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    Subject[PATCH 3/8] can: CAN Network device driver and SYSFS interface
    Date
    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 adds a SYSFS interface to set and get CAN device properties.
    When the CAN device is registered, a set of SYSFS files is created in
    "/sys/class/net/canX/". These files allow to set and get device
    properties like bit-timing parameters, state, controller mode and CAN
    statistics.

    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>
    ---
    drivers/net/can/Kconfig | 23 ++
    drivers/net/can/Makefile | 5 +
    drivers/net/can/dev.c | 528 ++++++++++++++++++++++++++++++++++++++++++++++
    drivers/net/can/sysfs.c | 509 ++++++++++++++++++++++++++++++++++++++++++++
    drivers/net/can/sysfs.h | 24 ++
    include/linux/can/dev.h | 136 ++++++++++++
    6 files changed, 1225 insertions(+), 0 deletions(-)
    create mode 100644 drivers/net/can/dev.c
    create mode 100644 drivers/net/can/sysfs.c
    create mode 100644 drivers/net/can/sysfs.h
    create mode 100644 include/linux/can/dev.h

    diff --git a/drivers/net/can/Kconfig b/drivers/net/can/Kconfig
    index 57def0d..d609895 100644
    --- a/drivers/net/can/Kconfig
    +++ b/drivers/net/can/Kconfig
    @@ -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 SYSFS support"
    + depends on CAN && SYSFS
    + default Y
    + ---help---
    + Enables the common framework for platform CAN drivers with SYSFS
    + 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 SYSFS file "bitrate" when the device gets
    + 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 SYSFS
    + files "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
    diff --git a/drivers/net/can/Makefile b/drivers/net/can/Makefile
    index c4bead7..557114b 100644
    --- a/drivers/net/can/Makefile
    +++ b/drivers/net/can/Makefile
    @@ -3,3 +3,8 @@
    #

    obj-$(CONFIG_CAN_VCAN) += vcan.o
    +
    +obj-$(CONFIG_CAN_DEV) += can-dev.o
    +can-dev-y := dev.o sysfs.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
    index 0000000..faa75d1
    --- /dev/null
    +++ b/drivers/net/can/dev.c
    @@ -0,0 +1,528 @@
    +/*
    + * Copyright (C) 2005 Marc Kleine-Budde, Pengutronix
    + * Copyright (C) 2006 Andrey Volkov, Varma Electronics
    + * Copyright (C) 2008 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/netdevice.h>
    +#include <linux/if_arp.h>
    +#include <linux/can.h>
    +#include <linux/can/dev.h>
    +#include <net/rtnetlink.h>
    +
    +#include "sysfs.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
    + */
    +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_priv *priv = netdev_priv(dev);
    + struct can_bittiming *bt = &priv->bittiming;
    + 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 = bt->clock / (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 = bt->clock / (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(ND2D(dev), "bitrate error %ld.%ld%% too high\n",
    + error / 10, error % 10);
    + return -EDOM;
    + } else {
    + dev_warn(ND2D(dev), "bitrate error %ld.%ld%%\n",
    + error / 10, error % 10);
    + }
    + }
    +
    + spt = can_update_spt(btc, sampl_pt, best_tseg, &tseg1, &tseg2);
    +
    + v64 = (u64)best_brp * 1000000000UL;
    + do_div(v64, bt->clock);
    + 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;
    +
    + return 0;
    +}
    +#else /* !CONFIG_CAN_CALC_BITTIMING */
    +static int can_calc_bittiming(struct net_device *dev)
    +{
    + dev_err(ND2D(dev), "bit-timing calculation not available\n");
    + return -EINVAL;
    +}
    +#endif /* CONFIG_CAN_CALC_BITTIMING */
    +
    +int can_sample_point(struct can_bittiming *bt)
    +{
    + return ((bt->prop_seg + bt->phase_seg1 + 1) * 1000) /
    + (bt->prop_seg + bt->phase_seg1 + bt->phase_seg2 + 1);
    +}
    +
    +static int can_fixup_bittiming(struct net_device *dev)
    +{
    + struct can_priv *priv = netdev_priv(dev);
    + struct can_bittiming *bt = &priv->bittiming;
    + const struct can_bittiming_const *btc = priv->bittiming_const;
    + int tseg1, alltseg;
    + u32 bitrate;
    + u64 brp64;
    +
    + if (!priv->bittiming_const)
    + return -ENOTSUPP;
    +
    + tseg1 = bt->prop_seg + bt->phase_seg1;
    + 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 -EINVAL;
    +
    + brp64 = (u64)bt->clock * (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;
    + bitrate = bt->clock / (bt->brp * alltseg);
    + bt->bitrate = bitrate;
    +
    + return 0;
    +}
    +
    +/*
    + * Set CAN bit-timing for the device
    + *
    + * This functions should be called in the open function of the device
    + * driver to determine, check and set appropriate bit-timing parameters.
    + */
    +int can_set_bittiming(struct net_device *dev)
    +{
    + struct can_priv *priv = netdev_priv(dev);
    + int err;
    +
    + /* Check if bit-timing parameters have been pre-defined */
    + if (!priv->bittiming.tq && !priv->bittiming.bitrate) {
    + dev_err(ND2D(dev), "bit-timing not yet defined\n");
    + return -EINVAL;
    + }
    +
    + /* Check if the CAN device has bit-timing parameters */
    + if (priv->bittiming_const) {
    +
    + /* Check if bit-timing parameters have already been set */
    + if (priv->bittiming.tq && priv->bittiming.bitrate)
    + return 0;
    +
    + /* Non-expert mode? Check if the bitrate has been pre-defined */
    + if (!priv->bittiming.tq)
    + /* Determine bit-timing parameters */
    + err = can_calc_bittiming(dev);
    + else
    + /* Check bit-timing params and calculate proper brp */
    + err = can_fixup_bittiming(dev);
    + if (err)
    + return err;
    + }
    +
    + if (priv->do_set_bittiming) {
    + /* Finally, set the bit-timing registers */
    + err = priv->do_set_bittiming(dev);
    + if (err)
    + return err;
    + }
    +
    + return 0;
    +}
    +EXPORT_SYMBOL_GPL(can_set_bittiming);
    +
    +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;
    + spin_lock_init(&priv->irq_lock);
    +
    + init_timer(&priv->timer);
    + priv->timer.expires = 0;
    +
    + return dev;
    +}
    +EXPORT_SYMBOL_GPL(alloc_candev);
    +
    +/*
    + * Allocate space of the CAN network device
    + */
    +void free_candev(struct net_device *dev)
    +{
    + free_netdev(dev);
    +}
    +EXPORT_SYMBOL_GPL(free_candev);
    +
    +/*
    + * Register the CAN network device
    + */
    +int register_candev(struct net_device *dev)
    +{
    + int err;
    +
    + err = register_netdev(dev);
    + if (err)
    + return err;
    +
    + can_create_sysfs(dev);
    +
    + return 0;
    +}
    +EXPORT_SYMBOL_GPL(register_candev);
    +
    +/*
    + * Unregister the CAN network device
    + */
    +void unregister_candev(struct net_device *dev)
    +{
    + can_remove_sysfs(dev);
    + unregister_netdev(dev);
    +}
    +EXPORT_SYMBOL_GPL(unregister_candev);
    +
    +/*
    + * 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.
    + */
    +void can_put_echo_skb(struct sk_buff *skb, struct net_device *dev, int idx)
    +{
    + struct can_priv *priv = netdev_priv(dev);
    +
    + /* set 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() ?? */
    + printk(KERN_ERR "%s: %s: BUG! echo_skb is occupied!\n",
    + dev->name, __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.
    + */
    +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
    + */
    +int can_restart_now(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;
    +
    + if (netif_carrier_ok(dev))
    + netif_carrier_off(dev);
    +
    + /* Cancel restart in progress */
    + if (priv->timer.expires) {
    + del_timer(&priv->timer);
    + priv->timer.expires = 0; /* mark inactive timer */
    + }
    +
    + can_flush_echo_skb(dev);
    +
    + err = priv->do_set_mode(dev, CAN_MODE_START);
    + if (err)
    + return err;
    +
    + netif_carrier_on(dev);
    +
    + dev_dbg(ND2D(dev), "restarted\n");
    + priv->can_stats.restarts++;
    +
    + /* send restart message upstream */
    + skb = dev_alloc_skb(sizeof(struct can_frame));
    + if (skb == NULL)
    + return -ENOMEM;
    + 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;
    +
    + return 0;
    +}
    +
    +static void can_restart_after(unsigned long data)
    +{
    + struct net_device *dev = (struct net_device *)data;
    + struct can_priv *priv = netdev_priv(dev);
    +
    + priv->timer.expires = 0; /* mark inactive timer */
    + can_restart_now(dev);
    +}
    +
    +/*
    + * 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(ND2D(dev), "bus-off\n");
    +
    + netif_carrier_off(dev);
    +
    + if (priv->restart_ms > 0 && !priv->timer.expires) {
    +
    + priv->timer.function = can_restart_after;
    + priv->timer.data = (unsigned long)dev;
    + priv->timer.expires =
    + jiffies + (priv->restart_ms * HZ) / 1000;
    + add_timer(&priv->timer);
    + }
    +}
    +EXPORT_SYMBOL_GPL(can_bus_off);
    +
    +/*
    + * Cleanup function before the device gets closed.
    + *
    + * This functions should be called in the close function of the device
    + * driver.
    + */
    +void can_close_cleanup(struct net_device *dev)
    +{
    + struct can_priv *priv = netdev_priv(dev);
    +
    + if (priv->timer.expires) {
    + del_timer(&priv->timer);
    + priv->timer.expires = 0;
    + }
    +
    + can_flush_echo_skb(dev);
    +}
    +EXPORT_SYMBOL_GPL(can_close_cleanup);
    +
    +static __init int can_dev_init(void)
    +{
    + printk(KERN_INFO MOD_DESC "\n");
    +
    + return 0;
    +}
    +module_init(can_dev_init);
    +
    +static __exit void can_dev_exit(void)
    +{
    +}
    +module_exit(can_dev_exit);
    diff --git a/drivers/net/can/sysfs.c b/drivers/net/can/sysfs.c
    new file mode 100644
    index 0000000..746f641
    --- /dev/null
    +++ b/drivers/net/can/sysfs.c
    @@ -0,0 +1,509 @@
    +/*
    + * Copyright (C) 2007-2008 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/capability.h>
    +#include <linux/kernel.h>
    +#include <linux/netdevice.h>
    +#include <linux/if_arp.h>
    +#include <net/sock.h>
    +#include <linux/rtnetlink.h>
    +
    +#include <linux/can.h>
    +#include <linux/can/dev.h>
    +
    +#include "sysfs.h"
    +
    +#ifdef CONFIG_SYSFS
    +
    +/*
    + * SYSFS access functions and attributes. Use same locking as
    + * net/core/net-sysfs.c does.
    + */
    +static inline int dev_isalive(const struct net_device *dev)
    +{
    + return dev->reg_state <= NETREG_REGISTERED;
    +}
    +
    +/* use same locking rules as GIF* ioctl's */
    +static ssize_t can_dev_show(struct device *d,
    + struct device_attribute *attr, char *buf,
    + ssize_t (*fmt)(struct net_device *, char *))
    +{
    + struct net_device *dev = to_net_dev(d);
    + ssize_t ret = -EINVAL;
    +
    + read_lock(&dev_base_lock);
    + if (dev_isalive(dev))
    + ret = (*fmt)(dev, buf);
    + read_unlock(&dev_base_lock);
    +
    + return ret;
    +}
    +
    +/* generate a show function for simple field */
    +#define CAN_DEV_SHOW(field, fmt_string) \
    +static ssize_t fmt_can_##field(struct net_device *dev, char *buf) \
    +{ \
    + struct can_priv *priv = netdev_priv(dev); \
    + return sprintf(buf, fmt_string, priv->field); \
    +} \
    +static ssize_t show_can_##field(struct device *d, \
    + struct device_attribute *attr, \
    + char *buf) \
    +{ \
    + return can_dev_show(d, attr, buf, fmt_can_##field); \
    +}
    +
    +/* use same locking and permission rules as SIF* ioctl's */
    +static ssize_t can_dev_store(struct device *d, struct device_attribute *attr,
    + const char *buf, size_t len,
    + int (*set)(struct net_device *, unsigned long))
    +{
    + struct net_device *dev = to_net_dev(d);
    + unsigned long new;
    + int ret = -EINVAL;
    +
    + if (!capable(CAP_NET_ADMIN))
    + return -EPERM;
    +
    + ret = strict_strtoul(buf, 0, &new);
    + if (ret)
    + goto out;
    +
    + rtnl_lock();
    + if (dev_isalive(dev)) {
    + ret = (*set)(dev, new);
    + if (!ret)
    + ret = len;
    + }
    + rtnl_unlock();
    +out:
    + return ret;
    +}
    +
    +#define CAN_CREATE_FILE(_dev, _name) \
    + if (device_create_file(&_dev->dev, &dev_attr_##_name)) \
    + dev_err(ND2D(_dev), \
    + "Couldn't create device file for ##_name\n")
    +
    +#define CAN_REMOVE_FILE(_dev, _name) \
    + device_remove_file(&_dev->dev, &dev_attr_##_name) \
    +
    +CAN_DEV_SHOW(ctrlmode, "0x%x\n");
    +
    +static int change_can_ctrlmode(struct net_device *dev, unsigned long ctrlmode)
    +{
    + struct can_priv *priv = netdev_priv(dev);
    + int err = 0;
    +
    + if (priv->state != CAN_STATE_STOPPED)
    + return -EBUSY;
    +
    + if (priv->do_set_ctrlmode)
    + err = priv->do_set_ctrlmode(dev, ctrlmode);
    +
    + if (!err)
    + priv->ctrlmode = ctrlmode;
    +
    + return err;
    +}
    +
    +static ssize_t store_can_ctrlmode(struct device *dev,
    + struct device_attribute *attr,
    + const char *buf, size_t len)
    +{
    + return can_dev_store(dev, attr, buf, len, change_can_ctrlmode);
    +}
    +
    +static DEVICE_ATTR(can_ctrlmode, S_IRUGO | S_IWUSR,
    + show_can_ctrlmode, store_can_ctrlmode);
    +
    +static const char *can_state_names[] = {
    + "active", "bus-warn", "bus-pass" , "bus-off",
    + "stopped", "sleeping", "unkown"
    +};
    +
    +static ssize_t printf_can_state(struct net_device *dev, char *buf)
    +{
    + struct can_priv *priv = netdev_priv(dev);
    + enum can_state state;
    + int err = 0;
    +
    + if (priv->do_get_state) {
    + err = priv->do_get_state(dev, &state);
    + if (err)
    + goto out;
    + priv->state = state;
    + } else
    + state = priv->state;
    +
    + if (state >= ARRAY_SIZE(can_state_names))
    + state = ARRAY_SIZE(can_state_names) - 1;
    + err = sprintf(buf, "%s\n", can_state_names[state]);
    +out:
    + return err;
    +}
    +
    +static ssize_t show_can_state(struct device *d,
    + struct device_attribute *attr, char *buf)
    +{
    + return can_dev_show(d, attr, buf, printf_can_state);
    +}
    +
    +static DEVICE_ATTR(can_state, S_IRUGO, show_can_state, NULL);
    +
    +CAN_DEV_SHOW(restart_ms, "%d\n");
    +
    +static int change_can_restart_ms(struct net_device *dev, unsigned long ms)
    +{
    + struct can_priv *priv = netdev_priv(dev);
    +
    + if (priv->restart_ms < 0)
    + return -EOPNOTSUPP;
    + priv->restart_ms = ms;
    + return 0;
    +}
    +
    +static ssize_t store_can_restart_ms(struct device *dev,
    + struct device_attribute *attr,
    + const char *buf, size_t len)
    +{
    + return can_dev_store(dev, attr, buf, len, change_can_restart_ms);
    +}
    +
    +static DEVICE_ATTR(can_restart_ms, S_IRUGO | S_IWUSR,
    + show_can_restart_ms, store_can_restart_ms);
    +
    +static ssize_t printf_can_echo(struct net_device *dev, char *buf)
    +{
    + return sprintf(buf, "%d\n", dev->flags & IFF_ECHO ? 1 : 0);
    +}
    +
    +static ssize_t show_can_echo(struct device *d,
    + struct device_attribute *attr, char *buf)
    +{
    + return can_dev_show(d, attr, buf, printf_can_echo);
    +}
    +
    +static int change_can_echo(struct net_device *dev, unsigned long on)
    +{
    + if (on)
    + dev->flags |= IFF_ECHO;
    + else
    + dev->flags &= ~IFF_ECHO;
    + return 0;
    +}
    +
    +static ssize_t store_can_echo(struct device *dev,
    + struct device_attribute *attr,
    + const char *buf, size_t len)
    +{
    + return can_dev_store(dev, attr, buf, len, change_can_echo);
    +}
    +
    +static DEVICE_ATTR(can_echo, S_IRUGO | S_IWUSR, show_can_echo, store_can_echo);
    +
    +static int change_can_restart(struct net_device *dev, unsigned long on)
    +{
    + return can_restart_now(dev);
    +}
    +
    +static ssize_t store_can_restart(struct device *dev,
    + struct device_attribute *attr,
    + const char *buf, size_t len)
    +{
    + return can_dev_store(dev, attr, buf, len, change_can_restart);
    +}
    +
    +static DEVICE_ATTR(can_restart, S_IWUSR, NULL, store_can_restart);
    +
    +/* Show a given attribute if the CAN bittiming group */
    +static ssize_t can_btc_show(const struct device *d,
    + struct device_attribute *attr, char *buf,
    + unsigned long offset)
    +{
    + struct net_device *dev = to_net_dev(d);
    + struct can_priv *priv = netdev_priv(dev);
    + struct can_bittiming_const *btc = priv->bittiming_const;
    + ssize_t ret = -EINVAL;
    +
    + WARN_ON(offset >= sizeof(struct can_bittiming_const) ||
    + offset % sizeof(u32) != 0);
    +
    + read_lock(&dev_base_lock);
    + if (dev_isalive(dev) && btc)
    + ret = sprintf(buf, "%d\n",
    + *(u32 *)(((u8 *)btc) + offset));
    +
    + read_unlock(&dev_base_lock);
    + return ret;
    +}
    +
    +/* Generate a read-only bittiming const attribute */
    +#define CAN_BT_CONST_ENTRY(name) \
    +static ssize_t show_##name(struct device *d, \
    + struct device_attribute *attr, char *buf) \
    +{ \
    + return can_btc_show(d, attr, buf, \
    + offsetof(struct can_bittiming_const, name));\
    +} \
    +static DEVICE_ATTR(hw_##name, S_IRUGO, show_##name, NULL)
    +
    +CAN_BT_CONST_ENTRY(tseg1_min);
    +CAN_BT_CONST_ENTRY(tseg1_max);
    +CAN_BT_CONST_ENTRY(tseg2_min);
    +CAN_BT_CONST_ENTRY(tseg2_max);
    +CAN_BT_CONST_ENTRY(sjw_max);
    +CAN_BT_CONST_ENTRY(brp_min);
    +CAN_BT_CONST_ENTRY(brp_max);
    +CAN_BT_CONST_ENTRY(brp_inc);
    +
    +static ssize_t can_bt_show(const struct device *d,
    + struct device_attribute *attr, char *buf,
    + unsigned long offset)
    +{
    + struct net_device *dev = to_net_dev(d);
    + struct can_priv *priv = netdev_priv(dev);
    + struct can_bittiming *bt = &priv->bittiming;
    + ssize_t ret = -EINVAL;
    + u32 *ptr, val;
    +
    + WARN_ON(offset >= sizeof(struct can_bittiming) ||
    + offset % sizeof(u32) != 0);
    +
    + read_lock(&dev_base_lock);
    + if (dev_isalive(dev)) {
    + ptr = (u32 *)(((u8 *)bt) + offset);
    + if (ptr == &bt->sample_point &&
    + priv->state != CAN_STATE_STOPPED)
    + val = can_sample_point(bt);
    + else
    + val = *ptr;
    + ret = sprintf(buf, "%d\n", val);
    + }
    + read_unlock(&dev_base_lock);
    + return ret;
    +}
    +
    +static ssize_t can_bt_store(const struct device *d,
    + struct device_attribute *attr,
    + const char *buf, size_t count,
    + unsigned long offset)
    +{
    + struct net_device *dev = to_net_dev(d);
    + struct can_priv *priv = netdev_priv(dev);
    + struct can_bittiming *bt = &priv->bittiming;
    + unsigned long new;
    + ssize_t ret = -EINVAL;
    + u32 *ptr;
    +
    + if (priv->state != CAN_STATE_STOPPED)
    + return -EBUSY;
    +
    + WARN_ON(offset >= sizeof(struct can_bittiming) ||
    + offset % sizeof(u32) != 0);
    +
    + ret = strict_strtoul(buf, 0, &new);
    + if (ret)
    + goto out;
    +
    + ptr = (u32 *)(((u8 *)bt) + offset);
    + rtnl_lock();
    + if (dev_isalive(dev)) {
    + *ptr = (u32)new;
    +
    + if ((ptr == &bt->bitrate) || (ptr == &bt->sample_point)) {
    + bt->tq = 0;
    + bt->brp = 0;
    + bt->sjw = 0;
    + bt->prop_seg = 0;
    + bt->phase_seg1 = 0;
    + bt->phase_seg2 = 0;
    + } else {
    + bt->bitrate = 0;
    + bt->sample_point = 0;
    + }
    + ret = count;
    + }
    + rtnl_unlock();
    +out:
    + return ret;
    +}
    +
    +#define CAN_BT_ENTRY_RO(name) \
    +static ssize_t show_##name(struct device *d, \
    + struct device_attribute *attr, char *buf) \
    +{ \
    + return can_bt_show(d, attr, buf, \
    + offsetof(struct can_bittiming, name)); \
    +} \
    +static DEVICE_ATTR(hw_##name, S_IRUGO, show_##name, NULL)
    +
    +CAN_BT_ENTRY_RO(clock);
    +
    +#define CAN_BT_ENTRY(name) \
    +static ssize_t show_##name(struct device *d, \
    + struct device_attribute *attr, char *buf) \
    +{ \
    + return can_bt_show(d, attr, buf, \
    + offsetof(struct can_bittiming, name)); \
    +} \
    +static ssize_t store_##name(struct device *d, \
    + struct device_attribute *attr, \
    + const char *buf, size_t count) \
    +{ \
    + return can_bt_store(d, attr, buf, count, \
    + offsetof(struct can_bittiming, name)); \
    +} \
    +static DEVICE_ATTR(name, S_IRUGO | S_IWUSR, show_##name, store_##name)
    +
    +CAN_BT_ENTRY(bitrate);
    +CAN_BT_ENTRY(sample_point);
    +CAN_BT_ENTRY(tq);
    +CAN_BT_ENTRY(prop_seg);
    +CAN_BT_ENTRY(phase_seg1);
    +CAN_BT_ENTRY(phase_seg2);
    +CAN_BT_ENTRY(sjw);
    +
    +static struct attribute *can_bittiming_attrs[] = {
    + &dev_attr_hw_tseg1_min.attr,
    + &dev_attr_hw_tseg1_max.attr,
    + &dev_attr_hw_tseg2_max.attr,
    + &dev_attr_hw_tseg2_min.attr,
    + &dev_attr_hw_sjw_max.attr,
    + &dev_attr_hw_brp_min.attr,
    + &dev_attr_hw_brp_max.attr,
    + &dev_attr_hw_brp_inc.attr,
    + &dev_attr_hw_clock.attr,
    + &dev_attr_bitrate.attr,
    + &dev_attr_sample_point.attr,
    + &dev_attr_tq.attr,
    + &dev_attr_prop_seg.attr,
    + &dev_attr_phase_seg1.attr,
    + &dev_attr_phase_seg2.attr,
    + &dev_attr_sjw.attr,
    + NULL
    +};
    +
    +static struct attribute_group can_bittiming_group = {
    + .name = "can_bittiming",
    + .attrs = can_bittiming_attrs,
    +};
    +
    +/* Show a given attribute in the CAN statistics group */
    +static ssize_t can_stat_show(const struct device *d,
    + struct device_attribute *attr, char *buf,
    + unsigned long offset)
    +{
    + struct net_device *dev = to_net_dev(d);
    + struct can_priv *priv = netdev_priv(dev);
    + struct can_device_stats *stats = &priv->can_stats;
    + ssize_t ret = -EINVAL;
    +
    + WARN_ON(offset >= sizeof(struct can_device_stats) ||
    + offset % sizeof(unsigned long) != 0);
    +
    + read_lock(&dev_base_lock);
    + if (dev_isalive(dev))
    + ret = sprintf(buf, "%ld\n",
    + *(unsigned long *)(((u8 *)stats) + offset));
    +
    + read_unlock(&dev_base_lock);
    + return ret;
    +}
    +
    +/* Generate a read-only CAN statistics attribute */
    +#define CAN_STAT_ENTRY(name) \
    +static ssize_t show_##name(struct device *d, \
    + struct device_attribute *attr, char *buf) \
    +{ \
    + return can_stat_show(d, attr, buf, \
    + offsetof(struct can_device_stats, name)); \
    +} \
    +static DEVICE_ATTR(name, S_IRUGO, show_##name, NULL)
    +
    +CAN_STAT_ENTRY(error_warning);
    +CAN_STAT_ENTRY(error_passive);
    +CAN_STAT_ENTRY(bus_error);
    +CAN_STAT_ENTRY(arbitration_lost);
    +CAN_STAT_ENTRY(data_overrun);
    +CAN_STAT_ENTRY(wakeup);
    +CAN_STAT_ENTRY(restarts);
    +
    +static struct attribute *can_statistics_attrs[] = {
    + &dev_attr_error_warning.attr,
    + &dev_attr_error_passive.attr,
    + &dev_attr_bus_error.attr,
    + &dev_attr_arbitration_lost.attr,
    + &dev_attr_data_overrun.attr,
    + &dev_attr_wakeup.attr,
    + &dev_attr_restarts.attr,
    + NULL
    +};
    +
    +static struct attribute_group can_statistics_group = {
    + .name = "can_statistics",
    + .attrs = can_statistics_attrs,
    +};
    +
    +void can_create_sysfs(struct net_device *dev)
    +{
    + struct can_priv *priv = netdev_priv(dev);
    + int err;
    +
    + CAN_CREATE_FILE(dev, can_ctrlmode);
    + CAN_CREATE_FILE(dev, can_echo);
    + CAN_CREATE_FILE(dev, can_restart);
    + CAN_CREATE_FILE(dev, can_state);
    + CAN_CREATE_FILE(dev, can_restart_ms);
    +
    + err = sysfs_create_group(&(dev->dev.kobj),
    + &can_statistics_group);
    + if (err) {
    + printk(KERN_EMERG
    + "couldn't create sysfs group for CAN statistics\n");
    + }
    +
    + if (priv->bittiming_const) {
    + err = sysfs_create_group(&(dev->dev.kobj),
    + &can_bittiming_group);
    + if (err) {
    + printk(KERN_EMERG "couldn't create sysfs "
    + "group for CAN bittiming\n");
    + }
    + }
    +}
    +
    +void can_remove_sysfs(struct net_device *dev)
    +{
    + struct can_priv *priv = netdev_priv(dev);
    +
    + CAN_REMOVE_FILE(dev, can_ctrlmode);
    + CAN_REMOVE_FILE(dev, can_echo);
    + CAN_REMOVE_FILE(dev, can_state);
    + CAN_REMOVE_FILE(dev, can_restart);
    + CAN_REMOVE_FILE(dev, can_restart_ms);
    +
    + sysfs_remove_group(&(dev->dev.kobj), &can_statistics_group);
    + if (priv->bittiming_const)
    + sysfs_remove_group(&(dev->dev.kobj), &can_bittiming_group);
    +}
    +
    +#endif /* CONFIG_SYSFS */
    +
    +
    +
    diff --git a/drivers/net/can/sysfs.h b/drivers/net/can/sysfs.h
    new file mode 100644
    index 0000000..e21f2fa
    --- /dev/null
    +++ b/drivers/net/can/sysfs.h
    @@ -0,0 +1,24 @@
    +/*
    + * Copyright (C) 2007 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
    + */
    +
    +#ifndef CAN_SYSFS_H
    +#define CAN_SYSFS_H
    +
    +void can_create_sysfs(struct net_device *dev);
    +void can_remove_sysfs(struct net_device *dev);
    +
    +#endif /* CAN_SYSFS_H */
    diff --git a/include/linux/can/dev.h b/include/linux/can/dev.h
    new file mode 100644
    index 0000000..078ac03
    --- /dev/null
    +++ b/include/linux/can/dev.h
    @@ -0,0 +1,136 @@
    +/*
    + * 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/error.h>
    +
    +/*
    + * CAN bitrate and bit-timing
    + */
    +struct can_bittiming {
    + u32 bitrate;
    + u32 sample_point;
    + u32 tq;
    + u32 prop_seg;
    + u32 phase_seg1;
    + u32 phase_seg2;
    + u32 sjw;
    + u32 clock;
    + u32 brp;
    +};
    +
    +struct can_bittiming_const {
    + u32 tseg1_min;
    + u32 tseg1_max;
    + u32 tseg2_min;
    + u32 tseg2_max;
    + u32 sjw_max;
    + u32 brp_min;
    + u32 brp_max;
    + u32 brp_inc;
    +};
    +
    +/*
    + * CAN mode
    + */
    +enum can_mode {
    + CAN_MODE_STOP = 0,
    + CAN_MODE_START,
    + CAN_MODE_SLEEP
    +};
    +
    +/*
    + * CAN controller mode
    + */
    +#define CAN_CTRLMODE_LOOPBACK 0x1
    +#define CAN_CTRLMODE_LISTENONLY 0x2
    +#define CAN_CTRLMODE_3_SAMPLES 0x4 /* Triple sampling mode */
    +
    +/*
    + * CAN operational and error states
    + */
    +enum can_state {
    + CAN_STATE_ACTIVE = 0,
    + CAN_STATE_BUS_WARNING,
    + CAN_STATE_BUS_PASSIVE,
    + CAN_STATE_BUS_OFF,
    + CAN_STATE_STOPPED,
    + CAN_STATE_SLEEPING
    +};
    +
    +/*
    + * CAN device statistics
    + */
    +struct can_device_stats {
    + unsigned long error_warning;
    + unsigned long data_overrun;
    + unsigned long wakeup;
    + unsigned long bus_error;
    + unsigned long error_passive;
    + unsigned long arbitration_lost;
    + unsigned long restarts;
    + unsigned long bus_error_at_init;
    +};
    +
    +/*
    + * 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;
    +
    + spinlock_t irq_lock;
    +
    + enum can_state state;
    + u32 ctrlmode;
    +
    + int restart_ms;
    + struct timer_list timer;
    +
    + struct sk_buff *echo_skb[CAN_ECHO_SKB_MAX];
    +
    + int (*do_set_bittiming)(struct net_device *dev);
    + int (*do_get_state)(struct net_device *dev, enum can_state *state);
    + int (*do_set_mode)(struct net_device *dev, enum can_mode mode);
    + int (*do_set_ctrlmode)(struct net_device *dev, u32 ctrlmode);
    + int (*do_get_ctrlmode)(struct net_device *dev, u32 *ctrlmode);
    +};
    +
    +#define ND2D(_ndev) (_ndev->dev.parent)
    +
    +
    +struct net_device *alloc_candev(int sizeof_priv);
    +void free_candev(struct net_device *dev);
    +int register_candev(struct net_device *dev);
    +void unregister_candev(struct net_device *dev);
    +
    +int can_set_bittiming(struct net_device *dev);
    +
    +int can_restart_now(struct net_device *dev);
    +
    +void can_bus_off(struct net_device *dev);
    +
    +void can_close_cleanup(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);
    +
    +int can_sample_point(struct can_bittiming *bt);
    +
    +#endif /* CAN_DEV_H */
    --
    1.5.6.6


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