+#define PM_SUSPEND_ON ((__force suspend_state_t) 0)
+#define PM_SUSPEND_STANDBY ((__force suspend_state_t) 1)
+#define PM_SUSPEND_MEM ((__force suspend_state_t) 3)
+#define PM_SUSPEND_MAX ((__force suspend_state_t) 4)
+
+/**
+ * struct platform_suspend_ops - Callbacks for managing platform dependent
+ * system sleep states.
+ *
+ * @valid: Callback to determine if given system sleep state is supported by
+ * the platform.
+ * Valid (ie. supported) states are advertised in /sys/power/state. Note
+ * that it still may be impossible to enter given system sleep state if the
+ * conditions aren't right.
+ * There is the %suspend_valid_only_mem function available that can be
+ * assigned to this if the platform only supports mem sleep.
+ *
+ * @begin: Initialise a transition to given system sleep state.
+ * @begin() is executed right prior to suspending devices. The information
+ * conveyed to the platform code by @begin() should be disregarded by it as
+ * soon as @end() is executed. If @begin() fails (ie. returns nonzero),
+ * @prepare(), @enter() and @finish() will not be called by the PM core.
+ * This callback is optional. However, if it is implemented, the argument
+ * passed to @enter() is redundant and should be ignored.
+ *
+ * @prepare: Prepare the platform for entering the system sleep state indicated
+ * by @begin().
+ * @prepare() is called right after devices have been suspended (ie. the
+ * appropriate .suspend() method has been executed for each device) and
+ * before the nonboot CPUs are disabled (it is executed with IRQs enabled).
+ * This callback is optional. It returns 0 on success or a negative
+ * error code otherwise, in which case the system cannot enter the desired
+ * sleep state (@enter() and @finish() will not be called in that case).
+ *
+ * @enter: Enter the system sleep state indicated by @begin() or represented by
+ * the argument if @begin() is not implemented.
+ * This callback is mandatory. It returns 0 on success or a negative
+ * error code otherwise, in which case the system cannot enter the desired
+ * sleep state.
+ *
+ * @finish: Called when the system has just left a sleep state, right after
+ * the nonboot CPUs have been enabled and before devices are resumed (it is
+ * executed with IRQs enabled).
+ * This callback is optional, but should be implemented by the platforms
+ * that implement @prepare(). If implemented, it is always called after
+ * @enter() (even if @enter() fails).
+ *
+ * @end: Called by the PM core right after resuming devices, to indicate to
+ * the platform that the system has returned to the working state or
+ * the transition to the sleep state has been aborted.
+ * This callback is optional, but should be implemented by the platforms
+ * that implement @begin(), but platforms implementing @begin() should
+ * also provide a @end() which cleans up transitions aborted before
+ * @enter().
+ */
+struct platform_suspend_ops {
+ int (*valid)(suspend_state_t state);
+ int (*begin)(suspend_state_t state);
+ int (*prepare)(void);
+ int (*enter)(suspend_state_t state);
+ void (*finish)(void);
+ void (*end)(void);
+};