From 2249412583c2b66b31e1cd2f34108d7417c7cd8c Mon Sep 17 00:00:00 2001 From: William Wu Date: Mon, 22 Jul 2019 10:33:28 +0800 Subject: [PATCH] usb: gadget: f_uac1: add iad descriptor According to the spec "USB Interface Association Descriptor Device Class Code and Use Model"[1], the Interface Association Descriptor (IAD) is needed for composite device which has multiple interfaces controlled independently of each other. Without the IAD, the device may not work as expected because the USB system software will not properly bind the interfaces with drivers (e.g UAC1 && UVC composite device not recognized in Win10). [1] https://www.usb.org/sites/default/files/iadclasscode_r10.pdf Change-Id: I446c771fe182bd556a054d9ae0ada1374442d1d0 Signed-off-by: William Wu --- drivers/usb/gadget/function/f_uac1.c | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) diff --git a/drivers/usb/gadget/function/f_uac1.c b/drivers/usb/gadget/function/f_uac1.c index 2746a926a8d9..1bb66bfbbd2f 100644 --- a/drivers/usb/gadget/function/f_uac1.c +++ b/drivers/usb/gadget/function/f_uac1.c @@ -48,6 +48,17 @@ 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 iad_desc = { + .bLength = sizeof(iad_desc), + .bDescriptorType = USB_DT_INTERFACE_ASSOCIATION, + + .bFirstInterface = 0, + .bInterfaceCount = 3, + .bFunctionClass = USB_CLASS_AUDIO, + .bFunctionSubClass = USB_SUBCLASS_AUDIOSTREAMING, + .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 +258,7 @@ static struct uac_iso_endpoint_descriptor as_iso_in_desc = { }; static struct usb_descriptor_header *f_audio_desc[] = { + (struct usb_descriptor_header *)&iad_desc, (struct usb_descriptor_header *)&ac_interface_desc, (struct usb_descriptor_header *)&ac_header_desc, @@ -276,6 +288,7 @@ static struct usb_descriptor_header *f_audio_desc[] = { }; enum { + STR_ASSOC, STR_AC_IF, STR_USB_OUT_IT, STR_USB_OUT_IT_CH_NAMES, @@ -290,6 +303,7 @@ enum { }; static struct usb_string strings_uac1[] = { + [STR_ASSOC].s = "Source/Sink", [STR_AC_IF].s = "AC Interface", [STR_USB_OUT_IT].s = "Playback Input terminal", [STR_USB_OUT_IT_CH_NAMES].s = "Playback Channels", @@ -523,6 +537,8 @@ 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); + + iad_desc.iFunction = us[STR_ASSOC].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 +575,7 @@ static int f_audio_bind(struct usb_configuration *c, struct usb_function *f) status = usb_interface_id(c, f); if (status < 0) goto fail; + iad_desc.bFirstInterface = status; ac_interface_desc.bInterfaceNumber = status; uac1->ac_intf = status; uac1->ac_alt = 0;