summaryrefslogtreecommitdiffstats
path: root/drivers/base/power/sysfs.c
diff options
context:
space:
mode:
authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-17 00:20:36 +0200
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-17 00:20:36 +0200
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /drivers/base/power/sysfs.c
downloadlinux-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.tar.xz
linux-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.zip
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 @@
+/*
+ * drivers/base/power/sysfs.c - sysfs entries for device PM
+ */
+
+#include <linux/device.h>
+#include "power.h"
+
+
+/**
+ * state - Control current power state of device
+ *
+ * show() returns the current power state of the device. '0' indicates
+ * the device is on. Other values (1-3) indicate the device is in a low
+ * power state.
+ *
+ * store() sets the current power state, which is an integer value
+ * between 0-3. If the device is on ('0'), and the value written is
+ * greater than 0, then the device is placed directly into the low-power
+ * state (via its driver's ->suspend() method).
+ * If the device is currently in a low-power state, and the value is 0,
+ * the device is powered back on (via the ->resume() method).
+ * If the device is in a low-power state, and a different low-power state
+ * is requested, the device is first resumed, then suspended into the new
+ * low-power state.
+ */
+
+static ssize_t state_show(struct device * dev, char * buf)
+{
+ return sprintf(buf, "%u\n", dev->power.power_state);
+}
+
+static ssize_t state_store(struct device * dev, const char * buf, size_t n)
+{
+ u32 state;
+ char * rest;
+ int error = 0;
+
+ state = simple_strtoul(buf, &rest, 10);
+ if (*rest)
+ return -EINVAL;
+ if (state)
+ error = dpm_runtime_suspend(dev, state);
+ else
+ dpm_runtime_resume(dev);
+ return error ? error : n;
+}
+
+static DEVICE_ATTR(state, 0644, state_show, state_store);
+
+
+static struct attribute * power_attrs[] = {
+ &dev_attr_state.attr,
+ NULL,
+};
+static struct attribute_group pm_attr_group = {
+ .name = "power",
+ .attrs = power_attrs,
+};
+
+int dpm_sysfs_add(struct device * dev)
+{
+ return sysfs_create_group(&dev->kobj, &pm_attr_group);
+}
+
+void dpm_sysfs_remove(struct device * dev)
+{
+ sysfs_remove_group(&dev->kobj, &pm_attr_group);
+}