linux-kernel - [PATCH 2/5] drm/bridge: dw-hdmi-qp: Provide SPD InfoFrame

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Message-Id: <20260125-dw-hdmi-qp-iframe-v1-2-e0f7649ecc4b@collabora.com>
Date: Sun, 25 Jan 2026 02:23:00 +0200
From: Cristian Ciocaltea <cristian.ciocaltea@...labora.com>
To: Andrzej Hajda <andrzej.hajda@...el.com>, 
 Neil Armstrong <neil.armstrong@...aro.org>, Robert Foss <rfoss@...nel.org>, 
 Laurent Pinchart <Laurent.pinchart@...asonboard.com>, 
 Jonas Karlman <jonas@...boo.se>, Jernej Skrabec <jernej.skrabec@...il.com>, 
 Maarten Lankhorst <maarten.lankhorst@...ux.intel.com>, 
 Maxime Ripard <mripard@...nel.org>, Thomas Zimmermann <tzimmermann@...e.de>, 
 David Airlie <airlied@...il.com>, Simona Vetter <simona@...ll.ch>
Cc: kernel@...labora.com, dri-devel@...ts.freedesktop.org, 
 linux-kernel@...r.kernel.org
Subject: [PATCH 2/5] drm/bridge: dw-hdmi-qp: Provide SPD InfoFrame

The hardware is capable of sending Source Product Description (SPD)
InfoFrames, hence enable the missing support.

Signed-off-by: Cristian Ciocaltea <cristian.ciocaltea@...labora.com>
---
 drivers/gpu/drm/bridge/synopsys/dw-hdmi-qp.c | 36 +++++++++++++++++++++++++++-
 drivers/gpu/drm/bridge/synopsys/dw-hdmi-qp.h |  1 +
 2 files changed, 36 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/bridge/synopsys/dw-hdmi-qp.c b/drivers/gpu/drm/bridge/synopsys/dw-hdmi-qp.c
index b37af6a7e194..429736486d85 100644
--- a/drivers/gpu/drm/bridge/synopsys/dw-hdmi-qp.c
+++ b/drivers/gpu/drm/bridge/synopsys/dw-hdmi-qp.c
@@ -986,6 +986,15 @@ static int dw_hdmi_qp_bridge_clear_hdr_drm_infoframe(struct drm_bridge *bridge)
 	return 0;
 }
 
+static int dw_hdmi_qp_bridge_clear_spd_infoframe(struct drm_bridge *bridge)
+{
+	struct dw_hdmi_qp *hdmi = bridge->driver_private;
+
+	dw_hdmi_qp_mod(hdmi, 0, PKTSCHED_SPDI_TX_EN, PKTSCHED_PKT_EN);
+
+	return 0;
+}
+
 static int dw_hdmi_qp_bridge_clear_audio_infoframe(struct drm_bridge *bridge)
 {
 	struct dw_hdmi_qp *hdmi = bridge->driver_private;
@@ -1054,6 +1063,28 @@ static int dw_hdmi_qp_bridge_write_hdr_drm_infoframe(struct drm_bridge *bridge,
 	return dw_hdmi_qp_config_drm_infoframe(hdmi, buffer, len);
 }
 
+static int dw_hdmi_qp_bridge_write_spd_infoframe(struct drm_bridge *bridge,
+						 const u8 *buffer, size_t len)
+{
+	struct dw_hdmi_qp *hdmi = bridge->driver_private;
+	size_t i;
+
+	dw_hdmi_qp_bridge_clear_spd_infoframe(bridge);
+
+	/* SPD packet header */
+	dw_hdmi_qp_write_pkt(hdmi, buffer, 1, 2, PKT_SPDI_CONTENTS0);
+
+	/* SPD packet body */
+	for (i = 0; i < len - 3; i += 4)
+		dw_hdmi_qp_write_pkt(hdmi, buffer + 3, i, min(len - i - 3, 4),
+				     PKT_SPDI_CONTENTS1 + i);
+
+	dw_hdmi_qp_mod(hdmi, PKTSCHED_SPDI_TX_EN, PKTSCHED_SPDI_TX_EN,
+		       PKTSCHED_PKT_EN);
+
+	return 0;
+}
+
 static int dw_hdmi_qp_bridge_write_audio_infoframe(struct drm_bridge *bridge,
 						   const u8 *buffer, size_t len)
 {
@@ -1252,6 +1283,8 @@ static const struct drm_bridge_funcs dw_hdmi_qp_bridge_funcs = {
 	.hdmi_write_hdmi_infoframe = dw_hdmi_qp_bridge_write_hdmi_infoframe,
 	.hdmi_clear_hdr_drm_infoframe = dw_hdmi_qp_bridge_clear_hdr_drm_infoframe,
 	.hdmi_write_hdr_drm_infoframe = dw_hdmi_qp_bridge_write_hdr_drm_infoframe,
+	.hdmi_clear_spd_infoframe = dw_hdmi_qp_bridge_clear_spd_infoframe,
+	.hdmi_write_spd_infoframe = dw_hdmi_qp_bridge_write_spd_infoframe,
 	.hdmi_clear_audio_infoframe = dw_hdmi_qp_bridge_clear_audio_infoframe,
 	.hdmi_write_audio_infoframe = dw_hdmi_qp_bridge_write_audio_infoframe,
 	.hdmi_audio_startup = dw_hdmi_qp_audio_enable,
@@ -1368,7 +1401,8 @@ struct dw_hdmi_qp *dw_hdmi_qp_bind(struct platform_device *pdev,
 			   DRM_BRIDGE_OP_EDID |
 			   DRM_BRIDGE_OP_HDMI |
 			   DRM_BRIDGE_OP_HDMI_AUDIO |
-			   DRM_BRIDGE_OP_HDMI_HDR_DRM_INFOFRAME;
+			   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;
diff --git a/drivers/gpu/drm/bridge/synopsys/dw-hdmi-qp.h b/drivers/gpu/drm/bridge/synopsys/dw-hdmi-qp.h
index 53688eae8dba..c07847e8d7dd 100644
--- a/drivers/gpu/drm/bridge/synopsys/dw-hdmi-qp.h
+++ b/drivers/gpu/drm/bridge/synopsys/dw-hdmi-qp.h
@@ -206,6 +206,7 @@
 #define PKTSCHED_PKT_EN					0xaa8
 #define PKTSCHED_DRMI_TX_EN				BIT(17)
 #define PKTSCHED_AUDI_TX_EN				BIT(15)
+#define PKTSCHED_SPDI_TX_EN				BIT(14)
 #define PKTSCHED_AVI_TX_EN				BIT(13)
 #define PKTSCHED_VSI_TX_EN				BIT(12)
 #define PKTSCHED_EMP_CVTEM_TX_EN			BIT(10)

-- 
2.52.0