Commit | Line | Data |
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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; | |
27 | int ret = 0; | |
28 | ||
29 | psd = kzalloc(sizeof(*psd), GFP_KERNEL); | |
30 | if (!psd) | |
31 | return -ENOMEM; | |
32 | ||
33 | spin_lock_irq(&dev->power.lock); | |
34 | ||
35 | if (dev->power.subsys_data) { | |
36 | dev->power.subsys_data->refcount++; | |
37 | } else { | |
38 | spin_lock_init(&psd->lock); | |
39 | psd->refcount = 1; | |
40 | dev->power.subsys_data = psd; | |
41 | pm_clk_init(dev); | |
42 | psd = NULL; | |
43 | ret = 1; | |
44 | } | |
45 | ||
46 | spin_unlock_irq(&dev->power.lock); | |
47 | ||
48 | /* kfree() verifies that its argument is nonzero. */ | |
49 | kfree(psd); | |
50 | ||
51 | return ret; | |
52 | } | |
53 | EXPORT_SYMBOL_GPL(dev_pm_get_subsys_data); | |
54 | ||
55 | /** | |
56 | * dev_pm_put_subsys_data - Drop reference to power.subsys_data. | |
57 | * @dev: Device to handle. | |
58 | * | |
59 | * If the reference counter of power.subsys_data is zero after dropping the | |
60 | * reference, power.subsys_data is removed. Return 1 if that happens or 0 | |
61 | * otherwise. | |
62 | */ | |
63 | int dev_pm_put_subsys_data(struct device *dev) | |
64 | { | |
65 | struct pm_subsys_data *psd; | |
66 | int ret = 0; | |
67 | ||
68 | spin_lock_irq(&dev->power.lock); | |
69 | ||
70 | psd = dev_to_psd(dev); | |
71 | if (!psd) { | |
72 | ret = -EINVAL; | |
73 | goto out; | |
74 | } | |
75 | ||
76 | if (--psd->refcount == 0) { | |
77 | dev->power.subsys_data = NULL; | |
78 | kfree(psd); | |
79 | ret = 1; | |
80 | } | |
81 | ||
82 | out: | |
83 | spin_unlock_irq(&dev->power.lock); | |
84 | ||
85 | return ret; | |
86 | } | |
87 | EXPORT_SYMBOL_GPL(dev_pm_put_subsys_data); |