From patchwork Tue May 4 15:59:45 2010 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: manjugk manjugk X-Patchwork-Id: 96816 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 o44G0XaA013775 for ; Tue, 4 May 2010 16:00:34 GMT Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759989Ab0EDQAR (ORCPT ); Tue, 4 May 2010 12:00:17 -0400 Received: from bear.ext.ti.com ([192.94.94.41]:57980 "EHLO bear.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759951Ab0EDQAP (ORCPT ); Tue, 4 May 2010 12:00:15 -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 o44FxsMk020522 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Tue, 4 May 2010 10:59:57 -0500 Received: from localhost.localdomain (localhost [127.0.0.1]) by dbdp31.itg.ti.com (8.13.8/8.13.8) with ESMTP id o44Fxl64006267; Tue, 4 May 2010 21:29:48 +0530 (IST) From: Manjunatha GK To: linux-omap@vger.kernel.org Cc: linux-i2c@vger.kernel.org, ben-linux@fluff.org, "Kalliguddi, Hema" , Nishanth Menon , Aaro Koskinen , Tony Lindgren Subject: [PATCH v7] OMAP2/3: I2C: Errata ID i207: Clear wrong RDR interrupt Date: Tue, 4 May 2010 21:29:45 +0530 Message-Id: <1272988786-2005-1-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, 04 May 2010 16:00:35 +0000 (UTC) diff --git a/drivers/i2c/busses/i2c-omap.c b/drivers/i2c/busses/i2c-omap.c index ef73483..5f5207e 100644 --- a/drivers/i2c/busses/i2c-omap.c +++ b/drivers/i2c/busses/i2c-omap.c @@ -166,6 +166,8 @@ enum { #define SYSC_IDLEMODE_SMART 0x2 #define SYSC_CLOCKACTIVITY_FCLK 0x2 +/* Errata definitions */ +#define I2C_OMAP_ERRATA_I207 (1 << 0) struct omap_i2c_dev { struct device *dev; @@ -199,6 +201,7 @@ struct omap_i2c_dev { u16 bufstate; u16 syscstate; u16 westate; + u16 errata; }; const static u8 reg_map[] = { @@ -498,6 +501,11 @@ 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 = 0; + + if (cpu_is_omap2430() || cpu_is_omap34xx()) + dev->errata |= I2C_OMAP_ERRATA_I207; + /* Enable interrupts */ dev->iestate = (OMAP_I2C_IE_XRDY | OMAP_I2C_IE_RRDY | OMAP_I2C_IE_ARDY | OMAP_I2C_IE_NACK | @@ -695,6 +703,34 @@ 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 bus is busy.\n"); + } + + } + } +} + /* rev1 devices are apparently only on some 15xx */ #ifdef CONFIG_ARCH_OMAP15XX @@ -826,6 +862,10 @@ complete: } if (stat & (OMAP_I2C_STAT_RRDY | OMAP_I2C_STAT_RDR)) { u8 num_bytes = 1; + + if (dev->errata & I2C_OMAP_ERRATA_I207) + i2c_omap_errata_i207(dev, stat); + if (dev->fifo_size) { if (stat & OMAP_I2C_STAT_RRDY) num_bytes = dev->fifo_size;