mwifiex: Add support for NL80211_ATTR_MAX_AP_ASSOC_STA

SD8997 firmware sends TLV_TYPE_MAX_CONN with struct hw_spec_max_conn to
inform kernel about maximum number of p2p connections and stations in AP
mode.

During initialization of SD8997 wifi chip kernel prints warning:

  mwifiex_sdio mmc0:0001:1: Unknown GET_HW_SPEC TLV type: 0x217

This patch adds support for parsing TLV_TYPE_MAX_CONN (0x217) and sets
appropriate cfg80211 member 'max_ap_assoc_sta' from retrieved structure.

It allows userspace to retrieve NL80211_ATTR_MAX_AP_ASSOC_STA attribute.
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/20200521123559.29028-1-pali@kernel.org

drivers/net/wireless/marvell/mwifiex/cfg80211.c

@@ -4335,6 +4335,11 @@ int mwifiex_register_cfg80211(struct mwifiex_adapter *adapter)
 		wiphy->iface_combinations = &mwifiex_iface_comb_ap_sta;
 	wiphy->n_iface_combinations = 1;
 
+	if (adapter->max_sta_conn > adapter->max_p2p_conn)
+		wiphy->max_ap_assoc_sta = adapter->max_sta_conn;
+	else
+		wiphy->max_ap_assoc_sta = adapter->max_p2p_conn;
+
 	/* Initialize cipher suits */
 	wiphy->cipher_suites = mwifiex_cipher_suites;
 	wiphy->n_cipher_suites = ARRAY_SIZE(mwifiex_cipher_suites);

drivers/net/wireless/marvell/mwifiex/cmdevt.c

@@ -1495,6 +1495,7 @@ int mwifiex_ret_get_hw_spec(struct mwifiex_private *priv,
 	struct mwifiex_adapter *adapter = priv->adapter;
 	struct mwifiex_ie_types_header *tlv;
 	struct hw_spec_api_rev *api_rev;
+	struct hw_spec_max_conn *max_conn;
 	u16 resp_size, api_id;
 	int i, left_len, parsed_len = 0;
 
@@ -1604,6 +1605,17 @@ int mwifiex_ret_get_hw_spec(struct mwifiex_private *priv,
 					break;
 				}
 				break;
+			case TLV_TYPE_MAX_CONN:
+				max_conn = (struct hw_spec_max_conn *)tlv;
+				adapter->max_p2p_conn = max_conn->max_p2p_conn;
+				adapter->max_sta_conn = max_conn->max_sta_conn;
+				mwifiex_dbg(adapter, INFO,
+					    "max p2p connections: %u\n",
+					    adapter->max_p2p_conn);
+				mwifiex_dbg(adapter, INFO,
+					    "max sta connections: %u\n",
+					    adapter->max_sta_conn);
+				break;
 			default:
 				mwifiex_dbg(adapter, FATAL,
 					    "Unknown GET_HW_SPEC TLV type: %#x\n",

drivers/net/wireless/marvell/mwifiex/fw.h

@@ -220,6 +220,7 @@ enum MWIFIEX_802_11_PRIVACY_FILTER {
 #define TLV_TYPE_BSS_MODE           (PROPRIETARY_TLV_BASE_ID + 206)
 #define TLV_TYPE_RANDOM_MAC         (PROPRIETARY_TLV_BASE_ID + 236)
 #define TLV_TYPE_CHAN_ATTR_CFG      (PROPRIETARY_TLV_BASE_ID + 237)
+#define TLV_TYPE_MAX_CONN           (PROPRIETARY_TLV_BASE_ID + 279)
 
 #define MWIFIEX_TX_DATA_BUF_SIZE_2K        2048
 
@@ -2388,4 +2389,11 @@ struct mwifiex_opt_sleep_confirm {
 	__le16 action;
 	__le16 resp_ctrl;
 } __packed;
+
+struct hw_spec_max_conn {
+	struct mwifiex_ie_types_header header;
+	u8 max_p2p_conn;
+	u8 max_sta_conn;
+} __packed;
+
 #endif /* !_MWIFIEX_FW_H_ */

drivers/net/wireless/marvell/mwifiex/main.h

@@ -1022,6 +1022,7 @@ struct mwifiex_adapter {
 	bool ext_scan;
 	u8 fw_api_ver;
 	u8 key_api_major_ver, key_api_minor_ver;
+	u8 max_p2p_conn, max_sta_conn;
 	struct memory_type_mapping *mem_type_mapping_tbl;
 	u8 num_mem_types;
 	bool scan_chan_gap_enabled;