Merge branch 'ptp-add-pulse-signal-loopback-support-for-debugging'

Wei Fang says:

====================
ptp: add pulse signal loopback support for debugging

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.fang@nxp.com/ #patch 3 and 9
====================

Link: https://patch.msgid.link/20250905030711.1509648-1-wei.fang@nxp.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

1 files changed, 10 insertions, 0 deletions

diff --git a/include/linux/ptp_clock_kernel.h b/include/linux/ptp_clock_kernel.h
index 7dd7951b23d5..884364596dd3 100644
--- a/include/linux/ptp_clock_kernel.h
+++ b/include/linux/ptp_clock_kernel.h
@@ -67,6 +67,8 @@ struct ptp_system_timestamp {
  * @n_ext_ts:  The number of external time stamp channels.
  * @n_per_out: The number of programmable periodic signals.
  * @n_pins:    The number of programmable pins.
+ * @n_per_lp:  The number of channels that support loopback the periodic
+ *             output signal.
  * @pps:       Indicates whether the clock supports a PPS callback.
  *
  * @supported_perout_flags:  The set of flags the driver supports for the
@@ -175,6 +177,11 @@ struct ptp_system_timestamp {
  *                scheduling time (>=0) or negative value in case further
  *                scheduling is not required.
  *
+ * @perout_loopback: Request driver to enable or disable the periodic output
+ *                   signal loopback.
+ *                   parameter index: index of the periodic output signal channel.
+ *                   parameter on: caller passes one to enable or zero to disable.
+ *
  * Drivers should embed their ptp_clock_info within a private
  * structure, obtaining a reference to it using container_of().
  *
@@ -189,6 +196,7 @@ struct ptp_clock_info {
 	int n_ext_ts;
 	int n_per_out;
 	int n_pins;
+	int n_per_lp;
 	int pps;
 	unsigned int supported_perout_flags;
 	unsigned int supported_extts_flags;
@@ -213,6 +221,8 @@ struct ptp_clock_info {
 	int (*verify)(struct ptp_clock_info *ptp, unsigned int pin,
 		      enum ptp_pin_function func, unsigned int chan);
 	long (*do_aux_work)(struct ptp_clock_info *ptp);
+	int (*perout_loopback)(struct ptp_clock_info *ptp, unsigned int index,
+			       int on);
 };
 
 struct ptp_clock;