Hi Mark,

The problem is that our used regulator TPS65273V from TI do not have the 
possibility to read the current voltage defined by the HW, means by the circuit 
of the regulator.
In this case the register holding the voltage to be set later by software has a 
reset value which is normally the min value the regulator can support. This 
value can be out of the range of the supported rail. Therefore before the 
regulator gets registered this register needs to be set with a 'good' value.
I assume the only practicable solution will be that we initialize this voltage 
register in the boot code where we also set the CPU frequency.
BR Thomas

-----Original Message-----
From: Mark Brown [mailto:[email protected]] 
Sent: Friday, June 30, 2017 14:15
To: Waldemar Rymarkiewicz <[email protected]>
Cc: [email protected]; Liam Girdwood <[email protected]>; 
Bartholomae, Thomas <[email protected]>
Subject: Re: Where to update regulator register with initial voltage set by HW

On Fri, Jun 30, 2017 at 01:37:32PM +0200, Waldemar Rymarkiewicz wrote:

> I am not sure if I understand. Do you mean, a regulator should 
> determine a voltage and update a register with a right selector when 
> system boots, so the regulator framework reading reg register knows 
> actual voltage?

Just don't provide a default value for the cache, regmap will do a physical 
read if there's nothing in the cache for that register and everything will work 
transparently.

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