From patchwork Sun May 30 22:56:59 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Chris Packham X-Patchwork-Id: 450411 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=-16.0 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, UNWANTED_LANGUAGE_BODY, USER_AGENT_GIT autolearn=ham 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 24778C47093 for ; Sun, 30 May 2021 23:00:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id EECBC611EE for ; Sun, 30 May 2021 23:00:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229917AbhE3W6t (ORCPT ); Sun, 30 May 2021 18:58:49 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34960 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229915AbhE3W6t (ORCPT ); Sun, 30 May 2021 18:58:49 -0400 Received: from gate2.alliedtelesis.co.nz (gate2.alliedtelesis.co.nz [IPv6:2001:df5:b000:5::4]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3C812C061574 for ; Sun, 30 May 2021 15:57:08 -0700 (PDT) Received: from svr-chch-seg1.atlnz.lc (mmarshal3.atlnz.lc [10.32.18.43]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by gate2.alliedtelesis.co.nz (Postfix) with ESMTPS id 257348364F; Mon, 31 May 2021 10:57:03 +1200 (NZST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=alliedtelesis.co.nz; s=mail181024; t=1622415423; bh=r1PeCdtDfQf/3d2GiJhstp2bICjzI0nnfAcIwqjbXZ4=; h=From:To:Cc:Subject:Date; b=lOXuLy/60scgTUC2Bu9b4Mb4n4eas1m020Az7oK+E8nZ4IzvYSFnShj8cEkRmMNen dCvIJZfAA3vjwOoekMBbVzQbjz1qeLYBvWQKaZo+/LleN6KZDLsoW9sJ+48xQhsTqu uPMn40ebp9NNg2/G2jyk8VMADGlhrSlm2gyYy/JpM6q0mhKGBjl043pYBBWgLZquLX jfTIDmxKDg+aAKD3NfVeWMTt2zDbeEcOffXCyDNgIVFVN9YPh7HR4h/ZF0wYn6ltF8 vtpMeT+3RJevKtKv9qxIS/N1c8f0alA0/xFVxW1avejPR4sd5SPYlJW/fWHwGN3p71 hv5nVHGDwcJxA== Received: from pat.atlnz.lc (Not Verified[10.32.16.33]) by svr-chch-seg1.atlnz.lc with Trustwave SEG (v8, 2, 6, 11305) id ; Mon, 31 May 2021 10:57:03 +1200 Received: from chrisp-dl.ws.atlnz.lc (chrisp-dl.ws.atlnz.lc [10.33.22.20]) by pat.atlnz.lc (Postfix) with ESMTP id 04F3413EEA1; Mon, 31 May 2021 10:57:03 +1200 (NZST) Received: by chrisp-dl.ws.atlnz.lc (Postfix, from userid 1030) id F2E75283A4E; Mon, 31 May 2021 10:57:02 +1200 (NZST) From: Chris Packham To: wsa@kernel.org, rjui@broadcom.com, sbranden@broadcom.com, bcm-kernel-feedback-list@broadcom.com Cc: linux-i2c@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Richard Laing , Chris Packham Subject: [PATCH] i2c: bcm-iproc: Add i2c recovery support Date: Mon, 31 May 2021 10:56:59 +1200 Message-Id: <20210530225659.17138-1-chris.packham@alliedtelesis.co.nz> X-Mailer: git-send-email 2.31.1 MIME-Version: 1.0 X-SEG-SpamProfiler-Analysis: v=2.3 cv=WOcBoUkR c=1 sm=1 tr=0 a=KLBiSEs5mFS1a/PbTCJxuA==:117 a=5FLXtPjwQuUA:10 a=Jg9UQ0_FWdfR-ABCIGgA:9 X-SEG-SpamProfiler-Score: 0 x-atlnz-ls: pat Precedence: bulk List-ID: X-Mailing-List: linux-i2c@vger.kernel.org From: Richard Laing The bcm-iproc controller can put the SDA/SCL lines into bit-bang mode, make use of this to support i2c bus recovery. Signed-off-by: Richard Laing Signed-off-by: Chris Packham --- Notes: Richard did most of the work on this. I'm just cleaning it up to get it upstream. drivers/i2c/busses/i2c-bcm-iproc.c | 115 +++++++++++++++++++++++++++++ 1 file changed, 115 insertions(+) diff --git a/drivers/i2c/busses/i2c-bcm-iproc.c b/drivers/i2c/busses/i2c-bcm-iproc.c index cceaf69279a9..d63a286c1660 100644 --- a/drivers/i2c/busses/i2c-bcm-iproc.c +++ b/drivers/i2c/busses/i2c-bcm-iproc.c @@ -26,6 +26,7 @@ #define CFG_RESET_SHIFT 31 #define CFG_EN_SHIFT 30 #define CFG_SLAVE_ADDR_0_SHIFT 28 +#define CFG_BIT_BANG_SHIFT 29 #define CFG_M_RETRY_CNT_SHIFT 16 #define CFG_M_RETRY_CNT_MASK 0x0f @@ -66,6 +67,12 @@ #define S_FIFO_RX_THLD_SHIFT 8 #define S_FIFO_RX_THLD_MASK 0x3f +#define M_BB_CTRL_OFFSET 0x14 +#define M_BB_SMBCLK_IN 31 +#define M_BB_SMBCLK_OUT_EN 30 +#define M_BB_SMBDAT_IN 29 +#define M_BB_SMBDAT_OUT_EN 28 + #define M_CMD_OFFSET 0x30 #define M_CMD_START_BUSY_SHIFT 31 #define M_CMD_STATUS_SHIFT 25 @@ -713,6 +720,112 @@ static void bcm_iproc_i2c_enable_disable(struct bcm_iproc_i2c_dev *iproc_i2c, iproc_i2c_wr_reg(iproc_i2c, CFG_OFFSET, val); } +static void bcm_iproc_i2c_reset(struct bcm_iproc_i2c_dev *iproc_i2c) +{ + u32 tmp; + + tmp = readl(iproc_i2c->base + CFG_OFFSET); + tmp |= BIT(CFG_RESET_SHIFT); + writel(tmp, iproc_i2c->base + CFG_OFFSET); + udelay(100); + +} + +static void bcm_iproc_i2c_prepare_recovery(struct i2c_adapter *adap) +{ + struct bcm_iproc_i2c_dev *iproc_i2c = i2c_get_adapdata(adap); + u32 tmp; + + dev_dbg(iproc_i2c->device, "Prepare recovery\n"); + + /* Disable interrupts */ + writel(0, iproc_i2c->base + IE_OFFSET); + readl(iproc_i2c->base + IE_OFFSET); + synchronize_irq(iproc_i2c->irq); + + bcm_iproc_i2c_reset(iproc_i2c); + + /* Switch to bit-bang mode */ + tmp = readl(iproc_i2c->base + CFG_OFFSET); + tmp |= BIT(CFG_BIT_BANG_SHIFT); + writel(tmp, iproc_i2c->base + CFG_OFFSET); +} + +static void bcm_iproc_i2c_unprepare_recovery(struct i2c_adapter *adap) +{ + struct bcm_iproc_i2c_dev *iproc_i2c = i2c_get_adapdata(adap); + u32 tmp; + + /* Switch to normal mode */ + tmp = readl(iproc_i2c->base + CFG_OFFSET); + tmp &= ~BIT(CFG_BIT_BANG_SHIFT); + writel(tmp, iproc_i2c->base + CFG_OFFSET); + udelay(100); + + bcm_iproc_i2c_init(iproc_i2c); + bcm_iproc_i2c_enable_disable(iproc_i2c, true); + + dev_dbg(iproc_i2c->device, "Recovery complete\n"); +} + +static int bcm_iproc_i2c_get_scl(struct i2c_adapter *adap) +{ + struct bcm_iproc_i2c_dev *iproc_i2c = i2c_get_adapdata(adap); + u32 tmp; + + tmp = readl(iproc_i2c->base + M_BB_CTRL_OFFSET); + + return !!(tmp & BIT(M_BB_SMBCLK_IN)); +} + +static void bcm_iproc_i2c_set_scl(struct i2c_adapter *adap, int val) +{ + struct bcm_iproc_i2c_dev *iproc_i2c = i2c_get_adapdata(adap); + u32 tmp; + + tmp = readl(iproc_i2c->base + M_BB_CTRL_OFFSET); + if (val) + tmp |= BIT(M_BB_SMBCLK_OUT_EN); + else + tmp &= ~BIT(M_BB_SMBCLK_OUT_EN); + + writel(tmp, iproc_i2c->base + M_BB_CTRL_OFFSET); +} + +static void bcm_iproc_i2c_set_sda(struct i2c_adapter *adap, int val) +{ + struct bcm_iproc_i2c_dev *iproc_i2c = i2c_get_adapdata(adap); + u32 tmp; + + tmp = readl(iproc_i2c->base + M_BB_CTRL_OFFSET); + if (val) + tmp |= BIT(M_BB_SMBDAT_OUT_EN); + else + tmp &= ~BIT(M_BB_SMBDAT_OUT_EN); + + writel(tmp, iproc_i2c->base + M_BB_CTRL_OFFSET); +} + +static int bcm_iproc_i2c_get_sda(struct i2c_adapter *adap) +{ + struct bcm_iproc_i2c_dev *iproc_i2c = i2c_get_adapdata(adap); + u32 tmp; + + tmp = readl(iproc_i2c->base + M_BB_CTRL_OFFSET); + + return !!(tmp & BIT(M_BB_SMBDAT_IN)); +} + +static struct i2c_bus_recovery_info bcm_iproc_recovery_info = { + .recover_bus = i2c_generic_scl_recovery, + .prepare_recovery = bcm_iproc_i2c_prepare_recovery, + .unprepare_recovery = bcm_iproc_i2c_unprepare_recovery, + .set_scl = bcm_iproc_i2c_set_scl, + .get_scl = bcm_iproc_i2c_get_scl, + .set_sda = bcm_iproc_i2c_set_sda, + .get_sda = bcm_iproc_i2c_get_sda, +}; + static int bcm_iproc_i2c_check_status(struct bcm_iproc_i2c_dev *iproc_i2c, struct i2c_msg *msg) { @@ -839,6 +952,7 @@ static int bcm_iproc_i2c_xfer_internal(struct bcm_iproc_i2c_dev *iproc_i2c, if (!!(iproc_i2c_rd_reg(iproc_i2c, M_CMD_OFFSET) & BIT(M_CMD_START_BUSY_SHIFT))) { dev_warn(iproc_i2c->device, "bus is busy\n"); + i2c_recover_bus(&iproc_i2c->adapter); return -EBUSY; } @@ -1111,6 +1225,7 @@ static int bcm_iproc_i2c_probe(struct platform_device *pdev) of_node_full_name(iproc_i2c->device->of_node)); adap->algo = &bcm_iproc_algo; adap->quirks = &bcm_iproc_i2c_quirks; + adap->bus_recovery_info = &bcm_iproc_recovery_info; adap->dev.parent = &pdev->dev; adap->dev.of_node = pdev->dev.of_node;