Add the rt linux 4.1.3-rt3 as base

[kvmfornfv.git] / kernel / Documentation / cpuidle / driver.txt

diff --git a/kernel/Documentation/cpuidle/driver.txt b/kernel/Documentation/cpuidle/driver.txt
new file mode 100644 (file)
index 0000000..1b0d81d
--- /dev/null
+++ b/kernel/Documentation/cpuidle/driver.txt
@@ -0,0 +1,37 @@
+
+
+               Supporting multiple CPU idle levels in kernel
+
+                               cpuidle drivers
+
+
+
+
+cpuidle driver hooks into the cpuidle infrastructure and handles the
+architecture/platform dependent part of CPU idle states. Driver
+provides the platform idle state detection capability and also
+has mechanisms in place to support actual entry-exit into CPU idle states.
+
+cpuidle driver initializes the cpuidle_device structure for each CPU device
+and registers with cpuidle using cpuidle_register_device.
+
+If all the idle states are the same, the wrapper function cpuidle_register
+could be used instead.
+
+It can also support the dynamic changes (like battery <-> AC), by using
+cpuidle_pause_and_lock, cpuidle_disable_device and cpuidle_enable_device,
+cpuidle_resume_and_unlock.
+
+Interfaces:
+extern int cpuidle_register(struct cpuidle_driver *drv,
+                            const struct cpumask *const coupled_cpus);
+extern int cpuidle_unregister(struct cpuidle_driver *drv);
+extern int cpuidle_register_driver(struct cpuidle_driver *drv);
+extern void cpuidle_unregister_driver(struct cpuidle_driver *drv);
+extern int cpuidle_register_device(struct cpuidle_device *dev);
+extern void cpuidle_unregister_device(struct cpuidle_device *dev);
+
+extern void cpuidle_pause_and_lock(void);
+extern void cpuidle_resume_and_unlock(void);
+extern int cpuidle_enable_device(struct cpuidle_device *dev);
+extern void cpuidle_disable_device(struct cpuidle_device *dev);