usb: gadget: uvc: configfs support in uvc function

Add support for using the uvc function as a component of USB gadgets composed
with configfs.

Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Andrzej Pietrasiewicz <andrzej.p@samsung.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>

1 files changed, 50 insertions, 0 deletions

diff --git a/drivers/usb/gadget/function/u_uvc.h b/drivers/usb/gadget/function/u_uvc.h
index c0706a3..4676b60 100644
--- a/drivers/usb/gadget/function/u_uvc.h
+++ b/drivers/usb/gadget/function/u_uvc.h
@@ -17,6 +17,7 @@
 #define U_UVC_H
 
 #include <linux/usb/composite.h>
+#include <linux/usb/video.h>
 
 #define fi_to_f_uvc_opts(f)	container_of(f, struct f_uvc_opts, func_inst)
 
@@ -26,11 +27,60 @@ struct f_uvc_opts {
 	unsigned int					streaming_interval;
 	unsigned int					streaming_maxpacket;
 	unsigned int					streaming_maxburst;
+
+	/*
+	 * Control descriptors array pointers for full-/high-speed and
+	 * super-speed. They point by default to the uvc_fs_control_cls and
+	 * uvc_ss_control_cls arrays respectively. Legacy gadgets must
+	 * override them in their gadget bind callback.
+	 */
 	const struct uvc_descriptor_header * const	*fs_control;
 	const struct uvc_descriptor_header * const	*ss_control;
+
+	/*
+	 * Streaming descriptors array pointers for full-speed, high-speed and
+	 * super-speed. They will point to the uvc_[fhs]s_streaming_cls arrays
+	 * for configfs-based gadgets. Legacy gadgets must initialize them in
+	 * their gadget bind callback.
+	 */
 	const struct uvc_descriptor_header * const	*fs_streaming;
 	const struct uvc_descriptor_header * const	*hs_streaming;
 	const struct uvc_descriptor_header * const	*ss_streaming;
+
+	/* Default control descriptors for configfs-based gadgets. */
+	struct uvc_camera_terminal_descriptor		uvc_camera_terminal;
+	struct uvc_processing_unit_descriptor		uvc_processing;
+	struct uvc_output_terminal_descriptor		uvc_output_terminal;
+	struct uvc_color_matching_descriptor		uvc_color_matching;
+
+	/*
+	 * Control descriptors pointers arrays for full-/high-speed and
+	 * super-speed. The first element is a configurable control header
+	 * descriptor, the other elements point to the fixed default control
+	 * descriptors. Used by configfs only, must not be touched by legacy
+	 * gadgets.
+	 */
+	struct uvc_descriptor_header			*uvc_fs_control_cls[5];
+	struct uvc_descriptor_header			*uvc_ss_control_cls[5];
+
+	/*
+	 * Streaming descriptors for full-speed, high-speed and super-speed.
+	 * Used by configfs only, must not be touched by legacy gadgets. The
+	 * arrays are allocated at runtime as the number of descriptors isn't
+	 * known in advance.
+	 */
+	struct uvc_descriptor_header			**uvc_fs_streaming_cls;
+	struct uvc_descriptor_header			**uvc_hs_streaming_cls;
+	struct uvc_descriptor_header			**uvc_ss_streaming_cls;
+
+	/*
+	 * Read/write access to configfs attributes is handled by configfs.
+	 *
+	 * This lock protects the descriptors from concurrent access by
+	 * read/write and symlink creation/removal.
+	 */
+	struct mutex			lock;
+	int				refcnt;
 };
 
 void uvc_set_trace_param(unsigned int trace);