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authorRafael J. Wysocki <rjw@sisk.pl>2009-08-18 23:38:32 +0200
committerRafael J. Wysocki <rjw@sisk.pl>2009-08-23 00:04:44 +0200
commit5e928f77a09a07f9dd595bb8a489965d69a83458 (patch)
treeef53ec90fa3214fd22e36b07c11c06b09e373d8d /include/linux/pm.h
parent8400146d0dc03590bba051399e4bb7e1cbf1c010 (diff)
PM: Introduce core framework for run-time PM of I/O devices (rev. 17)
Introduce a core framework for run-time power management of I/O devices. Add device run-time PM fields to 'struct dev_pm_info' and device run-time PM callbacks to 'struct dev_pm_ops'. Introduce a run-time PM workqueue and define some device run-time PM helper functions at the core level. Document all these things. Special thanks to Alan Stern for his help with the design and multiple detailed reviews of the pereceding versions of this patch and to Magnus Damm for testing feedback. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Acked-by: Magnus Damm <damm@igel.co.jp>
Diffstat (limited to 'include/linux/pm.h')
-rw-r--r--include/linux/pm.h101
1 files changed, 98 insertions, 3 deletions
diff --git a/include/linux/pm.h b/include/linux/pm.h
index b3f74764a58..2b6e20df0e5 100644
--- a/include/linux/pm.h
+++ b/include/linux/pm.h
@@ -22,6 +22,10 @@
#define _LINUX_PM_H
#include <linux/list.h>
+#include <linux/workqueue.h>
+#include <linux/spinlock.h>
+#include <linux/wait.h>
+#include <linux/timer.h>
/*
* Callbacks for platform drivers to implement.
@@ -165,6 +169,28 @@ typedef struct pm_message {
* It is allowed to unregister devices while the above callbacks are being
* executed. However, it is not allowed to unregister a device from within any
* of its own callbacks.
+ *
+ * There also are the following callbacks related to run-time power management
+ * of devices:
+ *
+ * @runtime_suspend: Prepare the device for a condition in which it won't be
+ * able to communicate with the CPU(s) and RAM due to power management.
+ * This need not mean that the device should be put into a low power state.
+ * For example, if the device is behind a link which is about to be turned
+ * off, the device may remain at full power. If the device does go to low
+ * power and if device_may_wakeup(dev) is true, remote wake-up (i.e., a
+ * hardware mechanism allowing the device to request a change of its power
+ * state, such as PCI PME) should be enabled for it.
+ *
+ * @runtime_resume: Put the device into the fully active state in response to a
+ * wake-up event generated by hardware or at the request of software. If
+ * necessary, put the device into the full power state and restore its
+ * registers, so that it is fully operational.
+ *
+ * @runtime_idle: Device appears to be inactive and it might be put into a low
+ * power state if all of the necessary conditions are satisfied. Check
+ * these conditions and handle the device as appropriate, possibly queueing
+ * a suspend request for it. The return value is ignored by the PM core.
*/
struct dev_pm_ops {
@@ -182,6 +208,9 @@ struct dev_pm_ops {
int (*thaw_noirq)(struct device *dev);
int (*poweroff_noirq)(struct device *dev);
int (*restore_noirq)(struct device *dev);
+ int (*runtime_suspend)(struct device *dev);
+ int (*runtime_resume)(struct device *dev);
+ int (*runtime_idle)(struct device *dev);
};
/**
@@ -315,14 +344,80 @@ enum dpm_state {
DPM_OFF_IRQ,
};
+/**
+ * Device run-time power management status.
+ *
+ * These status labels are used internally by the PM core to indicate the
+ * current status of a device with respect to the PM core operations. They do
+ * not reflect the actual power state of the device or its status as seen by the
+ * driver.
+ *
+ * RPM_ACTIVE Device is fully operational. Indicates that the device
+ * bus type's ->runtime_resume() callback has completed
+ * successfully.
+ *
+ * RPM_SUSPENDED Device bus type's ->runtime_suspend() callback has
+ * completed successfully. The device is regarded as
+ * suspended.
+ *
+ * RPM_RESUMING Device bus type's ->runtime_resume() callback is being
+ * executed.
+ *
+ * RPM_SUSPENDING Device bus type's ->runtime_suspend() callback is being
+ * executed.
+ */
+
+enum rpm_status {
+ RPM_ACTIVE = 0,
+ RPM_RESUMING,
+ RPM_SUSPENDED,
+ RPM_SUSPENDING,
+};
+
+/**
+ * Device run-time power management request types.
+ *
+ * RPM_REQ_NONE Do nothing.
+ *
+ * RPM_REQ_IDLE Run the device bus type's ->runtime_idle() callback
+ *
+ * RPM_REQ_SUSPEND Run the device bus type's ->runtime_suspend() callback
+ *
+ * RPM_REQ_RESUME Run the device bus type's ->runtime_resume() callback
+ */
+
+enum rpm_request {
+ RPM_REQ_NONE = 0,
+ RPM_REQ_IDLE,
+ RPM_REQ_SUSPEND,
+ RPM_REQ_RESUME,
+};
+
struct dev_pm_info {
pm_message_t power_state;
- unsigned can_wakeup:1;
- unsigned should_wakeup:1;
+ unsigned int can_wakeup:1;
+ unsigned int should_wakeup:1;
enum dpm_state status; /* Owned by the PM core */
-#ifdef CONFIG_PM_SLEEP
+#ifdef CONFIG_PM_SLEEP
struct list_head entry;
#endif
+#ifdef CONFIG_PM_RUNTIME
+ struct timer_list suspend_timer;
+ unsigned long timer_expires;
+ struct work_struct work;
+ wait_queue_head_t wait_queue;
+ spinlock_t lock;
+ atomic_t usage_count;
+ atomic_t child_count;
+ unsigned int disable_depth:3;
+ unsigned int ignore_children:1;
+ unsigned int idle_notification:1;
+ unsigned int request_pending:1;
+ unsigned int deferred_resume:1;
+ enum rpm_request request;
+ enum rpm_status runtime_status;
+ int runtime_error;
+#endif
};
/*