diff --git a/include/linux/timekeeping.h b/include/linux/timekeeping.h
index 984a866d293b..b4191a873c39 100644
--- a/include/linux/timekeeping.h
+++ b/include/linux/timekeeping.h
@@ -276,7 +276,7 @@ static inline bool ktime_get_aux_ts64(clockid_t id, struct timespec64 *kt) { ret
 #endif
 
 /**
- * struct system_time_snapshot - Simultaneous time capture of CLOCK_MONOTONIC_RAW,
+ * struct system_time_snapshot - Simultaneous time capture of monotonic raw time,
  *				 a selected CLOCK_* and the clocksource counter value
  * @cycles:		Clocksource counter value to produce the system times
  * @hw_cycles:		For derived clocksources, the hardware counter value from
@@ -289,6 +289,10 @@ static inline bool ktime_get_aux_ts64(clockid_t id, struct timespec64 *kt) { ret
  * @clock_was_set_seq:	The sequence number of clock-was-set events
  * @cs_was_changed_seq:	The sequence number of clocksource change events
  * @valid:		True if the snapshot is valid
+ *
+ * @monoraw is CLOCK_MONOTONIC_RAW for system time CLOCK ids. For CLOCK_AUX$N
+ * clock ids it's the monotonic raw time related to the AUX clock, which is
+ * CLOCK_MONOTONIC_RAW plus a AUX clock specific offset.
  */
 struct system_time_snapshot {
 	u64			cycles;
@@ -326,6 +330,10 @@ struct system_counterval_t {
  * @sys_counter:	Clocksource counter value simultaneous with device time
  * @sys_systime:	System time for @clock_id
  * @sys_monoraw:	Monotonic raw simultaneous with device time
+ *
+ * @sys_monoraw is CLOCK_MONOTONIC_RAW for system time CLOCK ids. For
+ * CLOCK_AUX$N clock ids it's the monotonic raw time related to the AUX clock,
+ * which is CLOCK_MONOTONIC_RAW plus a AUX clock specific offset.
  */
 struct system_device_crosststamp {
 	clockid_t			clock_id;
diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c
index b1b5ec43c0f2..5985d6652c1d 100644
--- a/kernel/time/timekeeping.c
+++ b/kernel/time/timekeeping.c
@@ -1202,10 +1202,21 @@ static inline u64 tk_clock_read_snapshot(const struct tk_read_base *tkr,
 
 /**
  * ktime_get_snapshot_id -  Simultaneously snapshot a given clock ID with
- *			    CLOCK_MONOTONIC_RAW and the underlying
+ *			    the corresponding monotonic raw and the underlying
  *			    clocksource counter value.
  * @clock_id:		The clock ID to snapshot
  * @systime_snapshot:	Pointer to struct receiving the system time snapshot
+ *
+ * For the system time keeping clocks (REALTIME, MONOTONIC and BOOTTIME) the
+ * monotonic raw clock is CLOCK_MONOTONIC_RAW. For AUX clocks this is the
+ * monotonic raw clock related to the AUX clock. These AUX clock related
+ * monotonic raw clocks have a strict linear offset to the system time
+ * CLOCK_MONOTONIC_RAW:
+ *
+ *	MONOTONIC_RAW(AUX$N) = CLOCK_MONOTONIC_RAW(system) + offset(AUX$N)
+ *
+ * The offset is established when a AUX clock is initialized, but it is
+ * currently not accessible.
  */
 void ktime_get_snapshot_id(clockid_t clock_id, struct system_time_snapshot *systime_snapshot)
 {
@@ -1512,6 +1523,9 @@ EXPORT_SYMBOL_GPL(ktime_real_to_base_clock);
  * @xtstamp:		Receives simultaneously captured system and device time
  *
  * Reads a timestamp from a device and correlates it to system time
+ *
+ * See documentation for ktime_get_snapshot_id() for information about the raw
+ * monotonic time stamp which is used here.
  */
 int get_device_system_crosststamp(int (*get_time_fn)
 				  (ktime_t *device_time,