wifi: ieee80211: Add helpers to fetch EMLSR delay and timeout values

Add helpers to get EMLSR transition delay, padding delay and transition
timeout values from EML capabilities field of Multi-link Element.

Signed-off-by: Rameshkumar Sundaram <quic_ramess@quicinc.com>
Link: https://patch.msgid.link/20250327051320.3253783-4-quic_ramess@quicinc.com
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

1 files changed, 74 insertions, 0 deletions

diff --git a/include/linux/ieee80211.h b/include/linux/ieee80211.h
index cbc3928aa504..15a87f522017 100644
--- a/include/linux/ieee80211.h
+++ b/include/linux/ieee80211.h
@@ -5618,6 +5618,80 @@ static inline bool ieee80211_tid_to_link_map_size_ok(const u8 *data, size_t len)
 	return len >= fixed + elem_len;
 }
 
+/**
+ * ieee80211_emlsr_pad_delay_in_us - Fetch the EMLSR Padding delay
+ *	in microseconds
+ * @eml_cap: EML capabilities field value from common info field of
+ *	the Multi-link element
+ * Return: the EMLSR Padding delay (in microseconds) encoded in the
+ *	EML Capabilities field
+ */
+
+static inline u32 ieee80211_emlsr_pad_delay_in_us(u16 eml_cap)
+{
+	/* IEEE Std 802.11be-2024 Table 9-417i—Encoding of the EMLSR
+	 * Padding Delay subfield.
+	 */
+	u32 pad_delay = u16_get_bits(eml_cap,
+				     IEEE80211_EML_CAP_EMLSR_PADDING_DELAY);
+
+	if (!pad_delay ||
+	    pad_delay > IEEE80211_EML_CAP_EMLSR_PADDING_DELAY_256US)
+		return 0;
+
+	return 32 * (1 << (pad_delay - 1));
+}
+
+/**
+ * ieee80211_emlsr_trans_delay_in_us - Fetch the EMLSR Transition
+ *	delay in microseconds
+ * @eml_cap: EML capabilities field value from common info field of
+ *	the Multi-link element
+ * Return: the EMLSR Transition delay (in microseconds) encoded in the
+ *	EML Capabilities field
+ */
+
+static inline u32 ieee80211_emlsr_trans_delay_in_us(u16 eml_cap)
+{
+	/* IEEE Std 802.11be-2024 Table 9-417j—Encoding of the EMLSR
+	 * Transition Delay subfield.
+	 */
+	u32 trans_delay =
+		u16_get_bits(eml_cap,
+			     IEEE80211_EML_CAP_EMLSR_TRANSITION_DELAY);
+
+	/* invalid values also just use 0 */
+	if (!trans_delay ||
+	    trans_delay > IEEE80211_EML_CAP_EMLSR_TRANSITION_DELAY_256US)
+		return 0;
+
+	return 16 * (1 << (trans_delay - 1));
+}
+
+/**
+ * ieee80211_eml_trans_timeout_in_us - Fetch the EMLSR Transition
+ *	timeout value in microseconds
+ * @eml_cap: EML capabilities field value from common info field of
+ *	the Multi-link element
+ * Return: the EMLSR Transition timeout (in microseconds) encoded in
+ *	the EML Capabilities field
+ */
+
+static inline u32 ieee80211_eml_trans_timeout_in_us(u16 eml_cap)
+{
+	/* IEEE Std 802.11be-2024 Table 9-417m—Encoding of the
+	 * Transition Timeout subfield.
+	 */
+	u8 timeout = u16_get_bits(eml_cap,
+				  IEEE80211_EML_CAP_TRANSITION_TIMEOUT);
+
+	/* invalid values also just use 0 */
+	if (!timeout || timeout > IEEE80211_EML_CAP_TRANSITION_TIMEOUT_128TU)
+		return 0;
+
+	return 128 * (1 << (timeout - 1));
+}
+
 #define for_each_mle_subelement(_elem, _data, _len)			\
 	if (ieee80211_mle_size_ok(_data, _len))				\
 		for_each_element(_elem,					\