Re: [PATCH 3/4] arm: am33xx: DT quirks for am33xx based beaglebone variants

From: Tony Lindgren
Date: Thu Feb 19 2015 - 13:41:59 EST


* Pantelis Antoniou <panto@xxxxxxxxxxxxxxxxxxxxxxx> [150219 10:32]:
> > On Feb 19, 2015, at 20:16 , Tony Lindgren <tony@xxxxxxxxxxx> wrote:
> >
> > Uhh I don't like the idea of duplicating the i2c-omap.c driver under
> > arch/arm.. And in general we should initialize things later rather
> > than earlier.
> >
> > What's stopping doing these quirk checks later on time with just
> > a regular device driver, something like drivers/misc/bbone-quirks.c?
> >
>
> We have no choice; we are way early in the boot process, right after
> the device tree unflattening step.

To me it seems the dt patching part should be done with minimal
code before any driver like features..

> Iâve toyed with the idea of using early platform devices but the omap-i2c driver
> would need some tender love and care to make it work, and I didnât want to get
> bogged down with i2c driver details at this point.

..so how about just parse a kernel cmdline for the quirks to apply
based on a version string or similar? That can be easily populated
by u-boot or set manually with setenv.

That leaves out the need for tinkering with i2c super early in
the kernel for revision detection.

Regards,

Tony
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