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Date: Fri, 3 May 2024 10:37:31 +0900
From: Mark Brown <broonie@kernel.org>
To: Alina Yu <alina_yu@richtek.com>
Cc: lgirdwood@gmail.com, linux-kernel@vger.kernel.org,
	johnny_lai@richtek.com, cy_huang@richtek.com
Subject: Re: [PATCH v2 2/4] regulator: rtq2208: Fix LDO to be compatible with
 both fixed and adjustable vout
Message-ID: <ZjQ_2_tywLZ5EaM-@finisterre.sirena.org.uk>
References: <cover.1714467553.git.alina_yu@richtek.com>
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On Thu, May 02, 2024 at 03:30:29PM +0800, Alina Yu wrote:
> On Wed, May 01, 2024 at 11:19:05AM +0900, Mark Brown wrote:
> > On Tue, Apr 30, 2024 at 05:58:25PM +0800, Alina Yu wrote:

> > > +		if (init_data->constraints.min_uV == init_data->constraints.max_uV) {
> > > +			desc->n_voltages = 1;
> > > +			desc->fixed_uV = init_data->constraints.min_uV;
> > > +			desc->ops = &rtq2208_regulator_ldo_fix_ops;
> > > +		} else {
> > > +			desc->n_voltages = ARRAY_SIZE(rtq2208_ldo_volt_table);
> > > +			desc->volt_table = rtq2208_ldo_volt_table;
> > > +			desc->ops = &rtq2208_regulator_ldo_adj_ops;
> > > +		}

> > Why are you making this change?  The operations supported by the
> > regulator don't change depending on if the system is going to chnage the
> > voltage.

> The change is necessary due to the requirement of the SD card for high/default and ultra-high-speed modes. The system needs to adjust the LDO Vout accordingly.
> In ultra-high-speed mode, the LDO Vout needs to be adjusted to 1.8V; otherwise, it will remain at 1.8V.

That just sounds like normal constraints usage, and something that
applies to a wide variety of systems not just this specific regulator.
If there are limits on what voltages can be configured the constraints
will enforce them.

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