From mboxrd@z Thu Jan 1 00:00:00 1970 From: Anton Vorontsov Subject: Re: [PATCH 1/3] gpio: Add simple poweroff-gpio driver Date: Mon, 12 Nov 2012 10:43:40 -0800 Message-ID: <20121112184340.GA15643@lizard> References: <1352650891-18356-1-git-send-email-andrew@lunn.ch> <1352650891-18356-2-git-send-email-andrew@lunn.ch> <50A020C5.4070506@wwwdotorg.org> <20121112082546.GU22029@lunn.ch> <50A1212C.2080601@wwwdotorg.org> <20121112181947.GS24583@lunn.ch> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: <20121112181947.GS24583-g2DYL2Zd6BY@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: devicetree-discuss-bounces+gldd-devicetree-discuss=m.gmane.org-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org Sender: "devicetree-discuss" To: Andrew Lunn Cc: Jason Cooper , devicetree-discuss-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org, jm-Pj/HzkgeCk7QXOPxS62xeg@public.gmane.org, linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, gmbnomis-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org List-Id: devicetree@vger.kernel.org On Mon, Nov 12, 2012 at 07:19:47PM +0100, Andrew Lunn wrote: [..] > > >>> Given appropriate devicetree bindings, this driver registers a > > >>> pm_power_off function to set a GPIO line high/low to power down > > >>> your board. > > > > >>> diff --git a/Documentation/devicetree/bindings/gpio/gpio-poweroff.txt b/Documentation/devicetree/bindings/gpio/gpio-poweroff.txt > > >> > > >>> +Required properties: > > >>> +- compatible : should be "gpio-poweroff". > > >>> +- gpios : The GPIO to set high/low, see "gpios property" in > > >>> + Documentation/devicetree/bindings/gpio/gpio.txt. If the pin should be > > >>> + low to power down the board set it to "Active Low", otherwise set > > >>> + gpio to "Active High". > > >> > > >> Unfortunately, not all GPIO bindings support active high/low flags in > > >> the GPIO specifier. As such, the flags there are basically useless. > > >> Other bindings (e.g. IIRC the fixed-regulator binding) have added a > > >> separate active-high property to indicate the GPIO polarity. This > > >> binding should probably follow suite. Should the gpio driver fix its bindings then?.. Polarity is a quite generic concept of a GPIO, and flags are there for a reason. I'd rather prefer having stuff-gpios = <0 0 1 0 2 1 3 0>; Rather than stuff-gpios = <0 1 2 3>; stuff-polarity-gpio-map = <0 0 1 0>; The first scheme existed like for years already. Has it been discussed that it is no longer preferred? > > > Humm, so are you saying of_get_named_gpio_flags() is deprecated? > > > > I don't know if it's deprecated, but it's certainly not useful in > > generic code. > > Hi Linus, Anton > > How do you see this? > > I'm happy to implement an enable-active-high property, but it seems to > go against the purpose of of_get_named_gpio_flags(). Is that function > deprecated? Never heard of any deprecation, and I disagree that it is "not useful in generic code". :) Thanks, Anton.