From 209a350d81cded4ac83c31088d9e941c6497eb0e Mon Sep 17 00:00:00 2001
From: Matthias Reichl <hias@horus.com>
Date: Tue, 17 Mar 2020 12:12:22 +0100
Subject: [PATCH] drm/vc4: add iec958 controls to vc4_hdmi

Although vc4 get an IEC958 formatted stream passed in from userspace
the driver needs the info from the channel status bits to properly
set up the hardware, eg for HBR passthrough.

Add iec958 controls so the channel status bits can be passed in
from userspace.

Signed-off-by: Matthias Reichl <hias@horus.com>
---
 drivers/gpu/drm/vc4/vc4_hdmi.c | 60 ++++++++++++++++++++++++++++++++++
 drivers/gpu/drm/vc4/vc4_hdmi.h |  2 ++
 2 files changed, 62 insertions(+)

--- a/drivers/gpu/drm/vc4/vc4_hdmi.c
+++ b/drivers/gpu/drm/vc4/vc4_hdmi.c
@@ -43,6 +43,7 @@
 #include <linux/pm_runtime.h>
 #include <linux/rational.h>
 #include <linux/reset.h>
+#include <sound/asoundef.h>
 #include <sound/dmaengine_pcm.h>
 #include <sound/pcm_drm_eld.h>
 #include <sound/pcm_params.h>
@@ -1106,6 +1107,47 @@ static int vc4_hdmi_audio_eld_ctl_get(st
 	return 0;
 }
 
+static int vc4_spdif_info(struct snd_kcontrol *kcontrol,
+			  struct snd_ctl_elem_info *uinfo)
+{
+	uinfo->type = SNDRV_CTL_ELEM_TYPE_IEC958;
+	uinfo->count = 1;
+	return 0;
+}
+
+static int vc4_spdif_playback_get(struct snd_kcontrol *kcontrol,
+				  struct snd_ctl_elem_value *ucontrol)
+{
+	struct snd_soc_component *component = snd_kcontrol_chip(kcontrol);
+	struct vc4_hdmi *vc4_hdmi = snd_component_to_hdmi(component);
+
+	memcpy(ucontrol->value.iec958.status, vc4_hdmi->audio.iec_status,
+		sizeof(vc4_hdmi->audio.iec_status));
+
+	return 0;
+}
+
+static int vc4_spdif_playback_put(struct snd_kcontrol *kcontrol,
+				  struct snd_ctl_elem_value *ucontrol)
+{
+	struct snd_soc_component *component = snd_kcontrol_chip(kcontrol);
+	struct vc4_hdmi *vc4_hdmi = snd_component_to_hdmi(component);
+
+	memcpy(vc4_hdmi->audio.iec_status, ucontrol->value.iec958.status,
+		sizeof(vc4_hdmi->audio.iec_status));
+
+	return 0;
+}
+
+static int vc4_spdif_mask_get(struct snd_kcontrol *kcontrol,
+			      struct snd_ctl_elem_value *ucontrol)
+{
+	memset(ucontrol->value.iec958.status, 0xff,
+		FIELD_SIZEOF(struct vc4_hdmi_audio, iec_status));
+
+	return 0;
+}
+
 static const struct snd_kcontrol_new vc4_hdmi_audio_controls[] = {
 	{
 		.access = SNDRV_CTL_ELEM_ACCESS_READ |
@@ -1115,6 +1157,19 @@ static const struct snd_kcontrol_new vc4
 		.info = vc4_hdmi_audio_eld_ctl_info,
 		.get = vc4_hdmi_audio_eld_ctl_get,
 	},
+	{
+		.iface =   SNDRV_CTL_ELEM_IFACE_MIXER,
+		.name =    SNDRV_CTL_NAME_IEC958("", PLAYBACK, DEFAULT),
+		.info =    vc4_spdif_info,
+		.get =     vc4_spdif_playback_get,
+		.put =     vc4_spdif_playback_put,
+	},
+	{
+		.iface =   SNDRV_CTL_ELEM_IFACE_MIXER,
+		.name =    SNDRV_CTL_NAME_IEC958("", PLAYBACK, MASK),
+		.info =    vc4_spdif_info,
+		.get =     vc4_spdif_mask_get,
+	},
 };
 
 static const struct snd_soc_dapm_widget vc4_hdmi_audio_widgets[] = {
@@ -1235,6 +1290,11 @@ static int vc4_hdmi_audio_init(struct vc
 	vc4_hdmi->audio.dma_data.addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
 	vc4_hdmi->audio.dma_data.maxburst = 2;
 
+	vc4_hdmi->audio.iec_status[0] = IEC958_AES0_CON_NOT_COPYRIGHT;
+	vc4_hdmi->audio.iec_status[1] =
+		IEC958_AES1_CON_ORIGINAL | IEC958_AES1_CON_PCM_CODER;
+	vc4_hdmi->audio.iec_status[3] = IEC958_AES3_CON_FS_48000;
+
 	ret = devm_snd_dmaengine_pcm_register(dev, &pcm_conf, 0);
 	if (ret) {
 		dev_err(dev, "Could not register PCM component: %d\n", ret);
--- a/drivers/gpu/drm/vc4/vc4_hdmi.h
+++ b/drivers/gpu/drm/vc4/vc4_hdmi.h
@@ -115,6 +115,8 @@ struct vc4_hdmi_audio {
 	struct snd_pcm_substream *substream;
 
 	bool streaming;
+
+	unsigned char iec_status[4];
 };
 
 /* General HDMI hardware state. */
