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Commit 958585f5 authored by Michael Hennerich's avatar Michael Hennerich Committed by Ben Dooks
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i2c: Blackfin I2C Driver: Functional power management support 



PM_SUSPEND_MEM: Blackfin does not maintain register state through
Hibernate. Save and restore peripheral base initialization during
PM transitions.

Signed-off-by: default avatarMichael Hennerich <michael.hennerich@analog.com>
Signed-off-by: default avatarBryan Wu <cooloney@kernel.org>
Signed-off-by: default avatarBen Dooks <ben-linux@fluff.org>
parent 31321b76

drivers/i2c/busses/i2c-bfin-twi.c

+24 −11
Original line number Diff line number Diff line
@@ -49,6 +49,8 @@ struct bfin_twi_iface { 
	struct i2c_msg 		*pmsg;

	int			msg_num;

	int			cur_msg;

	u16			saved_clkdiv;

	u16			saved_control;

	void __iomem		*regs_base;

};
@@ -565,32 +567,43 @@ static u32 bfin_twi_functionality(struct i2c_adapter *adap) 
	       I2C_FUNC_I2C;

}





static struct i2c_algorithm bfin_twi_algorithm = {

	.master_xfer   = bfin_twi_master_xfer,

	.smbus_xfer    = bfin_twi_smbus_xfer,

	.functionality = bfin_twi_functionality,

};





static int i2c_bfin_twi_suspend(struct platform_device *dev, pm_message_t state)

static int i2c_bfin_twi_suspend(struct platform_device *pdev, pm_message_t state)

{

	struct bfin_twi_iface *iface = platform_get_drvdata(dev);

	struct bfin_twi_iface *iface = platform_get_drvdata(pdev);



	iface->saved_clkdiv = read_CLKDIV(iface);

	iface->saved_control = read_CONTROL(iface);



	free_irq(iface->irq, iface);



	/* Disable TWI */

	write_CONTROL(iface, read_CONTROL(iface) & ~TWI_ENA);

	SSYNC();

	write_CONTROL(iface, iface->saved_control & ~TWI_ENA);



	return 0;

}



static int i2c_bfin_twi_resume(struct platform_device *dev)

static int i2c_bfin_twi_resume(struct platform_device *pdev)

{

	struct bfin_twi_iface *iface = platform_get_drvdata(dev);

	struct bfin_twi_iface *iface = platform_get_drvdata(pdev);



	/* Enable TWI */

	write_CONTROL(iface, read_CONTROL(iface) | TWI_ENA);

	SSYNC();

	int rc = request_irq(iface->irq, bfin_twi_interrupt_entry,

		IRQF_DISABLED, pdev->name, iface);

	if (rc) {

		dev_err(&pdev->dev, "Can't get IRQ %d !\n", iface->irq);

		return -ENODEV;

	}



	/* Resume TWI interface clock as specified */

	write_CLKDIV(iface, iface->saved_clkdiv);



	/* Resume TWI */

	write_CONTROL(iface, iface->saved_control);



	return 0;

}