From patchwork Wed May 6 16:50:27 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Felipe Balbi X-Patchwork-Id: 6351431 Return-Path: X-Original-To: patchwork-linux-omap@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork1.web.kernel.org (Postfix) with ESMTP id 4A5A79F1C2 for ; Wed, 6 May 2015 16:55:57 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 608B92034E for ; Wed, 6 May 2015 16:55:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6D42620115 for ; Wed, 6 May 2015 16:55:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752552AbbEFQzx (ORCPT ); Wed, 6 May 2015 12:55:53 -0400 Received: from bear.ext.ti.com ([192.94.94.41]:57545 "EHLO bear.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751733AbbEFQwf (ORCPT ); Wed, 6 May 2015 12:52:35 -0400 Received: from dflxv15.itg.ti.com ([128.247.5.124]) by bear.ext.ti.com (8.13.7/8.13.7) with ESMTP id t46Gq7Fq021848; Wed, 6 May 2015 11:52:07 -0500 Received: from DLEE70.ent.ti.com (dlee70.ent.ti.com [157.170.170.113]) by dflxv15.itg.ti.com (8.14.3/8.13.8) with ESMTP id t46Gq6Y7013726; Wed, 6 May 2015 11:52:06 -0500 Received: from dlep33.itg.ti.com (157.170.170.75) by DLEE70.ent.ti.com (157.170.170.113) with Microsoft SMTP Server id 14.3.224.2; Wed, 6 May 2015 11:52:06 -0500 Received: from localhost (ileax41-snat.itg.ti.com [10.172.224.153]) by dlep33.itg.ti.com (8.14.3/8.13.8) with ESMTP id t46Gq5Dh026348; Wed, 6 May 2015 11:52:06 -0500 From: Felipe Balbi To: CC: Tony Lindgren , Linux OMAP Mailing List , Linux ARM Kernel Mailing List , , , Felipe Balbi Subject: [PATCH] i2c: omap: implement bus recovery Date: Wed, 6 May 2015 11:50:27 -0500 Message-ID: <1430931027-19955-1-git-send-email-balbi@ti.com> X-Mailer: git-send-email 2.4.0.rc3 MIME-Version: 1.0 Sender: linux-omap-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-omap@vger.kernel.org X-Spam-Status: No, score=-6.9 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, T_RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP implement bus recovery methods for i2c-omap so we can recover from situations where SCL/SDA are stuck low. Signed-off-by: Felipe Balbi --- rebased on 4.1-rc2, switched over to generic i2c recover mechanism, retested on am437x sk and beaglebone black. drivers/i2c/busses/i2c-omap.c | 69 ++++++++++++++++++++++++++++++++++++++++--- 1 file changed, 65 insertions(+), 4 deletions(-) diff --git a/drivers/i2c/busses/i2c-omap.c b/drivers/i2c/busses/i2c-omap.c index 0e894193accf..dcf559ac92c5 100644 --- a/drivers/i2c/busses/i2c-omap.c +++ b/drivers/i2c/busses/i2c-omap.c @@ -481,10 +481,8 @@ static int omap_i2c_wait_for_bb(struct omap_i2c_dev *dev) timeout = jiffies + OMAP_I2C_TIMEOUT; while (omap_i2c_read_reg(dev, OMAP_I2C_STAT_REG) & OMAP_I2C_STAT_BB) { - if (time_after(jiffies, timeout)) { - dev_warn(dev->dev, "timeout waiting for bus ready\n"); - return -ETIMEDOUT; - } + if (time_after(jiffies, timeout)) + return i2c_recover_bus(&dev->adapter); msleep(1); } @@ -1209,6 +1207,68 @@ MODULE_DEVICE_TABLE(of, omap_i2c_of_match); #define OMAP_I2C_SCHEME_0 0 #define OMAP_I2C_SCHEME_1 1 +static int omap_i2c_get_scl(struct i2c_adapter *adap) +{ + struct omap_i2c_dev *dev = i2c_get_adapdata(adap); + u32 reg; + + reg = omap_i2c_read_reg(dev, OMAP_I2C_SYSTEST_REG); + + return reg & OMAP_I2C_SYSTEST_SCL_I_FUNC; +} + +static int omap_i2c_get_sda(struct i2c_adapter *adap) +{ + struct omap_i2c_dev *dev = i2c_get_adapdata(adap); + u32 reg; + + reg = omap_i2c_read_reg(dev, OMAP_I2C_SYSTEST_REG); + + return reg & OMAP_I2C_SYSTEST_SDA_I_FUNC; +} + +static void omap_i2c_set_scl(struct i2c_adapter *adap, int val) +{ + struct omap_i2c_dev *dev = i2c_get_adapdata(adap); + u32 reg; + + reg = omap_i2c_read_reg(dev, OMAP_I2C_SYSTEST_REG); + if (val) + reg |= OMAP_I2C_SYSTEST_SCL_O; + else + reg &= ~OMAP_I2C_SYSTEST_SCL_O; + omap_i2c_write_reg(dev, OMAP_I2C_SYSTEST_REG, reg); +} + +static void omap_i2c_prepare_recovery(struct i2c_adapter *adap) +{ + struct omap_i2c_dev *dev = i2c_get_adapdata(adap); + u32 reg; + + reg = omap_i2c_read_reg(dev, OMAP_I2C_SYSTEST_REG); + reg |= OMAP_I2C_SYSTEST_ST_EN; + omap_i2c_write_reg(dev, OMAP_I2C_SYSTEST_REG, reg); +} + +static void omap_i2c_unprepare_recovery(struct i2c_adapter *adap) +{ + struct omap_i2c_dev *dev = i2c_get_adapdata(adap); + u32 reg; + + reg = omap_i2c_read_reg(dev, OMAP_I2C_SYSTEST_REG); + reg &= ~OMAP_I2C_SYSTEST_ST_EN; + omap_i2c_write_reg(dev, OMAP_I2C_SYSTEST_REG, reg); +} + +static struct i2c_bus_recovery_info omap_i2c_bus_recovery_info = { + .get_scl = omap_i2c_get_scl, + .get_sda = omap_i2c_get_sda, + .set_scl = omap_i2c_set_scl, + .prepare_recovery = omap_i2c_prepare_recovery, + .unprepare_recovery = omap_i2c_unprepare_recovery, + .recover_bus = i2c_generic_scl_recovery, +}; + static int omap_i2c_probe(struct platform_device *pdev) { @@ -1358,6 +1418,7 @@ omap_i2c_probe(struct platform_device *pdev) adap->algo = &omap_i2c_algo; adap->dev.parent = &pdev->dev; adap->dev.of_node = pdev->dev.of_node; + adap->bus_recovery_info = &omap_i2c_bus_recovery_info; /* i2c device drivers may be active on return from add_adapter() */ adap->nr = pdev->id;