[PATCH v2] 8xx: Add support for the MPC852 based board from keymile.

Scott Wood scottwood at freescale.com
Wed Mar 19 03:56:37 EST 2008


Wolfgang Denk wrote:
> Dear Scott,
> 
> in message <20080318151132.GA17402 at ld0162-tx32.am.freescale.net> you wrote:
>> Well, the device tree is a mechanism for communicating from the firmware
>> to the kernel, and if we could control the firmware better we'd just make
>> it set the pins properly to begin with. :-)
> 
> Is this just a comment, or do you oppose Heiko's suggestion?

It was intended more as a gentle nudge to set up the pins in firmware 
when not constrained by existing firmwares in the field that must be 
supported.

> Other uses of the device tree seem possible and reasonable, too.  For
> example, we can use the device tree to configure the firmware (U-Boot
> in this case).
> 
> Using the device tree  to  describe  the  pin  configuration  of  the
> hardware  sounds  easier to me than hard-coding it in some source (or
> header) file - no matter if this is  in  the  kernel  and/or  in  the
> firmware.
> 
> What do you think?

I'm fine with putting it in the device tree for firmware's benefit, 
though I'm not sure I fully agree with the "easier" bit until we get 
support for expressions and named constants in dts, so that the flags 
would be less opaque.

-Scott



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