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From: Jayesh Choudhary <j-choudhary@ti.com>
To: <andrzej.hajda@intel.com>, <neil.armstrong@linaro.org>, <rfoss@kernel.org>,
        <Laurent.pinchart@ideasonboard.com>, <mripard@kernel.org>,
        <j-choudhary@ti.com>
CC: <jonas@kwiboo.se>, <jernej.skrabec@gmail.com>,
        <maarten.lankhorst@linux.intel.com>, <tzimmermann@suse.de>,
        <airlied@gmail.com>, <daniel@ffwll.ch>,
        <dri-devel@lists.freedesktop.org>, <linux-kernel@vger.kernel.org>
Subject: [PATCH] drm/bridge: sii902x: Fix mode_valid hook
Date: Mon, 8 Apr 2024 13:44:35 +0530
Message-ID: <20240408081435.216927-1-j-choudhary@ti.com>
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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@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@60Hz
+ * and 1920x1200 requiring a pixel clock of 165MHz and the minimum
+ * resolution supported is 480p@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