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Commit 18dbdda8 authored by Dirk Brandewie's avatar Dirk Brandewie Committed by Ben Dooks
Browse files

i2c-designware: Add runtime power management support 



Add runtime power management to the PCI driver.

Signed-off-by: default avatarDirk Brandewie <dirk.brandewie@gmail.com>
Signed-off-by: default avatarBen Dooks <ben-linux@fluff.org>
parent fe20ff5c

drivers/i2c/busses/i2c-designware-core.c

+8 −2
Original line number Diff line number Diff line
@@ -31,6 +31,7 @@ 
#include <linux/i2c.h>

#include <linux/interrupt.h>

#include <linux/io.h>

#include <linux/pm_runtime.h>

#include <linux/delay.h>

#include "i2c-designware-core.h"
@@ -501,6 +502,7 @@ i2c_dw_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num) 
	dev_dbg(dev->dev, "%s: msgs: %d\n", __func__, num);



	mutex_lock(&dev->lock);

	pm_runtime_get_sync(dev->dev);



	INIT_COMPLETION(dev->cmd_complete);

	dev->msgs = msgs;
@@ -550,6 +552,7 @@ i2c_dw_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num) 
	ret = -EIO;



done:

	pm_runtime_put(dev->dev);

	mutex_unlock(&dev->lock);



	return ret;
@@ -671,10 +674,13 @@ void i2c_dw_enable(struct dw_i2c_dev *dev) 
	dw_writel(dev, 1, DW_IC_ENABLE);

}



void i2c_dw_disable(struct dw_i2c_dev *dev)

u32 i2c_dw_is_enabled(struct dw_i2c_dev *dev)

{

	int ret;

	return dw_readl(dev, DW_IC_ENABLE);

}



void i2c_dw_disable(struct dw_i2c_dev *dev)

{

	/* Disable controller */

	dw_writel(dev, 0, DW_IC_ENABLE);

drivers/i2c/busses/i2c-designware-core.h

+1 −0
Original line number Diff line number Diff line
@@ -98,6 +98,7 @@ extern int i2c_dw_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], 
extern u32 i2c_dw_func(struct i2c_adapter *adap);

extern irqreturn_t i2c_dw_isr(int this_irq, void *dev_id);

extern void i2c_dw_enable(struct dw_i2c_dev *dev);

extern u32 i2c_dw_is_enabled(struct dw_i2c_dev *dev);

extern void i2c_dw_disable(struct dw_i2c_dev *dev);

extern void i2c_dw_clear_int(struct dw_i2c_dev *dev);

extern void i2c_dw_disable_int(struct dw_i2c_dev *dev);

drivers/i2c/busses/i2c-designware-pcidrv.c

+89 −0
Original line number Diff line number Diff line
@@ -38,6 +38,7 @@ 
#include <linux/io.h>

#include <linux/slab.h>

#include <linux/pci.h>

#include <linux/pm_runtime.h>

#include "i2c-designware-core.h"



#define DRIVER_NAME "i2c-designware-pci"
@@ -137,6 +138,82 @@ static struct i2c_algorithm i2c_dw_algo = { 
	.functionality	= i2c_dw_func,

};



static int i2c_dw_pci_suspend(struct pci_dev *pdev, pm_message_t mesg)

{

	struct dw_i2c_dev *i2c = pci_get_drvdata(pdev);

	int err;





	i2c_dw_disable(i2c);



	err = pci_save_state(pdev);

	if (err) {

		dev_err(&pdev->dev, "pci_save_state failed\n");

		return err;

	}



	err = pci_set_power_state(pdev, PCI_D3hot);

	if (err) {

		dev_err(&pdev->dev, "pci_set_power_state failed\n");

		return err;

	}



	return 0;

}



static int i2c_dw_pci_runtime_suspend(struct device *dev)

{

	struct pci_dev *pdev = to_pci_dev(dev);

	dev_dbg(dev, "PCI suspend called\n");

	return i2c_dw_pci_suspend(pdev, PMSG_SUSPEND);

}



static int i2c_dw_pci_resume(struct pci_dev *pdev)

{

	struct dw_i2c_dev *i2c = pci_get_drvdata(pdev);

	int err;

	u32 enabled;



	enabled = i2c_dw_is_enabled(i2c);

	if (enabled)

		return 0;



	err = pci_set_power_state(pdev, PCI_D0);

	if (err) {

		dev_err(&pdev->dev, "pci_set_power_state() failed\n");

		return err;

	}



	pci_restore_state(pdev);



	i2c_dw_init(i2c);

	i2c_dw_enable(i2c);

	return 0;

}



static int i2c_dw_pci_runtime_resume(struct device *dev)

{

	struct pci_dev *pdev = to_pci_dev(dev);

	dev_dbg(dev, "runtime_resume called\n");

	return i2c_dw_pci_resume(pdev);

}



static int i2c_dw_pci_runtime_idle(struct device *dev)

{

	int err = pm_schedule_suspend(dev, 500);

	dev_dbg(dev, "runtime_idle called\n");



	if (err != 0)

		return 0;

	return -EBUSY;

}



static const struct dev_pm_ops i2c_dw_pm_ops = {

	.runtime_suspend = i2c_dw_pci_runtime_suspend,

	.runtime_resume = i2c_dw_pci_runtime_resume,

	.runtime_idle = i2c_dw_pci_runtime_idle,

};



static u32 i2c_dw_get_clk_rate_khz(struct dw_i2c_dev *dev)

{

	return dev->controller->clk_khz;
@@ -245,6 +322,9 @@ const struct pci_device_id *id) 
		goto err_free_irq;

	}



	pm_runtime_put_noidle(&pdev->dev);

	pm_runtime_allow(&pdev->dev);



	return 0;



err_free_irq:
@@ -264,6 +344,10 @@ static void __devexit i2c_dw_pci_remove(struct pci_dev *pdev) 
{

	struct dw_i2c_dev *dev = pci_get_drvdata(pdev);



	i2c_dw_disable(dev);

	pm_runtime_forbid(&pdev->dev);

	pm_runtime_get_noresume(&pdev->dev);



	pci_set_drvdata(pdev, NULL);

	i2c_del_adapter(&dev->adapter);

	put_device(&pdev->dev);
@@ -297,6 +381,11 @@ static struct pci_driver dw_i2c_driver = { 
	.id_table	= i2_designware_pci_ids,

	.probe		= i2c_dw_pci_probe,

	.remove		= __devexit_p(i2c_dw_pci_remove),

	.resume         = i2c_dw_pci_resume,

	.suspend        = i2c_dw_pci_suspend,

	.driver         = {

		.pm     = &i2c_dw_pm_ops,

	},

};



static int __init dw_i2c_init_driver(void)