From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jacek Anaszewski Subject: Re: [PATCH v3] DT: Add documentation for the mfd Maxim max77693 Date: Mon, 30 Mar 2015 15:46:38 +0200 Message-ID: <551953BE.50506@samsung.com> References: <1427709149-15014-1-git-send-email-j.anaszewski@samsung.com> <1427709149-15014-2-git-send-email-j.anaszewski@samsung.com> <20150330115729.GG17971@leverpostej> <55194509.1070008@samsung.com> <20150330132002.GA29200@leverpostej> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-reply-to: <20150330132002.GA29200@leverpostej> Sender: linux-media-owner@vger.kernel.org To: Mark Rutland Cc: "linux-leds@vger.kernel.org" , "linux-media@vger.kernel.org" , "kyungmin.park@samsung.com" , "pavel@ucw.cz" , "cooloney@gmail.com" , "rpurdie@rpsys.net" , "sakari.ailus@iki.fi" , "s.nawrocki@samsung.com" , Andrzej Hajda , Lee Jones , Chanwoo Choi , "devicetree@vger.kernel.org" List-Id: devicetree@vger.kernel.org Hi Mark, On 03/30/2015 03:20 PM, Mark Rutland wrote: > Hi, > >>>> +Optional properties: >>>> +- maxim,trigger-type : Flash trigger type. >>>> + Possible trigger types: >>>> + LEDS_TRIG_TYPE_EDGE (0) - Rising edge of the signal triggers >>>> + the flash, >>>> + LEDS_TRIG_TYPE_LEVEL (1) - Strobe pulse length controls duration >>>> + of the flash. >>> >>> Surely this is required? What should be assumed if this property isn't >>> present? >> >> LEDS_TRIG_TYPE_LEVEL allows for an ISP to do e.g. short flash blink >> before the actual strobe - it is used for eliminating photographs with >> closed eyes, or can serve for probing ambient light conditions. >> >> With LEDS_TRIG_TYPE_EDGE flash strobe is triggered on rising edge >> and lasts until programmed timeout expires. >> >> This setting is tightly related to a camera sensor, which generates >> the strobe signal. Effectively it depends on board configuration. > > My comment wasn't to do with the semantics of eitehr option but rather > the optionality of the property. > > Surely it's vital to know what this should be, and hence this property > should be required rather than optional? > > If it isn't required, what would the assumed default be? Default is LEDS_TRIG_TYPE_EDGE. -- Best Regards, Jacek Anaszewski