From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from ozlabs.org (ozlabs.org [203.10.76.45]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client CN "mx.ozlabs.org", Issuer "CA Cert Signing Authority" (verified OK)) by bilbo.ozlabs.org (Postfix) with ESMTPS id 0BCABB7099 for ; Tue, 18 Aug 2009 09:38:37 +1000 (EST) Received: from buildserver.ru.mvista.com (unknown [213.79.90.228]) by ozlabs.org (Postfix) with ESMTP id 91FE0DDD0B for ; Tue, 18 Aug 2009 09:38:36 +1000 (EST) Date: Tue, 18 Aug 2009 03:38:33 +0400 From: Anton Vorontsov To: Grant Likely Subject: Re: simple gpio driver Message-ID: <20090817233833.GA3685@oksana.dev.rtsoft.ru> References: <4A83A976.60608@denx.de> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 In-Reply-To: Cc: linuxppc-dev@ozlabs.org, hs@denx.de Reply-To: avorontsov@ru.mvista.com List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Oops, I missed that patch, sorry. On Mon, Aug 17, 2009 at 03:18:37PM -0600, Grant Likely wrote: > On Wed, Aug 12, 2009 at 11:49 PM, Heiko Schocher wrote: > > Hello Anton, > > > > i am trying to use the arch/powerpc/sysdev/simple_gpio.c driver, > > for accessing some gpios, and found, that u8_gpio_get() > > returns not only a 1 or a 0, instead it returns the real bit > > position from the gpio: > > > > gpio    return > > base    value > > 0       0/0x01 > > 1       0/0x02 > > 2       0/0x04 > > 3       0/0x08 > > 4       0/0x10 > > 5       0/0x20 > > 6       0/0x40 > > 7       0/0x80 > > > > I also use the arch/powerpc/platforms/52xx/mpc52xx_gpio.c and > > mpc52xx_gpt.c drivers, they all return for a gpio just a 1 or 0, There is also arch/powerpc/sysdev/qe_lib/gpio.c and arch/powerpc/sysdev/mpc8xxx_gpio.c that don't do that. > > which seems correct to me, because a gpio can have only 1 or 0 > > as state ... what do you think? > > I think returning '1' is perhaps slightly 'better' (however you define > that), but I don't think the caller should make any assumptions beyond > zero/non-zero. Yep. So I don't think that the patch is needed. Thanks, -- Anton Vorontsov email: cbouatmailru@gmail.com irc://irc.freenode.net/bd2