ALSA: hda/hdmi: expose ELD control

Applications may want to read ELD information to
understand what codecs are supported on the HDMI
receiver and handle the a-v delay for better lip-sync.

ELD information is exposed in a device-specific
IFACE_PCM kcontrol. Tested both with amixer and
PulseAudio; with a corresponding patch passthrough modes
are enabled automagically.

ELD control size is set to zero in case of errors or
wrong configurations. No notifications are implemented
for now, it is expected that jack detection is used to
reconfigure the audio outputs.

Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

diff --git a/sound/pci/hda/hda_eld.c b/sound/pci/hda/hda_eld.c
index c34f730f481568042b334e4973ae0569f5fdea9b..f1c621d2f8e8277014690bc9ab8f19e0fbc000fc 100644 (file)
--- a/sound/pci/hda/hda_eld.c
+++ b/sound/pci/hda/hda_eld.c
@@ -318,6 +318,11 @@ int snd_hdmi_get_eld(struct hdmi_eld *eld,
        int size;
        unsigned char *buf;
 
+       /*
+        * ELD size is initialized to zero in caller function. If no errors and
+        * ELD is valid, actual eld_size is assigned in hdmi_update_eld()
+        */
+
        if (!eld->eld_valid)
                return -ENOENT;
 
@@ -327,14 +332,13 @@ int snd_hdmi_get_eld(struct hdmi_eld *eld,
                snd_printd(KERN_INFO "HDMI: ELD buf size is 0, force 128\n");
                size = 128;
        }
-       if (size < ELD_FIXED_BYTES || size > PAGE_SIZE) {
+       if (size < ELD_FIXED_BYTES || size > ELD_MAX_SIZE) {
                snd_printd(KERN_INFO "HDMI: invalid ELD buf size %d\n", size);
                return -ERANGE;
        }
 
-       buf = kmalloc(size, GFP_KERNEL);
-       if (!buf)
-               return -ENOMEM;
+       /* set ELD buffer */
+       buf = eld->eld_buffer;
 
        for (i = 0; i < size; i++) {
                unsigned int val = hdmi_get_eld_data(codec, nid, i);
@@ -356,7 +360,6 @@ int snd_hdmi_get_eld(struct hdmi_eld *eld,
        ret = hdmi_update_eld(eld, buf, size);
 
 error:
-       kfree(buf);
        return ret;
 }
 

diff --git a/sound/pci/hda/hda_local.h b/sound/pci/hda/hda_local.h
index aaefa7c81e6830e33e9d82c9da6d8f6e2dd0f9f7..04d730fffee2c0c4b461a0f5dd885ee153c46aac 100644 (file)
--- a/sound/pci/hda/hda_local.h
+++ b/sound/pci/hda/hda_local.h
@@ -621,6 +621,7 @@ struct cea_sad {
 };
 
 #define ELD_FIXED_BYTES        20
+#define ELD_MAX_SIZE    256
 #define ELD_MAX_MNL    16
 #define ELD_MAX_SAD    16
 
@@ -645,6 +646,7 @@ struct hdmi_eld {
        int     spk_alloc;
        int     sad_count;
        struct cea_sad sad[ELD_MAX_SAD];
+       char    eld_buffer[ELD_MAX_SIZE];
 #ifdef CONFIG_PROC_FS
        struct snd_info_entry *proc_entry;
 #endif

diff --git a/sound/pci/hda/patch_hdmi.c b/sound/pci/hda/patch_hdmi.c
index 3f1f6ac8e6432fe5fc49d8ec533e6722e57f8e74..342540128fb8f2bc4c8ce18b9f53e9c859c1c5d7 100644 (file)
--- a/sound/pci/hda/patch_hdmi.c
+++ b/sound/pci/hda/patch_hdmi.c
@@ -324,6 +324,66 @@ static int cvt_nid_to_cvt_index(struct hdmi_spec *spec, hda_nid_t cvt_nid)
        return -EINVAL;
 }
 
+static int hdmi_eld_ctl_info(struct snd_kcontrol *kcontrol,
+                       struct snd_ctl_elem_info *uinfo)
+{
+       struct hda_codec *codec = snd_kcontrol_chip(kcontrol);
+       struct hdmi_spec *spec;
+       int pin_idx;
+
+       spec = codec->spec;
+       uinfo->type = SNDRV_CTL_ELEM_TYPE_BYTES;
+
+       pin_idx = kcontrol->private_value;
+       uinfo->count = spec->pins[pin_idx].sink_eld.eld_size;
+
+       return 0;
+}
+
+static int hdmi_eld_ctl_get(struct snd_kcontrol *kcontrol,
+                       struct snd_ctl_elem_value *ucontrol)
+{
+       struct hda_codec *codec = snd_kcontrol_chip(kcontrol);
+       struct hdmi_spec *spec;
+       int pin_idx;
+
+       spec = codec->spec;
+       pin_idx = kcontrol->private_value;
+
+       memcpy(ucontrol->value.bytes.data,
+               spec->pins[pin_idx].sink_eld.eld_buffer, ELD_MAX_SIZE);
+
+       return 0;
+}
+
+static struct snd_kcontrol_new eld_bytes_ctl = {
+       .access = SNDRV_CTL_ELEM_ACCESS_READ | SNDRV_CTL_ELEM_ACCESS_VOLATILE,
+       .iface = SNDRV_CTL_ELEM_IFACE_PCM,
+       .name = "ELD",
+       .info = hdmi_eld_ctl_info,
+       .get = hdmi_eld_ctl_get,
+};
+
+static int hdmi_create_eld_ctl(struct hda_codec *codec, int pin_idx,
+                       int device)
+{
+       struct snd_kcontrol *kctl;
+       struct hdmi_spec *spec = codec->spec;
+       int err;
+
+       kctl = snd_ctl_new1(&eld_bytes_ctl, codec);
+       if (!kctl)
+               return -ENOMEM;
+       kctl->private_value = pin_idx;
+       kctl->id.device = device;
+
+       err = snd_hda_ctl_add(codec, spec->pins[pin_idx].pin_nid, kctl);
+       if (err < 0)
+               return err;
+
+       return 0;
+}
+
 #ifdef BE_PARANOID
 static void hdmi_get_dip_index(struct hda_codec *codec, hda_nid_t pin_nid,
                                int *packet_index, int *byte_index)
@@ -1193,6 +1253,14 @@ static int generic_hdmi_build_controls(struct hda_codec *codec)
                if (err < 0)
                        return err;
                snd_hda_spdif_ctls_unassign(codec, pin_idx);
+
+               /* add control for ELD Bytes */
+               err = hdmi_create_eld_ctl(codec,
+                                       pin_idx,
+                                       spec->pcm_rec[pin_idx].device);
+
+               if (err < 0)
+                       return err;
        }
 
        return 0;