Sean
On 11/27/19 12:40 AM, Sean Nyekjaer wrote:
On 26/11/2019 17.55, Dan Murphy wrote:
Let me check with our HW guys here to see if that is acceptable.
If it is we will need to update the DT doc and the code.
Got a response and it reminded me why I made it required. Can't
control CAN activity and did not want to reset the chip every time I
need to do a SPI write/read. So you might want to think about having
the HW guys wire up the wake up line.
The device looks for a transition to wake up. It should be OK to wire
it to ground, I believe. It will not stay awake, but note that once
you put it to sleep, your only option to wake it will be
1) CAN activity (out of your control)
2) Reset pin toggle
Dan
Hi Dan,
I could get them to wire the WAKE line, but not in the first batch I
have received.
We have wired the nWKRQ for wake-on-can, but I suspect it's linked to
sleep mode. :-S
Does the CAN transceiver go into sleep mode by it self? Or is it
something in the driver that does that?
Or only when suspending?
(I can't find it in the datasheet or driver)
I guess this have confused the hw guys:
Section "8.3.6 WAKE Pin" in the datasheet states:
"If local wake-up functionality is not needed in the end application,
WAKE can be tied directly to V SUP or GND."
and it can be controlled by setting the following bits: 16'h0800[31:30]
That would be a driver enhancement to disable wake config.
I just quickly did a patch to make the wake config pin optional and if
the wake pin is not defined disable the wake up to being disabled.
I will RFC it after I test it for your testing.
Dan
/Sean
