[PATCH] usb: gadget: function: f_uac1 add interface assoc desc

[liangshengjun]

Add f_uac1 interface association descriptor, make f_uac1 link other 
function(like f_uvc) is possible.

Signed-off-by: Liang Shengjun <liangsheng...@hisilicon.com>
---
 drivers/usb/gadget/function/f_uac1.c | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/drivers/usb/gadget/function/f_uac1.c 
b/drivers/usb/gadget/function/f_uac1.c
index 2746a92..28c1a78 100644
--- a/drivers/usb/gadget/function/f_uac1.c
+++ b/drivers/usb/gadget/function/f_uac1.c
@@ -48,6 +48,16 @@ static inline struct f_uac1 *func_to_uac1(struct 
usb_function *f)
 /* Number of streaming interfaces */
 #define F_AUDIO_NUM_INTERFACES         2
 
+static struct usb_interface_assoc_descriptor uac_iad = {
+       .bLength = sizeof(uac_iad),
+       .bDescriptorType = USB_DT_INTERFACE_ASSOCIATION,
+       .bFirstInterface = 0,
+       .bInterfaceCount = 3,
+       .bFunctionClass = USB_CLASS_AUDIO,
+       .bFunctionSubClass = 0,
+       .bFunctionProtocol = UAC_VERSION_1,
+};
+
 /* B.3.1  Standard AC Interface Descriptor */  static struct 
usb_interface_descriptor ac_interface_desc = {
        .bLength =              USB_DT_INTERFACE_SIZE,
@@ -247,6 +257,7 @@ static struct uac_iso_endpoint_descriptor as_iso_in_desc = 
{  };
 
 static struct usb_descriptor_header *f_audio_desc[] = {
+       (struct usb_descriptor_header *)&uac_iad,
        (struct usb_descriptor_header *)&ac_interface_desc,
        (struct usb_descriptor_header *)&ac_header_desc,
 
@@ -523,6 +534,7 @@ static int f_audio_bind(struct usb_configuration *c, struct 
usb_function *f)
        us = usb_gstrings_attach(cdev, uac1_strings, ARRAY_SIZE(strings_uac1));
        if (IS_ERR(us))
                return PTR_ERR(us);
+       uac_iad.iFunction = us[STR_AC_IF].id;
        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; @@ 
-559,6 +571,7 @@ static int f_audio_bind(struct usb_configuration *c, struct 
usb_function *f)
        status = usb_interface_id(c, f);
        if (status < 0)
                goto fail;
+       uac_iad.bFirstInterface = status;
        ac_interface_desc.bInterfaceNumber = status;
        uac1->ac_intf = status;
        uac1->ac_alt = 0;
--
2.7.4