[Intel-wired-lan] [PATCH next-queue v2 2/2] igc: enable auxiliary PHC functions for the i225

[Dvora Fuxbrumer]

On 19/02/2021 03:31, Ederson de Souza wrote:
> The i225 device offers a number of special PTP Hardware Clock features on
> the Software Defined Pins (SDPs) - much like i210, which is used as
> inspiration for this patch. It enables two possible functions, namely
> time stamping external events and periodic output signals.
> 
> The assignment of PHC functions to the four SDP can be freely chosen by
> the user.
> 
> For the external events time stamping, when the SDP (configured as input
> by user) level changes, an interrupt is generated and the kernel
> Precision Time Protocol (PTP) is informed.
> 
> For the periodic output signals, the i225 is configured to generate them
> (so the SDP level will change periodically) and the driver also has to
> keep updating the time of the next level change. However, this work is
> not necessary for some frequencies as the i225 takes care of them
> (namely, anything with a half-cycle of 500ms, 250ms, 125ms or < 70ms).
> 
> While i225 allows up to four timers to be used to source the time used
> on the external events or output signals, this patch uses only one of
> those timers. Main reason is to keep it simple, as it's not clear how
> these extra timers would be exposed to users. Note that currently a NIC
> can expose a single PTP device.
> 
> Signed-off-by: Ederson de Souza <ederson.desouza at intel.com>
> ---
>   drivers/net/ethernet/intel/igc/igc.h         |  11 +
>   drivers/net/ethernet/intel/igc/igc_defines.h |  63 +++++
>   drivers/net/ethernet/intel/igc/igc_main.c    |  55 +++-
>   drivers/net/ethernet/intel/igc/igc_ptp.c     | 269 ++++++++++++++++++-
>   drivers/net/ethernet/intel/igc/igc_regs.h    |  10 +
>   5 files changed, 405 insertions(+), 3 deletions(-)
> 
Tested-by: Dvora Fuxbrumer <dvorax.fuxbrumer at linux.intel.com>