[PATCH RFC v2 2/8] drm/meson: add HDMI div40 TMDS mode

[Neil Armstrong <narmstrong@baylibre.com>]

Add support for TMDS Clock > 3.4GHz for HDMI2.0 display modes.

Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
---
 drivers/gpu/drm/meson/meson_dw_hdmi.c | 24 ++++++++++++++++++++----
 1 file changed, 20 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/meson/meson_dw_hdmi.c b/drivers/gpu/drm/meson/meson_dw_hdmi.c
index 807111ebfdd9..b8775102b100 100644
--- a/drivers/gpu/drm/meson/meson_dw_hdmi.c
+++ b/drivers/gpu/drm/meson/meson_dw_hdmi.c
@@ -365,7 +365,8 @@ static int dw_hdmi_phy_init(struct dw_hdmi *hdmi, void *data,
 	unsigned int wr_clk =
 		readl_relaxed(priv->io_base + _REG(VPU_HDMI_SETTING));
 
-	DRM_DEBUG_DRIVER("%d:\"%s\"\n", mode->base.id, mode->name);
+	DRM_DEBUG_DRIVER("%d:\"%s\" div%d\n", mode->base.id, mode->name,
+			 mode->clock > 340000 ? 40 : 10);
 
 	/* Enable clocks */
 	regmap_update_bits(priv->hhi, HHI_HDMI_CLK_CNTL, 0xffff, 0x100);
@@ -385,9 +386,17 @@ static int dw_hdmi_phy_init(struct dw_hdmi *hdmi, void *data,
 	/* Enable normal output to PHY */
 	dw_hdmi_top_write(dw_hdmi, HDMITX_TOP_BIST_CNTL, BIT(12));
 
-	/* TMDS pattern setup (TOFIX pattern for 4k2k scrambling) */
-	dw_hdmi_top_write(dw_hdmi, HDMITX_TOP_TMDS_CLK_PTTN_01, 0x001f001f);
-	dw_hdmi_top_write(dw_hdmi, HDMITX_TOP_TMDS_CLK_PTTN_23, 0x001f001f);
+	/* TMDS pattern setup (TOFIX Handle the YUV420 case) */
+	if (mode->clock > 340000) {
+		dw_hdmi_top_write(dw_hdmi, HDMITX_TOP_TMDS_CLK_PTTN_01, 0);
+		dw_hdmi_top_write(dw_hdmi, HDMITX_TOP_TMDS_CLK_PTTN_23,
+				  0x03ff03ff);
+	} else {
+		dw_hdmi_top_write(dw_hdmi, HDMITX_TOP_TMDS_CLK_PTTN_01,
+				  0x001f001f);
+		dw_hdmi_top_write(dw_hdmi, HDMITX_TOP_TMDS_CLK_PTTN_23,
+				  0x001f001f);
+	}
 
 	/* Load TMDS pattern */
 	dw_hdmi_top_write(dw_hdmi, HDMITX_TOP_TMDS_CLK_PTTN_CNTL, 0x1);
@@ -413,6 +422,8 @@ static int dw_hdmi_phy_init(struct dw_hdmi *hdmi, void *data,
 	/* Disable clock, fifo, fifo_wr */
 	regmap_update_bits(priv->hhi, HHI_HDMI_PHY_CNTL1, 0xf, 0);
 
+	dw_hdmi_set_high_tmds_clock_ratio(hdmi);
+
 	msleep(100);
 
 	/* Reset PHY 3 times in a row */
@@ -562,6 +573,11 @@ dw_hdmi_mode_valid(struct drm_connector *connector,
 		mode->vdisplay, mode->vsync_start,
 		mode->vsync_end, mode->vtotal, mode->type, mode->flags);
 
+	/* If sink max TMDS clock < 340MHz, we reject the HDMI2.0 modes */
+	if (mode->clock > 340000 &&
+	    connector->display_info.max_tmds_clock < 340000)
+		return MODE_BAD;
+
 	/* Check against non-VIC supported modes */
 	if (!vic) {
 		status = meson_venc_hdmi_supported_mode(mode);
-- 
2.19.2