From mboxrd@z Thu Jan  1 00:00:00 1970
From: pawel.moll@arm.com (Pawel Moll)
Date: Tue, 18 Sep 2012 18:03:39 +0100
Subject: [PATCH v2 04/13] regulators: Versatile Express regulator driver
In-Reply-To: <20120918160909.GA15587@opensource.wolfsonmicro.com>
References: <1347977875-16855-1-git-send-email-pawel.moll@arm.com>
 <1347977875-16855-5-git-send-email-pawel.moll@arm.com>
 <20120918150212.GA12543@opensource.wolfsonmicro.com>
 <1347983056.11116.11.camel@hornet>
 <20120918160909.GA15587@opensource.wolfsonmicro.com>
Message-ID: <1347987819.11116.38.camel@hornet>
To: linux-arm-kernel@lists.infradead.org
List-Id: linux-arm-kernel.lists.infradead.org

On Tue, 2012-09-18 at 17:09 +0100, Mark Brown wrote:
> On Tue, Sep 18, 2012 at 04:44:16PM +0100, Pawel Moll wrote:
> 
> > Well, that's what it really is. The config API sends a request "set xyz
> > uV" to the microcontrollers. And the micro can (at least in theory) get
> > you any voltage within the min/max limits by whatever means it has (at
> > least some of the daugtherboards use micro's DAC to adjust reference
> > voltage for a DC/DC converter with a feedback loop using ADC).
> 
> And the microcontroller is incapable of telling us what it supports, 

No, there is no such . Device Tree defines per-device min/max
constraints and any value between these values should be supported.

> or even what's physically present?

You mean read back what voltage is set now? By all means - that's what
it is doing for "read only" devices.

> > But fair enough, I should have done better work in describing this.
> 
> So this is going to break interoperation with a bunch of consumer
> drivers that rely on being able to tell what voltages are supported.
> The key thing for them would be that regulator_is_supported_voltage()
> works, currently it relies on list_voltage() as that's the only way to
> do that right now.

Ok, I guess I should use regulator_list_voltage_linear() and
regulator_map_voltage_linear() then? I'll just have to carefully think
what step to choose.

> > v3 to follow.
> 
> v3?  I didn't see V2.  Please also CC posts to the relevant mailing
> lists for the subsystem (lkml in this case).

Sure, will do.

Pawel