From mboxrd@z Thu Jan 1 00:00:00 1970 From: Subject: [PATCH 1/2] i2c: ls1/ls2: add workaround for erratum ERR010027 Date: Wed, 27 Jan 2016 16:44:42 +0800 Message-ID: <1453884283-33414-1-git-send-email-ying.zhang22455@nxp.com> Mime-Version: 1.0 Content-Type: text/plain Return-path: Received: from mail-by2on0095.outbound.protection.outlook.com ([207.46.100.95]:55648 "EHLO na01-by2-obe.outbound.protection.outlook.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751803AbcA0JH6 (ORCPT ); Wed, 27 Jan 2016 04:07:58 -0500 Sender: linux-i2c-owner@vger.kernel.org List-Id: linux-i2c@vger.kernel.org To: linux-i2c@vger.kernel.org Cc: xiaobo.xie@nxp.com, york.sun@nxp.com, Ying Zhang From: Ying Zhang ERR010027/ERR008951: Attempting a start cycle while the bus is busy may generate a short clock pulse. Software must ensure that the I2C BUS is idle by checking the bus busy before switching to master mode and attempting a Start cycle. Signed-off-by: Ying Zhang --- drivers/i2c/busses/i2c-imx.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/drivers/i2c/busses/i2c-imx.c b/drivers/i2c/busses/i2c-imx.c index a2b132c..f1fe599 100644 --- a/drivers/i2c/busses/i2c-imx.c +++ b/drivers/i2c/busses/i2c-imx.c @@ -889,6 +889,13 @@ static int i2c_imx_xfer(struct i2c_adapter *adapter, dev_dbg(&i2c_imx->adapter.dev, "<%s>\n", __func__); + /* workround for ERR010027: ensure that the I2C BUS is idle + before switching to master mode and attempting a Start cycle + */ + result = i2c_imx_bus_busy(i2c_imx, 0); + if (result) + goto fail0; + result = pm_runtime_get_sync(i2c_imx->adapter.dev.parent); if (result < 0) goto out; -- 2.1.0.27.g96db324