[PATCH V2 0/2] drm/vc4: hdmi: Add jack detection to HDMI audio driver

[PATCH V2 0/2] drm/vc4: hdmi: Add jack detection to HDMI audio driver

[Stefan Wahren]

This series ensure the proper jack detection of HDMI audio.

Changes in V2:
- split initial patch into fix and jack detection feature as
  suggested by Dmitry

David Turner (1):
  drm/vc4: hdmi: Add jack detection to HDMI audio driver

Stefan Wahren (1):
  drm/vc4: hdmi: Call HDMI hotplug helper on disconnect

 drivers/gpu/drm/vc4/vc4_hdmi.c | 22 ++++++++++++++++++++--
 drivers/gpu/drm/vc4/vc4_hdmi.h |  7 +++++++
 2 files changed, 27 insertions(+), 2 deletions(-)

--
2.34.1

[PATCH V2 1/2] drm/vc4: hdmi: Call HDMI hotplug helper on disconnect

[Stefan Wahren]

drm_atomic_helper_connector_hdmi_hotplug() must be called
regardless of the connection status, otherwise the HDMI audio
disconnect event won't be notified.

Fixes: 2ea9ec5d2c20 ("drm/vc4: hdmi: use drm_atomic_helper_connector_hdmi_hotplug()")
Suggested-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Signed-off-by: Stefan Wahren <wahrenst@gmx.net>
---
 drivers/gpu/drm/vc4/vc4_hdmi.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/vc4/vc4_hdmi.c b/drivers/gpu/drm/vc4/vc4_hdmi.c
index 47d9ada98430..e4b027616d04 100644
--- a/drivers/gpu/drm/vc4/vc4_hdmi.c
+++ b/drivers/gpu/drm/vc4/vc4_hdmi.c
@@ -400,13 +400,13 @@ static void vc4_hdmi_handle_hotplug(struct vc4_hdmi *vc4_hdmi,
 	 * the lock for now.
 	 */

+	drm_atomic_helper_connector_hdmi_hotplug(connector, status);
+
 	if (status == connector_status_disconnected) {
 		cec_phys_addr_invalidate(vc4_hdmi->cec_adap);
 		return;
 	}

-	drm_atomic_helper_connector_hdmi_hotplug(connector, status);
-
 	cec_s_phys_addr(vc4_hdmi->cec_adap,
 			connector->display_info.source_physical_address, false);

--
2.34.1

Re: [PATCH V2 1/2] drm/vc4: hdmi: Call HDMI hotplug helper on disconnect

[Maxime Ripard]

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Hi,

On Tue, Mar 04, 2025 at 08:39:11PM +0100, Stefan Wahren wrote:
> drm_atomic_helper_connector_hdmi_hotplug() must be called
> regardless of the connection status, otherwise the HDMI audio
> disconnect event won't be notified.
> 
> Fixes: 2ea9ec5d2c20 ("drm/vc4: hdmi: use drm_atomic_helper_connector_hdmi_hotplug()")
> Suggested-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
> Signed-off-by: Stefan Wahren <wahrenst@gmx.net>

The patch makes sense to me, but I think we should also update the
documentation of drm_atomic_helper_connector_hdmi_hotplug to make it
clearer it needs to be called on any status update.

Maxime

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[PATCH V2 2/2] drm/vc4: hdmi: Add jack detection to HDMI audio driver

[Stefan Wahren]

From: David Turner <david.turner@raspberrypi.com>

Add ALSA jack detection to the vc4-hdmi audio driver so userspace knows
when to add/remove HDMI audio devices.

Signed-off-by: David Turner <david.turner@raspberrypi.com>
Signed-off-by: Stefan Wahren <wahrenst@gmx.net>
---
 drivers/gpu/drm/vc4/vc4_hdmi.c | 18 ++++++++++++++++++
 drivers/gpu/drm/vc4/vc4_hdmi.h |  7 +++++++
 2 files changed, 25 insertions(+)

diff --git a/drivers/gpu/drm/vc4/vc4_hdmi.c b/drivers/gpu/drm/vc4/vc4_hdmi.c
index e4b027616d04..f46a135568b2 100644
--- a/drivers/gpu/drm/vc4/vc4_hdmi.c
+++ b/drivers/gpu/drm/vc4/vc4_hdmi.c
@@ -51,6 +51,7 @@
 #include <linux/reset.h>
 #include <sound/dmaengine_pcm.h>
 #include <sound/hdmi-codec.h>
+#include <sound/jack.h>
 #include <sound/pcm_drm_eld.h>
 #include <sound/pcm_params.h>
 #include <sound/soc.h>
@@ -2203,6 +2204,22 @@ static const struct drm_connector_hdmi_audio_funcs vc4_hdmi_audio_funcs = {
 	.shutdown = vc4_hdmi_audio_shutdown,
 };

+static int vc4_hdmi_codec_init(struct snd_soc_pcm_runtime *rtd)
+{
+	struct vc4_hdmi *vc4_hdmi = snd_soc_card_get_drvdata(rtd->card);
+	struct snd_soc_component *component = snd_soc_rtd_to_codec(rtd, 0)->component;
+	int ret;
+
+	ret = snd_soc_card_jack_new(rtd->card, "HDMI Jack", SND_JACK_LINEOUT,
+				    &vc4_hdmi->hdmi_jack);
+	if (ret) {
+		dev_err(rtd->dev, "HDMI Jack creation failed: %d\n", ret);
+		return ret;
+	}
+
+	return snd_soc_component_set_jack(component, &vc4_hdmi->hdmi_jack, NULL);
+}
+
 static int vc4_hdmi_audio_init(struct vc4_hdmi *vc4_hdmi)
 {
 	const struct vc4_hdmi_register *mai_data =
@@ -2316,6 +2333,7 @@ static int vc4_hdmi_audio_init(struct vc4_hdmi *vc4_hdmi)
 	dai_link->cpus->dai_name = dev_name(dev);
 	dai_link->codecs->name = dev_name(&vc4_hdmi->connector.hdmi_audio.codec_pdev->dev);
 	dai_link->platforms->name = dev_name(dev);
+	dai_link->init = vc4_hdmi_codec_init;

 	card->dai_link = dai_link;
 	card->num_links = 1;
diff --git a/drivers/gpu/drm/vc4/vc4_hdmi.h b/drivers/gpu/drm/vc4/vc4_hdmi.h
index e3d989ca302b..a31157c99bee 100644
--- a/drivers/gpu/drm/vc4/vc4_hdmi.h
+++ b/drivers/gpu/drm/vc4/vc4_hdmi.h
@@ -4,6 +4,7 @@
 #include <drm/drm_connector.h>
 #include <media/cec.h>
 #include <sound/dmaengine_pcm.h>
+#include <sound/hdmi-codec.h>
 #include <sound/soc.h>

 #include "vc4_drv.h"
@@ -211,6 +212,12 @@ struct vc4_hdmi {
 	 * KMS hooks. Protected by @mutex.
 	 */
 	enum hdmi_colorspace output_format;
+
+	/**
+	 * @hdmi_jack: Represents the connection state of the HDMI plug, for
+	 * ALSA jack detection.
+	 */
+	struct snd_soc_jack hdmi_jack;
 };

 #define connector_to_vc4_hdmi(_connector)				\
--
2.34.1

Re: [PATCH V2 2/2] drm/vc4: hdmi: Add jack detection to HDMI audio driver

[Maxime Ripard]

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Hi,

On Tue, Mar 04, 2025 at 08:39:12PM +0100, Stefan Wahren wrote:
> From: David Turner <david.turner@raspberrypi.com>
> 
> Add ALSA jack detection to the vc4-hdmi audio driver so userspace knows
> when to add/remove HDMI audio devices.
> 
> Signed-off-by: David Turner <david.turner@raspberrypi.com>
> Signed-off-by: Stefan Wahren <wahrenst@gmx.net>
> ---
>  drivers/gpu/drm/vc4/vc4_hdmi.c | 18 ++++++++++++++++++
>  drivers/gpu/drm/vc4/vc4_hdmi.h |  7 +++++++
>  2 files changed, 25 insertions(+)
> 
> diff --git a/drivers/gpu/drm/vc4/vc4_hdmi.c b/drivers/gpu/drm/vc4/vc4_hdmi.c
> index e4b027616d04..f46a135568b2 100644
> --- a/drivers/gpu/drm/vc4/vc4_hdmi.c
> +++ b/drivers/gpu/drm/vc4/vc4_hdmi.c
> @@ -51,6 +51,7 @@
>  #include <linux/reset.h>
>  #include <sound/dmaengine_pcm.h>
>  #include <sound/hdmi-codec.h>
> +#include <sound/jack.h>
>  #include <sound/pcm_drm_eld.h>
>  #include <sound/pcm_params.h>
>  #include <sound/soc.h>
> @@ -2203,6 +2204,22 @@ static const struct drm_connector_hdmi_audio_funcs vc4_hdmi_audio_funcs = {
>  	.shutdown = vc4_hdmi_audio_shutdown,
>  };
> 
> +static int vc4_hdmi_codec_init(struct snd_soc_pcm_runtime *rtd)
> +{
> +	struct vc4_hdmi *vc4_hdmi = snd_soc_card_get_drvdata(rtd->card);
> +	struct snd_soc_component *component = snd_soc_rtd_to_codec(rtd, 0)->component;
> +	int ret;
> +
> +	ret = snd_soc_card_jack_new(rtd->card, "HDMI Jack", SND_JACK_LINEOUT,
> +				    &vc4_hdmi->hdmi_jack);
> +	if (ret) {
> +		dev_err(rtd->dev, "HDMI Jack creation failed: %d\n", ret);
> +		return ret;
> +	}
> +
> +	return snd_soc_component_set_jack(component, &vc4_hdmi->hdmi_jack, NULL);
> +}
> +
>  static int vc4_hdmi_audio_init(struct vc4_hdmi *vc4_hdmi)
>  {
>  	const struct vc4_hdmi_register *mai_data =
> @@ -2316,6 +2333,7 @@ static int vc4_hdmi_audio_init(struct vc4_hdmi *vc4_hdmi)
>  	dai_link->cpus->dai_name = dev_name(dev);
>  	dai_link->codecs->name = dev_name(&vc4_hdmi->connector.hdmi_audio.codec_pdev->dev);
>  	dai_link->platforms->name = dev_name(dev);
> +	dai_link->init = vc4_hdmi_codec_init;
> 
>  	card->dai_link = dai_link;
>  	card->num_links = 1;
> diff --git a/drivers/gpu/drm/vc4/vc4_hdmi.h b/drivers/gpu/drm/vc4/vc4_hdmi.h
> index e3d989ca302b..a31157c99bee 100644
> --- a/drivers/gpu/drm/vc4/vc4_hdmi.h
> +++ b/drivers/gpu/drm/vc4/vc4_hdmi.h
> @@ -4,6 +4,7 @@
>  #include <drm/drm_connector.h>
>  #include <media/cec.h>
>  #include <sound/dmaengine_pcm.h>
> +#include <sound/hdmi-codec.h>
>  #include <sound/soc.h>
> 
>  #include "vc4_drv.h"
> @@ -211,6 +212,12 @@ struct vc4_hdmi {
>  	 * KMS hooks. Protected by @mutex.
>  	 */
>  	enum hdmi_colorspace output_format;
> +
> +	/**
> +	 * @hdmi_jack: Represents the connection state of the HDMI plug, for
> +	 * ALSA jack detection.
> +	 */
> +	struct snd_soc_jack hdmi_jack;
>  };

It looks fairly generic to me. Is there any reason you didn't put it in
the HDMI audio helpers?

Maxime

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Re: [PATCH V2 2/2] drm/vc4: hdmi: Add jack detection to HDMI audio driver

[David Turner]

Hi all,

On Thu, 6 Mar 2025 at 13:39, Maxime Ripard <mripard@kernel.org> wrote:
> It looks fairly generic to me. Is there any reason you didn't put it in
> the HDMI audio helpers?

I originally wrote the downstream patch last year on 6.6, before the
generic HDMI audio code existed.

I just had a look at doing this.  At the moment drm_hdmi_audio_helper
doesn't manage the snd_soc_card (needed to setup the jack) at all,
that still lives in vc4_hdmi_audio, so I can't see an easy way to move
this over without a lot more reorganising.

David

Re: [PATCH V2 2/2] drm/vc4: hdmi: Add jack detection to HDMI audio driver

[Maxime Ripard]

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On Thu, Mar 06, 2025 at 03:47:27PM +0000, David Turner wrote:
> Hi all,
> 
> On Thu, 6 Mar 2025 at 13:39, Maxime Ripard <mripard@kernel.org> wrote:
> > It looks fairly generic to me. Is there any reason you didn't put it in
> > the HDMI audio helpers?
> 
> I originally wrote the downstream patch last year on 6.6, before the
> generic HDMI audio code existed.
> 
> I just had a look at doing this.  At the moment drm_hdmi_audio_helper
> doesn't manage the snd_soc_card (needed to setup the jack) at all,
> that still lives in vc4_hdmi_audio, so I can't see an easy way to move
> this over without a lot more reorganising.


Ah, yes, of course. Most (all?) the other drivers just use an external
I2S controller so the card is mostly likely going to be described
through simple-card.

I guess we can always turn that code into a helper if a similar case
comes along in the future.

Thanks,
Maxime

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Re: [PATCH V2 2/2] drm/vc4: hdmi: Add jack detection to HDMI audio driver

[Dmitry Baryshkov]

On Thu, 6 Mar 2025 at 14:39, Maxime Ripard <mripard@kernel.org> wrote:
>
> Hi,
>
> On Tue, Mar 04, 2025 at 08:39:12PM +0100, Stefan Wahren wrote:
> > From: David Turner <david.turner@raspberrypi.com>
> >
> > Add ALSA jack detection to the vc4-hdmi audio driver so userspace knows
> > when to add/remove HDMI audio devices.
> >
> > Signed-off-by: David Turner <david.turner@raspberrypi.com>
> > Signed-off-by: Stefan Wahren <wahrenst@gmx.net>
> > ---
> >  drivers/gpu/drm/vc4/vc4_hdmi.c | 18 ++++++++++++++++++
> >  drivers/gpu/drm/vc4/vc4_hdmi.h |  7 +++++++
> >  2 files changed, 25 insertions(+)
> >
> > diff --git a/drivers/gpu/drm/vc4/vc4_hdmi.c b/drivers/gpu/drm/vc4/vc4_hdmi.c
> > index e4b027616d04..f46a135568b2 100644
> > --- a/drivers/gpu/drm/vc4/vc4_hdmi.c
> > +++ b/drivers/gpu/drm/vc4/vc4_hdmi.c
> > @@ -51,6 +51,7 @@
> >  #include <linux/reset.h>
> >  #include <sound/dmaengine_pcm.h>
> >  #include <sound/hdmi-codec.h>
> > +#include <sound/jack.h>
> >  #include <sound/pcm_drm_eld.h>
> >  #include <sound/pcm_params.h>
> >  #include <sound/soc.h>
> > @@ -2203,6 +2204,22 @@ static const struct drm_connector_hdmi_audio_funcs vc4_hdmi_audio_funcs = {
> >       .shutdown = vc4_hdmi_audio_shutdown,
> >  };
> >
> > +static int vc4_hdmi_codec_init(struct snd_soc_pcm_runtime *rtd)
> > +{
> > +     struct vc4_hdmi *vc4_hdmi = snd_soc_card_get_drvdata(rtd->card);
> > +     struct snd_soc_component *component = snd_soc_rtd_to_codec(rtd, 0)->component;
> > +     int ret;
> > +
> > +     ret = snd_soc_card_jack_new(rtd->card, "HDMI Jack", SND_JACK_LINEOUT,
> > +                                 &vc4_hdmi->hdmi_jack);
> > +     if (ret) {
> > +             dev_err(rtd->dev, "HDMI Jack creation failed: %d\n", ret);
> > +             return ret;
> > +     }
> > +
> > +     return snd_soc_component_set_jack(component, &vc4_hdmi->hdmi_jack, NULL);
> > +}
> > +
> >  static int vc4_hdmi_audio_init(struct vc4_hdmi *vc4_hdmi)
> >  {
> >       const struct vc4_hdmi_register *mai_data =
> > @@ -2316,6 +2333,7 @@ static int vc4_hdmi_audio_init(struct vc4_hdmi *vc4_hdmi)
> >       dai_link->cpus->dai_name = dev_name(dev);
> >       dai_link->codecs->name = dev_name(&vc4_hdmi->connector.hdmi_audio.codec_pdev->dev);
> >       dai_link->platforms->name = dev_name(dev);
> > +     dai_link->init = vc4_hdmi_codec_init;
> >
> >       card->dai_link = dai_link;
> >       card->num_links = 1;
> > diff --git a/drivers/gpu/drm/vc4/vc4_hdmi.h b/drivers/gpu/drm/vc4/vc4_hdmi.h
> > index e3d989ca302b..a31157c99bee 100644
> > --- a/drivers/gpu/drm/vc4/vc4_hdmi.h
> > +++ b/drivers/gpu/drm/vc4/vc4_hdmi.h
> > @@ -4,6 +4,7 @@
> >  #include <drm/drm_connector.h>
> >  #include <media/cec.h>
> >  #include <sound/dmaengine_pcm.h>
> > +#include <sound/hdmi-codec.h>
> >  #include <sound/soc.h>
> >
> >  #include "vc4_drv.h"
> > @@ -211,6 +212,12 @@ struct vc4_hdmi {
> >        * KMS hooks. Protected by @mutex.
> >        */
> >       enum hdmi_colorspace output_format;
> > +
> > +     /**
> > +      * @hdmi_jack: Represents the connection state of the HDMI plug, for
> > +      * ALSA jack detection.
> > +      */
> > +     struct snd_soc_jack hdmi_jack;
> >  };
>
> It looks fairly generic to me. Is there any reason you didn't put it in
> the HDMI audio helpers?

I had a similar question in my mind, but after checking I also could
not find a good place for it. I had an idea of pushing this kind of
code to hdmi-codec.c / hdmi_probe(), but then I understood that it
might not work.
The codec can be registered independently from the platform sound card
device, the codec doesn't have a knowledge of the platform's data or
topology. We might not be able to specify the name (even through codec
platform data) if there are more than one HDMI connector / codec in
play.
So, I think that a sound card driver is a proper place for that (so it
belongs to the vc4 driver).



-- 
With best wishes
Dmitry