From patchwork Tue Apr 27 14:47:25 2010 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: manjugk manjugk X-Patchwork-Id: 95445 X-Patchwork-Delegate: tony@atomide.com Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by demeter.kernel.org (8.14.3/8.14.3) with ESMTP id o3RERIn7013233 for ; Tue, 27 Apr 2010 14:27:18 GMT Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756063Ab0D0O0p (ORCPT ); Tue, 27 Apr 2010 10:26:45 -0400 Received: from bear.ext.ti.com ([192.94.94.41]:39781 "EHLO bear.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753950Ab0D0O0n (ORCPT ); Tue, 27 Apr 2010 10:26:43 -0400 Received: from dbdp31.itg.ti.com ([172.24.170.98]) by bear.ext.ti.com (8.13.7/8.13.7) with ESMTP id o3REQPQ9011045 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Tue, 27 Apr 2010 09:26:28 -0500 Received: from localhost.localdomain (localhost [127.0.0.1]) by dbdp31.itg.ti.com (8.13.8/8.13.8) with ESMTP id o3REQH7l016673; Tue, 27 Apr 2010 19:56:18 +0530 (IST) From: Manjunatha GK To: linux-omap@vger.kernel.org Cc: Manjunatha GK , linux-i2c@vger.kernel.org, ben-linux@fluff.org, "Kalliguddi, Hema" , Nishanth Menon , Aaro Koskinen , Tony Lindgren Subject: [PATCH v5] OMAP2/3: I2C: Errata ID i207: Clear wrong RDR interrupt Date: Tue, 27 Apr 2010 20:17:25 +0530 Message-Id: <1272379645-20523-1-git-send-email-manjugk@ti.com> X-Mailer: git-send-email 1.6.0.4 Sender: linux-omap-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-omap@vger.kernel.org X-Greylist: IP, sender and recipient auto-whitelisted, not delayed by milter-greylist-4.2.3 (demeter.kernel.org [140.211.167.41]); Tue, 27 Apr 2010 14:27:21 +0000 (UTC) diff --git a/drivers/i2c/busses/i2c-omap.c b/drivers/i2c/busses/i2c-omap.c index ef73483..f232f96 100644 --- a/drivers/i2c/busses/i2c-omap.c +++ b/drivers/i2c/busses/i2c-omap.c @@ -199,6 +199,7 @@ struct omap_i2c_dev { u16 bufstate; u16 syscstate; u16 westate; + bool errata_i207; }; const static u8 reg_map[] = { @@ -498,6 +499,12 @@ static int omap_i2c_init(struct omap_i2c_dev *dev) /* Take the I2C module out of reset: */ omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, OMAP_I2C_CON_EN); + dev->errata_i207 = false; + + if (cpu_is_omap2430() || cpu_is_omap34xx()) { + dev->errata_i207 = true; + } + /* Enable interrupts */ dev->iestate = (OMAP_I2C_IE_XRDY | OMAP_I2C_IE_RRDY | OMAP_I2C_IE_ARDY | OMAP_I2C_IE_NACK | @@ -695,6 +702,34 @@ omap_i2c_ack_stat(struct omap_i2c_dev *dev, u16 stat) omap_i2c_write_reg(dev, OMAP_I2C_STAT_REG, stat); } +static inline void i2c_omap_errata_i207(struct omap_i2c_dev *dev, u16 stat) +{ + /* + * I2C Errata(Errata Nos. OMAP2: 1.67, OMAP3: 1.8) + * Not applicable for OMAP4. + * Under certain rare conditions, RDR could be set again + * when the bus is busy, then ignore the interrupt and + * clear the interrupt. + */ + if (stat & OMAP_I2C_STAT_RDR) { + /* Step 1: If RDR is set, clear it */ + omap_i2c_ack_stat(dev, OMAP_I2C_STAT_RDR); + + /* Step 2: */ + if(!(omap_i2c_read_reg(dev, OMAP_I2C_STAT_REG) + & OMAP_I2C_STAT_BB)) { + + /* Step 3: */ + if(omap_i2c_read_reg(dev,OMAP_I2C_STAT_REG) + & OMAP_I2C_STAT_RDR) { + omap_i2c_ack_stat(dev,OMAP_I2C_STAT_RDR); + dev_dbg(dev->dev,"RDR when the bus is busy.\n"); + } + + } + } +} + /* rev1 devices are apparently only on some 15xx */ #ifdef CONFIG_ARCH_OMAP15XX @@ -826,6 +861,10 @@ complete: } if (stat & (OMAP_I2C_STAT_RRDY | OMAP_I2C_STAT_RDR)) { u8 num_bytes = 1; + + if (dev->errata_i207) + i2c_omap_errata_i207(dev, stat); + if (dev->fifo_size) { if (stat & OMAP_I2C_STAT_RRDY) num_bytes = dev->fifo_size;