net: stmmac: Add hardware supported cross-timestamp

Cross timestamping is supported on Integrated Ethernet Controller in
Intel SoC such as EHL and TGL with Always Running Timer.

The hardware cross-timestamp result is made available to
applications through the PTP_SYS_OFFSET_PRECISE ioctl which calls
stmmac_getcrosststamp().

Device time is stored in the MAC Auxiliary register. The 64-bit System
time (ART timestamp) is stored in registers that are only addressable
by using MDIO space.

Signed-off-by: Tan Tee Min <tee.min.tan@intel.com>
Co-developed-by: Wong Vee Khee <vee.khee.wong@linux.intel.com>
Signed-off-by: Wong Vee Khee <vee.khee.wong@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Tan Tee Min 2021-03-23 19:07:34 +08:00 • committed by David S. Miller
commit 341f67e424
9 changed files with 193 additions and 0 deletions