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>

drivers/usb/gadget/function/f_uvc.c

@@ -27,10 +27,11 @@
 #include <media/v4l2-dev.h>
 #include <media/v4l2-event.h>
 
+#include "u_uvc.h"
 #include "uvc.h"
+#include "uvc_configfs.h"
 #include "uvc_v4l2.h"
 #include "uvc_video.h"
-#include "u_uvc.h"
 
 unsigned int uvc_gadget_trace_param;
 
@@ -788,25 +789,104 @@ static void uvc_free_inst(struct usb_function_instance *f)
 {
 	struct f_uvc_opts *opts = fi_to_f_uvc_opts(f);
 
+	mutex_destroy(&opts->lock);
 	kfree(opts);
 }
 
 static struct usb_function_instance *uvc_alloc_inst(void)
 {
 	struct f_uvc_opts *opts;
+	struct uvc_camera_terminal_descriptor *cd;
+	struct uvc_processing_unit_descriptor *pd;
+	struct uvc_output_terminal_descriptor *od;
+	struct uvc_color_matching_descriptor *md;
+	struct uvc_descriptor_header **ctl_cls;
 
 	opts = kzalloc(sizeof(*opts), GFP_KERNEL);
 	if (!opts)
 		return ERR_PTR(-ENOMEM);
 	opts->func_inst.free_func_inst = uvc_free_inst;
+	mutex_init(&opts->lock);
 
+	cd = &opts->uvc_camera_terminal;
+	cd->bLength			= UVC_DT_CAMERA_TERMINAL_SIZE(3);
+	cd->bDescriptorType		= USB_DT_CS_INTERFACE;
+	cd->bDescriptorSubType		= UVC_VC_INPUT_TERMINAL;
+	cd->bTerminalID			= 1;
+	cd->wTerminalType		= cpu_to_le16(0x0201);
+	cd->bAssocTerminal		= 0;
+	cd->iTerminal			= 0;
+	cd->wObjectiveFocalLengthMin	= cpu_to_le16(0);
+	cd->wObjectiveFocalLengthMax	= cpu_to_le16(0);
+	cd->wOcularFocalLength		= cpu_to_le16(0);
+	cd->bControlSize		= 3;
+	cd->bmControls[0]		= 2;
+	cd->bmControls[1]		= 0;
+	cd->bmControls[2]		= 0;
+
+	pd = &opts->uvc_processing;
+	pd->bLength			= UVC_DT_PROCESSING_UNIT_SIZE(2);
+	pd->bDescriptorType		= USB_DT_CS_INTERFACE;
+	pd->bDescriptorSubType		= UVC_VC_PROCESSING_UNIT;
+	pd->bUnitID			= 2;
+	pd->bSourceID			= 1;
+	pd->wMaxMultiplier		= cpu_to_le16(16*1024);
+	pd->bControlSize		= 2;
+	pd->bmControls[0]		= 1;
+	pd->bmControls[1]		= 0;
+	pd->iProcessing			= 0;
+
+	od = &opts->uvc_output_terminal;
+	od->bLength			= UVC_DT_OUTPUT_TERMINAL_SIZE;
+	od->bDescriptorType		= USB_DT_CS_INTERFACE;
+	od->bDescriptorSubType		= UVC_VC_OUTPUT_TERMINAL;
+	od->bTerminalID			= 3;
+	od->wTerminalType		= cpu_to_le16(0x0101);
+	od->bAssocTerminal		= 0;
+	od->bSourceID			= 2;
+	od->iTerminal			= 0;
+
+	md = &opts->uvc_color_matching;
+	md->bLength			= UVC_DT_COLOR_MATCHING_SIZE;
+	md->bDescriptorType		= USB_DT_CS_INTERFACE;
+	md->bDescriptorSubType		= UVC_VS_COLORFORMAT;
+	md->bColorPrimaries		= 1;
+	md->bTransferCharacteristics	= 1;
+	md->bMatrixCoefficients		= 4;
+
+	/* Prepare fs control class descriptors for configfs-based gadgets */
+	ctl_cls = opts->uvc_fs_control_cls;
+	ctl_cls[0] = NULL;	/* assigned elsewhere by configfs */
+	ctl_cls[1] = (struct uvc_descriptor_header *)cd;
+	ctl_cls[2] = (struct uvc_descriptor_header *)pd;
+	ctl_cls[3] = (struct uvc_descriptor_header *)od;
+	ctl_cls[4] = NULL;	/* NULL-terminate */
+	opts->fs_control =
+		(const struct uvc_descriptor_header * const *)ctl_cls;
+
+	/* Prepare hs control class descriptors for configfs-based gadgets */
+	ctl_cls = opts->uvc_ss_control_cls;
+	ctl_cls[0] = NULL;	/* assigned elsewhere by configfs */
+	ctl_cls[1] = (struct uvc_descriptor_header *)cd;
+	ctl_cls[2] = (struct uvc_descriptor_header *)pd;
+	ctl_cls[3] = (struct uvc_descriptor_header *)od;
+	ctl_cls[4] = NULL;	/* NULL-terminate */
+	opts->ss_control =
+		(const struct uvc_descriptor_header * const *)ctl_cls;
+
+	opts->streaming_interval = 1;
+	opts->streaming_maxpacket = 1024;
+
+	uvcg_attach_configfs(opts);
 	return &opts->func_inst;
 }
 
 static void uvc_free(struct usb_function *f)
 {
 	struct uvc_device *uvc = to_uvc(f);
-
+	struct f_uvc_opts *opts = container_of(f->fi, struct f_uvc_opts,
+					       func_inst);
+	--opts->refcnt;
 	kfree(uvc);
 }
 
@@ -832,6 +912,7 @@ static struct usb_function *uvc_alloc(struct usb_function_instance *fi)
 {
 	struct uvc_device *uvc;
 	struct f_uvc_opts *opts;
+	struct uvc_descriptor_header **strm_cls;
 
 	uvc = kzalloc(sizeof(*uvc), GFP_KERNEL);
 	if (uvc == NULL)
@@ -840,11 +921,30 @@ static struct usb_function *uvc_alloc(struct usb_function_instance *fi)
 	uvc->state = UVC_STATE_DISCONNECTED;
 	opts = fi_to_f_uvc_opts(fi);
 
+	mutex_lock(&opts->lock);
+	if (opts->uvc_fs_streaming_cls) {
+		strm_cls = opts->uvc_fs_streaming_cls;
+		opts->fs_streaming =
+			(const struct uvc_descriptor_header * const *)strm_cls;
+	}
+	if (opts->uvc_hs_streaming_cls) {
+		strm_cls = opts->uvc_hs_streaming_cls;
+		opts->hs_streaming =
+			(const struct uvc_descriptor_header * const *)strm_cls;
+	}
+	if (opts->uvc_ss_streaming_cls) {
+		strm_cls = opts->uvc_ss_streaming_cls;
+		opts->ss_streaming =
+			(const struct uvc_descriptor_header * const *)strm_cls;
+	}
+
 	uvc->desc.fs_control = opts->fs_control;
 	uvc->desc.ss_control = opts->ss_control;
 	uvc->desc.fs_streaming = opts->fs_streaming;
 	uvc->desc.hs_streaming = opts->hs_streaming;
 	uvc->desc.ss_streaming = opts->ss_streaming;
+	++opts->refcnt;
+	mutex_unlock(&opts->lock);
 
 	/* Register the function. */
 	uvc->func.name = "uvc";