From patchwork Thu Jul 21 15:23:38 2011 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Shubhrajyoti Datta X-Patchwork-Id: 995282 Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) by demeter2.kernel.org (8.14.4/8.14.4) with ESMTP id p6LFPts6006090 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO) for ; Thu, 21 Jul 2011 15:26:16 GMT Received: from canuck.infradead.org ([2001:4978:20e::1]) by merlin.infradead.org with esmtps (Exim 4.76 #1 (Red Hat Linux)) id 1Qjv7r-0007dc-5o; Thu, 21 Jul 2011 15:25:23 +0000 Received: from localhost ([127.0.0.1] helo=canuck.infradead.org) by canuck.infradead.org with esmtp (Exim 4.76 #1 (Red Hat Linux)) id 1Qjv7p-0006Sn-Ck; Thu, 21 Jul 2011 15:25:21 +0000 Received: from comal.ext.ti.com ([198.47.26.152]) by canuck.infradead.org with esmtps (Exim 4.76 #1 (Red Hat Linux)) id 1Qjv6a-0006A8-Im for linux-arm-kernel@lists.infradead.org; Thu, 21 Jul 2011 15:24:08 +0000 Received: from dbdp20.itg.ti.com ([172.24.170.38]) by comal.ext.ti.com (8.13.7/8.13.7) with ESMTP id p6LFNxvL011718 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Thu, 21 Jul 2011 10:24:02 -0500 Received: from dbde70.ent.ti.com (localhost [127.0.0.1]) by dbdp20.itg.ti.com (8.13.8/8.13.8) with ESMTP id p6LFNx3o005278; Thu, 21 Jul 2011 20:53:59 +0530 (IST) Received: from dbdp31.itg.ti.com (172.24.170.98) by DBDE70.ent.ti.com (172.24.170.148) with Microsoft SMTP Server id 8.3.106.1; Thu, 21 Jul 2011 20:53:59 +0530 Received: from a0393217ubnlt.india.ti.com ([172.24.190.93]) by dbdp31.itg.ti.com (8.13.8/8.13.8) with ESMTP id p6LFNgBl010077; Thu, 21 Jul 2011 20:53:55 +0530 (IST) From: Shubhrajyoti D To: Subject: [PATCHV4 4/4] OMAP: I2C: I2C register restore only if context is lost Date: Thu, 21 Jul 2011 20:53:38 +0530 Message-ID: <1311261818-25784-5-git-send-email-shubhrajyoti@ti.com> X-Mailer: git-send-email 1.7.1 In-Reply-To: <1311261818-25784-1-git-send-email-shubhrajyoti@ti.com> References: <1311261818-25784-1-git-send-email-shubhrajyoti@ti.com> MIME-Version: 1.0 X-CRM114-Version: 20090807-BlameThorstenAndJenny ( TRE 0.7.6 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20110721_112404_855937_31383B0F X-CRM114-Status: GOOD ( 13.74 ) X-Spam-Score: -3.5 (---) X-Spam-Report: SpamAssassin version 3.3.1 on canuck.infradead.org summary: Content analysis details: (-3.5 points) pts rule name description ---- ---------------------- -------------------------------------------------- -2.3 RCVD_IN_DNSWL_MED RBL: Sender listed at http://www.dnswl.org/, medium trust [198.47.26.152 listed in list.dnswl.org] -1.2 RP_MATCHES_RCVD Envelope sender domain matches handover relay domain Cc: khilman@ti.com, balajitk@ti.com, rnayak@ti.com, santosh.shilimkar@ti.com, linux-i2c@vger.kernel.org, Shubhrajyoti D , linux-arm-kernel@lists.infradead.org X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.12 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: linux-arm-kernel-bounces@lists.infradead.org Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Greylist: IP, sender and recipient auto-whitelisted, not delayed by milter-greylist-4.2.6 (demeter2.kernel.org [140.211.167.43]); Thu, 21 Jul 2011 15:26:16 +0000 (UTC) Currently i2c register restore is done always. Adding conditional restore. The i2c register restore is done only if the context is lost. Acked-by: Santosh Shilimkar Signed-off-by: Shubhrajyoti D --- drivers/i2c/busses/i2c-omap.c | 24 +++++++++++++++++------- 1 files changed, 17 insertions(+), 7 deletions(-) diff --git a/drivers/i2c/busses/i2c-omap.c b/drivers/i2c/busses/i2c-omap.c index 75bb62d..dffdbfd 100644 --- a/drivers/i2c/busses/i2c-omap.c +++ b/drivers/i2c/busses/i2c-omap.c @@ -40,6 +40,7 @@ #include #include #include +#include /* I2C controller revisions */ #define OMAP_I2C_OMAP1_REV_2 0x20 @@ -200,6 +201,7 @@ struct omap_i2c_dev { u16 syscstate; u16 westate; u16 errata; + u32 dev_lost_count; }; const static u8 reg_map_ip_v1[] = { @@ -260,6 +262,17 @@ static inline u16 omap_i2c_read_reg(struct omap_i2c_dev *i2c_dev, int reg) (i2c_dev->regs[reg] << i2c_dev->reg_shift)); } +static void omap_i2c_restore(struct omap_i2c_dev *dev) +{ + omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, 0); + omap_i2c_write_reg(dev, OMAP_I2C_PSC_REG, dev->pscstate); + omap_i2c_write_reg(dev, OMAP_I2C_SCLL_REG, dev->scllstate); + omap_i2c_write_reg(dev, OMAP_I2C_SCLH_REG, dev->sclhstate); + omap_i2c_write_reg(dev, OMAP_I2C_BUF_REG, dev->bufstate); + omap_i2c_write_reg(dev, OMAP_I2C_WE_REG, dev->westate); + omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, OMAP_I2C_CON_EN); +} + static void omap_i2c_unidle(struct omap_i2c_dev *dev) { struct platform_device *pdev; @@ -273,13 +286,9 @@ static void omap_i2c_unidle(struct omap_i2c_dev *dev) pm_runtime_get_sync(&pdev->dev); if (pdata->flags & OMAP_I2C_FLAG_RESET_REGS_POSTIDLE) { - omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, 0); - omap_i2c_write_reg(dev, OMAP_I2C_PSC_REG, dev->pscstate); - omap_i2c_write_reg(dev, OMAP_I2C_SCLL_REG, dev->scllstate); - omap_i2c_write_reg(dev, OMAP_I2C_SCLH_REG, dev->sclhstate); - omap_i2c_write_reg(dev, OMAP_I2C_BUF_REG, dev->bufstate); - omap_i2c_write_reg(dev, OMAP_I2C_WE_REG, dev->westate); - omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, OMAP_I2C_CON_EN); + u32 loss_cnt = omap_device_get_context_loss_count(pdev); + if (dev->dev_lost_count != loss_cnt) + omap_i2c_restore(dev); } dev->idle = 0; @@ -318,6 +327,7 @@ static void omap_i2c_idle(struct omap_i2c_dev *dev) } dev->idle = 1; + dev->dev_lost_count = omap_device_get_context_loss_count(pdev); pm_runtime_put_sync(&pdev->dev); }