From patchwork Wed Apr 11 13:24:58 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Pierre Yves MORDRET X-Patchwork-Id: 10335463 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id E1BE16053B for ; Wed, 11 Apr 2018 13:27:01 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id D8EA628905 for ; Wed, 11 Apr 2018 13:27:01 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id CBB55288E1; Wed, 11 Apr 2018 13:27:01 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.9 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,MAILING_LIST_MULTI autolearn=unavailable version=3.3.1 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 5E80D288D7 for ; Wed, 11 Apr 2018 13:27:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-ID:Date:Subject:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=V2RrZPPdYlRJTy0GsIhGIWy2Wl8UZCwia9bwZk6cEzo=; b=CBtCMxvA3JmoH1 Rju4MXniwZjbCJRy0+piXil6nLcc9goVVqtoFgA4Fpu6NU3nF2snk8GD7CqbF6cNMA4AGt25KuuIp KrtMup5tMrbQ+D85N7ObckmtTcS7337SDNcgnmp9IVqremXmLaznf3QrturCehrpAmnMF2L1GW4W2 4+Pc/SMCpnDyu6Pwy4ZsTt2m6mxmgpjVN/vD6nZL4j/eFMZGDTrFg1BPOnqYIEksjpqs+m+g+iygz kq7VlLSKj3vELMHUWgFGvAQjKzS7Zm7gz+WZjyx5OufDKSel8T0/xQimXz8X/MkN3ZCV+vaHDyk7a 2z7C+V7xWe/M5sP961sQ==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1f6Fly-0004cO-Rp; Wed, 11 Apr 2018 13:26:50 +0000 Received: from mx07-00178001.pphosted.com ([62.209.51.94]) by bombadil.infradead.org with esmtps (Exim 4.90_1 #2 (Red Hat Linux)) id 1f6FkX-0003J5-8k for linux-arm-kernel@lists.infradead.org; Wed, 11 Apr 2018 13:25:23 +0000 Received: from pps.filterd (m0046037.ppops.net [127.0.0.1]) by mx07-.pphosted.com (8.16.0.21/8.16.0.21) with SMTP id w3BDNnaD016531; Wed, 11 Apr 2018 15:25:07 +0200 Received: from beta.dmz-eu.st.com (beta.dmz-eu.st.com [164.129.1.35]) by mx07-00178001.pphosted.com with ESMTP id 2h9hc98mwe-1 (version=TLSv1 cipher=ECDHE-RSA-AES256-SHA bits=256 verify=NOT); Wed, 11 Apr 2018 15:25:07 +0200 Received: from zeta.dmz-eu.st.com (zeta.dmz-eu.st.com [164.129.230.9]) by beta.dmz-eu.st.com (STMicroelectronics) with ESMTP id 6FFD94A; Wed, 11 Apr 2018 13:25:07 +0000 (GMT) Received: from Webmail-eu.st.com (sfhdag5node2.st.com [10.75.127.14]) by zeta.dmz-eu.st.com (STMicroelectronics) with ESMTP id 50EF42926; Wed, 11 Apr 2018 13:25:07 +0000 (GMT) Received: from localhost (10.75.127.50) by SFHDAG5NODE2.st.com (10.75.127.14) with Microsoft SMTP Server (TLS) id 15.0.1347.2; Wed, 11 Apr 2018 15:25:06 +0200 From: Pierre-Yves MORDRET To: Wolfram Sang , Maxime Coquelin , Alexandre Torgue , , , Subject: [PATCH v3 6/6] i2c: i2c-stm32f7: Implement I2C release mechanism Date: Wed, 11 Apr 2018 15:24:58 +0200 Message-ID: <1523453098-3758-7-git-send-email-pierre-yves.mordret@st.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1523453098-3758-1-git-send-email-pierre-yves.mordret@st.com> References: <1523453098-3758-1-git-send-email-pierre-yves.mordret@st.com> MIME-Version: 1.0 X-Originating-IP: [10.75.127.50] X-ClientProxiedBy: SFHDAG2NODE3.st.com (10.75.127.6) To SFHDAG5NODE2.st.com (10.75.127.14) X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:, , definitions=2018-04-11_06:, , signatures=0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20180411_062521_625985_93EE7490 X-CRM114-Status: GOOD ( 12.89 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Pierre-Yves MORDRET Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Virus-Scanned: ClamAV using ClamSMTP Feature prevents I2C lock-ups. Mechanism resets I2C state machine and releases SCL/SDA signals but preserves I2C registers. Signed-off-by: Pierre-Yves MORDRET --- Version history: v1: * Initial v2: * Don't use i2c engine recovery mechanism since driver procedure only recover master and not the slave. v3: * s/recovery/release/ throughout the patch. Recovery is really something else --- --- drivers/i2c/busses/i2c-stm32f7.c | 27 ++++++++++++++++++++++++--- 1 file changed, 24 insertions(+), 3 deletions(-) diff --git a/drivers/i2c/busses/i2c-stm32f7.c b/drivers/i2c/busses/i2c-stm32f7.c index 63ea71c..0f87449 100644 --- a/drivers/i2c/busses/i2c-stm32f7.c +++ b/drivers/i2c/busses/i2c-stm32f7.c @@ -718,6 +718,20 @@ static void stm32f7_i2c_smbus_reload(struct stm32f7_i2c_dev *i2c_dev) writel_relaxed(cr2, i2c_dev->base + STM32F7_I2C_CR2); } +static int stm32f7_i2c_release_bus(struct i2c_adapter *i2c_adap) +{ + struct stm32f7_i2c_dev *i2c_dev = i2c_get_adapdata(i2c_adap); + + dev_info(i2c_dev->dev, "Trying to recover bus\n"); + + stm32f7_i2c_clr_bits(i2c_dev->base + STM32F7_I2C_CR1, + STM32F7_I2C_CR1_PE); + + stm32f7_i2c_hw_config(i2c_dev); + + return 0; +} + static int stm32f7_i2c_wait_free_bus(struct stm32f7_i2c_dev *i2c_dev) { u32 status; @@ -727,12 +741,18 @@ static int stm32f7_i2c_wait_free_bus(struct stm32f7_i2c_dev *i2c_dev) status, !(status & STM32F7_I2C_ISR_BUSY), 10, 1000); + if (!ret) + return 0; + + dev_info(i2c_dev->dev, "bus busy\n"); + + ret = stm32f7_i2c_release_bus(&i2c_dev->adap); if (ret) { - dev_dbg(i2c_dev->dev, "bus busy\n"); - ret = -EBUSY; + dev_err(i2c_dev->dev, "Failed to recover the bus (%d)\n", ret); + return ret; } - return ret; + return -EBUSY; } static void stm32f7_i2c_xfer_msg(struct stm32f7_i2c_dev *i2c_dev, @@ -1474,6 +1494,7 @@ static irqreturn_t stm32f7_i2c_isr_error(int irq, void *data) if (status & STM32F7_I2C_ISR_BERR) { dev_err(dev, "<%s>: Bus error\n", __func__); writel_relaxed(STM32F7_I2C_ICR_BERRCF, base + STM32F7_I2C_ICR); + stm32f7_i2c_release_bus(&i2c_dev->adap); f7_msg->result = -EIO; }