From mboxrd@z Thu Jan 1 00:00:00 1970 From: Thomas Chou Subject: Re: [uclinux-dist-devel] touch screen ads7846/7843 devicetree support Date: Thu, 03 Feb 2011 08:07:53 +0800 Message-ID: <4D49F1D9.70909@wytron.com.tw> References: <4D410C4C.7070005@wytron.com.tw> <4D414FED.706@wytron.com.tw> <544AC56F16B56944AEC3BD4E3D591771324C105D75@LIMKCMBX1.ad.analog.com> <20110202160355.GE20275@angua.secretlab.ca> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; Format="flowed" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20110202160355.GE20275-MrY2KI0G/OVr83L8+7iqerDks+cytr/Z@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: devicetree-discuss-bounces+gldd-devicetree-discuss=m.gmane.org-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org Errors-To: devicetree-discuss-bounces+gldd-devicetree-discuss=m.gmane.org-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org To: Grant Likely Cc: Nios2 development list , "Hennerich, Michael" , Mike Frysinger , "devicetree-discuss-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org" , "device-drivers-devel-ZG0+EudsQA8dtHy/vicBwGD2FQJk+8+b@public.gmane.org" , "uclinux-dist-devel-ZG0+EudsQA8dtHy/vicBwGD2FQJk+8+b@public.gmane.org" List-Id: devicetree@vger.kernel.org On 02/03/2011 12:03 AM, Grant Likely wrote: > On Thu, Jan 27, 2011 at 12:24:01PM +0000, Hennerich, Michael wrote: >> Thomas Chou wrote on 2011-01-27: >>> On 01/27/2011 02:18 PM, Mike Frysinger wrote: >>>> On Thu, Jan 27, 2011 at 01:10, Thomas Chou wrote: >>>>> We need devicetree support on ads7846/7843 touch screen driver. Do >>>>> you have plan on it? We are moving to devicetree on nios2, so do >>> arm/mips/x86. >>>> >>>> what part are you using exactly ? >>>> -mike >>>> >>> >>> ad7843 is used in a popular nios2 dev kit, NEEK. >> >> This driver is a SPI bus client driver. PPC is using devicetree for ages now, >> and they don't have problems instantiating this or any other SPI bus driver. > > However, the method used is by applying a heuristic (of_modalias_node) > which tries to name the device in a way that will match an existing > device driver. It works for a lot of spi drivers, but it isn't > always reliable. > > Alternatively, if of_match_table is populated in the spi_driver, then > the normal device tree match behaviour will always work. Thanks. The driver did match with the heuristic. But it needs to determine pen state. I will try to bind a gpio node in dts. linux/spi/ads7846.h int gpio_pendown; /* the GPIO used to decide the pendown * state if get_pendown_state == NULL */ - Thomas