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1 #ifndef CSR_TIME_H__
2 #define CSR_TIME_H__
3 /*****************************************************************************
4 
5 (c) Cambridge Silicon Radio Limited 2010
6 All rights reserved and confidential information of CSR
7 
8 Refer to LICENSE.txt included with this source for details
9 on the license terms.
10 
11 *****************************************************************************/
12 
13 #include <linux/types.h>
14 
15 /*******************************************************************************
16 
17 NAME
18 	CsrTimeGet
19 
20 DESCRIPTION
21 	Returns the current system time in a low and a high part. The low part
22 	is expressed in microseconds. The high part is incremented when the low
23 	part wraps to provide an extended range.
24 
25 	The caller may provide a NULL pointer as the high parameter.
26 	In this case the function just returns the low part and ignores the
27 	high parameter.
28 
29 	Although the time is expressed in microseconds the actual resolution is
30 	platform dependent and can be less. It is recommended that the
31 	resolution is at least 10 milliseconds.
32 
33 PARAMETERS
34 	high - Pointer to variable that will receive the high part of the
35 	       current system time. Passing NULL is valid.
36 
37 RETURNS
38 	Low part of current system time in microseconds.
39 
40 *******************************************************************************/
41 u32 CsrTimeGet(u32 *high);
42 
43 
44 /*------------------------------------------------------------------*/
45 /* CsrTime Macros */
46 /*------------------------------------------------------------------*/
47 
48 /*----------------------------------------------------------------------------*
49  *  NAME
50  *      CsrTimeAdd
51  *
52  *  DESCRIPTION
53  *      Add two time values. Adding the numbers can overflow the range of a
54  *      CsrTime, so the user must be cautious.
55  *
56  *  RETURNS
57  *      CsrTime - the sum of "t1" and "t2".
58  *
59  *----------------------------------------------------------------------------*/
60 #define CsrTimeAdd(t1, t2) ((t1) + (t2))
61 
62 /*----------------------------------------------------------------------------*
63  *  NAME
64  *      CsrTimeSub
65  *
66  *  DESCRIPTION
67  *      Subtract two time values. Subtracting the numbers can provoke an
68  *      underflow, so the user must be cautious.
69  *
70  *  RETURNS
71  *      CsrTime - "t1" - "t2".
72  *
73  *----------------------------------------------------------------------------*/
74 #define CsrTimeSub(t1, t2)    ((s32) (t1) - (s32) (t2))
75 
76 #endif
77