zc0301_core.c

linux内核源码

static int zc0301_stream_interrupt(struct zc0301_device* cam)
{
	long timeout;

	cam->stream = STREAM_INTERRUPT;
	timeout = wait_event_timeout(cam->wait_stream,
				     (cam->stream == STREAM_OFF) ||
				     (cam->state & DEV_DISCONNECTED),
				     ZC0301_URB_TIMEOUT);
	if (cam->state & DEV_DISCONNECTED)
		return -ENODEV;
	else if (cam->stream != STREAM_OFF) {
		cam->state |= DEV_MISCONFIGURED;
		DBG(1, "URB timeout reached. The camera is misconfigured. To "
		       "use it, close and open /dev/video%d again.",
		    cam->v4ldev->minor);
		return -EIO;
	}

	return 0;
}

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

static int
zc0301_set_compression(struct zc0301_device* cam,
		       struct v4l2_jpegcompression* compression)
{
	int r, err = 0;

	if ((r = zc0301_read_reg(cam, 0x0008)) < 0)
		err += r;
	err += zc0301_write_reg(cam, 0x0008, r | 0x11 | compression->quality);

	return err ? -EIO : 0;
}


static int zc0301_init(struct zc0301_device* cam)
{
	struct zc0301_sensor* s = &cam->sensor;
	struct v4l2_control ctrl;
	struct v4l2_queryctrl *qctrl;
	struct v4l2_rect* rect;
	u8 i = 0;
	int err = 0;

	if (!(cam->state & DEV_INITIALIZED)) {
		mutex_init(&cam->open_mutex);
		init_waitqueue_head(&cam->wait_open);
		qctrl = s->qctrl;
		rect = &(s->cropcap.defrect);
		cam->compression.quality = ZC0301_COMPRESSION_QUALITY;
	} else { /* use current values */
		qctrl = s->_qctrl;
		rect = &(s->_rect);
	}

	if (s->init) {
		err = s->init(cam);
		if (err) {
			DBG(3, "Sensor initialization failed");
			return err;
		}
	}

	if ((err = zc0301_set_compression(cam, &cam->compression))) {
		DBG(3, "set_compression() failed");
		return err;
	}

	if (s->set_crop)
		if ((err = s->set_crop(cam, rect))) {
			DBG(3, "set_crop() failed");
			return err;
		}

	if (s->set_ctrl) {
		for (i = 0; i < ARRAY_SIZE(s->qctrl); i++)
			if (s->qctrl[i].id != 0 &&
			    !(s->qctrl[i].flags & V4L2_CTRL_FLAG_DISABLED)) {
				ctrl.id = s->qctrl[i].id;
				ctrl.value = qctrl[i].default_value;
				err = s->set_ctrl(cam, &ctrl);
				if (err) {
					DBG(3, "Set %s control failed",
					    s->qctrl[i].name);
					return err;
				}
				DBG(3, "Image sensor supports '%s' control",
				    s->qctrl[i].name);
			}
	}

	if (!(cam->state & DEV_INITIALIZED)) {
		mutex_init(&cam->fileop_mutex);
		spin_lock_init(&cam->queue_lock);
		init_waitqueue_head(&cam->wait_frame);
		init_waitqueue_head(&cam->wait_stream);
		cam->nreadbuffers = 2;
		memcpy(s->_qctrl, s->qctrl, sizeof(s->qctrl));
		memcpy(&(s->_rect), &(s->cropcap.defrect),
		       sizeof(struct v4l2_rect));
		cam->state |= DEV_INITIALIZED;
	}

	DBG(2, "Initialization succeeded");
	return 0;
}

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

static void zc0301_release_resources(struct kref *kref)
{
	struct zc0301_device *cam = container_of(kref, struct zc0301_device,
						 kref);
	DBG(2, "V4L2 device /dev/video%d deregistered", cam->v4ldev->minor);
	video_set_drvdata(cam->v4ldev, NULL);
	video_unregister_device(cam->v4ldev);
	usb_put_dev(cam->usbdev);
	kfree(cam->control_buffer);
	kfree(cam);
}


static int zc0301_open(struct inode* inode, struct file* filp)
{
	struct zc0301_device* cam;
	int err = 0;

	if (!down_read_trylock(&zc0301_dev_lock))
		return -EAGAIN;

	cam = video_get_drvdata(video_devdata(filp));

	if (wait_for_completion_interruptible(&cam->probe)) {
		up_read(&zc0301_dev_lock);
		return -ERESTARTSYS;
	}

	kref_get(&cam->kref);

	if (mutex_lock_interruptible(&cam->open_mutex)) {
		kref_put(&cam->kref, zc0301_release_resources);
		up_read(&zc0301_dev_lock);
		return -ERESTARTSYS;
	}

	if (cam->state & DEV_DISCONNECTED) {
		DBG(1, "Device not present");
		err = -ENODEV;
		goto out;
	}

	if (cam->users) {
		DBG(2, "Device /dev/video%d is busy...", cam->v4ldev->minor);
		DBG(3, "Simultaneous opens are not supported");
		if ((filp->f_flags & O_NONBLOCK) ||
		    (filp->f_flags & O_NDELAY)) {
			err = -EWOULDBLOCK;
			goto out;
		}
		DBG(2, "A blocking open() has been requested. Wait for the "
		       "device to be released...");
		up_read(&zc0301_dev_lock);
		err = wait_event_interruptible_exclusive(cam->wait_open,
						(cam->state & DEV_DISCONNECTED)
							 || !cam->users);
		down_read(&zc0301_dev_lock);
		if (err)
			goto out;
		if (cam->state & DEV_DISCONNECTED) {
			err = -ENODEV;
			goto out;
		}
	}

	if (cam->state & DEV_MISCONFIGURED) {
		err = zc0301_init(cam);
		if (err) {
			DBG(1, "Initialization failed again. "
			       "I will retry on next open().");
			goto out;
		}
		cam->state &= ~DEV_MISCONFIGURED;
	}

	if ((err = zc0301_start_transfer(cam)))
		goto out;

	filp->private_data = cam;
	cam->users++;
	cam->io = IO_NONE;
	cam->stream = STREAM_OFF;
	cam->nbuffers = 0;
	cam->frame_count = 0;
	zc0301_empty_framequeues(cam);

	DBG(3, "Video device /dev/video%d is open", cam->v4ldev->minor);

out:
	mutex_unlock(&cam->open_mutex);
	if (err)
		kref_put(&cam->kref, zc0301_release_resources);
	up_read(&zc0301_dev_lock);
	return err;
}


static int zc0301_release(struct inode* inode, struct file* filp)
{
	struct zc0301_device* cam;

	down_write(&zc0301_dev_lock);

	cam = video_get_drvdata(video_devdata(filp));

	zc0301_stop_transfer(cam);
	zc0301_release_buffers(cam);
	cam->users--;
	wake_up_interruptible_nr(&cam->wait_open, 1);

	DBG(3, "Video device /dev/video%d closed", cam->v4ldev->minor);

	kref_put(&cam->kref, zc0301_release_resources);

	up_write(&zc0301_dev_lock);

	return 0;
}


static ssize_t
zc0301_read(struct file* filp, char __user * buf, size_t count, loff_t* f_pos)
{
	struct zc0301_device* cam = video_get_drvdata(video_devdata(filp));
	struct zc0301_frame_t* f, * i;
	unsigned long lock_flags;
	long timeout;
	int err = 0;

	if (mutex_lock_interruptible(&cam->fileop_mutex))
		return -ERESTARTSYS;

	if (cam->state & DEV_DISCONNECTED) {
		DBG(1, "Device not present");
		mutex_unlock(&cam->fileop_mutex);
		return -ENODEV;
	}

	if (cam->state & DEV_MISCONFIGURED) {
		DBG(1, "The camera is misconfigured. Close and open it "
		       "again.");
		mutex_unlock(&cam->fileop_mutex);
		return -EIO;
	}

	if (cam->io == IO_MMAP) {
		DBG(3, "Close and open the device again to choose the read "
		       "method");
		mutex_unlock(&cam->fileop_mutex);
		return -EBUSY;
	}

	if (cam->io == IO_NONE) {
		if (!zc0301_request_buffers(cam, cam->nreadbuffers, IO_READ)) {
			DBG(1, "read() failed, not enough memory");
			mutex_unlock(&cam->fileop_mutex);
			return -ENOMEM;
		}
		cam->io = IO_READ;
		cam->stream = STREAM_ON;
	}

	if (list_empty(&cam->inqueue)) {
		if (!list_empty(&cam->outqueue))
			zc0301_empty_framequeues(cam);
		zc0301_queue_unusedframes(cam);
	}

	if (!count) {
		mutex_unlock(&cam->fileop_mutex);
		return 0;
	}

	if (list_empty(&cam->outqueue)) {
		if (filp->f_flags & O_NONBLOCK) {
			mutex_unlock(&cam->fileop_mutex);
			return -EAGAIN;
		}
		timeout = wait_event_interruptible_timeout
			  ( cam->wait_frame,
			    (!list_empty(&cam->outqueue)) ||
			    (cam->state & DEV_DISCONNECTED) ||
			    (cam->state & DEV_MISCONFIGURED),
			    cam->module_param.frame_timeout *
			    1000 * msecs_to_jiffies(1) );
		if (timeout < 0) {
			mutex_unlock(&cam->fileop_mutex);
			return timeout;
		}
		if (cam->state & DEV_DISCONNECTED) {
			mutex_unlock(&cam->fileop_mutex);
			return -ENODEV;
		}
		if (!timeout || (cam->state & DEV_MISCONFIGURED)) {
			mutex_unlock(&cam->fileop_mutex);
			return -EIO;
		}
	}

	f = list_entry(cam->outqueue.prev, struct zc0301_frame_t, frame);

	if (count > f->buf.bytesused)
		count = f->buf.bytesused;

	if (copy_to_user(buf, f->bufmem, count)) {
		err = -EFAULT;
		goto exit;
	}
	*f_pos += count;

exit:
	spin_lock_irqsave(&cam->queue_lock, lock_flags);
	list_for_each_entry(i, &cam->outqueue, frame)
		i->state = F_UNUSED;
	INIT_LIST_HEAD(&cam->outqueue);
	spin_unlock_irqrestore(&cam->queue_lock, lock_flags);

	zc0301_queue_unusedframes(cam);

	PDBGG("Frame #%lu, bytes read: %zu",
	      (unsigned long)f->buf.index, count);

	mutex_unlock(&cam->fileop_mutex);

	return err ? err : count;
}


static unsigned int zc0301_poll(struct file *filp, poll_table *wait)
{
	struct zc0301_device* cam = video_get_drvdata(video_devdata(filp));
	struct zc0301_frame_t* f;
	unsigned long lock_flags;
	unsigned int mask = 0;

	if (mutex_lock_interruptible(&cam->fileop_mutex))
		return POLLERR;

	if (cam->state & DEV_DISCONNECTED) {
		DBG(1, "Device not present");
		goto error;
	}

	if (cam->state & DEV_MISCONFIGURED) {
		DBG(1, "The camera is misconfigured. Close and open it "
		       "again.");
		goto error;
	}

	if (cam->io == IO_NONE) {
		if (!zc0301_request_buffers(cam, cam->nreadbuffers, IO_READ)) {
			DBG(1, "poll() failed, not enough memory");
			goto error;
		}
		cam->io = IO_READ;
		cam->stream = STREAM_ON;
	}

	if (cam->io == IO_READ) {
		spin_lock_irqsave(&cam->queue_lock, lock_flags);
		list_for_each_entry(f, &cam->outqueue, frame)
			f->state = F_UNUSED;
		INIT_LIST_HEAD(&cam->outqueue);
		spin_unlock_irqrestore(&cam->queue_lock, lock_flags);
		zc0301_queue_unusedframes(cam);
	}

	poll_wait(filp, &cam->wait_frame, wait);

	if (!list_empty(&cam->outqueue))
		mask |= POLLIN | POLLRDNORM;

	mutex_unlock(&cam->fileop_mutex);

	return mask;

error:
	mutex_unlock(&cam->fileop_mutex);
	return POLLERR;
}


static void zc0301_vm_open(struct vm_area_struct* vma)
{
	struct zc0301_frame_t* f = vma->vm_private_data;
	f->vma_use_count++;
}


static void zc0301_vm_close(struct vm_area_struct* vma)
{
	/* NOTE: buffers are not freed here */
	struct zc0301_frame_t* f = vma->vm_private_data;
	f->vma_use_count--;
}


static struct vm_operations_struct zc0301_vm_ops = {
	.open = zc0301_vm_open,
	.close = zc0301_vm_close,
};


static int zc0301_mmap(struct file* filp, struct vm_area_struct *vma)
{
	struct zc0301_device* cam = video_get_drvdata(video_devdata(filp));
	unsigned long size = vma->vm_end - vma->vm_start,
		      start = vma->vm_start;
	void *pos;
	u32 i;

	if (mutex_lock_interruptible(&cam->fileop_mutex))
		return -ERESTARTSYS;

	if (cam->state & DEV_DISCONNECTED) {
		DBG(1, "Device not present");
		mutex_unlock(&cam->fileop_mutex);
		return -ENODEV;
	}

	if (cam->state & DEV_MISCONFIGURED) {
		DBG(1, "The camera is misconfigured. Close and open it "
		       "again.");
		mutex_unlock(&cam->fileop_mutex);
		return -EIO;
	}

	if (!(vma->vm_flags & (VM_WRITE | VM_READ))) {
		mutex_unlock(&cam->fileop_mutex);
		return -EACCES;
	}

	if (cam->io != IO_MMAP ||
	    size != PAGE_ALIGN(cam->frame[0].buf.length)) {
		mutex_unlock(&cam->fileop_mutex);
		return -EINVAL;
	}

	for (i = 0; i < cam->nbuffers; i++) {
		if ((cam->frame[i].buf.m.offset>>PAGE_SHIFT) == vma->vm_pgoff)
			break;
	}
	if (i == cam->nbuffers) {
		mutex_unlock(&cam->fileop_mutex);
		return -EINVAL;
	}

	vma->vm_flags |= VM_IO;
	vma->vm_flags |= VM_RESERVED;

	pos = cam->frame[i].bufmem;
	while (size > 0) { /* size is page-aligned */
		if (vm_insert_page(vma, start, vmalloc_to_page(pos))) {
			mutex_unlock(&cam->fileop_mutex);
			return -EAGAIN;
		}
		start += PAGE_SIZE;
		pos += PAGE_SIZE;
		size -= PAGE_SIZE;
	}

	vma->vm_ops = &zc0301_vm_ops;
	vma->vm_private_data = &cam->frame[i];
	zc0301_vm_open(vma);

	mutex_unlock(&cam->fileop_mutex);

	return 0;
}

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

static int
zc0301_vidioc_querycap(struct zc0301_device* cam, void __user * arg)
{
	struct v4l2_capability cap = {
		.driver = "zc0301",
		.version = ZC0301_MODULE_VERSION_CODE,
		.capabilities = V4L2_CAP_VIDEO_CAPTURE | V4L2_CAP_READWRITE |
				V4L2_CAP_STREAMING,
	};

	strlcpy(cap.card, cam->v4ldev->name, sizeof(cap.card));
	if (usb_make_path(cam->usbdev, cap.bus_info, sizeof(cap.bus_info)) < 0)
		strlcpy(cap.bus_info, cam->usbdev->dev.bus_id,
			sizeof(cap.bus_info));

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

	return 0;
}


static int
zc0301_vidioc_enuminput(struct zc0301_device* cam, void __user * arg)
{
	struct v4l2_input i;

	if (copy_from_user(&i, arg, sizeof(i)))
		return -EFAULT;

	if (i.index)
		return -EINVAL;

	memset(&i, 0, sizeof(i));
	strcpy(i.name, "Camera");
	i.type = V4L2_INPUT_TYPE_CAMERA;

	if (copy_to_user(arg, &i, sizeof(i)))