diff options
| author | Kamil Alkhouri <kamil.alkhouri@hs-offenburg.de> | 2020-11-03 08:10:58 +0100 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2020-11-05 14:04:49 -0800 |
| commit | f0d4ba9eff75a79fccb7793f4d9f12303d458603 (patch) | |
| tree | a429e4c4e9c6b3828be46d2a4f8086419981d24c /drivers/net/dsa/hirschmann/Makefile | |
| parent | ddd56dfe52c987d82964595902db0600970ef406 (diff) | |
net: dsa: hellcreek: Add support for hardware timestamping
The switch has the ability to take hardware generated time stamps per port for
PTPv2 event messages in Rx and Tx direction. That is useful for achieving needed
time synchronization precision for TSN devices/switches. So add support for it.
There are two directions:
* RX
The switch has a single register per port to capture a timestamp. That
mechanism is not used due to correlation problems. If the software processing
is too slow and a PTPv2 event message is received before the previous one has
been processed, false timestamps will be captured. Therefore, the switch can
do "inline" timestamping which means it can insert the nanoseconds part of
the timestamp directly into the PTPv2 event message. The reserved field (4
bytes) is leveraged for that. This might not be in accordance with (older)
PTP standards, but is the only way to get reliable results.
* TX
In Tx direction there is no correlation problem, because the software and the
driver has to ensure that only one event message is "on the fly". However,
the switch provides also a mechanism to check whether a timestamp is
lost. That can only happen when a timestamp is read and at this point another
message is timestamped. So, that lost bit is checked just in case to indicate
to the user that the driver or the software is somewhat buggy.
Signed-off-by: Kamil Alkhouri <kamil.alkhouri@hs-offenburg.de>
Signed-off-by: Kurt Kanzenbach <kurt@linutronix.de>
Acked-by: Richard Cochran <richardcochran@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'drivers/net/dsa/hirschmann/Makefile')
| -rw-r--r-- | drivers/net/dsa/hirschmann/Makefile | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/drivers/net/dsa/hirschmann/Makefile b/drivers/net/dsa/hirschmann/Makefile index 39de02a03640..f4075c2998b5 100644 --- a/drivers/net/dsa/hirschmann/Makefile +++ b/drivers/net/dsa/hirschmann/Makefile @@ -2,3 +2,4 @@ obj-$(CONFIG_NET_DSA_HIRSCHMANN_HELLCREEK) += hellcreek_sw.o hellcreek_sw-objs := hellcreek.o hellcreek_sw-objs += hellcreek_ptp.o +hellcreek_sw-objs += hellcreek_hwtstamp.o |