RE: Discussion: OMAP: PM: opp table handling

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>From: Pandita, Vikram
>
>
>Proposals for OPP table handling for OMAP34xx/35xx/36xx/44xx
>
>Thanks to all the community members for taking time for this discussion.
>This will aid upsteaming of 35xx/36xx/44xx in coming future.
>
>Attendees: Kevin Hilman, Paul, Nishant M, Santosh, Madhu, Benoit, Rajendra,
>Benoit, Vikram
>
>Problem Statement:
>	OMAP34xx has certain opp requirements (3420/3430/3440)
>	OMAP35xx reuses the opp's from 34xx
>	OMAP36xx has a totally new set of opps
>	OMAP44xx has a totally new set of opps
>
>Solution:
>	Align on a common approach to take for the Opp table definitions.
>
>Define Separate Tables for each family as follows:
>Step 1: Go with this approach:
>	3420(65nm) 		: new arrays [defer for now]
>	3430/35xx(65nm) 	: new arrays **
>	3440(65nm) 		: new arrays [defer for now]
>	3630(45nm) 		: new arrays
>	Omap4(45nm)		: new arrays
>
>	* new arrays = (mpu, dsp, l3)
>	** Check this valid flag. Kevin can take this base on comments
>		http://marc.info/?l=linux-omap&m=125512448216071&w=2
>		between 3430/35xx, opp's can be managed with a flag and same
>table re-used
>		35xx has requirement for 720Mhz opp
>
>Step 2:
>Kevin suggestion:
>Define accessor APIs get the OPPs
>Check Users of accessor API
>	DVFS
>	constraints
>	sysfs debug
>	Define accessor api's eg:
>		index = get_opp(VDD1_OPP1);
>		num = get_max_opp(VDD1);
>		set_opp(index);

I think we should as well change the naming and use the less confusing naming we are using on OMAP3630/4430. 
OPPs are now named using the performance delta from the nominal frequency.
OPP25, OPP50, OPP80, OPP100, OPP120... 

Regards,
Benoit

>Step 3:
>	Paul suggestion:
>	VSEL values in opp table should be in terms of voltage
>	Non TWL IC's need this
>
>Step4:
>	Paul suggestion:
>	VDD1 VDD2 dependencies for different chips
>	Inter-connect load predictor is absent on omap3 and hence VDD1-vdd2
>dependency
>	OMAP4
>		interconnect loading can be measured from registers
>		Multi-cores dependency
>
>Step 5:
>	Paul suggestion:
>	Board files adding OPPs, Modifying OPPs
>	Eg: Pendora passing its own opp



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