[PATCH v3 0/2] drm/bridge: it6505: add audio support with DRM HDMI codec framework

[PATCH v3 0/2] drm/bridge: it6505: add audio support with DRM HDMI codec framework

[Hermes Wu via B4 Relay]

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 implement necessary callbacks for the drm_bridge_connector 
to enable the HDMI codec.

Signed-off-by: Hermes Wu <Hermes.wu@ite.com.tw>
---
Changes in v3:
- Separate DRM_BRIDGE_OP_HDMI supports and audio callbacks into two commits.
- Link to v2: https://lore.kernel.org/r/20250203-add-audio-codec-v2-1-5c8cd72ee5bb@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

---
Hermes Wu (2):
      drm/bridge: it6505: add support DRM_BRIDGE_OP_HDMI to drm_bridge
      drm/bridge: it6505: add audio support to drm_bridge_funcs

 drivers/gpu/drm/bridge/ite-it6505.c | 231 +++++++++++++++++++++++++-----------
 1 file changed, 161 insertions(+), 70 deletions(-)
---
base-commit: fe003bcb69f7bff9ff2b30b659b004dbafe52907
change-id: 20250114-add-audio-codec-8c9d47062a6c

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

[PATCH v3 1/2] drm/bridge: it6505: add support DRM_BRIDGE_OP_HDMI to drm_bridge

[Hermes Wu via B4 Relay]

From: Hermes Wu <Hermes.wu@ite.com.tw>

Add DRM_BRIDGE_OP_HDMI to bridge.ops and implement necessary callback
functions.

The native AVI and AUDIO infoframe configuration API are removed.

In .atomic_enable use
drm_atomic_helper_connector_hdmi_update_infoframes().
for infoframe updates.

Signed-off-by: Hermes Wu <Hermes.wu@ite.com.tw>
---
 drivers/gpu/drm/bridge/ite-it6505.c | 185 ++++++++++++++++++++++--------------
 1 file changed, 115 insertions(+), 70 deletions(-)

diff --git a/drivers/gpu/drm/bridge/ite-it6505.c b/drivers/gpu/drm/bridge/ite-it6505.c
index 88ef76a37fe6accacdd343839ff2569b31b18ceb..4c766854de14093b80949bdb410488f504b24db8 100644
--- a/drivers/gpu/drm/bridge/ite-it6505.c
+++ b/drivers/gpu/drm/bridge/ite-it6505.c
@@ -25,6 +25,8 @@
 
 #include <drm/display/drm_dp_helper.h>
 #include <drm/display/drm_hdcp_helper.h>
+#include <drm/display/drm_hdmi_helper.h>
+#include <drm/display/drm_hdmi_state_helper.h>
 #include <drm/drm_atomic_helper.h>
 #include <drm/drm_bridge.h>
 #include <drm/drm_crtc.h>
@@ -1414,37 +1416,6 @@ static void it6505_variable_config(struct it6505 *it6505)
 	memset(it6505->bksvs, 0, sizeof(it6505->bksvs));
 }
 
-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;
-	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;
-	}
-
-	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)
-		return err;
-
-	return 0;
-}
-
 static void it6505_get_extcon_property(struct it6505 *it6505)
 {
 	int err;
@@ -1604,27 +1575,6 @@ static void it6505_enable_audio_source(struct it6505 *it6505)
 	it6505_write(it6505, REG_AUDIO_SRC_CTRL, audio_source_count);
 }
 
-static void it6505_enable_audio_infoframe(struct it6505 *it6505)
-{
-	struct device *dev = it6505->dev;
-	u8 audio_info_ca[] = { 0x00, 0x00, 0x01, 0x03, 0x07, 0x0B, 0x0F, 0x1F };
-
-	DRM_DEV_DEBUG_DRIVER(dev, "infoframe channel_allocation:0x%02x",
-			     audio_info_ca[it6505->audio.channel_count - 1]);
-
-	it6505_write(it6505, REG_AUD_INFOFRAM_DB1, it6505->audio.channel_count
-		     - 1);
-	it6505_write(it6505, REG_AUD_INFOFRAM_DB2, 0x00);
-	it6505_write(it6505, REG_AUD_INFOFRAM_DB3,
-		     audio_info_ca[it6505->audio.channel_count - 1]);
-	it6505_write(it6505, REG_AUD_INFOFRAM_DB4, 0x00);
-	it6505_write(it6505, REG_AUD_INFOFRAM_SUM, 0x00);
-
-	/* Enable Audio InfoFrame */
-	it6505_set_bits(it6505, REG_INFOFRAME_CTRL, EN_AUD_CTRL_PKT,
-			EN_AUD_CTRL_PKT);
-}
-
 static void it6505_disable_audio(struct it6505 *it6505)
 {
 	it6505_set_bits(it6505, REG_DATA_MUTE_CTRL, EN_AUD_MUTE, EN_AUD_MUTE);
@@ -1644,7 +1594,6 @@ static void it6505_enable_audio(struct it6505 *it6505)
 	it6505_setup_audio_channel_status(it6505);
 	it6505_setup_audio_format(it6505);
 	it6505_enable_audio_source(it6505);
-	it6505_enable_audio_infoframe(it6505);
 
 	it6505_write(it6505, REG_AUDIO_N_0_7, 0x00);
 	it6505_write(it6505, REG_AUDIO_N_8_15, 0x80);
@@ -3168,17 +3117,13 @@ it6505_bridge_mode_valid(struct drm_bridge *bridge,
 			 const struct drm_display_info *info,
 			 const struct drm_display_mode *mode)
 {
-	struct it6505 *it6505 = bridge_to_it6505(bridge);
-
-	if (mode->flags & DRM_MODE_FLAG_INTERLACE)
-		return MODE_NO_INTERLACE;
-
-	if (mode->clock > it6505->max_dpi_pixel_clock)
-		return MODE_CLOCK_HIGH;
+	unsigned long long rate;
 
-	it6505->video_info.clock = mode->clock;
+	rate = drm_hdmi_compute_mode_clock(mode, 8, HDMI_COLORSPACE_RGB);
+	if (rate == 0)
+		return MODE_NOCLOCK;
 
-	return MODE_OK;
+	return bridge->funcs->hdmi_tmds_char_rate_valid(bridge, mode, rate);
 }
 
 static void it6505_bridge_atomic_enable(struct drm_bridge *bridge,
@@ -3217,6 +3162,8 @@ static void it6505_bridge_atomic_enable(struct drm_bridge *bridge,
 	if (WARN_ON(!mode))
 		return;
 
+	drm_atomic_helper_connector_hdmi_update_infoframes(connector, state);
+
 	ret = drm_hdmi_avi_infoframe_from_display_mode(&frame,
 						       connector,
 						       mode);
@@ -3224,15 +3171,8 @@ static void it6505_bridge_atomic_enable(struct drm_bridge *bridge,
 		dev_err(dev, "Failed to setup AVI infoframe: %d", ret);
 
 	it6505_update_video_parameter(it6505, mode);
-
-	ret = it6505_send_video_infoframe(it6505, &frame);
-
-	if (ret)
-		dev_err(dev, "Failed to send AVI infoframe: %d", ret);
-
 	it6505_int_mask_enable(it6505);
 	it6505_video_reset(it6505);
-
 	it6505_drm_dp_link_set_power(&it6505->aux, &it6505->link,
 				     DP_SET_POWER_D0);
 }
@@ -3302,6 +3242,106 @@ static const struct drm_edid *it6505_bridge_edid_read(struct drm_bridge *bridge,
 	return drm_edid_dup(it6505->cached_edid);
 }
 
+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 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_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;
+
+	/*HW supports AVI and AUDIO infoframe only*/
+	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 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;
+
+	/*HW supports AVI and AUDIO infoframe only*/
+	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 enum drm_mode_status
+it6505_bridge_hdmi_tmds_char_rate_valid(const struct drm_bridge *bridge,
+					const struct drm_display_mode *mode,
+					unsigned long long tmds_rate)
+{
+	const struct it6505 *it6505 = container_of(bridge,
+						   const struct it6505,
+						   bridge);
+
+	if (mode->flags & DRM_MODE_FLAG_INTERLACE)
+		return MODE_NO_INTERLACE;
+
+	if (mode->clock > it6505->max_dpi_pixel_clock ||
+	    tmds_rate > 148500000)
+		return MODE_CLOCK_HIGH;
+
+	return MODE_OK;
+}
+
 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 +3355,9 @@ 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_clear_infoframe = it6505_bridge_hdmi_clear_infoframe,
+	.hdmi_write_infoframe = it6505_bridge_hdmi_write_infoframe,
+	.hdmi_tmds_char_rate_valid = it6505_bridge_hdmi_tmds_char_rate_valid,
 };
 
 static __maybe_unused int it6505_bridge_resume(struct device *dev)
@@ -3700,7 +3743,9 @@ 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";
 	drm_bridge_add(&it6505->bridge);
 
 	return 0;

-- 
2.34.1

[PATCH v3 2/2] drm/bridge: it6505: add audio support to drm_bridge_funcs

[Hermes Wu via B4 Relay]

From: 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.

Signed-off-by: Hermes Wu <Hermes.wu@ite.com.tw>
---
 drivers/gpu/drm/bridge/ite-it6505.c | 46 +++++++++++++++++++++++++++++++++++++
 1 file changed, 46 insertions(+)

diff --git a/drivers/gpu/drm/bridge/ite-it6505.c b/drivers/gpu/drm/bridge/ite-it6505.c
index 4c766854de14093b80949bdb410488f504b24db8..832c4e3ff4ada31367788faed9583da676e36cf8 100644
--- a/drivers/gpu/drm/bridge/ite-it6505.c
+++ b/drivers/gpu/drm/bridge/ite-it6505.c
@@ -3342,6 +3342,46 @@ it6505_bridge_hdmi_tmds_char_rate_valid(const struct drm_bridge *bridge,
 	return MODE_OK;
 }
 
+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);
+	int err;
+
+	err = it6505_audio_setup_hw_params(it6505, hparms);
+	if (err < 0)
+		return err;
+
+	return drm_atomic_helper_connector_hdmi_update_audio_infoframe(connector,
+								       &hparms->cea);
+}
+
+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 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,
@@ -3358,6 +3398,9 @@ static const struct drm_bridge_funcs it6505_bridge_funcs = {
 	.hdmi_clear_infoframe = it6505_bridge_hdmi_clear_infoframe,
 	.hdmi_write_infoframe = it6505_bridge_hdmi_write_infoframe,
 	.hdmi_tmds_char_rate_valid = it6505_bridge_hdmi_tmds_char_rate_valid,
+	.hdmi_audio_startup = it6505_bridge_hdmi_audio_startup,
+	.hdmi_audio_prepare = it6505_bridge_hdmi_audio_prepare,
+	.hdmi_audio_shutdown = it6505_bridge_hdmi_audio_shutdown,
 };
 
 static __maybe_unused int it6505_bridge_resume(struct device *dev)
@@ -3746,6 +3789,9 @@ static int it6505_i2c_probe(struct i2c_client *client)
 			     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;

-- 
2.34.1

Re: [PATCH v3 1/2] drm/bridge: it6505: add support DRM_BRIDGE_OP_HDMI to drm_bridge

[Dmitry Baryshkov]

On Wed, Feb 05, 2025 at 02:41:03PM +0800, Hermes Wu via B4 Relay wrote:
> From: Hermes Wu <Hermes.wu@ite.com.tw>
> 
> Add DRM_BRIDGE_OP_HDMI to bridge.ops and implement necessary callback
> functions.

Wait.... Now I feel really sorry. I stumbled upon HDMI_related bits and
then I thought that it's a HDMI bridge without actually checking the
datasheet. When you have a hammer, everything looks like a nail...
Except that IT6505 is neither a nail nor an HDMI bridge.

I'm really sorry for pushing you into the wrong way of OP_HDMI. However
I still think that DisplayPort bridges should not implement codec
callbacks directly. Let me play with that over the next few days. I
think in the end we should be able to use .hdmi_audio_*() callbacks
and drm_hdmi_audio_helper.c while not (over)using the OP_HDMI. I'll ping
you in the next few days.

> The native AVI and AUDIO infoframe configuration API are removed.
> 
> In .atomic_enable use
> drm_atomic_helper_connector_hdmi_update_infoframes().
> for infoframe updates.
> 
> Signed-off-by: Hermes Wu <Hermes.wu@ite.com.tw>
> ---
>  drivers/gpu/drm/bridge/ite-it6505.c | 185 ++++++++++++++++++++++--------------
>  1 file changed, 115 insertions(+), 70 deletions(-)
> 
-- 
With best wishes
Dmitry