[PATCH 10/28] drm/i915/writeback: Add hook to check modes

[Suraj Kandpal]

Add connector helper hooks to check if mode is valid or not.
We add this restriction to make sure mode is 3840x2160 60Hz.

Signed-off-by: Suraj Kandpal <suraj.kandpal at intel.com>
---
 .../gpu/drm/i915/display/intel_writeback.c    | 20 +++++++++++++++++++
 1 file changed, 20 insertions(+)

diff --git a/drivers/gpu/drm/i915/display/intel_writeback.c b/drivers/gpu/drm/i915/display/intel_writeback.c
index 7df99771fd6f..ff5f15ce3f5f 100644
--- a/drivers/gpu/drm/i915/display/intel_writeback.c
+++ b/drivers/gpu/drm/i915/display/intel_writeback.c
@@ -75,6 +75,25 @@ intel_writeback_connector_alloc(struct intel_connector *connector)
 	return 0;
 }
 
+static enum drm_mode_status
+intel_writeback_mode_valid(struct drm_connector *_connector,
+			   const struct drm_display_mode *mode)
+{
+	int refresh_rate;
+
+	if (mode->hdisplay > 3840)
+		return MODE_H_ILLEGAL;
+
+	if (mode->vdisplay > 2160)
+		return MODE_V_ILLEGAL;
+
+	refresh_rate = drm_mode_vrefresh(mode);
+	if (refresh_rate > 60)
+		return MODE_BAD;
+
+	return MODE_OK;
+}
+
 static int intel_writeback_get_modes(struct drm_connector *connector)
 {
 	return drm_add_modes_noedid(connector, 3840, 2160);
@@ -112,6 +131,7 @@ const struct drm_connector_funcs conn_funcs = {
 static const struct drm_connector_helper_funcs conn_helper_funcs = {
 	.get_writeback_connector = intel_get_writeback_connector,
 	.get_modes = intel_writeback_get_modes,
+	.mode_valid = intel_writeback_mode_valid,
 };
 
 static const struct drm_writeback_connector_helper_funcs writeback_conn_helper_funcs = {
-- 
2.34.1