From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 4B45B1D523 for ; Wed, 4 Oct 2023 18:07:32 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dmarc=fail (p=none dis=none) header.from=linuxfoundation.org Authentication-Results: smtp.subspace.kernel.org; spf=fail smtp.mailfrom=linuxfoundation.org Received: by smtp.kernel.org (Postfix) with ESMTPSA id C25DEC433CA; Wed, 4 Oct 2023 18:07:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1696442852; bh=COHNu42PaJ7H4lGZYOyX8QRf1Bud2lzI4V3rJP/+88k=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=lcOZUWochvL1jmcNetoXFKCT4ZDZgaTZVxefhs7ctU3UG+ipLEVV9ZnYB3kEPX7fR X/Ck+hvOHo8TEKj3u2AX2uqs0oIdOM6rgtf7LauEZlrYidt3dNFiC3+8VDa17gWxe3 e2LsYn9D+C09RLSBtEIOTVeijeMqcJRHCOMb91Kc= 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 5.15 132/183] spi: stm32: add a delay before SPI disable Date: Wed, 4 Oct 2023 19:56:03 +0200 Message-ID: <20231004175209.462373474@linuxfoundation.org> X-Mailer: git-send-email 2.42.0 In-Reply-To: <20231004175203.943277832@linuxfoundation.org> References: <20231004175203.943277832@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 5.15-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 3c6f201b5dd85..191baa6e45c08 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