can: dev: add CAN interface termination API
This patch adds a netlink interface to configure the CAN bus termination of
CAN interfaces.
Inside the driver an array of supported termination values is defined:
const u16 drvname_termination[] = { 60, 120, CAN_TERMINATION_DISABLED };
struct drvname_priv *priv;
priv = netdev_priv(dev);
priv->termination_const = drvname_termination;
priv->termination_const_cnt = ARRAY_SIZE(drvname_termination);
priv->termination = CAN_TERMINATION_DISABLED;
And the funtion to set the value has to be defined:
priv->do_set_termination = drvname_set_termination;
Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Reviewed-by: Ramesh Shanmugasundaram <Ramesh.shanmugasundaram@bp.renesas.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
diff --git a/drivers/net/can/dev.c b/drivers/net/can/dev.c
index 8d6208c..fefe2cd 100644
--- a/drivers/net/can/dev.c
+++ b/drivers/net/can/dev.c
@@ -958,6 +958,30 @@ static int can_changelink(struct net_device *dev,
}
}
+ if (data[IFLA_CAN_TERMINATION]) {
+ const u16 termval = nla_get_u16(data[IFLA_CAN_TERMINATION]);
+ const unsigned int num_term = priv->termination_const_cnt;
+ unsigned int i;
+
+ if (!priv->do_set_termination)
+ return -EOPNOTSUPP;
+
+ /* check whether given value is supported by the interface */
+ for (i = 0; i < num_term; i++) {
+ if (termval == priv->termination_const[i])
+ break;
+ }
+ if (i >= num_term)
+ return -EINVAL;
+
+ /* Finally, set the termination value */
+ err = priv->do_set_termination(dev, termval);
+ if (err)
+ return err;
+
+ priv->termination = termval;
+ }
+
return 0;
}
@@ -980,6 +1004,11 @@ static size_t can_get_size(const struct net_device *dev)
size += nla_total_size(sizeof(struct can_bittiming));
if (priv->data_bittiming_const) /* IFLA_CAN_DATA_BITTIMING_CONST */
size += nla_total_size(sizeof(struct can_bittiming_const));
+ if (priv->termination_const) {
+ size += nla_total_size(sizeof(priv->termination)); /* IFLA_CAN_TERMINATION */
+ size += nla_total_size(sizeof(*priv->termination_const) * /* IFLA_CAN_TERMINATION_CONST */
+ priv->termination_const_cnt);
+ }
return size;
}
@@ -1018,7 +1047,15 @@ static int can_fill_info(struct sk_buff *skb, const struct net_device *dev)
(priv->data_bittiming_const &&
nla_put(skb, IFLA_CAN_DATA_BITTIMING_CONST,
sizeof(*priv->data_bittiming_const),
- priv->data_bittiming_const)))
+ priv->data_bittiming_const)) ||
+
+ (priv->termination_const &&
+ (nla_put_u16(skb, IFLA_CAN_TERMINATION, priv->termination) ||
+ nla_put(skb, IFLA_CAN_TERMINATION_CONST,
+ sizeof(*priv->termination_const) *
+ priv->termination_const_cnt,
+ priv->termination_const))))
+
return -EMSGSIZE;
return 0;
@@ -1073,6 +1110,16 @@ static struct rtnl_link_ops can_link_ops __read_mostly = {
*/
int register_candev(struct net_device *dev)
{
+ struct can_priv *priv = netdev_priv(dev);
+
+ /* Ensure termination_const, termination_const_cnt and
+ * do_set_termination consistency. All must be either set or
+ * unset.
+ */
+ if ((!priv->termination_const != !priv->termination_const_cnt) ||
+ (!priv->termination_const != !priv->do_set_termination))
+ return -EINVAL;
+
dev->rtnl_link_ops = &can_link_ops;
return register_netdev(dev);
}