From mboxrd@z Thu Jan 1 00:00:00 1970 From: Russell King - ARM Linux Subject: Re: [PATCH v3 4/6] ARM: dts: imx6q{dl}: fix the wrong RTS/CTS pad name Date: Mon, 8 Jul 2013 08:50:04 +0100 Message-ID: <20130708075004.GR24642@n2100.arm.linux.org.uk> References: <1373004752-21302-1-git-send-email-b32955@freescale.com> <1373004752-21302-5-git-send-email-b32955@freescale.com> <20130706050803.GC30164@S2101-09.ap.freescale.net> <20953.22066.706534.773272@ipc1.ka-ro> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Received: from caramon.arm.linux.org.uk ([78.32.30.218]:36070 "EHLO caramon.arm.linux.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751301Ab3GHHvN (ORCPT ); Mon, 8 Jul 2013 03:51:13 -0400 Content-Disposition: inline In-Reply-To: <20953.22066.706534.773272@ipc1.ka-ro> Sender: linux-serial-owner@vger.kernel.org List-Id: linux-serial@vger.kernel.org To: Lothar =?iso-8859-1?Q?Wa=DFmann?= Cc: Shawn Guo , Huang Shijie , linux-serial@vger.kernel.org, linux-arm-kernel@lists.infradead.org, gregkh@linuxfoundation.org On Sun, Jul 07, 2013 at 01:51:14PM +0200, Lothar Wa=DFmann wrote: > Hi, >=20 > Shawn Guo writes: > > On Fri, Jul 05, 2013 at 02:12:30PM +0800, Huang Shijie wrote: > > > There is something wrong with the RTS/CTS pads: > > > The RTS pad is assigned with the CTS's value; > > > while the CTS pad is assigned with the RTS's value. > > >=20 > >=20 > > So basically, you are saying that select_input should be set up for= CTS > > rather than RTS. It seems that the people who generated the macro = got > > the wrong input from developer. > >=20 > programming 'select_input' only makes sense for inputs, not outputs. > Since CTS is an output signal, select_input only makes sense for the > RTS function of the pads. Note: If you are a DTE, then RTS is an output, CTS is an input. If you are a DCE, then RTS is an input and CTS is an output (normally on a standard UART, you just swap the wiring for RTS and CTS but really that= 's all that is going on.) So swapping them in software should be acceptab= le too, provided you're not having to disable any auto flow control facili= ties. -- To unsubscribe from this list: send the line "unsubscribe linux-serial"= in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html