> -----Original Message-----
> From: Pandita, Vikram 
> Sent: Wednesday, October 14, 2009 1:53 AM
> To: linux-omap@vger.kernel.org
> Cc: Kevin Hilman; Menon, Nishanth; Nataraju, Kiran; Premi, 
> Sanjeev; Shilimkar, Santosh; Chikkature Rajashekar, 
> Madhusudhan; Tony Lindgren; Sawant, Anand; Joshi, Rhishi; 
> Giles, Rick; Sripathy, Vishwanath; Paul Walmsley; Cousson, 
> Benoit; Nayak, Rajendra
> Subject: Discussion: OMAP: PM: opp table handling
> 
> 
> 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
[sp] Adding myself to attendees
~sanjeev

> 
> 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);
> 
> 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 
> 
> 
> Regards,
> Vikram 
> --
To unsubscribe from this list: send the line "unsubscribe linux-omap" in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Reply via email to