lkml.org 
[lkml]   [2022]   [Jun]   [8]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
Subject[PATCH v2 00/13] can: slcan: extend supported features
Date
This series originated as a result of CAN communication tests for an
application using the USBtin adapter (https://www.fischl.de/usbtin/).
The tests showed some errors but for the driver everything was ok.
Also, being the first time I used the slcan driver, I was amazed that
it was not possible to configure the bitrate via the ip tool.
For these two reasons, I started looking at the driver code and realized
that it didn't use the CAN network device driver interface.

Starting from these assumptions, I tried to:
- Use the CAN network device driver interface.
- Set the bitrate via the ip tool.
- Send the open/close command to the adapter from the driver.
- Add ethtool support to reset the adapter errors.
- Extend the protocol to forward the adapter CAN communication
errors and the CAN state changes to the netdev upper layers.

Except for the protocol extension patches (i. e. forward the adapter CAN
communication errors and the CAN state changes to the netdev upper
layers), the whole series has been tested under QEMU with Linux 4.19.208
using the USBtin adapter.
Testing the extension protocol patches requires updating the adapter
firmware. Before modifying the firmware I think it makes sense to know if
these extensions can be considered useful.

Before applying the series I used these commands:

slcan_attach -f -s6 -o /dev/ttyACM0
slcand ttyACM0 can0
ip link set can0 up

After applying the series I am using these commands:

slcan_attach /dev/ttyACM0
slcand ttyACM0 can0
ip link set dev can0 down
ip link set can0 type can bitrate 500000
ethtool --set-priv-flags can0 err-rst-on-open on
ip link set dev can0 up

Now there is a clearer separation between serial line and CAN,
but above all, it is possible to use the ip and ethtool commands
as it happens for any CAN device driver. The changes are backward
compatible, you can continue to use the slcand and slcan_attach
command options.


Changes in v2:
- Put the data into the allocated skb directly instead of first
filling the "cf" on the stack and then doing a memcpy().
- Move CAN_SLCAN Kconfig option inside CAN_DEV scope.
- Improve the commit message.
- Use the CAN framework support for setting fixed bit rates.
- Improve the commit message.
- Improve the commit message.
- Protect decoding against the case the len value is longer than the
received data.
- Continue error handling even if no skb can be allocated.
- Continue error handling even if no skb can be allocated.

Dario Binacchi (13):
can: slcan: use the BIT() helper
can: slcan: use netdev helpers to print out messages
can: slcan: use the alloc_can_skb() helper
can: slcan: use CAN network device driver API
can: slcan: simplify the device de-allocation
can: slcan: allow to send commands to the adapter
can: slcan: set bitrate by CAN device driver API
can: slcan: send the open command to the adapter
can: slcan: send the close command to the adapter
can: slcan: move driver into separate sub directory
can: slcan: add ethtool support to reset adapter errors
can: slcan: extend the protocol with error info
can: slcan: extend the protocol with CAN state info

drivers/net/can/Kconfig | 40 +-
drivers/net/can/Makefile | 2 +-
drivers/net/can/slcan/Makefile | 7 +
.../net/can/{slcan.c => slcan/slcan-core.c} | 526 ++++++++++++++----
drivers/net/can/slcan/slcan-ethtool.c | 65 +++
drivers/net/can/slcan/slcan.h | 18 +
6 files changed, 539 insertions(+), 119 deletions(-)
create mode 100644 drivers/net/can/slcan/Makefile
rename drivers/net/can/{slcan.c => slcan/slcan-core.c} (65%)
create mode 100644 drivers/net/can/slcan/slcan-ethtool.c
create mode 100644 drivers/net/can/slcan/slcan.h

--
2.32.0

\
 
 \ /
  Last update: 2022-06-08 18:57    [W:0.102 / U:2.784 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site