diff options
Diffstat (limited to 'drivers/net/can/dev/dev.c')
| -rw-r--r-- | drivers/net/can/dev/dev.c | 594 |
1 files changed, 594 insertions, 0 deletions
diff --git a/drivers/net/can/dev/dev.c b/drivers/net/can/dev/dev.c new file mode 100644 index 0000000000..735d5de3ca --- /dev/null +++ b/drivers/net/can/dev/dev.c @@ -0,0 +1,594 @@ +// 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/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/gpio/consumer.h> +#include <linux/of.h> + +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 sk_buff *skb; + struct can_frame *cf; + int err; + + if (netif_carrier_ok(dev)) + netdev_err(dev, "Attempt to restart for bus-off recovery, but carrier is OK?\n"); + + /* 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; + + netif_rx(skb); + +restart: + netdev_dbg(dev, "restarted\n"); + priv->can_stats.restarts++; + + /* Now restart the device */ + netif_carrier_on(dev); + err = priv->do_set_mode(dev, CAN_MODE_START); + if (err) { + netdev_err(dev, "Error %d during restart", err); + netif_carrier_off(dev); + } +} + +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 can_ml_priv *can_ml; + 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; + + can_ml = (void *)priv + ALIGN(sizeof_priv, NETDEV_ALIGN); + can_set_ml_priv(dev, can_ml); + + 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); + u32 ctrlmode_static = can_get_static_ctrlmode(priv); + + /* 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 (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) && + !(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); + +/* generic implementation of netdev_ops::ndo_eth_ioctl for CAN devices + * supporting hardware timestamps + */ +int can_eth_ioctl_hwts(struct net_device *netdev, struct ifreq *ifr, int cmd) +{ + struct hwtstamp_config hwts_cfg = { 0 }; + + switch (cmd) { + case SIOCSHWTSTAMP: /* set */ + if (copy_from_user(&hwts_cfg, ifr->ifr_data, sizeof(hwts_cfg))) + return -EFAULT; + if (hwts_cfg.tx_type == HWTSTAMP_TX_ON && + hwts_cfg.rx_filter == HWTSTAMP_FILTER_ALL) + return 0; + return -ERANGE; + + case SIOCGHWTSTAMP: /* get */ + hwts_cfg.tx_type = HWTSTAMP_TX_ON; + hwts_cfg.rx_filter = HWTSTAMP_FILTER_ALL; + if (copy_to_user(ifr->ifr_data, &hwts_cfg, sizeof(hwts_cfg))) + return -EFAULT; + return 0; + + default: + return -EOPNOTSUPP; + } +} +EXPORT_SYMBOL(can_eth_ioctl_hwts); + +/* generic implementation of ethtool_ops::get_ts_info for CAN devices + * supporting hardware timestamps + */ +int can_ethtool_op_get_ts_info_hwts(struct net_device *dev, + struct ethtool_ts_info *info) +{ + info->so_timestamping = + SOF_TIMESTAMPING_TX_SOFTWARE | + SOF_TIMESTAMPING_RX_SOFTWARE | + SOF_TIMESTAMPING_SOFTWARE | + SOF_TIMESTAMPING_TX_HARDWARE | + SOF_TIMESTAMPING_RX_HARDWARE | + SOF_TIMESTAMPING_RAW_HARDWARE; + info->phc_index = -1; + info->tx_types = BIT(HWTSTAMP_TX_ON); + info->rx_filters = BIT(HWTSTAMP_FILTER_ALL); + + return 0; +} +EXPORT_SYMBOL(can_ethtool_op_get_ts_info_hwts); + +/* 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); + +static int can_set_termination(struct net_device *ndev, u16 term) +{ + struct can_priv *priv = netdev_priv(ndev); + int set; + + if (term == priv->termination_gpio_ohms[CAN_TERMINATION_GPIO_ENABLED]) + set = 1; + else + set = 0; + + gpiod_set_value(priv->termination_gpio, set); + + return 0; +} + +static int can_get_termination(struct net_device *ndev) +{ + struct can_priv *priv = netdev_priv(ndev); + struct device *dev = ndev->dev.parent; + struct gpio_desc *gpio; + u32 term; + int ret; + + /* Disabling termination by default is the safe choice: Else if many + * bus participants enable it, no communication is possible at all. + */ + gpio = devm_gpiod_get_optional(dev, "termination", GPIOD_OUT_LOW); + if (IS_ERR(gpio)) + return dev_err_probe(dev, PTR_ERR(gpio), + "Cannot get termination-gpios\n"); + + if (!gpio) + return 0; + + ret = device_property_read_u32(dev, "termination-ohms", &term); + if (ret) { + netdev_err(ndev, "Cannot get termination-ohms: %pe\n", + ERR_PTR(ret)); + return ret; + } + + if (term > U16_MAX) { + netdev_err(ndev, "Invalid termination-ohms value (%u > %u)\n", + term, U16_MAX); + return -EINVAL; + } + + priv->termination_const_cnt = ARRAY_SIZE(priv->termination_gpio_ohms); + priv->termination_const = priv->termination_gpio_ohms; + priv->termination_gpio = gpio; + priv->termination_gpio_ohms[CAN_TERMINATION_GPIO_DISABLED] = + CAN_TERMINATION_DISABLED; + priv->termination_gpio_ohms[CAN_TERMINATION_GPIO_ENABLED] = term; + priv->do_set_termination = can_set_termination; + + return 0; +} + +static bool +can_bittiming_const_valid(const struct can_bittiming_const *btc) +{ + if (!btc) + return true; + + if (!btc->sjw_max) + return false; + + return true; +} + +/* Register the CAN network device */ +int register_candev(struct net_device *dev) +{ + struct can_priv *priv = netdev_priv(dev); + int err; + + /* 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; + + /* We only support either fixed bit rates or bit timing const. */ + if ((priv->bitrate_const || priv->data_bitrate_const) && + (priv->bittiming_const || priv->data_bittiming_const)) + return -EINVAL; + + if (!can_bittiming_const_valid(priv->bittiming_const) || + !can_bittiming_const_valid(priv->data_bittiming_const)) + return -EINVAL; + + if (!priv->termination_const) { + err = can_get_termination(dev); + if (err) + return err; + } + + 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; + + err = can_netlink_register(); + if (!err) + pr_info("CAN device driver interface\n"); + + return err; +} +module_init(can_dev_init); + +static __exit void can_dev_exit(void) +{ + can_netlink_unregister(); +} +module_exit(can_dev_exit); + +MODULE_ALIAS_RTNL_LINK("can"); |