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linux-next/drivers/usb/gadget/uvc.h
Bhupesh Sharma 41837c352f usb: gadget: uvc: Delay the status stage when setting alternate setting 1
This patch adds the support in UVC webcam gadget design for providing
USB_GADGET_DELAYED_STATUS in response to a set_interface(alt setting 1)
command issue by the Host.

The current UVC webcam gadget design generates a STREAMON event
corresponding to a set_interface(alt setting 1) command from the Host.
This STREAMON event will eventually be routed to a real V4L2 device.

To start video streaming, it may be required to perform some register
writes to a camera sensor device over slow external busses like I2C or
SPI. So, it makes sense to ensure that we delay the STATUS stage of the
set_interface (alt setting 1) command.

Otherwise, a lot of ISOC IN tokens sent by the Host will be replied to
by zero-length packets by the webcam device. On certain Hosts this may
even lead to ISOC URBs been cancelled from the Host side.

So, as soon as we finish doing all the "streaming" related stuff on the
real V4L2 device, we call a STREAMON ioctl on the UVC side and from here
we call the 'usb_composite_setup_continue' function to complete the
status stage of the set_interface(alt setting 1) command.

Further, we need to ensure that we queue no video buffers on the UVC
webcam gadget, until we de-queue a video buffer from the V4L2 device.
So, the application should call the STREAMON on UVC side only when it
has dequeued sufficient buffers from the V4L2 side and queued them to
the UVC gadget.

Signed-off-by: Bhupesh Sharma <bhupesh.sharma@st.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Tested-by: Bhupesh Sharma <bhupesh.sharma@st.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
2013-03-18 11:18:21 +02:00

201 lines
4.8 KiB
C

/*
* 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
{
__s32 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
/* ------------------------------------------------------------------------
* Debugging, printing and logging
*/
#ifdef __KERNEL__
#include <linux/usb.h> /* For usb_endpoint_* */
#include <linux/usb/gadget.h>
#include <linux/videodev2.h>
#include <linux/version.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_gadget_trace_param;
#define uvc_trace(flag, msg...) \
do { \
if (uvc_gadget_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 UVC_NUM_REQUESTS 4
#define UVC_MAX_REQUEST_SIZE 64
#define UVC_MAX_EVENTS 4
/* ------------------------------------------------------------------------
* 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 *fs_control;
const struct uvc_descriptor_header * const *ss_control;
const struct uvc_descriptor_header * const *fs_streaming;
const struct uvc_descriptor_header * const *hs_streaming;
const struct uvc_descriptor_header * const *ss_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)
/* ------------------------------------------------------------------------
* Functions
*/
extern void uvc_function_setup_continue(struct uvc_device *uvc);
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_ */