linux/drivers/base/power/common.c
Paul Gortmaker 51990e8254 device.h: cleanup users outside of linux/include (C files)
For files that are actively using linux/device.h, make sure
that they call it out.  This will allow us to clean up some
of the implicit uses of linux/device.h within include/*
without introducing build regressions.

Yes, this was created by "cheating" -- i.e. the headers were
cleaned up, and then the fallout was found and fixed, and then
the two commits were reordered.  This ensures we don't introduce
build regressions into the git history.

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2012-03-11 14:27:37 -04:00

88 lines
1.9 KiB
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;
int ret = 0;
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;
ret = 1;
}
spin_unlock_irq(&dev->power.lock);
/* kfree() verifies that its argument is nonzero. */
kfree(psd);
return ret;
}
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 = 0;
spin_lock_irq(&dev->power.lock);
psd = dev_to_psd(dev);
if (!psd) {
ret = -EINVAL;
goto out;
}
if (--psd->refcount == 0) {
dev->power.subsys_data = NULL;
kfree(psd);
ret = 1;
}
out:
spin_unlock_irq(&dev->power.lock);
return ret;
}
EXPORT_SYMBOL_GPL(dev_pm_put_subsys_data);