unsigned long val);
18
19 /**
20  * ewma_read() - Get average value
21  * @avg: Average structure
22  *
23  * Returns the average value held in @avg.
24  */
25 static inline unsigned long ewma_read(const struct ewma *avg)
26 {
27         return avg->internal >> avg->factor;
28 }
29
30 #endif /* _LINUX_AVERAGE_H */