From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sakari Ailus Subject: Re: [Patch v3 6/8] media: i2c: ov2659: Add powerdown/reset gpio handling Date: Wed, 25 Sep 2019 12:51:54 +0300 Message-ID: <20190925095154.GL9467@paasikivi.fi.intel.com> References: <20190924164414.21897-1-bparrot@ti.com> <20190924164414.21897-7-bparrot@ti.com> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: 8bit Return-path: Content-Disposition: inline In-Reply-To: <20190924164414.21897-7-bparrot@ti.com> Sender: linux-kernel-owner@vger.kernel.org To: Benoit Parrot Cc: Hans Verkuil , Prabhakar Lad , Rob Herring , linux-media@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org List-Id: devicetree@vger.kernel.org Hi Benoit, On Tue, Sep 24, 2019 at 11:44:12AM -0500, Benoit Parrot wrote: > On some board it is possible that the sensor 'powerdown' and or 'reset' > pin might be controlled by gpio instead of being tied. > > To implement we add pm_runtime support which will handle the power > up/down sequence when it is available otherwise the sensor will be > powered on at module insertion/probe and powered off at module removal. > > Now originally the driver assumed that the sensor would always stay > powered and keep its register setting. We cannot assume this anymore, so > every time we "power up" we need to re-program the initial registers > configuration first. This was previously done only at probe time. > > Signed-off-by: Benoit Parrot Thanks for the update. I missed the control interface is accessible also when the device is not streaming, and the driver doesn't appear to power on the sensor for that, leading to a failing I²C write. Could you address that as well, either here or as a separate patch? E.g. the smiapp driver does this. -- Kind regards, Sakari Ailus sakari.ailus@linux.intel.com