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author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 22:20:36 (GMT) |
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committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 22:20:36 (GMT) |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /drivers/base/power/sysfs.c | |
download | linux-fsl-qoriq-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.tar.xz |
Linux-2.6.12-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.c | 68 |
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 0000000..6ac9634 --- /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); +} |