pwc-if.c

基于S3CEB2410平台LINUX操作系统下 USB驱动源代码

			if (pdev->sbuf[i].urb != NULL)
				usb_free_urb(pdev->sbuf[i].urb);
			pdev->sbuf[i].urb = NULL;
			i--;
		}
		return ret;
	}
	
	
	/* init URB structure */	
	for (i = 0; i < MAX_ISO_BUFS; i++) {
		urb = pdev->sbuf[i].urb;

		urb->next = pdev->sbuf[(i + 1) % MAX_ISO_BUFS].urb;
		urb->dev = udev;
	        urb->pipe = usb_rcvisocpipe(udev, pdev->vendpoint);
		urb->transfer_flags = USB_ISO_ASAP;
	        urb->transfer_buffer = pdev->sbuf[i].data;
	        urb->transfer_buffer_length = ISO_BUFFER_SIZE;
	        urb->complete = pwc_isoc_handler;
	        urb->context = pdev;
		urb->start_frame = 0;
		urb->number_of_packets = ISO_FRAMES_PER_DESC;
		for (j = 0; j < ISO_FRAMES_PER_DESC; j++) {
			urb->iso_frame_desc[j].offset = j * ISO_MAX_FRAME_SIZE;
			urb->iso_frame_desc[j].length = ISO_MAX_FRAME_SIZE;
		}
	}

	/* link */
	for (i = 0; i < MAX_ISO_BUFS; i++) {
		ret = usb_submit_urb(pdev->sbuf[i].urb);
		if (ret)
			Err("isoc_init() submit_urb %d failed with error %d\n", i, ret);
		else
			Trace(TRACE_OPEN, "pwc_isoc_init(): URB submitted.\n");
	}

	/* data should stream in now */
	pdev->iso_init = 1;
	return 0;
}

static void pwc_isoc_cleanup(struct pwc_device *pdev)
{
	int i;
	
	if (pdev == NULL)
		return;
	if (!pdev->iso_init)
		return;
	/* Stop camera, but only if we are sure the camera is still there */
	if (!pdev->unplugged)
		usb_set_interface(pdev->udev, 0, 0);
	/* Unlinking ISOC buffers one by one */
	for (i = MAX_ISO_BUFS - 1; i >= 0; i--) {
		pdev->sbuf[i].urb->next = NULL;
		usb_unlink_urb(pdev->sbuf[i].urb);
		usb_free_urb(pdev->sbuf[i].urb);
		pdev->sbuf[i].urb = NULL;
	}
	pdev->iso_init = 0;
}

int pwc_try_video_mode(struct pwc_device *pdev, int width, int height, int new_fps, int new_compression, int new_snapshot)
{
	int ret;

	/* Stop isoc stuff */
	pwc_isoc_cleanup(pdev);
	/* Reset parameters */
	pwc_reset_buffers(pdev);
	/* Try to set video mode... */
	ret = pwc_set_video_mode(pdev, width, height, new_fps, new_compression, new_snapshot);
	if (ret) /* That failed... restore old mode (we know that worked) */
		ret = pwc_set_video_mode(pdev, pdev->view.x, pdev->view.y, pdev->vframes, pdev->vcompression, pdev->vsnapshot);
	else /* Set (new) alternate interface */
		ret = usb_set_interface(pdev->udev, 0, pdev->valternate);
	if (!ret)
		ret = pwc_isoc_init(pdev);
	pdev->drop_frames = 1; /* try to avoid garbage during switch */
	return ret;
}


static inline void set_mem_leak(void *ptr)
{
	down(&mem_lock);
	if (mem_leak != NULL)
		Err("Memleak: overwriting mem_leak pointer!\n");
	Trace(TRACE_MEMORY, "Setting mem_leak to 0x%p.\n", ptr);
	mem_leak = ptr;
	up(&mem_lock);
}

static inline void free_mem_leak(void)
{
	down(&mem_lock);
	if (mem_leak != NULL) {
		Trace(TRACE_MEMORY, "Freeing mem_leak ptr 0x%p.\n", mem_leak);
		kfree(mem_leak);
		mem_leak = NULL;
	}
	up(&mem_lock);
}


/***************************************************************************/
/* Video4Linux functions */

static int pwc_video_open(struct video_device *vdev, int mode)
{
	int i;
	struct pwc_device *pdev;

	Trace(TRACE_OPEN, "video_open called(0x%p, 0%o).\n", vdev, mode);
	
	if (vdev == NULL)
		BUG();
	pdev = (struct pwc_device *)vdev->priv;
	if (pdev == NULL)
		BUG();
	
	down(&pdev->modlock);
	if (!pdev->usb_init) {
		Trace(TRACE_OPEN, "Doing first time initialization.\n");
		/* Reset camera */
		if (usb_set_interface(pdev->udev, 0, 0))
			Info("Failed to set alternate interface to 0.\n");
		pdev->usb_init = 1;
	}

	/* Turn on camera */
	if (power_save) {
		i = pwc_camera_power(pdev, 1);
		if (i < 0)
			Info("Failed to restore power to the camera! (%d)\n", i);
	}
	/* Set LED on/off time */
	if (pwc_set_leds(pdev, led_on, led_off) < 0)
		Info("Failed to set LED on/off time.\n");

	/* Find our decompressor, if any */
	pdev->decompressor = pwc_find_decompressor(pdev->type);
#if PWC_DEBUG	
	Debug("Found decompressor for %d at 0x%p\n", pdev->type, pdev->decompressor);
#endif

	/* So far, so good. Allocate memory. */
	i = pwc_allocate_buffers(pdev);
	if (i < 0) {
		Trace(TRACE_OPEN, "Failed to allocate buffer memory.\n");
		up(&pdev->modlock);
		return i;
	}
	
	/* Reset buffers & parameters */
	pwc_reset_buffers(pdev);
	for (i = 0; i < default_mbufs; i++)
		pdev->image_used[i] = 0;
	pdev->vframe_count = 0;
	pdev->vframes_dumped = 0;
	pdev->vframes_error = 0;
	pdev->vpalette = default_palette;
#if PWC_DEBUG	
	pdev->sequence = 0;
#endif

	/* Set some defaults */
	pdev->vsnapshot = 0;
	if (pdev->type == 730 || pdev->type == 740 || pdev->type == 750)
		pdev->vsize = PSZ_QSIF;
	else
		pdev->vsize = PSZ_QCIF;
	pdev->vframes = 10;

	/* Start iso pipe for video; first try user-supplied size/fps, if
	   that fails try QCIF/10 or QSIF/10 (a reasonable default), 
	   then give up 
	 */
	i = pwc_set_video_mode(pdev, pwc_image_sizes[default_size].x, pwc_image_sizes[default_size].y, default_fps, pdev->vcompression, 0);
	if (i)	{
		Trace(TRACE_OPEN, "First attempt at set_video_mode failed.\n");
		if (pdev->type == 730 || pdev->type == 740 || pdev->type == 750)
			i = pwc_set_video_mode(pdev, pwc_image_sizes[PSZ_QSIF].x, pwc_image_sizes[PSZ_QSIF].y, 10, pdev->vcompression, 0);
		else
			i = pwc_set_video_mode(pdev, pwc_image_sizes[PSZ_QCIF].x, pwc_image_sizes[PSZ_QCIF].y, 10, pdev->vcompression, 0);
	}
	if (i) {
		Trace(TRACE_OPEN, "Second attempt at set_video_mode failed.\n");
		up(&pdev->modlock);
		return i;
	}
	
	i = usb_set_interface(pdev->udev, 0, pdev->valternate);
	if (i) {
		Trace(TRACE_OPEN, "Failed to set alternate interface = %d.\n", i);
		up(&pdev->modlock);
		return -EINVAL;
	}
	i = pwc_isoc_init(pdev);
	if (i) {
		Trace(TRACE_OPEN, "Failed to init ISOC stuff = %d.\n", i);
		MOD_DEC_USE_COUNT;
		up(&pdev->modlock);
		return i;
	}

	pdev->vopen++;
	/* lock decompressor; this has a small race condition, since we 
	   could in theory unload pwcx.o between pwc_find_decompressor()
	   above and this call. I doubt it's ever going to be a problem.
	 */
	if (pdev->decompressor != NULL)
		pdev->decompressor->lock();
	up(&pdev->modlock);
	Trace(TRACE_OPEN, "video_open() returning 0.\n");
	return 0;
}

/* Note that all cleanup is done in the reverse order as in _open */
static void pwc_video_close(struct video_device *vdev)
{
	struct pwc_device *pdev;
	int i;

	Trace(TRACE_OPEN, "video_close called(0x%p).\n", vdev);

	pdev = (struct pwc_device *)vdev->priv;
	if (pdev->vopen == 0)
		Info("video_close() called on closed device?\n");

	/* Free isoc URBs */
	pwc_isoc_cleanup(pdev);

	/* Dump statistics, but only if a reasonable amount of frames were
	   processed (to prevent endless log-entries in case of snap-shot
	   programs) 
	 */
	if (pdev->vframe_count > 20)
		Info("Closing video device: %d frames received, dumped %d frames, %d frames with errors.\n", pdev->vframe_count, pdev->vframes_dumped, pdev->vframes_error);

	if (pdev->unplugged) {
		/* The device was unplugged or some other error occured */
		/* We unregister the video_device */
		Trace(TRACE_OPEN, "Delayed video device unregistered.\n");
		video_unregister_device(pdev->vdev);
	}
	else {
		/* Normal close: stop isochronuous and interrupt endpoint */
		Trace(TRACE_OPEN, "Normal close(): setting interface to 0.\n");
		usb_set_interface(pdev->udev, 0, 0);

		/* Turn LEDs off */
		if (pwc_set_leds(pdev, 0, 0) < 0)
			Info("Failed to set LED on/off time..\n");
		/* Power down camere to save energy */
		if (power_save) {
			i = pwc_camera_power(pdev, 0);
			if (i < 0) 
				Err("Failed to power down camera (%d)\n", i);
		}
	}

	pdev->vopen = 0;
	if (pdev->decompressor != NULL) {
		pdev->decompressor->exit();
		pdev->decompressor->unlock();
	}
	pwc_free_buffers(pdev);

	/* wake up _disconnect() routine */
	if (pdev->unplugged)
		wake_up(&pdev->remove_ok);
}

/*
 *	FIXME: what about two parallel reads ????
 *      ANSWER: Not supported. You can't open the device more than once,
                despite what the V4L1 interface says. First, I don't see 
                the need, second there's no mechanism of alerting the 
                2nd/3rd/... process of events like changing image size.
                And I don't see the point of blocking that for the 
                2nd/3rd/... process.
                In multi-threaded environments reading parallel from any
                device is tricky anyhow.
 */
 
static long pwc_video_read(struct video_device *vdev, char *buf, unsigned long count, int noblock)
{
	struct pwc_device *pdev;
	DECLARE_WAITQUEUE(wait, current);

	Trace(TRACE_READ, "video_read(0x%p, %p, %ld, %d) called.\n", vdev, buf, count, noblock);
	if (vdev == NULL)
		return -EFAULT;
	pdev = vdev->priv;
	if (pdev == NULL)
		return -EFAULT;
	if (pdev->unplugged) {
		Info("pwc_video_read: Device got unplugged (1).\n");
		return -EPIPE; /* unplugged device! */
	}

	/* In case we're doing partial reads, we don't have to wait for a frame */
	if (pdev->image_read_pos == 0) {
		/* Do wait queueing according to the (doc)book */
		add_wait_queue(&pdev->frameq, &wait);
		while (pdev->full_frames == NULL) {
	                if (noblock) {
	                	remove_wait_queue(&pdev->frameq, &wait);
	                	set_current_state(TASK_RUNNING);
	                	return -EWOULDBLOCK;
	                }
	                if (signal_pending(current)) {
	                	remove_wait_queue(&pdev->frameq, &wait);
	                	set_current_state(TASK_RUNNING);
	                	return -ERESTARTSYS;
	                }
	                schedule();
	               	set_current_state(TASK_INTERRUPTIBLE);
		}
		remove_wait_queue(&pdev->frameq, &wait);
		set_current_state(TASK_RUNNING);
	                                                                                                                                                                                
		/* Decompress [, convert] and release frame */
		if (pwc_handle_frame(pdev))
			return -EFAULT;
	}

	Trace(TRACE_READ, "Copying data to user space.\n");
	/* copy bytes to user space; we allow for partial reads */
	if (count + pdev->image_read_pos > pdev->view.size)
		count = pdev->view.size - pdev->image_read_pos;
	if (copy_to_user(buf, pdev->image_ptr[pdev->fill_image] + pdev->image_read_pos, count))
		return -EFAULT;
	pdev->image_read_pos += count;
	if (pdev->image_read_pos >= pdev->view.size) { /* All data has been read */
		pdev->image_read_pos = 0;
		pwc_next_image(pdev);
	}
	return count;
}


static long pwc_video_write(struct video_device *vdev, const char *buf, unsigned long count, int noblock)
{
	return -EINVAL;   
}

static unsigned int pwc_video_poll(struct video_device *vdev, struct file *file, poll_table *wait)
{
	struct pwc_device *pdev;
	
	if (vdev == NULL)
		return -EFAULT;
	pdev = vdev->priv;
	if (pdev == NULL)
		return -EFAULT;
	
	poll_wait(file, &pdev->frameq, wait);
	if (pdev->unplugged) {
		Info("pwc_video_poll: Device got unplugged.\n");
		return POLLERR;
	}		
	if (pdev->full_frames != NULL) /* we have frames waiting */
		return (POLLIN | POLLRDNORM);

	return 0;
}
        
static int pwc_video_ioctl(struct video_device *vdev, unsigned int cmd, void *arg)
{
	struct pwc_device *pdev;
	DECLARE_WAITQUEUE(wait, current);
	
	if (vdev == NULL)
		return -EFAULT;
	pdev = vdev->priv;
	if (pdev == NULL)
		return -EFAULT;

	switch (cmd) {
		/* Query cabapilities */
		case VIDIOCGCAP: 
		{
			struct video_capability caps;

			strcpy(caps.name, vdev->name);
			caps.type = VID_TYPE_CAPTURE;
			caps.channels = 1;
			caps.audios = 1;
			caps.minwidth  = pdev->view_min.x;
			caps.minheight = pdev->view_min.y;
			caps.maxwidth  = pdev->view_max.x;
			caps.maxheight = pdev->view_max.y;
			if (copy_to_user(arg, &caps, sizeof(caps)))
				return -EFAULT;
			break;
		}

		/* Channel functions (simulate 1 channel) */
		case VIDIOCGCHAN:
		{
			struct video_channel v;

			if (copy_from_user(&v, arg, sizeof(v)))
				return -EFAULT;
			if (v.channel != 0)
				return -EINVAL;

			v.flags = 0;
			v.tuners = 0;
			v.type = VIDEO_TYPE_CAMERA;
			strcpy(v.name, "Webcam");

			if (copy_to_user(arg, &v, sizeof(v)))
				return -EFAULT;

			return 0;