Premi, Sanjeev wrote, on 03/08/2011 05:56 PM:
[...]
Add glue logic to hook-up AM35x processors
with TPS65023.
It seems that you are not really using Voltage layer for any
interaction
with TPS65023 as you are not using VP and VC. Then what is the
purpose of
registering this PMIC with Voltage layer. I fail to understand the
purpose
of this patch series.
[sp] Then, can you suggest how do I get the AM35x EVM to boot? Given
the
current limitation of all voltage related data being "extracted"
from
the voltage layer - which expects only TWLx0y0 PMICs.
Pls use regulator framework for setting the voltage for your PMIC.
[sp] If you follow the current framework, voltage.c is ingrained with
OMAP3 initialization and same holds good for opp[_3xxx_data].c.
It would have been great if current implementation allowed pluggable
interface to a PMIC. As it stands today, it isn't.
Partly true - there are PMIC abstractions that have been attempted in
current voltage layer - but only TWL is used - so yep, implementation
probably needs evolution and yes again that TPS here is a perfect choice
to make the implementation generic and scalable.
Until implemented, workarounds have to be put in place to get platform(s)
working. Though patch series is being done for AM35x with TPS65023. The
similar workaround would be required for OMAP3 with TPS65023 (for example).
...and I expect workaround to be simple and unobtrusive.
See:
core_initcall(omap_voltage_early_init);
device_initcall(omap3_opp_init);
late_initcall(omap2_common_pm_late_init);
Thinking from a generic soln perspective, lets try and split this into
multiple issues:
a) OPP and Voltage layer voltages - these need to be PMIC aware as well.
See my comment on http://marc.info/?l=linux-omap&m=129955003611548&w=2
-> essentially means that pmic_voltage information should be registered
earlier to opp init
b) split up structure information for voltage layer - this should be
done in a manner to make PMIC, Board and OMAP SoC information independent.
c) Ability to plug in multiple PMICs in two manners:
i) use PMIC with VC/VP/SR combinations.
ii) use PMIC which is plugged on regulator frameworks.
If anyone is attempting cleanups, it might be a good idea to base on the
accepted cleanups from pm-core branch which is planned for 39-rc1 to
prevent any surprises ;)
--
Regards,
Nishanth Menon
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