[PATCH v2] drm/bridge: it6505: support hdmi_codec_ops for audio stream setup

[Hermes Wu <Hermes.wu@ite.com.tw>]

For supporting audio form I2S to DP audio data sub stream.
Add hdmi_audio callbacks to drm_bridge_funcs for the
HDMI codec framework. The DRM_BRIDGE_OP_HDMI flag in bridge.ops
must be set, and hdmi_write_infoframe and hdmi_clear_infoframe
are necessary for the drm_bridge_connector to enable the HDMI codec.

Signed-off-by: Hermes Wu <Hermes.wu@ite.com.tw>
---
Changes in v2:
- Use DRM HDMI codec framewrok for audio stream setup.
- Link to v1: https://lore.kernel.org/r/20250121-add-audio-codec-v1-1-e3ff71b3c819@ite.com.tw
---
 drivers/gpu/drm/bridge/ite-it6505.c | 151 +++++++++++++++++++++++++++++++-----
 1 file changed, 132 insertions(+), 19 deletions(-)

diff --git a/drivers/gpu/drm/bridge/ite-it6505.c b/drivers/gpu/drm/bridge/ite-it6505.c
index 88ef76a37fe6accacdd343839ff2569b31b18ceb..361e2412b8e8f040cf4254479b60588d99e8c99a 100644
--- a/drivers/gpu/drm/bridge/ite-it6505.c
+++ b/drivers/gpu/drm/bridge/ite-it6505.c
@@ -1414,32 +1414,43 @@ static void it6505_variable_config(struct it6505 *it6505)
 	memset(it6505->bksvs, 0, sizeof(it6505->bksvs));
 }
 
+static int it6505_write_avi_infoframe(struct it6505 *it6505,
+				      const u8 *buffer, size_t len)
+{
+	struct device *dev = it6505->dev;
+
+	if (len - HDMI_INFOFRAME_HEADER_SIZE > 13) {
+		DRM_DEV_DEBUG_DRIVER(dev, "AVI size fail %d", len);
+		return -EINVAL;
+	}
+
+	it6505_set_bits(it6505, REG_INFOFRAME_CTRL, EN_AVI_PKT, 0);
+	regmap_bulk_write(it6505->regmap, REG_AVI_INFO_DB1,
+			  buffer + HDMI_INFOFRAME_HEADER_SIZE,
+			  len - HDMI_INFOFRAME_HEADER_SIZE);
+
+	it6505_write(it6505, REG_AVI_INFO_SUM, buffer[3]);
+	it6505_set_bits(it6505, REG_INFOFRAME_CTRL, EN_AVI_PKT,
+			EN_AVI_PKT);
+
+	return 0;
+}
+
 static int it6505_send_video_infoframe(struct it6505 *it6505,
 				       struct hdmi_avi_infoframe *frame)
 {
 	u8 buffer[HDMI_INFOFRAME_HEADER_SIZE + HDMI_AVI_INFOFRAME_SIZE];
-	int err;
+	int err, length;
 	struct device *dev = it6505->dev;
 
-	err = hdmi_avi_infoframe_pack(frame, buffer, sizeof(buffer));
-	if (err < 0) {
-		dev_err(dev, "Failed to pack AVI infoframe: %d", err);
-		return err;
+	length = hdmi_avi_infoframe_pack(frame, buffer, sizeof(buffer));
+	if (length < 0) {
+		dev_err(dev, "Failed to pack AVI infoframe: %d", length);
+		return length;
 	}
 
-	err = it6505_set_bits(it6505, REG_INFOFRAME_CTRL, EN_AVI_PKT, 0x00);
-	if (err)
-		return err;
-
-	err = regmap_bulk_write(it6505->regmap, REG_AVI_INFO_DB1,
-				buffer + HDMI_INFOFRAME_HEADER_SIZE,
-				frame->length);
-	if (err)
-		return err;
-
-	err = it6505_set_bits(it6505, REG_INFOFRAME_CTRL, EN_AVI_PKT,
-			      EN_AVI_PKT);
-	if (err)
+	err = it6505_write_avi_infoframe(it6505, buffer, length);
+	if (err < 0)
 		return err;
 
 	return 0;
@@ -1625,6 +1636,18 @@ static void it6505_enable_audio_infoframe(struct it6505 *it6505)
 			EN_AUD_CTRL_PKT);
 }
 
+static void it6505_write_audio_infoframe(struct it6505 *it6505,
+					 const u8 *buffer, size_t len)
+{
+	it6505_set_bits(it6505, REG_INFOFRAME_CTRL, EN_AUD_PKT, 0);
+	regmap_bulk_write(it6505->regmap, REG_AUD_INFOFRAM_DB1,
+			  buffer + HDMI_INFOFRAME_HEADER_SIZE,
+			  4);
+	it6505_write(it6505, REG_AUD_INFOFRAM_SUM, buffer[3]);
+	it6505_set_bits(it6505, REG_INFOFRAME_CTRL, EN_AUD_PKT,
+			EN_AUD_PKT);
+}
+
 static void it6505_disable_audio(struct it6505 *it6505)
 {
 	it6505_set_bits(it6505, REG_DATA_MUTE_CTRL, EN_AUD_MUTE, EN_AUD_MUTE);
@@ -3302,6 +3325,85 @@ static const struct drm_edid *it6505_bridge_edid_read(struct drm_bridge *bridge,
 	return drm_edid_dup(it6505->cached_edid);
 }
 
+static int it6505_bridge_hdmi_audio_startup(struct drm_connector *connector,
+					    struct drm_bridge *bridge)
+{
+	struct it6505 *it6505 = bridge_to_it6505(bridge);
+	struct device *dev = it6505->dev;
+
+	if (!it6505->powered || it6505->enable_drv_hold)
+		return -EIO;
+
+	DRM_DEV_DEBUG_DRIVER(dev, "Audio enable");
+	it6505_enable_audio(it6505);
+
+	return 0;
+}
+
+static int it6505_bridge_hdmi_audio_prepare(struct drm_connector *connector,
+					    struct drm_bridge *bridge,
+					    struct hdmi_codec_daifmt *fmt,
+					    struct hdmi_codec_params *hparms)
+{
+	struct it6505 *it6505 = bridge_to_it6505(bridge);
+
+	return it6505_audio_setup_hw_params(it6505, hparms);
+}
+
+static void it6505_bridge_hdmi_audio_shutdown(struct drm_connector *connector,
+					      struct drm_bridge *bridge)
+{
+	struct it6505 *it6505 = bridge_to_it6505(bridge);
+
+	if (it6505->powered && !it6505->enable_drv_hold)
+		it6505_disable_audio(it6505);
+}
+
+static int it6505_bridge_hdmi_clear_infoframe(struct drm_bridge *bridge,
+					      enum hdmi_infoframe_type type)
+{
+	struct it6505 *it6505 = bridge_to_it6505(bridge);
+	struct device *dev = it6505->dev;
+
+	switch (type) {
+	case HDMI_INFOFRAME_TYPE_AUDIO:
+		it6505_set_bits(it6505, REG_INFOFRAME_CTRL, EN_AUD_PKT, 0);
+		break;
+
+	case HDMI_INFOFRAME_TYPE_AVI:
+		it6505_set_bits(it6505, REG_INFOFRAME_CTRL, EN_AVI_PKT, 0);
+		break;
+	default:
+		dev_dbg(dev, "unsupported HDMI infoframe 0x%x\n", type);
+		break;
+	}
+
+	return 0;
+}
+
+static int it6505_bridge_hdmi_write_infoframe(struct drm_bridge *bridge,
+					      enum hdmi_infoframe_type type,
+					      const u8 *buffer, size_t len)
+{
+	struct it6505 *it6505 = bridge_to_it6505(bridge);
+	struct device *dev = it6505->dev;
+
+	switch (type) {
+	case HDMI_INFOFRAME_TYPE_AUDIO:
+		it6505_write_audio_infoframe(it6505, buffer, len);
+		break;
+
+	case HDMI_INFOFRAME_TYPE_AVI:
+		it6505_write_avi_infoframe(it6505, buffer, len);
+		break;
+	default:
+		dev_dbg(dev, "unsupported HDMI infoframe 0x%x\n", type);
+		break;
+	}
+
+	return 0;
+}
+
 static const struct drm_bridge_funcs it6505_bridge_funcs = {
 	.atomic_duplicate_state = drm_atomic_helper_bridge_duplicate_state,
 	.atomic_destroy_state = drm_atomic_helper_bridge_destroy_state,
@@ -3315,6 +3417,12 @@ static const struct drm_bridge_funcs it6505_bridge_funcs = {
 	.atomic_post_disable = it6505_bridge_atomic_post_disable,
 	.detect = it6505_bridge_detect,
 	.edid_read = it6505_bridge_edid_read,
+	.hdmi_audio_startup = it6505_bridge_hdmi_audio_startup,
+	.hdmi_audio_prepare = it6505_bridge_hdmi_audio_prepare,
+	.hdmi_audio_shutdown = it6505_bridge_hdmi_audio_shutdown,
+	.hdmi_clear_infoframe = it6505_bridge_hdmi_clear_infoframe,
+	.hdmi_write_infoframe = it6505_bridge_hdmi_write_infoframe,
+
 };
 
 static __maybe_unused int it6505_bridge_resume(struct device *dev)
@@ -3700,7 +3808,12 @@ static int it6505_i2c_probe(struct i2c_client *client)
 	it6505->bridge.funcs = &it6505_bridge_funcs;
 	it6505->bridge.type = DRM_MODE_CONNECTOR_DisplayPort;
 	it6505->bridge.ops = DRM_BRIDGE_OP_DETECT | DRM_BRIDGE_OP_EDID |
-			     DRM_BRIDGE_OP_HPD;
+			     DRM_BRIDGE_OP_HPD | DRM_BRIDGE_OP_HDMI;
+	it6505->bridge.vendor = "iTE";
+	it6505->bridge.product = "IT6505";
+	it6505->bridge.hdmi_audio_dev = dev;
+	it6505->bridge.hdmi_audio_max_i2s_playback_channels = 2;
+	it6505->bridge.hdmi_audio_dai_port = 1;
 	drm_bridge_add(&it6505->bridge);
 
 	return 0;

---
base-commit: fe003bcb69f7bff9ff2b30b659b004dbafe52907
change-id: 20250114-add-audio-codec-8c9d47062a6c

Best regards,
-- 
Hermes Wu <Hermes.wu@ite.com.tw>