From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Subject: Re: [PATCH] regulator: gpio: Reword the binding document References: <20190216174859.15738-1-marek.vasut@gmail.com> <83550921-b0ec-fa34-b120-2dd159f256d8@gmail.com> <75846117-242c-6861-ace5-dccf88711208@gmail.com> <7a993282-9137-caf4-ca0b-b2c01ea9959c@gmail.com> From: Marek Vasut Message-ID: <72363317-8259-eda2-4cd8-4f336f0c155f@gmail.com> Date: Tue, 19 Feb 2019 03:51:43 +0100 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit To: Harald Geyer Cc: devicetree@vger.kernel.org, Marek Vasut , Kuninori Morimoto , Linus Walleij , Mark Brown , Rob Herring , linux-renesas-soc@vger.kernel.org List-ID: On 2/18/19 11:18 PM, Harald Geyer wrote: > Marek Vasut writes: >> So what about >> >> gpios-states : Initial state of GPIO pins in "gpios" array, set on >> system start and retained until consumer changes the state. 0: LOW, 1: >> HIGH. Default is LOW if nothing else is specified. > > No. "retained until consumer changes the state" is promising more then > is guaranteed. > > From the explanations provided by Mark it is clear that this property > is an artifact of the implementation in linux. I think we should document > is as such. How about: > > gpios-states : On operating systems, that don't support reading back gpio > values in output mode (most notably linux), this array > provides the state of GPIO pins set when requesting them > from the gpio controller. That's good. > Systems, that are capable of > preserving state when requesting the lines, are free to > ignore this property. Are they ? I think there are systems which depend on preconfiguring the GPIO according to this property. > 0: LOW, 1: HIGH. Default is LOW if > nothing else is specified. > > HTH, > Harald > -- Best regards, Marek Vasut