ieee802154: add netlink APIs for smartMAC configuration

Introduce new netlink attributes for SET_PHY_ATTRS:
 * CSMA minimal backoff exponent
 * CSMA maximal backoff exponent
 * CSMA retry limit
 * frame retransmission limit

The CSMA attributes shall correspond to minBE, maxBE and maxCSMABackoffs of
802.15.4, respectively. The frame retransmission shall correspond to
maxFrameRetries of 802.15.4, unless given as -1: then the old behaviour
of the stack shall apply. For RF2xy, the old behaviour is to not do
channel sensing at all and simply send *right now*, which is not
intended behaviour for most applications and actually prohibited for
some channel/page combinations.

For all values except frame retransmission limit, the defaults of
802.15.4 apply. Frame retransmission limits are set to -1 to indicate
backward-compatible behaviour.

Signed-off-by: Phoebe Buckheister <phoebe.buckheister@itwm.fraunhofer.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/net/wpan-phy.h b/include/net/wpan-phy.h
index 0b570ad..10ab0fc 100644
--- a/include/net/wpan-phy.h
+++ b/include/net/wpan-phy.h
@@ -46,6 +46,10 @@
 	u32 channels_supported[32];
 	s8 transmit_power;
 	u8 cca_mode;
+	u8 min_be;
+	u8 max_be;
+	u8 csma_retries;
+	s8 frame_retries;
 
 	bool lbt;
 	s32 cca_ed_level;
@@ -61,6 +65,9 @@
 	int (*set_lbt)(struct wpan_phy *phy, bool on);
 	int (*set_cca_mode)(struct wpan_phy *phy, u8 cca_mode);
 	int (*set_cca_ed_level)(struct wpan_phy *phy, int level);
+	int (*set_csma_params)(struct wpan_phy *phy, u8 min_be, u8 max_be,
+			       u8 retries);
+	int (*set_frame_retries)(struct wpan_phy *phy, s8 retries);
 
 	char priv[0] __attribute__((__aligned__(NETDEV_ALIGN)));
 };