From patchwork Mon May 10 14:10:22 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andy Shevchenko X-Patchwork-Id: 433418 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,USER_AGENT_GIT autolearn=unavailable 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 0DC45C433ED for ; Mon, 10 May 2021 14:16:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id DF72E611BF for ; Mon, 10 May 2021 14:16:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233818AbhEJORC (ORCPT ); Mon, 10 May 2021 10:17:02 -0400 Received: from mga02.intel.com ([134.134.136.20]:10138 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232053AbhEJOMu (ORCPT ); Mon, 10 May 2021 10:12:50 -0400 IronPort-SDR: +u92cO7pzw8ynL9XLMYZmrzHMwHMYdpTM5+5pCqcLJvVdZNWs/UQXnKXt9283Qf7aJHzr+BYQq CIV00EQ3xdSA== X-IronPort-AV: E=McAfee;i="6200,9189,9980"; a="186339099" X-IronPort-AV: E=Sophos;i="5.82,287,1613462400"; d="scan'208";a="186339099" Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by orsmga101.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 10 May 2021 07:10:14 -0700 IronPort-SDR: KdH8su/4ZReo1i+QeV41PtXxu8f9iw/aS1LKiy9zYCDJvmMlKAFvO2X5wdH2TpvZes/DOKszOT IDrl1Sc0inuA== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.82,287,1613462400"; d="scan'208";a="536427303" Received: from black.fi.intel.com ([10.237.72.28]) by fmsmga001.fm.intel.com with ESMTP; 10 May 2021 07:10:11 -0700 Received: by black.fi.intel.com (Postfix, from userid 1003) id A50C6142; Mon, 10 May 2021 17:10:31 +0300 (EEST) From: Andy Shevchenko To: Mark Brown , linux-spi@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Linus Walleij , Andy Shevchenko , Liguang Zhang , Jay Fang , Sven Van Asbroeck , Xin Hao Subject: [PATCH v1 1/1] spi: Assume GPIO CS active high in ACPI case Date: Mon, 10 May 2021 17:10:22 +0300 Message-Id: <20210510141022.56499-1-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 --- drivers/spi/spi.c | 17 ++++++++++++++--- 1 file changed, 14 insertions(+), 3 deletions(-) diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c index 956dce3aafca..f56e0212ee97 100644 --- a/drivers/spi/spi.c +++ b/drivers/spi/spi.c @@ -820,12 +820,23 @@ 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)) { + /* + * 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. + */ + bool value = has_acpi_companion(&spi->dev) ? !enable : activate; + if (spi->cs_gpiod) - /* polarity handled by gpiolib */ - gpiod_set_value_cansleep(spi->cs_gpiod, activate); + /* Polarity handled by GPIO library */ + gpiod_set_value_cansleep(spi->cs_gpiod, value); else /* - * invert the enable line, as active low is + * Invert the enable line, as active low is * default for SPI. */ gpio_set_value_cansleep(spi->cs_gpio, !enable);