[PATCH v2 2/4] drm/bridge: use atomic enable/disable for bridge callbacks

[Vinod Polimera <quic_vpolimer@quicinc.com>]

Use atomic enable/disable for bridge callbacks to access certain
states like self-refresh.

This change avoids panel prepare/unprepare based on self-refresh
state.

Signed-off-by: Sankeerth Billakanti <quic_sbillaka@quicinc.com>
Signed-off-by: Kalyan Thota <quic_kalyant@quicinc.com>
Signed-off-by: Vinod Polimera <quic_vpolimer@quicinc.com>

Changes in V2:
- As per review suggestion by Dmitry.
---
 drivers/gpu/drm/bridge/panel.c | 102 +++++++++++++++++++++++++++++++++++++----
 1 file changed, 94 insertions(+), 8 deletions(-)

diff --git a/drivers/gpu/drm/bridge/panel.c b/drivers/gpu/drm/bridge/panel.c
index b32295a..5c7dc82 100644
--- a/drivers/gpu/drm/bridge/panel.c
+++ b/drivers/gpu/drm/bridge/panel.c
@@ -41,6 +41,40 @@ static int panel_bridge_connector_get_modes(struct drm_connector *connector)
 	return drm_panel_get_modes(panel_bridge->panel, connector);
 }
 
+static struct drm_crtc *bridge_drm_get_old_connector_crtc(struct drm_encoder *encoder,
+						struct drm_atomic_state *state)
+{
+	struct drm_connector *connector;
+	struct drm_connector_state *conn_state;
+
+	connector = drm_atomic_get_old_connector_for_encoder(state, encoder);
+	if (!connector)
+		return NULL;
+
+	conn_state = drm_atomic_get_old_connector_state(state, connector);
+	if (!conn_state)
+		return NULL;
+
+	return conn_state->crtc;
+}
+
+static struct drm_crtc *bridge_drm_get_new_connector_crtc(struct drm_encoder *encoder,
+						struct drm_atomic_state *state)
+{
+	struct drm_connector *connector;
+	struct drm_connector_state *conn_state;
+
+	connector = drm_atomic_get_new_connector_for_encoder(state, encoder);
+	if (!connector)
+		return NULL;
+
+	conn_state = drm_atomic_get_new_connector_state(state, connector);
+	if (!conn_state)
+		return NULL;
+
+	return conn_state->crtc;
+}
+
 static const struct drm_connector_helper_funcs
 panel_bridge_connector_helper_funcs = {
 	.get_modes = panel_bridge_connector_get_modes,
@@ -102,30 +136,82 @@ static void panel_bridge_detach(struct drm_bridge *bridge)
 		drm_connector_cleanup(connector);
 }
 
-static void panel_bridge_pre_enable(struct drm_bridge *bridge)
+static void panel_bridge_pre_enable(struct drm_bridge *bridge,
+		struct drm_bridge_state *old_bridge_state)
 {
 	struct panel_bridge *panel_bridge = drm_bridge_to_panel_bridge(bridge);
+	struct drm_atomic_state *old_state = old_bridge_state->base.state;
+	struct drm_encoder *encoder = bridge->encoder;
+	struct drm_crtc *crtc;
+	struct drm_crtc_state *old_crtc_state;
+
+	crtc = bridge_drm_get_new_connector_crtc(encoder, old_state);
+	if (!crtc)
+		return;
+
+	old_crtc_state = drm_atomic_get_old_crtc_state(old_state, crtc);
+	if (old_crtc_state && old_crtc_state->self_refresh_active)
+		return;
 
 	drm_panel_prepare(panel_bridge->panel);
 }
 
-static void panel_bridge_enable(struct drm_bridge *bridge)
+static void panel_bridge_enable(struct drm_bridge *bridge,
+		struct drm_bridge_state *old_bridge_state)
 {
 	struct panel_bridge *panel_bridge = drm_bridge_to_panel_bridge(bridge);
+	struct drm_atomic_state *old_state = old_bridge_state->base.state;
+	struct drm_encoder *encoder = bridge->encoder;
+	struct drm_crtc *crtc;
+	struct drm_crtc_state *old_crtc_state;
+
+	crtc = bridge_drm_get_new_connector_crtc(encoder, old_state);
+	if (!crtc)
+		return;
+
+	old_crtc_state = drm_atomic_get_old_crtc_state(old_state, crtc);
+	if (old_crtc_state && old_crtc_state->self_refresh_active)
+		return;
 
 	drm_panel_enable(panel_bridge->panel);
 }
 
-static void panel_bridge_disable(struct drm_bridge *bridge)
+static void panel_bridge_disable(struct drm_bridge *bridge,
+		struct drm_bridge_state *old_bridge_state)
 {
 	struct panel_bridge *panel_bridge = drm_bridge_to_panel_bridge(bridge);
+	struct drm_atomic_state *old_state = old_bridge_state->base.state;
+	struct drm_encoder *encoder = bridge->encoder;
+	struct drm_crtc *crtc;
+	struct drm_crtc_state *new_crtc_state;
+
+	crtc = bridge_drm_get_old_connector_crtc(encoder, old_state);
+	if (!crtc)
+		return;
+
+	new_crtc_state = drm_atomic_get_new_crtc_state(old_state, crtc);
+	if (new_crtc_state && new_crtc_state->self_refresh_active)
+		return;
 
 	drm_panel_disable(panel_bridge->panel);
 }
 
-static void panel_bridge_post_disable(struct drm_bridge *bridge)
+static void panel_bridge_post_disable(struct drm_bridge *bridge,
+		struct drm_bridge_state *old_bridge_state)
 {
 	struct panel_bridge *panel_bridge = drm_bridge_to_panel_bridge(bridge);
+	struct drm_atomic_state *old_state = old_bridge_state->base.state;
+	struct drm_encoder *encoder = bridge->encoder;
+	struct drm_crtc *crtc;
+	struct drm_crtc_state *new_crtc_state;
+
+	crtc = bridge_drm_get_old_connector_crtc(encoder, old_state);
+	if (!crtc)
+		return;
+
+	new_crtc_state = drm_atomic_get_new_crtc_state(old_state, crtc);
+	if (new_crtc_state && new_crtc_state->self_refresh_active)
+		return;
 
 	drm_panel_unprepare(panel_bridge->panel);
 }
@@ -141,10 +227,10 @@ static int panel_bridge_get_modes(struct drm_bridge *bridge,
 static const struct drm_bridge_funcs panel_bridge_bridge_funcs = {
 	.attach = panel_bridge_attach,
 	.detach = panel_bridge_detach,
-	.pre_enable = panel_bridge_pre_enable,
-	.enable = panel_bridge_enable,
-	.disable = panel_bridge_disable,
-	.post_disable = panel_bridge_post_disable,
+	.atomic_pre_enable = panel_bridge_pre_enable,
+	.atomic_enable = panel_bridge_enable,
+	.atomic_disable = panel_bridge_disable,
+	.atomic_post_disable = panel_bridge_post_disable,
 	.get_modes = panel_bridge_get_modes,
 	.atomic_reset = drm_atomic_helper_bridge_reset,
 	.atomic_duplicate_state = drm_atomic_helper_bridge_duplicate_state,
-- 
2.7.4