USB gadget: video class function driver

This USB video class function driver implements a video capture device from the
host's point of view. It creates a V4L2 output device on the gadget's side to
transfer data from a userspace application over USB.

The UVC-specific descriptors are passed by the gadget driver to the UVC
function driver, making them completely configurable without any modification
to the function's driver code.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 241 insertions, 0 deletions

diff --git a/drivers/usb/gadget/uvc.h b/drivers/usb/gadget/uvc.h
new file mode 100644
index 000000000000..0a705e63c936
--- /dev/null
+++ b/drivers/usb/gadget/uvc.h
@@ -0,0 +1,241 @@
+/*
+ *	uvc_gadget.h  --  USB Video Class Gadget driver
+ *
+ *	Copyright (C) 2009-2010
+ *	    Laurent Pinchart (laurent.pinchart@ideasonboard.com)
+ *
+ *	This program is free software; you can redistribute it and/or modify
+ *	it under the terms of the GNU General Public License as published by
+ *	the Free Software Foundation; either version 2 of the License, or
+ *	(at your option) any later version.
+ *
+ */
+
+#ifndef _UVC_GADGET_H_
+#define _UVC_GADGET_H_
+
+#include <linux/ioctl.h>
+#include <linux/types.h>
+#include <linux/usb/ch9.h>
+
+#define UVC_EVENT_FIRST			(V4L2_EVENT_PRIVATE_START + 0)
+#define UVC_EVENT_CONNECT		(V4L2_EVENT_PRIVATE_START + 0)
+#define UVC_EVENT_DISCONNECT		(V4L2_EVENT_PRIVATE_START + 1)
+#define UVC_EVENT_STREAMON		(V4L2_EVENT_PRIVATE_START + 2)
+#define UVC_EVENT_STREAMOFF		(V4L2_EVENT_PRIVATE_START + 3)
+#define UVC_EVENT_SETUP			(V4L2_EVENT_PRIVATE_START + 4)
+#define UVC_EVENT_DATA			(V4L2_EVENT_PRIVATE_START + 5)
+#define UVC_EVENT_LAST			(V4L2_EVENT_PRIVATE_START + 5)
+
+struct uvc_request_data
+{
+	unsigned int length;
+	__u8 data[60];
+};
+
+struct uvc_event
+{
+	union {
+		enum usb_device_speed speed;
+		struct usb_ctrlrequest req;
+		struct uvc_request_data data;
+	};
+};
+
+#define UVCIOC_SEND_RESPONSE		_IOW('U', 1, struct uvc_request_data)
+
+#define UVC_INTF_CONTROL		0
+#define UVC_INTF_STREAMING		1
+
+/* ------------------------------------------------------------------------
+ * UVC constants & structures
+ */
+
+/* Values for bmHeaderInfo (Video and Still Image Payload Headers, 2.4.3.3) */
+#define UVC_STREAM_EOH				(1 << 7)
+#define UVC_STREAM_ERR				(1 << 6)
+#define UVC_STREAM_STI				(1 << 5)
+#define UVC_STREAM_RES				(1 << 4)
+#define UVC_STREAM_SCR				(1 << 3)
+#define UVC_STREAM_PTS				(1 << 2)
+#define UVC_STREAM_EOF				(1 << 1)
+#define UVC_STREAM_FID				(1 << 0)
+
+struct uvc_streaming_control {
+	__u16 bmHint;
+	__u8  bFormatIndex;
+	__u8  bFrameIndex;
+	__u32 dwFrameInterval;
+	__u16 wKeyFrameRate;
+	__u16 wPFrameRate;
+	__u16 wCompQuality;
+	__u16 wCompWindowSize;
+	__u16 wDelay;
+	__u32 dwMaxVideoFrameSize;
+	__u32 dwMaxPayloadTransferSize;
+	__u32 dwClockFrequency;
+	__u8  bmFramingInfo;
+	__u8  bPreferedVersion;
+	__u8  bMinVersion;
+	__u8  bMaxVersion;
+} __attribute__((__packed__));
+
+/* ------------------------------------------------------------------------
+ * Debugging, printing and logging
+ */
+
+#ifdef __KERNEL__
+
+#include <linux/usb.h>	/* For usb_endpoint_* */
+#include <linux/usb/gadget.h>
+#include <linux/videodev2.h>
+#include <media/v4l2-fh.h>
+
+#include "uvc_queue.h"
+
+#define UVC_TRACE_PROBE				(1 << 0)
+#define UVC_TRACE_DESCR				(1 << 1)
+#define UVC_TRACE_CONTROL			(1 << 2)
+#define UVC_TRACE_FORMAT			(1 << 3)
+#define UVC_TRACE_CAPTURE			(1 << 4)
+#define UVC_TRACE_CALLS				(1 << 5)
+#define UVC_TRACE_IOCTL				(1 << 6)
+#define UVC_TRACE_FRAME				(1 << 7)
+#define UVC_TRACE_SUSPEND			(1 << 8)
+#define UVC_TRACE_STATUS			(1 << 9)
+
+#define UVC_WARN_MINMAX				0
+#define UVC_WARN_PROBE_DEF			1
+
+extern unsigned int uvc_trace_param;
+
+#define uvc_trace(flag, msg...) \
+	do { \
+		if (uvc_trace_param & flag) \
+			printk(KERN_DEBUG "uvcvideo: " msg); \
+	} while (0)
+
+#define uvc_warn_once(dev, warn, msg...) \
+	do { \
+		if (!test_and_set_bit(warn, &dev->warnings)) \
+			printk(KERN_INFO "uvcvideo: " msg); \
+	} while (0)
+
+#define uvc_printk(level, msg...) \
+	printk(level "uvcvideo: " msg)
+
+/* ------------------------------------------------------------------------
+ * Driver specific constants
+ */
+
+#define DRIVER_VERSION				"0.1.0"
+#define DRIVER_VERSION_NUMBER			KERNEL_VERSION(0, 1, 0)
+
+#define DMA_ADDR_INVALID			(~(dma_addr_t)0)
+
+#define UVC_NUM_REQUESTS			4
+#define UVC_MAX_REQUEST_SIZE			64
+#define UVC_MAX_EVENTS				4
+
+#define USB_DT_INTERFACE_ASSOCIATION_SIZE	8
+#define USB_CLASS_MISC				0xef
+
+/* ------------------------------------------------------------------------
+ * Structures
+ */
+
+struct uvc_video
+{
+	struct usb_ep *ep;
+
+	/* Frame parameters */
+	u8 bpp;
+	u32 fcc;
+	unsigned int width;
+	unsigned int height;
+	unsigned int imagesize;
+
+	/* Requests */
+	unsigned int req_size;
+	struct usb_request *req[UVC_NUM_REQUESTS];
+	__u8 *req_buffer[UVC_NUM_REQUESTS];
+	struct list_head req_free;
+	spinlock_t req_lock;
+
+	void (*encode) (struct usb_request *req, struct uvc_video *video,
+			struct uvc_buffer *buf);
+
+	/* Context data used by the completion handler */
+	__u32 payload_size;
+	__u32 max_payload_size;
+
+	struct uvc_video_queue queue;
+	unsigned int fid;
+};
+
+enum uvc_state
+{
+	UVC_STATE_DISCONNECTED,
+	UVC_STATE_CONNECTED,
+	UVC_STATE_STREAMING,
+};
+
+struct uvc_device
+{
+	struct video_device *vdev;
+	enum uvc_state state;
+	struct usb_function func;
+	struct uvc_video video;
+
+	/* Descriptors */
+	struct {
+		const struct uvc_descriptor_header * const *control;
+		const struct uvc_descriptor_header * const *fs_streaming;
+		const struct uvc_descriptor_header * const *hs_streaming;
+	} desc;
+
+	unsigned int control_intf;
+	struct usb_ep *control_ep;
+	struct usb_request *control_req;
+	void *control_buf;
+
+	unsigned int streaming_intf;
+
+	/* Events */
+	unsigned int event_length;
+	unsigned int event_setup_out : 1;
+};
+
+static inline struct uvc_device *to_uvc(struct usb_function *f)
+{
+	return container_of(f, struct uvc_device, func);
+}
+
+struct uvc_file_handle
+{
+	struct v4l2_fh vfh;
+	struct uvc_video *device;
+};
+
+#define to_uvc_file_handle(handle) \
+	container_of(handle, struct uvc_file_handle, vfh)
+
+extern struct v4l2_file_operations uvc_v4l2_fops;
+
+/* ------------------------------------------------------------------------
+ * Functions
+ */
+
+extern int uvc_video_enable(struct uvc_video *video, int enable);
+extern int uvc_video_init(struct uvc_video *video);
+extern int uvc_video_pump(struct uvc_video *video);
+
+extern void uvc_endpoint_stream(struct uvc_device *dev);
+
+extern void uvc_function_connect(struct uvc_device *uvc);
+extern void uvc_function_disconnect(struct uvc_device *uvc);
+
+#endif /* __KERNEL__ */
+
+#endif /* _UVC_GADGET_H_ */
+