From 531183e5d27312d68fab40352cd13426aa761473 Mon Sep 17 00:00:00 2001 From: Zhao Chenhui Date: Thu, 19 Apr 2012 17:51:34 +0800 Subject: [PATCH] i2c-mpc: avoid I2C abnormal after resuming from deep sleep 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 Signed-off-by: Wolfram Sang --- drivers/i2c/busses/i2c-mpc.c | 30 ++++++++++++++++++++++++++++++ 1 file changed, 30 insertions(+) diff --git a/drivers/i2c/busses/i2c-mpc.c b/drivers/i2c/busses/i2c-mpc.c index 206caacd30d7..b76731edbf10 100644 --- a/drivers/i2c/busses/i2c-mpc.c +++ b/drivers/i2c/busses/i2c-mpc.c @@ -64,6 +64,9 @@ struct mpc_i2c { struct i2c_adapter adap; int irq; u32 real_clk; +#ifdef CONFIG_PM + u8 fdr, dfsrr; +#endif }; struct mpc_i2c_divider { @@ -703,6 +706,30 @@ 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, }; @@ -747,6 +774,9 @@ 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 }, }; -- 2.39.5