brcmfmac: add firmware feature detection for gscan feature

Detect gscan support in firmware by doing pfn_gscan_cfg iovar with
invalid version.
Reviewed-by: Hante Meuleman <hante.meuleman@broadcom.com>
Reviewed-by: Pieter-Paul Giesberts <pieter-paul.giesberts@broadcom.com>
Reviewed-by: Franky Lin <franky.lin@broadcom.com>
Signed-off-by: Arend van Spriel <arend.vanspriel@broadcom.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>

drivers/net/wireless/broadcom/brcm80211/brcmfmac/feature.c

@@ -27,6 +27,7 @@
 #include "feature.h"
 #include "common.h"
 
+#define BRCMF_FW_UNSUPPORTED	23
 
 /*
  * expand feature list to array of feature strings.
@@ -113,6 +114,22 @@ static void brcmf_feat_iovar_int_get(struct brcmf_if *ifp,
 	}
 }
 
+static void brcmf_feat_iovar_data_set(struct brcmf_if *ifp,
+				      enum brcmf_feat_id id, char *name,
+				      const void *data, size_t len)
+{
+	int err;
+
+	err = brcmf_fil_iovar_data_set(ifp, name, data, len);
+	if (err != -BRCMF_FW_UNSUPPORTED) {
+		brcmf_dbg(INFO, "enabling feature: %s\n", brcmf_feat_names[id]);
+		ifp->drvr->feat_flags |= BIT(id);
+	} else {
+		brcmf_dbg(TRACE, "%s feature check failed: %d\n",
+			  brcmf_feat_names[id], err);
+	}
+}
+
 static void brcmf_feat_firmware_capabilities(struct brcmf_if *ifp)
 {
 	char caps[256];
@@ -136,11 +153,14 @@ void brcmf_feat_attach(struct brcmf_pub *drvr)
 {
 	struct brcmf_if *ifp = brcmf_get_ifp(drvr, 0);
 	struct brcmf_pno_macaddr_le pfn_mac;
+	struct brcmf_gscan_config gscan_cfg;
 	u32 wowl_cap;
 	s32 err;
 
 	brcmf_feat_firmware_capabilities(ifp);
-
+	memset(&gscan_cfg, 0, sizeof(gscan_cfg));
+	brcmf_feat_iovar_data_set(ifp, BRCMF_FEAT_GSCAN, "pfn_gscan_cfg",
+				  &gscan_cfg, sizeof(gscan_cfg));
 	brcmf_feat_iovar_int_get(ifp, BRCMF_FEAT_PNO, "pfn");
 	if (drvr->bus_if->wowl_supported)
 		brcmf_feat_iovar_int_get(ifp, BRCMF_FEAT_WOWL, "wowl");

drivers/net/wireless/broadcom/brcm80211/brcmfmac/feature.h

@@ -31,6 +31,7 @@
  * WOWL_GTK: (WOWL) GTK rekeying offload
  * WOWL_ARP_ND: ARP and Neighbor Discovery offload support during WOWL.
  * MFP: 802.11w Management Frame Protection.
+ * GSCAN: enhanced scan offload feature.
  */
 #define BRCMF_FEAT_LIST \
 	BRCMF_FEAT_DEF(MBSS) \
@@ -44,7 +45,8 @@
 	BRCMF_FEAT_DEF(WOWL_ND) \
 	BRCMF_FEAT_DEF(WOWL_GTK) \
 	BRCMF_FEAT_DEF(WOWL_ARP_ND) \
-	BRCMF_FEAT_DEF(MFP)
+	BRCMF_FEAT_DEF(MFP) \
+	BRCMF_FEAT_DEF(GSCAN)
 
 /*
  * Quirks:

drivers/net/wireless/broadcom/brcm80211/brcmfmac/fwil_types.h

@@ -835,4 +835,63 @@ struct brcmf_gtk_keyinfo_le {
 	u8 replay_counter[BRCMF_RSN_REPLAY_LEN];
 };
 
+/**
+ * struct brcmf_gscan_bucket_config - configuration data for channel bucket.
+ *
+ * @bucket_end_index: !unknown!
+ * @bucket_freq_multiple: !unknown!
+ * @flag: !unknown!
+ * @reserved: !unknown!
+ * @repeat: !unknown!
+ * @max_freq_multiple: !unknown!
+ */
+struct brcmf_gscan_bucket_config {
+	u8 bucket_end_index;
+	u8 bucket_freq_multiple;
+	u8 flag;
+	u8 reserved;
+	__le16 repeat;
+	__le16 max_freq_multiple;
+};
+
+/* version supported which must match firmware */
+#define BRCMF_GSCAN_CFG_VERSION                     1
+
+/**
+ * enum brcmf_gscan_cfg_flags - bit values for gscan flags.
+ *
+ * @BRCMF_GSCAN_CFG_FLAGS_ALL_RESULTS: send probe responses/beacons to host.
+ * @BRCMF_GSCAN_CFG_FLAGS_CHANGE_ONLY: indicated only flags member is changed.
+ */
+enum brcmf_gscan_cfg_flags {
+	BRCMF_GSCAN_CFG_FLAGS_ALL_RESULTS = BIT(0),
+	BRCMF_GSCAN_CFG_FLAGS_CHANGE_ONLY = BIT(7),
+};
+
+/**
+ * struct brcmf_gscan_config - configuration data for gscan.
+ *
+ * @version: version of the api to match firmware.
+ * @flags: flags according %enum brcmf_gscan_cfg_flags.
+ * @buffer_threshold: percentage threshold of buffer to generate an event.
+ * @swc_nbssid_threshold: number of BSSIDs with significant change that
+ *	will generate an event.
+ * @swc_rssi_window_size: size of rssi cache buffer (max=8).
+ * @count_of_channel_buckets: number of array members in @bucket.
+ * @retry_threshold: !unknown!
+ * @lost_ap_window: !unknown!
+ * @bucket: array of channel buckets.
+ */
+struct brcmf_gscan_config {
+	__le16 version;
+	u8  flags;
+	u8   buffer_threshold;
+	u8   swc_nbssid_threshold;
+	u8  swc_rssi_window_size;
+	u8  count_of_channel_buckets;
+	u8  retry_threshold;
+	__le16  lost_ap_window;
+	struct brcmf_gscan_bucket_config bucket[1];
+};
+
 #endif /* FWIL_TYPES_H_ */