[RFC 2/4] ARM: dts: Add ctrl-core DT node for DRA7

Archit Taneja archit at ti.com
Sun Apr 20 22:15:28 PDT 2014


On Friday 18 April 2014 10:48 PM, Tony Lindgren wrote:
> * Archit Taneja <archit at ti.com> [140416 06:20]:
>> Add DT node for the ctrl-core sub module of the DRA7 control module. We map the
>> CTRL_MODULE_CORE address region up to 0x4a002d60, this region contains register
>> fields which configure clocks. The remainder of the registers are related to
>> pad configurations or cross-bar configurations, and therefore aren't mapped.
> Can you please check if this can just use the existing
> regmap syscon mapping:
> syscon = <&dra7_ctrl_general>;
> See how the drivers/regulator/pbias-regulator.c is using the
> syscon to initialize a regulator and then omap_hsmmc.c just does
> the standard regulator calls.

The thing is that this bit needs to be set before the the DSS hwmods are 
reset, and that happens very early. If we don't do this, DSS won't reset 
properly, and not get back to an idle state.

I am not sure where I can configure the syscon register early enough 
that it happens before the hwmods are reset. With a syscon mapping, I 
guess we would access the register when the DSS driver is probed. But 
that's too late for us.

Ideally, it would be much better to have a syscon mapping. Do you have 
any suggestions how this can be achieved very early in boot?


> Depending what the range 0x4a002000 0x6d0 contains, you may
> want to set it up as another syscon area.
> Regards,
> Tony

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