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

[Stefan Wahren]

From: David Turner <david.tur...@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.tur...@raspberrypi.com>
Signed-off-by: Stefan Wahren <wahre...@gmx.net>
---
 drivers/gpu/drm/vc4/vc4_hdmi.c | 26 ++++++++++++++++++++++++--
 drivers/gpu/drm/vc4/vc4_hdmi.h |  7 +++++++
 2 files changed, 31 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/vc4/vc4_hdmi.c b/drivers/gpu/drm/vc4/vc4_hdmi.c
index 47d9ada98430..d24ae86d799e 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>
@@ -386,6 +387,12 @@ static void vc4_hdmi_handle_hotplug(struct vc4_hdmi 
*vc4_hdmi,
        struct drm_connector *connector = &vc4_hdmi->connector;
        int ret;

+       /*
+        * Needs to be called for both connects and disconnects for HDMI
+        * audio hotplug to work correctly.
+        */
+       drm_atomic_helper_connector_hdmi_hotplug(connector, status);
+
        /*
         * NOTE: This function should really be called with vc4_hdmi->mutex
         * held, but doing so results in reentrancy issues since
@@ -405,8 +412,6 @@ static void vc4_hdmi_handle_hotplug(struct vc4_hdmi 
*vc4_hdmi,
                return;
        }

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

@@ -2203,6 +2208,22 @@ 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 +2337,7 @@ 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