From patchwork Tue May 11 14:09:12 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andy Shevchenko X-Patchwork-Id: 12251117 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id B7916C433ED for ; Tue, 11 May 2021 14:08:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7DFDE61155 for ; Tue, 11 May 2021 14:08:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231495AbhEKOKE (ORCPT ); Tue, 11 May 2021 10:10:04 -0400 Received: from mga18.intel.com ([134.134.136.126]:43999 "EHLO mga18.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231489AbhEKOKD (ORCPT ); Tue, 11 May 2021 10:10:03 -0400 IronPort-SDR: UUpF4Asel6K6Uq7KxUJgiWDughsd7Vt8RDVnKJC35L95jfAVvXPqTEitvWfTM6XVeJVMgCxHbV EjyqtgRqvgZw== X-IronPort-AV: E=McAfee;i="6200,9189,9981"; a="186889752" X-IronPort-AV: E=Sophos;i="5.82,290,1613462400"; d="scan'208";a="186889752" Received: from fmsmga006.fm.intel.com ([10.253.24.20]) by orsmga106.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 11 May 2021 07:08:55 -0700 IronPort-SDR: 8dadsJuF5RYtBbWlx5WnJoGcWpfpwsIS5koHi4sqfYRhr9vOnvWm04+7DXJiMc6CiK7kx+9w20 CYbm84jxLdsg== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.82,290,1613462400"; d="scan'208";a="621826717" Received: from black.fi.intel.com ([10.237.72.28]) by fmsmga006.fm.intel.com with ESMTP; 11 May 2021 07:08:53 -0700 Received: by black.fi.intel.com (Postfix, from userid 1003) id D677314B; Tue, 11 May 2021 17:09:13 +0300 (EEST) From: Andy Shevchenko To: Mark Brown , linux-spi@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Andy Shevchenko , Liguang Zhang , Jay Fang , Sven Van Asbroeck , Xin Hao Subject: [PATCH v2 1/1] spi: Assume GPIO CS active high in ACPI case Date: Tue, 11 May 2021 17:09:12 +0300 Message-Id: <20210511140912.30757-1-andriy.shevchenko@linux.intel.com> X-Mailer: git-send-email 2.30.2 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-spi@vger.kernel.org Currently GPIO CS handling, when descriptors are in use, doesn't take into consideration that in ACPI case the default polarity is Active High and can't be altered. Instead we have to use the per-chip definition provided by SPISerialBus() resource. Fixes: 766c6b63aa04 ("spi: fix client driver breakages when using GPIO descriptors") Cc: Liguang Zhang Cc: Jay Fang Cc: Sven Van Asbroeck Signed-off-by: Andy Shevchenko Tested-by: Xin Hao --- v2: refactor to avoid ternary (Mark, Sven), dropped comment changes (Mark) drivers/spi/spi.c | 22 ++++++++++++++++++---- 1 file changed, 18 insertions(+), 4 deletions(-) diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c index cd40421b8f55..36ee33514b40 100644 --- a/drivers/spi/spi.c +++ b/drivers/spi/spi.c @@ -820,15 +820,29 @@ static void spi_set_cs(struct spi_device *spi, bool enable, bool force) if (spi->cs_gpiod || gpio_is_valid(spi->cs_gpio)) { if (!(spi->mode & SPI_NO_CS)) { - if (spi->cs_gpiod) - /* polarity handled by gpiolib */ - gpiod_set_value_cansleep(spi->cs_gpiod, activate); - else + if (spi->cs_gpiod) { + /* + * Historically ACPI has no means of the GPIO polarity and + * thus the SPISerialBus() resource defines it on the per-chip + * basis. In order to avoid a chain of negations, the GPIO + * polarity is considered being Active High. Even for the cases + * when _DSD() is involved (in the updated versions of ACPI) + * the GPIO CS polarity must be defined Active High to avoid + * ambiguity. That's why we use enable, that takes SPI_CS_HIGH + * into account. + */ + if (has_acpi_companion(&spi->dev)) + gpiod_set_value_cansleep(spi->cs_gpiod, !enable); + else + /* Polarity handled by GPIO library */ + gpiod_set_value_cansleep(spi->cs_gpiod, activate); + } else { /* * invert the enable line, as active low is * default for SPI. */ gpio_set_value_cansleep(spi->cs_gpio, !enable); + } } /* Some SPI masters need both GPIO CS & slave_select */ if ((spi->controller->flags & SPI_MASTER_GPIO_SS) &&