From mboxrd@z Thu Jan 1 00:00:00 1970 From: Rob Herring Subject: Re: [PATCH v2] backlight: lp855x: Add enable regulator Date: Tue, 14 Jun 2016 15:09:36 -0500 Message-ID: <20160614200936.GA9318@rob-hp-laptop> References: <1465587597-131467-1-git-send-email-briannorris@chromium.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <1465587597-131467-1-git-send-email-briannorris@chromium.org> Sender: linux-kernel-owner@vger.kernel.org To: Brian Norris Cc: Milo Kim , Jingoo Han , Lee Jones , Stephen Barber , Doug Anderson , Jean-Christophe Plagniol-Villard , Tomi Valkeinen , devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-fbdev@vger.kernel.org List-Id: devicetree@vger.kernel.org On Fri, Jun 10, 2016 at 12:39:57PM -0700, Brian Norris wrote: > The LP8556 datasheet describes an EN/VDDIO input, which serves "both as > a chip enable and as a power supply reference for PWM, SDA, and SCL > inputs." The LP8556 that I'm testing doesn't respond properly if I try > to talk I2C to it too quickly after enabling VDDIO, and the LP8555 > datasheet mentions a t_RESPONSE delay of up to 1 millisecond. > > Support this EN/VDDIO by adding a regulator property to the binding; > enabling this regulator at probe time; and sleeping for 1 to 2ms, if the > EN/VDDIO regulator was provided. > > Signed-off-by: Brian Norris > --- > v2: s/TS8555/LP8555/ in comment (typo) > > .../devicetree/bindings/leds/backlight/lp855x.txt | 2 ++ I would have picked 'vddio' as the name, but it's fine. Acked-by: Rob Herring > drivers/video/backlight/lp855x_bl.c | 29 ++++++++++++++++++++++ > 2 files changed, 31 insertions(+)