| /* |
| * 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/module.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); |