Re: [PATCH v3 2/2] soc: Add driver for Freescale Vybrid Platform

From: maitysanchayan
Date: Mon May 25 2015 - 06:20:27 EST


Hello Arnd,

On 15-05-22 15:20:00, Arnd Bergmann wrote:
> On Friday 22 May 2015 14:02:52 Stefan Agner wrote:
> > > Can you use syscon_regmap_lookup_by_phandle instead, and put the
> > > phandles in the fsl,vf610-mscm-cpucfg node?
> >
> > Hm, with that we would wire up hardware modules which does nothing has
> > to do with each other. We just happen to need a driver which collects
> > information accross the SoC. I'm not sure we should put the modules
> > required into the device tree.
> >
> > I don't think its nice to have the compatible strings in the source
> > code, however it feels more appropriate than in the device tree, IMHO...
>
> I see. Another option would be to point directly to the registers
> you need:
>
> ocotp-cfg0 = <&ocotp 0x10>;
> ocotp-cfg1 = <&ocotp 0x20>;
> rom-revision = <&rom 0x80>;
>
> We don't yet have an abstraction to access a register from a syscon
> reference like this, but you could either roll your own here, or
> add a generic abstraction.

Can you tell me a little about how can I start implementing it? I am not
clear on how to approach this.

>
> > > Also, I'd argue that the mscm should not be a syscon device at all,
> > > but instead I'd use platform_get_resource()/devm_ioremap_resource()
> > > to get an __iomem pointer.
> >
> > We need to have mscm-cpucfg to be syscon because we need to get the CPU
> > personality in the MSCM interrupt router driver (irq-vf610-mscm-ir.c).
>
> It can be both at the same time now.
>
> Arnd

Regards,
Sanchayan.
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