sn9c102_core.c

linux内核源码

							 SN9C102_Y_QTABLE1[i],
							 0x100 + i);
				err += sn9c102_write_reg(cam,
							 SN9C102_UV_QTABLE1[i],
							 0x140 + i);
			}
			err += sn9c102_write_reg(cam, cam->reg[0x18] & 0xbf,
						 0x18);
		} else if (compression->quality == 1) {
			for (i = 0; i <= 63; i++) {
				err += sn9c102_write_reg(cam,
							 SN9C102_Y_QTABLE1[i],
							 0x100 + i);
				err += sn9c102_write_reg(cam,
							 SN9C102_UV_QTABLE1[i],
							 0x140 + i);
			}
			err += sn9c102_write_reg(cam, cam->reg[0x18] | 0x40,
						 0x18);
		}
		break;
	}

	return err ? -EIO : 0;
}


static int sn9c102_set_scale(struct sn9c102_device* cam, u8 scale)
{
	u8 r = 0;
	int err = 0;

	if (scale == 1)
		r = cam->reg[0x18] & 0xcf;
	else if (scale == 2) {
		r = cam->reg[0x18] & 0xcf;
		r |= 0x10;
	} else if (scale == 4)
		r = cam->reg[0x18] | 0x20;

	err += sn9c102_write_reg(cam, r, 0x18);
	if (err)
		return -EIO;

	PDBGG("Scaling factor: %u", scale);

	return 0;
}


static int sn9c102_set_crop(struct sn9c102_device* cam, struct v4l2_rect* rect)
{
	struct sn9c102_sensor* s = &cam->sensor;
	u8 h_start = (u8)(rect->left - s->cropcap.bounds.left),
	   v_start = (u8)(rect->top - s->cropcap.bounds.top),
	   h_size = (u8)(rect->width / 16),
	   v_size = (u8)(rect->height / 16);
	int err = 0;

	err += sn9c102_write_reg(cam, h_start, 0x12);
	err += sn9c102_write_reg(cam, v_start, 0x13);
	err += sn9c102_write_reg(cam, h_size, 0x15);
	err += sn9c102_write_reg(cam, v_size, 0x16);
	if (err)
		return -EIO;

	PDBGG("h_start, v_start, h_size, v_size, ho_size, vo_size "
	      "%u %u %u %u", h_start, v_start, h_size, v_size);

	return 0;
}


static int sn9c102_init(struct sn9c102_device* cam)
{
	struct sn9c102_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);
	} else { /* use current values */
		qctrl = s->_qctrl;
		rect = &(s->_rect);
	}

	err += sn9c102_set_scale(cam, rect->width / s->pix_format.width);
	err += sn9c102_set_crop(cam, rect);
	if (err)
		return err;

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

	if (!(cam->state & DEV_INITIALIZED))
		if (cam->bridge == BRIDGE_SN9C101 ||
		    cam->bridge == BRIDGE_SN9C102 ||
		    cam->bridge == BRIDGE_SN9C103) {
			if (s->pix_format.pixelformat == V4L2_PIX_FMT_JPEG)
				s->pix_format.pixelformat= V4L2_PIX_FMT_SBGGR8;
			cam->compression.quality =  cam->reg[0x17] & 0x01 ?
						    0 : 1;
		} else {
			if (s->pix_format.pixelformat == V4L2_PIX_FMT_SN9C10X)
				s->pix_format.pixelformat = V4L2_PIX_FMT_JPEG;
			cam->compression.quality =  cam->reg[0x18] & 0x40 ?
						    0 : 1;
			err += sn9c102_set_compression(cam, &cam->compression);
		}
	else
		err += sn9c102_set_compression(cam, &cam->compression);
	err += sn9c102_set_pix_format(cam, &s->pix_format);
	if (s->set_pix_format)
		err += s->set_pix_format(cam, &s->pix_format);
	if (err)
		return err;

	if (s->pix_format.pixelformat == V4L2_PIX_FMT_SN9C10X ||
	    s->pix_format.pixelformat == V4L2_PIX_FMT_JPEG)
		DBG(3, "Compressed video format is active, quality %d",
		    cam->compression.quality);
	else
		DBG(3, "Uncompressed video format is active");

	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 sn9c102_release_resources(struct kref *kref)
{
	struct sn9c102_device *cam;

	mutex_lock(&sn9c102_sysfs_lock);

	cam = container_of(kref, struct sn9c102_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);

	mutex_unlock(&sn9c102_sysfs_lock);

}


static int sn9c102_open(struct inode* inode, struct file* filp)
{
	struct sn9c102_device* cam;
	int err = 0;

	/*
	   A read_trylock() in open() is the only safe way to prevent race
	   conditions with disconnect(), one close() and multiple (not
	   necessarily simultaneous) attempts to open(). For example, it
	   prevents from waiting for a second access, while the device
	   structure is being deallocated, after a possible disconnect() and
	   during a following close() holding the write lock: given that, after
	   this deallocation, no access will be possible anymore, using the
	   non-trylock version would have let open() gain the access to the
	   device structure improperly.
	   For this reason the lock must also not be per-device.
	*/
	if (!down_read_trylock(&sn9c102_dev_lock))
		return -ERESTARTSYS;

	cam = video_get_drvdata(video_devdata(filp));

	if (wait_for_completion_interruptible(&cam->probe)) {
		up_read(&sn9c102_dev_lock);
		return -ERESTARTSYS;
	}

	kref_get(&cam->kref);

	/*
	    Make sure to isolate all the simultaneous opens.
	*/
	if (mutex_lock_interruptible(&cam->open_mutex)) {
		kref_put(&cam->kref, sn9c102_release_resources);
		up_read(&sn9c102_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 already in use",
		       cam->v4ldev->minor);
		DBG(3, "Simultaneous opens are not supported");
		/*
		   open() must follow the open flags and should block
		   eventually while the device is in use.
		*/
		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(&sn9c102_dev_lock);
		/*
		   We will not release the "open_mutex" lock, so that only one
		   process can be in the wait queue below. This way the process
		   will be sleeping while holding the lock, without loosing its
		   priority after any wake_up().
		*/
		err = wait_event_interruptible_exclusive(cam->wait_open,
						(cam->state & DEV_DISCONNECTED)
							 || !cam->users);
		down_read(&sn9c102_dev_lock);
		if (err)
			goto out;
		if (cam->state & DEV_DISCONNECTED) {
			err = -ENODEV;
			goto out;
		}
	}

	if (cam->state & DEV_MISCONFIGURED) {
		err = sn9c102_init(cam);
		if (err) {
			DBG(1, "Initialization failed again. "
			       "I will retry on next open().");
			goto out;
		}
		cam->state &= ~DEV_MISCONFIGURED;
	}

	if ((err = sn9c102_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;
	sn9c102_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, sn9c102_release_resources);

	up_read(&sn9c102_dev_lock);
	return err;
}


static int sn9c102_release(struct inode* inode, struct file* filp)
{
	struct sn9c102_device* cam;

	down_write(&sn9c102_dev_lock);

	cam = video_get_drvdata(video_devdata(filp));

	sn9c102_stop_transfer(cam);
	sn9c102_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, sn9c102_release_resources);

	up_write(&sn9c102_dev_lock);

	return 0;
}


static ssize_t
sn9c102_read(struct file* filp, char __user * buf, size_t count, loff_t* f_pos)
{
	struct sn9c102_device* cam = video_get_drvdata(video_devdata(filp));
	struct sn9c102_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 (!sn9c102_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))
			sn9c102_empty_framequeues(cam);
		sn9c102_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;
		}
		if (!cam->module_param.frame_timeout) {
			err = wait_event_interruptible
			      ( cam->wait_frame,
				(!list_empty(&cam->outqueue)) ||
				(cam->state & DEV_DISCONNECTED) ||
				(cam->state & DEV_MISCONFIGURED) );
			if (err) {
				mutex_unlock(&cam->fileop_mutex);
				return err;
			}
		} else {
			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;
			} else if (timeout == 0 &&
				   !(cam->state & DEV_DISCONNECTED)) {
				DBG(1, "Video frame timeout elapsed");
				mutex_unlock(&cam->fileop_mutex);
				return -EIO;
			}
		}
		if (cam->state & DEV_DISCONNECTED) {
			mutex_unlock(&cam->fileop_mutex);
			return -ENODEV;
		}
		if (cam->state & DEV_MISCONFIGURED) {
			mutex_unlock(&cam->fileop_mutex);
			return -EIO;
		}
	}

	f = list_entry(cam->outqueue.prev, struct sn9c102_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);

	sn9c102_queue_unusedframes(cam);

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

	mutex_unlock(&cam->fileop_mutex);

	return count;
}


static unsigned int sn9c102_poll(struct file *filp, poll_table *wait)
{
	struct sn9c102_device* cam = video_get_drvdata(video_devdata(filp));
	struct sn9c102_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 (!sn9c102_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);
		sn9c102_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 sn9c102_vm_open(struct vm_area_struct* vma)
{
	struct sn9c102_frame_t* f = vma->vm_private_data;
	f->vma_use_count++;