disp: msm: add support for display early wakeup

Display clocks and IRQs are disabled during idle state
on command mode for power saving, and will be enabled
when a new frame commits to display driver. But enable
display clocks and IRQs will cause some latency.
So add a new SDE custom IOCTL for user-space to early wake
up display before first frame commits to kernel.

Change-Id: I6ca0188d321c4964f29c46e588b64d06b9634c59
Signed-off-by: Lei Chen <chenlei@codeaurora.org>

msm/sde/sde_encoder.h

@@ -167,6 +167,7 @@ struct sde_encoder_ops {
  * @rc_state:			resource controller state
  * @delayed_off_work:		delayed worker to schedule disabling of
  *				clks and resources after IDLE_TIMEOUT time.
+ * @early_wakeup_work:		worker to handle early wakeup event
  * @input_event_work:		worker to handle input device touch events
  * @esd_trigger_work:		worker to handle esd trigger events
  * @input_handler:			handler for input device events
@@ -232,6 +233,7 @@ struct sde_encoder_virt {
 	struct mutex rc_lock;
 	enum sde_enc_rc_states rc_state;
 	struct kthread_delayed_work delayed_off_work;
+	struct kthread_work early_wakeup_work;
 	struct kthread_work input_event_work;
 	struct kthread_work esd_trigger_work;
 	struct input_handler *input_handler;
@@ -265,6 +267,12 @@ void sde_encoder_get_hw_resources(struct drm_encoder *encoder,
 		struct sde_encoder_hw_resources *hw_res,
 		struct drm_connector_state *conn_state);
 
+/**
+ * sde_encoder_early_wakeup - early wake up display
+ * @encoder:	encoder pointer
+ */
+void sde_encoder_early_wakeup(struct drm_encoder *drm_enc);
+
 /**
  * sde_encoder_register_vblank_callback - provide callback to encoder that
  *	will be called on the next vblank.