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path: root/drivers/net/can/dev.c
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Diffstat (limited to 'drivers/net/can/dev.c')
-rw-r--r--drivers/net/can/dev.c47
1 files changed, 45 insertions, 2 deletions
diff --git a/drivers/net/can/dev.c b/drivers/net/can/dev.c
index 365a8cc62405..b1779566c5bb 100644
--- a/drivers/net/can/dev.c
+++ b/drivers/net/can/dev.c
@@ -27,6 +27,7 @@
#include <linux/can/skb.h>
#include <linux/can/netlink.h>
#include <linux/can/led.h>
+#include <linux/of.h>
#include <net/rtnetlink.h>
#define MOD_DESC "CAN device driver interface"
@@ -411,7 +412,7 @@ EXPORT_SYMBOL_GPL(can_change_state);
* Local echo of CAN messages
*
* CAN network devices *should* support a local echo functionality
- * (see Documentation/networking/can.txt). To test the handling of CAN
+ * (see Documentation/networking/can.rst). To test the handling of CAN
* interfaces that do not support the local echo both driver types are
* implemented. In the case that the driver does not support the echo
* the IFF_ECHO remains clear in dev->flags. This causes the PF_CAN core
@@ -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;