ieee820154: add max csma backoffs setting support

This patch add support for max csma backoffs setting via nl802154
framework.

Signed-off-by: Alexander Aring <alex.aring@gmail.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

4 files changed, 61 insertions, 0 deletions

diff --git a/include/net/cfg802154.h b/include/net/cfg802154.h
index 27e98d10fb2c..79b9ae0abb3b 100644
--- a/include/net/cfg802154.h
+++ b/include/net/cfg802154.h
@@ -45,6 +45,9 @@ struct cfg802154_ops {
         int     (*set_backoff_exponent)(struct wpan_phy *wpan_phy,
                                         struct wpan_dev *wpan_dev, u8 min_be,
                                         u8 max_be);
+        int     (*set_max_csma_backoffs)(struct wpan_phy *wpan_phy,
+                                         struct wpan_dev *wpan_dev,
+                                         u8 max_csma_backoffs);
 };
 
 struct wpan_phy {
diff --git a/net/ieee802154/nl802154.c b/net/ieee802154/nl802154.c
index d1cf3021ff36..af383553bdd2 100644
--- a/net/ieee802154/nl802154.c
+++ b/net/ieee802154/nl802154.c
@@ -642,6 +642,31 @@ nl802154_set_backoff_exponent(struct sk_buff *skb, struct genl_info *info)
         return rdev_set_backoff_exponent(rdev, wpan_dev, min_be, max_be);
 }
 
+static int
+nl802154_set_max_csma_backoffs(struct sk_buff *skb, struct genl_info *info)
+{
+        struct cfg802154_registered_device *rdev = info->user_ptr[0];
+        struct net_device *dev = info->user_ptr[1];
+        struct wpan_dev *wpan_dev = dev->ieee802154_ptr;
+        u8 max_csma_backoffs;
+
+        /* conflict here while other running iface settings */
+        if (netif_running(dev))
+                return -EBUSY;
+
+        if (!info->attrs[NL802154_ATTR_MAX_CSMA_BACKOFFS])
+                return -EINVAL;
+
+        max_csma_backoffs = nla_get_u8(
+                        info->attrs[NL802154_ATTR_MAX_CSMA_BACKOFFS]);
+
+        /* check 802.15.4 constraints */
+        if (max_csma_backoffs > 5)
+                return -EINVAL;
+
+        return rdev_set_max_csma_backoffs(rdev, wpan_dev, max_csma_backoffs);
+}
+
 #define NL802154_FLAG_NEED_WPAN_PHY     0x01
 #define NL802154_FLAG_NEED_NETDEV       0x02
 #define NL802154_FLAG_NEED_RTNL         0x04
@@ -784,6 +809,14 @@ static const struct genl_ops nl802154_ops[] = {
                 .internal_flags = NL802154_FLAG_NEED_NETDEV |
                                   NL802154_FLAG_NEED_RTNL,
         },
+        {
+                .cmd = NL802154_CMD_SET_MAX_CSMA_BACKOFFS,
+                .doit = nl802154_set_max_csma_backoffs,
+                .policy = nl802154_policy,
+                .flags = GENL_ADMIN_PERM,
+                .internal_flags = NL802154_FLAG_NEED_NETDEV |
+                                  NL802154_FLAG_NEED_RTNL,
+        },
 };
 
 /* initialisation/exit functions */
diff --git a/net/ieee802154/rdev-ops.h b/net/ieee802154/rdev-ops.h
index dbccfa9383fd..263095c8686c 100644
--- a/net/ieee802154/rdev-ops.h
+++ b/net/ieee802154/rdev-ops.h
@@ -50,4 +50,13 @@ rdev_set_backoff_exponent(struct cfg802154_registered_device *rdev,
                                                min_be, max_be);
 }
 
+static inline int
+rdev_set_max_csma_backoffs(struct cfg802154_registered_device *rdev,
+                           struct wpan_dev *wpan_dev,
+                           const u8 max_csma_backoffs)
+{
+        return rdev->ops->set_max_csma_backoffs(&rdev->wpan_phy, wpan_dev,
+                                                max_csma_backoffs);
+}
+
 #endif /* __CFG802154_RDEV_OPS */
diff --git a/net/mac802154/cfg.c b/net/mac802154/cfg.c
index 67c96f981693..d72feebb939d 100644
--- a/net/mac802154/cfg.c
+++ b/net/mac802154/cfg.c
@@ -125,6 +125,21 @@ ieee802154_set_short_addr(struct wpan_phy *wpan_phy, struct wpan_dev *wpan_dev,
         return 0;
 }
 
+static int ieee802154_set_max_csma_backoffs(struct wpan_phy *wpan_phy,
+                                            struct wpan_dev *wpan_dev,
+                                            const u8 max_csma_backoffs)
+{
+        struct ieee802154_local *local = wpan_phy_priv(wpan_phy);
+
+        ASSERT_RTNL();
+
+        if (!(local->hw.flags & IEEE802154_HW_CSMA_PARAMS))
+                return -EOPNOTSUPP;
+
+        wpan_dev->csma_retries = max_csma_backoffs;
+        return 0;
+}
+
 const struct cfg802154_ops mac802154_config_ops = {
         .add_virtual_intf_deprecated = ieee802154_add_iface_deprecated,
         .del_virtual_intf_deprecated = ieee802154_del_iface_deprecated,
@@ -132,4 +147,5 @@ const struct cfg802154_ops mac802154_config_ops = {
         .set_pan_id = ieee802154_set_pan_id,
         .set_short_addr = ieee802154_set_short_addr,
         .set_backoff_exponent = ieee802154_set_backoff_exponent,
+        .set_max_csma_backoffs = ieee802154_set_max_csma_backoffs,
 };