[deliverable/linux.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/kernel.h>
#include <linux/device.h>
#include <linux/export.h>
#include <linux/slab.h>
#include <linux/pm_clock.h>
#include <linux/acpi.h>
#include <linux/pm_domain.h>

#include "power.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 0 if new object has been created or refcount
 * increased, otherwise negative 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.
 */
void dev_pm_put_subsys_data(struct device *dev)
{
	struct pm_subsys_data *psd;

	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;

 out:
	spin_unlock_irq(&dev->power.lock);
	kfree(psd);
}
EXPORT_SYMBOL_GPL(dev_pm_put_subsys_data);

/**
 * dev_pm_domain_attach - Attach a device to its PM domain.
 * @dev: Device to attach.
 * @power_on: Used to indicate whether we should power on the device.
 *
 * The @dev may only be attached to a single PM domain. By iterating through
 * the available alternatives we try to find a valid PM domain for the device.
 * As attachment succeeds, the ->detach() callback in the struct dev_pm_domain
 * should be assigned by the corresponding attach function.
 *
 * This function should typically be invoked from subsystem level code during
 * the probe phase. Especially for those that holds devices which requires
 * power management through PM domains.
 *
 * Callers must ensure proper synchronization of this function with power
 * management callbacks.
 *
 * Returns 0 on successfully attached PM domain or negative error code.
 */
int dev_pm_domain_attach(struct device *dev, bool power_on)
{
	int ret;

	ret = acpi_dev_pm_attach(dev, power_on);
	if (ret)
		ret = genpd_dev_pm_attach(dev);

	return ret;
}
EXPORT_SYMBOL_GPL(dev_pm_domain_attach);

/**
 * dev_pm_domain_detach - Detach a device from its PM domain.
 * @dev: Device to detach.
 * @power_off: Used to indicate whether we should power off the device.
 *
 * This functions will reverse the actions from dev_pm_domain_attach() and thus
 * try to detach the @dev from its PM domain. Typically it should be invoked
 * from subsystem level code during the remove phase.
 *
 * Callers must ensure proper synchronization of this function with power
 * management callbacks.
 */
void dev_pm_domain_detach(struct device *dev, bool power_off)
{
	if (dev->pm_domain && dev->pm_domain->detach)
		dev->pm_domain->detach(dev, power_off);
}
EXPORT_SYMBOL_GPL(dev_pm_domain_detach);

/**
 * dev_pm_domain_set - Set PM domain of a device.
 * @dev: Device whose PM domain is to be set.
 * @pd: PM domain to be set, or NULL.
 *
 * Sets the PM domain the device belongs to. The PM domain of a device needs
 * to be set before its probe finishes (it's bound to a driver).
 *
 * This function must be called with the device lock held.
 */
void dev_pm_domain_set(struct device *dev, struct dev_pm_domain *pd)
{
	if (dev->pm_domain == pd)
		return;

	WARN(pd && device_is_bound(dev),
	     "PM domains can only be changed for unbound devices\n");
	dev->pm_domain = pd;
	device_pm_check_callbacks(dev);
}
EXPORT_SYMBOL_GPL(dev_pm_domain_set);
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
ef27bed1	9	#include <linux/kernel.h>
51990e82	10	#include <linux/device.h>
aaf19544	11	#include <linux/export.h>
ef27bed1	12	#include <linux/slab.h>
b5e8d269	13	#include <linux/pm_clock.h>
46420dd7 UH	14	#include <linux/acpi.h>
46420dd7 UH	15	#include <linux/pm_domain.h>
ef27bed1	16
aa8e54b5 TV	17	#include "power.h"
aa8e54b5 TV	18
ef27bed1 RW	19	/**
	20	* dev_pm_get_subsys_data - Create or refcount power.subsys_data for device.
	21	* @dev: Device to handle.
	22	*
	23	* If power.subsys_data is NULL, point it to a new object, otherwise increment
766bb53c UH	24	* its reference counter. Return 0 if new object has been created or refcount
766bb53c UH	25	* increased, otherwise negative error code.
ef27bed1 RW	26	*/
	27	int dev_pm_get_subsys_data(struct device *dev)
	28	{
	29	struct pm_subsys_data *psd;
ef27bed1 RW	30
	31	psd = kzalloc(sizeof(*psd), GFP_KERNEL);
	32	if (!psd)
	33	return -ENOMEM;
	34
	35	spin_lock_irq(&dev->power.lock);
	36
	37	if (dev->power.subsys_data) {
	38	dev->power.subsys_data->refcount++;
	39	} else {
	40	spin_lock_init(&psd->lock);
	41	psd->refcount = 1;
	42	dev->power.subsys_data = psd;
	43	pm_clk_init(dev);
	44	psd = NULL;
ef27bed1 RW	45	}
	46
	47	spin_unlock_irq(&dev->power.lock);
	48
	49	/* kfree() verifies that its argument is nonzero. */
	50	kfree(psd);
	51
77254950	52	return 0;
ef27bed1 RW	53	}
	54	EXPORT_SYMBOL_GPL(dev_pm_get_subsys_data);
	55
	56	/**
	57	* dev_pm_put_subsys_data - Drop reference to power.subsys_data.
	58	* @dev: Device to handle.
	59	*
	60	* If the reference counter of power.subsys_data is zero after dropping the
1e95e3b2	61	* reference, power.subsys_data is removed.
ef27bed1	62	*/
1e95e3b2	63	void dev_pm_put_subsys_data(struct device *dev)
ef27bed1 RW	64	{
ef27bed1 RW	65	struct pm_subsys_data *psd;
ef27bed1 RW	66
	67	spin_lock_irq(&dev->power.lock);
	68
	69	psd = dev_to_psd(dev);
d5e1670a	70	if (!psd)
ef27bed1	71	goto out;
ef27bed1	72
1e95e3b2	73	if (--psd->refcount == 0)
ef27bed1	74	dev->power.subsys_data = NULL;
1e95e3b2	75	else
d5e1670a	76	psd = NULL;
ef27bed1 RW	77
	78	out:
	79	spin_unlock_irq(&dev->power.lock);
d5e1670a	80	kfree(psd);
ef27bed1 RW	81	}
ef27bed1 RW	82	EXPORT_SYMBOL_GPL(dev_pm_put_subsys_data);
46420dd7 UH	83
	84	/**
	85	* dev_pm_domain_attach - Attach a device to its PM domain.
	86	* @dev: Device to attach.
	87	* @power_on: Used to indicate whether we should power on the device.
	88	*
	89	* The @dev may only be attached to a single PM domain. By iterating through
	90	* the available alternatives we try to find a valid PM domain for the device.
	91	* As attachment succeeds, the ->detach() callback in the struct dev_pm_domain
	92	* should be assigned by the corresponding attach function.
	93	*
	94	* This function should typically be invoked from subsystem level code during
	95	* the probe phase. Especially for those that holds devices which requires
	96	* power management through PM domains.
	97	*
	98	* Callers must ensure proper synchronization of this function with power
	99	* management callbacks.
	100	*
	101	* Returns 0 on successfully attached PM domain or negative error code.
	102	*/
	103	int dev_pm_domain_attach(struct device *dev, bool power_on)
	104	{
	105	int ret;
	106
	107	ret = acpi_dev_pm_attach(dev, power_on);
	108	if (ret)
	109	ret = genpd_dev_pm_attach(dev);
	110
	111	return ret;
	112	}
	113	EXPORT_SYMBOL_GPL(dev_pm_domain_attach);
	114
	115	/**
	116	* dev_pm_domain_detach - Detach a device from its PM domain.
4295733e	117	* @dev: Device to detach.
46420dd7 UH	118	* @power_off: Used to indicate whether we should power off the device.
	119	*
	120	* This functions will reverse the actions from dev_pm_domain_attach() and thus
	121	* try to detach the @dev from its PM domain. Typically it should be invoked
	122	* from subsystem level code during the remove phase.
	123	*
	124	* Callers must ensure proper synchronization of this function with power
	125	* management callbacks.
	126	*/
	127	void dev_pm_domain_detach(struct device *dev, bool power_off)
	128	{
	129	if (dev->pm_domain && dev->pm_domain->detach)
	130	dev->pm_domain->detach(dev, power_off);
	131	}
	132	EXPORT_SYMBOL_GPL(dev_pm_domain_detach);
989561de TV	133
	134	/**
	135	* dev_pm_domain_set - Set PM domain of a device.
	136	* @dev: Device whose PM domain is to be set.
	137	* @pd: PM domain to be set, or NULL.
	138	*
	139	* Sets the PM domain the device belongs to. The PM domain of a device needs
	140	* to be set before its probe finishes (it's bound to a driver).
	141	*
	142	* This function must be called with the device lock held.
	143	*/
	144	void dev_pm_domain_set(struct device dev, struct dev_pm_domain pd)
	145	{
	146	if (dev->pm_domain == pd)
	147	return;
	148
e79aee49	149	WARN(pd && device_is_bound(dev),
989561de TV	150	"PM domains can only be changed for unbound devices\n");
989561de TV	151	dev->pm_domain = pd;
aa8e54b5	152	device_pm_check_callbacks(dev);
989561de TV	153	}
989561de TV	154	EXPORT_SYMBOL_GPL(dev_pm_domain_set);