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Commit 940c147f authored by Gilad Avidov's avatar Gilad Avidov
Browse files

qup_i2c: correct and refactor PM callbacks 



Block system-suspend call until current transfer is done.
Refactor related code.

Change-Id: I374d482e4aab02c0ccb41a23cacdac345dab9e22
Signed-off-by: default avatarGilad Avidov <gavidov@codeaurora.org>
parent 792ce78d

drivers/i2c/busses/i2c-qup.c

+30 −38
Original line number Diff line number Diff line
@@ -135,8 +135,7 @@ enum { 
enum msm_i2c_state {

	MSM_I2C_PM_ACTIVE,

	MSM_I2C_PM_SUSPENDED,

	MSM_I2C_SYS_SUSPENDING,

	MSM_I2C_SYS_SUSPENDED,

	MSM_I2C_PM_SYS_SUSPENDED,

};

#define QUP_MAX_CLK_STATE_RETRIES	300

#define DEFAULT_CLK_RATE		(19200000)
@@ -562,11 +561,6 @@ static void i2c_qup_pm_resume_clk(struct qup_i2c_dev *dev) 


static void i2c_qup_suspend(struct qup_i2c_dev *dev)

{

	if (dev->pwr_state != MSM_I2C_PM_ACTIVE) {

		dev_err(dev->dev, "attempt to suspend when not active\n");

		return;

	}



	if (!dev->pdata->clk_ctl_xfer)

		i2c_qup_pm_suspend_clk(dev);
@@ -575,11 +569,32 @@ static void i2c_qup_suspend(struct qup_i2c_dev *dev) 
	i2c_qup_gpio_free(dev);

}



static void i2c_qup_resume(struct qup_i2c_dev *dev)

static void i2c_qup_sys_suspend(struct qup_i2c_dev *dev)

{

	if (dev->pwr_state == MSM_I2C_PM_ACTIVE)

		return;

	enum msm_i2c_state prev_pwr_state = dev->pwr_state;



	/* wait for ongoing transfer to complete */

	mutex_lock(&dev->mlock);

	dev->pwr_state = MSM_I2C_PM_SYS_SUSPENDED;

	mutex_unlock(&dev->mlock);



	if (prev_pwr_state == MSM_I2C_PM_ACTIVE) {

		i2c_qup_suspend(dev);

		/*

		 * Synchronize runtime-pm and system-pm states:

		 * at this point we are already suspended. However, the

		 * runtime-PM framework still thinks that we are active.

		 * The three calls below let the runtime-PM know that we are

		 * suspended already without re-invoking the suspend callback

		 */

		pm_runtime_disable(dev->dev);

		pm_runtime_set_suspended(dev->dev);

		pm_runtime_enable(dev->dev);

	}

}



static void i2c_qup_resume(struct qup_i2c_dev *dev)

{

	i2c_qup_gpio_request(dev);



	i2c_qup_clk_path_postponed_register(dev);
@@ -984,9 +999,9 @@ qup_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num) 
	 * we are in suspended state

	 */

	mutex_lock(&dev->mlock);

	if (dev->pwr_state >= MSM_I2C_SYS_SUSPENDING) {

	if (dev->pwr_state == MSM_I2C_PM_SYS_SUSPENDED) {

		dev_err(dev->dev,

			"xfer not allowed when systems is suspendeding. slv-addr:0x%x\n",

			"xfer not allowed when systems is suspended. slv-addr:0x%x\n",

			msgs->addr);

		mutex_unlock(&dev->mlock);

		return -EIO;
@@ -1711,12 +1726,7 @@ qup_i2c_remove(struct platform_device *pdev) 
{

	struct qup_i2c_dev *dev = platform_get_drvdata(pdev);



	/* Grab mutex to ensure ongoing transaction is over */

	mutex_lock(&dev->mlock);

	dev->pwr_state = MSM_I2C_SYS_SUSPENDING;

	mutex_unlock(&dev->mlock);

	i2c_qup_suspend(dev);

	dev->pwr_state = MSM_I2C_SYS_SUSPENDED;

	i2c_qup_sys_suspend(dev);

	mutex_destroy(&dev->mlock);

	platform_set_drvdata(pdev, NULL);

	if (dev->num_irqs == 3) {
@@ -1775,26 +1785,8 @@ static int i2c_qup_pm_suspend_sys_noirq(struct device *device) 
	struct platform_device *pdev = to_platform_device(device);

	struct qup_i2c_dev *dev = platform_get_drvdata(pdev);



	if (dev->pwr_state == MSM_I2C_PM_ACTIVE) {

	i2c_qup_sys_suspend(dev);

	dev_dbg(device, "system suspend\n");

		i2c_qup_suspend(dev);

		/*

		 * Synchronize runtime-pm and system-pm states:

		 * at this point we are already suspended. However, the

		 * runtime-PM framework still thinks that we are active.

		 * The three calls below let the runtime-PM know that we are

		 * suspended already without re-invoking the suspend callback

		 */

		pm_runtime_disable(device);

		pm_runtime_set_suspended(device);

		pm_runtime_enable(device);

	}

	/*

	 * Conceptually, here we are in runtime-suspended state and

	 * transitioning to sys-suspend state (in reality both suspends are the

	 * same).

	 */

	dev->pwr_state = MSM_I2C_SYS_SUSPENDED;

	return 0;

}