Add the rt linux 4.1.3-rt3 as base
[kvmfornfv.git] / kernel / drivers / usb / gadget / function / f_uac1.c
diff --git a/kernel/drivers/usb/gadget/function/f_uac1.c b/kernel/drivers/usb/gadget/function/f_uac1.c
new file mode 100644 (file)
index 0000000..7856b33
--- /dev/null
@@ -0,0 +1,992 @@
+/*
+ * f_audio.c -- USB Audio class function driver
+  *
+ * Copyright (C) 2008 Bryan Wu <cooloney@kernel.org>
+ * Copyright (C) 2008 Analog Devices, Inc
+ *
+ * Enter bugs at http://blackfin.uclinux.org/
+ *
+ * Licensed under the GPL-2 or later.
+ */
+
+#include <linux/slab.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/device.h>
+#include <linux/atomic.h>
+
+#include "u_uac1.h"
+
+static int generic_set_cmd(struct usb_audio_control *con, u8 cmd, int value);
+static int generic_get_cmd(struct usb_audio_control *con, u8 cmd);
+
+/*
+ * DESCRIPTORS ... most are static, but strings and full
+ * configuration descriptors are built on demand.
+ */
+
+/*
+ * We have two interfaces- AudioControl and AudioStreaming
+ * TODO: only supcard playback currently
+ */
+#define F_AUDIO_AC_INTERFACE   0
+#define F_AUDIO_AS_INTERFACE   1
+#define F_AUDIO_NUM_INTERFACES 1
+
+/* 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(1);
+
+#define UAC_DT_AC_HEADER_LENGTH        UAC_DT_AC_HEADER_SIZE(F_AUDIO_NUM_INTERFACES)
+/* 1 input terminal, 1 output terminal and 1 feature unit */
+#define UAC_DT_TOTAL_LENGTH (UAC_DT_AC_HEADER_LENGTH + UAC_DT_INPUT_TERMINAL_SIZE \
+       + UAC_DT_OUTPUT_TERMINAL_SIZE + UAC_DT_FEATURE_UNIT_SIZE(0))
+/* B.3.2  Class-Specific AC Interface Descriptor */
+static struct uac1_ac_header_descriptor_1 ac_header_desc = {
+       .bLength =              UAC_DT_AC_HEADER_LENGTH,
+       .bDescriptorType =      USB_DT_CS_INTERFACE,
+       .bDescriptorSubtype =   UAC_HEADER,
+       .bcdADC =               __constant_cpu_to_le16(0x0100),
+       .wTotalLength =         __constant_cpu_to_le16(UAC_DT_TOTAL_LENGTH),
+       .bInCollection =        F_AUDIO_NUM_INTERFACES,
+       .baInterfaceNr = {
+       /* Interface number of the first AudioStream interface */
+               [0] =           1,
+       }
+};
+
+#define INPUT_TERMINAL_ID      1
+static struct uac_input_terminal_descriptor input_terminal_desc = {
+       .bLength =              UAC_DT_INPUT_TERMINAL_SIZE,
+       .bDescriptorType =      USB_DT_CS_INTERFACE,
+       .bDescriptorSubtype =   UAC_INPUT_TERMINAL,
+       .bTerminalID =          INPUT_TERMINAL_ID,
+       .wTerminalType =        UAC_TERMINAL_STREAMING,
+       .bAssocTerminal =       0,
+       .wChannelConfig =       0x3,
+};
+
+DECLARE_UAC_FEATURE_UNIT_DESCRIPTOR(0);
+
+#define FEATURE_UNIT_ID                2
+static struct uac_feature_unit_descriptor_0 feature_unit_desc = {
+       .bLength                = UAC_DT_FEATURE_UNIT_SIZE(0),
+       .bDescriptorType        = USB_DT_CS_INTERFACE,
+       .bDescriptorSubtype     = UAC_FEATURE_UNIT,
+       .bUnitID                = FEATURE_UNIT_ID,
+       .bSourceID              = INPUT_TERMINAL_ID,
+       .bControlSize           = 2,
+       .bmaControls[0]         = (UAC_FU_MUTE | UAC_FU_VOLUME),
+};
+
+static struct usb_audio_control mute_control = {
+       .list = LIST_HEAD_INIT(mute_control.list),
+       .name = "Mute Control",
+       .type = UAC_FU_MUTE,
+       /* Todo: add real Mute control code */
+       .set = generic_set_cmd,
+       .get = generic_get_cmd,
+};
+
+static struct usb_audio_control volume_control = {
+       .list = LIST_HEAD_INIT(volume_control.list),
+       .name = "Volume Control",
+       .type = UAC_FU_VOLUME,
+       /* Todo: add real Volume control code */
+       .set = generic_set_cmd,
+       .get = generic_get_cmd,
+};
+
+static struct usb_audio_control_selector feature_unit = {
+       .list = LIST_HEAD_INIT(feature_unit.list),
+       .id = FEATURE_UNIT_ID,
+       .name = "Mute & Volume Control",
+       .type = UAC_FEATURE_UNIT,
+       .desc = (struct usb_descriptor_header *)&feature_unit_desc,
+};
+
+#define OUTPUT_TERMINAL_ID     3
+static struct uac1_output_terminal_descriptor output_terminal_desc = {
+       .bLength                = UAC_DT_OUTPUT_TERMINAL_SIZE,
+       .bDescriptorType        = USB_DT_CS_INTERFACE,
+       .bDescriptorSubtype     = UAC_OUTPUT_TERMINAL,
+       .bTerminalID            = OUTPUT_TERMINAL_ID,
+       .wTerminalType          = UAC_OUTPUT_TERMINAL_SPEAKER,
+       .bAssocTerminal         = FEATURE_UNIT_ID,
+       .bSourceID              = FEATURE_UNIT_ID,
+};
+
+/* B.4.1  Standard AS Interface Descriptor */
+static struct usb_interface_descriptor as_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_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_header_desc = {
+       .bLength =              UAC_DT_AS_HEADER_SIZE,
+       .bDescriptorType =      USB_DT_CS_INTERFACE,
+       .bDescriptorSubtype =   UAC_AS_GENERAL,
+       .bTerminalLink =        INPUT_TERMINAL_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_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 =           __constant_cpu_to_le16(1),
+};
+
+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 *)&input_terminal_desc,
+       (struct usb_descriptor_header *)&output_terminal_desc,
+       (struct usb_descriptor_header *)&feature_unit_desc,
+
+       (struct usb_descriptor_header *)&as_interface_alt_0_desc,
+       (struct usb_descriptor_header *)&as_interface_alt_1_desc,
+       (struct usb_descriptor_header *)&as_header_desc,
+
+       (struct usb_descriptor_header *)&as_type_i_desc,
+
+       (struct usb_descriptor_header *)&as_out_ep_desc,
+       (struct usb_descriptor_header *)&as_iso_out_desc,
+       NULL,
+};
+
+enum {
+       STR_AC_IF,
+       STR_INPUT_TERMINAL,
+       STR_INPUT_TERMINAL_CH_NAMES,
+       STR_FEAT_DESC_0,
+       STR_OUTPUT_TERMINAL,
+       STR_AS_IF_ALT0,
+       STR_AS_IF_ALT1,
+};
+
+static struct usb_string strings_uac1[] = {
+       [STR_AC_IF].s = "AC Interface",
+       [STR_INPUT_TERMINAL].s = "Input terminal",
+       [STR_INPUT_TERMINAL_CH_NAMES].s = "Channels",
+       [STR_FEAT_DESC_0].s = "Volume control & mute",
+       [STR_OUTPUT_TERMINAL].s = "Output terminal",
+       [STR_AS_IF_ALT0].s = "AS Interface",
+       [STR_AS_IF_ALT1].s = "AS Interface",
+       { },
+};
+
+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.
+ */
+
+/*-------------------------------------------------------------------------*/
+struct f_audio_buf {
+       u8 *buf;
+       int actual;
+       struct list_head list;
+};
+
+static struct f_audio_buf *f_audio_buffer_alloc(int buf_size)
+{
+       struct f_audio_buf *copy_buf;
+
+       copy_buf = kzalloc(sizeof *copy_buf, GFP_ATOMIC);
+       if (!copy_buf)
+               return ERR_PTR(-ENOMEM);
+
+       copy_buf->buf = kzalloc(buf_size, GFP_ATOMIC);
+       if (!copy_buf->buf) {
+               kfree(copy_buf);
+               return ERR_PTR(-ENOMEM);
+       }
+
+       return copy_buf;
+}
+
+static void f_audio_buffer_free(struct f_audio_buf *audio_buf)
+{
+       kfree(audio_buf->buf);
+       kfree(audio_buf);
+}
+/*-------------------------------------------------------------------------*/
+
+struct f_audio {
+       struct gaudio                   card;
+
+       /* endpoints handle full and/or high speeds */
+       struct usb_ep                   *out_ep;
+
+       spinlock_t                      lock;
+       struct f_audio_buf *copy_buf;
+       struct work_struct playback_work;
+       struct list_head play_queue;
+
+       /* Control Set command */
+       struct list_head cs;
+       u8 set_cmd;
+       struct usb_audio_control *set_con;
+};
+
+static inline struct f_audio *func_to_audio(struct usb_function *f)
+{
+       return container_of(f, struct f_audio, card.func);
+}
+
+/*-------------------------------------------------------------------------*/
+
+static void f_audio_playback_work(struct work_struct *data)
+{
+       struct f_audio *audio = container_of(data, struct f_audio,
+                                       playback_work);
+       struct f_audio_buf *play_buf;
+
+       spin_lock_irq(&audio->lock);
+       if (list_empty(&audio->play_queue)) {
+               spin_unlock_irq(&audio->lock);
+               return;
+       }
+       play_buf = list_first_entry(&audio->play_queue,
+                       struct f_audio_buf, list);
+       list_del(&play_buf->list);
+       spin_unlock_irq(&audio->lock);
+
+       u_audio_playback(&audio->card, play_buf->buf, play_buf->actual);
+       f_audio_buffer_free(play_buf);
+}
+
+static int f_audio_out_ep_complete(struct usb_ep *ep, struct usb_request *req)
+{
+       struct f_audio *audio = req->context;
+       struct usb_composite_dev *cdev = audio->card.func.config->cdev;
+       struct f_audio_buf *copy_buf = audio->copy_buf;
+       struct f_uac1_opts *opts;
+       int audio_buf_size;
+       int err;
+
+       opts = container_of(audio->card.func.fi, struct f_uac1_opts,
+                           func_inst);
+       audio_buf_size = opts->audio_buf_size;
+
+       if (!copy_buf)
+               return -EINVAL;
+
+       /* Copy buffer is full, add it to the play_queue */
+       if (audio_buf_size - copy_buf->actual < req->actual) {
+               list_add_tail(&copy_buf->list, &audio->play_queue);
+               schedule_work(&audio->playback_work);
+               copy_buf = f_audio_buffer_alloc(audio_buf_size);
+               if (IS_ERR(copy_buf))
+                       return -ENOMEM;
+       }
+
+       memcpy(copy_buf->buf + copy_buf->actual, req->buf, req->actual);
+       copy_buf->actual += req->actual;
+       audio->copy_buf = copy_buf;
+
+       err = usb_ep_queue(ep, req, GFP_ATOMIC);
+       if (err)
+               ERROR(cdev, "%s queue req: %d\n", ep->name, err);
+
+       return 0;
+
+}
+
+static void f_audio_complete(struct usb_ep *ep, struct usb_request *req)
+{
+       struct f_audio *audio = req->context;
+       int status = req->status;
+       u32 data = 0;
+       struct usb_ep *out_ep = audio->out_ep;
+
+       switch (status) {
+
+       case 0:                         /* normal completion? */
+               if (ep == out_ep)
+                       f_audio_out_ep_complete(ep, req);
+               else if (audio->set_con) {
+                       memcpy(&data, req->buf, req->length);
+                       audio->set_con->set(audio->set_con, audio->set_cmd,
+                                       le16_to_cpu(data));
+                       audio->set_con = NULL;
+               }
+               break;
+       default:
+               break;
+       }
+}
+
+static int audio_set_intf_req(struct usb_function *f,
+               const struct usb_ctrlrequest *ctrl)
+{
+       struct f_audio          *audio = func_to_audio(f);
+       struct usb_composite_dev *cdev = f->config->cdev;
+       struct usb_request      *req = cdev->req;
+       u8                      id = ((le16_to_cpu(ctrl->wIndex) >> 8) & 0xFF);
+       u16                     len = le16_to_cpu(ctrl->wLength);
+       u16                     w_value = le16_to_cpu(ctrl->wValue);
+       u8                      con_sel = (w_value >> 8) & 0xFF;
+       u8                      cmd = (ctrl->bRequest & 0x0F);
+       struct usb_audio_control_selector *cs;
+       struct usb_audio_control *con;
+
+       DBG(cdev, "bRequest 0x%x, w_value 0x%04x, len %d, entity %d\n",
+                       ctrl->bRequest, w_value, len, id);
+
+       list_for_each_entry(cs, &audio->cs, list) {
+               if (cs->id == id) {
+                       list_for_each_entry(con, &cs->control, list) {
+                               if (con->type == con_sel) {
+                                       audio->set_con = con;
+                                       break;
+                               }
+                       }
+                       break;
+               }
+       }
+
+       audio->set_cmd = cmd;
+       req->context = audio;
+       req->complete = f_audio_complete;
+
+       return len;
+}
+
+static int audio_get_intf_req(struct usb_function *f,
+               const struct usb_ctrlrequest *ctrl)
+{
+       struct f_audio          *audio = func_to_audio(f);
+       struct usb_composite_dev *cdev = f->config->cdev;
+       struct usb_request      *req = cdev->req;
+       int                     value = -EOPNOTSUPP;
+       u8                      id = ((le16_to_cpu(ctrl->wIndex) >> 8) & 0xFF);
+       u16                     len = le16_to_cpu(ctrl->wLength);
+       u16                     w_value = le16_to_cpu(ctrl->wValue);
+       u8                      con_sel = (w_value >> 8) & 0xFF;
+       u8                      cmd = (ctrl->bRequest & 0x0F);
+       struct usb_audio_control_selector *cs;
+       struct usb_audio_control *con;
+
+       DBG(cdev, "bRequest 0x%x, w_value 0x%04x, len %d, entity %d\n",
+                       ctrl->bRequest, w_value, len, id);
+
+       list_for_each_entry(cs, &audio->cs, list) {
+               if (cs->id == id) {
+                       list_for_each_entry(con, &cs->control, list) {
+                               if (con->type == con_sel && con->get) {
+                                       value = con->get(con, cmd);
+                                       break;
+                               }
+                       }
+                       break;
+               }
+       }
+
+       req->context = audio;
+       req->complete = f_audio_complete;
+       len = min_t(size_t, sizeof(value), len);
+       memcpy(req->buf, &value, len);
+
+       return len;
+}
+
+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_INTERFACE:
+               value = audio_set_intf_req(f, ctrl);
+               break;
+
+       case USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE:
+               value = audio_get_intf_req(f, ctrl);
+               break;
+
+       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 f_audio          *audio = func_to_audio(f);
+       struct usb_composite_dev *cdev = f->config->cdev;
+       struct usb_ep *out_ep = audio->out_ep;
+       struct usb_request *req;
+       struct f_uac1_opts *opts;
+       int req_buf_size, req_count, audio_buf_size;
+       int i = 0, err = 0;
+
+       DBG(cdev, "intf %d, alt %d\n", intf, alt);
+
+       opts = container_of(f->fi, struct f_uac1_opts, func_inst);
+       req_buf_size = opts->req_buf_size;
+       req_count = opts->req_count;
+       audio_buf_size = opts->audio_buf_size;
+
+       if (intf == 1) {
+               if (alt == 1) {
+                       err = config_ep_by_speed(cdev->gadget, f, out_ep);
+                       if (err)
+                               return err;
+
+                       usb_ep_enable(out_ep);
+                       out_ep->driver_data = audio;
+                       audio->copy_buf = f_audio_buffer_alloc(audio_buf_size);
+                       if (IS_ERR(audio->copy_buf))
+                               return -ENOMEM;
+
+                       /*
+                        * allocate a bunch of read buffers
+                        * and queue them all at once.
+                        */
+                       for (i = 0; i < req_count && err == 0; i++) {
+                               req = usb_ep_alloc_request(out_ep, GFP_ATOMIC);
+                               if (req) {
+                                       req->buf = kzalloc(req_buf_size,
+                                                       GFP_ATOMIC);
+                                       if (req->buf) {
+                                               req->length = req_buf_size;
+                                               req->context = audio;
+                                               req->complete =
+                                                       f_audio_complete;
+                                               err = usb_ep_queue(out_ep,
+                                                       req, GFP_ATOMIC);
+                                               if (err)
+                                                       ERROR(cdev,
+                                                       "%s queue req: %d\n",
+                                                       out_ep->name, err);
+                                       } else
+                                               err = -ENOMEM;
+                               } else
+                                       err = -ENOMEM;
+                       }
+
+               } else {
+                       struct f_audio_buf *copy_buf = audio->copy_buf;
+                       if (copy_buf) {
+                               list_add_tail(&copy_buf->list,
+                                               &audio->play_queue);
+                               schedule_work(&audio->playback_work);
+                       }
+               }
+       }
+
+       return err;
+}
+
+static void f_audio_disable(struct usb_function *f)
+{
+       return;
+}
+
+/*-------------------------------------------------------------------------*/
+
+static void f_audio_build_desc(struct f_audio *audio)
+{
+       struct gaudio *card = &audio->card;
+       u8 *sam_freq;
+       int rate;
+
+       /* Set channel numbers */
+       input_terminal_desc.bNrChannels = u_audio_get_playback_channels(card);
+       as_type_i_desc.bNrChannels = u_audio_get_playback_channels(card);
+
+       /* Set sample rates */
+       rate = u_audio_get_playback_rate(card);
+       sam_freq = as_type_i_desc.tSamFreq[0];
+       memcpy(sam_freq, &rate, 3);
+
+       /* Todo: Set Sample bits and other parameters */
+
+       return;
+}
+
+/* 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 f_audio          *audio = func_to_audio(f);
+       struct usb_string       *us;
+       int                     status;
+       struct usb_ep           *ep = NULL;
+       struct f_uac1_opts      *audio_opts;
+
+       audio_opts = container_of(f->fi, struct f_uac1_opts, func_inst);
+       audio->card.gadget = c->cdev->gadget;
+       /* set up ASLA audio devices */
+       if (!audio_opts->bound) {
+               status = gaudio_setup(&audio->card);
+               if (status < 0)
+                       return status;
+               audio_opts->bound = true;
+       }
+       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;
+       input_terminal_desc.iTerminal = us[STR_INPUT_TERMINAL].id;
+       input_terminal_desc.iChannelNames = us[STR_INPUT_TERMINAL_CH_NAMES].id;
+       feature_unit_desc.iFeature = us[STR_FEAT_DESC_0].id;
+       output_terminal_desc.iTerminal = us[STR_OUTPUT_TERMINAL].id;
+       as_interface_alt_0_desc.iInterface = us[STR_AS_IF_ALT0].id;
+       as_interface_alt_1_desc.iInterface = us[STR_AS_IF_ALT1].id;
+
+
+       f_audio_build_desc(audio);
+
+       /* allocate instance-specific interface IDs, and patch descriptors */
+       status = usb_interface_id(c, f);
+       if (status < 0)
+               goto fail;
+       ac_interface_desc.bInterfaceNumber = status;
+
+       status = usb_interface_id(c, f);
+       if (status < 0)
+               goto fail;
+       as_interface_alt_0_desc.bInterfaceNumber = status;
+       as_interface_alt_1_desc.bInterfaceNumber = status;
+
+       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->driver_data = cdev; /* claim */
+
+       status = -ENOMEM;
+
+       /* copy descriptors, and track endpoint copies */
+       status = usb_assign_descriptors(f, f_audio_desc, f_audio_desc, NULL);
+       if (status)
+               goto fail;
+       return 0;
+
+fail:
+       gaudio_cleanup(&audio->card);
+       if (ep)
+               ep->driver_data = NULL;
+       return status;
+}
+
+/*-------------------------------------------------------------------------*/
+
+static int generic_set_cmd(struct usb_audio_control *con, u8 cmd, int value)
+{
+       con->data[cmd] = value;
+
+       return 0;
+}
+
+static int generic_get_cmd(struct usb_audio_control *con, u8 cmd)
+{
+       return con->data[cmd];
+}
+
+/* Todo: add more control selecotor dynamically */
+static int control_selector_init(struct f_audio *audio)
+{
+       INIT_LIST_HEAD(&audio->cs);
+       list_add(&feature_unit.list, &audio->cs);
+
+       INIT_LIST_HEAD(&feature_unit.control);
+       list_add(&mute_control.list, &feature_unit.control);
+       list_add(&volume_control.list, &feature_unit.control);
+
+       volume_control.data[UAC__CUR] = 0xffc0;
+       volume_control.data[UAC__MIN] = 0xe3a0;
+       volume_control.data[UAC__MAX] = 0xfff0;
+       volume_control.data[UAC__RES] = 0x0030;
+
+       return 0;
+}
+
+static inline struct f_uac1_opts *to_f_uac1_opts(struct config_item *item)
+{
+       return container_of(to_config_group(item), struct f_uac1_opts,
+                           func_inst.group);
+}
+
+CONFIGFS_ATTR_STRUCT(f_uac1_opts);
+CONFIGFS_ATTR_OPS(f_uac1_opts);
+
+static void f_uac1_attr_release(struct config_item *item)
+{
+       struct f_uac1_opts *opts = to_f_uac1_opts(item);
+
+       usb_put_function_instance(&opts->func_inst);
+}
+
+static struct configfs_item_operations f_uac1_item_ops = {
+       .release        = f_uac1_attr_release,
+       .show_attribute = f_uac1_opts_attr_show,
+       .store_attribute = f_uac1_opts_attr_store,
+};
+
+#define UAC1_INT_ATTRIBUTE(name)                                       \
+static ssize_t f_uac1_opts_##name##_show(struct f_uac1_opts *opts,     \
+                                        char *page)                    \
+{                                                                      \
+       int result;                                                     \
+                                                                       \
+       mutex_lock(&opts->lock);                                        \
+       result = sprintf(page, "%u\n", opts->name);                     \
+       mutex_unlock(&opts->lock);                                      \
+                                                                       \
+       return result;                                                  \
+}                                                                      \
+                                                                       \
+static ssize_t f_uac1_opts_##name##_store(struct f_uac1_opts *opts,    \
+                                         const char *page, size_t len) \
+{                                                                      \
+       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;                                                     \
+}                                                                      \
+                                                                       \
+static struct f_uac1_opts_attribute f_uac1_opts_##name =               \
+       __CONFIGFS_ATTR(name, S_IRUGO | S_IWUSR,                        \
+                       f_uac1_opts_##name##_show,                      \
+                       f_uac1_opts_##name##_store)
+
+UAC1_INT_ATTRIBUTE(req_buf_size);
+UAC1_INT_ATTRIBUTE(req_count);
+UAC1_INT_ATTRIBUTE(audio_buf_size);
+
+#define UAC1_STR_ATTRIBUTE(name)                                       \
+static ssize_t f_uac1_opts_##name##_show(struct f_uac1_opts *opts,     \
+                                        char *page)                    \
+{                                                                      \
+       int result;                                                     \
+                                                                       \
+       mutex_lock(&opts->lock);                                        \
+       result = sprintf(page, "%s\n", opts->name);                     \
+       mutex_unlock(&opts->lock);                                      \
+                                                                       \
+       return result;                                                  \
+}                                                                      \
+                                                                       \
+static ssize_t f_uac1_opts_##name##_store(struct f_uac1_opts *opts,    \
+                                         const char *page, size_t len) \
+{                                                                      \
+       int ret = -EBUSY;                                               \
+       char *tmp;                                                      \
+                                                                       \
+       mutex_lock(&opts->lock);                                        \
+       if (opts->refcnt)                                               \
+               goto end;                                               \
+                                                                       \
+       tmp = kstrndup(page, len, GFP_KERNEL);                          \
+       if (tmp) {                                                      \
+               ret = -ENOMEM;                                          \
+               goto end;                                               \
+       }                                                               \
+       if (opts->name##_alloc)                                         \
+               kfree(opts->name);                                      \
+       opts->name##_alloc = true;                                      \
+       opts->name = tmp;                                               \
+       ret = len;                                                      \
+                                                                       \
+end:                                                                   \
+       mutex_unlock(&opts->lock);                                      \
+       return ret;                                                     \
+}                                                                      \
+                                                                       \
+static struct f_uac1_opts_attribute f_uac1_opts_##name =               \
+       __CONFIGFS_ATTR(name, S_IRUGO | S_IWUSR,                        \
+                       f_uac1_opts_##name##_show,                      \
+                       f_uac1_opts_##name##_store)
+
+UAC1_STR_ATTRIBUTE(fn_play);
+UAC1_STR_ATTRIBUTE(fn_cap);
+UAC1_STR_ATTRIBUTE(fn_cntl);
+
+static struct configfs_attribute *f_uac1_attrs[] = {
+       &f_uac1_opts_req_buf_size.attr,
+       &f_uac1_opts_req_count.attr,
+       &f_uac1_opts_audio_buf_size.attr,
+       &f_uac1_opts_fn_play.attr,
+       &f_uac1_opts_fn_cap.attr,
+       &f_uac1_opts_fn_cntl.attr,
+       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_opts *opts;
+
+       opts = container_of(f, struct f_uac1_opts, func_inst);
+       if (opts->fn_play_alloc)
+               kfree(opts->fn_play);
+       if (opts->fn_cap_alloc)
+               kfree(opts->fn_cap);
+       if (opts->fn_cntl_alloc)
+               kfree(opts->fn_cntl);
+       kfree(opts);
+}
+
+static struct usb_function_instance *f_audio_alloc_inst(void)
+{
+       struct f_uac1_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->req_buf_size = UAC1_OUT_EP_MAX_PACKET_SIZE;
+       opts->req_count = UAC1_REQ_COUNT;
+       opts->audio_buf_size = UAC1_AUDIO_BUF_SIZE;
+       opts->fn_play = FILE_PCM_PLAYBACK;
+       opts->fn_cap = FILE_PCM_CAPTURE;
+       opts->fn_cntl = FILE_CONTROL;
+       return &opts->func_inst;
+}
+
+static void f_audio_free(struct usb_function *f)
+{
+       struct f_audio *audio = func_to_audio(f);
+       struct f_uac1_opts *opts;
+
+       gaudio_cleanup(&audio->card);
+       opts = container_of(f->fi, struct f_uac1_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)
+{
+       usb_free_all_descriptors(f);
+}
+
+static struct usb_function *f_audio_alloc(struct usb_function_instance *fi)
+{
+       struct f_audio *audio;
+       struct f_uac1_opts *opts;
+
+       /* allocate and initialize one new instance */
+       audio = kzalloc(sizeof(*audio), GFP_KERNEL);
+       if (!audio)
+               return ERR_PTR(-ENOMEM);
+
+       audio->card.func.name = "g_audio";
+
+       opts = container_of(fi, struct f_uac1_opts, func_inst);
+       mutex_lock(&opts->lock);
+       ++opts->refcnt;
+       mutex_unlock(&opts->lock);
+       INIT_LIST_HEAD(&audio->play_queue);
+       spin_lock_init(&audio->lock);
+
+       audio->card.func.bind = f_audio_bind;
+       audio->card.func.unbind = f_audio_unbind;
+       audio->card.func.set_alt = f_audio_set_alt;
+       audio->card.func.setup = f_audio_setup;
+       audio->card.func.disable = f_audio_disable;
+       audio->card.func.free_func = f_audio_free;
+
+       control_selector_init(audio);
+
+       INIT_WORK(&audio->playback_work, f_audio_playback_work);
+
+       return &audio->card.func;
+}
+
+DECLARE_USB_FUNCTION_INIT(uac1, f_audio_alloc_inst, f_audio_alloc);
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Bryan Wu");