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i2c-mpc: avoid I2C abnormal after resuming from deep sleep

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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 <chenhui.zhao@freescale.com>
Signed-off-by: Li Yang <leoli@freescale.com>
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
This commit is contained in:
Zhao Chenhui 2012-04-19 17:51:34 +08:00 committed by Wolfram Sang
parent ad33707417
commit 531183e5d2
1 changed files with 30 additions and 0 deletions
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30
drivers/i2c/busses/i2c-mpc.c
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@ -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
},
};