Re: [PATCH v4 net-next 1/7] ptp: Add ioctls for PHC timestamps with quality attributes

+
+/*
+ * Clock timescale values for struct ptp_clock_attrs.timescale.
+ *
+ * These definitions describe the mathematical properties and reference
+ * epochs of the timescale provided by the PHC.
+ *
+ * Discipline: Describes the frequency/phase steering behavior.
+ * Continuity: Describes whether the timeline is uninterrupted.
+ */
+enum ptp_clock_timescale {
+	/* Unknown or unspecified timescale */
+	PTP_TIMESCALE_UNKNOWN = 0,
+
+	/********************* Absolute Atomic Timescales *********************
+	 * These timescales are continuous, monotonic standards based on atomic
+	 * physics. They do not experience phase jumps.
+	 **********************************************************************/
+
+	/**
+	 * International Atomic Time (TAI)
+	 * Epoch: 1958-01-01 00:00:00.
+	 * Continuity: Strictly monotonic and continuous; no leap seconds.
+	 * Discipline: Primary atomic reference; no phase jumps.
+	 */
+	PTP_TIMESCALE_TAI = 1,
+
+	/**
+	 * Terrestrial Time (TT)
+	 * Epoch: 1958-01-01 00:00:00.
+	 * Continuity: Strictly monotonic and continuous; no leap seconds.
+	 * Discipline: Defined as TAI + 32.184s constant offset.
+	 */
+	PTP_TIMESCALE_TT = 2,
+
+	/**
+	 * Global Positioning System (GPS) Time
+	 * Epoch: 1980-01-06 00:00:00.
+	 * Continuity: Strictly monotonic and continuous; no leap seconds.
+	 * Discipline: Defined by the GPS constellation; fixed offset from TAI.
+	 */
+	PTP_TIMESCALE_GPS = 3,
+
+	/****************** UTC-Based Timescales (Civil Time) *****************
+	 * These timescales are derived from TAI but adjusted to align with
+	 * the Earth's rotation, primarily through leap seconds.
+	 **********************************************************************/
+
+	/**
+	 * Coordinated Universal Time (UTC) - Wall-clock (CLOCK_REALTIME)
+	 * Epoch: 1970-01-01 00:00:00 (Unix epoch).
+	 * Continuity: Discontinuous; subject to 1-second leap second
+	 *             phase jumps.
+	 * Discipline: Frequency steered; incorporates leap second corrections.
+	 *
+	 * Note: Leap-smeared UTC MUST NOT be advertised as PTP_TIMESCALE_UTC.
+	 * Smear algorithms are not standardized and the resulting timescale
+	 * is ambiguous. Implementations using smeared UTC MUST advertise
+	 * PTP_TIMESCALE_UNKNOWN or PTP_TIMESCALE_PROPRIETARY instead.
+	 */
+	PTP_TIMESCALE_UTC = 4,
+
+	/**
+	 * POSIX Time (Unix Time)
+	 * Epoch: 1970-01-01 00:00:00.
+	 * Continuity: Discontinuous; leap seconds handled by
+	 *             repeating/skipping values.
+	 * Discipline: Follows UTC frequency steering and phase jumps.
+	 */
+	PTP_TIMESCALE_POSIX = 5,
+
+	/****************** System-Relative Monotonic Clocks ******************
+	 * These timescales are relative to a system event (like boot)
+	 * and are not synchronized to an external atomic standard.
+	 **********************************************************************/
+
+	/**
+	 * Monotonic System Clock (CLOCK_MONOTONIC)
+	 * Epoch: Arbitrary (System boot time).
+	 * Continuity: Strictly monotonic; no leap seconds.
+	 * Discipline: Frequency steered to match system reference;
+	 *             does not advance during suspend.
+	 */
+	PTP_TIMESCALE_MONOTONIC = 6,
+
+	/**
+	 * Raw Monotonic System Clock (CLOCK_MONOTONIC_RAW)
+	 * Epoch: Arbitrary (System boot time).
+	 * Continuity: Strictly monotonic; no leap seconds.
+	 * Discipline: Raw hardware oscillator; no frequency steering
+	 *             or discipline.
+	 */
+	PTP_TIMESCALE_MONOTONIC_RAW = 7,
+
+	/**
+	 * Boot Time System Clock (CLOCK_BOOTTIME)
+	 * Epoch: Arbitrary (System boot time).
+	 * Continuity: Strictly monotonic and continuous; no leap seconds.
+	 * Discipline: Frequency steered to match system reference;
+	 *             advances during suspend.
+	 */
+	PTP_TIMESCALE_BOOTTIME = 8,
+
+	/********************** Vendor-Specific Timescale *********************/
+
+	/* A proprietary or vendor-specific timescale with custom rules. */
+	PTP_TIMESCALE_PROPRIETARY = 9,
+};
+
  /*
   * struct ptp_clock_time - represents a time value
   *

@@ -94,6 +225,119 @@ struct ptp_clock_time {
  	__u32 reserved;
  };
  
+/*
+ * Hardware counter identifiers for struct ptp_sys_time.sys_counter_id
+ */
+enum ptp_counter_id {
+	/* Counter value not available or type not specified */
+	PTP_COUNTER_UNKNOWN = 0,
+
+	/* x86 Time Stamp Counter (TSC) */
+	PTP_COUNTER_X86_TSC = 1,
+
+	/* ARM Generic Timer virtual counter */
+	PTP_COUNTER_ARM_ARCH = 2,
+};
+
+/* Valid flags for struct ptp_clock_attrs.valid */
+#define PTP_ATTRS_VALID_ERROR_BOUND	(1 << 0)
+#define PTP_ATTRS_VALID_TIMESCALE	(1 << 1)
+#define PTP_ATTRS_VALID_STATUS		(1 << 2)
+
+/**
+ * struct ptp_clock_attrs - quality attributes for a PHC timestamp
+ *
+ * @valid:       Bitmask of PTP_ATTRS_VALID_* indicating which fields
+ *               are populated. Zero means no attributes available.
+ * @error_bound: Maximum error in nanoseconds. Valid only when
+ *               PTP_ATTRS_VALID_ERROR_BOUND is set.
+ * @timescale:   Clock timescale (enum ptp_clock_timescale). Valid only
+ *               when PTP_ATTRS_VALID_TIMESCALE is set.
+ * @status:      Synchronization status (enum ptp_clock_status). Valid
+ *               only when PTP_ATTRS_VALID_STATUS is set.
+ * @rsv:         Reserved for future use, must be zero.
+ */
+struct ptp_clock_attrs {
+	__u32 valid;
+	__u32 error_bound;