drm/bridge: sii902x: Fix mode_valid hook

Currently, mode_valid is defined only in drm_connector_helper_funcs.
When the bridge is attached with the 'DRM_BRIDGE_ATTACH_NO_CONNECTOR'
flag, the connector is not initialized, and so is the mode_valid
hook under connector helper funcs.
It also returns MODE_OK for all modes without actually checking the
modes.
So move the mode_valid hook to drm_bridge_funcs with proper clock
checks for maximum and minimum pixel clock supported by the bridge.
Signed-off-by: Jayesh Choudhary <j-choudhary@ti.com>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Acked-by: Sui Jingfeng <sui.jingfeng@linux.dev>
Reviewed-by: Aradhya Bhatia <a-bhatia1@ti.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240613083805.439337-2-j-choudhary@ti.comSigned-off-by: Maxime Ripard <mripard@kernel.org>

drivers/gpu/drm/bridge/sii902x.c

@@ -163,6 +163,14 @@
 
 #define SII902X_AUDIO_PORT_INDEX		3
 
+/*
+ * The maximum resolution supported by the HDMI bridge is 1080p@60Hz
+ * and 1920x1200 requiring a pixel clock of 165MHz and the minimum
+ * resolution supported is 480p@60Hz requiring a pixel clock of 25MHz
+ */
+#define SII902X_MIN_PIXEL_CLOCK_KHZ		25000
+#define SII902X_MAX_PIXEL_CLOCK_KHZ		165000
+
 struct sii902x {
 	struct i2c_client *i2c;
 	struct regmap *regmap;
@@ -310,17 +318,8 @@ static int sii902x_get_modes(struct drm_connector *connector)
 	return num;
 }
 
-static enum drm_mode_status sii902x_mode_valid(struct drm_connector *connector,
-					       struct drm_display_mode *mode)
-{
-	/* TODO: check mode */
-
-	return MODE_OK;
-}
-
 static const struct drm_connector_helper_funcs sii902x_connector_helper_funcs = {
 	.get_modes = sii902x_get_modes,
-	.mode_valid = sii902x_mode_valid,
 };
 
 static void sii902x_bridge_disable(struct drm_bridge *bridge)
@@ -504,6 +503,20 @@ static int sii902x_bridge_atomic_check(struct drm_bridge *bridge,
 	return 0;
 }
 
+static enum drm_mode_status
+sii902x_bridge_mode_valid(struct drm_bridge *bridge,
+			  const struct drm_display_info *info,
+			  const struct drm_display_mode *mode)
+{
+	if (mode->clock < SII902X_MIN_PIXEL_CLOCK_KHZ)
+		return MODE_CLOCK_LOW;
+
+	if (mode->clock > SII902X_MAX_PIXEL_CLOCK_KHZ)
+		return MODE_CLOCK_HIGH;
+
+	return MODE_OK;
+}
+
 static const struct drm_bridge_funcs sii902x_bridge_funcs = {
 	.attach = sii902x_bridge_attach,
 	.mode_set = sii902x_bridge_mode_set,
@@ -516,6 +529,7 @@ static const struct drm_bridge_funcs sii902x_bridge_funcs = {
 	.atomic_destroy_state = drm_atomic_helper_bridge_destroy_state,
 	.atomic_get_input_bus_fmts = sii902x_bridge_atomic_get_input_bus_fmts,
 	.atomic_check = sii902x_bridge_atomic_check,
+	.mode_valid = sii902x_bridge_mode_valid,
 };
 
 static int sii902x_mute(struct sii902x *sii902x, bool mute)