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Diffstat (limited to 'drivers/staging/csr/csr_time.h')
-rw-r--r-- | drivers/staging/csr/csr_time.h | 114 |
1 files changed, 114 insertions, 0 deletions
diff --git a/drivers/staging/csr/csr_time.h b/drivers/staging/csr/csr_time.h new file mode 100644 index 000000000000..2a45f3e4024d --- /dev/null +++ b/drivers/staging/csr/csr_time.h @@ -0,0 +1,114 @@ +#ifndef CSR_TIME_H__ +#define CSR_TIME_H__ +/***************************************************************************** + + (c) Cambridge Silicon Radio Limited 2010 + All rights reserved and confidential information of CSR + + Refer to LICENSE.txt included with this source for details + on the license terms. + +*****************************************************************************/ + +#include <linux/types.h> + +#ifdef __cplusplus +extern "C" { +#endif + +/******************************************************************************* + + NAME + CsrTime + + DESCRIPTION + Type to hold a value describing the current system time, which is a + measure of time elapsed since some arbitrarily defined fixed time + reference, usually associated with system startup. + +*******************************************************************************/ +typedef u32 CsrTime; + + +/******************************************************************************* + + NAME + CsrTimeUtc + + DESCRIPTION + Type to hold a value describing a UTC wallclock time expressed in + seconds and milliseconds elapsed since midnight January 1st 1970. + +*******************************************************************************/ +typedef struct +{ + u32 sec; + u16 msec; +} CsrTimeUtc; + + +/******************************************************************************* + + NAME + CsrTimeGet + + DESCRIPTION + Returns the current system time in a low and a high part. The low part + is expressed in microseconds. The high part is incremented when the low + part wraps to provide an extended range. + + The caller may provide a NULL pointer as the high parameter. In this case + the function just returns the low part and ignores the high parameter. + + Although the time is expressed in microseconds the actual resolution is + platform dependent and can be less. It is recommended that the + resolution is at least 10 milliseconds. + + PARAMETERS + high - Pointer to variable that will receive the high part of the + current system time. Passing NULL is valid. + + RETURNS + Low part of current system time in microseconds. + +*******************************************************************************/ +CsrTime CsrTimeGet(CsrTime *high); + + +/*------------------------------------------------------------------*/ +/* CsrTime Macros */ +/*------------------------------------------------------------------*/ + +/*----------------------------------------------------------------------------* + * NAME + * CsrTimeAdd + * + * DESCRIPTION + * Add two time values. Adding the numbers can overflow the range of a + * CsrTime, so the user must be cautious. + * + * RETURNS + * CsrTime - the sum of "t1" and "t2". + * + *----------------------------------------------------------------------------*/ +#define CsrTimeAdd(t1, t2) ((t1) + (t2)) + +/*----------------------------------------------------------------------------* + * NAME + * CsrTimeSub + * + * DESCRIPTION + * Subtract two time values. Subtracting the numbers can provoke an + * underflow, so the user must be cautious. + * + * RETURNS + * CsrTime - "t1" - "t2". + * + *----------------------------------------------------------------------------*/ +#define CsrTimeSub(t1, t2) ((s32) (t1) - (s32) (t2)) + +#ifdef __cplusplus +} +#endif + +#endif |