Hi,
On Fri, Aug 20, 2010 at 07:47:07AM +0200, ext Gadiyar, Anand wrote:
The differences between OMAP3 and OMAP4 are:
- The OMAP4 has a different set of clocks which do not exist on OMAP3.
- The register bits for configuring port modes is different
is it a different ip core or just a modification of the previous ?
For the clock handling:
One approach: On OMAP3, have a set of dummy clocks corresponding to the
per-port clocks on OMAP4. Then the driver wouldn't need to know which
SoC it is running on.
Another approach:
Have a different glue layer driver for OMAP4.
For the register bit differences, we do need to know which SoC we are
running on to be able to use the correct register bits. For this,
isn't the ehci ip revision different ? Why don't you use that instead of
cpu_is_omap*
One approach:
At the very minimum, we need a set of clocks to be enabled to be able to
read the UHH_REVISION register, and we could use that to figure out which
bits we need to use.
exactly
The other approach I can think of is to have platform data tell us (I'm
guessing this is a bad idea).
yeah, that would be bad...
What do you think?
another approach:
make ohci and ehci play well together have an omap3-specific and one
omap4-specific MFD-like driver that will instantiate ehci and ohci
platform_drivers and handle clock + locking to shared address space.
then you define a set of accessor functions for registers with different
offset that act differently depending on revision of the ip core.
Does that work ?
--
balbi
DefectiveByDesign.org
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