[PATCH v4 3/3] usb: gadget: add f_uac1 variant based on a new u_audio api

From: Ruslan Bilovol
Date: Wed May 17 2017 - 18:38:04 EST


This patch adds a new function 'f_uac1_acard'
(f_uac1 with virtual "ALSA card") that
uses recently created u_audio API. Comparing
to legacy f_uac1 function implementation it
doesn't require any real Audio codec to be
present on the device. In f_uac1_acard audio
streams are simply sinked to and sourced
from a virtual ALSA sound card created
using u_audio API.

Legacy f_uac1 approach is to write audio
samples directly to existing ALSA sound
card

f_uac1_acard approach is more generic/flexible
one - create an ALSA sound card that
represents USB Audio function and allows to
be used by userspace application that
may choose to do whatever it wants with the
data received from the USB Host and choose
to provide whatever it wants as audio data
to the USB Host.

f_uac1_acard also has capture support (gadget->host)
thanks to easy implementation via u_audio.
By default, capture interface has 48000kHz/2ch
configuration, same as playback channel has.

f_uac1_acard descriptors naming convention
uses f_uac2 driver naming convention that
makes it more common and meaningful.

Comparing to f_uac1, the f_uac1_acard doesn't
have volume/mute functionality. This is because
the f_uac1 volume/mute feature unit was dummy
implementation since that driver creation (2009)
and never had any real volume control or mute
functionality, so there is no any difference
here.

Since f_uac1_acard functionality, exposed
interface to userspace (virtual ALSA card),
input parameters are so different comparing
to legace f_uac1, that there is no any
reason to keep them in the same file/module,
and separate function was created.

g_audio can be built using one of existing
UAC functions (f_uac1, f_uac1_acard or f_uac2)

Signed-off-by: Ruslan Bilovol <ruslan.bilovol@xxxxxxxxx>
---
.../ABI/testing/configfs-usb-gadget-uac1_acard | 14 +
Documentation/usb/gadget-testing.txt | 45 ++
drivers/usb/gadget/Kconfig | 21 +
drivers/usb/gadget/function/Makefile | 2 +
drivers/usb/gadget/function/f_uac1_acard.c | 803 +++++++++++++++++++++
drivers/usb/gadget/function/u_uac1_acard.h | 41 ++
drivers/usb/gadget/legacy/Kconfig | 15 +-
drivers/usb/gadget/legacy/audio.c | 53 ++
8 files changed, 992 insertions(+), 2 deletions(-)
create mode 100644 Documentation/ABI/testing/configfs-usb-gadget-uac1_acard
create mode 100644 drivers/usb/gadget/function/f_uac1_acard.c
create mode 100644 drivers/usb/gadget/function/u_uac1_acard.h

diff --git a/Documentation/ABI/testing/configfs-usb-gadget-uac1_acard b/Documentation/ABI/testing/configfs-usb-gadget-uac1_acard
new file mode 100644
index 0000000..2cffeaa
--- /dev/null
+++ b/Documentation/ABI/testing/configfs-usb-gadget-uac1_acard
@@ -0,0 +1,14 @@
+What: /config/usb-gadget/gadget/functions/uac1_acard.name
+Date: May 2017
+KernelVersion: 4.13
+Description:
+ The attributes:
+
+ c_chmask - capture channel mask
+ c_srate - capture sampling rate
+ c_ssize - capture sample size (bytes)
+ p_chmask - playback channel mask
+ p_srate - playback sampling rate
+ p_ssize - playback sample size (bytes)
+ req_number - the number of pre-allocated request
+ for both capture and playback
diff --git a/Documentation/usb/gadget-testing.txt b/Documentation/usb/gadget-testing.txt
index fb0cc4d..ecff3ec 100644
--- a/Documentation/usb/gadget-testing.txt
+++ b/Documentation/usb/gadget-testing.txt
@@ -20,6 +20,7 @@ provided by gadgets.
17. UAC2 function
18. UVC function
19. PRINTER function
+20. UAC1 function (new API)


1. ACM function
@@ -772,3 +773,47 @@ host:

More advanced testing can be done with the prn_example
described in Documentation/usb/gadget-printer.txt.
+
+
+20. UAC1 function (virtual ALSA card, using u_audio API)
+=================
+
+The function is provided by usb_f_uac1_acard.ko module.
+It will create a virtual ALSA card and the audio streams are simply
+sinked to and sourced from it.
+
+Function-specific configfs interface
+------------------------------------
+
+The function name to use when creating the function directory
+is "uac1_acard". The uac1_acard function provides these attributes
+in its function directory:
+
+ c_chmask - capture channel mask
+ c_srate - capture sampling rate
+ c_ssize - capture sample size (bytes)
+ p_chmask - playback channel mask
+ p_srate - playback sampling rate
+ p_ssize - playback sample size (bytes)
+ req_number - the number of pre-allocated request for both capture
+ and playback
+
+The attributes have sane default values.
+
+Testing the UAC1 function
+-------------------------
+
+device: run the gadget
+host: aplay -l # should list our USB Audio Gadget
+
+This function does not require real hardware support, it just
+sends a stream of audio data to/from the host. In order to
+actually hear something at the device side, a command similar
+to this must be used at the device side:
+
+$ arecord -f dat -t wav -D hw:2,0 | aplay -D hw:0,0 &
+
+e.g.:
+
+$ arecord -f dat -t wav -D hw:CARD=UAC1Gadget,DEV=0 | \
+aplay -D default:CARD=OdroidU3
diff --git a/drivers/usb/gadget/Kconfig b/drivers/usb/gadget/Kconfig
index 2ba0ace..765089c 100644
--- a/drivers/usb/gadget/Kconfig
+++ b/drivers/usb/gadget/Kconfig
@@ -194,6 +194,9 @@ config USB_F_FS
config USB_F_UAC1
tristate

+config USB_F_UAC1_ACARD
+ tristate
+
config USB_F_UAC2
tristate

@@ -378,6 +381,24 @@ config USB_CONFIGFS_F_UAC1
This driver requires a real Audio codec to be present
on the device.

+config USB_CONFIGFS_F_UAC1_ACARD
+ bool "Audio Class 1.0 (Virtual ALSA Card)"
+ depends on USB_CONFIGFS
+ depends on SND
+ select USB_LIBCOMPOSITE
+ select SND_PCM
+ select USB_U_AUDIO
+ select USB_F_UAC1_ACARD
+ help
+ This Audio function implements 1 AudioControl interface,
+ 1 AudioStreaming Interface each for USB-OUT and USB-IN.
+ This driver doesn't expect any real Audio codec to be present
+ on the device - the audio streams are simply sinked to and
+ sourced from a virtual ALSA sound card created. The user-space
+ application may choose to do whatever it wants with the data
+ received from the USB Host and choose to provide whatever it
+ wants as audio data to the USB Host.
+
config USB_CONFIGFS_F_UAC2
bool "Audio Class 2.0"
depends on USB_CONFIGFS
diff --git a/drivers/usb/gadget/function/Makefile b/drivers/usb/gadget/function/Makefile
index b29f2ae..04ccde4 100644
--- a/drivers/usb/gadget/function/Makefile
+++ b/drivers/usb/gadget/function/Makefile
@@ -35,6 +35,8 @@ obj-$(CONFIG_USB_F_FS) += usb_f_fs.o
obj-$(CONFIG_USB_U_AUDIO) += u_audio.o
usb_f_uac1-y := f_uac1.o u_uac1.o
obj-$(CONFIG_USB_F_UAC1) += usb_f_uac1.o
+usb_f_uac1_acard-y := f_uac1_acard.o
+obj-$(CONFIG_USB_F_UAC1_ACARD) += usb_f_uac1_acard.o
usb_f_uac2-y := f_uac2.o
obj-$(CONFIG_USB_F_UAC2) += usb_f_uac2.o
usb_f_uvc-y := f_uvc.o uvc_queue.o uvc_v4l2.o uvc_video.o uvc_configfs.o
diff --git a/drivers/usb/gadget/function/f_uac1_acard.c b/drivers/usb/gadget/function/f_uac1_acard.c
new file mode 100644
index 0000000..a329f94
--- /dev/null
+++ b/drivers/usb/gadget/function/f_uac1_acard.c
@@ -0,0 +1,803 @@
+/*
+ * f_uac1_acard.c -- USB Audio Class 1.0 Function (using u_audio API)
+ *
+ * Copyright (C) 2016 Ruslan Bilovol <ruslan.bilovol@xxxxxxxxx>
+ *
+ * This driver doesn't expect any real Audio codec to be present
+ * on the device - the audio streams are simply sinked to and
+ * sourced from a virtual ALSA sound card created.
+ *
+ * This file is based on f_uac1.c which is
+ * Copyright (C) 2008 Bryan Wu <cooloney@xxxxxxxxxx>
+ * Copyright (C) 2008 Analog Devices, Inc
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+#include <linux/usb/audio.h>
+#include <linux/module.h>
+
+#include "u_audio.h"
+#include "u_uac1_acard.h"
+
+struct f_uac1 {
+ struct g_audio g_audio;
+ u8 ac_intf, as_in_intf, as_out_intf;
+ u8 ac_alt, as_in_alt, as_out_alt; /* needed for get_alt() */
+};
+
+static inline struct f_uac1 *func_to_uac1(struct usb_function *f)
+{
+ return container_of(f, struct f_uac1, g_audio.func);
+}
+
+/*
+ * DESCRIPTORS ... most are static, but strings and full
+ * configuration descriptors are built on demand.
+ */
+
+/*
+ * We have three interfaces - one AudioControl and two AudioStreaming
+ *
+ * The driver implements a simple UAC_1 topology.
+ * USB-OUT -> IT_1 -> OT_2 -> ALSA_Capture
+ * ALSA_Playback -> IT_3 -> OT_4 -> USB-IN
+ */
+#define F_AUDIO_AC_INTERFACE 0
+#define F_AUDIO_AS_OUT_INTERFACE 1
+#define F_AUDIO_AS_IN_INTERFACE 2
+/* Number of streaming interfaces */
+#define F_AUDIO_NUM_INTERFACES 2
+
+/* B.3.1 Standard AC Interface Descriptor */
+static struct usb_interface_descriptor ac_interface_desc = {
+ .bLength = USB_DT_INTERFACE_SIZE,
+ .bDescriptorType = USB_DT_INTERFACE,
+ .bNumEndpoints = 0,
+ .bInterfaceClass = USB_CLASS_AUDIO,
+ .bInterfaceSubClass = USB_SUBCLASS_AUDIOCONTROL,
+};
+
+/*
+ * The number of AudioStreaming and MIDIStreaming interfaces
+ * in the Audio Interface Collection
+ */
+DECLARE_UAC_AC_HEADER_DESCRIPTOR(2);
+
+#define UAC_DT_AC_HEADER_LENGTH UAC_DT_AC_HEADER_SIZE(F_AUDIO_NUM_INTERFACES)
+/* 2 input terminals and 2 output terminals */
+#define UAC_DT_TOTAL_LENGTH (UAC_DT_AC_HEADER_LENGTH \
+ + 2*UAC_DT_INPUT_TERMINAL_SIZE + 2*UAC_DT_OUTPUT_TERMINAL_SIZE)
+/* B.3.2 Class-Specific AC Interface Descriptor */
+static struct uac1_ac_header_descriptor_2 ac_header_desc = {
+ .bLength = UAC_DT_AC_HEADER_LENGTH,
+ .bDescriptorType = USB_DT_CS_INTERFACE,
+ .bDescriptorSubtype = UAC_HEADER,
+ .bcdADC = cpu_to_le16(0x0100),
+ .wTotalLength = cpu_to_le16(UAC_DT_TOTAL_LENGTH),
+ .bInCollection = F_AUDIO_NUM_INTERFACES,
+ .baInterfaceNr = {
+ /* Interface number of the AudioStream interfaces */
+ [0] = 1,
+ [1] = 2,
+ }
+};
+
+#define USB_OUT_IT_ID 1
+static struct uac_input_terminal_descriptor usb_out_it_desc = {
+ .bLength = UAC_DT_INPUT_TERMINAL_SIZE,
+ .bDescriptorType = USB_DT_CS_INTERFACE,
+ .bDescriptorSubtype = UAC_INPUT_TERMINAL,
+ .bTerminalID = USB_OUT_IT_ID,
+ .wTerminalType = UAC_TERMINAL_STREAMING,
+ .bAssocTerminal = 0,
+ .wChannelConfig = 0x3,
+};
+
+#define IO_OUT_OT_ID 2
+static struct uac1_output_terminal_descriptor io_out_ot_desc = {
+ .bLength = UAC_DT_OUTPUT_TERMINAL_SIZE,
+ .bDescriptorType = USB_DT_CS_INTERFACE,
+ .bDescriptorSubtype = UAC_OUTPUT_TERMINAL,
+ .bTerminalID = IO_OUT_OT_ID,
+ .wTerminalType = UAC_OUTPUT_TERMINAL_SPEAKER,
+ .bAssocTerminal = 0,
+ .bSourceID = USB_OUT_IT_ID,
+};
+
+#define IO_IN_IT_ID 3
+static struct uac_input_terminal_descriptor io_in_it_desc = {
+ .bLength = UAC_DT_INPUT_TERMINAL_SIZE,
+ .bDescriptorType = USB_DT_CS_INTERFACE,
+ .bDescriptorSubtype = UAC_INPUT_TERMINAL,
+ .bTerminalID = IO_IN_IT_ID,
+ .wTerminalType = UAC_INPUT_TERMINAL_MICROPHONE,
+ .bAssocTerminal = 0,
+ .wChannelConfig = 0x3,
+};
+
+#define USB_IN_OT_ID 4
+static struct uac1_output_terminal_descriptor usb_in_ot_desc = {
+ .bLength = UAC_DT_OUTPUT_TERMINAL_SIZE,
+ .bDescriptorType = USB_DT_CS_INTERFACE,
+ .bDescriptorSubtype = UAC_OUTPUT_TERMINAL,
+ .bTerminalID = USB_IN_OT_ID,
+ .wTerminalType = UAC_TERMINAL_STREAMING,
+ .bAssocTerminal = 0,
+ .bSourceID = IO_IN_IT_ID,
+};
+
+/* B.4.1 Standard AS Interface Descriptor */
+static struct usb_interface_descriptor as_out_interface_alt_0_desc = {
+ .bLength = USB_DT_INTERFACE_SIZE,
+ .bDescriptorType = USB_DT_INTERFACE,
+ .bAlternateSetting = 0,
+ .bNumEndpoints = 0,
+ .bInterfaceClass = USB_CLASS_AUDIO,
+ .bInterfaceSubClass = USB_SUBCLASS_AUDIOSTREAMING,
+};
+
+static struct usb_interface_descriptor as_out_interface_alt_1_desc = {
+ .bLength = USB_DT_INTERFACE_SIZE,
+ .bDescriptorType = USB_DT_INTERFACE,
+ .bAlternateSetting = 1,
+ .bNumEndpoints = 1,
+ .bInterfaceClass = USB_CLASS_AUDIO,
+ .bInterfaceSubClass = USB_SUBCLASS_AUDIOSTREAMING,
+};
+
+static struct usb_interface_descriptor as_in_interface_alt_0_desc = {
+ .bLength = USB_DT_INTERFACE_SIZE,
+ .bDescriptorType = USB_DT_INTERFACE,
+ .bAlternateSetting = 0,
+ .bNumEndpoints = 0,
+ .bInterfaceClass = USB_CLASS_AUDIO,
+ .bInterfaceSubClass = USB_SUBCLASS_AUDIOSTREAMING,
+};
+
+static struct usb_interface_descriptor as_in_interface_alt_1_desc = {
+ .bLength = USB_DT_INTERFACE_SIZE,
+ .bDescriptorType = USB_DT_INTERFACE,
+ .bAlternateSetting = 1,
+ .bNumEndpoints = 1,
+ .bInterfaceClass = USB_CLASS_AUDIO,
+ .bInterfaceSubClass = USB_SUBCLASS_AUDIOSTREAMING,
+};
+
+/* B.4.2 Class-Specific AS Interface Descriptor */
+static struct uac1_as_header_descriptor as_out_header_desc = {
+ .bLength = UAC_DT_AS_HEADER_SIZE,
+ .bDescriptorType = USB_DT_CS_INTERFACE,
+ .bDescriptorSubtype = UAC_AS_GENERAL,
+ .bTerminalLink = USB_OUT_IT_ID,
+ .bDelay = 1,
+ .wFormatTag = UAC_FORMAT_TYPE_I_PCM,
+};
+
+static struct uac1_as_header_descriptor as_in_header_desc = {
+ .bLength = UAC_DT_AS_HEADER_SIZE,
+ .bDescriptorType = USB_DT_CS_INTERFACE,
+ .bDescriptorSubtype = UAC_AS_GENERAL,
+ .bTerminalLink = USB_IN_OT_ID,
+ .bDelay = 1,
+ .wFormatTag = UAC_FORMAT_TYPE_I_PCM,
+};
+
+DECLARE_UAC_FORMAT_TYPE_I_DISCRETE_DESC(1);
+
+static struct uac_format_type_i_discrete_descriptor_1 as_out_type_i_desc = {
+ .bLength = UAC_FORMAT_TYPE_I_DISCRETE_DESC_SIZE(1),
+ .bDescriptorType = USB_DT_CS_INTERFACE,
+ .bDescriptorSubtype = UAC_FORMAT_TYPE,
+ .bFormatType = UAC_FORMAT_TYPE_I,
+ .bSubframeSize = 2,
+ .bBitResolution = 16,
+ .bSamFreqType = 1,
+};
+
+/* Standard ISO OUT Endpoint Descriptor */
+static struct usb_endpoint_descriptor as_out_ep_desc = {
+ .bLength = USB_DT_ENDPOINT_AUDIO_SIZE,
+ .bDescriptorType = USB_DT_ENDPOINT,
+ .bEndpointAddress = USB_DIR_OUT,
+ .bmAttributes = USB_ENDPOINT_SYNC_ADAPTIVE
+ | USB_ENDPOINT_XFER_ISOC,
+ .wMaxPacketSize = cpu_to_le16(UAC1_OUT_EP_MAX_PACKET_SIZE),
+ .bInterval = 4,
+};
+
+/* Class-specific AS ISO OUT Endpoint Descriptor */
+static struct uac_iso_endpoint_descriptor as_iso_out_desc = {
+ .bLength = UAC_ISO_ENDPOINT_DESC_SIZE,
+ .bDescriptorType = USB_DT_CS_ENDPOINT,
+ .bDescriptorSubtype = UAC_EP_GENERAL,
+ .bmAttributes = 1,
+ .bLockDelayUnits = 1,
+ .wLockDelay = cpu_to_le16(1),
+};
+
+static struct uac_format_type_i_discrete_descriptor_1 as_in_type_i_desc = {
+ .bLength = UAC_FORMAT_TYPE_I_DISCRETE_DESC_SIZE(1),
+ .bDescriptorType = USB_DT_CS_INTERFACE,
+ .bDescriptorSubtype = UAC_FORMAT_TYPE,
+ .bFormatType = UAC_FORMAT_TYPE_I,
+ .bSubframeSize = 2,
+ .bBitResolution = 16,
+ .bSamFreqType = 1,
+};
+
+/* Standard ISO OUT Endpoint Descriptor */
+static struct usb_endpoint_descriptor as_in_ep_desc = {
+ .bLength = USB_DT_ENDPOINT_AUDIO_SIZE,
+ .bDescriptorType = USB_DT_ENDPOINT,
+ .bEndpointAddress = USB_DIR_IN,
+ .bmAttributes = USB_ENDPOINT_SYNC_ASYNC
+ | USB_ENDPOINT_XFER_ISOC,
+ .wMaxPacketSize = cpu_to_le16(UAC1_OUT_EP_MAX_PACKET_SIZE),
+ .bInterval = 4,
+};
+
+/* Class-specific AS ISO OUT Endpoint Descriptor */
+static struct uac_iso_endpoint_descriptor as_iso_in_desc = {
+ .bLength = UAC_ISO_ENDPOINT_DESC_SIZE,
+ .bDescriptorType = USB_DT_CS_ENDPOINT,
+ .bDescriptorSubtype = UAC_EP_GENERAL,
+ .bmAttributes = 1,
+ .bLockDelayUnits = 0,
+ .wLockDelay = 0,
+};
+
+static struct usb_descriptor_header *f_audio_desc[] = {
+ (struct usb_descriptor_header *)&ac_interface_desc,
+ (struct usb_descriptor_header *)&ac_header_desc,
+
+ (struct usb_descriptor_header *)&usb_out_it_desc,
+ (struct usb_descriptor_header *)&io_out_ot_desc,
+ (struct usb_descriptor_header *)&io_in_it_desc,
+ (struct usb_descriptor_header *)&usb_in_ot_desc,
+
+ (struct usb_descriptor_header *)&as_out_interface_alt_0_desc,
+ (struct usb_descriptor_header *)&as_out_interface_alt_1_desc,
+ (struct usb_descriptor_header *)&as_out_header_desc,
+
+ (struct usb_descriptor_header *)&as_out_type_i_desc,
+
+ (struct usb_descriptor_header *)&as_out_ep_desc,
+ (struct usb_descriptor_header *)&as_iso_out_desc,
+
+ (struct usb_descriptor_header *)&as_in_interface_alt_0_desc,
+ (struct usb_descriptor_header *)&as_in_interface_alt_1_desc,
+ (struct usb_descriptor_header *)&as_in_header_desc,
+
+ (struct usb_descriptor_header *)&as_in_type_i_desc,
+
+ (struct usb_descriptor_header *)&as_in_ep_desc,
+ (struct usb_descriptor_header *)&as_iso_in_desc,
+ NULL,
+};
+
+enum {
+ STR_AC_IF,
+ STR_USB_OUT_IT,
+ STR_USB_OUT_IT_CH_NAMES,
+ STR_IO_OUT_OT,
+ STR_IO_IN_IT,
+ STR_IO_IN_IT_CH_NAMES,
+ STR_USB_IN_OT,
+ STR_AS_OUT_IF_ALT0,
+ STR_AS_OUT_IF_ALT1,
+ STR_AS_IN_IF_ALT0,
+ STR_AS_IN_IF_ALT1,
+};
+
+static struct usb_string strings_uac1[] = {
+ [STR_AC_IF].s = "AC Interface",
+ [STR_USB_OUT_IT].s = "Playback Input terminal",
+ [STR_USB_OUT_IT_CH_NAMES].s = "Playback Channels",
+ [STR_IO_OUT_OT].s = "Playback Output terminal",
+ [STR_IO_IN_IT].s = "Capture Input terminal",
+ [STR_IO_IN_IT_CH_NAMES].s = "Capture Channels",
+ [STR_USB_IN_OT].s = "Capture Output terminal",
+ [STR_AS_OUT_IF_ALT0].s = "Playback Inactive",
+ [STR_AS_OUT_IF_ALT1].s = "Playback Active",
+ [STR_AS_IN_IF_ALT0].s = "Capture Inactive",
+ [STR_AS_IN_IF_ALT1].s = "Capture Active",
+ { },
+};
+
+static struct usb_gadget_strings str_uac1 = {
+ .language = 0x0409, /* en-us */
+ .strings = strings_uac1,
+};
+
+static struct usb_gadget_strings *uac1_strings[] = {
+ &str_uac1,
+ NULL,
+};
+
+/*
+ * This function is an ALSA sound card following USB Audio Class Spec 1.0.
+ */
+
+static int audio_set_endpoint_req(struct usb_function *f,
+ const struct usb_ctrlrequest *ctrl)
+{
+ struct usb_composite_dev *cdev = f->config->cdev;
+ int value = -EOPNOTSUPP;
+ u16 ep = le16_to_cpu(ctrl->wIndex);
+ u16 len = le16_to_cpu(ctrl->wLength);
+ u16 w_value = le16_to_cpu(ctrl->wValue);
+
+ DBG(cdev, "bRequest 0x%x, w_value 0x%04x, len %d, endpoint %d\n",
+ ctrl->bRequest, w_value, len, ep);
+
+ switch (ctrl->bRequest) {
+ case UAC_SET_CUR:
+ value = len;
+ break;
+
+ case UAC_SET_MIN:
+ break;
+
+ case UAC_SET_MAX:
+ break;
+
+ case UAC_SET_RES:
+ break;
+
+ case UAC_SET_MEM:
+ break;
+
+ default:
+ break;
+ }
+
+ return value;
+}
+
+static int audio_get_endpoint_req(struct usb_function *f,
+ const struct usb_ctrlrequest *ctrl)
+{
+ struct usb_composite_dev *cdev = f->config->cdev;
+ int value = -EOPNOTSUPP;
+ u8 ep = ((le16_to_cpu(ctrl->wIndex) >> 8) & 0xFF);
+ u16 len = le16_to_cpu(ctrl->wLength);
+ u16 w_value = le16_to_cpu(ctrl->wValue);
+
+ DBG(cdev, "bRequest 0x%x, w_value 0x%04x, len %d, endpoint %d\n",
+ ctrl->bRequest, w_value, len, ep);
+
+ switch (ctrl->bRequest) {
+ case UAC_GET_CUR:
+ case UAC_GET_MIN:
+ case UAC_GET_MAX:
+ case UAC_GET_RES:
+ value = len;
+ break;
+ case UAC_GET_MEM:
+ break;
+ default:
+ break;
+ }
+
+ return value;
+}
+
+static int
+f_audio_setup(struct usb_function *f, const struct usb_ctrlrequest *ctrl)
+{
+ struct usb_composite_dev *cdev = f->config->cdev;
+ struct usb_request *req = cdev->req;
+ int value = -EOPNOTSUPP;
+ u16 w_index = le16_to_cpu(ctrl->wIndex);
+ u16 w_value = le16_to_cpu(ctrl->wValue);
+ u16 w_length = le16_to_cpu(ctrl->wLength);
+
+ /* composite driver infrastructure handles everything; interface
+ * activation uses set_alt().
+ */
+ switch (ctrl->bRequestType) {
+ case USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_ENDPOINT:
+ value = audio_set_endpoint_req(f, ctrl);
+ break;
+
+ case USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_ENDPOINT:
+ value = audio_get_endpoint_req(f, ctrl);
+ break;
+
+ default:
+ ERROR(cdev, "invalid control req%02x.%02x v%04x i%04x l%d\n",
+ ctrl->bRequestType, ctrl->bRequest,
+ w_value, w_index, w_length);
+ }
+
+ /* respond with data transfer or status phase? */
+ if (value >= 0) {
+ DBG(cdev, "audio req%02x.%02x v%04x i%04x l%d\n",
+ ctrl->bRequestType, ctrl->bRequest,
+ w_value, w_index, w_length);
+ req->zero = 0;
+ req->length = value;
+ value = usb_ep_queue(cdev->gadget->ep0, req, GFP_ATOMIC);
+ if (value < 0)
+ ERROR(cdev, "audio response on err %d\n", value);
+ }
+
+ /* device either stalls (value < 0) or reports success */
+ return value;
+}
+
+static int f_audio_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
+{
+ struct usb_composite_dev *cdev = f->config->cdev;
+ struct usb_gadget *gadget = cdev->gadget;
+ struct device *dev = &gadget->dev;
+ struct f_uac1 *uac1 = func_to_uac1(f);
+ int ret = 0;
+
+ /* No i/f has more than 2 alt settings */
+ if (alt > 1) {
+ dev_err(dev, "%s:%d Error!\n", __func__, __LINE__);
+ return -EINVAL;
+ }
+
+ if (intf == uac1->ac_intf) {
+ /* Control I/f has only 1 AltSetting - 0 */
+ if (alt) {
+ dev_err(dev, "%s:%d Error!\n", __func__, __LINE__);
+ return -EINVAL;
+ }
+ return 0;
+ }
+
+ if (intf == uac1->as_out_intf) {
+ uac1->as_out_alt = alt;
+
+ if (alt)
+ ret = u_audio_start_capture(&uac1->g_audio);
+ else
+ u_audio_stop_capture(&uac1->g_audio);
+ } else if (intf == uac1->as_in_intf) {
+ uac1->as_in_alt = alt;
+
+ if (alt)
+ ret = u_audio_start_playback(&uac1->g_audio);
+ else
+ u_audio_stop_playback(&uac1->g_audio);
+ } else {
+ dev_err(dev, "%s:%d Error!\n", __func__, __LINE__);
+ return -EINVAL;
+ }
+
+ return ret;
+}
+
+static int f_audio_get_alt(struct usb_function *f, unsigned intf)
+{
+ struct usb_composite_dev *cdev = f->config->cdev;
+ struct usb_gadget *gadget = cdev->gadget;
+ struct device *dev = &gadget->dev;
+ struct f_uac1 *uac1 = func_to_uac1(f);
+
+ if (intf == uac1->ac_intf)
+ return uac1->ac_alt;
+ else if (intf == uac1->as_out_intf)
+ return uac1->as_out_alt;
+ else if (intf == uac1->as_in_intf)
+ return uac1->as_in_alt;
+ else
+ dev_err(dev, "%s:%d Invalid Interface %d!\n",
+ __func__, __LINE__, intf);
+
+ return -EINVAL;
+}
+
+
+static void f_audio_disable(struct usb_function *f)
+{
+ struct f_uac1 *uac1 = func_to_uac1(f);
+
+ uac1->as_out_alt = 0;
+ uac1->as_in_alt = 0;
+
+ u_audio_stop_capture(&uac1->g_audio);
+}
+
+/*-------------------------------------------------------------------------*/
+
+/* audio function driver setup/binding */
+static int f_audio_bind(struct usb_configuration *c, struct usb_function *f)
+{
+ struct usb_composite_dev *cdev = c->cdev;
+ struct usb_gadget *gadget = cdev->gadget;
+ struct f_uac1 *uac1 = func_to_uac1(f);
+ struct g_audio *audio = func_to_g_audio(f);
+ struct f_uac1_acard_opts *audio_opts;
+ struct usb_ep *ep = NULL;
+ struct usb_string *us;
+ u8 *sam_freq;
+ int rate;
+ int status;
+
+ audio_opts = container_of(f->fi, struct f_uac1_acard_opts, func_inst);
+
+ us = usb_gstrings_attach(cdev, uac1_strings, ARRAY_SIZE(strings_uac1));
+ if (IS_ERR(us))
+ return PTR_ERR(us);
+ ac_interface_desc.iInterface = us[STR_AC_IF].id;
+ usb_out_it_desc.iTerminal = us[STR_USB_OUT_IT].id;
+ usb_out_it_desc.iChannelNames = us[STR_USB_OUT_IT_CH_NAMES].id;
+ io_out_ot_desc.iTerminal = us[STR_IO_OUT_OT].id;
+ as_out_interface_alt_0_desc.iInterface = us[STR_AS_OUT_IF_ALT0].id;
+ as_out_interface_alt_1_desc.iInterface = us[STR_AS_OUT_IF_ALT1].id;
+ io_in_it_desc.iTerminal = us[STR_IO_IN_IT].id;
+ io_in_it_desc.iChannelNames = us[STR_IO_IN_IT_CH_NAMES].id;
+ usb_in_ot_desc.iTerminal = us[STR_USB_IN_OT].id;
+ as_in_interface_alt_0_desc.iInterface = us[STR_AS_IN_IF_ALT0].id;
+ as_in_interface_alt_1_desc.iInterface = us[STR_AS_IN_IF_ALT1].id;
+
+ /* Set channel numbers */
+ usb_out_it_desc.bNrChannels = num_channels(audio_opts->c_chmask);
+ usb_out_it_desc.wChannelConfig = cpu_to_le16(audio_opts->c_chmask);
+ as_out_type_i_desc.bNrChannels = num_channels(audio_opts->c_chmask);
+ as_out_type_i_desc.bSubframeSize = audio_opts->c_ssize;
+ as_out_type_i_desc.bBitResolution = audio_opts->c_ssize * 8;
+ io_in_it_desc.bNrChannels = num_channels(audio_opts->p_chmask);
+ io_in_it_desc.wChannelConfig = cpu_to_le16(audio_opts->p_chmask);
+ as_in_type_i_desc.bNrChannels = num_channels(audio_opts->p_chmask);
+ as_in_type_i_desc.bSubframeSize = audio_opts->p_ssize;
+ as_in_type_i_desc.bBitResolution = audio_opts->p_ssize * 8;
+
+ /* Set sample rates */
+ rate = audio_opts->c_srate;
+ sam_freq = as_out_type_i_desc.tSamFreq[0];
+ memcpy(sam_freq, &rate, 3);
+ rate = audio_opts->p_srate;
+ sam_freq = as_in_type_i_desc.tSamFreq[0];
+ memcpy(sam_freq, &rate, 3);
+
+ /* allocate instance-specific interface IDs, and patch descriptors */
+ status = usb_interface_id(c, f);
+ if (status < 0)
+ goto fail;
+ ac_interface_desc.bInterfaceNumber = status;
+ uac1->ac_intf = status;
+ uac1->ac_alt = 0;
+
+ status = usb_interface_id(c, f);
+ if (status < 0)
+ goto fail;
+ as_out_interface_alt_0_desc.bInterfaceNumber = status;
+ as_out_interface_alt_1_desc.bInterfaceNumber = status;
+ uac1->as_out_intf = status;
+ uac1->as_out_alt = 0;
+
+ status = usb_interface_id(c, f);
+ if (status < 0)
+ goto fail;
+ as_in_interface_alt_0_desc.bInterfaceNumber = status;
+ as_in_interface_alt_1_desc.bInterfaceNumber = status;
+ uac1->as_in_intf = status;
+ uac1->as_in_alt = 0;
+
+ audio->gadget = gadget;
+
+ status = -ENODEV;
+
+ /* allocate instance-specific endpoints */
+ ep = usb_ep_autoconfig(cdev->gadget, &as_out_ep_desc);
+ if (!ep)
+ goto fail;
+ audio->out_ep = ep;
+ audio->out_ep->desc = &as_out_ep_desc;
+
+ ep = usb_ep_autoconfig(cdev->gadget, &as_in_ep_desc);
+ if (!ep)
+ goto fail;
+ audio->in_ep = ep;
+ audio->in_ep->desc = &as_in_ep_desc;
+
+ /* copy descriptors, and track endpoint copies */
+ status = usb_assign_descriptors(f, f_audio_desc, f_audio_desc, NULL,
+ NULL);
+ if (status)
+ goto fail;
+
+ audio->out_ep_maxpsize = as_out_ep_desc.wMaxPacketSize;
+ audio->in_ep_maxpsize = as_in_ep_desc.wMaxPacketSize;
+ audio->params.c_chmask = audio_opts->c_chmask;
+ audio->params.c_srate = audio_opts->c_srate;
+ audio->params.c_ssize = audio_opts->c_ssize;
+ audio->params.p_chmask = audio_opts->p_chmask;
+ audio->params.p_srate = audio_opts->p_srate;
+ audio->params.p_ssize = audio_opts->p_ssize;
+ audio->params.req_number = audio_opts->req_number;
+
+ status = g_audio_setup(audio, "UAC1_PCM", "UAC1_Gadget");
+ if (status)
+ goto err_card_register;
+
+ return 0;
+
+err_card_register:
+ usb_free_all_descriptors(f);
+fail:
+ return status;
+}
+
+/*-------------------------------------------------------------------------*/
+
+static inline struct
+f_uac1_acard_opts *to_f_uac1_acard_opts(struct config_item *item)
+{
+ return container_of(to_config_group(item), struct f_uac1_acard_opts,
+ func_inst.group);
+}
+
+static void f_uac1_attr_release(struct config_item *item)
+{
+ struct f_uac1_acard_opts *opts = to_f_uac1_acard_opts(item);
+
+ usb_put_function_instance(&opts->func_inst);
+}
+
+static struct configfs_item_operations f_uac1_item_ops = {
+ .release = f_uac1_attr_release,
+};
+
+#define UAC1_ATTRIBUTE(name) \
+static ssize_t f_uac1_acard_opts_##name##_show( \
+ struct config_item *item, \
+ char *page) \
+{ \
+ struct f_uac1_acard_opts *opts = to_f_uac1_acard_opts(item); \
+ int result; \
+ \
+ mutex_lock(&opts->lock); \
+ result = sprintf(page, "%u\n", opts->name); \
+ mutex_unlock(&opts->lock); \
+ \
+ return result; \
+} \
+ \
+static ssize_t f_uac1_acard_opts_##name##_store( \
+ struct config_item *item, \
+ const char *page, size_t len) \
+{ \
+ struct f_uac1_acard_opts *opts = to_f_uac1_acard_opts(item); \
+ int ret; \
+ u32 num; \
+ \
+ mutex_lock(&opts->lock); \
+ if (opts->refcnt) { \
+ ret = -EBUSY; \
+ goto end; \
+ } \
+ \
+ ret = kstrtou32(page, 0, &num); \
+ if (ret) \
+ goto end; \
+ \
+ opts->name = num; \
+ ret = len; \
+ \
+end: \
+ mutex_unlock(&opts->lock); \
+ return ret; \
+} \
+ \
+CONFIGFS_ATTR(f_uac1_acard_opts_, name)
+
+UAC1_ATTRIBUTE(c_chmask);
+UAC1_ATTRIBUTE(c_srate);
+UAC1_ATTRIBUTE(c_ssize);
+UAC1_ATTRIBUTE(p_chmask);
+UAC1_ATTRIBUTE(p_srate);
+UAC1_ATTRIBUTE(p_ssize);
+UAC1_ATTRIBUTE(req_number);
+
+static struct configfs_attribute *f_uac1_attrs[] = {
+ &f_uac1_acard_opts_attr_c_chmask,
+ &f_uac1_acard_opts_attr_c_srate,
+ &f_uac1_acard_opts_attr_c_ssize,
+ &f_uac1_acard_opts_attr_p_chmask,
+ &f_uac1_acard_opts_attr_p_srate,
+ &f_uac1_acard_opts_attr_p_ssize,
+ &f_uac1_acard_opts_attr_req_number,
+ NULL,
+};
+
+static struct config_item_type f_uac1_func_type = {
+ .ct_item_ops = &f_uac1_item_ops,
+ .ct_attrs = f_uac1_attrs,
+ .ct_owner = THIS_MODULE,
+};
+
+static void f_audio_free_inst(struct usb_function_instance *f)
+{
+ struct f_uac1_acard_opts *opts;
+
+ opts = container_of(f, struct f_uac1_acard_opts, func_inst);
+ kfree(opts);
+}
+
+static struct usb_function_instance *f_audio_alloc_inst(void)
+{
+ struct f_uac1_acard_opts *opts;
+
+ opts = kzalloc(sizeof(*opts), GFP_KERNEL);
+ if (!opts)
+ return ERR_PTR(-ENOMEM);
+
+ mutex_init(&opts->lock);
+ opts->func_inst.free_func_inst = f_audio_free_inst;
+
+ config_group_init_type_name(&opts->func_inst.group, "",
+ &f_uac1_func_type);
+
+ opts->c_chmask = UAC1_DEF_CCHMASK;
+ opts->c_srate = UAC1_DEF_CSRATE;
+ opts->c_ssize = UAC1_DEF_CSSIZE;
+ opts->p_chmask = UAC1_DEF_PCHMASK;
+ opts->p_srate = UAC1_DEF_PSRATE;
+ opts->p_ssize = UAC1_DEF_PSSIZE;
+ opts->req_number = UAC1_DEF_REQ_NUM;
+ return &opts->func_inst;
+}
+
+static void f_audio_free(struct usb_function *f)
+{
+ struct g_audio *audio;
+ struct f_uac1_acard_opts *opts;
+
+ audio = func_to_g_audio(f);
+ opts = container_of(f->fi, struct f_uac1_acard_opts, func_inst);
+ kfree(audio);
+ mutex_lock(&opts->lock);
+ --opts->refcnt;
+ mutex_unlock(&opts->lock);
+}
+
+static void f_audio_unbind(struct usb_configuration *c, struct usb_function *f)
+{
+ struct g_audio *audio = func_to_g_audio(f);
+
+ g_audio_cleanup(audio);
+ usb_free_all_descriptors(f);
+
+ audio->gadget = NULL;
+}
+
+static struct usb_function *f_audio_alloc(struct usb_function_instance *fi)
+{
+ struct f_uac1 *uac1;
+ struct f_uac1_acard_opts *opts;
+
+ /* allocate and initialize one new instance */
+ uac1 = kzalloc(sizeof(*uac1), GFP_KERNEL);
+ if (!uac1)
+ return ERR_PTR(-ENOMEM);
+
+ opts = container_of(fi, struct f_uac1_acard_opts, func_inst);
+ mutex_lock(&opts->lock);
+ ++opts->refcnt;
+ mutex_unlock(&opts->lock);
+
+ uac1->g_audio.func.name = "uac1_acard_func";
+ uac1->g_audio.func.bind = f_audio_bind;
+ uac1->g_audio.func.unbind = f_audio_unbind;
+ uac1->g_audio.func.set_alt = f_audio_set_alt;
+ uac1->g_audio.func.get_alt = f_audio_get_alt;
+ uac1->g_audio.func.setup = f_audio_setup;
+ uac1->g_audio.func.disable = f_audio_disable;
+ uac1->g_audio.func.free_func = f_audio_free;
+
+ return &uac1->g_audio.func;
+}
+
+DECLARE_USB_FUNCTION_INIT(uac1_acard, f_audio_alloc_inst, f_audio_alloc);
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Ruslan Bilovol");
diff --git a/drivers/usb/gadget/function/u_uac1_acard.h b/drivers/usb/gadget/function/u_uac1_acard.h
new file mode 100644
index 0000000..c172687
--- /dev/null
+++ b/drivers/usb/gadget/function/u_uac1_acard.h
@@ -0,0 +1,41 @@
+/*
+ * u_uac1_acard.h - Utility definitions for UAC1 function
+ *
+ * Copyright (C) 2016 Ruslan Bilovol <ruslan.bilovol@xxxxxxxxx>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#ifndef __U_UAC1_ACARD_H
+#define __U_UAC1_ACARD_H
+
+#include <linux/usb/composite.h>
+
+#define UAC1_OUT_EP_MAX_PACKET_SIZE 200
+#define UAC1_DEF_CCHMASK 0x3
+#define UAC1_DEF_CSRATE 48000
+#define UAC1_DEF_CSSIZE 2
+#define UAC1_DEF_PCHMASK 0x3
+#define UAC1_DEF_PSRATE 48000
+#define UAC1_DEF_PSSIZE 2
+#define UAC1_DEF_REQ_NUM 2
+
+
+struct f_uac1_acard_opts {
+ struct usb_function_instance func_inst;
+ int c_chmask;
+ int c_srate;
+ int c_ssize;
+ int p_chmask;
+ int p_srate;
+ int p_ssize;
+ int req_number;
+ unsigned bound:1;
+
+ struct mutex lock;
+ int refcnt;
+};
+
+#endif /* __U_UAC1_ACARD_H */
diff --git a/drivers/usb/gadget/legacy/Kconfig b/drivers/usb/gadget/legacy/Kconfig
index 5344064..4d0b6b5 100644
--- a/drivers/usb/gadget/legacy/Kconfig
+++ b/drivers/usb/gadget/legacy/Kconfig
@@ -54,9 +54,10 @@ config USB_AUDIO
depends on SND
select USB_LIBCOMPOSITE
select SND_PCM
- select USB_F_UAC1 if GADGET_UAC1
+ select USB_F_UAC1 if (GADGET_UAC1 && !GADGET_UAC1_ACARD)
+ select USB_F_UAC1_ACARD if (GADGET_UAC1 && GADGET_UAC1_ACARD)
select USB_F_UAC2 if !GADGET_UAC1
- select USB_U_AUDIO if USB_F_UAC2
+ select USB_U_AUDIO if (USB_F_UAC2 || USB_F_UAC1_ACARD)
help
This Gadget Audio driver is compatible with USB Audio Class
specification 2.0. It implements 1 AudioControl interface,
@@ -81,6 +82,16 @@ config GADGET_UAC1
paths hardwired to the Audio codec chip on-board and doesn't work
without one.

+config GADGET_UAC1_ACARD
+ bool "Virtual ALSA Card for UAC 1.0 driver"
+ depends on GADGET_UAC1
+ help
+ This is an alternative UAC Spec-1.0 driver implementation
+ that uses new API (u_audio), and doesn't expect any real
+ audio codec to be present on the device. The audio streams
+ are simply sinked to and sourced from a virtual ALSA sound
+ card created
+
config USB_ETH
tristate "Ethernet Gadget (with CDC Ethernet support)"
depends on NET
diff --git a/drivers/usb/gadget/legacy/audio.c b/drivers/usb/gadget/legacy/audio.c
index 8a39f42..6de194a 100644
--- a/drivers/usb/gadget/legacy/audio.c
+++ b/drivers/usb/gadget/legacy/audio.c
@@ -53,6 +53,39 @@
module_param(c_ssize, uint, S_IRUGO);
MODULE_PARM_DESC(c_ssize, "Capture Sample Size(bytes)");
#else
+#ifdef CONFIG_GADGET_UAC1_ACARD
+#include "u_uac1_acard.h"
+
+/* Playback(USB-IN) Default Stereo - Fl/Fr */
+static int p_chmask = UAC1_DEF_PCHMASK;
+module_param(p_chmask, uint, S_IRUGO);
+MODULE_PARM_DESC(p_chmask, "Playback Channel Mask");
+
+/* Playback Default 48 KHz */
+static int p_srate = UAC1_DEF_PSRATE;
+module_param(p_srate, uint, S_IRUGO);
+MODULE_PARM_DESC(p_srate, "Playback Sampling Rate");
+
+/* Playback Default 16bits/sample */
+static int p_ssize = UAC1_DEF_PSSIZE;
+module_param(p_ssize, uint, S_IRUGO);
+MODULE_PARM_DESC(p_ssize, "Playback Sample Size(bytes)");
+
+/* Capture(USB-OUT) Default Stereo - Fl/Fr */
+static int c_chmask = UAC1_DEF_CCHMASK;
+module_param(c_chmask, uint, S_IRUGO);
+MODULE_PARM_DESC(c_chmask, "Capture Channel Mask");
+
+/* Capture Default 48 KHz */
+static int c_srate = UAC1_DEF_CSRATE;
+module_param(c_srate, uint, S_IRUGO);
+MODULE_PARM_DESC(c_srate, "Capture Sampling Rate");
+
+/* Capture Default 16bits/sample */
+static int c_ssize = UAC1_DEF_CSSIZE;
+module_param(c_ssize, uint, S_IRUGO);
+MODULE_PARM_DESC(c_ssize, "Capture Sample Size(bytes)");
+#else /* CONFIG_GADGET_UAC1_ACARD */
#include "u_uac1.h"

static char *fn_play = FILE_PCM_PLAYBACK;
@@ -78,6 +111,7 @@
static int audio_buf_size = UAC1_AUDIO_BUF_SIZE;
module_param(audio_buf_size, int, S_IRUGO);
MODULE_PARM_DESC(audio_buf_size, "Audio buffer size");
+#endif /* CONFIG_GADGET_UAC1_ACARD */
#endif

/* string IDs are assigned dynamically */
@@ -207,8 +241,12 @@ static int audio_bind(struct usb_composite_dev *cdev)
#ifndef CONFIG_GADGET_UAC1
struct f_uac2_opts *uac2_opts;
#else
+#ifdef CONFIG_GADGET_UAC1_ACARD
+ struct f_uac1_acard_opts *uac1_opts;
+#else
struct f_uac1_opts *uac1_opts;
#endif
+#endif
int status;

#ifndef CONFIG_GADGET_UAC1
@@ -216,7 +254,11 @@ static int audio_bind(struct usb_composite_dev *cdev)
if (IS_ERR(fi_uac2))
return PTR_ERR(fi_uac2);
#else
+#ifdef CONFIG_GADGET_UAC1_ACARD
+ fi_uac1 = usb_get_function_instance("uac1_acard");
+#else
fi_uac1 = usb_get_function_instance("uac1");
+#endif
if (IS_ERR(fi_uac1))
return PTR_ERR(fi_uac1);
#endif
@@ -231,6 +273,16 @@ static int audio_bind(struct usb_composite_dev *cdev)
uac2_opts->c_ssize = c_ssize;
uac2_opts->req_number = UAC2_DEF_REQ_NUM;
#else
+#ifdef CONFIG_GADGET_UAC1_ACARD
+ uac1_opts = container_of(fi_uac1, struct f_uac1_acard_opts, func_inst);
+ uac1_opts->p_chmask = p_chmask;
+ uac1_opts->p_srate = p_srate;
+ uac1_opts->p_ssize = p_ssize;
+ uac1_opts->c_chmask = c_chmask;
+ uac1_opts->c_srate = c_srate;
+ uac1_opts->c_ssize = c_ssize;
+ uac1_opts->req_number = UAC1_DEF_REQ_NUM;
+#else /* CONFIG_GADGET_UAC1_ACARD */
uac1_opts = container_of(fi_uac1, struct f_uac1_opts, func_inst);
uac1_opts->fn_play = fn_play;
uac1_opts->fn_cap = fn_cap;
@@ -238,6 +290,7 @@ static int audio_bind(struct usb_composite_dev *cdev)
uac1_opts->req_buf_size = req_buf_size;
uac1_opts->req_count = req_count;
uac1_opts->audio_buf_size = audio_buf_size;
+#endif /* CONFIG_GADGET_UAC1_ACARD */
#endif

status = usb_string_ids_tab(cdev, strings_dev);
--
1.9.1