Commit 4bfa1616 authored by Vladimir Oltean's avatar Vladimir Oltean Committed by David S. Miller
Browse files

net: dsa: sja1105: make future_base_time a common helper 



Because the PTP_CLK pin starts toggling only at a time higher than the
current PTP clock, this helper from the time-aware shaper code comes in
handy here as well. We'll use it to transform generic user input for the
perout request into valid input for the sja1105 hardware.

Signed-off-by: default avatarVladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 79d5511c

drivers/net/dsa/sja1105/sja1105_ptp.h

+27 −0
Original line number Diff line number Diff line
@@ -21,6 +21,33 @@ static inline s64 sja1105_ticks_to_ns(s64 ticks) 
	return ticks * SJA1105_TICK_NS;

}



/* Calculate the first base_time in the future that satisfies this

 * relationship:

 *

 * future_base_time = base_time + N x cycle_time >= now, or

 *

 *      now - base_time

 * N >= ---------------

 *         cycle_time

 *

 * Because N is an integer, the ceiling value of the above "a / b" ratio

 * is in fact precisely the floor value of "(a + b - 1) / b", which is

 * easier to calculate only having integer division tools.

 */

static inline s64 future_base_time(s64 base_time, s64 cycle_time, s64 now)

{

	s64 a, b, n;



	if (base_time >= now)

		return base_time;



	a = now - base_time;

	b = cycle_time;

	n = div_s64(a + b - 1, b);



	return base_time + n * cycle_time;

}



struct sja1105_ptp_cmd {

	u64 ptpstrtsch;		/* start schedule */

	u64 ptpstopsch;		/* stop schedule */

drivers/net/dsa/sja1105/sja1105_tas.c

+0 −27
Original line number Diff line number Diff line
@@ -28,33 +28,6 @@ static s64 sja1105_delta_to_ns(s64 delta) 
	return delta * 200;

}



/* Calculate the first base_time in the future that satisfies this

 * relationship:

 *

 * future_base_time = base_time + N x cycle_time >= now, or

 *

 *      now - base_time

 * N >= ---------------

 *         cycle_time

 *

 * Because N is an integer, the ceiling value of the above "a / b" ratio

 * is in fact precisely the floor value of "(a + b - 1) / b", which is

 * easier to calculate only having integer division tools.

 */

static s64 future_base_time(s64 base_time, s64 cycle_time, s64 now)

{

	s64 a, b, n;



	if (base_time >= now)

		return base_time;



	a = now - base_time;

	b = cycle_time;

	n = div_s64(a + b - 1, b);



	return base_time + n * cycle_time;

}



static int sja1105_tas_set_runtime_params(struct sja1105_private *priv)

{

	struct sja1105_tas_data *tas_data = &priv->tas_data;

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