* [PATCH 1/2] usb: gadget: u_audio: pass channel counts explicitly
2026-07-29 5:41 [PATCH 0/2] usb: gadget: uac2: support explicit channel counts Kyle Farrell
@ 2026-07-29 5:41 ` Kyle Farrell
2026-07-29 5:41 ` [PATCH 2/2] usb: gadget: f_uac2: allow explicit channel counts Kyle Farrell
1 sibling, 0 replies; 3+ messages in thread
From: Kyle Farrell @ 2026-07-29 5:41 UTC (permalink / raw)
To: Greg Kroah-Hartman, linux-usb
Cc: Jonathan Corbet, Shuah Khan, linux-kernel, linux-doc,
Kyle Farrell
Add playback and capture channel count fields to struct uac_params and
initialize them in the UAC1 and UAC2 function drivers.
u_audio currently derives the channel count from the channel mask in
several places. Pass the resolved count explicitly instead, so the
shared audio implementation does not depend on how an individual USB
audio function represents its channel configuration.
Initialize the new fields from the existing channel masks, preserving
the generated descriptors and user-visible behavior.
Signed-off-by: Kyle Farrell <kaf@nwlink.com>
---
drivers/usb/gadget/function/f_uac1.c | 2 ++
drivers/usb/gadget/function/f_uac2.c | 2 ++
drivers/usb/gadget/function/u_audio.c | 32 ++++++++++++---------------
drivers/usb/gadget/function/u_audio.h | 2 ++
4 files changed, 20 insertions(+), 18 deletions(-)
diff --git a/drivers/usb/gadget/function/f_uac1.c b/drivers/usb/gadget/function/f_uac1.c
index 85c502e98f57..51cc49f097c0 100644
--- a/drivers/usb/gadget/function/f_uac1.c
+++ b/drivers/usb/gadget/function/f_uac1.c
@@ -1448,6 +1448,7 @@ static int f_audio_bind(struct usb_configuration *c, struct usb_function *f)
audio->out_ep_maxpsize = le16_to_cpu(as_out_ep_desc.wMaxPacketSize);
audio->in_ep_maxpsize = le16_to_cpu(as_in_ep_desc.wMaxPacketSize);
audio->params.c_chmask = audio_opts->c_chmask;
+ audio->params.c_channels = num_channels(audio_opts->c_chmask);
memcpy(audio->params.c_srates, audio_opts->c_srates,
sizeof(audio->params.c_srates));
audio->params.c_ssize = audio_opts->c_ssize;
@@ -1461,6 +1462,7 @@ static int f_audio_bind(struct usb_configuration *c, struct usb_function *f)
audio->params.p_fu.volume_res = audio_opts->p_volume_res;
}
audio->params.p_chmask = audio_opts->p_chmask;
+ audio->params.p_channels = num_channels(audio_opts->p_chmask);
memcpy(audio->params.p_srates, audio_opts->p_srates,
sizeof(audio->params.p_srates));
audio->params.p_ssize = audio_opts->p_ssize;
diff --git a/drivers/usb/gadget/function/f_uac2.c b/drivers/usb/gadget/function/f_uac2.c
index 897787d0803c..b8735b9065c3 100644
--- a/drivers/usb/gadget/function/f_uac2.c
+++ b/drivers/usb/gadget/function/f_uac2.c
@@ -1308,6 +1308,7 @@ afunc_bind(struct usb_configuration *cfg, struct usb_function *fn)
agdev->gadget = gadget;
agdev->params.p_chmask = uac2_opts->p_chmask;
+ agdev->params.p_channels = num_channels(uac2_opts->p_chmask);
memcpy(agdev->params.p_srates, uac2_opts->p_srates,
sizeof(agdev->params.p_srates));
agdev->params.p_ssize = uac2_opts->p_ssize;
@@ -1320,6 +1321,7 @@ afunc_bind(struct usb_configuration *cfg, struct usb_function *fn)
agdev->params.p_fu.volume_res = uac2_opts->p_volume_res;
}
agdev->params.c_chmask = uac2_opts->c_chmask;
+ agdev->params.c_channels = num_channels(uac2_opts->c_chmask);
memcpy(agdev->params.c_srates, uac2_opts->c_srates,
sizeof(agdev->params.c_srates));
agdev->params.c_ssize = uac2_opts->c_ssize;
diff --git a/drivers/usb/gadget/function/u_audio.c b/drivers/usb/gadget/function/u_audio.c
index e53f2927b539..3c923a73b8d0 100644
--- a/drivers/usb/gadget/function/u_audio.c
+++ b/drivers/usb/gadget/function/u_audio.c
@@ -390,25 +390,22 @@ static int uac_pcm_open(struct snd_pcm_substream *substream)
struct uac_params *params;
struct uac_rtd_params *prm;
int p_ssize, c_ssize;
- int p_chmask, c_chmask;
audio_dev = uac->audio_dev;
params = &audio_dev->params;
p_ssize = params->p_ssize;
c_ssize = params->c_ssize;
- p_chmask = params->p_chmask;
- c_chmask = params->c_chmask;
uac->p_residue_mil = 0;
runtime->hw = uac_pcm_hardware;
if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
runtime->hw.formats = uac_ssize_to_fmt(p_ssize);
- runtime->hw.channels_min = num_channels(p_chmask);
+ runtime->hw.channels_min = params->p_channels;
prm = &uac->p_prm;
} else {
runtime->hw.formats = uac_ssize_to_fmt(c_ssize);
- runtime->hw.channels_min = num_channels(c_chmask);
+ runtime->hw.channels_min = params->c_channels;
prm = &uac->c_prm;
}
@@ -730,8 +727,7 @@ int u_audio_start_playback(struct g_audio *audio_dev)
factor = 8000;
/* pre-compute some values for iso_complete() */
- uac->p_framesize = params->p_ssize *
- num_channels(params->p_chmask);
+ uac->p_framesize = params->p_ssize * params->p_channels;
uac->p_interval = factor / (1 << (ep_desc->bInterval - 1));
p_pktsize = min_t(unsigned int,
uac->p_framesize *
@@ -1185,7 +1181,7 @@ int g_audio_setup(struct g_audio *g_audio, const char *pcm_name,
struct snd_pcm *pcm;
struct snd_kcontrol *kctl;
struct uac_params *params;
- int p_chmask, c_chmask;
+ unsigned int p_channels, c_channels;
int i, err;
if (!g_audio)
@@ -1198,10 +1194,10 @@ int g_audio_setup(struct g_audio *g_audio, const char *pcm_name,
uac->audio_dev = g_audio;
params = &g_audio->params;
- p_chmask = params->p_chmask;
- c_chmask = params->c_chmask;
+ p_channels = params->p_channels;
+ c_channels = params->c_channels;
- if (c_chmask) {
+ if (c_channels) {
struct uac_rtd_params *prm = &uac->c_prm;
spin_lock_init(&prm->lock);
@@ -1225,7 +1221,7 @@ int g_audio_setup(struct g_audio *g_audio, const char *pcm_name,
}
}
- if (p_chmask) {
+ if (p_channels) {
struct uac_rtd_params *prm = &uac->p_prm;
spin_lock_init(&prm->lock);
@@ -1262,7 +1258,7 @@ int g_audio_setup(struct g_audio *g_audio, const char *pcm_name,
* Create a substream only for non-zero channel streams
*/
err = snd_pcm_new(uac->card, pcm_name, 0,
- p_chmask ? 1 : 0, c_chmask ? 1 : 0, &pcm);
+ p_channels ? 1 : 0, c_channels ? 1 : 0, &pcm);
if (err < 0)
goto snd_fail;
@@ -1277,12 +1273,12 @@ int g_audio_setup(struct g_audio *g_audio, const char *pcm_name,
* Create mixer and controls
* Create only if it's required on USB side
*/
- if ((c_chmask && g_audio->in_ep_fback)
- || (p_chmask && params->p_fu.id)
- || (c_chmask && params->c_fu.id))
+ if ((c_channels && g_audio->in_ep_fback)
+ || (p_channels && params->p_fu.id)
+ || (c_channels && params->c_fu.id))
strscpy(card->mixername, card_name);
- if (c_chmask && g_audio->in_ep_fback) {
+ if (c_channels && g_audio->in_ep_fback) {
kctl = snd_ctl_new1(&u_audio_controls[UAC_FBACK_CTRL],
&uac->c_prm);
if (!kctl) {
@@ -1298,7 +1294,7 @@ int g_audio_setup(struct g_audio *g_audio, const char *pcm_name,
goto snd_fail;
}
- if (p_chmask) {
+ if (p_channels) {
kctl = snd_ctl_new1(&u_audio_controls[UAC_P_PITCH_CTRL],
&uac->p_prm);
if (!kctl) {
diff --git a/drivers/usb/gadget/function/u_audio.h b/drivers/usb/gadget/function/u_audio.h
index 9512b8fccfaa..46e1d6b5ca4e 100644
--- a/drivers/usb/gadget/function/u_audio.h
+++ b/drivers/usb/gadget/function/u_audio.h
@@ -41,12 +41,14 @@ struct uac_fu_params {
struct uac_params {
/* playback */
int p_chmask; /* channel mask */
+ unsigned int p_channels; /* resolved number of channels */
int p_srates[UAC_MAX_RATES]; /* available rates in Hz (0 terminated list) */
int p_ssize; /* sample size */
struct uac_fu_params p_fu; /* Feature Unit parameters */
/* capture */
int c_chmask; /* channel mask */
+ unsigned int c_channels; /* resolved number of channels */
int c_srates[UAC_MAX_RATES]; /* available rates in Hz (0 terminated list) */
int c_ssize; /* sample size */
struct uac_fu_params c_fu; /* Feature Unit parameters */
--
2.34.1
^ permalink raw reply related [flat|nested] 3+ messages in thread* [PATCH 2/2] usb: gadget: f_uac2: allow explicit channel counts
2026-07-29 5:41 [PATCH 0/2] usb: gadget: uac2: support explicit channel counts Kyle Farrell
2026-07-29 5:41 ` [PATCH 1/2] usb: gadget: u_audio: pass channel counts explicitly Kyle Farrell
@ 2026-07-29 5:41 ` Kyle Farrell
1 sibling, 0 replies; 3+ messages in thread
From: Kyle Farrell @ 2026-07-29 5:41 UTC (permalink / raw)
To: Greg Kroah-Hartman, linux-usb
Cc: Jonathan Corbet, Shuah Khan, linux-kernel, linux-doc,
Kyle Farrell
USB Audio 2.0 permits bNrChannels to be specified independently of
bmChannelConfig. In particular, a zero channel-location bitmap indicates
that all channels have non-predefined spatial positions. f_uac2 currently
derives bNrChannels from the number of bits set in bmChannelConfig. Since
the channel-location bitmap provides only 27 predefined speaker positions,
this limits a stream to 27 channels.
Preserve the existing *_chmask interface and semantics by introducing
separate ConfigFS attributes for explicit channel counts. Add p_channels
and c_channels configfs attributes to configure the playback and capture
channel counts explicitly. A value of zero, which is the default, continues
to derive the channel count from the corresponding channel mask. The
explicit count is represented by the 8-bit bNrChannels field, allowing
channel counts beyond the 27 predefined locations and up to the UAC2 limit
of 255.
Use the effective channel count throughout descriptor generation and stream
configuration while continuing to populate bmChannelConfig directly from
the configured channel mask.
To keep the ConfigFS interface simple, require a nonzero channel mask to
describe every channel when an explicit channel count is also specified.
Partial channel-location assignments permitted by the UAC2 specification
are therefore not supported. Also reject Feature Unit configurations whose
descriptor length would exceed the one-byte bLength field.
Signed-off-by: Kyle Farrell <kaf@nwlink.com>
---
.../ABI/testing/configfs-usb-gadget-uac2 | 18 ++++-
Documentation/usb/gadget-testing.rst | 18 ++++-
drivers/usb/gadget/function/f_uac2.c | 71 +++++++++++++------
drivers/usb/gadget/function/u_uac2.h | 4 ++
4 files changed, 87 insertions(+), 24 deletions(-)
diff --git a/Documentation/ABI/testing/configfs-usb-gadget-uac2 b/Documentation/ABI/testing/configfs-usb-gadget-uac2
index 133e995c3e92..8e264843e492 100644
--- a/Documentation/ABI/testing/configfs-usb-gadget-uac2
+++ b/Documentation/ABI/testing/configfs-usb-gadget-uac2
@@ -5,7 +5,14 @@ Description:
The attributes:
===================== =======================================
- c_chmask capture channel mask
+ c_chmask capture channel-location mask. The number of
+ capture channels is derived from the number of
+ set bits unless c_channels is specified.
+ c_channels explicit capture channel count. A value of 0
+ derives the channel count from c_chmask. When
+ nonzero, c_chmask specifies channel locations
+ and may be 0. If both c_channels and c_chmask
+ are nonzero, the values must agree.
c_srate list of capture sampling rates (comma-separated)
c_ssize capture sample size (bytes)
c_hs_bint capture bInterval for HS/SS (1-4: fixed, 0: auto)
@@ -20,7 +27,14 @@ Description:
c_volume_res capture volume control resolution
(in 1/256 dB)
fb_max maximum extra bandwidth in async mode
- p_chmask playback channel mask
+ p_chmask playback channel-location mask. The number of
+ playback channels is derived from the number of
+ set bits unless p_channels is specified.
+ p_channels explicit playback channel count. A value of 0
+ derives the channel count from p_chmask. When
+ nonzero, p_chmask specifies channel locations
+ and may be 0. If both p_channels and p_chmask
+ are nonzero, the values must agree.
p_srate list of playback sampling rates (comma-separated)
p_ssize playback sample size (bytes)
p_hs_bint playback bInterval for HS/SS (1-4: fixed, 0: auto)
diff --git a/Documentation/usb/gadget-testing.rst b/Documentation/usb/gadget-testing.rst
index a6e8292f320a..8fa778a2ed15 100644
--- a/Documentation/usb/gadget-testing.rst
+++ b/Documentation/usb/gadget-testing.rst
@@ -744,7 +744,14 @@ The function name to use when creating the function directory is "uac2".
The uac2 function provides these attributes in its function directory:
================ ====================================================
- c_chmask capture channel mask
+ c_chmask capture channel-location mask. The number of
+ capture channels is derived from the number of
+ set bits unless c_channels is specified.
+ c_channels explicit capture channel count. A value of 0
+ derives the channel count from c_chmask. When
+ nonzero, c_chmask specifies channel locations
+ and may be 0. If both c_channels and c_chmask
+ are nonzero, the values must agree.
c_srate list of capture sampling rates (comma-separated)
c_ssize capture sample size (bytes)
c_sync capture synchronization type (async/adaptive)
@@ -755,7 +762,14 @@ The uac2 function provides these attributes in its function directory:
c_volume_res capture volume control resolution (in 1/256 dB)
c_hs_bint capture bInterval for HS/SS (1-4: fixed, 0: auto)
fb_max maximum extra bandwidth in async mode
- p_chmask playback channel mask
+ p_chmask playback channel-location mask. The number of
+ playback channels is derived from the number of
+ set bits unless p_channels is specified.
+ p_channels explicit playback channel count. A value of 0
+ derives the channel count from p_chmask. When
+ nonzero, p_chmask specifies channel locations
+ and may be 0. If both p_channels and p_chmask
+ are nonzero, the values must agree.
p_srate list of playback sampling rates (comma-separated)
p_ssize playback sample size (bytes)
p_mute_present playback mute control enable
diff --git a/drivers/usb/gadget/function/f_uac2.c b/drivers/usb/gadget/function/f_uac2.c
index b8735b9065c3..fab4c5bcb11b 100644
--- a/drivers/usb/gadget/function/f_uac2.c
+++ b/drivers/usb/gadget/function/f_uac2.c
@@ -50,8 +50,17 @@
#define UNFLW_CTRL 8
#define OVFLW_CTRL 10
-#define EPIN_EN(_opts) ((_opts)->p_chmask != 0)
-#define EPOUT_EN(_opts) ((_opts)->c_chmask != 0)
+static unsigned int uac2_num_channels(bool is_playback,
+ const struct f_uac2_opts *opts)
+{
+ u8 channels = is_playback ? opts->p_channels : opts->c_channels;
+ u32 chmask = is_playback ? opts->p_chmask : opts->c_chmask;
+
+ return channels ? channels : num_channels(chmask);
+}
+
+#define EPIN_EN(_opts) (uac2_num_channels(true, (_opts)) != 0)
+#define EPOUT_EN(_opts) (uac2_num_channels(false, (_opts)) != 0)
#define FUIN_EN(_opts) (EPIN_EN(_opts) \
&& ((_opts)->p_mute_present \
|| (_opts)->p_volume_present))
@@ -671,15 +680,16 @@ static int get_max_srate(const int *srates)
static int get_max_bw_for_bint(const struct f_uac2_opts *uac2_opts,
u8 bint, unsigned int factor, bool is_playback)
{
- int chmask, srate, ssize;
+ unsigned int channels;
+ int srate, ssize;
u16 max_size_bw;
if (is_playback) {
- chmask = uac2_opts->p_chmask;
+ channels = uac2_num_channels(true, uac2_opts);
srate = get_max_srate(uac2_opts->p_srates);
ssize = uac2_opts->p_ssize;
} else {
- chmask = uac2_opts->c_chmask;
+ channels = uac2_num_channels(false, uac2_opts);
srate = get_max_srate(uac2_opts->c_srates);
ssize = uac2_opts->c_ssize;
}
@@ -689,11 +699,11 @@ static int get_max_bw_for_bint(const struct f_uac2_opts *uac2_opts,
// Win10 requires max packet size + 1 frame
srate = srate * (1000 + uac2_opts->fb_max) / 1000;
// updated srate is always bigger, therefore DIV_ROUND_UP always yields +1
- max_size_bw = num_channels(chmask) * ssize *
+ max_size_bw = channels * ssize *
(DIV_ROUND_UP(srate, factor / (1 << (bint - 1))));
} else {
// adding 1 frame provision for Win10
- max_size_bw = num_channels(chmask) * ssize *
+ max_size_bw = channels * ssize *
(DIV_ROUND_UP(srate, factor / (1 << (bint - 1))) + 1);
}
return max_size_bw;
@@ -764,10 +774,11 @@ static int set_ep_max_packet_size_bint(struct device *dev, const struct f_uac2_o
return 0;
}
-static struct uac2_feature_unit_descriptor *build_fu_desc(int chmask)
+static struct uac2_feature_unit_descriptor *build_fu_desc(bool is_playback,
+ const struct f_uac2_opts *opts)
{
struct uac2_feature_unit_descriptor *fu_desc;
- int channels = num_channels(chmask);
+ unsigned int channels = uac2_num_channels(is_playback, opts);
int fu_desc_size = UAC2_DT_FEATURE_UNIT_SIZE(channels);
fu_desc = kzalloc(fu_desc_size, GFP_KERNEL);
@@ -976,13 +987,27 @@ static int afunc_validate_opts(struct g_audio *agdev, struct device *dev)
{
struct f_uac2_opts *opts = g_audio_to_uac2_opts(agdev);
const char *msg = NULL;
+ unsigned int p_channels = uac2_num_channels(true, opts);
+ unsigned int c_channels = uac2_num_channels(false, opts);
- if (!opts->p_chmask && !opts->c_chmask)
- msg = "no playback and capture channels";
- else if (opts->p_chmask & ~UAC2_CHANNEL_MASK)
+ if (opts->p_chmask & ~UAC2_CHANNEL_MASK)
msg = "unsupported playback channels mask";
else if (opts->c_chmask & ~UAC2_CHANNEL_MASK)
msg = "unsupported capture channels mask";
+ else if (!p_channels && !c_channels)
+ msg = "no playback and capture channels";
+ else if (opts->p_channels && opts->p_chmask &&
+ opts->p_channels != num_channels(opts->p_chmask))
+ msg = "playback channel count does not match channel mask";
+ else if (opts->c_channels && opts->c_chmask &&
+ opts->c_channels != num_channels(opts->c_chmask))
+ msg = "capture channel count does not match channel mask";
+ else if (FUIN_EN(opts) &&
+ UAC2_DT_FEATURE_UNIT_SIZE(p_channels) > U8_MAX)
+ msg = "too many playback channels for feature unit descriptor";
+ else if (FUOUT_EN(opts) &&
+ UAC2_DT_FEATURE_UNIT_SIZE(c_channels) > U8_MAX)
+ msg = "too many capture channels for feature unit descriptor";
else if ((opts->p_ssize < 1) || (opts->p_ssize > 4))
msg = "incorrect playback sample size";
else if ((opts->c_ssize < 1) || (opts->c_ssize > 4))
@@ -1059,12 +1084,12 @@ afunc_bind(struct usb_configuration *cfg, struct usb_function *fn)
return PTR_ERR(us);
if (FUOUT_EN(uac2_opts)) {
- out_feature_unit_desc = build_fu_desc(uac2_opts->c_chmask);
+ out_feature_unit_desc = build_fu_desc(false, uac2_opts);
if (!out_feature_unit_desc)
return -ENOMEM;
}
if (FUIN_EN(uac2_opts)) {
- in_feature_unit_desc = build_fu_desc(uac2_opts->p_chmask);
+ in_feature_unit_desc = build_fu_desc(true, uac2_opts);
if (!in_feature_unit_desc) {
ret = -ENOMEM;
goto err_free_fu;
@@ -1099,13 +1124,13 @@ afunc_bind(struct usb_configuration *cfg, struct usb_function *fn)
/* Initialize the configurable parameters */
- usb_out_it_desc.bNrChannels = num_channels(uac2_opts->c_chmask);
+ usb_out_it_desc.bNrChannels = uac2_num_channels(false, uac2_opts);
usb_out_it_desc.bmChannelConfig = cpu_to_le32(uac2_opts->c_chmask);
- io_in_it_desc.bNrChannels = num_channels(uac2_opts->p_chmask);
+ io_in_it_desc.bNrChannels = uac2_num_channels(true, uac2_opts);
io_in_it_desc.bmChannelConfig = cpu_to_le32(uac2_opts->p_chmask);
- as_out_hdr_desc.bNrChannels = num_channels(uac2_opts->c_chmask);
+ as_out_hdr_desc.bNrChannels = uac2_num_channels(false, uac2_opts);
as_out_hdr_desc.bmChannelConfig = cpu_to_le32(uac2_opts->c_chmask);
- as_in_hdr_desc.bNrChannels = num_channels(uac2_opts->p_chmask);
+ as_in_hdr_desc.bNrChannels = uac2_num_channels(true, uac2_opts);
as_in_hdr_desc.bmChannelConfig = cpu_to_le32(uac2_opts->p_chmask);
as_out_fmt1_desc.bSubslotSize = uac2_opts->c_ssize;
as_out_fmt1_desc.bBitResolution = uac2_opts->c_ssize * 8;
@@ -1308,7 +1333,7 @@ afunc_bind(struct usb_configuration *cfg, struct usb_function *fn)
agdev->gadget = gadget;
agdev->params.p_chmask = uac2_opts->p_chmask;
- agdev->params.p_channels = num_channels(uac2_opts->p_chmask);
+ agdev->params.p_channels = uac2_num_channels(true, uac2_opts);
memcpy(agdev->params.p_srates, uac2_opts->p_srates,
sizeof(agdev->params.p_srates));
agdev->params.p_ssize = uac2_opts->p_ssize;
@@ -1321,7 +1346,7 @@ afunc_bind(struct usb_configuration *cfg, struct usb_function *fn)
agdev->params.p_fu.volume_res = uac2_opts->p_volume_res;
}
agdev->params.c_chmask = uac2_opts->c_chmask;
- agdev->params.c_channels = num_channels(uac2_opts->c_chmask);
+ agdev->params.c_channels = uac2_num_channels(false, uac2_opts);
memcpy(agdev->params.c_srates, uac2_opts->c_srates,
sizeof(agdev->params.c_srates));
agdev->params.c_ssize = uac2_opts->c_ssize;
@@ -2086,10 +2111,12 @@ end: \
CONFIGFS_ATTR(f_uac2_opts_, name)
UAC2_ATTRIBUTE(u32, p_chmask);
+UAC2_ATTRIBUTE(u8, p_channels);
UAC2_RATE_ATTRIBUTE(p_srate);
UAC2_ATTRIBUTE(u32, p_ssize);
UAC2_ATTRIBUTE(u8, p_hs_bint);
UAC2_ATTRIBUTE(u32, c_chmask);
+UAC2_ATTRIBUTE(u8, c_channels);
UAC2_RATE_ATTRIBUTE(c_srate);
UAC2_ATTRIBUTE_SYNC(c_sync);
UAC2_ATTRIBUTE(u32, c_ssize);
@@ -2129,10 +2156,12 @@ UAC2_ATTRIBUTE(s16, c_terminal_type);
static struct configfs_attribute *f_uac2_attrs[] = {
&f_uac2_opts_attr_p_chmask,
+ &f_uac2_opts_attr_p_channels,
&f_uac2_opts_attr_p_srate,
&f_uac2_opts_attr_p_ssize,
&f_uac2_opts_attr_p_hs_bint,
&f_uac2_opts_attr_c_chmask,
+ &f_uac2_opts_attr_c_channels,
&f_uac2_opts_attr_c_srate,
&f_uac2_opts_attr_c_ssize,
&f_uac2_opts_attr_c_hs_bint,
@@ -2202,10 +2231,12 @@ static struct usb_function_instance *afunc_alloc_inst(void)
&f_uac2_func_type);
opts->p_chmask = UAC2_DEF_PCHMASK;
+ opts->p_channels = UAC2_DEF_PCHANNELS;
opts->p_srates[0] = UAC2_DEF_PSRATE;
opts->p_ssize = UAC2_DEF_PSSIZE;
opts->p_hs_bint = UAC2_DEF_PHSBINT;
opts->c_chmask = UAC2_DEF_CCHMASK;
+ opts->c_channels = UAC2_DEF_CCHANNELS;
opts->c_srates[0] = UAC2_DEF_CSRATE;
opts->c_ssize = UAC2_DEF_CSSIZE;
opts->c_hs_bint = UAC2_DEF_CHSBINT;
diff --git a/drivers/usb/gadget/function/u_uac2.h b/drivers/usb/gadget/function/u_uac2.h
index 0df808289ded..bacd841c9df6 100644
--- a/drivers/usb/gadget/function/u_uac2.h
+++ b/drivers/usb/gadget/function/u_uac2.h
@@ -17,10 +17,12 @@
#include "uac_common.h"
#define UAC2_DEF_PCHMASK 0x3
+#define UAC2_DEF_PCHANNELS 0 /* 0 = derive from p_chmask */
#define UAC2_DEF_PSRATE 48000
#define UAC2_DEF_PSSIZE 2
#define UAC2_DEF_PHSBINT 0
#define UAC2_DEF_CCHMASK 0x3
+#define UAC2_DEF_CCHANNELS 0 /* 0 = derive from c_chmask */
#define UAC2_DEF_CSRATE 64000
#define UAC2_DEF_CSSIZE 2
#define UAC2_DEF_CHSBINT 0
@@ -46,11 +48,13 @@ struct f_uac2_opts {
int p_srates[UAC_MAX_RATES];
int p_ssize;
u8 p_hs_bint;
+ u8 p_channels;
int c_chmask;
int c_srates[UAC_MAX_RATES];
int c_ssize;
int c_sync;
u8 c_hs_bint;
+ u8 c_channels;
bool p_mute_present;
bool p_volume_present;
--
2.34.1
^ permalink raw reply related [flat|nested] 3+ messages in thread