ASoC: hdmi-codec: Add iec958 controls

The IEC958 status bits can be exposed and modified by the userspace
through dedicated ALSA controls.

This patch implements those controls for the hdmi-codec driver. It
relies on a default value being setup at probe time that can later be
overridden by the control put.

The hw_params callback is then called with a buffer filled with the
proper bits for the current parameters being passed on so the underlying
driver can just reuse those bits as is.

Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Acked-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20210525132354.297468-5-maxime@cerno.tech

diff --git a/sound/soc/codecs/hdmi-codec.c b/sound/soc/codecs/hdmi-codec.c
index 65bde6f..a0834b7 100644 (file)
--- a/sound/soc/codecs/hdmi-codec.c
+++ b/sound/soc/codecs/hdmi-codec.c
@@ -277,6 +277,7 @@ struct hdmi_codec_priv {
        bool busy;
        struct snd_soc_jack *jack;
        unsigned int jack_status;
+       u8 iec_status[5];
 };
 
 static const struct snd_soc_dapm_widget hdmi_widgets[] = {
@@ -385,6 +386,47 @@ static int hdmi_codec_chmap_ctl_get(struct snd_kcontrol *kcontrol,
        return 0;
 }
 
+static int hdmi_codec_iec958_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 hdmi_codec_iec958_default_get(struct snd_kcontrol *kcontrol,
+                                        struct snd_ctl_elem_value *ucontrol)
+{
+       struct snd_soc_component *component = snd_kcontrol_chip(kcontrol);
+       struct hdmi_codec_priv *hcp = snd_soc_component_get_drvdata(component);
+
+       memcpy(ucontrol->value.iec958.status, hcp->iec_status,
+              sizeof(hcp->iec_status));
+
+       return 0;
+}
+
+static int hdmi_codec_iec958_default_put(struct snd_kcontrol *kcontrol,
+                                        struct snd_ctl_elem_value *ucontrol)
+{
+       struct snd_soc_component *component = snd_kcontrol_chip(kcontrol);
+       struct hdmi_codec_priv *hcp = snd_soc_component_get_drvdata(component);
+
+       memcpy(hcp->iec_status, ucontrol->value.iec958.status,
+              sizeof(hcp->iec_status));
+
+       return 0;
+}
+
+static int hdmi_codec_iec958_mask_get(struct snd_kcontrol *kcontrol,
+                                     struct snd_ctl_elem_value *ucontrol)
+{
+       memset(ucontrol->value.iec958.status, 0xff,
+              sizeof_field(struct hdmi_codec_priv, iec_status));
+
+       return 0;
+}
+
 static int hdmi_codec_startup(struct snd_pcm_substream *substream,
                              struct snd_soc_dai *dai)
 {
@@ -459,8 +501,9 @@ static int hdmi_codec_hw_params(struct snd_pcm_substream *substream,
                params_width(params), params_rate(params),
                params_channels(params));
 
-       ret = snd_pcm_create_iec958_consumer_hw_params(params, hp.iec.status,
-                                                      sizeof(hp.iec.status));
+       memcpy(hp.iec.status, hcp->iec_status, sizeof(hp.iec.status));
+       ret = snd_pcm_fill_iec958_consumer_hw_params(params, hp.iec.status,
+                                                    sizeof(hp.iec.status));
        if (ret < 0) {
                dev_err(dai->dev, "Creating IEC958 channel status failed %d\n",
                        ret);
@@ -621,6 +664,20 @@ static const struct snd_soc_dai_ops hdmi_codec_spdif_dai_ops = {
                         SNDRV_PCM_FMTBIT_IEC958_SUBFRAME_LE)
 
 struct snd_kcontrol_new hdmi_codec_controls[] = {
+       {
+               .access = SNDRV_CTL_ELEM_ACCESS_READ,
+               .iface = SNDRV_CTL_ELEM_IFACE_PCM,
+               .name = SNDRV_CTL_NAME_IEC958("", PLAYBACK, MASK),
+               .info = hdmi_codec_iec958_info,
+               .get = hdmi_codec_iec958_mask_get,
+       },
+       {
+               .iface = SNDRV_CTL_ELEM_IFACE_PCM,
+               .name = SNDRV_CTL_NAME_IEC958("", PLAYBACK, DEFAULT),
+               .info = hdmi_codec_iec958_info,
+               .get = hdmi_codec_iec958_default_get,
+               .put = hdmi_codec_iec958_default_put,
+       },
        {
                .access = (SNDRV_CTL_ELEM_ACCESS_READ |
                           SNDRV_CTL_ELEM_ACCESS_VOLATILE),
@@ -873,6 +930,11 @@ static int hdmi_codec_probe(struct platform_device *pdev)
        hcp->hcd = *hcd;
        mutex_init(&hcp->lock);
 
+       ret = snd_pcm_create_iec958_consumer_default(hcp->iec_status,
+                                                    sizeof(hcp->iec_status));
+       if (ret < 0)
+               return ret;
+
        daidrv = devm_kcalloc(dev, dai_count, sizeof(*daidrv), GFP_KERNEL);
        if (!daidrv)
                return -ENOMEM;