ieee802154: add support for setting CCA energy detection levels

Since three of the four clear channel assesment modes make use of energy
detection, provide an API to set the energy detection threshold.
Driver support for this is available in at86rf230 for the RF212 chips.
Since for these chips the minimal energy detection threshold depends on
page and channel used, add a field to struct at86rf230_local that stores
the minimal threshold. Actual ED thresholds are configured as offsets
from this value.

For RF212, setting the ED threshold will not work before a channel/page
has been set due to the dependency of energy detection in the chip and
the actual channel/page selected.

Signed-off-by: Phoebe Buckheister <phoebe.buckheister@itwm.fraunhofer.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/mac802154/ieee802154_dev.c b/net/mac802154/ieee802154_dev.c
index 4965e4c..4707f36 100644
--- a/net/mac802154/ieee802154_dev.c
+++ b/net/mac802154/ieee802154_dev.c
@@ -195,6 +195,16 @@
 	return priv->ops->set_cca_mode(&priv->hw, mode);
 }
 
+static int mac802154_set_cca_ed_level(struct wpan_phy *phy, s32 level)
+{
+	struct mac802154_priv *priv = wpan_phy_priv(phy);
+
+	if (!priv->ops->set_cca_ed_level)
+		return -ENOTSUPP;
+
+	return priv->ops->set_cca_ed_level(&priv->hw, level);
+}
+
 struct ieee802154_dev *
 ieee802154_alloc_device(size_t priv_data_len, struct ieee802154_ops *ops)
 {
@@ -275,6 +285,7 @@
 	priv->phy->set_txpower = mac802154_set_txpower;
 	priv->phy->set_lbt = mac802154_set_lbt;
 	priv->phy->set_cca_mode = mac802154_set_cca_mode;
+	priv->phy->set_cca_ed_level = mac802154_set_cca_ed_level;
 
 	rc = wpan_phy_register(priv->phy);
 	if (rc < 0)