usbvideo.c

来自「Linux Kernel 2.6.9 for OMAP1710」· C语言 代码 · 共 2,283 行 · 第 1/5 页

/*
 * usbvideo_Disconnect()
 *
 * This procedure stops all driver activity. Deallocation of
 * the interface-private structure (pointed by 'ptr') is done now
 * (if we don't have any open files) or later, when those files
 * are closed. After that driver should be removable.
 *
 * This code handles surprise removal. The uvd->user is a counter which
 * increments on open() and decrements on close(). If we see here that
 * this counter is not 0 then we have a client who still has us opened.
 * We set uvd->remove_pending flag as early as possible, and after that
 * all access to the camera will gracefully fail. These failures should
 * prompt client to (eventually) close the video device, and then - in
 * usbvideo_v4l_close() - we decrement uvd->uvd_used and usage counter.
 *
 * History:
 * 22-Jan-2000 Added polling of MOD_IN_USE to delay removal until all users gone.
 * 27-Jan-2000 Reworked to allow pending disconnects; see xxx_close()
 * 24-May-2000 Corrected to prevent race condition (MOD_xxx_USE_COUNT).
 * 19-Oct-2000 Moved to usbvideo module.
 */
static void usbvideo_Disconnect(struct usb_interface *intf)
{
	struct uvd *uvd = usb_get_intfdata (intf);
	int i;

	if (uvd == NULL) {
		err("%s($%p): Illegal call.", __FUNCTION__, intf);
		return;
	}

	usb_set_intfdata (intf, NULL);

	usbvideo_ClientIncModCount(uvd);
	if (uvd->debug > 0)
		info("%s(%p.)", __FUNCTION__, intf);

	down(&uvd->lock);
	uvd->remove_pending = 1; /* Now all ISO data will be ignored */

	/* At this time we ask to cancel outstanding URBs */
	GET_CALLBACK(uvd, stopDataPump)(uvd);

	for (i=0; i < USBVIDEO_NUMSBUF; i++)
		usb_free_urb(uvd->sbuf[i].urb);

	usb_put_dev(uvd->dev);
	uvd->dev = NULL;    	    /* USB device is no more */

	video_unregister_device(&uvd->vdev);
	if (uvd->debug > 0)
		info("%s: Video unregistered.", __FUNCTION__);

	if (uvd->user)
		info("%s: In use, disconnect pending.", __FUNCTION__);
	else
		usbvideo_CameraRelease(uvd);
	up(&uvd->lock);
	info("USB camera disconnected.");

	usbvideo_ClientDecModCount(uvd);
}

/*
 * usbvideo_CameraRelease()
 *
 * This code does final release of uvd. This happens
 * after the device is disconnected -and- all clients
 * closed their files.
 *
 * History:
 * 27-Jan-2000 Created.
 */
static void usbvideo_CameraRelease(struct uvd *uvd)
{
	if (uvd == NULL) {
		err("%s: Illegal call", __FUNCTION__);
		return;
	}

	RingQueue_Free(&uvd->dp);
	if (VALID_CALLBACK(uvd, userFree))
		GET_CALLBACK(uvd, userFree)(uvd);
	uvd->uvd_used = 0;	/* This is atomic, no need to take mutex */
}

/*
 * usbvideo_find_struct()
 *
 * This code searches the array of preallocated (static) structures
 * and returns index of the first one that isn't in use. Returns -1
 * if there are no free structures.
 *
 * History:
 * 27-Jan-2000 Created.
 */
static int usbvideo_find_struct(struct usbvideo *cams)
{
	int u, rv = -1;

	if (cams == NULL) {
		err("No usbvideo handle?");
		return -1;
	}
	down(&cams->lock);
	for (u = 0; u < cams->num_cameras; u++) {
		struct uvd *uvd = &cams->cam[u];
		if (!uvd->uvd_used) /* This one is free */
		{
			uvd->uvd_used = 1;	/* In use now */
			init_MUTEX(&uvd->lock);	/* to 1 == available */
			uvd->dev = NULL;
			rv = u;
			break;
		}
	}
	up(&cams->lock);
	return rv;
}

static struct file_operations usbvideo_fops = {
	.owner =  THIS_MODULE,
	.open =   usbvideo_v4l_open,
	.release =usbvideo_v4l_close,
	.read =   usbvideo_v4l_read,
	.mmap =   usbvideo_v4l_mmap,
	.ioctl =  usbvideo_v4l_ioctl,
	.llseek = no_llseek,
};
static struct video_device usbvideo_template = {
	.owner =      THIS_MODULE,
	.type =       VID_TYPE_CAPTURE,
	.hardware =   VID_HARDWARE_CPIA,
	.fops =       &usbvideo_fops,
};

struct uvd *usbvideo_AllocateDevice(struct usbvideo *cams)
{
	int i, devnum;
	struct uvd *uvd = NULL;

	if (cams == NULL) {
		err("No usbvideo handle?");
		return NULL;
	}

	devnum = usbvideo_find_struct(cams);
	if (devnum == -1) {
		err("IBM USB camera driver: Too many devices!");
		return NULL;
	}
	uvd = &cams->cam[devnum];
	dbg("Device entry #%d. at $%p", devnum, uvd);

	/* Not relying upon caller we increase module counter ourselves */
	usbvideo_ClientIncModCount(uvd);

	down(&uvd->lock);
	for (i=0; i < USBVIDEO_NUMSBUF; i++) {
		uvd->sbuf[i].urb = usb_alloc_urb(FRAMES_PER_DESC, GFP_KERNEL);
		if (uvd->sbuf[i].urb == NULL) {
			err("usb_alloc_urb(%d.) failed.", FRAMES_PER_DESC);
			uvd->uvd_used = 0;
			uvd = NULL;
			goto allocate_done;
		}
	}
	uvd->user=0;
	uvd->remove_pending = 0;
	uvd->last_error = 0;
	RingQueue_Initialize(&uvd->dp);

	/* Initialize video device structure */
	uvd->vdev = usbvideo_template;
	sprintf(uvd->vdev.name, "%.20s USB Camera", cams->drvName);
	/*
	 * The client is free to overwrite those because we
	 * return control to the client's probe function right now.
	 */
allocate_done:
	up (&uvd->lock);
	usbvideo_ClientDecModCount(uvd);
	return uvd;
}

EXPORT_SYMBOL(usbvideo_AllocateDevice);

int usbvideo_RegisterVideoDevice(struct uvd *uvd)
{
	char tmp1[20], tmp2[20];	/* Buffers for printing */

	if (uvd == NULL) {
		err("%s: Illegal call.", __FUNCTION__);
		return -EINVAL;
	}
	if (uvd->video_endp == 0) {
		info("%s: No video endpoint specified; data pump disabled.", __FUNCTION__);
	}
	if (uvd->paletteBits == 0) {
		err("%s: No palettes specified!", __FUNCTION__);
		return -EINVAL;
	}
	if (uvd->defaultPalette == 0) {
		info("%s: No default palette!", __FUNCTION__);
	}

	uvd->max_frame_size = VIDEOSIZE_X(uvd->canvas) *
		VIDEOSIZE_Y(uvd->canvas) * V4L_BYTES_PER_PIXEL;
	usbvideo_VideosizeToString(tmp1, sizeof(tmp1), uvd->videosize);
	usbvideo_VideosizeToString(tmp2, sizeof(tmp2), uvd->canvas);

	if (uvd->debug > 0) {
		info("%s: iface=%d. endpoint=$%02x paletteBits=$%08lx",
		     __FUNCTION__, uvd->iface, uvd->video_endp, uvd->paletteBits);
	}
	if (video_register_device(&uvd->vdev, VFL_TYPE_GRABBER, video_nr) == -1) {
		err("%s: video_register_device failed", __FUNCTION__);
		return -EPIPE;
	}
	if (uvd->debug > 1) {
		info("%s: video_register_device() successful", __FUNCTION__);
	}
	if (uvd->dev == NULL) {
		err("%s: uvd->dev == NULL", __FUNCTION__);
		return -EINVAL;
	}

	info("%s on /dev/video%d: canvas=%s videosize=%s",
	     (uvd->handle != NULL) ? uvd->handle->drvName : "???",
	     uvd->vdev.minor, tmp2, tmp1);

	usb_get_dev(uvd->dev);
	return 0;
}

EXPORT_SYMBOL(usbvideo_RegisterVideoDevice);

/* ******************************************************************** */

static int usbvideo_v4l_mmap(struct file *file, struct vm_area_struct *vma)
{
	struct uvd *uvd = file->private_data;
	unsigned long start = vma->vm_start;
	unsigned long size  = vma->vm_end-vma->vm_start;
	unsigned long page, pos;

	if (!CAMERA_IS_OPERATIONAL(uvd))
		return -EFAULT;

	if (size > (((USBVIDEO_NUMFRAMES * uvd->max_frame_size) + PAGE_SIZE - 1) & ~(PAGE_SIZE - 1)))
		return -EINVAL;

	pos = (unsigned long) uvd->fbuf;
	while (size > 0) {
		page = usbvideo_kvirt_to_pa(pos);
		if (remap_page_range(vma, start, page, PAGE_SIZE, PAGE_SHARED))
			return -EAGAIN;

		start += PAGE_SIZE;
		pos += PAGE_SIZE;
		if (size > PAGE_SIZE)
			size -= PAGE_SIZE;
		else
			size = 0;
	}

	return 0;
}

/*
 * usbvideo_v4l_open()
 *
 * This is part of Video 4 Linux API. The driver can be opened by one
 * client only (checks internal counter 'uvdser'). The procedure
 * then allocates buffers needed for video processing.
 *
 * History:
 * 22-Jan-2000 Rewrote, moved scratch buffer allocation here. Now the
 *             camera is also initialized here (once per connect), at
 *             expense of V4L client (it waits on open() call).
 * 27-Jan-2000 Used USBVIDEO_NUMSBUF as number of URB buffers.
 * 24-May-2000 Corrected to prevent race condition (MOD_xxx_USE_COUNT).
 */
static int usbvideo_v4l_open(struct inode *inode, struct file *file)
{
	struct video_device *dev = video_devdata(file);
	struct uvd *uvd = (struct uvd *) dev;
	const int sb_size = FRAMES_PER_DESC * uvd->iso_packet_len;
	int i, errCode = 0;

	if (uvd->debug > 1)
		info("%s($%p)", __FUNCTION__, dev);

	usbvideo_ClientIncModCount(uvd);
	down(&uvd->lock);

	if (uvd->user) {
		err("%s: Someone tried to open an already opened device!", __FUNCTION__);
		errCode = -EBUSY;
	} else {
		/* Clear statistics */
		memset(&uvd->stats, 0, sizeof(uvd->stats));

		/* Clean pointers so we know if we allocated something */
		for (i=0; i < USBVIDEO_NUMSBUF; i++)
			uvd->sbuf[i].data = NULL;

		/* Allocate memory for the frame buffers */
		uvd->fbuf_size = USBVIDEO_NUMFRAMES * uvd->max_frame_size;
		uvd->fbuf = usbvideo_rvmalloc(uvd->fbuf_size);
		RingQueue_Allocate(&uvd->dp, RING_QUEUE_SIZE);
		if ((uvd->fbuf == NULL) ||
		    (!RingQueue_IsAllocated(&uvd->dp))) {
			err("%s: Failed to allocate fbuf or dp", __FUNCTION__);
			errCode = -ENOMEM;
		} else {
			/* Allocate all buffers */
			for (i=0; i < USBVIDEO_NUMFRAMES; i++) {
				uvd->frame[i].frameState = FrameState_Unused;
				uvd->frame[i].data = uvd->fbuf + i*(uvd->max_frame_size);
				/*
				 * Set default sizes in case IOCTL (VIDIOCMCAPTURE)
				 * is not used (using read() instead).
				 */
				uvd->frame[i].canvas = uvd->canvas;
				uvd->frame[i].seqRead_Index = 0;
			}
			for (i=0; i < USBVIDEO_NUMSBUF; i++) {
				uvd->sbuf[i].data = kmalloc(sb_size, GFP_KERNEL);
				if (uvd->sbuf[i].data == NULL) {
					errCode = -ENOMEM;
					break;
				}
			}
		}
		if (errCode != 0) {
			/* Have to free all that memory */
			if (uvd->fbuf != NULL) {
				usbvideo_rvfree(uvd->fbuf, uvd->fbuf_size);
				uvd->fbuf = NULL;
			}
			RingQueue_Free(&uvd->dp);
			for (i=0; i < USBVIDEO_NUMSBUF; i++) {
				if (uvd->sbuf[i].data != NULL) {
					kfree (uvd->sbuf[i].data);
					uvd->sbuf[i].data = NULL;
				}
			}
		}
	}

	/* If so far no errors then we shall start the camera */
	if (errCode == 0) {
		/* Start data pump if we have valid endpoint */
		if (uvd->video_endp != 0)
			errCode = GET_CALLBACK(uvd, startDataPump)(uvd);
		if (errCode == 0) {
			if (VALID_CALLBACK(uvd, setupOnOpen)) {
				if (uvd->debug > 1)
					info("%s: setupOnOpen callback", __FUNCTION__);
				errCode = GET_CALLBACK(uvd, setupOnOpen)(uvd);
				if (errCode < 0) {
					err("%s: setupOnOpen callback failed (%d.).",
					    __FUNCTION__, errCode);
				} else if (uvd->debug > 1) {
					info("%s: setupOnOpen callback successful", __FUNCTION__);
				}
			}
			if (errCode == 0) {
				uvd->settingsAdjusted = 0;
				if (uvd->debug > 1)
					info("%s: Open succeeded.", __FUNCTION__);
				uvd->user++;
				file->private_data = uvd;
			}
		}
	}
	up(&uvd->lock);
	if (errCode != 0)
		usbvideo_ClientDecModCount(uvd);
	if (uvd->debug > 0)
		info("%s: Returning %d.", __FUNCTION__, errCode);
	return errCode;
}

/*
 * usbvideo_v4l_close()
 *
 * This is part of Video 4 Linux API. The procedure
 * stops streaming and deallocates all buffers that were earlier
 * allocated in usbvideo_v4l_open().
 *
 * History:
 * 22-Jan-2000 Moved scratch buffer deallocation here.
 * 27-Jan-2000 Used USBVIDEO_NUMSBUF as number of URB buffers.
 * 24-May-2000 Moved MOD_DEC_USE_COUNT outside of code that can sleep.
 */
static int usbvideo_v4l_close(struct inode *inode, struct file *file)
{
	struct video_device *dev = file->private_data;
	struct uvd *uvd = (struct uvd *) dev;
	int i;

	if (uvd->debug > 1)
		info("%s($%p)", __FUNCTION__, dev);

	down(&uvd->lock);
	GET_CALLBACK(uvd, stopDataPump)(uvd);
	usbvideo_rvfree(uvd->fbuf, uvd->fbuf_size);
	uvd->fbuf = NULL;
	RingQueue_Free(&uvd->dp);

	for (i=0; i < USBVIDEO_NUMSBUF; i++) {
		kfree(uvd->sbuf[i].data);
		uvd->sbuf[i].data = NULL;
	}

#if USBVIDEO_REPORT_STATS
	usbvideo_ReportStatistics(uvd);
#endif    

	uvd->user--;
	if (uvd->remove_pending) {
		if (uvd->debug > 0)
			info("usbvideo_v4l_close: Final disconnect.");
		usbvideo_CameraRelease(uvd);
	}
	up(&uvd->lock);
	usbvideo_ClientDecModCount(uvd);

	if (uvd->debug > 1)
		info("%s: Completed.", __FUNCTION__);
	file->private_data = NULL;
	return 0;
}

/*
 * usbvideo_v4l_ioctl()
 *
 * This is part of Video 4 Linux API. The procedure handles ioctl() calls.
 *
 * History:
 * 22-Jan-2000 Corrected VIDIOCSPICT to reject unsupported settings.
 */
static int usbvideo_v4l_do_ioctl(struct inode *inode, struct file *file,
				 unsigned int cmd, void *arg)
{
	struct uvd *uvd = file->private_data;

	if (!CAMERA_IS_OPERATIONAL(uvd))
		return -EIO;

	switch (cmd) {
		case VIDIOCGCAP:
		{