--- /dev/null
+/*
+ * Copyright (C) 2005 Marc Kleine-Budde, Pengutronix
+ * Copyright (C) 2006 Andrey Volkov, Varma Electronics
+ * Copyright (C) 2008-2009 Wolfgang Grandegger <wg@grandegger.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the version 2 of the GNU General Public License
+ * as published by the Free Software Foundation
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/netdevice.h>
+#include <linux/if_arp.h>
+#include <linux/can.h>
+#include <linux/can/dev.h>
+#include <linux/can/skb.h>
+#include <linux/can/netlink.h>
+#include <linux/can/led.h>
+#include <net/rtnetlink.h>
+
+#define MOD_DESC "CAN device driver interface"
+
+MODULE_DESCRIPTION(MOD_DESC);
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Wolfgang Grandegger <wg@grandegger.com>");
+
+/* CAN DLC to real data length conversion helpers */
+
+static const u8 dlc2len[] = {0, 1, 2, 3, 4, 5, 6, 7,
+ 8, 12, 16, 20, 24, 32, 48, 64};
+
+/* get data length from can_dlc with sanitized can_dlc */
+u8 can_dlc2len(u8 can_dlc)
+{
+ return dlc2len[can_dlc & 0x0F];
+}
+EXPORT_SYMBOL_GPL(can_dlc2len);
+
+static const u8 len2dlc[] = {0, 1, 2, 3, 4, 5, 6, 7, 8, /* 0 - 8 */
+ 9, 9, 9, 9, /* 9 - 12 */
+ 10, 10, 10, 10, /* 13 - 16 */
+ 11, 11, 11, 11, /* 17 - 20 */
+ 12, 12, 12, 12, /* 21 - 24 */
+ 13, 13, 13, 13, 13, 13, 13, 13, /* 25 - 32 */
+ 14, 14, 14, 14, 14, 14, 14, 14, /* 33 - 40 */
+ 14, 14, 14, 14, 14, 14, 14, 14, /* 41 - 48 */
+ 15, 15, 15, 15, 15, 15, 15, 15, /* 49 - 56 */
+ 15, 15, 15, 15, 15, 15, 15, 15}; /* 57 - 64 */
+
+/* map the sanitized data length to an appropriate data length code */
+u8 can_len2dlc(u8 len)
+{
+ if (unlikely(len > 64))
+ return 0xF;
+
+ return len2dlc[len];
+}
+EXPORT_SYMBOL_GPL(can_len2dlc);
+
+#ifdef CONFIG_CAN_CALC_BITTIMING
+#define CAN_CALC_MAX_ERROR 50 /* in one-tenth of a percent */
+
+/*
+ * Bit-timing calculation derived from:
+ *
+ * Code based on LinCAN sources and H8S2638 project
+ * Copyright 2004-2006 Pavel Pisa - DCE FELK CVUT cz
+ * Copyright 2005 Stanislav Marek
+ * email: pisa@cmp.felk.cvut.cz
+ *
+ * Calculates proper bit-timing parameters for a specified bit-rate
+ * and sample-point, which can then be used to set the bit-timing
+ * registers of the CAN controller. You can find more information
+ * in the header file linux/can/netlink.h.
+ */
+static int can_update_spt(const struct can_bittiming_const *btc,
+ int sampl_pt, int tseg, int *tseg1, int *tseg2)
+{
+ *tseg2 = tseg + 1 - (sampl_pt * (tseg + 1)) / 1000;
+ if (*tseg2 < btc->tseg2_min)
+ *tseg2 = btc->tseg2_min;
+ if (*tseg2 > btc->tseg2_max)
+ *tseg2 = btc->tseg2_max;
+ *tseg1 = tseg - *tseg2;
+ if (*tseg1 > btc->tseg1_max) {
+ *tseg1 = btc->tseg1_max;
+ *tseg2 = tseg - *tseg1;
+ }
+ return 1000 * (tseg + 1 - *tseg2) / (tseg + 1);
+}
+
+static int can_calc_bittiming(struct net_device *dev, struct can_bittiming *bt,
+ const struct can_bittiming_const *btc)
+{
+ struct can_priv *priv = netdev_priv(dev);
+ long best_error = 1000000000, error = 0;
+ int best_tseg = 0, best_brp = 0, brp = 0;
+ int tsegall, tseg = 0, tseg1 = 0, tseg2 = 0;
+ int spt_error = 1000, spt = 0, sampl_pt;
+ long rate;
+ u64 v64;
+
+ /* Use CiA recommended sample points */
+ if (bt->sample_point) {
+ sampl_pt = bt->sample_point;
+ } else {
+ if (bt->bitrate > 800000)
+ sampl_pt = 750;
+ else if (bt->bitrate > 500000)
+ sampl_pt = 800;
+ else
+ sampl_pt = 875;
+ }
+
+ /* tseg even = round down, odd = round up */
+ for (tseg = (btc->tseg1_max + btc->tseg2_max) * 2 + 1;
+ tseg >= (btc->tseg1_min + btc->tseg2_min) * 2; tseg--) {
+ tsegall = 1 + tseg / 2;
+ /* Compute all possible tseg choices (tseg=tseg1+tseg2) */
+ brp = priv->clock.freq / (tsegall * bt->bitrate) + tseg % 2;
+ /* chose brp step which is possible in system */
+ brp = (brp / btc->brp_inc) * btc->brp_inc;
+ if ((brp < btc->brp_min) || (brp > btc->brp_max))
+ continue;
+ rate = priv->clock.freq / (brp * tsegall);
+ error = bt->bitrate - rate;
+ /* tseg brp biterror */
+ if (error < 0)
+ error = -error;
+ if (error > best_error)
+ continue;
+ best_error = error;
+ if (error == 0) {
+ spt = can_update_spt(btc, sampl_pt, tseg / 2,
+ &tseg1, &tseg2);
+ error = sampl_pt - spt;
+ if (error < 0)
+ error = -error;
+ if (error > spt_error)
+ continue;
+ spt_error = error;
+ }
+ best_tseg = tseg / 2;
+ best_brp = brp;
+ if (error == 0)
+ break;
+ }
+
+ if (best_error) {
+ /* Error in one-tenth of a percent */
+ error = (best_error * 1000) / bt->bitrate;
+ if (error > CAN_CALC_MAX_ERROR) {
+ netdev_err(dev,
+ "bitrate error %ld.%ld%% too high\n",
+ error / 10, error % 10);
+ return -EDOM;
+ } else {
+ netdev_warn(dev, "bitrate error %ld.%ld%%\n",
+ error / 10, error % 10);
+ }
+ }
+
+ /* real sample point */
+ bt->sample_point = can_update_spt(btc, sampl_pt, best_tseg,
+ &tseg1, &tseg2);
+
+ v64 = (u64)best_brp * 1000000000UL;
+ do_div(v64, priv->clock.freq);
+ bt->tq = (u32)v64;
+ bt->prop_seg = tseg1 / 2;
+ bt->phase_seg1 = tseg1 - bt->prop_seg;
+ bt->phase_seg2 = tseg2;
+
+ /* check for sjw user settings */
+ if (!bt->sjw || !btc->sjw_max)
+ bt->sjw = 1;
+ else {
+ /* bt->sjw is at least 1 -> sanitize upper bound to sjw_max */
+ if (bt->sjw > btc->sjw_max)
+ bt->sjw = btc->sjw_max;
+ /* bt->sjw must not be higher than tseg2 */
+ if (tseg2 < bt->sjw)
+ bt->sjw = tseg2;
+ }
+
+ bt->brp = best_brp;
+ /* real bit-rate */
+ bt->bitrate = priv->clock.freq / (bt->brp * (tseg1 + tseg2 + 1));
+
+ return 0;
+}
+#else /* !CONFIG_CAN_CALC_BITTIMING */
+static int can_calc_bittiming(struct net_device *dev, struct can_bittiming *bt,
+ const struct can_bittiming_const *btc)
+{
+ netdev_err(dev, "bit-timing calculation not available\n");
+ return -EINVAL;
+}
+#endif /* CONFIG_CAN_CALC_BITTIMING */
+
+/*
+ * Checks the validity of the specified bit-timing parameters prop_seg,
+ * phase_seg1, phase_seg2 and sjw and tries to determine the bitrate
+ * prescaler value brp. You can find more information in the header
+ * file linux/can/netlink.h.
+ */
+static int can_fixup_bittiming(struct net_device *dev, struct can_bittiming *bt,
+ const struct can_bittiming_const *btc)
+{
+ struct can_priv *priv = netdev_priv(dev);
+ int tseg1, alltseg;
+ u64 brp64;
+
+ tseg1 = bt->prop_seg + bt->phase_seg1;
+ if (!bt->sjw)
+ bt->sjw = 1;
+ if (bt->sjw > btc->sjw_max ||
+ tseg1 < btc->tseg1_min || tseg1 > btc->tseg1_max ||
+ bt->phase_seg2 < btc->tseg2_min || bt->phase_seg2 > btc->tseg2_max)
+ return -ERANGE;
+
+ brp64 = (u64)priv->clock.freq * (u64)bt->tq;
+ if (btc->brp_inc > 1)
+ do_div(brp64, btc->brp_inc);
+ brp64 += 500000000UL - 1;
+ do_div(brp64, 1000000000UL); /* the practicable BRP */
+ if (btc->brp_inc > 1)
+ brp64 *= btc->brp_inc;
+ bt->brp = (u32)brp64;
+
+ if (bt->brp < btc->brp_min || bt->brp > btc->brp_max)
+ return -EINVAL;
+
+ alltseg = bt->prop_seg + bt->phase_seg1 + bt->phase_seg2 + 1;
+ bt->bitrate = priv->clock.freq / (bt->brp * alltseg);
+ bt->sample_point = ((tseg1 + 1) * 1000) / alltseg;
+
+ return 0;
+}
+
+static int can_get_bittiming(struct net_device *dev, struct can_bittiming *bt,
+ const struct can_bittiming_const *btc)
+{
+ int err;
+
+ /* Check if the CAN device has bit-timing parameters */
+ if (!btc)
+ return -EOPNOTSUPP;
+
+ /*
+ * Depending on the given can_bittiming parameter structure the CAN
+ * timing parameters are calculated based on the provided bitrate OR
+ * alternatively the CAN timing parameters (tq, prop_seg, etc.) are
+ * provided directly which are then checked and fixed up.
+ */
+ if (!bt->tq && bt->bitrate)
+ err = can_calc_bittiming(dev, bt, btc);
+ else if (bt->tq && !bt->bitrate)
+ err = can_fixup_bittiming(dev, bt, btc);
+ else
+ err = -EINVAL;
+
+ 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:
+ 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;
+ }
+}
+
+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
+ *
+ * CAN network devices *should* support a local echo functionality
+ * (see Documentation/networking/can.txt). 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
+ * to perform the echo as a fallback solution.
+ */
+static void can_flush_echo_skb(struct net_device *dev)
+{
+ struct can_priv *priv = netdev_priv(dev);
+ struct net_device_stats *stats = &dev->stats;
+ int i;
+
+ for (i = 0; i < priv->echo_skb_max; i++) {
+ if (priv->echo_skb[i]) {
+ kfree_skb(priv->echo_skb[i]);
+ priv->echo_skb[i] = NULL;
+ stats->tx_dropped++;
+ stats->tx_aborted_errors++;
+ }
+ }
+}
+
+/*
+ * Put the skb on the stack to be looped backed locally lateron
+ *
+ * The function is typically called in the start_xmit function
+ * of the device driver. The driver must protect access to
+ * priv->echo_skb, if necessary.
+ */
+void can_put_echo_skb(struct sk_buff *skb, struct net_device *dev,
+ unsigned int idx)
+{
+ struct can_priv *priv = netdev_priv(dev);
+
+ BUG_ON(idx >= priv->echo_skb_max);
+
+ /* check flag whether this packet has to be looped back */
+ if (!(dev->flags & IFF_ECHO) || skb->pkt_type != PACKET_LOOPBACK ||
+ (skb->protocol != htons(ETH_P_CAN) &&
+ skb->protocol != htons(ETH_P_CANFD))) {
+ kfree_skb(skb);
+ return;
+ }
+
+ if (!priv->echo_skb[idx]) {
+
+ skb = can_create_echo_skb(skb);
+ if (!skb)
+ return;
+
+ /* make settings for echo to reduce code in irq context */
+ skb->pkt_type = PACKET_BROADCAST;
+ skb->ip_summed = CHECKSUM_UNNECESSARY;
+ skb->dev = dev;
+
+ /* save this skb for tx interrupt echo handling */
+ priv->echo_skb[idx] = skb;
+ } else {
+ /* locking problem with netif_stop_queue() ?? */
+ netdev_err(dev, "%s: BUG! echo_skb is occupied!\n", __func__);
+ kfree_skb(skb);
+ }
+}
+EXPORT_SYMBOL_GPL(can_put_echo_skb);
+
+/*
+ * Get the skb from the stack and loop it back locally
+ *
+ * The function is typically called when the TX done interrupt
+ * is handled in the device driver. The driver must protect
+ * access to priv->echo_skb, if necessary.
+ */
+unsigned int can_get_echo_skb(struct net_device *dev, unsigned int idx)
+{
+ struct can_priv *priv = netdev_priv(dev);
+
+ BUG_ON(idx >= priv->echo_skb_max);
+
+ if (priv->echo_skb[idx]) {
+ struct sk_buff *skb = priv->echo_skb[idx];
+ struct can_frame *cf = (struct can_frame *)skb->data;
+ u8 dlc = cf->can_dlc;
+
+ if (!(skb->tstamp.tv64))
+ __net_timestamp(skb);
+
+ netif_rx(priv->echo_skb[idx]);
+ priv->echo_skb[idx] = NULL;
+
+ return dlc;
+ }
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(can_get_echo_skb);
+
+/*
+ * Remove the skb from the stack and free it.
+ *
+ * The function is typically called when TX failed.
+ */
+void can_free_echo_skb(struct net_device *dev, unsigned int idx)
+{
+ struct can_priv *priv = netdev_priv(dev);
+
+ BUG_ON(idx >= priv->echo_skb_max);
+
+ if (priv->echo_skb[idx]) {
+ dev_kfree_skb_any(priv->echo_skb[idx]);
+ priv->echo_skb[idx] = NULL;
+ }
+}
+EXPORT_SYMBOL_GPL(can_free_echo_skb);
+
+/*
+ * CAN device restart for bus-off recovery
+ */
+static void can_restart(unsigned long data)
+{
+ struct net_device *dev = (struct net_device *)data;
+ 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 == NULL) {
+ err = -ENOMEM;
+ goto restart;
+ }
+ cf->can_id |= CAN_ERR_RESTARTED;
+
+ netif_rx(skb);
+
+ stats->rx_packets++;
+ stats->rx_bytes += cf->can_dlc;
+
+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);
+}
+
+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;
+
+ /* Runs as soon as possible in the timer context */
+ mod_timer(&priv->restart_timer, jiffies);
+
+ 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);
+
+ netdev_dbg(dev, "bus-off\n");
+
+ netif_carrier_off(dev);
+
+ if (priv->restart_ms)
+ mod_timer(&priv->restart_timer,
+ jiffies + (priv->restart_ms * HZ) / 1000);
+}
+EXPORT_SYMBOL_GPL(can_bus_off);
+
+static 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;
+}
+
+struct sk_buff *alloc_can_skb(struct net_device *dev, struct can_frame **cf)
+{
+ struct sk_buff *skb;
+
+ skb = netdev_alloc_skb(dev, sizeof(struct can_skb_priv) +
+ sizeof(struct can_frame));
+ if (unlikely(!skb))
+ return NULL;
+
+ __net_timestamp(skb);
+ skb->protocol = htons(ETH_P_CAN);
+ skb->pkt_type = PACKET_BROADCAST;
+ skb->ip_summed = CHECKSUM_UNNECESSARY;
+
+ skb_reset_mac_header(skb);
+ skb_reset_network_header(skb);
+ skb_reset_transport_header(skb);
+
+ can_skb_reserve(skb);
+ can_skb_prv(skb)->ifindex = dev->ifindex;
+
+ *cf = (struct can_frame *)skb_put(skb, sizeof(struct can_frame));
+ memset(*cf, 0, sizeof(struct can_frame));
+
+ return skb;
+}
+EXPORT_SYMBOL_GPL(alloc_can_skb);
+
+struct sk_buff *alloc_canfd_skb(struct net_device *dev,
+ struct canfd_frame **cfd)
+{
+ struct sk_buff *skb;
+
+ skb = netdev_alloc_skb(dev, sizeof(struct can_skb_priv) +
+ sizeof(struct canfd_frame));
+ if (unlikely(!skb))
+ return NULL;
+
+ __net_timestamp(skb);
+ skb->protocol = htons(ETH_P_CANFD);
+ skb->pkt_type = PACKET_BROADCAST;
+ skb->ip_summed = CHECKSUM_UNNECESSARY;
+
+ skb_reset_mac_header(skb);
+ skb_reset_network_header(skb);
+ skb_reset_transport_header(skb);
+
+ can_skb_reserve(skb);
+ can_skb_prv(skb)->ifindex = dev->ifindex;
+
+ *cfd = (struct canfd_frame *)skb_put(skb, sizeof(struct canfd_frame));
+ memset(*cfd, 0, sizeof(struct canfd_frame));
+
+ return skb;
+}
+EXPORT_SYMBOL_GPL(alloc_canfd_skb);
+
+struct sk_buff *alloc_can_err_skb(struct net_device *dev, struct can_frame **cf)
+{
+ struct sk_buff *skb;
+
+ skb = alloc_can_skb(dev, cf);
+ if (unlikely(!skb))
+ return NULL;
+
+ (*cf)->can_id = CAN_ERR_FLAG;
+ (*cf)->can_dlc = CAN_ERR_DLC;
+
+ return skb;
+}
+EXPORT_SYMBOL_GPL(alloc_can_err_skb);
+
+/*
+ * Allocate and setup space for the CAN network device
+ */
+struct net_device *alloc_candev(int sizeof_priv, unsigned int echo_skb_max)
+{
+ struct net_device *dev;
+ struct can_priv *priv;
+ int size;
+
+ if (echo_skb_max)
+ size = ALIGN(sizeof_priv, sizeof(struct sk_buff *)) +
+ echo_skb_max * sizeof(struct sk_buff *);
+ else
+ size = sizeof_priv;
+
+ dev = alloc_netdev(size, "can%d", NET_NAME_UNKNOWN, can_setup);
+ if (!dev)
+ return NULL;
+
+ priv = netdev_priv(dev);
+
+ if (echo_skb_max) {
+ priv->echo_skb_max = echo_skb_max;
+ priv->echo_skb = (void *)priv +
+ ALIGN(sizeof_priv, sizeof(struct sk_buff *));
+ }
+
+ priv->state = CAN_STATE_STOPPED;
+
+ init_timer(&priv->restart_timer);
+
+ return dev;
+}
+EXPORT_SYMBOL_GPL(alloc_candev);
+
+/*
+ * 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:
+ priv->ctrlmode &= ~CAN_CTRLMODE_FD;
+ break;
+
+ case CANFD_MTU:
+ if (!(priv->ctrlmode_supported & 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);
+
+ setup_timer(&priv->restart_timer, can_restart, (unsigned long)dev);
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(open_candev);
+
+/*
+ * 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);
+
+ del_timer_sync(&priv->restart_timer);
+ can_flush_echo_skb(dev);
+}
+EXPORT_SYMBOL_GPL(close_candev);
+
+/*
+ * CAN netlink interface
+ */
+static const struct nla_policy can_policy[IFLA_CAN_MAX + 1] = {
+ [IFLA_CAN_STATE] = { .type = NLA_U32 },
+ [IFLA_CAN_CTRLMODE] = { .len = sizeof(struct can_ctrlmode) },
+ [IFLA_CAN_RESTART_MS] = { .type = NLA_U32 },
+ [IFLA_CAN_RESTART] = { .type = NLA_U32 },
+ [IFLA_CAN_BITTIMING] = { .len = sizeof(struct can_bittiming) },
+ [IFLA_CAN_BITTIMING_CONST]
+ = { .len = sizeof(struct can_bittiming_const) },
+ [IFLA_CAN_CLOCK] = { .len = sizeof(struct can_clock) },
+ [IFLA_CAN_BERR_COUNTER] = { .len = sizeof(struct can_berr_counter) },
+ [IFLA_CAN_DATA_BITTIMING]
+ = { .len = sizeof(struct can_bittiming) },
+ [IFLA_CAN_DATA_BITTIMING_CONST]
+ = { .len = sizeof(struct can_bittiming_const) },
+};
+
+static int can_changelink(struct net_device *dev,
+ struct nlattr *tb[], struct nlattr *data[])
+{
+ struct can_priv *priv = netdev_priv(dev);
+ int err;
+
+ /* We need synchronization with dev->stop() */
+ ASSERT_RTNL();
+
+ if (data[IFLA_CAN_BITTIMING]) {
+ struct can_bittiming bt;
+
+ /* Do not allow changing bittiming while running */
+ if (dev->flags & IFF_UP)
+ return -EBUSY;
+ memcpy(&bt, nla_data(data[IFLA_CAN_BITTIMING]), sizeof(bt));
+ err = can_get_bittiming(dev, &bt, priv->bittiming_const);
+ if (err)
+ return err;
+ memcpy(&priv->bittiming, &bt, sizeof(bt));
+
+ if (priv->do_set_bittiming) {
+ /* Finally, set the bit-timing registers */
+ err = priv->do_set_bittiming(dev);
+ if (err)
+ return err;
+ }
+ }
+
+ if (data[IFLA_CAN_CTRLMODE]) {
+ struct can_ctrlmode *cm;
+
+ /* Do not allow changing controller mode while running */
+ if (dev->flags & IFF_UP)
+ return -EBUSY;
+ cm = nla_data(data[IFLA_CAN_CTRLMODE]);
+
+ /* check whether changed bits are allowed to be modified */
+ if (cm->mask & ~priv->ctrlmode_supported)
+ return -EOPNOTSUPP;
+
+ /* clear bits to be modified and copy the flag values */
+ priv->ctrlmode &= ~cm->mask;
+ priv->ctrlmode |= (cm->flags & cm->mask);
+
+ /* CAN_CTRLMODE_FD can only be set when driver supports FD */
+ if (priv->ctrlmode & CAN_CTRLMODE_FD)
+ dev->mtu = CANFD_MTU;
+ else
+ dev->mtu = CAN_MTU;
+ }
+
+ if (data[IFLA_CAN_RESTART_MS]) {
+ /* Do not allow changing restart delay while running */
+ if (dev->flags & IFF_UP)
+ return -EBUSY;
+ priv->restart_ms = nla_get_u32(data[IFLA_CAN_RESTART_MS]);
+ }
+
+ if (data[IFLA_CAN_RESTART]) {
+ /* Do not allow a restart while not running */
+ if (!(dev->flags & IFF_UP))
+ return -EINVAL;
+ err = can_restart_now(dev);
+ if (err)
+ return err;
+ }
+
+ if (data[IFLA_CAN_DATA_BITTIMING]) {
+ struct can_bittiming dbt;
+
+ /* Do not allow changing bittiming while running */
+ if (dev->flags & IFF_UP)
+ return -EBUSY;
+ memcpy(&dbt, nla_data(data[IFLA_CAN_DATA_BITTIMING]),
+ sizeof(dbt));
+ err = can_get_bittiming(dev, &dbt, priv->data_bittiming_const);
+ if (err)
+ return err;
+ memcpy(&priv->data_bittiming, &dbt, sizeof(dbt));
+
+ if (priv->do_set_data_bittiming) {
+ /* Finally, set the bit-timing registers */
+ err = priv->do_set_data_bittiming(dev);
+ if (err)
+ return err;
+ }
+ }
+
+ return 0;
+}
+
+static size_t can_get_size(const struct net_device *dev)
+{
+ struct can_priv *priv = netdev_priv(dev);
+ size_t size = 0;
+
+ if (priv->bittiming.bitrate) /* IFLA_CAN_BITTIMING */
+ size += nla_total_size(sizeof(struct can_bittiming));
+ if (priv->bittiming_const) /* IFLA_CAN_BITTIMING_CONST */
+ size += nla_total_size(sizeof(struct can_bittiming_const));
+ size += nla_total_size(sizeof(struct can_clock)); /* IFLA_CAN_CLOCK */
+ size += nla_total_size(sizeof(u32)); /* IFLA_CAN_STATE */
+ size += nla_total_size(sizeof(struct can_ctrlmode)); /* IFLA_CAN_CTRLMODE */
+ size += nla_total_size(sizeof(u32)); /* IFLA_CAN_RESTART_MS */
+ if (priv->do_get_berr_counter) /* IFLA_CAN_BERR_COUNTER */
+ size += nla_total_size(sizeof(struct can_berr_counter));
+ if (priv->data_bittiming.bitrate) /* IFLA_CAN_DATA_BITTIMING */
+ size += nla_total_size(sizeof(struct can_bittiming));
+ if (priv->data_bittiming_const) /* IFLA_CAN_DATA_BITTIMING_CONST */
+ size += nla_total_size(sizeof(struct can_bittiming_const));
+
+ return size;
+}
+
+static int can_fill_info(struct sk_buff *skb, const struct net_device *dev)
+{
+ struct can_priv *priv = netdev_priv(dev);
+ struct can_ctrlmode cm = {.flags = priv->ctrlmode};
+ struct can_berr_counter bec;
+ enum can_state state = priv->state;
+
+ if (priv->do_get_state)
+ priv->do_get_state(dev, &state);
+
+ if ((priv->bittiming.bitrate &&
+ nla_put(skb, IFLA_CAN_BITTIMING,
+ sizeof(priv->bittiming), &priv->bittiming)) ||
+
+ (priv->bittiming_const &&
+ nla_put(skb, IFLA_CAN_BITTIMING_CONST,
+ sizeof(*priv->bittiming_const), priv->bittiming_const)) ||
+
+ nla_put(skb, IFLA_CAN_CLOCK, sizeof(cm), &priv->clock) ||
+ nla_put_u32(skb, IFLA_CAN_STATE, state) ||
+ nla_put(skb, IFLA_CAN_CTRLMODE, sizeof(cm), &cm) ||
+ nla_put_u32(skb, IFLA_CAN_RESTART_MS, priv->restart_ms) ||
+
+ (priv->do_get_berr_counter &&
+ !priv->do_get_berr_counter(dev, &bec) &&
+ nla_put(skb, IFLA_CAN_BERR_COUNTER, sizeof(bec), &bec)) ||
+
+ (priv->data_bittiming.bitrate &&
+ nla_put(skb, IFLA_CAN_DATA_BITTIMING,
+ sizeof(priv->data_bittiming), &priv->data_bittiming)) ||
+
+ (priv->data_bittiming_const &&
+ nla_put(skb, IFLA_CAN_DATA_BITTIMING_CONST,
+ sizeof(*priv->data_bittiming_const),
+ priv->data_bittiming_const)))
+ return -EMSGSIZE;
+
+ return 0;
+}
+
+static size_t can_get_xstats_size(const struct net_device *dev)
+{
+ return sizeof(struct can_device_stats);
+}
+
+static int can_fill_xstats(struct sk_buff *skb, const struct net_device *dev)
+{
+ struct can_priv *priv = netdev_priv(dev);
+
+ if (nla_put(skb, IFLA_INFO_XSTATS,
+ sizeof(priv->can_stats), &priv->can_stats))
+ goto nla_put_failure;
+ return 0;
+
+nla_put_failure:
+ return -EMSGSIZE;
+}
+
+static int can_newlink(struct net *src_net, struct net_device *dev,
+ struct nlattr *tb[], struct nlattr *data[])
+{
+ return -EOPNOTSUPP;
+}
+
+static struct rtnl_link_ops can_link_ops __read_mostly = {
+ .kind = "can",
+ .maxtype = IFLA_CAN_MAX,
+ .policy = can_policy,
+ .setup = can_setup,
+ .newlink = can_newlink,
+ .changelink = can_changelink,
+ .get_size = can_get_size,
+ .fill_info = can_fill_info,
+ .get_xstats_size = can_get_xstats_size,
+ .fill_xstats = can_fill_xstats,
+};
+
+/*
+ * Register the CAN network device
+ */
+int register_candev(struct net_device *dev)
+{
+ dev->rtnl_link_ops = &can_link_ops;
+ 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 = rtnl_link_register(&can_link_ops);
+ if (!err)
+ printk(KERN_INFO MOD_DESC "\n");
+
+ return err;
+}
+module_init(can_dev_init);
+
+static __exit void can_dev_exit(void)
+{
+ rtnl_link_unregister(&can_link_ops);
+
+ can_led_notifier_exit();
+}
+module_exit(can_dev_exit);
+
+MODULE_ALIAS_RTNL_LINK("can");
Code Review / kvmfornfv.git / blobdiff