Commit 86f7ef77 authored by Ricardo Ribalda's avatar Ricardo Ribalda Committed by Mauro Carvalho Chehab
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media: uvcvideo: Add support for per-device control mapping overrides 



Some devices do not implement all their controls in a way that complies
with the UVC specification. This is for instance the case for several
devices that do not support the disabled mode for the power line
frequency control. Add a mechanism to allow per-device control mapping
overrides to avoid errors when accessing non-compliant controls.

Signed-off-by: default avatarRicardo Ribalda <ribalda@chromium.org>
Signed-off-by: default avatarLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: default avatarMauro Carvalho Chehab <mchehab@kernel.org>
parent 71087116

drivers/media/usb/uvc/uvc_ctrl.c

+25 −2
Original line number Diff line number Diff line
@@ -2444,14 +2444,37 @@ static void uvc_ctrl_init_ctrl(struct uvc_video_chain *chain, 
	if (!ctrl->initialized)

		return;



	/* Process common mappings first. */

	/*

	 * First check if the device provides a custom mapping for this control,

	 * used to override standard mappings for non-conformant devices. Don't

	 * process standard mappings if a custom mapping is found. This

	 * mechanism doesn't support combining standard and custom mappings for

	 * a single control.

	 */

	if (chain->dev->info->mappings) {

		bool custom = false;

		unsigned int i;



		for (i = 0; (mapping = chain->dev->info->mappings[i]); ++i) {

			if (uvc_entity_match_guid(ctrl->entity, mapping->entity) &&

			    ctrl->info.selector == mapping->selector) {

				__uvc_ctrl_add_mapping(chain, ctrl, mapping);

				custom = true;

			}

		}



		if (custom)

			return;

	}



	/* Process common mappings next. */

	for (; mapping < mend; ++mapping) {

		if (uvc_entity_match_guid(ctrl->entity, mapping->entity) &&

		    ctrl->info.selector == mapping->selector)

			__uvc_ctrl_add_mapping(chain, ctrl, mapping);

	}



	/* And then version-specific mappings. */

	/* Finally process version-specific mappings. */

	if (chain->dev->uvc_version < 0x0150) {

		mapping = uvc_ctrl_mappings_uvc11;

		mend = mapping + ARRAY_SIZE(uvc_ctrl_mappings_uvc11);

drivers/media/usb/uvc/uvcvideo.h

+1 −0
Original line number Diff line number Diff line
@@ -668,6 +668,7 @@ struct uvc_device_info { 
	u32	quirks;

	u32	meta_format;

	u16	uvc_version;

	const struct uvc_control_mapping **mappings;

};



struct uvc_device {