From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id E1E47E7C4E7 for ; Wed, 4 Oct 2023 18:18:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S244112AbjJDSSR (ORCPT ); Wed, 4 Oct 2023 14:18:17 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58220 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S244114AbjJDSSQ (ORCPT ); Wed, 4 Oct 2023 14:18:16 -0400 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D5B799E for ; Wed, 4 Oct 2023 11:18:12 -0700 (PDT) Received: by smtp.kernel.org (Postfix) with ESMTPSA id E4D64C433C7; Wed, 4 Oct 2023 18:18:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1696443492; bh=CSQG5WkVvtvQ9zUKm+2uLj5/gwe5gB1Rna/8/ra8N3o=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=XFmhG+PlWUENiagnIR8J0Md87Bmyl88Kp9zByOQLUj4GcRr2vwvXuQpJoOX4EGSgN UN4DNe8XnMPC/3uCBZZ8W7aN8Gjp+APg6ZGd9/+CZHH8CStwkTOeNcorRb2MVo4ksO 0qfwMYMkFNKYockLuCt2cLPZV+uwOL5CpPTiYS7Y= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Valentin Caron , Mark Brown , Sasha Levin Subject: [PATCH 6.1 175/259] spi: stm32: add a delay before SPI disable Date: Wed, 4 Oct 2023 19:55:48 +0200 Message-ID: <20231004175225.317113630@linuxfoundation.org> X-Mailer: git-send-email 2.42.0 In-Reply-To: <20231004175217.404851126@linuxfoundation.org> References: <20231004175217.404851126@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org 6.1-stable review patch. If anyone has any objections, please let me know. ------------------ From: Valentin Caron [ Upstream commit 6de8a70c84ee0586fdde4e671626b9caca6aed74 ] As explained in errata sheet, in section "2.14.5 Truncation of SPI output signals after EOT event": On STM32MP1x, EOT interrupt can be thrown before the true end of communication. So we add a delay of a half period to wait the real end of the transmission. Link: https://www.st.com/resource/en/errata_sheet/es0539-stm32mp131x3x5x-device-errata-stmicroelectronics.pdf Signed-off-by: Valentin Caron Link: https://lore.kernel.org/r/20230906132735.748174-1-valentin.caron@foss.st.com Signed-off-by: Mark Brown Signed-off-by: Sasha Levin --- drivers/spi/spi-stm32.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/drivers/spi/spi-stm32.c b/drivers/spi/spi-stm32.c index def09cf0dc147..12241815510d4 100644 --- a/drivers/spi/spi-stm32.c +++ b/drivers/spi/spi-stm32.c @@ -268,6 +268,7 @@ struct stm32_spi_cfg { * @fifo_size: size of the embedded fifo in bytes * @cur_midi: master inter-data idleness in ns * @cur_speed: speed configured in Hz + * @cur_half_period: time of a half bit in us * @cur_bpw: number of bits in a single SPI data frame * @cur_fthlv: fifo threshold level (data frames in a single data packet) * @cur_comm: SPI communication mode @@ -294,6 +295,7 @@ struct stm32_spi { unsigned int cur_midi; unsigned int cur_speed; + unsigned int cur_half_period; unsigned int cur_bpw; unsigned int cur_fthlv; unsigned int cur_comm; @@ -454,6 +456,8 @@ static int stm32_spi_prepare_mbr(struct stm32_spi *spi, u32 speed_hz, spi->cur_speed = spi->clk_rate / (1 << mbrdiv); + spi->cur_half_period = DIV_ROUND_CLOSEST(USEC_PER_SEC, 2 * spi->cur_speed); + return mbrdiv - 1; } @@ -695,6 +699,10 @@ static void stm32h7_spi_disable(struct stm32_spi *spi) return; } + /* Add a delay to make sure that transmission is ended. */ + if (spi->cur_half_period) + udelay(spi->cur_half_period); + if (spi->cur_usedma && spi->dma_tx) dmaengine_terminate_all(spi->dma_tx); if (spi->cur_usedma && spi->dma_rx) -- 2.40.1