brcmfmac: Enable 40MHz bandwidth in 2GHz band and OBSS scanning operations

This patch enables 40MHz bandwidth in 2GHz band after checking whether
cfg80211 allows it or not, and enables OBSS scanning operations to
to support 20/40 BSS coexistence.
Reviewed-by: Arend Van Spriel <arend@broadcom.com>
Reviewed-by: Hante Meuleman <meuleman@broadcom.com>
Reviewed-by: Pieter-Paul Giesberts <pieterpg@broadcom.com>
Signed-off-by: Daniel Kim <dekim@broadcom.com>
Signed-off-by: Arend van Spriel <arend@broadcom.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

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

@@ -48,6 +48,11 @@
 
 #define BRCMF_MAXRATES_IN_SET		16	/* max # of rates in rateset */
 
+/* OBSS Coex Auto/On/Off */
+#define BRCMF_OBSS_COEX_AUTO		(-1)
+#define BRCMF_OBSS_COEX_OFF		0
+#define BRCMF_OBSS_COEX_ON		1
+
 enum brcmf_fil_p2p_if_types {
 	BRCMF_FIL_P2P_IF_CLIENT,
 	BRCMF_FIL_P2P_IF_GO,
@@ -87,6 +92,11 @@ struct brcmf_fil_bss_enable_le {
 	__le32 enable;
 };
 
+struct brcmf_fil_bwcap_le {
+	__le32 band;
+	__le32 bw_cap;
+};
+
 /**
  * struct tdls_iovar - common structure for tdls iovars.
  *

drivers/net/wireless/brcm80211/brcmfmac/wl_cfg80211.c

@@ -191,6 +191,7 @@ static struct ieee80211_supported_band __wl_band_2ghz = {
 	.n_channels = ARRAY_SIZE(__wl_2ghz_channels),
 	.bitrates = wl_g_rates,
 	.n_bitrates = wl_g_rates_size,
+	.ht_cap = {IEEE80211_HT_CAP_SUP_WIDTH_20_40, true},
 };
 
 static struct ieee80211_supported_band __wl_band_5ghz_a = {
@@ -4929,6 +4930,19 @@ static void init_vif_event(struct brcmf_cfg80211_vif_event *event)
 	mutex_init(&event->vif_event_lock);
 }
 
+static int brcmf_set_bwcap(struct brcmf_if *ifp, u32 band, u32 bw_cap)
+{
+	struct brcmf_fil_bwcap_le band_bwcap;
+	int err;
+
+	band_bwcap.band = cpu_to_le32(band);
+	band_bwcap.bw_cap = cpu_to_le32(bw_cap);
+	err = brcmf_fil_iovar_data_set(ifp, "bw_cap", &band_bwcap,
+				       sizeof(band_bwcap));
+
+	return err;
+}
+
 struct brcmf_cfg80211_info *brcmf_cfg80211_attach(struct brcmf_pub *drvr,
 						  struct device *busdev)
 {
@@ -4986,6 +5000,18 @@ struct brcmf_cfg80211_info *brcmf_cfg80211_attach(struct brcmf_pub *drvr,
 		goto cfg80211_p2p_attach_out;
 	}
 
+	/* If cfg80211 didn't disable 40MHz HT CAP in wiphy_register(),
+	 * setup 40MHz in 2GHz band and enable OBSS scanning.
+	 */
+	if (wiphy->bands[IEEE80211_BAND_2GHZ]->ht_cap.cap &
+	    IEEE80211_HT_CAP_SUP_WIDTH_20_40) {
+		err = brcmf_set_bwcap(ifp, WLC_BAND_2G, WLC_BW_CAP_40MHZ);
+		if (!err) {
+			err = brcmf_fil_iovar_int_set(ifp, "obss_coex",
+						      BRCMF_OBSS_COEX_AUTO);
+		}
+	}
+
 	err = brcmf_fil_iovar_int_set(ifp, "tdls_enable", 1);
 	if (err) {
 		brcmf_dbg(INFO, "TDLS not enabled (%d)\n", err);