disp: msm: add low power mode notifier

Introduce low power mode so that listeners are aware when
display is going into low power mode. This requires moving notifier
inside sde code to be able to retrieve the low power state.

Change-Id: I8671e86af29c959d97e1b8ad758a07719ffa4bec
(cherry picked from commit c4b15f56dd63d24d6f4482deab2423809c700d7a)
Signed-off-by: Adrian Salido <salidoa@google.com>
[samtran@codeaurora.org: move changes to different file as
downstream use of notifier struct comes from different file]
Signed-off-by: Samantha Tran <samtran@codeaurora.org>
Signed-off-by: Dhaval Patel <pdhaval@codeaurora.org>
Signed-off-by: Narendra Muppalla <NarendraM@codeaurora.org>

msm/sde/sde_kms.c

@@ -20,6 +20,7 @@
 
 #include <drm/drm_crtc.h>
 #include <drm/drm_fixed.h>
+#include <drm/drm_panel.h>
 #include <linux/debugfs.h>
 #include <linux/of_address.h>
 #include <linux/of_irq.h>
@@ -939,6 +940,80 @@ static int _sde_kms_unmap_all_splash_regions(struct sde_kms *sde_kms)
 	return ret;
 }
 
+static int _sde_kms_get_blank(struct drm_crtc_state *crtc_state,
+		struct drm_connector_state *conn_state)
+{
+	int lp_mode, blank;
+
+	if (crtc_state->active)
+		lp_mode = sde_connector_get_property(conn_state,
+							CONNECTOR_PROP_LP);
+	else
+		lp_mode = SDE_MODE_DPMS_OFF;
+
+	switch (lp_mode) {
+	case SDE_MODE_DPMS_ON:
+		blank = DRM_PANEL_BLANK_UNBLANK;
+		break;
+	case SDE_MODE_DPMS_LP1:
+	case SDE_MODE_DPMS_LP2:
+		blank = DRM_PANEL_BLANK_LP;
+		break;
+	case SDE_MODE_DPMS_OFF:
+	default:
+		blank = DRM_PANEL_BLANK_POWERDOWN;
+		break;
+	}
+
+	return blank;
+}
+
+static void _sde_kms_drm_check_dpms(struct drm_atomic_state *old_state,
+			unsigned long event)
+{
+	struct drm_connector *connector;
+	struct drm_connector_state *old_conn_state;
+	struct drm_crtc_state *old_crtc_state;
+	int i, old_mode, new_mode, old_fps, new_fps;
+
+	for_each_old_connector_in_state(old_state, connector,
+			old_conn_state, i) {
+		if (!connector->state->crtc)
+			continue;
+
+		new_fps = connector->state->crtc->state->mode.vrefresh;
+		new_mode = _sde_kms_get_blank(connector->state->crtc->state,
+						connector->state);
+		if (old_conn_state->crtc) {
+			old_crtc_state = drm_atomic_get_existing_crtc_state(
+					old_state, old_conn_state->crtc);
+
+			old_fps = old_crtc_state->mode.vrefresh;
+			old_mode = _sde_kms_get_blank(old_crtc_state,
+							old_conn_state);
+		} else {
+			old_fps = 0;
+			old_mode = DRM_PANEL_BLANK_POWERDOWN;
+		}
+
+		if ((old_mode != new_mode) || (old_fps != new_fps)) {
+			struct drm_panel_notifier notifier_data;
+
+			pr_debug("change detected (power mode %d->%d, fps %d->%d)\n",
+				old_mode, new_mode, old_fps, new_fps);
+
+			notifier_data.data = &new_mode;
+			notifier_data.refresh_rate = new_fps;
+			notifier_data.id = connector->base.id;
+
+			if (connector->panel)
+				drm_panel_notifier_call_chain(connector->panel,
+							event, &notifier_data);
+		}
+	}
+
+}
+
 int sde_kms_vm_primary_prepare_commit(struct sde_kms *sde_kms,
 				      struct drm_atomic_state *state)
 {
@@ -1079,6 +1154,7 @@ static void sde_kms_prepare_commit(struct msm_kms *kms,
 
 	if (vm_ops->vm_prepare_commit)
 		vm_ops->vm_prepare_commit(sde_kms, state);
+	_sde_kms_drm_check_dpms(state, DRM_PANEL_EARLY_EVENT_BLANK);
 end:
 	SDE_ATRACE_END("prepare_commit");
 }
@@ -1417,6 +1493,7 @@ static void sde_kms_complete_commit(struct msm_kms *kms,
 			SDE_ERROR("vm post commit failed, rc = %d\n",
 				  rc);
 	}
+	_sde_kms_drm_check_dpms(old_state, DRM_PANEL_EVENT_BLANK);
 
 	pm_runtime_put_sync(sde_kms->dev->dev);