[PATCH 1/5] drm/bridge: dw-hdmi-qp: Provide HDMI Vendor Specific InfoFrame

[Cristian Ciocaltea <cristian.ciocaltea@collabora.com>]

Since commit b626b1a1c9cc ("drm/bridge: refactor HDMI InfoFrame
callbacks"), the following warning is generated:

  [   13.654149] rockchip-drm display-subsystem: [drm] HDMI VSI not supported

Add the missing support for sending HDMI Vendor-Specific Infoframes.

Additionally, introduce the dw_hdmi_qp_write_pkt() utility function, as
a prerequisite to rework the *_write_*_infoframe() callbacks and get rid
of some boilerplate code.

Signed-off-by: Cristian Ciocaltea <cristian.ciocaltea@collabora.com>
---
 drivers/gpu/drm/bridge/synopsys/dw-hdmi-qp.c | 32 +++++++++++++++++++++++++---
 drivers/gpu/drm/bridge/synopsys/dw-hdmi-qp.h |  2 ++
 2 files changed, 31 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/bridge/synopsys/dw-hdmi-qp.c b/drivers/gpu/drm/bridge/synopsys/dw-hdmi-qp.c
index 036316e2b60d..b37af6a7e194 100644
--- a/drivers/gpu/drm/bridge/synopsys/dw-hdmi-qp.c
+++ b/drivers/gpu/drm/bridge/synopsys/dw-hdmi-qp.c
@@ -11,6 +11,7 @@
 #include <linux/export.h>
 #include <linux/i2c.h>
 #include <linux/irq.h>
+#include <linux/minmax.h>
 #include <linux/module.h>
 #include <linux/mutex.h>
 #include <linux/of.h>
@@ -969,9 +970,9 @@ static int dw_hdmi_qp_bridge_clear_avi_infoframe(struct drm_bridge *bridge)
 
 static int dw_hdmi_qp_bridge_clear_hdmi_infoframe(struct drm_bridge *bridge)
 {
-	/* FIXME: add support for this InfoFrame */
+	struct dw_hdmi_qp *hdmi = bridge->driver_private;
 
-	drm_warn_once(bridge->encoder->dev, "HDMI VSI not supported\n");
+	dw_hdmi_qp_mod(hdmi, 0, PKTSCHED_VSI_TX_EN, PKTSCHED_PKT_EN);
 
 	return 0;
 }
@@ -998,6 +999,18 @@ static int dw_hdmi_qp_bridge_clear_audio_infoframe(struct drm_bridge *bridge)
 	return 0;
 }
 
+static void dw_hdmi_qp_write_pkt(struct dw_hdmi_qp *hdmi, const u8 *buffer,
+				 size_t start, size_t len, unsigned int reg)
+{
+	u32 val = 0;
+	size_t i;
+
+	for (i = start; i < start + len; i++)
+		val |= buffer[i] << ((i % 4) * 8);
+
+	dw_hdmi_qp_write(hdmi, val, reg);
+}
+
 static int dw_hdmi_qp_bridge_write_avi_infoframe(struct drm_bridge *bridge,
 						 const u8 *buffer, size_t len)
 {
@@ -1011,9 +1024,22 @@ static int dw_hdmi_qp_bridge_write_avi_infoframe(struct drm_bridge *bridge,
 static int dw_hdmi_qp_bridge_write_hdmi_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_hdmi_infoframe(bridge);
 
-	/* FIXME: add support for the HDMI VSI */
+	/* VSI packet header */
+	dw_hdmi_qp_write_pkt(hdmi, buffer, 1, 2, PKT_VSI_CONTENTS0);
+
+	/* VSI 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_VSI_CONTENTS1 + i);
+
+	dw_hdmi_qp_mod(hdmi, 0, PKTSCHED_VSI_FIELDRATE, PKTSCHED_PKT_CONFIG1);
+	dw_hdmi_qp_mod(hdmi, PKTSCHED_VSI_TX_EN, PKTSCHED_VSI_TX_EN,
+		       PKTSCHED_PKT_EN);
 
 	return 0;
 }
diff --git a/drivers/gpu/drm/bridge/synopsys/dw-hdmi-qp.h b/drivers/gpu/drm/bridge/synopsys/dw-hdmi-qp.h
index 91a15f82e32a..53688eae8dba 100644
--- a/drivers/gpu/drm/bridge/synopsys/dw-hdmi-qp.h
+++ b/drivers/gpu/drm/bridge/synopsys/dw-hdmi-qp.h
@@ -198,6 +198,7 @@
 #define PKTSCHED_PRQUEUE2_CONFIG2			0xa94
 #define PKTSCHED_PKT_CONFIG0				0xa98
 #define PKTSCHED_PKT_CONFIG1				0xa9c
+#define PKTSCHED_VSI_FIELDRATE				BIT(14)
 #define PKTSCHED_DRMI_FIELDRATE				BIT(13)
 #define PKTSCHED_AVI_FIELDRATE				BIT(12)
 #define PKTSCHED_PKT_CONFIG2				0xaa0
@@ -206,6 +207,7 @@
 #define PKTSCHED_DRMI_TX_EN				BIT(17)
 #define PKTSCHED_AUDI_TX_EN				BIT(15)
 #define PKTSCHED_AVI_TX_EN				BIT(13)
+#define PKTSCHED_VSI_TX_EN				BIT(12)
 #define PKTSCHED_EMP_CVTEM_TX_EN			BIT(10)
 #define PKTSCHED_AMD_TX_EN				BIT(8)
 #define PKTSCHED_GCP_TX_EN				BIT(3)

-- 
2.52.0