1 files changed, 468 insertions, 0 deletions
diff --git a/drivers/net/can/dev/dev.c b/drivers/net/can/dev/dev.c
new file mode 100644
index 000000000000..d9281ae853f8
--- /dev/null
+++ b/drivers/net/can/dev/dev.c
@@ -0,0 +1,468 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* Copyright (C) 2005 Marc Kleine-Budde, Pengutronix
+ * Copyright (C) 2006 Andrey Volkov, Varma Electronics
+ * Copyright (C) 2008-2009 Wolfgang Grandegger <wg@grandegger.com>
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/netdevice.h>
+#include <linux/if_arp.h>
+#include <linux/workqueue.h>
+#include <linux/can.h>
+#include <linux/can/can-ml.h>
+#include <linux/can/dev.h>
+#include <linux/can/skb.h>
+#include <linux/can/led.h>
+#include <linux/of.h>
+
+#define MOD_DESC "CAN device driver interface"
+
+MODULE_DESCRIPTION(MOD_DESC);
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Wolfgang Grandegger <wg@grandegger.com>");
+
+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:
+		priv->can_stats.bus_off++;
+		break;
+	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;
+	}
+}
+
+const char *can_get_state_str(const enum can_state state)
+{
+	switch (state) {
+	case CAN_STATE_ERROR_ACTIVE:
+		return "Error Active";
+	case CAN_STATE_ERROR_WARNING:
+		return "Error Warning";
+	case CAN_STATE_ERROR_PASSIVE:
+		return "Error Passive";
+	case CAN_STATE_BUS_OFF:
+		return "Bus Off";
+	case CAN_STATE_STOPPED:
+		return "Stopped";
+	case CAN_STATE_SLEEPING:
+		return "Sleeping";
+	default:
+		return "<unknown>";
+	}
+
+	return "<unknown>";
+}
+EXPORT_SYMBOL_GPL(can_get_state_str);
+
+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, "Controller changed from %s State (%d) into %s State (%d).\n",
+		   can_get_state_str(priv->state), priv->state,
+		   can_get_state_str(new_state), new_state);
+
+	can_update_state_error_stats(dev, new_state);
+	priv->state = new_state;
+
+	if (!cf)
+		return;
+
+	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);
+
+/* CAN device restart for bus-off recovery */
+static void can_restart(struct net_device *dev)
+{
+	struct can_priv *priv = netdev_priv(dev);
+	struct net_device_stats *stats = &dev->stats;
+	struct sk_buff *skb;
+	struct can_frame *cf;
+	int err;
+
+	BUG_ON(netif_carrier_ok(dev));
+
+	/* No synchronization needed because the device is bus-off and
+	 * no messages can come in or go out.
+	 */
+	can_flush_echo_skb(dev);
+
+	/* send restart message upstream */
+	skb = alloc_can_err_skb(dev, &cf);
+	if (!skb)
+		goto restart;
+
+	cf->can_id |= CAN_ERR_RESTARTED;
+
+	stats->rx_packets++;
+	stats->rx_bytes += cf->len;
+
+	netif_rx_ni(skb);
+
+restart:
+	netdev_dbg(dev, "restarted\n");
+	priv->can_stats.restarts++;
+
+	/* Now restart the device */
+	err = priv->do_set_mode(dev, CAN_MODE_START);
+
+	netif_carrier_on(dev);
+	if (err)
+		netdev_err(dev, "Error %d during restart", err);
+}
+
+static void can_restart_work(struct work_struct *work)
+{
+	struct delayed_work *dwork = to_delayed_work(work);
+	struct can_priv *priv = container_of(dwork, struct can_priv,
+					     restart_work);
+
+	can_restart(priv->dev);
+}
+
+int can_restart_now(struct net_device *dev)
+{
+	struct can_priv *priv = netdev_priv(dev);
+
+	/* A manual restart is only permitted if automatic restart is
+	 * disabled and the device is in the bus-off state
+	 */
+	if (priv->restart_ms)
+		return -EINVAL;
+	if (priv->state != CAN_STATE_BUS_OFF)
+		return -EBUSY;
+
+	cancel_delayed_work_sync(&priv->restart_work);
+	can_restart(dev);
+
+	return 0;
+}
+
+/* CAN bus-off
+ *
+ * This functions should be called when the device goes bus-off to
+ * tell the netif layer that no more packets can be sent or received.
+ * If enabled, a timer is started to trigger bus-off recovery.
+ */
+void can_bus_off(struct net_device *dev)
+{
+	struct can_priv *priv = netdev_priv(dev);
+
+	if (priv->restart_ms)
+		netdev_info(dev, "bus-off, scheduling restart in %d ms\n",
+			    priv->restart_ms);
+	else
+		netdev_info(dev, "bus-off\n");
+
+	netif_carrier_off(dev);
+
+	if (priv->restart_ms)
+		schedule_delayed_work(&priv->restart_work,
+				      msecs_to_jiffies(priv->restart_ms));
+}
+EXPORT_SYMBOL_GPL(can_bus_off);
+
+void can_setup(struct net_device *dev)
+{
+	dev->type = ARPHRD_CAN;
+	dev->mtu = CAN_MTU;
+	dev->hard_header_len = 0;
+	dev->addr_len = 0;
+	dev->tx_queue_len = 10;
+
+	/* New-style flags. */
+	dev->flags = IFF_NOARP;
+	dev->features = NETIF_F_HW_CSUM;
+}
+
+/* Allocate and setup space for the CAN network device */
+struct net_device *alloc_candev_mqs(int sizeof_priv, unsigned int echo_skb_max,
+				    unsigned int txqs, unsigned int rxqs)
+{
+	struct net_device *dev;
+	struct can_priv *priv;
+	int size;
+
+	/* We put the driver's priv, the CAN mid layer priv and the
+	 * echo skb into the netdevice's priv. The memory layout for
+	 * the netdev_priv is like this:
+	 *
+	 * +-------------------------+
+	 * | driver's priv           |
+	 * +-------------------------+
+	 * | struct can_ml_priv      |
+	 * +-------------------------+
+	 * | array of struct sk_buff |
+	 * +-------------------------+
+	 */
+
+	size = ALIGN(sizeof_priv, NETDEV_ALIGN) + sizeof(struct can_ml_priv);
+
+	if (echo_skb_max)
+		size = ALIGN(size, sizeof(struct sk_buff *)) +
+			echo_skb_max * sizeof(struct sk_buff *);
+
+	dev = alloc_netdev_mqs(size, "can%d", NET_NAME_UNKNOWN, can_setup,
+			       txqs, rxqs);
+	if (!dev)
+		return NULL;
+
+	priv = netdev_priv(dev);
+	priv->dev = dev;
+
+	dev->ml_priv = (void *)priv + ALIGN(sizeof_priv, NETDEV_ALIGN);
+
+	if (echo_skb_max) {
+		priv->echo_skb_max = echo_skb_max;
+		priv->echo_skb = (void *)priv +
+			(size - echo_skb_max * sizeof(struct sk_buff *));
+	}
+
+	priv->state = CAN_STATE_STOPPED;
+
+	INIT_DELAYED_WORK(&priv->restart_work, can_restart_work);
+
+	return dev;
+}
+EXPORT_SYMBOL_GPL(alloc_candev_mqs);
+
+/* Free space of the CAN network device */
+void free_candev(struct net_device *dev)
+{
+	free_netdev(dev);
+}
+EXPORT_SYMBOL_GPL(free_candev);
+
+/* changing MTU and control mode for CAN/CANFD devices */
+int can_change_mtu(struct net_device *dev, int new_mtu)
+{
+	struct can_priv *priv = netdev_priv(dev);
+
+	/* Do not allow changing the MTU while running */
+	if (dev->flags & IFF_UP)
+		return -EBUSY;
+
+	/* allow change of MTU according to the CANFD ability of the device */
+	switch (new_mtu) {
+	case CAN_MTU:
+		/* 'CANFD-only' controllers can not switch to CAN_MTU */
+		if (priv->ctrlmode_static & CAN_CTRLMODE_FD)
+			return -EINVAL;
+
+		priv->ctrlmode &= ~CAN_CTRLMODE_FD;
+		break;
+
+	case CANFD_MTU:
+		/* check for potential CANFD ability */
+		if (!(priv->ctrlmode_supported & CAN_CTRLMODE_FD) &&
+		    !(priv->ctrlmode_static & CAN_CTRLMODE_FD))
+			return -EINVAL;
+
+		priv->ctrlmode |= CAN_CTRLMODE_FD;
+		break;
+
+	default:
+		return -EINVAL;
+	}
+
+	dev->mtu = new_mtu;
+	return 0;
+}
+EXPORT_SYMBOL_GPL(can_change_mtu);
+
+/* Common open function when the device gets opened.
+ *
+ * This function should be called in the open function of the device
+ * driver.
+ */
+int open_candev(struct net_device *dev)
+{
+	struct can_priv *priv = netdev_priv(dev);
+
+	if (!priv->bittiming.bitrate) {
+		netdev_err(dev, "bit-timing not yet defined\n");
+		return -EINVAL;
+	}
+
+	/* For CAN FD the data bitrate has to be >= the arbitration bitrate */
+	if ((priv->ctrlmode & CAN_CTRLMODE_FD) &&
+	    (!priv->data_bittiming.bitrate ||
+	     priv->data_bittiming.bitrate < priv->bittiming.bitrate)) {
+		netdev_err(dev, "incorrect/missing data bit-timing\n");
+		return -EINVAL;
+	}
+
+	/* Switch carrier on if device was stopped while in bus-off state */
+	if (!netif_carrier_ok(dev))
+		netif_carrier_on(dev);
+
+	return 0;
+}
+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);
+	of_node_put(dn);
+	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.
+ *
+ * This function should be called in the close function of the device
+ * driver.
+ */
+void close_candev(struct net_device *dev)
+{
+	struct can_priv *priv = netdev_priv(dev);
+
+	cancel_delayed_work_sync(&priv->restart_work);
+	can_flush_echo_skb(dev);
+}
+EXPORT_SYMBOL_GPL(close_candev);
+
+/* Register the CAN network device */
+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;
+
+	if (!priv->bitrate_const != !priv->bitrate_const_cnt)
+		return -EINVAL;
+
+	if (!priv->data_bitrate_const != !priv->data_bitrate_const_cnt)
+		return -EINVAL;
+
+	dev->rtnl_link_ops = &can_link_ops;
+	netif_carrier_off(dev);
+
+	return register_netdev(dev);
+}
+EXPORT_SYMBOL_GPL(register_candev);
+
+/* Unregister the CAN network device */
+void unregister_candev(struct net_device *dev)
+{
+	unregister_netdev(dev);
+}
+EXPORT_SYMBOL_GPL(unregister_candev);
+
+/* Test if a network device is a candev based device
+ * and return the can_priv* if so.
+ */
+struct can_priv *safe_candev_priv(struct net_device *dev)
+{
+	if (dev->type != ARPHRD_CAN || dev->rtnl_link_ops != &can_link_ops)
+		return NULL;
+
+	return netdev_priv(dev);
+}
+EXPORT_SYMBOL_GPL(safe_candev_priv);
+
+static __init int can_dev_init(void)
+{
+	int err;
+
+	can_led_notifier_init();
+
+	err = can_netlink_register();
+	if (!err)
+		pr_info(MOD_DESC "\n");
+
+	return err;
+}
+module_init(can_dev_init);
+
+static __exit void can_dev_exit(void)
+{
+	can_netlink_unregister();
+
+	can_led_notifier_exit();
+}
+module_exit(can_dev_exit);
+
+MODULE_ALIAS_RTNL_LINK("can");