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 X-Spam-Level: X-Spam-Status: No, score=-9.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,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 845CFC2D0DB for ; Thu, 30 Jan 2020 18:44:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5E463217BA for ; Thu, 30 Jan 2020 18:44:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1580409870; bh=xwn2pakitxhWYFtw+8wAFTZXzu/ntQeMjykG2ynSlZ0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=VdoRlDnMPSRAgLx8fNKvg0o+o9MjH+tHFpvU9VHsKW3TIXGCDuttmoddCwP7sb0nu qL4+oY4OUaqPO2NGRAPfnMpzIoV5fDDdl+R16ibWD8/6korPiY/DLybgImjqxDqkE+ z5OfhrZmfmkSgNlcm0d8VdL0xRAWVqPrb7WM8I3M= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730565AbgA3So3 (ORCPT ); Thu, 30 Jan 2020 13:44:29 -0500 Received: from mail.kernel.org ([198.145.29.99]:53552 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730811AbgA3SoY (ORCPT ); Thu, 30 Jan 2020 13:44:24 -0500 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id BEE552465B; Thu, 30 Jan 2020 18:44:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1580409864; bh=xwn2pakitxhWYFtw+8wAFTZXzu/ntQeMjykG2ynSlZ0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=rpzY7zRH8QD3ge6cenk6nfMIE3QKbUkW1WhmsOixsm31eYQfaAQCefm8SgctWM0JE ooTnJtCJwBztlMl7DamjBrE4nj09Ich0+I9YsVxYTjmkDDJVaTZbdxBnss8qKd5BFN UWKgk87k4kdLgsm7oH/JVGGDIeeibXYEkObbyFUQ= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Sean Nyekjaer , Marc Kleine-Budde , Sasha Levin Subject: [PATCH 5.4 064/110] can: tcan4x5x: tcan4x5x_parse_config(): reset device before register access Date: Thu, 30 Jan 2020 19:38:40 +0100 Message-Id: <20200130183622.387523067@linuxfoundation.org> X-Mailer: git-send-email 2.25.0 In-Reply-To: <20200130183613.810054545@linuxfoundation.org> References: <20200130183613.810054545@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Sean Nyekjaer [ Upstream commit c3083124e6a1c0d6cd4fe3b3f627b488bd3b10c4 ] It's a good idea to reset a ip-block/spi device before using it, this patch will reset the device. And a generic reset function if needed elsewhere. Signed-off-by: Sean Nyekjaer Signed-off-by: Marc Kleine-Budde Signed-off-by: Sasha Levin --- drivers/net/can/m_can/tcan4x5x.c | 27 ++++++++++++++++++++++++++- 1 file changed, 26 insertions(+), 1 deletion(-) diff --git a/drivers/net/can/m_can/tcan4x5x.c b/drivers/net/can/m_can/tcan4x5x.c index d797912e665a5..b233756345f83 100644 --- a/drivers/net/can/m_can/tcan4x5x.c +++ b/drivers/net/can/m_can/tcan4x5x.c @@ -164,6 +164,28 @@ static void tcan4x5x_check_wake(struct tcan4x5x_priv *priv) } } +static int tcan4x5x_reset(struct tcan4x5x_priv *priv) +{ + int ret = 0; + + if (priv->reset_gpio) { + gpiod_set_value(priv->reset_gpio, 1); + + /* tpulse_width minimum 30us */ + usleep_range(30, 100); + gpiod_set_value(priv->reset_gpio, 0); + } else { + ret = regmap_write(priv->regmap, TCAN4X5X_CONFIG, + TCAN4X5X_SW_RESET); + if (ret) + return ret; + } + + usleep_range(700, 1000); + + return ret; +} + static int regmap_spi_gather_write(void *context, const void *reg, size_t reg_len, const void *val, size_t val_len) @@ -341,6 +363,7 @@ static int tcan4x5x_init(struct m_can_classdev *cdev) static int tcan4x5x_parse_config(struct m_can_classdev *cdev) { struct tcan4x5x_priv *tcan4x5x = cdev->device_data; + int ret; tcan4x5x->device_wake_gpio = devm_gpiod_get(cdev->dev, "device-wake", GPIOD_OUT_HIGH); @@ -354,7 +377,9 @@ static int tcan4x5x_parse_config(struct m_can_classdev *cdev) if (IS_ERR(tcan4x5x->reset_gpio)) tcan4x5x->reset_gpio = NULL; - usleep_range(700, 1000); + ret = tcan4x5x_reset(tcan4x5x); + if (ret) + return ret; tcan4x5x->device_state_gpio = devm_gpiod_get_optional(cdev->dev, "device-state", -- 2.20.1