Lines Matching full:driver
14 <a href="#androidPowerKernelRegistration">Registering Drivers with the PM Driver</a><br/>
40 <p>If the suspend operation has already started when locking a wakelock, the system will abort the suspend operation as long it has not already reached the <code>suspend_late</code> stage. This means that locking a wakelock from an interrupt handler or a freezeable thread always works, but if you lock a wakelock from a <code>suspend_late</code> handler, you must also return an error from that handler to abort suspend. You can use wakelocks to allow the user-space to decide which keys should wake the full system and turn on the screen. Use <code>set_irq_wake</code> or a platform-specific API to ensure that the keypad interrupt wakes up the CPU. Once the keypad driver has resumed, the sequence of events can look like this:</p>
42 <li> The Keypad driver receives an interrupt, locks the keypad-scan wakelock,
45 driver. </li>
46 <li>The input-event driver sees the key change, enqueues an event, and locks
52 <li>The input-event driver dequeues the key-event and, since the queue is now
67 <a name="driverAPI"></a><h3>Driver API</h3>
68 <p>A driver can use the wakelock API by adding a wakelock variable to its state and calling <code>wake_lock_init</code>, as illustrated in the snippet below:</p>
81 <p> When the driver determines that it needs to run (usually in an interrupt handler), it calls <code>wake_lock</code>:</p>
93 <p> This works whether or not the wakelock is already held. It is useful if the driver woke up other parts of the system that do not use wakelocks but still need to run. Avoid this when possible, since it will waste power if the timeout is long or may fail to finish needed work if the timeout is short.</p>
165 <a name="androidPowerKernelRegistration"></a><h2>Registering Drivers with the PM Driver</h2>
167 <p>You can register Kernel-level drivers with the Android Power Manager driver so that they're notified immediately before power down or after power up. For example, you might set a display driver to completely power down when a request comes in to power down from the user space (see the Android MSM MDDI display driver for a sample implementation).</p>
168 <p>To register drivers with the Android PM driver, implement call-back handlers and register them with the Android PM, as illustrated in the snippet below:</p>
