[alsa-devel] [PATCH v2 1/3] ASoC: topology: Update TLV support so we can support more TLV types

[Liam Girdwood]

From: Mengdong Lin <mengdong.lin at intel.com>

Currently the TLV topology structure is targeted at only supporting the
DB scale data. This patch extends support for the other TLV types so they
can be easily added at a later stage.

TLV structure is moved to common topology control header since it's a
common field for controls and can be processed in a general way.

Users must set a proper access flag for a control since it's used to
decide if the TLV field is valid and if a TLV callback is needed.

Removed the following fields from topology TLV struct:
- size/count: type can decide the size.
- numid: not needed to initialize TLV for kcontrol.
- data: replaced by the type specific struct.

Added TLV structure to generic control header and removed TLV structure
from mixer control.

Signed-off-by: Mengdong Lin <mengdong.lin at intel.com>
Signed-off-by: Liam Girdwood <liam.r.girdwood at linux.intel.com>
---
 include/uapi/sound/asoc.h | 19 +++++++++++-----
 sound/soc/soc-topology.c  | 58 +++++++++++++++++++++++++++++++++--------------
 2 files changed, 54 insertions(+), 23 deletions(-)

diff --git a/include/uapi/sound/asoc.h b/include/uapi/sound/asoc.h
index 2819fc1..aa3a79b 100644
--- a/include/uapi/sound/asoc.h
+++ b/include/uapi/sound/asoc.h
@@ -137,11 +137,19 @@ struct snd_soc_tplg_private {
 /*
  * Kcontrol TLV data.
  */
+struct snd_soc_tplg_tlv_dbscale {
+	__le32 min;
+	__le32 step;
+	__le32 mute;
+} __attribute__((packed));
+
 struct snd_soc_tplg_ctl_tlv {
-	__le32 size;	/* in bytes aligned to 4 */
-	__le32 numid;	/* control element numeric identification */
-	__le32 count;	/* number of elem in data array */
-	__le32 data[SND_SOC_TPLG_TLV_SIZE];
+	__le32 size;	/* in bytes of this structure */
+	__le32 type;	/* SNDRV_CTL_TLVT_*, type of TLV */
+	union {
+		__le32 data[SND_SOC_TPLG_TLV_SIZE];
+		struct snd_soc_tplg_tlv_dbscale scale;
+	};
 } __attribute__((packed));
 
 /*
@@ -172,7 +180,7 @@ struct snd_soc_tplg_ctl_hdr {
 	char name[SNDRV_CTL_ELEM_ID_NAME_MAXLEN];
 	__le32 access;
 	struct snd_soc_tplg_kcontrol_ops_id ops;
-	__le32 tlv_size;	/* non zero means control has TLV data */
+	struct snd_soc_tplg_ctl_tlv tlv;
 } __attribute__((packed));
 
 /*
@@ -260,7 +268,6 @@ struct snd_soc_tplg_mixer_control {
 	__le32 invert;
 	__le32 num_channels;
 	struct snd_soc_tplg_channel channel[SND_SOC_TPLG_MAX_CHAN];
-	struct snd_soc_tplg_ctl_tlv tlv;
 	struct snd_soc_tplg_private priv;
 } __attribute__((packed));
 
diff --git a/sound/soc/soc-topology.c b/sound/soc/soc-topology.c
index df3ddf0..2799abe 100644
--- a/sound/soc/soc-topology.c
+++ b/sound/soc/soc-topology.c
@@ -33,6 +33,7 @@
 #include <sound/soc.h>
 #include <sound/soc-dapm.h>
 #include <sound/soc-topology.h>
+#include <sound/tlv.h>
 
 /*
  * We make several passes over the data (since it wont necessarily be ordered)
@@ -579,28 +580,51 @@ static int soc_tplg_init_kcontrol(struct soc_tplg *tplg,
 	return 0;
 }
 
+
+static int soc_tplg_create_tlv_db_scale(struct soc_tplg *tplg,
+	struct snd_kcontrol_new *kc, struct snd_soc_tplg_tlv_dbscale *scale)
+{
+	unsigned int item_len = 2 * sizeof(unsigned int);
+	unsigned int *p;
+
+	p = kzalloc(item_len + 2 * sizeof(unsigned int), GFP_KERNEL);
+	if (!p)
+		return -ENOMEM;
+
+	p[0] = SNDRV_CTL_TLVT_DB_SCALE;
+	p[1] = item_len;
+	p[2] = scale->min;
+	p[3] = (scale->step & TLV_DB_SCALE_MASK)
+			| (scale->mute ? TLV_DB_SCALE_MUTE : 0);
+
+	kc->tlv.p = (void *)p;
+	return 0;
+}
+
 static int soc_tplg_create_tlv(struct soc_tplg *tplg,
-	struct snd_kcontrol_new *kc, struct snd_soc_tplg_ctl_tlv *tplg_tlv)
+	struct snd_kcontrol_new *kc, struct snd_soc_tplg_ctl_hdr *tc)
 {
-	struct snd_ctl_tlv *tlv;
-	int size;
+	struct snd_soc_tplg_ctl_tlv *tplg_tlv;
 
-	if (tplg_tlv->count == 0)
+	if (!(tc->access & SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE))
 		return 0;
 
-	size = ((tplg_tlv->count + (sizeof(unsigned int) - 1)) &
-		~(sizeof(unsigned int) - 1));
-	tlv = kzalloc(sizeof(*tlv) + size, GFP_KERNEL);
-	if (tlv == NULL)
-		return -ENOMEM;
-
-	dev_dbg(tplg->dev, " created TLV type %d size %d bytes\n",
-		tplg_tlv->numid, size);
+	if (tc->access & SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK) {
+		kc->tlv.c = snd_soc_bytes_tlv_callback;
+	} else {
+		tplg_tlv = &tc->tlv;
+		switch (tplg_tlv->type) {
+		case SNDRV_CTL_TLVT_DB_SCALE:
+			return soc_tplg_create_tlv_db_scale(tplg, kc,
+					&tplg_tlv->scale);
 
-	tlv->numid = tplg_tlv->numid;
-	tlv->length = size;
-	memcpy(&tlv->tlv[0], tplg_tlv->data, size);
-	kc->tlv.p = (void *)tlv;
+		/* TODO: add support for other TLV types */
+		default:
+			dev_dbg(tplg->dev, "Unsupported TLV type %d\n",
+					tplg_tlv->type);
+			return -EINVAL;
+		}
+	}
 
 	return 0;
 }
@@ -772,7 +796,7 @@ static int soc_tplg_dmixer_create(struct soc_tplg *tplg, unsigned int count,
 		}
 
 		/* create any TLV data */
-		soc_tplg_create_tlv(tplg, &kc, &mc->tlv);
+		soc_tplg_create_tlv(tplg, &kc, &mc->hdr);
 
 		/* register control here */
 		err = soc_tplg_add_kcontrol(tplg, &kc,
-- 
2.1.4