[mle] simplify CslClockAccuracyTlv (#12905)

This commit updates `CslClockAccuracyTlv` to use the `SimpleTlvInfo`
and a separate `CslClockAccuracyTlvValue` class. This change
simplifies how the TLV is appended to and read from messages
by leveraging the `Tlv::Append<TlvType>` and `Tlv::Find<TlvType>`
helper methods (avoiding the use of `FindTlv()`).

src/core/thread/mle.cpp

@@ -3852,13 +3852,8 @@ Error Mle::TxMessage::AppendCslTimeoutTlv(void)
 #if OPENTHREAD_CONFIG_MAC_CSL_TRANSMITTER_ENABLE
 Error Mle::TxMessage::AppendCslClockAccuracyTlv(void)
 {
-    CslClockAccuracyTlv cslClockAccuracyTlv;
-
-    cslClockAccuracyTlv.Init();
-    cslClockAccuracyTlv.SetCslClockAccuracy(Get<Radio>().GetCslAccuracy());
-    cslClockAccuracyTlv.SetCslUncertainty(Get<Radio>().GetCslUncertainty());
-
-    return Append(cslClockAccuracyTlv);
+    return Tlv::Append<CslClockAccuracyTlv>(
+        *this, CslClockAccuracyTlvValue(Get<Radio>().GetCslAccuracy(), Get<Radio>().GetCslUncertainty()));
 }
 #endif
 
@@ -4237,13 +4232,11 @@ exit:
 #if OPENTHREAD_CONFIG_MAC_CSL_RECEIVER_ENABLE
 Error Mle::RxMessage::ReadCslClockAccuracyTlv(Mac::CslAccuracy &aCslAccuracy) const
 {
-    Error               error;
-    CslClockAccuracyTlv clockAccuracyTlv;
+    Error                    error;
+    CslClockAccuracyTlvValue tlvValue;
 
-    SuccessOrExit(error = Tlv::FindTlv(*this, clockAccuracyTlv));
-    VerifyOrExit(clockAccuracyTlv.IsValid(), error = kErrorParse);
-    aCslAccuracy.SetClockAccuracy(clockAccuracyTlv.GetCslClockAccuracy());
-    aCslAccuracy.SetUncertainty(clockAccuracyTlv.GetCslUncertainty());
+    SuccessOrExit(error = Tlv::Find<CslClockAccuracyTlv>(*this, tlvValue));
+    tlvValue.Get(aCslAccuracy);
 
 exit:
     return error;

src/core/thread/mle_tlvs.cpp

@@ -196,5 +196,24 @@ void LeaderDataTlvValue::Get(LeaderData &aLeaderData) const
     aLeaderData.SetLeaderRouterId(mLeaderRouterId);
 }
 
+//---------------------------------------------------------------------------------------------------------------------
+// CslClockAccuracyTlvValue
+
+#if OPENTHREAD_CONFIG_MAC_CSL_RECEIVER_ENABLE || OPENTHREAD_CONFIG_MAC_CSL_TRANSMITTER_ENABLE
+
+CslClockAccuracyTlvValue::CslClockAccuracyTlvValue(uint8_t aClockAccuracy, uint8_t aUncertainty)
+    : mClockAccuracy(aClockAccuracy)
+    , mUncertainty(aUncertainty)
+{
+}
+
+void CslClockAccuracyTlvValue::Get(Mac::CslAccuracy &aAccuracy) const
+{
+    aAccuracy.SetClockAccuracy(mClockAccuracy);
+    aAccuracy.SetUncertainty(mUncertainty);
+}
+
+#endif
+
 } // namespace Mle
 } // namespace ot

src/core/thread/mle_tlvs.hpp

@@ -926,63 +926,44 @@ private:
 #endif // OPENTHREAD_CONFIG_TIME_SYNC_ENABLE
 
 #if OPENTHREAD_CONFIG_MAC_CSL_RECEIVER_ENABLE || OPENTHREAD_CONFIG_MAC_CSL_TRANSMITTER_ENABLE
+
 /**
- * Implements CSL Clock Accuracy TLV generation and parsing.
+ * Represents CSL Clock Accuracy TLV value.
  */
 OT_TOOL_PACKED_BEGIN
-class CslClockAccuracyTlv : public Tlv, public TlvInfo<Tlv::kCslClockAccuracy>
+class CslClockAccuracyTlvValue
 {
 public:
     /**
-     * Initializes the TLV.
+     * Default constructor.
      */
-    void Init(void)
-    {
-        SetType(kCslClockAccuracy);
-        SetLength(sizeof(*this) - sizeof(Tlv));
-    }
+    CslClockAccuracyTlvValue(void) = default;
 
     /**
-     * Indicates whether or not the TLV appears to be well-formed.
+     * Initializes the TLV value with given clock accuracy and uncertainty.
      *
-     * @retval TRUE   If the TLV appears to be well-formed.
-     * @retval FALSE  If the TLV does not appear to be well-formed.
+     * @param[in] aClockAccuracy  The clock accuracy in ppm.
+     * @param[in] aUncertainty    The clock uncertainty in units of 10 us.
      */
-    bool IsValid(void) const { return GetLength() >= sizeof(*this) - sizeof(Tlv); }
+    CslClockAccuracyTlvValue(uint8_t aClockAccuracy, uint8_t aUncertainty);
 
     /**
-     * Returns the CSL Clock Accuracy value.
+     * Gets the CSL clock accuracy and uncertainty values.
      *
-     * @returns The CSL Clock Accuracy value.
+     * @param[out] aAccuracy  A reference to a `Mac::CslAccuracy` to return the values.
      */
-    uint8_t GetCslClockAccuracy(void) const { return mCslClockAccuracy; }
-
-    /**
-     * Sets the CSL Clock Accuracy value.
-     *
-     * @param[in]  aCslClockAccuracy  The CSL Clock Accuracy value.
-     */
-    void SetCslClockAccuracy(uint8_t aCslClockAccuracy) { mCslClockAccuracy = aCslClockAccuracy; }
-
-    /**
-     * Returns the Clock Uncertainty value.
-     *
-     * @returns The Clock Uncertainty value.
-     */
-    uint8_t GetCslUncertainty(void) const { return mCslUncertainty; }
-
-    /**
-     * Sets the CSL Uncertainty value.
-     *
-     * @param[in]  aCslUncertainty  The CSL Uncertainty value.
-     */
-    void SetCslUncertainty(uint8_t aCslUncertainty) { mCslUncertainty = aCslUncertainty; }
+    void Get(Mac::CslAccuracy &aAccuracy) const;
 
 private:
-    uint8_t mCslClockAccuracy;
-    uint8_t mCslUncertainty;
+    uint8_t mClockAccuracy;
+    uint8_t mUncertainty;
 } OT_TOOL_PACKED_END;
 
+/**
+ * Defines CSL Clock Accuracy TLV constants and types.
+ */
+typedef SimpleTlvInfo<Tlv::kCslClockAccuracy, CslClockAccuracyTlvValue> CslClockAccuracyTlv;
+
 #endif // OPENTHREAD_CONFIG_MAC_CSL_RECEIVER_ENABLE || OPENTHREAD_CONFIG_MAC_CSL_TRANSMITTER_ENABLE
 /**
  * @}