drm/vc4: hdmi: Unregister codec device on unbind

On bind we will register the HDMI codec device but we don't unregister
it on unbind, leading to a device leakage. Unregister our device at
unbind.
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220127111452.222002-1-maxime@cerno.tech

drivers/gpu/drm/vc4/vc4_hdmi.c

@@ -1749,6 +1749,7 @@ static int vc4_hdmi_audio_init(struct vc4_hdmi *vc4_hdmi)
 		dev_err(dev, "Couldn't register the HDMI codec: %ld\n", PTR_ERR(codec_pdev));
 		return PTR_ERR(codec_pdev);
 	}
+	vc4_hdmi->audio.codec_pdev = codec_pdev;
 
 	dai_link->cpus		= &vc4_hdmi->audio.cpu;
 	dai_link->codecs	= &vc4_hdmi->audio.codec;
@@ -1788,6 +1789,12 @@ static int vc4_hdmi_audio_init(struct vc4_hdmi *vc4_hdmi)
 
 }
 
+static void vc4_hdmi_audio_exit(struct vc4_hdmi *vc4_hdmi)
+{
+	platform_device_unregister(vc4_hdmi->audio.codec_pdev);
+	vc4_hdmi->audio.codec_pdev = NULL;
+}
+
 static irqreturn_t vc4_hdmi_hpd_irq_thread(int irq, void *priv)
 {
 	struct vc4_hdmi *vc4_hdmi = priv;
@@ -2660,6 +2667,7 @@ static void vc4_hdmi_unbind(struct device *dev, struct device *master,
 	kfree(vc4_hdmi->hdmi_regset.regs);
 	kfree(vc4_hdmi->hd_regset.regs);
 
+	vc4_hdmi_audio_exit(vc4_hdmi);
 	vc4_hdmi_cec_exit(vc4_hdmi);
 	vc4_hdmi_hotplug_exit(vc4_hdmi);
 	vc4_hdmi_connector_destroy(&vc4_hdmi->connector);

drivers/gpu/drm/vc4/vc4_hdmi.h

@@ -116,6 +116,7 @@ struct vc4_hdmi_audio {
 	struct snd_soc_dai_link_component platform;
 	struct snd_dmaengine_dai_dma_data dma_data;
 	struct hdmi_audio_infoframe infoframe;
+	struct platform_device *codec_pdev;
 	bool streaming;
 };