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=-9.0 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,T_DKIMWL_WL_HIGH,URIBL_BLOCKED,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 B92E3C28CC1 for ; Sat, 1 Jun 2019 06:12:02 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 90DDD2714A for ; Sat, 1 Jun 2019 06:12:02 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="IpEY9jMX"; dkim=fail reason="signature verification failed" (2048-bit key) header.d=sifive.com header.i=@sifive.com header.b="d+cvo2gI" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 90DDD2714A Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=sifive.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-riscv-bounces+infradead-linux-riscv=archiver.kernel.org@lists.infradead.org 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:MIME-Version:List-Subscribe:List-Help: List-Post:List-Archive:List-Unsubscribe:List-Id:References:In-Reply-To: Message-Id:Date:Subject:To:From:Reply-To:Cc:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=haDMJV087DKTVS1FcjlLr7TtSrCuoWHqRDpZXy5+368=; b=IpEY9jMXrNLDwD zYjXrxcziihxTpQqInQG1zL1wVsi53i2SYNCY6qOKvJ59ZxiX+MRkb+5vA//1hycrWLYQGh8p2oX0 SET7I9zamx9HHXbWvbg0zqC17k/Z0wWQRbAuY+CQbAsv17QzS+OwecaPPUMPk4MCh9GIcPeJgEwDc ii/O+QIZdVsXLUZRMjHzXM0nQVZ+DbuntFrFqve5zFvD0XF+IQ5DYsZJj/OQAnJUHirwG+VxSBYdu yE7PerFAQ0Aog3y4RFD+hd9Vx/weN0J6Lo/zoiOIReIWy2iKH4b8ltUrswRRezC3VH/vQr3WMEzXz tGtwGHDihnk/i2pCb0Ow==; 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 1hWxFG-00048R-0V; Sat, 01 Jun 2019 06:11:58 +0000 Received: from mail-pf1-x444.google.com ([2607:f8b0:4864:20::444]) by bombadil.infradead.org with esmtps (Exim 4.90_1 #2 (Red Hat Linux)) id 1hWxFD-000472-Gw for linux-riscv@lists.infradead.org; Sat, 01 Jun 2019 06:11:56 +0000 Received: by mail-pf1-x444.google.com with SMTP id c14so5079215pfi.1 for ; Fri, 31 May 2019 23:11:55 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=sifive.com; s=google; h=from:to:subject:date:message-id:in-reply-to:references; bh=SOLuY/R/QS+l1W9FKWqgele10Viv9LvbKIwVAA0kNm8=; b=d+cvo2gIFq6hLOlcwYDfGirRUjDXJLuj5z61HgVDs72gYfgBpvUrHrxic6IdRyYNK6 64sdFMaYgyrIM2I+55keFM26XVesvzBEkNS4lRyfEazbFN5tmkBNX4Sn+iAUsB/jlxou IbVPwJUO6aw4M9lkQj+5SJhH1n9mi86mK/afg8kY9OWezCV/Yqjxh8h1QKiDAoOJdwgP iiLDalPwwEIFUx3jdSrigiQSZuccIHWEe8o2hPC6WAd3m13lOpnUjCBMvuJPQr3nYARI Dv225GD/CMEyRl+ZchLqkU2PrF0q38vB7knwerfSNZEfPVmSk/R+Q6RBiMnEE0IEVIOY 2pXA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:subject:date:message-id:in-reply-to :references; bh=SOLuY/R/QS+l1W9FKWqgele10Viv9LvbKIwVAA0kNm8=; b=bXsNOkOjKziPYY60q+s9JZLvT+mo13nKzkzEV/IaULC1aPMnt5X1b+XmdK80SzYpXM d2MUu1AQFrfMzJaP6l3gmXhQoCa7H3+kWRR16UuSG21a9PxgasRd/IL/6sxoAcI0ZSo4 0yKOTo1Z8qS60t0w9RBsLNFJYRTHUoENVOdwPFU4PY1liVHRZZP0vRjykQ2IQ0A3ZJZx jVkrQN24HKMUnV6sZSkhKnInDeVi7DJQZ1Ltw083t+FtilYEDMVz5nxMD3H/LacfyY87 gh0ZTxcfiFITPUJHsDBDGdOnpTTxcmPOJUbtvG79LwfVvEq8Pi4QEemXrOby99Qr9nDM z21w== X-Gm-Message-State: APjAAAUDmLOoZTu/9FtzVg3KsTo5eROZhshDuN7mlb4wuCdAibdqwcfT HGeYd3ugAh2DyBEPbHaoAtbGmQ== X-Google-Smtp-Source: APXvYqyaFP3RwpKW0rt3bz1dzY/B4BEYi8u/4Gpw4jzlPR9FDwU98CbU1B23zpMqMoCntWhYDmyfag== X-Received: by 2002:a62:5f02:: with SMTP id t2mr15171599pfb.7.1559369514886; Fri, 31 May 2019 23:11:54 -0700 (PDT) Received: from buildserver-90.open-silicon.com ([114.143.65.226]) by smtp.googlemail.com with ESMTPSA id 2sm8935850pgl.40.2019.05.31.23.11.51 (version=TLS1_2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Fri, 31 May 2019 23:11:54 -0700 (PDT) From: Sagar Shrikant Kadam To: robh+dt@kernel.org, mark.rutland@arm.com, peter@korsgaard.com, andrew@lunn.ch, palmer@sifive.com, paul.walmsley@sifive.com, sagar.kadam@sifive.com, linux-i2c@vger.kernel.org, devicetree@vger.kernel.org, linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org Subject: [PATCH REPOST v8 3/3] i2c-ocores: sifive: add polling mode workaround for FU540-C000 SoC. Date: Sat, 1 Jun 2019 11:41:15 +0530 Message-Id: <1559369475-15374-4-git-send-email-sagar.kadam@sifive.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1559369475-15374-1-git-send-email-sagar.kadam@sifive.com> References: <1559369475-15374-1-git-send-email-sagar.kadam@sifive.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190531_231155_587278_E1ABF39E X-CRM114-Status: GOOD ( 15.40 ) X-BeenThere: linux-riscv@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-riscv" Errors-To: linux-riscv-bounces+infradead-linux-riscv=archiver.kernel.org@lists.infradead.org The i2c-ocore driver already has a polling mode interface.But it needs a workaround for FU540 Chipset on HiFive unleashed board (RevA00). There is an erratum in FU540 chip that prevents interrupt driven i2c transfers from working, and also the I2C controller's interrupt bit cannot be cleared if set, due to this the existing i2c polling mode interface added in mainline earlier doesn't work, and CPU stall's infinitely, when-ever i2c transfer is initiated. Ref: commit dd7dbf0eb090 ("i2c: ocores: refactor setup for polling") The workaround / fix under OCORES_FLAG_BROKEN_IRQ is particularly for FU540-COOO SoC. The polling function identifies a SiFive device based on the device node and enables the workaround. Signed-off-by: Sagar Shrikant Kadam Reviewed-by: Andrew Lunn --- drivers/i2c/busses/i2c-ocores.c | 24 ++++++++++++++++++++++-- 1 file changed, 22 insertions(+), 2 deletions(-) diff --git a/drivers/i2c/busses/i2c-ocores.c b/drivers/i2c/busses/i2c-ocores.c index b334fa2..4117f1a 100644 --- a/drivers/i2c/busses/i2c-ocores.c +++ b/drivers/i2c/busses/i2c-ocores.c @@ -35,6 +35,7 @@ struct ocores_i2c { int iobase; u32 reg_shift; u32 reg_io_width; + unsigned long flags; wait_queue_head_t wait; struct i2c_adapter adap; struct i2c_msg *msg; @@ -84,6 +85,8 @@ struct ocores_i2c { #define TYPE_GRLIB 1 #define TYPE_SIFIVE_REV0 2 +#define OCORES_FLAG_BROKEN_IRQ BIT(1) /* Broken IRQ for FU540-C000 SoC */ + static void oc_setreg_8(struct ocores_i2c *i2c, int reg, u8 value) { iowrite8(value, i2c->base + (reg << i2c->reg_shift)); @@ -236,9 +239,12 @@ static irqreturn_t ocores_isr(int irq, void *dev_id) struct ocores_i2c *i2c = dev_id; u8 stat = oc_getreg(i2c, OCI2C_STATUS); - if (!(stat & OCI2C_STAT_IF)) + if (i2c->flags & OCORES_FLAG_BROKEN_IRQ) { + if ((stat & OCI2C_STAT_IF) && !(stat & OCI2C_STAT_BUSY)) + return IRQ_NONE; + } else if (!(stat & OCI2C_STAT_IF)) { return IRQ_NONE; - + } ocores_process(i2c, stat); return IRQ_HANDLED; @@ -353,6 +359,11 @@ static void ocores_process_polling(struct ocores_i2c *i2c) ret = ocores_isr(-1, i2c); if (ret == IRQ_NONE) break; /* all messages have been transferred */ + else { + if (i2c->flags & OCORES_FLAG_BROKEN_IRQ) + if (i2c->state == STATE_DONE) + break; + } } } @@ -595,6 +606,7 @@ static int ocores_i2c_probe(struct platform_device *pdev) { struct ocores_i2c *i2c; struct ocores_i2c_platform_data *pdata; + const struct of_device_id *match; struct resource *res; int irq; int ret; @@ -677,6 +689,14 @@ static int ocores_i2c_probe(struct platform_device *pdev) irq = platform_get_irq(pdev, 0); if (irq == -ENXIO) { ocores_algorithm.master_xfer = ocores_xfer_polling; + + /* + * Set in OCORES_FLAG_BROKEN_IRQ to enable workaround for + * FU540-C000 SoC in polling mode. + */ + match = of_match_node(ocores_i2c_match, pdev->dev.of_node); + if (match && (long)match->data == TYPE_SIFIVE_REV0) + i2c->flags |= OCORES_FLAG_BROKEN_IRQ; } else { if (irq < 0) return irq; -- 1.9.1 _______________________________________________ linux-riscv mailing list linux-riscv@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-riscv