/* * drivers/base/power/common.c - Common device power management code. * * Copyright (C) 2011 Rafael J. Wysocki <rjw@sisk.pl>, Renesas Electronics Corp. * * This file is released under the GPLv2. */ #include <linux/init.h>#include <linux/kernel.h>#include <linux/device.h>#include <linux/export.h>#include <linux/slab.h>#include <linux/pm_clock.h> /** * dev_pm_get_subsys_data - Create or refcount power.subsys_data for device. * @dev: Device to handle. * * If power.subsys_data is NULL, point it to a new object, otherwise increment * its reference counter.  Return 1 if a new object has been created, otherwise * return 0 or error code. */int dev_pm_get_subsys_data(struct device *dev){	struct pm_subsys_data *psd; 	psd = kzalloc(sizeof(*psd), GFP_KERNEL);	if (!psd)		return -ENOMEM; 	spin_lock_irq(&dev->power.lock); 	if (dev->power.subsys_data) {		dev->power.subsys_data->refcount++;	} else {		spin_lock_init(&psd->lock);		psd->refcount = 1;		dev->power.subsys_data = psd;		pm_clk_init(dev);		psd = NULL;	} 	spin_unlock_irq(&dev->power.lock); 	/* kfree() verifies that its argument is nonzero. */	kfree(psd); 	return 0;}EXPORT_SYMBOL_GPL(dev_pm_get_subsys_data); /** * dev_pm_put_subsys_data - Drop reference to power.subsys_data. * @dev: Device to handle. * * If the reference counter of power.subsys_data is zero after dropping the * reference, power.subsys_data is removed.  Return 1 if that happens or 0 * otherwise. */int dev_pm_put_subsys_data(struct device *dev){	struct pm_subsys_data *psd;	int ret = 1; 	spin_lock_irq(&dev->power.lock); 	psd = dev_to_psd(dev);	if (!psd)		goto out; 	if (--psd->refcount == 0) {		dev->power.subsys_data = NULL;	} else {		psd = NULL;		ret = 0;	}  out:	spin_unlock_irq(&dev->power.lock);	kfree(psd); 	return ret;}EXPORT_SYMBOL_GPL(dev_pm_put_subsys_data);