--- /dev/null
- netif_rx_ni(skb);
-
+// 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;
+ }
+}
+
+static 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>";
+}
+
+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");
projects / platform / kernel / linux-starfive.git / commitdiff