[PATCH v2 1/2] drm/bridge: it6505: Add audio support
From: Daniel Golle
Date: Mon Jul 20 2026 - 11:56:11 EST
From: Jiaxin Yu <jiaxin.yu@xxxxxxxxxxxx>
Add audio support for it6505 by bridging to the hdmi-codec, registering
an "hdmi-audio-codec" platform device from probe. The it6505's audio
setup/shutdown helpers were merged earlier as unused code; wire them up
via hdmi_codec_ops so the DAI actually appears, which unblocks the
mt8186-mt6366 sound card that references it6505 as the I2S3 codec.
Some DP-to-HDMI dongles get into a bad state if InfoFrame is sent
without audio data, so it6505's audio is only enabled once the stream
is unmuted.
Signed-off-by: Jiaxin Yu <jiaxin.yu@xxxxxxxxxxxx>
Link: https://lore.kernel.org/all/20230730180803.22570-4-jiaxin.yu@xxxxxxxxxxxx/
Signed-off-by: Daniel Golle <daniel@xxxxxxxxxxxxxx>
---
djg: respin of Jiaxin Yu's v3, rebased onto current mainline. Changes
from v3: hdmi_codec_ops lost .trigger, so drive enable/disable from
.mute_stream; drop the now-redundant __maybe_unused; use it6505->dev
instead of &client->dev, addressing AngeloGioacchino Del Regno's v3
review. Also fix issues in v3: initialise delayed_audio before
registering the codec device; keep and unregister the platform_device
and cancel delayed_audio on remove to avoid a leak and a
use-after-free; cancel the delayed work on audio shutdown; and
actually disable audio (not just cancel the pending enable) when the
stream is muted.
Note: it6505_enable_audio()/it6505_disable_audio() can still run
concurrently from the delayed work, the .mute_stream / .audio_shutdown
callbacks and the audio-FIFO-error IRQ; as in v3 these are left
unserialised -- input welcome on whether a lock is warranted.
v2:
* store the hdmi-codec platform_device and unregister it on i2c
remove, fixing a resource leak and use-after-free on unbind
* initialise the delayed audio work before registering the codec
device instead of after
* synchronously cancel the delayed audio work on audio shutdown and
on driver remove (cancel_delayed_work_sync)
* rework the mute path to cancel pending work synchronously and
disable audio immediately when muting, removing a race with the
delayed enable work
drivers/gpu/drm/bridge/ite-it6505.c | 101 +++++++++++++++++++++++-----
1 file changed, 85 insertions(+), 16 deletions(-)
diff --git a/drivers/gpu/drm/bridge/ite-it6505.c b/drivers/gpu/drm/bridge/ite-it6505.c
index 8ecb43611dba..d84441926e8e 100644
--- a/drivers/gpu/drm/bridge/ite-it6505.c
+++ b/drivers/gpu/drm/bridge/ite-it6505.c
@@ -476,6 +476,7 @@ struct it6505 {
bool enable_enhanced_frame;
hdmi_codec_plugged_cb plugged_cb;
struct device *codec_dev;
+ struct platform_device *audio_pdev;
struct delayed_work delayed_audio;
struct it6505_audio_data audio;
struct dentry *debugfs;
@@ -2320,19 +2321,12 @@ static void it6505_stop_link_train(struct it6505 *it6505)
static void it6505_link_train_ok(struct it6505 *it6505)
{
- struct device *dev = it6505->dev;
-
it6505->link_state = LINK_OK;
/* disalbe mute enable avi info frame */
it6505_set_bits(it6505, REG_DATA_MUTE_CTRL, EN_VID_MUTE, 0x00);
it6505_set_bits(it6505, REG_INFOFRAME_CTRL,
EN_VID_CTRL_PKT, EN_VID_CTRL_PKT);
- if (it6505_audio_input(it6505)) {
- DRM_DEV_DEBUG_DRIVER(dev, "Enable audio!");
- it6505_enable_audio(it6505);
- }
-
if (it6505->hdcp_desired)
it6505_start_hdcp(it6505);
}
@@ -2960,7 +2954,7 @@ static void it6505_remove_notifier_module(struct it6505 *it6505)
}
}
-static void __maybe_unused it6505_delayed_audio(struct work_struct *work)
+static void it6505_delayed_audio(struct work_struct *work)
{
struct it6505 *it6505 = container_of(work, struct it6505,
delayed_audio.work);
@@ -2974,9 +2968,9 @@ static void __maybe_unused it6505_delayed_audio(struct work_struct *work)
it6505_enable_audio(it6505);
}
-static int __maybe_unused it6505_audio_setup_hw_params(struct it6505 *it6505,
- struct hdmi_codec_params
- *params)
+static int it6505_audio_setup_hw_params(struct it6505 *it6505,
+ struct hdmi_codec_params
+ *params)
{
struct device *dev = it6505->dev;
int i = 0;
@@ -3031,18 +3025,52 @@ static int __maybe_unused it6505_audio_setup_hw_params(struct it6505 *it6505,
return 0;
}
-static void __maybe_unused it6505_audio_shutdown(struct device *dev, void *data)
+static void it6505_audio_shutdown(struct device *dev, void *data)
{
struct it6505 *it6505 = dev_get_drvdata(dev);
+ cancel_delayed_work_sync(&it6505->delayed_audio);
if (it6505->powered)
it6505_disable_audio(it6505);
}
-static int __maybe_unused it6505_audio_hook_plugged_cb(struct device *dev,
- void *data,
- hdmi_codec_plugged_cb fn,
- struct device *codec_dev)
+static int it6505_audio_hw_params(struct device *dev, void *data,
+ struct hdmi_codec_daifmt *daifmt,
+ struct hdmi_codec_params *params)
+{
+ struct it6505 *it6505 = dev_get_drvdata(dev);
+
+ return it6505_audio_setup_hw_params(it6505, params);
+}
+
+static int it6505_audio_mute(struct device *dev, void *data,
+ bool enable, int direction)
+{
+ struct it6505 *it6505 = dev_get_drvdata(dev);
+
+ DRM_DEV_DEBUG_DRIVER(dev, "mute: %d", enable);
+
+ /*
+ * Some DP-to-HDMI dongles get into a bad state if the InfoFrame is
+ * sent without audio data, so only enable it6505's audio once the
+ * stream is unmuted (i.e. actually playing).
+ */
+ if (enable) {
+ cancel_delayed_work_sync(&it6505->delayed_audio);
+ if (it6505->powered)
+ it6505_disable_audio(it6505);
+ } else {
+ queue_delayed_work(system_wq, &it6505->delayed_audio,
+ msecs_to_jiffies(180));
+ }
+
+ return 0;
+}
+
+static int it6505_audio_hook_plugged_cb(struct device *dev,
+ void *data,
+ hdmi_codec_plugged_cb fn,
+ struct device *codec_dev)
{
struct it6505 *it6505 = data;
@@ -3053,6 +3081,39 @@ static int __maybe_unused it6505_audio_hook_plugged_cb(struct device *dev,
return 0;
}
+static const struct hdmi_codec_ops it6505_audio_codec_ops = {
+ .hw_params = it6505_audio_hw_params,
+ .mute_stream = it6505_audio_mute,
+ .audio_shutdown = it6505_audio_shutdown,
+ .hook_plugged_cb = it6505_audio_hook_plugged_cb,
+};
+
+static int it6505_register_audio_driver(struct device *dev)
+{
+ struct it6505 *it6505 = dev_get_drvdata(dev);
+ struct hdmi_codec_pdata codec_data = {
+ .ops = &it6505_audio_codec_ops,
+ .max_i2s_channels = 8,
+ .i2s = 1,
+ .no_capture_mute = 1,
+ .data = it6505,
+ };
+ struct platform_device *pdev;
+
+ INIT_DELAYED_WORK(&it6505->delayed_audio, it6505_delayed_audio);
+
+ pdev = platform_device_register_data(dev, HDMI_CODEC_DRV_NAME,
+ PLATFORM_DEVID_AUTO, &codec_data,
+ sizeof(codec_data));
+ if (IS_ERR(pdev))
+ return PTR_ERR(pdev);
+
+ it6505->audio_pdev = pdev;
+ DRM_DEV_DEBUG_DRIVER(dev, "bound to %s", HDMI_CODEC_DRV_NAME);
+
+ return 0;
+}
+
static inline struct it6505 *bridge_to_it6505(struct drm_bridge *bridge)
{
return container_of(bridge, struct it6505, bridge);
@@ -3612,6 +3673,12 @@ static int it6505_i2c_probe(struct i2c_client *client)
return err;
}
+ err = it6505_register_audio_driver(dev);
+ if (err < 0) {
+ dev_err(dev, "Failed to register audio driver: %d", err);
+ return err;
+ }
+
INIT_WORK(&it6505->link_works, it6505_link_training_work);
INIT_WORK(&it6505->hdcp_wait_ksv_list, it6505_hdcp_wait_ksv_list);
INIT_DELAYED_WORK(&it6505->hdcp_work, it6505_hdcp_work);
@@ -3644,6 +3711,8 @@ static void it6505_i2c_remove(struct i2c_client *client)
{
struct it6505 *it6505 = i2c_get_clientdata(client);
+ platform_device_unregister(it6505->audio_pdev);
+ cancel_delayed_work_sync(&it6505->delayed_audio);
drm_bridge_remove(&it6505->bridge);
drm_dp_aux_unregister(&it6505->aux);
it6505_debugfs_remove(it6505);
--
2.55.0