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ptp: ptp_clock: make scaled_ppm_to_ppb static inline

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Make scaled_ppm_to_ppb static inline to be able to build drivers that
use this function even with PTP_1588_CLOCK disabled.

Signed-off-by: Radu Pirea (NXP OSS) <radu-nicolae.pirea@oss.nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Radu Pirea (NXP OSS) 2021-05-10 18:34:32 +03:00 committed by David S. Miller
parent 532062b099
commit 9d9d415f00
2 changed files with 26 additions and 29 deletions
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21
drivers/ptp/ptp_clock.c
View file

@ -63,27 +63,6 @@ static void enqueue_external_timestamp(struct timestamp_event_queue *queue,
spin_unlock_irqrestore(&queue->lock, flags);
}
s32 scaled_ppm_to_ppb(long ppm)
{
/*
* The 'freq' field in the 'struct timex' is in parts per
* million, but with a 16 bit binary fractional field.
*
* We want to calculate
*
* ppb = scaled_ppm * 1000 / 2^16
*
* which simplifies to
*
* ppb = scaled_ppm * 125 / 2^13
*/
s64 ppb = 1 + ppm;
ppb *= 125;
ppb >>= 13;
return (s32) ppb;
}
EXPORT_SYMBOL(scaled_ppm_to_ppb);
/* posix clock implementation */
static int ptp_clock_getres(struct posix_clock *pc, struct timespec64 *tp)

34
include/linux/ptp_clock_kernel.h
View file

@ -186,6 +186,32 @@ struct ptp_clock_event {
};
};
/**
* scaled_ppm_to_ppb() - convert scaled ppm to ppb
*
* @ppm: Parts per million, but with a 16 bit binary fractional field
*/
static inline s32 scaled_ppm_to_ppb(long ppm)
{
/*
* The 'freq' field in the 'struct timex' is in parts per
* million, but with a 16 bit binary fractional field.
*
* We want to calculate
*
* ppb = scaled_ppm * 1000 / 2^16
*
* which simplifies to
*
* ppb = scaled_ppm * 125 / 2^13
*/
s64 ppb = 1 + ppm;
ppb *= 125;
ppb >>= 13;
return (s32)ppb;
}
#if IS_REACHABLE(CONFIG_PTP_1588_CLOCK)
/**
@ -229,14 +255,6 @@ extern void ptp_clock_event(struct ptp_clock *ptp,
extern int ptp_clock_index(struct ptp_clock *ptp);
/**
* scaled_ppm_to_ppb() - convert scaled ppm to ppb
*
* @ppm: Parts per million, but with a 16 bit binary fractional field
*/
extern s32 scaled_ppm_to_ppb(long ppm);
/**
* ptp_find_pin() - obtain the pin index of a given auxiliary function
*