ASoC: SDCA: support Q7.8 volume format

The SDCA specification uses Q7.8 volume format.
This patch adds a field to indicate whether it is SDCA volume control
and supports the volume settings.

Signed-off-by: Shuming Fan <shumingf@realtek.com>

Author: shumingfan

include/sound/soc.h

@@ -555,6 +555,7 @@ int snd_soc_get_volsw(struct snd_kcontrol *kcontrol,
 	struct snd_ctl_elem_value *ucontrol);
 int snd_soc_put_volsw(struct snd_kcontrol *kcontrol,
 	struct snd_ctl_elem_value *ucontrol);
+
 #define snd_soc_get_volsw_2r snd_soc_get_volsw
 #define snd_soc_put_volsw_2r snd_soc_put_volsw
 int snd_soc_get_volsw_sx(struct snd_kcontrol *kcontrol,
@@ -1225,6 +1226,7 @@ struct soc_mixer_control {
 	unsigned int sign_bit;
 	unsigned int invert:1;
 	unsigned int autodisable:1;
+	unsigned int sdca_vol_q7p8:1;
 #ifdef CONFIG_SND_SOC_TOPOLOGY
 	struct snd_soc_dobj dobj;
 #endif

sound/soc/sdca/sdca_asoc.c

@@ -795,7 +795,6 @@ static int control_limit_kctl(struct device *dev,
 	struct sdca_control_range *range;
 	int min, max, step;
 	unsigned int *tlv;
-	int shift;
 
 	if (control->type != SDCA_CTL_DATATYPE_Q7P8DB)
 		return 0;
@@ -814,37 +813,23 @@ static int control_limit_kctl(struct device *dev,
 	min = sign_extend32(min, control->nbits - 1);
 	max = sign_extend32(max, control->nbits - 1);
 
-	/*
-	 * FIXME: Only support power of 2 step sizes as this can be supported
-	 * by a simple shift.
-	 */
-	if (hweight32(step) != 1) {
-		dev_err(dev, "%s: %s: currently unsupported step size\n",
-			entity->label, control->label);
-		return -EINVAL;
-	}
-
-	/*
-	 * The SDCA volumes are in steps of 1/256th of a dB, a step down of
-	 * 64 (shift of 6) gives 1/4dB. 1/4dB is the smallest unit that is also
-	 * representable in the ALSA TLVs which are in 1/100ths of a dB.
-	 */
-	shift = max(ffs(step) - 1, 6);
-
 	tlv = devm_kcalloc(dev, 4, sizeof(*tlv), GFP_KERNEL);
 	if (!tlv)
 		return -ENOMEM;
 
-	tlv[0] = SNDRV_CTL_TLVT_DB_SCALE;
+	tlv[0] = SNDRV_CTL_TLVT_DB_MINMAX;
 	tlv[1] = 2 * sizeof(*tlv);
 	tlv[2] = (min * 100) >> 8;
-	tlv[3] = ((1 << shift) * 100) >> 8;
+	tlv[3] = (max * 100) >> 8;
+
+	step = (step * 100) >> 8;
 
-	mc->min = min >> shift;
-	mc->max = max >> shift;
-	mc->shift = shift;
-	mc->rshift = shift;
-	mc->sign_bit = 15 - shift;
+	mc->min = ((int)tlv[2] / step);
+	mc->max = ((int)tlv[3] / step);
+	mc->shift = step;
+	mc->rshift = step;
+	mc->sign_bit = 15;
+	mc->sdca_vol_q7p8 = 1;
 
 	kctl->tlv.p = tlv;
 	kctl->access |= SNDRV_CTL_ELEM_ACCESS_TLV_READ;

sound/soc/soc-ops.c

@@ -113,12 +113,19 @@ EXPORT_SYMBOL_GPL(snd_soc_put_enum_double);
 static int soc_mixer_reg_to_ctl(struct soc_mixer_control *mc, unsigned int reg_val,
 				unsigned int mask, unsigned int shift, int max)
 {
-	int val = (reg_val >> shift) & mask;
+	int val = reg_val;
+
+	if (!mc->sdca_vol_q7p8)
+		val = (reg_val >> shift) & mask;
 
 	if (mc->sign_bit)
 		val = sign_extend32(val, mc->sign_bit);
 
 	val = clamp(val, mc->min, mc->max);
+
+	if (mc->sdca_vol_q7p8)
+		val = (((val * 100) >> 8) / (int)shift);
+
 	val -= mc->min;
 
 	if (mc->invert)
@@ -131,14 +138,19 @@ static unsigned int soc_mixer_ctl_to_reg(struct soc_mixer_control *mc, int val,
 					 unsigned int mask, unsigned int shift,
 					 int max)
 {
-	unsigned int reg_val;
+	unsigned int reg_val, ret_val;
 
 	if (mc->invert)
 		val = max - val;
 
 	reg_val = val + mc->min;
 
-	return (reg_val & mask) << shift;
+	if (mc->sdca_vol_q7p8)
+		ret_val = (((int)(((int)reg_val * shift) << 8)) / 100);
+	else
+		ret_val = (reg_val & mask) << shift;
+
+	return ret_val;
 }
 
 static int soc_mixer_valid_ctl(struct soc_mixer_control *mc, long val, int max)
@@ -198,7 +210,7 @@ static int soc_put_volsw(struct snd_kcontrol *kcontrol,
 			 struct soc_mixer_control *mc, int mask, int max)
 {
 	struct snd_soc_component *component = snd_kcontrol_chip(kcontrol);
-	unsigned int val1, val_mask;
+	unsigned int val1, val_mask = mask;
 	unsigned int val2 = 0;
 	bool double_r = false;
 	int ret;
@@ -209,7 +221,9 @@ static int soc_put_volsw(struct snd_kcontrol *kcontrol,
 
 	val1 = soc_mixer_ctl_to_reg(mc, ucontrol->value.integer.value[0],
 				    mask, mc->shift, max);
-	val_mask = mask << mc->shift;
+
+	if (!mc->sdca_vol_q7p8)
+		val_mask = mask << mc->shift;
 
 	if (snd_soc_volsw_is_stereo(mc)) {
 		ret = soc_mixer_valid_ctl(mc, ucontrol->value.integer.value[1], max);
@@ -220,7 +234,8 @@ static int soc_put_volsw(struct snd_kcontrol *kcontrol,
 			val1 |= soc_mixer_ctl_to_reg(mc,
 						     ucontrol->value.integer.value[1],
 						     mask, mc->rshift, max);
-			val_mask |= mask << mc->rshift;
+			if (!mc->sdca_vol_q7p8)
+				val_mask |= mask << mc->rshift;
 		} else {
 			val2 = soc_mixer_ctl_to_reg(mc,
 						    ucontrol->value.integer.value[1],