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_ */
+