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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /drivers/base/power/suspend.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/suspend.c')
-rw-r--r--drivers/base/power/suspend.c144
1 files changed, 144 insertions, 0 deletions
diff --git a/drivers/base/power/suspend.c b/drivers/base/power/suspend.c
new file mode 100644
index 00000000000..a0b5cf689e6
--- /dev/null
+++ b/drivers/base/power/suspend.c
@@ -0,0 +1,144 @@
+/*
+ * suspend.c - Functions for putting devices to sleep.
+ *
+ * Copyright (c) 2003 Patrick Mochel
+ * Copyright (c) 2003 Open Source Development Labs
+ *
+ * This file is released under the GPLv2
+ *
+ */
+
+#include <linux/device.h>
+#include "power.h"
+
+extern int sysdev_suspend(pm_message_t state);
+
+/*
+ * The entries in the dpm_active list are in a depth first order, simply
+ * because children are guaranteed to be discovered after parents, and
+ * are inserted at the back of the list on discovery.
+ *
+ * All list on the suspend path are done in reverse order, so we operate
+ * on the leaves of the device tree (or forests, depending on how you want
+ * to look at it ;) first. As nodes are removed from the back of the list,
+ * they are inserted into the front of their destintation lists.
+ *
+ * Things are the reverse on the resume path - iterations are done in
+ * forward order, and nodes are inserted at the back of their destination
+ * lists. This way, the ancestors will be accessed before their descendents.
+ */
+
+
+/**
+ * suspend_device - Save state of one device.
+ * @dev: Device.
+ * @state: Power state device is entering.
+ */
+
+int suspend_device(struct device * dev, pm_message_t state)
+{
+ int error = 0;
+
+ dev_dbg(dev, "suspending\n");
+
+ dev->power.prev_state = dev->power.power_state;
+
+ if (dev->bus && dev->bus->suspend && !dev->power.power_state)
+ error = dev->bus->suspend(dev, state);
+
+ return error;
+}
+
+
+/**
+ * device_suspend - Save state and stop all devices in system.
+ * @state: Power state to put each device in.
+ *
+ * Walk the dpm_active list, call ->suspend() for each device, and move
+ * it to dpm_off.
+ * Check the return value for each. If it returns 0, then we move the
+ * the device to the dpm_off list. If it returns -EAGAIN, we move it to
+ * the dpm_off_irq list. If we get a different error, try and back out.
+ *
+ * If we hit a failure with any of the devices, call device_resume()
+ * above to bring the suspended devices back to life.
+ *
+ */
+
+int device_suspend(pm_message_t state)
+{
+ int error = 0;
+
+ down(&dpm_sem);
+ down(&dpm_list_sem);
+ while (!list_empty(&dpm_active) && error == 0) {
+ struct list_head * entry = dpm_active.prev;
+ struct device * dev = to_device(entry);
+
+ get_device(dev);
+ up(&dpm_list_sem);
+
+ error = suspend_device(dev, state);
+
+ down(&dpm_list_sem);
+
+ /* Check if the device got removed */
+ if (!list_empty(&dev->power.entry)) {
+ /* Move it to the dpm_off or dpm_off_irq list */
+ if (!error) {
+ list_del(&dev->power.entry);
+ list_add(&dev->power.entry, &dpm_off);
+ } else if (error == -EAGAIN) {
+ list_del(&dev->power.entry);
+ list_add(&dev->power.entry, &dpm_off_irq);
+ error = 0;
+ }
+ }
+ if (error)
+ printk(KERN_ERR "Could not suspend device %s: "
+ "error %d\n", kobject_name(&dev->kobj), error);
+ put_device(dev);
+ }
+ up(&dpm_list_sem);
+ if (error)
+ dpm_resume();
+ up(&dpm_sem);
+ return error;
+}
+
+EXPORT_SYMBOL_GPL(device_suspend);
+
+
+/**
+ * device_power_down - Shut down special devices.
+ * @state: Power state to enter.
+ *
+ * Walk the dpm_off_irq list, calling ->power_down() for each device that
+ * couldn't power down the device with interrupts enabled. When we're
+ * done, power down system devices.
+ */
+
+int device_power_down(pm_message_t state)
+{
+ int error = 0;
+ struct device * dev;
+
+ list_for_each_entry_reverse(dev, &dpm_off_irq, power.entry) {
+ if ((error = suspend_device(dev, state)))
+ break;
+ }
+ if (error)
+ goto Error;
+ if ((error = sysdev_suspend(state)))
+ goto Error;
+ Done:
+ return error;
+ Error:
+ printk(KERN_ERR "Could not power down device %s: "
+ "error %d\n", kobject_name(&dev->kobj), error);
+ dpm_power_up();
+ goto Done;
+}
+
+EXPORT_SYMBOL_GPL(device_power_down);
+