[PATCH v2 23/28] drm/bridge: display-connector: Implement readout support

[Maxime Ripard <mripard@kernel.org>]

The display-connector bridge is the last bridge in the chain on
platforms using drm_bridge_connector, and is responsible for the
physical connector interface.

Implement the atomic_sro_readout_state hook and wire up the default
drm_atomic_helper_bridge_compare_state() as the compare hook.

Signed-off-by: Maxime Ripard <mripard@kernel.org>
---
 drivers/gpu/drm/bridge/display-connector.c | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/drivers/gpu/drm/bridge/display-connector.c b/drivers/gpu/drm/bridge/display-connector.c
index 16c0631adeb1..94b645248368 100644
--- a/drivers/gpu/drm/bridge/display-connector.c
+++ b/drivers/gpu/drm/bridge/display-connector.c
@@ -12,10 +12,11 @@
 #include <linux/of.h>
 #include <linux/platform_device.h>
 #include <linux/regulator/consumer.h>
 
 #include <drm/drm_atomic_helper.h>
+#include <drm/drm_atomic_sro_helper.h>
 #include <drm/drm_bridge.h>
 #include <drm/drm_edid.h>
 
 struct display_connector {
 	struct drm_bridge	bridge;
@@ -173,19 +174,33 @@ static u32 *display_connector_get_input_bus_fmts(struct drm_bridge *bridge,
 	return prev_bridge->funcs->atomic_get_input_bus_fmts(prev_bridge, prev_bridge_state,
 							     crtc_state, conn_state, output_fmt,
 							     num_input_fmts);
 }
 
+static int
+display_connector_readout_state(struct drm_bridge *bridge,
+				struct drm_atomic_sro_state *state,
+				struct drm_bridge_state *bridge_state,
+				struct drm_crtc_state *crtc_state,
+				struct drm_connector_state *conn_state)
+{
+	// TODO: Actually implement it
+
+	return 0;
+}
+
 static const struct drm_bridge_funcs display_connector_bridge_funcs = {
 	.attach = display_connector_attach,
 	.detect = display_connector_bridge_detect,
 	.edid_read = display_connector_edid_read,
 	.atomic_get_output_bus_fmts = display_connector_get_output_bus_fmts,
 	.atomic_get_input_bus_fmts = display_connector_get_input_bus_fmts,
 	.atomic_duplicate_state = drm_atomic_helper_bridge_duplicate_state,
 	.atomic_destroy_state = drm_atomic_helper_bridge_destroy_state,
 	.atomic_reset = drm_atomic_helper_bridge_reset,
+	.atomic_sro_readout_state	= display_connector_readout_state,
+	.atomic_sro_compare_state	= drm_atomic_helper_bridge_compare_state,
 };
 
 static irqreturn_t display_connector_hpd_irq(int irq, void *arg)
 {
 	struct display_connector *conn = arg;

-- 
2.53.0