1. Set and get CAN device properties like bit-rate and controller mode.The first points sound pretty regular. The last one - just triggering
2. Show CAN bus state (active, error-passive or bus-off).
3. Get device constants like clock frequency and bit-timing parameters.
4. Dump CAN device statistics.
5. Trigger device restart if CAN bus-off state has been detected.
Not sure yet, if the interface if good for all purposes. Especially
point 5. might be better handled by an IOCTL.
it is no problem of course, but since I don't know how the detection
works, I can't really tell whether its suitable.
CAN errors and state changes might be delivered as CAN error messages to
the receiving socket/application, like normal messages. When the
application realizes the state change to CAN bus-off, it may want to
trigger a bus-off recovery (controller restart). The CAN controller HW
enters bus-off, when too much errors occurred on the bus. No more
messages can then be sent of received and therefore the driver calls
netif_carrier_off(). Is there already an interface for the user to
restart? An appropriate IOCTL request would be a simply option, but they
are generally deprecated, AFAIK. Using netlink would be more cumbersome,
as with SYSFS.
And we need a user spaceThats pretty standard :)
tool, e.g. canconfig, to handle the user requests and communicate with
the kernel side.
For the iproute2 utility "ip", mainliy a netlink_can.c would be
required. But a dedicated tool for CAN seems more appropriate to me.