[alsa-devel] [PATCH] ALSA: hda - Update chmap tlv to report sink's capability

[Subhransu S. Prusty]

Currently channel map controls don't reflect the sink's
capability to userspace. It reports the complete hdmi spec
channel allocation table to the userspace which is of little use
to the userspace applications.

With this patch, tlv callback is modified to read the speaker
allocation block from sink, and a mapping alsa channel map is
presented to the userspace.

Signed-off-by: Subhransu S. Prusty <subhransu.s.prusty at intel.com>
Signed-off-by: Vinod Koul <vinod.koul at intel.com>
---
 include/sound/hda_chmap.h  |  2 ++
 sound/hda/hdmi_chmap.c     | 90 +++++++++++++++++++++++++++++-----------------
 sound/pci/hda/patch_hdmi.c | 13 +++++++
 3 files changed, 72 insertions(+), 33 deletions(-)

diff --git a/include/sound/hda_chmap.h b/include/sound/hda_chmap.h
index e20d219..babd445 100644
--- a/include/sound/hda_chmap.h
+++ b/include/sound/hda_chmap.h
@@ -36,6 +36,8 @@ struct hdac_chmap_ops {
 	int (*chmap_validate)(struct hdac_chmap *hchmap, int ca,
 			int channels, unsigned char *chmap);
 
+	int (*get_spk_alloc)(struct hdac_device *hdac, int pcm_idx);
+
 	void (*get_chmap)(struct hdac_device *hdac, int pcm_idx,
 					unsigned char *chmap);
 	void (*set_chmap)(struct hdac_device *hdac, int pcm_idx,
diff --git a/sound/hda/hdmi_chmap.c b/sound/hda/hdmi_chmap.c
index d7ec862..9406203 100644
--- a/sound/hda/hdmi_chmap.c
+++ b/sound/hda/hdmi_chmap.c
@@ -625,13 +625,40 @@ static void hdmi_cea_alloc_to_tlv_chmap(struct hdac_chmap *hchmap,
 	WARN_ON(count != channels);
 }
 
+static struct hdac_cea_channel_speaker_allocation *get_cap_from_spk_alloc(
+							int spk_alloc)
+{
+	int i, spk_mask = 0;
+
+	if (!spk_alloc)
+		return &channel_allocations[0];
+
+	for (i = 0; i < ARRAY_SIZE(eld_speaker_allocation_bits); i++) {
+		if (spk_alloc & (1 << i))
+			spk_mask |= eld_speaker_allocation_bits[i];
+	}
+
+	/* Get num channels using spk mask */
+	for (i = 0; i < ARRAY_SIZE(channel_allocations); i++) {
+		if ((spk_mask & channel_allocations[i].spk_mask) == spk_mask)
+			return &channel_allocations[i];
+	}
+
+	return &channel_allocations[0];
+}
+
 static int hdmi_chmap_ctl_tlv(struct snd_kcontrol *kcontrol, int op_flag,
 			      unsigned int size, unsigned int __user *tlv)
 {
 	struct snd_pcm_chmap *info = snd_kcontrol_chip(kcontrol);
 	struct hdac_chmap *chmap = info->private_data;
+	int pcm_idx = kcontrol->private_value;
 	unsigned int __user *dst;
-	int chs, count = 0;
+	int chs, count = 0, chs_bytes;
+	int type;
+	unsigned int tlv_chmap[8];
+	int spk_alloc;
+	struct hdac_cea_channel_speaker_allocation *cap;
 
 	if (size < 8)
 		return -ENOMEM;
@@ -639,40 +666,37 @@ static int hdmi_chmap_ctl_tlv(struct snd_kcontrol *kcontrol, int op_flag,
 		return -EFAULT;
 	size -= 8;
 	dst = tlv + 2;
-	for (chs = 2; chs <= chmap->channels_max; chs++) {
-		int i;
-		struct hdac_cea_channel_speaker_allocation *cap;
-
-		cap = channel_allocations;
-		for (i = 0; i < ARRAY_SIZE(channel_allocations); i++, cap++) {
-			int chs_bytes = chs * 4;
-			int type = chmap->ops.chmap_cea_alloc_validate_get_type(
-								chmap, cap, chs);
-			unsigned int tlv_chmap[8];
-
-			if (type < 0)
-				continue;
-			if (size < 8)
-				return -ENOMEM;
-			if (put_user(type, dst) ||
-			    put_user(chs_bytes, dst + 1))
-				return -EFAULT;
-			dst += 2;
-			size -= 8;
-			count += 8;
-			if (size < chs_bytes)
-				return -ENOMEM;
-			size -= chs_bytes;
-			count += chs_bytes;
-			chmap->ops.cea_alloc_to_tlv_chmap(chmap, cap,
-						tlv_chmap, chs);
-			if (copy_to_user(dst, tlv_chmap, chs_bytes))
-				return -EFAULT;
-			dst += chs;
-		}
-	}
+
+	if (size < 8)
+		return -ENOMEM;
+
+	spk_alloc = chmap->ops.get_spk_alloc(chmap->hdac, pcm_idx);
+	cap = get_cap_from_spk_alloc(spk_alloc);
+	chs = cap->channels;
+
+	chs_bytes = chs * 4;
+	type = chmap->ops.chmap_cea_alloc_validate_get_type(chmap, cap, chs);
+	if (type < 0)
+		return -ENODEV;
+
+	if (put_user(type, dst) ||
+	    put_user(chs_bytes, dst + 1))
+		return -EFAULT;
+
+	dst += 2;
+	size -= 8;
+	count += 8;
+	if (size < chs_bytes)
+		return -ENOMEM;
+
+	count += chs_bytes;
+	chmap->ops.cea_alloc_to_tlv_chmap(chmap, cap, tlv_chmap, chs);
+	if (copy_to_user(dst, tlv_chmap, chs_bytes))
+		return -EFAULT;
+
 	if (put_user(count, tlv + 1))
 		return -EFAULT;
+
 	return 0;
 }
 
diff --git a/sound/pci/hda/patch_hdmi.c b/sound/pci/hda/patch_hdmi.c
index 5af372d..dd25f2c 100644
--- a/sound/pci/hda/patch_hdmi.c
+++ b/sound/pci/hda/patch_hdmi.c
@@ -1838,6 +1838,18 @@ static const struct hda_pcm_ops generic_ops = {
 	.cleanup = generic_hdmi_playback_pcm_cleanup,
 };
 
+static int hdmi_get_spk_alloc(struct hdac_device *hdac, int pcm_idx)
+{
+	struct hda_codec *codec = container_of(hdac, struct hda_codec, core);
+	struct hdmi_spec *spec = codec->spec;
+	struct hdmi_spec_per_pin *per_pin = pcm_idx_to_pin(spec, pcm_idx);
+
+	if (!per_pin)
+		return 0;
+
+	return per_pin->sink_eld.info.spk_alloc;
+}
+
 static void hdmi_get_chmap(struct hdac_device *hdac, int pcm_idx,
 					unsigned char *chmap)
 {
@@ -2249,6 +2261,7 @@ static int patch_generic_hdmi(struct hda_codec *codec)
 	spec->chmap.ops.get_chmap = hdmi_get_chmap;
 	spec->chmap.ops.set_chmap = hdmi_set_chmap;
 	spec->chmap.ops.is_pcm_attached = is_hdmi_pcm_attached;
+	spec->chmap.ops.get_spk_alloc = hdmi_get_spk_alloc,
 
 	codec->spec = spec;
 	hdmi_array_init(spec, 4);
-- 
1.9.1