>From: Kitszel, Przemyslaw <przemyslaw.kits...@intel.com> >Sent: Tuesday, October 29, 2024 9:25 AM >Subject: Re: [PATCH net-next v2 1/2] ptp: add control over HW timestamp >latch point > >On 10/28/24 21:47, Arkadiusz Kubalewski wrote: >> Currently HW support of PTP/timesync solutions in network PHY chips >> can be implemented with two different approaches, the timestamp maybe >> latched either at the beginning or after the Start of Frame Delimiter >>(SFD) [1]. >> >> Allow ptp device drivers to provide user with control over the HW >> timestamp latch point with ptp sysfs ABI. Provide a new file under >> sysfs ptp device (/sys/class/ptp/ptp<N>/ts_point). The file is >> available for the user, if the device driver implements at least one >> of newly provided callbacks. If the file is not provided the user >> shall find a PHY timestamp latch point within the HW vendor >>specification. >> >> The file is designed for root user/group access only, as the read for >> regular user could impact performance of the ptp device. >> >> Usage, examples: >> >> ** Obtain current state: >> $ cat /sys/class/ptp/ptp<N>/ts_point >> Command returns enum/integer: >> * 0 - timestamp latched by PHY at the beginning of SFD, >> * 1 - timestamp latched by PHY after the SFD, >> * None - callback returns error to the user. >> >> ** Configure timestamp latch point at the beginning of SFD: >> $ echo 0 > /sys/class/ptp/ptp<N>/ts_point >> >> ** Configure timestamp latch point after the SFD: >> $ echo 1 > /sys/class/ptp/ptp<N>/ts_point >> >> [1] https://www.ieee802.org/3/cx/public/april20/tse_3cx_01_0420.pdf >> >> Reviewed-by: Aleksandr Loktionov <aleksandr.loktio...@intel.com> >> Signed-off-by: Arkadiusz Kubalewski <arkadiusz.kubalew...@intel.com> > >[...] > >> diff --git a/include/linux/ptp_clock_kernel.h >> b/include/linux/ptp_clock_kernel.h >> index c892d22ce0a7..ea1bcca7f7f6 100644 >> --- a/include/linux/ptp_clock_kernel.h >> +++ b/include/linux/ptp_clock_kernel.h >> @@ -55,6 +55,24 @@ struct ptp_system_timestamp { >> clockid_t clockid; >> }; >> >> +/** >> + * enum ptp_ts_point - possible timestamp latch points (IEEE 802.3cx) >> + * >> + * @PTP_TS_POINT_SFD: timestamp latched at the beginning of sending >Start >> + * of Frame Delimiter (SFD) >> + * @PTP_TS_POINT_POST_SFD: timestamp latched after the end of sending >Start >> + * of Frame Delimiter (SFD) >> + */ >> +enum ptp_ts_point { >> + PTP_TS_POINT_SFD, >> + PTP_TS_POINT_POST_SFD, >> + >> + /* private: */ >> + __PTP_TS_POINT_MAX >> +}; >> + >> +#define PTP_TS_POINT_MAX (__PTP_TS_POINT_MAX - 1) > >I would move PTP_TS_POINT_MAX into the enum >
Fixed in v3. Thank you! Arkadiusz
