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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 18:20:36 -0400
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 18:20:36 -0400
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /drivers/base/power/sysfs.c
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
Diffstat (limited to 'drivers/base/power/sysfs.c')
-rw-r--r--drivers/base/power/sysfs.c68
1 files changed, 68 insertions, 0 deletions
diff --git a/drivers/base/power/sysfs.c b/drivers/base/power/sysfs.c
new file mode 100644
index 000000000000..6ac96349a8e8
--- /dev/null
+++ b/drivers/base/power/sysfs.c
@@ -0,0 +1,68 @@
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
27static ssize_t state_show(struct device * dev, char * buf)
28{
29 return sprintf(buf, "%u\n", dev->power.power_state);
30}
31
32static ssize_t state_store(struct device * dev, const char * buf, size_t n)
33{
34 u32 state;
35 char * rest;
36 int error = 0;
37
38 state = simple_strtoul(buf, &rest, 10);
39 if (*rest)
40 return -EINVAL;
41 if (state)
42 error = dpm_runtime_suspend(dev, state);
43 else
44 dpm_runtime_resume(dev);
45 return error ? error : n;
46}
47
48static DEVICE_ATTR(state, 0644, state_show, state_store);
49
50
51static struct attribute * power_attrs[] = {
52 &dev_attr_state.attr,
53 NULL,
54};
55static struct attribute_group pm_attr_group = {
56 .name = "power",
57 .attrs = power_attrs,
58};
59
60int dpm_sysfs_add(struct device * dev)
61{
62 return sysfs_create_group(&dev->kobj, &pm_attr_group);
63}
64
65void dpm_sysfs_remove(struct device * dev)
66{
67 sysfs_remove_group(&dev->kobj, &pm_attr_group);
68}