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From: Marco Felsch <m.felsch@pengutronix.de>
To: Adam Thomson <Adam.Thomson.Opensource@diasemi.com>
Cc: Mark Brown <broonie@kernel.org>,
	"devicetree@vger.kernel.org" <devicetree@vger.kernel.org>,
	Support Opensource <Support.Opensource@diasemi.com>,
	"linux-aspeed@lists.ozlabs.org" <linux-aspeed@lists.ozlabs.org>,
	"bgolaszewski@baylibre.com" <bgolaszewski@baylibre.com>,
	"andrew@aj.id.au" <andrew@aj.id.au>,
	"linus.walleij@linaro.org" <linus.walleij@linaro.org>,
	"lgirdwood@gmail.com" <lgirdwood@gmail.com>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	"linux-gpio@vger.kernel.org" <linux-gpio@vger.kernel.org>,
	"robh+dt@kernel.org" <robh+dt@kernel.org>,
	"joel@jms.id.au" <joel@jms.id.au>,
	"kernel@pengutronix.de" <kernel@pengutronix.de>,
	"lee.jones@linaro.org" <lee.jones@linaro.org>,
	"linux-arm-kernel@lists.infradead.org" 
	<linux-arm-kernel@lists.infradead.org>
Subject: Re: [PATCH v3 3/6] dt-bindings: mfd: da9062: add regulator voltage selection documentation
Date: Tue, 17 Dec 2019 13:31:16 +0100
Message-ID: <20191217123116.GB29666@pengutronix.de> (raw)
In-Reply-To: <AM5PR1001MB099460B2D291644F088707BA80500@AM5PR1001MB0994.EURPRD10.PROD.OUTLOOK.COM>

On 19-12-17 09:53, Adam Thomson wrote:
> On 17 December 2019 09:01, Marco Felsch wrote:
> 
> > > > The enabel control signal is always available, please check [1] table
> > > > 63. There is a mux in front of the enable pin so:
> > > >
> > > >              +-------------
> > > >  Seq. |\     |   Regulator
> > > >  GPI1 | \    |
> > > >  GPI2 | | -- > Enable
> > > >  GPI3 | /    |
> > > >       |/     .
> > > >              .
> > > >              .
> > > >
> > > > Adam please correct me if this is wrong.
> > >
> > > Yes the register can always be configured regardless of the associated pin
> > > configuration, but if say GPIO1 was configured as a GPO but a regulator was
> > > configured to use GPIO1 as its GPI control mechanism, the output signal from
> > > GPIO1 would be ignored, the sequencer control would not have any effect and
> > > you're simply left with manual I2C control. Really we shouldn't be getting into
> > > that situation though. If a GPIO is to be used as a regulator control signal
> > > then it should be marked as such and I don't think we should be able to use that
> > > pin for anything other than regulator control.
> > 
> > I see, so we have to guarantee that the requested gpio is configured as
> > input. This can be done by:
> 
> This is one of the reasons I thought this was better suited to being done in the
> pinctrl/pinmux side. If you configure the GPIO as for regulator control then
> the code can automatically configure the GPIO for input. That doesn't then need
> to be in the regulator driver.

I still don't prefer that way.. pls check my arguments I already made
and I don't wanna repeat it again.

> But yes we wouldn't really want to configure a regulator to be controlled via a
> GPI when it's configured as a GPO as it makes no sense.

Okay, so the check is all we need to hardening the driver against wrong
usage :)

Regards,
  Marco

> 
> > 
> >   if (gpi->flags & FLAG_IS_OUT)
> >   	return -EINVAL;
> > 
> > Regards,
> >   Marco
> 

-- 
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  reply index

Thread overview: 38+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-11-29 17:25 [PATCH v3 0/6] DA9062 PMIC features Marco Felsch
2019-11-29 17:25 ` [PATCH v3 1/6] gpio: treewide rename gpio_chip_hwgpio to gpiod_to_offset Marco Felsch
2019-12-02  2:59   ` Andrew Jeffery
2019-11-29 17:25 ` [PATCH v3 2/6] gpio: make gpiod_to_offset() available for other users Marco Felsch
2019-12-02  3:00   ` Andrew Jeffery
2019-11-29 17:25 ` [PATCH v3 3/6] dt-bindings: mfd: da9062: add regulator voltage selection documentation Marco Felsch
2019-12-04 13:46   ` Mark Brown
2019-12-10  9:41     ` Marco Felsch
2019-12-11 16:14       ` Adam Thomson
2019-12-11 17:09         ` Marco Felsch
2019-12-12 15:08           ` Linus Walleij
2019-12-12 15:55             ` Marco Felsch
2019-12-12 16:10           ` Mark Brown
2019-12-12 16:21             ` Marco Felsch
2019-12-12 16:51               ` Mark Brown
2019-12-16  8:55                 ` Marco Felsch
2019-12-16 11:44                   ` Mark Brown
2019-12-17  7:35                     ` Marco Felsch
2019-12-17 12:58                       ` Mark Brown
2020-01-07  8:36                         ` Marco Felsch
2020-01-07 13:09                           ` Mark Brown
2020-01-07 13:38                             ` Marco Felsch
2020-01-14 15:43                               ` Mark Brown
2019-12-16 16:32                   ` Adam Thomson
2019-12-17  9:00                     ` Marco Felsch
2019-12-17  9:12                       ` Marco Felsch
2019-12-17  9:53                       ` Adam Thomson
2019-12-17 12:31                         ` Marco Felsch [this message]
2019-12-17 13:13                           ` Adam Thomson
2019-12-16 16:32                   ` Adam Thomson
2019-12-16 12:28               ` Linus Walleij
2019-11-29 17:25 ` [PATCH v3 4/6] regulator: da9062: add voltage selection gpio support Marco Felsch
2019-11-29 17:25 ` [PATCH v3 5/6] dt-bindings: mfd: da9062: add regulator gpio enable/disable documentation Marco Felsch
2019-12-13 22:23   ` Rob Herring
2019-12-16 16:31   ` Lee Jones
2019-11-29 17:25 ` [PATCH v3 6/6] regulator: da9062: add gpio based regulator dis-/enable support Marco Felsch
2019-12-02 11:44 ` [PATCH v3 0/6] DA9062 PMIC features Linus Walleij
2019-12-02 12:04   ` Lee Jones

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