[RFC PATCH 03/11] ALSA: mixer_audient: clarify USB control message definition
From: Christian Ruppert
Date: Sat Oct 31 2026 - 20:05:15 EST
Previously, base values for wIndex and wValue were directly given in the
control type. Construct them from a unit ID and selector for clarity.
Signed-off-by: Christian Ruppert <arc@xxxxxx>
---
sound/usb/mixer_audient.c | 76 +++++++++++++++++++++------------------
1 file changed, 41 insertions(+), 35 deletions(-)
diff --git a/sound/usb/mixer_audient.c b/sound/usb/mixer_audient.c
index 917b5bc53869..82591c32140f 100644
--- a/sound/usb/mixer_audient.c
+++ b/sound/usb/mixer_audient.c
@@ -45,15 +45,15 @@ static const struct snd_audient_ctrl_type {
int integer;
} max;
const unsigned int *tlv;
- u16 wValue;
- u16 wIndex;
+ u8 unit;
+ u8 sel;
} snd_audient_ctypes[SND_AUDIENT_TYPE_NCTYPES] = {
[SND_AUDIENT_TYPE_MONITOR] = {
.type = SNDRV_CTL_ELEM_TYPE_INTEGER,
.min.integer = 0,
.max.integer = 127,
- .wValue = 0x0000,
- .wIndex = 0x3800,
+ .unit = 0x38,
+ .sel = 0x00,
/* no TLV here because we can't describe the cross-fader */
},
[SND_AUDIENT_TYPE_PHANTOM] = {
@@ -61,31 +61,31 @@ static const struct snd_audient_ctrl_type {
.invert = false,
.min.integer = 0,
.max.integer = 1,
- .wValue = 0x0000,
- .wIndex = 0x3A00,
+ .unit = 0x3A,
+ .sel = 0x00,
},
[SND_AUDIENT_TYPE_MUTE] = {
.type = SNDRV_CTL_ELEM_TYPE_BOOLEAN,
.invert = true,
.min.integer = 0,
.max.integer = 1,
- .wValue = 0x0200,
- .wIndex = 0x3A00,
+ .unit = 0x3A,
+ .sel = 0x02,
},
[SND_AUDIENT_TYPE_MUTE_OUT] = {
.type = SNDRV_CTL_ELEM_TYPE_BOOLEAN,
.invert = true,
.min.integer = 0,
.max.integer = 1,
- .wValue = 0x0100,
- .wIndex = 0x3B00,
+ .unit = 0x3B,
+ .sel = 0x01,
},
[SND_AUDIENT_TYPE_MIXER] = {
.type = SNDRV_CTL_ELEM_TYPE_INTEGER,
.min.integer = -128 * 256,
.max.integer = 6 * 256,
- .wValue = 0x0100,
- .wIndex = 0x3C00,
+ .unit = 0x3C,
+ .sel = 0x01,
.tlv = snd_audient_tlv_mixer,
},
};
@@ -209,7 +209,7 @@ const struct snd_audient_ctrl_type *snd_audient_kctl_type(struct snd_kcontrol
return &snd_audient_ctypes[kctl->private_value & 0xFF];
}
-static __always_inline u16 snd_audient_kctl_valoffs(struct snd_kcontrol *kctl)
+static __always_inline u16 snd_audient_kctl_cidxoffs(struct snd_kcontrol *kctl)
{
return (kctl->private_value >> 8) & 0xFF;
}
@@ -233,11 +233,16 @@ static inline u16 snd_audient_kctl_channels(struct snd_kcontrol *kctl)
#define AUDIENT_REQTYPE_GET (USB_DIR_IN | USB_TYPE_CLASS \
| USB_RECIP_INTERFACE)
+#define U8_U8(HI, LO) ((((u16)(HI)) << 8) | ((LO) & 0xFF))
+
static inline int snd_audient_get_cur(struct usb_mixer_interface *mixer,
- u16 value, u16 index,
- void *buf, size_t len)
+ const u8 unit, const u8 sel,
+ const u8 cidx,
+ void *const buf, const size_t len)
{
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);
return snd_usb_ctl_msg(dev, usb_rcvctrlpipe(dev, 0),
UAC2_CS_CUR, AUDIENT_REQTYPE_GET,
@@ -245,10 +250,13 @@ static inline int snd_audient_get_cur(struct usb_mixer_interface *mixer,
}
static inline int snd_audient_set_cur(struct usb_mixer_interface *mixer,
- u16 value, u16 index,
- void *buf, size_t len)
+ const u8 unit, const u8 sel,
+ const u8 cidx,
+ void *const buf, const size_t len)
{
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);
return snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0),
UAC2_CS_CUR, AUDIENT_REQTYPE_SET,
@@ -266,8 +274,7 @@ static int snd_ctl_audient_boolean_get(struct snd_kcontrol *kctl,
const unsigned int hwchan = snd_audient_kctl_hwchannels(kctl);
const struct snd_audient_ctrl_type *const ctype
= snd_audient_kctl_type(kctl);
- const u16 value = ctype->wValue + snd_audient_kctl_valoffs(kctl);
- const u16 index = ctype->wIndex;
+ const u8 base = snd_audient_kctl_cidxoffs(kctl);
int i;
@@ -279,8 +286,8 @@ static int snd_ctl_audient_boolean_get(struct snd_kcontrol *kctl,
u32 buf;
int ret;
- ret = snd_audient_get_cur(mixer, value + i, index,
- &buf, sizeof(buf));
+ ret = snd_audient_get_cur(mixer, ctype->unit, ctype->sel,
+ base + i, &buf, sizeof(buf));
if (ret < 0)
return ret;
@@ -307,8 +314,7 @@ static int snd_ctl_audient_boolean_set(struct snd_kcontrol *kctl,
const unsigned int hwchan = snd_audient_kctl_hwchannels(kctl);
const struct snd_audient_ctrl_type *const ctype
= snd_audient_kctl_type(kctl);
- const u16 value = ctype->wValue + snd_audient_kctl_valoffs(kctl);
- const u16 index = ctype->wIndex;
+ const u8 base = snd_audient_kctl_cidxoffs(kctl);
int changed = 0;
int i;
@@ -325,15 +331,16 @@ static int snd_ctl_audient_boolean_set(struct snd_kcontrol *kctl,
if (ctype->invert)
buf ^= cpu_to_le32(0x1);
- ret = snd_audient_get_cur(mixer, value + i, index,
- &rbuf, sizeof(rbuf));
+ ret = snd_audient_get_cur(mixer, ctype->unit, ctype->sel,
+ base + i, &rbuf, sizeof(rbuf));
if (ret < 0)
return ret;
if (rbuf != buf) {
changed = 1;
- ret = snd_audient_set_cur(mixer, value + i, index,
+ ret = snd_audient_set_cur(mixer, ctype->unit,
+ ctype->sel, base + i,
&buf, sizeof(buf));
if (ret < 0)
return ret;
@@ -353,8 +360,7 @@ static int snd_ctl_audient_integer_get(struct snd_kcontrol *kctl,
const unsigned int hwchan = snd_audient_kctl_hwchannels(kctl);
const struct snd_audient_ctrl_type *const ctype
= snd_audient_kctl_type(kctl);
- const u16 value = ctype->wValue + snd_audient_kctl_valoffs(kctl);
- const u16 index = ctype->wIndex;
+ const u8 base = snd_audient_kctl_cidxoffs(kctl);
int i;
@@ -367,8 +373,8 @@ static int snd_ctl_audient_integer_get(struct snd_kcontrol *kctl,
s16 val;
int ret;
- ret = snd_audient_get_cur(mixer, value + i, index,
- &buf, sizeof(buf));
+ ret = snd_audient_get_cur(mixer, ctype->unit, ctype->sel,
+ base + i, &buf, sizeof(buf));
if (ret < 0)
return ret;
@@ -391,8 +397,7 @@ static int snd_ctl_audient_integer_set(struct snd_kcontrol *kctl,
const unsigned int hwchan = snd_audient_kctl_hwchannels(kctl);
const struct snd_audient_ctrl_type *const ctype
= snd_audient_kctl_type(kctl);
- const u16 value = ctype->wValue + snd_audient_kctl_valoffs(kctl);
- const u16 index = ctype->wIndex;
+ const u8 base = snd_audient_kctl_cidxoffs(kctl);
int changed = 0;
int i;
@@ -406,15 +411,16 @@ static int snd_ctl_audient_integer_set(struct snd_kcontrol *kctl,
s16 buf = cpu_to_le16(ctl_val->value.integer.value[i]);
int ret;
- ret = snd_audient_get_cur(mixer, value + i, index,
- &rbuf, sizeof(rbuf));
+ ret = snd_audient_get_cur(mixer, ctype->unit, ctype->sel,
+ base + i, &rbuf, sizeof(rbuf));
if (ret < 0)
return ret;
if (rbuf != buf) {
changed = 1;
- ret = snd_audient_set_cur(mixer, value + i, index,
+ ret = snd_audient_set_cur(mixer, ctype->unit,
+ ctype->sel, base + i,
&buf, sizeof(buf));
if (ret < 0)
return ret;
--
2.56.0