can: CAN Network device driver and Netlink interface
Wolfgang Grandegger [Fri, 15 May 2009 23:39:29 +0000 (23:39 +0000)]
The CAN network device driver interface provides a generic interface to
setup, configure and monitor CAN network devices. It exports a set of
common data structures and functions, which all real CAN network device
drivers should use. Please have a look to the SJA1000 or MSCAN driver
to understand how to use them. The name of the module is can-dev.ko.

Furthermore, it adds a Netlink interface allowing to configure the CAN
device using the program "ip" from the iproute2 utility suite.

For further information please check "Documentation/networking/can.txt"

Signed-off-by: Wolfgang Grandegger <wg@grandegger.com>
Signed-off-by: Oliver Hartkopp <oliver.hartkopp@volkswagen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/can/Kconfig
drivers/net/can/Makefile
drivers/net/can/dev.c [new file with mode: 0644]
include/linux/can/Kbuild
include/linux/can/dev.h [new file with mode: 0644]
include/linux/can/netlink.h [new file with mode: 0644]

index 57def0d..77adb8e 100644 (file)
@@ -12,6 +12,29 @@ config CAN_VCAN
          This driver can also be built as a module.  If so, the module
          will be called vcan.
 
+config CAN_DEV
+       tristate "Platform CAN drivers with Netlink support"
+       depends on CAN
+       default Y
+       ---help---
+         Enables the common framework for platform CAN drivers with Netlink
+         support. This is the standard library for CAN drivers.
+         If unsure, say Y.
+
+config CAN_CALC_BITTIMING
+       bool "CAN bit-timing calculation"
+       depends on CAN_DEV
+       default Y
+       ---help---
+         If enabled, CAN bit-timing parameters will be calculated for the
+         bit-rate specified via Netlink argument "bitrate" when the device
+         get started. This works fine for the most common CAN controllers
+         with standard bit-rates but may fail for exotic bit-rates or CAN
+         source clock frequencies. Disabling saves some space, but then the
+         bit-timing parameters must be specified directly using the Netlink
+         arguments "tq", "prop_seg", "phase_seg1", "phase_seg2" and "sjw".
+         If unsure, say Y.
+
 config CAN_DEBUG_DEVICES
        bool "CAN devices debugging messages"
        depends on CAN
index c4bead7..6c86547 100644 (file)
@@ -3,3 +3,8 @@
 #
 
 obj-$(CONFIG_CAN_VCAN)         += vcan.o
+
+obj-$(CONFIG_CAN_DEV)          += can-dev.o
+can-dev-y                      := dev.o
+
+ccflags-$(CONFIG_CAN_DEBUG_DEVICES) := -DDEBUG
diff --git a/drivers/net/can/dev.c b/drivers/net/can/dev.c
new file mode 100644 (file)
index 0000000..52b0e7d
--- /dev/null
@@ -0,0 +1,657 @@
+/*
+ * 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, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/netdevice.h>
+#include <linux/if_arp.h>
+#include <linux/can.h>
+#include <linux/can/dev.h>
+#include <linux/can/netlink.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>");
+
+#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)
+{
+       struct can_priv *priv = netdev_priv(dev);
+       const struct can_bittiming_const *btc = priv->bittiming_const;
+       long rate, best_rate = 0;
+       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;
+       u64 v64;
+
+       if (!priv->bittiming_const)
+               return -ENOTSUPP;
+
+       /* 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;
+               best_rate = rate;
+               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) {
+                       dev_err(dev->dev.parent,
+                               "bitrate error %ld.%ld%% too high\n",
+                               error / 10, error % 10);
+                       return -EDOM;
+               } else {
+                       dev_warn(dev->dev.parent, "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;
+       bt->sjw = 1;
+       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)
+{
+       dev_err(dev->dev.parent, "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)
+{
+       struct can_priv *priv = netdev_priv(dev);
+       const struct can_bittiming_const *btc = priv->bittiming_const;
+       int tseg1, alltseg;
+       u64 brp64;
+
+       if (!priv->bittiming_const)
+               return -ENOTSUPP;
+
+       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;
+}
+
+int can_get_bittiming(struct net_device *dev, struct can_bittiming *bt)
+{
+       struct can_priv *priv = netdev_priv(dev);
+       int err;
+
+       /* Check if the CAN device has bit-timing parameters */
+       if (priv->bittiming_const) {
+
+               /* Non-expert mode? Check if the bitrate has been pre-defined */
+               if (!bt->tq)
+                       /* Determine bit-timing parameters */
+                       err = can_calc_bittiming(dev, bt);
+               else
+                       /* Check bit-timing params and calculate proper brp */
+                       err = can_fixup_bittiming(dev, bt);
+               if (err)
+                       return err;
+       }
+
+       return 0;
+}
+
+/*
+ * 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 < CAN_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, int idx)
+{
+       struct can_priv *priv = netdev_priv(dev);
+
+       /* check flag whether this packet has to be looped back */
+       if (!(dev->flags & IFF_ECHO) || skb->pkt_type != PACKET_LOOPBACK) {
+               kfree_skb(skb);
+               return;
+       }
+
+       if (!priv->echo_skb[idx]) {
+               struct sock *srcsk = skb->sk;
+
+               if (atomic_read(&skb->users) != 1) {
+                       struct sk_buff *old_skb = skb;
+
+                       skb = skb_clone(old_skb, GFP_ATOMIC);
+                       kfree_skb(old_skb);
+                       if (!skb)
+                               return;
+               } else
+                       skb_orphan(skb);
+
+               skb->sk = srcsk;
+
+               /* make settings for echo to reduce code in irq context */
+               skb->protocol = htons(ETH_P_CAN);
+               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() ?? */
+               dev_err(dev->dev.parent, "%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.
+ */
+void can_get_echo_skb(struct net_device *dev, int idx)
+{
+       struct can_priv *priv = netdev_priv(dev);
+
+       if ((dev->flags & IFF_ECHO) && priv->echo_skb[idx]) {
+               netif_rx(priv->echo_skb[idx]);
+               priv->echo_skb[idx] = NULL;
+       }
+}
+EXPORT_SYMBOL_GPL(can_get_echo_skb);
+
+/*
+ * CAN device restart for bus-off recovery
+ */
+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 = dev_alloc_skb(sizeof(struct can_frame));
+       if (skb == NULL) {
+               err = -ENOMEM;
+               goto out;
+       }
+       skb->dev = dev;
+       skb->protocol = htons(ETH_P_CAN);
+       cf = (struct can_frame *)skb_put(skb, sizeof(struct can_frame));
+       memset(cf, 0, sizeof(struct can_frame));
+       cf->can_id = CAN_ERR_FLAG | CAN_ERR_RESTARTED;
+       cf->can_dlc = CAN_ERR_DLC;
+
+       netif_rx(skb);
+
+       dev->last_rx = jiffies;
+       stats->rx_packets++;
+       stats->rx_bytes += cf->can_dlc;
+
+       dev_dbg(dev->dev.parent, "restarted\n");
+       priv->can_stats.restarts++;
+
+       /* Now restart the device */
+       err = priv->do_set_mode(dev, CAN_MODE_START);
+
+out:
+       netif_carrier_on(dev);
+       if (err)
+               dev_err(dev->dev.parent, "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);
+
+       dev_dbg(dev->dev.parent, "bus-off\n");
+
+       netif_carrier_off(dev);
+       priv->can_stats.bus_off++;
+
+       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 = sizeof(struct can_frame);
+       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_NO_CSUM;
+}
+
+/*
+ * Allocate and setup space for the CAN network device
+ */
+struct net_device *alloc_candev(int sizeof_priv)
+{
+       struct net_device *dev;
+       struct can_priv *priv;
+
+       dev = alloc_netdev(sizeof_priv, "can%d", can_setup);
+       if (!dev)
+               return NULL;
+
+       priv = netdev_priv(dev);
+
+       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);
+
+/*
+ * 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.tq && !priv->bittiming.bitrate) {
+               dev_err(dev->dev.parent, "bit-timing not yet defined\n");
+               return -EINVAL;
+       }
+
+       setup_timer(&priv->restart_timer, can_restart, (unsigned long)dev);
+
+       return 0;
+}
+EXPORT_SYMBOL(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);
+
+       if (del_timer_sync(&priv->restart_timer))
+               dev_put(dev);
+       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) },
+};
+
+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_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]);
+               priv->ctrlmode &= ~cm->mask;
+               priv->ctrlmode |= cm->flags;
+       }
+
+       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));
+               if ((!bt.bitrate && !bt.tq) || (bt.bitrate && bt.tq))
+                       return -EINVAL;
+               err = can_get_bittiming(dev, &bt);
+               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_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;
+       }
+
+       return 0;
+}
+
+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};
+       enum can_state state = priv->state;
+
+       if (priv->do_get_state)
+               priv->do_get_state(dev, &state);
+       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);
+       NLA_PUT(skb, IFLA_CAN_BITTIMING,
+               sizeof(priv->bittiming), &priv->bittiming);
+       NLA_PUT(skb, IFLA_CAN_CLOCK, sizeof(cm), &priv->clock);
+       if (priv->bittiming_const)
+               NLA_PUT(skb, IFLA_CAN_BITTIMING_CONST,
+                       sizeof(*priv->bittiming_const), priv->bittiming_const);
+
+       return 0;
+
+nla_put_failure:
+       return -EMSGSIZE;
+}
+
+static int can_fill_xstats(struct sk_buff *skb, const struct net_device *dev)
+{
+       struct can_priv *priv = netdev_priv(dev);
+
+       NLA_PUT(skb, IFLA_INFO_XSTATS,
+               sizeof(priv->can_stats), &priv->can_stats);
+
+       return 0;
+
+nla_put_failure:
+       return -EMSGSIZE;
+}
+
+static struct rtnl_link_ops can_link_ops __read_mostly = {
+       .kind           = "can",
+       .maxtype        = IFLA_CAN_MAX,
+       .policy         = can_policy,
+       .setup          = can_setup,
+       .changelink     = can_changelink,
+       .fill_info      = can_fill_info,
+       .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);
+
+static __init int can_dev_init(void)
+{
+       int err;
+
+       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);
+}
+module_exit(can_dev_exit);
+
+MODULE_ALIAS_RTNL_LINK("can");
index eff898a..8cb05aa 100644 (file)
@@ -1,3 +1,4 @@
 header-y += raw.h
 header-y += bcm.h
 header-y += error.h
+header-y += netlink.h
diff --git a/include/linux/can/dev.h b/include/linux/can/dev.h
new file mode 100644 (file)
index 0000000..4a37a56
--- /dev/null
@@ -0,0 +1,70 @@
+/*
+ * linux/can/dev.h
+ *
+ * Definitions for the CAN network device driver interface
+ *
+ * Copyright (C) 2006 Andrey Volkov <avolkov@varma-el.com>
+ *               Varma Electronics Oy
+ *
+ * Copyright (C) 2008 Wolfgang Grandegger <wg@grandegger.com>
+ *
+ * Send feedback to <socketcan-users@lists.berlios.de>
+ */
+
+#ifndef CAN_DEV_H
+#define CAN_DEV_H
+
+#include <linux/can/netlink.h>
+#include <linux/can/error.h>
+
+/*
+ * CAN mode
+ */
+enum can_mode {
+       CAN_MODE_STOP = 0,
+       CAN_MODE_START,
+       CAN_MODE_SLEEP
+};
+
+/*
+ * CAN common private data
+ */
+#define CAN_ECHO_SKB_MAX  4
+
+struct can_priv {
+       struct can_device_stats can_stats;
+
+       struct can_bittiming bittiming;
+       struct can_bittiming_const *bittiming_const;
+       struct can_clock clock;
+
+       enum can_state state;
+       u32 ctrlmode;
+
+       int restart_ms;
+       struct timer_list restart_timer;
+
+       struct sk_buff *echo_skb[CAN_ECHO_SKB_MAX];
+
+       int (*do_set_bittiming)(struct net_device *dev);
+       int (*do_set_mode)(struct net_device *dev, enum can_mode mode);
+       int (*do_get_state)(const struct net_device *dev,
+                           enum can_state *state);
+};
+
+struct net_device *alloc_candev(int sizeof_priv);
+void free_candev(struct net_device *dev);
+
+int open_candev(struct net_device *dev);
+void close_candev(struct net_device *dev);
+
+int register_candev(struct net_device *dev);
+void unregister_candev(struct net_device *dev);
+
+int can_restart_now(struct net_device *dev);
+void can_bus_off(struct net_device *dev);
+
+void can_put_echo_skb(struct sk_buff *skb, struct net_device *dev, int idx);
+void can_get_echo_skb(struct net_device *dev, int idx);
+
+#endif /* CAN_DEV_H */
diff --git a/include/linux/can/netlink.h b/include/linux/can/netlink.h
new file mode 100644 (file)
index 0000000..9ecbb78
--- /dev/null
@@ -0,0 +1,113 @@
+/*
+ * linux/can/netlink.h
+ *
+ * Definitions for the CAN netlink interface
+ *
+ * Copyright (c) 2009 Wolfgang Grandegger <wg@grandegger.com>
+ *
+ * Send feedback to <socketcan-users@lists.berlios.de>
+ *
+ */
+
+#ifndef CAN_NETLINK_H
+#define CAN_NETLINK_H
+
+#include <linux/types.h>
+
+/*
+ * CAN bit-timing parameters
+ *
+ * For futher information, please read chapter "8 BIT TIMING
+ * REQUIREMENTS" of the "Bosch CAN Specification version 2.0"
+ * at http://www.semiconductors.bosch.de/pdf/can2spec.pdf.
+ */
+struct can_bittiming {
+       __u32 bitrate;          /* Bit-rate in bits/second */
+       __u32 sample_point;     /* Sample point in one-tenth of a percent */
+       __u32 tq;               /* Time quanta (TQ) in nanoseconds */
+       __u32 prop_seg;         /* Propagation segment in TQs */
+       __u32 phase_seg1;       /* Phase buffer segment 1 in TQs */
+       __u32 phase_seg2;       /* Phase buffer segment 2 in TQs */
+       __u32 sjw;              /* Synchronisation jump width in TQs */
+       __u32 brp;              /* Bit-rate prescaler */
+};
+
+/*
+ * CAN harware-dependent bit-timing constant
+ *
+ * Used for calculating and checking bit-timing parameters
+ */
+struct can_bittiming_const {
+       char name[16];          /* Name of the CAN controller hardware */
+       __u32 tseg1_min;        /* Time segement 1 = prop_seg + phase_seg1 */
+       __u32 tseg1_max;
+       __u32 tseg2_min;        /* Time segement 2 = phase_seg2 */
+       __u32 tseg2_max;
+       __u32 sjw_max;          /* Synchronisation jump width */
+       __u32 brp_min;          /* Bit-rate prescaler */
+       __u32 brp_max;
+       __u32 brp_inc;
+};
+
+/*
+ * CAN clock parameters
+ */
+struct can_clock {
+       __u32 freq;             /* CAN system clock frequency in Hz */
+};
+
+/*
+ * CAN operational and error states
+ */
+enum can_state {
+       CAN_STATE_ERROR_ACTIVE = 0,     /* RX/TX error count < 96 */
+       CAN_STATE_ERROR_WARNING,        /* RX/TX error count < 128 */
+       CAN_STATE_ERROR_PASSIVE,        /* RX/TX error count < 256 */
+       CAN_STATE_BUS_OFF,              /* RX/TX error count >= 256 */
+       CAN_STATE_STOPPED,              /* Device is stopped */
+       CAN_STATE_SLEEPING,             /* Device is sleeping */
+       CAN_STATE_MAX
+};
+
+/*
+ * CAN controller mode
+ */
+struct can_ctrlmode {
+       __u32 mask;
+       __u32 flags;
+};
+
+#define CAN_CTRLMODE_LOOPBACK  0x1     /* Loopback mode */
+#define CAN_CTRLMODE_LISTENONLY        0x2     /* Listen-only mode */
+#define CAN_CTRLMODE_3_SAMPLES 0x4     /* Triple sampling mode */
+
+/*
+ * CAN device statistics
+ */
+struct can_device_stats {
+       __u32 bus_error;        /* Bus errors */
+       __u32 error_warning;    /* Changes to error warning state */
+       __u32 error_passive;    /* Changes to error passive state */
+       __u32 bus_off;          /* Changes to bus off state */
+       __u32 arbitration_lost; /* Arbitration lost errors */
+       __u32 restarts;         /* CAN controller re-starts */
+};
+
+/*
+ * CAN netlink interface
+ */
+enum {
+       IFLA_CAN_UNSPEC,
+       IFLA_CAN_BITTIMING,
+       IFLA_CAN_BITTIMING_CONST,
+       IFLA_CAN_CLOCK,
+       IFLA_CAN_STATE,
+       IFLA_CAN_CTRLMODE,
+       IFLA_CAN_RESTART_MS,
+       IFLA_CAN_RESTART,
+       __IFLA_CAN_MAX
+};
+
+#define IFLA_CAN_MAX   (__IFLA_CAN_MAX - 1)
+
+#endif /* CAN_NETLINK_H */