diff options
author | Jiri Kosina <jkosina@suse.cz> | 2011-11-13 20:55:35 +0100 |
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committer | Jiri Kosina <jkosina@suse.cz> | 2011-11-13 20:55:53 +0100 |
commit | 2290c0d06d82faee87b1ab2d9d4f7bf81ef64379 (patch) | |
tree | e075e4d5534193f28e6059904f61e5ca03958d3c /drivers/base/power/common.c | |
parent | 4da669a2e3e5bc70b30a0465f3641528681b5f77 (diff) | |
parent | 52e4c2a05256cb83cda12f3c2137ab1533344edb (diff) |
Merge branch 'master' into for-next
Sync with Linus tree to have 157550ff ("mtd: add GPMI-NAND driver
in the config and Makefile") as I have patch depending on that one.
Diffstat (limited to 'drivers/base/power/common.c')
-rw-r--r-- | drivers/base/power/common.c | 86 |
1 files changed, 86 insertions, 0 deletions
diff --git a/drivers/base/power/common.c b/drivers/base/power/common.c new file mode 100644 index 00000000000..4af7c1cbf90 --- /dev/null +++ b/drivers/base/power/common.c @@ -0,0 +1,86 @@ +/* + * 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/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); |