From c4e54b063f42f20a6b3ad1ffa61c574e631e0216 Mon Sep 17 00:00:00 2001 From: Dario Binacchi Date: Tue, 28 Jun 2022 18:31:29 +0200 Subject: 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 ++++++++++++++++++++-------------------- 1 file changed, 20 insertions(+), 20 deletions(-) (limited to 'drivers/net/can/Kconfig') 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 -- cgit