[alsa-devel] [PATCH v2 1/2] topology: update ABI to improve support for different TLV object 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/sound/asoc.h | 19 +++++++++++++------
 src/topology/ctl.c   | 20 ++++++++------------
 2 files changed, 21 insertions(+), 18 deletions(-)

diff --git a/include/sound/asoc.h b/include/sound/asoc.h
index bb6dcf3..73eb80e 100644
--- a/include/sound/asoc.h
+++ b/include/sound/asoc.h
@@ -135,11 +135,19 @@ 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));
 
 /*
@@ -170,7 +178,7 @@ 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));
 
 /*
@@ -258,7 +266,6 @@ 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/src/topology/ctl.c b/src/topology/ctl.c
index aa06ff6..930b508 100644
--- a/src/topology/ctl.c
+++ b/src/topology/ctl.c
@@ -28,10 +28,7 @@ static int copy_tlv(struct tplg_elem *elem, struct tplg_elem *ref)
 	tplg_dbg("TLV '%s' used by '%s\n", ref->id, elem->id);
 
 	/* TLV has a fixed size */
-	mixer_ctrl->tlv = *tlv;
-
-	/* set size of TLV data */
-	mixer_ctrl->hdr.tlv_size = tlv->count * sizeof(uint32_t);
+	mixer_ctrl->hdr.tlv = *tlv;
 	return 0;
 }
 
@@ -209,20 +206,19 @@ static int tplg_parse_tlv_dbscale(snd_config_t *cfg, struct tplg_elem *elem)
 	snd_config_iterator_t i, next;
 	snd_config_t *n;
 	struct snd_soc_tplg_ctl_tlv *tplg_tlv;
+	struct snd_soc_tplg_tlv_dbscale *scale;
 	const char *id = NULL, *value = NULL;
-	int *data;
 
 	tplg_dbg(" scale: %s\n", elem->id);
 
 	tplg_tlv = calloc(1, sizeof(*tplg_tlv));
 	if (!tplg_tlv)
 		return -ENOMEM;
-	data = (int*)(tplg_tlv->data);
 
 	elem->tlv = tplg_tlv;
-	tplg_tlv->numid = SNDRV_CTL_TLVT_DB_SCALE;
-	tplg_tlv->count = 8;
-	tplg_tlv->size = sizeof(*tplg_tlv);
+	tplg_tlv->size = sizeof(struct snd_soc_tplg_ctl_tlv);
+	tplg_tlv->type = SNDRV_CTL_TLVT_DB_SCALE;
+	scale = &tplg_tlv->scale;
 
 	snd_config_for_each(i, next, cfg) {
 
@@ -242,11 +238,11 @@ static int tplg_parse_tlv_dbscale(snd_config_t *cfg, struct tplg_elem *elem)
 
 		/* get TLV data */
 		if (strcmp(id, "min") == 0)
-			data[0] = atoi(value);
+			scale->min = atoi(value);
 		else if (strcmp(id, "step") == 0)
-			data[1] = atoi(value);
+			scale->step = atoi(value);
 		else if (strcmp(id, "mute") == 0)
-			data[2] = atoi(value);
+			scale->mute = atoi(value);
 		else
 			SNDERR("error: unknown key %s\n", id);
 	}
-- 
2.1.4