From patchwork Tue Apr 6 10:36:06 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Marc Kleine-Budde X-Patchwork-Id: 416336 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 C12E0C433B4 for ; Tue, 6 Apr 2021 10:36:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9F78E613C2 for ; Tue, 6 Apr 2021 10:36:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241380AbhDFKgW (ORCPT ); Tue, 6 Apr 2021 06:36:22 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48210 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232103AbhDFKgT (ORCPT ); Tue, 6 Apr 2021 06:36:19 -0400 Received: from metis.ext.pengutronix.de (metis.ext.pengutronix.de [IPv6:2001:67c:670:201:290:27ff:fe1d:cc33]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id AD111C06175F for ; Tue, 6 Apr 2021 03:36:11 -0700 (PDT) Received: from gallifrey.ext.pengutronix.de ([2001:67c:670:201:5054:ff:fe8d:eefb] helo=bjornoya.blackshift.org) by metis.ext.pengutronix.de with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1lTj46-0003pD-9B for netdev@vger.kernel.org; Tue, 06 Apr 2021 12:36:10 +0200 Received: from dspam.blackshift.org (localhost [127.0.0.1]) by bjornoya.blackshift.org (Postfix) with SMTP id A096F60864F for ; Tue, 6 Apr 2021 10:36:08 +0000 (UTC) Received: from hardanger.blackshift.org (unknown [172.20.34.65]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange ECDHE (P-384) server-signature RSA-PSS (4096 bits) server-digest SHA256) (Client did not present a certificate) by bjornoya.blackshift.org (Postfix) with ESMTPS id B24C4608642; Tue, 6 Apr 2021 10:36:07 +0000 (UTC) Received: from blackshift.org (localhost [::1]) by hardanger.blackshift.org (OpenSMTPD) with ESMTP id b8c8af25; Tue, 6 Apr 2021 10:36:07 +0000 (UTC) From: Marc Kleine-Budde To: netdev@vger.kernel.org Cc: davem@davemloft.net, kuba@kernel.org, linux-can@vger.kernel.org, kernel@pengutronix.de, Marc Kleine-Budde , Tim Harvey , Gerhard Bertelsmann Subject: [net] can: mcp251x: fix support for half duplex SPI host controllers Date: Tue, 6 Apr 2021 12:36:06 +0200 Message-Id: <20210406103606.1847506-2-mkl@pengutronix.de> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210406103606.1847506-1-mkl@pengutronix.de> References: <20210406103606.1847506-1-mkl@pengutronix.de> MIME-Version: 1.0 X-SA-Exim-Connect-IP: 2001:67c:670:201:5054:ff:fe8d:eefb X-SA-Exim-Mail-From: mkl@pengutronix.de X-SA-Exim-Scanned: No (on metis.ext.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: netdev@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Some SPI host controllers do not support full-duplex SPI transfers. The function mcp251x_spi_trans() does a full duplex transfer. It is used in several places in the driver, where a TX half duplex transfer is sufficient. To fix support for half duplex SPI host controllers, this patch introduces a new function mcp251x_spi_write() and changes all callers that do a TX half duplex transfer to use mcp251x_spi_write(). Fixes: e0e25001d088 ("can: mcp251x: add support for half duplex controllers") Link: https://lore.kernel.org/r/20210330100246.1074375-1-mkl@pengutronix.de Cc: Tim Harvey Tested-By: Tim Harvey Reported-by: Gerhard Bertelsmann Signed-off-by: Marc Kleine-Budde --- drivers/net/can/spi/mcp251x.c | 24 ++++++++++++++++++------ 1 file changed, 18 insertions(+), 6 deletions(-) base-commit: 08c27f3322fec11950b8f1384aa0f3b11d028528 diff --git a/drivers/net/can/spi/mcp251x.c b/drivers/net/can/spi/mcp251x.c index f69fb4238a65..a57da43680d8 100644 --- a/drivers/net/can/spi/mcp251x.c +++ b/drivers/net/can/spi/mcp251x.c @@ -314,6 +314,18 @@ static int mcp251x_spi_trans(struct spi_device *spi, int len) return ret; } +static int mcp251x_spi_write(struct spi_device *spi, int len) +{ + struct mcp251x_priv *priv = spi_get_drvdata(spi); + int ret; + + ret = spi_write(spi, priv->spi_tx_buf, len); + if (ret) + dev_err(&spi->dev, "spi write failed: ret = %d\n", ret); + + return ret; +} + static u8 mcp251x_read_reg(struct spi_device *spi, u8 reg) { struct mcp251x_priv *priv = spi_get_drvdata(spi); @@ -361,7 +373,7 @@ static void mcp251x_write_reg(struct spi_device *spi, u8 reg, u8 val) priv->spi_tx_buf[1] = reg; priv->spi_tx_buf[2] = val; - mcp251x_spi_trans(spi, 3); + mcp251x_spi_write(spi, 3); } static void mcp251x_write_2regs(struct spi_device *spi, u8 reg, u8 v1, u8 v2) @@ -373,7 +385,7 @@ static void mcp251x_write_2regs(struct spi_device *spi, u8 reg, u8 v1, u8 v2) priv->spi_tx_buf[2] = v1; priv->spi_tx_buf[3] = v2; - mcp251x_spi_trans(spi, 4); + mcp251x_spi_write(spi, 4); } static void mcp251x_write_bits(struct spi_device *spi, u8 reg, @@ -386,7 +398,7 @@ static void mcp251x_write_bits(struct spi_device *spi, u8 reg, priv->spi_tx_buf[2] = mask; priv->spi_tx_buf[3] = val; - mcp251x_spi_trans(spi, 4); + mcp251x_spi_write(spi, 4); } static u8 mcp251x_read_stat(struct spi_device *spi) @@ -618,7 +630,7 @@ static void mcp251x_hw_tx_frame(struct spi_device *spi, u8 *buf, buf[i]); } else { memcpy(priv->spi_tx_buf, buf, TXBDAT_OFF + len); - mcp251x_spi_trans(spi, TXBDAT_OFF + len); + mcp251x_spi_write(spi, TXBDAT_OFF + len); } } @@ -650,7 +662,7 @@ static void mcp251x_hw_tx(struct spi_device *spi, struct can_frame *frame, /* use INSTRUCTION_RTS, to avoid "repeated frame problem" */ priv->spi_tx_buf[0] = INSTRUCTION_RTS(1 << tx_buf_idx); - mcp251x_spi_trans(priv->spi, 1); + mcp251x_spi_write(priv->spi, 1); } static void mcp251x_hw_rx_frame(struct spi_device *spi, u8 *buf, @@ -888,7 +900,7 @@ static int mcp251x_hw_reset(struct spi_device *spi) mdelay(MCP251X_OST_DELAY_MS); priv->spi_tx_buf[0] = INSTRUCTION_RESET; - ret = mcp251x_spi_trans(spi, 1); + ret = mcp251x_spi_write(spi, 1); if (ret) return ret;