On Jan 29, 2008, at 23:10, Russell McGuire wrote:

All,

I have gotten my HDLC driver up to the point where it can register  
itself
with the Linux kernel. However now I am faced with a dilemma and style
question, that is probably best answered by you driver developers  
that have
more experience.

I am putting support for multiple PHY's into the HDLC driver, but  
after
converting it to use the of_device tree, and inserting a UCC@5000  
for a
single UCC HDLC driver, it occurred to me that if I insert more  
devices
(UCC@6000, UCC@7000, UCC@8000) that the driver will attempt to load  
multiple
times.

There is already a mechanism to ensure modules aren't loaded again  
when a new device is found.  Look at the gianfar support again.  The  
mpc8548 CDS has 4 eTSEC devices and one driver which handles them all  
(gianfar).  The driver is initialized once.  The probe function will  
be called for each instance of the device.  You need to make sure  
your driver's probe function can be called once per device.

Solution 3:
Have phy-count=4; defined in the driver header, or a module  
parameter, and
have a single module instance of the driver itself responsible for  
creating
a single private data structure and setting up multiple UCC's and  
PHY's?

No, please.  If the PHYs aren't discoverable, you might need  
something like that.  But I suspect you just have one PHY per  
device.  If you have more, how is that configured?  Is the hardware  
aware of the number of PHYs?  Or are you just selecting between  
different PHY addresses?

This also feeds into a question on SET_NETDEV_DEV. How does it  
react to
multiple net devices attached to a single base driver?

SET_NETDEV_DEV declares the base *device* of the net device.  The  
driver is a separate issue.  And it shouldn't be a problem, because  
each device instance has its own private structure.

Andy