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Commit 531183e5 authored by Zhao Chenhui's avatar Zhao Chenhui Committed by Wolfram Sang
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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: default avatarZhao Chenhui <chenhui.zhao@freescale.com>
Signed-off-by: default avatarLi Yang <leoli@freescale.com>
Signed-off-by: default avatarWolfram Sang <w.sang@pengutronix.de>
parent ad337074

drivers/i2c/busses/i2c-mpc.c

+30 −0
Original line number Diff line number Diff line
@@ -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

	},

};