Some PTP devices support looping back the periodic pulse signal for debugging. For example, the PTP device of QorIQ platform and the NETC v4 Timer has the ability to loop back the pulse signal and record the extts events for the loopback signal. So we can make sure that the pulse intervals and their phase alignment are correct from the perspective of the emitting PHC's time base. In addition, we can use this loopback feature as a built-in extts event generator when we have no external equipment which does that. Therefore, add the generic debugfs interfaces to the ptp_clock driver. The first two patch are separated from the previous patch set [1]. The third patch is new added.
[1]: https://lore.kernel.org/imx/20250827063332.1217664-1-wei.f...@nxp.com/ #patch 3 and 9 --- v2 changes: 1. The value of "enable" is restricted to 0 or 1. 2. Fix the typo: covert --> convert 3. Improve the cover-letter --- Wei Fang (3): ptp: add debugfs interfaces to loop back the periodic output signal ptp: netc: add the periodic output signal loopback support ptp: qoriq: convert to use generic interfaces to set loopback mode MAINTAINERS | 1 - drivers/ptp/Kconfig | 2 +- drivers/ptp/Makefile | 4 +- drivers/ptp/ptp_clock.c | 69 +++++++++++++++++++++ drivers/ptp/ptp_netc.c | 25 ++++++++ drivers/ptp/ptp_qoriq.c | 24 +++++++- drivers/ptp/ptp_qoriq_debugfs.c | 101 ------------------------------- include/linux/fsl/ptp_qoriq.h | 10 --- include/linux/ptp_clock_kernel.h | 10 +++ 9 files changed, 128 insertions(+), 118 deletions(-) delete mode 100644 drivers/ptp/ptp_qoriq_debugfs.c -- 2.34.1
