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Date: Thu, 19 Feb 2009 20:01:17 +0100
From: Wolfgang Grandegger <wg@...ndegger.com>
To: netdev@...r.kernel.org
Cc: linux-kernel@...r.kernel.org,
Wolfgang Grandegger <wg@...ndegger.com>,
Oliver Hartkopp <oliver.hartkopp@...kswagen.de>
Subject: [PATCH 3/8] can: CAN Network device driver and SYSFS interface
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@...ndegger.com>
Signed-off-by: Oliver Hartkopp <oliver.hartkopp@...kswagen.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@...ndegger.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@...ndegger.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@....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@...ndegger.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@...ndegger.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@...ma-el.com>
+ * Varma Electronics Oy
+ *
+ * Copyright (C) 2008 Wolfgang Grandegger <wg@...ndegger.com>
+ *
+ * Send feedback to <socketcan-users@...ts.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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