Thread (7 messages) flat view 7 messages, 6 authors, 2008-01-14

Re: I2C and CAN bus on MPC5200B device tree

From: Wolfgang Grandegger <hidden>
Date: 2008-01-14 08:10:01

Grant Likely wrote:
On 1/13/08, Matt Sealey [off-list ref] wrote:
quoted
Hi guys,

I know the I2C stuff is up in the air (I cannot pinpoint the documentation
for it) and have not found any CAN bus documentation for device trees.

I want to update the firmware tree to add these but, am basically looking
for those docs, or someone to go over a few points.. is there some kind of
tree standard I should be looking at, or some patch I missed which has
a driver which implements something that looks at a compatible tree?
I think some consensus has been achieved for describing i2c busses and
their attached devices, but I don't think booting-without-of.txt has
been updated with the details yet.  I need to look into that more.

I don't think anyone has tackled CAN.  Best bet is to draft a tree in
the way you think it should be described and post it to the list.
That will give a starting point for us to discuss it and come to
consensus.
For MSCAN on the MPC5200 we currently have:

		mscan@900 {
			device_type = "mscan";
			compatible = "mpc5200b-mscan","mpc5200-mscan";
			cell-index = <0>;
			interrupts = <2 11 0>;
			interrupt-parent = <&mpc5200_pic>;
			reg = <900 80>;
		};

		mscan@980 {
			device_type = "mscan";
			compatible = "mpc5200b-mscan","mpc5200-mscan";
			cell-index = <1>;
			interrupts = <2 12 0>;
			interrupt-parent = <&mpc5200_pic>;
			reg = <980 80>;
		};

The only thing missing is a property defining the routing of the CAN
signals, CAN 1 on I2C1 pins or CAN 2 on TMR01 pins. I think it does not
make sense to describe CAN devices on the CAN bus like for I2C.

Wolfgang.
Keyboard shortcuts
hback out one level
jnext message in thread
kprevious message in thread
ldrill in
Escclose help / fold thread tree
?toggle this help