From 3cd864901bc5d5aa2bd38533dcd63d2bf2387030 Mon Sep 17 00:00:00 2001 From: Dario Binacchi Date: Tue, 28 Jun 2022 18:31:25 +0200 Subject: [PATCH 01/12] can: slcan: use the BIT() helper Use the BIT() helper instead of an explicit shift. Link: https://lore.kernel.org/all/20220628163137.413025-2-dario.binacchi@amarulasolutions.com Signed-off-by: Dario Binacchi Tested-by: Jeroen Hofstee Signed-off-by: Marc Kleine-Budde --- drivers/net/can/slcan.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/net/can/slcan.c b/drivers/net/can/slcan.c index 64a3aee8a7da..b37d35c2a23a 100644 --- a/drivers/net/can/slcan.c +++ b/drivers/net/can/slcan.c @@ -413,7 +413,7 @@ static int slc_open(struct net_device *dev) if (sl->tty == NULL) return -ENODEV; - sl->flags &= (1 << SLF_INUSE); + sl->flags &= BIT(SLF_INUSE); netif_start_queue(dev); return 0; } From da6788ea025c62343fec81f92409012d82096a09 Mon Sep 17 00:00:00 2001 From: Dario Binacchi Date: Tue, 28 Jun 2022 18:31:26 +0200 Subject: [PATCH 02/12] can: slcan: use netdev helpers to print out messages Replace printk() calls with corresponding netdev helpers. Link: https://lore.kernel.org/all/20220628163137.413025-3-dario.binacchi@amarulasolutions.com Signed-off-by: Dario Binacchi Tested-by: Jeroen Hofstee Signed-off-by: Marc Kleine-Budde --- drivers/net/can/slcan.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/drivers/net/can/slcan.c b/drivers/net/can/slcan.c index b37d35c2a23a..6162a9c21672 100644 --- a/drivers/net/can/slcan.c +++ b/drivers/net/can/slcan.c @@ -365,7 +365,7 @@ static netdev_tx_t slc_xmit(struct sk_buff *skb, struct net_device *dev) spin_lock(&sl->lock); if (!netif_running(dev)) { spin_unlock(&sl->lock); - printk(KERN_WARNING "%s: xmit: iface is down\n", dev->name); + netdev_warn(dev, "xmit: iface is down\n"); goto out; } if (sl->tty == NULL) { @@ -776,8 +776,7 @@ static void __exit slcan_exit(void) sl = netdev_priv(dev); if (sl->tty) { - printk(KERN_ERR "%s: tty discipline still running\n", - dev->name); + netdev_err(dev, "tty discipline still running\n"); } unregister_netdev(dev); From 92a31782c8487e496a9f1b2be3995e5c9c9a3265 Mon Sep 17 00:00:00 2001 From: Dario Binacchi Date: Tue, 28 Jun 2022 18:31:27 +0200 Subject: [PATCH 03/12] can: slcan: use the alloc_can_skb() helper It is used successfully by most (if not all) CAN device drivers. It allows to remove replicated code. Link: https://lore.kernel.org/all/20220628163137.413025-4-dario.binacchi@amarulasolutions.com Signed-off-by: Dario Binacchi Tested-by: Jeroen Hofstee Signed-off-by: Marc Kleine-Budde --- drivers/net/can/slcan.c | 70 +++++++++++++++++++---------------------- 1 file changed, 33 insertions(+), 37 deletions(-) diff --git a/drivers/net/can/slcan.c b/drivers/net/can/slcan.c index 6162a9c21672..c39580b142e0 100644 --- a/drivers/net/can/slcan.c +++ b/drivers/net/can/slcan.c @@ -54,6 +54,7 @@ #include #include #include +#include #include #include @@ -143,85 +144,80 @@ static struct net_device **slcan_devs; static void slc_bump(struct slcan *sl) { struct sk_buff *skb; - struct can_frame cf; + struct can_frame *cf; int i, tmp; u32 tmpid; char *cmd = sl->rbuff; - memset(&cf, 0, sizeof(cf)); + skb = alloc_can_skb(sl->dev, &cf); + if (unlikely(!skb)) { + sl->dev->stats.rx_dropped++; + return; + } switch (*cmd) { case 'r': - cf.can_id = CAN_RTR_FLAG; + cf->can_id = CAN_RTR_FLAG; fallthrough; case 't': /* store dlc ASCII value and terminate SFF CAN ID string */ - cf.len = sl->rbuff[SLC_CMD_LEN + SLC_SFF_ID_LEN]; + cf->len = sl->rbuff[SLC_CMD_LEN + SLC_SFF_ID_LEN]; sl->rbuff[SLC_CMD_LEN + SLC_SFF_ID_LEN] = 0; /* point to payload data behind the dlc */ cmd += SLC_CMD_LEN + SLC_SFF_ID_LEN + 1; break; case 'R': - cf.can_id = CAN_RTR_FLAG; + cf->can_id = CAN_RTR_FLAG; fallthrough; case 'T': - cf.can_id |= CAN_EFF_FLAG; + cf->can_id |= CAN_EFF_FLAG; /* store dlc ASCII value and terminate EFF CAN ID string */ - cf.len = sl->rbuff[SLC_CMD_LEN + SLC_EFF_ID_LEN]; + cf->len = sl->rbuff[SLC_CMD_LEN + SLC_EFF_ID_LEN]; sl->rbuff[SLC_CMD_LEN + SLC_EFF_ID_LEN] = 0; /* point to payload data behind the dlc */ cmd += SLC_CMD_LEN + SLC_EFF_ID_LEN + 1; break; default: - return; + goto decode_failed; } if (kstrtou32(sl->rbuff + SLC_CMD_LEN, 16, &tmpid)) - return; + goto decode_failed; - cf.can_id |= tmpid; + cf->can_id |= tmpid; /* get len from sanitized ASCII value */ - if (cf.len >= '0' && cf.len < '9') - cf.len -= '0'; + if (cf->len >= '0' && cf->len < '9') + cf->len -= '0'; else - return; + goto decode_failed; /* RTR frames may have a dlc > 0 but they never have any data bytes */ - if (!(cf.can_id & CAN_RTR_FLAG)) { - for (i = 0; i < cf.len; i++) { + if (!(cf->can_id & CAN_RTR_FLAG)) { + for (i = 0; i < cf->len; i++) { tmp = hex_to_bin(*cmd++); if (tmp < 0) - return; - cf.data[i] = (tmp << 4); + goto decode_failed; + + cf->data[i] = (tmp << 4); tmp = hex_to_bin(*cmd++); if (tmp < 0) - return; - cf.data[i] |= tmp; + goto decode_failed; + + cf->data[i] |= tmp; } } - skb = dev_alloc_skb(sizeof(struct can_frame) + - sizeof(struct can_skb_priv)); - if (!skb) - return; - - skb->dev = sl->dev; - skb->protocol = htons(ETH_P_CAN); - skb->pkt_type = PACKET_BROADCAST; - skb->ip_summed = CHECKSUM_UNNECESSARY; - - can_skb_reserve(skb); - can_skb_prv(skb)->ifindex = sl->dev->ifindex; - can_skb_prv(skb)->skbcnt = 0; - - skb_put_data(skb, &cf, sizeof(struct can_frame)); - sl->dev->stats.rx_packets++; - if (!(cf.can_id & CAN_RTR_FLAG)) - sl->dev->stats.rx_bytes += cf.len; + if (!(cf->can_id & CAN_RTR_FLAG)) + sl->dev->stats.rx_bytes += cf->len; netif_rx(skb); + return; + +decode_failed: + sl->dev->stats.rx_errors++; + dev_kfree_skb(skb); } /* parse tty input stream */ From 036bff2800cbcf8217dd0bc93d8421b5b8f72476 Mon Sep 17 00:00:00 2001 From: Dario Binacchi Date: Tue, 28 Jun 2022 18:31:28 +0200 Subject: [PATCH 04/12] can: netlink: dump bitrate 0 if can_priv::bittiming.bitrate is -1U Upcoming changes on slcan driver will require you to specify a bitrate of value -1 to prevent the open_candev() from failing but at the same time highlighting that it is a fake value. In this case the command `ip --details -s -s link show' would print 4294967295 as the bitrate value. The patch change this value in 0. Link: https://lore.kernel.org/all/20220628163137.413025-5-dario.binacchi@amarulasolutions.com Suggested-by: Marc Kleine-Budde Signed-off-by: Dario Binacchi Tested-by: Jeroen Hofstee Signed-off-by: Marc Kleine-Budde --- drivers/net/can/dev/netlink.c | 3 ++- include/linux/can/bittiming.h | 2 ++ 2 files changed, 4 insertions(+), 1 deletion(-) diff --git a/drivers/net/can/dev/netlink.c b/drivers/net/can/dev/netlink.c index 037824011266..8efa22d9f214 100644 --- a/drivers/net/can/dev/netlink.c +++ b/drivers/net/can/dev/netlink.c @@ -511,7 +511,8 @@ static int can_fill_info(struct sk_buff *skb, const struct net_device *dev) if (priv->do_get_state) priv->do_get_state(dev, &state); - if ((priv->bittiming.bitrate && + if ((priv->bittiming.bitrate != CAN_BITRATE_UNSET && + priv->bittiming.bitrate != CAN_BITRATE_UNKNOWN && nla_put(skb, IFLA_CAN_BITTIMING, sizeof(priv->bittiming), &priv->bittiming)) || diff --git a/include/linux/can/bittiming.h b/include/linux/can/bittiming.h index 7ae21c0f7f23..ef0a77173e3c 100644 --- a/include/linux/can/bittiming.h +++ b/include/linux/can/bittiming.h @@ -11,6 +11,8 @@ #define CAN_SYNC_SEG 1 +#define CAN_BITRATE_UNSET 0 +#define CAN_BITRATE_UNKNOWN (-1U) #define CAN_CTRLMODE_TDC_MASK \ (CAN_CTRLMODE_TDC_AUTO | CAN_CTRLMODE_TDC_MANUAL) From c4e54b063f42f20a6b3ad1ffa61c574e631e0216 Mon Sep 17 00:00:00 2001 From: Dario Binacchi Date: Tue, 28 Jun 2022 18:31:29 +0200 Subject: [PATCH 05/12] can: slcan: use CAN network device driver API As suggested by commit [1], now the driver uses the functions and the data structures provided by the CAN network device driver interface. Currently the driver doesn't implement a way to set bitrate for SLCAN based devices via ip tool, so you'll have to do this by slcand or slcan_attach invocation through the -sX parameter: - slcan_attach -f -s6 -o /dev/ttyACM0 - slcand -f -s8 -o /dev/ttyUSB0 where -s6 in will set adapter's bitrate to 500 Kbit/s and -s8 to 1Mbit/s. See the table below for further CAN bitrates: - s0 -> 10 Kbit/s - s1 -> 20 Kbit/s - s2 -> 50 Kbit/s - s3 -> 100 Kbit/s - s4 -> 125 Kbit/s - s5 -> 250 Kbit/s - s6 -> 500 Kbit/s - s7 -> 800 Kbit/s - s8 -> 1000 Kbit/s In doing so, the struct can_priv::bittiming.bitrate of the driver is not set and since the open_candev() checks that the bitrate has been set, it must be a non-zero value, the bitrate is set to a fake value (-1U) before it is called. Using the rtnl_lock()/rtnl_unlock() functions has become a bit more tricky as the register_candev() function indirectly calls rtnl_lock() via register_netdev(). To avoid a deadlock it is therefore necessary to call rtnl_unlock() before calling register_candev(). The same goes for the unregister_candev() function. [1] commit 39549eef3587f ("can: CAN Network device driver and Netlink interface") Link: https://lore.kernel.org/all/20220628163137.413025-6-dario.binacchi@amarulasolutions.com Signed-off-by: Dario Binacchi Tested-by: Jeroen Hofstee Signed-off-by: Marc Kleine-Budde --- drivers/net/can/Kconfig | 40 ++++++++++---------- drivers/net/can/slcan.c | 82 ++++++++++++++++++++--------------------- 2 files changed, 60 insertions(+), 62 deletions(-) diff --git a/drivers/net/can/Kconfig b/drivers/net/can/Kconfig index 4078d0775572..3048ad77edb3 100644 --- a/drivers/net/can/Kconfig +++ b/drivers/net/can/Kconfig @@ -49,26 +49,6 @@ config CAN_VXCAN This driver can also be built as a module. If so, the module will be called vxcan. -config CAN_SLCAN - tristate "Serial / USB serial CAN Adaptors (slcan)" - depends on TTY - help - CAN driver for several 'low cost' CAN interfaces that are attached - via serial lines or via USB-to-serial adapters using the LAWICEL - ASCII protocol. The driver implements the tty linediscipline N_SLCAN. - - As only the sending and receiving of CAN frames is implemented, this - driver should work with the (serial/USB) CAN hardware from: - www.canusb.com / www.can232.com / www.mictronics.de / www.canhack.de - - Userspace tools to attach the SLCAN line discipline (slcan_attach, - slcand) can be found in the can-utils at the linux-can project, see - https://github.com/linux-can/can-utils for details. - - The slcan driver supports up to 10 CAN netdevices by default which - can be changed by the 'maxdev=xx' module option. This driver can - also be built as a module. If so, the module will be called slcan. - config CAN_NETLINK bool "CAN device drivers with Netlink support" default y @@ -172,6 +152,26 @@ config CAN_KVASER_PCIEFD Kvaser Mini PCI Express HS v2 Kvaser Mini PCI Express 2xHS v2 +config CAN_SLCAN + tristate "Serial / USB serial CAN Adaptors (slcan)" + depends on TTY + help + CAN driver for several 'low cost' CAN interfaces that are attached + via serial lines or via USB-to-serial adapters using the LAWICEL + ASCII protocol. The driver implements the tty linediscipline N_SLCAN. + + As only the sending and receiving of CAN frames is implemented, this + driver should work with the (serial/USB) CAN hardware from: + www.canusb.com / www.can232.com / www.mictronics.de / www.canhack.de + + Userspace tools to attach the SLCAN line discipline (slcan_attach, + slcand) can be found in the can-utils at the linux-can project, see + https://github.com/linux-can/can-utils for details. + + The slcan driver supports up to 10 CAN netdevices by default which + can be changed by the 'maxdev=xx' module option. This driver can + also be built as a module. If so, the module will be called slcan. + config CAN_SUN4I tristate "Allwinner A10 CAN controller" depends on MACH_SUN4I || MACH_SUN7I || COMPILE_TEST diff --git a/drivers/net/can/slcan.c b/drivers/net/can/slcan.c index c39580b142e0..bf84698f1a81 100644 --- a/drivers/net/can/slcan.c +++ b/drivers/net/can/slcan.c @@ -56,7 +56,6 @@ #include #include #include -#include MODULE_ALIAS_LDISC(N_SLCAN); MODULE_DESCRIPTION("serial line CAN interface"); @@ -79,6 +78,7 @@ MODULE_PARM_DESC(maxdev, "Maximum number of slcan interfaces"); #define SLC_EFF_ID_LEN 8 struct slcan { + struct can_priv can; int magic; /* Various fields. */ @@ -394,6 +394,8 @@ static int slc_close(struct net_device *dev) clear_bit(TTY_DO_WRITE_WAKEUP, &sl->tty->flags); } netif_stop_queue(dev); + close_candev(dev); + sl->can.state = CAN_STATE_STOPPED; sl->rcount = 0; sl->xleft = 0; spin_unlock_bh(&sl->lock); @@ -405,20 +407,34 @@ static int slc_close(struct net_device *dev) static int slc_open(struct net_device *dev) { struct slcan *sl = netdev_priv(dev); + int err; if (sl->tty == NULL) return -ENODEV; + /* The baud rate is not set with the command + * `ip link set type can bitrate ' and therefore + * can.bittiming.bitrate is CAN_BITRATE_UNSET (0), causing + * open_candev() to fail. So let's set to a fake value. + */ + sl->can.bittiming.bitrate = CAN_BITRATE_UNKNOWN; + err = open_candev(dev); + if (err) { + netdev_err(dev, "failed to open can device\n"); + return err; + } + + sl->can.state = CAN_STATE_ERROR_ACTIVE; sl->flags &= BIT(SLF_INUSE); netif_start_queue(dev); return 0; } -/* Hook the destructor so we can free slcan devs at the right point in time */ -static void slc_free_netdev(struct net_device *dev) +static void slc_dealloc(struct slcan *sl) { - int i = dev->base_addr; + int i = sl->dev->base_addr; + free_candev(sl->dev); slcan_devs[i] = NULL; } @@ -434,24 +450,6 @@ static const struct net_device_ops slc_netdev_ops = { .ndo_change_mtu = slcan_change_mtu, }; -static void slc_setup(struct net_device *dev) -{ - dev->netdev_ops = &slc_netdev_ops; - dev->needs_free_netdev = true; - dev->priv_destructor = slc_free_netdev; - - dev->hard_header_len = 0; - dev->addr_len = 0; - dev->tx_queue_len = 10; - - dev->mtu = CAN_MTU; - dev->type = ARPHRD_CAN; - - /* New-style flags. */ - dev->flags = IFF_NOARP; - dev->features = NETIF_F_HW_CSUM; -} - /****************************************** Routines looking at TTY side. ******************************************/ @@ -514,11 +512,8 @@ static void slc_sync(void) static struct slcan *slc_alloc(void) { int i; - char name[IFNAMSIZ]; struct net_device *dev = NULL; - struct can_ml_priv *can_ml; struct slcan *sl; - int size; for (i = 0; i < maxdev; i++) { dev = slcan_devs[i]; @@ -531,16 +526,14 @@ static struct slcan *slc_alloc(void) if (i >= maxdev) return NULL; - sprintf(name, "slcan%d", i); - size = ALIGN(sizeof(*sl), NETDEV_ALIGN) + sizeof(struct can_ml_priv); - dev = alloc_netdev(size, name, NET_NAME_UNKNOWN, slc_setup); + dev = alloc_candev(sizeof(*sl), 1); if (!dev) return NULL; + snprintf(dev->name, sizeof(dev->name), "slcan%d", i); + dev->netdev_ops = &slc_netdev_ops; dev->base_addr = i; sl = netdev_priv(dev); - can_ml = (void *)sl + ALIGN(sizeof(*sl), NETDEV_ALIGN); - can_set_ml_priv(dev, can_ml); /* Initialize channel control data */ sl->magic = SLCAN_MAGIC; @@ -605,26 +598,28 @@ static int slcan_open(struct tty_struct *tty) set_bit(SLF_INUSE, &sl->flags); - err = register_netdevice(sl->dev); - if (err) + rtnl_unlock(); + err = register_candev(sl->dev); + if (err) { + pr_err("slcan: can't register candev\n"); goto err_free_chan; + } + } else { + rtnl_unlock(); } - /* Done. We have linked the TTY line to a channel. */ - rtnl_unlock(); tty->receive_room = 65536; /* We don't flow control */ /* TTY layer expects 0 on success */ return 0; err_free_chan: + rtnl_lock(); sl->tty = NULL; tty->disc_data = NULL; clear_bit(SLF_INUSE, &sl->flags); - slc_free_netdev(sl->dev); - /* do not call free_netdev before rtnl_unlock */ + slc_dealloc(sl); rtnl_unlock(); - free_netdev(sl->dev); return err; err_exit: @@ -658,9 +653,11 @@ static void slcan_close(struct tty_struct *tty) synchronize_rcu(); flush_work(&sl->tx_work); - /* Flush network side */ - unregister_netdev(sl->dev); - /* This will complete via sl_free_netdev */ + slc_close(sl->dev); + unregister_candev(sl->dev); + rtnl_lock(); + slc_dealloc(sl); + rtnl_unlock(); } static void slcan_hangup(struct tty_struct *tty) @@ -768,14 +765,15 @@ static void __exit slcan_exit(void) dev = slcan_devs[i]; if (!dev) continue; - slcan_devs[i] = NULL; sl = netdev_priv(dev); if (sl->tty) { netdev_err(dev, "tty discipline still running\n"); } - unregister_netdev(dev); + slc_close(dev); + unregister_candev(dev); + slc_dealloc(sl); } kfree(slcan_devs); From 52f9ac85b8766d16021775f2c1bb85a903a582ff Mon Sep 17 00:00:00 2001 From: Dario Binacchi Date: Tue, 28 Jun 2022 18:31:30 +0200 Subject: [PATCH 06/12] can: slcan: allow to send commands to the adapter This is a preparation patch for the upcoming support to change the bitrate via ip tool, reset the adapter error states via the ethtool API and, more generally, send commands to the adapter. Since the close command (i. e. "C\r") will be sent in the ndo_stop() where netif_running() returns false, a new flag bit (i. e. SLF_XCMD) for serial transmission has to be added. Link: https://lore.kernel.org/all/20220628163137.413025-7-dario.binacchi@amarulasolutions.com Signed-off-by: Dario Binacchi Tested-by: Jeroen Hofstee Signed-off-by: Marc Kleine-Budde --- drivers/net/can/slcan.c | 46 ++++++++++++++++++++++++++++++++++++++++- 1 file changed, 45 insertions(+), 1 deletion(-) diff --git a/drivers/net/can/slcan.c b/drivers/net/can/slcan.c index bf84698f1a81..dfccf8d6c9a5 100644 --- a/drivers/net/can/slcan.c +++ b/drivers/net/can/slcan.c @@ -97,6 +97,9 @@ struct slcan { unsigned long flags; /* Flag values/ mode etc */ #define SLF_INUSE 0 /* Channel in use */ #define SLF_ERROR 1 /* Parity, etc. error */ +#define SLF_XCMD 2 /* Command transmission */ + wait_queue_head_t xcmd_wait; /* Wait queue for commands */ + /* transmission */ }; static struct net_device **slcan_devs; @@ -314,12 +317,22 @@ static void slcan_transmit(struct work_struct *work) spin_lock_bh(&sl->lock); /* First make sure we're connected. */ - if (!sl->tty || sl->magic != SLCAN_MAGIC || !netif_running(sl->dev)) { + if (!sl->tty || sl->magic != SLCAN_MAGIC || + (unlikely(!netif_running(sl->dev)) && + likely(!test_bit(SLF_XCMD, &sl->flags)))) { spin_unlock_bh(&sl->lock); return; } if (sl->xleft <= 0) { + if (unlikely(test_bit(SLF_XCMD, &sl->flags))) { + clear_bit(SLF_XCMD, &sl->flags); + clear_bit(TTY_DO_WRITE_WAKEUP, &sl->tty->flags); + spin_unlock_bh(&sl->lock); + wake_up(&sl->xcmd_wait); + return; + } + /* Now serial buffer is almost free & we can start * transmission of another packet */ sl->dev->stats.tx_packets++; @@ -383,6 +396,36 @@ static netdev_tx_t slc_xmit(struct sk_buff *skb, struct net_device *dev) * Routines looking at netdevice side. ******************************************/ +static int slcan_transmit_cmd(struct slcan *sl, const unsigned char *cmd) +{ + int ret, actual, n; + + spin_lock(&sl->lock); + if (!sl->tty) { + spin_unlock(&sl->lock); + return -ENODEV; + } + + n = snprintf(sl->xbuff, sizeof(sl->xbuff), "%s", cmd); + set_bit(TTY_DO_WRITE_WAKEUP, &sl->tty->flags); + actual = sl->tty->ops->write(sl->tty, sl->xbuff, n); + sl->xleft = n - actual; + sl->xhead = sl->xbuff + actual; + set_bit(SLF_XCMD, &sl->flags); + spin_unlock(&sl->lock); + ret = wait_event_interruptible_timeout(sl->xcmd_wait, + !test_bit(SLF_XCMD, &sl->flags), + HZ); + clear_bit(SLF_XCMD, &sl->flags); + if (ret == -ERESTARTSYS) + return ret; + + if (ret == 0) + return -ETIMEDOUT; + + return 0; +} + /* Netdevice UP -> DOWN routine */ static int slc_close(struct net_device *dev) { @@ -540,6 +583,7 @@ static struct slcan *slc_alloc(void) sl->dev = dev; spin_lock_init(&sl->lock); INIT_WORK(&sl->tx_work, slcan_transmit); + init_waitqueue_head(&sl->xcmd_wait); slcan_devs[i] = dev; return sl; From dca796299462579dad380413783588192b0c3433 Mon Sep 17 00:00:00 2001 From: Dario Binacchi Date: Tue, 28 Jun 2022 18:31:31 +0200 Subject: [PATCH 07/12] can: slcan: set bitrate by CAN device driver API It allows to set the bitrate via ip tool, as it happens for the other CAN device drivers. It still remains possible to set the bitrate via slcand or slcan_attach utilities. In case the ip tool is used, the driver will send the serial command to the adapter. Link: https://lore.kernel.org/all/20220628163137.413025-8-dario.binacchi@amarulasolutions.com Signed-off-by: Dario Binacchi Tested-by: Jeroen Hofstee Signed-off-by: Marc Kleine-Budde --- drivers/net/can/slcan.c | 41 ++++++++++++++++++++++++++++++++++++++--- 1 file changed, 38 insertions(+), 3 deletions(-) diff --git a/drivers/net/can/slcan.c b/drivers/net/can/slcan.c index dfccf8d6c9a5..74033e2d7097 100644 --- a/drivers/net/can/slcan.c +++ b/drivers/net/can/slcan.c @@ -104,6 +104,11 @@ struct slcan { static struct net_device **slcan_devs; +static const u32 slcan_bitrate_const[] = { + 10000, 20000, 50000, 100000, 125000, + 250000, 500000, 800000, 1000000 +}; + /************************************************************************ * SLCAN ENCAPSULATION FORMAT * ************************************************************************/ @@ -439,6 +444,9 @@ static int slc_close(struct net_device *dev) netif_stop_queue(dev); close_candev(dev); sl->can.state = CAN_STATE_STOPPED; + if (sl->can.bittiming.bitrate == CAN_BITRATE_UNKNOWN) + sl->can.bittiming.bitrate = CAN_BITRATE_UNSET; + sl->rcount = 0; sl->xleft = 0; spin_unlock_bh(&sl->lock); @@ -450,7 +458,8 @@ static int slc_close(struct net_device *dev) static int slc_open(struct net_device *dev) { struct slcan *sl = netdev_priv(dev); - int err; + unsigned char cmd[SLC_MTU]; + int err, s; if (sl->tty == NULL) return -ENODEV; @@ -460,15 +469,39 @@ static int slc_open(struct net_device *dev) * can.bittiming.bitrate is CAN_BITRATE_UNSET (0), causing * open_candev() to fail. So let's set to a fake value. */ - sl->can.bittiming.bitrate = CAN_BITRATE_UNKNOWN; + if (sl->can.bittiming.bitrate == CAN_BITRATE_UNSET) + sl->can.bittiming.bitrate = CAN_BITRATE_UNKNOWN; + err = open_candev(dev); if (err) { netdev_err(dev, "failed to open can device\n"); return err; } - sl->can.state = CAN_STATE_ERROR_ACTIVE; sl->flags &= BIT(SLF_INUSE); + + if (sl->can.bittiming.bitrate != CAN_BITRATE_UNKNOWN) { + for (s = 0; s < ARRAY_SIZE(slcan_bitrate_const); s++) { + if (sl->can.bittiming.bitrate == slcan_bitrate_const[s]) + break; + } + + /* The CAN framework has already validate the bitrate value, + * so we can avoid to check if `s' has been properly set. + */ + + snprintf(cmd, sizeof(cmd), "C\rS%d\r", s); + err = slcan_transmit_cmd(sl, cmd); + if (err) { + netdev_err(dev, + "failed to send bitrate command 'C\\rS%d\\r'\n", + s); + close_candev(dev); + return err; + } + } + + sl->can.state = CAN_STATE_ERROR_ACTIVE; netif_start_queue(dev); return 0; } @@ -581,6 +614,8 @@ static struct slcan *slc_alloc(void) /* Initialize channel control data */ sl->magic = SLCAN_MAGIC; sl->dev = dev; + sl->can.bitrate_const = slcan_bitrate_const; + sl->can.bitrate_const_cnt = ARRAY_SIZE(slcan_bitrate_const); spin_lock_init(&sl->lock); INIT_WORK(&sl->tx_work, slcan_transmit); init_waitqueue_head(&sl->xcmd_wait); From 5bac315be7eb6a7442d390c6b99e7ff5cb61f848 Mon Sep 17 00:00:00 2001 From: Dario Binacchi Date: Tue, 28 Jun 2022 18:31:32 +0200 Subject: [PATCH 08/12] can: slcan: send the open/close commands to the adapter In case the bitrate has been set via ip tool, this patch changes the driver to send the open ("O\r") and close ("C\r) commands to the adapter. Link: https://lore.kernel.org/all/20220628163137.413025-9-dario.binacchi@amarulasolutions.com Signed-off-by: Dario Binacchi Tested-by: Jeroen Hofstee Signed-off-by: Marc Kleine-Budde --- drivers/net/can/slcan.c | 24 ++++++++++++++++++++++-- 1 file changed, 22 insertions(+), 2 deletions(-) diff --git a/drivers/net/can/slcan.c b/drivers/net/can/slcan.c index 74033e2d7097..249b5ade06fc 100644 --- a/drivers/net/can/slcan.c +++ b/drivers/net/can/slcan.c @@ -435,9 +435,20 @@ static int slcan_transmit_cmd(struct slcan *sl, const unsigned char *cmd) static int slc_close(struct net_device *dev) { struct slcan *sl = netdev_priv(dev); + int err; spin_lock_bh(&sl->lock); if (sl->tty) { + if (sl->can.bittiming.bitrate && + sl->can.bittiming.bitrate != CAN_BITRATE_UNKNOWN) { + spin_unlock_bh(&sl->lock); + err = slcan_transmit_cmd(sl, "C\r"); + spin_lock_bh(&sl->lock); + if (err) + netdev_warn(dev, + "failed to send close command 'C\\r'\n"); + } + /* TTY discipline is running. */ clear_bit(TTY_DO_WRITE_WAKEUP, &sl->tty->flags); } @@ -496,14 +507,23 @@ static int slc_open(struct net_device *dev) netdev_err(dev, "failed to send bitrate command 'C\\rS%d\\r'\n", s); - close_candev(dev); - return err; + goto cmd_transmit_failed; + } + + err = slcan_transmit_cmd(sl, "O\r"); + if (err) { + netdev_err(dev, "failed to send open command 'O\\r'\n"); + goto cmd_transmit_failed; } } sl->can.state = CAN_STATE_ERROR_ACTIVE; netif_start_queue(dev); return 0; + +cmd_transmit_failed: + close_candev(dev); + return err; } static void slc_dealloc(struct slcan *sl) From 98b12064591d635db86da4957b547067dc6897cc Mon Sep 17 00:00:00 2001 From: Dario Binacchi Date: Tue, 28 Jun 2022 18:31:33 +0200 Subject: [PATCH 09/12] can: slcan: move driver into separate sub directory This patch moves the slcan driver into a separate directory, a later patch will add more files. Link: https://lore.kernel.org/all/20220628163137.413025-10-dario.binacchi@amarulasolutions.com Signed-off-by: Dario Binacchi Signed-off-by: Marc Kleine-Budde --- drivers/net/can/Makefile | 2 +- drivers/net/can/slcan/Makefile | 6 ++++++ drivers/net/can/{slcan.c => slcan/slcan-core.c} | 0 3 files changed, 7 insertions(+), 1 deletion(-) create mode 100644 drivers/net/can/slcan/Makefile rename drivers/net/can/{slcan.c => slcan/slcan-core.c} (100%) diff --git a/drivers/net/can/Makefile b/drivers/net/can/Makefile index cafa0e0a3dfe..61c75ce9d500 100644 --- a/drivers/net/can/Makefile +++ b/drivers/net/can/Makefile @@ -5,7 +5,7 @@ obj-$(CONFIG_CAN_VCAN) += vcan.o obj-$(CONFIG_CAN_VXCAN) += vxcan.o -obj-$(CONFIG_CAN_SLCAN) += slcan.o +obj-$(CONFIG_CAN_SLCAN) += slcan/ obj-y += dev/ obj-y += rcar/ diff --git a/drivers/net/can/slcan/Makefile b/drivers/net/can/slcan/Makefile new file mode 100644 index 000000000000..2e84f7bf7617 --- /dev/null +++ b/drivers/net/can/slcan/Makefile @@ -0,0 +1,6 @@ +# SPDX-License-Identifier: GPL-2.0 + +obj-$(CONFIG_CAN_SLCAN) += slcan.o + +slcan-objs := +slcan-objs += slcan-core.o diff --git a/drivers/net/can/slcan.c b/drivers/net/can/slcan/slcan-core.c similarity index 100% rename from drivers/net/can/slcan.c rename to drivers/net/can/slcan/slcan-core.c From 4de0e8efa052b1f0b3dae9e7c1538163cad216e7 Mon Sep 17 00:00:00 2001 From: Dario Binacchi Date: Tue, 28 Jun 2022 18:31:34 +0200 Subject: [PATCH 10/12] can: slcan: add ethtool support to reset adapter errors This patch adds a private flag to the slcan driver to switch the "err-rst-on-open" setting on and off. "err-rst-on-open" on - Reset error states on opening command "err-rst-on-open" off - Don't reset error states on opening command (default) The setting can only be changed if the interface is down: ip link set dev can0 down ethtool --set-priv-flags can0 err-rst-on-open {off|on} ip link set dev can0 up Link: https://lore.kernel.org/all/20220628163137.413025-11-dario.binacchi@amarulasolutions.com Signed-off-by: Dario Binacchi Signed-off-by: Marc Kleine-Budde --- drivers/net/can/slcan/Makefile | 1 + drivers/net/can/slcan/slcan-core.c | 36 +++++++++++++++ drivers/net/can/slcan/slcan-ethtool.c | 65 +++++++++++++++++++++++++++ drivers/net/can/slcan/slcan.h | 18 ++++++++ 4 files changed, 120 insertions(+) create mode 100644 drivers/net/can/slcan/slcan-ethtool.c create mode 100644 drivers/net/can/slcan/slcan.h diff --git a/drivers/net/can/slcan/Makefile b/drivers/net/can/slcan/Makefile index 2e84f7bf7617..8a88e484ee21 100644 --- a/drivers/net/can/slcan/Makefile +++ b/drivers/net/can/slcan/Makefile @@ -4,3 +4,4 @@ obj-$(CONFIG_CAN_SLCAN) += slcan.o slcan-objs := slcan-objs += slcan-core.o +slcan-objs += slcan-ethtool.o diff --git a/drivers/net/can/slcan/slcan-core.c b/drivers/net/can/slcan/slcan-core.c index 249b5ade06fc..c1fd1e934d93 100644 --- a/drivers/net/can/slcan/slcan-core.c +++ b/drivers/net/can/slcan/slcan-core.c @@ -57,6 +57,8 @@ #include #include +#include "slcan.h" + MODULE_ALIAS_LDISC(N_SLCAN); MODULE_DESCRIPTION("serial line CAN interface"); MODULE_LICENSE("GPL"); @@ -98,6 +100,8 @@ struct slcan { #define SLF_INUSE 0 /* Channel in use */ #define SLF_ERROR 1 /* Parity, etc. error */ #define SLF_XCMD 2 /* Command transmission */ + unsigned long cmd_flags; /* Command flags */ +#define CF_ERR_RST 0 /* Reset errors on open */ wait_queue_head_t xcmd_wait; /* Wait queue for commands */ /* transmission */ }; @@ -109,6 +113,28 @@ static const u32 slcan_bitrate_const[] = { 250000, 500000, 800000, 1000000 }; +bool slcan_err_rst_on_open(struct net_device *ndev) +{ + struct slcan *sl = netdev_priv(ndev); + + return !!test_bit(CF_ERR_RST, &sl->cmd_flags); +} + +int slcan_enable_err_rst_on_open(struct net_device *ndev, bool on) +{ + struct slcan *sl = netdev_priv(ndev); + + if (netif_running(ndev)) + return -EBUSY; + + if (on) + set_bit(CF_ERR_RST, &sl->cmd_flags); + else + clear_bit(CF_ERR_RST, &sl->cmd_flags); + + return 0; +} + /************************************************************************ * SLCAN ENCAPSULATION FORMAT * ************************************************************************/ @@ -510,6 +536,15 @@ static int slc_open(struct net_device *dev) goto cmd_transmit_failed; } + if (test_bit(CF_ERR_RST, &sl->cmd_flags)) { + err = slcan_transmit_cmd(sl, "F\r"); + if (err) { + netdev_err(dev, + "failed to send error command 'F\\r'\n"); + goto cmd_transmit_failed; + } + } + err = slcan_transmit_cmd(sl, "O\r"); if (err) { netdev_err(dev, "failed to send open command 'O\\r'\n"); @@ -629,6 +664,7 @@ static struct slcan *slc_alloc(void) snprintf(dev->name, sizeof(dev->name), "slcan%d", i); dev->netdev_ops = &slc_netdev_ops; dev->base_addr = i; + slcan_set_ethtool_ops(dev); sl = netdev_priv(dev); /* Initialize channel control data */ diff --git a/drivers/net/can/slcan/slcan-ethtool.c b/drivers/net/can/slcan/slcan-ethtool.c new file mode 100644 index 000000000000..bf0afdc4e49d --- /dev/null +++ b/drivers/net/can/slcan/slcan-ethtool.c @@ -0,0 +1,65 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* Copyright (c) 2022 Amarula Solutions, Dario Binacchi + * + */ + +#include +#include +#include +#include +#include + +#include "slcan.h" + +static const char slcan_priv_flags_strings[][ETH_GSTRING_LEN] = { +#define SLCAN_PRIV_FLAGS_ERR_RST_ON_OPEN BIT(0) + "err-rst-on-open", +}; + +static void slcan_get_strings(struct net_device *ndev, u32 stringset, u8 *data) +{ + switch (stringset) { + case ETH_SS_PRIV_FLAGS: + memcpy(data, slcan_priv_flags_strings, + sizeof(slcan_priv_flags_strings)); + } +} + +static u32 slcan_get_priv_flags(struct net_device *ndev) +{ + u32 flags = 0; + + if (slcan_err_rst_on_open(ndev)) + flags |= SLCAN_PRIV_FLAGS_ERR_RST_ON_OPEN; + + return flags; +} + +static int slcan_set_priv_flags(struct net_device *ndev, u32 flags) +{ + bool err_rst_op_open = !!(flags & SLCAN_PRIV_FLAGS_ERR_RST_ON_OPEN); + + return slcan_enable_err_rst_on_open(ndev, err_rst_op_open); +} + +static int slcan_get_sset_count(struct net_device *netdev, int sset) +{ + switch (sset) { + case ETH_SS_PRIV_FLAGS: + return ARRAY_SIZE(slcan_priv_flags_strings); + default: + return -EOPNOTSUPP; + } +} + +static const struct ethtool_ops slcan_ethtool_ops = { + .get_strings = slcan_get_strings, + .get_priv_flags = slcan_get_priv_flags, + .set_priv_flags = slcan_set_priv_flags, + .get_sset_count = slcan_get_sset_count, +}; + +void slcan_set_ethtool_ops(struct net_device *netdev) +{ + netdev->ethtool_ops = &slcan_ethtool_ops; +} diff --git a/drivers/net/can/slcan/slcan.h b/drivers/net/can/slcan/slcan.h new file mode 100644 index 000000000000..d463c8d99e22 --- /dev/null +++ b/drivers/net/can/slcan/slcan.h @@ -0,0 +1,18 @@ +/* SPDX-License-Identifier: GPL-2.0 + * slcan.h - serial line CAN interface driver + * + * Copyright (C) Laurence Culhane + * Copyright (C) Fred N. van Kempen + * Copyright (C) Oliver Hartkopp + * Copyright (C) 2022 Amarula Solutions, Dario Binacchi + * + */ + +#ifndef _SLCAN_H +#define _SLCAN_H + +bool slcan_err_rst_on_open(struct net_device *ndev); +int slcan_enable_err_rst_on_open(struct net_device *ndev, bool on); +void slcan_set_ethtool_ops(struct net_device *ndev); + +#endif /* _SLCAN_H */ From b32ff4668544e1333b694fcc7812b2d7397b4d6a Mon Sep 17 00:00:00 2001 From: Dario Binacchi Date: Tue, 28 Jun 2022 18:31:35 +0200 Subject: [PATCH 11/12] can: slcan: extend the protocol with error info It extends the protocol to receive the adapter CAN communication errors and forward them to the netdev upper levels. Link: https://lore.kernel.org/all/20220628163137.413025-12-dario.binacchi@amarulasolutions.com Signed-off-by: Dario Binacchi Signed-off-by: Marc Kleine-Budde --- drivers/net/can/slcan/slcan-core.c | 140 ++++++++++++++++++++++++++++- 1 file changed, 139 insertions(+), 1 deletion(-) diff --git a/drivers/net/can/slcan/slcan-core.c b/drivers/net/can/slcan/slcan-core.c index c1fd1e934d93..4269b2267be2 100644 --- a/drivers/net/can/slcan/slcan-core.c +++ b/drivers/net/can/slcan/slcan-core.c @@ -175,7 +175,7 @@ int slcan_enable_err_rst_on_open(struct net_device *ndev, bool on) ************************************************************************/ /* Send one completely decapsulated can_frame to the network layer */ -static void slc_bump(struct slcan *sl) +static void slc_bump_frame(struct slcan *sl) { struct sk_buff *skb; struct can_frame *cf; @@ -254,6 +254,144 @@ static void slc_bump(struct slcan *sl) dev_kfree_skb(skb); } +/* An error frame can contain more than one type of error. + * + * Examples: + * + * e1a : len 1, errors: ACK error + * e3bcO: len 3, errors: Bit0 error, CRC error, Tx overrun error + */ +static void slc_bump_err(struct slcan *sl) +{ + struct net_device *dev = sl->dev; + struct sk_buff *skb; + struct can_frame *cf; + char *cmd = sl->rbuff; + bool rx_errors = false, tx_errors = false, rx_over_errors = false; + int i, len; + + /* get len from sanitized ASCII value */ + len = cmd[1]; + if (len >= '0' && len < '9') + len -= '0'; + else + return; + + if ((len + SLC_CMD_LEN + 1) > sl->rcount) + return; + + skb = alloc_can_err_skb(dev, &cf); + + if (skb) + cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR; + + cmd += SLC_CMD_LEN + 1; + for (i = 0; i < len; i++, cmd++) { + switch (*cmd) { + case 'a': + netdev_dbg(dev, "ACK error\n"); + tx_errors = true; + if (skb) { + cf->can_id |= CAN_ERR_ACK; + cf->data[3] = CAN_ERR_PROT_LOC_ACK; + } + + break; + case 'b': + netdev_dbg(dev, "Bit0 error\n"); + tx_errors = true; + if (skb) + cf->data[2] |= CAN_ERR_PROT_BIT0; + + break; + case 'B': + netdev_dbg(dev, "Bit1 error\n"); + tx_errors = true; + if (skb) + cf->data[2] |= CAN_ERR_PROT_BIT1; + + break; + case 'c': + netdev_dbg(dev, "CRC error\n"); + rx_errors = true; + if (skb) { + cf->data[2] |= CAN_ERR_PROT_BIT; + cf->data[3] = CAN_ERR_PROT_LOC_CRC_SEQ; + } + + break; + case 'f': + netdev_dbg(dev, "Form Error\n"); + rx_errors = true; + if (skb) + cf->data[2] |= CAN_ERR_PROT_FORM; + + break; + case 'o': + netdev_dbg(dev, "Rx overrun error\n"); + rx_over_errors = true; + rx_errors = true; + if (skb) { + cf->can_id |= CAN_ERR_CRTL; + cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW; + } + + break; + case 'O': + netdev_dbg(dev, "Tx overrun error\n"); + tx_errors = true; + if (skb) { + cf->can_id |= CAN_ERR_CRTL; + cf->data[1] = CAN_ERR_CRTL_TX_OVERFLOW; + } + + break; + case 's': + netdev_dbg(dev, "Stuff error\n"); + rx_errors = true; + if (skb) + cf->data[2] |= CAN_ERR_PROT_STUFF; + + break; + default: + if (skb) + dev_kfree_skb(skb); + + return; + } + } + + if (rx_errors) + dev->stats.rx_errors++; + + if (rx_over_errors) + dev->stats.rx_over_errors++; + + if (tx_errors) + dev->stats.tx_errors++; + + if (skb) + netif_rx(skb); +} + +static void slc_bump(struct slcan *sl) +{ + switch (sl->rbuff[0]) { + case 'r': + fallthrough; + case 't': + fallthrough; + case 'R': + fallthrough; + case 'T': + return slc_bump_frame(sl); + case 'e': + return slc_bump_err(sl); + default: + return; + } +} + /* parse tty input stream */ static void slcan_unesc(struct slcan *sl, unsigned char s) { From 0a9cdcf098a4a52b1a44b522022d1466a2d2680d Mon Sep 17 00:00:00 2001 From: Dario Binacchi Date: Tue, 28 Jun 2022 18:31:36 +0200 Subject: [PATCH 12/12] can: slcan: extend the protocol with CAN state info It extends the protocol to receive the adapter CAN state changes (warning, busoff, etc.) and forward them to the netdev upper levels. Link: https://lore.kernel.org/all/20220628163137.413025-13-dario.binacchi@amarulasolutions.com Signed-off-by: Dario Binacchi Signed-off-by: Marc Kleine-Budde --- drivers/net/can/slcan/slcan-core.c | 74 +++++++++++++++++++++++++++++- 1 file changed, 73 insertions(+), 1 deletion(-) diff --git a/drivers/net/can/slcan/slcan-core.c b/drivers/net/can/slcan/slcan-core.c index 4269b2267be2..54d29a410ad5 100644 --- a/drivers/net/can/slcan/slcan-core.c +++ b/drivers/net/can/slcan/slcan-core.c @@ -78,7 +78,11 @@ MODULE_PARM_DESC(maxdev, "Maximum number of slcan interfaces"); #define SLC_CMD_LEN 1 #define SLC_SFF_ID_LEN 3 #define SLC_EFF_ID_LEN 8 - +#define SLC_STATE_LEN 1 +#define SLC_STATE_BE_RXCNT_LEN 3 +#define SLC_STATE_BE_TXCNT_LEN 3 +#define SLC_STATE_FRAME_LEN (1 + SLC_CMD_LEN + SLC_STATE_BE_RXCNT_LEN + \ + SLC_STATE_BE_TXCNT_LEN) struct slcan { struct can_priv can; int magic; @@ -254,6 +258,72 @@ static void slc_bump_frame(struct slcan *sl) dev_kfree_skb(skb); } +/* A change state frame must contain state info and receive and transmit + * error counters. + * + * Examples: + * + * sb256256 : state bus-off: rx counter 256, tx counter 256 + * sa057033 : state active, rx counter 57, tx counter 33 + */ +static void slc_bump_state(struct slcan *sl) +{ + struct net_device *dev = sl->dev; + struct sk_buff *skb; + struct can_frame *cf; + char *cmd = sl->rbuff; + u32 rxerr, txerr; + enum can_state state, rx_state, tx_state; + + switch (cmd[1]) { + case 'a': + state = CAN_STATE_ERROR_ACTIVE; + break; + case 'w': + state = CAN_STATE_ERROR_WARNING; + break; + case 'p': + state = CAN_STATE_ERROR_PASSIVE; + break; + case 'b': + state = CAN_STATE_BUS_OFF; + break; + default: + return; + } + + if (state == sl->can.state || sl->rcount < SLC_STATE_FRAME_LEN) + return; + + cmd += SLC_STATE_BE_RXCNT_LEN + SLC_CMD_LEN + 1; + cmd[SLC_STATE_BE_TXCNT_LEN] = 0; + if (kstrtou32(cmd, 10, &txerr)) + return; + + *cmd = 0; + cmd -= SLC_STATE_BE_RXCNT_LEN; + if (kstrtou32(cmd, 10, &rxerr)) + return; + + skb = alloc_can_err_skb(dev, &cf); + if (skb) { + cf->data[6] = txerr; + cf->data[7] = rxerr; + } else { + cf = NULL; + } + + tx_state = txerr >= rxerr ? state : 0; + rx_state = txerr <= rxerr ? state : 0; + can_change_state(dev, cf, tx_state, rx_state); + + if (state == CAN_STATE_BUS_OFF) + can_bus_off(dev); + + if (skb) + netif_rx(skb); +} + /* An error frame can contain more than one type of error. * * Examples: @@ -387,6 +457,8 @@ static void slc_bump(struct slcan *sl) return slc_bump_frame(sl); case 'e': return slc_bump_err(sl); + case 's': + return slc_bump_state(sl); default: return; }