[PATCH] drm/bridge: sii902x: Fix mode_valid hook

[Jayesh Choudhary]

Currently, mode_valid hook returns all mode as valid. Add the check
for the maximum and minimum pixel clock that the bridge can support
while validating a mode.

Signed-off-by: Jayesh Choudhary <j-choudhary at ti.com>
---
 drivers/gpu/drm/bridge/sii902x.c | 16 +++++++++++++++-
 1 file changed, 15 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/bridge/sii902x.c b/drivers/gpu/drm/bridge/sii902x.c
index 8f84e98249c7..658819199c84 100644
--- a/drivers/gpu/drm/bridge/sii902x.c
+++ b/drivers/gpu/drm/bridge/sii902x.c
@@ -163,6 +163,16 @@
 
 #define SII902X_AUDIO_PORT_INDEX		3
 
+/*
+ * The maximum resolution supported by the HDMI bridge is 1080p at 60Hz
+ * and 1920x1200 requiring a pixel clock of 165MHz and the minimum
+ * resolution supported is 480p at 60Hz requiring a pixel clock of 25MHz
+ *
+ * (drm_display_mode clock is in kHz)
+ */
+#define SII902X_MIN_PIXEL_CLOCK			25000
+#define SII902X_MAX_PIXEL_CLOCK			165000
+
 struct sii902x {
 	struct i2c_client *i2c;
 	struct regmap *regmap;
@@ -313,7 +323,11 @@ static int sii902x_get_modes(struct drm_connector *connector)
 static enum drm_mode_status sii902x_mode_valid(struct drm_connector *connector,
 					       struct drm_display_mode *mode)
 {
-	/* TODO: check mode */
+	if (mode->clock < SII902X_MIN_PIXEL_CLOCK)
+		return MODE_CLOCK_LOW;
+
+	if (mode->clock > SII902X_MAX_PIXEL_CLOCK)
+		return MODE_CLOCK_HIGH;
 
 	return MODE_OK;
 }
-- 
2.25.1