linux-kernel - Re: regulator: tps51632: Seems current code doesn't properly support dvfs_step

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Message-ID: <509228EF.7000307@nvidia.com>
Date:	Thu, 1 Nov 2012 13:16:55 +0530
From:	Laxman Dewangan <ldewangan@...dia.com>
To:	Axel Lin <axel.lin@...ics.com>
CC:	Mark Brown <broonie@...nsource.wolfsonmicro.com>,
	Liam Girdwood <lrg@...com>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: Re: regulator: tps51632: Seems current code doesn't properly support
 dvfs_step_20mV case

On Thursday 01 November 2012 12:18 PM, Axel Lin wrote:
> Hi Laxman,
>
> While reading the tps51632 driver, I found there is a dvfs_step_20mV setting
> in platform data. But seems current code doesn't properly handle the case when
> dvfs_step_20mV is true.
>
> I guess if pdata->dvfs_step_20mV is true, we need:
>
> tps->desc.uV_step = TPS51632_VOLATGE_STEP_20mV;
> Fix TPS51632_VOLT_VSEL macro to support dvfs_step_20mV case.
> Also I'm wondering if either TPS51632_MAX_VSEL/TPS51632_MAX_VOLATGE or
> desc.n_voltages needs change for dvfs_step_20mV case.
>
> Oh, I don't have the datasheet, so my understanding might be wrong.

The steps for voltage and voltage base registers are the 10mV always.
The DVFS steps are used only when the steps (offsets) are provided 
through PWM.

So in DVFS case the  vout = voltage_base + pwm_offset* dvfs_steps.
And voltage_base = min_volt + sel * 10mV.
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