Commit b3c839bd authored by Daniel Scally's avatar Daniel Scally Committed by Greg Kroah-Hartman
Browse files

usb: gadget: uvc: Make bSourceID read/write 



At the moment, the UVC function graph is hardcoded IT -> PU -> OT.
To add XU support we need the ability to insert the XU descriptors
into the chain. To facilitate that, make the output terminal's
bSourceID attribute writeable so that we can configure its source.

Signed-off-by: default avatarDaniel Scally <dan.scally@ideasonboard.com>
Link: https://lore.kernel.org/r/20230206161802.892954-2-dan.scally@ideasonboard.com


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent a7efe3fc

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

+1 −1
Original line number Diff line number Diff line
@@ -54,7 +54,7 @@ Date: Dec 2014 
KernelVersion:	4.0

Description:	Default output terminal descriptors



		All attributes read only:

		All attributes read only except bSourceID:



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

		iTerminal	index of string descriptor

drivers/usb/gadget/function/uvc_configfs.c

+58 −1
Original line number Diff line number Diff line
@@ -484,11 +484,68 @@ UVC_ATTR_RO(uvcg_default_output_, cname, aname) 
UVCG_DEFAULT_OUTPUT_ATTR(b_terminal_id, bTerminalID, 8);

UVCG_DEFAULT_OUTPUT_ATTR(w_terminal_type, wTerminalType, 16);

UVCG_DEFAULT_OUTPUT_ATTR(b_assoc_terminal, bAssocTerminal, 8);

UVCG_DEFAULT_OUTPUT_ATTR(b_source_id, bSourceID, 8);

UVCG_DEFAULT_OUTPUT_ATTR(i_terminal, iTerminal, 8);



#undef UVCG_DEFAULT_OUTPUT_ATTR



static ssize_t uvcg_default_output_b_source_id_show(struct config_item *item,

						    char *page)

{

	struct config_group *group = to_config_group(item);

	struct f_uvc_opts *opts;

	struct config_item *opts_item;

	struct mutex *su_mutex = &group->cg_subsys->su_mutex;

	struct uvc_output_terminal_descriptor *cd;

	int result;



	mutex_lock(su_mutex); /* for navigating configfs hierarchy */



	opts_item = group->cg_item.ci_parent->ci_parent->

			ci_parent->ci_parent;

	opts = to_f_uvc_opts(opts_item);

	cd = &opts->uvc_output_terminal;



	mutex_lock(&opts->lock);

	result = sprintf(page, "%u\n", le8_to_cpu(cd->bSourceID));

	mutex_unlock(&opts->lock);



	mutex_unlock(su_mutex);



	return result;

}



static ssize_t uvcg_default_output_b_source_id_store(struct config_item *item,

						     const char *page, size_t len)

{

	struct config_group *group = to_config_group(item);

	struct f_uvc_opts *opts;

	struct config_item *opts_item;

	struct mutex *su_mutex = &group->cg_subsys->su_mutex;

	struct uvc_output_terminal_descriptor *cd;

	int result;

	u8 num;



	mutex_lock(su_mutex); /* for navigating configfs hierarchy */



	opts_item = group->cg_item.ci_parent->ci_parent->

			ci_parent->ci_parent;

	opts = to_f_uvc_opts(opts_item);

	cd = &opts->uvc_output_terminal;



	result = kstrtou8(page, 0, &num);

	if (result)

		return result;



	mutex_lock(&opts->lock);

	cd->bSourceID = num;

	mutex_unlock(&opts->lock);



	mutex_unlock(su_mutex);



	return len;

}

UVC_ATTR(uvcg_default_output_, b_source_id, bSourceID);



static struct configfs_attribute *uvcg_default_output_attrs[] = {

	&uvcg_default_output_attr_b_terminal_id,

	&uvcg_default_output_attr_w_terminal_type,