From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Brownell Subject: Re: [PATCH] twl4030-gpio: Fix getting the value of the TWL4030 GPIO output pin Date: Wed, 11 Feb 2009 18:16:41 -0800 Message-ID: <200902111816.41569.david-b@pacbell.net> References: <4e1455be0902062213o769a4d15ha0c892508839dbad@mail.gmail.com> <200902070000.49089.david-b@pacbell.net> <4e1455be0902090502l554ca462m9c096e359a5b29c3@mail.gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Received: from smtp128.sbc.mail.sp1.yahoo.com ([69.147.65.187]:39029 "HELO smtp128.sbc.mail.sp1.yahoo.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1754921AbZBLCQn (ORCPT ); Wed, 11 Feb 2009 21:16:43 -0500 In-Reply-To: <4e1455be0902090502l554ca462m9c096e359a5b29c3@mail.gmail.com> Content-Disposition: inline Sender: linux-omap-owner@vger.kernel.org List-Id: linux-omap@vger.kernel.org To: Joonyoung Shim Cc: Tony Lindgren , linux-arm-kernel@lists.arm.linux.org.uk, linux-kernel@vger.kernel.org, linux-omap@vger.kernel.org On Monday 09 February 2009, Joonyoung Shim wrote: > but, it doesn't return actual value of the pin if twl4030 GPIO pin is= output. So it would seem that these GPIOs don't support bidirectional usage. Documentation/gpio.txt includes: >>> However, note that not all platforms can >>> read the value of output pins; those that can't >>> should always return zero. =20 Which is exactly what's happening here, it seems... > For example, the GPIO13 pin of twl4030 is configured as an output > using gpio_direction_output() and assigns the GPIO's value to 1 > using gpio_set_value_cansleep(), the result of "# cat /sys/kernel/deb= ug/gpio" > reports to me as follows. >=20 > GPIOs 192-209, platform/twl4030_gpio, twl4030, can sleep: > =A0gpio-205 (keyled =A0 =A0 =A0 =A0 =A0 =A0 =A0) out lo >=20 > but it should have reported "hi" instead of "lo". >=20 -- To unsubscribe from this list: send the line "unsubscribe linux-omap" i= n the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html