From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mark Rutland Date: Fri, 04 Jul 2014 16:31:19 +0000 Subject: Re: [RFC v4 2/2] backlight: device tree: add new tps611xx backlight binding Message-Id: <20140704163119.GB7106@leverpostej> List-Id: References: <1404367277-12003-1-git-send-email-gshark.jeong@gmail.com> <1404367277-12003-3-git-send-email-gshark.jeong@gmail.com> <20140703090447.GC29837@leverpostej> In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8bit To: Daniel Jeong Cc: Jingoo Han , Bryan Wu , Lee Jones , Jean-Christophe Plagniol-Villard , Tomi Valkeinen , "grant.likely@linaro.org" , Rob Herring , Randy Dunlap , Daniel Jeong , "linux-kernel@vger.kernel.org" , "linux-fbdev@vger.kernel.org" , "devicetree@vger.kernel.org" , "linux-doc@vger.kernel.org" > > +- rfa-enable: enable request for acknowledge. > > +  If RFA is enabled, the data byte includes the RFA bit and device will > wait > > +  and check acknowledge from device. > > You didn't answer my question as to why this should be in the DT. > > > According to the RFA enable, the easy scale pin works differently. > This value should be set before the first data transfer. Sure, things works differently if this is set. That I understood. What I haven't heard is a rationale as to why this configuration option shuold be in the DT. Can I enable this on all implementations, or not? When would I enable this and when would I not? The property reads like a switch to turn a feature on, rather than the description of the presence of a feature. Mark.