diff --git a/drivers/net/can/dev.c b/drivers/net/can/dev.c index 365a8cc62405..cc94604b23e0 100644 --- a/drivers/net/can/dev.c +++ b/drivers/net/can/dev.c @@ -27,6 +27,7 @@ #include #include #include +#include #include #define MOD_DESC "CAN device driver interface" @@ -814,6 +815,29 @@ int open_candev(struct net_device *dev) } EXPORT_SYMBOL_GPL(open_candev); +#ifdef CONFIG_OF +/* Common function that can be used to understand the limitation of + * a transceiver when it provides no means to determine these limitations + * at runtime. + */ +void of_can_transceiver(struct net_device *dev) +{ + struct device_node *dn; + struct can_priv *priv = netdev_priv(dev); + struct device_node *np = dev->dev.parent->of_node; + int ret; + + dn = of_get_child_by_name(np, "can-transceiver"); + if (!dn) + return; + + ret = of_property_read_u32(dn, "max-bitrate", &priv->bitrate_max); + if ((ret && ret != -EINVAL) || (!ret && !priv->bitrate_max)) + netdev_warn(dev, "Invalid value for transceiver max bitrate. Ignoring bitrate limit.\n"); +} +EXPORT_SYMBOL_GPL(of_can_transceiver); +#endif + /* * Common close function for cleanup before the device gets closed. * @@ -913,6 +937,13 @@ static int can_changelink(struct net_device *dev, struct nlattr *tb[], priv->bitrate_const_cnt); if (err) return err; + + if (priv->bitrate_max && bt.bitrate > priv->bitrate_max) { + netdev_err(dev, "arbitration bitrate surpasses transceiver capabilities of %d bps\n", + priv->bitrate_max); + return -EINVAL; + } + memcpy(&priv->bittiming, &bt, sizeof(bt)); if (priv->do_set_bittiming) { @@ -997,6 +1028,13 @@ static int can_changelink(struct net_device *dev, struct nlattr *tb[], priv->data_bitrate_const_cnt); if (err) return err; + + if (priv->bitrate_max && dbt.bitrate > priv->bitrate_max) { + netdev_err(dev, "canfd data bitrate surpasses transceiver capabilities of %d bps\n", + priv->bitrate_max); + return -EINVAL; + } + memcpy(&priv->data_bittiming, &dbt, sizeof(dbt)); if (priv->do_set_data_bittiming) { @@ -1064,6 +1102,7 @@ static size_t can_get_size(const struct net_device *dev) if (priv->data_bitrate_const) /* IFLA_CAN_DATA_BITRATE_CONST */ size += nla_total_size(sizeof(*priv->data_bitrate_const) * priv->data_bitrate_const_cnt); + size += sizeof(priv->bitrate_max); /* IFLA_CAN_BITRATE_MAX */ return size; } @@ -1121,7 +1160,11 @@ static int can_fill_info(struct sk_buff *skb, const struct net_device *dev) nla_put(skb, IFLA_CAN_DATA_BITRATE_CONST, sizeof(*priv->data_bitrate_const) * priv->data_bitrate_const_cnt, - priv->data_bitrate_const)) + priv->data_bitrate_const)) || + + (nla_put(skb, IFLA_CAN_BITRATE_MAX, + sizeof(priv->bitrate_max), + &priv->bitrate_max)) ) return -EMSGSIZE; diff --git a/include/linux/can/dev.h b/include/linux/can/dev.h index 61f1cf2d9f44..055aaf5ed9af 100644 --- a/include/linux/can/dev.h +++ b/include/linux/can/dev.h @@ -46,6 +46,7 @@ struct can_priv { unsigned int bitrate_const_cnt; const u32 *data_bitrate_const; unsigned int data_bitrate_const_cnt; + u32 bitrate_max; struct can_clock clock; enum can_state state; @@ -166,6 +167,12 @@ void can_put_echo_skb(struct sk_buff *skb, struct net_device *dev, unsigned int can_get_echo_skb(struct net_device *dev, unsigned int idx); void can_free_echo_skb(struct net_device *dev, unsigned int idx); +#ifdef CONFIG_OF +void of_can_transceiver(struct net_device *dev); +#else +static inline void of_can_transceiver(struct net_device *dev) { } +#endif + struct sk_buff *alloc_can_skb(struct net_device *dev, struct can_frame **cf); struct sk_buff *alloc_canfd_skb(struct net_device *dev, struct canfd_frame **cfd); diff --git a/include/uapi/linux/can/netlink.h b/include/uapi/linux/can/netlink.h index 96710e76d5ce..9f56fad4785b 100644 --- a/include/uapi/linux/can/netlink.h +++ b/include/uapi/linux/can/netlink.h @@ -132,6 +132,7 @@ enum { IFLA_CAN_TERMINATION_CONST, IFLA_CAN_BITRATE_CONST, IFLA_CAN_DATA_BITRATE_CONST, + IFLA_CAN_BITRATE_MAX, __IFLA_CAN_MAX };