Commit 324e4f85 authored by Dan Vacura's avatar Dan Vacura Committed by Greg Kroah-Hartman
Browse files

usb: gadget: uvc: allow changing interface name via configfs 



Add a configfs entry, "function_name", to change the iInterface field
for VideoControl. This name is used on host devices for user selection,
useful when multiple cameras are present. The default will remain "UVC
Camera".

Signed-off-by: default avatarDan Vacura <w36195@motorola.com>
Link: https://lore.kernel.org/r/20220401160447.5919-1-w36195@motorola.com


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 31231092

Documentation/ABI/testing/configfs-usb-gadget-uvc

+1 −0
Original line number Diff line number Diff line
@@ -7,6 +7,7 @@ Description: UVC function directory 
		streaming_maxburst	0..15 (ss only)

		streaming_maxpacket	1..1023 (fs), 1..3072 (hs/ss)

		streaming_interval	1..16

		function_name		string [32]

		===================	=============================



What:		/config/usb-gadget/gadget/functions/uvc.name/control

Documentation/usb/gadget-testing.rst

+1 −0
Original line number Diff line number Diff line
@@ -787,6 +787,7 @@ The uvc function provides these attributes in its function directory: 
	streaming_maxpacket maximum packet size this endpoint is capable of

			    sending or receiving when this configuration is

			    selected

	function_name       name of the interface

	=================== ================================================



There are also "control" and "streaming" subdirectories, each of which contain

drivers/usb/gadget/function/f_uvc.c

+3 −1
Original line number Diff line number Diff line
@@ -44,7 +44,7 @@ MODULE_PARM_DESC(trace, "Trace level bitmask"); 
#define UVC_STRING_STREAMING_IDX		1



static struct usb_string uvc_en_us_strings[] = {

	[UVC_STRING_CONTROL_IDX].s = "UVC Camera",

	/* [UVC_STRING_CONTROL_IDX].s = DYNAMIC, */

	[UVC_STRING_STREAMING_IDX].s = "Video Streaming",

	{  }

};
@@ -676,6 +676,7 @@ uvc_function_bind(struct usb_configuration *c, struct usb_function *f) 
	uvc_hs_streaming_ep.bEndpointAddress = uvc->video.ep->address;

	uvc_ss_streaming_ep.bEndpointAddress = uvc->video.ep->address;



	uvc_en_us_strings[UVC_STRING_CONTROL_IDX].s = opts->function_name;

	us = usb_gstrings_attach(cdev, uvc_function_strings,

				 ARRAY_SIZE(uvc_en_us_strings));

	if (IS_ERR(us)) {
@@ -866,6 +867,7 @@ static struct usb_function_instance *uvc_alloc_inst(void) 


	opts->streaming_interval = 1;

	opts->streaming_maxpacket = 1024;

	snprintf(opts->function_name, sizeof(opts->function_name), "UVC Camera");



	ret = uvcg_attach_configfs(opts);

	if (ret < 0) {

drivers/usb/gadget/function/u_uvc.h

+1 −0
Original line number Diff line number Diff line
@@ -27,6 +27,7 @@ struct f_uvc_opts { 


	unsigned int					control_interface;

	unsigned int					streaming_interface;

	char						function_name[32];



	/*

	 * Control descriptors array pointers for full-/high-speed and

drivers/usb/gadget/function/uvc_configfs.c

+41 −0
Original line number Diff line number Diff line
@@ -2425,10 +2425,51 @@ UVCG_OPTS_ATTR(streaming_maxburst, streaming_maxburst, 15); 


#undef UVCG_OPTS_ATTR



#define UVCG_OPTS_STRING_ATTR(cname, aname)				\

static ssize_t f_uvc_opts_string_##cname##_show(struct config_item *item,\

					 char *page)			\

{									\

	struct f_uvc_opts *opts = to_f_uvc_opts(item);			\

	int result;							\

									\

	mutex_lock(&opts->lock);					\

	result = snprintf(page, sizeof(opts->aname), "%s", opts->aname);\

	mutex_unlock(&opts->lock);					\

									\

	return result;							\

}									\

									\

static ssize_t f_uvc_opts_string_##cname##_store(struct config_item *item,\

					  const char *page, size_t len)	\

{									\

	struct f_uvc_opts *opts = to_f_uvc_opts(item);			\

	int ret = 0;							\

									\

	mutex_lock(&opts->lock);					\

	if (opts->refcnt) {						\

		ret = -EBUSY;						\

		goto end;						\

	}								\

									\

	ret = snprintf(opts->aname, min(sizeof(opts->aname), len),	\

			"%s", page);					\

									\

end:									\

	mutex_unlock(&opts->lock);					\

	return ret;							\

}									\

									\

UVC_ATTR(f_uvc_opts_string_, cname, aname)



UVCG_OPTS_STRING_ATTR(function_name, function_name);



#undef UVCG_OPTS_STRING_ATTR



static struct configfs_attribute *uvc_attrs[] = {

	&f_uvc_opts_attr_streaming_interval,

	&f_uvc_opts_attr_streaming_maxpacket,

	&f_uvc_opts_attr_streaming_maxburst,

	&f_uvc_opts_string_attr_function_name,

	NULL,

};