From patchwork Thu Mar 17 11:45:30 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mark Brown X-Patchwork-Id: 8610301 Return-Path: X-Original-To: patchwork-linux-spi@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork2.web.kernel.org (Postfix) with ESMTP id 40A55C0553 for ; Thu, 17 Mar 2016 11:45:54 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 4497E2017E for ; Thu, 17 Mar 2016 11:45:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4285620165 for ; Thu, 17 Mar 2016 11:45:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S935719AbcCQLpo (ORCPT ); Thu, 17 Mar 2016 07:45:44 -0400 Received: from mezzanine.sirena.org.uk ([106.187.55.193]:39569 "EHLO mezzanine.sirena.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S935712AbcCQLpm (ORCPT ); Thu, 17 Mar 2016 07:45:42 -0400 Received: from debutante.sirena.org.uk ([2a01:348:6:8808:fab::3] helo=debutante) by mezzanine.sirena.org.uk with esmtpsa (TLS1.2:RSA_AES_128_CBC_SHA1:128) (Exim 4.80) (envelope-from ) id 1agWMv-0001k8-Qy; Thu, 17 Mar 2016 11:45:34 +0000 Received: from broonie by debutante with local (Exim 4.86) (envelope-from ) id 1agWMs-000201-H8; Thu, 17 Mar 2016 11:45:30 +0000 From: Mark Brown To: Knut Wohlrab , Dirk Behme , Sascha Hauer , Mark Brown Cc: linux-spi@vger.kernel.org In-Reply-To: <1458048276-31884-1-git-send-email-dirk.behme@de.bosch.com> Message-Id: Date: Thu, 17 Mar 2016 11:45:30 +0000 X-SA-Exim-Connect-IP: 2a01:348:6:8808:fab::3 X-SA-Exim-Mail-From: broonie@sirena.org.uk X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 Subject: Applied "spi: imx: only do necessary changes to ECSPIx_CONFIGREG" to the spi tree X-SA-Exim-Version: 4.2.1 (built Mon, 26 Dec 2011 16:24:06 +0000) X-SA-Exim-Scanned: Yes (on mezzanine.sirena.org.uk) Sender: linux-spi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-spi@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP The patch spi: imx: only do necessary changes to ECSPIx_CONFIGREG has been applied to the spi tree at git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi.git All being well this means that it will be integrated into the linux-next tree (usually sometime in the next 24 hours) and sent to Linus during the next merge window (or sooner if it is a bug fix), however if problems are discovered then the patch may be dropped or reverted. You may get further e-mails resulting from automated or manual testing and review of the tree, please engage with people reporting problems and send followup patches addressing any issues that are reported if needed. If any updates are required or you are submitting further changes they should be sent as incremental updates against current git, existing patches will not be replaced. Please add any relevant lists and maintainers to the CCs when replying to this mail. Thanks, Mark From 793c7f9212fdb7bea5e017427e750afa11217c29 Mon Sep 17 00:00:00 2001 From: Knut Wohlrab Date: Tue, 15 Mar 2016 14:24:36 +0100 Subject: [PATCH] spi: imx: only do necessary changes to ECSPIx_CONFIGREG If the SPI chip select (CS) for a dedicated channel is done manually by the used higher device driver, the CS may be active while writing to ECSPIx_CONFIGREG. To prevent unwanted clock edges when selecting the clock mode, only do the necessary changes to the i.MX SPI configuration register and leave not selected channels untouched. To prevent unwanted clock edges on first use, an empty dummy transmission shall be done by the initialization procedure of the device driver of this channel. This will set the clock mode to the correct state. Signed-off-by: Knut Wohlrab Signed-off-by: Dirk Behme Acked-by: Sascha Hauer Signed-off-by: Mark Brown --- drivers/spi/spi-imx.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) diff --git a/drivers/spi/spi-imx.c b/drivers/spi/spi-imx.c index e7a19be87c38..b79d70d6dabf 100644 --- a/drivers/spi/spi-imx.c +++ b/drivers/spi/spi-imx.c @@ -333,8 +333,9 @@ static void __maybe_unused mx51_ecspi_trigger(struct spi_imx_data *spi_imx) static int __maybe_unused mx51_ecspi_config(struct spi_imx_data *spi_imx, struct spi_imx_config *config) { - u32 ctrl = MX51_ECSPI_CTRL_ENABLE, cfg = 0; + u32 ctrl = MX51_ECSPI_CTRL_ENABLE; u32 clk = config->speed_hz, delay, reg; + u32 cfg = readl(spi_imx->base + MX51_ECSPI_CONFIG); /* * The hardware seems to have a race condition when changing modes. The @@ -358,13 +359,20 @@ static int __maybe_unused mx51_ecspi_config(struct spi_imx_data *spi_imx, if (config->mode & SPI_CPHA) cfg |= MX51_ECSPI_CONFIG_SCLKPHA(config->cs); + else + cfg &= ~MX51_ECSPI_CONFIG_SCLKPHA(config->cs); if (config->mode & SPI_CPOL) { cfg |= MX51_ECSPI_CONFIG_SCLKPOL(config->cs); cfg |= MX51_ECSPI_CONFIG_SCLKCTL(config->cs); + } else { + cfg &= ~MX51_ECSPI_CONFIG_SCLKPOL(config->cs); + cfg &= ~MX51_ECSPI_CONFIG_SCLKCTL(config->cs); } if (config->mode & SPI_CS_HIGH) cfg |= MX51_ECSPI_CONFIG_SSBPOL(config->cs); + else + cfg &= ~MX51_ECSPI_CONFIG_SSBPOL(config->cs); if (spi_imx->usedma) ctrl |= MX51_ECSPI_CTRL_SMC;