[PATCH] gpu/drm: mediatek: hdmi: check for valid modes on MT8167

[Neil Armstrong <narmstrong@baylibre.com>]

On MT8167, only CEA modes and anything using a clock below 148500 is
supported for HDMI. This change adds some checks to make sure the
video format is OK for MT8167.

Signed-off-by: Fabien Parent <fparent@baylibre.com>
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
---
 drivers/gpu/drm/mediatek/mtk_hdmi.c | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/drivers/gpu/drm/mediatek/mtk_hdmi.c b/drivers/gpu/drm/mediatek/mtk_hdmi.c
index 8ee55f9e2954..991e2e935b93 100644
--- a/drivers/gpu/drm/mediatek/mtk_hdmi.c
+++ b/drivers/gpu/drm/mediatek/mtk_hdmi.c
@@ -148,6 +148,8 @@ struct hdmi_audio_param {
 
 struct mtk_hdmi_conf {
 	bool tz_disabled;
+	unsigned long max_mode_clock;
+	bool cea_modes_only;
 };
 
 struct mtk_hdmi {
@@ -1259,6 +1261,13 @@ static int mtk_hdmi_conn_mode_valid(struct drm_connector *conn,
 			return MODE_BAD;
 	}
 
+	if (hdmi->conf->cea_modes_only && !drm_match_cea_mode(mode))
+		return MODE_BAD;
+
+	if (hdmi->conf->max_mode_clock &&
+	    mode->clock > hdmi->conf->max_mode_clock)
+		return MODE_CLOCK_HIGH;
+
 	if (mode->clock < 27000)
 		return MODE_CLOCK_LOW;
 	if (mode->clock > 297000)
@@ -1810,10 +1819,18 @@ static const struct mtk_hdmi_conf mtk_hdmi_conf_mt2701 = {
 	.tz_disabled = true,
 };
 
+static const struct mtk_hdmi_conf mtk_hdmi_conf_mt8167 = {
+	.max_mode_clock = 148500,
+	.cea_modes_only = true,
+};
+
 static const struct of_device_id mtk_drm_hdmi_of_ids[] = {
 	{ .compatible = "mediatek,mt2701-hdmi",
 	  .data = &mtk_hdmi_conf_mt2701,
 	},
+	{ .compatible = "mediatek,mt8167-hdmi",
+	  .data = &mtk_hdmi_conf_mt8167,
+	},
 	{ .compatible = "mediatek,mt8173-hdmi",
 	},
 	{}
-- 
2.25.1