From mboxrd@z Thu Jan 1 00:00:00 1970 From: Anton Vorontsov Subject: [PATCH 3/9] spi_mpc83xx: Add small delay after asserting chip-select line Date: Fri, 1 May 2009 03:48:24 +0400 Message-ID: <20090430234824.GC7901@oksana.dev.rtsoft.ru> References: <20090430234739.GA27709@oksana.dev.rtsoft.ru> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: linuxppc-dev-mnsaURCQ41sdnm+yROfE0A@public.gmane.org, Andrew Morton , David Brownell , linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, spi-devel-general-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org To: Kumar Gala Return-path: Content-Disposition: inline In-Reply-To: <20090430234739.GA27709-wnGakbxT3iijyJ0x5qLZdcN33GVbZNy3@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: spi-devel-general-bounces-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org List-Id: linux-spi.vger.kernel.org This is needed for some underlaying GPIO controllers that may be a bit slow, or if chip-select signal need some time to stabilize. For what it's worth, we already have the similar delay for chip-select de-assertion case. Signed-off-by: Anton Vorontsov --- drivers/spi/spi_mpc83xx.c | 4 +++- 1 files changed, 3 insertions(+), 1 deletions(-) diff --git a/drivers/spi/spi_mpc83xx.c b/drivers/spi/spi_mpc83xx.c index 08b49d2..d378d5e 100644 --- a/drivers/spi/spi_mpc83xx.c +++ b/drivers/spi/spi_mpc83xx.c @@ -383,8 +383,10 @@ static void mpc83xx_spi_work(struct work_struct *work) break; } - if (cs_change) + if (cs_change) { mpc83xx_spi_chipselect(spi, BITBANG_CS_ACTIVE); + ndelay(nsecs); + } cs_change = t->cs_change; if (t->len) status = mpc83xx_spi_bufs(spi, t); -- 1.6.2.2 ------------------------------------------------------------------------------ Register Now & Save for Velocity, the Web Performance & Operations Conference from O'Reilly Media. Velocity features a full day of expert-led, hands-on workshops and two days of sessions from industry leaders in dedicated Performance & Operations tracks. Use code vel09scf and Save an extra 15% before 5/3. http://p.sf.net/sfu/velocityconf From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from buildserver.ru.mvista.com (unknown [213.79.90.228]) by ozlabs.org (Postfix) with ESMTP id 9046EDF45A for ; Fri, 1 May 2009 09:48:26 +1000 (EST) Date: Fri, 1 May 2009 03:48:24 +0400 From: Anton Vorontsov To: Kumar Gala Subject: [PATCH 3/9] spi_mpc83xx: Add small delay after asserting chip-select line Message-ID: <20090430234824.GC7901@oksana.dev.rtsoft.ru> References: <20090430234739.GA27709@oksana.dev.rtsoft.ru> MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 In-Reply-To: <20090430234739.GA27709@oksana.dev.rtsoft.ru> Cc: linuxppc-dev@ozlabs.org, Andrew Morton , David Brownell , linux-kernel@vger.kernel.org, spi-devel-general@lists.sourceforge.net List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , This is needed for some underlaying GPIO controllers that may be a bit slow, or if chip-select signal need some time to stabilize. For what it's worth, we already have the similar delay for chip-select de-assertion case. Signed-off-by: Anton Vorontsov --- drivers/spi/spi_mpc83xx.c | 4 +++- 1 files changed, 3 insertions(+), 1 deletions(-) diff --git a/drivers/spi/spi_mpc83xx.c b/drivers/spi/spi_mpc83xx.c index 08b49d2..d378d5e 100644 --- a/drivers/spi/spi_mpc83xx.c +++ b/drivers/spi/spi_mpc83xx.c @@ -383,8 +383,10 @@ static void mpc83xx_spi_work(struct work_struct *work) break; } - if (cs_change) + if (cs_change) { mpc83xx_spi_chipselect(spi, BITBANG_CS_ACTIVE); + ndelay(nsecs); + } cs_change = t->cs_change; if (t->len) status = mpc83xx_spi_bufs(spi, t); -- 1.6.2.2 From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1762269AbZD3Xtb (ORCPT ); Thu, 30 Apr 2009 19:49:31 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1761045AbZD3Xs0 (ORCPT ); Thu, 30 Apr 2009 19:48:26 -0400 Received: from ru.mvista.com ([213.79.90.228]:5196 "EHLO buildserver.ru.mvista.com" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1761501AbZD3XsZ (ORCPT ); Thu, 30 Apr 2009 19:48:25 -0400 Date: Fri, 1 May 2009 03:48:24 +0400 From: Anton Vorontsov To: Kumar Gala Cc: Andrew Morton , David Brownell , linuxppc-dev@ozlabs.org, spi-devel-general@lists.sourceforge.net, linux-kernel@vger.kernel.org Subject: [PATCH 3/9] spi_mpc83xx: Add small delay after asserting chip-select line Message-ID: <20090430234824.GC7901@oksana.dev.rtsoft.ru> References: <20090430234739.GA27709@oksana.dev.rtsoft.ru> MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Disposition: inline In-Reply-To: <20090430234739.GA27709@oksana.dev.rtsoft.ru> User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This is needed for some underlaying GPIO controllers that may be a bit slow, or if chip-select signal need some time to stabilize. For what it's worth, we already have the similar delay for chip-select de-assertion case. Signed-off-by: Anton Vorontsov --- drivers/spi/spi_mpc83xx.c | 4 +++- 1 files changed, 3 insertions(+), 1 deletions(-) diff --git a/drivers/spi/spi_mpc83xx.c b/drivers/spi/spi_mpc83xx.c index 08b49d2..d378d5e 100644 --- a/drivers/spi/spi_mpc83xx.c +++ b/drivers/spi/spi_mpc83xx.c @@ -383,8 +383,10 @@ static void mpc83xx_spi_work(struct work_struct *work) break; } - if (cs_change) + if (cs_change) { mpc83xx_spi_chipselect(spi, BITBANG_CS_ACTIVE); + ndelay(nsecs); + } cs_change = t->cs_change; if (t->len) status = mpc83xx_spi_bufs(spi, t); -- 1.6.2.2