sorry for replying this early comment now, i have to study on tlv first.
+/* dl pga gain */ +static const char *const dl_pga_gain[] = {
- "8Db", "7Db", "6Db", "5Db", "4Db",
- "3Db", "2Db", "1Db", "0Db", "-1Db",
- "-2Db", "-3Db", "-4Db", "-5Db", "-6Db",
- "-7Db", "-8Db", "-9Db", "-10Db", "-40Db",
+};
These gains should be put in TLVs rather than an enum so userspace can handle them (also it should be dB not Db). You can handle irregular step sizes like these with DECLARE_TLV_DB_SCALE(), there's several examples in the code already.
We declare this enum for user space to operate on enum directly, unlike alsa-lib, we use tinyalsa in Android, if declared in tlv, the mixer control just become a integer control, which is not informative for user space.
+static int dl_pga_get(struct snd_kcontrol *kcontrol,
struct snd_ctl_elem_value *ucontrol)+{
- struct snd_soc_codec *codec = snd_soc_kcontrol_codec(kcontrol);
- struct mt6351_priv *priv = snd_soc_codec_get_drvdata(codec);
- ucontrol->value.integer.value[0] = priv->ana_gain[kcontrol->id.device];
- if (ucontrol->value.integer.value[0] == 0x1f) /* reg idx for -40dB*/
ucontrol->value.integer.value[0] = ARRAY_SIZE(dl_pga_gain) - 1;Why do this rewriting?
A little awkward gain register here, the range is for 8dB ~ -10dB and -40dB, corresponding to reg index 0 ~ 18 and 31.
00000: +8dB. 00001: +7dB. 10010: -10dB 11111: -40dB(Mute).
and where 19 ~ 30 is not defined, and shouldn't be set.
i think tlv not yet support this kind of gain control?
Maybe i'll just declare 8dB ~ -10dB for now.