[PATCH 08/15] drm/rockchip: dw-hdmi: require valid vpll clock rate on rk3228/rk3328

[Jonas Karlman]

RK3228/RK3328 can only support clock rates defined in the pre pll table.
Lets validate the mode clock rate against the pre pll config and filter
out any mode with a clock rate returning error from clk_round_rate().

Signed-off-by: Jonas Karlman <jonas at kwiboo.se>
---
 drivers/gpu/drm/rockchip/dw_hdmi-rockchip.c | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/drivers/gpu/drm/rockchip/dw_hdmi-rockchip.c b/drivers/gpu/drm/rockchip/dw_hdmi-rockchip.c
index fae38b323a0c..45fcdce3f27f 100644
--- a/drivers/gpu/drm/rockchip/dw_hdmi-rockchip.c
+++ b/drivers/gpu/drm/rockchip/dw_hdmi-rockchip.c
@@ -245,6 +245,22 @@ static void dw_hdmi_rockchip_encoder_disable(struct drm_encoder *encoder)
 {
 }
 
+static enum drm_mode_status
+dw_hdmi_rockchip_encoder_mode_valid(struct drm_encoder *encoder,
+				    const struct drm_display_mode *mode)
+{
+	struct rockchip_hdmi *hdmi = to_rockchip_hdmi(encoder);
+	long rate;
+
+	if (hdmi->vpll_clk) {
+		rate = clk_round_rate(hdmi->vpll_clk, mode->clock * 1000);
+		if (rate < 0)
+			return MODE_CLOCK_RANGE;
+	}
+
+	return MODE_OK;
+}
+
 static bool
 dw_hdmi_rockchip_encoder_mode_fixup(struct drm_encoder *encoder,
 				    const struct drm_display_mode *mode,
@@ -306,6 +322,7 @@ dw_hdmi_rockchip_encoder_atomic_check(struct drm_encoder *encoder,
 }
 
 static const struct drm_encoder_helper_funcs dw_hdmi_rockchip_encoder_helper_funcs = {
+	.mode_valid = dw_hdmi_rockchip_encoder_mode_valid,
 	.mode_fixup = dw_hdmi_rockchip_encoder_mode_fixup,
 	.mode_set   = dw_hdmi_rockchip_encoder_mode_set,
 	.enable     = dw_hdmi_rockchip_encoder_enable,
-- 
2.17.1