Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
2 | * drivers/base/power/sysfs.c - sysfs entries for device PM | |
3 | */ | |
4 | ||
5 | #include <linux/device.h> | |
6 | #include "power.h" | |
7 | ||
8 | ||
9 | /** | |
10 | * state - Control current power state of device | |
11 | * | |
12 | * show() returns the current power state of the device. '0' indicates | |
13 | * the device is on. Other values (1-3) indicate the device is in a low | |
14 | * power state. | |
15 | * | |
16 | * store() sets the current power state, which is an integer value | |
17 | * between 0-3. If the device is on ('0'), and the value written is | |
18 | * greater than 0, then the device is placed directly into the low-power | |
19 | * state (via its driver's ->suspend() method). | |
20 | * If the device is currently in a low-power state, and the value is 0, | |
21 | * the device is powered back on (via the ->resume() method). | |
22 | * If the device is in a low-power state, and a different low-power state | |
23 | * is requested, the device is first resumed, then suspended into the new | |
24 | * low-power state. | |
25 | */ | |
26 | ||
74880c06 | 27 | static ssize_t state_show(struct device * dev, struct device_attribute *attr, char * buf) |
1da177e4 | 28 | { |
ca078bae | 29 | return sprintf(buf, "%u\n", dev->power.power_state.event); |
1da177e4 LT |
30 | } |
31 | ||
74880c06 | 32 | static ssize_t state_store(struct device * dev, struct device_attribute *attr, const char * buf, size_t n) |
1da177e4 | 33 | { |
ca078bae | 34 | pm_message_t state; |
1da177e4 LT |
35 | char * rest; |
36 | int error = 0; | |
37 | ||
ca078bae | 38 | state.event = simple_strtoul(buf, &rest, 10); |
1da177e4 LT |
39 | if (*rest) |
40 | return -EINVAL; | |
ca078bae | 41 | if (state.event) |
1da177e4 LT |
42 | error = dpm_runtime_suspend(dev, state); |
43 | else | |
44 | dpm_runtime_resume(dev); | |
45 | return error ? error : n; | |
46 | } | |
47 | ||
48 | static DEVICE_ATTR(state, 0644, state_show, state_store); | |
49 | ||
50 | ||
51 | static struct attribute * power_attrs[] = { | |
52 | &dev_attr_state.attr, | |
53 | NULL, | |
54 | }; | |
55 | static struct attribute_group pm_attr_group = { | |
56 | .name = "power", | |
57 | .attrs = power_attrs, | |
58 | }; | |
59 | ||
60 | int dpm_sysfs_add(struct device * dev) | |
61 | { | |
62 | return sysfs_create_group(&dev->kobj, &pm_attr_group); | |
63 | } | |
64 | ||
65 | void dpm_sysfs_remove(struct device * dev) | |
66 | { | |
67 | sysfs_remove_group(&dev->kobj, &pm_attr_group); | |
68 | } |