Add support for SCDC scrambling and the high TMDS clock ratio required
by HDMI 2.0 modes with TMDS character rates above 340 MHz, such as
4K@60Hz.
Hook the bridge into the DRM HDMI connector scrambling helpers so the
sink-side SCDC state and the controller scrambler are updated together
as part of the atomic enable and disable paths. This allows the driver
to advertise HDMI 2.0 support when HPD is available.
Keep no-HPD configurations limited to HDMI 1.4, since SCDC access
requires a connected HDMI sink.
Modes above the HDMI 2.0 600 MHz TMDS character-rate limit are now
implicitly rejected by the DRM HDMI connector/bridge infrastructure,
making the dw_hdmi_qp_bridge_tmds_char_rate_valid() callback redundant.
Drop it.
Tested-by: Diederik de Haas <diederik@cknow-tech.com>
Tested-by: Maud Spierings <maud_spierings@hotmail.com>
Acked-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Cristian Ciocaltea <cristian.ciocaltea@collabora.com>
---
drivers/gpu/drm/bridge/synopsys/dw-hdmi-qp.c | 60 ++++++++++++++++++----------
1 file changed, 39 insertions(+), 21 deletions(-)
@@ -2,6 +2,7 @@
/*
* Copyright (c) 2021-2022 Rockchip Electronics Co., Ltd.
* Copyright (c) 2024 Collabora Ltd.
+ * Copyright (c) 2025 Amazon.com, Inc. or its affiliates.
*
* Author: Algea Cao <algea.cao@rock-chips.com>
* Author: Cristian Ciocaltea <cristian.ciocaltea@collabora.com>
@@ -751,6 +752,7 @@ static void dw_hdmi_qp_bridge_atomic_enable(struct drm_bridge *bridge,
struct drm_connector_state *conn_state;
struct drm_connector *connector;
unsigned int op_mode;
+ int ret;
connector = drm_atomic_get_new_connector_for_encoder(state, bridge->encoder);
if (WARN_ON(!connector))
@@ -761,14 +763,20 @@ static void dw_hdmi_qp_bridge_atomic_enable(struct drm_bridge *bridge,
return;
if (connector->display_info.is_hdmi) {
- dev_dbg(hdmi->dev, "%s mode=HDMI %s rate=%llu bpc=%u\n", __func__,
- drm_hdmi_connector_get_output_format_name(conn_state->hdmi.output_format),
- conn_state->hdmi.tmds_char_rate, conn_state->hdmi.output_bpc);
op_mode = 0;
hdmi->tmds_char_rate = conn_state->hdmi.tmds_char_rate;
+
+ ret = drm_connector_hdmi_enable_scrambling(connector, conn_state);
+ if (ret)
+ dev_warn(hdmi->dev, "Failed to enable scrambling: %d\n", ret);
+
+ dev_dbg(hdmi->dev, "%s mode=HDMI %s rate=%llu bpc=%u scramb=%d\n", __func__,
+ drm_hdmi_connector_get_output_format_name(conn_state->hdmi.output_format),
+ conn_state->hdmi.tmds_char_rate, conn_state->hdmi.output_bpc,
+ connector->hdmi.scrambler_enabled);
} else {
- dev_dbg(hdmi->dev, "%s mode=DVI\n", __func__);
op_mode = OPMODE_DVI;
+ dev_dbg(hdmi->dev, "%s mode=DVI\n", __func__);
}
hdmi->phy.ops->init(hdmi, hdmi->phy.data);
@@ -783,9 +791,13 @@ static void dw_hdmi_qp_bridge_atomic_disable(struct drm_bridge *bridge,
struct drm_atomic_commit *state)
{
struct dw_hdmi_qp *hdmi = bridge->driver_private;
+ struct drm_connector *connector;
hdmi->tmds_char_rate = 0;
+ connector = drm_atomic_get_old_connector_for_encoder(state, bridge->encoder);
+ drm_connector_hdmi_disable_scrambling(connector);
+
hdmi->phy.ops->disable(hdmi, hdmi->phy.data);
}
@@ -820,24 +832,24 @@ dw_hdmi_qp_bridge_edid_read(struct drm_bridge *bridge,
return drm_edid;
}
-static enum drm_mode_status
-dw_hdmi_qp_bridge_tmds_char_rate_valid(const struct drm_bridge *bridge,
- const struct drm_display_mode *mode,
- unsigned long long rate)
+static int dw_hdmi_qp_bridge_scrambler_enable(struct drm_bridge *bridge)
{
struct dw_hdmi_qp *hdmi = bridge->driver_private;
- /*
- * TODO: when hdmi->no_hpd is 1 we must not support modes that
- * require scrambling, including every mode with a clock above
- * HDMI_1_3_TMDS_CHAR_RATE_MAX_HZ.
- */
- if (rate > HDMI_1_3_TMDS_CHAR_RATE_MAX_HZ) {
- dev_dbg(hdmi->dev, "Unsupported TMDS char rate: %lld\n", rate);
- return MODE_CLOCK_HIGH;
- }
+ dw_hdmi_qp_write(hdmi, 1, SCRAMB_CONFIG0);
+ dev_dbg(hdmi->dev, "scrambler enabled\n");
- return MODE_OK;
+ return 0;
+}
+
+static int dw_hdmi_qp_bridge_scrambler_disable(struct drm_bridge *bridge)
+{
+ struct dw_hdmi_qp *hdmi = bridge->driver_private;
+
+ dw_hdmi_qp_write(hdmi, 0, SCRAMB_CONFIG0);
+ dev_dbg(hdmi->dev, "scrambler disabled\n");
+
+ return 0;
}
static int dw_hdmi_qp_bridge_clear_avi_infoframe(struct drm_bridge *bridge)
@@ -1213,7 +1225,8 @@ static const struct drm_bridge_funcs dw_hdmi_qp_bridge_funcs = {
.hpd_enable = dw_hdmi_qp_bridge_hpd_enable,
.hpd_disable = dw_hdmi_qp_bridge_hpd_disable,
.edid_read = dw_hdmi_qp_bridge_edid_read,
- .hdmi_tmds_char_rate_valid = dw_hdmi_qp_bridge_tmds_char_rate_valid,
+ .hdmi_scrambler_enable = dw_hdmi_qp_bridge_scrambler_enable,
+ .hdmi_scrambler_disable = dw_hdmi_qp_bridge_scrambler_disable,
.hdmi_clear_avi_infoframe = dw_hdmi_qp_bridge_clear_avi_infoframe,
.hdmi_write_avi_infoframe = dw_hdmi_qp_bridge_write_avi_infoframe,
.hdmi_clear_hdmi_infoframe = dw_hdmi_qp_bridge_clear_hdmi_infoframe,
@@ -1341,13 +1354,18 @@ struct dw_hdmi_qp *dw_hdmi_qp_bind(struct platform_device *pdev,
DRM_BRIDGE_OP_HDMI_AUDIO |
DRM_BRIDGE_OP_HDMI_HDR_DRM_INFOFRAME |
DRM_BRIDGE_OP_HDMI_SPD_INFOFRAME;
- if (!hdmi->no_hpd)
- hdmi->bridge.ops |= DRM_BRIDGE_OP_HPD;
hdmi->bridge.of_node = pdev->dev.of_node;
hdmi->bridge.type = DRM_MODE_CONNECTOR_HDMIA;
hdmi->bridge.vendor = "Synopsys";
hdmi->bridge.product = "DW HDMI QP TX";
+ if (hdmi->no_hpd) {
+ hdmi->bridge.supported_hdmi_ver = HDMI_VERSION_1_4;
+ } else {
+ hdmi->bridge.supported_hdmi_ver = HDMI_VERSION_2_0;
+ hdmi->bridge.ops |= DRM_BRIDGE_OP_HPD;
+ }
+
if (plat_data->supported_formats)
hdmi->bridge.supported_formats = plat_data->supported_formats;