1 files changed, 652 insertions, 22 deletions

diff --git a/drivers/usb/gadget/function/f_uac1.c b/drivers/usb/gadget/function/f_uac1.c
index d04707580068..3b3db1a8df75 100644
--- a/drivers/usb/gadget/function/f_uac1.c
+++ b/drivers/usb/gadget/function/f_uac1.c
@@ -22,13 +22,26 @@
 /* UAC1 spec: 3.7.2.3 Audio Channel Cluster Format */
 #define UAC1_CHANNEL_MASK 0x0FFF
 
+#define USB_OUT_FU_ID	(out_feature_unit_desc->bUnitID)
+#define USB_IN_FU_ID	(in_feature_unit_desc->bUnitID)
+
 #define EPIN_EN(_opts) ((_opts)->p_chmask != 0)
 #define EPOUT_EN(_opts) ((_opts)->c_chmask != 0)
+#define FUIN_EN(_opts) ((_opts)->p_mute_present \
+			|| (_opts)->p_volume_present)
+#define FUOUT_EN(_opts) ((_opts)->c_mute_present \
+			|| (_opts)->c_volume_present)
 
 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() */
+
+	struct usb_ctrlrequest setup_cr;	/* will be used in data stage */
+
+	/* Interrupt IN endpoint of AC interface */
+	struct usb_ep	*int_ep;
+	atomic_t	int_count;
 };
 
 static inline struct f_uac1 *func_to_uac1(struct usb_function *f)
@@ -58,7 +71,7 @@ static inline struct f_uac1_opts *g_audio_to_uac1_opts(struct g_audio *audio)
 static struct usb_interface_descriptor ac_interface_desc = {
 	.bLength =		USB_DT_INTERFACE_SIZE,
 	.bDescriptorType =	USB_DT_INTERFACE,
-	.bNumEndpoints =	0,
+	/* .bNumEndpoints =	DYNAMIC */
 	.bInterfaceClass =	USB_CLASS_AUDIO,
 	.bInterfaceSubClass =	USB_SUBCLASS_AUDIOCONTROL,
 };
@@ -106,6 +119,19 @@ static struct uac1_output_terminal_descriptor usb_in_ot_desc = {
 	/* .bSourceID =		DYNAMIC */
 };
 
+static struct uac_feature_unit_descriptor *in_feature_unit_desc;
+static struct uac_feature_unit_descriptor *out_feature_unit_desc;
+
+/* AC IN Interrupt Endpoint */
+static struct usb_endpoint_descriptor ac_int_ep_desc = {
+	.bLength = USB_DT_ENDPOINT_SIZE,
+	.bDescriptorType = USB_DT_ENDPOINT,
+	.bEndpointAddress = USB_DIR_IN,
+	.bmAttributes = USB_ENDPOINT_XFER_INT,
+	.wMaxPacketSize = cpu_to_le16(2),
+	.bInterval = 4,
+};
+
 /* B.4.1  Standard AS Interface Descriptor */
 static struct usb_interface_descriptor as_out_interface_alt_0_desc = {
 	.bLength =		USB_DT_INTERFACE_SIZE,
@@ -232,8 +258,13 @@ static struct usb_descriptor_header *f_audio_desc[] = {
 
 	(struct usb_descriptor_header *)&usb_out_it_desc,
 	(struct usb_descriptor_header *)&io_out_ot_desc,
+	(struct usb_descriptor_header *)&out_feature_unit_desc,
+
 	(struct usb_descriptor_header *)&io_in_it_desc,
 	(struct usb_descriptor_header *)&usb_in_ot_desc,
+	(struct usb_descriptor_header *)&in_feature_unit_desc,
+
+	(struct usb_descriptor_header *)&ac_int_ep_desc,
 
 	(struct usb_descriptor_header *)&as_out_interface_alt_0_desc,
 	(struct usb_descriptor_header *)&as_out_interface_alt_1_desc,
@@ -263,6 +294,8 @@ enum {
 	STR_IO_IN_IT,
 	STR_IO_IN_IT_CH_NAMES,
 	STR_USB_IN_OT,
+	STR_FU_IN,
+	STR_FU_OUT,
 	STR_AS_OUT_IF_ALT0,
 	STR_AS_OUT_IF_ALT1,
 	STR_AS_IN_IF_ALT0,
@@ -277,6 +310,8 @@ static struct usb_string strings_uac1[] = {
 	[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_FU_IN].s = "Capture Volume",
+	[STR_FU_OUT].s = "Playback Volume",
 	[STR_AS_OUT_IF_ALT0].s = "Playback Inactive",
 	[STR_AS_OUT_IF_ALT1].s = "Playback Active",
 	[STR_AS_IN_IF_ALT0].s = "Capture Inactive",
@@ -298,6 +333,376 @@ static struct usb_gadget_strings *uac1_strings[] = {
  * This function is an ALSA sound card following USB Audio Class Spec 1.0.
  */
 
+static void audio_notify_complete(struct usb_ep *_ep, struct usb_request *req)
+{
+	struct g_audio *audio = req->context;
+	struct f_uac1 *uac1 = func_to_uac1(&audio->func);
+
+	atomic_dec(&uac1->int_count);
+	kfree(req->buf);
+	usb_ep_free_request(_ep, req);
+}
+
+static int audio_notify(struct g_audio *audio, int unit_id, int cs)
+{
+	struct f_uac1 *uac1 = func_to_uac1(&audio->func);
+	struct usb_request *req;
+	struct uac1_status_word *msg;
+	int ret;
+
+	if (!uac1->int_ep->enabled)
+		return 0;
+
+	if (atomic_inc_return(&uac1->int_count) > UAC1_DEF_INT_REQ_NUM) {
+		atomic_dec(&uac1->int_count);
+		return 0;
+	}
+
+	req = usb_ep_alloc_request(uac1->int_ep, GFP_ATOMIC);
+	if (req == NULL) {
+		ret = -ENOMEM;
+		goto err_dec_int_count;
+	}
+
+	msg = kmalloc(sizeof(*msg), GFP_ATOMIC);
+	if (msg == NULL) {
+		ret = -ENOMEM;
+		goto err_free_request;
+	}
+
+	msg->bStatusType = UAC1_STATUS_TYPE_IRQ_PENDING
+				| UAC1_STATUS_TYPE_ORIG_AUDIO_CONTROL_IF;
+	msg->bOriginator = unit_id;
+
+	req->length = sizeof(*msg);
+	req->buf = msg;
+	req->context = audio;
+	req->complete = audio_notify_complete;
+
+	ret = usb_ep_queue(uac1->int_ep, req, GFP_ATOMIC);
+
+	if (ret)
+		goto err_free_msg;
+
+	return 0;
+
+err_free_msg:
+	kfree(msg);
+err_free_request:
+	usb_ep_free_request(uac1->int_ep, req);
+err_dec_int_count:
+	atomic_dec(&uac1->int_count);
+
+	return ret;
+}
+
+static int
+in_rq_cur(struct usb_function *fn, const struct usb_ctrlrequest *cr)
+{
+	struct usb_request *req = fn->config->cdev->req;
+	struct g_audio *audio = func_to_g_audio(fn);
+	struct f_uac1_opts *opts = g_audio_to_uac1_opts(audio);
+	u16 w_length = le16_to_cpu(cr->wLength);
+	u16 w_index = le16_to_cpu(cr->wIndex);
+	u16 w_value = le16_to_cpu(cr->wValue);
+	u8 entity_id = (w_index >> 8) & 0xff;
+	u8 control_selector = w_value >> 8;
+	int value = -EOPNOTSUPP;
+
+	if ((FUIN_EN(opts) && (entity_id == USB_IN_FU_ID)) ||
+			(FUOUT_EN(opts) && (entity_id == USB_OUT_FU_ID))) {
+		unsigned int is_playback = 0;
+
+		if (FUIN_EN(opts) && (entity_id == USB_IN_FU_ID))
+			is_playback = 1;
+
+		if (control_selector == UAC_FU_MUTE) {
+			unsigned int mute;
+
+			u_audio_get_mute(audio, is_playback, &mute);
+
+			*(u8 *)req->buf = mute;
+			value = min_t(unsigned int, w_length, 1);
+		} else if (control_selector == UAC_FU_VOLUME) {
+			__le16 c;
+			s16 volume;
+
+			u_audio_get_volume(audio, is_playback, &volume);
+
+			c = cpu_to_le16(volume);
+
+			value = min_t(unsigned int, w_length, sizeof(c));
+			memcpy(req->buf, &c, value);
+		} else {
+			dev_err(&audio->gadget->dev,
+				"%s:%d control_selector=%d TODO!\n",
+				__func__, __LINE__, control_selector);
+		}
+	} else {
+		dev_err(&audio->gadget->dev,
+			"%s:%d entity_id=%d control_selector=%d TODO!\n",
+			__func__, __LINE__, entity_id, control_selector);
+	}
+
+	return value;
+}
+
+static int
+in_rq_min(struct usb_function *fn, const struct usb_ctrlrequest *cr)
+{
+	struct usb_request *req = fn->config->cdev->req;
+	struct g_audio *audio = func_to_g_audio(fn);
+	struct f_uac1_opts *opts = g_audio_to_uac1_opts(audio);
+	u16 w_length = le16_to_cpu(cr->wLength);
+	u16 w_index = le16_to_cpu(cr->wIndex);
+	u16 w_value = le16_to_cpu(cr->wValue);
+	u8 entity_id = (w_index >> 8) & 0xff;
+	u8 control_selector = w_value >> 8;
+	int value = -EOPNOTSUPP;
+
+	if ((FUIN_EN(opts) && (entity_id == USB_IN_FU_ID)) ||
+			(FUOUT_EN(opts) && (entity_id == USB_OUT_FU_ID))) {
+		unsigned int is_playback = 0;
+
+		if (FUIN_EN(opts) && (entity_id == USB_IN_FU_ID))
+			is_playback = 1;
+
+		if (control_selector == UAC_FU_VOLUME) {
+			__le16 r;
+			s16 min_db;
+
+			if (is_playback)
+				min_db = opts->p_volume_min;
+			else
+				min_db = opts->c_volume_min;
+
+			r = cpu_to_le16(min_db);
+
+			value = min_t(unsigned int, w_length, sizeof(r));
+			memcpy(req->buf, &r, value);
+		} else {
+			dev_err(&audio->gadget->dev,
+				"%s:%d control_selector=%d TODO!\n",
+				__func__, __LINE__, control_selector);
+		}
+	} else {
+		dev_err(&audio->gadget->dev,
+			"%s:%d entity_id=%d control_selector=%d TODO!\n",
+			__func__, __LINE__, entity_id, control_selector);
+	}
+
+	return value;
+}
+
+static int
+in_rq_max(struct usb_function *fn, const struct usb_ctrlrequest *cr)
+{
+	struct usb_request *req = fn->config->cdev->req;
+	struct g_audio *audio = func_to_g_audio(fn);
+	struct f_uac1_opts *opts = g_audio_to_uac1_opts(audio);
+	u16 w_length = le16_to_cpu(cr->wLength);
+	u16 w_index = le16_to_cpu(cr->wIndex);
+	u16 w_value = le16_to_cpu(cr->wValue);
+	u8 entity_id = (w_index >> 8) & 0xff;
+	u8 control_selector = w_value >> 8;
+	int value = -EOPNOTSUPP;
+
+	if ((FUIN_EN(opts) && (entity_id == USB_IN_FU_ID)) ||
+			(FUOUT_EN(opts) && (entity_id == USB_OUT_FU_ID))) {
+		unsigned int is_playback = 0;
+
+		if (FUIN_EN(opts) && (entity_id == USB_IN_FU_ID))
+			is_playback = 1;
+
+		if (control_selector == UAC_FU_VOLUME) {
+			__le16 r;
+			s16 max_db;
+
+			if (is_playback)
+				max_db = opts->p_volume_max;
+			else
+				max_db = opts->c_volume_max;
+
+			r = cpu_to_le16(max_db);
+
+			value = min_t(unsigned int, w_length, sizeof(r));
+			memcpy(req->buf, &r, value);
+		} else {
+			dev_err(&audio->gadget->dev,
+				"%s:%d control_selector=%d TODO!\n",
+				__func__, __LINE__, control_selector);
+		}
+	} else {
+		dev_err(&audio->gadget->dev,
+			"%s:%d entity_id=%d control_selector=%d TODO!\n",
+			__func__, __LINE__, entity_id, control_selector);
+	}
+
+	return value;
+}
+
+static int
+in_rq_res(struct usb_function *fn, const struct usb_ctrlrequest *cr)
+{
+	struct usb_request *req = fn->config->cdev->req;
+	struct g_audio *audio = func_to_g_audio(fn);
+	struct f_uac1_opts *opts = g_audio_to_uac1_opts(audio);
+	u16 w_length = le16_to_cpu(cr->wLength);
+	u16 w_index = le16_to_cpu(cr->wIndex);
+	u16 w_value = le16_to_cpu(cr->wValue);
+	u8 entity_id = (w_index >> 8) & 0xff;
+	u8 control_selector = w_value >> 8;
+	int value = -EOPNOTSUPP;
+
+	if ((FUIN_EN(opts) && (entity_id == USB_IN_FU_ID)) ||
+			(FUOUT_EN(opts) && (entity_id == USB_OUT_FU_ID))) {
+		unsigned int is_playback = 0;
+
+		if (FUIN_EN(opts) && (entity_id == USB_IN_FU_ID))
+			is_playback = 1;
+
+		if (control_selector == UAC_FU_VOLUME) {
+			__le16 r;
+			s16 res_db;
+
+			if (is_playback)
+				res_db = opts->p_volume_res;
+			else
+				res_db = opts->c_volume_res;
+
+			r = cpu_to_le16(res_db);
+
+			value = min_t(unsigned int, w_length, sizeof(r));
+			memcpy(req->buf, &r, value);
+		} else {
+			dev_err(&audio->gadget->dev,
+				"%s:%d control_selector=%d TODO!\n",
+				__func__, __LINE__, control_selector);
+		}
+	} else {
+		dev_err(&audio->gadget->dev,
+			"%s:%d entity_id=%d control_selector=%d TODO!\n",
+			__func__, __LINE__, entity_id, control_selector);
+	}
+
+	return value;
+}
+
+static void
+out_rq_cur_complete(struct usb_ep *ep, struct usb_request *req)
+{
+	struct g_audio *audio = req->context;
+	struct usb_composite_dev *cdev = audio->func.config->cdev;
+	struct f_uac1_opts *opts = g_audio_to_uac1_opts(audio);
+	struct f_uac1 *uac1 = func_to_uac1(&audio->func);
+	struct usb_ctrlrequest *cr = &uac1->setup_cr;
+	u16 w_index = le16_to_cpu(cr->wIndex);
+	u16 w_value = le16_to_cpu(cr->wValue);
+	u8 entity_id = (w_index >> 8) & 0xff;
+	u8 control_selector = w_value >> 8;
+
+	if (req->status != 0) {
+		dev_dbg(&cdev->gadget->dev, "completion err %d\n", req->status);
+		return;
+	}
+
+	if ((FUIN_EN(opts) && (entity_id == USB_IN_FU_ID)) ||
+			(FUOUT_EN(opts) && (entity_id == USB_OUT_FU_ID))) {
+		unsigned int is_playback = 0;
+
+		if (FUIN_EN(opts) && (entity_id == USB_IN_FU_ID))
+			is_playback = 1;
+
+		if (control_selector == UAC_FU_MUTE) {
+			u8 mute = *(u8 *)req->buf;
+
+			u_audio_set_mute(audio, is_playback, mute);
+
+			return;
+		} else if (control_selector == UAC_FU_VOLUME) {
+			__le16 *c = req->buf;
+			s16 volume;
+
+			volume = le16_to_cpu(*c);
+			u_audio_set_volume(audio, is_playback, volume);
+
+			return;
+		} else {
+			dev_err(&audio->gadget->dev,
+				"%s:%d control_selector=%d TODO!\n",
+				__func__, __LINE__, control_selector);
+			usb_ep_set_halt(ep);
+		}
+	} else {
+		dev_err(&audio->gadget->dev,
+			"%s:%d entity_id=%d control_selector=%d TODO!\n",
+			__func__, __LINE__, entity_id, control_selector);
+		usb_ep_set_halt(ep);
+
+	}
+}
+
+static int
+out_rq_cur(struct usb_function *fn, const struct usb_ctrlrequest *cr)
+{
+	struct usb_request *req = fn->config->cdev->req;
+	struct g_audio *audio = func_to_g_audio(fn);
+	struct f_uac1_opts *opts = g_audio_to_uac1_opts(audio);
+	struct f_uac1 *uac1 = func_to_uac1(&audio->func);
+	u16 w_length = le16_to_cpu(cr->wLength);
+	u16 w_index = le16_to_cpu(cr->wIndex);
+	u16 w_value = le16_to_cpu(cr->wValue);
+	u8 entity_id = (w_index >> 8) & 0xff;
+	u8 control_selector = w_value >> 8;
+
+	if ((FUIN_EN(opts) && (entity_id == USB_IN_FU_ID)) ||
+			(FUOUT_EN(opts) && (entity_id == USB_OUT_FU_ID))) {
+		memcpy(&uac1->setup_cr, cr, sizeof(*cr));
+		req->context = audio;
+		req->complete = out_rq_cur_complete;
+
+		return w_length;
+	} else {
+		dev_err(&audio->gadget->dev,
+			"%s:%d entity_id=%d control_selector=%d TODO!\n",
+			__func__, __LINE__, entity_id, control_selector);
+	}
+	return -EOPNOTSUPP;
+}
+
+static int ac_rq_in(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:
+		return in_rq_cur(f, ctrl);
+	case UAC_GET_MIN:
+		return in_rq_min(f, ctrl);
+	case UAC_GET_MAX:
+		return in_rq_max(f, ctrl);
+	case UAC_GET_RES:
+		return in_rq_res(f, ctrl);
+	case UAC_GET_MEM:
+		break;
+	case UAC_GET_STAT:
+		value = len;
+		break;
+	default:
+		break;
+	}
+
+	return value;
+}
+
 static int audio_set_endpoint_req(struct usb_function *f,
 		const struct usb_ctrlrequest *ctrl)
 {
@@ -383,7 +788,13 @@ f_audio_setup(struct usb_function *f, const struct usb_ctrlrequest *ctrl)
 	case USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_ENDPOINT:
 		value = audio_get_endpoint_req(f, ctrl);
 		break;
-
+	case USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE:
+		if (ctrl->bRequest == UAC_SET_CUR)
+			value = out_rq_cur(f, ctrl);
+		break;
+	case USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE:
+		value = ac_rq_in(f, ctrl);
+		break;
 	default:
 		ERROR(cdev, "invalid control req%02x.%02x v%04x i%04x l%d\n",
 			ctrl->bRequestType, ctrl->bRequest,
@@ -411,6 +822,7 @@ 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 g_audio *audio = func_to_g_audio(f);
 	struct f_uac1 *uac1 = func_to_uac1(f);
 	int ret = 0;
 
@@ -426,6 +838,14 @@ static int f_audio_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
 			dev_err(dev, "%s:%d Error!\n", __func__, __LINE__);
 			return -EINVAL;
 		}
+
+		/* restart interrupt endpoint */
+		if (uac1->int_ep) {
+			usb_ep_disable(uac1->int_ep);
+			config_ep_by_speed(gadget, &audio->func, uac1->int_ep);
+			usb_ep_enable(uac1->int_ep);
+		}
+
 		return 0;
 	}
 
@@ -481,10 +901,33 @@ static void f_audio_disable(struct usb_function *f)
 
 	u_audio_stop_playback(&uac1->g_audio);
 	u_audio_stop_capture(&uac1->g_audio);
+	if (uac1->int_ep)
+		usb_ep_disable(uac1->int_ep);
 }
 
 /*-------------------------------------------------------------------------*/
+static struct uac_feature_unit_descriptor *build_fu_desc(int chmask)
+{
+	struct uac_feature_unit_descriptor *fu_desc;
+	int channels = num_channels(chmask);
+	int fu_desc_size = UAC_DT_FEATURE_UNIT_SIZE(channels);
+
+	fu_desc = kzalloc(fu_desc_size, GFP_KERNEL);
+	if (!fu_desc)
+		return NULL;
+
+	fu_desc->bLength = fu_desc_size;
+	fu_desc->bDescriptorType = USB_DT_CS_INTERFACE;
+
+	fu_desc->bDescriptorSubtype = UAC_FEATURE_UNIT;
+	fu_desc->bControlSize  = 2;
 
+	/* bUnitID, bSourceID and bmaControls will be defined later */
+
+	return fu_desc;
+}
+
+/* B.3.2  Class-Specific AC Interface Descriptor */
 static struct
 uac1_ac_header_descriptor *build_ac_header_desc(struct f_uac1_opts *opts)
 {
@@ -530,9 +973,23 @@ static void setup_descriptor(struct f_uac1_opts *opts)
 		io_out_ot_desc.bTerminalID = i++;
 	if (EPIN_EN(opts))
 		usb_in_ot_desc.bTerminalID = i++;
-
-	usb_in_ot_desc.bSourceID = io_in_it_desc.bTerminalID;
-	io_out_ot_desc.bSourceID = usb_out_it_desc.bTerminalID;
+	if (FUOUT_EN(opts))
+		out_feature_unit_desc->bUnitID = i++;
+	if (FUIN_EN(opts))
+		in_feature_unit_desc->bUnitID = i++;
+
+	if (FUIN_EN(opts)) {
+		usb_in_ot_desc.bSourceID = in_feature_unit_desc->bUnitID;
+		in_feature_unit_desc->bSourceID = io_in_it_desc.bTerminalID;
+	} else {
+		usb_in_ot_desc.bSourceID = io_in_it_desc.bTerminalID;
+	}
+	if (FUOUT_EN(opts)) {
+		io_out_ot_desc.bSourceID = out_feature_unit_desc->bUnitID;
+		out_feature_unit_desc->bSourceID = usb_out_it_desc.bTerminalID;
+	} else {
+		io_out_ot_desc.bSourceID = usb_out_it_desc.bTerminalID;
+	}
 
 	as_out_header_desc.bTerminalLink = usb_out_it_desc.bTerminalID;
 	as_in_header_desc.bTerminalLink = usb_in_ot_desc.bTerminalID;
@@ -544,6 +1001,8 @@ static void setup_descriptor(struct f_uac1_opts *opts)
 
 		len += sizeof(usb_in_ot_desc);
 		len += sizeof(io_in_it_desc);
+		if (FUIN_EN(opts))
+			len += in_feature_unit_desc->bLength;
 		ac_header_desc->wTotalLength = cpu_to_le16(len);
 	}
 	if (EPOUT_EN(opts)) {
@@ -551,6 +1010,8 @@ static void setup_descriptor(struct f_uac1_opts *opts)
 
 		len += sizeof(usb_out_it_desc);
 		len += sizeof(io_out_ot_desc);
+		if (FUOUT_EN(opts))
+			len += out_feature_unit_desc->bLength;
 		ac_header_desc->wTotalLength = cpu_to_le16(len);
 	}
 
@@ -561,13 +1022,20 @@ static void setup_descriptor(struct f_uac1_opts *opts)
 	if (EPOUT_EN(opts)) {
 		f_audio_desc[i++] = USBDHDR(&usb_out_it_desc);
 		f_audio_desc[i++] = USBDHDR(&io_out_ot_desc);
+		if (FUOUT_EN(opts))
+			f_audio_desc[i++] = USBDHDR(out_feature_unit_desc);
 	}
 
 	if (EPIN_EN(opts)) {
 		f_audio_desc[i++] = USBDHDR(&io_in_it_desc);
 		f_audio_desc[i++] = USBDHDR(&usb_in_ot_desc);
+		if (FUIN_EN(opts))
+			f_audio_desc[i++] = USBDHDR(in_feature_unit_desc);
 	}
 
+	if (FUOUT_EN(opts) || FUIN_EN(opts))
+		f_audio_desc[i++] = USBDHDR(&ac_int_ep_desc);
+
 	if (EPOUT_EN(opts)) {
 		f_audio_desc[i++] = USBDHDR(&as_out_interface_alt_0_desc);
 		f_audio_desc[i++] = USBDHDR(&as_out_interface_alt_1_desc);
@@ -614,6 +1082,28 @@ static int f_audio_validate_opts(struct g_audio *audio, struct device *dev)
 		return -EINVAL;
 	}
 
+	if (opts->p_volume_max <= opts->p_volume_min) {
+		dev_err(dev, "Error: incorrect playback volume max/min\n");
+			return -EINVAL;
+	} else if (opts->c_volume_max <= opts->c_volume_min) {
+		dev_err(dev, "Error: incorrect capture volume max/min\n");
+			return -EINVAL;
+	} else if (opts->p_volume_res <= 0) {
+		dev_err(dev, "Error: negative/zero playback volume resolution\n");
+			return -EINVAL;
+	} else if (opts->c_volume_res <= 0) {
+		dev_err(dev, "Error: negative/zero capture volume resolution\n");
+			return -EINVAL;
+	}
+
+	if ((opts->p_volume_max - opts->p_volume_min) % opts->p_volume_res) {
+		dev_err(dev, "Error: incorrect playback volume resolution\n");
+			return -EINVAL;
+	} else if ((opts->c_volume_max - opts->c_volume_min) % opts->c_volume_res) {
+		dev_err(dev, "Error: incorrect capture volume resolution\n");
+			return -EINVAL;
+	}
+
 	return 0;
 }
 
@@ -647,6 +1137,21 @@ static int f_audio_bind(struct usb_configuration *c, struct usb_function *f)
 	if (!ac_header_desc)
 		return -ENOMEM;
 
+	if (FUOUT_EN(audio_opts)) {
+		out_feature_unit_desc = build_fu_desc(audio_opts->c_chmask);
+		if (!out_feature_unit_desc) {
+			status = -ENOMEM;
+			goto fail;
+		}
+	}
+	if (FUIN_EN(audio_opts)) {
+		in_feature_unit_desc = build_fu_desc(audio_opts->p_chmask);
+		if (!in_feature_unit_desc) {
+			status = -ENOMEM;
+			goto err_free_fu;
+		}
+	}
+
 	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;
@@ -659,6 +1164,21 @@ static int f_audio_bind(struct usb_configuration *c, struct usb_function *f)
 	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;
 
+	if (FUOUT_EN(audio_opts)) {
+		u8 *i_feature;
+
+		i_feature = (u8 *)out_feature_unit_desc +
+					out_feature_unit_desc->bLength - 1;
+		*i_feature = us[STR_FU_OUT].id;
+	}
+	if (FUIN_EN(audio_opts)) {
+		u8 *i_feature;
+
+		i_feature = (u8 *)in_feature_unit_desc +
+					in_feature_unit_desc->bLength - 1;
+		*i_feature = us[STR_FU_IN].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);
@@ -671,6 +1191,27 @@ static int f_audio_bind(struct usb_configuration *c, struct usb_function *f)
 	as_in_type_i_desc.bSubframeSize = audio_opts->p_ssize;
 	as_in_type_i_desc.bBitResolution = audio_opts->p_ssize * 8;
 
+	if (FUOUT_EN(audio_opts)) {
+		__le16 *bma = (__le16 *)&out_feature_unit_desc->bmaControls[0];
+		u32 control = 0;
+
+		if (audio_opts->c_mute_present)
+			control |= UAC_FU_MUTE;
+		if (audio_opts->c_volume_present)
+			control |= UAC_FU_VOLUME;
+		*bma = cpu_to_le16(control);
+	}
+	if (FUIN_EN(audio_opts)) {
+		__le16 *bma = (__le16 *)&in_feature_unit_desc->bmaControls[0];
+		u32 control = 0;
+
+		if (audio_opts->p_mute_present)
+			control |= UAC_FU_MUTE;
+		if (audio_opts->p_volume_present)
+			control |= UAC_FU_VOLUME;
+		*bma = cpu_to_le16(control);
+	}
+
 	/* Set sample rates */
 	rate = audio_opts->c_srate;
 	sam_freq = as_out_type_i_desc.tSamFreq[0];
@@ -682,7 +1223,7 @@ static int f_audio_bind(struct usb_configuration *c, struct usb_function *f)
 	/* allocate instance-specific interface IDs, and patch descriptors */
 	status = usb_interface_id(c, f);
 	if (status < 0)
-		goto fail;
+		goto err_free_fu;
 	ac_interface_desc.bInterfaceNumber = status;
 	uac1->ac_intf = status;
 	uac1->ac_alt = 0;
@@ -692,7 +1233,7 @@ static int f_audio_bind(struct usb_configuration *c, struct usb_function *f)
 	if (EPOUT_EN(audio_opts)) {
 		status = usb_interface_id(c, f);
 		if (status < 0)
-			goto fail;
+			goto err_free_fu;
 		as_out_interface_alt_0_desc.bInterfaceNumber = status;
 		as_out_interface_alt_1_desc.bInterfaceNumber = status;
 		ac_header_desc->baInterfaceNr[ba_iface_id++] = status;
@@ -703,7 +1244,7 @@ static int f_audio_bind(struct usb_configuration *c, struct usb_function *f)
 	if (EPIN_EN(audio_opts)) {
 		status = usb_interface_id(c, f);
 		if (status < 0)
-			goto fail;
+			goto err_free_fu;
 		as_in_interface_alt_0_desc.bInterfaceNumber = status;
 		as_in_interface_alt_1_desc.bInterfaceNumber = status;
 		ac_header_desc->baInterfaceNr[ba_iface_id++] = status;
@@ -715,11 +1256,24 @@ static int f_audio_bind(struct usb_configuration *c, struct usb_function *f)
 
 	status = -ENODEV;
 
+	ac_interface_desc.bNumEndpoints = 0;
+
+	/* allocate AC interrupt endpoint */
+	if (FUOUT_EN(audio_opts) || FUIN_EN(audio_opts)) {
+		ep = usb_ep_autoconfig(cdev->gadget, &ac_int_ep_desc);
+		if (!ep)
+			goto err_free_fu;
+		uac1->int_ep = ep;
+		uac1->int_ep->desc = &ac_int_ep_desc;
+
+		ac_interface_desc.bNumEndpoints = 1;
+	}
+
 	/* allocate instance-specific endpoints */
 	if (EPOUT_EN(audio_opts)) {
 		ep = usb_ep_autoconfig(cdev->gadget, &as_out_ep_desc);
 		if (!ep)
-			goto fail;
+			goto err_free_fu;
 		audio->out_ep = ep;
 		audio->out_ep->desc = &as_out_ep_desc;
 	}
@@ -727,7 +1281,7 @@ static int f_audio_bind(struct usb_configuration *c, struct usb_function *f)
 	if (EPIN_EN(audio_opts)) {
 		ep = usb_ep_autoconfig(cdev->gadget, &as_in_ep_desc);
 		if (!ep)
-			goto fail;
+			goto err_free_fu;
 		audio->in_ep = ep;
 		audio->in_ep->desc = &as_in_ep_desc;
 	}
@@ -738,17 +1292,37 @@ static int f_audio_bind(struct usb_configuration *c, struct usb_function *f)
 	status = usb_assign_descriptors(f, f_audio_desc, f_audio_desc, NULL,
 					NULL);
 	if (status)
-		goto fail;
+		goto err_free_fu;
 
 	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_srate = audio_opts->c_srate;
 	audio->params.c_ssize = audio_opts->c_ssize;
+	if (FUIN_EN(audio_opts)) {
+		audio->params.p_fu.id = USB_IN_FU_ID;
+		audio->params.p_fu.mute_present = audio_opts->p_mute_present;
+		audio->params.p_fu.volume_present =
+				audio_opts->p_volume_present;
+		audio->params.p_fu.volume_min = audio_opts->p_volume_min;
+		audio->params.p_fu.volume_max = audio_opts->p_volume_max;
+		audio->params.p_fu.volume_res = audio_opts->p_volume_res;
+	}
 	audio->params.p_chmask = audio_opts->p_chmask;
 	audio->params.p_srate = audio_opts->p_srate;
 	audio->params.p_ssize = audio_opts->p_ssize;
+	if (FUOUT_EN(audio_opts)) {
+		audio->params.c_fu.id = USB_OUT_FU_ID;
+		audio->params.c_fu.mute_present = audio_opts->c_mute_present;
+		audio->params.c_fu.volume_present =
+				audio_opts->c_volume_present;
+		audio->params.c_fu.volume_min = audio_opts->c_volume_min;
+		audio->params.c_fu.volume_max = audio_opts->c_volume_max;
+		audio->params.c_fu.volume_res = audio_opts->c_volume_res;
+	}
 	audio->params.req_number = audio_opts->req_number;
+	if (FUOUT_EN(audio_opts) || FUIN_EN(audio_opts))
+		audio->notify = audio_notify;
 
 	status = g_audio_setup(audio, "UAC1_PCM", "UAC1_Gadget");
 	if (status)
@@ -758,6 +1332,11 @@ static int f_audio_bind(struct usb_configuration *c, struct usb_function *f)
 
 err_card_register:
 	usb_free_all_descriptors(f);
+err_free_fu:
+	kfree(out_feature_unit_desc);
+	out_feature_unit_desc = NULL;
+	kfree(in_feature_unit_desc);
+	in_feature_unit_desc = NULL;
 fail:
 	kfree(ac_header_desc);
 	ac_header_desc = NULL;
@@ -783,7 +1362,15 @@ static struct configfs_item_operations f_uac1_item_ops = {
 	.release	= f_uac1_attr_release,
 };
 
-#define UAC1_ATTRIBUTE(name)						\
+#define uac1_kstrtou32			kstrtou32
+#define uac1_kstrtos16			kstrtos16
+#define uac1_kstrtobool(s, base, res)	kstrtobool((s), (res))
+
+static const char *u32_fmt = "%u\n";
+static const char *s16_fmt = "%hd\n";
+static const char *bool_fmt = "%u\n";
+
+#define UAC1_ATTRIBUTE(type, name)					\
 static ssize_t f_uac1_opts_##name##_show(				\
 					  struct config_item *item,	\
 					  char *page)			\
@@ -792,7 +1379,7 @@ static ssize_t f_uac1_opts_##name##_show(				\
 	int result;							\
 									\
 	mutex_lock(&opts->lock);					\
-	result = sprintf(page, "%u\n", opts->name);			\
+	result = sprintf(page, type##_fmt, opts->name);			\
 	mutex_unlock(&opts->lock);					\
 									\
 	return result;							\
@@ -804,7 +1391,7 @@ static ssize_t f_uac1_opts_##name##_store(				\
 {									\
 	struct f_uac1_opts *opts = to_f_uac1_opts(item);		\
 	int ret;							\
-	u32 num;							\
+	type num;							\
 									\
 	mutex_lock(&opts->lock);					\
 	if (opts->refcnt) {						\
@@ -812,7 +1399,7 @@ static ssize_t f_uac1_opts_##name##_store(				\
 		goto end;						\
 	}								\
 									\
-	ret = kstrtou32(page, 0, &num);					\
+	ret = uac1_kstrto##type(page, 0, &num);				\
 	if (ret)							\
 		goto end;						\
 									\
@@ -826,13 +1413,25 @@ end:									\
 									\
 CONFIGFS_ATTR(f_uac1_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);
+UAC1_ATTRIBUTE(u32, c_chmask);
+UAC1_ATTRIBUTE(u32, c_srate);
+UAC1_ATTRIBUTE(u32, c_ssize);
+UAC1_ATTRIBUTE(u32, p_chmask);
+UAC1_ATTRIBUTE(u32, p_srate);
+UAC1_ATTRIBUTE(u32, p_ssize);
+UAC1_ATTRIBUTE(u32, req_number);
+
+UAC1_ATTRIBUTE(bool, p_mute_present);
+UAC1_ATTRIBUTE(bool, p_volume_present);
+UAC1_ATTRIBUTE(s16, p_volume_min);
+UAC1_ATTRIBUTE(s16, p_volume_max);
+UAC1_ATTRIBUTE(s16, p_volume_res);
+
+UAC1_ATTRIBUTE(bool, c_mute_present);
+UAC1_ATTRIBUTE(bool, c_volume_present);
+UAC1_ATTRIBUTE(s16, c_volume_min);
+UAC1_ATTRIBUTE(s16, c_volume_max);
+UAC1_ATTRIBUTE(s16, c_volume_res);
 
 static struct configfs_attribute *f_uac1_attrs[] = {
 	&f_uac1_opts_attr_c_chmask,
@@ -842,6 +1441,19 @@ static struct configfs_attribute *f_uac1_attrs[] = {
 	&f_uac1_opts_attr_p_srate,
 	&f_uac1_opts_attr_p_ssize,
 	&f_uac1_opts_attr_req_number,
+
+	&f_uac1_opts_attr_p_mute_present,
+	&f_uac1_opts_attr_p_volume_present,
+	&f_uac1_opts_attr_p_volume_min,
+	&f_uac1_opts_attr_p_volume_max,
+	&f_uac1_opts_attr_p_volume_res,
+
+	&f_uac1_opts_attr_c_mute_present,
+	&f_uac1_opts_attr_c_volume_present,
+	&f_uac1_opts_attr_c_volume_min,
+	&f_uac1_opts_attr_c_volume_max,
+	&f_uac1_opts_attr_c_volume_res,
+
 	NULL,
 };
 
@@ -879,6 +1491,19 @@ static struct usb_function_instance *f_audio_alloc_inst(void)
 	opts->p_chmask = UAC1_DEF_PCHMASK;
 	opts->p_srate = UAC1_DEF_PSRATE;
 	opts->p_ssize = UAC1_DEF_PSSIZE;
+
+	opts->p_mute_present = UAC1_DEF_MUTE_PRESENT;
+	opts->p_volume_present = UAC1_DEF_VOLUME_PRESENT;
+	opts->p_volume_min = UAC1_DEF_MIN_DB;
+	opts->p_volume_max = UAC1_DEF_MAX_DB;
+	opts->p_volume_res = UAC1_DEF_RES_DB;
+
+	opts->c_mute_present = UAC1_DEF_MUTE_PRESENT;
+	opts->c_volume_present = UAC1_DEF_VOLUME_PRESENT;
+	opts->c_volume_min = UAC1_DEF_MIN_DB;
+	opts->c_volume_max = UAC1_DEF_MAX_DB;
+	opts->c_volume_res = UAC1_DEF_RES_DB;
+
 	opts->req_number = UAC1_DEF_REQ_NUM;
 	return &opts->func_inst;
 }
@@ -903,6 +1528,11 @@ static void f_audio_unbind(struct usb_configuration *c, struct usb_function *f)
 	g_audio_cleanup(audio);
 	usb_free_all_descriptors(f);
 
+	kfree(out_feature_unit_desc);
+	out_feature_unit_desc = NULL;
+	kfree(in_feature_unit_desc);
+	in_feature_unit_desc = NULL;
+
 	kfree(ac_header_desc);
 	ac_header_desc = NULL;