From mboxrd@z Thu Jan 1 00:00:00 1970 From: Lars-Peter Clausen Subject: Re: [PATCHv2 1/3] Documentation: ad5064: Added devicetree bindings documentation Date: Tue, 13 Oct 2015 13:11:17 +0200 Message-ID: <561CE6D5.2000400@metafoo.de> References: <1444650634-12025-1-git-send-email-paul.cercueil@analog.com> <20151012151857.GC7452@leverpostej> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20151012151857.GC7452@leverpostej> Sender: linux-iio-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Mark Rutland , Paul Cercueil Cc: Jonathan Cameron , Michael Hennerich , Hartmut Knaack , Peter Meerwald , Rob Herring , Pawel Moll , Ian Campbell , Kumar Gala , devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-iio-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: devicetree@vger.kernel.org >> + >> +Optional properties: >> + - vref-supply: phandle to the external reference voltage supply. >> + This should only be set if there is an external reference voltage >> + connected to the vref or vref[A-D] pins. > > I don't understand. Surely the latter case means you're describing the > same supply twice (as it should already be in vref*-supply)? > > What vref pins does the HW actually have? Some off the devices supported by the binding have a shared reference for all DAC outputs, while others have a separate reference for each output. In addition to that some of them have an internal reference that can used, in which case the external reference is optional, otherwise the external reference is required. The bindings documentation should clarify on which applies to which device.