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From: Marco Felsch <m.felsch@pengutronix.de>
To: Adam Thomson <Adam.Thomson.Opensource@diasemi.com>
Cc: "devicetree@vger.kernel.org" <devicetree@vger.kernel.org>,
	Support Opensource <Support.Opensource@diasemi.com>,
	"linux-aspeed@lists.ozlabs.org" <linux-aspeed@lists.ozlabs.org>,
	"linux-gpio@vger.kernel.org" <linux-gpio@vger.kernel.org>,
	"andrew@aj.id.au" <andrew@aj.id.au>,
	"linus.walleij@linaro.org" <linus.walleij@linaro.org>,
	"lgirdwood@gmail.com" <lgirdwood@gmail.com>,
	"robh+dt@kernel.org" <robh+dt@kernel.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	"bgolaszewski@baylibre.com" <bgolaszewski@baylibre.com>,
	Mark Brown <broonie@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 10:12:36 +0100
Message-ID: <20191217091236.GA15806@pengutronix.de> (raw)
In-Reply-To: <20191217090034.GD31182@pengutronix.de>

On 19-12-17 10:00, Marco Felsch wrote:
> On 19-12-16 16:32, Adam Thomson wrote:
> > On 16 December 2019 08:55, Marco Felsch wrote:
> > 
> > > On 19-12-12 16:51, Mark Brown wrote:
> > > > On Thu, Dec 12, 2019 at 05:21:53PM +0100, Marco Felsch wrote:
> > > >
> > > > > "... what's driving the input ..":
> > > > > Sorry I didn't get you here. What did you mean? The input is driven by
> > > > > the host. This can be any gpio line and in my case it is a gpio line
> > > > > driven by the soc-hw during a suspend operation.
> > > >
> > > > Something needs to say what that thing is, especially if it's runtime
> > > > controllable.  In your case from the point of view of software there is
> > > > actually no enable control so we shouldn't be providing an enable
> > > > operation to the framework.
> > > 
> > > 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:
> 
>   if (gpi->flags & FLAG_IS_OUT)
>   	return -EINVAL;

Sorry didn't noticed that the flags are only used internally. The
correct check must be:

	/* GPIO must be configured as input */
	if (!gpiod_get_direction(gpi)) {
		ret = -EINVAL;
		goto free;
	}

> 
> Regards,
>   Marco
> 
> > > 
> > > [1] https://www.dialog-
> > > semiconductor.com/sites/default/files/da9062_datasheet_3v6.pdf
> > > 
> > > Regards,
> > >   Marco
> > > 
> > > > _______________________________________________
> > > > linux-arm-kernel mailing list
> > > > linux-arm-kernel@lists.infradead.org
> > > > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
> > 
> > _______________________________________________
> > linux-arm-kernel mailing list
> > linux-arm-kernel@lists.infradead.org
> > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
> > 
> 
> -- 
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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 [this message]
2019-12-17  9:53                       ` Adam Thomson
2019-12-17 12:31                         ` Marco Felsch
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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