1 files changed, 78 insertions, 0 deletions
diff --git a/drivers/net/can/dev.c b/drivers/net/can/dev.c
index 2cfe5012e4e5..3ec8f6f25e5f 100644
--- a/drivers/net/can/dev.c
+++ b/drivers/net/can/dev.c
@@ -273,6 +273,84 @@ static int can_get_bittiming(struct net_device *dev, struct can_bittiming *bt,
 	return err;
 }
 
+static void can_update_state_error_stats(struct net_device *dev,
+					 enum can_state new_state)
+{
+	struct can_priv *priv = netdev_priv(dev);
+
+	if (new_state <= priv->state)
+		return;
+
+	switch (new_state) {
+	case CAN_STATE_ERROR_WARNING:
+		priv->can_stats.error_warning++;
+		break;
+	case CAN_STATE_ERROR_PASSIVE:
+		priv->can_stats.error_passive++;
+		break;
+	case CAN_STATE_BUS_OFF:
+	default:
+		break;
+	};
+}
+
+static int can_tx_state_to_frame(struct net_device *dev, enum can_state state)
+{
+	switch (state) {
+	case CAN_STATE_ERROR_ACTIVE:
+		return CAN_ERR_CRTL_ACTIVE;
+	case CAN_STATE_ERROR_WARNING:
+		return CAN_ERR_CRTL_TX_WARNING;
+	case CAN_STATE_ERROR_PASSIVE:
+		return CAN_ERR_CRTL_TX_PASSIVE;
+	default:
+		return 0;
+	}
+}
+
+static int can_rx_state_to_frame(struct net_device *dev, enum can_state state)
+{
+	switch (state) {
+	case CAN_STATE_ERROR_ACTIVE:
+		return CAN_ERR_CRTL_ACTIVE;
+	case CAN_STATE_ERROR_WARNING:
+		return CAN_ERR_CRTL_RX_WARNING;
+	case CAN_STATE_ERROR_PASSIVE:
+		return CAN_ERR_CRTL_RX_PASSIVE;
+	default:
+		return 0;
+	}
+}
+
+void can_change_state(struct net_device *dev, struct can_frame *cf,
+		      enum can_state tx_state, enum can_state rx_state)
+{
+	struct can_priv *priv = netdev_priv(dev);
+	enum can_state new_state = max(tx_state, rx_state);
+
+	if (unlikely(new_state == priv->state)) {
+		netdev_warn(dev, "%s: oops, state did not change", __func__);
+		return;
+	}
+
+	netdev_dbg(dev, "New error state: %d\n", new_state);
+
+	can_update_state_error_stats(dev, new_state);
+	priv->state = new_state;
+
+	if (unlikely(new_state == CAN_STATE_BUS_OFF)) {
+		cf->can_id |= CAN_ERR_BUSOFF;
+		return;
+	}
+
+	cf->can_id |= CAN_ERR_CRTL;
+	cf->data[1] |= tx_state >= rx_state ?
+		       can_tx_state_to_frame(dev, tx_state) : 0;
+	cf->data[1] |= tx_state <= rx_state ?
+		       can_rx_state_to_frame(dev, rx_state) : 0;
+}
+EXPORT_SYMBOL_GPL(can_change_state);
+
 /*
  * Local echo of CAN messages
  *