Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757551Ab2B2KiM (ORCPT ); Wed, 29 Feb 2012 05:38:12 -0500 Received: from tx2ehsobe002.messaging.microsoft.com ([65.55.88.12]:37970 "EHLO TX2EHSOBE004.bigfish.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751810Ab2B2KiK (ORCPT ); Wed, 29 Feb 2012 05:38:10 -0500 X-SpamScore: 0 X-BigFish: VS0(zzzz1202hzz8275bhz2dh2a8h668h839h) X-Forefront-Antispam-Report: CIP:70.37.183.190;KIP:(null);UIP:(null);IPV:NLI;H:mail.freescale.net;RD:none;EFVD:NLI From: Zhao Chenhui To: CC: , Zhao Chenhui , Li Yang Subject: [PATCH] i2c-mpc: avoid I2C abnormal after resuming from deep sleep Date: Wed, 29 Feb 2012 18:39:21 +0800 Message-ID: <1330511961-22498-1-git-send-email-chenhui.zhao@freescale.com> X-Mailer: git-send-email 1.6.4.1 MIME-Version: 1.0 Content-Type: text/plain X-OriginatorOrg: freescale.com Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2306 Lines: 87 When entering deep sleep, the value in the registers I2CFDR and I2CDFSRR are lost. This causes I2C access to fail after resuming. Add suspend/resume routines to save/restore the registers I2CFDR and I2CDFSRR. Signed-off-by: Zhao Chenhui Signed-off-by: Li Yang --- drivers/i2c/busses/i2c-mpc.c | 34 +++++++++++++++++++++++++++++++++- 1 files changed, 33 insertions(+), 1 deletions(-) diff --git a/drivers/i2c/busses/i2c-mpc.c b/drivers/i2c/busses/i2c-mpc.c index a8ebb84..f95a647 100644 --- a/drivers/i2c/busses/i2c-mpc.c +++ b/drivers/i2c/busses/i2c-mpc.c @@ -1,7 +1,9 @@ /* * (C) Copyright 2003-2004 * Humboldt Solutions Ltd, adrian@humboldt.co.uk. - + * + * Copyright 2012 Freescale Semiconductor, Inc. + * * This is a combined i2c adapter and algorithm driver for the * MPC107/Tsi107 PowerPC northbridge and processors that include * the same I2C unit (8240, 8245, 85xx). @@ -64,6 +66,9 @@ struct mpc_i2c { struct i2c_adapter adap; int irq; u32 real_clk; +#ifdef CONFIG_PM + u8 fdr, dfsrr; +#endif }; struct mpc_i2c_divider { @@ -668,6 +673,30 @@ static int __devexit fsl_i2c_remove(struct platform_device *op) return 0; }; +#ifdef CONFIG_PM +static int mpc_i2c_suspend(struct device *dev) +{ + struct mpc_i2c *i2c = dev_get_drvdata(dev); + + i2c->fdr = readb(i2c->base + MPC_I2C_FDR); + i2c->dfsrr = readb(i2c->base + MPC_I2C_DFSRR); + + return 0; +} + +static int mpc_i2c_resume(struct device *dev) +{ + struct mpc_i2c *i2c = dev_get_drvdata(dev); + + writeb(i2c->fdr, i2c->base + MPC_I2C_FDR); + writeb(i2c->dfsrr, i2c->base + MPC_I2C_DFSRR); + + return 0; +} + +SIMPLE_DEV_PM_OPS(mpc_i2c_pm_ops, mpc_i2c_suspend, mpc_i2c_resume); +#endif + static struct mpc_i2c_data mpc_i2c_data_512x __devinitdata = { .setup = mpc_i2c_setup_512x, }; @@ -712,6 +741,9 @@ static struct platform_driver mpc_i2c_driver = { .owner = THIS_MODULE, .name = DRV_NAME, .of_match_table = mpc_i2c_of_match, +#ifdef CONFIG_PM + .pm = &mpc_i2c_pm_ops, +#endif }, }; -- 1.6.4.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/