Re: Where to update regulator register with initial voltage set by HW

From	Waldemar Rymarkiewicz <waldemar.rymarkiewicz@gmail.com>
Newsgroups	linux.kernel
Subject	Re: Where to update regulator register with initial voltage set by HW
Date	2017-07-03 17:40 +0200
Message-ID	<tZbC9-3oO-3@gated-at.bofh.it> (permalink)
References	(1 earlier) <tY1ER-4os-9@gated-at.bofh.it> <tY2rh-4Tg-23@gated-at.bofh.it> <tY33Y-5nU-13@gated-at.bofh.it> <tY3dE-5r3-3@gated-at.bofh.it> <tZbiP-3ib-49@gated-at.bofh.it>
Organization	linux.* mail to news gateway

Show all headers | View raw

On 3 July 2017 at 17:11, Mark Brown <broonie@kernel.org> wrote:
> On Fri, Jun 30, 2017 at 12:26:52PM +0000, Bartholomae, Thomas wrote:
>> 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.
>
> You probably need platform data to tell the kernelw hat teh startup
> value is.

I've asked also on TI forum if this is typical to the regulator not to
determine the startup voltage but still waiting for feedback. Anyway,
if this is the case I guess a driver is a good place to update
register before we register to the regulator framework.

Thanks Mark for your feedback.

/Waldek

Thread

Where to update regulator register with initial voltage set by HW Waldemar Rymarkiewicz <waldemar.rymarkiewicz@gmail.com> - 2017-06-29 09:20 +0200
  Re: Where to update regulator register with initial voltage set by HW Mark Brown <broonie@kernel.org> - 2017-06-30 12:50 +0200
    Re: Where to update regulator register with initial voltage set by HW Waldemar Rymarkiewicz <waldemar.rymarkiewicz@gmail.com> - 2017-06-30 13:40 +0200
      Re: Where to update regulator register with initial voltage set by HW Mark Brown <broonie@kernel.org> - 2017-06-30 14:20 +0200
        RE: Where to update regulator register with initial voltage set by  HW "Bartholomae, Thomas" <t.bartholomae@intel.com> - 2017-06-30 14:30 +0200
          Re: Where to update regulator register with initial voltage set by HW Mark Brown <broonie@kernel.org> - 2017-07-03 17:20 +0200
            Re: Where to update regulator register with initial voltage set by HW Mark Brown <broonie@kernel.org> - 2017-07-03 17:40 +0200
              Re: Where to update regulator register with initial voltage set by HW Waldemar Rymarkiewicz <waldemar.rymarkiewicz@gmail.com> - 2017-07-04 13:00 +0200
                Re: Where to update regulator register with initial voltage set by HW Mark Brown <broonie@kernel.org> - 2017-07-04 13:30 +0200
            Re: Where to update regulator register with initial voltage set by HW Waldemar Rymarkiewicz <waldemar.rymarkiewicz@gmail.com> - 2017-07-03 17:40 +0200
        Re: Where to update regulator register with initial voltage set by HW Waldemar Rymarkiewicz <waldemar.rymarkiewicz@gmail.com> - 2017-06-30 17:30 +0200

csiph-web