rt2x00: Implement get_antenna and set_antenna callback functions

Implement the get_antenna and set_antenna callback functions, which will
allow clients to control the antenna for all non-11n hardware (Antenna handling
in rt2800 is still a bit magical, so we can't use the set_antenna for those drivers
yet).

To best support the set_antenna callback some modifications are needed in the
diversity handling. We should never look at the default antenna settings to determine
if software diversity is enabled. Instead we should set the diversity flag when
possible, which will allow the link_tuner to automatically pick up the tuning.

Signed-off-by: Ivo van Doorn <IvDoorn@gmail.com>
Acked-by: Gertjan van Wingerde <gwingerde@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 65 insertions, 0 deletions

diff --git a/drivers/net/wireless/rt2x00/rt2x00mac.c b/drivers/net/wireless/rt2x00/rt2x00mac.c
index 6d1d38329e52..93bec140e598 100644
--- a/drivers/net/wireless/rt2x00/rt2x00mac.c
+++ b/drivers/net/wireless/rt2x00/rt2x00mac.c
@@ -738,6 +738,71 @@ void rt2x00mac_flush(struct ieee80211_hw *hw, bool drop)
 }
 EXPORT_SYMBOL_GPL(rt2x00mac_flush);
 
+int rt2x00mac_set_antenna(struct ieee80211_hw *hw, u32 tx_ant, u32 rx_ant)
+{
+	struct rt2x00_dev *rt2x00dev = hw->priv;
+	struct link_ant *ant = &rt2x00dev->link.ant;
+	struct antenna_setup *def = &rt2x00dev->default_ant;
+	struct antenna_setup setup;
+
+	// The antenna value is not supposed to be 0,
+	// or exceed the maximum number of antenna's.
+	if (!tx_ant || (tx_ant & ~3) || !rx_ant || (rx_ant & ~3))
+		return -EINVAL;
+
+	// When the client tried to configure the antenna to or from
+	// diversity mode, we must reset the default antenna as well
+	// as that controls the diversity switch.
+	if (ant->flags & ANTENNA_TX_DIVERSITY && tx_ant != 3)
+		ant->flags &= ~ANTENNA_TX_DIVERSITY;
+	if (ant->flags & ANTENNA_RX_DIVERSITY && rx_ant != 3)
+		ant->flags &= ~ANTENNA_RX_DIVERSITY;
+
+	// If diversity is being enabled, check if we need hardware
+	// or software diversity. In the latter case, reset the value,
+	// and make sure we update the antenna flags to have the
+	// link tuner pick up the diversity tuning.
+	if (tx_ant == 3 && def->tx == ANTENNA_SW_DIVERSITY) {
+		tx_ant = ANTENNA_SW_DIVERSITY;
+		ant->flags |= ANTENNA_TX_DIVERSITY;
+	}
+
+	if (rx_ant == 3 && def->rx == ANTENNA_SW_DIVERSITY) {
+		rx_ant = ANTENNA_SW_DIVERSITY;
+		ant->flags |= ANTENNA_RX_DIVERSITY;
+	}
+
+	setup.tx = tx_ant;
+	setup.rx = rx_ant;
+
+	rt2x00lib_config_antenna(rt2x00dev, setup);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(rt2x00mac_set_antenna);
+
+int rt2x00mac_get_antenna(struct ieee80211_hw *hw, u32 *tx_ant, u32 *rx_ant)
+{
+	struct rt2x00_dev *rt2x00dev = hw->priv;
+	struct link_ant *ant = &rt2x00dev->link.ant;
+	struct antenna_setup *active = &rt2x00dev->link.ant.active;
+
+	// When software diversity is active, we must report this to the
+	// client and not the current active antenna state.
+	if (ant->flags & ANTENNA_TX_DIVERSITY)
+		*tx_ant = ANTENNA_HW_DIVERSITY;
+	else
+		*tx_ant = active->tx;
+
+	if (ant->flags & ANTENNA_RX_DIVERSITY)
+		*rx_ant = ANTENNA_HW_DIVERSITY;
+	else
+		*rx_ant = active->rx;
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(rt2x00mac_get_antenna);
+
 void rt2x00mac_get_ringparam(struct ieee80211_hw *hw,
 			     u32 *tx, u32 *tx_max, u32 *rx, u32 *rx_max)
 {