Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753905Ab3ISMhn (ORCPT ); Thu, 19 Sep 2013 08:37:43 -0400 Received: from 217-155-41-104.dsl.in-addr.zen.co.uk ([217.155.41.104]:51753 "EHLO centos1.newflow.co.uk" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1752343Ab3ISMhm (ORCPT ); Thu, 19 Sep 2013 08:37:42 -0400 Message-ID: <523AF014.5040806@newflow.co.uk> Date: Thu, 19 Sep 2013 13:37:40 +0100 From: Mark Jackson User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130804 Thunderbird/17.0.8 MIME-Version: 1.0 To: George Cherian CC: Nishanth Menon , balbi@ti.com, Laurent Pinchart , Linus Walleij , Laurent Pinchart , Kuninori Morimoto , "linux-gpio@vger.kernel.org" , Linux Kernel Mailing List , Linux OMAP Mailing List Subject: Re: PCF857x and 16-bit GPIO expanders References: <20130917190732.GD15645@radagast> <2356541.62QktiIBr5@avalon> <20130918173636.GT21559@radagast> <523AB235.1000808@ti.com> <523AE8FF.9020209@ti.com> <523AEC0C.6010005@ti.com> In-Reply-To: <523AEC0C.6010005@ti.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1967 Lines: 47 On 19/09/13 13:20, George Cherian wrote: > On 9/19/2013 5:37 PM, Nishanth Menon wrote: >> On 09/19/2013 03:13 AM, George Cherian wrote: >>> On 9/18/2013 11:06 PM, Felipe Balbi wrote: >>>> Hi, >>>> >>>> On Wed, Sep 18, 2013 at 07:18:04PM +0200, Laurent Pinchart wrote: >>>>> On Wednesday 18 September 2013 13:16:27 Linus Walleij wrote: >>>>>> On Tue, Sep 17, 2013 at 9:07 PM, Felipe Balbi wrote: >>>>>>> has anyone ever successfully using gpio-pcf857x.c driver with 16-bit >>>>>>> gpio expanders ? We're having some issues here where toggling the last >>>>>>> gpio pin (gpio 15) on a PCF8575 device causes platform to hang and I >>>>>>> can't come up with any explanation of why would it hang... >>>>>> Bouncing the question to George, Laurent and Kuninori... >>>>> I've got a board with a PCF8575 chip, but it uses I/Os 8 to 14 only as far as >>>>> I know. >>>>> >>>>> I can try toggling I/O 15, but that will need to wait until next week as I'm >>>>> currently travelling without access to the hardware. >>>> alright, that'd help me a lot :-) Just want to make sure if we're having >>>> a board issue, or PCF8575 is a bit screwy ;-) >>> Is it on dra7x-evm if so which pcf device (i2c address)? >>> The pins i were interested were only 1 and 2 I never tried pin 15. >>> >>> Just tried toggling through sysfs and it works for me. >> When I look at the data sheet for PCF8575[1] Page 7, Figure 4 Write >> mode (output) >> I see the data writes are of the order: >> I2c 1's byte: address >> I2c 2'nd byte:P[7-0] >> I2c 3rd byte:P[17-10] > > I read it as an octal numbering. Kind of ... looking at the pinout, you have pins:- P00...P07 P10...P17 So that's Port 0, bits 0..7, and Port 1, bits 0..7. Mark J. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/