[RFC V2 PATCH 05/11] ALSA: mixer_audient: make USB control transfer size configurable

[Christian Ruppert <arc@gmx.li>]

Previously, the USB transfer size was hardcoded in the datatype get/set
functions. Make it configurable in the ctype structure in preparation of
new control types for the id14.

Signed-off-by: Christian Ruppert <arc@gmx.li>
---
 sound/usb/mixer_audient.c | 131 ++++++++++++++++++++++++--------------
 1 file changed, 84 insertions(+), 47 deletions(-)

diff --git a/sound/usb/mixer_audient.c b/sound/usb/mixer_audient.c
index 1f3744a7c10a..57d856d25271 100644
--- a/sound/usb/mixer_audient.c
+++ b/sound/usb/mixer_audient.c
@@ -12,6 +12,8 @@
 #include <linux/usb.h>
 #include <linux/usb/audio-v2.h>
 #include <linux/slab.h>
+#include <linux/types.h>
+#include <linux/bitops.h>
 #include <sound/core.h>
 #include <sound/control.h>
 #include <sound/tlv.h>
@@ -35,8 +37,12 @@ enum snd_audient_type {
 /* Mixer matrix: -128dB (mute) to +6dB */
 static const DECLARE_TLV_DB_MINMAX_MUTE(snd_audient_tlv_mixer, -12800, 600);
 
+#define SND_AUDIENT_CTYPE_FLAGS_SIGNED		BIT(0)
+
 static const struct snd_audient_ctrl_type {
 	snd_ctl_elem_type_t type;
+	unsigned long flags;
+	size_t len;		/* datatype size, can be 1, 2 or 4 bytes */
 	bool invert;
 	union {
 		int integer;
@@ -50,6 +56,7 @@ static const struct snd_audient_ctrl_type {
 } snd_audient_ctypes[SND_AUDIENT_TYPE_NCTYPES] = {
 	[SND_AUDIENT_TYPE_MONITOR] = {
 		.type = SNDRV_CTL_ELEM_TYPE_INTEGER,
+		.len = 2,
 		.min.integer = 0,
 		.max.integer = 127,
 		.unit = 0x38,
@@ -59,6 +66,7 @@ static const struct snd_audient_ctrl_type {
 	[SND_AUDIENT_TYPE_PHANTOM] = {
 		.type = SNDRV_CTL_ELEM_TYPE_BOOLEAN,
 		.invert = false,
+		.len = 4,
 		.min.integer = 0,
 		.max.integer = 1,
 		.unit = 0x3A,
@@ -67,6 +75,7 @@ static const struct snd_audient_ctrl_type {
 	[SND_AUDIENT_TYPE_MUTE] = {
 		.type = SNDRV_CTL_ELEM_TYPE_BOOLEAN,
 		.invert = true,
+		.len = 4,
 		.min.integer = 0,
 		.max.integer = 1,
 		.unit = 0x3A,
@@ -75,6 +84,7 @@ static const struct snd_audient_ctrl_type {
 	[SND_AUDIENT_TYPE_MUTE_OUT] = {
 		.type = SNDRV_CTL_ELEM_TYPE_BOOLEAN,
 		.invert = true,
+		.len = 4,
 		.min.integer = 0,
 		.max.integer = 1,
 		.unit = 0x3B,
@@ -82,6 +92,8 @@ static const struct snd_audient_ctrl_type {
 	},
 	[SND_AUDIENT_TYPE_MIXER] = {
 		.type = SNDRV_CTL_ELEM_TYPE_INTEGER,
+		.flags = SND_AUDIENT_CTYPE_FLAGS_SIGNED,
+		.len = 2,
 		.min.integer = -128 * 256,
 		.max.integer = 6 * 256,
 		.unit = 0x3C,
@@ -236,44 +248,91 @@ static inline u16 snd_audient_kctl_channels(struct snd_kcontrol *kctl)
 #define U8_U8(HI, LO) ((((u16)(HI)) << 8) | ((LO) & 0xFF))
 
 static inline int snd_audient_get_cur(struct usb_mixer_interface *mixer,
-				      const u8 unit, const u8 sel,
-				      const u8 cidx,
-				      void *const buf, const size_t len)
+			const struct snd_audient_ctrl_type *const ctype,
+			const u8 cidx, void *const buf)
 {
 	struct usb_device *const dev = mixer->chip->dev;
-	const u16 value = U8_U8(sel, cidx);
-	const u16 index = U8_U8(unit, mixer->hostif->desc.bInterfaceNumber);
+	const u16 value = U8_U8(ctype->sel, cidx);
+	const u16 index = U8_U8(ctype->unit,
+				mixer->hostif->desc.bInterfaceNumber);
 
 	const int ret = snd_usb_ctl_msg(dev, usb_rcvctrlpipe(dev, 0),
 					UAC2_CS_CUR, AUDIENT_REQTYPE_GET,
-					value, index, buf, len);
+					value, index, buf, ctype->len);
 
-	if ((ret >= 0) && (ret != len))
+	if ((ret >= 0) && (ret != ctype->len))
 		return -EIO;
 
 	return ret;
 }
 
 static inline int snd_audient_set_cur(struct usb_mixer_interface *mixer,
-				      const u8 unit, const u8 sel,
-				      const u8 cidx,
-				      void *const buf, const size_t len)
+			const struct snd_audient_ctrl_type *const ctype,
+			const u8 cidx, void *const buf)
 {
 	struct usb_device *const dev = mixer->chip->dev;
-	const u16 value = U8_U8(sel, cidx);
-	const u16 index = U8_U8(unit, mixer->hostif->desc.bInterfaceNumber);
+	const u16 value = U8_U8(ctype->sel, cidx);
+	const u16 index = U8_U8(ctype->unit,
+				mixer->hostif->desc.bInterfaceNumber);
 
 	const int ret = snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0),
 					UAC2_CS_CUR, AUDIENT_REQTYPE_SET,
-					value, index, buf, len);
+					value, index, buf, ctype->len);
 
-	if ((ret >= 0) && (ret != len))
+	if ((ret >= 0) && (ret != ctype->len))
 		return -EIO;
 
 	return ret;
 }
 
 
+static int snd_audient_raw_get_one(struct usb_mixer_interface *const mixer,
+			const struct snd_audient_ctrl_type *const ctype,
+			const u8 cidx, u32 *const value)
+{
+	int ret;
+	__le32 buf = 0;
+	s32 val;
+
+	ret = snd_audient_get_cur(mixer, ctype, cidx, &buf);
+	if (ret < 0)
+		return ret;
+
+	val = le32_to_cpu(buf);
+
+	if (ctype->flags & SND_AUDIENT_CTYPE_FLAGS_SIGNED)
+		val = sign_extend32(val, 8 * ctype->len - 1);
+
+	*value = val;
+
+	return ret;
+}
+
+static int snd_audient_raw_set_one(struct usb_mixer_interface *const mixer,
+			const struct snd_audient_ctrl_type *const ctype,
+			const u8 cidx, const u32 value)
+{
+	int ret;
+	u32 val;
+
+	ret = snd_audient_raw_get_one(mixer, ctype, cidx, &val);
+	if (ret < 0)
+		return ret;
+
+	if (val != value) {
+		__le32 buf = cpu_to_le32(value);
+
+		ret = snd_audient_set_cur(mixer, ctype, cidx, &buf);
+		if (ret < 0)
+			return ret;
+
+		return 1;
+	}
+
+	return 0;
+}
+
+
 static int snd_ctl_audient_boolean_get(struct snd_kcontrol *kctl,
 				       struct snd_ctl_elem_value *ctl_val)
 {
@@ -296,12 +355,11 @@ static int snd_ctl_audient_boolean_get(struct snd_kcontrol *kctl,
 		u32 buf;
 		int ret;
 
-		ret = snd_audient_get_cur(mixer, ctype->unit, ctype->sel,
-					  base + i, &buf, sizeof(buf));
+		ret = snd_audient_raw_get_one(mixer, ctype, base + i, &buf);
 		if (ret < 0)
 			return ret;
 
-		ctl_val->value.integer.value[i] = le32_to_cpu(buf) ? 1 : 0;
+		ctl_val->value.integer.value[i] = buf ? 1 : 0;
 
 		if (ctype->invert)
 			ctl_val->value.integer.value[i] ^= 0x1;
@@ -334,27 +392,18 @@ static int snd_ctl_audient_boolean_set(struct snd_kcontrol *kctl,
 		return pm.err;
 
 	for (i = 0; i < hwchan; i++) {
-		u32 rbuf;
-		u32 buf = cpu_to_le32(ctl_val->value.integer.value[i] ? 1 : 0);
+		u32 buf = ctl_val->value.integer.value[i] ? 1 : 0;
 		int ret;
 
 		if (ctype->invert)
-			buf ^= cpu_to_le32(0x1);
+			buf ^= 0x1;
 
-		ret = snd_audient_get_cur(mixer, ctype->unit, ctype->sel,
-					  base + i, &rbuf, sizeof(rbuf));
+		ret = snd_audient_raw_set_one(mixer, ctype, base + i, buf);
 		if (ret < 0)
 			return ret;
 
-		if (rbuf != buf) {
+		if (ret)
 			changed = 1;
-
-			ret = snd_audient_set_cur(mixer, ctype->unit,
-						  ctype->sel, base + i,
-						  &buf, sizeof(buf));
-			if (ret < 0)
-				return ret;
-		}
 	}
 
 	return changed;
@@ -379,16 +428,13 @@ static int snd_ctl_audient_integer_get(struct snd_kcontrol *kctl,
 		return pm.err;
 
 	for (i = 0; i < hwchan; i++) {
-		u16 buf;
-		s16 val;
+		s32 val;
 		int ret;
 
-		ret = snd_audient_get_cur(mixer, ctype->unit, ctype->sel,
-					  base + i, &buf, sizeof(buf));
+		ret = snd_audient_raw_get_one(mixer, ctype, base + i, &val);
 		if (ret < 0)
 			return ret;
 
-		val = le16_to_cpu(buf);
 		ctl_val->value.integer.value[i] = val;
 	}
 
@@ -417,24 +463,15 @@ static int snd_ctl_audient_integer_set(struct snd_kcontrol *kctl,
 		return pm.err;
 
 	for (i = 0; i < hwchan; i++) {
-		s16 rbuf;
-		s16 buf = cpu_to_le16(ctl_val->value.integer.value[i]);
+		s32 val = ctl_val->value.integer.value[i];
 		int ret;
 
-		ret = snd_audient_get_cur(mixer, ctype->unit, ctype->sel,
-					  base + i, &rbuf, sizeof(rbuf));
+		ret = snd_audient_raw_set_one(mixer, ctype, base + i, val);
 		if (ret < 0)
 			return ret;
 
-		if (rbuf != buf) {
+		if (ret)
 			changed = 1;
-
-			ret = snd_audient_set_cur(mixer, ctype->unit,
-						  ctype->sel, base + i,
-						  &buf, sizeof(buf));
-			if (ret < 0)
-				return ret;
-		}
 	}
 
 	return changed;
-- 
2.56.0