Merge master.kernel.org:/pub/scm/linux/kernel/git/davej/cpufreq

[powerpc.git] / drivers / base / power / sysfs.c

diff --git a/drivers/base/power/sysfs.c b/drivers/base/power/sysfs.c
index f3a0c56..2d47517 100644 (file)
--- a/drivers/base/power/sysfs.c
+++ b/drivers/base/power/sysfs.c
@@ -7,48 +7,69 @@
 #include "power.h"
 
 
+#ifdef CONFIG_PM_SYSFS_DEPRECATED
+
 /**
  *     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
+ *     the device is on. Other values (2) indicate the device is in some 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.
+ *     store() sets the current power state, which is an integer valued
+ *     0, 2, or 3.  Devices with bus.suspend_late(), or bus.resume_early()
+ *     methods fail this operation; those methods couldn't be called.
+ *     Otherwise,
+ *
+ *     - If the recorded dev->power.power_state.event matches the
+ *       target value, nothing is done.
+ *     - If the recorded event code is nonzero, the device is reactivated
+ *       by calling bus.resume() and/or class.resume().
+ *     - If the target value is nonzero, the device is suspended by
+ *       calling class.suspend() and/or bus.suspend() with event code
+ *       PM_EVENT_SUSPEND.
+ *
+ *     This mechanism is DEPRECATED and should only be used for testing.
  */
 
 static ssize_t state_show(struct device * dev, struct device_attribute *attr, char * buf)
 {
-       return sprintf(buf, "%u\n", dev->power.power_state.event);
+       if (dev->power.power_state.event)
+               return sprintf(buf, "2\n");
+       else
+               return sprintf(buf, "0\n");
 }
 
 static ssize_t state_store(struct device * dev, struct device_attribute *attr, const char * buf, size_t n)
 {
        pm_message_t state;
-       char * rest;
-       int error = 0;
+       int error = -EINVAL;
 
-       state.event = simple_strtoul(buf, &rest, 10);
-       if (*rest)
-               return -EINVAL;
-       if (state.event)
+       /* disallow incomplete suspend sequences */
+       if (dev->bus && (dev->bus->suspend_late || dev->bus->resume_early))
+               return error;
+
+       state.event = PM_EVENT_SUSPEND;
+       /* Older apps expected to write "3" here - confused with PCI D3 */
+       if ((n == 1) && !strcmp(buf, "3"))
                error = dpm_runtime_suspend(dev, state);
-       else
+
+       if ((n == 1) && !strcmp(buf, "2"))
+               error = dpm_runtime_suspend(dev, state);
+
+       if ((n == 1) && !strcmp(buf, "0")) {
                dpm_runtime_resume(dev);
+               error = 0;
+       }
+
        return error ? error : n;
 }
 
 static DEVICE_ATTR(state, 0644, state_show, state_store);
 
 
+#endif /* CONFIG_PM_SYSFS_DEPRECATED */
+
 /*
  *     wakeup - Report/change current wakeup option for device
  *
@@ -122,7 +143,9 @@ static DEVICE_ATTR(wakeup, 0644, wake_show, wake_store);
 
 
 static struct attribute * power_attrs[] = {
+#ifdef CONFIG_PM_SYSFS_DEPRECATED
        &dev_attr_state.attr,
+#endif
        &dev_attr_wakeup.attr,
        NULL,
 };