From mboxrd@z Thu Jan 1 00:00:00 1970 From: Maxime Ripard Subject: Re: Re: [PATCH 4/5] ARM: dts: sun5i: Add dts file for the Empire Electronix D709 tablet Date: Mon, 21 Dec 2015 17:11:32 +0100 Message-ID: <20151221161132.GA30359@lukather> References: <1450611782-9494-1-git-send-email-hdegoede@redhat.com> <1450611782-9494-4-git-send-email-hdegoede@redhat.com> <5677D87A.90805@redhat.com> Reply-To: maxime.ripard-wi1+55ScJUtKEb57/3fJTNBPR1lH4CV8@public.gmane.org Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="F4Dl6XKrV7PH8SJF" Return-path: Content-Disposition: inline In-Reply-To: <5677D87A.90805-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org> List-Post: , List-Help: , List-Archive: , List-Unsubscribe: , To: Hans de Goede Cc: Chen-Yu Tsai , linux-arm-kernel , devicetree , linux-sunxi List-Id: devicetree@vger.kernel.org --F4Dl6XKrV7PH8SJF Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline Hi,x On Mon, Dec 21, 2015 at 11:46:18AM +0100, Hans de Goede wrote: > >On the side, any thoughts on how to handle the differences between various "Q8" > >tablets, like different I2C-based sensors and WiFi chips? > > For i2c based sensors the plan is to use devicetree overlays + an in kernel > overlay manager which probes the i2c bus (checking known touchscreen / accelerometer > addresses) and then picks the right touchscreen + accelerometer overlays. > > Wifi is somewhat more tricky I must admit, esp. since there seem to be q8 a23 based > tablet variants with usb wifi and others with sdio wifi. Since both busses are > discoverable I'm tempted to just enable both in devicetree, and let the kernel probe > and see what is actually there. This assume that the way the wifichip is powered > is the same on all boards, or at least that it is safe to enable the necessary > regulators on all boards ... > > >I'm asking because with Maxime's couple-regulator we should be able to get the > >RTL8723BS on the Q8 A23/33 v1.5 working. > > So this means enabled the sdio controller (should be safe on all boards?) and > enabling 2 regulators to power the wifi-chip. I think it will be safe to do this > even on boards where those regulators are not used, what do you think ? Wouldn't that introduce some useless power drain on those boards? Thanks! Maxime -- Maxime Ripard, Free Electrons Embedded Linux, Kernel and Android engineering http://free-electrons.com --F4Dl6XKrV7PH8SJF--