[GitHub/mt8127/android_kernel_alcatel_ttab.git] / drivers / base / power / common.c

/*
 * 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);
Commit	Line	Data
ef27bed1 RW	1	/*
	2	* drivers/base/power/common.c - Common device power management code.
	3	*
	4	* Copyright (C) 2011 Rafael J. Wysocki <rjw@sisk.pl>, Renesas Electronics Corp.
	5	*
	6	* This file is released under the GPLv2.
	7	*/
	8
	9	#include <linux/init.h>
	10	#include <linux/kernel.h>
51990e82	11	#include <linux/device.h>
aaf19544	12	#include <linux/export.h>
ef27bed1	13	#include <linux/slab.h>
b5e8d269	14	#include <linux/pm_clock.h>
ef27bed1 RW	15
	16	/**
	17	* dev_pm_get_subsys_data - Create or refcount power.subsys_data for device.
	18	* @dev: Device to handle.
	19	*
	20	* If power.subsys_data is NULL, point it to a new object, otherwise increment
	21	* its reference counter. Return 1 if a new object has been created, otherwise
	22	* return 0 or error code.
	23	*/
	24	int dev_pm_get_subsys_data(struct device *dev)
	25	{
	26	struct pm_subsys_data *psd;
ef27bed1 RW	27
	28	psd = kzalloc(sizeof(*psd), GFP_KERNEL);
	29	if (!psd)
	30	return -ENOMEM;
	31
	32	spin_lock_irq(&dev->power.lock);
	33
	34	if (dev->power.subsys_data) {
	35	dev->power.subsys_data->refcount++;
	36	} else {
	37	spin_lock_init(&psd->lock);
	38	psd->refcount = 1;
	39	dev->power.subsys_data = psd;
	40	pm_clk_init(dev);
	41	psd = NULL;
ef27bed1 RW	42	}
	43
	44	spin_unlock_irq(&dev->power.lock);
	45
	46	/* kfree() verifies that its argument is nonzero. */
	47	kfree(psd);
	48
77254950	49	return 0;
ef27bed1 RW	50	}
	51	EXPORT_SYMBOL_GPL(dev_pm_get_subsys_data);
	52
	53	/**
	54	* dev_pm_put_subsys_data - Drop reference to power.subsys_data.
	55	* @dev: Device to handle.
	56	*
	57	* If the reference counter of power.subsys_data is zero after dropping the
	58	* reference, power.subsys_data is removed. Return 1 if that happens or 0
	59	* otherwise.
	60	*/
	61	int dev_pm_put_subsys_data(struct device *dev)
	62	{
	63	struct pm_subsys_data *psd;
d5e1670a	64	int ret = 1;
ef27bed1 RW	65
	66	spin_lock_irq(&dev->power.lock);
	67
	68	psd = dev_to_psd(dev);
d5e1670a	69	if (!psd)
ef27bed1	70	goto out;
ef27bed1 RW	71
	72	if (--psd->refcount == 0) {
	73	dev->power.subsys_data = NULL;
d5e1670a SK	74	} else {
	75	psd = NULL;
	76	ret = 0;
ef27bed1 RW	77	}
	78
	79	out:
	80	spin_unlock_irq(&dev->power.lock);
d5e1670a	81	kfree(psd);
ef27bed1 RW	82
	83	return ret;
	84	}
	85	EXPORT_SYMBOL_GPL(dev_pm_put_subsys_data);