From mboxrd@z Thu Jan 1 00:00:00 1970 From: maxime.ripard@free-electrons.com (Maxime Ripard) Date: Mon, 13 Apr 2015 18:09:51 +0200 Subject: [PATCH] ARM: dts: sun7i: Add Goodix GT911 nodes for Wexler TAB7200 In-Reply-To: <20150411191816.cdc5ec802b01028eb2913906@gmail.com> References: <1427789897-4085-1-git-send-email-mamlinav@gmail.com> <20150331144338.GG23664@lukather> <20150331221420.3b65d2540c7dbe1d12611e12@gmail.com> <20150402092259.GK23664@lukather> <20150411191816.cdc5ec802b01028eb2913906@gmail.com> Message-ID: <20150413160951.GJ29832@lukather> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Sat, Apr 11, 2015 at 07:18:16PM +0300, Aleksei Mamlin wrote: > On Thu, 2 Apr 2015 11:22:59 +0200 > Maxime Ripard wrote: > > > On Tue, Mar 31, 2015 at 10:14:20PM +0300, Aleksei Mamlin wrote: > > > On Tue, 31 Mar 2015 07:43:38 -0700 > > > Maxime Ripard wrote: > > > > > > > Hi, > > > > > > > > On Tue, Mar 31, 2015 at 11:18:17AM +0300, Aleksei Mamlin wrote: > > > > > This patch adds nodes for the Goodix GT911 touchscreen controller found > > > > > on the Wexler TAB7200 tablet. Controller uses one of following I2C > > > > > addresses: 0x5d or 0x14, so just add two nodes. > > > > > > > > In which case are these different addresses encountered? Different > > > > revisions of the same board? > > > > > > According to the datasheet it is a feature of the controller. > > > The address(0x5d or 0x14) can be configured using a reset sequence, > > > which has not yet been implemented in the driver. > > > > Which address is set up by the bootloader then? > > I assume that bootloader(u-boot) didn't sets up any address, but touchscreen > controller usually uses 0x5d. Sometimes, after hard reset, it uses 0x14. > For this we need nodes on both adresses. I'm confused, who changes that address then? The controller itself? Maxime -- Maxime Ripard, Free Electrons Embedded Linux, Kernel and Android engineering http://free-electrons.com -------------- next part -------------- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 819 bytes Desc: Digital signature URL: