[PATCHv5] omap3: Add basic support for 720MHz part

[Laurent Pinchart]

Hi Nishanth,

On Friday 07 February 2014 07:51:00 Nishanth Menon wrote:
> On Thu, Feb 6, 2014 at 1:26 PM, Laurent Pinchart wrote:
> > On Friday 22 June 2012 11:33:51 Laurent Pinchart wrote:
> >> On Thursday 10 February 2011 08:45:00 Kevin Hilman wrote:
> >> > Sanjeev Premi <premi at ti.com> writes:
> >> > > This patch adds support for speed enhanced variant of OMAP35x
> >> > > processors. These parts allow ARM and IVA running at 720MHz
> >> > > and 520MHz respectively.
> >> > > 
> >> > > These parts can be detected at runtime by reading contents of
> >> > > PRODID.SKUID[3:0] at 0x4830A20C [1].
> >> > > 
> >> > > This patch specifically does following:
> >> > >  * Add new OPP to omap34xx_opp_def_list[] - disabled by default.
> >> > >  * Detect devices capable of running at new OPP.
> >> > >  * Enable new OPP only if device supports it.
> >> > >  * Check for presence of IVA before attempting to enable the
> >> > >    corresponding OPP.
> >> > >   
> >> > >   [1] http://focus.ti.com/lit/ug/spruff1d/spruff1d.pdf
> >> > > 
> >> > > It appears from discussions (on this patch) that a variant of
> >> > > OMAP3430 supports this OPP but lacks runtime detection. This
> >> > > OPP can be enabled for these device by either:
> >> > >  1) Setting the bit corresponding to OMAP3_HAS_720MHZ
> >> > >     in 'omap3_features'. (Refer changes to id.c)
> >> > >  
> >> > >  2) Removing check for omap3_has_720mhz() before enabling
> >> > >     the OPP. (Refer changes to opp3xxx_data.c)
> >> > >  
> >> > >  3) Calling opp_enable() for 720MHz/VDD1 and 520MHz/VDD2 in
> >> > >     the board file. (Refer changes to opp3xxx_data.c).
> >> > >     This should, ideally, be done before omap3_opp_init() is
> >> > >     called during device_initcall().
> >> > > 
> >> > > CAUTION: This should be done for identified parts only.
> >> > >          Else, the device could be damaged permanently.
> >> > > 
> >> > > Signed-off-by: Sanjeev Premi <premi at ti.com>
> >> > > Reviewed-by: G, Manjunath Kondaiah <manjugk at ti.com>
> >> > 
> >> > Acked-by: Kevin Hilman <khilman at ti.com>
> >> 
> >> This patch seems to never have made it upstream. Is there a reason for
> >> that
> >> ?
> > 
> > Ping ?
> 
> We'd have to figure out a proper opp modifier logic with device tree.
> considering that non-dt boot is slowly getting dismantled in mach-omap2, to
> add new capabilities in non-dt is not really a good idea at this point in
> time - Further, we do have equivalent requirements in other TI SoCs as well 

Good point, but I'm not sure to see where this patch is specific to legacy 
boot. The two functions it modifies, and omap3xxx_check_features() and 
omap3_opp_init(), are called for DT boot as well.

-- 
Regards,

Laurent Pinchart